Comparative Energetic and Exergetic Assessment of Different Cooling Systems in Vegetable Cold Storage Applications

Abstract

In this study, four different cooling systems have been thermodynamically analysed for vegetable cold storage application, considering a fixed cooling demand of 10 kW. Both vapour absorption refrigeration (VAR) and compression refrigeration (VCR) cycles are considered, each with two different working fluids. For the VCR cycles, R410A and R134a are considered as refrigerants, whereas for the VAR cycles, NH3–water and LiBr–water solutions are considered as refrigerant–absorbent pairs. Both energetic and exergetic performances are assessed and compared between the cycles. The system performances are assessed by varying the conditions of the evaporator and condenser. The effects of ambient temperature on the system performances are also studied. The study reveals that VAR systems can provide feasible alternatives to VCR systems for the cold space temperature range applicable for vegetable storage with the exception that LiBr–H2O cycle cannot be used for cold space temperature below 2 °C. Exergetic performance (ECOP) of the LiBr–H2O-based cooling system matches well with that of VCR systems for evaporator temperature 2–5 °C, and it exceeds the ECOP of R410A cycle at 2 °C evaporator temperature. When the ambient temperature is reached above 35 °C, the exergetic performance of LiBr–H2O-based system is better than that of both the VCR systems. For higher condenser temperature also (40 °C and above), the VAR and VCR cycles show closer ECOP values.