Chapter
Chapter
1 Executive Summary
This project is being done in cooperation with the Iowa Energy Center’s (IEC) Energy Resource Station (ERS) located in Ankeny, Iowa. Throughout the year, the ERS offers Direct Digital Controls (DDC) Workshops in which various industry representatives of the heating, ventilation, and air conditioning (HVAC) field are trained on various controls and control loops. With improvements in technology, the IEC wanted to improve upon their existing workshop, making them more beneficial to their students. Three primary areas were targeted for improvement in the class - expansion of the existing DDC lab station, creation of a demonstration device, and integration of the controllers into a real world environment.
The first phase deals with the expansion of the DDC lab station. The original lab station (Figure 1) contained only an Automated Logic control system containing a communications interface and controller, along with various input/output (I/O) devices, an operator workstation, and a control panel. In order to allow for the students to compare and contrast various functions and characteristics of two different vendors, a second controller and corresponding control panel were needed. A Control Systems International (CSI) controller was then added with similar analog and digital inputs and outputs to the lab station, allowing the user to operate both the AL and CSI control systems.
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Figure 1. Original DDC lab station
For the second phase, a demonstration device was required that could physical demonstrate two-position, floating, and proportional integral derivative (PID) control loops that the students were simulating on the lab station. Without this device, the students were unable to visualize the process of the different control loops and how they differed. The primary goal was to allow the students to decide which loops would be appropriate for a given system based on the reaction speed and cost efficiency.
The final phase of the project was to implement a CSI controller into a real world heating, ventilation, and air-conditioning (HVAC) environment. Once the students had grasped the basic concepts through the lab station and had a greater understanding of the various control loops and their positives and negatives, they could then implement these on an existing system.
This project was able to upgrade the existing lab station with the CSI control system and the corresponding control panel. Along with this, a demonstration device was constructed using a water level detection system. This device measured the level of the water and then based on a disturbance by the user, controlled a valve to allow the proper amount of water to flow into the tank based on the desired level of water. The real world integration of the controller was viewed as a phase that could be conducted at a later time.
Chapter
2 Acknowledgements
The Dec00-05 Senior Design Group - The DDC Lab Station and Demonstration Device, would like to personally thank the Andy Suby and Curt Klaassen of the Iowa Energy Center for the contribution of this project and for their financial and design contributions. In addition, a great deal of thanks is given to Bob Schultz, CSI representative and DDC class instructor, for his guidance in the project. The team would also like to thank the faculty advisors, John Lamont and Nicola Elia, for their technical and academic support.
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Figure 2. Acknowledgements
(Top left: IEC, top right: CSI, bottom: ISU)
Chapter
3 Definition of Terms
In this section, each term and acronym is defined. The terms are listed in alphabetical order. Table 1 contains a listing of the included terms in their corresponding area. Table 2 lists all acronyms defined in the Definition of Terms section.
Table 1. Definition of Terms Index
|SECTION |PAGE | |SECTION |PAGE |
|Control Loops | | |Demonstration Device | |
|Floating point |12 | |Actuator |5 |
|Proportional |15 | |Ball valve |7 |
|Proportional-integral |16 | |Container |8 |
|Proportional-integral-derivative |17 | |Control loop demonstration |9 |
|Two-position |19 | | Device | |
| | | |Direct acting valve |10 |
|Control Systems | | |Flowmeter |13 |
|Automated Logic control | | |Globe valve |13 |
| System |6 | |Liquid crystal display screen |14 |
|Analog input |6 | |Non-spring return valve |14 |
|Analog output |6 | |On/off valve |14 |
|Communications Interface |7 | |Proportional valve |15 |
|Controller |8 | |Relay |18 |
|Control loop |8 | |Reservoir |18 |
|Control Systems International |10 | |Reverse acting valve |18 |
| Control system | | | | |
|Direct digital controls |11 | |Spring-return valve |18 |
|Digital input |10 | | | |
|Digital output |10 | |Iowa Energy Center | |
|Heating, ventilating, and air |13 | |Energy Resource Station |11 |
| conditioning | | |Iowa Energy Center |14 |
| | | | | |
|DDC Lab Station | | | | |
|Control panel |9 | | | |
|DDC lab station |11 | | | |
|Operator workstation |14 | | | |
Table 2. Acronyms Index
|Acronym |Full Name |Page |
|AI |Analog input |6 |
|AL |Automated Logic |6 |
|AO |Analog output |6 |
|CSI control system |Control Systems International control system |10 |
|DDC |Direct digital controls |11 |
|DI |Digital input |10 |
|DO |Digital output |10 |
|ERS |Energy Resource Station |11 |
|HVAC |Heating, ventilating, and air conditioning |13 |
|IEC |Iowa Energy Center |14 |
|LCD |Liquid crystal display |14 |
|P |Proportional |15 |
|PI |Proportional-integral |16 |
|PID |Proportional-integral-derivative |17 |
Actuator - Device used in conjunction with a control valve. This device receives the signal from the controller and then controls the valves state. In Figure 3, the Siemens actuator is the blue box on top of the valve. The picture on the right shows the top view of the actuator. The dial allows the user to see how many volts are supplied to the actuator on a scale of 0 – 10 V. The dial in Figure 3 currently reads 0 V, which in a direct acting valve would equate to fully open. When the dial reads 5 V, the valve is 50% closed. A Johnson Controls proportional valve and actuator are shown in Figure 25.
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Figure 3. Siemens Actuator
Analog input (AI) - Those used on the DDC lab station include thermistors and potentiometers and are shown in Figure 4.
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Figure 4. Analog Inputs – Thermistor and Potentiometer
Analog output (AO) - An LCD screen is used on the DDC lab station and is shown in Figure 23.
Automated Logic (AL) control system - consists of Automated Logic G8102 controller (Figure 5) and AL GCM2 communications interface. Vendor one of lab station. Also referred to as AL control system.
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Figure 5. Automated Logic M8102 Controller (similar to G8102)
Ball valve - Type of valve that operates by rotating a ball with a cylinder board through the middle inside of a tube. This type of valve is extremely non-linear. (Figure 6)
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Figure 6. Ball Valve
Communications interface - Device that provides communications between an operator workstation and a controller. The Automated Logic control system requires a communications interface that is separate from the controller. The communications interface used is the Automated Logic GCM2 communications module (Figure 7). The CSI control system has a built-in communications interface on the same board as the controller.
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Figure 7. Automated Logic GCM2 Communications Device
Container - Device used to hold water in demonstration device in which the level of the water is measured. (Figure 8)
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Figure 8. Container
Controller - An electronic device that processes a given set of inputs and returns a set of outputs based on a set of instructions and algorithms. (Figure 9)
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Figure 9. Controller
Control loop - A control loop consists of three main components: a sensor, a controller, and a controlled device that interact to control a medium. The sensor measures the data, the controller processes the data, and the controlled device causes an action. (Figure 10)
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Figure 10. DDC Control Loop
Control loop demonstration device - Phase two of project. Device will demonstrate the positives and negatives of three types of control loops (PID, two-position, and floating point) in different situations. Figure 11 shows the demonstration device, picture dated 11/20/00.
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Figure 11. Control Loop Demonstration Device
Control panel - Panel on DDC lab station that contains a set of analog inputs and outputs and a set of digital inputs and outputs that are used in conjunction with the control system. The Automated Logic control panel is shown in Figure 12.
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Figure 12. AL Control Panel
Control Systems International (CSI) control system - consists of a single board, model number 7718-C (Figure 13), containing the controller and communications interface. Vendor number two of lab station.
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Figure 13. CSI Control System
Digital input (DI) - Those used on the DDC lab station include toggle switches and push buttons. (Figure 14)
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Figure 14. Digital Inputs – Toggle Switch and Push Button
Digital output (DO) - A light bulb is used on the DDC lab station. (Figure 15)
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Figure 15. Digital Output – Light Bulb
Direct acting valve - Valve that is normally open.
Direct digital control (DDC) - consists of microprocessor-based controllers with the control logic performed by software. Analog-to-digital (A/D) converters transform analog values into digital signals that a microprocessor can use. Analog sensors can be resistance, voltage or current generators. Most systems distribute the software to remote controllers to eliminate the need for continuous communication capability (stand-alone). The computer is primarily used to monitor the status of the energy management system, store back-up copies of the programs and record alarming and trending functions. Complex strategies and energy management functions are readily available at the lowest level in the system architecture. If pneumatic actuation is required, it is accomplished with electronic to pneumatic transducers. Calibration of sensors is mathematical; consequently the total man-hours for calibration are greatly reduced. The central diagnostic capabilities are a significant asset. Software and programming are constantly improving, becoming increasingly user-friendly with each update. (taken from IEC web page)
Direct digital control (DDC) lab station - Lab station used by the Iowa Energy Center to teach basic controls systems and control loops. The expanded lab station (Figure 16) will consist of an operator workstation, control panel, Automated Logic control system, CSI control system, and two control panels.
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Figure 16. Updated DDC Lab Station
Energy Resource Station (ERS) - IEC facility located in Ankeny, IA. (Figure 17)
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Figure 17. Energy Resource Station
Floating point control loop - Floating control is a control response that produces two possible digital outputs based on a change in a variable input. One output increases the signal to the controlled device, while the other output decreases the signal to the controlled device. This control response also involves an upper and lower limit with the output changing as the variable input crosses these limits. There are no standards for defining these limits, but the terms set point and dead-band are common. The set-point sets a midpoint and the dead-band sets the difference between the upper and lower limits.
When the measured variable is within the dead-band or neutral zone, neither output is energized and the controlled device does not change - it stays in its last position. For this control response to be stable, the sensor must sense the effect of the controlled device movement very rapidly. Floating control does not function well where there is significant thermodynamic lag in the control loop. Fast airside control loops respond well to floating control. An example of floating controls is shown in Figure 18 with a graph of water level over time using floating control in Figure 19. (taken from IEC web page)
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Figure 18. Floating Point Control Loop Response
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Figure 19. Floating Point Control Over Time
Flow meter - Device used in demonstration device to measure flow rate visually. (Figure 20)
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Figure 20. Flow Meter
Globe valve - Valve that uses a wedge to block the flow through an opening. Is much more linear than a globe valve. (Figure 21)
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Figure 21. Globe Valve
Heating, ventilation, and air conditioning (HVAC) - Figure 22 shows an existing test HVAC system at the ERS.
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Figure 22. HVAC Test System at ERS
Iowa Energy Center (IEC) - A research, demonstration and educational organization dedicated to increasing Iowa's energy efficiency and use of renewable fuels. In pursuit of these goals, the Center has established an array of research and demonstration projects that address energy-related issues and their associated economic and environmental impacts. The IEC is striving to develop practical, cost-effective approaches to energy use that will create positive economic, social and environmental changes in Iowa's communities. The IEC has three facilities located in Ankeny (ERS), Ames, and Neveda, Iowa. (taken from IEC web page)
Liquid crystal display (LCD) screen - Used on DDC lab station as an analog output.
(Figure 23)
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Figure 23. LCD Screen
Non-spring return valve - Valve that remains in current position when input signal is ceased.
On/off valve - Valve that operates in one of two positions: on or off.
Operator workstation – A workstation, consisting of a personal computer (Figure 24) with the required software to interface with the Automated Logic and CSI control systems, that is a component of the DDC lab station.
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Figure 24. Operator Workstation
Proportional valve - Valve that may operates in a range from 0 – 100% open depending on input signal. For example, if valve operates from 0 – 10 V input and 7.5 V is sent, the valve will be 75% open. Used in demonstration device for PID and floating control loops. A Johnson Controls proportional valve and actuator are shown in Figure 25. A Siemens proportional valve is shown in Figure 3.
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Figure 25. Johnson Controls Proportional Valve and Actuator
Proportional integral derivative - PID control loop
Proportional (P) - A proportional control response produces an analog or variable output change in proportion to a varying input. In this control response, there is a linear relationship between the input and the output. A set-point, throttling range and action typically define this relationship. In a proportional control response, there is a unique value of the measured variable that corresponds to full travel of the controlled device and a unique value that corresponds to zero travel on the controlled device. The change in the measured variable that causes the controlled device to move from fully closed to fully open is called the throttling range. It is within this range that the control loop will control, assuming that the system has the capacity to meet the requirements.
The action dictates the slope of the control response. In a direct acting proportional control response, the output will rise with an increase in the measured variable. In a reverse acting response, the output will decrease as the measure variable increases. The set-point is an instruction to the control loop and corresponds to a specified value of the controlled device, usually half-travel. An example is shown in Figure 26.
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Figure 26. Proportional Control Loop
In a proportional control system, the value of the measured variable at any given moment is called the control point. Offset is defined as the difference between the control point and the desired condition. One way to reduce offset is to reduce throttling range. Reducing the throttling range too far may lead to instability. The sooner the control response affects the sensor, the larger the throttling range has to be to produce stable control.
Proportional Integral (PI) - PI control involves the measurement of the offset or “error” over time. This error is integrated, and a final adjustment is made to the output signal from the proportional part of this model. This type of control strategy reduces the offset to zero. A correctly constructed PI control loop will operate in a narrow band close to the set point. It will not operate over the entire throttling range (Figure 27). PI control loops do not perform well when set points are dynamic, where sudden load changes occur, or if the throttling range is small.
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Figure 27. PI Control Loop
Proportional Integral Derivative (PID) - PID control adds a predictive element to the control response. In addition to the proportional and integral calculation, the derivative or slope of the control response will be computed. This calculation will have the effect of dampening a control response that is returning to set-point so quickly that it will “overshoot” the set-point.
PID is a precision process control response and is not always required for HVAC applications. The routine application of PID control to every control loop is labor intensive and its application should be selective. (taken from IEC web page)
An example of PID is displayed in Figure 28. This graph represents water level over a
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Figure 28. PID Control Over Time
small period of time. The somewhat straight line on the left represents the proportional portion of the control response, the sinusoidal section that follows represents the integral response, and finally the dampening represents the derivative response.
Relay - Power switching device that is controlled by a smaller power logic system. In the case of the DDC lab station, 5 V is the output of the controller, however the digital output devices require a power supply of 24 V. Therefore, when a 5 V signal is applied at the relay, a magnet is activated and pulls a lever down, completing a circuit that routes a 24 V signal is routed from the transformer, into the relay, and out to the digital output device. (Figure 29)
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Figure 29. Relay
Reservoir - Device used to hold water that drains from the container. Theoretically, this should hold the water of the entire system. Located inside the cabinet of the demonstration device. (Figure 30)
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Figure 30. Reservoir
Reverse acting valve - Valve that is normally closed
Spring return valve - Valve that returns to default state when input signal is ceased.
Two-position control loop - Two-position control compares the monitoring of an analog or variable input with instructions and generates a digital (two-position) output. The instructions involve the definition of an upper and lower limit. The output changes its value as the input crosses these limit values. There are no standards for defining these limits. The most common terminology used is set-point and differential. The set-point indicates the point where the output “pulls-in,” “energizes” or is “true.” The output changes back or “drops-out” after the input value crosses through the value equal to the difference between the set-point and the differential.
Two-position control can be used for simple control loops (temperature control) or limit control (outside air temperature limits). The analog value can be any measured variable including temperature, relative humidity, pressure, current and liquid levels.
Time can also be the input to a two-position control response. This control response functions like a time clock with pins. The output “pulls-in” when the time is in the defined “on” time and drops out during the defined “off” time. Figure 31 shows water level controlled by a two-position control loop over time.
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Figure 31. Two-position Control Over Time
Figure 32 shows an example of two-position control in a home heating system, where the thermostat is set to energize the heating system when the space temperature falls below 70( F and to turn off when the temperature rises to 72( F in the space. This is an example of a set-point of 70( F with a two-degree differential. (taken from IEC web page)
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Figure 32. Two-position Control Loop
Chapter
4 Introduction
Chapter
4 Introduction
The Iowa Energy Center’s primary mission is “improve the total energy picture of the State (of Iowa), its businesses, and communities.” The IEC's main office is located in Ames, Iowa near Iowa State University, the administrator for the IEC. The IEC also maintains the Energy Resource Station (ERS) at the Des Moines Area Community College (DMACC) in Ankeny, Iowa and the Biomass Energy Conversion (BECON) facility in Nevada, Iowa. They sponsor a number of projects that allow people to understand how their homes can become more comfortable and affordable along with helping Iowa industries and businesses run efficiently so that they can be more productive and profitable. Along with this, the IEC is striving to make Iowa energy independent from other states by lowering the dependence on imported fuels and decreasing reliance on energy production from nonrenewable resources. By increasing energy efficiency in all areas of Iowa’s energy use, energy costs will decrease as well as energy consumption.
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Figure 33. Renewable Energy Sources
In order to accomplish these goals, many studies are done concerning energy efficiency. These studies focus on how to maximize the energy resources in business buildings. Such studies involve work with various pieces of control equipment and the different control loops. Various tests are conducted at the ERS in six experimental conference rooms, allowing for an easy comparison of the results of each test.
The IEC also sponsors a direct digital controls (DDC) workshop for various members of the HVAC field. The workshop is designed to show how a DDC system gathers information, makes decisions and does its job by adjusting control equipment, tracking energy use and issuing alarms. Workshop labs and classroom demonstrations are used in conjunction with commercial HVAC equipment and DDC control equipment. This class is designed for people with an existing working knowledge of HVAC systems such as building operators, facility engineers, HVAC design engineers, controls contractors, facility managers, and energy efficiency professionals. Figure 34 shows two students working on the DDC lab station during one of the workshops.
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Figure 34. Students at DDC Workshop
The workshop is broken down into three distinct phases. In the beginning, the students become familiar with components, features and communication protocols of a DDC system. They then progress to the next level and learn about the types of programming tools available today and the strengths of each one. Finally, they learn how to program an actual DDC system to control several types of common HVAC systems. A detailed course outline is listed in Section 18.4.
In order to improve upon the existing DDC Workshop, three problem areas were targeted. The first was that the existing lab station contained only one control system. Also, the students of the class were simply simulating control loops on the operator workstation monitor, making visualization of the control loops near impossible. Finally, there was no real world connection to be made between the simulations and an existing HVAC system.
The first issue could be resolved by expanding the current lab station to include a second vendor. This second vendor would be mounted on the same lab station as the AL controller, but have a separate control panel consisting of similar analog and digital inputs and outputs as the AL control panel. A selector switch would be added to the lab station to allow the user to select the desired controller to be used. This objective will be referred to as the first phase of the project forthwith.
The second objective of the project was be to design and build a classroom demonstration device in order to allow for physical visualization. This device would exhibit how three different control methods (two-position, floating-point, and PID) manage a medium to achieve a desired result. This demonstration device will use a CSI controller at the request of the DDC class instructor. This is the second phase of the project.
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Figure 35. Efficiency Mural
The third objective, which will be referred to as the third phase, is to demonstrate the above mentioned control methods on a “real-world” system, such as a HVAC system. Once the students have grasped the basic concepts through the lab station experiments and achieve a greater visual understanding of the various control loop responses, this knowledge would be expanded to an existing system, such as the test HVAC systems at the ERS. This would involve implementing a CSI controller to operate various portions of these systems.
The DDC workstation will be used to teach DDC control basics to individuals with different technical backgrounds ranging from businessmen to engineers. The students will learn how two different controllers manage a medium to achieve the same results. The only direct link between the two controllers will be the operator workstation that has software for each control device.
A water reservoir system will be used in the second phase to physically demonstrate the control methods simulated on the lab station. This will show the positives and negatives of each control method in systems of various speeds to determine the most efficient method. The input to the controller will be the level of water in a container and the output will be the position of one of two control valves (proportional and on/off) of the system in order to control the flow into the reservoir, therefore controlling the level of the water in the container.
The workstation and the demonstration device will be primarily used in an indoor classroom environment at the Energy Resource Station located in Ankeny, IA. The mobility of the demonstration device should allow for transport by van to other classroom environments. However the third phase of the project calls for a “real-world” system to be controlled, therefore this environment could have harsh industrial plant conditions, requiring greater protection of the control system being used.
The workstation along with the demonstration devices will be used primarily during the direct digital controls workshop, as well as other courses taught by the IEC.
The users of the lab stations and demonstration device will consist of the instructor and students of the DDC Workshop and other various IEC employees. The students of the workshop consist of people with an existing working knowledge of HVAC systems such as building operators, facility engineers, HVAC design engineers, controls contractors, facility managers, and energy efficiency professionals. Also, IEC employees may conduct various demonstrations to members of industry and academia using the demonstration device.
The assumptions for the project are as follows:
• The demonstration device will be used in a manner it was intended.
• There will be ample space on the current lab station to fully upgrade with desired controller and control panel and can therefore be modified
• Qualified personnel will do all maintenance of the workstation and demonstration device.
• In the use of the demonstration device, there will be no outside disturbances other than atmospheric pressure and gravity to the system in order to better represent a closed system.
• The environment in which the lab workstations will be used will be a dry and dustless environment with no extreme temperature changes.
• A technical product list and expectations for the project will be provided by the IEC.
• Support and needed hardware and software will be provided by CSI in conjunction with the new 7718-C CSI controller.
• The users of the demonstration device will be knowledgeable of the system and aware that the water medium will be used in close proximities with an electric control panel and wires.
• The IEC will supply needed funds and CSI will supply needed controllers and corresponding hardware.
• IEC and CSI will supply needed documentation and supplies for the project ahead of time.
• The water reservoir will hold all of the water in the system.
• The container on the top of the desk will be clear, so students can see the water level.
• There will always be one on/off valve and one proportional valve in the system for the CSI controller to control.
The limitations for the DDC lab station are as follows:
• The entire project must be completed by December 4, 2000, in order to be used for the DDC class.
• The technical knowledge and experience of the design group is limited to classroom and intern experience, much of which has been outside of the controls area. This will require much outside learning by team members in order to be up to speed with the terminology.
• Delays on communication between the design group, the Iowa Energy Center, the project advisors, and the CSI contacts are unavoidable.
• Design group will be unable to meet in a 40 hour per week fashion such as normal working engineers.
• The demonstration device will use a CSI 7718-C controller at the request of the DDC class instructor.
• The budget of the IEC for this project is finite.
• The water pump used will obtain the needed gallons per minute (GPM) at the appropriate foot of head. The pump should also run at a low enough noise level as to not disturb the class exercise
• The cart used for the demonstration device will be mobile and contain a locked cabinet for storage.
• The valves that can be interchanged in the system are of ½ inch.
• The pump can put out a maximum flow of water into the tank of 2 gallons per minute.
• The water level in the tank can only change between 4 and 20 inches.
• The sensor for measuring the level of the tank has a 1% tolerance, so small level changes may not be detected.
• The proportional valve currently being used takes 90 seconds to go from open to close, so changes may be somewhat slow.
• The tank cannot discharge more than 2 gallons per minute with both hand valves fully opened.
Chapter
5 Design Requirements
Phase 1 – CSI Controller Addition
Phase 1 will consist of the addition of a CSI controller and a respective control panel to the original lab station. The motivation behind this is to allow for the comparison of two different control systems on a single DDC lab station. The following are the design objectives for Phase 1.
• Install and integrate a CSI controller with the original lab station. The new controller is to utilize the same operator workstation as the pre-existing Automated Logic controller, but is to otherwise be completely independent of the original system.
• Install a new control panel for the CSI controller similar to the pre-existing control panel used with the Automated Logic controller.
• Install an easily accessible mechanical switch onto the front of the lab desk for the purpose of switching between the two controllers.
• Produce wiring schematics of the new lab station setup to allow IEC technicians to complete the same upgrade to the remaining eleven lab stations.
Phase 2 – Control Loop Demonstration Device
Phase 2 will consist of the construction of a demonstration device that will illustrate two-position, floating point, and PID control loops. The device will be capable of interfacing with any operator workstation in the DDC classroom. The following are the design objectives for Phase 2.
( Design and construct a demonstration device that will interface with its own CSI controller and illustrate two-position, floating point, and PID control loops.
( Design the device in such a way that the CSI controller will control both a proportional valve and a separate on/off valve contained within the demonstration device.
( Design the device in such a way that the control loop illustrations are clearly visible to every student in the DDC classroom.
( Integrate the demonstration device with the CSI controller and demonstrate the capabilities of the system including the three control loops.
( Construct the demonstration device to be easily mobile and stable so it can be relocated within the classroom for demonstration purposes.
Phase 3 – Control of IEC HVAC Systems
Phase 3 will consist of the production of an interface between the demonstration device and actual HVAC systems located at the ERS in Ankeny, IA. This would allow for the illustration of control loops in a real-world environment. The following are the design objectives for Phase 3.
• Design a system to allow the CSI controller to interface with actual HVAC systems of the IEC to demonstrate the three control loops.
Phase 1 – CSI Controller Addition
Phase 1 will consist of the addition of a CSI controller and a respective control panel to the original lab station. The motivation behind this is to allow for the comparison of two different control systems on a single DDC lab station. The following are the functional requirements for Phase 1.
• The CSI controller on the lab station will be capable of receiving each input from the user, handling the input as specified by the user, and producing the correct response as defined by the user.
• The user will be able to select which of the two controllers to use via a mechanical switch on the front of the lab desk.
• The added CSI controller will allow the user to observe the subtle differences between control systems of different vendors that accomplish the same task.
Phase 2 – Control Loop Demonstration Device
Phase 2 will consist of the construction of a demonstration device that will illustrate two-position, floating point, and PID control loops. The device will be capable of interfacing with any operator workstation in the DDC classroom. The following are the functional requirements for Phase 2.
• The demonstration device will be capable of illustrating the aforementioned control loops by interfacing with its CSI controller and any operator workstation.
• The demonstration device will be easily mobile and able to relocate and connect easily to any lab station in the DDC classroom.
Phase 3 – Control of IEC HVAC Systems
Phase 3 will consist of the production of an interface between the demonstration device and actual HVAC systems located at the ERS in Ankeny, IA. This would allow for the illustration of control loops in a real-world environment. The following are the functional requirements for Phase 3.
• The CSI controller of the demonstration device will be able to interface easily with the HVAC systems of the IEC to demonstrate the use of control loops in “real-life” systems.
Phase 1 – CSI Controller Addition
Phase 1 will consist of the addition of a CSI controller and a respective control panel to the original lab station. The motivation behind this is to allow for the comparison of two different control systems on a single DDC lab station. The following are the design constraints for Phase 1.
• The CSI controller is required to utilize the existing operator workstation but a separate control panel for inputs and outputs.
• The requirements set forth by the DDC course instructor will be fully satisfied regarding the expanded lab station.
• Wiring schematics will be needed in order for IEC personnel to duplicate the work on eleven remaining lab stations.
Phase 2 – Control Loop Demonstration Device
Phase 2 will consist of the construction of a demonstration device that will illustrate two-position, floating point, and PID control loops. The device will be capable of interfacing with any operator workstation in the DDC classroom. The following are the design constraints for Phase 2.
• The demonstration device is required to utilize a CSI controller.
• The demonstration device is required to have the capability of demonstrating each of the three control loops in a manner easily understood by the user.
• The requirements set forth by the DDC course instructor will be fully satisfied regarding the demonstration device.
• The demonstration device is required to be easily mobile within the DDC classroom yet large enough to allow all students a clear view of the demonstrations.
Phase 3 – Control of IEC HVAC Systems
Phase 3 will consist of the production of an interface between the demonstration device and actual HVAC systems located at the ERS in Ankeny, IA. This would allow for the illustration of control loops in a real-world environment. The following are the design constraints for Phase 3.
( The CSI controller of the demonstration device is to interface with both the demonstration device and the actual HVAC systems at the IEC.
• Cables for interfacing the CSI controller with the IEC HVAC systems must be long enough to allow for easy connections.
Phase 1 – CSI Controller Addition
Phase 1 will consist of the addition of a CSI controller and a respective control panel to the original lab station. The motivation behind this is to allow for the comparison of two different control systems on a single DDC lab station. The following are the measurable milestones for Phase 1.
• Design the general layout of the expanded lab station including the CSI controller and extra control panel.
• Mount the CSI controller on the desk, apply power to it, and verify its operation.
• Add the inputs and outputs for the new control panel and verify their operation.
• Mount and connect a mechanical switch to be used for controller selection and verify its operation.
• Demonstrate the expanded lab station’s capabilities to the IEC.
Phase 2 – Control Loop Demonstration Device
Phase 2 will consist of the construction of a demonstration device that will illustrate two-position, floating point, and PID control loops. The device will be capable of interfacing with any operator workstation in the DDC classroom. The following are the measurable milestones for Phase 2.
• Design the demonstration device, including component specifications.
• Research, evaluate, and obtain individual components for use in the demonstration device.
• Construct the demonstration device per the design.
• Integrate the device with its CSI controller and verify its operation to the IEC.
Phase 3 – Control of IEC HVAC Systems
Phase 3 will consist of the production of an interface between the demonstration device and actual HVAC systems located at the ERS in Ankeny, IA. This would allow for the illustration of control loops in a real-world environment. The following are the measurable milestones for Phase 3.
( Determine the inputs needed for the HVAC systems of the IEC.
( Determine which outputs will be used from the controller.
( Provide an interface to connect the IEC controller to the HVAC systems.
( Test the interface and demonstrate the operation to the IEC.
Chapter
6 End-Product
Description
The end product will consist of an expanded DDC lab station (Figure 27) and a demonstration device that will display three types of control methods. The expanded lab station will utilize one operator workstation to interface with an AL and CSI control system, each containing their own control panel and corresponding controller. Included will be a mechanical switch for selecting the desired control system. The operator workstation will also interface with a control loop demonstration device using a CSI controller. The device will be capable of demonstrating two-position, floating, and PID control loops by sensing the level of water in a container and then controlling a valve position to regulate the flow of water into the tank. This level may be disturbed by a change in desired water level or by altering the flow of water out of the tank.
[pic] [pic]
Figure 36. Expanded DDC Lab Station and Control Loop Demonstration Device
Chapter
7 Approach and Design
Figure 37 gives a high level description of the technical approach to the project. Residing in the upper dashed box is the original lab station containing the AL control system. The lower dashed box contains the CSI control system as well as the demonstration device.
[pic]
Figure 37. DDC Lab Station Flowchart
It can be seen in this figure that the interfaces between the AL controller and the CSI controller are nearly identical. The one difference is the Automated Logic controller uses a separate interface to communicate with the workstation while the CSI device uses an onboard communication device. This is significant in that it conserves lab station space. The control panels for each device are nearly identical with the exception of some minor changes to input and output controls. The demonstration device is represented by the “Floating point loop demonstration”, “Two-position loop demonstration”, and “PID loop demonstration” boxes stemming from the CSI controller.
The design for phase 2 involved a series of valves in addition to a flow meter and a level sensor, which measure the height of the water in the container. Figure 38 gives a general overview of the water demonstration. The basic idea behind this device is to control water flow between two water reservoirs through the use of sensors, valves, and the CSI device. Of the two valves controlled by the CSI device, only one operates at any time: when one is under the control of the CSI device, the other will be open. The purpose of the user-controlled valves is to provide a mechanism by which the water flow can be varied. The CSI controller will be constantly monitoring and controlling the water flow through the use of a sensor. The sensor(s) detect an increased or decreased water flow and the controller will take the necessary control actions.
[pic]
Figure 38. Phase 2 General System Overview
After consulting with Mr. Schultz and the IEC and presenting a list of possible demonstration devices, it was decided to implement a control loop involving water flow. A list of all the alternatives considered is presented below:
( Spring
( Airflow
( Temperature
( Lights
( Magnetic field
( Suspended ball
( Water reservoir(s)
- Control pump speed
- Control valve position
The spring option would involve using a spring as a suspension system. The general idea would be to control the amount of vertical movement of the spring using the CSI device. This option was rejected because of complexity and time issues. It was also felt that this implementation was not the best way to demonstrate direct digital controls.
The airflow idea was another model that was rejected. This model would use a device similar to an airplane wing. The CSI device would control flaps on the wing by measuring airflow. The complexity of this problem coupled with the time constraints led to this alternative being rejected. The general consensus was that a simpler and more powerful demonstration could be designed with less effort.
The temperature model would incorporate the use of a temperature sensor and some kind of heating device. The sensor would measure the temperature change and base it’s actions on the sensor’s reading. This model was rejected because it was felt that the temperature would change too slowly. How fast the temperature varied would depend on what kind of heating device was used.
Another possible implementation was the use of lights to demonstrate a direct digital control loop. A row of lights would act as an analog meter with successive bulbs lighting in response to a user-controlled event. This idea was rejected because the speed of light meant that the control loop would be too fast. This would directly affect how much the student would learn about controls.
Another idea that was rejected was suspending a small metal ball in a magnetic field. The user would vary the height of the ball and the CSI controller would adjust the magnetic field to keep the ball suspended. This idea was rejected because of the complexity involved in implementing it.
The final idea was the use of a water reservoir and pumps to regulate water flow. This idea had several advantages over the previous models. One of them was that water could be easily measured and understood. Students learning about direct digital controls can easily grasp the concept of controls if a water demonstration is used. Another advantage was that a water demonstration would use a relatively fast acting loop. The previous implementations all had the problem that the loop would be either too fast or too slow. The water model presented the least amount of problems and it was selected to be the demonstration model for phase 2.
Before finally settling on the technical approach described in section 7.1, several alternative implementations of the water model were discussed and evaluated. All of the alternatives had the same fundamental idea: The use of water reservoirs in addition to sensors and valves to control water flow.
The first water model that was considered had the CSI device controlling the pump (Figure 39). The valve would be user controlled and would vary the amount of water flowing out of the main reservoir. This alternative was eventually rejected because of complexity issues. It was decided that the pump would be difficult to control. Leaving the pump operating at a constant rate and controlling the valves (through the CSI controller or the user) would be much easier to design and implement.
[pic]
Figure 39. Phase 2 Design Alternative #1
Design alternative #2 (Figure 40) was a slight variation on alternative #1 (Figure 39). This model was rejected for the same reasons as #1, namely that the pump would be much harder to control than the valves.
[pic]
Figure 40. Phase 2 Design Alternative #2
Design alternative #3 (Figure 41) would involve controlling a scaled down version of a hydroelectric plant. It was decided that a real world model was not necessary to demonstrate direct digital control loops and so this model was rejected.
[pic]
Figure 41. Phase 2 Design Alternative #3
Design alternative #4 is the implementation that had the greatest number of benefits. This is the technical approach that was finally adopted and is discussed in section 7.1. The advantages are that the user can vary water flow with a valve (adding to the “hands-on” experience) and the pump would not be under the control of the CSI device.
The actual demonstration device that was implemented is pictured in Figure 42. This demonstration device has several additional components as compared to the general system diagram shown in Figure 38. NOTE: For complete technical specifications of each component along with brand names and place of purchase, please refer to Appendices 18.3 and 18.4 at the end of this document.
[pic]
Figure 42. Demonstration Device Final Design
Table 3. Demonstration Device Components
|Point |Name |Description |
|A |Water level sensor |Detects water level in the container (B) |
|B |Container |Container for water in the system |
|C |Disturbance valve |Controls the flow of water out of the container (B) |
|D |Flow regulator valve |Regulates the constant flow out of the container (B) |
|E |Reservoir |Secondary water storage reservoir |
|F |Water pump |Circulates water to the control valves (M,L) |
|G |Diverting valve |Regulates amount of water diverting back into the reservoir (E) |
|H |Flow regulator valve |Regulates discharge of water pump (F) |
|I |Flow meter |Measures flow of water through the system |
|J |Switching valves |Used to stop flow of water when swapping control valves (M,L) |
|K |Unions |Connect control valve sections to rest of system |
|L |On-off valve |Valve controlled by the CSI controller (N) |
|M |Proportional valve |Valve controlled by the CSI controller (N) |
|N |CSI controller |Attached to PC; controls (M) & (L) through software loops |
|O |Cart |Contains entire system |
The point labeled ‘A’ is the water level sensor (Figure 43), which measures the height of the water in the container by pulsing an alpha sonic sound wave from the base of the transducer five times per second. The sound wave travels down the wave-guide and reflects against the water before returning back to the receiver. The electronics measure the time of flight between the sound generation and receipt, and translates this figure into the distance between the transducer and water level below.
7
Figure 43. Flowline Cricket Low Cost Alphasonic Level Transmitter (A)
Point ‘B’ section is the container section of the device, shown in Figure 44. Many different options were explored in searching for a container of the desired dimensions. The resulting container was custom built to meet the design specifications.
[pic]
Figure 44. Container (B)
Point ‘C’ is a disturbance, ¼ turn, ball valve (Figure 45), which will reflect outside user input. A picture of the hand valves used in the system is shown in Figure 46. A user can change the position of this valve to cause water to drain slower or faster out of the container. Since linearity was not of great importance in this valve, a ball valve was sufficient. However, for visual aid, a ¼ turn valve was used so that the user could know the exact position of the valve just by observing the position of the handle as opposed to a turn handle.
[pic]
Figure 45. Ball Valve (C,D,G,J,O)
[pic]
Figure 46. Hand Valve (C,D,G,J,O)
The left valve at point ‘D’ is a globe valve (Figure 47) used to regulate the constant drainage from the container to the reservoir below. This has been put in place for the scenario of when the water level is to be lowered, yet the disturbance valve is to be closed. Without this drainage valve, no water would drain. Therefore, this simulates the controller’s ability to lower the water level under these conditions. It also acts as a realistic “leak” muck like one would find in an HVAC system. When a room is heated, heat will escape through various cracks and openings. In hopes of tuning this valve to a precise flow, a globe valve was used for a more linear affect.
[pic]
Figure 47. Globe Valve (D,H)
The lower reservoir at point ‘E’ and is shown in Figure 48. It has been selected to hold the water of the entire system. This should allow for ease of filling and emptying the system and also act as a safety device knowing that the water of the entire system can be contained in one device.
[pic]
Figure 48. Reservoir (E)
The water from here is sucked out through the pump, shown in Figure 49, at point ‘F’. In order to properly select the pump, two considerations must be taken into account: the gallons of
[pic]
Figure 49. Flotec FP0F360AC Water Pump (F)
water per hour (GPH) or per minute (GPM) that the pump will discharge and the foot-head that the pump will need to drive the water through the system. In calculating this, two factors must be determined: GPM and inside diameter (I.D.) of the piping system. To coincide with the corresponding calculations, the number will be denoted by the calculation letter in (). For the demonstration device, 2 GPM (a) would be sent through a ½” schedule 80 piping system (b). The schedule 80 pipe was chosen to aid in bearing the weight of the control valves. An example of the schedule 80 pipe used in the system is shown in Figure 50 with various fittings shown in Figure 51.
a. Pump discharge = 2 GPM
b. Piping I.D. = ½”
[pic]
Figure 50. Schedule 80 pipe
[pic] [pic] [pic]
Figure 51. Fittings: T, Elbow, and Coupling
Once these values have been determined, the equivalent foot length (EFL) of the piping system must be found (f). This is done by summing the total length of pipe in the system (c), the equivalent length of joints (found in Table 15,16) (d), and the equivalent length of hand valves (found in Table 17) (e). For this system, since the hand valves I.D. equals that of the piping system, they can be treated as normal pipe length.
c. Length of pipe = 183” = 15.25’
d. 7 elbows at 1.6’ per elbow = 134.4” = 11.2’
e. 4 hand valves at 3” per valve = 12” = 1.00’
f. Total EFL of pipe = 329.4” = 27.45’
The GPM (a) and piping diameter (b) are then used to find the friction loss of the piping system. Using Table 18, the GPM line is intersected with the piping diameter line and the result is the friction loss in feet per 100’. In this case, the friction loss was 8’ of water per 100’ (g).
g. Friction loss of water per 100’ = 8’
This number was then multiplied by the EFL (f) to find the foot-head of the piping system (h).
h. Foot-head of piping system: 8/100 * 27.45 = 2.20 foot-head
The next step is to calculate the foot-head of the remaining device (control valves and flow meter). This is done by calculating the pressure drop in psi based on the GPM of the system and the CV of the device using equation (i).
i. Pressure drop = (GPM / CV) 2
The noted values for the flow meter (j) and control valves (k,l) are listed below. Note that since the path of the water through the system will be through only one of the control valves (they are in series), that only one valve need be taken into account for the system.
j. Flow meter pressure drop = 0.5 psi
k. Control valve CV = 1.5
l. Control valve pressure drop = (2 / 1.5)2 = 1.78 psi
To convert from pressure drop to foot head, the psi value is multiplied by the constant 2.3 (m).
m. Foot-head = pressure drop * 2.3
This results in the following values for the flow meter (n) and control valve (o).
n. Flow meter foot-head = 1.15 foot-head
o. Control valve foot-head = 4.14 foot-head
The final value needed is the elevation drop of the system. For the demonstration device, this measurement will be taken from the average water level of the container to that of the reservoir (p).
p. Elevation drop = 5’
The final foot-head value is simply the sum of the various measurements - h,n,o,p - and is noted in (q).
q. Foot-head of entire system = h + n + o + p = 12.5 foot-head
This number was then compared with the GPM of various pumps and what was thought to be the correct pump was then chosen. However, during the testing of the system, a new model (as shown in Figure 49) was purchased.
In order to keep the pump from burning up in the scenario when both control valves are completely closed, a hand valve was placed as a diverting valve at point ‘G’. This will be opened slightly so that water may flow through the pump at all times instead of the pump pushing the water into a blockage.
In the case that the water pump is desired to have a lower discharge rate, a linear globe valve is placed at point ‘H’ to allow the user to lower the GPM of the system.
To keep in line with the visualization of the system, a flow-meter is placed at point ‘I’. This allows the user to visually observe the flow rate of the system.
At point ‘J’, and the corresponding point on the lower branch, a hand valve is placed in order to seal the corresponding branch when replacing or switching control valves. This is allowed by the unions placed at point ‘K’ in both branches as well as to the right of both control valves, ‘L’ and ‘M’. The sections are 9 ¼”, thus allowing any number of combinations of different control valves to be placed within the system at any given time. This allows for greater flexibility of the demonstration device.
Valve ‘L’ is the on/off valve (Figure 52) that will be used to demonstrate two-position control loops.
[pic]
Figure 52. Danfass On/off Valve (L)
The valve labeled ‘M’ is the proportional valve that is used to demonstrate floating and PID control loops. Both a direct acting and reverse acting valve were obtained for the demonstration device. This will allow for the user to compare the two types of valves and their characteristics, making this a more flexible device in its usage. The direct acting valve is shown in Figure 53. As noted before, at the request of IEC these valves, ‘L’ and ‘M’, are interchangeable and can be taken off of the demonstration device to test and be replaced.
[pic]
Figure 53. Siemens Direct Acting Proportional Valve (M)
‘N’ designates the CSI controller. The input enters the controller on the right side from the water level sensor ‘A’ and the two outputs from the control valves ‘L’ and ‘M’ exit the board at the top side
The cart that the entire demonstration device is attached to is labeled ‘O’. This cart was custom built to meet the specifications of the demonstration device. Many pre-fabricated carts were found and priced. Their specifications were very similar to that of the custom built cart, however they contained extra braces and shelving that were unwanted and would need to be removed for use as the demonstration device cart.
After some initial testing was done on the lab station, it became evident that overall testing would follow two paths, hardware and software. Since this lab station is going to be used as a training aid, it is imperative that errors of any kind are kept to a minimum to avoid any possible confusion to the student. One of the effects of designing a lab station with errors is that technicians could possibly be kept from getting the best training possible. This would be costly to the IEC in terms of both manpower and money costs. A successful lab station allows the IEC to train employees with a minimum of effort and upkeep. The same applies to the demonstration device that was built. Errors were simply unacceptable because of the inherent precision required to demonstrate control loops. For example, an error in construction could lead to a possible water leak, which in turn could spill on one of the electronic components. This could be catastrophic.
DDC Lab Station Testing
Testing was broken down into two general areas. Each area corresponded to the phase that was being worked on. Phase 1 involved incorporating the CSI controller onto the lab station. The first part of phase 1 testing was to configure the CSI controller and software to communicate together. This required the use of a CSI Hand Held Controller (HHC). The HHC (Figure 54) is a small device that allows the user to set up a number of internal CSI parameters. Using the HHC, the controller’s baud rate, LAN rate, and system address was set. The system address is essential as this is used to identify the controller to the host PC. The host PC is simply the computer that the CSI controller will be attached to (via a standard serial port).
[pic]
Figure 54. Hand Held Controller
The CSI board was configured by first connecting the HHC to the provided port on the board. The system address was set by pressing [DCU ADDR], entering the digit 02, and then pressing enter. This set the CSI system address in ROM (Read Only Memory) to 02. Next, the baud rate was set by pressing [CODE](91([INC] until 9600 was displayed, then [ENTER]. This sets the speed that the CSI controller “talks” to the host PC. After the ROM on the CSI controller had been set, the software on the host PC was configured to communicate with the CSI controller. This was done by first downloading an operating system (OS) onto the controller. The OS is the “brains” of the controller, giving the user an easy to use interface to deal with the system hardware. The next thing to do was “restore” the system database. The system database contains lookup tables and state descriptions for all the points in the system. Once this was done, the controller and PC were ready to be tested.
[pic]
Figure 55. Configuring CSI Controller with HHC and Aid of Bob Schultz
After successfully setting the controller’s parameters and downloading an operating system, the team moved on to the second part of phase 1 testing, which was to simply test inputs and outputs. The functionality of the inputs and outputs was determined by the input and output LEDs on the CSI board (Figure 56) along with the “Controller Summary” screen (Figure 57) on the CSI software on the operator workstation.
[pic]
Figure 56. Input / Output LEDs
[pic]
Figure 57. Controller Summary Screen
This phase proved to be anything but simple. The wiring of the CSI side of the lab station was completed at the end of the first semester and testing was scheduled to begin the second semester. At that time, the lab station was given power and its inputs and outputs tested. No response was seen on the control software or on the input/output LEDs. Upon further analysis, it was determined that the three binary inputs (switches) were in fact working correctly. When turned on or off, the switch’s respective input LED would display the correct state of the input and the proper state would also be shown on the controller display on the workstation.
After experimenting with the switches, attention was turned toward the binary output (light). Initially, this output failed to function properly. The team was not able to turn the light on or off from the operator workstation. Additionally, this and only this output utilized a small relay to route power to it. So, after a crash course on relay operation, the relay was rewired and the light tested and verified. This output now worked correctly in the fact that it could be turned on or off via the operator workstation and its state displayed on the controller software. Now, the problem was with the switches.
[pic]
Figure 58. CSI Controller Layout
It was determined that the switches would work for approximately seven seconds after initialization of the board. During this seven-second period, the input LEDs on the board would turn on/off corresponding to the switches’ position. The switches’ state would also be correctly read by the controller software on the workstation. At the seven-second mark however, every input LED would illuminate briefly then turn off. After this mark, none of the inputs would work correctly until the board was re-initialized. It was later determined that this occurrence was caused by incorrect routing of power.
Another anomaly was encountered when the relay was energized (and thus the light was on). When the relay was in this state, all three switches would work as expected. When the relay was not energized, the seven-second anomaly was again seen. It was later determined that this too was caused by incorrect power wiring. Eventually, experimenting with the switches caused the CSI controller to lose communication with the operator workstation and no inputs/outputs would work subsequently. The team was never again able to regain communication with the first CSI controller used.
[pic]
Figure 59. Testing of Transformer on DDC Lab Station
After receiving and testing a second controller from CSI, it was determined that this board too was inoperable. A third board was then acquired from CSI, tested, and remains on the lab station at the time of this writing.
Initially, the third board was demonstrating the same problems as had the first board. For instance, the seven-second anomaly was still being seen. After ruling out a problem with the board (since the first one had also behaved this way), the team basically just started from scratch. An IEC technician was also consulted, resulting in the decision to not ground the board as it had been previously. Since no correlation between the relay and the switches was seen, the relay was removed from the circuit altogether attempting to get the switches working properly. Furthermore, the powering of the board was re-evaluated, resulting in the connection of only one input at a time for testing. It was determined that everything up to and including the transformer (Figure 60) was good. However, the power from the transformer to the board had been incorrect. In this configuration, with the board powered correctly, the team was finally able to get all three switches working correctly without the relay energized. Now, the problem was with the light.
[pic]
Figure 60. Double-wound Transformer
After re-connecting and testing the relay and light bulb into the system, it was found that it did not function correctly. On a hunch, the team decided to again ground the board upon which the light bulb indeed worked as expected. At this point, the three switches and the light bulb worked correctly. This still left the three analog inputs (thermistor and two potentiometers) and the analog output (LCD screen).
It was determined that the potentiometers had been wired incorrectly and they both worked after rewiring was done. The thermistor had not yet been wired and it also worked as soon as it was connected to the board. Lastly, the LCD screen was given power and a signal resulting in some kind of output on the LCD screen as well as on the controller display on the workstation.
Once this was complete there was a need for compatibility testing to verify that the new controller did not interfere with the operation of the existing (Automated Logic) controller. In addition to compatibility issues, there were also some usability issues that were tested. How much stress the device could handle was a large issue since many students will use the lab station.
Demonstration Device Testing
Phase 2 testing was much more complex than the testing for phase 1. In addition to testing the controller, the demonstration device needed to be thoroughly tested. Two-position, floating, and PID control loops needed to be implemented in the design so they were tested accordingly. As stated before, the design of phase 2 calls for a number of valves in addition to a water pump and a water level sensor. Tests were preformed on each component to make sure it was working correctly and to verify that all of the components were interacting properly.
The demonstration device was tested in much the same manner as the expanded lab station. Starting from an initial state, the device was tested after each major addition to it. The first thing that was tested was the integrity of the upper water reservoir (B). The first additions to this were the disturbance valve (C) and the flow regulator valve (D). Once these two valves were put in place, the container (B) was filled with water to test the fittings of the two valves. They both worked as expected.
The next addition was the upper valve assembly. This portion entails everything from the flow meter (I) to the emergency valve (O) exclusive of these two components. This portion was constructed and tested independently of the previous stage. Once all the fittings were secured in their final positions, glued, and let to dry, this assembly was also tested for leaks. The system performed as expected.
The next step was to test these two portions together with the lower reservoir (E). After filling the reservoir with a sufficient amount of water, the water pump (F) was also brought into the system to pump the water from the lower reservoir up through the upper valve assembly and into the upper reservoir. With the system basically in the same configuration as it would be when finally mounted on the table, it worked as expected. The valve fittings were checked for leaks then tested for functionality. One thing that was realized during this test was the definite need for some type of splash-guard device for the water entering the upper reservoir. Without it, the level of the container is somewhat erratic and therefore difficult to determine by the water level sensor (A).
Once the cart arrived, the individual modules were tied together and the unit was tested as a whole. Two problems were observed at this time. The first was that the pump was not discharging enough water to make the system as fast-acting as desired. With the control valves wide open and the diverting valve completely closed, only 1 GPM flowed through the system. It was then determined to purchase a new pump. The second pump was the Simer BW85P pump (shown in Figure 95). This had approximately 2.5 times the discharge capacity as the Simer M40P pump. However, this was a 12VDC/12A pump. After spending one day searching for an appropriate power supply and concluding that a battery power was not a suitable permanent source, a third pump was purchased. The Flotec FP0F360AC pump was found to be inbetween the two Simer brand pumps. Once installed, this pump discharged at approximately 4 GPM with the system wide-open, thus meeting the speed requirements.
The second problem concerned the water discharge of the piping system into the container when the system was draining. Upon completion of the experiments with the demo device, the container would then be fully emptied. However, when the water level was at its minimum (due to the discharge units on the front, not all water could drain through out), that was still above the bottom of the discharge pipe, which created enough pressure to not allow the water in the piping system to flow out through the system. Therefore, the discharge pipe was shortened to a level above the minimum water level, allowing the system to drain properly.
Testing was then done on the proportional and on/off valves and actuators in conjunction with the controller. The proportional valve functioned as expected as an analog output of the controller. By setting the output number in the software, that related to the position of the valve interms of percent open. Thus, 100 was fully open and 0 was fully closed. The on/off actuator was treated as a digital output with the relay in the same manner as the lights used as digital outputs on the DDC lab station. However, the team was unable to get this actuator to function properly by the project’s end.
The water level sensor was tested individually and found to be operational. However, integration into the system was not possible as a 249 Ohm, 1/8 Watt, 0.1% resistor was needed for the input on the CSI controller. After much searching, one was found, however the part could not be obtained by the project’s end.
In order to avoid unnecessary risk taking, the overall project design was broken down into 3 phases. There were several reasons this was done. The main reason was that it allowed the design team to take an incremental approach to the design. By breaking the project down into small, easy to manage “chunks”, an incremental design approach along with a thorough analysis of all assumptions and decisions allowed for a more complete control over risks. Separating the design into 3 phases allowed the design team to pick which phases had higher priority. By assigning higher priorities to design-critical work, this helped to control time constraints.
Another possible risk that was addressed was budget overrun. That risk was effectively handled because of the large amount of donated materials given to the design team. Phase 1 components were donated by the IEC and CSI. In addition, CSI provided the controllers and a Plexiglas shell for phase 2. The demonstration device components were funded by the IEC.
Another risk that was encountered was lack of proper testing and configuration equipment. For example, when testing was first started on the lab station, it was assumed that all of the board’s memory would be pre-configured. Only after a week of frustration attempting to get the controller communicating with the PC was it realized that the HHC was needed. Without the HHC, there was no possible way the testing could have continued. Another example is the complete lack of software documentation. There was no shortage of documentation on how to configure the CSI’s hardware. However, the group received no documentation on how to write programs for the controller once all of the setup was complete. This has been a major stumbling block, since the software is a relatively unique language using a picture based programming structure. The group only had previous experience in dealing with text based programming languages. This stumbling block has been aided by asking Mr. Schultz questions on software.
One unexpected risk that was encountered was the loss of one the client contacts. Andy Suby, advisor and employee of the Iowa Energy Center, changed jobs and took a position with a different organization. The group was introduced to the new client contact, Mr. Curt Klaassen, and time was spent acquainting Mr. Klaassen with the group members and the project itself. The loss of these few weeks were not catastrophic, as most of this time was spent testing the lab station and consulting with Dr. Lamont and Dr. Elia.
At this time, it is expected that the lab station will be fully constructed and tested and that the demonstration device will be fully designed and constructed by the projected date. This leaves only the final tuning of the demonstration device and the remaining software to be written for the completion of phase 2. Phase 3 has yet to be implemented as it was deamed beyond the scope of this project. It is recommended that this phase be pursued vigorously by whoever may take over the project.
It is not expected that the lab station or demonstration device will become commercial products. The abundance of HVAC controllers and the relative ease of creating a lab station with basic inputs and outputs means that most learning centers would probably opt for building their own lab stations. The design of the lab station unfortunately creates a situation where upgradeability is limited. All inputs and outputs are fixed on the station, making a I/O upgrade very difficult. Since the CSI controller is mounted on the station with Velcro, upgrading to a different controller should be relatively painless.
The demonstration device, like the lab station was built solely for the purpose of instructing students on the basics of controls. It is a scaled-down version of a real-life system and no plans have been made to commercially market it. The demonstration device was designed with a certain amount of flexibility in mind. All of the computer-controlled valves have been placed on the device so that they can be interchanged easily. In addition, the controller card can easily be replaced.
Chapter
8 Financial Budget
The following is the estimated cost of the project modules as a whole. Parties represented in parentheses are those that donated money and/or parts to that section.
Table 4. Project Financial Budget - Total
|Item |Original Estimated Cost |Revised Estimated Cost |Actual Final Cost |
|Lab Station |$2800 |$2600 |$2600 |(IEC & CSI) |
|Demonstration Device |$5350 |$4400 |$4600 |(IEC & CSI) |
|Class Work |$50 |$50 |$115 |(ISU & team) |
|Total Cost |$8200 |$7050 |$7255 | |
[pic]
Figure 61. Project Financial Budget - Total
The following is the estimated cost of the project components listed individually.
Table 5. Component Financial Budget
|Quantity |Part Description |Estimated Cost |Revised Estimated |Actual Cost |
| | | |Cost | |
|DDC Lab Station |
|3 |Toggle switches |3 @ $1 |3 @ $1 |3 @ $3 |
|2 |20 k ohm 10 turn potentiometers |2 @ $4 |2 @ $4 |2 @ $4 |
|1 |10 V DC LCD meter |1 @ $10 |1 @ $10 |1 @ $12 |
|1 |Ice cube relay with port |1 @ $20 |1 @ $20 |NA |
|4 |Lights |1 @ $2 |1 @ $2 |4 @ $6 |
|3 |9 pin ribbon cables |$0 |3 @ $10 |3 @ $10 |
|1 |DC transformer |1 @ $20 |1 @ $20 |NA |
|0 |Plexiglas case |1 @ $200 |$0 |$0 |
|1 |A / B switch |1 @ $15 |1 @ $15 |1 @ $15 |
| | | | | |
|Control Loop Demonstration Device |
|1 |Thermistor |1 @ $10 |1 @ $10 |NA |
|1 |Water pump |1 @ $100 |1 @ $35 |$65 |
|1 |Pipe cutter |$0 |$0 |$26 |
| |Pipe fittings and joints |$25 |$35 |$40 |
| |Straight pipe |$25 |$35 |$15 |
| |Hose and fittings |$0 |$0 |$10 |
|1 |Pipe cleaner / cement |$10 |$10 |$10 |
|2 |Proportional valve |$2,000 |1 @ $500 |2 @ $500 |
|1 |On/off valve |$200 |$200 |$250 |
|1 |Water level sensor |$200 |$500 |$250 |
|1 |Flow meter |$0 |$100 |$250 |
|7 |Hand valves |4 @ $3 |7 @ $3 |7 @ $3 |
|1 |Container |$100 |$200 |$180 |
|1 |Reservoir |$100 |$25 |$10 |
|1 |Stand |$50 |$250 |$300 |
| | | | | |
|Both |
|1 |CSI controller |2 @ $2500 |2 @ $2500 |1 @ $2500 |
|0 |CSI software and documentation |2 @ $500 |$0 |$0 |
| | | | | |
|Class Work |
|1 |Poster |1 @ $50 |1 @ $50 |1 @ $55 |
|1 |Final paper |$0 |$0 |1 @ $60 |
| | | | | |
Chapter
9 Personal Effort
Budget
The estimated time to complete the project is 1500 hours, 2/3 of which will occur during the second semester. This breaks down into about 1200 technical hours and 300 non-technical hours. The technical hours consists of any time requiring engineering work, while the non-technical hours consists of any time requiring secretarial type of work.
Table 6. Personal Effort Budget - Total
|Personnel |Original Estimated Effort |Revised Estimated Effort |Actual Final Effort |
|David Boege |315 hours |235 hours |197 hours |
|Ashley Herr |283 hours |273 hours |344 hours |
|Aaron Kammeyer |313 hours |253 hours |207 hours |
|Sam Lozano |323 hours |228 hours |172 hours |
|Joe Lomax |295 hours |241 hours |163 hours |
[pic]
Figure 62. Personal Effort Budget – Total
Table 7. Personal Effort Budget - Itemized
|Total Project |Due |Estimated | |Actual | |
| | |Date |Time Usage | |Time Usage |
| |Ashley Herr |2/15/2000 |2 |2 |3 |
| |Ashley Herr | | |2 | |
| |Ashley Herr |On-going |20 | |31 |
| |Ashley Herr |3/22/2000 |2 |3 |9 |
| |Ashley Herr |4/18/2000 |3 |1 |20 |1 |
| | |Due |Engineering Time |Non-Technical |Engineering Time |
| |Ashley Herr |On-going | |20 | |
| |Ashley Herr |11/1/2000 |50 |10 |40 |
| |Ashley Herr |12/1/2000 | |20 |18 |
| |Ashley Herr |12/1/2000 |2 |1 |1 |
| |Ashley Herr | |
|Bob Schultz |[pic] |
|Director, Applications Services – CSI | |
|1650 W. Crosby Road |Figure 67. CSI Logo |
|Carrollton, TX 75006 | |
|Voice: (972) - 323 - 5460 | |
|Cell: (972) - 824 - 2696 | |
|bob_schultz@ | |
Dr. John Lamont Dr. Nicola Elia
324 Town Engineering 3131 Coover Hall
Ames, IA 50014 Ames, IA 50014
Voice: (515) - 294 – 3600 Voice: (515) – 294 - 3579
Fax: (515) – 294 – 6760 Fax: (515) – 294 – 8432
jwlamont@iastate.edu nelia@iastate.edu
Dec00-05: DDC Lab Station
Senior Design Lab
322 Town Engineering
Ames, IA 50014
Voice: (515) - 294 - 1996
dec0005@iastate.edu
[pic]
Figure 68. Dec00-05 DDC Lab Station Team
Dave Boege - EE Joe Lomax - EE
116 N. Hyland Ave #10 3022 Oakland St.
Ames, IA 50014 Ames, IA 50012
(515) - 292 - 7222 (515) - 292 - 7726
dboege@iastate.edu jlomax@iastate.edu
Ashley Herr – EE Sam Lozano - CprE
Team Leader 307 Lynn Ave. #100
505 8th St. #3 Ames, IA 50012
Ames, IA 50010 (515) - 451 - 6592
(515) - 292 - 4276 slozano@iastate.edu
ajherr@iastate.edu
Aaron Kammeyer - EE
4412 Castlewood Pl #1
Ames, IA 50014
(515) - 292 - 8909
akamms@iastate.edu
Chapter
16 Summary
This project proved to be a successful project for all parties involved. The five-member team took from this project a great learning experience of a large-scale project from design to construction that will be similar to those done in industry. Increased time management and leadership skills along with communication and organizational skills were also gained. There was also be a technical education in the area of controls for the team, specifically in HVAC DDC controls. The Iowa Energy Center received an update to its teaching resources with the expanded lab station and the lab demonstration device, thus making its classes more effective and the improving the education for their students. Iowa State University also created a continued relationship with the IEC in senior design projects.
Chapter
17 References
Automated Logic web site:
CSI web site:
DEC00-05 group web site:
Flowline web site:
IEC web site:
Kele on-line catalog
Senior Design web site:
Simer web site:
Automated Logic M8102e Control Module Manual
- Photocopy provided by the IEC.
Automated Logic GCM2 Communications Module Manual
- Photocopy provided by the IEC.
Carrier Air Conditioning Company Piping Design
- Copy provided by Iowa Energy Center
Control Systems International 7718-C Manual
- Provided by Bob Schultz of CSI
Direct Digital Control Lab Notes
- Copy provided by Iowa Energy Center
Flowline Level Superstore Catalogue Volume 5
- Provided by Iowa Energy Center
Johnson’s Controls Product/Technical Bulletin VA-7150
VA-715x Electric Valve Actuator
FANs 977, 125, 1628.3
Issue Date - 0297
- Copy provided by Iowa Energy Center
Johnson’s Controls Product/Technical Bulletin VG7000
VG7000 Series Bronze Control Valves
FANs 977, 125, 1628.3
Issue Date - 0300
- Copy provided by Iowa Energy Center
Landis & Gyr Technical Instruction
VE VVI Electronic Two-way Normally Open Valves
Document Number 155-126
February, 1996
- Copy provided by Iowa Energy Center
Brooks Instrument Installation and Operation Manual
Model 1305 O-ring Seal Flowmeter
X-1305
January, 1998
Issue 7
- Copy provided by Iowa Energy Center
Chapter
18 Appendices
The following is the schematic for the layout of the automated logic side of the lab station.
[pic]
Figure 69. Automated Logic Layout
The following is the schematic for the wiring of the Automated Logic Controller.
[pic]
Figure 70. Automated Logic Wiring Diagram
The following is a schematic of the layout of the CSI side of the lab station.
[pic]
Figure 71. CSI Layout
The following is the schematic for the wiring of the CSI controller.
[pic]
Figure 72. CSI Wiring Diagram
The following is a general schematic for the inputs of the CSI controller. The resistor in C is used as a voltage divider, while the resistor in B is a pull-up to +5V, and the resistor in A sets up the input as an analog input.
[pic]
Figure 73. CSI Inputs
The following schematic is the way the controller is set up when a 20 k ohm potentiometer is used.
[pic]
Figure 74. CSI Analog Inputs
The following schematic is the way the controller is set up when a 10 k ohm thermistor is used as the input to the controller.
[pic]
Figure 75. CSI Thermistor Input
The following schematic is the way the controller is set up when the toggle switches are connected to the input of the controller. This will cause a “1” to be read when the switch is open and a “0” when the switch is closed.
[pic]
Figure 76. CSI Digital Inputs
Table 8. Component Purchases
|Component |Model |Place of Purchase |
|Container | |Country Plastics, Ames, IA |
|Demo Device Cart | |IEC |
|Flowmeter |1305 O-ring Seal |IEC |
|Hose and fittings | |Lowes, Ames, IA |
|On/off Valve | |IEC |
|Proportional Valve |SQS65.5 |IEC |
|Proportional Valve |VA-715x |IEC |
|PVC pipe |Schedule 80 |Lowes, Ames, IA |
|PVC pipe fittings |Schedule 80 |Lowes, Ames, IA |
|Reservoir | |Menards, Ankeny, IA |
|Water Level Sensor |Cricket LA-12 |Flowline |
|Water Pump | |Menards, Ankeny, IA |
| | | |
Container:
Company: Country Plastics
Dimensions: 12.75” wide x 12.75” deep x 24.375” tall
[pic]
Figure 77. Container
The following is the layout for the pieces needed for the demonstration device container.
[pic]
Figure 78. Container Pieces
The following are the views of the demonstration device container from the front/back, both sides, and the top.
[pic]
Figure 79. Container Views
The following are the layouts of the drilled holes on the front side of the demonstration device container for the water drainage.
[pic]
Figure 80. Container Front Holes
The following are the layouts of the drilled holes on the top side of the demonstration device container for the water input hole and the sensor hole.
[pic]
Figure 81. Container Top Holes
Demo Device Cart:
Company: Iowa Energy Center
Dimensions:
Cart: 36” wide x 22” deep x 30” tall
Backboard: 36” wide x 30” tall
[pic]
Figure 82. Demonstration Device Cart (similar to custom built cart)
Flowmeter:
Company: Brooks Instruments (Fisher-Rosemount)
Model: 1305 O-ring Seal
Data: courtesy of:
Brooks Instrument Installation and Operation Manual
Model 1305 O-ring Seal Flowmeter
X-1305
January, 1998
Issue 7
[pic]
Figure 83. 1305 O-ring Seal Flowmeter
[pic]
Figure 84. 1305 Flowmeter Dimensions
Table 9. 1305 Flowmeter Dimensions
[pic]
Table 10. 1305 Flowmeter Specifications
[pic]
On/off Valve:
Company: Johnson Controls
Model:
Actuator: Danfass
[pic][pic]
Figure 85. Johnson Controls On/off Valve Dimensions and Picture
Table 11. Johnson Controls On/off Valve Dimensions
[pic]
Proportional valve 1:
Company: Landis & Gyr
Model: SQS65.5
Data: courtesy of:
Landis & Gyr Technical Instruction
VE VVI Electronic Two-way Normally Open Valves
Document Number 155-126
February, 1996
[pic]
Figure 86. Landis & Gyr Proportional Valve
Table 12. SQS65.5 Specifications
[pic][pic]
Proportional Valve 2:
Company: Johnson Controls
Model: VA-715x
Data: courtesy of:
Johnson’s Controls Product/Technical Bulletin VA-7150
VA-715x Electric Valve Actuator
FANs 977, 125, 1628.3
Issue Date - 0297
Johnson’s Controls Product/Technical Bulletin VG7000
VG7000 Series Bronze Control Valves
FANs 977, 125, 1628.3
Issue Date - 0300
[pic]
Figure 87. VA-715x Proportional Valve and Actuator
[pic]
Figure 88. VA-715x Dimensions
[pic]
Figure 89. VA-715x Installation
Table 13. VA-715x Specifications
[pic]
Water Level Sensor:
Company: Flowline
Model: Cricket LA-12 (Low Cost Alphasonic Level Transmitter)
Data: courtesy of:
Flowline website
|[pic] |Table 14. Cricket Specifications |
| | |
|Figure 90. Sensor | |
| |LA12 Cricket Alphasonic Transmitter |
| | |
| |Range: |
| |0.3 to 10' (9 cm to 3 m) |
| | |
| |Accuracy: |
| |± 1% of span in air |
| | |
| |Resolution: |
| |0.125" (3 mm) |
| | |
| |Frequency: |
| |2 kHz (nominal) |
| | |
| |Pulse rate: |
| |5 per second |
| | |
| |Dead band: |
| |0.3' (5 cm) minimum |
| | |
| |Supply voltage: |
| |12-36 VDC |
| | |
| |Loop resistance: |
| |600 ohms @ 36 VDC |
| | |
| |Signal output: |
| |4-20 mA, 12-36 VDC |
| | |
| |Signal invert: |
| |4-20 mA or 20-4 mA |
| | |
| |Minimum range: |
| |8" |
| | |
| |Maximum range: |
| |120" |
| | |
| |Span adjustment: |
| |Potentiometer |
| | |
| |Indication: |
| |LED for power status |
| | |
| |Temperature rating: |
| |F: -40 degrees to 140 degrees |
| |C: -40 - 60 degrees |
| | |
| |Temp. compensation: |
| |Automatic over range |
| | |
| |Pressure rating: |
| |Atmospheric |
| | |
| |Wave guide: |
| |Schedule 40 or 80, 1/2" or 20 mm |
| | |
| |Guide materials: |
| |PVC, PP or PVDF |
| | |
| |Enclosure rating: |
| |NEMA 4X / IP65 |
| | |
| |Enclosure material: |
| |Polypropylene, U.L. 94 VO |
| | |
| |Diaphragm material: |
| |Polyethylene |
| | |
| |Mounting threads: |
| |1" NPT (1" G) |
| | |
| |Mounting gasket: |
| |Viton 1" (metric only) |
| | |
| |Conduit connection: |
| |1/2" NPT |
| | |
| |Thread material: |
| |PP |
| | |
| |CE compliance: |
| |EN 50082-2 immunity |
| |EN 55011 emission |
| | |
| | |
[pic]
Figure 91. Cricket LA-12 Dimensions
[pic]
Figure 92. Cricket LA-12 Derating Charts
Water Pump:
Company: Simer
Model: M40P MiniVac
Data: courtesy of:
Component packaging
[pic]
Figure 93. Flotec FP0F360AC Water Pump
[pic]
Figure 94. Flotec FP0F360AC Water Pump
[pic]
Figure 95. Simer BW85P Water Pump Discharge
[pic]
Figure 96. Simer M40P Water Pump Discharge (F)
The following tables in Section 18.5 are taken from the Carrier Air Conditioning Company Piping Design manual.
Table 15. Fitting Losses of Joints in Equivalent Feet of Pipe
[pic]
Table 16. Fitting Losses of Joints in Equivalent Feet of Pipe
[pic]
Table 17. Valve Losses in Equivalent Feet of Pipe
[pic]
Table 18. Friction Loss for Closed and Open Piping Systems
[pic]
See following 2 figures for the forms used when testing the lab station (Figure 97) and demonstration device (Figure 98).
[pic]
Figure 97. DDC Lab Station Test Form
[pic]
Figure 98. DDC Lab Station Test Form
The following is a detailed course outline of the DDC Workshop taught by Bob Schultz of CSI at the Energy Resource Station. This outline is courtesy of the IEC.
|Day 1: |Day 2: |
|Orientation to the Energy Resource Station | |
| | |
|Introduction to Direct Digital Controls (DDC) |Programming Tools |
|Fundamentals |Line Programming |
|Terminology |Object Oriented |
|Control Loop Elements |Application Specific |
|Control Loop Response |Logic Symbols |
|- Two Position | |
|- Floating |Proportional, Integral, Derivative |
|- Proportional |Open Loop Response |
|- P + Integral |Loop Response Terminology |
|- PI + Derivative |Proportional/Integral |
|Inputs/Outputs |PID- The Derivative |
|Set-point Options |Loop Tuning |
|Control System Options |Scan Rate |
|DDC Benefits |Demonstrations |
|Programming Methods | |
| |Writing Good Sequences |
|Systems Architecture |Basic Loop Requirements |
|Proprietary Local Area Networks |Set-point Options |
|Multiple LAN Systems |Limits/Conditions |
|Commercial LAN Systems |Interloop Communications |
|External Communication | |
|BACNET/Echelon |Mixed Air Subsystem |
|ICI's |Fixed Minimum Outdoor Air |
|Operating Systems |Economizer Control |
| |Economizer with Fixed Min. |
|Input/Output/Scaling |Enthalpy Considerations |
|Input Devices |Mixed Air Reset |
|- Digital |Preheat Control Options |
|- Linear |Advanced Mixed Air Options |
|- Non-linear |- Indoor AQ Strategies |
|- Flow |Demonstrations |
|- Scaling |Class Problem Exercise |
|Output Devices | |
|- Discrete |Lab: Loop Tuning |
|- Analog | |
|- True | |
|- Pulse Width | |
|- Transducers | |
|Scaling | |
|Addressing | |
| | |
|Lab: Input/Output Scaling | |
| | |
|Day 3: |Day 4: |
| | |
|AHU Coils/Humidifier/Reheat |VAV Systems |
|Heating Coil Control |VAV Subsystems |
|Steam with Face & Bypass |Air Flow Measurement |
|Cooling Coil Control |Communication with Zone |
|Humidifier Control |Return Fan Tracking |
|Reheat Humidity Control |Communication with Mixed Air Section |
|Reset Strategies/Options |Typical Control Strategies |
|Communication with Zone |Alternate Control Strategies |
|Demonstrations |Reset Options |
| |Class Example |
|Fan Control |Demonstrations |
|Supply Fan | |
|Return Fan |Pumping Control |
|Coordination with Mixed Air |Constant Volume |
| |Variable Volume |
|VAV Terminal Unit Control |Primary/Secondary |
|Cooling Only VAV |Central Plant Control |
|With Reheat Coils |Cooling Tower Control |
|Fan Powered Boxes |Chiller Control Strategies |
|Demonstrations |Interface with Packaged Chiller Controls |
| |Converter Control |
|Constant Volume SZ Systems | |
|Simple Single Zone |System Control Logic |
|Life/Safety Control Issues | |
|Single Zone with Reheat |Lab: System Control Logic |
| | |
|Constant Volume MZ Systems |"State-of-the-Art" |
|Multi-zone Systems |Trends |
|Dual Duct Systems |Future of DDC |
| | |
|Mixed Air/AHU/Multiple Subsystem Control Logic |Course Wrap-Up & Adjourn |
| | |
|Lab: Mixed Air/AHU/Multiple Subsystem Control | |
| | |
|Day 5: | |
| | |
|Friday, December 10 | |
|Defining Your System | |
|Architecture | |
|- Networked | |
|- Stand Alone | |
|Controllers | |
|- Resolution | |
|- Sophistication & Costs | |
|Interfaces | |
|Personnel &Training Issues | |
|Operator Interfaces | |
| | |
|Specifying Your System | |
|Hardware | |
|Software | |
|Operator Interfaces | |
|Graphics | |
|Trending | |
|Documentation | |
|Training | |
|Schedule | |
| | |
|Acquisition/Commissioning Your System | |
|Procurement Issues | |
|Commissioning Controls | |
| | |
|Where the Industry is Headed | |
-----------------------
4.6 Limitations
4.1 General Background
4.5 Assumptions
4.4 Intended User(s) and Use(s)
4.3 Operating Environment
4.2 Technical Problem
5.4 Measurable Milestones
5.3 Design Constraints
5.2 Functional Requirements
5.1 Design Objectives
7.1 Technical Approaches
7.2 Technical Design
7.3 Testing Description
7.4 Risks and Risk Management
15.1 Clients
15.2 Faculty Advisors
15.3 Team Members
13.1 Technical
17.1 Web Sites
17.2 Manuals
7.5 Recommendation for Follow-on Work
18.1 Automated Logic Schematics
13.2 Non-technical
18.2 CSI Schematics
18.6 DDC Workshop Course Outline
18.3 Demonstration Device Components
18.4 System Modeling
18.5 Testing Forms
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