The Analysis Of Drying Medlar By Using Solar Energy Combined Heat Pump Drying System

The production of medlar in Qinghai is high and the medlar distributes widely and has a high edible value and medicinal value.However,it can not be preserved for a long time without dry processing after being picked.Dry processing of the product is essential for ease of transport and storage.On the other hand,in Qinghai area,the solar radiation is sufficient.Therefore,the use of solar collectors can utilize abundant solar energy.In this study,in consideration of saving energy consumption,shortening the drying cycle,maintaining hygiene during drying and drying,a solar collector-air source heat pump dual heat source drying device for mobile farmers was developed.The device is used for medlar drying research.Based on the actual situation in Qinghai,this study uses the combination of theory and practice to complete the following items:1.Because the temperature in the actual segmentation drying changes,the temperature in the drying chamber is gradually increased,and the difference between the actual segmentation drying and the constant temperature experiment,so The variable temperature drying model based on the experimental Page model has some deviations from the actual one.Therefore,some coefficients of the Page model established by constant temperature drying are corrected,and the variable temperature drying model obtained by further modeling based on the modified Page model makes a more accurate prediction of the time required for the actual temperature change drying.2.Through the operation and analysis of the original solar collector-air source heat pump dual-source combined drying system,the original drying equipment was improved,and the second generation solar collector-air source heat pump dual heat source combined drying system was built in Delingha.We performed three modes of drying experiments with a 75 kg red sputum experiment.The three modes are three modes: separate collector drying,collector-air source heat pump dual heat source combined drying,and air source heat pump drying alone.The collector’s separate operating mode took 28 hours and consumed 3.3kwh.The heat pump alone consumes 24.6kwh of electricity.The combined drying power consumption is 18.1kwh.The energy saving rate was 26.4%.The SMER of the second generation solar collector-air source heat pump deal-source combined drying system is 2.91kg/kwh.The SMER of the heat pump alone is 2.14kg/kwh.From the value of SMER,the joint operation mode under the same temperature setting has more advantages.Through field experiments and analysis of various indexes of the whole system,the designed drying device can not only save energy and reduce energy consumption,but also ensure all-weather operation of the system and improve drying efficiency with the assistance of air source heat pump.Not only for the actual drying of wolfberry has a certain guiding significance,but also in line with the concept of energy saving and emission reduction.