A boiler flame detector cooling air switching device

Abstract

The utility model relates to the technical field of thermal power plants, and discloses a boiler flame detector cooling air switching device, which includes a flame detector air main pipe and a micro-oil combustion-supporting air pipe. The air switching component includes a three-way reversing baffle threadedly connected to the outer surface of the flame detector air main pipe. The two ends of the three-way reversing baffle are respectively threadedly installed with an air guiding pipe and an air conveying pipe. The air guiding pipe is threadedly connected to the three-way air pipe. The outer surface of the micro-oil combustion-supporting air pipe is provided with an air diversion opening for diverting wind power, and the air diversion opening is threadedly connected to the air conveying pipe. The middle end of the air conveying pipe is flange-connected with a manual valve. Through the three-way reversing baffle, the flame detector fan A, the flame detector fan B, the three-way air pipe and the air guiding pipe form a set of systems and are used as spares for the micro-oil combustion-supporting air pipe, the manual valve and the air conveying pipe which form another set of systems. The original flame detector fan A and flame detector fan B are used as standby air sources and cooling air sources during the start-up and shutdown of the unit. By rotating the control end of the three-way reversing baffle, the automatic control of the air path is realized.

Description

Technical Field

[0001] This utility model relates to the technical field of thermal power plants, specifically to a boiler fire detection cooling air switching device. Background Technology

[0002] Currently, the flame detection cooling air system used in coal-fired boilers to cool flame detection probes employs two flame detection cooling fans, one in operation and one on standby, with local air intake. These fans are centrifugal, resulting in a small air volume and frequent fan malfunctions. Operating at high temperatures, the fans are prone to causing coking or burning of the flame detection probes, posing a threat to the safe and economical operation of the unit. When all flame detection cooling fans stop or the pressure in the flame detection cooling air supply main pipe is too low, the boiler triggers a main fuel trip (MFT).

[0003] Current retrofitting schemes in other power plants involve using the boiler's 12m platform cold primary air to micro-oil combustion air duct as the air source for flame detector cooling air. The duct uses carbon steel pipes of the same diameter as the main flame detector cooling air duct, and a manual gate valve is added to the newly installed duct. The original flame detector cooling fan outlet duct remains unchanged, allowing for manual opening of the cold primary air to the main flame detector cooling air duct for emergency use in case of failure of either of the two flame detector fans. However, this retrofitting scheme is relatively simple, providing only basic emergency air supply. Normally, the two flame detector fans still provide cooling air, and in case of fan failure, operators must manually operate the valve to send cold primary air into the flame detector fan duct. This requires manual operation, has a slow response time, and since the flame detector fans are still running normally, energy savings cannot be achieved.

[0004] Therefore, we propose a boiler fire detector cooling air switching device to solve the problems mentioned above. Utility Model Content

[0005] The purpose of this utility model is to provide a boiler flame detector cooling air switching device to solve the problem mentioned in the background art that when the fan fails, the operator needs to go to the site to manually operate the valve to send primary cold air into the flame detector fan main pipe.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a boiler flame detection cooling air switching device, comprising a flame detection air main pipe and a micro-oil combustion air pipe, wherein a ventilation component is threadedly installed on the outer surface of the flame detection air main pipe, a three-ventilation pipe is threadedly installed at one end of the ventilation component, and flame detection fan A and flame detection fan B are connected to both ends of the three-ventilation pipe, and one end of the ventilation component is threadedly installed on the outer surface of the micro-oil combustion air pipe;

[0007] The ventilation component includes a three-way reversing baffle that is threaded to the outer surface of the fire detector air main pipe. The two ends of the three-way reversing baffle are respectively threaded with an air intake pipe and an air supply pipe. The air intake pipe and the three-way air intake pipe are threaded together. The outer surface of the micro-oil combustion air pipe is provided with an air distribution port for diverting airflow. The air distribution port is threaded together with the air supply pipe. A manual valve is connected to the flange at the middle end of the air supply pipe.

[0008] Preferably, both ends of the middle section of the micro-oil combustion-supporting air duct are screwed to bend pipe A and bend pipe B, and bend pipe A and bend pipe B are screwed together.

[0009] Preferably, the inner walls of the curved pipe A and curved pipe B are equipped with inclined frames, and polypropylene adsorption nets are installed inside the inclined frames.

[0010] Preferably, the outer surface of the micro-oil combustion-supporting air duct is threaded with a T-shaped connecting pipe, and the T-shaped connecting pipe is located between the air distribution port and the bend pipe A. The lower end of the T-shaped connecting pipe has a threaded groove. An oil fume sensor is welded to one end of the T-shaped connecting pipe and the inner side of the micro-oil combustion-supporting air duct. An installation box is welded to the outer surface of the micro-oil combustion-supporting air duct.

[0011] Preferably, the outer surface of the mounting box is welded with a heat dissipation mesh, the interior of the mounting box is equipped with a current-limiting resistor and a microcontroller, the top of the mounting box is threaded with an LED light, and the outer surface of the micro-oil combustion-supporting air duct is threaded with a threaded cap at the corresponding position of the T-shaped connecting pipe.

[0012] Preferably, heat sinks are welded to the outer surface of the air duct.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. The present invention discloses a boiler flame detector cooling air switching device, which uses a three-way reversing baffle to make flame detector fan A, flame detector fan B, three-way ventilation duct and exhaust duct one system and micro-oil combustion air duct, manual valve and air supply duct another system for mutual backup. The original flame detector fan A and flame detector fan B are used as backup air source and cooling air source during unit start-up and shutdown. The exhaust duct and air supply duct are made of carbon steel pipe with a diameter of DN300 mm. The control end of the three-way reversing baffle is rotated to realize the automatic control of the air path.

[0015] 2. The present invention discloses a boiler fire detection cooling air switching device. An oil fume sensor threaded between the air supply pipe and the bend pipe A monitors the oil stains inside the micro-oil combustion air pipe. When the oil stains inside the micro-oil combustion air pipe exceed the standard, the microcontroller controls the LED light to light up as a reminder. By adding heat sinks to increase the surface area of ​​the air supply pipe, the contact area between the air and the air supply pipe is increased, effectively improving the heat dissipation efficiency and protecting the oil fume sensor. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the ventilation component structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the air duct structure of this utility model;

[0019] Figure 4 This is a schematic diagram of the micro-oil combustion-supporting air duct structure of this utility model.

[0020] In the diagram: 1. Flame detection air main duct; 2. Air exchange component; 21. Three-way reversing baffle; 22. Exhaust duct; 23. Supply duct; 231. Heat sink; 24. Manual valve; 3. Flame detection fan A; 4. Flame detection fan B; 5. Three-way ventilation duct; 6. Micro-oil combustion duct; 61. Bend pipe A; 62. Bend pipe B; 63. Inclined frame; 631. Polypropylene adsorption mesh; 64. Air distribution outlet; 65. T-shaped connecting pipe; 66. Threaded groove; 67. Oil fume sensor; 68. Mounting box; 681. Heat dissipation mesh; 682. LED light; 683. Current limiting resistor; 684. Microcontroller; 69. Threaded cap. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1: Please refer to Figures 1-4 A boiler flame detection cooling air switching device includes a flame detection air main pipe 1 and a micro-oil combustion air pipe 6. A ventilation component 2 is threadedly installed on the outer surface of the flame detection air main pipe 1. A three-ventilation pipe 5 is threadedly installed at one end of the ventilation component 2. Flame detection fan A3 and flame detection fan B4 are connected to both ends of the three-ventilation pipe 5. One end of the ventilation component 2 is threadedly installed on the outer surface of the micro-oil combustion air pipe 6.

[0023] The ventilation component 2 includes a three-way reversing baffle 21 threadedly connected to the outer surface of the fire detector air main pipe 1. The two ends of the three-way reversing baffle 21 are respectively threadedly installed with an air intake pipe 22 and an air supply pipe 23. The air intake pipe 22 is threadedly connected to the three-way ventilation pipe 5. The outer surface of the micro-oil combustion air pipe 6 is provided with an air distribution port 64 for diverting air force. The air distribution port 64 is threadedly connected to the air supply pipe 23. The middle flange of the air supply pipe 23 is connected to a manual valve 24.

[0024] In this embodiment: the air source for the micro-oil combustion duct 6 is the primary air from the 12 m platform of the boiler. One end of the air supply duct 23 is connected to the air distribution port 64. The micro-oil combustion duct 6 serves as the cooling air source for the flame detection system. The three-way reversing baffle 21 connects the flame detection fan A3, flame detection fan B4, three-way duct 5, and exhaust duct 22 as one system, and the micro-oil combustion duct 6, manual valve 24, and exhaust duct 23 as another system, serving as backups for each other. The original flame detection fans A3 and B4 are used as backup air sources and cooling air sources during unit start-up and shutdown. The exhaust duct 22 and exhaust duct 23 use a diameter of DN300. The carbon steel pipe is made of mm. By rotating the control end of the three-way reversing baffle 21, the air path can be automatically controlled. The manual valve 24 is opened, and the air inside the micro-oil combustion air pipe 6 flows to the flame detection air main pipe 1 through the air supply pipe 23 and the three-way reversing baffle 21, completing the switching of the flame detection cooling air. This facilitates the daily maintenance of the flame detection fan A3 and the flame detection fan B4, and does not affect the cooling effect on the flame detection probe.

[0025] Example 2: This example is an improvement upon Example 1. For details, please refer to [link / reference]. Figures 2-4 Both ends of the middle section of the micro-oil combustion air duct 6 are screwed to bend pipe A61 and bend pipe B62. The bend pipe A61 and bend pipe B62 are screwed together to facilitate the disassembly of bend pipe A61 and bend pipe B62.

[0026] An inclined frame 63 is installed on the inner wall of the bends A61 and B62. A polypropylene adsorption net 631 is installed inside the inclined frame 63. The polypropylene adsorption net 631 is set on the inner and outer sides of the bends A61 and B62 and is used to adsorb oil stains.

[0027] A T-shaped connecting pipe 65 is threaded onto the outer surface of the micro-oil combustion-supporting air duct 6, and the T-shaped connecting pipe 65 is located between the air distribution port 64 and the bend pipe A61. A threaded groove 66 is formed at the lower end of the T-shaped connecting pipe 65. An oil fume sensor 67 is welded to one end of the T-shaped connecting pipe 65 and to the inner side of the micro-oil combustion-supporting air duct 6. A mounting box 68 is welded to the outer surface of the micro-oil combustion-supporting air duct 6. The oil fume sensor 67 is a ZE03 model, and its basic principle is based on the influence of oil on conductivity. The sensor's resistance changes with the concentration of oil. The molecular structure of oil is usually insulating; when oil mist or oil fume comes into contact with the sensor surface, a certain change in resistance occurs.

[0028] A heat dissipation mesh 681 is welded to the outer surface of the mounting box 68. A current-limiting resistor 683 and a microcontroller 684 are installed inside the mounting box 68. An LED light 682 is threaded onto the top of the mounting box 68. A threaded cap 69 is threaded onto the outer surface of the micro-oil combustion duct 6 at the corresponding position of the T-shaped connecting pipe 65. The heat dissipation mesh 681 is used to dissipate heat from the current-limiting resistor 683 and the microcontroller 684. Rotating the threaded cap 69 allows for cleaning of the oil fume sensor 67. The oil fume sensor 67 outputs a resistance value related to the oil concentration. A bridge circuit converts the resistance change into a voltage signal. The converted analog signal (voltage value) is input to the analog input pin of the microcontroller 684 for sampling. The microcontroller 684 can convert the analog signal into oil concentration data. When the oil concentration exceeds a threshold, the microcontroller 684 can control the GPIO pin to output a signal to drive the LED light 682. The current-limiting resistor 683 protects the LED light 682 from damage due to excessive current and ensures its stable and reliable operation.

[0029] Heat sinks 231 are welded to the outer surface of the air duct 23 to improve the heat dissipation effect of the air duct 23.

[0030] In this embodiment: A bend in pipe A61 and a bend in pipe B62 are installed in the middle section of the micro-oil combustion duct 6. A polypropylene adsorption mesh 631 installed inside bends A61 and B62 filters the oil in the micro-oil combustion duct 6, preventing oil from flowing back to the threaded groove 66 with the combustion air. An oil fume sensor 67, threaded between the air duct 23 and bend A61, monitors the oil inside the micro-oil combustion duct 6. When the oil level inside the micro-oil combustion duct 6 exceeds the standard, the microcontroller 684 controls an LED light 682 to illuminate as a warning. The mesh used for bends A61 and B62 is rotated... After installing the screws on B62, the bent pipes A61 and B62 can be disassembled to clean the polypropylene adsorption net 631. This prevents oil from being discharged into the flame detector air header 1 through the air supply pipe 23 when switching cooling air. When using the cooling system of the oil-assisted combustion air duct 6, manual valve 24, and air supply pipe 23, the heat in the flame detector air header 1 is discharged into the air supply pipe 23. By adding heat sinks 231, the surface area of ​​the air supply pipe 23 is increased, improving the contact area between the air and the air supply pipe 23, effectively improving heat dissipation efficiency and protecting the oil fume sensor 67.

[0031] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0032] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A boiler flame detection cooling air switching device, comprising a flame detection air main pipe (1) and a micro-oil combustion-supporting air pipe (6), characterized in that: The outer surface of the fire detection air main pipe (1) is threaded with a ventilation component (2), one end of the ventilation component (2) is threaded with a three-ventilation pipe (5), the two ends of the three-ventilation pipe (5) are connected to the fire detection fan A (3) and the fire detection fan B (4), and one end of the ventilation component (2) is threaded on the outer surface of the micro-oil combustion air pipe (6). The ventilation component (2) includes a three-way reversing baffle (21) threaded to the outer surface of the fire detector air main pipe (1). The two ends of the three-way reversing baffle (21) are respectively threaded with an air intake pipe (22) and an air supply pipe (23). The air intake pipe (22) is threaded to the three-way ventilation pipe (5). The outer surface of the micro-oil combustion air pipe (6) is provided with an air distribution port (64) for diverting air force. The air distribution port (64) is threaded to the air supply pipe (23). The middle flange of the air supply pipe (23) is connected to a manual valve (24).

2. The boiler flame detector cooling air switching device according to claim 1, characterized in that: Both ends of the middle section of the micro-oil combustion air duct (6) are screwed to bend pipe A (61) and bend pipe B (62), and bend pipe A (61) and bend pipe B (62) are screwed together.

3. A boiler flame detector cooling air switching device according to claim 2, characterized in that: The inner walls of the curved pipe A (61) and the curved pipe B (62) are equipped with inclined frames (63), and polypropylene adsorption nets (631) are installed inside the inclined frames (63).

4. A boiler flame detector cooling air switching device according to claim 3, characterized in that: The outer surface of the micro-oil combustion duct (6) is threaded with a T-shaped connecting pipe (65), and the T-shaped connecting pipe (65) is located between the air distribution port (64) and the bend pipe A (61). The lower end of the T-shaped connecting pipe (65) is provided with a threaded groove (66). An oil fume sensor (67) is welded to one end of the T-shaped connecting pipe (65) and inside the micro-oil combustion duct (6). An installation box (68) is welded to the outer surface of the micro-oil combustion duct (6).

5. A boiler flame detector cooling air switching device according to claim 4, characterized in that: The outer surface of the mounting box (68) is welded with a heat dissipation mesh (681). The inside of the mounting box (68) is equipped with a current limiting resistor (683) and a microcontroller (684). An LED light (682) is threaded on the top of the mounting box (68). A threaded cap (69) is threaded on the outer surface of the micro-oil combustion air duct (6) and at the corresponding position of the T-shaped connecting pipe (65).

6. A boiler flame detector cooling air switching device according to claim 1, characterized in that: The outer surface of the air duct (23) is welded with heat sinks (231).

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