Regenerative heating furnace regenerative exhaust control method

Abstract

The application discloses a heat accumulating exhaust control method for a heat accumulating heating furnace. The heat accumulating exhaust control method comprises the following steps: for each furnace section of the heat accumulating heating furnace, a PID controller is arranged, and a heat accumulating exhaust target data is preset; a data difference between actual heat accumulating exhaust data of the furnace section and the preset heat accumulating exhaust target data is taken as an input parameter and input into the PID controller; the PID controller calculates an opening value of a heat accumulating exhaust adjusting valve according to the input data difference; the opening of the heat accumulating exhaust adjusting valve is controlled according to the opening value, so as to adjust the heat accumulating exhaust flow of the furnace section; the actual heat accumulating exhaust data is actual heat accumulating exhaust temperature, and the heat accumulating exhaust target data is heat accumulating exhaust target temperature. The heat accumulating exhaust control method dynamically adjusts the heat accumulating exhaust flow of the furnace section according to the heat accumulating exhaust data by using the PID controller, so that a desired good heat accumulating exhaust effect is realized.

Description

Technical Field

[0001] This invention relates to a regenerative heating furnace technology, and more particularly to a method for controlling the regenerative exhaust gas of a regenerative heating furnace. Background Technology

[0002] A heating furnace is a commonly used piece of equipment in the metallurgical industry, used to heat metal materials or workpieces to the temperatures required for subsequent processes. Specifically, a heating furnace typically consists of multiple interconnected furnace sections. Each section is equipped with a main gas pipeline, a main air pipeline, and a conventional exhaust gas pipeline. The regulating valve on the main gas pipeline is called the gas regulating valve for that section, and the regulating valve on the main air pipeline is called the air regulating valve. The conventional exhaust gas pipeline is directly connected to the furnace chamber. A certain number of burners are installed within the furnace chamber of each section. The air pipelines of the burners are connected to the main air pipeline of the section, and the gas pipelines of the burners are connected to the main gas pipeline of the section. The gas and air mix and burn in the burners, thus heating the metal materials or workpieces within the furnace chamber.

[0003] With the increasing demands for energy conservation in industrial production, regenerative thermal radiators have been widely adopted. Like conventional radiators, regenerative thermal radiators consist of multiple interconnected furnace sections. However, unlike conventional radiators, each furnace section is equipped with a main regenerative exhaust pipe. The regulating valve on this main exhaust pipe is called the regenerative exhaust regulating valve for that section. Furthermore, the burners within each section are arranged in pairs, forming a regenerative burner assembly. The two burners in each assembly alternately burn to heat the furnace chamber. A heat storage box is also installed in the air pipe of each burner, containing high-temperature resistant heat storage balls that absorb and store the heat from the passing high-temperature gas.

[0004] See Figure 1 Taking a set of regenerative burner assembly 10 in the furnace section as an example, the regenerative burner assembly 10 includes two burners 11. Each burner 11 is equipped with a gas valve 12, an air valve 13, a flue gas valve 14, and a heat storage box 15. The air pipeline of the burner 11 is connected to the main air pipeline 22 and the main regenerative flue gas pipeline 23 of the furnace section through the air valve 13 and the flue gas valve 14, respectively. The gas pipeline of the burner 11 is connected to the main gas pipeline 21 of the furnace section through the gas valve 12. The heat storage box 15 is installed in the air pipeline of the burner 11. An induced draft fan (not shown in the figure) is also installed in the main regenerative flue gas pipeline 23. The function of the induced draft fan is to force the air to be drawn into the main regenerative flue gas pipeline 23, so that the high-temperature flue gas in the furnace section passes through the heat storage box 15 and is discharged into the main regenerative flue gas pipeline 23 through the flue gas valve 14.

[0005] Under normal circumstances, one burner 11 in the regenerative burner assembly 10 is in combustion mode, while the other burner 11 is in regenerative mode. Figure 1 Taking the regenerative burner assembly 10 shown as an example, when the left burner 11 is in combustion mode and the right burner 11 is in regenerative mode ( Figure 1 (This is the state shown in the image). The gas valve 12 and air valve 13 of the left burner 11 are open, and the flue gas valve 14 of the left burner 11 is closed. The gas valve 12 and air valve 13 of the right burner 11 are closed, and the flue gas valve 14 of the right burner 11 is open. At this time, the gas and air entering through the gas valve 12 and air valve 13 of the left burner 11 are mixed in the left burner 11 and then sprayed out for combustion. During this process, the air is heated as it passes through the heat storage box 15 of the left burner 11. The small ball is heated, and the heat storage box 15 of the left burner 11 is in a heat release state. The high-temperature flue gas generated by the combustion of the left burner 11 reaches the heat storage exhaust main pipe 23 after passing through the heat storage box 15 of the right burner 11 and the flue gas valve 14. The flue gas in the heat storage exhaust main pipe 23 is then discharged through the heat storage exhaust regulating valve (not shown in the figure). During this process, the high-temperature flue gas heats the heat storage ball when passing through the heat storage box 15 of the right burner 11, and the heat storage box 15 of the right burner 11 is in a heat storage state. After a set period of time, the left burner 11 switches to heat storage mode, while the right burner 11 switches to combustion mode. In this state, the gas valve 12 and air valve 13 of the left burner 11 are closed, and the flue gas valve 14 of the left burner 11 is open. Conversely, the gas valve 12 and air valve 13 of the right burner 11 are open, and the flue gas valve 14 of the right burner 11 is closed. At this time, the gas and air entering through the gas valve 12 and air valve 13 of the right burner 11 mix and are then ejected for combustion. During this process, the air... When the gas passes through the heat storage box 15 of the right burner 11, it is heated by the heat storage ball, and the heat storage box 15 of the right burner 11 is in a heat release state. The high-temperature flue gas generated by the combustion of the right burner 11 passes through the heat storage box 15 of the left burner 11 and the flue gas valve 14 to reach the heat storage exhaust main pipe 23. The flue gas in the heat storage exhaust main pipe 23 is then discharged through the heat storage exhaust regulating valve (not shown in the figure). During this process, the high-temperature flue gas heats the heat storage ball when passing through the heat storage box 15 of the left burner 11, and the heat storage box 15 of the left burner 11 is in a heat storage state. Under normal circumstances, the above process is repeated cyclically, and the left burner 11 and the right burner 11 alternately burn and store heat.

[0006] Controlling the thermal regenerative flue gas extraction rate is achieved by adjusting the thermal regenerative flue gas flow rate through the regulating valves in the furnace section. Currently, the control of these regulating valves is done manually, setting their opening degree. This manual method, rather than dynamically adjusting the valves based on the actual operating conditions of the furnace section, results in poor overall thermal regenerative flue gas extraction efficiency. For example, when the thermal regenerative tank overheats, the regulating valve will not be adjusted downwards; conversely, when the thermal regenerative flue gas extraction rate is low, the regulating valve will not be adjusted upwards.

[0007] It should be noted that the overheating phenomenon of the heat storage tank refers to the situation where the temperature of the heat storage tank exceeds the designed standard operating temperature range during heat storage. Generally speaking, when the temperature of the heat storage tank exceeds 230℃, it is considered that the heat storage tank is overheating.

[0008] It's important to understand that the flue gas generated during combustion within the furnace section of a regenerative thermal radiator is not entirely discharged through the regenerative exhaust manifold. When the flue gas in the furnace section cannot be discharged through the regenerative exhaust manifold, it is discharged through the conventional exhaust manifold. Flue gas discharged through the regenerative exhaust manifold is called regenerative exhaust, and flue gas discharged through the conventional exhaust manifold is called conventional exhaust. The ratio of the regenerative exhaust flow rate to the total exhaust flow rate is called the regenerative exhaust gas extraction rate, where the total exhaust flow rate is the sum of the conventional exhaust flow rate and the regenerative exhaust flow rate. Summary of the Invention

[0009] The purpose of this invention is to provide a method for controlling the heat storage exhaust gas of a regenerative heating furnace. This method uses a PID controller to dynamically adjust the heat storage exhaust gas flow rate of the furnace section based on the heat storage exhaust gas data, so as to achieve the desired good heat storage exhaust gas effect.

[0010] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0011] A method for controlling the regenerative flue gas of a regenerative heater includes the following steps:

[0012] Step 1: For each section of the regenerative heating furnace, set up a PID controller and pre-set the target data for regenerative flue gas exhaust.

[0013] Step 2: Input the data difference between the actual data of the heat storage and flue gas in the furnace section and the preset target data of heat storage and flue gas into the PID controller as an input parameter;

[0014] Step 3: The PID controller calculates the opening value of the thermal storage and flue gas regulating valve based on the difference in the input data.

[0015] Step 4: The PID controller uses the opening value to control and adjust the opening of the heat storage flue gas regulating valve to adjust the heat storage flue gas flow rate of the furnace section.

[0016] Furthermore, the actual data for heat storage and smoke exhaust uses the actual temperature of heat storage and smoke exhaust, and the target data for heat storage and smoke exhaust uses the target temperature of heat storage and smoke exhaust.

[0017] Furthermore, the target temperature for the heat storage and flue gas exhaust is in the range of 220–230°C.

[0018] Furthermore, the actual data for heat storage and smoke exhaust uses the actual flow rate of heat storage and smoke exhaust, and the target data for heat storage and smoke exhaust uses the target flow rate of heat storage and smoke exhaust.

[0019] Furthermore, the target flow rate of the heat storage flue gas is set as: furnace section gas flow rate × theoretical smoke-fuel ratio × target flue gas extraction rate × burner condition correction coefficient, wherein the furnace section gas flow rate is the gas flow rate in the total gas pipeline of the furnace section, the theoretical smoke-fuel ratio is the theoretical value of the ratio of the amount of flue gas generated by the burner combustion to the amount of gas consumed, and the burner condition correction coefficient = number of flue gas burners / number of combustion burners.

[0020] Furthermore, the target flue gas extraction rate is dynamically determined using a flue gas temperature following method, which includes:

[0021] i) Set a flue gas temperature fluctuation range and set the range of the target flue gas extraction rate;

[0022] ii) When the heat storage flue gas temperature is lower than the lower limit of the flue gas temperature fluctuation range, the target flue gas extraction rate starts to rise at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the upper limit value of the range, at which point the target flue gas extraction rate stops rising and remains constant.

[0023] iii) When the heat storage flue gas temperature is higher than the upper limit of the flue gas temperature fluctuation range, the target flue gas extraction rate will start to decrease at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the lower limit of the range, at which point the target flue gas extraction rate will stop decreasing and remain constant.

[0024] Furthermore, in the flue gas temperature following method, the flue gas temperature fluctuation range is set to 210℃~230℃, and the target flue gas extraction rate is set to a range of 0.65~0.8.

[0025] Furthermore, step 4 also includes: when adjusting the thermal regenerative flue gas regulating valve, setting an upper limit and a lower limit for the opening of the thermal regenerative flue gas regulating valve; the upper limit is: 40% + furnace section air volume percentage × λ, and the lower limit is: furnace section air volume percentage / 2.5, wherein the furnace section air volume percentage is the percentage of the actual air flow in the furnace section's total air pipeline relative to the designed maximum flow, and λ is a correction coefficient.

[0026] Furthermore, step 4 also includes: when the temperature of the heat storage flue gas exceeds the limit, initiating a flue gas over-temperature regulation process;

[0027] The smoke exhaust overheating regulation process includes:

[0028] a) Stop using the opening value calculated by the PID controller to control and adjust the thermal storage and flue gas regulating valve;

[0029] b) Gradually reduce the opening of the heat storage flue gas regulating valve until the heat storage flue gas temperature does not exceed the limit.

[0030] c) Restore the opening value calculated by the PID controller to control and adjust the heat storage and flue gas regulating valve.

[0031] Furthermore, during the process of regulating the exhaust temperature, as the opening of the heat storage exhaust regulating valve is gradually reduced, the opening of the heat storage exhaust regulating valve is adjusted at a rate of 0.06% per second.

[0032] The thermal storage and smoke exhaust control method of the present invention has the following advantages over the prior art:

[0033] 1) In the heat storage and flue gas control method of the present invention, a PID controller is used to dynamically adjust the heat storage and flue gas flow rate of the furnace section according to the heat storage and flue gas data, which can meet the operating process requirements of the furnace section to the greatest extent and achieve the desired good heat storage and flue gas effect.

[0034] 2) When using a PID controller to regulate the thermal storage flue gas regulating valve, there are upper and lower limits set for the opening of the thermal storage flue gas regulating valve. This can prevent the PID controller from adjusting the opening of the thermal storage flue gas regulating valve too much, thereby preventing the instantaneous overheating of the heat storage box of the burner in the furnace section.

[0035] 3) When the temperature of the heat storage flue gas exceeds the limit, the flue gas overheat regulation process is activated, which can quickly reduce the temperature of the heat storage flue gas and prevent excessive heat storage flue gas from damaging the main heat storage flue gas pipeline. At the same time, it can also prevent the heat storage box of the burner from overheating. Attached Figure Description

[0036] Figure 1 A schematic diagram of the structure of a regenerative burner assembly in the prior art;

[0037] Figure 2 This is a schematic diagram of a furnace section of the regenerative heating furnace involved in the regenerative flue gas control method of the regenerative heating furnace of the present invention. The diagram is a top view.

[0038] Figure 3 This is a flowchart of the heat storage and smoke exhaust control method of the present invention.

[0039] In the diagram: 10-Regenerative burner assembly, 11-Burner, 12-Gas valve, 13-Air valve, 14-Flue gas valve, 15-Regenerative box, 20-Furnace section, 21-Main gas pipeline, 22-Main air pipeline, 23-Regenerative flue gas exhaust pipeline. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0041] The background of this embodiment is the heating furnace operation area of ​​a hot rolling plant of a steel company. In this operation area, a regenerative heating furnace is used to heat the slab before hot rolling in order to meet the temperature requirements of the hot rolling process.

[0042] The regenerative heating furnace is composed of multiple furnace sections connected in series, see [link to relevant documentation]. Figure 2 , Figure 2 The diagram shows a furnace section 20 of the regenerative heating furnace. Within this furnace section 20, five sets of regenerative burner assemblies 10 are sequentially arranged from the inlet to the outlet. Two burners 11 in each regenerative burner assembly 10 are located on opposite sides of the furnace section 20. Under normal conditions, one burner 11 in each regenerative burner assembly 10 is in combustion mode, while the other burner 11 is in regenerative mode. The two burners 11 in each regenerative burner assembly 10 alternately burn to heat the furnace chamber of the furnace section 20. A regenerative flue gas regulating valve is installed on the main regenerative flue gas pipe of the furnace section 20.

[0043] See Figure 3 This embodiment provides a method for controlling the regenerative exhaust gas of a regenerative heater, including the following steps:

[0044] Step 1: For each section of the regenerative heating furnace, set up a PID controller and pre-set the target data for regenerative flue gas exhaust.

[0045] Step 2: Input the difference between the actual data of the heat storage and flue gas in the furnace section and the preset target data of heat storage and flue gas into the PID controller as an input parameter.

[0046] Step 3: The PID controller calculates the opening value of the thermal storage and flue gas regulating valve based on the difference in the input data.

[0047] Step 4: The PID controller uses the opening value to control and adjust the opening of the heat storage flue gas regulating valve to adjust the heat storage flue gas flow rate of the furnace section.

[0048] It's important to understand that a PID controller (Proportional-Integral-Derivative) is a prior art device composed of a proportional unit (P), an integral unit (I), and a derivative unit (D). A PID controller is a common feedback loop component in industrial control applications. This controller compares collected data with a reference value and uses the difference to calculate a new input value. The purpose of this new input value is to ensure that the system data reaches or remains at the reference value. In this embodiment, the PID controller can adjust the thermal storage and flue gas regulating valve using the deviation between actual data and target data as an input parameter.

[0049] The actual data for heat storage and flue gas exhaust can be the actual temperature of the heat storage and flue gas exhaust, while the target data for heat storage and flue gas exhaust is the target temperature of the heat storage and flue gas exhaust. When using the target temperature of the heat storage and flue gas exhaust as the target data for heat storage and flue gas exhaust, the target temperature is usually taken between 220 and 230℃. The specific value must take into account the physical properties of the heat storage balls in the heat storage box, as well as the temperature resistance of each flue gas valve. It is necessary to maximize the heat storage performance of the heat storage balls, ensure the safety performance of each flue gas valve, and prevent the heat storage box from overheating.

[0050] The actual data for heat storage flue gas can also be the actual flow rate of heat storage flue gas, in which case the target data for heat storage flue gas is the target flow rate of heat storage flue gas. When using the target flow rate of heat storage flue gas as the target data for heat storage flue gas, the target flow rate of heat storage flue gas is set as: furnace section gas flow rate × theoretical smoke-fuel ratio × target flue gas extraction rate × burner condition correction coefficient, where the furnace section gas flow rate is the gas flow rate in the main gas pipeline of the furnace section; the theoretical smoke-fuel ratio is the theoretical value of the ratio of the amount of flue gas produced by the burner combustion to the amount of gas consumed, and this theoretical smoke-fuel ratio is determined according to the calorific value and composition of the gas; the burner condition correction coefficient = number of flue gas burners / number of combustion burners, and the purpose of setting the burner condition correction coefficient is to reduce the impact of flue gas valve failure.

[0051] The target flue gas extraction rate can be dynamically determined using the flue gas temperature following method. Specifically, the flue gas temperature following method includes:

[0052] i) Set a flue gas temperature fluctuation range and set a target flue gas extraction rate range. In this embodiment, the flue gas temperature fluctuation range is set to 210℃~230℃, and the target flue gas extraction rate range is set to 0.65~0.8.

[0053] ii) When the heat storage flue gas temperature is lower than the lower limit of the flue gas temperature fluctuation range, the target flue gas extraction rate is increased at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the upper limit of the range, at which point the target flue gas extraction rate stops increasing and remains constant. Specifically, in this embodiment, when the heat storage flue gas temperature is lower than 210℃, the target flue gas extraction rate is increased at a rate of 0.01 / min until the heat storage flue gas temperature reaches 220℃, or the target flue gas extraction rate reaches 0.8, at which point the target flue gas extraction rate stops increasing and remains constant.

[0054] iii) When the heat storage flue gas temperature exceeds the upper limit of the flue gas temperature fluctuation range, the target flue gas extraction rate begins to decrease at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the lower limit of the range. At this point, the target flue gas extraction rate stops decreasing and remains constant. Specifically, in this embodiment, when the heat storage flue gas temperature exceeds 230°C, the target flue gas extraction rate begins to decrease at a rate of 0.01 / min until the heat storage flue gas temperature reaches 220°C, or the target flue gas extraction rate reaches 0.65. At this point, the target flue gas extraction rate stops decreasing and remains constant.

[0055] The target flue gas extraction rate is dynamically determined using the flue gas temperature following method. Its advantage is that it can simultaneously take into account the heat storage flue gas temperature and the heat storage flue gas extraction rate, so that both the heat storage flue gas temperature and the heat storage flue gas extraction rate are within a reasonable range. While ensuring the heat storage flue gas extraction rate, it can also avoid damage to the equipment caused by the heat storage flue gas temperature exceeding the limit.

[0056] Using a PID controller to control the opening of the thermal storage flue gas regulating valve based on the target temperature of the flue gas, ensuring that the actual temperature of the flue gas is close to the target temperature, can prevent the thermal storage tank from overheating due to excessively high actual flue gas temperature. Furthermore, using a PID controller to control the opening of the thermal storage flue gas regulating valve based on the target flow rate, which is dynamically determined according to the target flue gas extraction rate, ensures that the actual flue gas extraction rate is close to the target extraction rate, thus guaranteeing efficient recovery of flue gas heat energy. When it is necessary to ensure that the heat storage box does not overheat, a PID controller is used to control the opening of the heat storage exhaust regulating valve according to the target temperature of the heat storage exhaust. When it is necessary to ensure the efficient recovery of flue gas heat energy, a PID controller is used to control the opening of the heat storage exhaust regulating valve according to the target flow rate of the heat storage exhaust. In short, using a PID controller to dynamically adjust the heat storage exhaust flow rate of the furnace section according to the heat storage exhaust data can maximize the satisfaction of the furnace section's operating process requirements and achieve the desired good heat storage exhaust effect.

[0057] Preferably, step 4 further includes: when adjusting the thermal regenerative exhaust valve, setting an upper limit and a lower limit for the opening of the thermal regenerative exhaust valve, wherein the upper limit is: 40% + furnace section air volume percentage × λ; and the lower limit is: furnace section air volume percentage / 2.5; wherein, the furnace section air volume percentage is the percentage of the actual air flow in the furnace section's total air pipeline relative to the designed maximum flow; λ is a correction coefficient, which is taken in the range of 0.4 to 0.5 according to different furnace sections. Specifically, the value of λ can be determined according to the heat load design of each furnace section or the amount of heat load distribution of each furnace section during actual production.

[0058] It should be noted that the opening degree of the heat storage and smoke exhaust regulating valve is expressed as a percentage. Specifically, when the heat storage and smoke exhaust regulating valve is fully closed, its opening degree is expressed as 0%, and when the heat storage and smoke exhaust regulating valve is fully open, its opening degree is expressed as 100%. The upper and lower limits for the opening degree of the heat storage and smoke exhaust regulating valve are also set as percentages.

[0059] The purpose of setting upper and lower limits for the opening of the thermal regenerative exhaust regulating valve is to prevent instantaneous overheating of the burner's heat storage tank within the furnace section. Specifically, when using a PID controller to adjust the opening of the thermal regenerative exhaust regulating valve, it's inevitable that the adjustment range will become too large. For example, if the PID controller output data diverges, the adjustment range of the thermal regenerative exhaust regulating valve will become increasingly larger. At any given moment, if the adjustment range of the thermal regenerative exhaust regulating valve is too large, it will lead to an excessively large instantaneous thermal regenerative exhaust flow rate, which in turn will further cause instantaneous overheating of the burner's heat storage tank within the furnace section. Setting upper and lower limits for the opening of the thermal regenerative exhaust regulating valve can prevent this instantaneous overheating of the heat storage tank.

[0060] Preferably, step 4 further includes: when the temperature of the heat storage flue gas exceeds the limit, initiating a flue gas over-temperature regulation process; the flue gas over-temperature regulation process includes:

[0061] a) Stop using the opening value calculated by the PID controller to control and adjust the thermal storage and flue gas regulating valve;

[0062] b) Gradually reduce the opening of the thermal storage exhaust valve until the thermal storage exhaust temperature does not exceed the limit; while gradually reducing the opening of the thermal storage exhaust valve, the opening of the thermal storage exhaust valve is adjusted at a rate of 0.06% per second.

[0063] c) Restore the opening value calculated by the PID controller to control and adjust the heat storage and flue gas regulating valve.

[0064] When the temperature of the heat storage flue gas exceeds the limit, the flue gas overheat regulation process is activated, which can quickly reduce the temperature of the heat storage flue gas. On the one hand, it can prevent the heat storage flue gas from being damaged by excessively high temperature (mainly the valves). On the other hand, it can also prevent the heat storage box of the burner from overheating.

[0065] It should be noted that in this embodiment, the criterion for determining the overheating of the thermal storage exhaust gas temperature is that the thermal storage exhaust gas temperature exceeds 230°C. In other embodiments, the overheating temperature of the thermal storage exhaust gas temperature can be determined based on the actual operating conditions of the thermal storage heater.

[0066] The advantages of the heat storage and smoke exhaust control method in this embodiment are:

[0067] 1) A PID controller is used to dynamically adjust the heat storage and flue gas flow rate of the furnace section based on the heat storage and flue gas data, thereby achieving a good heat storage and flue gas effect;

[0068] 2) When adjusting the heat storage flue gas regulating valve, there are upper and lower limits for the opening of the heat storage flue gas regulating valve to prevent instantaneous overheating of the heat storage box of the burner in the furnace section.

[0069] 3) When the temperature of the heat storage flue gas exceeds the limit, the flue gas overheat regulation process is activated, which can quickly reduce the temperature of the heat storage flue gas and prevent excessive heat storage flue gas from damaging the main heat storage flue gas pipeline. At the same time, it can also prevent the heat storage box of the burner from overheating.

[0070] It should be noted that the heat storage exhaust control method of the present invention is not limited to the heat storage furnace involved in this embodiment. In other embodiments, the heat storage exhaust control method of the present invention can also be used in other heat storage furnaces that have a heat storage exhaust regulating valve installed on the heat storage exhaust main pipeline.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the regenerative exhaust gas of a regenerative heating furnace, characterized in that: Includes the following steps: Step 1: For each section of the regenerative heating furnace, set up a PID controller and pre-set the target data for regenerative flue gas exhaust. Step 2: Input the data difference between the actual data of the heat storage and flue gas in the furnace section and the preset target data of heat storage and flue gas into the PID controller as an input parameter; Step 3: The PID controller calculates the opening value of the thermal storage and flue gas regulating valve based on the difference in the input data. Step 4: The PID controller uses the opening value to control and adjust the opening of the heat storage flue gas regulating valve to adjust the heat storage flue gas flow rate of the furnace section. The actual data for thermal storage and flue gas exhaust is the actual flow rate of thermal storage and flue gas exhaust, and the target data for thermal storage and flue gas exhaust is the target flow rate of thermal storage and flue gas exhaust. The target flow rate for heat storage flue gas is set as: furnace section gas flow rate × theoretical flue gas ratio × target flue gas extraction rate × burner condition correction coefficient, where the furnace section gas flow rate is the gas flow rate in the main gas pipeline of the furnace section, the theoretical flue gas ratio is the theoretical value of the ratio of the amount of flue gas generated by the burner combustion to the amount of gas consumed, and the burner condition correction coefficient = number of flue gas burners / number of combustion burners; The target flue gas extraction rate is dynamically determined using the flue gas temperature following method, which includes: i) Set a flue gas temperature fluctuation range and set the range of the target flue gas extraction rate; ii) When the heat storage flue gas temperature is lower than the lower limit of the flue gas temperature fluctuation range, the target flue gas extraction rate starts to rise at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the upper limit value of the range, at which point the target flue gas extraction rate stops rising and remains constant. iii) When the heat storage flue gas temperature is higher than the upper limit of the flue gas temperature fluctuation range, the target flue gas extraction rate will start to decrease at a rate of 0.01 / min until the heat storage flue gas temperature reaches the median value of the flue gas temperature fluctuation range, or the target flue gas extraction rate reaches the lower limit of the range, at which point the target flue gas extraction rate will stop decreasing and remain constant.

2. The method for controlling the regenerative flue gas exhaust of the regenerative heating furnace according to claim 1, characterized in that: The actual data for heat storage and smoke exhaust uses the actual temperature of heat storage and smoke exhaust, while the target data for heat storage and smoke exhaust uses the target temperature of heat storage and smoke exhaust.

3. The method for controlling the regenerative flue gas exhaust of the regenerative heating furnace according to claim 2, characterized in that: The target temperature for heat storage and flue gas exhaust is in the range of 220–230℃.

4. The method for controlling the regenerative flue gas exhaust of the regenerative heating furnace according to claim 1, characterized in that: In the flue gas temperature following method, the flue gas temperature fluctuation range is set to 210℃~230℃, and the target flue gas extraction rate is set to a range of 0.65~0.

8.

5. The method for controlling the regenerative flue gas exhaust of the regenerative heater according to claim 1, characterized in that: Step 4 further includes: when adjusting the thermal regenerative flue gas regulating valve, setting an upper limit and a lower limit for the opening of the thermal regenerative flue gas regulating valve; the upper limit is: 40% + furnace section air volume percentage × λ, and the lower limit is: furnace section air volume percentage / 2.5, where the furnace section air volume percentage is the percentage of the actual air flow in the furnace section's total air pipeline compared to the designed maximum flow, and λ is a correction coefficient.

6. The method for controlling the regenerative flue gas exhaust of the regenerative heating furnace according to claim 1, characterized in that: Step 4 also includes: when the temperature of the heat storage flue gas exceeds the limit, a flue gas over-temperature regulation process is initiated. The smoke exhaust overheating regulation process includes: a) Stop using the opening value calculated by the PID controller to control and adjust the thermal storage and flue gas regulating valve; b) Gradually reduce the opening of the heat storage flue gas regulating valve until the heat storage flue gas temperature does not exceed the limit. c) Restore the opening value calculated by the PID controller to control and adjust the heat storage and flue gas regulating valve.

7. The method for controlling the regenerative flue gas exhaust of the regenerative heating furnace according to claim 6, characterized in that: During the process of regulating the exhaust temperature, as the opening of the heat storage exhaust regulating valve is gradually reduced, the opening of the heat storage exhaust regulating valve is adjusted at a rate of 0.06% per second.

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