Experimental investigation on thermal performance of self-service cold storage cabinet based on the orthogonal test

Self-service cold storage cabinets (SCSCs) are widely used in the delivery end of cold chain logistics for fresh agricultural products, to maintain the freshness of the products in a low temperature environment. Based on the three-factor and four-level orthogonal test, this paper first analyzed the impact of pure geometric structure factors on the thermal performance of SCSC. The priority of the geometric structure factors of the SCSC on the thermal performance is determined by means of four evaluation metrics. Then, two operating factors including air supply velocity and temperature are added to the consideration, and a five-factor and four-level orthogonal test is conducted based on the aforementioned five factors. The priority and optimal level of various factors were determined based on the test results. By comparing the results of two sets of orthogonal tests, it is found that the optimal level of the structure is affected by the change of air supply conditions. After optimizing the SCSC, the temperature range, temperature inhomogeneity coefficient, and velocity inhomogeneity coefficient decreased by 1.316 degrees C, 21.16%, and 2.18% respectively, while the average temperature increased by 2.028 degrees C, and the power consumption decreased by 4.81% compared to the original level of factors (test plan 1).