A comprehensive energy, exergy, environmental, and economic analysis of dedicated mechanical subcooled vapor compression refrigeration system

In the modern world, the vapor compression refrigeration (VCR) system is essential in various global applications, including climate control, refrigeration, and food preservation, contributing significantly to energy consumption. The significant energy demands associated with these applications highlight the urgency for sustainable and energy-efficient alternatives that can help diminish our dependence on electrical power. To reduce energy consumption and enhance energy efficiency, a dedicated mechanical subcooled (DMS) system can be integrated with a vapor compression system (VCR) system. This study aims to evaluate and optimize the dedicated mechanical subcooled-vapor compressor refrigeration system (DMS-VCR) system using refrigerant R134a for a 100 kW commercial chiller used for water cooling application. The primary objective is to assess the system from multiple angles which include energy, exergy, environmental, economic analysis (4E's) and optimizing it to enhance its overall effectiveness to reduce the system's annual cost. It is thermo-economically optimized, allowing for independent optimization of the evaporator, condenser-1, condenser-2, and sub-cooler components. The proposed system reduces electrical energy consumption by 17.24% and CO2 emissions by 12.4%. The DMS-VCR system outperforms the standalone VCR system. The DMS-VCR system's annual operating costs are 6.71% lower than an equivalent VCR system, and optimization further reduces costs by 1.88% (case-I: irate = 10%, Ny = 5 years, and toper = 4000 h) and 16.36% (case-II: irate = 2%, Ny = 10 years, and toper = 5000 h).The study underscores the importance of subcooling within the DMS-VCR system, highlighting its desirability as it varies with the recovery factor and annual operation period. As a result of the DMS-VCR system's better efficiency, design engineers are likely to find it more attractive.