Experiment platform for simulating fire in underground traffic conversion channel

Abstract

The present disclosure provides an experiment platform for simulating fire in an underground traffic conversion channel, including: a model body configured to simulate fire in the an underground traffic conversion channel; a burner connected to the model body and configured to generate smoke; and a smoke imaging system including laser sheet light sources and image recording devices configured to record smoke distribution images. The laser sheet light sources are in the model body, and plane laser light emitted by the laser sheet light sources is parallel to a flow direction of the smoke. The image recording devices are in one-to-one correspondence to the laser sheet light sources and are arranged outside an observation window of the model body. One laser sheet light source and one image recording device corresponding thereto each have a filter configured to filter out laser light of a same wavelength.

Claims

1. An experiment platform for simulating fire in an underground traffic conversion channel, comprising: a model body configured to simulate the underground traffic conversion channel, a burner connected to the model body and configured to generate smoke; and a smoke imaging system comprising a plurality of laser sheet light sources and a plurality of image recording devices configured to record smoke distribution images, wherein the plurality of laser sheet light sources are arranged in the model body, plane laser light emitted by the plurality of laser sheet light sources is parallel to a flow direction of the smoke, and the flow direction of the smoke and a direction of the plurality of laser sheet light sources are consistent with a length direction of the underground traffic conversion channel; the plurality of image recording devices are in one-to-one correspondence to the plurality of laser sheet light sources and are arranged outside an observation window of the model body, and in a horizontal plane corresponding to the underground traffic conversion channel, a direction of the plurality of image recording devices is perpendicular to the length direction of the underground traffic conversion channel; and one of the plurality of laser sheet light sources and one of the plurality of image recording devices corresponding thereto each have a filter configured to filter out laser light of a same wavelength.

2. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 1, wherein the model body is formed as a cavity structure, and a size of the model body is 1/9 to ⅙ of a size of an actual underground project.

3. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 1, wherein the burner is formed as a vertically arranged cavity structure, and sequentially comprises, from bottom to top, a mixing chamber and a rectification chamber; a lower part of the mixing chamber is provided with a fuel-gas inlet port and an air inlet port, and gas formed by mixing fuel-gas and air is mixed gas; and an upper part of the rectification chamber is provided with a gas outlet port that is connected to a cavity of the model body.

4. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 3, wherein a cavity of the mixing chamber is provided therein with an upper annular duct and a lower annular duct that are arranged side by side and have a same shape; each of the upper annular duct and the lower annular duct is an annular cavity structure formed by rotating a rectangular cross-section around a circumference, and comprises an inner side wall and an outer side wall that are concentric; and the outer side wall of the upper annular duct and the outer side wall of the lower annular duct are respectively connected to the fuel-gas inlet port and the air inlet port, and the inner side wall of the upper annular duct and the inner side wall of the lower annular duct are each provided with a plurality of gas outlet micropores.

5. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 4, wherein a cross-section of the mixing chamber is a square, the outer side wall of the annular duct is tangent to an inner wall of the mixing chamber, and a length w.sub.1 of a side of the square and a flow rate Q of the mixed gas satisfy a following formula: $w_{1} \geq \max (\sqrt{\frac{Q}{2160}}, 0.05);$ where a unit of w.sub.1 is m, and a unit of Q is m.sup.3/h.

6. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 5, wherein an inner diameter R.sub.2 and an outer diameter R.sub.1 of the annular duct satisfy a following formula:
0.6R.sub.1≤R.sub.2≤0.8R.sub.1; a height h.sub.1 of the mixing chamber and the inner diameter R.sub.2 of the annular duct satisfy a following formula:
h.sub.1≥8R.sub.2; a distance S.sub.0 between the upper annular duct and lower annular duct satisfies a following formula:
h.sub.1−S.sub.2−0.2<S.sub.0<h.sub.1−S.sub.2−0.1; where S1 denotes a height of the upper annular duct, S2 denotes a height of the lower annular duct, and units of S1 and S2 are both m; and an aperture ratio n.sub.0 of the inner side wall satisfies a following formula: $n_{0} \leq \frac{0.15 (R_{1} - R_{2})}{π R_{1}} .$

7. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 3, wherein the rectification chamber sequentially comprises a trapezoid and a cuboid from bottom to top, and the gas outlet port is provided at a top surface of the cuboid; an upper bottom of the trapezoid is a square that is connected to the mixing chamber, and a lower bottom of the trapezoid is a rectangle that is connected to the cuboid; an arc-shaped flow distribution plate is provided between the upper bottom and the lower bottom of the trapezoid; the cuboid is provided with a horizontal primary flow equalization web at a middle position in a height direction, and the gas outlet port is provided with a horizontal secondary flow equalization web; two side surfaces of the trapezoid are perpendicular to a horizontal plane, and an angle formed between each of the other two side surfaces of and the trapezoid and the horizontal plane is within a range from 10° to 45°; a center angle corresponding to the arc-shaped flow distribution plate is within a range from 5° to 8°; an angle formed between a lower end of the arc-shaped flow distribution plate and the horizontal plane is within a range from 67.5° to 80°; a distance between the primary flow equalization web and the arc-shaped flow distribution plate is within a range from 100 mm to 150 mm; and the primary flow equalization web has an aperture ratio within a range from 25% to 40%, and an aperture diameter within a range from 4 mm to 6 mm.

8. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 7, wherein a distance h.sub.4 between the primary flow equalization web and the secondary flow equalization web satisfies a following formula: $h_{4} \geq \max [(\frac{2.4}{n} - 3.5) r_{0}, 0.05];$ where n and r.sub.0 respectively denote the aperture ratio of the primary flow equalization web and an aperture radius of the primary flow equalization web, and units of r.sub.0 and h.sub.4 are both mm; and an aperture ratio n′ of the secondary flow equalization web satisfies a following formula: $n^{'} \leq \min (\frac{Q}{2.5 A}, 8 %),$ where Q denotes a flow rate of the mixed gas, and has a unit of m.sup.3/s, and A denotes an area of a rectangular top surface of the cuboid, and has a unit of m.sup.2.

9. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 1, wherein the plurality of laser sheet light sources are arranged in two columns in the model body, respectively along a width direction and a height direction of the model body, and each column of laser sheet light sources comprises 2 to 5 laser sheet light sources spaced apart from each other by a spacing smaller than 0.3 m.

10. The experiment platform for simulating fire in the underground traffic conversion channel according to claim 1, wherein a wavelength λ of the laser light emitted by the plurality of laser sheet light sources and a characteristic particle diameter D.sub.32 of a specific surface area of the smoke satisfy a following formula:
π.Math.D.sub.32−10<λ<π.Math.D.sub.32+10; where units of λ and D.sub.32 are both nm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a structural schematic diagram of an embodiment of an experiment platform for simulating fire in an underground traffic conversion channel;

(2) FIG. 2 is a front view of an experiment platform for simulating fire in an underground traffic conversion channel;

(3) FIG. 3 is a structural schematic diagram of a column of laser sheet light sources and corresponding image recording devices;

(4) FIG. 4 is a structural schematic diagram of a burner and a gas supply device;

(5) FIG. 5 is a schematic diagram of a profile of a burner;

(6) FIG. 6 is a schematic diagram of an internal structure of a burner;

(7) FIG. 7 is a smoke slice image obtained at a fire source in an embodiment;

(8) FIG. 8 is a smoke slice image obtained at a position near an observation window in an embodiment;

(9) FIG. 9 is a smoke slice image obtained at a position away from an observation window in an embodiment;

(10) FIG. 10 is a smoke slice image obtained using the related art;

(11) FIG. 11 illustrates relative concentration distribution of particle sizes when ethanol is burned in different burners;

(12) FIG. 12 illustrates change in calorific value when ethanol is burned in different burners.

(13) Description of reference signs in the drawing: 1. model body; 11. open section unit; 12. corrugated hose; 13. communication channel unit; 14. jack; 15. fixed hinge support; 16. first reserved port; 17. second reserved port; 18. third reserved port; 19. gas interface; 2. burner; 22. mixing chamber; 221. fuel-gas inlet port; 222. air inlet port; 223. annular pipe; 2231. height of upper annular pipe; 2232. height of lower annular pipe; 224. gas outlet micropore; 23. rectification chamber; 231. trapezoid; 232. cuboid; 233. gas outlet port; 234. arc-shaped flow distribution plate 235. primary flow equalization web; 236. secondary flow equalization web; 31. laser sheet light source; 32. image recording device; 33. filter; 4. ventilation and smoke exhaust system; 41. variable frequency fan; 42. drainage duct; 43. jet nozzle; 5. air compressor; 6. pressure reducing valve; 7. pressure gauge; 8. gas flow meter; 9. fuel-gas tank; 10. fuel-liquid bottle; 101. electronic balance; 21. three-way valve.

DESCRIPTION OF EMBODIMENTS

(14) The technical solutions in the embodiments of the present disclosure will be described clearly and completely in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts fall within the protection scope of the present disclosure.

(15) It should be noted that when referring that one component is “connected” to another component, it can be directly connected to another component or there may be an intermediate component. When a component is considered to be “provided at/on/in” another component, it may be provided directly at/on/in another component or there may be an intermediate component.

(16) Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present disclosure. The terms used in the specification of the present disclosure herein is for the purpose of describing specific embodiments and not intended to limit the present disclosure.

(17) As shown in FIG. 1 and FIG. 3, an experiment platform for simulating fire in an underground traffic conversion channel includes: a model body 1 for simulating an underground traffic conversion channel, a burner 2 that is connected to the model body 1 and generates smoke, and a smoke imaging system. The smoke imaging system includes a laser sheet light source 31 and an image recording device 32 that records smoke distribution images. A plurality of laser sheet light sources 31 are provided in the model body 1, and plane laser light emitted by the laser sheet light source 31 is parallel to a flow direction of the smoke. A plurality of image recording devices 32 one-to-one correspond to the plurality of laser sheet light sources 31 and are provided in the model body 1. One laser sheet light source 31 and one image recording device 32 corresponding thereto each have a filter 33 configured to filter out laser light of a same wavelength.

(18) The arrangement of the plurality of laser sheet light sources 31 can avoid mutual influence between the laser light emitted by the laser sheet light sources 31, so that each of the image recording devices 32 obtains a clear image. One of the laser sheet light sources 31 and one of the image recording devices 32 form one group, and a slice image of one smoke profile can be obtained, with the slice being parallel to the flow direction of the smoke (as indicated by an arrow in FIG. 1); a group of slices parallel to each other can reflect spread characteristics of smoke in a horizontal direction (perpendicular to the flow direction of the smoke) or a longitudinal direction (perpendicular to the flow direction of the smoke).

(19) Based on the above arrangement, in other embodiments, a column of laser sheet light source groups are arranged along a lateral direction and respectively provided at a position of a fire source, at a position near an observation window and at a position away from the observation window, to obtain a group of slice images of the smoke contours, as shown in FIG. 7, FIG. 8 and FIG. 9, respectively. If the technology described in this present disclosure is not adopted and it is only that three laser sheet light sources are provided at corresponding positions, then a phenomenon, where the smoke contours are stacked on each other as shown in FIG. 10, will be observed, and compared with FIG. 10, the slice image group obtained by the improved device can better reflect real situations of the smoke contours at different positions.

(20) In other embodiments, as shown in FIG. 1, the model body 1 is formed as a cavity structure, and a size of the model body is 1/9 to ⅙ of a size of an actual underground project. The model body 1 includes an open section unit 11, and each of two ends of the open section unit 11 is connected to a communication channel unit 13 through a corrugated hose 12. The communication channel unit 13 is connected to a fixed hinge support 15 and a jack 14 for adjusting gradient of the communication channel unit 13. A side wall of the communication channel unit 13 is provided with a first reserved port 16. Through the first reserved port 16, a bifurcation of a simulated underground garage can be connected, and fireproof glass can also be embedded as an observation window. A side wall of the open section unit 11 is provided with a second reserved port 17. A wind speed sensor 111, a pressure sensor 112 and a temperature sensor 113 in the related art can be connected thereto through the second reserved port 17. Bottoms of the open section unit 11 and the communication channel unit are provided with a third reserved port 18, and the burner 2 is connected thereto through the third reserved port 18.

(21) In other embodiments, as shown in FIG. 1, the model body 1 includes an air duct in which fresh air and the smoke flow and a model wall surrounding the air duct, and a plurality of air interfaces 19 are provided at the model wall. The experiment platform for simulating fire in the underground traffic conversion channel further includes a ventilation and smoke exhaust system 4 connected to the model body 1. The ventilation and smoke exhaust system 4 includes a plurality of sets of variable frequency fans 41, drainage ducts 42 and jet nozzles 43 connected in sequence. Fresh air generated by the variable frequency fan 41 flows out of the jet nozzle 43 after passing through the drainage duct 42, and the fresh air is connected to the gas interface 19 through the jet nozzle 43. The jet nozzle 43 is installed above the model wall of the communication channel unit 13, a jet boosting effect in a longitudinal ventilation system of a tunnel can be simulated, and adjustment of a wind speed of the fresh air can be achieved by adjusting a working frequency of the variable frequency fan 41.

(22) In other embodiments, as shown in FIG. 1 and FIG. 3, the plurality of laser sheet light sources 31 are arranged in two columns in the model body 1, respectively along a width direction and a height direction of the model body 1. Each column of laser sheet light sources 31 includes 2 to 5 laser sheet light sources 31 spaced from each other by a spacing smaller than 0.3 m. A wavelength λ of the laser light emitted by the laser sheet light source 31 and a peak particle diameter D of the smoke generated by combustion of fuel satisfy π.Math.D−10<λ<π.Math.D+10. In the formula, units of λ and D are both nm.

(23) In order to facilitate control and measurement of a supply amount of the fuel, in other embodiments, as shown in FIG. 4, the experiment platform for simulating fire in the underground traffic conversion channel further includes a fuel supply module and an air supply module that are connected to the burner 2. The air supply module includes an air compressor 5, a pressure reducing valve 6, a pressure gauge 7, and a gas flow meter 8 that are sequentially connected to an air delivery pipeline. The fuel supply module includes a gas fuel supply module and a liquid fuel supply module.

(24) The gas fuel supply module includes a gas tank 9, a pressure reducing valve 6, a pressure gauge 7, and a gas flow meter 8 that are sequentially connected to a gas fuel delivery pipeline. The liquid fuel supply module includes an air compressor 5, a pressure reducing valve 6, a pressure gauge 7, and a fuel-liquid bottle 10 filled with the liquid fuel that are sequentially connected to the liquid fuel delivery pipeline. An electronic balance 101, that represents a flow rate of the liquid fuel by measuring a mass of the liquid fuel in the fuel-liquid bottle 10, is provided below the fuel-liquid bottle 10. The air passes the fuel-liquid bottle 10 to bring vapor of the liquid fuel into the liquid fuel delivery pipeline. The air supply module is directly connected to the burner 2, and one of the gas fuel supply module and the liquid fuel supply module is selected by a three-way valves 21 to be connected to the burner 2.

(25) Through the above arrangement, it is already possible to observe a three-dimensional image of the lateral spread characteristics of the smoke in the underground traffic conversion channel having obvious wide and shallow characteristics. In order to make the observation result closer to the smoke spread characteristics of the real fire site so as to make the results of the simulation experiment more instructive, existing smoke generation systems can be further improved.

(26) In other embodiments, as shown in FIG. 5 and FIG. 6, the burner 2 is a vertically arranged cavity structure, and sequentially includes: a mixing chamber 22 and a rectification chamber 23 from bottom to top. A lower part of the mixing chamber 22 is provided with a fuel-gas inlet port 221 and an air inlet port 222, and the gas formed by mixing the fuel-gas and the air is mixed gas. An upper part of the rectification chamber 23 is provided with a gas outlet port 233 which is connected to a cavity of the model body.

(27) The cavity of the mixing chamber 22 is provided therein with two, i.e., upper and lower annular ducts 223 arranged side by side and having a same shape. Each of the two annular ducts 223 is an annular cavity structure that is formed by rotating a rectangular cross-section around a circumference and includes an inner side wall and an outer side wall that are concentric. The outer side walls of the two annular ducts are respectively connected to the fuel-gas inlet port and the air inlet port, and the inner side walls of the two annular ducts are each provided with a plurality of gas outlet micropores 224.

(28) The rectification chamber 23 includes a trapezoid 231 and a cuboid 232 from bottom to top, and the gas outlet port 233 is provided at a top surface of the cuboid. An upper bottom of the trapezoid 231 is a square that is connected to the mixing chamber 22, and a lower bottom of the trapezoid 231 is a rectangle that is connected to the cuboid 232. An arc-shaped flow distribution plate 234 is provided between the upper bottom and the lower bottom of the trapezoid 231. The cuboid 232 is provided with a horizontal primary flow equalization web 235 at a middle position in the height direction, and the gas outlet port 233 is provided with a horizontal secondary flow equalization web 236.

(29) In other embodiments, the cross-section of the mixing chamber 22 is a square, the outer side wall of the annular duct 223 is tangent to the inner wall of the mixing chamber 22, and a length w.sub.1 of a side of the square and the flow rate Q of the mixed gas satisfy a following formula.

(30) $w_{1} \geq \max (\sqrt{\frac{Q}{2160}}, 0.05)$

(31) In the formula, a unit of w.sub.1 is m, and a unit of Q is m.sup.3/h.

(32) An inner diameter R.sub.2 and an outer diameter R.sub.1 of the annular duct 223 satisfy a following formula.
0.6R.sub.1≤R.sub.2≤0.8R.sub.1

(33) A height h.sub.1 of the mixing chamber 22 and the inner diameter R.sub.2 of the annular duct 223 satisfy a following formula.
h.sub.1≥8R.sub.2

(34) A distance S.sub.0 between the upper and lower annular ducts 223 satisfies a following formula.
h.sub.1−S.sub.1−S.sub.2−0.2<S.sub.0<h.sub.1−S.sub.1−S.sub.2−0.1;

(35) In the formula, S.sub.1 denotes a height 2231 of the upper annular duct, S.sub.2 denotes a height 2232 of the lower annular duct, and units of S.sub.1 and S.sub.2 are both m.

(36) An aperture ratio n.sub.0 of the inner side wall satisfies a following formula.

(37) $n_{0} \leq \frac{0.15 (R_{1} - R_{2})}{π R_{1}} .$

(38) Two side surfaces of the trapezoid 231 are perpendicular to the horizontal plane, and an angle θ formed between each of the other two side surfaces and the horizontal plane is within a range from 10° to 45°. A center angle corresponding to the arc-shaped flow distribution plate 234 is within a range from 5° to 8°. An angle formed between a lower end of the arc-shaped flow distribution plate 234 and the horizontal plane is within a range from 67.5° to 80°. A distance between the primary flow equalization web 235 and the arc-shaped flow distribution plate 234 is within a range from 100 mm to 150 mm. An aperture ratio n of the primary flow equalization web 235 is within a range from 25% to 40%, and an aperture diameter of the primary flow equalization web 235 is within a range from 4 mm to 6 mm. A distance h4 between the primary flow equalization web 235 and the secondary flow equalization web 236 satisfies a following formula.

(39) $h_{4} \geq \max [(\frac{2.4}{n} - 3.5) r_{0}, 0.05]$

(40) In the formula, n and r.sub.0 are respectively the aperture ratio and an aperture radius of the primary flow equalization web, and units of r.sub.0 and h.sub.4 are both mm.

(41) The aperture ratio n′ of the secondary flow equalization web 236 satisfies a following formula.

(42) $n^{'} \leq \min (\frac{Q}{2.5 A}, 8 %)$

(43) In the formula, Q denotes the flow rate of the mixed gas, and the unit is m.sup.3/s. A denotes an area of a rectangular top surface of the cuboid 232, and the unit is m.sup.2.

(44) In other embodiments, the open section unit 11 has a length of 11.6 m, a width of 4.5 m and a height of 0.83 m. The communication channel unit 13 has a length of 3.7 m. The fuel-gas is obtained by mixing liquid ethanol and air at a ratio of 1 g:4 L. The flow rate of the mixed gas in the mixing chamber 22 is 17.47 m.sup.3/s. A side length of the square is 0.1 m. The inner diameter of the annular duct 223 is 0.06 m. The height of the mixing chamber 22 is 0.5 m. The distance between the upper and lower annular ducts 223 is 0.015 m. The aperture ratio of the inner side wall of the annular duct 223 is 1.5%. The center angle of the arc-shaped flow distribution plate is 7°. The angle formed between the lower end of the arc-shaped flow distribution plate 234 and the horizontal plane is 75°, the distance between the primary flow equalization web 235 and the arc-shaped flow distribution plate 234 is 120 mm. The aperture ratio of the primary flow equalization web 235 is 30%, and the aperture diameter of the primary flow equalization web 235 is 5 mm. The distance between the primary flow equalization web 235 and the secondary flow equalization web 236 is 0.15 m. The aperture ratio of the secondary flow equalization web 236 is 5%. Relative concentration distribution of the smoke particle sizes obtained by using the burner described above is as shown in FIG. 11, and the calorific value released with time is as shown in FIG. 12. Compared with the burner in the related art, the particle sizes of the smoke produced by the burner in the present disclosure are more uniform and the calorific value of the fuel is fully released. The data of fire simulation using this device is closer to true values.

(45) The above embodiment only illustrates several implementations of the present disclosure, and its description is relatively specific and detailed, but it should not be understood as limiting the scope of the present disclosure. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subjected to the appended claims.

Experiment platform for simulating fire in underground traffic conversion channel

Assignee

Inventors

Cpc classification

Classification Explorer

G09B25/00

PHYSICS

Classification Explorer

G09B23/12

PHYSICS

Classification Explorer

A62C99/0081

HUMAN NECESSITIES

Classification Explorer

G09B9/00

PHYSICS

International classification

Classification Explorer

G09B23/12

PHYSICS

Abstract

Claims

Description