Research On Control System Design Of Edible Fungi Multi Energy Complementary Drying Room

With the rapid development of edible fungi industry in China,the output of edible fungi ranks first in the world all the year round.Drying is one of the important links of edible fungi in post harvest processing.Dry products are easy to transport and can be stored for a long time.How to dry edible fungi quickly and well is a research hotspot in recent years.At present,traditional drying is still the main drying method in China,which has some problems,such as low mechanization,unstable drying quality,high energy consumption,heavy pollution and so on.In order to solve the above problems,this paper designs a multi energy complementary drying room control system based on PLC,which aims to realize the automatic control of temperature and humidity in the drying process,reduce energy consumption and improve drying efficiency.The main work and research results are as follows:(1)The overall structure and key components of edible fungi multi energy complementary drying room were completed.Put forward the overall structure design scheme and analyzed the working principle of the drying room.The biomass combustion furnace and heat dissipation device,solar energy expansion heat collector plate and dustproof cloth,moisture removal and circulation system were designed.Finally,completed the selection of motor and fan.(2)The modeling and simulation of the temperature control system of the drying room were completed.Expounded the working principle of drying room.Targeted at the characteristics of large time delay and non-linearity of temperature control in drying room,the model was built through the step response method,and the simulation models of conventional PID algorithm,fuzzy PID algorithm and fuzzy algorithm were built on the Simulink platform of MATLAB software.Carried out simulation test and judged the advantages and disadvantages of different algorithms by the temperature response curve.It was found that the response curve of the fuzzy algorithm is smoother and there is almost no overshoot.Finally,the fuzzy algorithm was selected as the temperature control algorithm.(3)The design of multi energy complementary drying room control system was completed.By analyzing the advantages and disadvantages of constant temperature drying and variable temperature drying process,it was determined that the control system adopts the split temperature drying process.The system used Siemens S7-200 PLC as the control core,and the drying process was divided into four drying sub stages and one medium short wave infrared drying stage based on the drying process of split-range variable temperature.The data acquisition was completed through the temperature and humidity sensor,and the operation of heating and dehumidification was achieved by controlling the on-off of the relay,so as to realize the purpose of drying.At the same time,carried out the hardware and software design of PLC,the design of human-computer interaction interface and the communication setting of each functional module.(4)The control system performance of drying room and the drying effect of lentinus edodes through experiments were analyzed.Developed a edible fungi multi energy complementary drying room.Taking lentinus edodes as the experimental object,experiments were carried out on the operation of unfolding and taking back about the expansion heat collector plate and rainproof cloth,on-off stability of medium and short infrared wave lamp,humidity control stability and temperature control accuracy,and the drying effect of lentinus edodes.It was found that the drying operation of drying room is stable,the temperature control precision was± 0.8 ℃,the drying time of lentinus edodes was 12 hours.The reliability of the control system and the high efficiency of drying room were verified.