Study On The Optimization Of Air Source Heat Pump Drying Technology In The Production Of Mosquito Coil

With the development of economy and technological advancement,the demand for energy from mankind will continue to increase.The energy crisis will cause economic shock to a certain extent.With the issuance of the “13th Five-Year Plan for Energy Development” to promote the development and utilization of renewable energy,an energy structure that mainly uses fossil fuels and clean energy coexists.Drying is a high energy-consuming process,the first problem to be solved is to ensure product quality and reduce energy consumption.As a high-efficiency and energy-saving technology applied to the drying process,the heat pump has the advantages of energy conservation,product quality improvement,and environmental friendliness.Compared the common heat pump drying system form,determined the working principle and energy-saving advantages of the closed system.Explained the influencing factors of the heat pump drying system performance briefly,and introduced the theory of heat and mass transfer in the drying process and typical material stages.Proposed the unit of energy consumption and dehumidification(SMER)as a system performance evaluation index.The thermodynamic law is used to theoretically calculate the air circulation and the refrigerant circulation in a heat pump drying system.Mosquito coil experiment was conducted to determine the air temperature and wind speed as the main influencing factors,the effect of temperature on the moisture content of mosquito coils was greater than the wind speed.The effect of wind speed was determined by the drying stage.The Henderson and Pabis model was used as the mosquito coil drying model,and the mosquito coils were water-bearing.The relationship between rate and supply air temperature,cross-section wind speed and drying time can be used to predict the moisture content of mosquito coils at any time under different drying conditions.A mixed flow return air drying method was proposed,and determined to be superior to the 45° horizontal air supply.The mosquito coil drying process model was established by MATLAB software,which considered the drying rate change during the actual drying process and the temperature rise of mosquito coils.The validated model was used to analyze the influencing factors of the drying chamber.The air temperature,cross-section wind speed,return air position and drying chamber length of the end and discharge end were analyzed.Combined with the system performance evaluation indicators and production requirements,the temperature of the feed end of the smokeless mosquito-repellent incense was determined to be 55°C,and the cross-section wind speed was 1.1m/s,the air temperature at the discharge end was 70°C,the cross-section wind speed was 1.3m/s.The air temperature at the feed end of the incense-shaped mosquito coil was 60°C,the cross-section wind speed was 0.9m/s,and the discharge end delivers air.the temperature was 70°C,and the cross-section wind speed was 1.3m/s.Completed the energy consumption analysis in the form of traditional one-way and mixed-flow return air,and the production of the drying room in winter and summer is compared.The heat pump unit is designed as a closed circulatory system with condensate recovery.Compared with the traditional direct drying method,determined the heat pumping unit's energy saving advantages.The LMS AMEsim software is used to model compressors,evaporators,condensers,and capillaries.Analyzed the influencing factors of the heat pump unit,and optimize the configuration through orthogonal test.The degree of influence of each component on the COP is compressor displacement,evaporator heat exchange area,condenser heat exchange area and capillary length,and the optimized heat pump unit COP has more than 10% increase.Used LMS AMEsim software and MALTAB/Simulink software for heat pump drying system simulation calculation,compared with the actual measurement results,verified the accuracy of the heat pump drying system model.According to the optimization results to complete the heat pump unit prototype design and heat pump drying system form design.The optimized system performance evaluation index SMER increased by 11.6%~15.8%,and the unit power consumption decreased by 10.6%~13.7%.