Subway station platform stairway air curtain smoke prevention simulation experiment table

Abstract

The invention provides a subway station platform stairway air curtain smoke prevention simulation experiment table, which belongs to the technical field of fire safety and comprises a station hall layer, a platform layer, a smoke exhaust system, an air supply system, an air curtain system, an experiment parameter measurement system and a fire source smoke simulation system. The experiment platform can be used for researching a series of basic theories and engineering practical problems such as flue gas flow characteristics of a platform stairway and an air curtain jet flow smoke blocking effect of the stairway when a fire happens to the platform of the subway station. The experiment system solves the problem of research on the air curtain jet flow smoke blocking effect of the subway station platform stairway, and can realize three-dimensional experiment simulation of smoke flow characteristics and spreading conditions of the platform stairway when the smoke exhaust system operates independently, the air curtain operates independently and the air curtain and the smoke exhaust system operate jointly.

Description

Technical Field

[0001] This invention belongs to the field of fire safety technology, specifically involving a simulation test bench for testing the flow characteristics of fire smoke in the platform or concourse level and optimizing smoke control modes under various fire scenarios in platforms and concourses. It can comprehensively realize different combination modes and parameter adjustments of various smoke control systems such as platform smoke exhaust system, platform air supply system, concourse smoke exhaust system, concourse air supply system, air curtain system, and smoke barrier; it can also measure parameters such as temperature field, smoke layer thickness, air curtain jet velocity, smoke exhaust volume, and air supply volume. Background Technology

[0002] With rapid economic development, urban road traffic is becoming increasingly congested. To alleviate this pressure, subways have seen rapid development due to their convenience, efficiency, and cleanliness. Subway stations experience high passenger flow and density, but their limited and relatively enclosed spaces, along with relatively low platform heights, make platform fires more risky, dangerous, and difficult to control. In the event of a fire on a subway platform, the smoke generated can easily spread to the concourse via the stairwells connecting the platform and the concourse due to thermal buoyancy. After a fire breaks out, platform passengers need to evacuate to the concourse via these stairwells, and then, together with those in the concourse, to a safe area outside the station. Clearly, the direction of smoke spread from the platform fire coincides with the direction of passenger evacuation, making the stairwells used for evacuation a pathway for smoke. This inevitably affects the efficiency of evacuation and threatens the safety of those being evacuated. Therefore, studying the spread of fire smoke in subway station platforms, stairwells connecting platforms and concourses, and the corresponding smoke control measures is of great significance for the ventilation and smoke extraction engineering of subway stations.

[0003] Domestic and international experimental research on subway station fires mainly focuses on scaled-down experiments. Drysdale et al. constructed a 1:15 scaled-down experimental model for a specific study of escalator fires at London King's Cross Underground Station. This model was made of 9.5mm thick plywood, with a total length of 2460mm, a trench height of 200mm on both sides, and a spacing of 280mm. Its cross-section maintains geometric similarity to the escalator in an actual fire scenario. Korean scholar Kim built a 1:20 scaled-down subway tunnel model, with the tunnel model measuring 39m long, 250mm high, and 210mm wide, and a matching simulated train model measuring 3m long, 225mm high, and 156mm wide. By adjusting the motor speed, the model can simulate different train speeds, thus enabling research on the characteristics of piston wind induced by subway vehicle operation.

[0004] Because my country's subway construction started later than that of developed countries, experimental research in the field of subway fires has lagged behind. Zhong Wei, Ji Jie, and others built a 1:8 scale miniature subway platform experimental device. Based on this platform, they systematically explored the maximum temperature distribution law of the ceiling jet under platform fire scenarios and quantitatively analyzed the smoke layer mass entrainment rate at different stages of smoke spread within the subway platform. Zhao Mingqiao et al. constructed a 1:10 scale miniature subway station model and conducted station curtain zoned smoke control experiments using this experimental platform. By setting different fire scales and critical smoke exhaust conditions, they obtained critical smoke exhaust test data under different curtain heights from the ground. Zhu Wei et al. conducted simulation experiments in a miniature model of subway station entrances and exits, using relative temperature indexes to analyze the temperature decay law and influencing factors of subway fire smoke spreading along station entrances and exits; simultaneously, through gas composition detection data, they revealed the characteristic law of a stepwise change in CO mass fraction in the smoke at the exit.

[0005] The 1:50 scale subway station model designed by Luo Na et al. can be used to study the smoke control effect of different ventilation modes in different locations of a three-level underground subway station during a fire; however, the model does not consider the smoke-blocking effect of air curtains at stairwells. The 1:5 scale subway disaster simulation experimental platform designed by Zhong Maohua et al., while usable for studying the evolution mechanism and control strategies of station fires, does not consider systematically studying smoke control facilities (such as smoke curtains and air curtain systems) at the connection between the platform and the concourse. This makes it impossible to support in-depth analysis of the smoke flow characteristics of subway station fires, thus hindering the optimized design and calibration of key parameters of the smoke control system. The 1:10 scale subway station fire smoke control simulation experimental platform designed by Hu Longhua et al. can study the smoke flow characteristics and control modes at key junctions of the platform, concourse, and tunnel track area during a subway station fire; the model comprehensively considers the station's ventilation and smoke exhaust system and air curtain system.

[0006] A review and analysis of existing technical literature reveals that most subway fire simulation experimental platforms have limitations in structural design and functional coverage. Most platforms focus on single scenarios, such as a single fire location or a single smoke control system. In particular, research on smoke spread patterns at platform stairwells, and the collaborative optimization strategies and parameter calibration of multiple smoke control systems, including air curtain systems, lacks a readily available basic experimental platform. From the perspective of impact mechanisms, in platform fire scenarios, the setting of different system parameters (such as smoke exhaust volume, air curtain jet velocity, and angle) to prevent the spread of platform smoke to the concourse by the platform ventilation and smoke exhaust system, the concourse ventilation system, and the stairwell air curtain system lacks corresponding basic experimental research platform support. The aforementioned research is of great significance for conducting smoke control and personnel evacuation during subway station fires.

[0007] In summary, this invention designs and develops a smoke control simulation experimental platform at the stairwell of a subway station during a fire, enabling fire simulation experiments under different fire scenarios on the platform in a laboratory. Through systematic experiments, it reveals the spread patterns of smoke on the platform and at stairwells, the effectiveness of smoke control strategies, and optimizes the parameter settings of various smoke control systems. Summary of the Invention

[0008] The purpose of this invention is to provide a smoke control simulation test bench at the platform stairwell of a subway station during a fire. This bench can simulate the spread and control of smoke on the platform, platform stairwell, and station hall during a fire in a subway station, and can measure parameters such as temperature field and velocity field within the station.

[0009] The technical solution of the present invention to achieve the above objectives is as follows:

[0010] A simulated smoke prevention test bench for air curtain at the stairwell of a subway station is characterized by comprising a main model of the subway station and a fire source system, a smoke supply and exhaust system, an air curtain system, and a fire parameter measurement system installed in the main model.

[0011] The main model of the subway station includes a concourse level and a platform level. To facilitate the conduct of subway station fire simulation experiments: (1) Both the platform level and the concourse level adopt a steel frame structure. The ceiling, ground and end face of both levels are made of fireproof boards. One side of the platform level is made of fireproof glass to facilitate the observation of experimental phenomena. The other side and the side of the concourse are made of fireproof boards. The experimental measuring device is set up before the platform side panels are spliced. (2) Two square holes are opened on the side of the platform level made of fireproof boards, and matching swing doors are installed to facilitate the placement of fire source oil pools and smoke bombs. (3) A staircase leading to the concourse level is set on the platform level, and a smoke curtain is set below the platform ceiling at the staircase entrance. The height of the smoke curtain can be adjusted. (4) Detachable side panels made of galvanized iron are set on both sides of the staircase entrance to facilitate the simulation of a subway station with side walls on some staircases, and to cooperate with the air curtain at the staircase entrance for smoke prevention.

[0012] The smoke exhaust and air supply outlets of the ventilation and smoke extraction system are connected to axial flow fans via longitudinal (station length direction) smoke exhaust and air supply ducts and vertical smoke exhaust and air supply ducts. The airflow at each outlet is regulated by dampers on the vertical ducts. Each fan is powered by a DC regulated power supply, allowing for airflow adjustment. The duct height of the smoke exhaust and ventilation system is freely adjustable to simulate the smoke control effect at different heights of the smoke exhaust and air supply outlets.

[0013] The air curtain system is installed at the platform stairwell. The jet velocity of the air curtain system can be adjusted by regulating the rotation speed of the axial flow fan via a frequency converter. During the experiment, the jet angle and jet velocity of the air curtain outlet can be adjusted.

[0014] The fire parameter measurement system includes a smoke temperature measurement system, a smoke layer thickness measurement system, and a smoke spread velocity measurement system.

[0015] The flue gas temperature measurement system includes a longitudinal thermocouple string under the platform roof, a vertical thermocouple string at the longitudinal center section of the platform level, vertical thermocouple strings on both sides of the air curtain air supply outlet at the stairwell, and a flue gas temperature data acquisition device connected to the thermocouple strings.

[0016] The smoke layer thickness measurement system includes a scale attached to the fireproof glass on the side of the platform level and a laser pointer.

[0017] The simulated smoke-proof air curtain test platform for subway station stairwells is characterized by being constructed at a 1:10 scale of an actual subway station. The simulated platform level is 5.0m long, 1.0m wide, and 0.5m high, while the simulated concourse level is 5.0m long, 1.0m wide, and 0.6m high. The platform and concourse levels are connected by a staircase, which is made of bent sheet metal and forms a 30° angle with the platform floor. The stairwell opening in the platform ceiling is 0.6m long and 0.4m wide.

[0018] The platform and station hall ceilings are evenly provided with a series of openings that match the dimensions of the vertical air ducts to facilitate the installation of vertical smoke exhaust (air supply) ducts.

[0019] The smoke curtain inserted below the platform ceiling on the front side of the stairwell can be freely adjusted by pulling it upwards.

[0020] The air curtain system is located at the platform stairwell. The air curtain air supply outlet is 0.4m long and 0.03m wide, and the jet angle can be freely adjusted between 0-90°.

[0021] This experimental platform, designed at a 1:10 scale, enables precise real-time measurement of key parameters such as temperature and velocity. It not only provides a reliable experimental platform for relevant scientific research in the laboratory but also effectively simulates two typical scenarios: subway station platform fires and station hall fires. This allows for the exploration of smoke flow characteristics at the platform level and stairwells, providing crucial data support and experimental evidence for smoke control research in these scenarios. The platform offers significant practical guidance for the effective design, performance testing, and effect evaluation of smoke control systems at subway station platform stairwells, and possesses broad engineering application prospects. Its beneficial technical effects are mainly reflected in the following aspects:

[0022] (1) In terms of experimental operation, the experimental platform is equipped with a swing door that can be opened freely on the side to facilitate the arrangement of the fire source system during the experiment.

[0023] (2) During the smoke spread simulation, the experimental platform can simulate the spread of smoke in the station hall, the platform, and the stairwell of the station hall during a fire. The platform can also record the changes of various parameters of the smoke spread over time and space through the temperature and smoke layer thickness measurement system.

[0024] (3) In terms of flue gas control, each air supply and exhaust system does not affect each other. During the experiment, the start and stop of each flue gas control system can be freely adjusted through circuit control to achieve the optimal combination of different flue gas control systems. The air volume or wind speed of the air supply and exhaust system can be adjusted through frequency converter and DC power supply.

[0025] (4) In terms of experimental parameter measurement system, a complete temperature measurement system, wind speed measurement system and flue gas layer thickness measurement system can be used to conduct comprehensive observation and research on flue gas flow parameters and flue gas control effect. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the smoke-proof air curtain simulation test platform for subway station platform stairwells described in this invention.

[0027] Figure 2 This is a schematic diagram of the air curtain system structure of one embodiment of the experimental platform described in this invention.

[0028] Figure 3 This is a schematic diagram of the AA (vertical) cross-section of an embodiment of the smoke-proof simulation test platform for air curtains at the stairwells of a subway station as described in this invention.

[0029] Figure 4 This is a schematic diagram of the BB (vertical) cross-section of an embodiment of the smoke-proof simulation test bench for air curtains at the stairwells of subway stations according to the present invention.

[0030] Figure 5 This is a schematic diagram of the layout of the flue gas control system exhaust port and air supply port in one embodiment of the experimental platform described in this invention.

[0031] 1-Simulated concourse level; 2-Simulated platform level; 3-Longitudinal duct of concourse smoke exhaust system; 4-Longitudinal duct of concourse air supply system; 5-Vertical duct of concourse smoke exhaust system; 6-Vertical duct of concourse air supply system; 7-Fan of concourse smoke exhaust system; 8-Fan of concourse air supply system; 9-Longitudinal duct of platform air supply system; 10-Longitudinal duct of platform smoke exhaust system; 11-Vertical duct of platform air supply system; 12-Vertical duct of platform smoke exhaust system; 13-Fan of platform air supply system; 14-Fan of platform smoke exhaust system; 15-Opening of wind speed measurement probe; 16-Manual damper for smoke exhaust / air supply outlet; 17-Simulated staircase; 18-Smoke curtain; 19-Horizontal opening at the top of platform; 20-Baffles on both sides of staircase entrance; 21-Openable swing door on the side of platform; 22-Main steel support frame of experimental table; 23-Pressure stabilizing box of air curtain system. 24 - Axial flow fan for air curtain system supply; 25 - Support for axial flow fan for air curtain system supply; 26 - Connecting aluminum foil hose for air curtain system; 27 - Pressure stabilizing box for air curtain system; 28 - Connecting canvas tube for air curtain system; 29 - Air supply duct for air curtain system; 30 - Support rod for air supply duct for air curtain system; 31 - Fixing hinge for air supply duct for air curtain system; 32 - Air outlet for air curtain system; 33 - Angle gauge; 34 - Longitudinal thermocouple string below the ceiling of the concourse level; 35 - Vertical thermocouple string of the concourse level; 36 - Longitudinal thermocouple string below the ceiling of the platform level; 37 - Vertical thermocouple string of the platform level; 38 - Vertical thermocouple string on the left side of the air curtain air outlet on the platform level; 39 - Vertical thermocouple string on the right side of the air curtain air outlet on the platform level; 40 - Support base for longitudinal duct of air supply and exhaust system; 41 - Air outlet; 42 - Smoke exhaust outlet. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] See Figure 1The main body of the smoke-proof air curtain simulation experimental platform at the stairwell of a subway station consists of a simulated concourse level 1 and a simulated platform level 2. The simulated concourse level is 5.0m long, 1.0m wide, and 0.5m high; the simulated platform level is 5.0m long, 1.0m wide, and 0.6m high. The main body of the experimental platform adopts a steel frame structure, supported by a support frame 22. The platform level is 0.25m above the ground. Two swing doors 21 are opened on one side of the fireproof board of the platform level to facilitate the arrangement of the fire source system during the experiment. The swing doors are 0.5m long and 0.3m wide. Fireproof glass is installed on the other side of the platform level to facilitate the observation of experimental phenomena and the measurement of smoke layer thickness during the experiment. The air supply and smoke exhaust system includes: a concourse air supply system consisting of longitudinal duct 4, vertical duct 6, and fan 8; a concourse smoke exhaust system consisting of longitudinal duct 3, vertical duct 5, and fan 7; a platform air supply system consisting of longitudinal duct 9, vertical duct 11, and fan 13; and a platform smoke exhaust system consisting of longitudinal duct 10, vertical duct 12, and fan 14. Each vertical duct is equipped with a manual damper 16, allowing adjustment of the airflow by adjusting the damper's rotation angle. Each longitudinal duct has a wind speed probe opening 15 for inserting a wind speed probe. 19 is a horizontal opening at the top of the platform level, 0.6m long and 0.4m wide. The top and end faces of the platform level and the concourse level are sealed with fireproof boards and fixed with steel frame supports.

[0034] See Figure 2 The air curtain system mainly consists of an axial flow fan 24, a pressure stabilizing box 27, and an air supply duct 29. An aluminum foil flexible hose 26 connects the axial flow fan and the pressure stabilizing box. The fan and the aluminum foil flexible hose, as well as the pressure stabilizing box and the air supply duct, are connected by canvas pipes 28. The air curtain air supply duct is supported and fixed by support rods 30 and hinges 31. The air supply angle of the air outlet 32 ​​can be freely adjusted using an angle gauge 33. The air outlet of the air curtain system is adjacent to the smoke curtain wall and at the same height as the lower edge of the smoke curtain wall.

[0035] join Figure 3The platform level and the concourse level are connected by a simulated staircase 17, which is made of thin sheet metal bent at a 30° angle to the platform floor. At the front of the staircase, a smoke curtain 18 is installed below the platform ceiling, the lower edge of which is adjustable above the platform floor. Longitudinal thermocouple strings 34 and 36 are arranged below the concourse ceiling. These strings are 0.02m from the ceiling and spaced 0.2m apart. Vertical thermocouple strings 35 and 37 are arranged at the longitudinal center sections of the concourse and platform areas, each string containing 11 probes spaced 0.04m apart. The horizontal spacing between the vertical thermocouple strings is 1.4m. At the platform staircase entrance, one vertical thermocouple string 38 and 39 are installed on the left and right sides of the air curtain vent 32 to measure the flue gas temperature distribution before and after the air curtain jet. The vertical thermocouple string 38 on the left side of the air curtain air supply outlet is 0.01m from the stair tread and 0.05m from the smoke curtain wall, with a total of 9 probes; the thermocouple string 39 on the right side of the air curtain air supply outlet is 0.03m from the smoke curtain wall.

[0036] See Figure 4 The air supply system for the concourse level consists of longitudinal air supply ducts, vertical air ducts, and fans, as shown in numbers 4, 6, and 8. The smoke exhaust system for the platform level consists of longitudinal air supply ducts, vertical air ducts, and fans, as shown in numbers 10, 12, and 14. Both the air supply and smoke exhaust systems have five vertical air ducts and vents, evenly distributed below the ceiling. The vent height can be freely adjusted via the support base 38 below the longitudinal air ducts.

[0037] See Figure 5 Air supply vents 41 and smoke exhaust vents 42 are evenly arranged below the ceiling.

Claims

1. A simulated smoke-proof air curtain test bench for subway station platform stairwells, characterized in that: This includes the main model of the subway station, as well as the fire source system, station ventilation and smoke exhaust system, air curtain system, and fire parameter measurement system deployed in the main model; The main model of the subway station includes a platform level and a concourse level; the platform level platform screen door system is considered to be a fully enclosed platform screen door system; a staircase leading to the concourse level is provided on the platform level, and a smoke curtain and air curtain air supply outlet are provided below the platform ceiling at the staircase entrance; The fire source system includes oil pools of different sizes, fuel storage tanks, smoke cakes, and a four-legged piezoelectric weighing scale. Different fire source power is achieved through oil pools of different sizes. The mass loss rate during combustion of oil pools of different sizes can be measured by the electronic scale to calculate the fire source power corresponding to oil pools of different sizes. The station's air supply and smoke exhaust system includes a concourse air supply and smoke exhaust system and a platform air supply and smoke exhaust system. The fire parameter measurement system includes a smoke temperature measurement system, a smoke layer thickness measurement system, and a wind speed measurement system. The flue gas temperature measurement system includes a longitudinal thermocouple string arranged under the ceiling of the platform level and the concourse level, a vertical thermocouple string in the longitudinal center section of the station, and a flue gas temperature data acquisition device connected to the thermocouple string for electrical signal; wherein, the vertical thermocouple string in the platform level includes vertical thermocouple strings on the left and right sides of the air curtain air supply outlet. The smoke layer thickness measurement system mainly includes a scale installed on the fireproof glass on the side of the platform and a laser light device on the platform; The wind speed measurement system includes wind speed probes arranged in the longitudinal duct and at the air curtain outlet, as well as a wind speed data acquisition device that is electrically connected to the wind speed probes.

2. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The simulation test platform is a scaled-down experimental model, with a similar scale of 1:10 to the actual subway station; the simulated platform floor is 5.0m long, 1.0m wide, and 0.5m high; the simulated concourse floor is 5.0m long, 1.0m wide, and 0.6m high.

3. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The simulation test platform is constructed from multiple fireproof panels connected by angle steel. The two sides of the platform level are designed as fully enclosed shielded doors, with one side using a fireproof panel and the other side using fireproof glass to facilitate observation of experimental phenomena. Doors are opened on the fireproof panels on the sides of the platform level to facilitate experimental operations such as placing oil tanks (fire sources), adjusting the position of the oil tanks, and adding fuel to the oil tanks. The two end faces of the platform level and the enclosure structure of the concourse level are all made of fireproof panels.

4. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The simulated smoke curtain is positioned below the platform ceiling in front of the stairwell, and its height can be freely adjusted.

5. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The air curtain system mainly includes a blower, a pressure stabilizing box, and air supply ducts. The air curtain air supply duct is a long and narrow rectangular structure, sealed on all four sides. The lower end is the air curtain nozzle, and the upper opening is sealed to the lower outlet of the pressure stabilizing box through a waterproof canvas hose. The pressure stabilizing box and the axial flow fan are connected through an aluminum foil hose. The air curtain air supply duct is supported by steel bars erected on the ceiling of the station hall. The jet angle of the air supply nozzle can be adjusted using an angle gauge. The speed of the blower in the air curtain system can be adjusted by a frequency converter (0~50Hz) to achieve different air curtain jet velocities.

6. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The simulated air curtain air supply outlet model is arranged at the platform stairwell. The air curtain air supply outlet is at the same height as the lower edge of the smoke curtain, and its length is the same as the width of the stairwell. It can simulate the fire scenario when the air curtain jet at the platform stairwell is used for smoke prevention in the event of a fire on the platform.

7. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The fire source system is mainly located on the platform level to simulate different fire scenarios of platform fires, and can also simulate different fire scenarios when a fire occurs on the concourse level.

8. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: The exhaust and air supply outlets of the air supply and exhaust system are connected to the axial flow fans through vertical ducts below the platform roof and longitudinal ducts above the platform roof; openings are provided in the longitudinal ducts for inserting wind speed probes; the rotational speed of each axial flow fan is adjusted by a corresponding DC regulated power supply to adjust the exhaust and air supply volumes.

9. The smoke-proof simulation test platform for air curtains at subway station platform stairwells according to claim 1, characterized in that: It can comprehensively realize one or different combinations of station smoke exhaust system, station air supply system and air curtain system and adjust parameters.

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