CN111816016A - A Fire Simulation System for a Complex Ventilation Network - Google Patents

Abstract

The invention discloses a complex ventilation network fire simulation system, comprising a sub-channel main body, a support frame, a fire source simulation system, a ventilation system and a monitoring system; the sub-channel main body consists of a first sub-channel, a second sub-channel and a third sub-channel , the fourth sub-channel, the fifth sub-channel, the sixth sub-channel and the seventh sub-channel are spliced together, each sub-channel includes a top plate, a bottom plate and two side plates, and flanges are used between the sub-channels, and the two The interlayer between the flanges is sealed with a gasket; it is convenient to study series, parallel, series-parallel, upward and downward ventilation control and multiple ignition sources, key characteristics of flue gas flow under multiple factors, smoke flow reversal and wind flow reversal. Criteria for discrimination provide theoretical support for pre-disaster prevention and post-disaster emergency rescue.

Description

A Fire Simulation System for Complex Ventilation Networks

technical field

The invention relates to safety science and engineering technology, in particular to a complex ventilation network fire simulation system.

Background technique

In the process of social development, in order to meet the needs of human life, production and travel, above-ground and underground buildings such as shopping malls, office buildings, subways, tunnels, and mines have gradually presented complex network structures that intersect with each other. Due to the complexity of this structure and the impact of forced ventilation in the network system, once a fire occurs, it will cause incalculable losses to human life and property safety. The high-temperature smoke generated by the fire spreads in the building, and when it encounters combustibles, it will cause a secondary fire to further expand the scope of the disaster; the toxic and harmful gases contained in the high-temperature smoke can poison and suffocate the trapped people; If the wind flow is lower than the critical wind speed, the smoke flow will be reversed or the wind flow of the side air channel will be reversed, which will affect the retreat of the trapped people and the safety of the entire ventilation network. Therefore, it is of great significance to study the key characteristics of fire smoke flow, smoke flow reversal and wind flow reversal in complex ventilation networks.

Numerical simulation and experimental research are the main methods to carry out fire research on complex ventilation network. Numerical simulation methods often need to simplify boundary conditions and material properties in the process of simulation analysis, and in the process of numerical calculation, different forms of structure discretization are selected, resulting in different results and accuracy, lacking reliability. Experimental studies include full-scale experiments and reduced-scale experiments. Full-scale experiments consume a lot of financial and human resources, are not easy to carry out, and are difficult to obtain a large amount of data. Small-scale experiments that meet similar ratios have been widely used because of their low cost, repeatable experiments, and reliable results.

The small-scale fire simulation system in the prior art has certain limitations in structure and function, and cannot simulate the fire scene of a complex ventilation network system.

The experimental system is a single sub-channel, and it cannot simultaneously study the key characteristics of fire smoke flow in series, parallel, and series-parallel sub-channels, and the key criteria for distinguishing smoke flow reversal and wind flow reversal. Simulate the flow of fire smoke under two ventilation control conditions of upward and downward; the number of fire sources is single, and the fire scene with multiple ignition sources is not considered; the experimental system is fixed, and the key characteristics of fire smoke flow under multi-factor conditions cannot be carried out Research on key discriminant criteria such as smoke flow reversal and wind flow reversal.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a complex ventilation network fire simulation system.

The purpose of this invention is to realize through the following technical solutions:

The complex ventilation network fire simulation system of the present invention includes a sub-channel main body, a support frame, a fire source simulation system, a ventilation system and a monitoring system;

The sub-channel main body is formed by splicing a first sub-channel, a second sub-channel, a third sub-channel, a fourth sub-channel, a fifth sub-channel, a sixth sub-channel and a seventh sub-channel, and each sub-channel includes a top plate , the bottom plate and the two side plates, the sub-channels are connected by flanges, and the interlayer between the two flanges is sealed with a gasket;

The top plate, bottom plate and one side plate of the fifth sub-channel are made of carbon steel, and the other side plate is made of fireproof glass, which is sealed and embedded in the glass frame, and the top plate, bottom plate and two The material used for the side plates is carbon steel.

It can be seen from the technical solutions provided by the present invention that the complex ventilation network fire simulation system provided by the embodiment of the present invention is convenient for studying series, parallel, series-parallel, upward and downward ventilation control, multiple ignition sources, and flue gas under multiple factors. The key judging criteria such as key flow characteristics, smoke flow reversal and wind flow reversal provide theoretical support for pre-disaster prevention and post-disaster emergency rescue.

Description of drawings

1 is a schematic top view of a complex ventilation network fire simulation system provided by an embodiment of the present invention;

2 is a front view of a complex ventilation network fire simulation system provided by an embodiment of the present invention;

3 is a left side view of a complex ventilation network fire simulation system provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a three-way pipe in an embodiment of the present invention.

In the picture:

1, the first sub-pipeline, 2, the second sub-pipeline, 3, the third sub-pipeline, 4, the fourth sub-pipeline, 5, the fifth sub-pipeline, 6, the sixth sub-pipeline, 7, the seventh sub-pipeline, 8 , three-way one, 9, three-way two, 10, elbow, 11, smoke-proof valve, 12, temperature sensor, 13, temperature string sensor, 14, pressure sensor, 15, wind speed sensor, 16, oxygen concentration meter, 17 , carbon monoxide concentration meter, 18, carbon dioxide sensor concentration meter, 19, variable frequency fan, 20, bracket, 21, beam, 22, oil pan one, 23, gas supply pipe one, 24, oil pan two, 25, gas supply pipe two, 26, oil storage tank, 27, double-layer fireproof and thickened smoke exhaust hose, 28, flange, 29, bending plate, 30, rear plate.

Detailed ways

The embodiments of the present invention will be described in further detail below. Contents that are not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

The preferred specific embodiment of the complex ventilation network fire simulation system of the present invention is:

Including sub-channel main body, support frame, fire source simulation system, ventilation system and monitoring system;

The sub-channel main body is formed by splicing a first sub-channel, a second sub-channel, a third sub-channel, a fourth sub-channel, a fifth sub-channel, a sixth sub-channel and a seventh sub-channel, and each sub-channel includes a top plate , the bottom plate and the two side plates, the sub-channels are connected by flanges, and the interlayer between the two flanges is sealed with a gasket;

The top plate, bottom plate and one side plate of the fifth sub-channel are made of carbon steel, and the other side plate is made of fireproof glass, which is sealed and embedded in the glass frame, and the top plate, bottom plate and two The material used for the side plates is carbon steel.

One end of the first sub-channel and the middle of the second sub-channel are connected by a flange through a tee pipe;

Both ends of the fourth sub-channel are respectively connected with the middle of the fifth sub-channel and the middle of the third sub-channel by flanges through a tee, so that the fourth sub-channel is parallel to the horizontal plane;

Both ends of the second sub-channel are respectively connected with the third sub-channel and the fifth sub-channel by flanges through elbows;

Both ends of the sixth sub-channel are respectively connected with the third sub-channel and the fifth sub-channel by flanges through elbows;

One end of the seventh sub-channel and the middle of the sixth sub-channel are connected by a flange through a tee pipe;

The whole system is inclined upward by the third sub-channel and the fifth sub-channel, and the remaining sub-channels are kept level with the ground.

A plurality of circular openings are arranged on the top plate of the fifth sub-channel along the longitudinal centerline direction, and sensors are arranged at the openings;

Two circular openings are arranged on the bottom plate of the fifth sub-channel along the longitudinal centerline direction, and oil pans are placed at the openings or closed with refractory materials;

A plurality of circular openings are respectively provided on the top plate of other sub-channels along the longitudinal centerline direction, and hole plugs or sensors are arranged at the openings.

The support frame is composed of beams and support columns, the material used is carbon steel, the support frame is installed at the bottom of each sub-channel, and the height of the support columns of the first and second sub-channels is 50cm, and the height of the support columns of the sixth sub-channel is 150cm, so that the third sub-channel and the fifth sub-channel form an included angle of 12° with the ground.

The fire source simulation system includes an oil storage tank and an air supply pipe, the oil storage tank includes an oil pump and two sub-oil tanks, and the two oil pans placed at the opening of the bottom plate of the fifth sub-channel are respectively connected with the oil storage tank through the air supply pipe. Two sub-tank connections;

The oil level in the oil pan is kept at a stable height by using the principle of the connector.

The ventilation system includes a variable frequency fan, a smoke prevention valve and a fire and smoke exhaust hose, and the variable frequency fan is respectively arranged in the first sub-channel and the seventh sub-channel;

By changing the position of the fan, the system's up and down ventilation control mode can be changed.

The smoke-proof valves are respectively arranged at the tee pipes of the second and fourth sub-channels, and at the intersection of the sixth sub-channel and the seventh sub-channel, and a total of six smoke-proof valves are arranged;

By adjusting the switch of the anti-smoke valve, the wind speed of the sub-channel and the series-parallel mode of the system are changed.

The monitoring system includes a temperature testing system, a flow field detection system, a paperless recorder and an image recording system;

The temperature testing system includes a temperature string sensor and a temperature sensor, the temperature string sensor is arranged in the fifth sub-channel, and the circular openings of the other sub-channels are provided with temperature sensors as required;

The flow field detection system includes a pressure sensor, an wind speed sensor, a carbon monoxide concentration meter, a carbon dioxide concentration meter and an oxygen concentration meter;

The image recording system is a digital camera, which is arranged on one side of the fireproof glass surface of the fifth sub-channel.

The complex ventilation network fire simulation system of the present invention can be respectively studied in the series, parallel, and series-parallel ventilation systems in the series, parallel, and series-parallel ventilation systems by changing the switch of the smoke-proof valve, the position and air volume of the variable-frequency fan, the number of fire sources, and the power of the fire source. Research on key discriminant criteria such as key characteristics of fire smoke flow, smoke flow reversal and wind flow reversal under conditions of downdraft ventilation control, multiple ignition sources, and multiple factors. It is convenient to study series, parallel, series-parallel, upward and downward ventilation control and multiple ignition sources, key characteristics of flue gas flow under multiple factors, and key criteria such as smoke flow reversal and wind flow reversal, providing pre-disaster prevention and post-disaster emergency rescue. theoretical support.

Specific examples:

1-3, the present invention provides a complex ventilation network fire simulation system, including a sub-channel main body, a support frame, a fire source simulation system, a ventilation system, and a monitoring system.

The main body of the sub-channel is connected by the flange of the first sub-channel 1, the second sub-channel 2, the third sub-channel 3, the fourth sub-channel 4, the fifth sub-channel 5, the sixth sub-channel 6 and the seventh sub-channel 7. is formed, and the sub-channel main body is symmetrical with the first sub-channel 1 as the symmetry axis.

The first sub-channel 1 and the second sub-channel 2 are connected by a flange through a tee pipe 1 . The fourth sub-channel 4 and the fifth sub-channel 5, the fourth sub-channel 4 and the third sub-channel 3 are all connected by flanges through the tee pipe 2, so that the fourth sub-channel 4 is parallel to the horizontal plane.

The second sub-channel 1 , the third sub-channel 2 , the fifth sub-channel 5 , the sixth sub-channel 6 , the third sub-channel 3 , and the fifth sub-channel 5 are all connected by flanges through elbows 10 .

The cross sections of the main sub-channels are all 30*30 cm square, wherein the length of the first sub-channel 1 is 200 cm, and the length of the second sub-channel 2, the fourth sub-channel 4 and the sixth sub-channel 6 are all 400 cm. Both the third sub-channel 3 and the fifth sub-channel 5 are 500 cm long. The seventh sub-channel 7 is 300 cm long. The materials used in each sub-channel except the fifth sub-channel are carbon steel.

The material used for the top plate, bottom plate and rear side plate of the fifth sub-channel 5 is carbon steel, and the front side plate is formed by sealing fireproof glass with a thickness of 4mm and embedding it into the glass frame, so as to observe the smoke flow phenomenon after the fire source is burned.

The bottom plate of the fifth sub-channel 5 is provided with two circular openings along the longitudinal centerline direction for placing the oil pan, and is closed with refractory material when the oil pan is not placed. There are 10 circular openings on the main board of the top plate of the fifth sub-channel 5 at intervals of 50cm along the longitudinal centerline direction, which are used to install temperature string sensors. These temperature string sensors can measure the longitudinal and transverse smoke of the fire source branches. changes in flow temperature. A plurality of circular openings are respectively provided on the main board of the top plate of the other sub-channels along the longitudinal centerline direction for installing each sensor, and hole plugs are arranged on the reserved openings.

The support frame is composed of a bracket 20 and a beam 21 . The materials used for the bracket 20 and the beam 21 are carbon steel. The supporting frame is located below each sub-channel, and the supporting frame of the first sub-channel 1 is 50 cm high, and the supporting frame of the sixth sub-channel 6 is 150 cm high, so that the third sub-channel 3 and the fifth sub-channel 5 are inclined along the horizontal direction 12 °.

Referring to FIG. 4 , the intersection of the fourth sub-channel 4 and the fifth sub-channel 5 is connected by a tee pipe 2 through a flange. The three-way pipe 2 is composed of a flange 28 , a bent plate 29 and a rear plate 30 . This connection method can ensure that the fifth sub-channel is level with the ground.

Referring to FIG. 1 , the fire source simulation system includes two oil pans 2 , two gas supply pipes 3 , two oil pans 4 , two gas supply pipes 5 , and an oil storage tank 26 . The oil storage tank includes the oil pump and two sub-tanks. The oil pan is connected to the two sub-tanks in the oil storage tank respectively through the air supply pipe. The oil level in the oil pan is kept at a stable height by using the principle of the connector. Closed with refractory material when no oil pan is placed

The distance between the second oil pan 3 and the port of the fifth sub-channel 5 is 117.5 cm, and the distance between the oil pan two 4 and the port of the fifth sub-channel 5 is 382.5 cm. When only the second oil pan 4 is placed in the fifth sub-channel 5, the conditions for judging the wind flow reversal in the fourth sub-channel 4 can be studied. When the oil pan 2 3 and the oil pan 2 4 are placed in the fifth sub-channel 5 at the same time, the key discriminant criteria such as the key characteristics of fire smoke flow, smoke flow reversal and wind flow reversal can be studied under the condition of dual fire sources.

Referring to Figures 1-3, the ventilation system consists of a variable frequency fan 19, a smoke-proof valve 11 and a double-layer fireproof and thickened smoke exhaust hose 27. A double-layer fireproof and thickened smoke exhaust hose 27 is installed at the end of the seventh sub-channel. The variable frequency fan 19 can be installed at the end of the first sub-channel 1, and can be pressed into the air supply to form upward ventilation control; it can also be installed on the outside of the double-layer fireproof and thickened smoke exhaust hose 27, and can be pressed into the air supply to form downward ventilation. control.

The variable frequency fan 19 is selected from SE-A250H axial flow variable frequency fan, the maximum air volume is 2000m3/h, stepless frequency conversion, press-in air supply, and the vertical ventilation rate can be arbitrarily changed by adjusting the frequency, and then the fire smoke reversal and wind flow can be studied. Reversed critical wind speed.

Referring to FIG. 1 , the smoke prevention valves 11 are respectively installed at the tee pipes of the second sub-channel 2 , the fourth sub-channel 4 , and the intersection of the sixth sub-channel 6 and the seventh sub-channel 7 , a total of 6 are installed Smoke control valve. The size of the air door opening can be adjusted arbitrarily, and the wind speed and the series-parallel mode of the system can be changed by adjusting the switch of the air door.

Referring to Figures 1-3, the monitoring system includes a temperature testing system, a flow field detection system, a paperless recorder and an image recording system. The temperature testing system includes a temperature sensor 12, a temperature string sensor 13, and the flow field detection system includes a pressure sensor 14, an air velocity sensor 15, an oxygen concentration meter 16, a carbon monoxide concentration meter 17, a carbon dioxide sensor concentration meter 18,

The temperature string sensor 13 is arranged on the longitudinal centerline at a certain distance below the top plate of the fifth sub-channel 5 . The arrangement interval of each string of temperature string sensors 13 is 50 cm, and a total of 10 strings are arranged. The temperature string sensor 13 is composed of three K-type thermocouple wires of different lengths and a protective sleeve. The thermocouple wires of the temperature string sensors 13 are all resistant to temperature of 1000°C. The protective sleeves of the two strings of temperature string sensors 13 near the center of the fire source are resistant to temperature of 2520°C, and the protective sleeves of the other temperature string sensors 13 are resistant to temperature of 1000°C.

The distances from the three thermocouple wires of the two strings of temperature string sensors near the center of the fire source to the top plate along the longitudinal center line are L1=6.4cm, L2=15.4cm, and L3=24.4cm, respectively. The distances from the three thermocouple wires of the remaining eight temperature string sensors to the top plate along the longitudinal center line are L1=9.4cm, L2=19.4cm, and L3=29.4cm, respectively.

The temperature sensors 12 are respectively arranged on the longitudinal centerlines of the first sub-channel 1 , the third sub-channel 3 , the fourth sub-channel 4 , and the seventh sub-channel 7 9 cm below the top plate. The temperature sensor 12 is a k-type thermocouple with a temperature resistance of 1000°C.

The pressure sensor 14 and the wind speed sensor 15 are both arranged on the longitudinal centerline at 10 cm below the top plate of the sub-channel to measure the wind speed and wind pressure in the sub-channel. The arrangement positions of the pressure sensor 14 and the wind speed sensor 15 can be adjusted according to actual needs.

Referring to Figure 1, the oxygen concentration meter 16, the carbon monoxide concentration meter 17, and the carbon dioxide sensing concentration meter 18 are respectively arranged on the longitudinal centerline at 10 cm below the top plate of the second sub-channel 2 and the sixth sub-channel 6 to observe Changes in the concentration of gases produced by fire.

The image recording system adopts a digital camera, and the digital camera is placed on the fireproof glass side of the fifth sub-channel 5 to record the smoke regression and the distribution of the smoke layer in the fifth sub-channel 5 where the fire source is located. The placement of the digital camera can be adjusted according to specific research needs.

The basic principles, main features and advantages of the present invention have been described in detail above. It should be understood by those skilled in the art that the present invention is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions describe only the principles of the present invention. Without departing from the spirit and scope of the present invention, there are various Variations and improvements are intended to fall within the scope of the claimed invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims (8)

1. A fire simulation system of a complex ventilation network is characterized by comprising a sub-channel main body, a support frame, a fire source simulation system, a ventilation system and a monitoring system;

the sub-channel main body is formed by splicing a first sub-channel, a second sub-channel, a third sub-channel, a fourth sub-channel, a fifth sub-channel, a sixth sub-channel and a seventh sub-channel, each sub-channel comprises a top plate, a bottom plate and two side plates, the sub-channels are connected through flanges, and an interlayer between the two flanges is sealed by a sealing pad;

the top plate, the bottom plate and the side plate on one side of the fifth sub-channel are made of carbon steel, the side plate on the other side of the fifth sub-channel is made of fireproof glass, the fireproof glass is hermetically embedded into the glass frame, and the top plate, the bottom plate and the two side plates of the rest sub-channels are made of carbon steel.

2. The complex ventilation network fire simulation system of claim 1, wherein:

one end of the first sub-channel is connected with the middle part of the second sub-channel through a three-way pipe by a flange;

two ends of the fourth sub-channel are respectively connected with the middle part of the fifth sub-channel and the middle part of the third sub-channel through a three-way pipe by flanges, so that the fourth sub-channel is parallel to the horizontal plane;

two ends of the second sub-channel are respectively connected with the third sub-channel and the fifth sub-channel through elbows by flanges;

two ends of the sixth sub-channel are respectively connected with the third sub-channel and the fifth sub-channel through elbows by flanges;

one end of the seventh sub-channel is connected with the middle part of the sixth sub-channel through a three-way pipe by a flange;

the whole system is inclined upwards by the third sub-channel and the fifth sub-channel, and the rest sub-channels are kept horizontal to the ground.

3. The complex ventilation network fire simulation system of claim 2, wherein:

a plurality of circular openings are formed in the top plate of the fifth sub-channel along the longitudinal center line direction, and sensors are arranged at the openings;

2 circular openings are formed in the bottom plate of the fifth sub-channel along the longitudinal center line direction, and oil pans are placed at the openings or are sealed by adopting refractory materials;

and a plurality of circular openings are respectively arranged on the top plates of other sub-channels along the direction of the longitudinal central line, and hole plugs or sensors are arranged at the openings.

4. The complex ventilation network fire simulation system of claim 3, wherein the support frame is composed of cross beams and support columns, the material used is carbon steel, the support frame is installed at the bottom of each sub-channel, the height of the support column of the first sub-channel and the height of the support column of the second sub-channel are 50cm, the height of the support column of the sixth sub-channel is 150cm, and therefore the third sub-channel and the fifth sub-channel form an included angle of 12 degrees with the ground.

5. The complex ventilation network fire simulation system as claimed in claim 4, wherein the fire source simulation system comprises an oil storage tank and an air supply pipe, the oil storage tank comprises an oil pump and two oil distribution tanks, and the 2 oil pans placed at the bottom plate openings of the fifth sub-channels are respectively connected with the two oil distribution tanks of the oil storage tank through the air supply pipe;

the oil level in the oil pan is maintained at a stable height using the principle of the communicating vessel.

6. The complex ventilation network fire simulation system of claim 5, wherein the ventilation system comprises a variable frequency fan, a smoke prevention valve and a fire prevention and smoke exhaust hose, and the variable frequency fan is respectively arranged in the first sub-channel and the seventh sub-channel;

the ventilation control mode of going up and down mountains of the system is changed by changing the position of the fan.

7. The complex ventilation network fire simulation system of claim 6, wherein the smoke prevention valves are respectively arranged at the tee pipes of the second and fourth sub-channels and the intersection of the sixth sub-channel and the seventh sub-channel, and six smoke prevention valves are arranged;

the wind speed of the sub-channel and the series-parallel connection mode of the system are changed by adjusting the switch of the smoke-proof valve.

8. The complex ventilation network fire simulation system of claim 7, wherein the monitoring system comprises a temperature testing system, a flow field detection system, a paperless recorder, and an image recording system;

the temperature testing system comprises a temperature string sensor and a temperature sensor, wherein the temperature string sensor is arranged in the fifth sub-channel, and the circular openings of other sub-channels are provided with the temperature sensors as required;

the flow field detection system comprises a pressure sensor, an air velocity sensor, a carbon monoxide concentration meter, a carbon dioxide concentration meter and an oxygen concentration meter;

the image recording system is characterized in that a digital camera is arranged on one side of the fireproof glass surface of the fifth sub-channel.

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