THERMODYNAMIC & ENVIRONMENTAL ANALYSIS OF NOVEL MULTI TARGET TEMPERATURE CASCADE REFRIGERATION SYSTEM

Abstract

A novel multi target temperature cascade refrigeration system has been proposed in this study. This system is a type of multi evaporator refrigeration system. A thermodynamic model of the system has been developed using engineering equation solver for theoretical investigation. The results of system’s performance have been compared with another configuration of multi target temperature cascade refrigeration system proposed by Zhu et al. [10] which was proved to be better than two configurations of combined cascade refrigeration systems. This novel system has three circuits, namely high, medium and low temperature circuits, and the high temperature circuit is connected to medium and low separately by cascade heat exchangers. For performance enhancement, this system utilizes two throttles in high temperature circuit, to maintain optimum temperature in cascade heat exchangers, a much efficient scroll compressor, and a subcooler. First law and second law analysis have been performed for parametric analysis of the system. This novel system functions really well as on average, the system’s COP is almost 10% higher and can even rise to nearly 21% in some operating conditions. This system utilizes low global warming potential (GWP) refrigerants like ammonia, carbon dioxide, and R1234ze(z), therefore, for environmental assessment of the system, the total equivalent warming impact (TEWI) of the system has been calculated.