Reactor temperature automatic control method, valve opening upper and lower limit controller and system

Abstract

The method for automatically controlling the temperature of the reactor provided by the invention comprises the following steps: obtaining the lower limit R of the heating rate in the reactor min with an upper limit on the heating rate R max , to obtain the lower limit of the initial valve opening L of the flow regulating valve of the heating medium min and initial valve opening upper limit L max ;Get the valve opening L of the flow regulating valve at the sampling time t t and the heating rate R in the reactor t , R t =(T t -T t‑1 ) / Δt, T t Obtain the temperature detection value in the reactor for the sampling time t, (t-1) is the previous sampling time adjacent to the sampling time t; according to the heating rate R t with the lower limit of the heating rate R min and an upper limit on the heating rate R max The relationship between the valve opening L t and initial valve opening lower limit L min and initial valve opening upper limit L max The relationship between, and the temperature detection value T t with temperature set point T s The relationship between the upper limit of the valve opening and the lower limit of the valve opening of the flow regulating valve is adjusted to obtain the updated upper limit of the valve opening and the updated lower limit of the valve opening.

Description

technical field [0001] The invention relates to the technical field of chemical automatic control, in particular to a method for automatically controlling the temperature of a reaction kettle, a controller for an upper and lower limit of valve opening, and a system. Background technique [0002] Reactors are widely used in the chemical industry. The effect of reactor temperature control will directly affect the quality of the final product. Therefore, it is of great significance to conduct related research on the temperature control methods of reactors and improve the stability of reactor temperature control. [0003] In the industry, PID controllers are generally used to adjust the temperature of the reactor. The PID controller outputs adjustment signals to the reactor to adjust the valve opening of the heating medium flow regulating valve in the reactor, and then adjust the temperature in the reactor to make the reaction The temperature in the kettle is close to the temper...

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Problems solved by technology

In the prior art, the temperature setting value, the initial proportional gain coefficient, the initial integral gain coefficient and the initial differential gain coefficient of the PID controller are all manually set, and the PID controller tends to overshoot the controlled variable during the adjustment process. The output value makes the valve opening of the heating medium flow regulating valve too large or too small. Due to the hysteresis of the temperature response of the reactor, the overshoot phenomenon is more obvious. Therefore, for the temperature control of the reactor, it is often used before the reactor reaction. Set the upper limit and lower limit of the valve opening of the heating medium flow regulating valve in advance to make the temperature adjustment process of the reactor more stable. When the temperature is further adjusted, due to the limitation of the upper limit of the valve opening and the lower limit of the valve opening of the heating medium flow regulating valve, the temperature regulation is restricted

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