Long-time fire retardant structure with radial heat insulation function

Abstract

The invention relates to the field of flame arresters, and discloses a long-time flame arresting structure with a radial heat insulation function, which comprises a shell provided with a pressure relief air inlet end, a pressure relief air outlet end and a cavity; the burning-resistant structure is arranged at the pressure relief exhaust end and comprises a burning-resistant layer, the burning-resistant layer comprises a burning-resistant layer outer ring area, a burning-resistant layer inner ring area and a burning-resistant layer middle area which are sequentially arranged from outside to inside, the burning-resistant layer outer ring area and the burning-resistant layer middle area can allow pressure relief airflow to circulate, and the burning-resistant layer inner ring area is a closed heat insulation area. Therefore, under the condition that the burning-resistant structure burns, the closed heat insulation area can effectively slow down the transmission of burning heat of the burning-resistant layer outer ring area to the burning-resistant layer middle area, so that the phenomena of tempering and burnthrough caused by the accumulation of a large amount of burning heat of the burning-resistant layer middle area are avoided, and a large amount of burning heat can be quickly dissipated outwards in the burning-resistant layer outer ring area; and meanwhile, the outer ring area of the burning-resistant layer and the middle area of the burning-resistant layer are beneficial to considering the circulation efficiency of pressure relief airflow.

Description

Technical Field

[0001] The present invention belongs to the technical field of flame arresters, and particularly relates to a long-time flame arrestor structure with radial heat insulation function. Background Art

[0002] During the feeding and discharging process of a storage tank in a petrochemical plant or when the external temperature rises, the gas pressure in the tank will increase. To prevent overpressure damage or pressure buildup in the storage tank, a breather valve is generally installed on the tank top. When there is an ignition source in the outside world, it may ignite the combustible gas exhaled from the storage tank, causing the flame to spread back to the storage tank, thus triggering a storage tank fire or explosion. Therefore, the breather valve needs to have a flame arrestor function, and a product that has undergone an overall flame arrestor test should be selected for an all-weather flame arrestor breather valve.

[0003] However, most of the combustible gases exhaled from the storage tank are premixed combustible gases with high calorific values. Existing pipe-end flame arresters or flame arrestor breather valves generally have problems such as being unable to withstand burning for a long time, resulting in the inability to provide long-time burning resistance protection before long-time burning at the pipe end and effective emergency rescue measures are in place, thus causing the accident to expand further. Summary of the Invention

[0004] The purpose of the present invention is to provide a long-time flame arrestor structure with radial heat insulation function, which can provide long-time burning resistance protection when accidents such as fire occur at the pressure relief position of a petrochemical plant storage tank, so as to prevent the accident from expanding further and leave more preparation time for emergency rescue.

[0005] To achieve the above purpose, the present invention provides a long-time flame arrestor structure with radial heat insulation function, which comprises:

[0006] A housing, provided with a pressure relief air inlet end, a pressure relief air outlet end, and a cavity connecting the pressure relief air inlet end and the pressure relief air outlet end; and

[0007] A burning resistance structure, arranged at the pressure relief air outlet end and comprising a burning resistance layer, the burning resistance layer comprising a burning resistance layer outer ring area, a burning resistance layer inner ring area, and a burning resistance layer middle area arranged in sequence from outside to inside, both the burning resistance layer outer ring area and the burning resistance layer middle area can allow the pressure relief air flow to pass through, and the burning resistance layer inner ring area is a closed heat insulation area.

[0008] In some embodiments, the fire-resistant layer includes a second closed heat-insulating disc, a plurality of second fire-blocking discs, and a single third fire-blocking disc. The outer ring area, the inner ring area, and the middle area of the fire-resistant layer are all disposed on the second closed heat-insulating disc. A plurality of second mounting openings are formed at intervals along the circumferential direction in the outer ring area of the fire-resistant layer of the second closed heat-insulating disc, and the plurality of second fire-blocking discs are respectively mounted in the plurality of second mounting openings. A third mounting opening is provided in the middle area of the fire-resistant layer of the second closed heat-insulating disc, and the third fire-blocking disc is mounted in the third mounting opening.

[0009] In some embodiments, a hollow cavity is provided inside the second closed heat-insulating disc.

[0010] In some embodiments, the hollow cavity of the second closed heat-insulating disc is evacuated or filled with a material having a low thermal conductivity.

[0011] In some embodiments, the fire-resistant layer includes a fire-blocking ring, a closed heat-insulating ring, and a fourth fire-blocking disc nested in sequence from outside to inside. The outer ring area of the fire-resistant layer is disposed on the fire-blocking ring, the inner ring area of the fire-resistant layer is disposed on the closed heat-insulating ring, and the middle area of the fire-resistant layer is disposed on the fourth fire-blocking disc.

[0012] In some embodiments, a hollow cavity is provided inside the closed heat-insulating ring.

[0013] In some embodiments, the hollow cavity of the closed heat-insulating ring is evacuated or filled with a material having a low thermal conductivity.

[0014] In some embodiments, the long-time fire-blocking structure further includes:

[0015] A flow guiding structure, which is disposed inside the housing and upstream of the fire-resistant structure, and is used for dividing the pressure relief air flow inside the housing into multiple regional air flows flowing towards different regions of the fire-resistant structure.

[0016] In some embodiments, the flow guiding structure includes:

[0017] A cavity flow guiding structure, which is disposed inside the cavity and is used for dividing the pressure relief air flow flowing into the cavity into an outer region air flow and an inner region air flow flowing respectively in the outer region and the inner region of the cavity, and making the flow rate of the outer region air flow greater than that of the inner region air flow, and / or making the flow rate of the outer region air flow greater than that of the inner region air flow.

[0018] In some embodiments, the flow guiding structure includes:

[0019] A cavity flow guiding structure is arranged inside the cavity and is used for dividing the pressure relief air flow flowing into the cavity into an outer ring area air flow, an inner ring area air flow, and a middle area air flow that are sequentially distributed from the outside to the inside in the cavity, and making the flow velocity of the outer ring area air flow, the flow velocity of the middle area air flow, and the flow velocity of the inner ring area air flow be distributed from large to small, and / or making the flow rate of the outer ring area air flow, the flow rate of the middle area air flow, and the flow rate of the inner ring area air flow be distributed from large to small.

[0020] In some embodiments, the flow guiding structure includes:

[0021] An air inlet end flow guiding structure is arranged inside the pressure relief air inlet end and is used for dividing the pressure relief air flow flowing into the pressure relief air inlet end into an outer layer area air flow and an inner area air flow that respectively flow in the outer layer area and the inner area in the pressure relief air inlet end, and making the flow velocity of the outer layer area air flow be greater than the flow velocity of the inner area air flow, and / or making the flow rate of the outer layer area air flow be greater than the flow rate of the inner area air flow.

[0022] In some embodiments, the flow guiding structure includes:

[0023] An air inlet end flow guiding structure is arranged inside the pressure relief air inlet end and is used for dividing the pressure relief air flow flowing into the pressure relief air inlet end into an outer layer area air flow, an inner layer area air flow, and a middle area air flow that respectively flow in the outer layer area, the inner layer area, and the middle area in the pressure relief air inlet end, and making the flow velocity of the outer layer area air flow, the flow velocity of the middle area air flow, and the flow velocity of the inner layer area air flow be distributed from large to small, and / or making the flow rate of the outer layer area air flow, the flow rate of the middle area air flow, and the flow rate of the inner layer area air flow be distributed from large to small.

[0024] Through the above technical solution, since the long-time fire resistance structure of the present invention is provided with an inner ring area of the fire-resistant layer as a closed heat insulation area, in the case of the combustion of the fire-resistant structure, the closed heat insulation area can effectively slow down the transfer of the combustion heat of the outer ring area of the fire-resistant layer to the middle area of the fire-resistant layer, so as to prevent a large amount of combustion heat from accumulating in the middle area of the fire-resistant layer and causing phenomena such as backfire and burning through. A large amount of combustion heat can be quickly dissipated outward from the outer ring area of the fire-resistant layer, thereby effectively extending the fire resistance duration. At the same time, the outer ring area and the middle area of the fire-resistant layer are beneficial to taking into account the flow efficiency of the pressure relief air flow.

[0025] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific embodiment part. Brief Description of the Drawings

[0026] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and form a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not limit the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings. In the accompanying drawings:

[0027] Figure 1 It is a schematic diagram of a long-time fire-resistant structure in a specific embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with two protective side fire-resistant layers;

[0029] Figure 3 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with a middle flow guide member;

[0030] Figure 4 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with a middle flow guide member, and the middle flow guide member is a curved plate with a flow-through structure;

[0031] Figure 5 It is an axial schematic diagram of a middle flow guide member in a specific embodiment of the present invention. The middle flow guide member in the figure includes a middle circular region provided with a flow-through structure;

[0032] Figure 6 It is a schematic diagram of a long-time fire-resistant structure applied as a breathing valve in a specific embodiment of the present invention;

[0033] Figure 7 It is a schematic diagram of a long-time fire-resistant structure applied as a breather valve in a specific embodiment of the present invention;

[0034] Figure 8 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with a middle flow guide member and a first annular flow guide member;

[0035] Figure 9 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with a middle flow guide member, a first annular flow guide member and two protective side fire-resistant layers;

[0036] Figure 10 It is a schematic diagram of another long-time fire-resistant structure in a specific embodiment of the present invention. The long-time fire-resistant structure in the figure is provided with a middle flow guide member, a first annular flow guide member and a second annular flow guide member;

[0037] Figure 11 The regional air flow distribution diagram in the cavity when a long-time fire retardant structure in the specific embodiment of the present invention is provided with a cavity diversion structure;

[0038] Figure 12 The regional air flow distribution diagram in the cavity when another long-time fire retardant structure in the specific embodiment of the present invention is provided with a cavity diversion structure;

[0039] Figure 13 For Figure 3 The structural parameter schematic diagram of the long-time fire retardant structure in

[0040] Figure 14 The schematic diagram of an air inlet end diversion structure in the specific embodiment of the present invention;

[0041] Figure 15 The regional air flow distribution diagram in the cavity when a long-time fire retardant structure in the specific embodiment of the present invention is provided with an air inlet end diversion structure;

[0042] Figure 16 The regional air flow distribution diagram in the cavity when another long-time fire retardant structure in the specific embodiment of the present invention is provided with an air inlet end diversion structure;

[0043] Figures 17 to 19 The axial schematic diagram of three optional heat insulation support structures in the specific embodiment of the present invention;

[0044] Figures 20 to 21 The side views of two other optional heat insulation support structures in the specific embodiment of the present invention;

[0045] Figure 22 The schematic diagram of another long-time fire retardant structure in the specific embodiment of the present invention. In the figure, each fire-resistant layer is provided with a fire-resistant layer outer ring area and a fire-resistant layer inner side area, and the fire-resistant layer inner side area can be a closed heat insulation area;

[0046] Figure 23 The axial schematic diagram of a fire-resistant layer in the specific embodiment of the present invention. The fire-resistant layer in the figure includes a first closed heat insulation disc and a plurality of first fire retardant discs;

[0047] Figure 24 The schematic diagram of another long-time fire retardant structure in the specific embodiment of the present invention. In the figure, each fire-resistant layer is provided with a fire-resistant layer outer ring area, a fire-resistant layer inner ring area and a fire-resistant layer middle area, and the fire-resistant layer inner ring area can be a closed heat insulation area;

[0048] Figure 25 The axial schematic diagram of another fire-resistant layer in the specific embodiment of the present invention. The fire-resistant layer in the figure includes a fire retardant ring, a closed heat insulation ring and a fourth fire retardant disc;

[0049] Figure 26 It is an axial schematic diagram of another fire-resistant layer in the specific embodiment of the present invention. The fire-resistant layer in the figure includes a second closed heat-insulating disc, a plurality of second fire-blocking discs and a single third fire-blocking disc;

[0050] Figure 27 It is a schematic diagram of a stacked porous fire-resistant layer in the specific embodiment of the present invention;

[0051] Figure 28 It is a schematic diagram of a combustion-side fire-resistant layer in the specific embodiment of the present invention. The combustion-side fire-resistant layer in the figure is provided with a fire-resistant layer disc portion and a fire-resistant layer convex portion;

[0052] Figure 29 It is a schematic diagram of a fire-blocking structure for comparative experiments in the specific embodiment of the present invention. There is no gap left between the combustion-side fire-resistant layer and the protection-side fire-resistant layer of the fire-blocking structure in the figure.

[0053] Description of reference numerals

[0054] 1 Housing;

[0055] 11 Pressure relief air inlet end, 12 Pressure relief exhaust end, 13 Cavity;

[0056] 2 Fire-resistant layer;

[0057] 21a Combustion-side fire-resistant layer, 21b Protection-side fire-resistant layer;

[0058] 22a Fire-resistant layer outer ring area, 22b Fire-resistant layer inner ring area, 22c Fire-resistant layer middle area;

[0059] 23a First closed heat-insulating disc, 23b First fire-blocking disc;

[0060] 24a Second closed heat-insulating disc, 24b Second fire-blocking disc, 24c Third fire-blocking disc;

[0061] 25a Fire-blocking ring, 25b Closed heat-insulating ring, 25c Fourth fire-blocking disc;

[0062] 26a First layer of shell, 26b Stacked particles;

[0063] 27a Fire-resistant layer disc portion, 27b Fire-resistant layer convex portion;

[0064] 3 Heat-insulating support structure;

[0065] 31 Heat-insulating support unit;

[0066] 32a Heat-insulating support body portion, 32b Heat-insulating support protruding portion;

[0067] 4 Middle flow guide member;

[0068] 41 Overcurrent structure, 42 Bending plate, 43 Pressure relief valve disc;

[0069] 5 First annular flow guide;

[0070] 6 Second annular flow guide;

[0071] 7 First circumferential partition;

[0072] 8 Second circumferential partition;

[0073] G11 Airflow in the outer region, G12 Airflow in the inner region;

[0074] G21 Airflow in the outer ring region, G22 Airflow in the inner ring region, G23 Airflow in the middle region;

[0075] G31 Airflow in the outer layer region, G32 Airflow in the inner region, G321 Airflow in the inner layer region, G322 Airflow in the middle region Detailed implementation manners

[0076] The following will describe in detail the specific implementation manners of the present invention with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0077] The following describes a long-time flame arrester structure according to the present invention with reference to the drawings.

[0078] Through analysis, during long-time combustion of the existing pipe-end flame arresters or flame arrestor breathing valves, the combustion heat has three heat transfer directions. One is to transfer to the inside of the flame arrester through heat conduction and thermal radiation. The second is to be carried away by some combustible gases discharged by the flame arrester. The third is to be dissipated to the outside atmosphere through heat conduction and thermal radiation, etc.

[0079] The second and third heat transfer directions mentioned above are both beneficial to preventing the combustion heat from accumulating in the flame arrester, making the flame arrest effect of the flame arrester better. The first heat transfer direction is not the case. The transfer of combustion heat to the inside of the flame arrester will increase the risk of flashback and burning-through of the flame arrester.

[0080] However, due to the limitations of the existing pipe-end flame arresters or flame arrestor breathing valves in terms of their flame arrest structures and internal structure forms, during the combustion of the flame arrest structure, the heat transfer direction of the combustion heat is mainly the first one mentioned above. Therefore, the combustion heat will quickly accumulate in the flame arrest structure and will accumulate in a local area (usually the middle area) of the flame arrest structure, and it is easy to have a burning-through phenomenon in this local area.

[0081] To address the deficiencies of the existing technology, the long-time fire-blocking structure of the present invention is mainly optimized based on two design directions: one is to enhance the heat transfer in the second and third heat transfer directions as much as possible, that is, to enhance the external dissipation of combustion heat; the other is to weaken the heat transfer in the first heat transfer direction as much as possible, that is, to weaken the transfer of combustion heat to the inside of the long-time fire-blocking structure.

[0082] Multiple alternative embodiments of the long-time fire-blocking structure of the present invention will be provided hereinafter. Each embodiment is designed by adopting at least one of the above two design directions, and can effectively extend the fire-blocking duration.

[0083] In each alternative embodiment, first refer to Figure 1 , the basic structure of the long-time fire-blocking structure includes a housing 1 and a fire-resistant structure. Specifically, the housing 1 is provided with a pressure-relief air inlet end 11, a pressure-relief exhaust end 12, and a cavity 13 connecting the pressure-relief air inlet end 11 and the pressure-relief exhaust end 12. When it is necessary to release the gas pressure through the long-time fire-blocking structure, the pressure-relief air flow passes through the pressure-relief air inlet end 11, the cavity 13, and the pressure-relief exhaust end 12 in sequence and is discharged. In addition, the fire-resistant structure is arranged at the pressure-relief exhaust end 12. In order to ensure that the pressure-relief air flow can be discharged from the pressure-relief exhaust end 12, structures such as holes and gaps need to be provided in the fire-resistant structure.

[0084] When there is an ignition source in the outside world and the pressure-relief air flow is ignited on the downstream side of the fire-resistant structure, there are the following two working conditions:

[0085] One is the non-long-time fire-resistant working condition. At this time, the pressure-relief air flow is not continuously discharged through the pressure-relief exhaust end 12. Therefore, under the quenching and external heat transfer effects of the fire-resistant structure, the fire-resistant structure can prevent the flame from spreading upstream (i.e., the inside of the long-time fire-blocking structure) of the fire-resistant structure;

[0086] The other is the long-time fire-resistant working condition. At this time, the pressure-relief air flow is continuously discharged through the pressure-relief exhaust end 12, and there will be a flame on the downstream side of the fire-resistant structure for a long time. The fire-resistant structure may not be able to prevent the flame from spreading upstream of the fire-resistant structure, and even the flame may burn through the fire-resistant structure. These situations are likely to cause more serious accidents such as storage tank fires or explosions.

[0087] The following will introduce multiple alternative embodiments that can effectively extend the fire-blocking duration one by one:

[0088] Airflow control method 1 (cavity diversion structure)

[0089] Refer to Figure 3 and Figure 11The long-term fire-blocking structure may include a cavity guide structure disposed in the cavity 13. Specifically, the cavity guide structure may include a middle guide member 4 disposed in alignment with the pressure relief air inlet end 11. Under the guiding effect of the middle guide member 4, the pressure relief airflow flowing from the pressure relief air inlet end 11 into the cavity 13 may be divided into an outer area airflow G11 flowing in the outer area of ​​the cavity 13 and an inner area airflow G12 flowing in the inner area of ​​the cavity 13.

[0090] Compared with the long-term combustion conditions of existing flame arresters, in which the combustion heat is concentrated in a local area (usually the middle area) of the fire-blocking structure, which makes it difficult to dissipate the combustion heat and even causes the fire-blocking structure to be burned through, the long-term fire-blocking structure of this embodiment can actively divert the pressure relief airflow flowing into the cavity 13 by setting a middle guide member 4. The diverted outer area airflow G11 and inner area airflow G12 can disperse the heat in the burn-resistant structure to different areas, thereby effectively reducing the risk of flashback and burn-through, and effectively extending the fire-blocking time.

[0091] Further, refer to Figure 4 and Figure 12 , the middle flow guide 4 may be provided with a flow structure 41 (such as a plurality of holes or gaps) throughout. At this time, the pressure relief airflow flowing into the cavity 13 from the pressure relief air inlet end 11 will pass through the middle flow guide 4 from the outer periphery of the middle flow guide 4 and the flow structure 41, and the pressure relief airflow passing through the outer periphery of the middle flow guide 4 will be split into two airflows, wherein the airflow in the outer area is the outer ring area airflow G21, and part of the airflow in the inner area will converge with the pressure relief airflow passing through the flow structure 41, so that the airflow in the inner area is further formed into two split airflows with different flow velocities and / or flow rates, namely, the inner ring area airflow G22 and the middle area airflow G23.

[0092] In other words, from a holistic perspective, after the pressure relief airflow passes through the middle flow guide 4 provided with the flow-through structure 41, there will be an outer ring area airflow G21, an inner ring area airflow G22 and a middle area airflow G23 distributed from outside to inside in the area of ​​the cavity 13 downstream of the middle flow guide 4. This flow field form can disperse the heat in the fire-resistant structure to more different areas, further extending the fire-blocking time.

[0093] Reference Figure 4 In order to reduce the pressure relief airflow resistance, the middle guide 4 can be set as a curved plate 42 (such as an arc-shaped plate), and the curved convex surface of the curved plate 42 faces the pressure relief air inlet end 11. In this way, the pressure relief airflow has a smaller airflow resistance when passing through the outer peripheral edge of the middle guide 4, ensuring that the long-term fire-blocking structure has a higher pressure relief speed, and at the same time, it is conducive to taking away the heat in the cavity 13 more quickly.

[0094] In addition to being set as the curved plate 42, the middle flow guide member 4 can also be set into other streamlined shapes, such as conical, spindle-shaped, water droplet-shaped, etc., and the present invention does not limit this.

[0095] Referring to Figure 6 and Figure 7 , when the long-time fire resistance structure is applied to a breathing valve (or exhalation valve), the middle flow guide member 4 can be used as the pressure relief valve disc 43 of the breathing valve (or exhalation valve) to switch the on-off state between the cavity 13 and the pressure relief air inlet end 11. When the pressure relief valve disc 43 moves downward to open and the cavity 13 is communicated with the pressure relief air inlet end 11, the pressure relief valve disc 43 plays the above-mentioned guiding and flow splitting roles.

[0096] Referring to Figure 5 , the flow-through structure 41 can include a plurality of flow-through holes formed in the middle circular area of the middle flow guide member 4. In addition to roughly limiting the flow range of the air flow G23 in the middle area to the middle cylindrical area of the cavity 13, the flow velocity and flow rate of the air flow G23 in the middle area can also be adjusted by designing different aperture sizes and hole distribution densities, etc.

[0097] In a specific embodiment, the total flow-through area of the flow-through structure 41 is not greater than one-third of the flow-through area of the pressure relief air inlet end 11, so as to prevent the problem that the middle area of the fire resistance structure overheats due to the excessive flow rate of the air flow G23 in the middle area from not being effectively solved.

[0098] In a specific embodiment, the area of the axial projection of the middle flow guide member 4 is not greater than the area of the axial projection of the pressure relief air inlet end 11, so as to prevent the radial dimension of the middle flow guide member 4 from being too large and affecting the discharge speed of the pressure relief air flow.

[0099] In a specific embodiment, referring to Figure 13 , the diameter of the middle flow guide member 4 is D1, the distance between the middle flow guide member 4 and the inner wall of the upstream end of the cavity 13 is H1, the distance between the middle flow guide member 4 and the inner wall of the downstream end of the cavity 13 is H2, the inner diameter of the cavity 13 is D, and the inner diameter of the pressure relief air inlet end 11 is d, satisfying:

[0100] wherein, e is the natural constant, and its value is approximately 2.718.

[0101] The above relationship mainly preferably limits the size and position of the middle flow guide member 4. Generally, in order to obtain better flow performance, the inner diameter D of the cavity 13 is more than twice the inner diameter d of the pressure relief air inlet end 11. However, in the case where the middle flow guide member 4 is not provided, after the pressure relief air flow enters the cavity 13 from the pressure relief air inlet end 11, the flow velocity in the middle area of the cavity will be higher than that in the outer ring area of the cavity, resulting in the pressure relief air flow concentrating on passing through the middle area of the fire resistance structure and a large pressure drop.

[0102] From the perspective of optimizing the flow field distribution, the above relationship designs the range of the diameter D1 of the specific middle flow guide member 4, and respectively limits the ranges of the distance H1 between the middle flow guide member 4 and the inner wall of the upstream end of the cavity 13, and the distance H2 between the middle flow guide member 4 and the inner wall of the downstream end of the cavity 13.

[0103] Specifically, the diameter D1 is mainly considered to enable the main air flow of the pressure relief air flow to impact the middle flow guide member 4, and then flow to the downstream from the outer peripheral edge of the middle flow guide member 4. If the diameter D1 is too large, the flow space of the outer air flow will be reduced. Therefore, according to the experimental data and the basic principles of fluid mechanics, the above range limitation of the diameter D1 is carried out.

[0104] The distance H1 is mainly considered to ensure that the flow area required for the pressure relief air flow to pass through here is larger than the incoming flow area of the pressure relief air inlet end 11, so as to reduce the pressure loss caused by the 90° bend.

[0105] The distance H2 is considered to ensure that the incoming flow develops fully after passing through the middle flow guide member 4, so that the refraction flow generated by the air flow impacting the inner wall of the downstream end of the cavity 13 can have a good disturbing effect on the air flow, and then form a relatively uniform flow velocity distribution. It is mainly derived from the fluid mechanics theory, numerical simulation and experimental results.

[0106] Refer to Figure 8 、 Figure 9 and Figure 12 As shown in, the cavity flow guide structure may further include a first annular flow guide member 5 disposed on the downstream side of the middle flow guide member 4. Wherein, the outer circumferential wall of the first annular flow guide member 5 is spaced from the inner circumferential wall of the cavity 13. When the outer region air flow G11 and the inner region air flow G12 have been separated by the middle flow guide member 4, the outer region air flow G11 and the inner region air flow G12 can be further separated when passing through the first annular flow guide member 5. At this time, the air flow of the outer part of the outer region air flow G11 flows downstream through the spaced area between the outer circumferential wall of the first annular flow guide member 5 and the inner circumferential wall of the cavity 13, and this part of the air flow is the outer ring region air flow G21; while the air flow of the inner part of the outer region air flow G11 and the air flow of the outer part of the inner region air flow G12 are separated when passing through the inner circumferential edge of the first annular flow guide member 5. The separated air flow close to the inner circumferential edge of the first annular flow guide member 5 is the inner ring region air flow G22, and the separated air flow far from the inner circumferential edge of the first annular flow guide member 5 (i.e., the separated air flow flowing in the middle region of the cavity 13) is the middle region air flow G23.

[0107] In other words, overall, after the pressure relief airflow is divided by the middle flow guide member 4 and the first annular flow guide member 5, in the area of the cavity 13 downstream of the first annular flow guide member 5, there will be an outer ring area airflow G21, an inner ring area airflow G22, and a middle area airflow G23 that are distributed in sequence from the outside to the inside. This flow field form can disperse the heat in the fire-resistant structure to more different areas, further extending the fire resistance duration.

[0108] It should be noted that when the middle flow guide member 4 is provided with a flow-through structure 41 and the cavity flow guide structure is provided with the first annular flow guide member 5, there will also be an outer ring area airflow G21, an inner ring area airflow G22, and a middle area airflow G23 that are distributed in sequence from the outside to the inside in the area of the cavity 13 downstream of the first annular flow guide member 5. This is because the flow-through structure 41 mainly affects the flow rate and / or flow velocity of the middle area airflow G23.

[0109] Refer to Figure 10 , the cavity flow guide structure may further include a second annular flow guide member 6 provided on the downstream side of the first annular flow guide member 5. Among them, the outer circumferential wall of the second annular flow guide member 6 is spaced from the inner circumferential wall of the cavity 13, and the outer ring radius of the second annular flow guide member 6 is greater than the outer ring radius of the first annular flow guide member 5. Obviously, the second annular flow guide member 6 can further guide and divide the flow field form of the outer ring area airflow G21, the inner ring area airflow G22, and the middle area airflow G23 to adjust the flow rate and / or flow velocity of the airflow in each area, or can further divide into more strands of area airflow, as evenly as possible to disperse the heat in the fire-resistant structure to achieve an excellent effect of extending the fire resistance duration.

[0110] The present invention only lists some optional forms of the cavity flow guide structure for illustration. It can be understood that other cavity flow guide structure forms that can also divide the pressure relief airflow in the cavity 13 into multiple strands of area airflow should also belong to the concept scope of the present invention.

[0111] Airflow control method 2 (inlet end diversion structure)

[0112] Refer to Figure 14 and Figure 15 , the long-term fire resistance structure may include an intake end flow guide structure provided in the pressure relief intake end 11. Specifically, the intake end flow guide structure may include a first circumferential partition 7, and the outer circumferential wall of the first circumferential partition 7 is spaced from the inner circumferential wall of the pressure relief intake end 11. In this way, the pressure relief airflow flowing into the pressure relief intake end 11 can be divided into an outer layer area airflow G31 flowing between the inner circumferential wall of the pressure relief intake end 11 and the outer circumferential wall of the first circumferential partition 7 and an inner area airflow G32 flowing inside the first circumferential partition 7 under the guiding action of the first circumferential partition 7.

[0113] Compared with the existing flame arresters in long-term combustion conditions where the combustion heat accumulates in the local area (usually the middle area) of the flame arrestment structure, making it difficult for the combustion heat to dissipate and even causing the flame arrestment structure to be burned through, the long-term flame arrestment structure of this embodiment can actively shunt the pressure relief air flow flowing into the pressure relief air inlet end 11 by setting the first circumferential partition 7. The outer region air flow G31 and the inner region air flow G32 shunted can disperse the heat in the heat-resistant structure to different regions, thereby effectively reducing the risk of flashback and burning through, effectively extending the flame arrestment duration, and achieving long-term flame arrestment.

[0114] Further, referring to Figure 14 and Figure 16 , the air inlet end diversion structure may further include a second circumferential partition 8 arranged inside the first circumferential partition 7, and the second circumferential partition 8 is arranged at an interval inside and outside the first circumferential partition 7. At this time, under the diversion action of the second circumferential partition 8, the inner region air flow G32 can be further divided into an inner layer region air flow G321 flowing between the first circumferential partition 7 and the second circumferential partition 8 and an intermediate region air flow G322 flowing inside the second circumferential partition 8.

[0115] In other words, overall, when the pressure relief air flow passes through the air inlet end diversion structure provided with the first circumferential partition 7 and the second circumferential partition 8, there will be an outer region air flow G31, an inner layer region air flow G321, and an intermediate region air flow G322 distributed in sequence from outside to inside in the pressure relief air inlet end 11. This flow field form can disperse the heat in the heat-resistant structure to more different regions, further extending the flame arrestment duration.

[0116] In a specific embodiment, the structural parameter relationship between the heat-resistant structure and the air inlet end diversion structure is defined. Specifically, the heat-resistant structure may include an outer layer flow-through structure, an inner layer flow-through structure, and an intermediate layer flow-through structure respectively used for the outer region air flow G31, the inner layer region air flow G321, and the intermediate region air flow G322 to flow through; the porosity of the outer layer flow-through structure, the inner layer flow-through structure, and the intermediate layer flow-through structure are σ1, σ2, and σ3 respectively; the flow-through areas of the outer layer flow-through structure, the inner layer flow-through structure, and the intermediate layer flow-through structure are S1, S2, and S3 respectively.

[0117] In addition, the inlet end diversion ratios of the annular region between the inner peripheral wall of the pressure relief air inlet end 11 and the outer peripheral wall of the first circumferential partition 7, the annular region between the first circumferential partition 7 and the second circumferential partition 8, and the inner region of the second circumferential partition 8 are a, b, and c respectively.

[0118] Furthermore, the total inlet end flow-through area of the air inlet end diversion structure is S0.

[0119] Based on the principle of flow conservation, the following relationships are set such that the flow rate of the pressure relief air flowing into the annular region between the inner peripheral wall of the pressure relief air inlet end 11 and the outer peripheral wall of the first circumferential partition 7 is equal to the flow rate of the pressure relief air flowing through the outer layer flow structure of the fire-resistant structure, the flow rate of the pressure relief air flowing into the annular region between the first circumferential partition 7 and the second circumferential partition 8 is equal to the flow rate of the pressure relief air flowing through the inner layer flow structure of the fire-resistant structure, and the flow rate of the pressure relief air flowing into the inner region of the second circumferential partition 8 is equal to the flow rate of the pressure relief air flowing through the intermediate flow structure of the fire-resistant structure. The specific relationships are as follows:

[0120] (S1*σ1) / (S0*a) ≤ 2 / 3;

[0121] (S2*σ2) / (S0*b) ≥ 5;

[0122] 1 ≤ (S3*σ3) / (S0*c) ≤ 3.

[0123] It should be noted that the air inlet end flow guiding structure may also be provided with more circumferential partitions other than the first circumferential partition 7 and the second circumferential partition 8 to divide more regional airflows and disperse the heat in the fire-resistant structure as evenly as possible to achieve an excellent effect of extending the fire resistance duration.

[0124] In the present invention, only some optional forms of the air inlet end flow guiding structure are listed for illustration. It can be understood that other forms of the air inlet end flow guiding structure that can also divide the pressure relief air in the pressure relief air inlet end 11 into multiple regional airflows should also fall within the scope of the concept of the present invention.

[0125] In addition, in addition to the cavity flow guiding structure and the air inlet end flow guiding structure provided above, other forms of flow guiding structures may also be provided in the housing 1. For example, an integral housing flow guiding structure that simultaneously occupies the spaces of the cavity 13 and the pressure relief air inlet end 11 can also be designed. In other words, the present invention does not limit the specific form of the flow guiding structure provided in the housing 1, as long as the flow guiding structure is located upstream of the fire-resistant structure and can divide the pressure relief air in the housing 1 into multiple regional airflows flowing towards different regions of the fire-resistant structure, the effect of extending the fire resistance duration can be achieved.

[0126] Airflow control method 3 (porosity distribution of the fire-resistant structure)

[0127] By providing multiple fire-resistant layer partitions with different porosity in the fire-resistant structure, the pressure relief air can have different flow velocities and / or flow rates when passing through the multiple fire-resistant layer partitions. For example, for the regions in the fire-resistant structure that are prone to local overheating during combustion, the porosity of these regions can be relatively small to reduce the flow rate passing through these regions, thereby reducing the combustion heat in these regions.

[0128] Compared with the existing flame arresters in long-term combustion conditions where the combustion heat accumulates in a local area (usually the middle area) of the flame arrestment structure, making it difficult for the combustion heat to dissipate and even causing the flame arrestment structure to be burned through, the long-term flame arrestment structure of this embodiment can actively divert the pressure-relief air flow passing through the flame-resistant structure by reasonably setting the porosity of multiple flame-resistant layer partitions, preventing local overheating of the flame-resistant structure, thereby effectively reducing the risk of flashback and burning through, effectively extending the flame arrestment duration, and achieving long-term flame arrestment.

[0129] Referring to Figure 22 , the flame-resistant layer partition may include a flame-resistant layer outer ring area 22a and a flame-resistant layer inner area located inside the flame-resistant layer outer ring area 22a. In this way, when the pressure-relief air flow passes through the flame-resistant structure, it will be divided into two regional air flows, and the two regional air flows are discharged through the flame-resistant layer outer ring area 22a and the flame-resistant layer inner area respectively.

[0130] Further, referring to Figure 24 , the flame-resistant layer inner area may include a flame-resistant layer inner ring area 22b and a flame-resistant layer middle area 22c. At this time, the flame-resistant layer outer ring area 22a, the flame-resistant layer inner ring area 22b, and the flame-resistant layer middle area 22c are arranged in sequence from outside to inside. In this way, when the pressure-relief air flow passes through the flame-resistant structure, it will be divided into three regional air flows, and the three regional air flows are discharged through the flame-resistant layer outer ring area 22a, the flame-resistant layer inner ring area 22b, and the flame-resistant layer middle area 22c respectively.

[0131] In a specific embodiment, the radius of the flame-resistant layer middle area 22c is r1, the outer ring radius of the flame-resistant layer inner ring area 22b is r2, and the outer ring radius of the flame-resistant layer outer ring area 22a is R, satisfying: 0 ≤ r1 ≤ R / 3, R / 3 ≤ r2 ≤ 2R / 3. In particular, when r1 = 0, it is equivalent to that the flame-resistant layer partition includes the flame-resistant layer outer ring area 22a and the flame-resistant layer inner area, and the flame-resistant layer inner area is not further divided into the flame-resistant layer inner ring area 22b and the flame-resistant layer middle area 22c.

[0132] It should be noted that more annular flame-resistant layer partitions can also be divided in the flame-resistant structure to divide more regional air flows and disperse the heat in the flame-resistant structure as evenly as possible to achieve an excellent effect of extending the flame arrestment duration.

[0133] The specific structural forms of the flame-resistant layer outer ring area 22a, the flame-resistant layer inner area, the flame-resistant layer inner ring area 22b, and the flame-resistant layer middle area 22c can refer to the embodiments of radial heat insulation of the flame-resistant structure in the following text, and will not be elaborated in detail here. It can be understood that other structural forms of flame-resistant layer partitions that can also divide the pressure-relief air flow into multiple regional air flows should also fall within the scope of the concept of the present invention.

[0134] Flow velocity and flow rate distribution form under airflow control

[0135] It has been experimentally proven by the designers of the present invention that when the fire-resistant structure burns, the faster the flow rate of the pressure-relief air flow through the fire-resistant structure, the smaller the combustion heat transferred to the interior of the long-time flame-retardant structure. Analyzing from the theoretical level, mainly because the air flow with a high flow rate can carry away the combustion heat accumulated in the fire-resistant structure faster, accelerating the outward dissipation of the combustion heat.

[0136] Therefore, when dividing the pressure-relief air flow into multiple regional air flows through the active shunt technology (i.e., the aforementioned air flow control methods one, two, and three), the porosity distribution form of the cavity diversion structure, the intake-end diversion structure, or the fire-resistant structure can be adjusted in terms of structure and parameters, so that the flow rate and flow distribution form of each regional air flow meet the need to extend the flame-retardant duration.

[0137] Now, two optional flow rate and flow distribution forms with better flame-retardant duration extension effects are provided:

[0138] The first distribution form is: making the regional air flow with a high flow rate and a large flow pass through the outer region of the fire-resistant structure, and making the regional air flow with a low flow rate and a low flow pass through the inner region of the fire-resistant structure. And in particular, there may be no regional air flow passing through the inner region of the fire-resistant structure.

[0139] When the fire-resistant structure burns, the regional air flow with a large flow will pass through the outer region of the fire-resistant structure with a relatively high heat dissipation efficiency at a high speed, taking away a large amount of combustion heat faster and further increasing the dissipation speed of the combustion heat. And the regional air flow with a low flow will pass through the inner region (including the middle region) of the fire-resistant structure at a low speed, or there is no regional air flow passing through the inner region of the fire-resistant structure. Compared with the existing flame arrester in which the pressure-relief air flow passes through the middle region of the fire-resistant structure with a large flow, the problem of local heat concentration in the middle region of the fire-resistant structure can be effectively solved, and the risk of flashback and the middle region being burned through can be effectively reduced.

[0140] The second distribution form is: making the regional air flow with a high flow rate and a large flow pass through the outer ring region of the fire-resistant structure, making the regional air flow with a low flow rate and a low flow pass through the inner ring region of the fire-resistant structure, and making the regional air flow with a medium flow rate and a medium flow pass through the middle region of the fire-resistant structure. And in particular, there may be no regional air flow passing through the inner ring region of the fire-resistant structure.

[0141] When the burn-resistant structure burns, the regional airflow with a large flow rate will pass through the outer ring area of ​​the burn-resistant structure, which originally has a relatively high heat dissipation efficiency, at a high speed, taking away a large amount of combustion heat more quickly, and further increasing the rate of heat dissipation. The regional airflow with a medium flow rate will pass through the middle area of ​​the burn-resistant structure at a high speed. Compared with the existing flame arrester in which the pressure relief airflow passes through the middle area of ​​the burn-resistant structure at a large flow rate, it can effectively solve the problem of local heat concentration in the middle area of ​​the burn-resistant structure, and effectively reduce the risk of flashback and burn-through in the middle area. In addition, the regional airflow with a low flow rate will pass through the inner ring area of ​​the burn-resistant structure at a low speed, or there will be no regional airflow passing through the inner ring area of ​​the burn-resistant structure, which is equivalent to forming the inner ring area of ​​the burn-resistant structure into a low thermal conductivity area between the outer ring area and the middle area, thereby weakening the transfer of combustion heat from the outer ring area of ​​the burn-resistant structure to the middle area, and further reducing the risk of flashback and burn-through in the middle area of ​​the burn-resistant structure.

[0142] In a specific embodiment, the average velocity of the airflow in the area with high flow rate and large flow is defined as v1 and the flow area is defined as s1, the average velocity of the airflow in the area with low flow rate and low flow is defined as v2 and the flow area is defined as s2, the average velocity of the airflow in the area with medium flow rate and medium flow is defined as v3 and the flow area is defined as s3, and the average velocity of the pressure relief airflow flowing into the pressure relief air inlet end 11 is defined as v and the flow area is defined as s.

[0143] At this time, the porosity distribution of the cavity guide structure, the air inlet end guide structure or the burn-resistant structure can be adjusted in terms of structure and parameters to satisfy the following relationship:

[0144] v1≥1.2v, preferably v1≥1.5v;

[0145] v3≤0.8v, preferably v3≤0.5v;

[0146] v2≤0.4v, preferably v2≤0.2v;

[0147] v1*s1≥0.5v*s, preferably v1*s1≥0.7v*s;

[0148] v3*s3≤0.5v*s, preferably v3*s3≤0.3v*s;

[0149] v2*s2≤0.3v*s, preferably v2*s2≤0.1v*s.

[0150] For the cavity flow guide structure (air flow control method 1):

[0151] Reference Figure 11, when the cavity flow guiding structure divides the outer region airflow G11 and the inner region airflow G12 in the cavity 13, the flow velocity of the outer region airflow G11 can be made greater than that of the inner region airflow G12, and / or the flow rate of the outer region airflow G11 can be made greater than that of the inner region airflow G12, so as to meet the aforementioned first flow velocity and flow rate distribution form.

[0152] Refer to Figure 12 , when the cavity flow guiding structure divides the outer ring region airflow G21, the inner ring region airflow G22, and the middle region airflow G23 in the cavity 13, the flow velocities of the outer ring region airflow G21, the middle region airflow G23, and the inner ring region airflow G22 can be distributed from large to small, and / or the flow rates of the outer ring region airflow G21, the middle region airflow G23, and the inner ring region airflow G22 can be distributed from large to small, so as to meet the aforementioned second flow velocity and flow rate distribution form.

[0153] It should be noted that a series of parameters such as the radius of the middle flow guiding member 4, the first annular flow guiding member 5, and the second annular flow guiding member 6 of the cavity flow guiding structure, the spacing in the upstream and downstream directions, and the spacing from the inner peripheral wall of the cavity 13 can be adjusted to meet the actual required flow velocity and flow rate distribution form.

[0154] For the intake end flow guiding structure (airflow control method 2):

[0155] Refer to Figure 15 , when the intake end flow guiding structure divides the outer layer region airflow G31 and the inner region airflow G32 in the pressure relief intake end 11, the flow velocity of the outer layer region airflow G31 can be made greater than that of the inner region airflow G32, and / or the flow rate of the outer layer region airflow G31 can be made greater than that of the inner region airflow G32, so as to meet the aforementioned first flow velocity and flow rate distribution form;

[0156] For example, the inlet end flow area of the annular region between the inner peripheral wall of the pressure relief intake end 11 and the first circumferential partition 7 can be made greater than the inlet end flow area of the inner region of the first circumferential partition 7, so as to achieve that the flow rate of the outer layer region airflow G31 is greater than that of the inner region airflow G32;

[0157] In addition, the outlet end flow area of the annular region between the inner peripheral wall of the pressure relief intake end 11 and the first circumferential partition 7 can be made smaller than the outlet end flow area of the inner region of the first circumferential partition 7, so as to achieve that the flow velocity of the outer layer region airflow G31 is greater than that of the inner region airflow G32.

[0158] Refer to Figure 16, when the intake-end flow guiding structure divides the outer-layer region airflow G31, the inner-layer region airflow G321, and the middle-region airflow G322 within the pressure-relief intake end 11, it can make the flow velocities of the outer-layer region airflow G31, the middle-region airflow G322, and the inner-layer region airflow G321 be distributed from large to small, and / or make the flow rates of the outer-layer region airflow G31, the middle-region airflow G322, and the inner-layer region airflow G321 be distributed from large to small, so as to meet the aforementioned second flow velocity and flow rate distribution form;

[0159] For example, the inlet-end flow splitting ratio of the annular region between the inner peripheral wall of the pressure-relief intake end 11 and the first circumferential partition 7 can be set as a, the inlet-end flow splitting ratio of the annular region between the first circumferential partition 7 and the second circumferential partition 8 can be set as b, and the inlet-end flow splitting ratio of the inner region of the second circumferential partition 8 can be set as c, satisfying: a > c > b, so as to achieve the distribution of the flow rates of the outer-layer region airflow G31, the middle-region airflow G322, and the inner-layer region airflow G321 from large to small;

[0160] In addition, the outlet-end flow-through areas of the annular region between the inner peripheral wall of the pressure-relief intake end 11 and the first circumferential partition 7, the outlet-end flow-through area of the inner region of the second circumferential partition 8, and the outlet-end flow-through area of the annular region between the first circumferential partition 7 and the second circumferential partition 8 can be set from small to large, so as to achieve the distribution of the flow velocities of the outer-layer region airflow G31, the middle-region airflow G322, and the inner-layer region airflow G321 from large to small.

[0161] For the porosity distribution of the fire-resistant structure (airflow control method three):

[0162] Refer to Figure 22 , when the fire-resistant structure is provided with a fire-resistant layer outer ring area 22a and a fire-resistant layer inner side area located inside the fire-resistant layer outer ring area 22a, the porosity of the fire-resistant layer outer ring area 22a can be made greater than the porosity of the fire-resistant layer inner side area, so as to meet the aforementioned first flow velocity and flow rate distribution form.

[0163] Refer to Figure 24 , when the fire-resistant structure is provided with a fire-resistant layer outer ring area 22a, a fire-resistant layer inner ring area 22b, and a fire-resistant layer middle area 22c arranged in sequence from outside to inside, the porosity of the fire-resistant layer outer ring area 22a, the porosity of the fire-resistant layer middle area 22c, and the porosity of the fire-resistant layer inner ring area 22b can be set from large to small, so as to meet the aforementioned second flow velocity and flow rate distribution form.

[0164] The porosity mainly needs to meet the requirements of fire resistance and burning resistance while taking into account the requirements of flow-through performance, and at the same time can achieve the requirement of changing the porosity design to change the flow field distribution. For the fire resistance requirement, for different combustible gases, the porosity requirements are different. According to the experimental results of the representative gases in the following table:

[0165]

[0166] The porosity can be constructed to have a relationship with the outer ring diameter of the fire-resistant layer outer ring area 22a, the inner ring area 22b of the fire-resistant layer, and the middle area 22c of the fire-resistant layer, which is related to the type of gas. The following relational expressions are fitted:

[0167]

[0168]

[0169] Among them, ε max is the set of upper limit values of porosity, ε min is the set of lower limit values of porosity. The radius of the middle area 22c of the fire-resistant layer is r1, the outer ring radius of the inner ring area 22b of the fire-resistant layer is r2, the outer ring radius of the outer ring area 22a of the fire-resistant layer is R, MESG is the maximum experimental safe gap, MESG (maximum experimental safe gap). For all concentrations of the measured gas or vapor, when the internal mixture is ignited, it is the maximum gap between two parts of an internal cavity with a 25-mm long flame path to prevent the external gas mixture from being ignited. The safe gap is measured according to IEC60079-20-1:2010.

[0170] It should be noted that the porosity of the middle area 22c of the fire-resistant layer should be lower than the minimum porosity of the outer ring area 22a of the fire-resistant layer.

[0171] Multi-layered fire-resistant structure

[0172] Referring to Figure 1 and Figure 2 , the fire-resistant structure may include a plurality of fire-resistant layers 2 arranged at intervals along the axial direction of the pressure relief exhaust end 12. Among them, the fire-resistant layer 2 located at the most downstream is formed as the combustion-side fire-resistant layer 21a, and the fire-resistant layer 2 located upstream of the combustion-side fire-resistant layer 21a is formed as the protection-side fire-resistant layer 21b.

[0173] When the combustible pressure relief gas flow continuously passes through the pressure relief exhaust end 12 and is ignited on the downstream side of the combustion-side fire-resistant layer 21a, the combustion-side fire-resistant layer 21a will burn for a long time. At this time, since there is at least one protection-side fire-resistant layer 21b provided upstream of the combustion-side fire-resistant layer 21a, it can greatly increase the heat dissipation area of the combustion heat, effectively reduce the risk of the combustion-side fire-resistant layer 21a being burned through due to heat accumulation, and even if the combustion-side fire-resistant layer 21a is burned through, the protection-side fire-resistant layer 21b can also take over to play a fire-blocking role, thereby greatly extending the fire-blocking duration of the fire-resistant structure.

[0174] The following provides some embodiments of the fire-resistant structure parameters that have been experimentally proven to obtain a better effect of extending the fire-blocking duration:

[0175] In a specific embodiment, the protective refractory layer 21b closest to the combustion-side refractory layer 21a is defined as the first protective refractory layer. The distance between the combustion-side refractory layer 21a and the first protective refractory layer is L, and the diameter of the first protective refractory layer is D2, satisfying: L = 3.31 + 2.615MESG - 0.012D 2 , where MESG is the maximum experimental safe gap. For all concentrations of the gas or vapor being measured, when the internal mixture is ignited, it is the maximum gap between two parts of an internal cavity with a 25-mm long flame path to prevent the external gas mixture from being ignited. The safe gap is measured in accordance with IEC60079-20-1:2010.

[0176] From the above relationship, it can be seen that L is related to D 2 and the fireproof rating (the fireproof rating is represented by the MESG value of the representative gas).

[0177] It should be noted that the distance L has a great influence on the fireproof and refractory performance. When the distance L is small, since the heat transfer from the combustion-side refractory layer 21a is mainly heat conduction and thermal radiation, it will cause the heat transfer to increase geometrically, especially thermal radiation, which is inversely proportional to the square of the distance L. The increase in heat will cause the temperature of the first protective refractory layer to rise rapidly, increasing the risk of fireproof failure; when the distance L is large, after the combustion-side refractory layer 21a burns for a long time, the temperature on its upstream side is relatively high, and it is easy to ignite the combustible gas in the gap between the combustion-side refractory layer 21a and the first protective refractory layer. The combustible gas burns continuously in the large gap, which is likely to cause a smoldering phenomenon, and the combustion heat in the gap is more difficult to dissipate outward, and most of it is transferred upstream, also increasing the risk of fireproof failure.

[0178] Therefore, in order to obtain a better fireproof effect, preferably, the size of the distance L is limited by the above relationship. The above relationship is related to the type of gas and is obtained by fitting the experimental results in the following table:

[0179]

[0180] In a specific embodiment, when the long-time fireproof structure is actually applied, to obtain a better effect of extending the fireproof duration, it is necessary to satisfy:

[0181] For Group IIA combustible gases, L ≤ 6 mm. Preferably, 2 mm ≤ L ≤ 4 mm;

[0182] For Group IIB3 combustible gases, L ≤ 4 mm. Preferably, 1 mm ≤ L ≤ 2 mm.

[0183] By limiting L, it is possible to prevent L from taking too large a value, reduce the risk that the pressure-relief air flow in the interval region between the burn-resistant layer 21a on the combustion side and the first protection-side burn-resistant layer is directly ignited by the high-temperature burn-resistant layer, thus avoiding the phenomenon of interlayer smoldering, and thereby reducing the risk of fire-blocking failure. In addition, it is possible to prevent L from taking too small a value, thereby preventing the enhancement of heat conduction between the burn-resistant layer 21a on the combustion side and the first protection-side burn-resistant layer.

[0184] In a specific embodiment, the total thickness of the plurality of burn-resistant layers 2 is T, and the porosity of the burn-resistant layer 2 is δ, satisfying: T≥3.14e 4.58δ 。

[0185] In a specific embodiment, in order to reduce the flow resistance, it satisfies: T<6.28e 4.58δ 。

[0186] In a specific embodiment, the thickness of the protection-side burn-resistant layer 21b is T2, satisfying: T2≤1.57e 4.58δ 。

[0187] In a specific embodiment, in order to obtain a better effect of extending the fire-blocking duration and a smaller flow resistance, it satisfies: 0.4≤δ≤0.6.

[0188] In a specific embodiment, the thickness of the burn-resistant layer 21a on the combustion side is T1, satisfying: T1≥T2.

[0189] In a specific embodiment, when the long-time fire-blocking structure is actually applied, in order to obtain a better effect of extending the fire-blocking duration and a smaller flow resistance, it satisfies: T≥30mm.

[0190] In a specific embodiment, the gap value of the burn-resistant layer 21a on the combustion side is h1, and the gap value of the protection-side burn-resistant layer 21b is h2, satisfying: h1≤h2.

[0191] In a specific embodiment, h1≤MESG, preferably, h1≤0.5MESG.

[0192] In a specific embodiment, h2≤MESG, preferably, h2≤0.8MESG.

[0193] In a specific embodiment, the gap of the burn-resistant layer 21a on the combustion side is axially deflected relative to the burn-resistant layer 21a on the combustion side, and the deflection angle is α, satisfying: T1*tanα≥h1.

[0194] In a specific embodiment, the flow area of each burn-resistant layer 2 is not less than the flow area of the pressure-relief air inlet end 11.

[0195] Axial heat insulation of the fire-resistant structure (heat insulation support structure)

[0196] Refer to Figure 1and Figure 2 The long-term fireproof structure may include a heat insulation support structure 3 disposed between two adjacent fire-resistant layers 2, and the heat insulation support structure 3 is in contact with the two adjacent fire-resistant layers 2.

[0197] The heat insulation support structure 3 has a heat insulation function and can effectively weaken the heat radiation and heat conduction between its two adjacent fire-resistant layers 2, thereby reducing and delaying the transfer of combustion heat to the inside of the housing 1; at the same time, the heat insulation support structure 3 also has a support function. When the downstream fire-resistant layer 2 is deformed by heat, it can support the deformed fire-resistant layer 2 to prevent it from coming into direct contact with the upstream fire-resistant layer 2 too quickly, thereby also slowing down the transfer of combustion heat to the inside of the housing 1 and taking into account the overall structural integrity of the fire-resistant structure.

[0198] To improve the support strength, the heat insulation support structure 3 can be arranged to form a support within the entire radial range of the fire-resistant layer 2, thereby effectively preventing the downstream fire-resistant layer 2 from deforming and collapsing after a long-term combustion. For example, referring to Figure 18 a triangular heat insulation support structure 3 can be adopted, and the diameter of the circumscribed circle of the triangle can be set to be equal to the diameter of the fire-resistant layer 2; or, referring to Figure 17 a cross-shaped heat insulation support structure 3 can be adopted, and the lengths of the two straight line segments forming the cross can be set to be equal to the diameter of the fire-resistant layer 2.

[0199] To enhance the heat insulation effect, the total contact area of the heat insulation support structure 3 with the two adjacent fire-resistant layers 2 should be as small as possible. If the ratio of the total contact area of the heat insulation support structure 3 with the two adjacent fire-resistant layers 2 to the cross-sectional area of the fire-resistant layer 2 is defined as and the thermal conductivity of the heat insulation support structure 3 is defined as λ, then it satisfies: In other words, is related to λ.

[0200] In a specific embodiment, is not greater than 3%, preferably, is not greater than 1%.

[0201] In a specific embodiment, the heat insulation support structure 3 forms a point contact with the fire-resistant layer 2. For example, the heat insulation support structure 3 can be in contact with the fire-resistant layer 2 by providing a convex point structure.

[0202] In a specific embodiment, the heat insulation support structure 3 forms a line contact with the fire-resistant layer 2. For example, a slender cylindrical heat insulation support structure 3 can be adopted.

[0203] In a specific embodiment, the heat insulation support structure 3 forms a surface contact with the fire-resistant layer 2. For example, a slender rectangular heat insulation support structure 3 can be adopted.

[0204] To enhance the heat insulation effect, it can also be achieved by increasing the thickness of the heat insulation support structure 3.

[0205] In a specific embodiment, the heat insulation support structure 3 is a multi-layer heat insulation support structure. For example, referring to Figure 19 and Figure 20 , the multi-layer heat insulation support structure may include a plurality of heat insulation support units 31 stacked in sequence along the axial direction, that is, the total thickness of the heat insulation support structure 3 is increased by stacking a plurality of independent heat insulation support units 31; or, referring to Figure 21 , the multi-layer heat insulation support structure may also include a heat insulation support body portion 32a and a heat insulation support protrusion portion 32b protruding from the heat insulation support body portion 32a along the axial direction, that is, the total thickness of the heat insulation support structure 3 is increased by providing a height increasing structure (heat insulation support protrusion portion 32b) in the integral heat insulation support structure 3.

[0206] In addition, the heat insulation support structure 3 should be made of high-temperature resistant materials to ensure that when the fire-resistant structure burns for a long time and continuously transfers heat to the heat insulation support structure 3, the heat insulation support structure 3 will not deform or deform excessively and lose its good support strength.

[0207] In a specific embodiment, the heat-resistant temperature of the heat insulation support structure 3 is not less than 1000 °C.

[0208] In a specific embodiment, the linear change rate of the heat insulation support structure 3 is not greater than 10%, preferably, the linear change rate of the heat insulation support structure 3 is not greater than 5%, so that the heat insulation support structure 3 can have no obvious deformation when heated for a long time.

[0209] Furthermore, the present invention does not limit the internal structure of the heat insulation support structure 3. For example, the heat insulation support structure 3 can be a solid heat insulation support structure, a porous heat insulation support structure with a porous structure, and a hollow heat insulation support structure with a hollow cavity, etc.

[0210] Radial heat insulation of the fire-resistant structure

[0211] Based on the content in the embodiment of the foregoing air flow control method three, obviously, when the fire-resistant structure is provided with one or more fire-resistant layers 2, a single fire-resistant layer 2 can refer to Figure 22 , and divide the outer ring area 22a of the fire-resistant layer and the inner area of the fire-resistant layer located inside the outer ring area 22a of the fire-resistant layer; or, a single fire-resistant layer 2 can refer to Figure 24 , and divide the outer ring area 22a of the fire-resistant layer, the inner ring area 22b of the fire-resistant layer, and the middle area 22c of the fire-resistant layer arranged in sequence from outside to inside.

[0212] Referring to Figure 22 , when the fire-resistant layer 2 is provided with the outer ring area 22a of the fire-resistant layer and the inner area of the fire-resistant layer, the porosity of the inner area of the fire-resistant layer can be zero, and thus the inner area of the fire-resistant layer can be set as a closed heat insulation area, while the outer ring area 22a of the fire-resistant layer can allow the pressure relief air flow to circulate.

[0213] Since the inner area of the fire-resistant layer is closed and has a heat-insulating function, the pressure-relief air flow cannot directly flow through the inner area of the fire-resistant layer to the downstream inner area of the fire-resistant layer 2, thereby reducing the generation of combustion heat in the downstream inner area. In addition, the inner area of the fire-resistant layer can effectively slow down the transfer of the combustion heat of the outer ring area 22a of the fire-resistant layer to the inside. Therefore, a large amount of combustion heat can be quickly dissipated outward from the outer ring area 22a of the fire-resistant layer, thereby effectively prolonging the fire-blocking duration.

[0214] In a specific embodiment, referring to Figure 23 , the fire-resistant layer 2 may include a first closed heat-insulating disc 23a and a plurality of first fire-blocking discs 23b. Among them, both the outer ring area 22a and the inner area of the fire-resistant layer are arranged on the first closed heat-insulating disc 23a. A plurality of first fitting openings formed at intervals in the circumferential direction are provided in the outer ring area 22a of the first closed heat-insulating disc 23a, and the plurality of first fire-blocking discs 23b are correspondingly fitted into the plurality of first fitting openings one by one.

[0215] With such an arrangement, the plurality of first fire-blocking discs 23b can all allow the pressure-relief air flow to pass through, thereby ensuring the flowability of the outer ring area 22a of the fire-resistant layer. In addition, in the first closed heat-insulating disc 23a, except for the area where the plurality of first fire-blocking discs 23b are fitted, the rest of the area cannot allow the pressure-relief air flow to pass through and has a heat-insulating function at the same time. It can not only effectively slow down the transfer of the combustion heat of the outer ring area 22a of the fire-resistant layer to the inside, but also slow down the heat transfer between the plurality of first fire-blocking discs 23b, so that more combustion heat is dissipated to the outside atmosphere.

[0216] Referring to Figure 24 , when the fire-resistant layer 2 is provided with an outer ring area 22a, an inner ring area 22b and an intermediate area 22c of the fire-resistant layer, the porosity of the inner ring area 22b of the fire-resistant layer can be zero. Thus, the inner ring area 22b of the fire-resistant layer can be set as a closed heat-insulating area, while the outer ring area 22a and the intermediate area 22c of the fire-resistant layer can both allow the pressure-relief air flow to pass through.

[0217] The above setting takes into account the flow efficiency of the pressure-relief air flow and retains the flowability of the intermediate area 22c of the fire-resistant layer. At the same time, the inner ring area 22b of the fire-resistant layer is closed and has a heat-insulating function, which can effectively slow down the transfer of the combustion heat of the outer ring area 22a of the fire-resistant layer to the intermediate area 22c of the fire-resistant layer, so as to prevent a large amount of combustion heat from accumulating in the intermediate area 22c of the fire-resistant layer and causing phenomena such as flashback and burn-through. A large amount of combustion heat can be quickly dissipated outward from the outer ring area 22a of the fire-resistant layer, thereby effectively prolonging the fire-blocking duration.

[0218] In a specific embodiment, referring to Figure 26, the fire-resistant layer 2 may include a second closed heat-insulating disc 24a, a plurality of second fire-blocking discs 24b, and a single third fire-blocking disc 24c. Among them, the outer ring area 22a, the inner ring area 22b, and the middle area 22c of the fire-resistant layer are all arranged on the second closed heat-insulating disc 24a. A plurality of second embedding ports formed at intervals in the circumferential direction are provided in the outer ring area 22a of the fire-resistant layer of the second closed heat-insulating disc 24a, and the plurality of second fire-blocking discs 24b are correspondingly embedded in the plurality of second embedding ports. A third embedding port is provided in the middle area 22c of the fire-resistant layer of the second closed heat-insulating disc 24a, and the third fire-blocking disc 24c is embedded in the third embedding port.

[0219] With such an arrangement, both the third fire-blocking disc 24c and the plurality of second fire-blocking discs 24b can allow the pressure-relief air flow to pass through, thereby ensuring the flowability of the middle area 22c and the outer ring area 22a of the fire-resistant layer. In the second closed heat-insulating disc 24a, except for the areas where the third fire-blocking disc 24c and the plurality of second fire-blocking discs 24b are embedded, the rest of the areas cannot allow the pressure-relief air flow to pass through, and at the same time have a heat-insulating function. It can not only effectively slow down the transfer of the combustion heat in the outer ring area 22a of the fire-resistant layer to the middle area 22c of the fire-resistant layer, but also slow down the heat transfer between the plurality of second fire-blocking discs 24b, so that more combustion heat is dissipated to the outside atmosphere.

[0220] In a specific embodiment, referring to Figure 25 , the fire-resistant layer 2 may include a fire-blocking ring 25a, a closed heat-insulating ring 25b, and a fourth fire-blocking disc 25c nested in sequence from the outside to the inside. Among them, the outer ring area 22a of the fire-resistant layer is arranged on the fire-blocking ring 25a, the inner ring area 22b of the fire-resistant layer is arranged on the closed heat-insulating ring 25b, and the middle area 22c of the fire-resistant layer is arranged on the fourth fire-blocking disc 25c.

[0221] With such an arrangement, both the fire-blocking ring 25a and the fourth fire-blocking disc 25c can allow the pressure-relief air flow to pass through, thereby ensuring the flowability of the outer ring area 22a and the middle area 22c of the fire-resistant layer. The closed heat-insulating ring 25b cannot allow the pressure-relief air flow to pass through, and at the same time has a heat-insulating function, which can effectively slow down the transfer of the combustion heat in the outer ring area 22a of the fire-resistant layer to the middle area 22c of the fire-resistant layer, so that more combustion heat is dissipated to the outside atmosphere.

[0222] It should be noted that the above-mentioned first closed heat-insulating disc 23a, second closed heat-insulating disc 24a, closed heat-insulating ring 25b or other forms of closed heat-insulating structures should be made of materials with low thermal conductivity. The inside of these closed heat-insulating structures can be set as a hollow structure, and in the hollow state, it can be vacuum-treated or filled with low-thermal-conductivity materials to achieve good heat-insulating performance.

[0223] Stacked porous fire-resistant layer

[0224] The fire-resistant layer 2 can adopt structures such as a corrugated plate fire arrester with a porous structure, a sintered porous fire-resistant layer, and a stacked porous fire-resistant layer. In this embodiment, specifically for the stacked porous fire-resistant layer, some specific embodiments that can obtain a better effect of extending the fire arrest duration are provided.

[0225] In a specific embodiment, referring to Figure 27 , the stacked porous fire-resistant layer may include a first shell 26a and a plurality of stacked particles 26b stacked within the first shell 26a.

[0226] Both the first shell 26a and the stacked particles 26b have high temperature resistance. Multiple particle gaps are formed between the plurality of stacked particles 26b, thereby forming a porous structure and thus having a certain fluidity. In addition, a plurality of first shell through-holes are provided on both the upstream sidewall and the downstream sidewall of the first shell 26a. The pressure relief air flow can flow into the interior of the fire-resistant layer through the plurality of first shell through-holes on the upstream sidewall, then flow through the multiple particle gaps to the downstream sidewall, and finally flow out of the fire-resistant layer through the plurality of first shell through-holes on the downstream sidewall. To ensure that the stacked particles 26b do not fall out of the first shell through-holes, the diameter of the first shell through-holes should be smaller than the diameter of the stacked particles 26b.

[0227] It should be noted that there is a risk that the plurality of stacked particles 26b may expand due to heat, causing the particle gaps in some areas to expand excessively. At this time, the air flow rate in the particle gaps in these areas increases excessively, which is likely to cause flashback and lead to fire arrest failure. Therefore, the thermal deformation of the stacked particles 26b should be minimized as much as possible.

[0228] For example, the distance between the upstream inner sidewall and the downstream inner sidewall of the first shell 26a can be made the same as the total stacking thickness of the plurality of stacked particles 26b along the axial direction of the stacked porous fire-resistant layer to compact the plurality of stacked particles 26b, which can effectively reduce the thermal expansion amplitude of the plurality of stacked particles 26b, avoid excessive expansion of the particle gaps, and thus effectively reduce the probability of fire arrest failure.

[0229] In addition, the diameter d1 of the stacked particles 26b and the total stacking thickness T3 of the plurality of stacked particles 26b along the axial direction of the stacked porous fire-resistant layer are related to the gas explosion grade. To achieve a better effect of extending the fire arrest duration, d1 and T3 can be set according to the following relational formula, and the relational formula is as follows:

[0230] When the pressure relief air flow is Class IIA gas, 1 ≤ [0.068ln(d1) + 0.31] * d1 / [(0.69 - 0.068ln(d1)] ≤ 1.5;

[0231] When the pressure relief air flow is Class IIB3 gas, 0.6 ≤ [0.068ln(d1) + 0.31] * d1 / [(0.69 - 0.068ln(d1)] ≤ 1.2;

[0232] T3 ≥ d1 / [ξ(1 - ξ)MESG], where MESG is the maximum experimental safe gap. For all concentrations of the gas or vapor being measured, when the internal mixture is ignited, it is the maximum gap between two parts of an internal cavity with a 25 - mm long flame path to prevent the external gas mixture from being ignited. The safe gap is measured in accordance with IEC60079 - 20 - 1:2010.

[0233] If the combustible gas is a mixed gas, its MESG value can be calculated based on its different gas components, or it can be simplified to refer to the MESG value of a typical gas of the corresponding explosion class. For example, for Group IIA gases, propane is selected as the representative gas with an MESG value of 0.93 mm; for Group IIB3 gases, ethylene is selected as the representative gas with an MESG value of 0.67 mm; for Group IIC gases, hydrogen is selected as the representative gas with an MESG value of 0.31 mm.

[0234] For the stacked - type porous fire - resistant layer, the pressure - relief air flow needs to pass through the gaps between the stacked particles. When the particle size of the stacked particles 26b is larger, the gap between the stacked particles is also larger. However, an overly large gap between the stacked particles will cause the flame to burn in the gap, thereby triggering flashback and resulting in the failure of fire prevention.

[0235] The above - mentioned relational expression limits the equivalent pore size represented by the gap value formed between the stacked particles 26b, enabling the flame to be quenched between the pores, thereby achieving fire prevention. At the same time, to ensure the flow performance, the total stacked thickness T3 is limited.

[0236] In a specific embodiment, the stacked - type porous fire - resistant layer may include a second - layer shell and a plurality of lightweight spheres stacked inside the second - layer shell.

[0237] Both the second - layer shell and the lightweight spheres have high - temperature resistance. There are multiple sphere gaps formed between the plurality of lightweight spheres, thus forming a porous structure and having a certain flowability. In addition, a plurality of through - holes of the second - layer shell are provided on both the upstream side wall and the downstream side wall of the second - layer shell. The pressure - relief air flow can flow into the interior of the fire - resistant layer through the plurality of through - holes of the upstream side wall of the second - layer shell, then flow through the multiple sphere gaps to the downstream side wall, and finally flow out of the fire - resistant layer through the plurality of through - holes of the downstream side wall of the second - layer shell. To ensure that the lightweight spheres do not fall out of the through - holes of the second - layer shell, the diameter of the through - holes of the second - layer shell should be smaller than the diameter of the lightweight spheres.

[0238] Particularly, due to the small mass of the lightweight spheres, when the pressure - relief air flow passes through the multiple sphere gaps, it can drive the plurality of lightweight spheres to rotate, realizing the cold - hot cycle of the lightweight spheres, prolonging the heat transfer time, and being beneficial to improving the fire - prevention performance.

[0239] Convex design of the combustion-side fire-resistant layer

[0240] By protruding at least a partial area of the downstream side surface of the combustion-side fire-resistant layer 21a downstream, the area of the downstream side surface of the combustion-side fire-resistant layer 21a is enlarged, the heat dissipation effect of the downstream side surface can be strengthened, the problem of combustion heat accumulation can be effectively improved, and thus the fire-blocking duration of the combustion-side fire-resistant layer 21a can be extended.

[0241] For example, the downstream side surface of the combustion-side fire-resistant layer 21a can be set as a fire-resistant layer curved surface, and the fire-resistant layer curved surface has at least one protruding position, and can be in different specific forms such as a variable curvature curved surface and a fixed curvature curved surface; when adopting a fixed curvature curved surface with a single protruding position, the fire-resistant layer curved surface is a partial spherical surface (that is, a part of a complete spherical surface), so that both the improvement of the heat dissipation effect and the simplification of processing can be taken into account, which is beneficial to reducing production costs.

[0242] In other words, the specific form of the protruding area of the downstream side surface of the combustion-side fire-resistant layer 21a in this embodiment is not limited, as long as it is beneficial to improving the heat dissipation effect.

[0243] In a specific embodiment, referring to Figure 28 , the combustion-side fire-resistant layer 21a includes a fire-resistant layer disc portion 27a and a fire-resistant layer convex portion 27b connected to the downstream side of the fire-resistant layer disc portion 27a. At this time, the downstream side surface of the fire-resistant layer convex portion 27b is set to protrude downstream as a partial spherical surface. In this way, in the downstream side part of the combustion-side fire-resistant layer 21a, the fire-resistant layer convex portion 27b can improve the heat dissipation effect. In the upstream side part of the combustion-side fire-resistant layer 21a, the shape of the fire-resistant layer disc portion 27a is the same as that of the protection-side fire-resistant layer 21b. The upstream side surfaces of the fire-resistant layer disc portion 27a and the protection-side fire-resistant layer 21b are both flat straight surfaces, which can ensure that the distance between the upstream side surface of the fire-resistant layer disc portion 27a and the downstream side surface of the protection-side fire-resistant layer 21b is the same at each point within the radial range, avoiding enhanced heat conduction due to too small a distance or smoldering due to too large a distance in a local range.

[0244] In addition, the radian corresponding to the partial spherical surface is β, which is related to the structural dimensions of the combustion-side fire-resistant layer 21a and the fire-blocking and fire-resistant grade.

[0245] The fire-blocking and fire-resistant grade is classified according to ISO16852. The commonly used fire-blocking and fire-resistant grades are IIA, IIB3, and IIC, and the typical representative combustible gases are n-hexane, ethylene, and hydrogen respectively.

[0246] In order to better represent the relationship between β and the structural dimensions of the combustion-side fire-resistant layer 21a and the fire-blocking and fire-resistant grade, the MESG values of the typical representative combustible gases (n-hexane, ethylene, and hydrogen) can be taken as the characterization method of the fire-blocking and fire-resistant grade. At this time, it satisfies:

[0247] β = 3.78ε -0.8arctan(T4 / R1);

[0248] Among them, ε is the MESG value of typical representative combustible gases such as n - hexane, ethylene, and hydrogen, R1 is the radius of the disk part 27a of the fire - resistant layer, and T4 is the thickness of the disk part 27a of the fire - resistant layer.

[0249] By designing the combustion - side fire - resistant layer 21a through the above - mentioned relational expression, a better effect of extending the fire - blocking duration can be obtained.

[0250] High-temperature resistant coating

[0251] To improve the fire - blocking and fire - resistant performance, a high - temperature - resistant coating can be coated on at least the downstream side surface of the fire - resistant layer 2 itself. Preferably, a high - temperature - resistant coating that has no performance damage under long - term combustion conditions of not less than 2 hours and above 450 °C is coated.

[0252] In a specific embodiment, the high - temperature - resistant coating is provided to cover the outer surface of the fire - resistant layer 2, including the entire surface composed of the downstream side surface, upstream side surface, circumferential wall surface, surface of holes or gaps, etc. of the fire - resistant layer 2 itself, so as to improve the fire - blocking and fire - resistant performance of the fire - resistant layer 2 over a larger area.

[0253] In a specific embodiment, for the combustion - side fire - resistant layer 21a, a high - temperature - resistant coating with a high heat - radiation rate or a high reflectivity is preferably coated. For example, the reflectivity of the high - temperature - resistant coating is not less than 70%, and preferably, the reflectivity is not less than 90%.

[0254] In a specific embodiment, the thickness of the high - temperature - resistant coating coated on the combustion - side fire - resistant layer 21a is 200 μm to 500 μm, and preferably, the thickness is 300 μm to 500 μm.

[0255] In a specific embodiment, for the protection - side fire - resistant layer 21b, a high - temperature - resistant coating with a low thermal conductivity is preferably coated. For example, the thermal conductivity of the high - temperature - resistant coating is not greater than 0.2 W / (m·K).

[0256] In a specific embodiment, the thickness of the high - temperature - resistant coating coated on the protection - side fire - resistant layer 21b is 20 μm to 50 μm.

[0257] In a specific embodiment, the thickness of the high - temperature - resistant coating is T t , at this time, the fire - blocking gap characteristic value of the fire - resistant layer 2 is h g , the thickness of the fire - resistant layer 2 is T0, and it satisfies:

[0258]

[0259] T0≥3.14e 1.31MESG+1.88 ;

[0260] Among them, MESG is the maximum experimental safe gap. For all concentrations of the tested gas or vapor, when the internal mixture is ignited, it is the maximum gap between the two parts of the internal cavity through a 25mm long flame path to prevent the external gas mixture from being ignited. The safety gap is measured in accordance with IEC60079-20-1:2010.

[0261] It should be noted that the characteristic value of the fire-resistant gap h of the refractory layer 2 is g It is closely related to the fire resistance and burning resistance. When the characteristic value of the fire resistance gap h g When it is larger, the flow rate of the pressure relief airflow that can flow is larger, and its combustion heat is high, so that more heat per unit area is transferred to the downstream refractory layer 2, thereby affecting the fire-resistant and refractory effect; and when the characteristic value of the fire-resistant gap h g When it is smaller, although the flow rate of the pressure relief air flow is smaller and the combustion heat is low, the circulation performance is poor. Therefore, in order to obtain better circulation performance in practical applications, a larger burn-resistant layer area is required. However, as the area of ​​the burn-resistant layer increases, the total combustion heat does not decrease. The heat in the middle area of ​​the burn-resistant layer will be more difficult to dissipate due to the increase in the area of ​​the burn-resistant layer, thereby affecting the fire-retardant and burn-resistant performance.

[0262] In the case of high temperature resistant coating, the characteristic value of the fire barrier gap of the burning resistant layer 2 is h g Therefore, preferably, the characteristic value of the fire-blocking gap is h through the above relationship. g And the characteristic value of the fire-blocking gap is h g Thickness T of high temperature resistant coating t etc. to limit.

[0263] Long-term fire resistance working condition not less than 2 hours

[0264] At present, some domestic storage tanks or tank areas are difficult to meet the nitrogen sealing requirements, which will cause the gas phase space to be Zone 1. API2000 recommends that for storage tanks with a gas phase space of Zone 1 after nitrogen sealing (or other gas sealing), the flame arrester or flame arresting breathing valve on the tank should be an atmospheric deflagration type flame arrester with long-term flame retardancy and fire resistance, and the flame retardancy and fire resistance time should be no less than 2 hours. However, it is difficult for existing flame arresters or flame arresting breathing valves to meet the requirement of a fire retardancy and fire resistance time of no less than 2 hours.

[0265] Based on the above concept, the present invention further provides multiple embodiments of long-time fire-blocking structures with a fire-blocking time of not less than 2 hours, and sets multiple comparative examples for comparison to better reflect the effect of the present invention on improving the fire-blocking time.

[0266] In the experimental tests of multiple embodiments and comparative examples, the pipe diameter specification of the pressure relief air inlet end 11 is DN100, and the experimental test medium is a mixture of n-hexane and air recommended by ISO16852, where the volume fraction of n-hexane in the mixture is 2.1%. In addition, during the experimental test process, the temperature changes on the upstream side and downstream side of the fire-resistant structure are concerned, the duration required for the upstream side temperature to rise by 20 °C, and whether the fire can be blocked after burning for 2 hours, etc.

[0267] Example 1:

[0268] Refer to Figure 8 and Figure 18 , and the specific structural parameters in the long-term fire-blocking structure are as follows:

[0269] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0270] The middle flow guide member 4 adopts a metal circular plate with a diameter of 0.8d, and is spaced 0.25d from the upstream side wall of the cavity 13;

[0271] The first annular flow guide member 5 adopts a metal annular plate with inner and outer diameters of 1.3d and 1.6d respectively, and is axially spaced 0.25d from the middle flow guide member 4;

[0272] The fire-resistant layer 21b on the protection side adopts a corrugated plate fire-blocking disc with a diameter of 2d, a thickness of 15 mm, and a fire-blocking gap value of 0.45 mm;

[0273] The fire-resistant layer 21a on the combustion side adopts a corrugated plate fire-blocking disc with a diameter of 2d, a thickness of 15 mm, and a fire-blocking gap value of 0.45 mm;

[0274] The heat insulation support structure 3 adopts high-temperature resistant metal wires with a cross-sectional diameter of 2 mm. The heat insulation support structure 3 is arranged in a triangle, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the fire-resistant layer 21a on the combustion side.

[0275] Example 2:

[0276] Refer to Figure 4 , Figure 5 and Figure 18 , and the specific structural parameters in the long-term fire-blocking structure are as follows:

[0277] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0278] The middle flow guide member 4 is made of an arc-shaped metal circular plate, and a plurality of through holes are provided in the middle circular region thereof; wherein, along the radial direction of the pressure relief air inlet end 11, the maximum span of the arc-shaped metal circular plate is equal to the diameter d of the pressure relief air inlet end 11; in addition, the most upstream end of the arc-shaped metal circular plate is spaced 0.25d from the upstream side wall of the cavity 13; furthermore, the boundary diameter of the middle circular region of the middle flow guide member 4 is 0.5d, and the total flow area of all the through holes is half of the total area of this middle circular region;

[0279] The protection side fire-resistant layer 21b adopts a corrugated plate firestop disc, with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0280] The combustion side fire-resistant layer 21a adopts a corrugated plate firestop disc, with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0281] The heat insulation support structure 3 adopts high-temperature resistant metal wires, with a cross-sectional diameter of 2 mm. The heat insulation support structure 3 is arranged in a triangle, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the combustion side fire-resistant layer 21a.

[0282] Embodiment 3:

[0283] Refer to Figure 10 and Figure 18 , and the specific structural parameters in the long-time firestop structure are as follows:

[0284] The cavity 13 adopts a coaxial and equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0285] The middle flow guide member 4 is made of a metal circular plate, with a diameter of 0.8d, and is spaced 0.25d from the upstream side wall of the cavity 13;

[0286] The first annular flow guide member 5 is made of a metal annular plate, with an inner diameter and an outer diameter of d and 1.4d respectively, and is axially spaced 0.15d from the middle flow guide member 4;

[0287] The second annular flow guide member 6 is made of a metal annular plate, with an inner diameter and an outer diameter of 1.3d and 1.6d respectively, and is axially spaced 0.15d from the first annular flow guide member 5;

[0288] The protection side fire-resistant layer 21b adopts a corrugated plate firestop disc, with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0289] The combustion side fire-resistant layer 21a adopts a corrugated plate firestop disc, with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0290] The heat insulation support structure 3 is made of high-temperature resistant metal wire with a cross-sectional diameter of 2 mm. The heat insulation support structure 3 is arranged in a triangle, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the combustion-side fire-resistant layer 21a.

[0291] Example 4:

[0292] Referring to Figure 24 and Figure 18 , the specific structural parameters in the long-time fire-resistant structure are as follows:

[0293] The cavity 13 adopts a coaxial and equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0294] The middle flow guide member 4 adopts a metal circular plate with a diameter of 0.8d, and is spaced 0.25d from the upstream side wall of the cavity 13;

[0295] The first annular flow guide member 5 adopts a metal annular plate with inner and outer diameters of 1.3d and 1.6d respectively, and is axially spaced 0.25d from the middle flow guide member 4;

[0296] The protection-side fire-resistant layer 21b includes a corrugated plate fire-resistant disc, a closed heat-insulating metal ring, and a corrugated plate fire-resistant ring sleeved in sequence from the inside to the outside. The closed heat-insulating metal ring is provided with a hollow cavity or a low thermal conductivity material is filled in the hollow cavity thereof; for the corrugated plate fire-resistant disc, its diameter is 0.8d, its thickness is 15 mm, and the fire-resistant gap value is 0.45 mm; for the corrugated plate fire-resistant ring, its inner and outer diameters are 1.3d and 1.6d respectively, its thickness is 15 mm, and the fire-resistant gap value is 0.45 mm;

[0297] The combustion-side fire-resistant layer 21a includes a corrugated plate fire-resistant disc, a closed heat-insulating metal ring, and a corrugated plate fire-resistant ring sleeved in sequence from the inside to the outside. The closed heat-insulating metal ring is provided with a hollow cavity or a low thermal conductivity material is filled in the hollow cavity thereof; for the corrugated plate fire-resistant disc, its diameter is 0.8d, its thickness is 15 mm, and the fire-resistant gap value is 0.45 mm; for the corrugated plate fire-resistant ring, its inner and outer diameters are 1.3d and 1.6d respectively, its thickness is 15 mm, and the fire-resistant gap value is 0.45 mm;

[0298] The heat insulation support structure 3 is made of high-temperature resistant metal wire with a cross-sectional diameter of 2 mm. The heat insulation support structure 3 is arranged in a triangle, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the combustion-side fire-resistant layer 21a.

[0299] Example 5:

[0300] Referring to Figure 9 and Figure 18 , the specific structural parameters in the long-time fire-resistant structure are as follows:

[0301] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief and air inlet end 11 is d, and D = 2d;

[0302] The middle flow guide member 4 adopts a metal circular plate with a diameter of 0.8d and is spaced 0.25d from the upstream side wall of the cavity 13;

[0303] The first annular flow guide member 5 adopts a metal annular plate with inner and outer diameters of 1.3d and 1.6d respectively, and is axially spaced 0.25d from the middle flow guide member 4;

[0304] Both of the two protective side fire-resistant layers 21b adopt corrugated plate fire-resistant discs, each with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0305] The combustion side fire-resistant layer 21a adopts a corrugated plate fire-resistant disc with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0306] Both of the two heat insulation support structures 3 adopt high-temperature resistant metal wires, each with a cross-sectional diameter of 2 mm. Both of the two heat insulation support structures 3 are arranged in a triangular shape, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the combustion side fire-resistant layer 21a.

[0307] Example 6:

[0308] Refer to Figure 8 and Figure 19 , and the specific structural parameters in the long-term fire-resistant structure are as follows:

[0309] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief and air inlet end 11 is d, and D = 2d;

[0310] The middle flow guide member 4 adopts a metal circular plate with a diameter of 0.8d and is spaced 0.25d from the upstream side wall of the cavity 13;

[0311] The first annular flow guide member 5 adopts a metal annular plate with inner and outer diameters of 1.3d and 1.6d respectively, and is axially spaced 0.25d from the middle flow guide member 4;

[0312] The protective side fire-resistant layer 21b adopts a corrugated plate fire-resistant disc with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0313] The combustion side fire-resistant layer 21a adopts a corrugated plate fire-resistant disc with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0314] The heat insulation support structure 3 adopts double-layer high-temperature resistant metal wires. For each layer of high-temperature resistant metal wire, its cross-sectional diameter is 2 mm, and it is arranged in a triangular shape. The diameter of the circumscribed circle of the triangle is equal to the diameter of the combustion side fire-resistant layer 21a.

[0315] Example 7:

[0316] Referring to Figure 8 and Figure 21 , the specific structural parameters in the long-time fire-resistant structure are as follows:

[0317] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0318] The middle flow guide member 4 adopts a metal circular plate with a diameter of 0.8d and is spaced 0.25d from the upstream side wall of the cavity 13;

[0319] The first annular flow guide member 5 adopts a metal annular plate with inner and outer diameters of 1.3d and 1.6d respectively, and is axially spaced 0.25d from the middle flow guide member 4;

[0320] The protective side fire-resistant layer 21b adopts a corrugated plate fire-resistant disc with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0321] The combustion side fire-resistant layer 21a adopts a corrugated plate fire-resistant disc with a diameter of 2d, a thickness of 15 mm, and a fire-resistant gap value of 0.45 mm;

[0322] The heat insulation support structure 3 adopts high-temperature resistant metal wires with a heat insulation support body part 32a and a heat insulation support protruding part 32b. The cross-sectional diameter of the heat insulation support body part 32a is 2 mm, the thickness of the heat insulation support protruding part 32b protruding from the heat insulation support body part 32a is 1 mm, and the heat insulation support protruding part 32b is a hemispherical structure.

[0323] Example 8:

[0324] Referring to Figure 6 and Figure 18 , the long-time fire-resistant structure can be applied as a breather valve, and its specific structural parameters are as follows:

[0325] The cavity 13 adopts a coaxial equal-diameter cavity. The diameter of the cavity 13 is D, and the diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0326] A first flange is provided at the upstream end of the pressure relief air inlet end 11;

[0327] The middle flow guide member 4 serves as the pressure relief valve disc 43 of the breather valve. The pressure relief valve disc 43 is connected to a first guide rod, and the first guide rod can slide in the first guide groove in the upstream and downstream directions. The pressure relief valve disc 43 can switch the on-off state between the cavity 13 and the pressure relief air inlet end 11. When the pressure relief valve disc 43 moves downstream to open and the cavity 13 is communicated with the pressure relief air inlet end 11, the pressure relief valve disc 43 plays a role in guiding and distributing the flow; among them, the diameter of the pressure relief valve disc 43 is d, and it is spaced 0.25d from the upstream side wall of the cavity 13;

[0328] The first annular flow guide member 5 is made of a metal annular plate with an inner diameter and an outer diameter of 1.3d and 1.6d respectively, and is axially spaced from the middle flow guide member 4 by 0.25d;

[0329] The fire-resistant layer 21b on the protection side adopts a corrugated plate firestop disc with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0330] The fire-resistant layer 21a on the combustion side adopts a corrugated plate firestop disc with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0331] The heat-insulating support structure 3 is made of high-temperature-resistant metal wires with a cross-sectional diameter of 2 mm. The heat-insulating support structure 3 is arranged in a triangular shape, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the fire-resistant layer 21a on the combustion side.

[0332] Example 9:

[0333] Refer to Figure 7 and Figure 18 , the long-term firestop structure can be applied to a breather valve, and its specific structural parameters are as follows:

[0334] The cavity 13 adopts a coaxial and equal-diameter cavity with a diameter of D. The diameter of the pressure relief air inlet end 11 is d, and D = 2d;

[0335] A second flange is provided at the upstream end of the pressure relief air inlet end 11;

[0336] The middle flow guide member 4 serves as the pressure relief valve disc 43 of the breather valve. The pressure relief valve disc 43 is connected to a second guide rod, and the second guide rod can slide in the second guide groove in the upstream and downstream directions. The pressure relief valve disc 43 can switch the on-off state between the cavity 13 and the pressure relief air inlet end 11. When the pressure relief valve disc 43 moves downstream to open and the cavity 13 is communicated with the pressure relief air inlet end 11, the pressure relief valve disc 43 plays a role in guiding and distributing the flow; among them, the diameter of the pressure relief valve disc 43 is d, and it is axially spaced from the upstream side wall of the cavity 13 by 0.25d;

[0337] The first annular flow guide member 5 is made of a metal annular plate with an inner diameter and an outer diameter of 1.3d and 1.6d respectively, and is axially spaced from the middle flow guide member 4 by 0.25d;

[0338] The fire-resistant layer 21b on the protection side adopts a corrugated plate firestop disc with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0339] The fire-resistant layer 21a on the combustion side adopts a corrugated plate firestop disc with a diameter of 2d, a thickness of 15 mm, and a firestop gap value of 0.45 mm;

[0340] The heat insulation support structure 3 is made of high-temperature resistant metal wire with a cross-sectional diameter of 2 mm. The heat insulation support structure 3 is arranged in a triangle, and the diameter of the circumscribed circle of the triangle is equal to the diameter of the burn-resistant layer 21a on the combustion side.

[0341] Comparative Example 1:

[0342] Refer to Figure 29 , the fire-blocking structure in the figure can be regarded as a structural simplification and adjustment based on the long-time fire-blocking structure provided in Embodiment 1. Except for the differences specifically described below, the structural parameters of the common structures in Comparative Example 1 and Embodiment 1 are the same.

[0343] The difference between Comparative Example 1 and Embodiment 1 is that: the fire-blocking structure in Comparative Example 1 does not have a heat insulation support structure 3, a middle flow guide member 4, and a first annular flow guide member 5, and there is no gap left between the burn-resistant layer 21a on the combustion side and the burn-resistant layer 21b on the protection side.

[0344] Comparative Example 2:

[0345] Continuing with Figure 29 as an example, the difference between Comparative Example 2 and Comparative Example 1 is only that: the fire-blocking gap values of the burn-resistant layer 21a on the combustion side and the burn-resistant layer 21b on the protection side in Comparative Example 1 are both 0.45 mm, while the fire-blocking gap values of the burn-resistant layer 21a on the combustion side and the burn-resistant layer 21b on the protection side in Comparative Example 2 are both 0.85 mm.

[0346] The following table shows the comparison of experimental data between Embodiments 1-9 and Comparative Examples 1-2:

[0347]

[0348]

[0349] As can be seen from the above table, the long-time fire-blocking structure of the present invention, when having multiple layers of burn-resistant structures, a heat insulation support structure 3, and adopting an active flow splitting technology, has been experimentally proven to achieve a fire-blocking and burn-resistant duration of not less than 2 hours, and the fire-blocking effect has been significantly improved compared with the prior art.

[0350] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0351] In the present invention, unless otherwise clearly specified or limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or capable of communicating with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0352] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0353] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A long-time fire-resistant structure with radial heat insulation function, characterized in that, the long-time fire-resistant structure includes: a housing (1) provided with a pressure-relief air inlet end (11), a pressure-relief air outlet end (12), and a cavity (13) communicating the pressure-relief air inlet end (11) and the pressure-relief air outlet end (12); and a fire-resistant structure disposed at the pressure-relief air outlet end (12) and including a fire-resistant layer (2), the fire-resistant layer (2) including a fire-resistant layer outer ring area (22a), the fire-resistant layer inner ring area (22b), and the fire-resistant layer middle area (22c) arranged in sequence from outside to inside, both the fire-resistant layer outer ring area (22a) and the fire-resistant layer middle area (22c) can allow the pressure-relief air flow to pass through, and the fire-resistant layer inner ring area (22b) is a closed heat insulation area.

2. The long-time fire-resistant structure with radial heat insulation function according to claim 1, characterized in that, the fire-resistant layer (2) includes a second closed heat insulation disc (24a), a plurality of second fire-resistant discs (24b), and a single third fire-resistant disc (24c), the fire-resistant layer outer ring area (22a), the fire-resistant layer inner ring area (22b), and the fire-resistant layer middle area (22c) are all arranged on the second closed heat insulation disc (24a), a plurality of second installation openings formed at intervals in the circumferential direction are provided in the fire-resistant layer outer ring area (22a) of the second closed heat insulation disc (24a), and a plurality of the second fire-resistant discs (24b) are correspondingly installed in the plurality of second installation openings one by one, a third installation opening is provided in the fire-resistant layer middle area (22c) of the second closed heat insulation disc (24a), and the third fire-resistant disc (24c) is installed in the third installation opening.

3. The long-time fire-resistant structure with radial heat insulation function according to claim 2, characterized in that, a hollow cavity is provided inside the second closed heat insulation disc (24a).

4. The long-time fire-resistant structure with radial heat insulation function according to claim 3, characterized in that, the hollow cavity of the second closed heat insulation disc (24a) is evacuated or filled with a low thermal conductivity material.

5. The long-time fire-resistant structure with radial heat insulation function according to claim 1, characterized in that, the fire-resistant layer (2) includes a fire-resistant ring (25a), a closed heat insulation ring (25b), and a fourth fire-resistant disc (25c) nested in sequence from outside to inside, the fire-resistant layer outer ring area (22a) is arranged on the fire-resistant ring (25a), the fire-resistant layer inner ring area (22b) is arranged on the closed heat insulation ring (25b), and the fire-resistant layer middle area (22c) is arranged on the fourth fire-resistant disc (25c).

6. The long-time fire-resistant structure with radial heat insulation function according to claim 5, characterized in that, a hollow cavity is provided inside the closed heat insulation ring (25b).

7. The long-time fire-resistant structure with radial heat insulation function according to claim 6, characterized in that, the hollow cavity of the closed heat insulation ring (25b) is evacuated or filled with a low thermal conductivity material.

8. The long-time fire-resistant structure with radial heat insulation function according to any one of claims 1 to 7, characterized in that, the long-time fire-resistant structure further includes: A diversion structure is arranged inside the housing (1) and upstream of the fire-resistant structure, and is used for dividing the pressure-relief airflow inside the housing (1) into multiple regional airflows flowing towards different regions of the fire-resistant structure.

9. The long-time fire-blocking structure with radial heat insulation function according to claim 8, characterized in that the diversion structure includes: A cavity diversion structure is arranged inside the cavity (13), and is used for dividing the pressure-relief airflow flowing into the cavity (13) into an outer-region airflow (G11) and an inner-region airflow (G12) flowing respectively in the outer region and the inner region of the cavity (13), and making the flow rate of the outer-region airflow (G11) greater than that of the inner-region airflow (G12), and / or making the flow rate of the outer-region airflow (G11) greater than that of the inner-region airflow (G12).

10. The long-time fire-blocking structure with radial heat insulation function according to claim 8, characterized in that the diversion structure includes: A cavity diversion structure is arranged inside the cavity (13), and is used for dividing the pressure-relief airflow flowing into the cavity (13) into an outer-ring region airflow (G21), an inner-ring region airflow (G22), and a middle-region airflow (G23) that are sequentially distributed from outside to inside in the cavity (13), and making the flow rates of the outer-ring region airflow (G21), the middle-region airflow (G23), and the inner-ring region airflow (G22) decrease in that order, and / or making the flow rates of the outer-ring region airflow (G21), the middle-region airflow (G23), and the inner-ring region airflow (G22) decrease in that order.

11. The long-time fire-blocking structure with radial heat insulation function according to claim 8, characterized in that the diversion structure includes: An air inlet end diversion structure is arranged inside the pressure-relief air inlet end (11), and is used for dividing the pressure-relief airflow flowing into the pressure-relief air inlet end (11) into an outer-layer region airflow (G31) and an inner-region airflow (G32) flowing respectively in the outer layer region and the inner region of the pressure-relief air inlet end (11), and making the flow rate of the outer-layer region airflow (G31) greater than that of the inner-region airflow (G32), and / or making the flow rate of the outer-layer region airflow (G31) greater than that of the inner-region airflow (G32).

12. The long-time fire-blocking structure with radial heat insulation function according to claim 8, characterized in that the diversion structure includes: An intake-end flow guiding structure is disposed within the pressure relief intake end (11), and is configured to divide the pressure relief air flow flowing into the pressure relief intake end (11) into an outer-region air flow (G31), an inner-region air flow (G321), and an intermediate-region air flow (G322) that flow in the outer region, the inner region, and the intermediate region within the pressure relief intake end (11) respectively, and to cause the flow velocities of the outer-region air flow (G31), the intermediate-region air flow (G322), and the inner-region air flow (G321) to be distributed from large to small, and / or to cause the flow rates of the outer-region air flow (G31), the intermediate-region air flow (G322), and the inner-region air flow (G321) to be distributed from large to small.

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