Fuzzy-Control On Gas-Fired Water-Heated Of Application

The fuel gas water—heater becomes one of electrical appliances products to enter everyone. An important characteristic has the constant temperature function. Must guarantee the fuel gas water heater the elevation of temperature or the temperature decrease stage rapidity and the heat preservation stability, needs to clarify the fuel gas water heater this research object characteristic, in order to actually time controls, must express during internal variable its causal relation with mathematics relationship quota, this needs the modelling. The establishment model usually has two means, namely mechanism modelling and statistical modelling. The mechanism modelling must (physics) embark from the water heater itself mechanism, infers through the theory establishes the mathematical model. But regarding the fuel gas water heater said is very difficult. Through to the actual system gauging, namely obtains the input output data, then carries on processing to these data, thus establishes its statistical model. This method does not need to understand the water heater internal mechanism, only needs to focus on the system overall characteristic, this is this article needs to recognize to the fuel gas water heater system. The system recognizes has very many methods, for instance divides into the parameter according to its structure to recognize recognizes with the non-parameter. Recognizes in the non-parameter divides into the step leap response law, the frequency response and the related analytic method. In the parameter method may have least squares method, the stochastic approximation, the enormous likelihood law and the forecast error method. Uses in the parameter analytic method in this article to be most basic, simple least squares method carries on the analysis object the mathematical model, and makes the simple narration to other methods. In after establishes the object the number to permit the model carries on the actual object the control, for instance the classics PID control, its parameter characteristic in some condition and divides into possibly has the very good control effect, but when the condition changes or appears the big disturbance, the system closed loop feedback has the unstable situation, then controls the effect not to be able to satisfy each kind of operating mode the request. For instance the fuel gas water heater fuel gas type divides into the natural gas, the liquified petroleum gas, the artificial coal gas and so on, however in identical center fuel gas if ingredient ratio different that its fuel value is very dissimilar, the supposition is the identical fuel gas identical component, however under...