Creating a Program - Latest Seminar Topics for Engineering ...



Boiler Automation Using Programmable Logic ControllerIntroductionPLC applications are extensively used in industry to control and facilitate repetitive processes such as manufacturing cell management, fly-by-wire control, or nuclear plant shutdown systems. One of these applications is industrial automation which includes numerous automated processes. This again includes automation of boiler which demands determination of certain physical parameters (viz. pressure, temperature, etc.) & utilizing these parameters to make the boiler start-stop or function in any manner we want, but automatically, without involvement of any personal.Project In BriefOBJECTIVE: Designing of a PLC controlled boiler for production of steam. PROJECT AT A GLANCE:LOOVERALL PROJECT VIEW14SOFTWARE AND COMPONENTS USED:KGL software (make LG)PLC module (make LG)MotorWater reserve Closed air tight container Level sensor(Digital)Temperature sensor with current output(Analog)Pressure sensor(Analog)Solenoid valve(Digital) The most common parameters that have to be controlled in the boiler are temperature, pressure, water level. The controlling mechanism can be achieved by using microprocessor and microcontroller, PID controller or using PLC. Programmable logic control (PLC) provides an easy and sophisticated method to design automation in industry. It also provides easy trouble shooting method and flexibility to the industry. Generally an industry has an emergency stop button to stop the whole process instantly if any error occurred during operation. The emergency stop buttons are normally closed type. To start the mechanism a start button (normally open type) switch is used which is connected after stop button. When start button is made ON the lower level sensor sense the water level below the lower level hence it start the motor to pump the water in to the boiler. The pump runs till the water reaches the higher level sensor. After that the pump stops running. The temperature sensor provides the temperature information to the PLC. If the temp. is less then the preset value the heater starts after 5 sec of motor OFF time. Temperature rises continuously and form water steam. The temp. should not rise beyond tolerance level of boiler hence the temp. should rise up to certain limit and the heater should stop at that moment. The temp. again decreases and if goes below preset value it start the heater. The above process continues. The steam produce in the boiler exert a pressure on the boiler which is picked up by the pressure sensor. If pressure reaches the preset value it make the valve open and steam with a definite pressure goes out through the pipe. The preset value of the pressure should be calculated carefully and it should not exceed maximum limit of boiler tolerance. This process result in decrease in water level and if falls below the lower level sensor the motor starts during which the heater stops and whole process repeats. STARTFLOW CHART:NOIs stop button NC?YESIs start button NO? YESNOIs motor coil NO?NO Is LLS NC? YES NOIs HLS NC? A NONOIs heater timer NC? YESSTOP MOTOR AND START MOTOR TIMER START MOTOR NOIs upper temp. ReachDYESCBNOYESBCIs heater coil made NO?Is temp less then preset?YESENOEIs LLS switch NO?YESHEATER COIL IS OFFNOHeater memory coil is ON ANOIs motor timer NC? YESIs heater mem. Coil NO?YESHEATER COIL IS OFF AND TIMER IS ONNOHEATER COIL IS onANOIs press. Reaches presets?YESVALVE REMAIN CLOSED STOPOPEN THE VALVEDIFFERENT SECTIONS OF THE PROJECT: The project incorporates the requirement of a physical PLC trainer kit which is responsible for collection of data from field sensors (within the boiler), evaluate them & generate appropriate output for the boiler to operate in a specific desired procedure. Initially, we divided our project into four sections viz., power supply section, water supply section, boiler (including sensors) section, process controlling section. Boiler Section: Boiling container, sensors (presssure,temperature & level sensors) & a heater assemble altogether to give rise to the boiler section. Controlling Section: This section includes the PLC trainer kit which is responsible for data collection from field sensors, evaluation of collected data & generation of appropriate output signals for automatic actuation and termination of different peripherals incorporated in the overall system. Water Supply Section: Water supply to the boiler is ensured by a water pump whose actuation & termination is controlled by the PLC trainer.Power Supply Section: This takes care of the power requirements for the whole project. This mostly comprises of the circuits providing DC power for the field sensors and valves (solenoids). APPLICATIONS: The main advantage of using PLCs is the drastic reduction in the requirement of electrical components in terms of number of switches, relays, wiring, etc.the applications of this project are solely the applications of a boiler i.e., production of steam and using it for numerous processes like rotating the generator fins and hence producing power for commercial or industrial purposes.Stages Of Project Design:We divided the overall construction of the project in two stages. These are described as follows:STAGE 1:This stage basically focuses on:Software design & simulation Hardware design(A).Power supply & .Sensing unit Level Sensing UnitTemperature sensing unitSoftware Design & SimulationThe software design and simulation part of the whole project is done by using the software “KGL”. This software is used to design the ladder diagram of the overall project simulation in order to study it`s behaviour.The ladder design hence obtained is downloaded into the PLC CPU and thereby generating appropriate output signals required for the simulation.Features of KGL for WindowsKGL for Windows is the Programming and Debugging Tool for LG Master-K Series.KGL for Windows has abundant Features as below.1) Program Compatible between LG Master-K Series.A user can use the Program (*.PGM) created in LG Master-K Series for the Program created in other LG Master-K Series As well. The Program, Parameter or Variable/Comment created in KGL-DOS or GSIKGL can be also used in KGL for Windows.2) PLC System Configuration by Project StructureKGL for Windows manages the User-Defined Program as one Project including Parameter and Variable/Comment. Also a user can save a Program (*.PRG), Parameter (*.PMT), Variable (*.VAR) or Comment (*.CNT) respectively and the stored each File can be used for other Project files.3) User Friendly InterfaceEasy and useful interface for Creating, Editing and Monitoring.4) Online EditingA Real Time Editing is available in online mode. The Program edited in the online condition can be downloaded automatically without stopping PLC Hardware.5) Monitoring the Information from PLCA user can easily monitor PLC status such as Error Status, Network Information and System Status.6) Debugging and Self-diagnosis (in New MASTER-K Series)Trigger and Forced I/O Enable are available for the accurate DebuggingCreating a ProgramCreating a Ladder Program??This chapter describes creating a program in Ladder Window using the Tool Bar.#After selecting the Normally Open Contact icon in the Ladder Tool Bar, Move the cursor to the place to insert theContact#Click the left button of the mouse or press Enter key, then the contact input dialog box appears.#?Type in the contact name (M0000) you want to insert and click OK button or press Enter key.#?Select the Output Coil icon in the Ladder Tool Bar and move the cursor to the next column of P000.Click the mouse button or press Enter key.#Type in the Output Coil (P040) and click OK button or press Enter key.Create a ProjectAbout a Project#?A Project is the highest level to communicate with PLC and KGL for Windows.A Project consists of Program, Parameter and Variable/Comment of Device. #KGL for Windows deals with User Defined Programs and includes all elements necessary for describing a Project.#?A Project consists of 3 Items (Program, Parameter and Variable/Comment) and Monitoring is activated when the Monitoring Window is opened. Each Item can be saved respectively for another Project.#Saved Items (Program, Parameter and Variable/Comment) can be used for creating other Projects or to reuse for other Projects.#A Project includes not only Program, Parameter and Variable/Comment, but also PLC type, used status of KGL and various information registered for monitoring. Thus, when you reopen the Project after saving a Project, the Window keeps the previous working condition.#?Only Program and Parameters can be downloaded to PLC.#?A Project is saved as *.PRJ File.Create a Project#?To create a New Project file, Select File--New Project… ( ) from the Project pull-down Menu.The New Project dialog box will appear as below.#?Open a Blank Project#It creates a new Project.#Create from Old Files#To create a New Project using the already existed Item (Program or Parameters or Variable/Comment),Select Item or items to be used by clicking the Find button in the dialog box.#Click OK button after registering Items.#?Up to 3 items can be selected and non-selected items are set to default (Initial data).#?After selecting PLC Type and Programming Language, press the OK button. Then Project, Message and Program Windows will be opened.#Create from DOS KGL file#?To create a New Project using Items (Program, Parameter and Variable/Comment) created in KGL for DOS,Select PLC Type and Programming Language after selecting already created Items in KGL for DOS. Then, a NewProject will be opened.#?Create from KGL file#?To create a New Project from KGL file, Select already created files (*.PGM, *.CMT) from GSIKGL in the dialog box and select PLC Type and Programming Language.Hot-Keys for Ladder Program ModeSimulation partEnd Of Software Design & Simulation****** ******Hardware DesignChip Specifications:215900011385551).LM35 (Precision Centigrade Temperature Sensors)Description:The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in °Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling.Features:Calibrated directly in ° Celsius (Centigrade) Linear + 10.0 mV/°C scale factor0.5°C accuracy guarantee able (at +25°C)Rated for full ?55° to +150°C rangeSuitable for remote applicationsLow cost due to wafer-level trimmingOperates from 4 to 30 voltsLess than 60 μA current drainLow self-heating, 0.08°C in still airNonlinearity only ±1?4°C typicalLow impedance output, 0.1 ??for 1 mA loadAbsolute Maximum Ratings:Supply Voltage +35V to ?0.2VOutput Voltage +6V to ?1.0VOutput Current 10 mAStorage Temp. TO-220 Package ?65°C to +150°CLead Temp. TO-92 and TO-220 Package, 260°C.(Soldering, 10 seconds) 2).LM317 (3-Terminal Positive Adjustable Regulator)Description:3735705788035This monolithic integrated circuit is an adjustable 3-terminal positive voltage regulator designed to supply more than 1.5A of load current with an output voltage adjustable over a 1.2V to 37V. It employs internal current limiting, thermal shut-down and safe area compensation.Features:Output Current In Excess of 1.5AOutput Adjustable Between 1.2V and 37VInternal Thermal Overload ProtectionInternal Short Circuit Current LimitingOutput Transistor Safe Operating Area Compensation Absolute Maximum Ratings:Input-Output Voltage Differential - 40 V.Operating Junction Temperature - 0 ~ +125 °CRangeStorage Temperature Range -65 ~ +125 °C.Temperature Coefficient of ±0.02 % /°C Output Voltage .3).LM78XX (7805 & 7812)Series Voltage Regulators26212805953760Description:The LM78XX series of three terminal regulators is available with several fixed output voltages making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.FeaturesOutput current in excess of 1AInternal thermal overload protectionNo external components requiredOutput transistor safe area protectionInternal short circuit current limitAvailable in the aluminum TO-3 packageVoltage Range:LM7805C 5VLM7812C 12VLM7815C 15VAbsolute Maximum Ratings:Input Voltage (for VO = 5V to 18V) 35V. (For VO = 24V)40V.Thermal Resistance Junction-Cases (TO-220) 5 ?C/W.Thermal Resistance Junction-Air (TO-220) 65 ?C/W.Operating Temperature Range (KA78XX/A/R) 0 ~ +125 ?C.Storage Temperature Range - -65 ~ +150 ?C.4).HCF4093B: QUAD 2 INPUT NAND SCHMITT TRIGGERDescription:The HCF4093B is a monolithic integrated circuit fabricated in Metal Oxide Semiconductor technology available in DIP and SOP packages. The HCF4093B type consists of four Schmitt trigger circuits. Each circuit functions as a two input NAND gate with Schmitt trigger action on both inputs. The gate switches at different points for positive and negative going signals. The difference between the positive voltage (VP) and the negative voltage (VN) is defined as hysteresis voltage (VH).Features:SCHMITT TRIGGER ACTION ON EACH INPUT WITH NO EXTERNAL COMPONENTS HYSTERESIS VOLTAGE TYPICALLY 0.9V at VDD = 5V AND 2.3V at VDD = 10VNOISE IMMUNITY GREATER THAN 50%OF VDD (Typ.)NO LIMIT ON INPUT RISE AND FALL TIMESQUIESCENT CURRENT SPECIFIED UP TO 20VSTANDARDIZED SYMMETRICAL OUTPUT CHARACTERISTICS5V, 10V AND 15V PARAMETRIC RATINGSINPUT LEAKAGE CURRENT II = 100nA (MAX) AT VDD = 18V TA = 25°C100% TESTED FOR QUIESCENT CURRENT.righttopABSOLUTE MAXIMUM RATINGS:Supply Voltage -0.5 to +22 VDC Input Voltage -0.5 to VDD + 0.5 VDC Input Current ± 10 mAPower Dissipation per Package 200 mWPower Dissipation per Output Transistor 100 mWOperating Temperature -55 to +125 °CStorage Temperature -65 to +150 °CPower supply:This comprises of 12V DC & 5V DC supply for the four sensors (2 level sensors, 1 temperature sensor & 1 pressure sensor) used in the boiler. The 230V AC supply is first stepped down to 12V AC using a step down transformer. The output of this transformer is then passed through a bridge rectifier to convert it to 12V DC output and hence to 5V. For the voltage consistency, IC 7812 & IC 7805 chips are used. The 12V DC and 5V hence obtained is utilized to activate all the four sensors. Design Of Liquid Level SensorMost of the sensor placed inside the water cause electrolytic reaction between liquid and sensor causing loss of effectiveness. One solution to this problem is to ensure an AC potential rather than DC potential between the electrodes. The constant reversal of electrode polarity drastically inhibits the electrolytic process so that corrosion is considerable reduced and effectiveness doesn’t hampered. In this liquid level sensor AC is generated by an oscillator by connecting a capacitor (C1) to the input of IC4093 (a NAND) gate and proving a feedback through the resistor (R1). This AC current is given to the capacitor (C4) to charge up through the AC coupled capacitors C2 and C3. Between C2 and C3 two sensor electrodes are placed so that when the liquid touches the electrode, a conducting path is being created by the liquid so that C4 can be charged. Two diodes D1 and D2 provide blockage to discharge capacitor C4. This high input of the charged capacitor C4 is given to the IC4093 whose output is used to drive the base of transistor BC557. A relay is connected to ground through BC557. As the transistor is driven by IC4093 which drive relay in and the 230 volt ac output of relay is used to drive the motor. Circuit diagram of liquid level sensorDesign of temperature sensorVOLTAGE REGULATOR CIRCUITA voltage regulator circuit provides a fixed value of voltage for particular values of circuit components. A 12 volt DC voltage circuit can be designed by connecting a 230:12 volt transformer, a bridge rectifier circuit and a capacitor, an IC7812.The transform gives 12 volt AC output which is rectified by bridge circuit, a capacitor is used to bypass the AC component and the IC7812 is used to provide constant 12 volt output which is use to drive other instruments.Circuit diagram for voltage regulator circuit Future work:The 2nd stage of the project is to be done in the successive semester. 2nd stage of the project involves:Designing the pressure sensor circuitInterfacing of sensors with the plc trainer kit. Implementing the software program. Construction of boiler setup & incorporation of the sensor within the boiler.referenceLM 35 Precision Centigrade Temperature Sensors, National semiconductors, November – 2000.LM78XX Series Voltage Regulators, National semiconductors, May – 2000.User Manual for PLC Trainer Kit, LG Programmable logic controller KGL for windows [MASTER-K Series].Project Guide: Project Group Members:Ms. Limali Sahoo DHIRAJ KUMAR (348074013 GAURI SHANKAR KUMAR (348074030) Md. ASRARUL HAQUE (348074017) ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download