Monitoring And Control Of Substrate Fermentation Process Based On Internet Of Things

Stack fermentation is an important technical means of matriculation and fertilizer utilization of agricultural waste.However,at present,the parameters monitoring and the dynamic change analysis of the parameters in the heap fermentation process were insufficient,resulting in the substrate production efficiency and product quality was not ideal.In order to solve the above problems,this paper design and develop a modular combined substrate fermentation parameter monitoring system according to the production characteristics of substrate stack fermentation.The dynamic model of substrate fermentation process was established through experimental analysis,and the automatic control system of substrate fermentation operation system based on tilting load was developed.The intelligent control platform of substrate production process for monitoring,data management,and intelligent decision-making was constructed by using Internet of things technology to achieve accurate management of substrate composting fermentation process.The main research contents and results of this paper are as follows:(1)Development of substrate fermentation monitoring system with combinable self-adaptive configurationAiming at the problems of cumbersome installation and configuration of monitoring equipment and poor maintainability of substrate fermentation production process,a modular and low power consumption combined multilayer substrate fermentation parameter monitoring system was designed.CAN bus was used to realize the adaptive identification and matching of detection modules,connection,and automatic configuration of host modules.The hardware and software cooperative power management mode is designed to realize the low-power long-term operation of the monitoring system.The field test showed that the R~2 between the measured values and the standard values of the monitoring system is more than 0.99,and the RSD is less than 5%.The energy consumption of the system in the mode of hardware/software co-power management is 31%lower than that in the mode of non-low power management.The system can work continuously for2 months without external power supply.(2)Study on parameters change and kinetics model of substrate fermentation processThe fermentation reactor was treated with four treatments,namely,no turning over and turning over at intervals of 2d,4d,and 6d.The temperature,water content,CO2 gas,CH4 gas,and other parameters of the fermentation process were monitored by online monitoring.There were significant differences in the parameters of fermentation process with different tilting frequencies,which indicated that tilting could replenish oxygen in time for the fermentation reactor,improving the activity and degradation ability of microorganisms,and effectively reduce the local anaerobic area in the reactor.However,turning over the heap too frequently could not ensure the internal temperature of the heap,which prolongs the fermentation time.According to the principle of organic matter degradation and the characteristics of substrate fermentation stack,the kinetic model of organic matter degradation based on first-order reaction kinetics was established,and the heat balance model of fermentation stack based on the principle of organic matter degradation heat generation was established to simulate the substrate fermentation process.The experimental data were used to verify the model.The kinetic model R~2 of organic matter degradation was 0.943 and RMSE was 1.274,and the thermal balance model R~2 was 0.959 and RMSE was 2.717,which indicated that the model could simulate the fermentation process and provided a theoretical basis for the parameter control of the fermentation process.(3)Feedback control of heap turning operation process based on heap turning loadThere was a regulation for manual operation of machine was not accurate,resulting in low efficiency,easy to boring machine and so on,through the test to build the flip heap machine operation load and the material moisture content,pile machine walking speed relation model,and combining the heap of frequency control of motor speed control model,using DDPG improved PID algorithm to optimize control speed regulation system of double pile of homework.The experimental results showed that compared with traditional PID algorithm,the overshoot of DDPG improved PID algorithm is reduced by 4%,the adjustment time is reduced by 2s,and the adjustment time was reduced by 6s compared with manual control.(4)Development of accurate control system for substrate fermentation processAn accurate control system of organic substrate production process based on the Internet of Things was developed to realize adaptive management of monitoring data of substrate fermentation process and automatic decision-making of stack turning operation.The decision control model of fermentation dump operation based on fermentation dynamics model was established,and the intelligent control PC system and We Chat small program were developed.The practical application test showed that the duration of high temperature of fermentation reactor controlled by intelligent control system was 2d longer than that controlled by artificial traditional control.Production line operation efficiency can be increased by more than 10%,and in the process of operation,there is no stuffy machine and other failures.