Shell and Disk type형 열교환기에 적용한 R22와 NH3의 특성에 관한 실험적 연구

Abstract

Nowadays HCFCs refrigerant are restricted because it cause depletion of ozone layer. However, natural gases such as ammonia as an organic compound, propane and propylene as hydrocarbon are easy and cheap to obtain as well as environmental. Accordingly, this experiment apply the NH3 and R22 to study the performance characteristic from the superheat control and compare the energy efficiency of two refrigerants from the high performance. The condensing pressure of refrigeration system is increased from 15bar to 16bar and degree of superheat is increased from 0 to 10℃ at each condensing pressure. This study conducted the comparative analysis of performance of refrigerating systems using NH3 and R22 with respect to the change in condensing pressure and superheat and the results are presented as follows. 1. The mass flow rate for NH3 was more comfortable for a change of the condensing pressure and the degree of superheat than R22. We found that NH3 is more superior than R22 for miniaturization of refrigerator. 2. As the condensing pressure and the mass flow rate is changed, we found that NH3 is easier than R22 for the mass flow control of cooling water. 3. When the degree of superheat temperature is above 4℃, the COP of NH3 was higher than R22. If it operates by the same load, NH3 will be more superior than R22. 4. We found that NH3 is suitable for substitution of R22.