The Research On Measurement And Control System Of VOCs Treatment With Discharge Plasma

As an new treatment technology, VOCs treatment technology with plasma was proved to have advantages of high efficiency, low energy consumption, and wider range of application. However, in the current industrial applications, VOCs treatment with discharge plasma is limited because of low degree of automation, low energy efficiency, and unable to achieve online monitoring and control. On the basis of analyzing the mechanism and process characteristics of VOCs treatment with discharge plasma, and combined with the technology of other application of discharge plasma, this paper set the parameters and developed the intelligent measurement and control system of VOCs treatment with discharge plasma to resolve these problems.This paper determined the parameters of the system for the monitoring and control were concentration, temperature, humidity, air flow rate and input power. An overall design proposal about intelligent measurement and control system of VOCs treatment with discharge plasma was raised that adopt sensors and actuators as the field level, TMS320F28335 as the core control layer, and PC as a remote monitoring and management of the three-layer structure. The emission concentration was controlled by adjusting power and gas flow. Specifically, it means adjusting the output waveform duty cycle of the high voltage source inverter bridge and the degree of opening of pneumatic valve. This paper chose fuzzy control and has designed the fuzzy controller. Simulink was used to simulate the fuzzy control system. This paper compared the effect of fuzzy control with the traditional PID control, and the results showed excellent control effect of fuzzy controller. Monitoring and control of gas flow was achieved by the valve and the turbine flowmeter with stepper motor. This paper measured the power supply with quasi-synchronous sampling algorithm, and designed voltage and current signal conditioning circuit. Some circuits had been designed to measuring gas temperature, humidity and concentration; LCD display circuit and RS485 communication circuit had been designed for real-time display and communication. In software terms, this paper wrote C program with processor TMS320F28335 as the core, and gave software flow chart, including the DSP main program and other subroutines. Based on LabVIEW virtual instrument, the PC application interface was designed for real-time curve data display, storage and other functions. Finally, this paper gave the anti-jamming design for the measurement and control system from two perspectives: hardware and software, and gave the experimental waveforms and simulation waveforms of the critical parts. The results showed that the measurement and control system can meet the requirement and bear very strong practical value.