Performance Analysis of an Automotive Air Conditioning System Using HFC-134a as an Alternative Refrigerant

HFC-134a를 대체냉매로 사용한 자동차 냉방시스템의 성능해석

As concerns increase over the dangers of environmental destruction on a global scale, CFC regulations have finally been carried out and some CFC's are expected to be phased out by the end of 1995. The research for alternative refrigerants is very demanding. The major activities related to alternative refrigerants are focused on two different areas; one is the development of mixed refrigerants by using the existing refrigerants, and the other is the development of new HFC refrigerants. One of the most promising alternative refrigerant for CFC-12 is HFC-134a. HFC-134a has often been used as a replacement of CFC-12 for automotive air-conditioners. However, due to different thermodynamic properties of HFC-134a, performances of the replaced system are degraded compared with those of the CFC-12 system. Sometimes, the complete redesign of the system is required. In order to analyse and design the new system effectively, the developement of a system simulation program, in which HFC-134a can be selected as a refrigerant, is recommended. Therefore, the summary of this research is as follows : (1) The various thermodynamic properties of HFC-134a are ana lysed and programmed. (2) The model for serpentine heat exchanger is developed and programmed. (3) These subroutines are integrated to develop to develop an automotive air conditioning system simulation program which is verified by the test results. (4) The verified program is used to analyse the performance of a selected automotive air conditioning system.