heat pump newsletter 1热泵通讯.doc

HEXAG NEWS HEXAG NEWSThe Newsletter of the Heat Exchanger Action GroupIssue 21, April 2005.The Newsletter of the Heat Exchanger Action GroupEDITORIALAs 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 Smiths 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: DARHEXAG Web Site: www.hexag.hw.ac.ukIN 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.Shockaeat.co.uk Richard will give assistance and advice.+Heat pumps for water heating - Interesting solutions with useful by-productsThe Heat Pump Association (see http:/www.feta.co.uk/hpa/ ) 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 hotels 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 HousingA 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 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 ClubNational Energy CentreDavy AvenueKnowlhillMilton KeynesMK5 8NGTel: 01908 665555Fax: 01908 665577Contact: Theresa Q.uk+Generic Heat Transfer Simulation for Engineering ApplicationsA 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 modelling2) Extreme modelling flexibility3) Engineering-strength models and correlations4) Full implementation of conservation laws5) Transient and dynamic simulationThese 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: http:/www.heattransferconsult.nl 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-KrieglHeat Transfer ConsultDoelenstraat 65, 2611NS Delft, the NetherlandsT +31-15-2142474, F +31-15-2143973 E infoheattransferconsult.nlMichael described his simulator at the last HEXAG meeting at London South Bank University+P&W succeeds with scramjet heat exchangerA 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 Forces 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 rigs combustor it was exposed to gases at 2.200C (4,000F) and was simultaneously cooled by the engines 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&Ws advanced materials and structures for hypersonics programme manager, Ravi Nigam.Future research will see the exchangers 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 exchangers carbon-carbon composite material could also be used for a hypersonic vehicles scramjet exhaust nozzle, leading edges and control surfaces. The test was part of NASAS Next Generation Launch Technology programme.Source: Flight International, 2004.+Condenser gives 11% COP improvementALFA Lavals 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 Laval01276 63383*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.www.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 This is the NEW web address of the Process Intensification Network PIN.www.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 creamOn April 15, 2004, Earth Day, Ben & Jerrys announced the development of an environmentally friendly thermo-acoustic chilling prototype. Following a company-wide audit of Ben & Jerrys refrigeration uses and its impact on the environment, acousticians at Pennsylvania State University, in coordination with Ben & jerrys 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:/releases/2004/04/040421232304.htm*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 TOOLThe 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 Clariants 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, Clariants 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) TechnologyCOFLUX 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: The heat 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. TCTCIn 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 m