1993 Fiscal Year Final Research Report Summary
Development of a High Performance Heat Pump System Using Refrigerant Mixtures as Working Fluids
| Project/Area Number |
04555049
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Kyushu University |
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Principal Investigator |
FUJII Tetsu Kyushu Univ., Institute of Advanced Material Study, Professor, 機能物質科学研究所, 教授 (20038574)
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| Co-Investigator(Kenkyū-buntansha) |
KITANI Kazuo Sumitomo Precision Products Co.Ltd., Heat Ex.Dep., Engineer, 熱交技術部, 参事
HORIEA Tetsuji Sumitomo Precision Products Co.Ltd., Heat Ex.Dep., Manager, 熱交技術部, 産業チーム長
KUWAHARA Ken Kyushu Univ., Institute of Advanced Material Study, Research Associate, 機能物質科学研究所, 助手 (90243964)
KOYAMA Shigeru Kyushu Univ., Institute of Advanced Material Study, Associate Professor, 機能物質科学研究所, 助教授 (00153693)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Heat pump system / Plate-fin evaporator / Plate-fin condenser / Zeotropic refrigerant mixtures / Cycle Performance / Coefficient of Performance / Flow Pattern / Heat transfer characteristics |
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| Research Abstract |
This project aims to contribute the development of high-performance vapor compression heat pump/ refrigeration systems using zeotropic refrigerant mixtures as working fluids. In this project the cycle performance was investigated experimentally for two kinds of mixtures of HFC134a/HCFC123 and HCFC22/CFC114 using a vapor compression heat pump system, which consisted of a hermetic type compressor, a vertical plate-fin condenser, an expansion value and a falling-film type plate-fin evaporator. The characteristics of heat transfer and flow pattern of refrigerant condensing and evaporating in plate-fin heat exchangers were also tested in wide ranges of heat flux and mass velocity. The results obtained are as follows :
(1) Cycle Performance
The effect of the refrigerant composition, heat source and heat sink conditions on the coefficient of performance was investigated, and the necessary conditions for improvement in the COP by using zeotropic refrigerant mixtures was clarified ; the optimum c
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ondition is determined by the thermodynamic properties and the heat transfer performance of zeotropic refrigerant mixtures.
(2) Heat Transfer of Zeotropic Refrigerant Mixture in A Falling-film-type Plate-fin Evaporator
Prior to the experiment on the evaporation heat transfer, several kinds of trial liquid distributors were tested, and the method to distribute the refrigerant liquid uniformly in an falling-film type evaporator was founded. The test evaporator was manufactured and tested in the range of mass velocity G=28-70 kg/(m2 s). From the observation, the flow patterns were classified into five typical types : plane liquid film, wavy liquid film, liquid film with dry patch, liquid film with dripping and liquid film with mists. Then, the relation between the heat transfer and the flow pattern was clarified. The method to predict the heat transfer characteristics of pure and mixed refrigerants was also developed.
(3) Heat Transfer of Zeotropic Refrigerant Mixture in A Plate-fin Condenser
It was founded that the heat transfer coefficients of pure refrigerants in a plate-fin condenser were about 10 times higher than the values predicted by a semi-empirical equation for falling liquid film of a pure refrigerant on a smooth surface, and the heat transfer coefficients of mixed refrigerants were lower than those of pure refrigerants depending on the mass fraction and the mass velocity. The method to predict the heat transfer characteristics of pure and mixed refrigerants was also developed. Less
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Research Products
(12 results)
