1991 Fiscal Year Final Research Report Summary
Performance of Evaporator in Absorption Heat Pump Systems using Water/LiBr as Main Refrigerant
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Osaka City University |
NOMURA Tomohiro Osaka City University Professor -> 大阪市立大学, 工学部, 教授 (50164736)
KASHIWAGI Takao Tokyo Univ. of Agri. & Tech. Professor, 工学部, 教授 (10092545)
NISHIMURA Nobuya Osaka City University Research Associate, 工学部, 助手 (30189310)
|Project Period (FY)
1990 – 1991
|Keywords||Absorption Type Heat Pump / Non-Azeotropic Refrigerant Mixtures / Evaparator in Heat Pump / Auxiliary Refrigerant / Evaporation Temperature / 気液平衡曲線|
Today's air-condition market is still dominate by electrically-driven compression cycle heat pump. While absorption technology is relatively complex, involving both mechanical and chemical engineering disciplines, absorption heat pumps and refrigeration systems using water as working fluid have been the object of renewed attention recently. This is due not only to the achievement of higher performances, but also to the fact that they usually operate with non-CFC fluids.
Now a day, there are two main effects for absorption heat pump by the view-point of utilization. That is to say the use by heat of low-temperature heat sources and a complicated pump system.
It is, therefore, necessary to develop an advanced single effect absorption cycle which could reach the double effect efficiency, and keep the advantages of a single effect cycle for the sake of effective utilization of energy, cost and miniaturization.
The advanced absorption cycle with the circulation of the auxiliary refrigerant bet
ween the absorber and evaporator has been proposed, and this cycle has been studied to improve the efficiency and to utilize low-temperature heat sources.
In the cycle simulation, a counter flow-type heat exchanger was assumed for each component with the water/LiBr as the main refrigerant and absorbent combination. Since the auxiliary refrigerant should be immiscible with main fluid pair, pentanol was selected as the auxiliary refrigerant. Computer simulation was carried out based on these fluid combinations and the cycle performance was obtained.
Next, we focused on the evaporator simulation and the experiments to verify the evaporating principles and the performance characteristics.
The temperature-composition diagram for the water/LiBr mixture at lower constant pressure than the atmosphere pressure was obtained experimentally and theoretically. A new counter flow type evaporator with auxiliary refrigerant was proposed and the characteristics was analyzed.
The strong point of evaporator is to be operated also under the different evaporating temperature condition in spite of keeping the pressure in the evaporator constantly. Less
Research Products (10 results)