Analysis of the efficiency of eco-friendly refrigerants of a new generation in the operation of high temperature heat pumps
The article deals with high-temperature heat pump operation using refrigerant R-134a for heating DH system water. High temperature heat pumps of large capacity with two-stage centrifugal compressors can provide hot water heating up to 85 - 90 ° C and have a coefficient of heat transformation μ = 2.3 – 2.6 running by wastewaters depending on the temperature of refrigerant in the evaporator. The results of the study allow determining the most effective thermal circuits with high temperature heat pumps for district heating systems in various climatic regions. It was found that the efficiency of heat pump as a heat source depends on the type of refrigerant used as working fluid. The application of new refrigerant R-1234yf of a fourth-generation gives high efficiency to air conditioning systems. It ensures minimal negative impact on the environment because it has zero ozone-depleting potential and minimal potential of global warming. However, the preference of R-1234yf is not optimal for high temperature heat pumps due to low values of the coefficient of heat transformation. Therefore, it is necessary to develop new refrigerants that do not affect global warming and the ozone layer.
Key words: heat pump; refrigerant; ozone-depleting potential; global warming potential; coefficient of heat transformation.