| The cultivation and production of rape is an important income guarantee for the majority of farmers in our country.The planting area of rape is large,and the annual production is very large,which has very high economic benefits.When it comes to the harvest of rapeseed in the south,it is usually rainy and rainy,and the weather conditions are poor.Rapeseed is very easy to become moldy and bad,which is especially difficult to save.In addition,the general rapeseed dryer has a large size and complex control,which is not conducive to general promotion.Under the premise of high efficiency,low energy consumption,easy control and convenient operation,the high germination rate and high quality rapeseed are an important problem to be solved urgently.Based on the design of the vacuum drying machine of rapeseed,this paper focuses on the design of the PLC based drying control system based on the design of the vacuum drying machine of rapeseed.With rapeseed moisture content up to standard for the control system as the research target,to influence the efficiency of the rapeseed drying temperature,vacuum degree,humidity and so on has carried on the related experimental study,and based on PSO-BP neural network algorithm for rapeseed drying technology parameters are optimized.The main research is as follows:(1)In drying machine at home and abroad,working principle,drying was studied,on the basis of control theory and control system,this paper selects the homemade rapeseed rapeseed drying vacuum drying machine,and design the corresponding drying control system based on PLC to implement the control of temperature,vacuum degree,humidity,etc.(2)Mechanical part of the design of rapeseed vacuum drying machine,the machine is surrounded by resistance wire heating of rapeseed,driven by rotary screw mixing plant rapeseed circulate in the dryer operation,uniform heat,start the fan out high temperature moisture within the confined space,Meanwhile,the drying efficiency of the rapeseed can be accomplished by the positive negative pressure blower to improve the drying efficiency.(3)Design the hardware part of drying control system based on PLC,the specific hardware including the S7-200 cpu224 module(with EM235 extension module),a personal computer(PC)and a communication cable,temperature,pressure,humidity sensors,the human-computer interaction interface,frequency converter,etc.(4)Based on the hardware part of the PLC control system,the software part is designed and the control flow chart is designed through the drying of rapeseed,write the corresponding PLC ladder diagram drying control system,realize the intelligent control of rapeseed vacuum drying machine in.(5)Based on the PSO-BP neural network and particle swarm algorithm,the drying process parameters of rapeseed are optimized and the optimal model of drying process is obtained.(6)The sample machine of rapeseed vacuum drying machine was tested and the optimum drying conditions for the rapeseed dryer were obtained. |
