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Experimental investigation of Seyhan River and dam lake as heat source-sink for a heat pump
15 Environment
(pollution, health protection.
safety)
hettct- design, and greater fire resistance than previrms modules, and it promises to help accelerale the use of PV module\ in residential application\.
Optimal cool storage capacity for load management
03/01444
Ashok. S. and Banerjee, R. ~~~r~r. 2003. 2X. (2). I I5 126. Cud storage is a load management strategy for air conditioning loads, which shifts peak load by storing cooling capacity during off-peak period. It allows the customer’s electricity use for cooling to he shifted to off-peak period, benefiting both the consumer and the utility. Reduction in peak demand and electricity cost depend on electricity tariff rrates, operating strategy, cool storage capacity and climatic conditions. In this paper, a methodology is presented to determine the optimal chilled water storage (CWS) capacity and corresponding operating strategy for the air conditioning loads for different electricity tariffs. This model minimizes the total operating cost of the air conditioning plant by a trade-off between the cost involved for providing the storage and accessories and savings achieved under the specified electricity tariff. A case study for a typical office complex shows that a reduction of 3X%, in peak demand is possible by adopting the optimal CWS strategy under time of use (TOU) tariff. The corresponding saving in the operating cost for the consumer is 5.9%. The results show that under flat tariffs, the prevalent high consumer discount rates make cool storage unviable. This provides justification for utility intervention in cool storage demand side management (DSM) programs. 03/01445 Optimization of a building’s cooling plant for operating cost and energy use Massie, D. D. Intrnmtionuf Jr~rd of’Thrw~crl S~icnw.s. 2002. 4 I. (I 2). I I21 .I 129. An optimal neural network-based controller for an ice thermal storage system has been developed and tested. The controller consists of four neural networks, three of which map equipment behaviour and one that acts as a global controller. The controller self-learns equipment responses to the environment and then determines the control settings required to minimize operating cost. It has the advantage over other controllers in that it always remains calibrated. Since it does not rely upon rules or assumptions, it is able to provide optimal control under any utility pricing and operating condition. Although originally designed to minimize operating costs, simulation and optimization techniques often determine minimum energy use as well.
Passive ventilation and heating by natural convection in a multi-storey building
03/01446
Letan, R. (‘I al. Btrildiriirg rrntl Emironmmt, 2003. 38, (2). 1977208. Passive ventilation and heating in a multi-storey structure, by natural convection in a heated vertical duct were studied. Experimental study and computer simulations were first performed in a scaled-down laboratory model, divided into three levels, and connected by a duct, in which an electrically heated plate was used. The experiments included temperature and velocity measurements at each inner space, and inside the duct. The results obtained from the simulations and supported by the measurements. indicated that effective ventilation and heating, by the proposed method, were achievable in the laboratory structure. For a real-size structure of a five-storey building. which has a duct heated by solar irradiation, computer simulations were performed. Temperature fields and average temperatures were obtained at all levels of the building. The results have shown that even at low solar irradiation fluxes ventilation was achieved in summer, and heating in winter. The study has demonstrated that the proposed method is operable and feasible. 03/01447 Technical and economical model for the freezing cost comparison of immersion, cryomechanical and air blast freezing processes Chourot, J. M. cf al. Energtgl Conecr.~ion nnd Managcmunf. 2003. 44. (4). 55Y.571. This paper presents a detailed calculation model able to evaluate and compare the technical and economic aspects of different freezing techniques (immersion, air blast and cryomechanical freezing). This model relies on both established thermodynamic rules and also on an expert study of the specific technical parameters of the freezing techniques with respect to the product behaviour. It provides a detailed stage-by-stage overview of the effective costs: investment costs, operational costs (human resource costs) and specific costs of each process (such as brine regeneration and cryogen loss). The results are in good agreement with existing data, and complete them.
264
Fuel and Energy Abstracts
July 2003
14 HEAT PUMPS 03/01446 Experimental investigation of Seyhan River and dam lake as heat source-sink for a heat pump Biiyiikalaca. 0. 6’1LI/ k>rl,r.~~,.200;. 2s. (2). IS? 169. Usage of r-&r. lake or underground water as heat source--sink in heat pump systems is rare in Turkey. in general, and in the city of Adana, in particular. which i*l situated 30 km inland from the north-eastern corner of the Mediterranean Sea. In this study, the possibility of using Seyhan River. which bisect\ Adana and Seyhan dam lake. as heat source-sinh i\ investigatctl. The temperature of Seyhan River was monitored throughout the year and the data were compared with those of the amhient air. Analysis of the results of the experimental study carried out using ;I heat pump system that was capable of utilizing both air and water as heat source-sink revealed that the USCof Seyhan River instead of amhient air cold he advantagcow during the whole heating and cooling \eawn\
03/01449 Experimental study of a closed loop vertical ground source heat pump system Hepbasli. A. er rrl. &cr,cr. Corirer.r~o,~ (/)I(/ ,~~rrnugrrmn(, 20113. 44. (4). 527 548. Ground source heat pumps (GSHPs), also known as geothermal heat pumps, are a promising new technology that has heen used for the last three years in the Turkish market. The main objective of the present study, which was performed for the first time in Turkey at the university level, is to investigate the performance characteristics of a GSHP system with a SO m vertical in. nominal diame,ter U-bend ground heat exchanger. This system was installed in a 65 m’- room in the Solar Energy Institute, Ege University, Izmir (568 degree days cooling. base: 22’C, 1226 degree days heating. base: 18’C). Turkey. The Institute, huilt in 1986, has a livable floor area of 3000 m’ and uses passive solar techniques. The heating and cooling loads of the room were 3.8 and 4.2 kW at design conditions, respectively. The system was commissioned in May 2000 and performance tests have been conducted since then. Based upon the measurements made in the heating mode, the heat extraction rate from the soil, with an average thermal diffusivity of 0.00375 ma/h, was found to be. on average, 1 I W/m of bore depth, while the required horehole length in meter per kW of heating capacity was ohtained as 14.7. The entering water temperature to the unit ranged from 5.5 to 13.2‘C. with an average value of 8°C. The heating coefficient of performance of the heat pump and the whole system was extremely low when compared to other heat pumps operating under conditions at or near design values. The primary reasons for this were discussed in detail, and the potential for performance improvements was also suggested.
15
ENVIRONMENT Pollution,
health protection,
safety
03/01450 A consistent and verifiable macrosco tc model for the dlssotutlon of liquid CO* In water under Rydrate forming conditions Radhakrishnan, R. cr (11.Energy C‘orfwmion anti Managcmen/, 2003. 44. (5) 7733782. Direct injection of liquid CO2 into the ocean has been proposed as one method to reduce the emission levels of COz into the atmosphere. When liquid COa is injected (normally as droplets) at ocean depths 1500 m, a solid interfacial region between the COz and the water is observed to form. This region consists of hydrate clathrates and hinders the rate of dissolution of CO*. It is, therefore, expected to have a significant impact on the injection of liquid COz into the ocean. Up until now, no consistent and predictive mode1 for the shrinking of droplets of COa under hydrate forming conditions has been proposed. This is because all models proposed to date have had too many unknowns. By computing rates of the physical and chemical processes in hydrates via molecular dynamics simulations, it has been possible to determine some of these unknowns independently. The most reasonable model has then been proposed and used to make independent predictions of the rates of mass transfer and thickness of the hydrate region. These predictions are compared to measurements, and implications to the rates of shrinkage of CO: droplets under varying flow conditions are discussed.
(pollution, health protection.
safety)
hettct- design, and greater fire resistance than previrms modules, and it promises to help accelerale the use of PV module\ in residential application\.
Optimal cool storage capacity for load management
03/01444
Ashok. S. and Banerjee, R. ~~~r~r. 2003. 2X. (2). I I5 126. Cud storage is a load management strategy for air conditioning loads, which shifts peak load by storing cooling capacity during off-peak period. It allows the customer’s electricity use for cooling to he shifted to off-peak period, benefiting both the consumer and the utility. Reduction in peak demand and electricity cost depend on electricity tariff rrates, operating strategy, cool storage capacity and climatic conditions. In this paper, a methodology is presented to determine the optimal chilled water storage (CWS) capacity and corresponding operating strategy for the air conditioning loads for different electricity tariffs. This model minimizes the total operating cost of the air conditioning plant by a trade-off between the cost involved for providing the storage and accessories and savings achieved under the specified electricity tariff. A case study for a typical office complex shows that a reduction of 3X%, in peak demand is possible by adopting the optimal CWS strategy under time of use (TOU) tariff. The corresponding saving in the operating cost for the consumer is 5.9%. The results show that under flat tariffs, the prevalent high consumer discount rates make cool storage unviable. This provides justification for utility intervention in cool storage demand side management (DSM) programs. 03/01445 Optimization of a building’s cooling plant for operating cost and energy use Massie, D. D. Intrnmtionuf Jr~rd of’Thrw~crl S~icnw.s. 2002. 4 I. (I 2). I I21 .I 129. An optimal neural network-based controller for an ice thermal storage system has been developed and tested. The controller consists of four neural networks, three of which map equipment behaviour and one that acts as a global controller. The controller self-learns equipment responses to the environment and then determines the control settings required to minimize operating cost. It has the advantage over other controllers in that it always remains calibrated. Since it does not rely upon rules or assumptions, it is able to provide optimal control under any utility pricing and operating condition. Although originally designed to minimize operating costs, simulation and optimization techniques often determine minimum energy use as well.
Passive ventilation and heating by natural convection in a multi-storey building
03/01446
Letan, R. (‘I al. Btrildiriirg rrntl Emironmmt, 2003. 38, (2). 1977208. Passive ventilation and heating in a multi-storey structure, by natural convection in a heated vertical duct were studied. Experimental study and computer simulations were first performed in a scaled-down laboratory model, divided into three levels, and connected by a duct, in which an electrically heated plate was used. The experiments included temperature and velocity measurements at each inner space, and inside the duct. The results obtained from the simulations and supported by the measurements. indicated that effective ventilation and heating, by the proposed method, were achievable in the laboratory structure. For a real-size structure of a five-storey building. which has a duct heated by solar irradiation, computer simulations were performed. Temperature fields and average temperatures were obtained at all levels of the building. The results have shown that even at low solar irradiation fluxes ventilation was achieved in summer, and heating in winter. The study has demonstrated that the proposed method is operable and feasible. 03/01447 Technical and economical model for the freezing cost comparison of immersion, cryomechanical and air blast freezing processes Chourot, J. M. cf al. Energtgl Conecr.~ion nnd Managcmunf. 2003. 44. (4). 55Y.571. This paper presents a detailed calculation model able to evaluate and compare the technical and economic aspects of different freezing techniques (immersion, air blast and cryomechanical freezing). This model relies on both established thermodynamic rules and also on an expert study of the specific technical parameters of the freezing techniques with respect to the product behaviour. It provides a detailed stage-by-stage overview of the effective costs: investment costs, operational costs (human resource costs) and specific costs of each process (such as brine regeneration and cryogen loss). The results are in good agreement with existing data, and complete them.
264
Fuel and Energy Abstracts
July 2003
14 HEAT PUMPS 03/01446 Experimental investigation of Seyhan River and dam lake as heat source-sink for a heat pump Biiyiikalaca. 0. 6’1LI/ k>rl,r.~~,.200;. 2s. (2). IS? 169. Usage of r-&r. lake or underground water as heat source--sink in heat pump systems is rare in Turkey. in general, and in the city of Adana, in particular. which i*l situated 30 km inland from the north-eastern corner of the Mediterranean Sea. In this study, the possibility of using Seyhan River. which bisect\ Adana and Seyhan dam lake. as heat source-sinh i\ investigatctl. The temperature of Seyhan River was monitored throughout the year and the data were compared with those of the amhient air. Analysis of the results of the experimental study carried out using ;I heat pump system that was capable of utilizing both air and water as heat source-sink revealed that the USCof Seyhan River instead of amhient air cold he advantagcow during the whole heating and cooling \eawn\
03/01449 Experimental study of a closed loop vertical ground source heat pump system Hepbasli. A. er rrl. &cr,cr. Corirer.r~o,~ (/)I(/ ,~~rrnugrrmn(, 20113. 44. (4). 527 548. Ground source heat pumps (GSHPs), also known as geothermal heat pumps, are a promising new technology that has heen used for the last three years in the Turkish market. The main objective of the present study, which was performed for the first time in Turkey at the university level, is to investigate the performance characteristics of a GSHP system with a SO m vertical in. nominal diame,ter U-bend ground heat exchanger. This system was installed in a 65 m’- room in the Solar Energy Institute, Ege University, Izmir (568 degree days cooling. base: 22’C, 1226 degree days heating. base: 18’C). Turkey. The Institute, huilt in 1986, has a livable floor area of 3000 m’ and uses passive solar techniques. The heating and cooling loads of the room were 3.8 and 4.2 kW at design conditions, respectively. The system was commissioned in May 2000 and performance tests have been conducted since then. Based upon the measurements made in the heating mode, the heat extraction rate from the soil, with an average thermal diffusivity of 0.00375 ma/h, was found to be. on average, 1 I W/m of bore depth, while the required horehole length in meter per kW of heating capacity was ohtained as 14.7. The entering water temperature to the unit ranged from 5.5 to 13.2‘C. with an average value of 8°C. The heating coefficient of performance of the heat pump and the whole system was extremely low when compared to other heat pumps operating under conditions at or near design values. The primary reasons for this were discussed in detail, and the potential for performance improvements was also suggested.
15
ENVIRONMENT Pollution,
health protection,
safety
03/01450 A consistent and verifiable macrosco tc model for the dlssotutlon of liquid CO* In water under Rydrate forming conditions Radhakrishnan, R. cr (11.Energy C‘orfwmion anti Managcmen/, 2003. 44. (5) 7733782. Direct injection of liquid CO2 into the ocean has been proposed as one method to reduce the emission levels of COz into the atmosphere. When liquid COa is injected (normally as droplets) at ocean depths 1500 m, a solid interfacial region between the COz and the water is observed to form. This region consists of hydrate clathrates and hinders the rate of dissolution of CO*. It is, therefore, expected to have a significant impact on the injection of liquid COz into the ocean. Up until now, no consistent and predictive mode1 for the shrinking of droplets of COa under hydrate forming conditions has been proposed. This is because all models proposed to date have had too many unknowns. By computing rates of the physical and chemical processes in hydrates via molecular dynamics simulations, it has been possible to determine some of these unknowns independently. The most reasonable model has then been proposed and used to make independent predictions of the rates of mass transfer and thickness of the hydrate region. These predictions are compared to measurements, and implications to the rates of shrinkage of CO: droplets under varying flow conditions are discussed.