Design And Implementation Of A New Control System For Heat Pump Dryer

Since the implementation of the Poverty Alleviation Policy,China has made a breakthrough in tackling poverty.This topic comes from our school's mission to help the poverty alleviation in Cangxi County of Qinba Mountain Area.It is based on the idea of poverty alleviation with science and technology,aiming at the rich resources of wild treasures(wild fungi and other plants)in Cangxi County.Because Local farmers lack deep processing technology and equipment,various types of mountain treasures after collected can only be processed together which will make the dry products be tainted by other odor easily,resulting in bad quality and economic benefits.Besides,farmers can't dry wild treasures all by themselves and can't face the market independently.Therefore,based on the needs of local people and the scientific and technological advantages of colleges and universities,we decide to develop a new type of closed-loop dehumidifying heat pump dryer,suitable for family workshop in cangxi county,helping to form the drying industry of the wild treasures,thus the farmers in Cangxi County can get rid of poverty and the regional economy can be developed.The paper tries to develop the new heat pump dryer,which is a new type of drying equipment for facility agriculture.One goal is that farmers can adjust the drying process and carry out personalized and automatic drying design to meet the needs of various drying materials.The other goal is that farmers are willing to buy the dryer,use the dryer,and can afford the dryer.The development work is challenging and innovative.The paper must have a breakthrough in the structural design of the heat pump dryer.It is not to adjust the drying capacity by simple adjustment of the damper switch.Instead,it is to adjust the working fluid path in the heat pump circuit to improve the energy efficiency of the heat pump.Through the ingenious switching of the auxiliary heat exchanger,the efficiency of heating,condensing and removing moisture can be improved.The paper pays attention to the cost performance in the design of the control system.The STM32F103VET6 microprocessor is applied to build an integrated control machine and peripheral interface.The system operation and display part adopts the serial touch LCD screen.PLC logic control and improved PID algorithm are integrated in control modes such as heating,dehumidification and constant temperature.The cost-effective,convenient and practical control system based on temperature and humidity control is designed.The operation procedure is programmable,including setting temperature,humidity,time and so on.The mature technology can be stored and used by pressing one button to meet the application needs of farmers to dry all kinds of wild treasures.The experiment proves that the new dryer has the advantages of simple operation,strong practicability,reliable operation,selection of drying process,suitable for household workshop drying,etc.,and has broad application prospects.