Control System Design And Experimental Research On Solar Steam Dryer

Drying of agriculture products is an extremely important link in the agriculturalprocessing. For a long time, the main energy of drying is coal, electricity and gas, which isnot only high energy consumption, but also leading environmental pollution problems.Low-cost, clean solar energy resources used in drying agricultural products can saveenergy and reduce pollution. Solar energy research in the field of agricultural drying aremore concentrated in low-temperature, this paper carried out design and research oncontrol system of solar steam supply device, dryer temperature and humidity detectingsystem and steam control system that are based on the solar steam system inhigh-temperature applications. And taking carrots as object to verified the device byexperimental.The solar steam hot-air drying device is the use of solar energy in high-temperature,and it can substitute and partial substitute of the traditional steam generating steam fromelectric power and coal-fired boiler, realizing drying and processing of agriculturalproducts. Solar steam generation and control, dryer temperature and humidity detectingand controlling are vital to the solar steam hot air drying that if it can meet the dryingrequirements of agricultural products.The solar steam control system core is based on forced circulation of the workingfluid temperature control system, supplemented by automatic replenishment system tocomplete the electrical design of the steam supply device. According to XMTD-JK208temperature difference controller and DF-96B water level controllers to implement steamsupply device continuous work, ensuring that the heat supply when the belt dryer working.The temperature and humidity of the drying machine detection and vapor controlsystems is build, STC89C51microcontroller as the core, using SHT11digital temperatureand humidity sensor to implement the data real-time collecting of temperature andhumidity inside and outside of the dryer. Complete the design of synchronous serialcommunications interface circuits, display circuit, power circuit, the solenoid valve controlcircuit. On software part, using C++software to implement on the main control interfaceand programming interface module, data acquisition, control parameter settings. Achievethe function of the control solenoid valve switching when the ambient temperature reachesthe stetted upper and lower limits.The study also verifies the accuracy of temperature and humidity detection system，the control of forced circulation steam supply device and the control of temperature by experiment. It has been proved that the control system of the test device is reasonable indesign, and the expected goals have been achieved.The study of this paper may be applied to the production of the new dryer, and it canalso be used for the improvement of the original dryer. It has a broad application prospect.