A Solver-TOPSIS technique for multi-objective optimisation of innovative multi-stage VCR systems by using Microsoft Excel

Multi-objective optimisation analyses using Microsoft Excel

Abstract

This paper describes a method for conducting multi-objective optimisation of multistage vapour-compression refrigeration (VCR) systems by utilising the single-objective solver of Microsoft Excel and TOPSIS decision-making method. The paper illustrates the Solver-TOPSIS method by analysing an innovative two-stage VCR system that adds a heat-recovery intercooler to the conventional system after the first-stage compressor. The Excel-aided model developed for the system calculates its coefficient of performance (COP), exergetic efficiency, total cost rate, and total equivalent warming impact (TEWI) with four design parameters as variables which are the evaporator and condenser temperatures, the isentropic efficiency of the compressor, and the cooling water flow rate. Comparison of the four performance indicators of the system as optimised by the proposed method and by the MIDACO solver shows that the method yields higher values of the system’s COP and exergetic efficiency and lower TEWI at the expense of increasing the total cost rate. The total rate of exergy destruction in the system which is optimised by method is also lower than the one optimised by MIDACO.