Multi-stage Series Heat Pump Drying System with Dehumidification Simulation and Experiment Verification

Abstract

Abstract.A multi-stage series heat pump drying system with dehumidification is proposed to meet the demand of corn drying in Northeast China. The mathematical model of the system is developed in EES (Engineering Equation Solver). After building the model, the system's performance under stable conditions is simulated. The result shows that a 5-stage system has a dehumidification rate of 400 kg·h -1 and a SMER (specific moisture extraction rate) of 4 kg/kW·h. The primary air flowrate, air inlet temperature and air inlet relative humidity are the main parameters influencing the system performance. The dehumidification rate and SMER of the system have positive correlations with them. The air inlet temperature and air inlet relative humidity have more significant influence. An experiment of 4-stage system is conducted and the result is consistent with simulation. Currently, coal is the main energy source for drying corn in Northeast China, not only wasting a lot of energy, but also causing serious pollution. Compared with burning coal, the proposed system has great potential for energy saving and environmental protection.