Development of inorganic phase change material and cold charging performance analysis based on cold storage refrigerator

Abstract

Phase change cold storage refrigerators are a core of low-carbon development in cold chain logistics. This study is dedicated to optimizing the performance of phase-change cold storage refrigerators for the refrigerated transport of fruits and vegetables. Firstly, a high-performance inorganic phase change material was developed. By selecting a ratio of 2 wt% Carboxymethyl cellulose and 0.25 wt% Fumed Silica to solve the defects of supercooling and phase separation of this material, Subsequently, an experimental platform was built based on this material to test the charging and cooling characteristics of the phase change module. It was found that the opening of the expansion valve, the compressor’s speed, and the condenser fan’s speed were positively correlated to the charging and cooling efficiencies. Still, the effects of the first two on the system performance coefficient had optimal value points. However, there is an optimum point for the impact of the first two on the system performance coefficient. The optimized system coefficient of performance is increased to 1.62, and the charging time is reduced by 47.6 %, which is a good balance between energy efficiency and transport efficiency. In addition, it was found that the radial thermal resistance of the evaporator tubes in the charging module was more significant than the axial direction, and a new type of finned tube was designed to enhance the heat transfer, which resulted in a further reduction of 29 percent in the charge time.