A thermodynamic analysis of the Linde-Hampson cycle using low-GWP R1234yf-blends

The Linde-Hampson cycle (LHC) exhibits a promising future as a cooling method to achieve cooling temperatures below −40 °C, and are highly desirable in commercial refrigeration. This paper investigated the refrigerant replacement options of low-GWP blends i.e. R1234yf/R1132a, R1234yf/R170, R1234yf/R41 and R1234yf/R744 in the LHC by using thermodynamic analysis. The compressor temperature, cooling capacity, coefficient of performance (COP) and exergy efficiency were chosen as the objective parameters. The modelling results show that the R1234yf/R41 mixture has larger cooling capacities, while the R1234yf/R1132a mixture has higher energy efficiency. Under a typical operating condition, the R1234yf/R1132a mixture attained a COP of 1.4162 and an exergy efficiency of 28.49%, demonstrating high priority for improving energy and exergy performances. Besides, the system performance will be improved significantly with increasing R1234yf mass fraction, but the cooling temperature will also increase. In addition, the condenser and expansion valve are the two components that deplete exergy the most, which should be the focus for performance improvement. These results have important guiding significance for understanding the effects of different operating conditions on the thermodynamic performance of the LHC, and also expand the selectivity towards the refrigeration system and its working fluids.