Simulation and Exergy Analysis of a Refrigeration System Using an Open-Source Web-Based Interactive Tool—Comparison of the Conventional Approach and a Novel One for Avoidable Exergy Destruction Estimation

Abstract

Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy conversion system can be computed by applying advanced exergy analysis. Their calculation is crucial for the correct assessment of the real thermodynamic enhancement achievable by the investigated energy conversion system. This work proposes a new approach to estimate the avoidable exergy destruction rates of system components, being more rigorous compared to the conventional method due to the elimination of the need for the implementation of theoretical assumptions associated with the idealization of processes. An open-source web-based interactive tool was implemented to contrast the results of the conventional advanced exergy analysis to those involving the new approach for avoidable exergy destruction estimation. The comparison was based on the same case study, i.e., a refrigeration system selected from the literature. It was observed that the developed tool can be properly employed for comparing the two approaches within exergy analyses, and the results obtained presented some differences for the compressor and the condenser. Compared to the new approach, the existing methodology of advanced exergy analysis suggests lower values of the avoidable part of exergy destruction, which can be reduced by improving the efficiency of the compressor and the condenser. Moreover, the avoidable parts of exergy destruction, which could be removed within these components by improving the efficiencies of the remaining components, were higher in the case of the application of the existing advanced exergetic analysis as compared with the findings obtained by the proposed approach. These differences were due to the impossibility of the existing advanced exergy analysis to implement complete thermodynamic “idealization” for the condenser and evaporator.

A unified deduction of the expressions of exergy and flow exergy

“…Many scientific papers presenting results of exergy analysis appear every year in the literature. They concern, for instance, combined cycle power plants [1][2][3][4], steam Rankine cycles [5][6][7][8], organic Rankine cycles [9][10][11][12], refrigeration cycles [13][14][15][16], thermal and PV solar systems [17][18][19][20], fuel cells [21][22][23][24], heat exchangers [25][26][27][28]. Review papers on the exergy analysis of combined cycle power plants [29], steam power plants [30], solar energy applications [31], fuel cells [32], and heat exchangers [33] are available.…”

Exergy and Exergoeconomic Analyses of Air Conditioning Applications Integrated with an Air Membrane Exchanger

“…Numerous researchers are now using an exergy approach to investigate the performance of HVAC systems to obtain useful information concerning the sources of the system inefficiencies. Voloshchuk et al [20] conducted an exergy analysis of a refrigeration system using a new advanced approach to evaluate avoidable endogenous/exogenous parts of the exergy destruction. The proposed method showed quite different results compared to conventional advanced exergy analysis, in particular for the values associated with the compressor and the condenser.…”