Heat pump newsletter 1 - Hexag



EDITORIAL

As we get well into 2005, it is appropriate to remind manufacturers of Compact Heat Exchangers that you can apply to be on the approved list concerning Enhanced Capital Allowances. (See first article below). The rise in energy prices should stimulate investment in more energy-efficient plant and processes, of which CHEs are prime examples. One would hope that governments will provide increased stimulation for investment in such plant, as the warnings concerning increased CO2 emissions grow in severity and further evidence of the impact of these on our environment is presented.

The New, updated, Edition of Eric Smith’s book on heat exchangers has been published – see below – and a review will be included in the next issue of HEXAG News.

The next HEXAG meeting will be at Birmingham University, but a date has yet to be arranged. It will be after the UK National Heat Transfer Conference, this time in Manchester, for which there is still time to send in an abstract – see Forthcoming Events towards the end of this issue.

David Reay – HEXAG Co-ordinator,

PO Box 25, Whitley Bay, Tyne & Wear, NE26 1QT, UK. Tel: 0191 251 2985. Fax: 0191 252 2229. Email: DAReay@

HEXAG Web Site: hexag.hw.ac.uk

IN THIS ISSUE

*Editorial

* Enhanced Capital Allowances for Compact Heat Exchangers * Heat Pumps for Water Heating *The Ground Source Heat Pump Club *Generic Heat Transfer Simulation for Engineering Applications *P&W Succeeds with Scramjet Heat Exchanger * Condenser gives 11% COP Improvement * Useful web sites * Sound Waves to Chill Ice Cream * Clariant Completes Successful Trials of New Process Analytical Tool * Taking the Heat * LAST Resort for Waste Heat * New Heat Exchanger Book *Coil Breakthrough * New Water-cooled Cabinets Reduce Floor Space * Opportunities for Collaboration * A New-concept Direct-impact Heat Exchanger* Press Cuttings * News from the Carbon Trust *Recent Literature *Forthcoming Events/Calls for Papers *The next HEXAG Meeting.

ENHANCED CAPITAL ALLOWANCES FOR COMPACT HEAT EXCHANGERS

Data relating to Enhanced Capital Allowances (ECAs) for compact heat exchangers can be found on the ECA web site – .uk Those wishing to pursue the inclusion of their products on the approved list are advised to contact Richard Shock at Future Energy Solutions – Richard.Shock@aeat.co.uk Richard will give assistance and advice.

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Heat pumps for water heating - Interesting solutions with useful by-products

The Heat Pump Association (see ) publishes a regular Newsletter describing the activities of its members and other organisations in the heat pump area. The article below is taken from a recent issue – Calorex being a major player in the heat pump field:

When it comes to beer cellar cooling, not to mention wine and produce storage, the hotel and catering sector has much to gain from heat recovery systems. Heat pumps will provide localised cooling in commercial kitchens and also offer waste heat recovery from plant boiler rooms creating free hot water, favourably comparing with conventional cooling where domestic hot water usage exceeds 500 litres per day, pay back from initial investment in complete heat recovery packages can be less than one year.

Owners at the Hundred House Hotel in Norton, Shropshire, were delighted when the first of two Calorex cellar cooling heat pumps had already paid for itself within months of installation while the payback period of the second was about 18 months.

A Calorex AW450SC in the wine cellar is directly linked into the hotel’s 1300 litre hot water storage tanks. This produces some 135 litres of hot water (10-50oC) per hour. Electric emersion heaters top up the temperature for the kitchen and at times of peak demand, an oil-fired boiler may be used.

Although the wine cellar was cooled to 10oC, the beer cellar next to it remained a little warm. A second AW450SC heat pump was installed that will allow the wine cellar temperature to be maintained and keep the beer cellar at a constant 13oC. In addition, the system produces 270 litres of effectively ‘free’ hot water per hour. Hot water use is sufficient to ensure operation of the coolers when needed.

The two units combined produce 12.6kW of heat to water and 8.8kW of cooling to the air for an effective COP of 3.15:1 per machine. This means that for every 1kW of electricity supplied to the machines, 3.15kW of water heating is available.

Social Housing

A 32-flat site in Paisley is a joint development programme between the Scottish and Danish Housing Authorities.

In the roof space of the building, a Calorex air to water heat pump converts air from the common kitchen and bathroom extract system to pre-heat the domestic hot water system. The heat pump is added in this task by a vertical mounted solar collector.

All the flats in the building use a common extract system that will feed a supply of room temperature air to the heat pump at around 21oC. This air stream feeds into the heat pump, where the energy is recovered to provide pre-heated domestic water in the 35-45oC temperature range.

The heat pump and subsidiary solar panels between them generate 80,000 kWhrs per annum of low cost energy.

Calorex Tel: 01621 856611 or



For those with an interest in heat pump technology, the major growth opportunity, seen overseas and increasingly so in the UK, is the use of ground as the heat source.

A Ground Source Heat Pump Club has been formed, contact details for which are given below:

The Ground Source Heat Pump Club

National Energy Centre

Davy Avenue

Knowlhill

Milton Keynes

MK5 8NG

Tel: 01908 665555

Fax: 01908 665577

Contact: Theresa Quinn

theresa@.uk

.uk

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Generic Heat Transfer Simulation for Engineering Applications

A generic heat transfer simulator is under development by Heat Transfer Consult, Delft, the Netherlands. The name of this tool is AHTL, which stands for a(nother) heat transfer language. It has a unique ground-breaking design and its main advantages are:

1) Ease of modelling

2) Extreme modelling flexibility

3) Engineering-strength models and correlations

4) Full implementation of conservation laws

5) Transient and dynamic simulation

These properties are achieved through object-oriented equipment modelling. Main models are: streams (with fluid property data and friction models), walls (with solid property data) and heat transfer models. Thus, the equipment is modelled by its components. The modeller can choose the spatial discretisation to suit the applicable needs and engineering models. Together with customary correlations, identical results as with traditional programs are obtained. However, the models are much more powerful and flexible. Detailed models can be built with few limitations on geometry and different types of exchangers can be combined in one simulation.

All low level models mentioned above have the pertinent physical quantities as their attributes, so that they can fully co-operate to rigorous standards just by referring to each other. This greatly reduces the modelling effort. Simulation results become much more realistic because the sub-models behave naturally. The conservation laws are fully implemented, so no aspect (like kinetic, potential energy, static heads and acceleration losses) is neglected. Numerical solution is in the time domain and is automatic. All low level sub-models are parameterized in straightforward engineering data.

At the moment, this simulator is a command-line application an it is operational to the extent that Heat Transfer Consult can do serious calculations with it. The tool has progressed past the proof of concept stadium. A number of components is still to be added: radiation, an interpreter that can access all and modify many variables in the simulator (can be used for proces control, event handlers, mixers, calculation of arbitrary correlations), I/O routines, manuals and, front and back-ends for specific applications. This is still much work but the basis appears to be accurate, fast, rock solid and very flexible.

Additional information and examples can be found at:

A lot of deep background material is contained at this site. However, it has been found that a personal explanation can be enlightening. Heat Transfer Consult is happy to provide such explanations and hopes to find visionary partners that consider this development a promising way forward and who are interested in evaluating, testing, supporting and using this unique new tool. Because of its generality, it is capable to open up an undreamt new range of possibilities in heat transfer simulation.

Ir. Michael Janeschitz-Kriegl

Heat Transfer Consult

Doelenstraat 65, 2611NS Delft, the Netherlands

T +31-15-2142474, F +31-15-2143973

E info@heattransferconsult.nl

Michael described his simulator at the last HEXAG meeting at London South Bank University

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P&W succeeds with scramjet heat exchanger

A scramjet heat exchanger for future hypersonic vehicles such as a reusable satellite launcher or global reach cruise missile has been successfully tested by Pratt & Whitney.

The test success means the exchanger could be used on the US Air Force’s Waverider scramjet engine demonstrator vehicle, expected to fly in 2007. The 152mm (6in)-wide, 762mm-long carbon-carbon composite heat exchanger plate was ‘flown’ in a wind tunnel at Mach 6.5. Using an anti-oxidation coating system, the exchanger survived the test undamaged at United Technologies’ research centre in Connecticut.

Mounted in the scramjet rig’s combustor it was exposed to gases at 2.200C (4,000F) and was simultaneously cooled by the engine’s JP-7 aviation fuel flowing through it.

“The idea behind it is to reduce the weight. The composite heat exchanger is 35% lighter than a metallic baseline system with similar performance”, says P&W’s advanced materials and structures for hypersonics programme manager, Ravi Nigam.

Future research will see the exchanger’s size and speed increased for it to become useful for a space or long-range atmospheric vehicle. For these purposes, the exchanger could be many metres long. The exchanger’s carbon-carbon composite material could also be used for a hypersonic vehicle’s scramjet exhaust nozzle, leading edges and control surfaces. The test was part of NASA’S Next Generation Launch Technology programme.

Source: Flight International, 2004.

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Condenser gives 11% COP improvement

ALFA Laval’s latest condenser, model CDEW, has been developed for use with refrigerant 407C in air conditioning chillers.

According to Alfa Laval, the shell and tube unit provides significant improvement in performance and energy efficiency compared with the standard condenser series using R22. COP is improved at least 11% while energy requirements are reduced by as much as 6%. The CDEW ranges from 57 to860KW which complied with ASME (USA) and up to 1680KW. Which complies with European CE standards. Options include stainless steel construction and, in larger models in the range, the provision of a sight-glass.

The series is suitable for the temperature range -10oC to +90oC and a new header configuration increases the permitted water pressure to 10 bar.

Alfa Laval

01276 63383

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SOME USEFUL WEB SITES

International Institute of Refrigeration. The IIR has a bimonthly newsletter, which carries information on conferences in the refrigeration/cryogenics area, news of IIR activities, and information on other IIR publications.

thecarbontrust.co.uk For up-to-date information on R&D funding opportunities etc. (SEE BELOW)

.uk For data on new support programmes. The Innovation Report makes good reading.

This is the NEW web address of the Process Intensification Network – PIN.

microfloss.co.uk For information on the Microfloss anti-fouling concept (as described at HEXAG meetings) and for contacts etc.

Sound waves to chill ice cream

On April 15, 2004, Earth Day, Ben & Jerry’s announced the development of an environmentally friendly thermo-acoustic chilling prototype. Following a company-wide audit of Ben & Jerry’s refrigeration uses and its impact on the environment, acousticians at Pennsylvania State University, in coordination with Ben & jerry’s and Unilever, developed a prototype. This prototype uses a “bellow bounce” resonator with high-amplitude sound waves in an inert gas – helium, which is converted into cooling power. According to Pennsylvania State University, the thermo-acoustic refrigeration process has many advantages, in particular less maintenance, due to the elimination of mechanical equipment, and better temperature control. This new concept approach to thermo-acoustic chillers is expected to be easily adopted for beverage vending machines and ice-cream sales cabinets, as well as for cooling microprocessor chips in computers. Although the main advantage of thermo-acoustic chilling is being more environmentally friendly through the use of natural inert gases, many obstacles to its development remain, particularly cost.

Source:



040421232304.htm

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HEXAG Members may well remember the talk on the use of heat transfer surface regulation to control batch reactors, given by Ashe Morris Ltd. at the Nottingham University HEXAG Meeting some two years ago. Since then the technology has [progressed, as reported below:

CLARIANT COMPLETES SUCCESSFUL TRIALS OF NEW PROCESS ANALYTICAL TOOL

The first field trials of a Constant Flux reaction calorimeter have been carried out by Clariant Chemicals at their plant in Horsforth, UK. These tests were undertaken to assess the potential benefits of the new reactor for Clariant’s R&D and manufacturing operations.

Constant Flux control (COFLUXTM) is a patented technology developed by Ashe Morris Ltd of Hertfordshire, who introduced the concept at a HEXAG meeting at Nottingham University meeting, and later in more detail at a meeting of the Process Intensification Network – see . It permits stirred tank reactors of virtually any size or type to be operated as precision calorimeters. It offers a uniquely simple and versatile solution for on-line monitoring of chemical, physical and biological processes.

The system used in the Clariant trials was a 10 litre Constant Flux reaction calorimeter with a Hastelloy body. Power and enthalpy data were monitored in real time and displayed on a Eurotherm 5180v data management unit (CFR21 part 11 compliant).

Clariant carried out a series of test reactions in the trial unit and used the on-line monitoring features to track progress in real time. They were able to observe the rate of change (powder dissolution and reaction) throughout the experiments and they could successfully detect the start and finish of each step.

The results were very encouraging and Jim Wilson, Clariant’s R&D Manager at the Horsforth site observed that “an insight into the mechanics of the chemical reactions were provided due to highly responsive online metrics”.

He concluded that “Constant Flux could be utilised to optimise synthesis processes within Clariant”. He pointed to potential benefits arising from “reduced cycle times and increased material efficiencies, as well as reduced energy requirements".

Robert Ashe, a co-founder of Ashe Morris, pointed out that “no calibration was required between experiments and [that] a single monitoring tool had been able to continuously track two entirely different unit operations [powder dissolution and chemical reaction] without interruption”. He further stated: “We believe that no other process monitoring techniques can match COFLUX calorimetry for its combination of simplicity, reliability and versatility”.

Further trials are now in progress with other manufacturers (including AstraZeneca) within the UK and US. Constant Flux technology is being licensed to leading laboratory and industrial equipment manufacturers, and systems based on this concept will be available in 2005.

Clariant are currently undertaking further review of Constant Flux technology in their Corporate Technology Centre in Switzerland.

Background: Constant Flux (COFLUX™) Technology

COFLUX™ is a technology developed and patented by Ashe Morris Ltd. Constant Flux heat exchangers vary the heating or cooling power by regulating the heat transfer area (rather than the temperature of the heat transfer surface). An illustration of a batch reactor designed on the principle of constant flux control is shown in the diagram below:

[pic]In addition to normal capabilities of a traditional reactor, the Constant Flux design delivers some major advantages:

• A very simple and versatile solution for on-line monitoring. This can be used to improve process safety, yield, quality and batch cycle time.

• Temperature control is inherently faster and more stable.

• Improved energy efficiency.

• Greater uniformity of temperature at the heat transfer surface can be achieved. The new jacket design for batch reactors can also deliver improved heat transfer capacity.

• The height of the cooling/heating fluid in the jacket can be restricted to liquid covered surfaces. This prevents product from being damaged by extreme temperatures in the splash zone above the liquid surface.

Constant Flux reactors are simple to build and the new jacket design can be repaired or modified in situ. Standard industrial intruments (mass flow meter and temperature elements) are used in order to deliver the on-line monitoring capabilities.

Clariant

Clariant is a global leader in the field of specialty chemicals. Strong business relationships, commitment to outstanding service and wide-ranging application know-how make Clariant a preferred partner for its customers. Clariant, which is represented on five continents with over 100 group companies, employs about 26,500 people. Headquartered in Muttenz near Basel, it generated sales of around CHF 8.5 billion in 2003. Clariant’s businesses are organized in five divisions: Textile, Leather & Paper Chemicals, Pigments & Additives, Masterbatches, Functional Chemicals and Life Science & Electronic Chemicals.

Clariant is committed to sustainable growth springing from its own innovative strength. Clariant’s innovative products play a key role in its customers’ manufacturing and treatment processes or else add value to their end products. The company’s success is based on the know-how of its people and their ability to identify new customer needs at an early stage and to work together with customers to develop innovative, efficient solutions

Ashe Morris

Founded in 2000, Ashe Morris is an award-winning specialist engineering design and intellectual property company that focuses on breakthrough technologies in the field of heat transfer. Ashe Morris has filed multiple patents covering the concept of Constant Flux and a variety of enabling technologies in such areas as heat exchanger design and process analytical control.

The initial reaction from the engineering community was highly sceptical. A notable exception to this was Imperial College who immediately took strong interest. They undertook a study and their findings supported Ashe Morris’s claims. Ashe Morris published a series of articles in UK and US process engineering magazines to promote the technology. They also gave presentations to a variety of Industrial and regulatory bodies (IChemE, FDA, ISPE and CIA) and end users. The credibility of the new technology improved gradually and in 2003, Ashe Morris qualified as finalists in two categories of IChemE Awards (Crystal Faraday Award for Green Chemical Technology and the Haden Freeman Award for Engineering Excellence).

Ashe Morris works closely with its licensees and customers to develop and deliver the full benefits that its proprietary technologies can deliver. Within the lab market, Ashe Morris has licensed the COFLUX™ technology to Syrris and Radleys. Licence discussions are also currently underway with a number of other potential licensees in the pilot and industrial reactor markets.

Ashe Morris’ patented technology has received widespread acclaim including a DTI Smart Award. It was also voted runner-up in two categories in the 2003 IChemE Awards – the Crystal Faraday Award for Green Chemical Technology and the Haden Freeman Award for Engineering Excellence.

Ashe Morris is based in Elstree, Hertfordshire UK

Contacts

For further information, please contact:

|Ashe Morris Ltd |Clariant (UK) Ltd |

|Robert Ashe |Jim Wilson |

|Chairman & Technical Director |R&D/NP&T Manager, Horsforth Site |

|tel: +44 20 8387 4136 |tel: +44 113 2584 646 |

|fax: +44 20 8387 4137 |fax: +44 113 2398 473 |

|email: press@ |email: james.wilson@ |

|web: |web: |

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Clean engine is primed for university challenge

Environmentally friendly powerplant could slash nitrogen oxide emissions by up to 80%

A demonstrator engine designed to reduce nitrogen oxide emissions by 80% and carbon dioxide output and fuel consumption by one-fifth is to undergo testing at Stuttgart University in Germany next month. The work is being carried out under the European Union Fifth Framework research programme.

The Component Validator for Environmentally Friendly Aero Engine – also known as Clean – uses a compressor with software-controlled variable guide vanes. The combustor features adaptable fuel flow and injection for burning zone control, and a heat exchanger pre-heats air leaving the compressor.

Firms taking part in Clean are: combustor designer Avio; Snecma, which developed the core engine; Volvo Aero, which assembled the engine in July; and MTU Aero Engines, which fitted the demonstrator engine’s instrumentation.

“With this demonstrator, we will prove that oxides of nitrogen emissions can be reduced by as much as 80%, carbon dioxide emissions by 20% and fuel consumption by 20%”, says Dr Gunter Wilfert, Clean programme manager at German manufacturer MTU Aero Engines.

The compressor’s efficiency is boosted by the use of sensors attached to the engine casing that were developed under a Fourth Framework research project. These provide feedback to control the variable guide vanes and optimise performance. The computer control also allows one or two rows of vanes to be removed, saving weight. Another improvement is the 15-20% energy saving expected from the heat exchanger. This heats air leaving the compressor by 150-200oC (300-390oF), using energy from the exhaust, before sending it into the combustion chamber. The heat exchanger’s weight will have to be reduced, however.

The consortium foresees engines with Clean’s predicted characteristics entering service by 2020. The research work could become a sixth framework project, proposals for which are now being considered by the European Commission.

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Taking the Heat

Engineers from Pratt & Whitney Space Propulsion and NASA’S Glenn Research Center have successfully rig-tested a carbon-carbon composite, hydrocarbon fuel-cooled heat exchanger panel under Mach 6.5 conditions at the United Technologies Research Center in Hartford, Conn. The 6 X 30-in. heat exchanger was made up of the carbon-carbon “hot” face sheet backed by a metallic structure. It was mounted in a “combustor”, and JP-7 fuel was used for cooling. Pratt officials say the heat exchanger performed better than predicted, with no evidence of structural degradation following the trials. Aimed at future aerospace propulsion concepts, the lightweight heat-exchange system could reduce the flowpath weight of a supersonic combustion ramjet, or scramjet by more than 35%. The tests were performed as part of NASA’S Next Generation Launch Technology effort

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LAST resort for waste heat

Heat recovery is commonplace in many process plant. So called ‘waste’ heat can be used for process heating purposes, and even to generate power. It usually requires large amounts of complex piping and equipment. But imagine if a lump of material could convert that waste heat directly into electricity without any intervening equipment.

This is known as the thermoelectric effect, and materials which exhibit this property have been known for some time. However, they’ve tended to be regarded as curiosities, as they are too inefficient to be useful. A team from Michigan State University has discovered that a semiconductor composed of ultrapure lead, antimony, silver and tellurium, known as LAST, is much more efficient. “With this class of semiconductors, when you have a temperature gradient you can generate electric current”, explains Mihal Gross of the US Office of Naval Research, which founded the project. ‘Or, if you pass an electrical current through the material, you can get a temperature gradient for cooling.

LAST works so well because it has very high electrical conductivity, but very low thermal conductivity, explains lead researcher Mercouri Kanatzidis. This seems to stem from its structure, which contains nano-scale structures which impede the flow of heat through the material. Theoretically, a solid-state LAST module could replace shipboard steam plants, which run generators, and produce electricity directly. A similar technique could help use the energy thrown off by microchips, which currently has to be dissipated by fans, and on a large scale, could harness the waste heat from chemical reactions and other processes in chemical plants.

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NEW HEAT EXCHANGER BOOK

The new book written by Eric Smith of Energy Systems, is now available from Wiley. Priced at £85, the book has over 500 pages, 11 Chapters and extensive Appendices, and is extended and improved since Eric’s earlier book was published some years ago – to such an extent that this is a totally new Edition.

The full reference is:

Eric M. Smith. Advances in Thermal Design of Heat Exchangers. A Numerical Approach: Direct-sizing, Step-wise Rating and Transients. Wiley, Chichester, 2005. ISBN 1-860258-461-6

I will be including a review of the book in the next issue of HEXAG News, meanwhile I have already used some data from it for a paper on microfluidics, so it is certainly a topical text!

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Coil ‘breakthrough’

SINCE the company’s last appearance at IKK Lordan, a major player in the European heat transfer coil market, has expanded its market penetration by setting up a production facility in the UK and introduced a significant number of developments, all of which can be seen at the show.

Described as a breakthrough in the coil market, the 7mm stainless steel mini-coils, (some the size of a cellular phone) are designed for the high-tech industrial market. With improved size and weight, the coils can cool high-performance such as lasers, fuel cells, computers, switchboards and other temperature-critical systems.

These units can use different cooling liquids form distilled/de-ionized water, alcohol and many various oils. These coils are being used by several leading developers of air conditioners, operating with CO2 for transport applications.

The stainless steel tubes provide a corrosion-free environment and may be integrated with either aluminium or copper fins.

Lordan claims its new Triple Seven coil pattern has proved successful in improving performance and reducing costs. Another major development from the company is Formicoat, a trademarked cost efficient coating for coils preventing formicary corrosion in copper tubing.

972-4-690-7140

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New water-cooled cabinets reduce floor space by up to 80%

A range of water-cooled server cabinets has been launched, which helps manufacturers deal with the growing problem of how to dissipate heat from electronic equipment, while reducing floor space and facility operating costs.

Knurr’s ‘CoolTherm’ enclosure uses a readily available chilled water supply connected into an air-to water heat exchanger, fitted in the base of each cabinet.

Sealed to1P54 and with standard widths of 700mm and 800mm, the cabinets operate in their own controlled environment, independent of ambient room air.

Closed loop temperature-controlled, redundant fan-blown air circulates within the cabinet, passing through the heat exchanger, which, with an ideal chilled water temperature of 12oC, can dissipate up to 20kW of heat. Compared to the cooling of servers using air conditioning, which typically dissipates around 3.6kW of heat, the number of cabinets and floor space can be reduced by up to 80%.

Knurr is not the only enclosure manufacturer developing water-cooled cabinets. Rittal of Rotherham makes a range of cabinets for scientific and server applications, that remove heat directly from the source and pump it to a remote heat exchanger. A simple, liquid-filled heat exchanger is fitted around the heat source and coupled to a manifold incorporated as part of the vertical structure of the rack. The manifold is connected to pipework which terminates in an air-to-liquid heat exchanger, which can be located outside the server or control room.

Rittal’s system uses snap-together pipework connections and includes a manifold in the uprights of the server rack itself, therefore only a single flow and return are needed between the rack and the remote water-to-air or water-to-water heat exchanger. DP

Knurr UK

Rittal

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OPPORTUNITIES FOR COLLABORATION

The European Commission publication ‘RTD Results’ produces summaries of current/recently completed projects, in particular those in which the participants are seeking further collaborations.

Optimal waste heat recovery in connection with feed water preheating

Search for the result at cordis.lu/marketplace/

A Swedish energy consultant firm with many years of experience in the pulp and paper industry has developed a novel method for using waste heat of low or medium temperature in preheating of feed water into steam boilers.. The firm is looking for a licence agreement or a commercial agreement with technical assistance, or coming into direct contact with the users.

The method uses standard heat exchangers, which are connected, sized and controlled in an optimal way. It is suitable in feed water systems with high requirements on clean feed water, and where mixed bed filters are used. The method results in a simple system solution with a minimum of arrangements and still guaranteed optimal waste heat recovery in all operating modes. The method could be applied whenever the three conditions below are present:

• Part of steam is consumed or lost in the plant, i.e. fresh feed water is added;

• All the feed water is passed through mixed bed filters (or other filters operating with temperature limits);

• A waste or a secondary heat source is available

The main advantages are:

• Only one line of mixed bed filters is required

• The mixed bed filters are operating at low and optimal temperatures;

• The waste heat source is cooled to the lowest possible temperature;

• The feed water always reaches highest possible pre-heating, which is equivalent to fuel saving

Innovative Aspects

The most innovative part of the method is in the arrangement of heat exchangers and control strategy which results in a simple and reliable system, but still with optimal heat recovery.

Promoted by Innovation Relay Centres (IRC) Network

Potential market applications

Energy audits

The project is looking for partners to collaborate on

Licence agreement; Marketing Agreement; Information Exchange/Training; Other

WIDEN, Anette

ALMI Foretagspartner

Uppsala AB

Kristallen

S-754 51 Uppsala

Tel: +46-18-185215

Fax: +46-18-185210

E-mail: anette.widen@aimi.se



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A New-Concept Direct-Impact Heat Exchanger

A UK inventor has developed a new technology for heat exchangers. A way to force moving mass to impact onto surfaces has been confirmed by Computer Fluid Dynamics and results in energy transfer that far surpasses any available heat transfer technology currently available. An extensive range of heat transfer products is envisaged for this concept from car radiators, central heating boilers, hot water heaters, industrial applications to fusion reactors. All types of agreement will be considered..

A method of forcing gases to impact on surfaces has been refined and confirmed to achieve complete impaction to transfer kinetic momentum energy to surfaces. This impinging jet technology forces all the molecules to touch the surface of the heat exchangers, thus vastly improving the energy transfer characteristics of energy transfer systems. The end result makes substantially better use of energy, saving of fuel, reduction of greenhouse gases, reduction of the size of the heat exchanger unit and the many other benefits that result from more efficient energy exchange between surfaces moving masses.

The design works because the hot gases are forced to flow through perforated plates that are arranged in sequence and offset, so that where there is a hole in the leading plate, there is a solid surface in the path of the traversing mass, in the offset trailing plate. The effect is achieved by presenting a regular hole distribution in all plates of the unit but the odd and even plates, are so arranged that the trailing disks are offset by 45%. The solid space between the holes occurs exactly in the central path of the flowing mass, in each of the trailing discs.

Odd discs are taken as disc 1, 3, 5, etc., (and even disc as 2, 4, 6, etc.), and are aligned in sequence along a given axis. The holes are 2 mm in diameter, separated by a distance of 3.5 mm centre-to-centre and arranged in a square arrangement. By offsetting the hole distribution by 45o in all even discs and arranging the discs in sequence, an arrangement is achieved which forces the traversing media to impact on the solid inter-hole space of each disc. The trailing disc of the assembly, i.e. third in line on any axis, is an odd disc with the hole distribution the same as that of the first disc, presenting a solid surface to the mass emerging from the holes in the even disc. By arranging alternate discs throughout the assembly, all the mass traversing the unit is forced to impact on disc surfaces and thus transfer energy on every impaction. It is intended to provide assemblies of discs that will extract all the energy out of, for example, burning gases in a hot water boiler.

The patent applied for technology is a substantial improvement on existing technology. The effect of the hot gas jets emerging out of any hole in the disc arrangement is that the stream of hot gases traverses the small gap between the sequential disc assemblies, repeatedly impacts on surfaces and each impaction achieves direct contact between the molecules of the flowing mass and the body of the disc. Direct impaction results in energy transfer by conduction rather than convection, as is the case in all existing heat exchangers. The heat energy is then conducted through the body of the disc to the second part of the unit where a counter-flow of the cooling mass is similarly impacting on the outer part of the chamber to pick up heat energy by a reverse process. In this second chamber, completely isolated from the first chamber, cool gas or liquid flows in the opposite direction to impact on the plate assembly, to pick up energy on impaction with the hot disc surface. The cooling mass flows through the assembly to become heated in the process.

Direct impact improves the rate of energy transfer because conduction is known to be much more effective at energy transfer than convection. The invention allows the design of conductive heat exchangers.

The main advantages are: a much greater energy transfer rate achieved fuel saving, reduction of greenhouse gases and a reduction in size of heat exchanger unit.

Innovative aspects

Invention allows for the design of conductive heat exchangers

Promoted by Innovation Relay Centres (IRC) Network

Potential market applications

Heating, air conditioning; Waste heat recovery; Hydrotechnologies; Waste management (non-radioactive); Water treatment

Interested parties are invited to collaborate on

Joint venture agreement; Licence agreement; Manufacturing agreement; Information exchange/Training; Other

DUCKWORTH, Adrian

Coventry University Enterprises Ltd.

The Technocentre, Puma Way

Coventry CV1 2TT, United Kingdom

Tel: +44-2476-236236

Fax: +44-2476-236024

E-mail; mirc@coventry.ac.uk

http:/.uk

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PRESS CUTTINGS

Life’s a gas for Tube

Metronet, the company rejuvenating two-thirds of the London Tube system, is now using energy saving heat pumps for the first time at East Ham and Uxbridge Underground stations. It estimates that the use of the pumps will reduce carbon dioxide emissions by up to 18 tonnes, and reduce power consumption by 70%

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NEWS FROM THE CARBON TRUST

(FROM THE CT WEB SITE)

“Do you have that unique idea, concept or technology that could underpin change in the low carbon economy?

The Carbon Trust provides funding for genuine innovation through an Open Call process and through the Carbon Vision Partnership, consortia that push the limit of ‘blue sky’ research.

thecarbontrust.co.uk

The CT has on its web site a chart, reproduced below, showing priority areas for R&D. The chart has remained constant in its content for quite a while now.

[pic]

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Recent Literature & Patents

In this regular section of HEXAG News, recent publications are briefly reviewed, and patents believed of interest to readers are identified. The Editor invites contributions identified by HEXAG members in order to increase awareness of heat exchanger activities world-wide. The transfer of technology from one sector to another allows you to eliminate unnecessary R&D, and helps the solution of problems which may be outside your normal areas of experience or expertise. Some of the reviews are obviously aimed at encouraging this. In this issue, some additional patent web sites are detailed.

Searches in all databases can be done on the basis of key words for the technology, patent numbers, (where known), companies or inventors. Care should be taken in ascertaining where ‘free’ access stops and charges begin, e.g. for ordering the full patent specification.

The UK Patent Office has its own web site, offering a variety of facilities. Free access to patent abstracts and other services is available:

Once onto the UK Patent Office Home Page, directions to the patent search are given. On clicking on this, one is given access to the interface to the published patent application databases of the UK Patent Office, the European Patent Office and other European national patent offices. There is also access to the database of published patent applications: Esp@cenet The patents shown in this Issue are taken from the European Patent Database.

Full copies of the specification, drawings and claims can be viewed on line, if they are available. Using a key word search for compact heat exchangers, for example, the user will find patent abstracts from Eastern and Western Europe, as well as the USA.

Perhaps the best data sources for patents, in terms of web accessibility and ease of searching, are those associated with United States Patents. Abstracts, and other limited access is free of charge, (except for your own web time charges) at two sites:

- This is the United States Patent and Trademark Office Home Page and is the official site for searching the US patent database.

The Delphion Intellectual Property Network also lists US patents, searchable by key words, patent numbers, assignees, etc.

For access to more specific data sources on patents, such as vehicle patents, use the web search engine with key words such as ‘patents’ or ‘’US patents’ to obtain a full listing..

One useful feature of some patent databases is that you can view a picture of the device being patented – Patents are one area where a picture is worth many thousands of words!

RECENT LITERATURE

Single-phase liquid cooled microchannel heat sink for electronic packages

H.Y. Zhang a, D. Pinjala a, T.N. Wong b, K.C. Toh b, Y.K. Joshi c

a Institute of Microelectronics, 11 Science Park Road, Science Park II, Singapore 117685, Singapore

b School of Mechanical and Production Engineering, Nanyang Technological University, Singapore 639798, Singapore

c George W. Woodruff School of Mechanical Engineering, Atlanta, GA 30332-0405, USA

Applied Thermal Engineering 25 (2005) 1472–1487

Abstract

The study of a single-phase liquid cooled microchannel heat sink for electronic packages is reported. Two flip chip ball grid array packages (FCBGA) with different chip footprints, 12 mm · 12 mm and 10 mm · 10 mm, were used for high heat flux characterizations. A liquid-cooled aluminium heat sink with finned base dimensions of 15 mm (L) · 12.2 mm (W) populated by microchannels was designed and fabricated. The microchannel heat sink was assembled onto the chip, using a thermal interface material to reduce the contact thermal resistance at the interface. The measured junction to inlet fluid thermal resistances ranged from 0.44 to 0.32 oC/W for the 12 mm chip under the test flowrate range. The higher thermal resistance range from 0.59 to 0.44 oC/W was obtained for the 10 mm chip due to the higher heat spreading resistance at the heat sink base. An analytical method that takes into account the simultaneous developing flow in microchannel heat sinks is developed to predict the pressure drop and thermal resistance. The calculations agree well with the measured pressure drop and thermal resistances. The respective thermal resistance elements are also analysed and presented.

Keywords: Liquid cooling; Microchannel heat sink; Flip chip ball grid array (FCBGA);

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Influence of temperature inversions on wet-cooling tower performance

J.C. Kloppers (a), D.G. Kröger (b)

aSasol Technology (Pty) Ltd, Private Bag X1034, Secunda 2302, South Africa

bDepartment of Mechanical Engineering, University of Stellenbosch, 7600 Stellenbosch, South Africa

Applied Thermal Engineering

Volume 25, Issues 8-9 , June 2005, Pages 1325-1336

Abstract

Nocturnal temperature inversions have a detrimental effect on the performance of natural draft wet-cooling towers. The effects of the temperature inversion profile, the height of the inversion and the height from which air is drawn into the cooling tower, on the performance of cooling towers are investigated. Relatively simple and accurate equations are employed in the analysis to determine the temperature inversion profiles and inversion heights, which only have ground based measurements as input. The detrimental effect in tower performance, during nocturnal temperature inversions, is due to the reduced potential in draft and the increase of the effective air inlet temperature.

Keywords: Wet-cooling tower performance; Nocturnal temperature inversion

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Experimental investigation of a solid adsorption chiller based on a heat exchanger coated with hydrophobic zeolite

G. Restuccia, A. Freni, F. Russo and S. Vasta

CNR–ITAE, Istituto di Tecnologie Avanzate per l’Energia “Nicola Giordano”, St. Lucia Sopra Contesse, 98126 Messina, Italy

Applied Thermal Engineering

Volume 25, Issue 10 , July 2005, Pages 1419-1428

Abstract

In this paper, the experimental results of a lab scale adsorption chiller working with hydrophobic Y zeolite–methanol are presented and discussed. The main feature of this chiller is the innovative adsorbent bed consisting of a shell and tube heat exchanger in which the finned tubes are coated with a zeolite layer. In this way, the interesting sorption properties of the Y type zeolite and the good heat transfer quality of the coated heat exchanger are joined in an advanced sorption machine, driven by a low temperature heat source.

The experimental results on the device show a specific power of 30–60 W/kg of adsorbent (binder included) and a cycle time of 15–20 min depending on the working conditions. These values are sensibly better than those measured with a same zeolite pelletised bed. This latter bed was realized starting from the same zeolite powder that was extruded using the same amount and type of binder. The good results obtained, evidently due to the improved heat transfer properties of the advanced bed, sound attractive for those applications in which a quick dynamic cycle is important.

Keywords: Adsorption; Hydrophobic zeolite; Coated heat exchanger; Air conditioning

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A new semi-empirical model for predicting heat transfer characteristics in porous channels.

Tzer-Ming Jeng et al

Experimental Thermal & Fluid Science, Vol. 29, pp. 9-21, 2004.

Abstract

A new semi- empirical model associated with an improved single blow method for exploring the heat transfer behaviour in porous channels is successfully developed. The heat transfer paths and mechanisms in such a complicated porous channel have systematically been investigated. From the present results, it is found that the conventional transient liquid crystal method cannot be applied to perform the heat transfer investigation in porous channels because of the following two factors: (1) the existence of a very large solid capacity of porous metallic foam in the channel, and (2) a significant heat transfer path existed in solid-wall interface. The assumptions of constant hb and hi for using the model of 1-D semi-infinite transient conduction in transient liquid crystal method are valid only for the cases with negligible hsw and (Cp)s values.

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FORTHCOMING EVENTS

The 9th UK Heat Transfer Conference,

UK National Committee for Heat Transfer

Manchester 5-6th September 2005.

CALL FOR PAPERS EXTENDED TO 30 APRIL 2005.

Following the success of the previous meeting in Oxford in 2003, we hope

the conference will be an informal and lively occasion, and would

particularly wish to encourage participation by graduate students and

others at early stages in their careers in heat transfer. To aid this,

a generous donation has enabled us to keep registration fees for

students at a particularly low rate.

Details of the conference scope, format, location and registration are available on the web at



The deadline for receiving abstracts for contributed papers has been

extended, and these can now be accepted until April 30th. Abstracts

may be submitted via the above website.

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Fifth International Conference on

Enhanced, Compact and Ultra-Compact Heat Exchangers: Science, Engineering and Technology

Whistler, British Columbia, Canada

September 11-16, 2005

Chair:

R.K. Shah, Rochester Institute of Technology, Rochester, NY, USA

Co-Chairs:

M. Ishizuka, Toyama Prefectural University, Toyama, Japan

T.M. Rudy, ExxonMobil Research & Engineering Co., Fairfax, VA, USA

V.V. Wadekar, HTFS, Hyprotech UK Ltd, Harwell, Oxfordshire, UK

Conference Theme

To promote the use of advanced heat exchanger technology in modern industrial applications that require high and ultra high performance at cost competitive base.

Conference Objectives

I. To provide a forum for discussion of the latest advances in R&D of compact, ultra-compact heat exchangers in automotive, process (e.g., refining, chemical), electronics cooling, power, air-conditioning and refrigeration, aerospace, and other industrial applications.

II. To identify present applications of advanced heat exchanger technology in traditional and emerging industrial applications, evaluating benefits and drawbacks; and to identify further areas where such advanced technology could be used.

III. To identify barriers, real and perceived, to broaden applications.

IV. To identify actions which can be taken by the various parties and disciplines to overcome these barriers, and to provide communication channels to the several segments of the technical community.

Scope of the Conference

A. To disseminate and discuss basic and applied research, engineering and technology developments in compact and ultra-compact heat exchangers for conventional and emerging technologies. These CHEs could also include various type of enhanced heat transfer (EHT) concepts and devices that result in significant reduction of heat exchanger size compared to traditional technology. The scope of the conference will include fundamental research, thermal and mechanical design and development, manufacturing technology, and field experience. Papers describing advanced technology, basic phenomena, single-phase and two-phase flows, phase change heat transfer, analysis and numerical modelling, flow and temperature visualization, experimental and computational methods, heat transfer enhancement in single-phase and multiphase flow, design methods and operating problems, and mechanical design aspects are solicited for a variety of CHEs. Papers are also encouraged in applications areas such as electronics cooling, automotive, air-conditioning and refrigeration, aerospace, process integration and case studies.

B. The uncertainty arising from fouling is a major barrier/concern for wide use of CHEs in industrial applications. Papers are solicited on fouling characteristics, mitigation methods and design approaches with fouling to clearly show the advances made in the recent past for potential applications of CHEs.

C. There are many barriers and concerns of durability, reliability and safety in the use of CHEs in industrial applications. Papers are solicited dealing with these topics – including case studies – to show how to overcome these barriers.

D. Equally important, papers dealing with manufacturing techniques and associated intricacies are solicited to provide thorough understanding of how these exchangers are being designed and manufactured.

E. Papers in related areas other than those listed above are also welcome.

APPLICATION FORM/REQUEST FOR NEXT MAILING

Submit electronically from 5aq.html

Or return to:

Engineering Conferences International

6 MetroTech Center, Brooklyn, NY 11201

Tel: 1-718-260-3743; Fax: 1-718-260-3754; E-mail: info@eci.poly.edu

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Heat Transfer and Fluid Flow in Microscale, Tuscany, 25-30 September, 2005.

ECI (Engineering Conferences International) has announced the above Conference. To be included on the mailing list/call for papers, visit:

5ah.html

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THE NEXT HEXAG MEETING

THIS WILL BE HELD IN MECHANICAL ENGINEERING, BIRMINGHAM UNIVERSITY, AT THE INVITATION OF DR. RAIHA AL-DADAH

You will be notified of the date (September/October 2005) as soon as it is finalised.

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Issue 21, April 2005.

The Newsletter of the Heat Exchanger Action Group

HEXAG NEWS

The Newsletter of the Heat Exchanger Action Group

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üìÞÚÓÏËǽ°¦°˜?½~n~b¦X¦°NEÇhÐ*6?OJQJhjqqCJOJQJh‰&ŠOJQJaJhjqqCJOJQJaJhjqqhjqq6?CJOJQJaJhjqqhjqqCJOJQJaJhjqqhjqqOJQJhjqqhjqqH*[?]OJat transfer surface is comprised of multiple separate elements. Each heating/cooling element can be turned on or off by means of a motorised piston (or rotary) valve. The heat exchanger can regulate the heating/cooling power by modifying the number of heating/cooling elements in service. This allows the user to control temperature without altering the velocity or temperature of the heat transfer fluid.

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