Energy performance assessment of R1243zf/R134a, R1243zf/RE170, and R1243zf/R227ea as possible alternatives to R410A refrigerant in precision air conditioning unit

Currently, R410A refrigerant is widely used in the air conditioning system. However, R410A is a kind of binary hydrofluorocarbon mixtures that has significant climate change effect and scheduled to be phased out in future. To explore the possible alternative refrigerants, this study investigates several azeotropic and near-azeotropic mixtures consist of the new generation fluorinated refrigerant HFO-1243zf and its performance enhancer. First, a mathematical simulation model of the precision air conditioning system with a reheater was built and verified. Based on this, the refrigerating cycle performance, refrigerant charge, global warming potential, total equivalent warming impact (TEWI), flammability and economic analysis matters of R1243zf/R134a, R1243zf/RE170, and R1243zf/R227ea were studied. It is found that the required refrigerant charge can be reduced as 3.13% to 35.9%, compared to R410A; besides, the coefficients of performance are elevated in range of 1.05% to 10.25% with the proportion variation of R1243zf. All the new mixtures have smaller TEWI values than R410A, reducing 8.2% to 18.3%. The estimated prices of R1243zf/RE170 and R1243zf/R134a are lower than R410A. The flammability of R1243zf/R134a and R1243zf/R227ea are acceptable as the requirements of ISO standard 5149, but not for R1243zf/RE170. Comprehensively considering, R1243zf/R134a mixture with approximately equal mass ratio is thought to be an ideal substitute to R410A in precision air conditioning system under the current situation.