Experimental study and theoretic analysis of a heat pump for grain drying

Based on the heat pump assisted fluidized bed grain drying equipment developed recently, a experimental analysis of the heat pump was performed. The influencing factors and their effects on the temperature of air outflow from the condenser and the coefficient of performance of the heat pump in a drying experimental system were gained from the experimental results. Coupled with corresponding theoretical analysis, it was found out that the higher the flow quantity through the evaporator and the lower the outlet temperature of the condenser; the better performance the heat pump can achieve. According to those results, a plan to improve the heat pump drying system was set up, and the performance quality of the improved heat pump and its corresponding economic evaluation of the drying system were predicted. It was shown that the improved heat pump can achieve its COP up to about 3.856, and the cost drying reduced sharply.