阅读说明：本技术 加热炉及加热炉炉温的控制方法和控制系统 (Heating furnace and control method and control system for temperature of heating furnace ) 是由 王培培 陈铎 张小松 徐海松 肖楠 张弛 于 2021-01-13 设计创作，主要内容包括：本发明公开了一种加热炉炉温的控制方法,包括：对加热炉进行分区,获得N个炉温控制区；获取N个炉温控制区对应的加热炉分段工况；判断每个炉温控制区对应的加热炉分段工况是否满足第一预设条件；若是,根据第一控制模式,对炉温控制区进行控制；若否,根据第二控制模式,对炉温控制区进行控制,具体如下：判断加热炉分段工况是否满足第二预设条件；若是,根据空煤气串级控制逻辑,对炉温控制区进行控制；若否,根据流量控制逻辑,对炉温控制区进行控制；上述控制方法实现了多种控制模式之间的无绕切换；能够同时克服脉冲加热对加热炉工况要求高、炉压波动大的问题,以及常规加热模式板坯加热质量差的问题。(The invention discloses a method for controlling the temperature of a heating furnace, which comprises the following steps: partitioning the heating furnace to obtain N furnace temperature control areas; acquiring segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas; judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not; if so, controlling the furnace temperature control area according to a first control mode; if not, controlling the furnace temperature control area according to a second control mode, specifically as follows: judging whether the segmented working condition of the heating furnace meets a second preset condition or not; if so, controlling a furnace temperature control area according to the air gas cascade control logic; if not, controlling the furnace temperature control area according to the flow control logic; the control method realizes the winding-free switching among a plurality of control modes; the problems of high requirement on the working condition of the heating furnace and large fluctuation of furnace pressure in pulse heating and the problem of poor heating quality of the plate blank in a conventional heating mode can be simultaneously solved.)

1. A method for controlling the temperature of a heating furnace is characterized by comprising the following steps:

partitioning the heating furnace to obtain N furnace temperature control areas;

acquiring segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas;

judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not;

if so, controlling the furnace temperature control area according to a first control mode;

if not, controlling the furnace temperature control area according to a second control mode, specifically as follows:

judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

if so, controlling the furnace temperature control area according to the air gas cascade control logic;

if not, controlling the furnace temperature control area according to the flow control logic;

wherein the first control mode includes:

determining the output load of the burner in each furnace temperature control area;

determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the air-gas cascade control logic comprises:

acquiring a set furnace temperature and an actual furnace temperature of the furnace temperature control area;

determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

controlling the furnace temperature control area according to the first gas flow set value and the first air flow set value;

the flow control logic comprises:

acquiring a second gas flow set value and a second air flow set value;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

2. The method of claim 1, wherein the determining the output load of the burners in each furnace temperature control zone comprises:

partitioning the furnace temperature control area to obtain a plurality of furnace temperature sub-control areas;

acquiring the actual furnace temperature of each furnace temperature sub-control area and setting the furnace temperature;

determining the output load amount of the burner in each furnace temperature sub-control area according to a first temperature deviation between the actual furnace temperature and a set furnace temperature;

the determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount specifically comprises the following steps:

and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature sub-control area according to the output load amount.

3. The control method according to claim 2, wherein the first control mode further includes:

judging whether a second temperature deviation between a first furnace temperature sub-control area positioned on one side of the heating furnace and a second furnace temperature sub-control area positioned on the opposite side of the heating furnace is larger than a temperature difference threshold value or not;

if yes, the action control of the gas fast-switching valve of the first furnace temperature sub-control area and the action control of the gas fast-switching valve of the second furnace temperature sub-control area are synchronous; and synchronizing the action control of the air quick-switching valve of the first furnace temperature sub-control area and the action control of the air quick-switching valve of the second furnace temperature sub-control area.

4. The control method of claim 1, wherein the first control mode further comprises:

acquiring the opening state of the air quick-cutting valve;

judging whether the air quick-cutting valve is opened in place or not according to the opening state of the air quick-cutting valve;

and when the air quick-cut valve is opened in place, the gas quick-cut valve corresponding to the air quick-cut valve is opened.

5. The control method of claim 1, wherein the first control mode further comprises:

judging whether the segmented working condition of the heating furnace in the furnace temperature control area meets a third preset condition or not;

if so, determining a third gas flow set value and a third air flow set value of the furnace temperature control area;

and controlling the furnace temperature control area according to the third gas flow set value and the third air flow set value.

6. The control method of claim 1, wherein the air gas cascade control logic further comprises:

acquiring actual air flow corresponding to each burner in the furnace temperature control area;

according to the actual air flow, carrying out amplitude limiting on the first gas flow set value; the range of the amplitude limit value of the first gas flow set value is 0.85 multiplied by the actual value of the air flow to 1.15 multiplied by the actual value of the air flow.

7. The control method of claim 1, wherein the gas flow regulating valve supports manual and automatic opening setting, the flow control logic further comprising:

when the coal gas flow regulating valve is switched from the manual opening degree setting to the automatic opening degree setting, obtaining a maximum coal gas flow corresponding to each burner and an actual coal gas flow corresponding to each burner at the current moment;

and determining the target opening value of the coal gas flow regulating valve corresponding to each burner at the initial moment of automatically setting the opening degree according to the actual value/maximum value of the coal gas flow.

8. The control method according to claim 1, characterized by further comprising:

acquiring a preset data pair of the heat value and the air-fuel ratio of the coal gas;

performing linear interpolation according to the preset data pair to obtain a mapping relation between a coal gas heat value subsection interval and an air-fuel ratio subsection interval comprising the preset data pair;

and controlling the air-fuel ratio of the heating furnace according to the mapping relation between the coal gas heat value subsection interval and the air-fuel ratio subsection interval.

9. A control system for the temperature of a heating furnace, characterized in that the control system comprises:

the partitioning module is used for partitioning the heating furnace to obtain N furnace temperature control areas;

the acquisition module is used for acquiring the segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas;

the first judgment module is used for judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not;

if so, controlling the furnace temperature control area according to a first control mode;

if not, controlling the furnace temperature control area according to a second control mode;

a first control module to execute the first control mode, comprising:

determining the output load of the burner in each furnace temperature control area;

determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the second control module is used for executing the second control mode and comprises a second judgment module, an air gas cascade control submodule and a flow control submodule;

the second judgment module is used for judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

if so, controlling the furnace temperature control area according to the air gas cascade control logic;

if not, controlling the furnace temperature control area according to the flow control logic;

the air gas cascade control submodule is used for executing the air gas cascade control logic and comprises:

acquiring a set furnace temperature and an actual furnace temperature of the furnace temperature control area;

determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

controlling the furnace temperature control area according to the first gas flow set value and the first air flow set value;

the flow control sub-module is configured to execute the flow control logic, and includes:

acquiring a second gas flow set value and a second air flow set value;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

10. A heating furnace comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the control method according to any one of claims 1 to 8 are implemented when the processor executes the program.

Technical Field

The application relates to the technical field of hot-rolled slab heating, in particular to a heating furnace and a control method and a control system for the furnace temperature of the heating furnace.

Background

In the metallurgical industry, a heating furnace is a key device of a hot rolling production line, and the performance of a heated slab directly influences the slab rolling process and the quality of a finished product. Different control strategies are designed for the heating furnace according to the characteristics of the furnace type, and common control strategies comprise conventional control and pulse control. The conventional control controls the furnace temperature by controlling the opening degrees of air and gas flow regulating valves, and the conventional control mode has the problems of poor heating quality of the plate blank and high oxidation burning loss rate; particularly, when the burner is in low thermal load, the flow regulating valve works in a nonlinear region, and the defects of low temperature control precision, imbalance of air-fuel ratio, poor flame rigidity and the like are caused; the pulse control is to control the opening and closing time sequence of the gas and air fast-switching valves corresponding to the burners to control the furnace temperature through a pulse controller, and the burners are in a full-load state once working, so the flame rigidity can be ensured by the pulse control, but the problem of large furnace pressure fluctuation of the heating furnace exists due to frequent opening and closing of the burner fast-switching valves, and higher requirements are provided for the working conditions of the heating furnace, such as the opening and closing performance of the fast-switching valves corresponding to the burners. For some heating furnaces which are already in service for a period of time, the conditions that the working conditions such as the state of a quick-cutting valve of a burner are not satisfactory are easy to occur locally, so that the pulse control mode cannot be used normally, and the heating mass of the plate blank is influenced.

Disclosure of Invention

The invention provides a heating furnace, a control method and a control system for the furnace temperature of the heating furnace, and aims to solve or partially solve the technical problems that the heating quality of a plate blank is poor when the conventional control is adopted by the conventional heating furnace, and the whole heating furnace has large furnace pressure fluctuation and high requirement on the whole working condition of the heating furnace when pulse control is adopted.

In order to solve the technical problem, the invention provides a method for controlling the temperature of a heating furnace, which comprises the following steps:

partitioning the heating furnace to obtain N furnace temperature control areas;

acquiring segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas;

judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not;

if so, controlling the furnace temperature control area according to a first control mode;

if not, controlling the furnace temperature control area according to a second control mode, specifically as follows:

judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

if so, controlling a furnace temperature control area according to the air gas cascade control logic;

if not, controlling the furnace temperature control area according to the flow control logic;

wherein the first control mode includes:

determining the output load of the burner in each furnace temperature control area;

determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the air-gas cascade control logic comprises:

acquiring a set furnace temperature and an actual furnace temperature of a furnace temperature control area;

determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

controlling a furnace temperature control area according to the first gas flow set value and the first air flow set value;

the flow control logic includes:

acquiring a second gas flow set value and a second air flow set value;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

Optionally, determining the output load of the burner in each furnace temperature control area specifically includes:

partitioning the furnace temperature control area to obtain a plurality of furnace temperature sub-control areas;

acquiring the actual furnace temperature of each furnace temperature sub-control area and setting the furnace temperature;

determining the output load amount of the burner in each furnace temperature sub-control area according to a first temperature deviation between the actual furnace temperature and the set furnace temperature;

according to the output load, determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area, and specifically comprising the following steps:

and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature sub-control area according to the output load amount.

Further, the first control mode further includes:

judging whether a second temperature deviation between a first furnace temperature sub-control area positioned on one side of the heating furnace and a second furnace temperature sub-control area positioned on the opposite side of the heating furnace is larger than a temperature difference threshold value or not;

if so, synchronizing the action control of the gas fast-switching valve of the first furnace temperature sub-control area and the action control of the gas fast-switching valve of the second furnace temperature sub-control area; and the action control of the air fast-switching valve of the first furnace temperature sub-control area and the action control of the air fast-switching valve of the second furnace temperature sub-control area are synchronized.

Optionally, the first control mode further includes:

acquiring the opening state of the air quick-cutting valve;

judging whether the air quick-cutting valve is opened in place or not according to the opening state of the air quick-cutting valve;

and when the air quick-cut valve is opened in place, the gas quick-cut valve corresponding to the air quick-cut valve is opened.

Optionally, the first control mode further includes:

judging whether the segmented working conditions of the heating furnace in the furnace temperature control area meet a third preset condition or not;

if so, determining a third gas flow set value and a third air flow set value of the furnace temperature control area;

and controlling the furnace temperature control area according to the third gas flow set value and the third air flow set value.

Optionally, the air-gas cascade control logic further includes:

acquiring actual air flow corresponding to each burner in a furnace temperature control area;

according to the actual air flow, carrying out amplitude limiting on a first gas flow set value; the range of the limiting value of the first gas flow set value is 0.85 multiplied by the actual value of the air flow to 1.15 multiplied by the actual value of the air flow.

Optionally, the gas flow control valve supports manual setting of the opening degree and automatic setting of the opening degree, and the flow control logic further includes:

when the opening degree of the coal gas flow regulating valve is switched from manual setting to automatic setting, acquiring the maximum coal gas flow corresponding to each burner and the actual coal gas flow corresponding to each burner at the current moment;

and determining the target opening value of the coal gas flow regulating valve corresponding to each burner at the initial moment of automatically setting the opening degree according to the actual value/maximum value of the coal gas flow.

Optionally, the control method further includes:

acquiring a preset data pair of the heat value and the air-fuel ratio of the coal gas;

performing linear interpolation according to preset data pairs to obtain a mapping relation between a coal gas heat value subsection interval and an air-fuel ratio subsection interval comprising the preset data pairs;

and controlling the air-fuel ratio of the heating furnace according to the mapping relation between the coal gas heat value subsection interval and the air-fuel ratio subsection interval.

Based on the same inventive concept of the foregoing technical solution, the present invention also provides a control system for a furnace temperature of a heating furnace, comprising:

the partitioning module is used for partitioning the heating furnace to obtain N furnace temperature control areas;

the acquisition module is used for acquiring segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas;

the first judgment module is used for judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not;

if so, controlling the furnace temperature control area according to a first control mode;

if not, controlling the furnace temperature control area according to a second control mode;

a first control module for executing a first control mode, comprising:

determining the output load of the burner in each furnace temperature control area;

determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the second control module is used for executing a second control mode and comprises a second judgment module, an air gas cascade control submodule and a flow control submodule;

the second judgment module is used for judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

if so, controlling a furnace temperature control area according to the air gas cascade control logic;

if not, controlling the furnace temperature control area according to the flow control logic;

the air gas cascade control submodule is used for executing air gas cascade control logic and comprises:

acquiring a set furnace temperature and an actual furnace temperature of a furnace temperature control area;

determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

controlling a furnace temperature control area according to the first gas flow set value and the first air flow set value;

a flow control submodule, configured to execute flow control logic, comprising:

acquiring a second gas flow set value and a second air flow set value;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

Based on the same inventive concept of the foregoing technical solutions, the present invention further provides a heating furnace, which includes a memory, a processor, and a computer program stored on the memory and capable of running on the processor, and when the processor executes the program, the steps of the control method in the foregoing technical solutions are implemented.

Through one or more technical schemes of the invention, the invention has the following beneficial effects or advantages:

the invention provides a method for controlling the furnace temperature of a heating furnace, which comprises the steps of dividing the heating furnace into a plurality of furnace temperature control areas, sequentially judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition, and if the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets the first preset condition, adopting a first control mode, namely a pulse control mode to control the current furnace temperature control area; if the first preset condition is not met, a second control mode, namely a conventional control mode, is adopted to control the current furnace temperature control area; judging whether the segmented working condition of the heating furnace corresponding to the current furnace temperature control area meets a second preset condition or not in a conventional control mode, if so, adopting an air gas cascade control logic, and if not, adopting a flow control logic; the control method is characterized in that the specific segmented working conditions of different furnace temperature control areas are combined, and the furnace temperature control area is differentially determined to adopt any one of pulse control, air gas cascade control and flow control; for example, when the current state of a burner fast-cutting valve in a certain furnace temperature control area is good, pulse control can be adopted; the working condition of a burner fast-cutting valve in the other furnace temperature control area is poor, and standard process control is executed, and air gas cascade control in conventional control can be adopted; the working condition of a burner quick-cutting valve in the furnace temperature control area is not good enough, and special process control is executed, and the flow control in the conventional control can be adopted; because different heating control modes are implemented on different furnace temperature control areas in a differentiated mode, instead of uniformly implementing pulse control or conventional control heating modes in the whole effective heating length of the heating furnace, the problems of high requirement of pulse heating on the working condition of the heating furnace and large furnace pressure fluctuation and the problems of poor slab heating quality in the conventional heating modes, particularly the problems of low temperature control precision, imbalance of air-fuel ratio and poor flame rigidity in a burner low-load area, can be simultaneously solved.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 shows a flowchart of a method for controlling the furnace temperature of a heating furnace according to an embodiment of the invention;

FIG. 2 shows a layout of a heating furnace apparatus according to an embodiment of the present invention;

FIG. 3 shows a furnace Z5 according to one embodiment of the invention: a detailed layout on the second heating section;

fig. 4 shows a schematic view of a control apparatus for the furnace temperature of a heating furnace according to an embodiment of the present invention;

description of reference numerals:

1. a gas main pipe quick-cut valve; 2. a gas main pipe pressure detector; 3. an air flow regulating valve; 4. a gas flow regulating valve; 5. an air quick-cut valve; 6. a gas quick-cutting valve.

Detailed Description

In order to make the present application more clearly understood by those skilled in the art to which the present application pertains, the following detailed description of the present application is made with reference to the accompanying drawings by way of specific embodiments. Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control. Unless otherwise specifically stated, various apparatuses and the like used in the present invention are either commercially available or can be prepared by existing methods.

At present, the pulse combustion control technology has the advantages of high temperature control precision, good furnace temperature distribution uniformity, small slab burning loss, good heating quality and the like, so the pulse combustion control technology is widely applied to hot rolling heating furnaces. The heating effective furnace length of the modern slab heating furnace is very long, the number of internal burners is large, so that the overall working conditions (burner states, fast switching valve opening and closing performances and the like) of the heating furnace are reduced for some heating furnaces with long service time, local areas do not accord with the requirements of pulse heating any more, frequent maintenance is needed, the normal production of a hot rolling production line can be frequently influenced, and high maintenance cost is caused.

Although the conventional control mode of the heating furnace is not good for the accuracy degree of temperature control and the heating quality of the plate blank as compared with pulse control, researches show that if the working condition of a part of area in the heating furnace does not meet the requirement of pulse control any more or the part of area is in a non-small load state, the conventional control mode can also be adopted, if the part of area is converted into the conventional control mode, other areas still adopt pulse control, so that the plate blank can be well heated, and meanwhile, the problems of poor flame rigidity and low temperature control accuracy of the conventional control mode, high requirement of the pulse control on the whole working condition of the heating furnace and large fluctuation of the whole furnace pressure in the heating furnace are solved.

Based on the above improved idea, in an alternative embodiment, as shown in fig. 1, a method for controlling a furnace temperature of a heating furnace is provided, including:

s1: partitioning the heating furnace to obtain N furnace temperature control areas; n is more than or equal to 8;

s2: acquiring segmented working conditions of the heating furnace corresponding to the N furnace temperature control areas;

s3: judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition or not;

s4: if so, controlling the furnace temperature control area according to a first control mode;

s5: if not, controlling the furnace temperature control area according to a second control mode, specifically as follows:

s51: judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

s52: if so, controlling a furnace temperature control area according to the air gas cascade control logic;

s53: if not, controlling the furnace temperature control area according to the flow control logic;

wherein the first control mode includes:

s41: determining the output load of the burner in each furnace temperature control area;

s42: determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the air-gas cascade control logic comprises:

s521: acquiring a set furnace temperature and an actual furnace temperature of a furnace temperature control area;

s522: determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

s523: controlling a furnace temperature control area according to the first gas flow set value and the first air flow set value;

the flow control logic includes:

s531: acquiring a second gas flow set value and a second air flow set value;

s532: and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

Specifically, the present embodiment provides a composite control mode in which pulse control is combined with conventional control. Firstly, dividing an effective heating section of a heating furnace into temperature control areas; for example, as shown in fig. 2, the heating furnace may be divided into four heating sections: a preheating section, a first heating section, a second heating section and a soaking section; each heating section is divided into two temperature control areas according to the upper part and the lower part, so that 8 temperature control areas can be obtained: the upper part of the soaking section, the lower part of the soaking section, the upper part of the first heating section, the lower part of the first heating section, the upper part of the second heating section, the lower part of the second heating section, the upper part of the soaking section and the lower part of the soaking section. Each temperature control area comprises a plurality of burners, and according to the arrangement direction of the heating furnace in the embodiment, the number of the burner positioned on the north side in each temperature control area is N, and the number of the burner positioned on the south side is S. Air and gas pipelines in front of each burner are respectively provided with an air quick-cutting valve and a gas quick-cutting valve to control whether air or gas enters the furnace for combustion.

In order to implement the conventional control, as shown in fig. 2, a gas main fast-switching valve 1 and a gas main pressure detector 2 are arranged on a gas main of the heating furnace; and each temperature control area is provided with 1 air flow regulating valve and 1 gas flow regulating valve. The furnace therefore comprises 8 air flow regulating valves and 8 gas flow regulating valves in total. The air flow regulating valve is connected with a combustion fan through an air pipeline and supplies air required by combustion; the gas flow regulating valve is connected with the gas main pipeline through a gas pipeline and supplies gas required by combustion. Each furnace temperature control area is provided with a conventional temperature controller and a flow controller, and the flow controller comprises a gas flow controller and an air flow controller; therefore, for the above-described heating furnace, 8 conventional temperature controllers, 8 air flow controllers and 8 gas flow controllers were provided in total. The coal gas flow controller adjusts the actual coal gas flow to a set value of the coal gas flow by controlling the opening degree of the coal gas flow adjusting valve; the air flow controller adjusts the actual air flow rate to a set value of the air flow rate by controlling the opening degree of the air flow rate adjusting valve.

The two plus one upper Z5 region is used as an example for illustration. As shown in fig. 2 to 3, 1 air flow regulating valve 3 and 1 gas flow regulating valve 4 are arranged in the region Z5, 8 burners N1-N4 and S1-S4 are arranged, and 1 air quick-cut valve 5 and 1 gas quick-cut valve 6 are respectively arranged in front of each burner. And the coal gas and the air required by combustion respectively pass through a coal gas main pipe and an air main pipe and enter branch pipelines in front of each burner through a coal gas flow regulating valve 4 and an air flow regulating valve 3 on the upper part of the second feeding section. Air and coal gas respectively enter the burner through an air quick-cutting valve 5 and a coal gas quick-cutting valve 6 of a branch pipeline in front of the burner, and the burner mixes the air and the coal gas into the furnace for combustion.

In order to implement pulse control, a pulse temperature controller and a pulse time sequence controller are correspondingly arranged in each furnace temperature control area; the pulse temperature controller takes the difference value between the actual temperature and the set temperature of the current furnace temperature control area as input, and calculates the output load amount of each burner; and the pulse time sequence controller determines the opening and closing time sequences (including parameters such as start-stop sequence, opening time and the like) of the coal gas quick-cutting valve and the air quick-cutting valve in front of the burner according to the output load quantity and the pulse period.

Starting to describe the control logic, in this embodiment, the control method is to obtain the operating condition information of each furnace temperature control area, and then determine whether the current furnace temperature control area adopts the pulse control mode or the conventional control mode according to the operating condition information:

first, when the current furnace temperature control area meets a first preset condition, a first control mode, namely a pulse control mode, is implemented. Optionally, the first preset condition specifically includes:

judging whether a coal gas quick-cutting valve and an air quick-cutting valve in a furnace temperature control area are normal or not;

or judging whether a gas flow regulating valve or an air flow regulating valve in the furnace temperature control area is in fault;

or judging whether the output load quantity of the burner in the furnace temperature control area is smaller than a preset threshold value.

If the judgment result of any condition is 'yes', pulse control is started for the current furnace temperature control area; that is, if the working conditions of all burners and air and gas quick-switching valves in the current furnace temperature control area meet the pulse control requirement, or the output load of the current burners is small (such as in a soaking area), a pulse control mode should be adopted, so that the heating quality of the plate blank can be improved, the defects that the burners of certain furnace temperature control areas are frequently in low-load operation, and if conventional control is adopted, the temperature control precision is low, the air-fuel ratio is disordered, the flame rigidity is poor and the like are overcome. The preset threshold values need to be respectively specified according to different heating furnaces, and are not specifically limited herein.

The basic logic of pulse control is: acquiring the set furnace temperature and the actual furnace temperature of each furnace temperature control area; determining the output load amount of the burner in each furnace temperature control area according to the difference between the set furnace temperature and the actual furnace temperature; and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load, wherein the opening and closing time sequence comprises the opening time and the opening duration information of each burner.

And if the current furnace temperature control area does not meet the first preset condition, implementing a second control mode, namely a conventional control mode.

Taking fig. 2 as an example, if a certain quick-switching valve on the second heating segment Z5 has a fault, the normal control mode can be selected; the flow regulating valve on the Z5 second heating section has a fault, and a pulse control mode can be selected; the load capacity of the burner at the Z8 soaking heating section is small, the conventional furnace temperature reduction control is difficult, and pulse control can be selected. The intelligent steel burning device can be flexibly switched by combining actual conditions, and can meet the intelligent steel burning requirements under different requirements.

The conventional control mode is further subdivided into air gas cascade control and flow control, so that a second preset condition is introduced to judge whether the current furnace temperature control area enters the air gas cascade control or the flow control. The second preset condition includes: and determining whether the slab heating process executes secondary set parameters or not, whether heating furnace equipment meets normal production conditions or whether subsequent equipment (descaling water, rough rolling and finish rolling) of a hot rolling production line meets the production conditions or not. When the above conditions are met, namely in a normal hot rolling production state, performing air gas cascade control; and under the abnormal production condition or the personalized production condition, if the slab temporarily executes a special heating process or the current working condition of the heating furnace does not meet the production standard, the flow control is executed.

In the air gas cascade control mode, a conventional temperature controller and a flow controller are used, and the basic control logic is as follows: acquiring a set furnace temperature and an actual furnace temperature according to the furnace temperature control area, wherein the set furnace temperature can be selected to read L2 level set furnace temperature or L1 level set furnace temperature; the conventional temperature controller calculates a set value of the gas flow according to a difference value between the actual furnace temperature and the set furnace temperature; the set value of the air flow is adjusted along with the gas flow; the gas flow controller and the air flow controller automatically control the opening values of the gas flow regulating valve and the air flow regulating valve respectively according to the gas flow set value and the air flow set value calculated in real time.

Under cascade control, the air consumption is matched according to the gas consumption, and the complete combustion of the fuel is realized. In order to realize the optimal air-fuel ratio, the air flow controller performs air quantity proportioning according to the actually detected gas flow value so as to realize the real-time optimal air-fuel ratio, and the method specifically comprises the following steps: the air flow set value output by the air flow controller is a detected value of gas flow and an air-fuel ratio and an air excess coefficient. Therefore, the air flow set value is calculated by adopting the actually detected gas flow value instead of the gas flow set value, and the full combustion is more favorably realized.

In the flow control mode, only the flow controller is used, and the flow controller can obtain a flow set value set by a technician from an HMI picture to directly control the opening degree of the air and gas flow regulating valve, so that the individual requirements of production are met.

The flow controller can support manual and automatic switching functions according to two control logics of cascade control and flow control: under the air-gas cascade control mode, the automatic control of air flow and gas flow can be selected, and the opening degree of the air and gas flow regulating valve is automatically controlled; in the flow control mode, the manual control (manually setting the opening degree of the regulating valve) of the gas flow regulating valve and the automatic control of the air regulating valve can be selected, namely, the gas regulating valve is opened to a fixed opening degree through manual setting, and the air flow controller automatically controls the air regulating valve according to the air-fuel ratio; the manual control of the gas flow regulating valve and the manual control of the air flow regulating valve can be selected, and the opening degree of the regulating valve is manually controlled.

For the control logics of the manual control of the gas flow regulating valve and the automatic control of the air regulating valve, the control logics are as follows:

acquiring a second gas flow set value and an air-fuel ratio;

determining a second air flow set value according to the second gas flow set value and the air-fuel ratio;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

Avoid flow controller when carrying out hand automatic switch-over, gas flow produces big fluctuation, influences the slab and adds thermal mass, and gas flow controller designs the hand automatic nothing around the switching function, specifically as follows:

optionally, the gas flow control valve supports manual setting of the opening degree and automatic setting of the opening degree, and the flow control logic further includes:

when the opening degree of the coal gas flow regulating valve is switched from manual setting to automatic setting, acquiring the maximum coal gas flow corresponding to each burner and the actual coal gas flow corresponding to each burner at the current moment;

and determining the target opening value of the coal gas flow regulating valve corresponding to each burner at the initial moment of automatically setting the opening degree according to the actual value/maximum value of the coal gas flow. Through the control logic, the output opening degree of the gas flow controller is continuously changed, and sudden change of the opening degree of the gas flow regulating valve caused by manual automatic switching is prevented. The maximum value of the gas flow is the maximum design gas flow value of the burner.

Optionally, in the control method provided in this embodiment, the working condition of the furnace temperature control area is obtained in real time, and the determination of the first preset condition and the second preset condition using the working condition information may be continuously performed according to a certain preset time interval, so that a standard working condition parameter table corresponding to the first preset condition and the second preset condition is preset in the control system of the heating furnace, and when the preset time interval is reached, according to the updated working condition information, by comparing the actually detected working condition parameter with the standard working condition parameter table, what kind of control logic the current working condition is suitable for is re-determined, thereby implementing wrap-less switching between the three control logics. The predetermined time interval may be 1 to 30 minutes. For example, at 10:00, the switching performance of the Z5 section quick-switching valve is normal, pulse control is applied at the moment, at 10:05, the working condition of the Z5 section is updated, the fact that the quick-switching valve of the N3 burner cannot be opened well is displayed, and the control system of the heating furnace switches the Z5 section from no-winding to conventional control according to the information; meanwhile, other sections also independently judge and select the corresponding control modes according to respective working conditions. Therefore, a dynamic control mechanism for flexibly selecting the control mode according to the actual working conditions of each furnace temperature control area is formed.

The embodiment provides a method for controlling the furnace temperature of a heating furnace, which includes dividing the heating furnace into a plurality of furnace temperature control areas, sequentially judging whether the segmented working conditions of the heating furnace corresponding to each furnace temperature control area meet a first preset condition, and if the segmented working conditions meet the first preset condition, adopting a first control mode, namely a pulse control mode to control the current furnace temperature control area; if the first preset condition is not met, a second control mode, namely a conventional control mode, is adopted to control the current furnace temperature control area; judging whether the segmented working condition of the heating furnace corresponding to the current furnace temperature control area meets a second preset condition or not in a conventional control mode, if so, adopting an air gas cascade control logic, and if not, adopting a flow control logic; the control method is characterized in that specific segmented working conditions of different furnace temperature control areas are combined, the furnace temperature control area is differentially determined to adopt any one of pulse control, air gas cascade control and flow control, and the non-winding switching can be carried out according to the dynamic state of the segmented working conditions of the heating furnace; for example, when the current state of a burner fast-cutting valve in a certain furnace temperature control area is good, pulse control can be adopted; the working condition of a burner fast-cutting valve in the other furnace temperature control area is poor, and standard process control is executed, and air gas cascade control in conventional control can be adopted; the working condition of a burner quick-cutting valve in the furnace temperature control area is not good enough, and special process control is executed, and the flow control in the conventional control can be adopted; because different heating control modes are implemented on different furnace temperature control areas in a differentiated mode, instead of uniformly implementing pulse control or conventional control heating modes in the whole effective heating length of the heating furnace, the problems of high requirement of pulse heating on the working condition of the heating furnace and large furnace pressure fluctuation and the problems of poor slab heating quality in the conventional heating modes, particularly the problems of low temperature control precision, imbalance of air-fuel ratio and poor flame rigidity in a burner low-load area, can be simultaneously solved.

In order to further improve the temperature control accuracy of the control method in the foregoing embodiment, based on the same inventive concept in the foregoing embodiment, in yet another optional embodiment, the function of the control method is further expanded, which is specifically as follows:

for the pulse control mode, optionally, a heating segment virtual partition control function is added to the pulse timing controller, specifically as follows:

determining the output load of the burner in each furnace temperature control area, which specifically comprises the following steps:

partitioning the furnace temperature control area to obtain a plurality of furnace temperature sub-control areas;

acquiring the actual furnace temperature of each furnace temperature sub-control area and setting the furnace temperature;

determining the output load amount of the burner in each furnace temperature sub-control area according to a first temperature deviation between the actual furnace temperature and the set furnace temperature;

according to the output load, determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area, and specifically comprising the following steps:

and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature sub-control area according to the output load amount.

The virtual subarea is used for further subarea division of the furnace temperature control area, one furnace temperature control area in the conventional control is divided into a plurality of furnace temperature control subareas, after the subareas are divided, a pulse controller is arranged in each furnace temperature control subarea, and each furnace temperature control subarea is respectively provided with a furnace temperature set value. As shown in fig. 2, taking the second heating stage Z5 as an example, 8 burners are divided into 4 furnace temperature control zones, and each two burners are one furnace temperature control sub-zone, and the target values of the furnace temperatures are set. Therefore, the original furnace temperature control area is further virtually subdivided into four furnace temperature control subareas, so that the furnace temperature control in the pulse control mode is more accurate and flexible.

Optionally, a function of compensating for furnace temperature deviation is added to the pulse timing controller, specifically as follows:

judging whether a second temperature deviation between a first furnace temperature sub-control area positioned on one side of the heating furnace and a second furnace temperature sub-control area positioned on the opposite side of the heating furnace is larger than a temperature difference threshold value or not;

if so, synchronizing the action control of the gas fast-switching valve of the first furnace temperature sub-control area and the action control of the gas fast-switching valve of the second furnace temperature sub-control area; and the action control of the air fast-switching valve of the first furnace temperature sub-control area and the action control of the air fast-switching valve of the second furnace temperature sub-control area are synchronized.

Taking a heating furnace in a north-south layout as an example, when a second temperature deviation between two furnace temperature sub-control areas positioned on opposite sides of the south and the north is detected to be larger than a temperature difference threshold (the optional range of the temperature difference threshold is 30-60 ℃, and is preferably 40 ℃), the actual furnace temperature deviation on the north and the south is considered to be large at the moment, furnace temperature deviation compensation is triggered, furnace temperature control areas corresponding to the two furnace temperature control sub-areas of the north and the south trigger the same pulse time schedule controller to control, so that the quick cutting valves of the burners on the north and the south are correspondingly opened, and the quality problem that the temperature difference between the head and the tail of a plate blank. Specifically, taking the second heating section Z5 as an example, when the temperature deviation of two sub-areas of [ N1, N2] and [ S1, S2] is detected to exceed 40 ℃, the furnace temperature deviation compensation is triggered, so that the air quick-cutting valves of the burners N1-N2 are triggered to act, and the air quick-cutting valves of the burners S1-S2 are triggered to act simultaneously; similarly, when the gas fast-switching valves of the burners N1-N2 act, the gas fast-switching valves of the burners S1-S2 are triggered to act at the same time. The burner nozzles on the north and south sides can burn simultaneously, and the deviation of the furnace temperatures on the north and south sides is reduced.

Optionally, a burner safety protection function is added to the pulse timing controller, specifically as follows:

acquiring the opening state of the air quick-cutting valve;

judging whether the air quick-cutting valve is opened in place or not according to the opening state of the air quick-cutting valve;

and when the air quick-cut valve is opened in place, the gas quick-cut valve corresponding to the air quick-cut valve is opened.

The difference between the safety protection function of the burner and the prior art is as follows: in the prior art, the gas quick-cutting valve is usually opened after an opening command is given to the air quick-cutting valve for a certain period of time (e.g. 3 seconds, 5 seconds). However, practice shows that if the state of the air quick-cutting valve is not good, after an opening instruction is issued, the air quick-cutting valve is not opened or is not opened in place, so that after the gas quick-cutting valve is opened again, the temperature of the burner is too high, the phenomenon that the burner burns red appears, and serious damage is caused to equipment. Therefore, in the embodiment, the opening logic of the gas quick-cutting valve is modified into the interlocking protection of the opening command of the gas quick-cutting valve after the signal that the air quick-cutting valve is opened in place is judged or received, so that the safety of equipment is protected.

Optionally, the pulse control adds a flow control function, which is specifically as follows:

judging whether the segmented working conditions of the heating furnace in the furnace temperature control area meet a third preset condition or not;

if so, determining a third gas flow set value and a third air flow set value of the furnace temperature control area;

and controlling the furnace temperature control area according to the third gas flow set value and the third air flow set value.

When the flow control is realized in the pulse control mode, the conventional control and the pulse control share the same flow controller to control the air flow and the coal gas flow, but the set values of the air flow and the coal gas flow in the two modes are different. By adding a pulse flow calculating module in the pulse temperature controller, when the flow control function is started in pulse control, the flow set values of the air and gas flow regulating valves are calculated and output to the air flow controller and the gas flow controller for air and gas flow control. Specifically, the pulse flow calculation module can control the flow through the load quantity required by the combustion burner; the opening degree of the coal gas during switching can be kept during switching pulse control through conventional control, and the air flow is controlled through air-fuel ratio proportioning; the opening degree of the gas regulating valve can be manually fixed according to actual requirements.

The third preset condition is that the flow control in the pulse control mode is activated according to the actual situation of the site, so that the pulse control mode can also support the flow control, and various burst requirements of the site can be more flexibly adapted.

Optionally, manual control switching is added in the pulse control, specifically as follows:

the pulse control also includes a quick-cut valve manual control and a temperature manual control. When the manual control of the quick-cutting valve is selected, the burner quick-cutting valve selected for manual control does not participate in the time sequence calculation of the pulse time sequence control period (such as the period of 40 s), and other automatic-control quick-cutting valves perform time sequence calculation; when the manual control of the temperature is selected, the pulse time sequence controller selects the load quantity input by a technician on an HMI picture of the control system to carry out the time sequence control of the quick-switching valve, and the specific steps are as follows:

acquiring the output load of the burner in each furnace temperature control area from a primary control system; and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount.

For a conventional control mode, in order to better perform air-fuel ratio adjustment, a gas setting flow limiting function is added, specifically as follows:

the air-gas cascade control logic further comprises:

acquiring actual air flow corresponding to each burner in a furnace temperature control area;

according to the actual air flow, carrying out amplitude limiting on a first gas flow set value; the range of the limiting value of the first gas flow set value is 0.85 multiplied by the actual value of the air flow to 1.15 multiplied by the actual value of the air flow.

Therefore, the purpose of limiting the set value of the gas flow according to the actual air flow is to avoid that under some special conditions, if the heating temperature of the plate blank needs to be raised suddenly, a conventional temperature controller can calculate a target gas amount with larger amplitude, so that the set value of the gas flow is suddenly increased or reduced, the instantaneous misadjustment of the ratio of the set value of the gas flow and the actual air amount is caused, and the phenomenon of furnace temperature overshoot caused by the severe fluctuation of the gas amount is reduced. Through the amplitude limiting function, the coal gas flow set value is slowly increased to the target coal gas flow along with the actual air flow value, so that the instantaneous misadjustment of the coal gas flow and the actual air flow ratio is avoided.

Whether pulse control or conventional control, it is important to control the air-fuel ratio to achieve optimal combustion. In the conventional control, the air-fuel ratio is roughly estimated as a gas calorific value/2000. In the present application, however, for more precise control of the air-fuel ratio, an interpolation control method of the air-fuel ratio is as follows:

acquiring a preset data pair of the heat value and the air-fuel ratio of the coal gas;

performing linear interpolation according to preset data pairs to obtain a mapping relation between a coal gas heat value subsection interval and an air-fuel ratio subsection interval comprising the preset data pairs;

and controlling the air-fuel ratio of the heating furnace according to the mapping relation between the coal gas heat value subsection interval and the air-fuel ratio subsection interval.

In the scheme, the air-fuel ratio is calculated by adopting segmented interpolation, so that the air-fuel ratio is accurately controlled. The heat value of the coal gas is divided into different intervals, corresponding to the air-fuel ratio intervals, the air-fuel ratios under different heat values can realize interpolation calculation, and the specific interval division can be designed according to actual requirements.

For example, let the calorific value of the gas be Q, in KJ/m³The air-fuel ratio is K; through experiments and field authentication, a set of preferable preset data pairs (Q, K) of the gas heat value and the air-fuel ratio is obtained as follows: (6270,1.5),(7524,1.74),(8360,1.97),(10450,2.53),(12540,3.1),(20000,5.13),

according to the preset data pair, calculating the air-fuel ratio under any heat value in the interval by adopting linear interpolation y ═ kx + b, and finally obtaining the mapping relation between the coal gas heat value subsection interval and the air-fuel ratio subsection interval, wherein the specific steps are as follows:

q is more than or equal to 0 and less than 6270.0, and the air-fuel ratio K is 1.5;

q is more than or equal to 6270.0 and less than 7524.0, and K is more than or equal to 1.5 and less than 1.74.

Q is more than or equal to 7524.0 and less than 8360.0, and K is more than or equal to 1.74 and less than 1.97;

q is more than or equal to 8360.0 and less than 10450, and K is more than or equal to 1.97 and less than 2.53;

q is more than or equal to 10450 and less than 12540, and K is more than or equal to 2.53 and less than 3.1;

q is more than or equal to 12540 and less than 20000, and K is more than or equal to 3.1 and less than 5.13.

Practice shows that the air-fuel ratio-gas heat value segmented mapping relation obtained by applying the segmented interpolation in the heating furnace can be closer to the actual field production, the optimal air-fuel ratio is realized, and the combustion efficiency of the heating furnace and the slab heating quality are improved.

Optionally, a different number of thermocouples can be installed in each heating section, that is, each furnace temperature control area includes a plurality of thermocouples, so that the thermocouples can be manually selected according to actual requirements, and the functions of automatically replacing the thermocouples with other thermocouples after the thermocouples fail are designed. Optionally, a south thermocouple, a north thermocouple, and a thermocouple average. A thermocouple fault judgment module is added, so that automatic switching is performed when the thermocouple at the north side and the south side fails, large furnace temperature control fluctuation is avoided, and the calculated temperature of the slab is abnormal.

Based on the same inventive concept of the foregoing embodiment, in yet another alternative embodiment, as shown in fig. 4, there is provided a control device for a furnace temperature of a heating furnace, including:

the partitioning module 10 is used for partitioning the heating furnace to obtain N furnace temperature control areas;

the acquisition module 20 is configured to acquire heating furnace segment conditions corresponding to the N furnace temperature control areas;

the first judging module 30 is used for judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition;

if so, controlling the furnace temperature control area according to a first control mode;

if not, controlling the furnace temperature control area according to a second control mode;

a first control module 40 for executing a first control mode, comprising:

determining the output load of the burner in each furnace temperature control area;

determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area according to the output load amount;

the second control module 50 is used for executing a second control mode and comprises a second judgment module, an air gas cascade control submodule and a flow control submodule;

the second judging module 51 is used for judging whether the segmented working condition of the heating furnace meets a second preset condition or not;

if so, controlling a furnace temperature control area according to the air gas cascade control logic;

if not, controlling the furnace temperature control area according to the flow control logic;

an air gas cascade control submodule 52 configured to execute an air gas cascade control logic, including:

acquiring a set furnace temperature and an actual furnace temperature of a furnace temperature control area;

determining a first gas flow set value and a first air flow set value according to the set furnace temperature and the actual furnace temperature;

controlling a furnace temperature control area according to the first gas flow set value and the first air flow set value;

a flow control submodule 53, configured to execute flow control logic, includes:

acquiring a second gas flow set value and a second air flow set value;

and controlling the furnace temperature control area according to the second gas flow set value and the second air flow set value.

Optionally, the first control module 40 is specifically configured to:

partitioning the furnace temperature control area to obtain a plurality of furnace temperature sub-control areas;

acquiring the actual furnace temperature of each furnace temperature sub-control area and setting the furnace temperature;

determining the output load amount of the burner in each furnace temperature sub-control area according to a first temperature deviation between the actual furnace temperature and the set furnace temperature;

according to the output load, determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature control area, and specifically comprising the following steps:

and determining the opening and closing time sequence of the gas quick-switching valve and the air quick-switching valve in each furnace temperature sub-control area according to the output load amount.

Further, the first control module 40 is further configured to:

judging whether a second temperature deviation between a first furnace temperature sub-control area positioned on one side of the heating furnace and a second furnace temperature sub-control area positioned on the opposite side of the heating furnace is larger than a temperature difference threshold value or not;

if so, synchronizing the action control of the gas fast-switching valve of the first furnace temperature sub-control area and the action control of the gas fast-switching valve of the second furnace temperature sub-control area; and the action control of the air fast-switching valve of the first furnace temperature sub-control area and the action control of the air fast-switching valve of the second furnace temperature sub-control area are synchronized.

Optionally, the first control module 40 is further configured to:

acquiring the opening state of the air quick-cutting valve;

judging whether the air quick-cutting valve is opened in place or not according to the opening state of the air quick-cutting valve;

and when the air quick-cut valve is opened in place, the gas quick-cut valve corresponding to the air quick-cut valve is opened.

Optionally, the first control module 40 is further configured to:

judging whether the segmented working conditions of the heating furnace in the furnace temperature control area meet a third preset condition or not;

if so, determining a third gas flow set value and a third air flow set value of the furnace temperature control area;

and controlling the furnace temperature control area according to the third gas flow set value and the third air flow set value.

Optionally, the air-gas cascade control submodule 52 is further configured to:

acquiring actual air flow corresponding to each burner in a furnace temperature control area;

according to the actual air flow, carrying out amplitude limiting on a first gas flow set value; the range of the limiting value of the first gas flow set value is 0.85 multiplied by the actual value of the air flow to 1.15 multiplied by the actual value of the air flow.

Optionally, the gas flow regulating valve includes an opening degree manual setting and an opening degree automatic setting, and the second control module 50 is further configured to:

when the opening degree of the coal gas flow regulating valve is switched from manual setting to automatic setting, acquiring the maximum coal gas flow corresponding to each burner and the actual coal gas flow corresponding to each burner at the current moment;

and determining the target opening value of the coal gas flow regulating valve corresponding to each burner at the initial moment of automatically setting the opening degree according to the actual value/maximum value of the coal gas flow.

Optionally, the first control module 40 and the second control module 50 are further configured to:

acquiring a preset corresponding relation between the heat value of the coal gas and the air-fuel ratio;

performing linear interpolation on the preset corresponding relation to obtain a mapping relation between a coal gas heat value subsection interval and an air-fuel ratio subsection interval;

and controlling the air-fuel ratio of the heating furnace according to the mapping relation between the coal gas heat value subsection interval and the air-fuel ratio subsection interval.

Based on the same inventive concept of the foregoing embodiments, in yet another alternative embodiment, there is provided a heating furnace, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the control method in the foregoing embodiments when executing the program.

Through one or more embodiments of the present invention, the present invention has the following advantageous effects or advantages:

the invention provides a method for controlling the furnace temperature of a heating furnace, which comprises the steps of dividing the heating furnace into a plurality of furnace temperature control areas, sequentially judging whether the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets a first preset condition, and if the segmented working condition of the heating furnace corresponding to each furnace temperature control area meets the first preset condition, adopting a first control mode, namely a pulse control mode to control the current furnace temperature control area; if the first preset condition is not met, a second control mode, namely a conventional control mode, is adopted to control the current furnace temperature control area; judging whether the segmented working condition of the heating furnace corresponding to the current furnace temperature control area meets a second preset condition or not in a conventional control mode, if so, adopting an air gas cascade control logic, and if not, adopting a flow control logic; the control method is characterized in that specific segmented working conditions of different furnace temperature control areas are combined, the furnace temperature control area is differentially determined to adopt any one of pulse control, air gas cascade control and flow control, and the non-winding switching can be carried out according to the dynamic state of the segmented working conditions of the heating furnace; for example, when the current state of a burner fast-cutting valve in a certain furnace temperature control area is good, pulse control can be adopted; the working condition of a burner fast-cutting valve in the other furnace temperature control area is poor, and standard process control is executed, and air gas cascade control in conventional control can be adopted; the working condition of a burner quick-cutting valve in the furnace temperature control area is not good enough, and special process control is executed, and the flow control in the conventional control can be adopted; because different heating control modes are implemented on different furnace temperature control areas in a differentiated mode, instead of uniformly implementing pulse control or conventional control heating modes in the whole effective heating length of the heating furnace, the problems of high requirement of pulse heating on the working condition of the heating furnace and large furnace pressure fluctuation and the problems of poor slab heating quality in the conventional heating modes, particularly the problems of low temperature control precision, imbalance of air-fuel ratio and poor flame rigidity in a burner low-load area, can be simultaneously solved.

Furthermore, on the basis of the control method, a series of control logics such as gas flow amplitude limiting, air-fuel ratio segmented interpolation calculation, heating furnace temperature deviation compensation, further virtual partitioning, burner safety protection and the like are added, so that the pulse control logic and the conventional control logic are further optimized, the advantages of the conventional control and the pulse control are fully exerted, each furnace temperature control area is flexibly controlled, and intelligent steel burning under different process requirements and equipment states is realized.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.