A Comparative Life Cycle Climate Performance (LCCP) Analysis of Natural Refrigerants in Supermarket Applications: Propane (R290) Plug-in Units vs. Transcritical CO2 (R744) Centralized Systems

Description This record presents a comprehensive, granular technical comparison and Life Cycle Climate Performance (LCCP) analysis of the two dominant natural refrigerants in the commercial retail sector: Propane (R290) and Carbon Dioxide (R744). Driven by the stringent mandates of the European F-Gas Regulation and the Kigali Amendment to the Montreal Protocol, this study moves beyond simplistic Global Warming Potential (GWP) metrics to evaluate the total "Cradle-to-Grave" environmental and thermodynamic impacts of commercial refrigeration infrastructure. The analysis evaluates two diametrically opposed system architectures across distinct supermarket formats and climate configurations: Decentralized Architecture (Scenario A): R290 plug-in units integrated with a Hydroloop glycol-water system, focusing on small-format convenience stores (the COOP PRIX model). This configuration highlights charge optimization strategies using headerless microchannel heat exchangers to safely remain under the EN 378 mandated 150g limit. Centralized Architecture (Scenario B): Remote Transcritical R744 Booster rack systems designed for large-format hypermarkets (the OBS model), incorporating advanced efficiency mechanisms such as parallel compression, two-phase ejectors, and internal heat exchangers (IHX). Key Focus Areas & Methodology: Thermodynamic & Fluid Dynamic Foundations: A comparative review of volumetric cooling capacities, transport properties, suction line dynamics, mass flow rates, and Reynolds numbers. LCCP Mathematical Modeling: Breakdown of direct emissions (leakage rates and End-of-Life losses) and indirect emissions, with a specific focus on manufacturing carbon coefficients for raw materials (Steel, Virgin vs. Recycled Aluminum, Copper, and Plastics). Climatic Sensitivity & The "Crossover" Phenomenon: An evaluation of cycle efficiencies across varying climates (e.g., Chicago vs. Miami/Phoenix). The study demonstrates how R744 centralized systems with heat recovery excel in heating-dominated northern climates, while R290’s stable subcritical cycle often yields a superior LCCP in hot, high-ambient regions. Economic & Operational Trade-offs: Comparative analysis of Total Cost of Ownership (TCO), initial CAPEX premiums, lubricant longevity (oil dilution in POE/AB vs. supercritical stress), leak sensitivities, and specialized technician training requirements. This study provides a strategic, data-driven roadmap for retail supermarket operators, R&D engineers, and environmental analysts navigating the net-zero transition toward future-proofed, sustainable cooling infrastructure.