Device Design And Simulation Of Intelligent Photocatalytic Decomposition Of Ethylene Plant Based On Fruit Preservation

Storage is an important part of fruit preservation.Mature fruits release ethylene gas,and too much ethylene will speed up the ripening of fruits and lead to rot,which is not conducive to the storage of fruits.Therefore,the decomposition of ethylene has important applications.In this paper,STM32 microcontroller with ethylene concentration sensor and other components,using TiO₂ as a catalyst,under the action of ultraviolet light catalytic decomposition of ethylene,intelligent monitoring of ethylene concentration in the storage environment;and using COMSOL software for numerical simulation of the reactor to study the light intensity and the entrance Effect of Wind Speed on Decomposition Rate of Ethylene.The main work of this paper is as follows:?1?An intelligent ethylene decomposition device was designed.The system consists of six parts:STM32 microcontroller,reactor module,liquid crystal display,ethylene detection module,temperature and humidity detection module,and Android APP control program.Among them,the reactor module includes an ultraviolet lamp,a TiO₂ catalytic reactor,and a fan.The ethylene detection module includes an ethylene concentration sensor and a wireless transmission device.The temperature and humidity detection module has a temperature and humidity sensor.?2?The intelligent ethylene decomposition device control model was designed.STM32monitoring system includes five aspects:main control chip design,fan speed control function,data transmission rules,ethylene concentration acquisition,temperature and humidity acquisition;APP software includes the main interface of the ethylene decomposition device management system,and the setting of fruit threshold concentration in the device,UV lamp intelligent control settings,ethylene concentration data collection.The system first detects the ethylene concentration in the closed box and uses the wireless transmission module to transfer the information to the STM32 microcontroller to determine if the current concentration has reached the threshold,and intelligently starts the UV tube and fan according to the threshold conditions to automatically perform the ethylene decomposition reaction.The mobile phone intelligently monitors and records the changes in ethylene concentration,temperature and humidity,fan speed,and humidity in the air,and can forcibly start and control the number of light pipes and the fan speed.The system design mainly uses the software design of STM32 system and the software design based on the Android APP system for transmission and communication.It includes the software development environment,program flow chart and program analysis and implementation.Among them,STM32 single chip microcomputer system program analysis design includes five aspects:main control chip design,fan speed regulation function,data transmission rules,ethylene concentration collection,temperature and humidity collection.Among them,the APP design includes the main interface of ethylene decomposition device management system,the setting of fruit threshold concentration in the device,intelligent control setting of ultraviolet lamp,and collection of ethylene concentration data.?3?Simulation and optimization of ethylene-catalyzed reaction based on COMSOL software.Based on the photocatalytic mechanism of TiO2,a photocatalytic ethylene reactor model was established.The physical conditions such as laminar flow,dilute mass transfer,and general form of boundary partial differential equation were used to set boundary conditions and initial conditions.Under different light intensity?single tube,double tube?,ethylene inlet flow rate?0.001m/s,0.0007m/s,0.00013m/s,etc.?,the ethylene concentration field distribution and decomposition rate were obtained.The results show that the ethylene decomposition rate is directly proportional to the light intensity and compared with the experimental results.The ethylene inlet flow rate of 0.01m/s has the highest decomposition rate,which provides a basis for subsequent research.