Experimental and Numerical Analysis on the Grain Drying Based on Solar Collectors and Heat Pump
Abstract
To solve the problems of poor uniform and long drying time of grain with higher initial moisture in high grain piles, a novel solar assisted heat pump (SAHP) system for in-bin grain drying was proposed. A numerical investigation into the effects of different ambient parameters on the combined operating performance of the solar collector and heat pump was conducted. Besides, the experimental in-bin grain drying performance of SAHP system under four working scenarios was also carried out. The results indicated that the average heating capacity and COP of the SAHP system on December 12 were 130.2 kW and 6.86, respectively, consistent with the simulation results under a typical sunny day in winter. The moisture content of corn dropped from 12.94% to 12.5%, while the temperature stabilized at 20.8 ℃ after 42 hours of drying. The operating cost and initial investment cost of SAHP grain drying were 9.3 CNY/ton and 300,000 CNY. This investigation provided guidance for expanding future research on grain drying.