Rotational flow combustion device capable of adjusting length-diameter ratio of pre-combustion chamber and rotational flow combustion method

Abstract

The invention discloses a rotational flow combustion device capable of adjusting the length-diameter ratio of a pre-combustion chamber and a rotational flow combustion method, relates to an industrial pulverized coal boiler combustion device, and aims to thoroughly solve the problem of slag bonding of a boiler applying a pre-combustion chamber combustor when the coal quality changes, a primary air pipeline, an inner secondary air pipeline and an outer secondary air pipeline are sequentially arranged from inside to outside; an outlet of the primary air pipeline, an outlet of the inner secondary air pipeline and an outlet of the outer secondary air pipeline all communicate with a combustion chamber of the adjustable pre-combustion chamber, a driving part of the adjustable pre-combustion chamber is installed outside the outer secondary air pipeline, and the outer secondary air pipeline and the combustion chamber of the adjustable pre-combustion chamber are sleeved with the separation secondary air pipeline. The length of a combustion chamber of the adjustable pre-combustion chamber is adjusted in the axial direction of the outer secondary air pipeline, and the video flame detection device, the outlet temperature sensor and the cylinder wall temperature sensor are installed on the combustion chamber of the adjustable pre-combustion chamber. The invention belongs to the field of boilers.

Description

Technical Field

[0001] The invention relates to an industrial pulverized coal boiler combustion device, and in particular to a swirl combustion device and a swirl combustion method capable of adjusting the aspect ratio of a pre-combustion chamber. The invention is used in the field of boilers. Background Art

[0002] Boilers equipped with precombustion chamber burners have the advantages of stable combustion, convenient start and stop, low pollutant emission concentration and wide load adjustment range, and are widely used in power supply and heating fields. my country's coal can be divided into anthracite, bituminous coal, lean coal and lignite according to different volatile matter. There are obvious differences in the ignition and combustion characteristics of different types of coal. In the actual operation of coal-fired boilers, mixed coal or different types of coal are often put into operation. When the quality of the coal used changes, if the boiler lacks a matching combustion system, problems such as coal powder being difficult to burn out and furnace slagging will occur. Slagging in the precombustion chamber and near the outlet may cause the temperature in the furnace to rise; the negative pressure in the furnace decreases and gradually becomes positive; slagging on the wall of the precombustion chamber may affect the aerodynamic field in the precombustion chamber and affect the stable combustion of the boiler; large pieces of slag falling may damage the cold ash hopper at the bottom of the furnace or the water-cooled wall pipe of the furnace, causing serious safety accidents. Therefore, preventing slagging is of great significance to improving the safety and economy of boiler operation.

[0003] In order to completely solve the slagging problem of a boiler using a pre-combustion chamber burner when the coal quality changes, the present invention proposes a swirl combustion device and a swirl combustion method. Summary of the invention

[0004] In order to completely solve the slagging problem of a boiler using a precombustion chamber burner when the coal quality changes, the present invention further proposes a swirl combustion device and a swirl combustion method.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] A swirl combustion device with an adjustable pre-combustion chamber aspect ratio, comprising a primary air duct, an inner secondary air duct, an outer secondary air duct and a separated secondary air duct; it also comprises a video fire detection device, an outlet temperature sensor, a cylinder wall temperature sensor and an adjustable pre-combustion chamber;

[0008] The primary air duct, the inner secondary air duct and the outer secondary air duct are arranged in sequence from the inside to the outside. The primary air duct outlet, the inner secondary air duct outlet and the outer secondary air duct outlet are all connected to the combustion chamber of the adjustable precombustion chamber. The driving part of the adjustable precombustion chamber is installed on the outside of the outer secondary air duct. The separation secondary air duct is sleeved on the outside of the outer secondary air duct and the combustion chamber of the adjustable precombustion chamber. The length of the combustion chamber of the adjustable precombustion chamber is adjusted along the axial direction of the outer secondary air duct. The video fire detection device, the outlet temperature sensor and the barrel wall temperature sensor are installed on the combustion chamber of the adjustable precombustion chamber.

[0009] Further, the combustion chamber of the adjustable pre-combustion chamber includes a pre-combustion chamber inner sleeve and a pre-combustion chamber outer sleeve;

[0010] The outlet end of the outer sleeve of the precombustion chamber is installed at the entrance of the furnace and is connected to the furnace. The inner sleeve of the precombustion chamber is slidably arranged in the outer sleeve of the precombustion chamber. The primary air duct outlet, the inner secondary air duct outlet and the outer secondary air duct outlet are all connected to the inner sleeve of the precombustion chamber.

[0011] Furthermore, the inner wall of the outer sleeve of the precombustion chamber is provided with multiple slide rails along the length direction, and limit switches are installed at both ends of each slide rail. At least two rows of rollers are provided on the outer wall of the outlet of the inner sleeve of the precombustion chamber, and the sleeve of the precombustion chamber is slidably arranged on the slide rails of the outer sleeve of the precombustion chamber through the rollers.

[0012] Further, the driving part of the adjustable pre-combustion chamber includes a bracket, two pull rods, two connecting mechanisms, four limit nuts and four washers;

[0013] Two pull rods are arranged opposite to each other on the bracket, and the pull rods are processed with threaded sections. The threaded section of each pull rod is arranged on the bracket, and the threaded section of each pull rod is threadedly connected to two limit nuts, and the two limit nuts are located on both sides of the bracket. A gasket is provided between each limit nut and the bracket, and one end of each pull rod is connected to the sleeve in the pre-combustion chamber through a connecting mechanism.

[0014] Furthermore, a video fire detection device is installed on the inner sleeve of the precombustion chamber near the outlet of the external secondary air duct, an outlet temperature sensor is installed on the inner sleeve of the precombustion chamber near the connecting mechanism, and a barrel wall temperature sensor is installed on the outer sleeve of the precombustion chamber near the furnace wall of the furnace.

[0015] A swirl combustion method of a swirl combustion device capable of adjusting the aspect ratio of a pre-combustion chamber, the method being implemented according to the following steps:

[0016] Step 1: According to the softening temperature ST of the coal, the temperature T1 of the outlet temperature sensor and the temperature T2 of the barrel wall temperature sensor, the recirculation zone in the precombustion chamber can be adjusted in combination with slagging, and the distance m1 between the burner outlet and the starting point of the recirculation zone, the length m of the recirculation zone and the diameter d of the recirculation zone are adjusted to the ratio of the diameter of the precombustion chamber respectively;

[0017] Step 2: The slagging condition at the outlet of the adjustable pre-combustion chamber is observed through the DSC of the boiler, and the slagging blocks are cleaned by controlling the adjustable pre-combustion chamber 20 to adjust the aspect ratio.

[0018] Furthermore, in method 1 of step 1: when the softening temperature ST of the burning coal is greater than 1390°C, or 800°C ≥ the temperature T1 of the outlet temperature sensor is greater than 150°C, or 200 ≥ the temperature T2 of the barrel wall temperature sensor is greater than 150°C, and the thickness of the slag layer is between 0 and 30 mm, a large recirculation zone is required in the precombustion chamber. Therefore, the pull rod is pulled to adjust the position of the sleeve in the precombustion chamber so that L = 1.2 to 1.4, where L is the length of the precombustion chamber, and m1 = 0.05 to 0.1D, m = 1.0 to 1.15D, and d = 0.8 to 0.85D of the central recirculation zone in the precombustion chamber.

[0019] Furthermore, in method 2 of step 1: when the softening temperature ST of the burning coal is between 1260 and 1390°C, or 850≥the temperature T1 of the outlet temperature sensor is greater than 800°C, or the temperature T2 of the barrel wall temperature sensor is greater than 200°C, and the thickness of the slag layer is between 30-100mm, a large recirculation zone is required in the precombustion chamber. Therefore, the pull rod is pulled to adjust the position of the sleeve in the precombustion chamber so that L=1.0~1.2D, L is the length of the precombustion chamber, and m1=0.1~0.15D, m=0.7~1.0D, and d=0.6~0.8D of the central recirculation zone in the precombustion chamber.

[0020] Furthermore, in method three of step one: when the softening temperature ST of the burning coal is less than or equal to 1260, or the temperature T1 of the outlet temperature sensor is greater than 850°C, and the thickness of the slag layer is greater than 100mm, a small recirculation zone is required in the precombustion chamber. Therefore, the pull rod is pulled to adjust the position of the sleeve in the precombustion chamber so that L=0.8~1.0D, L is the length of the precombustion chamber, and m1=0.15~0.25D, m=0.6~0.7D, and d=0.5~0.6D of the central recirculation zone in the precombustion chamber.

[0021] Furthermore, in step 2, the slag blocks are cleaned by controlling the adjustable aspect ratio of the precombustion chamber, pulling the pull rod to extend and retract the inner sleeve of the precombustion chamber within the outer sleeve of the precombustion chamber, and shaking off the slag blocks.

[0022] Beneficial effects of the present invention:

[0023] 1. The swirl combustion device and swirl combustion method of the present application effectively prevent slagging at the outlet of the pre-combustion chamber:

[0024] When burning slagging coal, if there is a large recirculation zone in the precombustion chamber, the ignition position of the coal powder will move forward, the coal powder will burn for a long time in the precombustion chamber, release more energy, and make the temperature in the precombustion chamber too high, which will lead to slagging at the outlet of the precombustion chamber. If there is a small recirculation zone in the precombustion chamber, the intense combustion process of the coal powder will be pushed into the furnace, but it will increase the difficulty of coal powder ignition. Therefore, the length of the precombustion chamber needs to be adjusted according to the slagging characteristics of the coal type and the temperature of the precombustion chamber, so that there is a recirculation zone of a suitable range in the precombustion chamber.

[0025] When the slagging tendency of the pre-combustion chamber is serious (ST≤1260℃ or T1>850℃), the present invention reduces the length of the pre-combustion chamber (L=0.8~1.0D), so that a small-scale recirculation zone (m=0.6~0.7D, d=0.5~0.6D) exists in the pre-combustion chamber. At this time, the amount of high-temperature flue gas entrained in the recirculation zone is small, the coal powder ignites late, the combustion time of the coal powder in the pre-combustion chamber is short, the heat released is small, and the temperature in the pre-combustion chamber is 1000~1100℃. At this time, the coal powder will not slag and melt in the pre-combustion chamber, which can effectively prevent slagging. At the same time, the recirculation zone is far away from the burner nozzle (m1=0.15~0.25D), so as to prevent the recirculation zone from being too close to the nozzle and causing burning. When the slagging tendency of the pre-combustion chamber is slight (ST>1390℃ or 800≥T1>150℃ or 200≥T2>150℃), increase the length of the pre-combustion chamber (L=1.2~1.4D) so that there is a large range of recirculation zone in the pre-combustion chamber (m=1.0~1.15D, d=0.8~0.85D). At this time, the amount of high-temperature flue gas sucked in the recirculation zone is large, which can ensure that the coal powder will ignite in time. The temperature in the pre-combustion chamber is 1200~1300℃, and the coal powder will not slag and melt in the pre-combustion chamber, which can effectively prevent slagging. The starting point of the recirculation zone is close to the burner nozzle (m1=0.05~0.1D), so the coal powder can be ignited in time. When the slagging tendency of the precombustion chamber is moderate (ST=1260~1390℃ or 850≥T1>800℃ or T2>200℃), adjust the length of the precombustion chamber (L=1.0~1.2D) so that there is a recirculation zone of an appropriate range in the precombustion chamber (m1=0.1~0.15D, m=0.7~1.0D, d=0.6~0.8D), and the temperature in the precombustion chamber is 1100~1200℃, which can prevent slagging and burning of the burner and precombustion chamber nozzle while ensuring the ignition performance of the coal powder.

[0026] 2. Clean up the slag blocks by moving the pre-combustion chamber

[0027] By using the device of the present invention, the slagging at the outlet of the precombustion chamber can be monitored by DSC. When slagging at the outlet of the precombustion chamber is observed, the pull rod is adjusted to extend and retract the precombustion chamber, and the slag blocks near the outlet of the precombustion chamber (m2=0-0.4D) are shaken off. The advantage of the movable precombustion chamber can prevent the accumulation of slag blocks to the greatest extent, and prevent large pieces of slag blocks from falling and damaging the cold ash hopper at the bottom of the furnace or the water-cooled wall pipe of the furnace, thereby ensuring the safe operation of the boiler.

[0028] 3. Check the slagging and flame combustion status through temperature sensors and video fire detection devices

[0029] When only a temperature sensor is available, it is difficult to accurately grasp the actual situation of slagging based on temperature information alone. If only video monitoring is used, the slagging trend cannot be predicted. Using the device described in the present invention, the temperature data measured by the temperature sensor can be read through the DSC interface to achieve real-time temperature monitoring. At the same time, through DSC, a clear picture captured by the video fire detection device can be directly observed to check the slagging situation in the pre-combustion chamber and the combustion state of the flame, thereby achieving multi-dimensional and all-round observation of the pre-combustion chamber condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the main view of the overall structure of this application.

[0031] Figure 2 for Figure 1 AA section view.

[0032] Figure 3 This is the schematic diagram of the video fire detection device.

[0033] Figure 4 This is the schematic diagram of the temperature sensor.

[0034] Figure 5 This is a schematic diagram of the position and size of the central recirculation zone in the adjustable pre-combustion chamber of the present invention. DETAILED DESCRIPTION

[0035] Specific implementation method 1: Combination Figure 1-Figure 2 The present embodiment is described. The present embodiment is a swirl combustion device with an adjustable pre-combustion chamber aspect ratio, which comprises a primary air duct 1, an inner secondary air duct 2, an outer secondary air duct 3 and a separation secondary air duct 6; it also comprises a video fire detection device 4, an outlet temperature sensor 5, a cylinder wall temperature sensor 7 and an adjustable pre-combustion chamber 20;

[0036] The primary air duct 1, the inner secondary air duct 2 and the outer secondary air duct 3 are arranged in sequence from the inside to the outside. The outlet of the primary air duct 1, the outlet of the inner secondary air duct 2 and the outlet of the outer secondary air duct 3 are all connected to the combustion chamber of the adjustable precombustion chamber 20. The driving part of the adjustable precombustion chamber 20 is installed on the outside of the outer secondary air duct 3. The secondary air duct 6 is sleeved on the outside of the outer secondary air duct 3 and the combustion chamber of the adjustable precombustion chamber 20. The length of the combustion chamber of the adjustable precombustion chamber 20 is adjusted along the axial direction of the outer secondary air duct 3. The video fire detection device 4, the outlet temperature sensor 5 and the barrel wall temperature sensor 7 are installed on the combustion chamber of the adjustable precombustion chamber 20.

[0037] In this embodiment, an inner secondary air blade 2 - 1 is provided at the outlet of the inner secondary air duct 2 , an outer secondary air blade 3 - 1 is provided at the outlet of the outer secondary air duct 3 , and a separation secondary air blade 6 - 1 is provided at the outlet of the separation secondary air duct 6 .

[0038] Specific implementation method 2: Combination Figure 1 , Figure 2 This embodiment is described. In this embodiment, a swirl combustion device with an adjustable pre-combustion chamber aspect ratio is described. The combustion chamber of the adjustable pre-combustion chamber 20 includes a pre-combustion chamber inner sleeve 14 and a pre-combustion chamber outer sleeve 15;

[0039] The outlet end of the outer sleeve 15 of the precombustion chamber is installed at the entrance of the furnace 19 and is connected to the furnace 19. The inner sleeve 14 of the precombustion chamber is slidably arranged in the inner sleeve 15 of the precombustion chamber. The outlet of the primary air duct 1, the outlet of the inner secondary air duct 2 and the outlet of the outer secondary air duct 3 are all connected to the inner sleeve 14 of the precombustion chamber. The outlet end of the outer sleeve 15 of the precombustion chamber is installed flush with the furnace 19. Other methods are the same as those of the first specific implementation method.

[0040] Specific implementation method three: Combination Figure 1 , Figure 2 This embodiment is described. In this embodiment, a swirl combustion device with an adjustable aspect ratio of the precombustion chamber is provided. The inner wall of the inner sleeve 15 of the precombustion chamber is provided with a plurality of slide rails 16 along the length direction, and both ends of each slide rail 16 are provided with limiters 18. The outer wall of the outlet of the precombustion chamber sleeve 14 is provided with at least two rows of rollers 17. The precombustion chamber sleeve 14 is slidably provided on the slide rails 16 of the outer sleeve 15 of the precombustion chamber through the rollers 17. Other methods are the same as those of the second embodiment.

[0041] Specific implementation method four: Combination Figure 1 , Figure 2 The present embodiment is described as a swirl combustion device with an adjustable aspect ratio of the pre-combustion chamber. The driving part of the adjustable pre-combustion chamber 20 includes a bracket 12, two tie rods 9, two connecting mechanisms 13, four limit nuts 10 and four washers 11;

[0042] Two tie rods 9 are arranged on the bracket 12 relatively, and the tie rods 9 are processed with threaded sections. The threaded section of each tie rod 9 is arranged on the bracket 12, and the threaded section of each tie rod 9 is threadedly connected to two limit nuts 10, and the two limit nuts 10 are located on both sides of the bracket 12. A gasket 11 is provided between each limit nut 10 and the bracket 12, and one end of each tie rod 9 is connected to the pre-combustion chamber inner sleeve 14 through a connecting mechanism 13. Pulling the tie rod 9 can adjust the position of the pre-combustion chamber inner sleeve 14 in the pre-combustion chamber outer sleeve 15. A ruler 8 is provided on the bracket 12, and the ruler 8 is used to observe the position of the adjustable pre-combustion chamber 20. Tighten the limit nut 10 at the desired position to fix the tie rod 9 on the bracket 12, so as to adjust the length of the adjustable pre-combustion chamber 20. By adjusting the length of the pre-combustion chamber 20, the range of the recirculation zone in the pre-combustion chamber is controlled, and the range of the recirculation zone includes the length and diameter of the recirculation zone. Other methods are the same as the specific implementation method three.

[0043] Specific implementation method five: Combination Figure 1 , Figure 2 The present embodiment is described. The present embodiment describes a swirl combustion device with an adjustable aspect ratio of the precombustion chamber. The video fire detection device 4 is installed on the inner sleeve 14 of the precombustion chamber near the outlet of the external secondary air duct 3. An outlet temperature sensor 5 is installed on the inner sleeve 14 of the precombustion chamber near the connecting mechanism 13. A barrel wall temperature sensor 7 is installed on the outer sleeve 15 of the precombustion chamber near the furnace wall of the furnace 19. The video fire detection device 4 is composed of a high-temperature probe, a camera system, a cooling and protective device, a thruster, a power control box, an air source filter and pressure control box, and a monitor, and is connected to the DCS system through a cable. The probe and the camera system are installed horizontally. When it is necessary to take pictures, the thruster is controlled to extend the probe, the camera system and the cooling and protective device from the connector into the precombustion chamber. The camera system sends the obtained video signal to the controller, and the controller sends the received video signal to the DSC. The slagging and flame combustion conditions in the precombustion chamber are monitored by the DSC. Figure 3 As shown, the specific steps are: the first step is to open the purge and cooling air valves to confirm that the air pressure in the air source control box reaches the protection pressure; the second step is to open the power control box door, check the circuit and close the air switch; the third step is to adjust the display to the "video" state, and press the "enter" button on the operator in the control room. When the indicator light is on, it means that the thruster has entered the position; finally, after the probe enters the working position, the picture displayed on the display is the furnace condition that needs to be observed. The temperature sensor is fixed by the support tube on the outer wall of the precombustion chamber, and some temperature measuring elements and protective sleeves are extended into the inner wall of the precombustion chamber for temperature measurement. The temperature measuring element can transmit the temperature signal to the DSC in real time, and the temperature information of the precombustion chamber outlet and the barrel wall position is monitored by the DSC. Other methods are the same as the second specific implementation method.

[0044] Specific implementation method six: Combination Figure 1-Figure 5This embodiment describes a swirl combustion method of a swirl combustion device with an adjustable aspect ratio of a pre-combustion chamber, and the method is implemented according to the following steps:

[0045] Step 1: According to the softening temperature ST of the coal, the temperature T1 of the outlet temperature sensor 5 and the temperature T2 of the barrel wall temperature sensor 7, the recirculation zone in the adjustable precombustion chamber 20 is adjusted in combination with the slagging, and the distance m1 between the burner outlet and the starting point of the recirculation zone, the length m of the recirculation zone and the diameter d of the recirculation zone are adjusted to the ratio of the diameter of the precombustion chamber respectively;

[0046] Step 2: The slagging condition at the outlet of the adjustable precombustion chamber 20 is observed through the DSC of the boiler, and the slagging blocks are cleaned by controlling the adjustable aspect ratio of the adjustable precombustion chamber 20.

[0047] Specific implementation method seven: Combination Figure 1-Figure 5 The present embodiment is described. The present embodiment is a swirl combustion method of a swirl combustion device capable of adjusting the aspect ratio of a pre-combustion chamber.

[0048] Method 1 in step 1: When the softening temperature ST of the burning coal is greater than 1390°C, or 800°C ≥ the temperature T1 of the outlet temperature sensor 5 is greater than 150°C, or 200 ≥ the temperature T2 of the barrel wall temperature sensor 7 is greater than 150°C, and the thickness of the slag layer is between 0 and 30 mm, a large range of recirculation zone is required in the pre-combustion chamber, so the pull rod 9 is pulled to adjust the position of the sleeve 14 in the pre-combustion chamber, so that L = 1.2 to 1.4, L is the length of the pre-combustion chamber, and m1 = 0.05 to 0.1D, m = 1.0 to 1.15D, and d = 0.8 to 0.85D in the central recirculation zone in the pre-combustion chamber. Other methods are the same as those in the sixth embodiment.

[0049] Specific implementation method eight: Combination Figure 1-Figure 5 The present embodiment is described. The present embodiment is a swirl combustion method of a swirl combustion device capable of adjusting the aspect ratio of a pre-combustion chamber.

[0050] Method 2 in step 1: When the softening temperature ST of the coal is between 1260 and 1390°C, or 850 ≥ the temperature T1 of the outlet temperature sensor 5> 800°C, or the temperature T2 of the barrel wall temperature sensor 7> 200°C, the thickness of the slagging slag layer is between 30-100mm, and a large range of recirculation zone is required in the pre-combustion chamber. Therefore, the pull rod 9 is pulled to adjust the position of the sleeve 14 in the pre-combustion chamber so that L=1.0~1.2D, L is the length of the pre-combustion chamber, and m1=0.1~0.15D, m=0.7~1.0D, and d=0.6~0.8D in the central recirculation zone of the pre-combustion chamber. Other methods are the same as those in the sixth embodiment.

[0051] Specific implementation method nine: Combination Figure 1-Figure 5The present embodiment is described. The present embodiment is a swirl combustion method of a swirl combustion device capable of adjusting the aspect ratio of a pre-combustion chamber.

[0052] Method 3 in step 1: When the softening temperature ST of the coal used is less than or equal to 1260, or the temperature T1 of the outlet temperature sensor 5 is greater than 850°C, and the thickness of the slagging slag layer is greater than 100mm, and the slagging tendency is serious, a small range of reflow zone is required in the pre-combustion chamber, so pull the pull rod 9 to adjust the position of the sleeve 14 in the pre-combustion chamber, so that L = 0.8 ~ 1.0D, L is the length of the pre-combustion chamber, and m1 = 0.15 ~ 0.25D, m = 0.6 ~ 0.7D, d = 0.5 ~ 0.6D in the central reflow zone in the pre-combustion chamber. Other methods are the same as the specific implementation method 6.

[0053] Specific implementation method ten: Combination Figure 1-Figure 5 This embodiment is described. In the embodiment, a swirl combustion method of a swirl combustion device with an adjustable precombustion chamber aspect ratio is described. In step 2, the adjustable precombustion chamber 20 is controlled to adjust the aspect ratio to clean the slag blocks, and the pull rod 9 is pulled to make the inner sleeve 14 of the precombustion chamber extend and retract in the outer sleeve 15 of the precombustion chamber, and the slag blocks are shaken off. Other methods are the same as those in the specific embodiment 6.

[0054] The pulverized coal-air mixture enters the adjustable pre-combustion chamber 20 through the primary air duct 1. The inner secondary air in the inner secondary air duct 2 forms a rotating airflow after passing through the inner secondary air blade 2-1; the outer secondary air in the outer secondary air duct 3 forms a rotating airflow after passing through the outer secondary air blade 3-1, and the airflow has the same rotation direction as the airflow in the inner secondary air duct 2; the separated secondary air in the separated secondary air duct 6 forms a rotating airflow after passing through the separated secondary air blade 6-1, and the airflow has the same rotation direction as the airflow in the inner secondary air duct 2. The direct primary air-powder airflow enters the adjustable pre-combustion chamber 20, and rapidly diffuses to the outer secondary air area under the entrainment of the rotating inner secondary air flow, and mixes with the rotating outer secondary air. The inner secondary air flow and the outer secondary air flow rotating in the same direction are mixed in the pre-combustion chamber to form a large-scale central recirculation zone. The rotating separated secondary air moves around the furnace, mixes with the high-temperature flue gas in the furnace, and replenishes the air required for the combustion of pulverized coal.

[0055] Pull the rod 9 to adjust the position of the sleeve 14 in the pre-combustion chamber, and change the length of the adjustable pre-combustion chamber 20. The scale 8 on the bracket 12 is used to observe the position of the pre-combustion chamber. Tighten the limit nut 10 at the desired position to fix the rod 9 on the bracket 11, thereby fixing the length of the adjustable pre-combustion chamber 20. By controlling the length of the pre-combustion chamber, the range of the recirculation zone in the pre-combustion chamber is controlled.

[0056] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A swirl combustion device with an adjustable length-to-diameter ratio of a pre-combustion chamber, comprising a primary air duct (1), an inner secondary air duct (2), an outer secondary air duct (3) and a separation secondary air duct (6); characterized in that: It also includes a video fire detection device (4), an outlet temperature sensor (5), a barrel wall temperature sensor (7) and an adjustable pre-combustion chamber (20); The primary air duct (1), the inner secondary air duct (2) and the outer secondary air duct (3) are arranged in sequence from the inside to the outside. The outlet of the primary air duct (1), the outlet of the inner secondary air duct (2) and the outlet of the outer secondary air duct (3) are all connected to the combustion chamber of the adjustable precombustion chamber (20). The driving part of the adjustable precombustion chamber (20) is installed outside the outer secondary air duct (3). The separation secondary air duct (6) is sleeved outside the outer secondary air duct (3) and the combustion chamber of the adjustable precombustion chamber (20). The length of the combustion chamber of the adjustable precombustion chamber (20) is adjusted along the axial direction of the outer secondary air duct (3). The video fire detection device (4), the outlet temperature sensor (5) and the barrel wall temperature sensor (7) are installed on the combustion chamber of the adjustable precombustion chamber (20).

2. A swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 1, characterized in that: The combustion chamber of the adjustable pre-combustion chamber (20) comprises a pre-combustion chamber inner sleeve (14) and a pre-combustion chamber outer sleeve (15); The outlet end of the outer sleeve (15) of the precombustion chamber is installed at the entrance of the furnace (19) and is connected to the furnace (19); the outer sleeve (14) of the precombustion chamber is slidably arranged in the outer sleeve (15) of the precombustion chamber; the outlet of the primary air duct (1), the outlet of the inner secondary air duct (2) and the outlet of the outer secondary air duct (3) are all connected to the inner sleeve (14) of the precombustion chamber.

3. A swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 2, characterized in that: The inner wall of the pre-combustion chamber outer sleeve (15) is provided with a plurality of slide rails (16) along the length direction, and both ends of each slide rail (16) are provided with limiters (18); the outer wall of the outlet of the pre-combustion chamber inner sleeve (14) is provided with at least two rows of rollers (17); the pre-combustion chamber inner sleeve (14) is slidably arranged on the slide rails (16) of the pre-combustion chamber outer sleeve (15) via the rollers (17).

4. According to claim 2, a swirl combustion device with adjustable pre-combustion chamber aspect ratio is characterized in that: The driving part of the adjustable pre-combustion chamber (20) comprises a bracket (12), two pull rods (9), two connecting mechanisms (13), four limit nuts (10) and four washers (11); Two tie rods (9) are arranged on a bracket (12) opposite to each other. The tie rods (9) are processed with threaded sections. The threaded section of each tie rod (9) is arranged on the bracket (12), and the threaded section of each tie rod (9) is threadedly connected to two limit nuts (10). The two limit nuts (10) are located on both sides of the bracket (12). A gasket (11) is provided between each limit nut (10) and the bracket (12). One end of each tie rod (9) is connected to a sleeve (14) in the pre-combustion chamber through a connecting mechanism (13).

5. The swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 2, characterized in that: A video fire detection device (4) is installed on the pre-combustion chamber inner sleeve (14) near the outlet of the external secondary air duct (3); an outlet temperature sensor (5) is installed on the pre-combustion chamber inner sleeve (14) near the connection mechanism (13); and a wall temperature sensor (7) is installed on the pre-combustion chamber outer sleeve (15) near the furnace wall of the furnace chamber (19).

6. A swirl combustion method of a swirl combustion device with an adjustable pre-combustion chamber aspect ratio, characterized in that: The method is implemented according to the following steps: Step 1: adjusting the recirculation zone in the adjustable pre-combustion chamber (20) according to the softening temperature ST of the used coal, the temperature T1 of the outlet temperature sensor (5) and the temperature T2 of the barrel wall temperature sensor (7) in combination with the slagging, and adjusting the distance m1 between the burner outlet and the starting point of the recirculation zone, the length m of the recirculation zone and the ratio of the diameter d of the recirculation zone to the diameter of the pre-combustion chamber respectively; Step 2: The slagging condition at the outlet of the adjustable pre-combustion chamber (20) is observed through the DSC of the boiler, and the slagging blocks are cleaned by controlling the adjustable aspect ratio of the adjustable pre-combustion chamber (20).

7. The swirl combustion method of the swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 6, characterized in that: Method 1 in step 1: When the softening temperature ST of the burning coal is greater than 1390°C, or 800°C ≥ the temperature T1 of the outlet temperature sensor (5) is greater than 150°C, or 200 ≥ the temperature T2 of the barrel wall temperature sensor (7) is greater than 150°C, and the thickness of the slag layer is between 0 and 30 mm, a large recirculation zone is required in the precombustion chamber. Therefore, the pull rod (9) is pulled to adjust the position of the sleeve (14) in the precombustion chamber so that L = 1.2 to 1.4, where L is the length of the precombustion chamber, and m1 = 0.05 to 0.1D, m = 1.0 to 1.15D, and d = 0.8 to 0.85D of the central recirculation zone in the precombustion chamber.

8. The swirl combustion method of the swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 6, characterized in that: Method 2 in step 1: When the softening temperature ST of the burning coal is between 1260 and 1390°C, or 850≥the temperature T1 of the outlet temperature sensor (5)>800°C, or the temperature T2 of the barrel wall temperature sensor (7)>200°C, and the thickness of the slag layer is between 30 and 100 mm, a large recirculation zone is required in the precombustion chamber. Therefore, the pull rod (9) is pulled to adjust the position of the sleeve (14) in the precombustion chamber so that L=1.0~1.2D, L is the length of the precombustion chamber, and m1=0.1~0.15D, m=0.7~1.0D, and d=0.6~0.8D of the central recirculation zone in the precombustion chamber.

9. The swirl combustion method of the swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 6, characterized in that: Method three in step one: when the softening temperature ST of the burning coal is less than or equal to 1260, or the temperature T1 of the outlet temperature sensor (5) is greater than 850°C, and the thickness of the slag layer is greater than 100mm, a small recirculation zone is required in the precombustion chamber, so the pull rod (9) is pulled to adjust the position of the sleeve (14) in the precombustion chamber so that L=0.8~1.0D, L is the length of the precombustion chamber, and m1=0.15~0.25D, m=0.6~0.7D, and d=0.5~0.6D of the central recirculation zone in the precombustion chamber.

10. The swirl combustion method of the swirl combustion device with adjustable pre-combustion chamber aspect ratio according to claim 6, characterized in that: In step 2, the adjustable pre-combustion chamber (20) is controlled to adjust the length-diameter ratio to clean the slag blocks, and the pull rod (9) is pulled to make the inner sleeve (14) of the pre-combustion chamber expand and contract within the outer sleeve (15) of the pre-combustion chamber, and the slag blocks are shaken off.

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