Anti-blocking system of air pre-heater of coal-fired boiler and coal-fired boiler

Abstract

The invention discloses an anti-blocking system of an air pre-heater of a coal-fired boiler and the coal-fired boiler, the anti-blocking system of the air pre-heater of the coal-fired boiler comprises an air pre-heater main body, the air pre-heater main body is internally provided with a hot end heat exchanger and a cold end heat exchanger, and a heat exchange space is formed between the hot end heat exchanger and the cold end heat exchanger; and the heating unit is arranged on the air pre-heater main body and can heat the heat exchange space. The invention discloses an anti-blocking system of an air preheater of a coal-fired boiler and the coal-fired boiler. The anti-blocking system aims at solving the problem that an existing air preheater is blocked.

Description

Technical Field

[0001] The present application relates to the technical field of boilers, and more specifically, to an anti-blocking system for an air preheater of a coal-fired boiler and a coal-fired boiler. Background Art

[0002] At present, when coal-fired boilers are in use, the heat exchange elements of the air preheater are often blocked by ammonium bisulfate and smoke, resulting in increased power consumption of the forced draft fan and induced draft fan. In severe cases, the fan may stall due to air rush and cause shutdown, seriously affecting the stability and safety of the unit operation.

[0003] Therefore, a coal-fired boiler air preheater anti-blocking system and a coal-fired boiler are needed to solve the above problems. Summary of the invention

[0004] In view of this, the purpose of the present application is to propose an anti-blocking system for an air preheater of a coal-fired boiler and a coal-fired boiler to solve the problem of blockage of the existing air preheater.

[0005] Based on the above purpose, the present application provides a coal-fired boiler air preheater anti-blocking system, comprising:

[0006] An air preheater body, wherein the air preheater body has a hot end heat exchanger and a cold end heat exchanger built therein, and a heat exchange space is provided between the hot end heat exchanger and the cold end heat exchanger;

[0007] A heating unit is arranged on the air preheater body and can heat the heat exchange space.

[0008] Optionally, the heating unit includes a gas gun, which includes a gas gun body, a gun rod and an igniter arranged on the gas gun body; the flame-spraying end of the gun rod is arranged corresponding to the heat exchange space; the ignition end of the igniter is arranged corresponding to the flame-spraying end of the gun rod.

[0009] Optionally, the outside of the air preheater body has an installation platform, and the air preheater body has an inlet and outlet unit corresponding to the heat exchange space; the heating unit is arranged on the installation platform, and when the inlet and outlet unit is opened, the heating unit can heat the heat exchange space through the inlet and outlet unit.

[0010] Optionally, the anti-blocking system of the coal-fired boiler air preheater also includes a driving unit, which is drivingly connected to the heating unit and the entrance and exit unit; when the driving unit drives the entrance and exit unit to be in an open state, the driving unit can drive at least a part of the heating unit to enter or exit the heat exchange space from the entrance and exit unit.

[0011] Optionally, the anti-blocking system of the air preheater of a coal-fired boiler also includes a control unit and a temperature monitoring unit for monitoring the temperature in the heat exchange space; the control unit for controlling the heating unit to start or stop heating according to the temperature signal monitored by the temperature monitoring unit is connected to the temperature monitoring unit and the heating unit respectively.

[0012] Optionally, there are multiple temperature monitoring units, and the monitoring areas of the multiple temperature monitoring units are configured to at least cover the area occupied by the heat exchange space.

[0013] Optionally, there are multiple heating units, and the multiple heating units are arranged along the circumference of the air preheater body, and the heating areas of the multiple heating units are configured to at least cover the area occupied by the heat exchange space.

[0014] Optionally, the anti-blocking system of the coal-fired boiler air preheater further includes a fuel supply unit, which is connected to the heating unit; the fuel supply unit includes a chemical tail gas collection unit and / or a fuel gas supply unit.

[0015] Optionally, the height of the hot-end heat exchanger is less than or equal to the height of the cold-end heat exchanger; and / or the length of the hot-end heat exchanger is less than or equal to the length of the cold-end heat exchanger.

[0016] In addition, optionally, the present application also provides a coal-fired boiler, including a boiler body and an anti-blocking system for an air preheater of a coal-fired boiler as described above, which is arranged on the boiler body.

[0017] It can be seen from the above that the technical solution provided by the present application has the following advantages compared with the prior art: the anti-blocking system of the air preheater of a coal-fired boiler can effectively increase the temperature of the heat exchange space in the air preheater to achieve gasification of the blockage attached to the heat exchange element of the air preheater, for example, ammonium bisulfate can be gasified, and the ammonium bisulfate attached to the heat exchange element of the air preheater can be gasified and taken away with the boiler flue gas, thereby avoiding ammonium bisulfate from blocking the heat exchange element, and thus avoiding blockage of the air preheater. At the same time, in winter when the outdoor temperature is low, in order to increase the temperature of the air entering the boiler furnace, ensure the economy of the boiler and prevent low-temperature corrosion, the temperature of the air entering the furnace can be increased by adding a heating unit, thereby improving the economy and preventing low-temperature corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above-mentioned features and technical advantages of the present application will become clearer and easier to understand through the following description of its embodiments in conjunction with the accompanying drawings.

[0019] Figure 1 A schematic cross-sectional view of an anti-blocking system for an air preheater of a coal-fired boiler provided in the present application;

[0020] Figure 2 A schematic diagram of the structure of a heating unit provided in this application;

[0021] Figure 3 A schematic diagram of the structure of another heating unit provided in this application;

[0022] Figure 4 A schematic diagram of the location structure of the temperature measuring points of an anti-blocking system for an air preheater of a coal-fired boiler provided in this application.

[0023] The reference numerals are:

[0024] 10: air preheater body; 11: installation platform; 12: inlet and outlet unit; 20: hot end heat exchanger;

[0025] 30: cold end heat exchanger; 40: heat exchange space; 50: heating unit; 51: burner body;

[0026] 52: gun barrel; 521: flame-throwing end; 53: igniter; 531: ignition end; 60: temperature measuring point. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. The same parts are represented by the same figure numerals. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the accompanying drawings. The words "inside" and "outside" used refer to the direction toward or away from the geometric center of a specific component, respectively.

[0028] The inventor found in the practice of this application that the generation of ammonium bisulfate (ABS) is inevitable in the process of selective catalytic reduction (SCR) denitration in coal-fired boilers in traditional technology. In the conventional design of air preheaters (hereinafter referred to as air preheaters), the temperature range of the medium temperature section is approximately 120-230°C. Since the content of ammonium bisulfate (ABS) in flue gas is relatively small, its dew point temperature is relatively low, generally around 120°C. When the cold end comprehensive temperature is above 160°C, the temperature of most areas of the air preheater can be guaranteed to be above 120°C, reducing the generation of ammonium bisulfate. When the flue gas passes through the medium temperature section, ammonium bisulfate (ABS) is just in the condensation stage. At this time, ammonium bisulfate (ABS) is extremely viscous and will quickly adhere to the surface of the heat exchange element of the air preheater, adsorb a large amount of fly ash in the flue gas and block the air preheater, resulting in an increase in the power consumption of the blower and the induced draft fan. In severe cases, the blower will be shut down due to the stall of the blower, which seriously affects the stability and safety of the unit operation.

[0029] Based on the above reasons, the inventor provides the technical solution of the present application, which can effectively alleviate the blockage problem of the above-mentioned air preheater.

[0030] Figure 1 A cross-sectional structural diagram of an anti-blocking system for an air preheater of a coal-fired boiler provided in this application is shown in FIG. Figure 1 As shown, the anti-blocking system of the air preheater of a coal-fired boiler comprises: an air preheater body 10 and a heating unit 50. .

[0031] The anti-blocking system of the air preheater of a coal-fired boiler comprises: an air preheater body 10 and a heating unit 50; the air preheater body 10 is provided with a hot end heat exchanger 20 and a cold end heat exchanger 30, and a heat exchange space 40 is provided between the hot end heat exchanger 20 (which may be referred to as the hot end) and the cold end heat exchanger 30 (which may be referred to as the cold end); the heating unit 50 is arranged on the air preheater body 10, and can heat the heat exchange space 40.

[0032] The heat exchange space 40 can be heated by the heating unit 50. When the heat exchange space 40 is heated, the entire area and components of the air preheater can be heated. For example, the temperature of the hot-end heat exchanger 20 and the cold-end heat exchanger 30 of the air preheater can be heated. By increasing the temperature of the hot and cold ends of the local air preheater, such as increasing the temperature to 400°C, the ammonium bisulfate attached to the heat exchange element of the air preheater can be gasified.

[0033] By adopting the anti-blocking system of the coal-fired boiler air preheater, the coal-fired boiler air preheater can effectively increase the temperature of the heat exchange space in the air preheater to achieve gasification of the blockage attached to the heat exchange element of the air preheater, for example, ammonium bisulfate can be gasified, and the ammonium bisulfate attached to the air preheater heat exchange element can be gasified and carried away with the boiler flue gas to avoid ammonium bisulfate blocking the heat exchange element, thereby avoiding blockage of the air preheater. At the same time, in winter when the outdoor temperature is low, in order to increase the temperature of the air entering the boiler furnace, ensure the economy of the boiler and prevent low-temperature corrosion, the temperature of the air entering the furnace can be increased by adding a heating unit 50, thereby improving the economy and preventing low-temperature corrosion.

[0034] Figure 2 A schematic diagram of the structure of a heating unit provided in this application; Figure 3 This is a schematic diagram of the structure of another heating unit provided in this application. Figure 2 and Figure 3 As shown, the heating unit 50 comprises a gas gun.

[0035] Optionally, the heating unit 50 includes a gas gun, which includes a gun body 51, a gun rod 52 and an igniter 53 arranged on the gun body 51; the flame spraying end 521 of the gun rod 52 is arranged corresponding to the heat exchange space 40; the ignition end 531 of the igniter 53 is arranged corresponding to the flame spraying end 521 of the gun rod 52. The gun body 51 is used to provide a connection matrix for the gun rod 52 and the igniter 53. At the same time, a control element for controlling the ignition of the igniter 53 and the flame spraying of the gun rod 52 is also arranged in the gun body 51. When a heating operation is required, the gun body 51 controls the gun rod 52 to deliver fuel, and the ignition end 531 of the igniter 53 ignites corresponding to the flame spraying end 521 of the gun rod 52, so that the gun rod 52 sprays fire to the heat exchange space 40, thereby heating the heat exchange space 40. When heated to a predetermined temperature, the gun body 51 controls the gun rod 52 to stop spraying fire. The heating unit has good performance, is easy to assemble, reduces the difficulty of operation, and is convenient for operators to use.

[0036] According to different heating requirements, the gas gun also includes a variety of flame spraying methods. In one embodiment of the present application, see Figure 2 The end of the gun rod 52 away from the burner body 51 is a flame spraying end 521, and the end of the igniter 53 away from the burner body 51 is an ignition end 531. After the ignition operation of the ignition end 531, a heating flame is ejected from the end of the gun rod 52 away from the burner body 51 to heat the heat exchange space 40.

[0037] In another embodiment of the present application, see Figure 3 On the basis that the end of the gun rod 52 away from the burner body 51 is a flame spraying end 521, a plurality of flame spraying ends 521 are distributed along the axial direction of the gun rod 52, or can also be called flame spraying ports. The end of the igniter 53 away from the burner body 51 is an ignition end 531, and correspondingly, a plurality of ignition ends 531 are branched out correspondingly to other flame spraying ports on the gun rod 52, such as ignition ends 531a to d. After the synchronous ignition operation of each ignition end 531, the heating flame is sprayed from each flame spraying port of the gun rod 52 to heat the heat exchange space 40.

[0038] In order to facilitate the effective heating of the heat exchange space 40, the present application also makes corresponding settings for the size of the heat exchange space 40. In one embodiment of the present application, see Figure 1 , the height of the heat exchange space 40 is increased, that is, the distance d between the hot end heat exchanger 20 and the cold end heat exchanger 30 is increased, and the value of d is greater than 10 cm. Preferably, the value of d can be selected as 20 cm, so that the space is large enough to meet the corresponding heating requirements and also meet the requirements of setting the heating unit 50.

[0039] For example, adding a gas gun 20 cm apart between the cold and hot ends of the air preheater can increase the temperature locally between the cold and hot ends of the air preheater. The temperature between the cold and hot ends can be increased in a short time. For example, the temperature between the cold and hot ends can be increased by 400°C within 2 minutes. Ammonium bisulfate can be vaporized at 200°C, and the ammonium bisulfate attached to the heat exchange element of the air preheater can be vaporized and carried away with the boiler flue gas, thus avoiding blockage of the air preheater.

[0040] According to different heating requirements, the position setting of the heating unit 50 can also be achieved in a variety of ways. In one embodiment of the present application, the heating unit 50 is set in the heat exchange space 40, so that the heating operation can be completed by controlling the heating action of the heating unit 50.

[0041] The heating unit 50 may also be arranged outside the heat exchange space 40. Optionally, the air preheater body 10 has an installation platform 11 outside, and the air preheater body 10 has an inlet and outlet unit 12 corresponding to the heat exchange space 40. The heating unit 50 is arranged on the installation platform 11. When the inlet and outlet unit 12 is opened, the heating unit 50 can heat the heat exchange space 40 through the inlet and outlet unit 12. The heating unit 50 is arranged outside the heat exchange space 40, which can effectively reduce the turbulence of the air in the heat exchange space 40 and ensure the smoothness of the air circulation in the heat exchange space 40.

[0042] There are two implementations of the inlet and outlet unit 12, one of which is that the inlet and outlet unit 12 includes an opening, that is, the inlet and outlet unit 12 is a normally open opening, and accordingly, the mounting platform 11 is a relatively closed space, and the space of the mounting platform 11 is connected to the heat exchange space 40 through the opening. When heating is required, the heating unit 50 heats the heat exchange space 40 through the opening, for example, a gas gun sprays fire to the heat exchange space 40 through the opening to heat the heat exchange space 40, so that the entire area and components of the air preheater are heated to gasify the ammonium bisulfate.

[0043] Another implementation of the entrance and exit unit 12 is that the entrance and exit unit 12 includes an opening and an isolation door arranged at the opening, and the opening can be opened or closed by opening and closing the isolation door. By opening and closing the isolation door, the installation platform 11 can be a relatively closed space or an open space. When heating is required, the isolation door is started to open the opening, and the space of the installation platform 11 is connected to the heat exchange space 40 through the opening, and the heating unit 50 can heat the heat exchange space 40 through the opening. When heating is not required, the isolation door is closed to close the opening, and the space of the installation platform 11 is isolated from the heat exchange space 40 by the isolation door, and they become relatively independent spaces.

[0044] In order to further enable the heating unit 50 to heat the heat exchange space 40 better and more fully, the heating unit 50 can be moved into the heat exchange space 40, so as to fully heat the heat exchange space 40. Optionally, the anti-blocking system of the coal-fired boiler air preheater also includes a driving unit, which is connected to the heating unit 50 and the inlet and outlet unit 12; when the driving unit drives the inlet and outlet unit 12 to be in an open state, the driving unit can drive at least a part of the heating unit 50 to enter or exit the heat exchange space 40 from the inlet and outlet unit 12.

[0045] The driving unit can drive the heating unit 50 to move, thereby adjusting the position of the heating unit 50 so as to adjust the heating area of ​​the heating unit 50. The driving unit can be implemented in various ways. For example, the driving unit can include a driving motor and a transmission system, or include a cylinder, a telescopic rod and a slide, etc.

[0046] Take the example of the entrance and exit unit 12 including an opening and an isolation door arranged at the opening. The driving unit can drive the isolation door to move, so that the opening is in an open state or a closed state. When heating is required, the driving unit drives the isolation door to open the opening, and at the same time drives at least a part of the heating unit 50 from the entrance and exit unit 12 into the heat exchange space 40, such as the gun rod 52 of the gas gun enters the heat exchange space 40, and the gun rod 52 sprays fire to heat the heat exchange space 40. When heating, the gun rod 52 can be fixed at a predetermined position for heating, or it can be adjusted under the drive of the driving unit to heat multiple areas separately.

[0047] When the heating operation is completed, the driving unit drives the heating unit 50 to exit the heat exchange space 40 through the opening. After the heating unit 50 completely exits the heat exchange space 40, the driving unit drives the isolation door again to close the opening, so that the space of the installation platform 11 is isolated from the heat exchange space 40 by the isolation door, and they become relatively independent spaces.

[0048] In order to enable the heating unit 50 and the driving unit to coordinate operations with each other, optionally, the anti-blocking system of the coal-fired boiler air preheater also includes a control unit, which is connected to the heating unit 50 and the driving unit and can control the heating unit 50 and the driving unit to work in coordination.

[0049] In order to better monitor the regional temperature of the heat exchange space 40, the anti-blocking system of the coal-fired boiler air preheater may further include a control unit and a temperature monitoring unit for monitoring the temperature in the heat exchange space 40; a control unit for controlling the heating unit 50 to start or stop heating according to the temperature signal monitored by the temperature monitoring unit is respectively connected to the temperature monitoring unit and the heating unit 50. The temperature monitoring unit includes but is not limited to an infrared sensor, and the control unit determines whether the heat exchange unit needs to be heated by monitoring the temperature of the heat exchange space 40.

[0050] In one embodiment of the present application, when the temperature monitoring unit detects that the temperature of the heat exchange space 40 is lower than the first temperature threshold, such as lower than 130°C, ammonium bisulfate may be in the condensation stage and will quickly adhere to the surface of the heat exchange element, absorb a large amount of fly ash in the flue gas and block the air preheater. At this time, the control unit will control the heating unit 50 and other components to heat the heat exchange space 40, such as controlling the gas gun to spray the heat exchange space 40, to increase the temperature between the cold and hot ends of the air preheater, such as increasing the temperature between the cold and hot ends by 400°C within 2 minutes, and ammonium bisulfate can be gasified at 200°C, and the ammonium bisulfate attached to the heat exchange element of the air preheater can be gasified and taken away with the boiler flue gas to avoid blockage of the air preheater.

[0051] When the temperature monitoring unit detects that the temperature of the heat exchange space 40 is higher than the second threshold value, such as higher than 400°C, the control unit will control the heating unit 50 and other components to stop heating the heat exchange space 40, such as controlling the gas gun to stop spraying fire, and controlling the driving unit to drive the gas gun to exit the heat exchange space 40. Alternatively, when the temperature of the heat exchange space 40 is higher than the second threshold value, such as higher than 400°C, the control unit delays for a preset time, such as 60 seconds, and then controls the heating unit 50 to stop heating the heat exchange space 40, such as delaying the control of the gas gun to stop spraying fire, and then controls the driving unit to drive the gas gun to exit the heat exchange space 40.

[0052] Figure 4 This is a schematic diagram of the location structure of the temperature measurement points of the anti-blocking system of the air preheater of a coal-fired boiler provided in this application. Figure 4 As shown, a plurality of temperature measuring points 60 are arranged in the anti-blocking system of the air preheater of the coal-fired boiler.

[0053] To reduce the blocked area, optionally, there are multiple temperature monitoring units, and the monitoring areas of the multiple temperature monitoring units are configured to at least cover the area occupied by the heat exchange space 40. Multiple temperature monitoring units are configured to monitor at multiple temperature measuring points 60, and the temperature of each area of ​​the heat exchange space 40 is monitored in real time through multiple temperature monitoring units. By adding temperature measuring points 60, the temperature of the cold and hot end areas and the heat exchange space 40 area can be paid attention to in time, so that the control unit can accurately determine when to control the heating unit 50 to heat, when to stop heating, and to heat certain areas in a targeted manner.

[0054] In one embodiment of the present application, see Figure 4 A plurality of temperature measuring points 60 are arranged along the circumference of the air preheater body 10 , and a plurality of temperature monitoring units monitor the temperature of the area occupied by the heat exchange space 40 at the temperature measuring points 60 .

[0055] In order to improve the heating efficiency and ensure that the heat exchange space 40 is heated more fully, optionally, there are multiple heating units 50, and the multiple heating units 50 are arranged along the circumference of the air preheater body 10, and the heating areas of the multiple heating units 50 are configured to at least cover the area occupied by the heat exchange space 40. The multiple heating units 50 can cooperate with each other for heating, such as heating separately, heating at the same time, and heating alternately. For example, multiple gas guns are arranged around the air preheater, and one gas gun is withdrawn every 5 seconds to increase the chamber heat exchange temperature and reduce the occurrence of blockage.

[0056] In order to reduce heating costs and facilitate the acquisition of heating fuel, the anti-blocking system of the coal-fired boiler air preheater optionally also includes a fuel supply unit, which is connected to the heating unit 50; the fuel supply unit includes a chemical tail gas collection unit and / or a gas supply unit. According to different needs and different application scenarios of the boiler, the fuel supply unit can provide only chemical tail gas as heating fuel for the heating unit 50, or only provide gas as heating fuel, or, according to needs, alternately provide chemical tail gas and gas to the heating unit 50. Using chemical tail gas or gas as the heating fuel for the heating unit 50 can effectively reduce heating costs, improve the overall economy of the company, and avoid the loss of the generated tail gas that cannot be burned and discharged.

[0057] In order to achieve the purpose of anti-blocking, in addition to adding a heating unit 50 and a temperature measuring point 60, the anti-blocking system of the coal-fired boiler air preheater has also improved the structure of the air preheater, such as increasing the height of the heat exchange space 40, that is, increasing the distance between the hot end heat exchanger 20 and the cold end heat exchanger 30.

[0058] In order to further improve the anti-blocking effect, optionally, the height of the hot end heat exchanger 20 is less than or equal to the height of the cold end heat exchanger 30; and / or the length of the hot end heat exchanger 20 is less than or equal to the length of the cold end heat exchanger 30. That is, the hot end heat exchange element becomes narrower and shorter, and the cold end heat exchange element is lengthened and higher.

[0059] The following further introduces the use of the anti-blocking system of the coal-fired boiler air preheater.

[0060] The heat exchange space 40 in the air preheater body 10 can be heated by the heating unit 50. When the heat exchange space 40 is heated, the entire air preheater area and each component can be heated. For example, the temperature of the hot end heat exchanger 20 and the cold end heat exchanger 30 of the air preheater can be heated. By increasing the temperature of the hot and cold ends of the local air preheater, such as increasing the temperature to 400°C, the ammonium bisulfate attached to the heat exchange element of the air preheater can be gasified. The ammonium bisulfate is gasified and taken away with the boiler flue gas to avoid ammonium bisulfate blocking the heat exchange element and the air preheater. The driving unit, control unit, temperature monitoring unit, heating unit and fuel supply unit cooperate with each other to improve the automation and accuracy of the anti-blocking system of the coal-fired boiler air preheater, further ensure the anti-blocking effect, reduce the difficulty of operation and improve convenience.

[0061] The present application also provides a coal-fired boiler, including a boiler body and an anti-blocking system for an air preheater of a coal-fired boiler as described above, which is arranged on the boiler body. The implementation of the anti-blocking system can refer to the implementation of the anti-blocking system in the above embodiment, which will not be described here one by one.

[0062] In summary, it can be seen from the above that the technical solution provided by the present application has the following advantages compared with the prior art: the anti-blocking system of the air preheater of a coal-fired boiler can effectively increase the temperature of the heat exchange space in the air preheater to achieve gasification of the blockage attached to the heat exchange element of the air preheater, for example, ammonium bisulfate can be gasified, and the ammonium bisulfate attached to the heat exchange element of the air preheater can be gasified and taken away with the boiler flue gas, thereby avoiding ammonium bisulfate from blocking the heat exchange element, and thus avoiding blockage of the air preheater. At the same time, in winter when the outdoor temperature is low, in order to increase the temperature of the air entering the boiler furnace, ensure the economy of the boiler and prevent low-temperature corrosion, the temperature of the air entering the furnace can be increased by adding a heating unit, thereby improving the economy and preventing low-temperature corrosion.

[0063] A person skilled in the art should understand that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A coal-fired boiler air preheater anti-blocking system, characterized in that: include: An air preheater body, wherein the air preheater body has a hot end heat exchanger and a cold end heat exchanger built therein, and a heat exchange space is provided between the hot end heat exchanger and the cold end heat exchanger; A heating unit is arranged on the air preheater body and can heat the heat exchange space.

2. The anti-blocking system for air preheater of coal-fired boiler according to claim 1 is characterized by: The heating unit comprises a gas gun, which comprises a gun body, a gun rod and an igniter arranged on the gun body; the flame-spraying end of the gun rod is arranged corresponding to the heat exchange space; the ignition end of the igniter is arranged corresponding to the flame-spraying end of the gun rod.

3. The anti-blocking system for air preheater of coal-fired boiler according to claim 1, characterized in that: The outside of the air preheater body is provided with a mounting platform, and the air preheater body is provided with an inlet and outlet unit corresponding to the heat exchange space; the heating unit is arranged on the mounting platform, and when the inlet and outlet unit is opened, the heating unit can heat the heat exchange space through the inlet and outlet unit.

4. The anti-blocking system for air preheater of coal-fired boiler according to claim 3, characterized in that: Also includes: A driving unit, the driving unit being drivingly connected to the heating unit and the inlet and outlet unit; When the driving unit drives the inlet and outlet unit to be in an open state, the driving unit may drive at least a portion of the heating unit to enter or exit the heat exchange space from the inlet and outlet unit.

5. The anti-blocking system for air preheater of coal-fired boiler according to claim 1, characterized in that: Also includes: A control unit and a temperature monitoring unit for monitoring the temperature in the heat exchange space; The control unit, which controls the heating unit to start or stop heating according to the temperature signal monitored by the temperature monitoring unit, is connected to the temperature monitoring unit and the heating unit respectively.

6. The anti-blocking system for air preheater of coal-fired boiler according to claim 5, characterized in that: There are multiple temperature monitoring units, and the monitoring areas of the multiple temperature monitoring units are configured to at least cover the area occupied by the heat exchange space.

7. The anti-blocking system for air preheater of a coal-fired boiler according to any one of claims 1 to 6, characterized in that: There are a plurality of heating units, and the plurality of heating units are arranged along the circumferential direction of the air preheater body, and the heating areas of the plurality of heating units are configured to at least cover the area occupied by the heat exchange space.

8. The anti-blocking system for air preheater of a coal-fired boiler according to any one of claims 1 to 6, characterized in that: Also includes: A fuel supply unit, wherein the fuel supply unit is connected to the heating unit; the fuel supply unit comprises a chemical tail gas collection unit and / or a fuel gas supply unit.

9. The anti-blocking system for air preheater of a coal-fired boiler according to any one of claims 1 to 6, characterized in that: The height of the hot-end heat exchanger is less than or equal to the height of the cold-end heat exchanger; and / or the length of the hot-end heat exchanger is less than or equal to the length of the cold-end heat exchanger.

10. A coal-fired boiler, characterized in that: The utility model comprises a boiler body and an anti-blocking system for an air preheater of a coal-fired boiler as claimed in any one of claims 1 to 9 arranged on the boiler body.

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