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01569 Influence of thermodynamic and thermophysical properties of water-based working fluids for bubble pump operated vapor absorption refrigerator
15
Environment
(pollution,
health
protection,
safety)
characteristics, installations, energy systems and consumption of existing residential buildings throughout Europe. A comparative analysis of the data will reveal the common characteristics and differences in terms of energy behaviour. indoor environmental quality and building structure for the existing building stock in Europe and examine potential implications of the forthcoming European action on labelling of buildings. 00/01568 Improving cooling water system performance Rampf, _I. M~lrer. Pcrfbrnt., 1999. 3X. (2). 48 -51. NACE International. In 1992 a new synthetic fuels complex was commissioned, which resulted in several serious problems being encountered in three different cooling water systems. Heat exchanger fouling with a silica sediment and cases of microbiological growth were observed. These problems persisted, and after the first year of operation. serious corrosion damage, iron precipitation and microbiological fouling of carbon steel exchanger tubes were detected. Since July 1994 dramatic improvements have been made in terms of corrosion and fouling control, pH control and the control of microbiological species, all these aspects are discussed in this paper. 00/01569 Influence of thermodynamic and thermophysical properties of water-based working fluids for bubble pump operated vapor absorption refrigerator Saravanan, R. and Maiya. M. P. Ener,e.t, Co!ircr.\. Mtomge.. 1999. 40. (8). 845-860. Elsevier Science Ltd. This paper is concerned with the miniaturization of the absorption refrigerator. The process requires installation of an air-cooled absorber and condenser, plus the replacement of the customary solution pump by a bubble pump. The operating pressures in the bubble pump-operated twofluid vapour absorption refrigerator have to be very low (vacuum) to make use of the hydrostatic principle to maintain the required pressure difference between the condenser and evaporator. Hence, only working fluid combinations based on water and alcohol are found suitable. Thermodynamic properties, such as specific heat and heat of mixing and thermophysical properties, such as vapor pressure, density, viscosity, surface tension and solubility, are necessary for the overall performance evaluation of such a refrigerator. Sixteen water based working combinations are analysed in this paper. 00/01570 Potential for energy conservation in apartment buildings Balaras, C. A. Enc~rg~,cnitl Brti/&rgs, 2000, 3 1, (2) 143-l 54. The potential for energy conservation in apartment buildings is investigated following the EPIQR methodology and software. Several scenarios are evaluated for various apartment buildings located in three climatic zones of Hellas. The proposed retrofit actions concentrate on space heating and cooling, domestic hot water production and lighting. Energy savings for the corresponding actions in each building are accounted for in order to suitable for different building identity the most effective scenarios, constructions. installations and system characteristics. 00101571 Results of experimental investigations of the nonthrottling granryd refrigerator Szargut. J. and Skorek, J. Int. J. Etwrg.~ RES.. 1999. 23. (IS), 1325-1330. The operation of the non-throttling Granryd refrigerator has been analysed. The experimental installation is presented. The measurement method and obtained results are presented and discussed. The mathematical model of the process was also built to analyse the influence of several design and operation parameters on the efficiency of the refrigerator. The importance of the internal thermal insulation of the expansion tank has been pointed out. 00/01572 Simple thermodynamic diagrams for real refrigeration systems Gordon, J. M. J. AppI. Plrw.. 1999, 85, (2). 641-646. American Institute of Physics. Simple rectangular temperature entropy diagrams can be used to summarize the thermodynamic performance of real irreversible cooling and refrigeration systems (chillers). The key to translating complex dissipative losses into this graphical framework is the process average temperature a factor that can be calculated from nonintrusive experimental measurements, for converting entropy production into lost work. The governing chiller performance equations can be transformed into an easily interpreted graph, by using an uncomplicated thermodynamic model. Examples based upon actual data from commercial reciprocating (workdriven) and absorption (heat-driven) chillers are presented and are used to highlight the predominance of internal dissipation in determining chiller efficiency. 00/01573 Simulation on energy use for mechanical ventilation and alr-conditioning (MVAC) systems in train compartments Chow, W. K. and Yu, P. C. H. E/iergr. 2000. 25. (I). l-13. Unlike the conventional automotive, modem railway trains are designed with non-openable windows; and a mechanical ventilation and airconditioning (MVAC) system is installed in each train compartment for better indoor air quality as well as to provide a thermally comfortable environment. The ventilation rate is no doubt a critical element in the design of a MVAC system, especially in Hong Kong where the daily passenger load is extremely heavy. Earlier studies illustrated that carbon dioxide can be controlled at 1000 ppm by increasing the ventilation rate to
174
Fual and Energy Abstracts
May 2000
25.2 m’ H-l; however, it will also lead to an increase in energy consumption. In this paper, the electrical energy consumption at various ventilation rates was studied, and the cost of maintaining a low carbon dioxide level was estimated. These provide solid information for the local railway companies to improve the air quality inside the train compartments.
14 HEAT PUMPS 00101574 A survey on GHP technology D’Accadia, M. D. AES (At??. Sec. Mech. E!rg./. 1998. 3X. 313-323. American Society of Mechanical Engineers. The Gas engine driven Heat Pump (GHP) consists of a reversible vapour compression heat pump with an open compressor. driven by an internal combustion gas fuelled engine instead of an electric engine. The possibility of recovering waste heat produced by the engine via a jacket and an exhaust heat exchanger, together with the use of an alternative engine can be regarded as the most important aspects of this equipment. The features of this GHP allow higher performances and lower running costs than equivalent electric heat pumps (EHP). The results of the study and research performed by the Department of the FEDERICO II University of Naples are reported in this review. Related topic are also covered in this article, including the historical development and market situation, plus the main reasons for using GHP. 00101575 Enhancing the impact of heat pump water heaters in the South African commercial sector Rousseau, P. G. and Greyvenstein, G. P. Errr,:p?~. 2000. 25. (I). 51-70. By far the largest application of heat pumps in the South African commercial sector is in the heating of sanitary hot water in buildings like hotels, hospitals, prisons and residences at universities, technikons and schools. In most of these cases, heat pumps serve as an alternative to direct electrical resistance heaters. Heat pump water heaters (HPWHs) have, however, penetrated only 16% of the commercial water heater market in South Africa despite the fact that they consume about a third of the electricity required by resistance heaters. The reason for this is poor design practice, which leads to poor economics. This paper proposes an improved system integration methodology aimed at enhancing the potential impact of HPWHs with regard to energy consumption, peak electrical demand and the economic attractiveness to building owners. A simulation investigation is combined with results from a survey conducted on water heating in the commercial sector to illustrate the advantages posed by the new methodology. The new methodology entails combining an in-line heat pump and in-line auxiliary resistance heater with the correct control strategy while deliberately undersizing the heat pump. A procedure to determine the optimum heat pump size for such installations is also discussed. A case study is presented in which it is shown that for a typical installation the optimized design approach can lead to a reduction in the life-cycle cost by a factor of 2.4. 00101576 Study of a solvent extraction type of absorption heat pump Cheng, C-S. Energ?: Coftrers. Mormge. 2000. 41, (7). 727.-736. The coefficient of performance for the cooling cycle COP and for the heating cycle COPh of a traditional absorption heat pump (AHP), defined as COP = Qe/(Qo + w)l and COP” = ,(Q,, + Qc):(Qc; + B’), usually has a value less than 0.80 for a cooling system and less than I.XO for a heating system. This paper proposes a new type of absorption heat pump that employs a second liquid to extract the refrigerant from the dilute absorbent solution in the absorber (EXAHP system). The proposed system achieves COP’ and COP” values that exceed those values in a tradition absorption heat pump. The calculated COP‘ and COP” values reach as high as 1.6 and 2.3. respectively which are approximately lOOnA,and SO’% higher than those of the conventional systems. Using LiBr.‘H?Ojacetophenone as
an example, this paper presents the concept design and operation the proposed plant.
analysis of
15 ENVIRONMENT Pollution,
health protection,
safety
00101577 A study of PAH emissions from an AFBC system Han, W. Proc. - A,~nu. ht. Pittsburgh Coal Conf.. 1998, 1008-1018. 15th Pittsburgh Coal Conference, University of Pittsburgh. The combustion process produces environmentally harmful emissions, including particulates in the form of smoke and dust, as well as sulfur oxides and nitrogen oxides. There is also a growing concern about emissions of
Environment
(pollution,
health
protection,
safety)
characteristics, installations, energy systems and consumption of existing residential buildings throughout Europe. A comparative analysis of the data will reveal the common characteristics and differences in terms of energy behaviour. indoor environmental quality and building structure for the existing building stock in Europe and examine potential implications of the forthcoming European action on labelling of buildings. 00/01568 Improving cooling water system performance Rampf, _I. M~lrer. Pcrfbrnt., 1999. 3X. (2). 48 -51. NACE International. In 1992 a new synthetic fuels complex was commissioned, which resulted in several serious problems being encountered in three different cooling water systems. Heat exchanger fouling with a silica sediment and cases of microbiological growth were observed. These problems persisted, and after the first year of operation. serious corrosion damage, iron precipitation and microbiological fouling of carbon steel exchanger tubes were detected. Since July 1994 dramatic improvements have been made in terms of corrosion and fouling control, pH control and the control of microbiological species, all these aspects are discussed in this paper. 00/01569 Influence of thermodynamic and thermophysical properties of water-based working fluids for bubble pump operated vapor absorption refrigerator Saravanan, R. and Maiya. M. P. Ener,e.t, Co!ircr.\. Mtomge.. 1999. 40. (8). 845-860. Elsevier Science Ltd. This paper is concerned with the miniaturization of the absorption refrigerator. The process requires installation of an air-cooled absorber and condenser, plus the replacement of the customary solution pump by a bubble pump. The operating pressures in the bubble pump-operated twofluid vapour absorption refrigerator have to be very low (vacuum) to make use of the hydrostatic principle to maintain the required pressure difference between the condenser and evaporator. Hence, only working fluid combinations based on water and alcohol are found suitable. Thermodynamic properties, such as specific heat and heat of mixing and thermophysical properties, such as vapor pressure, density, viscosity, surface tension and solubility, are necessary for the overall performance evaluation of such a refrigerator. Sixteen water based working combinations are analysed in this paper. 00/01570 Potential for energy conservation in apartment buildings Balaras, C. A. Enc~rg~,cnitl Brti/&rgs, 2000, 3 1, (2) 143-l 54. The potential for energy conservation in apartment buildings is investigated following the EPIQR methodology and software. Several scenarios are evaluated for various apartment buildings located in three climatic zones of Hellas. The proposed retrofit actions concentrate on space heating and cooling, domestic hot water production and lighting. Energy savings for the corresponding actions in each building are accounted for in order to suitable for different building identity the most effective scenarios, constructions. installations and system characteristics. 00101571 Results of experimental investigations of the nonthrottling granryd refrigerator Szargut. J. and Skorek, J. Int. J. Etwrg.~ RES.. 1999. 23. (IS), 1325-1330. The operation of the non-throttling Granryd refrigerator has been analysed. The experimental installation is presented. The measurement method and obtained results are presented and discussed. The mathematical model of the process was also built to analyse the influence of several design and operation parameters on the efficiency of the refrigerator. The importance of the internal thermal insulation of the expansion tank has been pointed out. 00/01572 Simple thermodynamic diagrams for real refrigeration systems Gordon, J. M. J. AppI. Plrw.. 1999, 85, (2). 641-646. American Institute of Physics. Simple rectangular temperature entropy diagrams can be used to summarize the thermodynamic performance of real irreversible cooling and refrigeration systems (chillers). The key to translating complex dissipative losses into this graphical framework is the process average temperature a factor that can be calculated from nonintrusive experimental measurements, for converting entropy production into lost work. The governing chiller performance equations can be transformed into an easily interpreted graph, by using an uncomplicated thermodynamic model. Examples based upon actual data from commercial reciprocating (workdriven) and absorption (heat-driven) chillers are presented and are used to highlight the predominance of internal dissipation in determining chiller efficiency. 00/01573 Simulation on energy use for mechanical ventilation and alr-conditioning (MVAC) systems in train compartments Chow, W. K. and Yu, P. C. H. E/iergr. 2000. 25. (I). l-13. Unlike the conventional automotive, modem railway trains are designed with non-openable windows; and a mechanical ventilation and airconditioning (MVAC) system is installed in each train compartment for better indoor air quality as well as to provide a thermally comfortable environment. The ventilation rate is no doubt a critical element in the design of a MVAC system, especially in Hong Kong where the daily passenger load is extremely heavy. Earlier studies illustrated that carbon dioxide can be controlled at 1000 ppm by increasing the ventilation rate to
174
Fual and Energy Abstracts
May 2000
25.2 m’ H-l; however, it will also lead to an increase in energy consumption. In this paper, the electrical energy consumption at various ventilation rates was studied, and the cost of maintaining a low carbon dioxide level was estimated. These provide solid information for the local railway companies to improve the air quality inside the train compartments.
14 HEAT PUMPS 00101574 A survey on GHP technology D’Accadia, M. D. AES (At??. Sec. Mech. E!rg./. 1998. 3X. 313-323. American Society of Mechanical Engineers. The Gas engine driven Heat Pump (GHP) consists of a reversible vapour compression heat pump with an open compressor. driven by an internal combustion gas fuelled engine instead of an electric engine. The possibility of recovering waste heat produced by the engine via a jacket and an exhaust heat exchanger, together with the use of an alternative engine can be regarded as the most important aspects of this equipment. The features of this GHP allow higher performances and lower running costs than equivalent electric heat pumps (EHP). The results of the study and research performed by the Department of the FEDERICO II University of Naples are reported in this review. Related topic are also covered in this article, including the historical development and market situation, plus the main reasons for using GHP. 00101575 Enhancing the impact of heat pump water heaters in the South African commercial sector Rousseau, P. G. and Greyvenstein, G. P. Errr,:p?~. 2000. 25. (I). 51-70. By far the largest application of heat pumps in the South African commercial sector is in the heating of sanitary hot water in buildings like hotels, hospitals, prisons and residences at universities, technikons and schools. In most of these cases, heat pumps serve as an alternative to direct electrical resistance heaters. Heat pump water heaters (HPWHs) have, however, penetrated only 16% of the commercial water heater market in South Africa despite the fact that they consume about a third of the electricity required by resistance heaters. The reason for this is poor design practice, which leads to poor economics. This paper proposes an improved system integration methodology aimed at enhancing the potential impact of HPWHs with regard to energy consumption, peak electrical demand and the economic attractiveness to building owners. A simulation investigation is combined with results from a survey conducted on water heating in the commercial sector to illustrate the advantages posed by the new methodology. The new methodology entails combining an in-line heat pump and in-line auxiliary resistance heater with the correct control strategy while deliberately undersizing the heat pump. A procedure to determine the optimum heat pump size for such installations is also discussed. A case study is presented in which it is shown that for a typical installation the optimized design approach can lead to a reduction in the life-cycle cost by a factor of 2.4. 00101576 Study of a solvent extraction type of absorption heat pump Cheng, C-S. Energ?: Coftrers. Mormge. 2000. 41, (7). 727.-736. The coefficient of performance for the cooling cycle COP and for the heating cycle COPh of a traditional absorption heat pump (AHP), defined as COP = Qe/(Qo + w)l and COP” = ,(Q,, + Qc):(Qc; + B’), usually has a value less than 0.80 for a cooling system and less than I.XO for a heating system. This paper proposes a new type of absorption heat pump that employs a second liquid to extract the refrigerant from the dilute absorbent solution in the absorber (EXAHP system). The proposed system achieves COP’ and COP” values that exceed those values in a tradition absorption heat pump. The calculated COP‘ and COP” values reach as high as 1.6 and 2.3. respectively which are approximately lOOnA,and SO’% higher than those of the conventional systems. Using LiBr.‘H?Ojacetophenone as
an example, this paper presents the concept design and operation the proposed plant.
analysis of
15 ENVIRONMENT Pollution,
health protection,
safety
00101577 A study of PAH emissions from an AFBC system Han, W. Proc. - A,~nu. ht. Pittsburgh Coal Conf.. 1998, 1008-1018. 15th Pittsburgh Coal Conference, University of Pittsburgh. The combustion process produces environmentally harmful emissions, including particulates in the form of smoke and dust, as well as sulfur oxides and nitrogen oxides. There is also a growing concern about emissions of