Research And Design Of Portable Humidity Generator With Shunt Method

Flue gas humidity is a required parameter in the flue gas working condition,which has a great influence on the flue gas treatment system,flue gas humidity is usually measured by high temperature flue gas moisture meter.In view of the requirement of calibration for measurement deviation of high temperature flue gas moisture meter in long-term use,a shunt method portable humidity generator with closed-loop control characteristics was designed.It has been tested and verified that the instrument can realize the humidity occurrence range of 0-30Vol%,its humidification accuracy ?±1.5Vol%,and the response time ?3min,which can satisfy the detection and calibration of most high-temperature flue gas moisture meters.The humidity generation system is a complex,time-varying and nonlinear hybrid system,which is complementary to each other.In order to facilitate the research and analysis,the humidity generating system was separated and controlled in this paper.among them,the traditional PID algorithm was used to control the gas-path heat tracking control system,the saturator temperature control system was controlled by BP neural network PID algorithm,and the humidity feedback control system was controlled by the fuzzy self-tuning PID algorithm.The three subsystems were simulated by Simulink software,and the step signal was used as the input signal to verify the control performance of the algorithm.Based on STM32,the hardware circuit required for the realization of humidity generation system was designed in this paper.It mainly includes the overall structure of the hardware platform,temperature and humidity detection module,heating driver module,quality flow control module,communication module,etc.In this paper,C language was used as the software development language of humidity generation system.Based on Keil,the software program of the gas-path heat tracking control system,the water temperature control system in saturator,and the humidity feedback adjustment control system were designed.To facilitate user operation,the configuration software was used to design the human-computer interaction interface in the touch screen display module,and the Modbus communication protocol was used to realize data transmission between the controller and the touch screen.The working performance of the humidity generating system can be directly reflected by the system test.A test plan was formulated in this paper,which can test the hardware function,the ability to emit moisture and standard degree of moisture of the humidity generating system in detail.After the testing was completed,according to the test data analyzed the working performance of the system in detail and gave a test report.