A water-cooled capillary low-concentration gas fire arrester and method

Abstract

The present invention discloses a water-cooled capillary type low-concentration gas fire-blocking device and method. First, the flame counter-fire-blocking module diverts and reverses the flame direction through two counter-flow channels to counteract the backflow flame of the main channel, thereby suppressing the propagation speed of the backflow flame to achieve first-level fire blocking and improving the fire blocking efficiency of the subsequent two fire blocking modules; then, the dense capillaries in the water-cooled capillary fire-blocking module can divide the backflow flame, thereby increasing the specific surface area of ​​the flame in contact with the wall, and at the same time, the circulating cold water enhances the wall heat dissipation effect by cooling, reducing the flame temperature and the combustion reaction rate, thereby quenching the backflow flame in the capillary to achieve second-level fire blocking; finally, the porous medium fire-blocking module improves the heat dissipation efficiency by dividing the flame again, and the three fire-blocking modules work together to play a fire-blocking role to achieve a third-level fire blocking effect, thereby being able to effectively and stably block the backflow flame and high-temperature energy generated by the deflagration, thereby ensuring the safety of the ground gas transmission pipeline.

Description

Technical Field

[0001] The present invention relates to a water-cooled capillary type low-concentration gas fire arresting device and method, belonging to the relevant technical and engineering fields of safe utilization of low-concentration gas in coal mines. Background Art

[0002] Coal mine methane (CMM), a by-product of coal, is not only a major contributor to mining disasters but also a clean energy source and a potent greenhouse gas. Its greenhouse effect is 28 times that of carbon dioxide. Direct discharge of CMM results in significant resource waste and environmental pollution. Therefore, reducing and utilizing CMM emissions not only increases the supply of clean gas energy but also protects the environment. Low-concentration CMM (30% or less but greater than 8%) falls within the flammable limits of premixed gas. Furthermore, the generation of backflow flames and high-temperature energy during gas internal combustion engine power generation and direct combustion for heat extraction significantly increases the risk of deflagration in pipelines, limiting its utilization.

[0003] To prevent backflow flames, a flame arrester needs to be installed in the transmission pipeline to prevent flame transmission. Existing flame arresters use porous media as the flame arrester core. When the backflow flame arrives, the porous medium suppresses the combustion reaction rate by dividing the flame front and uses the wall effect to improve the heat dissipation efficiency, thereby achieving the flame arresting effect. However, the flame arresting effect of the porous medium is strongly dependent on the thickness and pore density of the flame arrester core (i.e., the greater the thickness and the greater the pore density, the better the flame arresting effect). Since the flame arrester formed by a single porous medium is fixed once it is finalized (i.e., determined by its thickness and pore density), the flame arresting effect of this flame arrester on flame propagation will be significantly reduced as the deflagration intensity increases. Therefore, in order to maximize the flame arresting ability of the flame arrester, it is necessary to prepare a flame arrester with a larger porous medium thickness and pore density. However, this will result in a larger flame arrester, which is not only inconvenient to install, but the larger thickness and pore size will also reduce the flow of gas through the flame arrester.

[0004] Therefore, how to provide a new fire-blocking device and method that can adjust the fire-blocking capacity according to the intensity of the deflagration, so as to effectively and stably block the backflow flame and high-temperature energy generated by the deflagration in the low-concentration gas utilization equipment, and ensure the flow rate of gas flowing through the fire-blocking device, is the research direction required by the present invention. Summary of the Invention

[0005] In response to the problems existing in the above-mentioned prior art, the present invention provides a water-cooled capillary low-concentration gas fire-arresting device and method. Through a three-level fire-arresting method, the fire-arresting capacity can be adjusted according to the intensity of the deflagration, thereby effectively and stably blocking the backflow flame and high-temperature energy generated by the deflagration in the low-concentration gas utilization equipment, and ensuring the flow rate of gas flowing through the fire-arresting device.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a water-cooled capillary low-concentration gas fire-retardant device, including a porous medium fire-retardant module, a water-cooled capillary fire-retardant module and a flame counter-fire-retardant module; the water-cooled capillary fire-retardant module is located between the porous medium fire-retardant module and the flame counter-fire-retardant module, and its two ends are respectively connected to the two.

[0007] The porous medium fire-blocking module includes a first shell and a porous medium layer. An inlet 1 and an outlet 1 are respectively provided at both ends of the first shell. The inlet 1 is connected to the ground gas transmission pipeline. The porous medium layer is installed in the first shell and separates the inlet 1 and the outlet 1 on both sides. It is used to filter large-particle impurities in the low-concentration gas input by the inlet 1 before reaching the outlet 1, and at the same time, it can block the backflow flame entering the outlet 1 from flowing to the inlet 1.

[0008] The water-cooled capillary fire-retardant module includes a second shell and multiple capillaries, which are distributed parallel to each other in the second shell, and a gap is left between adjacent capillaries to form a flow channel; the ends of the two adjacent capillaries are connected, and multiple through holes are evenly opened on both sides of the second shell, and the multiple through holes are connected to the flow channel, so that the low-concentration gas discharged from the outlet 1 passes through the water-cooled capillary fire-retardant module through the flow channel; the upper and lower ends of the second shell are respectively provided with a water inlet and a water outlet, the water inlet is connected to the capillary closest to it, and the water outlet is connected to the capillary closest to it, and cold water is injected through the water inlet, and the cold water flows through each capillary and is discharged from the water outlet, so that the capillary has a lower wall temperature, and the backflow flame and high-temperature energy are blocked by low temperature to diffuse to the porous medium fire-retardant module.

[0009] The flame counter-flow fire-blocking module includes a third shell, which has an inlet two and an outlet two at both ends respectively. Outlet two is connected to the low-concentration gas utilization equipment through a pipeline, and a main channel, a first counter-flow channel and a second counter-flow channel are provided inside the third shell; the two ends of the main channel are respectively connected to inlet two and outlet two, and are used to transport the low-concentration gas discharged from the water-cooled capillary fire-blocking module and entering through inlet two to outlet two; the first counter-flow channel and the second counter-flow channel are symmetrically arranged on both sides of the main channel, and the first counter-flow channel and the second counter-flow channel have the same shape, both are U-shaped channels, one end of the two counter-flow channels is connected to outlet two, and the other end is connected to the main channel, and the other end is facing outlet two. When the backflow flame generated by the low-concentration gas utilization equipment enters the third shell from outlet two, the backflow flame is diverted through the main channel, the first counter-flow channel and the second counter-flow channel, and the flame changes its flow direction in the two counter-flow channels and enters the main channel from the other end, and counter-flows with the flame flowing in the main channel, thereby achieving the effect of blocking the spread of the backflow flame.

[0010] Furthermore, the port of the main channel near inlet 2 is trumpet-shaped. This shape facilitates the low-concentration gas entering the third shell from inlet 2, where it is guided by the trumpet shape and converges to the center of the main channel, where it flows to outlet 2. Furthermore, since both ends of the first and second counter-flow channels face outlet 2, the low-concentration gas is not affected by the two counter-flow channels during its flow from inlet 2 to outlet 2, ensuring smooth delivery of the low-concentration gas to the low-concentration gas utilization equipment.

[0011] Furthermore, the porous medium fire-stop module is equipped with a first flange and a second flange at both ends, the water-cooled capillary fire-stop module is equipped with a third flange and a fourth flange at both ends, and the flame counter-fire-stop module is equipped with a fifth flange and a sixth flange at both ends, which is convenient for disassembly and installation.

[0012] Furthermore, the flange connections between the porous medium fire-stop module, the water-cooled capillary fire-stop module and the flame counterattack fire-stop module are all provided with rubber gaskets to ensure air tightness.

[0013] Furthermore, the porous medium layer is made of non-combustible material and can be detachably fixed in the first shell, making it easy to replace and repair the porous medium layer.

[0014] Furthermore, the surface gas transmission pipeline is a transmission pipeline for the surface extraction pump station to transport gas to the low-concentration gas utilization equipment; the low-concentration gas utilization equipment includes low-concentration gas power generation and utilization equipment and direct combustion heat energy extraction equipment for industrial utilization.

[0015] The working method of the above-mentioned water-cooled capillary low-concentration gas fire arrester comprises the following specific steps:

[0016] A. Install low-concentration gas fire-retardant device: Install the low-concentration gas fire-retardant device between the ground gas transmission pipeline and the low-concentration gas utilization equipment, and connect the water inlet of the water-cooled capillary fire-retardant module to the water pump and cold water source through a pipeline.

[0017] B. Transporting low-concentration gas: first set the cold water source temperature, then start the water pump to flow cold water of the set temperature through the capillary tubes, so that the wall temperature of each capillary tube is relatively low; then transport the low-concentration gas to the low-concentration gas fire-retardant device through the ground gas transportation pipeline, and pass through the porous medium fire-retardant module, the water-cooled capillary tube fire-retardant module and the flame counter-fire-retardant module in sequence before reaching the low-concentration gas utilization equipment. When passing through the porous medium fire-retardant module, large-particle impurities in the low-concentration gas are blocked and filtered by the porous medium layer, which is convenient for subsequent gas combustion and utilization; when passing through the water-cooled capillary tube fire-retardant module, the low-concentration gas is cooled by heat exchange with each capillary tube through the flow channel. The cooling method can reduce the possibility of gas explosion during subsequent transportation; when passing through the flame counter-fire-retardant module, the low-concentration gas that has been decontaminated and cooled is transported to the low-concentration gas utilization equipment for utilization.

[0018] C. Blocking backflow flame: When low-concentration gas utilization equipment generates backflow flame and reaches the low-concentration gas fire arrester, the specific fire arresting process is as follows:

[0019] ① The first-level fire-blocking process of the flame counter-flow fire-blocking module is as follows: after the backflow flame enters the third shell from outlet two, it is diverted through the main channel, the first counter-flow channel and the second counter-flow channel, and the backflow flame in the main channel flows toward inlet two. Since the two counter-flow channels are U-shaped channels, the flow direction of the backflow flame in the two counter-flow channels changes toward outlet two, and enters the main channel from the other end of the two counter-flow channels, and counter-flows with the flame flowing toward inlet two in the main channel, thereby achieving the first-level barrier to the spread of the backflow flame and reducing the flow rate of the backflow flame, and its barrier effect increases with the increase of the flow rate of the backflow flame; the reason is: the higher the flow rate of the backflow flame, the higher the flame flow rate entering the two counter-flow channels after diversion, so the counter-flow effect generated during subsequent counter-flow is greater, so the counter-flow fire-blocking effect can be improved accordingly with the backflow flame situation.

[0020] The secondary flame arresting process of the water-cooled capillary fire arrester module is as follows: after the flame counteracts the primary flame arresting action of the fire arrester module, the backflow flame enters the flow channel within the water-cooled capillary fire arrester module. Each capillary tube divides the backflow flame, reducing the collision rate of active free radicals during combustion, blocking the combustion chain reaction, and significantly increasing the specific surface area of ​​contact between the backflow flame and the capillary tube wall. At the same time, circulating cold water keeps the capillary tube wall at a lower temperature, and the backflow flame continuously exchanges heat with the capillary tube wall to reduce the flame temperature. This not only significantly improves the heat dissipation efficiency of the backflow flame in the water-cooled capillary fire arrester module, but also effectively inhibits the conduction of high temperature to the ground gas transmission pipeline, reducing the risk of low-concentration gas explosion caused by the high wall temperature of the ground gas transmission pipeline, achieving secondary flame flow and high-temperature conduction barrier. The secondary flame arresting effect can be enhanced by adjusting the cold water temperature. Since the lower the temperature, the greater the heat dissipation efficiency, the flame flow and high-temperature conduction barrier effects are improved.

[0021] ③ The three-stage fire-blocking process of the water-cooled capillary fire-blocking module is as follows: after the flame counter-fire-blocking module and the water-cooled capillary fire-blocking module have been used to block the flame, the backflow flame enters the first shell, and the porous medium layer divides the backflow flame through tiny apertures, thereby increasing the specific surface area of ​​contact between the flame and the porous medium, and quickly reducing the flame temperature and combustion reaction rate through the wall heat dissipation effect, thereby achieving a three-stage flame flow and high-temperature conduction process. Finally, the backflow flame is blocked from propagating to the ground gas transmission pipeline through the three-stage fire-blocking method, ensuring the safety of low-concentration gas transportation.

[0022] Furthermore, the low-concentration gas refers to gas with a concentration less than or equal to 30% but higher than 8%.

[0023] Compared with the prior art, the present invention adopts a combination of a porous medium fire-blocking module, a water-cooled capillary fire-blocking module and a flame counter-fire-blocking module, which has the following advantages:

[0024] 1) The special layout structure of the main channel and the two counter-flow channels of the flame counter-fire retardant module in the present invention can achieve the goal of not counteracting the low-concentration gas when it flows from inlet 2 to outlet 2 in the main channel, thereby ensuring the smooth transportation of low-concentration gas; at the same time, the backflow flame is diverted by the main channel, the first counter-flow channel and the second counter-flow channel when it flows back from outlet 2, and the flames in the two counter-flow channels change direction and counter-flow with the flames in the main channel, thereby blocking the propagation of the backflow flame and reducing the flow rate of the backflow flame; and its blocking effect is enhanced with the increase of the flow rate of the backflow flame, and has the effect of enhancing the first-level fire retardant capacity accordingly as the deflagration intensity (i.e., the flow rate of the backflow flame) increases without changing the volume.

[0025] 2) The water-cooled capillary fire-retardant module in the present invention improves the fire-retardant effect on low-concentration gas explosion by enhancing the wall heat dissipation effect. By arranging dense capillaries in the second shell and leaving gaps between adjacent capillaries to form a flow channel, circulating cold water is introduced into the capillary to reduce the wall temperature of the capillary. When low-concentration gas passes through the water-cooled capillary fire-retardant module through the flow channel, the low-concentration gas exchanges heat with the capillary wall to reduce its temperature. The possibility of gas explosion during subsequent transportation can be reduced by cooling. When the backflow flame enters the flow channel of the water-cooled capillary fire-retardant module, each capillary divides the backflow flame. The specific surface area of ​​the flame in contact with the wall is increased, thereby achieving the effect of improving the heat dissipation efficiency of the flame and reducing the combustion rate. At the same time, the circulating cold water keeps the capillary wall at a lower temperature, and the backflow flame will continue to exchange heat with the capillary wall to reduce the flame temperature. This can not only significantly improve the heat dissipation efficiency of the backflow flame in the water-cooled capillary fire-retardant module, but also effectively inhibit the high temperature from being transmitted to the ground gas transmission pipeline, reducing the risk of low-concentration gas explosion caused by the high wall temperature of the ground gas transmission pipeline; and according to the explosion intensity (i.e., the backflow flame flow rate), the secondary fire-retardant effect is enhanced by lowering the cold water temperature without changing the structure.

[0026] 3) When a backflow flame occurs, the present invention sequentially blocks the flame through the flame counterattack module, the water-cooled capillary tube fire-blocking module, and the porous medium fire-blocking module, achieving a three-stage flame-blocking effect through the synergistic flame-blocking effect of the three fire-blocking modules. First, the flame counterattack module divides and reverses the flame direction through two counterattack flow channels to counterattack the backflow flame in the main flow channel, thereby suppressing the propagation speed of the backflow flame to achieve a primary flame-blocking effect, and improving the flame-blocking efficiency of the subsequent porous medium fire-blocking module and the water-cooled capillary tube fire-blocking module. Then, the dense capillaries in the water-cooled capillary fire-retardant module can split the backflow flame, thereby increasing the specific surface area of ​​the flame in contact with the wall. At the same time, the circulating cold water enhances the heat dissipation effect of the wall by cooling, reducing the flame temperature and the combustion reaction rate, thereby quenching the backflow flame in the capillary, achieving a secondary fire-retardant effect; finally, the porous medium fire-retardant module improves the heat dissipation efficiency by splitting the flame again to achieve a tertiary fire-retardant effect, thereby effectively and stably blocking the backflow flame and high-temperature energy generated by the deflagration in the low-concentration gas utilization equipment, and since there is no need to increase the volume, the flow rate of the gas flowing through the fire-retardant device can also be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall layout of the present invention.

[0028] Figure 2 It is a schematic diagram of the porous medium fire-blocking module in the present invention.

[0029] Figure 3 It is a schematic diagram of the water-cooled capillary fire-retardant module in the present invention.

[0030] Figure 4 It is a schematic diagram of the flame counter-fire arresting module in the present invention.

[0031] In the figure: 1-porous medium fire-proof module, 2-first flange, 3-inlet one, 4-porous medium layer, 5-second flange, 6-third flange, 7-water inlet, 8-water outlet, 9-water-cooled capillary fire-proof module, 10-fourth flange, 11-fifth flange, 12-flow channel, 13-capillary, 14-flame counter-flow fire-proof module, 15-first counter-flow channel, 16-main flow channel, 17-second counter-flow channel, 18-sixth flange, 19-outlet two. DETAILED DESCRIPTION

[0032] The present invention will be further described below.

[0033] like Figure 1 As shown, a water-cooled capillary type low-concentration gas fire-stop device includes a porous medium fire-stop module 1, a water-cooled capillary fire-stop module 9 and a flame counter-fire-stop module 14; the water-cooled capillary fire-stop module 9 is located between the porous medium fire-stop module 1 and the flame counter-fire-stop module 14, and its two ends are respectively connected to the two.

[0034] like Figure 2 As shown, the porous medium fire-blocking module 1 includes a first shell and a porous medium layer 4. An inlet 3 and an outlet 1 are respectively provided at both ends of the first shell. The inlet 3 is connected to the ground gas delivery pipeline, and the ground gas delivery pipeline is a delivery pipeline for the ground extraction pump station to transport gas to the low-concentration gas utilization equipment; the porous medium layer 4 is installed in the first shell and separates the inlet 3 and the outlet 1 on both sides, and is used to filter the large-particle impurities in the low-concentration gas input by the inlet 3 before reaching the outlet 1, and at the same time can block the backflow flame entering the outlet 1 from flowing to the inlet 3; the porous medium layer 4 is a non-combustible material, and it can be detachably fixed in the first shell, so as to facilitate the replacement and maintenance of the porous medium layer 4.

[0035] like Figure 3 As shown, the water-cooled capillary fire-retardant module includes a second shell and a plurality of capillaries 13, and the plurality of capillaries 13 are distributed parallel to each other in the second shell, and a gap is left between two adjacent capillaries 13 to form a flow channel 12; the ends of the two adjacent capillaries are connected, and a plurality of through holes are evenly opened on both sides of the second shell, and the plurality of through holes are connected to the flow channel, so that the low-concentration gas discharged from the outlet 1 passes through the water-cooled capillary fire-retardant module through the flow channel 12; the upper and lower ends of the second shell are respectively provided with a water inlet 7 and a water outlet 8, the water inlet 7 is connected to the capillary 13 closest to it, and the water outlet 8 is connected to the capillary 13 closest to it, and cold water is injected through the water inlet 7, and the cold water flows through each capillary 13 and is discharged from the water outlet 8, so that the capillary 13 has a lower wall temperature, and the backflow flame and high-temperature energy are diffused to the porous medium fire-retardant module by blocking the backflow flame at low temperature.

[0036] like Figure 4As shown, the flame counter-fire arresting module includes a third shell, and an inlet 2 and an outlet 2 19 are respectively provided at both ends of the third shell. The outlet 2 19 is connected to the low-concentration gas utilization equipment through a pipeline. The low-concentration gas utilization equipment includes low-concentration gas power generation and utilization equipment and direct combustion to extract heat energy for industrial utilization. A main channel 16, a first counter-flow channel 15 and a second counter-flow channel 17 are provided inside the third shell; the two ends of the main channel 16 are respectively connected to inlet 2 and outlet 2 19, and are used to transport the low-concentration gas discharged from the water-cooled capillary fire-retardant module and entering through inlet 2 to outlet 2 19; the first counter-flow channel 15 and the second counter-flow channel 17 are symmetrically arranged on both sides of the main channel 16, and the first counter-flow channel 15 and the second counter-flow channel 17 have the same shape, both are U-shaped channels, one end of the two counter-flow channels is connected to outlet 2 19, and the other end is connected to the main channel 16, and the other end is facing outlet 2. When the backflow flame generated by the low-concentration gas utilization equipment enters the third shell from outlet 2 19, the backflow flame is diverted through the main channel 16, the first counter-flow channel 15 and the second counter-flow channel 17, and the flame changes its flow direction in the two counter-flow channels and enters the main channel 16 from the other end, and counter-flows with the flame flowing in the main channel, thereby achieving the effect of blocking the spread of the backflow flame.

[0037] As an improvement to the present invention, the port of the main flow channel 16 near the second inlet is trumpet-shaped. This shape facilitates the low-concentration gas entering the third shell from the second inlet to be guided by the trumpet shape and converged in the middle of the main flow channel 16, and then flows through the main flow channel 16 to the second outlet 19. Moreover, because both ends of the first counter-flow channel 15 and the second counter-flow channel 17 face the second outlet 19, the low-concentration gas is not affected by the two counter-flow channels during its flow from the second inlet to the second outlet 19, ensuring smooth delivery of the low-concentration gas to the low-concentration gas utilization equipment.

[0038] As another improvement of the present invention, the porous medium fire-blocking module is provided with a first flange 2 and a second flange 5 at both ends, the water-cooled capillary fire-blocking module is provided with a third flange 6 and a fourth flange 10 at both ends, and the flame counter-fire-blocking module is provided with a fifth flange 11 and a sixth flange 18 at both ends, which are convenient for disassembly and installation; the flange connections between the porous medium fire-blocking module, the water-cooled capillary fire-blocking module and the flame counter-fire-blocking module are provided with rubber gaskets to ensure air tightness.

[0039] The working method of the above-mentioned water-cooled capillary low-concentration gas fire arrester comprises the following specific steps:

[0040] A. Install low-concentration gas fire-retardant device: Install the low-concentration gas fire-retardant device between the ground gas transmission pipeline and the low-concentration gas utilization equipment, and connect the water inlet of the water-cooled capillary fire-retardant module to the water pump and cold water source through a pipeline.

[0041] B. Transporting low-concentration gas: first set the cold water source temperature, then start the water pump to flow cold water of the set temperature through the capillary 13, so that the wall temperature of each capillary 13 is relatively low; then transport the low-concentration gas to the low-concentration gas fire-retardant device through the ground gas transportation pipeline, where the low-concentration gas refers to gas with a concentration less than or equal to 30% but higher than 8%, and passes through the porous medium fire-retardant module, the water-cooled capillary fire-retardant module and the flame counter-fire-retardant module in sequence before reaching the low-concentration gas utilization equipment. When passing through the porous medium fire-retardant module, large-particle impurities in the low-concentration gas are blocked and filtered by the porous medium layer 4, which is convenient for subsequent gas combustion and utilization; when passing through the water-cooled capillary fire-retardant module, the low-concentration gas is cooled by heat exchange with each capillary 13 through the flow channel. The cooling method can reduce the possibility of gas explosion during subsequent transportation; when passing through the flame counter-fire-retardant module, the impurity-removed and cooled low-concentration gas is transported to the low-concentration gas utilization equipment for utilization.

[0042] C. Blocking backflow flame: When low-concentration gas utilization equipment generates backflow flame and reaches the low-concentration gas fire arrester, the specific fire arresting process is as follows:

[0043] ① The first-level fire-blocking process of the flame counter-flow fire-blocking module is as follows: after the backflow flame enters the third shell from the second outlet 19, it is diverted through the main channel 16, the first counter-flow channel 15 and the second counter-flow channel 17, and the backflow flame in the main channel 16 flows toward the second inlet. Since the two counter-flow channels are U-shaped channels, the flow direction of the backflow flame in the two counter-flow channels changes toward the second outlet 19, and enters the main channel 16 from the other end of the two counter-flow channels, and counter-flows with the flame flowing in the main channel 16 toward the second inlet 19, thereby achieving the first-level barrier to the spread of the backflow flame and reducing the flow rate of the backflow flame, and its barrier effect increases with the increase of the flow rate of the backflow flame; the reason is: the higher the flow rate of the backflow flame, the higher the flame flow rate entering the two counter-flow channels after diversion, so the counter-flow effect generated during the subsequent counter-flow is greater, so the counter-flow fire-blocking effect can be improved accordingly with the backflow flame situation.

[0044] ② The secondary fire arresting process of the water-cooled capillary fire arrester module is as follows: after the flame counteracts the primary fire arresting effect of the fire arrester module, the backflow flame enters the flow channel in the water-cooled capillary fire arrester module. Each capillary 13 reduces the collision rate of active free radicals in the combustion process by dividing the backflow flame, thereby blocking the chain reaction of combustion and significantly increasing the specific surface area of ​​contact between the backflow flame and the wall of the capillary 13. At the same time, the circulating cold water keeps the wall of the capillary 13 at a lower temperature, and the backflow flame will continue to exchange heat with the wall of the capillary 13 to reduce the flame temperature. This can not only significantly improve the heat dissipation efficiency of the backflow flame in the water-cooled capillary fire arrester module, but also effectively inhibit the high temperature from being transmitted to the ground gas transmission pipeline, reducing the risk of low-concentration gas explosion caused by the high wall temperature of the ground gas transmission pipeline, achieving secondary flame flow and high-temperature conduction blocking. The secondary fire arresting effect can be improved by adjusting the cold water temperature. Since the lower the temperature, the higher the heat dissipation efficiency, the effect of blocking flame flow and high-temperature conduction is improved.

[0045] ③ The three-stage fire-blocking process of the water-cooled capillary fire-blocking module is as follows: after the flame counter-fire-blocking module and the water-cooled capillary fire-blocking module have fire-blocking effects, the backflow flame enters the first shell, and the porous medium layer 4 divides the backflow flame through tiny apertures, thereby increasing the specific surface area of ​​contact between the flame and the porous medium, and quickly reducing the flame temperature and combustion reaction rate through the wall heat dissipation effect, thereby achieving a three-stage flame flow and high-temperature conduction process, and finally blocking the backflow flame from propagating to the ground gas transmission pipeline through the three-stage fire-blocking method, thereby ensuring the safety of low-concentration gas transportation.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A water-cooled capillary low-concentration gas fire arrester, characterized in that: It includes a porous medium fire-stop module, a water-cooled capillary fire-stop module and a flame counter-fire-stop module; the water-cooled capillary fire-stop module is located between the porous medium fire-stop module and the flame counter-fire-stop module, and its two ends are connected to the two respectively; The porous medium fire-blocking module includes a first shell and a porous medium layer. An inlet 1 and an outlet 1 are respectively provided at both ends of the first shell. The inlet 1 is connected to the ground gas transmission pipeline. The porous medium layer is installed in the first shell and separates the inlet 1 and the outlet 1 on both sides. It is used to filter large-particle impurities in the low-concentration gas input by the inlet 1 before it reaches the outlet 1, and at the same time, it can block the backflow flame entering the outlet 1 from flowing to the inlet 1. The water-cooled capillary fire-retardant module includes a second shell and a plurality of capillaries, wherein the plurality of capillaries are distributed in parallel within the second shell, and a gap is left between adjacent capillaries to form a flow channel; the ends of the two adjacent capillaries are connected, and a plurality of through holes are evenly provided on both sides of the second shell, and the plurality of through holes are connected to the flow channel, so that the low-concentration gas discharged from the outlet 1 passes through the flow channel and passes through the water-cooled capillary fire-retardant module; the upper and lower ends of the second shell are respectively provided with a water inlet and a water outlet, the water inlet is connected to the capillary closest to it, and the water outlet is connected to the capillary closest to it, and cold water is injected through the water inlet, and the cold water flows through each capillary and is discharged from the water outlet, so that the capillary has a lower wall temperature, and the backflow flame and high-temperature energy are blocked by low temperature to diffuse to the porous medium fire-retardant module; The flame counter-flow fire-blocking module includes a third shell, which has an inlet two and an outlet two at both ends respectively. Outlet two is connected to the low-concentration gas utilization equipment through a pipeline, and a main channel, a first counter-flow channel and a second counter-flow channel are provided inside the third shell; the two ends of the main channel are respectively connected to inlet two and outlet two, and are used to transport the low-concentration gas discharged from the water-cooled capillary fire-blocking module and entering through inlet two to outlet two; the first counter-flow channel and the second counter-flow channel are symmetrically arranged on both sides of the main channel, and the first counter-flow channel and the second counter-flow channel have the same shape, both are U-shaped channels, one end of the two counter-flow channels is connected to outlet two, and the other end is connected to the main channel, and the other end is facing outlet two. When the backflow flame generated by the low-concentration gas utilization equipment enters the third shell from outlet two, the backflow flame is diverted through the main channel, the first counter-flow channel and the second counter-flow channel, and the flame changes its flow direction in the two counter-flow channels and enters the main channel from the other end, and counter-flows with the flame flowing in the main channel, thereby achieving the effect of blocking the spread of the backflow flame.

2. The water-cooled capillary low-concentration gas fire arrester according to claim 1, characterized in that: The port of the main channel close to the second inlet is trumpet-shaped.

3. The water-cooled capillary low-concentration gas fire arrester according to claim 1, characterized in that: The porous medium fire-stop module is provided with a first flange and a second flange at both ends, the water-cooled capillary fire-stop module is provided with a third flange and a fourth flange at both ends, and the flame counter-fire-stop module is provided with a fifth flange and a sixth flange at both ends, which are convenient for disassembly and installation.

4. The water-cooled capillary low-concentration gas fire arrester according to claim 3, characterized in that: The flange connections between the porous medium fire-stop module, the water-cooled capillary fire-stop module and the flame counterattack fire-stop module are all provided with rubber gaskets to ensure air tightness.

5. The water-cooled capillary low-concentration gas fire arrester according to claim 1, characterized in that: The porous medium layer is made of non-combustible material and is detachably fixed in the first shell.

6. The water-cooled capillary low-concentration gas fire arrester according to claim 1, characterized in that: The surface gas transmission pipeline is a transmission pipeline that transports gas from the surface extraction pump station to the low-concentration gas utilization equipment; the low-concentration gas utilization equipment includes low-concentration gas power generation and utilization equipment and equipment for direct combustion to extract heat energy for industrial utilization.

7. A method for operating the water-cooled capillary low-concentration gas fire arrester according to any one of claims 1 to 6, characterized in that: The specific steps are: A. Install low-concentration gas fire arrester: Install the low-concentration gas fire arrester between the ground gas transmission pipeline and the low-concentration gas utilization equipment, and connect the water inlet of the water-cooled capillary fire arrester module to the water pump and cold water source through a pipeline; B. Transporting low-concentration gas: first set the cold water source temperature, then start the water pump to flow cold water of the set temperature through the capillary tubes, so that the wall temperature of each capillary tube is relatively low; then transport the low-concentration gas to the low-concentration gas fire-retardant device through the ground gas transportation pipeline, and pass through the porous medium fire-retardant module, the water-cooled capillary tube fire-retardant module and the flame counter-fire-retardant module in sequence before reaching the low-concentration gas utilization equipment. When passing through the porous medium fire-retardant module, large-particle impurities in the low-concentration gas are blocked and filtered by the porous medium layer, which is convenient for subsequent gas combustion and utilization; when passing through the water-cooled capillary tube fire-retardant module, the low-concentration gas is cooled by heat exchange with each capillary tube through the flow channel. The cooling method can reduce the possibility of gas explosion during subsequent transportation; when passing through the flame counter-fire-retardant module, the impurity-removed and cooled low-concentration gas is transported to the low-concentration gas utilization equipment for utilization; C. Blocking backflow flame: When low-concentration gas utilization equipment generates backflow flame and reaches the low-concentration gas fire arrester, the specific fire arresting process is as follows: ① The first-level flame arresting process of the flame counter-attack fire-arresting module is as follows: after the backflow flame enters the third shell from the second outlet, it is divided through the main channel, the first counter-attack channel, and the second counter-attack channel. The backflow flame in the main channel flows toward the second inlet. Since the two counter-attack channels are U-shaped channels, the flow direction of the backflow flame in the two counter-attack channels changes to toward the second outlet, and enters the main channel from the other end of the two counter-attack channels, and counter-attacks the flame flowing toward the second in the main channel, thereby achieving the first-level barrier to the spread of the backflow flame and reducing the flow velocity of the backflow flame. The barrier effect is enhanced as the flow velocity of the backflow flame increases. ② The secondary fire arresting process of the water-cooled capillary fire arrester module is as follows: after the flame counteracts the primary fire arresting effect of the fire arrester module, the backflow flame enters the flow channel inside the water-cooled capillary fire arrester module. Each capillary reduces the collision rate of active free radicals in the combustion process by dividing the backflow flame, thereby blocking the chain reaction of combustion and significantly increasing the specific surface area of ​​the backflow flame in contact with the capillary wall. At the same time, the circulating cold water keeps the capillary wall at a lower temperature, and the backflow flame continuously exchanges heat with the capillary wall to reduce the flame temperature. This not only significantly improves the heat dissipation efficiency of the backflow flame in the water-cooled capillary fire arrester module, but also effectively inhibits the high temperature from being transmitted to the ground gas transmission pipeline, reducing the risk of low-concentration gas explosion caused by the high wall temperature of the ground gas transmission pipeline, achieving secondary barrier to flame flow and high-temperature conduction, and the secondary fire arresting effect can be improved by adjusting the cold water temperature. ③ The three-stage fire-blocking process of the water-cooled capillary fire-blocking module is as follows: after the flame counter-fire-blocking module and the water-cooled capillary fire-blocking module have been used to block the flame, the backflow flame enters the first shell, and the porous medium layer divides the backflow flame through tiny apertures, thereby increasing the specific surface area of ​​contact between the flame and the porous medium, and quickly reducing the flame temperature and combustion reaction rate through the wall heat dissipation effect, thereby achieving a three-stage flame flow and high-temperature conduction process. Finally, the backflow flame is blocked from propagating to the ground gas transmission pipeline through the three-stage fire-blocking method, ensuring the safety of low-concentration gas transportation.

8. The working method according to claim 7, characterized in that: The low-concentration gas refers to gas with a concentration less than or equal to 30% but higher than 8%.

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