High-temperature ignition prevention mechanism of air preheater

Abstract

The invention provides an air preheater high-temperature ignition prevention mechanism which comprises a preheater assembly, a flow guide assembly, a pressing assembly, a pressure relief assembly and a monitoring assembly, the preheater assembly is composed of a shell, a cooling mechanism is fixedly installed on the side wall of the top of the shell, the flow guide assembly is fixedly installed on the top of the shell, and the flow guide assembly is composed of a fairing. The pressing assembly is fixedly installed on one side of the fairing, one end of the pressing assembly makes contact with the pressing plate, a movably-connected plug is arranged in the pressure relief assembly, the monitoring assembly is composed of a heat receiver and a vertical pipe, and the heat receiver is fixedly installed in the shell. High-temperature flue gas and air are conveyed through the preheater assembly, the fairing is arranged on the shell and can be used for guiding the flue gas and conducting pressure relief operation, the fairing can be rapidly opened when the temperature is too high, rapid cooling of the flue gas can be effectively achieved through cooperation of the cooling mechanism, automatic opening can be achieved when the temperature reaches a temperature threshold value, and the energy consumption is reduced. And the steel high-temperature ignition function of the air preheater is improved.

Description

Technical Field

[0001] The present invention relates to a high-temperature fire prevention mechanism for an air preheater, belonging to the technical field of air preheaters. Background Art

[0002] An air preheater is a heating surface in the flue gas duct at the tail of a boiler, where the flue gas inside heats the air before entering the boiler to a certain temperature through internal fins. It is a device used to improve the heat exchange performance of the boiler and reduce energy consumption. Air preheaters are generally divided into plate type, rotary type, and tubular type. Taking the tubular air preheater as an example, it utilizes the heat energy carried by the flue gas at the boiler outlet and transfers heat superconductively through heat pipes to preheat the combustion-supporting air of the boiler or for other drying purposes. The heat pipe type air preheater adopts a reset placement form, with the flue gas and air flowing horizontally in opposite directions to form gas-gas heat exchange, maximizing the flue gas heat exchange efficiency. The heat pipe type air preheater consists of a box body, a heat tube bundle, and an intermediate partition.

[0003] An air preheater is a device used to absorb the flue gas of a boiler for air preheating. When the air preheater is introduced with high-temperature flue gas, it needs to withstand excessive temperatures. However, when the flue gas temperature may change and become too high, being in a high-temperature state for a long time may cause damage to the air preheater. In severe cases, it may lead to a fire, increasing safety hazards, and the continuous high-temperature and high-pressure state reduces the service life of the air preheater. Summary of the Invention

[0004] The present invention provides a high-temperature fire prevention mechanism for an air preheater to solve the above-mentioned technical problems.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a high-temperature fire prevention mechanism for an air preheater, and the high-temperature fire prevention mechanism for an air preheater includes:

[0007] A preheater assembly, the preheater assembly consists of a housing, and a cooling mechanism is fixedly installed on the side wall at the top of the housing;

[0008] A flow guiding component, the flow guiding component is fixedly installed on the top of the housing. The flow guiding component (200) consists of a fairing. Sealing plates and pressing plates are respectively arranged inside both sides of the fairing. The pressing plate contacts the end of the sealing plate, and the sealing plate is fitted and connected to the inside of the opening formed on the top of the housing;

[0009] A pressing assembly, a pressure relief assembly and a monitoring assembly. The pressing assembly is fixedly installed on one side of the fairing. The movable end of the pressing assembly contacts the pressing plate. The pressure relief assembly is fixedly installed at the other end of the pressing assembly. A plug is movably connected inside the pressure relief assembly. The monitoring assembly consists of a heater and a riser. The heater is fixedly installed inside the housing. The heater is communicated with the riser. Both ends of the riser are fixedly connected to the top of the housing and the pressure relief assembly respectively. And a resisting rod contacting the plug is arranged inside the riser.

[0010] In this technical solution, a smoke inlet and a smoke outlet are respectively fixedly installed at both ends of the housing. The smoke inlet and the smoke outlet are respectively on both sides of the housing. Arc-shaped flow guiding plates are fixedly connected inside both ends of the housing. And the two flow guiding plates are respectively distributed corresponding to the smoke inlet and the smoke outlet. A plurality of heat exchange tubes are evenly distributed inside the housing. Both ends of the heat exchange tubes penetrate and are connected to the inside of the flow guiding plates.

[0011] In this technical solution, both ends of the housing are fixedly connected to flow equalizing covers. The two flow equalizing covers respectively penetrate and are connected to both ends of the heat exchange tubes. Circular holes communicated with the heat exchange tubes are opened in both flow equalizing covers. And the two flow equalizing covers are respectively fixedly connected to an air inlet and an air outlet pipe.

[0012] In this technical solution, the cooling mechanism consists of nozzles. The nozzles penetrate and are connected to both sides of the top of the housing. The number of nozzles is several and they are evenly arranged above the heat exchange tubes. A plurality of nozzles on the same side are communicated with a branch pipe. The middle parts of the branch pipes are respectively fixedly connected to both ends of a vertical pipe. And both ends of the vertical pipe are fixedly connected to valves. The vertical pipe is arranged above the fairing. And a horizontal pipe located on one side of the fairing is fixedly connected to the vertical pipe.

[0013] In this technical solution, the fairing is arranged on one side of the air outlet. The top of the fairing is fixedly connected to a smoke exhaust pipe. The smoke exhaust pipe is communicated with a flue gas collection device. The inside of both sides of the fairing is respectively rotatably connected to a rotating plate and a pressing plate. The rotating plate is fixedly connected to a sealing plate. An inclined edge is arranged at the edge of the sealing plate. And the inclined edge at the edge of the sealing plate is in fitting connection with the opening.

[0014] In this technical solution, the pressing assembly consists of a fixed pipe. The fixed pipe is obliquely arranged on one side of the fairing. A movable plug is hermetically slid inside the fixed pipe. The movable plug is fixedly connected to one end of a movable rod. One end of the movable rod extends to the outside of the fixed pipe. The bottom end of the movable rod is rotatably connected to a pulley. And the pulley contacts the top surface of the pressing plate.

[0015] In this technical solution, a limiting ring is fixedly connected to the inside of the fixed pipe. The limiting ring is arranged between the pressure relief assembly and the movable plug. A communicating pipe is fixedly connected to the top end of the fixed pipe. The communicating pipe is fixedly connected to a control valve. And the other end of the communicating pipe is connected to a gas source.

[0016] In this technical solution, the pressure relief component is composed of a pressure relief pipe. The pressure relief pipe is fixedly connected to one side of the top of the fixed pipe. The other end of the pressure relief pipe is fixedly connected to a buzzer, and a plurality of vibration plates are arranged at the air outlet of the buzzer. A first fixing ring and a second fixing ring are fixedly connected inside the pressure relief pipe. One side of the first fixing ring is connected to a plug through a spring, and the plug is fitted and inserted into the second fixing ring. The plug has a tip with an arc-shaped structure, and the maximum outer diameter of the plug is smaller than the inner diameter of the pressure relief pipe.

[0017] In this technical solution, the heater is arranged on one side of the deflector and is distributed corresponding to the smoke inlet. A number of heat conducting fins are evenly arranged on the surface of the heater, and an expansion material is arranged inside the heater. The expansion material is one of nitinol alloy, aluminum alloy, copper alloy, and silicon nitride.

[0018] In this technical solution, the top of the riser pipe is fixedly connected to the pressure relief pipe. A connecting rod is movably sleeved inside the riser pipe. The two ends of the connecting rod are respectively fixedly connected to a head and a resisting rod. The head penetrates through the housing and is located inside the heater. The head is in sealed sliding contact with the inside of the heater and contacts the expansion material. The resisting rod extends into the pressure relief pipe, and the top of the resisting rod has a tip structure and contacts the plug.

[0019] On the basis of conforming to the common knowledge in the art, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0020] The positive and progressive effects of the present invention are as follows:

[0021] For the above-mentioned high-temperature fire prevention mechanism of the air preheater, it uses the preheater assembly to realize the transportation of high-temperature flue gas and air, which can enable the high-temperature flue gas to flow smoothly inside the housing. A fairing is arranged on the housing for guiding the flue gas, so as to perform pressure relief operation under high temperature and high pressure, and at the same time discharge the flue gas from another channel, which can reduce the high temperature pressure inside it, avoid damage to the air preheater caused by excessive temperature, effectively reduce potential safety hazards, and since the temperature and pressure of the flue gas in the preheater are proportional, it can quickly open the fairing when the temperature is too high, and cooperate with the cooling mechanism to effectively realize the rapid cooling of the flue gas, which can play a guarantee role when the air preheater is operating unstably, and can be automatically opened when the temperature threshold is reached to ensure safety performance and improve the high-temperature fire prevention function of the air preheater. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic three-dimensional structure diagram of the whole of the present invention.

[0023] Figure 2 It is a schematic three-dimensional structure diagram at the heat exchange tube of the present invention.

[0024] Figure 3 Schematic diagram of the half-section structure of the present invention.

[0025] Figure 4 For the present invention Figure 3 Schematic diagram of the partially enlarged structure at position A in the present invention.

[0026] Figure 5 For the present invention Figure 3 Schematic diagram of the partially enlarged structure at position B in the present invention.

[0027] Figure 6 Schematic diagram of the front internal view of the present invention.

[0028] Figure 7 Schematic diagram of the side view at the riser pipe of the present invention.

[0029] Figure 8 Schematic diagram of the front external view of the present invention.

[0030] Figure 9 Schematic diagram of the side view at the air outlet of the present invention.

[0031] Figure 10 Schematic diagram of the top external view of the present invention.

[0032] Description of the reference numerals

[0033] 100, preheater assembly; 101, housing; 102, smoke inlet; 103, smoke outlet; 104, flow equalizing cover; 105, air inlet; 106, air outlet; 107, heat exchange tube; 108, guide plate; 109, nozzle; 110, branch pipe; 111, vertical pipe; 112, valve; 113, horizontal pipe;

[0034] 200, flow guiding assembly; 201, fairing; 202, smoke exhaust pipe; 203, opening; 204, rotating plate; 205, sealing plate; 206, pressing plate;

[0035] 300, pressing assembly; 301, fixed pipe; 302, movable plug; 303, movable rod; 304, pulley; 305, connecting pipe; 306, control valve; 307, limiting ring;

[0036] 400, pressure relief assembly; 401, pressure relief pipe; 402, buzzer; 403, vibrating piece; 404, first fixing ring; 405, second fixing ring; 406, spring; 407, plug;

[0037] 500, monitoring assembly; 501, heater; 502, heat conducting sheet; 503, expansion material; 504, end; 505, riser pipe; 506, connecting rod; 507, abutting rod. Detailed implementation manners

[0038] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments accordingly.

[0039] As Figure 1-10 shown, the high-temperature ignition prevention mechanism of the air preheater includes:

[0040] A preheater assembly 100, which is composed of a housing 101, and a cooling mechanism is fixedly installed on the top side wall of the housing 101;

[0041] A flow guiding component 200, which is fixedly installed on the top of the housing 101. The flow guiding component (200) is composed of a fairing 201. Sealing plates 205 and pressing plates 206 are respectively arranged inside both sides of the fairing 201. The pressing plate 206 contacts the end of the sealing plate 205, and the sealing plate 205 is fitted and connected to the inside of an opening 203 formed in the top of the housing 101;

[0042] A pressing component 300, a pressure relief component 400, and a monitoring component 500. The pressing component 300 is fixedly installed on one side of the fairing 201, and the movable end of the pressing component 300 contacts the pressing plate 206. The pressure relief component 400 is fixedly installed at the other end of the pressing component 300. A plug 407 is movably connected inside the pressure relief component 400. The monitoring component 500 is composed of a heater 501 and a riser 505. The heater 501 is fixedly installed inside the housing 101. The heater 501 is communicated with the riser 505. Both ends of the riser 505 are fixedly connected to the top of the housing 101 and the pressure relief component 400 respectively, and a resisting rod 507 contacting the plug 407 is arranged inside the riser 505.

[0043] An inlet smoke port 102 and an exhaust smoke port 103 are respectively fixedly installed at both ends of the housing 101. The inlet smoke port 102 and the exhaust smoke port 103 are respectively located on both sides of the housing 101. Arc-shaped flow guiding plates 108 are fixedly connected inside both ends of the housing 101, and the two flow guiding plates 108 are respectively distributed corresponding to the inlet smoke port 102 and the exhaust smoke port 103. A plurality of uniformly distributed heat exchange tubes 107 are arranged inside the housing 101. Both ends of the heat exchange tubes 107 are connected through the inside of the flow guiding plates 108; Both ends of the housing 101 are fixedly connected to flow equalizing covers 104. The two flow equalizing covers 104 are respectively connected through the two ends of the heat exchange tubes 107. Circular holes communicated with the heat exchange tubes 107 are opened in both of the two flow equalizing covers 104, and the two flow equalizing covers 104 are respectively connected to an air inlet 105 and an outlet pipe.

[0044] In this technical solution, high-temperature flue gas enters from the smoke inlet 102, and is guided by the deflector plate 108 so that the flue gas is discharged from the smoke outlet 103. At this time, the high temperature is absorbed by the heat exchange tube 107, and normal-temperature air enters from the air inlet 105, and after being evenly distributed by the flow equalizing cover 104, it flows through multiple heat exchange tubes 107. The air absorbs the heat of the flue gas and is discharged from the air outlet 106, thereby realizing the preheating of the air.

[0045] The temperature reduction mechanism is composed of nozzles 109. The nozzles 109 are connected through both sides of the top of the housing 101. The number of nozzles 109 is several and they are evenly arranged above the heat exchange tubes 107. A plurality of nozzles 109 on the same side are connected to the uniform branch pipes 110. The middle parts of the branch pipes 110 are respectively fixedly connected to both ends of the vertical pipe 111, and both ends of the vertical pipe 111 are fixedly connected to the valves 112. The vertical pipe 111 is arranged above the flow straightening cover 201, and the vertical pipe 111 is fixedly connected to a horizontal pipe 113 located on one side of the flow straightening cover 201. The flow straightening cover 201 is arranged on one side of the air outlet 106. The top of the flow straightening cover 201 is fixedly connected to the smoke exhaust pipe 202, and the smoke exhaust pipe 202 is communicated with the flue gas collection device. The inside of both sides of the flow straightening cover 201 is respectively rotatably connected to the rotating plate 204 and the pressing plate 206. The rotating plate 204 is fixedly connected to the sealing plate 205. The edge of the sealing plate 205 is provided with an inclined edge, and the inclined edge of the edge of the sealing plate 205 is in fitting connection with the opening 203.

[0046] In this technical solution, when the temperature is too high, at this time, the external gas is transported from the horizontal pipe 113 into the vertical pipe 111, and after the valve 112 is opened, the air is ejected from the nozzle group. The nozzle 109 overcomes the pressure inside the housing 101 to discharge the air flow, and mixes with the flue gas to reduce the temperature of the flue gas, so as to perform temperature reduction treatment to avoid the problem of ignition caused by too high temperature, improve the safety performance, and the flue gas used for temperature reduction is discharged from the flow straightening cover 201, and the air inside the flow straightening cover 201 can be synchronously cooled.

[0047] The pressing component 300 is composed of a fixed pipe 301. The fixed pipe 301 is inclined and arranged on one side of the flow straightening cover 201. An active plug 302 is hermetically slid inside the fixed pipe 301. The active plug 302 is fixedly connected to one end of the active rod 303. One end of the active rod 303 extends to the outside of the fixed pipe 301. The bottom end of the active rod 303 is rotatably connected to a pulley 304, and the pulley 304 is in contact with the top surface of the pressing plate 206. The inside of the fixed pipe 301 is fixedly connected to a limiting ring 307. The limiting ring 307 is arranged between the pressure relief component 400 and the active plug 302. The top end of the fixed pipe 301 is fixedly connected to a communicating pipe 305. The communicating pipe 305 is fixedly connected to a control valve 306, and the other end of the communicating pipe 305 is connected to a gas source.

[0048] In this technical solution, the pressing component 300 can be used to control the sealing plate 205. During use, the gas source is connected to the connecting pipe 305 and the control valve 306 is opened. At this time, positive pressure is formed in the fixed pipe 301. The pressure relief pipe 401 is equivalent to a check valve structure, so that the positive pressure gas pushes the movable plug 302 downward, and the pulley 304 at the bottom of the movable rod 303 is pushed to contact the pressing plate 206. When the pressing plate 206 is pushed downward, it drives the sealing plate 205 and the rotating plate 204 to rotate, so that the rotating plate 204 drives the sealing plate 205 to abut against the opening 203, and the inclined slope at the edge of the sealing plate 205 cooperates with the opening 203 to achieve extrusion sealing. After the opening 203 is closed, the control valve 306 is closed, thereby realizing the control, so that the flue gas will not be discharged from the fairing 201 when the air preheater is in normal use.

[0049] The pressure relief component 400 is composed of a pressure relief pipe 401. The pressure relief pipe 401 is fixedly connected to one side of the top of the fixed pipe 301. The other end of the pressure relief pipe 401 is fixedly connected with a buzzer 402, and a plurality of vibrating pieces 403 are arranged at the air outlet 106 of the buzzer. A first fixing ring 404 and a second fixing ring 405 are fixedly connected to a part inside the pressure relief pipe 401. One side of the first fixing ring 404 is connected to a plug 407 through a spring 406, and the plug 407 is fitted and inserted into the inside of the second fixing ring 405. The plug 407 is provided with a tip with an arc-shaped structure, and the maximum outer diameter of the plug 407 is smaller than the inner diameter of the pressure relief pipe 401.

[0050] In this technical solution, when the temperature inside the housing 101 is too high, at this time, the monitoring component 500 transmits a thrust to move the plug 407. The plug 407 overcomes the air pressure inside the housing 101 and the elasticity of the spring 406 to move it to the right. The plug 407 is separated from the inside of the second fixing ring 405. At this time, the air pressure in the fixed pipe 301 is discharged from the gap between the plug 407 and the pressure relief pipe 401. At this time, the movable plug 302 in the fixed pipe 301 is not restricted, and the positive pressure of the flue gas inside the housing 101 pushes the sealing plate 205 to open, so that part of the flue gas is discharged from the fairing 201 and collected. The flue gas can be shunted when the temperature of the air preheater suddenly increases, and at the same time, a lower medium is sprayed at the nozzle 109 for cooling to avoid ignition problems when the temperature is too high. When the temperature of the air preheater returns to normal, the air pressure is continuously replenished into the fixed pipe 301 to continue to seal the sealing plate 205, thereby realizing the normal flow of the flue gas.

[0051] The heater 501 is arranged on one side of the deflector 108 and is distributed corresponding to the smoke inlet 102. A plurality of heat conducting fins 502 are evenly arranged on the surface of the heater 501, and an expansion material 503 is arranged inside the heater 501. The expansion material 503 is one of nitinol alloy, aluminum alloy, copper alloy and silicon nitride. The top end of the riser 505 is fixedly connected to the pressure relief pipe 401. A connecting rod 506 is movably sleeved inside the riser 505. Both ends of the connecting rod 506 are fixedly connected to the end head 504 and the abutting rod 507 respectively. The end head 504 penetrates through the housing 101 and is located inside the heater 501. The end head 504 is in sealed sliding contact with the inside of the heater 501 and contacts the expansion material 503. The abutting rod 507 extends into the pressure relief pipe 401, and the top of the abutting rod 507 is a tip structure and contacts the plug 407.

[0052] In this technical solution, the heater 501 arranged on one side of the deflector 108 can be used for monitoring high-temperature flue gas, so that when the excessive flue gas enters the housing 101, the temperature change can be felt in time. When the temperature is too high, the high-temperature flue gas is absorbed by the heat conducting fins 502, causing the expansion material 503 to expand due to heat. When the temperature exceeds the threshold value, the expansion material 503 pushes the end head 504 to move a certain distance. The end head 504 pushes the connecting rod 506 to move inside the riser 505, causing the connecting rod 506 to drive the abutting rod 507 to move upward a small distance. Since the top of the abutting rod 507 and the tip of the plug 407 are in contact with each other, a certain amount of lateral thrust is generated when the abutting rod 507 moves upward, thereby driving the plug 407 to deflect a certain distance, forming a gap between the plug 407 and the second fixing ring 405, resulting in the discharge of the gas in the fixed pipe 301. When the gas is discharged, it is discharged from the buzzer 402. When the gas is quickly discharged, the vibrating piece 403 vibrates at a high frequency, thereby generating an alarm warning sound, which is convenient for timely pressure relief and cooling when the air preheater appears at a high temperature and exceeds the threshold value. At the same time, the alarm function is realized, the use safety of the air preheater is improved, and the anti-high-temperature ignition function of the preheater is improved.

[0053] The present invention is not limited to the above embodiments. No matter what changes are made in its shape or structure, they all fall within the protection scope of the present invention. The protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. Air preheater high temperature fire prevention mechanism, characterized in that: The air preheater high temperature fire prevention mechanism comprises: A preheater assembly (100), the preheater assembly (100) is composed of a shell (101), and a cooling mechanism is fixedly installed on the top side wall of the shell (101); A flow guide assembly (200), the flow guide assembly (200) is fixedly mounted on the top of the shell (101), the flow guide assembly (200) is composed of a fairing (201), and sealing plates (205) and pressure plates (206) are respectively provided inside the two sides of the fairing (201), the pressure plates (206) contact the ends of the sealing plates (205), and the sealing plates (205) are embedded and connected inside the opening (203) provided at the top of the shell (101); A clamping assembly (300), a pressure relief assembly (400) and a monitoring assembly (500), wherein the clamping assembly (300) is fixedly mounted on one side of a fairing (201), a movable end of the clamping assembly (300) contacts a pressure plate (206), the pressure relief assembly (400) is fixedly mounted on the other end of the clamping assembly (300), a movably connected plug (407) is provided inside the pressure relief assembly (400), and the monitoring assembly (500) is composed of a heat receiver (501) and a riser (505), the heat receiver (501) is fixedly mounted inside a shell (101), the heat receiver (501) is connected to the riser (505), two ends of the riser (505) are respectively fixedly connected to the top of the shell (101) and the pressure relief assembly (400), and a stopper (507) in contact with the plug (407) is provided inside the riser (505).

2. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: A smoke inlet (102) and a smoke exhaust port (103) are fixedly mounted at both ends of the shell (101), and the smoke inlet (102) and the smoke exhaust port (103) are respectively connected to two sides of the shell (101). A guide plate (108) with an arc structure is fixedly connected inside both ends of the shell (101), and the two guide plates (108) are respectively distributed corresponding to the smoke inlet (102) and the smoke exhaust port (103). A plurality of evenly distributed heat exchange tubes (107) are arranged inside the shell (101), and both ends of the heat exchange tubes (107) are connected to the inside of the guide plate (108).

3. The air preheater high temperature fire prevention mechanism according to claim 2, characterized in that: Both ends of the shell (101) are fixedly connected to the flow equalizer (104), and the two flow equalizers (104) are respectively connected to the two ends of the heat exchange tube (107). The two flow equalizers (104) are each provided with a circular hole connected to the heat exchange tube (107), and the two flow equalizers (104) are respectively fixedly connected to the air inlet (105) and the air outlet pipe.

4. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The cooling mechanism is composed of a nozzle (109), wherein the nozzle (109) is connected through both sides of the top of the shell (101), the number of the nozzles (109) is multiple and they are evenly arranged above the heat exchange tube (107), and the multiple nozzles (109) located on the same side are evenly connected to a branch pipe (110), the middle of the branch pipe (110) is fixedly connected to both ends of a vertical pipe (111), and both ends of the vertical pipe (111) are fixedly connected to a valve (112), the vertical pipe (111) is arranged above the fairing (201), and the vertical pipe (111) is fixedly connected to a horizontal pipe (113) located on one side of the fairing (201).

5. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The fairing (201) is arranged on one side of the air outlet (106), the top of the fairing (201) is fixedly connected to the smoke exhaust pipe (202), the smoke exhaust pipe (202) is connected to the smoke collection device, the inside of the two sides of the fairing (201) are rotatably connected to the rotating plate (204) and the pressure plate (206), the rotating plate (204) is fixedly connected to the sealing plate (205), the edge of the sealing plate (205) is provided with a bevel, and the bevel of the edge of the sealing plate (205) is fitted and connected to the opening (203).

6. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The clamping assembly (300) is composed of a fixed tube (301), which is tiltedly arranged on one side of the fairing (201). A movable plug (302) is sealed and slidably provided inside the fixed tube (301). The movable plug (302) is fixedly connected to one end of a movable rod (303), and one end of the movable rod (303) extends to the outside of the fixed tube (301). The bottom end of the movable rod (303) is rotatably connected to a pulley (304), and the pulley (304) is in contact with the top surface of the pressure plate (206).

7. The air preheater high temperature fire prevention mechanism according to claim 6, characterized in that: The interior of the fixed tube (301) is fixedly connected to a limit ring (307), and the limit ring (307) is arranged between the pressure relief assembly (400) and the movable plug (302). The top end of the fixed tube (301) is fixedly connected to a connecting tube (305), and the connecting tube (305) is fixedly connected to a control valve (306), and the other end of the connecting tube (305) is connected to a gas source.

8. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The pressure relief assembly (400) is composed of a pressure relief pipe (401), wherein the pressure relief pipe (401) is fixedly connected to one side of the top of the fixed pipe (301), and the other end of the pressure relief pipe (401) is fixedly connected to a buzzer (402), and a plurality of vibration plates (403) are arranged at the air outlet (106) of the buzzer. The inner part of the pressure relief pipe (401) is fixedly connected to a first fixing ring (404) and a second fixing ring (405), and one side of the first fixing ring (404) is connected to a plug (407) through a spring (406), and the plug (407) is inserted and engaged with the inner part of the second fixing ring (405), and the plug (407) is provided with a tip with an arc structure, and the maximum outer diameter of the plug (407) is smaller than the inner diameter of the pressure relief pipe (401).

9. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The heat receiver (501) is arranged on one side of the guide plate (108) and distributed corresponding to the smoke inlet (102); a plurality of evenly distributed heat conducting plates (502) are provided on the surface of the heat receiver (501); and an expansion material (503) is provided inside the heat receiver (501); the expansion material (503) is one of nitinol alloy, aluminum alloy, copper alloy and silicon nitride.

10. The air preheater high temperature fire prevention mechanism according to claim 1, characterized in that: The top of the riser (505) is fixedly connected to the pressure relief pipe (401), and a connecting rod (506) is movably sleeved inside the riser (505). The two ends of the connecting rod (506) are respectively fixedly connected to the end head (504) and the push rod (507). The end head (504) passes through the shell (101) and is located inside the heat receiver (501). The end head (504) is sealed and slidable inside the heat receiver (501), and the end head (504) is in contact with the expansion material (503). The push rod (507) extends into the pressure relief pipe (401), and the top of the push rod (507) is a pointed structure and is in contact with the plug (407).

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