Thermal Performance and Energy Conservation Effect of Grain Bin Walls Incorporating PCM in Different Ecological Areas of China

Abstract

China, as one of the largest grain production countries, is faced with a storage loss of at least 20 billion kilograms each year. The energy consumption from grain bin buildings has been rising due to the preferred environmental demand for the long-term storage of grain in China. A prefabricated phase change material (PCM) plate was incorporated into the bin walls to reduce energy consumption. The physical model of PCM bin walls was numerically simulated to optimize the latent heat and phase change temperature of PCMs for ecological grain storage area. The thermal regulating performance of the prefabricated PCM plate on the grain bin wall was optimized. It was indicated that a higher value of latent heat of the PCM is more suitable for the hotter region for storing grain in bins in this paper. The energy saving did not increase in the same proportion as the increase in latent heat, suggesting a diminishing return. In this study, the optimal latent heat ranged from 180 to 250 kJ/kg. The values of phase change temperature were selected as 31 °C, 28 °C, and 28 °C for Guangzhou, Zhengzhou, and Harbin cities, respectively, corresponding to hot, warm, and cold climates. The percentages of energy saving were 12.5%, 14.8%, and 17.5% with the corresponding phase change temperatures, which showed an advantage of the PCM used in grain bin walls.