INTEGRATING ENERGY MANAGEMENT STRATEGIES INTO THE COLD CHAIN FOR HERB STORAGE

Abstract

The increasing demand for locally cultivated sweet basil as a prospective antiviral herb has resulted in the implementation of cold storage to preserve its quality. From a financial perspective, however, storage costs are also a significant concern. An important factor in operating costs is the energy consumption required for chilling the basil. Thus, this study examined energy management strategies for a cold storage system with an evaporative condenser used in the production of chilled sweet basil. The system features a 15 HP compressor (380 V) operating with R22 refrigerant, with an upper-wall-mounted evaporator connected to a water-cooled pad evaporative condenser. Experiments were conducted at five precooling temperatures (8°C, 10°C, 12°C, 14°C, and 16°C) and three product mass fractions (50%, 75%, and 100%). The results showed that, while precooling temperature had a significant impact on the coefficient of performance (COP), COP decreased with increasing temperature under cooling load. A mass fraction increase from 50% to 75% slightly improved COP, with a marginal gain at 100%. The optimal condition, balancing energy efficiency and product quality, was observed at 12°C precooling temperature and 75% mass fraction. Under this setting, the system not only maintained favorable thermal performance but also achieved cost-effective operation with a chilling cost of 11.8 baht per kilogram of sweet basil, demonstrating its economic viability for commercial applications.