Control system and control method for combustion of steel rolling heating furnace

Abstract

The invention discloses a control system and a control method for combustion of a steel rolling heating furnace and belongs to the field of heating furnace combustion control. The control system comprises the steel rolling heating furnace, a laser detection mechanism and a temperature detector, wherein the laser detecting mechanism is used for detecting components of smoke in the steel rolling heating furnace, and the temperature detector is used for directly measuring the surface temperature of a steel billet. The control method comprises the following steps that firstly, the control system is prepared; secondly, nozzles of all sections are controlled to carry out combustion; thirdly, the content of O2 and the content of CO are fed back; and fourthly, according to feedback, the air and gas flow of all the nozzles is adjusted to control the content of O2 and the content of CO in the steel rolling heating furnace within a target range. The control system and the control method for combustion of the steel rolling heating furnace are provided to overcome the defect that in existing steel rolling working procedures, the oxidation burning loss amount is relatively high, and the oxidation burning loss amount of the steel billet in the steel rolling heating furnace is effectively reduced.

Description

technical field [0001] The invention relates to the field of combustion control of heating furnaces, and more specifically relates to a combustion control system and control method of a steel rolling heating furnace. Background technique [0002] The heating furnace is the main energy-consuming equipment in the steel rolling process. While meeting the requirements of the rolling process, it is the goal of the production process of the steel rolling heating furnace to achieve the optimal control of the furnace atmosphere, heating time, and heating temperature, and to reduce oxidation burning loss and energy consumption. [0003] Steel rolling is the final process of steel production (the comprehensive energy consumption of domestic steelmaking is about 600kg standard coal per ton of steel), and the oxidation burning loss is relatively high, which not only brings a lot of energy waste, but also affects the steel rolling yield and directly affects the economic benefits of the e...

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Problems solved by technology

[0005] However, in actual production, the above two control methods cannot directly reflect the furnace gas conditions in each section of the heating furnace, and there are many problems: (1) The combustion method of the heating furnace is adjusted based on the calorific value of the gas detected by the calorific value meter. The indirect control of the combustion atmosphere of the furnace, which calculates the air-fuel ratio through the detection of the gas calorific value, guides the adjustment of the air-fuel ratio of the burners in each section of the heating furnace, and achieves the purpose of optimal combustion; Within a certain range of fluctuations, the gas calorific value meter is relatively accurate. When the gas composition changes and the calorific value fluctuation exceeds the applicable range, the error will increase

In addition, the calculated air-fuel ratio of calorific value is only an empirical data, and the accuracy is not high

At present, the calorific value meter mainly adopts the working principle of the combustion method (reflecting the calorific value through the flame temperature), which cannot reflect the composition of the gas, and it is impossible to accurately calculate the air-fuel ratio based on the calorific value; (2) Air flow meter or gas flow meter detection often exists Larger errors and other reasons cannot reflect the actual flow conditions. Therefore, the ratio on the operation screen cannot indicate whether there is excess oxygen in the furnace; (3) Restricted by the operating temperature, the zirconia probe is generally installed at the end of the furnace. It reflects whether the overall furnace has excess oxygen, and it is impossible to know whether the ratio of different heating areas is appropriate, and the reflected data is not strong for reference

[0006] At the same time, at present, the determination of billet temperature in the heating furnace mainly depends on the calculation of the temperature of the flue gas thermocouple in the furnace through a mathematical model. It uses an indirect measurement method, which has a large uncertainty. The problem of increased consumption and increased burning loss

[0007] Based on the analysis of the above reasons, it can be seen that at present, without the guidance of accurate air-fuel ratio and billet temperature, it is impossible to achieve the best combustion control of the heating furnace and reduce the oxidation loss rate by relying on the operation mode of adjusting the air-fuel ratio and indirectly measuring the billet temperature based on experience and burn-up targets

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