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03189 Heat transfer enhancement by additives
13
Space heating and cooling
Focus on chillers 97103183 Anon ASHRAE J., February 1997, 39, (2). 62 A review of new types of US chillers. A genetic algorithm optimization technique for 97103184 compact high intensity cooler design Schmit, T. S. et al. Journal of Enhanced Heat Transfer, 1997, 3, (4) 281290. The operation and design criteria for a compact high intensity cooler (CHIC) unit as used in avionic equipment is reviewed. High heat loads are dissipated via multiple impinging jets fed sequentially through a series of fins connected to the heat source by a bus bar. The analytical basis for the heat transfer design is shown to more accurately predict the performance of CHIC units, permitting design optimization. Most optimization techniques depend on continuous variables, while in the design of CHIC unit many of the critical geometrical variables must assume discrete values. A genetic algorithm that looks for an optimum by simulating an evolutionary process was found to be satisfactory for this problem with its mixture of discrete and continuous variables. It is also shown that in an actual optimization problem, where the fluid pressure drop across the unit has to be balanced against a low overall thermal resistance, an optimum geometrical design can be determined. German integrated research in refrigeration-past, 97103185 present and future Lortz, H. and Jahn K. Ki L@. Kaltetech., November 1996, 32, (I 1), 494495. (In German) The outcome of the last four years of research by the German Research Association for Refrigeration Technology which focuses on research of interest to small and medium-size enterprises is summarized. Guideline methods of calculating TEWI 97103186 British Refrigeration Association, BRA BRA Specification. 1996, Issue I, 26PP. The paper claims that TEWI (Total Equivalent Warming Impact) is the best method for measuring climate change in many refrigeration and air conditioning systems. This concept is comprehensively covered, presenting standardised methods of calculating TEWI. Simple and more complex apphcations are exemplified with calculations. 97103187 3HePHe dilution refrigerator precooled by GiffordMcfulahon refrigerator Uhlig, K. and Hehn, W. Cryogenics, 1997, 37, 279-282. A commercial two-stage Gifford-McMahon closed cycle refrigerator is used to cool the dilution unit in this “Hei4He dilution refrigerator. This is in place of a dewar with liquid helium. A soft connecting element which decouples the vibrations of the cold head of the closed cycle refrigerator from the dilution unit is described in the paper. 97103188 Heat exchange Smith, T. et al. Refrig. Air Condit. Heat., December 1996, 99, (1185), 2131. Heat exchange in air conditioning and refrigeration applications is the focus of these four brief articles. 97103189 Ziegler, F.
Heat transfer enhancement by additives 1996, 19, (5), 301-309.
Int. J. R&g.,
97103190 The Heppenheim block heat and power stationdifferent in many respects Karel, A. and Lorentzen, P. Euroheat and Pwr. Fern. Internat., January/ February 1997, 26, (l/2), 36-44. The paper presents the Heppenheim block heat and power station. The technological features of a scheme to supply heat from this station to a new housing estate with around 300 dwellings, a planned hotel and a school as well as apartment buildings with approximately 250 flats are detailed. Procedures of preparing and implementing the concept and the results achieved are described. 97103191 How we conditioned ourselves Casale, C. Installatore Ital., February 1997, 48, (2), 183-190. Fifty years of air conditioning in Italy is discussed in this series of papers. 97103192 HVAC system trend analysis Austin, S. B. ASHRAE J., February 1997, 39, 2, 44-50. The author claims system trend analysis is essential for the proper performance of an air handling system. A step-by-step study of system analysis is presented. A long-term observation of the simultaneous interaction under a variety of conditions is necessary to evaluate the system effectively. In this way the analysis can be used for solving operating problems, increasing energy efficiency, locating defective hardware, identifying out-of-calibration devices, improving occupant comfort and extending equipment life.
260
Fuel and Energy Abstracts
July 1997
Implications of indoor climate control for comfort, 97103193 energy and environment Mabdavi, A. and Kumar, S. Energy and Bldgs., October 1996, 24, (3) lh7177. This paper subjects indoor climate control technologies and the HVAC industry to critical assessment. The authors ask if ‘total environmental control’ is possible, effective or even desirable. The methods and terminology of thermal comfort science are approached, with the question of predictability of people’s environmental preferences forming the focus of the investigation. Recent critical observations and ideas that transcend conventional control technologies are reviewed and corresponding comfort standards toward new vistas in environmental design are discussed. 97103194 Indirect evaporative cooling in retail Bartlett, T. A. Heat. Pip. Air Condit., December 1996, 68, (12), 48-52. A combination of indirect evaporative cooling with mechanical refrigeration in a custom-built mechanical penthouse to provide a I26,OOO ft-, two-level retail store in Albuquerque with an energy-efficient HVAC system. System design, selection and performance are reviewed. The operation of the initial system gave very positive results. 97103195 Industry status of CFC chiller retrofits and replacements Dooley E W. Heat. Pip. Air Condit., January 1997, 69, (I). 131-135. The USA Air conditioning and Refrigeration Institute (ARI) is now projecting supply shortages for RI1 and R/2 as a result of the slow phaseout of CFCs in the USA. In consequence, much higher costs are likely to arise. Options for treating the CFC phaseout are examined and the author supports waiting longer for the industry to correct itself. The ARI’s chiller survey results and analyses are reported. 97103196 Influence of the new refrigerant thermodynamic properties on some refrigerating turbocompressor characteristics Sarevski, M. N. Int. J. Refrig., July 1996, 19, (6), 382-389. Working with various refrigerants, the main geometrical and operating parameters of centrifugal compressors are compared. The influence of refrigerant substitution on turbocompressor performance characteristics are investigated through some theoretical observations. The scope for replacing the refrigerant in existing refrigerating machines is considered. 97103197 Investigation of heat transfer in a polymeric phasechange material for low level heat storage Royon, L. et al. Energy Comers. Mgmt, 1997, 38, (6) 51-524. The paper investigates a new material for low level heat storage. It is a stable mixture of water with a water soluble polymerized and cross-linked monomer such as polyacrylamid. Quantitative results regarding the thermophysical properties of the material are presented. These parameters are used in a theoretical approach describing the progression of a phasechange front in a slab of finite thickness, and the computed results arc found to be in good agreement with the experimental data. 97103198 Low energy ventilation, heating and cooling systems Saman, W. AIRAH J., November 196, 50, (1 I), 36-46. Natural and low energy alternatives available for ventilation, heating and cooling are presented. The possible use of both the prevailing wind and stack effect for natural ventilation purposes is explored and developments in building-integrated solar and natural heating and cooling systems are considered. In addition the paper looks at systems which utilise return air for preheating/precooling the fresh air. The development and potential applications of some prototypes of multistage and ventilation, heating and cooling systems are discussed. 97103199 New Fourier-Reynolds correlations for refrigeration applications Dincer, I. Int. J. Energy Res., 21. (7) 661-666. Recently developed Fourier-Reynolds correlations for determining the cooling process parameters of products subject to air cooling are presented. The experimental data were taken from the author’s previous work, processed and used in the development of new Fourier-Reynolds correlations and dia rams. These Fourier-Reynolds correlations are Q” For, = 42.465Re-“.s and Fos = 125.21 Rem”51”3 for half cooling times and seven-eighths cooling times, respectively. The results of this study indicate that there is a strong relationship between the Fourier and Reynolds numbers, and the Fourier-Reynolds correlations and diagrams are simple and effective tools for determining the cooling process parameters for such objects cooled in air flows. It is believed that these could be beneficial to the refrigeration industry. 97103200 Noise generated by air conditioning equipment Bouteloup J et al. Chaud. Froid Plomh., November 1996, 50, (585). 101111. (In French) Various solutions which can be implemented individually or in association. depending on the required degree of sound attenuation, are proposed.
Space heating and cooling
Focus on chillers 97103183 Anon ASHRAE J., February 1997, 39, (2). 62 A review of new types of US chillers. A genetic algorithm optimization technique for 97103184 compact high intensity cooler design Schmit, T. S. et al. Journal of Enhanced Heat Transfer, 1997, 3, (4) 281290. The operation and design criteria for a compact high intensity cooler (CHIC) unit as used in avionic equipment is reviewed. High heat loads are dissipated via multiple impinging jets fed sequentially through a series of fins connected to the heat source by a bus bar. The analytical basis for the heat transfer design is shown to more accurately predict the performance of CHIC units, permitting design optimization. Most optimization techniques depend on continuous variables, while in the design of CHIC unit many of the critical geometrical variables must assume discrete values. A genetic algorithm that looks for an optimum by simulating an evolutionary process was found to be satisfactory for this problem with its mixture of discrete and continuous variables. It is also shown that in an actual optimization problem, where the fluid pressure drop across the unit has to be balanced against a low overall thermal resistance, an optimum geometrical design can be determined. German integrated research in refrigeration-past, 97103185 present and future Lortz, H. and Jahn K. Ki L@. Kaltetech., November 1996, 32, (I 1), 494495. (In German) The outcome of the last four years of research by the German Research Association for Refrigeration Technology which focuses on research of interest to small and medium-size enterprises is summarized. Guideline methods of calculating TEWI 97103186 British Refrigeration Association, BRA BRA Specification. 1996, Issue I, 26PP. The paper claims that TEWI (Total Equivalent Warming Impact) is the best method for measuring climate change in many refrigeration and air conditioning systems. This concept is comprehensively covered, presenting standardised methods of calculating TEWI. Simple and more complex apphcations are exemplified with calculations. 97103187 3HePHe dilution refrigerator precooled by GiffordMcfulahon refrigerator Uhlig, K. and Hehn, W. Cryogenics, 1997, 37, 279-282. A commercial two-stage Gifford-McMahon closed cycle refrigerator is used to cool the dilution unit in this “Hei4He dilution refrigerator. This is in place of a dewar with liquid helium. A soft connecting element which decouples the vibrations of the cold head of the closed cycle refrigerator from the dilution unit is described in the paper. 97103188 Heat exchange Smith, T. et al. Refrig. Air Condit. Heat., December 1996, 99, (1185), 2131. Heat exchange in air conditioning and refrigeration applications is the focus of these four brief articles. 97103189 Ziegler, F.
Heat transfer enhancement by additives 1996, 19, (5), 301-309.
Int. J. R&g.,
97103190 The Heppenheim block heat and power stationdifferent in many respects Karel, A. and Lorentzen, P. Euroheat and Pwr. Fern. Internat., January/ February 1997, 26, (l/2), 36-44. The paper presents the Heppenheim block heat and power station. The technological features of a scheme to supply heat from this station to a new housing estate with around 300 dwellings, a planned hotel and a school as well as apartment buildings with approximately 250 flats are detailed. Procedures of preparing and implementing the concept and the results achieved are described. 97103191 How we conditioned ourselves Casale, C. Installatore Ital., February 1997, 48, (2), 183-190. Fifty years of air conditioning in Italy is discussed in this series of papers. 97103192 HVAC system trend analysis Austin, S. B. ASHRAE J., February 1997, 39, 2, 44-50. The author claims system trend analysis is essential for the proper performance of an air handling system. A step-by-step study of system analysis is presented. A long-term observation of the simultaneous interaction under a variety of conditions is necessary to evaluate the system effectively. In this way the analysis can be used for solving operating problems, increasing energy efficiency, locating defective hardware, identifying out-of-calibration devices, improving occupant comfort and extending equipment life.
260
Fuel and Energy Abstracts
July 1997
Implications of indoor climate control for comfort, 97103193 energy and environment Mabdavi, A. and Kumar, S. Energy and Bldgs., October 1996, 24, (3) lh7177. This paper subjects indoor climate control technologies and the HVAC industry to critical assessment. The authors ask if ‘total environmental control’ is possible, effective or even desirable. The methods and terminology of thermal comfort science are approached, with the question of predictability of people’s environmental preferences forming the focus of the investigation. Recent critical observations and ideas that transcend conventional control technologies are reviewed and corresponding comfort standards toward new vistas in environmental design are discussed. 97103194 Indirect evaporative cooling in retail Bartlett, T. A. Heat. Pip. Air Condit., December 1996, 68, (12), 48-52. A combination of indirect evaporative cooling with mechanical refrigeration in a custom-built mechanical penthouse to provide a I26,OOO ft-, two-level retail store in Albuquerque with an energy-efficient HVAC system. System design, selection and performance are reviewed. The operation of the initial system gave very positive results. 97103195 Industry status of CFC chiller retrofits and replacements Dooley E W. Heat. Pip. Air Condit., January 1997, 69, (I). 131-135. The USA Air conditioning and Refrigeration Institute (ARI) is now projecting supply shortages for RI1 and R/2 as a result of the slow phaseout of CFCs in the USA. In consequence, much higher costs are likely to arise. Options for treating the CFC phaseout are examined and the author supports waiting longer for the industry to correct itself. The ARI’s chiller survey results and analyses are reported. 97103196 Influence of the new refrigerant thermodynamic properties on some refrigerating turbocompressor characteristics Sarevski, M. N. Int. J. Refrig., July 1996, 19, (6), 382-389. Working with various refrigerants, the main geometrical and operating parameters of centrifugal compressors are compared. The influence of refrigerant substitution on turbocompressor performance characteristics are investigated through some theoretical observations. The scope for replacing the refrigerant in existing refrigerating machines is considered. 97103197 Investigation of heat transfer in a polymeric phasechange material for low level heat storage Royon, L. et al. Energy Comers. Mgmt, 1997, 38, (6) 51-524. The paper investigates a new material for low level heat storage. It is a stable mixture of water with a water soluble polymerized and cross-linked monomer such as polyacrylamid. Quantitative results regarding the thermophysical properties of the material are presented. These parameters are used in a theoretical approach describing the progression of a phasechange front in a slab of finite thickness, and the computed results arc found to be in good agreement with the experimental data. 97103198 Low energy ventilation, heating and cooling systems Saman, W. AIRAH J., November 196, 50, (1 I), 36-46. Natural and low energy alternatives available for ventilation, heating and cooling are presented. The possible use of both the prevailing wind and stack effect for natural ventilation purposes is explored and developments in building-integrated solar and natural heating and cooling systems are considered. In addition the paper looks at systems which utilise return air for preheating/precooling the fresh air. The development and potential applications of some prototypes of multistage and ventilation, heating and cooling systems are discussed. 97103199 New Fourier-Reynolds correlations for refrigeration applications Dincer, I. Int. J. Energy Res., 21. (7) 661-666. Recently developed Fourier-Reynolds correlations for determining the cooling process parameters of products subject to air cooling are presented. The experimental data were taken from the author’s previous work, processed and used in the development of new Fourier-Reynolds correlations and dia rams. These Fourier-Reynolds correlations are Q” For, = 42.465Re-“.s and Fos = 125.21 Rem”51”3 for half cooling times and seven-eighths cooling times, respectively. The results of this study indicate that there is a strong relationship between the Fourier and Reynolds numbers, and the Fourier-Reynolds correlations and diagrams are simple and effective tools for determining the cooling process parameters for such objects cooled in air flows. It is believed that these could be beneficial to the refrigeration industry. 97103200 Noise generated by air conditioning equipment Bouteloup J et al. Chaud. Froid Plomh., November 1996, 50, (585). 101111. (In French) Various solutions which can be implemented individually or in association. depending on the required degree of sound attenuation, are proposed.