Heating furnace combustion control technology for overcoming fuel gas heat value and production rhythm fluctuation

Abstract

Aiming at the ubiquitous problems that in heating furnace combustion control, a fuel gas heat value is unstable and the production rhythm changes frequently, the invention provides a novel combustion control method. According to the method, traditional temperature-fuel gas flow cascade control is reserved, namely, temperature control serves as a main loop, fuel gas flows serve as an auxiliary loop, and the cascade system structure can solve the fluctuation problem of fuel gas pressure. A production rate fuzzy feedforward module is superposed on an auxiliary loop set value, so that rapidness, following a temperature set value, of a temperature control system is effectively improved when the production rhythm changes. Meanwhile, air flows are set according to production rate model optimization, the reasonable optimum air requirement amount can be accurately obtained according to heat supply quantity calculation, the optimum air-fuel ratio is obtained objectively, and the defect that in the prior combustion control technology, an air-fuel ratio is difficult to automatically correct when the production rhythm fluctuates is overcome. The control technology not only solves the combustion efficiency problem when the heat value and the production rhythm fluctuate better, but also can greatly improve control quality of furnace chamber temperature, the control scheme is simple and easy to implement, and on-site implementation and maintenance are easy.

Description

technical field [0001] The invention relates to a combustion control technology of a hot rolling heating furnace. Background technique [0002] The purpose of the traditional combustion control of the heating furnace is to ensure the accuracy of the furnace temperature control on the one hand, and on the other hand to ensure a reasonable ratio of gas to combustion air flow, so as to ensure that it can be fully burned and achieve the highest combustion efficiency. Excellent heating furnace control technology can not only improve the heating quality of products, but also has specific significance for energy saving and emission reduction. [0003] In fact, most of the heating furnaces operating in China currently use a mixture of blast furnace gas and coke oven gas, and its calorific value is often affected by the working conditions of the blast furnace and coke oven and often fluctuates. The cascade ratio and double-crossing limiting combustion control strategies are still th...

AI Technical Summary

Problems solved by technology

[0004]Generally speaking, the rhythm of heating furnace production follows the rolling rhythm. With the change of product specifications, roll changes, failures, etc., the rolling rhythm must be Variations can occur, which often result in large fluctuations in the temperature of the furnace

The main reason for this situation is the large inertia of the temperature object. If the gas cannot be increased or decreased in time when the rolling rhythm changes, it will inevitably cause a period of gas excess or shortage. As a result, the temperature will rise or fall rapidly, and must be slow to adjust

At present, most heating furnace temperature control inevitably requires manual intervention when the rolling rhythm fluctuates greatly

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