Research On Measuring&Control System Of Coal Gasification Boiler

In China, coal is very important in the frame of energy sources. When coal burns directly, it generates sulfur dioxide and sulfureted hydrogen which pollutes the air seriously. So, it is very important to research the technology of coal gasification which has higher efficience, lower wastage and lower contamination.As the temperature of gasification layer changes quickly, optical fiber temperature whose explorer head is single crystal sapphire stick is designed to measure the temperature of the exit of coal gasification boiler. The melting point of sapphire stick is 2 045℃, so it can also be used to measure the temperature of gasification layer. Amplifing circuit of photoelectricity detect is designed. It can make the detector have higher resolving power and larger measure range. And it can minish the circuit yawp. After experiment test, it has the accuracy of 1℃.In allusion to the instability of velocity of flow in gas pipe, ultrasonic flowmeter which is based on time difference is used to measure the steam flux. Only the direct time and countercurrent time are need to sampling, and transmitting speed is not needed. Its measure precision is high, and it is not affected by the physical and chemic character of the liquid.As the coal gasification boiler has nonlinear character, and its parameter is not steady, then its math model is hard to establish. The effect is not good to use traditional PID control system. The quality of the temperature control system is depended on the design of arithmetic. In this paper, chaos PID control is used. The arithmetic of PID control which is based on chaos optimization is designed. The idea is by introducing PID parameters into chaos system, chaos variables will search PID parameters extensively and intensively within global extent according to the selected optimum-solution-searching conditions and the extra control-system-stability conditions. And finally, the global optimum solutions ofPID parameters are obtained.Simulation results have shown that the method of PID parameter optimization based on chaos variables is better than other methods.