250721 Cogent Engineering New Manuscript.docx

This study evaluates a transcritical CO₂ vapor-compression refrigeration cycle of R744 with an internal heat exchanger (IHX) using Simscape and Simulink, under conditions closely representing real-world environments. The analysis considers three key thermal boundary parameters: ambient temperature, refrigerant superheat, and initial IHX pressures. Three simulation scenarios were conducted using outdoor temperature data from Seoul, superheat variation from 3 °C to 15 °C at a constant 35 °C ambient condition, and systematic changes to high- and low-side IHX pressures. Results show that rising ambient temperature increases refrigerant flow and cooling capacity but significantly reduces COP from 9.8 to 2 due to higher compressor power. While elevated superheat prevents liquid carryover, it leads to reduced efficiency. An optimal high-side pressure range of 10–12 MPa is identified. Unlike prior studies focused on steady-state conditions, this work emphasizes dynamic performance using real climate data. The findings offer practical insights into efficient system operation in warm climates and contribute to the development of climate-resilient refrigeration strategies, supporting future research in experimental validation and AI-driven control.