Thermodynamic, economic and environmental assessment of advanced transcritical CO2 supermarket refrigeration architectures with maintenance-cost sensitivity analysis

Abstract

Modern supermarket refrigeration systems are progressively transitioning toward low-global-warming-potential solutions, with transcritical CO₂ architectures emerging as promising alternatives to conventional synthetic refrigerants. However, the thermodynamically optimal refrigeration technology may not necessarily coincide with the most suitable solution for industrial implementation. This study compares a conventional booster cycle (BC), a parallel-compression system (PC), and a booster cycle with low-pressure ejectors (BLPE) through a thermodynamic, economic, environmental, and dual-layer multi-criteria assessment. Annual simulations are performed using location-specific outdoor dry-bulb temperature profiles for Berlin (Germany), Lisbon (Portugal), Albuquerque (United States), and Singapore under a fixed supermarket load profile, while LCC, TEWI, and the quantitative technical-MCDM assessment are restricted to the Lisbon reference case. Relative to BC, model-predicted annual electricity-consumption reductions range from 10.55% to 11.68% for PC and from 12.38% to 12.62% for BLPE. In Lisbon, PC and BLPE reduce LCC by 7.11% and 8.74%, respectively, and TEWI by 10.80% and 12.50%. BLPE therefore provides the best quantitative technical performance, although its baseline LCC advantage over PC is eliminated by an additional annual maintenance-cost premium of approximately 803 Euro/year. In contrast, the expert-informed adoption-readiness layer ranks PC first; PC occupies first position in 85.5% of bootstrap expert-resampling realizations and in 99.293–99.957% of Monte Carlo criterion-weight realizations across TOPSIS, VIKOR, and EDAS. These results indicate that thermodynamic superiority and industrial adoption readiness may diverge, and that maintenance-cost tolerance and implementation perceptions should be considered alongside modeled performance when selecting advanced CO₂ refrigeration architectures.