Evaluation of The Use R450A as an Alternative to R134a in Low and Medium Temperature Heat Pump Systems: 4-E (Energy, Exergy, Environmental and Enviro-Economic) Analysis

Authors : Ragıp YILDIRIM

Pages : 556-569

Doi:10.28979/jarnas.939582

View : 19 | Download : 15

Publication Date : 2021-12-15

Article Type : Research Paper

Abstract :This investigation presents a theoretical evaluation of the use R450A replace to R134a in the low and medium temperature heat pump systems. The energy, exergy, environmental and enviro-economic analyzes of heat pumps have been performed for two refrigerants (R134a and its alternative R450A). The thermodynamic and environmental analyses have been made for two heat source temperatures (10 oC and 20 oC) and six heat sink temperatures (from 30 oC to 55 oC). It has been observed that R450A's mass flow rate is lower than R134a. Because the density of R450A in the heat pump suction line is lower than R134a. Although the heating capacity of R134a is more than R450A, the reason why R134a has a similar COP value with R450A is that R450A's compressor energy consumption is lower than R134a. Exergy destruction occurred mostly in the compressor under all operating conditions for both refrigerants. At low heat sink temperatures, minimum exergy destruction occurs in the expansion valve, as the minimum exergy destruction occurs in the evaporator at high heat sink temperatures. The exergy results show that R450A behaves similarly to R134a. In conclusion, as alternative refrigerant R450A can be used in heat pumps replace to R134a according to energy, exergy, environmental and environmental-economic analysis results.
Keywords : Climate change, Energy and exergy, Global warming, Heat pump, New generating refrigerants