Self-adjusting fuzzy Smith-PID temperature control system and method

Abstract

The invention discloses a self-adjusting fuzzy Smith-PID temperature control system and method. The system comprises a self-adjusting fuzzy Smith-PID controller, a programmable controller, a temperature control execution device and a temperature sensor; the self-adjusting fuzzy Smith-PID controller is formed in a way that a fuzzy controller and a Simth pre-estimation compensator are introduced into a PID controller. The method comprises the following steps: 1, outputting collected temperature variable data to the fuzzy Smith-PID controller; 2, solving a temperature deviation value and a temperature deviation change rate; 3, determining a discourse domain and a quantization factor; 4, selecting a language variable fuzzy set of input and output variables; 5, solving fuzzy adjustment values of three control parameters of the PID controller; 6, carrying out defuzzification processing on the fuzzy value; 7, adding a Simth estimation compensation controller; 8, controlling a pusher and a fire grate.

Description

technical field [0001] The invention relates to the field of temperature control of waste incineration power plants, in particular to a self-adjusting fuzzy Smith-PID temperature control system and method. Background technique [0002] At present, the way of waste treatment in my country is gradually shifting from landfill to incineration. In the process of waste incineration, if the combustion temperature is unstable, it is easy to cause low burnout rate, more secondary pollutants, corrosion of boiler heating surface, slagging and clumping. Accidents such as failure of the furnace, or even shutdown of the furnace will have a serious impact on the safety, economy and environmental protection of the incinerator. Therefore, effective control of the furnace temperature of the garbage incinerator has become an urgent problem to be solved. Many industrial processes have the characteristics of large inertia, large time variation, and pure hysteresis nonlinearity. Waste incinerator...

AI Technical Summary

Problems solved by technology

Moreover, in the process of continuous feeding and incineration of waste incineration plants, the combustion state in the incinerator changes all the time, presenting a highly nonlinear system characteristic. For this highly nonlinear system, it is difficult to obtain an accurate mathematical model

Even if an accurate mathematical model is obtained, some harsh assumptions must be put forward and followed, and these assumptions are often unrealistic in applications, so it is difficult to achieve stable control using conventional PID control or general mathematical control models

At present, many waste incineration plants mainly use manual control in the actual operation process. When the calorific value of waste is relatively stable for a period of time, the fluctuation range of furnace temperature can be greatly reduced, but there are still situations of unstable combustion.

Moreover, due to the large workload of the operators and too many manual operations, there may be more operational errors

Therefore, whether it is traditional PID control or manual control, it is generally difficult to achieve stable control of the furnace temperature of the waste incineration boiler in the waste incineration plant.

In the case of such unstable combustion temperature, it is easy to cause accidents such as low burnout rate, many secondary pollutants, corrosion of the heating surface of the boiler, slagging and agglomeration of the furnace, and even flameout and shutdown, which have great impact on the safety of the incinerator, Serious impact on economy and environmental protection

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