An automatic burnout air regulating device and method for a counter-firing boiler

Abstract

This disclosure provides an automatic burnout air adjustment device and method for a counter-firing boiler. The device includes: a burnout air box disposed at the inlet of the flue gas duct inside the furnace of the boiler, with a burnout air nozzle inside the burnout air box and a flow regulating component disposed at the air inlet of the burnout air nozzle; a carbon monoxide concentration detection device disposed at the outlet of the flue gas duct inside the furnace; a heat exchanger arranged along the flow direction of the flue gas inside the furnace and disposed between the inlet and outlet of the flue gas duct; a temperature detection device disposed on the outer wall of the heat exchanger; and a control device electrically connected to the carbon monoxide concentration detection device, the temperature detection device, and the flow regulating component. The control device controls the flow regulating component to adjust the air volume supplied by the burnout air nozzle based on a comparison between the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device and a preset carbon monoxide concentration value, or based on a comparison between the actual wall temperature detected by the temperature detection device and a preset wall temperature value.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the technical field of thermal power unit equipment, specifically relating to an automatic adjustment device and method for burnout air in a counter-firing boiler. Background Technology

[0002] As energy conservation and carbon reduction efforts in thermal power units deepen, the requirements for operating parameters of coal-fired boilers are becoming increasingly stringent. To reduce unit coal consumption, boiler oxygen levels and steam temperatures typically need to reach or exceed design values. Under these stringent operating conditions, precise optimization and adjustment of the boiler are crucial, with burnout air serving as a key means of adjusting boiler combustion.

[0003] Currently, numerous scholars and practitioners both domestically and internationally have conducted research on burnout air adjustment. They have found that burnout air adjustment in counter-firing boilers has a significant impact on key parameters such as boiler combustion deviation, wall temperature, and CO concentration. In combustion adjustment tests, reasonable adjustment of burnout air can help improve combustion uniformity, reduce local high wall temperature and CO high points, and improve boiler operation safety and economy.

[0004] However, currently, the adjustment of the burnout air, especially the adjustment of the burnout air lever, can only be done manually. Based on experimental results, it is fixed at a certain position and remains unchanged during daily operation. In reality, the boiler combustion state varies greatly under different loads, mill combinations, and coal qualities. The current manual adjustment mode of the burnout air is difficult to adapt to the flexible operation of thermal power units. When combustion conditions change, the burnout air cannot follow suit, leading to problems such as boiler overheating and reduced combustion efficiency. Summary of the Invention

[0005] The embodiments disclosed herein aim to at least solve one of the technical problems existing in the prior art, and provide an automatic adjustment device and method for burnout air in a counter-fired boiler.

[0006] A first aspect of the embodiments of this disclosure provides an automatic burnout air regulating device for a counter-firing boiler, comprising:

[0007] A burnout air box is installed at the inlet of the flue inside the furnace of a combustion boiler. The burnout air box is equipped with a burnout air nozzle and a flow regulating component installed at the air inlet of the burnout air nozzle. The flow regulating component is used to regulate the air supply volume of the burnout air nozzle.

[0008] The carbon monoxide concentration detection device is installed at the outlet of the flue inside the furnace to detect the carbon monoxide concentration in the flue gas.

[0009] The heat exchanger is arranged along the flow direction of the flue gas in the furnace and is located between the inlet and outlet of the flue gas to absorb heat from the flue gas.

[0010] A temperature detection device is installed on the outer wall of the heat exchanger to detect the wall temperature of the heat exchanger;

[0011] The control device is electrically connected to the carbon monoxide concentration detection device, the temperature detection device, and the flow regulator, respectively. The control device controls the flow regulator to adjust the air volume of the burnout air nozzle based on the comparison between the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device and the preset carbon monoxide concentration value; or the control device controls the flow regulator to adjust the air volume of the burnout air nozzle based on the comparison between the actual wall temperature detected by the temperature detection device and the preset wall temperature value.

[0012] Optionally, there are multiple burnout air nozzles, and the multiple burnout air nozzles are spaced apart along the width direction of the furnace; there are multiple flow regulators, and the multiple flow regulators are configured to correspond one-to-one with the multiple burnout air nozzles.

[0013] There are multiple carbon monoxide concentration detection devices and multiple temperature detection devices;

[0014] The furnace contains multiple burnout air zones arranged in the width direction. Each burnout air zone includes a burnout air nozzle and at least one temperature detection device and one carbon monoxide concentration detection device are sequentially arranged along the burnout air flow sprayed from the burnout air nozzle.

[0015] A second aspect of the embodiments of this disclosure provides a method for automatically adjusting the burnout air of a counter-firing boiler, the method being implemented according to the aforementioned automatic burnout air adjusting device for a counter-firing boiler, comprising:

[0016] Detect the actual carbon monoxide concentration in the flue gas of each burnout air zone inside the boiler flue.

[0017] Detect the actual wall temperature of the heat exchanger in each burnout air zone within the boiler flue.

[0018] Based on the comparison between the actual wall temperature value detected by the temperature detection device and the preset wall temperature value, or based on the comparison between the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device and the preset carbon monoxide concentration value, the flow regulating component is controlled to adjust the air volume of the burnout air nozzle.

[0019] Optionally, based on the comparison result that the actual wall temperature value detected by the temperature detection device is higher than the preset wall temperature value, the opening of the flow regulating component is increased to increase the air volume delivered by the burnout air nozzle.

[0020] Optionally, after increasing the opening of the flow rate regulating component to increase the air volume delivered by the burnout air nozzle, the method further includes:

[0021] The actual wall temperature of the heat exchanger in the burnout air area is detected after the opening of the flow regulating component is increased.

[0022] Based on the comparison result that the actual wall temperature value detected by the temperature detection device is higher than the preset wall temperature value, the opening of the flow regulating component in the burnout air area other than the burnout air area is reduced.

[0023] Optionally, based on the comparison result that the actual carbon monoxide concentration detected by the carbon monoxide detection device is higher than the preset carbon monoxide concentration, the opening of the flow regulating component is increased to increase the air volume delivered by the burnout air nozzle.

[0024] Furthermore, after increasing the opening of the flow rate regulating component to increase the air volume delivered by the burnout air nozzle, the method further includes:

[0025] The actual carbon monoxide concentration in the flue gas within the burnout air zone is detected after the opening of the flow regulator is increased.

[0026] Based on the comparison result that the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device is higher than the preset carbon monoxide concentration, the opening of the flow regulating component in the burnout air area other than the burnout air area is reduced.

[0027] Furthermore, it also includes: detecting the actual wall temperature of the heat exchanger in the burnout air area; and, based on the comparison result that the actual wall temperature detected by the temperature detection device is higher than the preset wall temperature value, adjusting the opening of the flow regulating component according to the actual wall temperature value.

[0028] The beneficial effects of the embodiments of this disclosure include:

[0029] In this disclosure, by detecting the carbon monoxide concentration in the flue gas and automatically adjusting the burnout air volume based on the comparison between the actual and preset carbon monoxide concentration, the amount of incompletely burned fuel can be effectively reduced, thus improving combustion efficiency. By detecting the heat exchanger wall temperature and automatically adjusting the burnout air volume based on the comparison between the actual and preset wall temperature, localized overheating and tube rupture can be prevented, improving the safety of the heat exchanger. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of an automatic burnout air regulating device for a counter-firing boiler according to an embodiment of the present disclosure;

[0031] Figure 2 This is a schematic flowchart illustrating an automatic burnout air adjustment method for a counter-firing boiler, according to another embodiment of this disclosure.

[0032] In the diagram, 1 is the burnout air nozzle; 2 is the heat exchanger; 3 is the economizer outlet; 5 is the furnace; 6 is the burnout air box; 21 is the screen-type superheater; 22 is the high-temperature superheater; and 23 is the high-temperature reheater. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed descriptions and accompanying drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0035] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0036] like Figure 1 As shown, an automatic adjustment device and method for burnout air in a counter-firing boiler is disclosed. The burnout air box is installed at the inlet of the flue inside the furnace 5 of the boiler. The burnout air box 6 is provided with a burnout air nozzle 1 and a flow regulating component installed at the air inlet of the burnout air nozzle. The flow regulating component is used to adjust the air supply volume of the burnout air nozzle.

[0037] The carbon monoxide concentration detection device is installed at the outlet of the flue inside furnace 5. Figure 1 At the economizer outlet 3), a device is used to detect the carbon monoxide concentration in the flue gas. The heat exchanger is arranged along the flow direction of the flue gas in the furnace and is located between the inlet and outlet of the flue gas to absorb heat from the flue gas. A temperature detection device is installed on the outer wall of the heat exchanger 2 to detect the wall temperature of the heat exchanger.

[0038] The control device is electrically connected to a carbon monoxide concentration detection device, a temperature detection device, and a flow regulator. Based on a comparison between the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device and a preset carbon monoxide concentration value, the control device controls the flow regulator to adjust the airflow from the burnout air nozzle. Alternatively, based on a comparison between the actual wall temperature detected by the temperature detection device and a preset wall temperature value, the control device controls the flow regulator to adjust the airflow from the burnout air nozzle.

[0039] In this disclosure, by detecting the carbon monoxide concentration in the flue gas and automatically adjusting the burnout air volume based on a comparison between the actual and preset carbon monoxide concentration, unburned fuel can be effectively reduced, thus improving combustion efficiency. By detecting the heat exchanger wall temperature and automatically adjusting the burnout air volume based on a comparison between the actual and preset wall temperature, localized overheating and tube rupture can be prevented, improving the heat exchanger's safety. In some embodiments, the heat exchanger includes a screen-type superheater 21, a high-temperature superheater 22, and a high-temperature reheater 23 arranged sequentially along the flue gas flow direction within the furnace.

[0040] In some embodiments, the carbon monoxide concentration detection device is an online CO measurement instrument.

[0041] In some embodiments, the flow rate regulator is a burnout air volume regulating lever.

[0042] In some embodiments, there are multiple burnout air nozzles, spaced apart along the width of the furnace. There are also multiple flow regulators, each corresponding to one of the multiple burnout air nozzles. Multiple carbon monoxide concentration detectors and multiple temperature detectors are also included.

[0043] The furnace contains multiple burnout air zones arranged in the width direction. Each burnout air zone includes a burnout air nozzle and at least one temperature detection device and one carbon monoxide concentration detection device are sequentially installed along the burnout air flow sprayed from the nozzle.

[0044] In this disclosure, by arranging multiple burnout air zones along the width of the furnace, each zone is equipped with an independent burnout air nozzle, flow regulator, temperature detection device, and carbon monoxide concentration detection device, enabling precise control of each zone. Each burnout air zone can be independently adjusted according to its own temperature and carbon monoxide concentration, avoiding the imbalance problems caused by global adjustment and improving the overall combustion uniformity and efficiency.

[0045] Furthermore, through multi-point detection and local adjustment, combustion conditions in each zone can be controlled more accurately, reducing incomplete combustion of fuel and improving combustion efficiency. Moreover, the flow regulators in each zone can be dynamically adjusted based on real-time detection data, ensuring that combustion conditions in each zone are always at their optimal state.

[0046] like Figure 2 As shown, a second aspect of the embodiments of this disclosure provides an automatic adjustment method for burnout air in a counter-firing boiler. The adjustment method is implemented according to the above-described automatic adjustment device for burnout air in a counter-firing boiler, and includes:

[0047] S101. Detect the actual carbon monoxide concentration in the flue gas of each burnout air zone in the boiler flue.

[0048] S102. Detect the actual wall temperature of the heat exchanger in each burnout air zone inside the boiler flue.

[0049] S103. Based on the comparison between the actual wall temperature value detected by the temperature detection device and the preset wall temperature value, or based on the comparison between the actual carbon monoxide concentration detected by the carbon monoxide concentration detection device and the preset carbon monoxide concentration value, control the flow regulating component to adjust the air supply volume of the burnout air nozzle.

[0050] In this disclosure, by detecting the carbon monoxide concentration in the flue gas and the wall temperature of the heat exchanger in each burnout air zone, and making local adjustments based on the detection results, precise control of each zone can be achieved, thereby improving combustion efficiency. Each burnout air zone can be independently adjusted according to its own temperature and carbon monoxide concentration, avoiding the imbalance problems caused by global adjustment and ensuring that the combustion conditions in each zone are always at their optimal state.

[0051] The wall temperature in each area can be monitored in real time by an independent temperature detection device, allowing for timely adjustment of the burnout air supply to prevent equipment damage caused by localized overheating.

[0052] In some embodiments, based on the comparison results of the actual wall temperature value detected by the temperature detection device being higher than the preset wall temperature value, the opening of the flow regulating component is increased to increase the air volume delivered by the burnout air nozzle.

[0053] In this disclosure, by real-time monitoring of the wall temperature and comparing the actual wall temperature with the preset value, the opening of the flow regulator is rapidly increased, enabling a quick response to temperature changes and ensuring that the combustion process is always in optimal condition. By increasing the air volume of the burnout air, the wall temperature can be effectively reduced, ensuring the safety of the equipment. In addition, it can also promote complete combustion of fuel, improve combustion efficiency, and reduce unburned fuel.

[0054] In some embodiments, after increasing the opening of the flow rate regulator to increase the air volume supplied by the burnout air nozzle, the method further includes:

[0055] The actual wall temperature of the heat exchanger in the burnout air zone was measured after the opening of the flow regulator was increased.

[0056] Based on the comparison results of the actual wall temperature value detected by the temperature detection equipment being higher than the preset wall temperature value, the opening of the flow regulator in the burnout air area other than the burnout air area is reduced.

[0057] In this disclosure, by increasing the opening of the flow regulator in a certain burnout air zone and then detecting the carbon monoxide concentration in that zone, the combustion conditions in that zone can be optimized, thus improving combustion efficiency. By decreasing the opening of the flow regulators in other burnout air zones, the relative airflow in that burnout air zone can be increased, effectively reducing the flue gas temperature, thereby lowering the wall temperature and ensuring the safety of the equipment.

[0058] In some embodiments, based on the comparison results of the actual carbon monoxide concentration detected by the carbon monoxide detection device being higher than the preset carbon monoxide concentration, the opening of the flow regulating component is increased to increase the air volume delivered by the burnout air nozzle.

[0059] In this disclosure, by real-time monitoring of carbon monoxide concentration and rapidly increasing the opening of the flow regulator based on the comparison between the actual and preset values, incomplete combustion can be quickly addressed, ensuring that the combustion process is always in optimal condition. Increasing the supply air volume of the burnout air promotes complete combustion of fuel, reduces unburned fuel, and improves combustion efficiency.

[0060] Furthermore, by increasing the airflow rate of the burnout air, the concentration of carbon monoxide in the flue gas can be effectively reduced, thereby decreasing the emission of harmful gases and improving environmental performance. A lower carbon monoxide concentration means more complete combustion, reducing unburned byproducts and further decreasing the formation of other harmful substances.

[0061] In some embodiments, after increasing the opening of the flow rate regulator to increase the air volume supplied by the burnout air nozzle, the method further includes:

[0062] The actual carbon monoxide concentration in the flue gas within the combustion air zone was measured after the opening of the flow regulator was increased.

[0063] Based on the comparison results of the actual carbon monoxide concentration detected by the carbon monoxide concentration detection equipment being higher than the preset carbon monoxide concentration value, the opening of the flow regulator in the burnout air area other than the burnout air area is reduced.

[0064] In this disclosure, by increasing the opening of the flow regulator in a certain burnout air zone and then detecting the carbon monoxide concentration in that zone, the combustion conditions in that zone can be optimized, thus improving combustion efficiency. By decreasing the opening of the flow regulators in other burnout air zones, the relative air intake in that burnout air zone can be increased, thereby ensuring complete combustion in that burnout air zone and reducing the generation of incomplete combustion products and other harmful substances.

[0065] In some embodiments, the method further includes detecting the actual wall temperature of the heat exchanger in the burnout air zone.

[0066] Based on the comparison results of the actual wall temperature value detected by the temperature detection equipment being higher than the preset wall temperature value, the opening of the flow regulating component is adjusted according to the actual wall temperature value.

[0067] In this disclosure, equipment safety takes precedence over environmental safety, that is, the wall temperature regulation mode takes precedence over the carbon monoxide regulation mode.

[0068] One specific example provided in this disclosure includes:

[0069] like Figure 1 As shown, Figure 1 The diagram shows the flue gas flow path from the burnout air nozzle to the economizer outlet of the offset combustion boiler. There are 1 to N burnout air zones arranged from side A to side B in the width direction of the furnace. Each burnout air zone corresponds to a burnout air nozzle and an economizer outlet. Downstream of the burnout air nozzle is a series of heat exchangers (including screen-type superheaters, high-temperature superheaters and high-temperature reheaters). After passing through the economizer, the flue gas at the furnace outlet is divided into two flues, side A and side B.

[0070] In this disclosed scheme, in order to accurately determine the CO concentration generated during pulverized coal combustion, an online CO measuring instrument is installed at the economizer outlet flue, as shown in the attached diagram. Figure 1 As shown, the number of CO online measuring instruments is the same as the number N of single-layer burnout air outlets, and their arrangement in the flue width direction corresponds one-to-one with the burnout air position in the furnace width direction.

[0071] Based on the arrangement of the burnout air nozzles, and using the center line of adjacent burnout air nozzles as the dividing line, the screen-type superheater, high-temperature superheater, and high-temperature reheater are divided into N burnout air zones in the width direction.

[0072] The regulating device disclosed herein includes a wall temperature priority regulation mode: the maximum allowable wall temperature of the screen-type superheater, high-temperature superheater, and high-temperature reheater is denoted as Tmax. When the wall temperature (actual wall temperature) of the screen-type superheater, high-temperature superheater, and high-temperature reheater in the burnout air zone Ni exceeds Tmax (preset wall temperature value), the regulating device will prioritize regulating the wall temperature for unit operation safety. The adjustment method is as follows:

[0073] 1) Based on the control device, increase the opening of the burnout air volume adjustment lever in the Ni burnout air area. If the wall temperature drops below Tmax, stop the adjustment. 2) If, within the Ni burnout air area, the wall temperature (actual wall temperature) is still higher than Tmax (preset wall temperature) after the burnout air volume adjustment lever is opened to 100%, then, based on the control device, decrease the opening of the other burnout air volume adjustment levers (except for the Ni burnout air) until the wall temperature drops below Tmax. The lower limit of adjustment is 30%.

[0074] CO Priority Adjustment Mode: When the wall temperature (actual wall temperature) of the screen-type superheater, high-temperature superheater, and high-temperature reheater does not exceed Tmax (preset wall temperature) in the burnout air zone Ni, the regulating device will prioritize adjusting the CO concentration at the economizer outlet to improve boiler combustion thermal efficiency. Based on the economizer outlet CO instrument data, the high CO concentration zone is determined. Assuming the highest CO concentration is found in the burnout air zone Ni, the adjustment method is similar to the wall temperature condition method, as follows:

[0075] 1) Based on the control device, the burnout air volume adjustment lever in burnout air zone Ni is opened. If the CO concentration (actual value of carbon monoxide concentration) drops below the carbon monoxide concentration value (preset value of carbon monoxide concentration) of other burnout air zones, the adjustment is stopped; 2) If the CO concentration is still higher than other zones after the burnout air volume adjustment lever in burnout air zone Ni is opened to 100%, the burnout air volume adjustment levers in other zones except burnout air zone Ni are closed based on the control device until the CO concentration drops below that of other zones. The adjustment lower limit is 30%; 3) If the wall temperature exceeds Tmax during the CO concentration adjustment process, the system returns to the wall temperature priority adjustment mode.

[0076] A third aspect of the embodiments of this disclosure provides a computer-readable storage medium having a computer program stored thereon.

[0077] When the computer program is executed by the processor, it can realize the above-described method for automatically adjusting the burnout air of a counter-firing boiler.

[0078] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. An overfire air automatic regulating device for a boiler, characterized in that, The application relates to a boiler, which comprises the following parts: a burnout air box arranged at the entrance of a flue in a furnace of a combustion boiler, wherein a burnout air nozzle is arranged in the burnout air box, and a flow adjusting part arranged at the air inlet of the burnout air nozzle is used to adjust the air supply amount of the burnout air nozzle; a carbon monoxide concentration detecting device arranged at the exit of the flue in the furnace and used to detect the carbon monoxide concentration in flue gas; a heat exchanger arranged along the flow direction of flue gas in the flue in the furnace and arranged between the entrance and the exit of the flue and used to absorb the heat in the flue gas; a temperature detecting device arranged at the outer wall of the heat exchanger and used to detect the wall temperature of the heat exchanger; and a control device electrically connected with the carbon monoxide concentration detecting device, the temperature detecting device and the flow adjusting part, wherein the control device controls the flow adjusting part to adjust the air supply amount of the burnout air nozzle according to the comparison between the actual value of the carbon monoxide concentration detected by the carbon monoxide concentration detecting device and the preset value of the carbon monoxide concentration, or the control device controls the flow adjusting part to adjust the air supply amount of the burnout air nozzle according to the comparison between the actual value of the wall temperature detected by the temperature detecting device and the preset value of the wall temperature; the control device is configured to preferentially start a wall temperature priority adjusting mode when the actual value of the wall temperature detected by the temperature detecting device exceeds the preset value of the wall temperature, and to start a carbon monoxide priority adjusting mode when the actual value of the wall temperature is lower than the preset value of the wall temperature; the burnout air nozzle is a plurality of burnout air nozzles arranged at intervals along the width direction of the furnace; the flow adjusting part is a plurality of flow adjusting parts corresponding to the plurality of burnout air nozzles; the carbon monoxide concentration detecting device is a plurality of carbon monoxide concentration detecting devices; and the temperature detecting device is a plurality of temperature detecting devices; wherein a plurality of burnout air regions are arranged along the width direction in the furnace, each burnout air region comprises one burnout air nozzle and at least one temperature detecting device and one carbon monoxide concentration detecting device arranged in sequence along the flow direction of the burnout air jetted from the burnout air nozzle. The application also relates to a method for controlling the boiler, which comprises the following steps: detecting the actual value of the carbon monoxide concentration in flue gas in each burnout air region in the flue of a boiler; detecting the actual value of the wall temperature of the heat exchanger in each burnout air region in the flue of the boiler; and controlling the flow adjusting part to adjust the air supply amount of the burnout air nozzle according to the comparison between the actual value of the wall temperature detected by the temperature detecting device and the preset value of the wall temperature, or according to the comparison between the actual value of the carbon monoxide concentration detected by the carbon monoxide concentration detecting device and the preset value of the carbon monoxide concentration; the control device is configured to preferentially start a wall temperature priority adjusting mode when the actual value of the wall temperature detected by the temperature detecting device exceeds the preset value of the wall temperature, and to start a carbon monoxide priority adjusting mode when the actual value of the wall temperature is lower than the preset value of the wall temperature. According to the comparison result that the actual value of the wall temperature detected by the temperature detecting device is higher than the preset value of the wall temperature, the opening degree of the flow adjusting part is increased to increase the air supply amount of the burnout air nozzle. After the opening degree of the flow adjusting part is increased to increase the air supply amount of the burnout air nozzle, the method further comprises the following steps: detecting the actual value of the wall temperature of the heat exchanger in the burnout air region after the opening degree of the flow adjusting part is increased. ​ ​ ​ ​ ​ ​ 2. The method for automatically adjusting overfire air of a opposed firing boiler according to claim 1, wherein the method is implemented by the device for automatically adjusting overfire air of a opposed firing boiler according to claim 1. ​ ​ ​ ​ ​ 3. A method for automatic regulation of overfire air in a tangentially fired boiler according to claim 2, characterized in that, ​ 4. A method for automatic regulation of overfire air in an opposed firing boiler as recited in claim 3, wherein, ​ ​ According to the comparison result that the wall temperature actual value detected by the temperature detecting device is higher than the wall temperature preset value, the opening degree of the flow adjusting member in the overfire air region except the overfire air region is adjusted.

5. A method for automatic regulation of overfire air in a tangentially fired boiler as recited in claim 2, wherein, According to the comparison result that the carbon monoxide concentration actual value detected by the carbon monoxide concentration detecting device is higher than the carbon monoxide concentration preset value, the opening degree of the flow adjusting member is adjusted to increase the air supply amount of the overfire air nozzle.

6. A method for automatic regulation of overfire air in a tangentially fired boiler according to claim 5, characterized in that, After the opening degree of the flow adjusting member is adjusted to increase the air supply amount of the overfire air nozzle, the method further comprises: detecting the carbon monoxide concentration actual value in the flue gas in the overfire air region after the opening degree of the flow adjusting member is adjusted; According to the comparison result that the carbon monoxide concentration actual value detected by the carbon monoxide concentration detecting device is higher than the carbon monoxide concentration preset value, the opening degree of the flow adjusting member in the overfire air region except the overfire air region is adjusted.

7. A method for automatic regulation of overfire air in a tangentially fired boiler as recited in claim 5, wherein, Further comprising: detecting the wall temperature actual value of the heat exchanger in the overfire air region; and according to the comparison result that the wall temperature actual value detected by the temperature detecting device is higher than the wall temperature preset value, adjusting the opening degree of the flow adjusting member according to the wall temperature actual value.

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