CN116575966A - Method and device for inhibiting smoke valve penetration phenomenon of tunnel key smoke discharge - Google Patents
Method and device for inhibiting smoke valve penetration phenomenon of tunnel key smoke discharge Download PDFInfo
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- 239000000779 smoke Substances 0.000 title claims abstract description 412
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- 230000002401 inhibitory effect Effects 0.000 title claims abstract description 14
- 230000035515 penetration Effects 0.000 title claims description 18
- 238000007599 discharging Methods 0.000 claims abstract description 59
- 239000003517 fume Substances 0.000 claims abstract description 15
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000003546 flue gas Substances 0.000 claims abstract description 12
- 230000008859 change Effects 0.000 claims abstract description 6
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F1/00—Ventilation of mines or tunnels; Distribution of ventilating currents
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
- E21F17/18—Special adaptations of signalling or alarm devices
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
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Abstract
The invention discloses a method and a device for inhibiting a smoke exhaust valve from sucking through a tunnel key smoke exhaust. Through carrying out intelligent monitoring to the tunnel that adopts key to discharge fume, formulate reasonable exhaust valve and fan and open the tactics to reform into the normal close type electric exhaust valve of the mode of opening of "back" shape that has the surplus with traditional exhaust valve, set up the effective smoke discharging area of each exhaust valve of multispeed switch control, judge the emergence of inhaling through the wind speed and the temperature sensor that confirm the conflagration position and discharge fume the mouth below, thereby change the rate of opening of different position exhaust valve, restrain the suction through of key exhaust fume tunnel discharge fume mouth, and let more flue gas follow the discharge fume mouth that is close from the fire source and discharge fume efficiency, control the flue gas in the shorter distance, be favorable to the safe evacuation of tunnel conflagration personnel.
Description
Technical Field
The invention belongs to the technical field of tunnel smoke discharge, and particularly relates to a method and a device for inhibiting a smoke valve penetration phenomenon of tunnel key smoke discharge.
Background
Due to the complexity and relative sealing of the structure of the tunnel, once a fire accident occurs, smoke is difficult to control, and the fire safety of the tunnel becomes a problem which is concerned and needs to be solved urgently. Smoke is the most important factor causing casualties in a fire, a tunnel belongs to a limited space, and when the fire occurs, a large amount of high-concentration toxic smoke is generated by incomplete combustion due to insufficient air in the tunnel, and is difficult to rapidly discharge, so that high-temperature smoke generated by the fire is extremely unfavorable for safe evacuation of personnel and fire-extinguishing rescue, and disastrous results are often caused. How to effectively control the smoke in a certain range, reasonably and effectively control the spread of fire smoke in the tunnel, and has important significance for guaranteeing the tunnel structure, equipment and facilities and personnel safety.
At present, more mechanical smoke discharging modes adopted in China mainly comprise longitudinal ventilation smoke discharging and transverse ventilation smoke discharging. The stable layering of fire smoke in the tunnel can be damaged by longitudinal ventilation, people downstream of an early fire source are more unfavorably evacuated, and the safety of people and vehicles is greatly reduced under the conditions of bidirectional traffic and vehicle blockage. The transverse ventilation utilizes the independent smoke discharge channel to discharge smoke, so that the spreading and sedimentation of the smoke can be effectively controlled, and the rescue safety is improved. The key smoke exhaust is a transverse ventilation smoke exhaust system, which is characterized in that a top partition plate is arranged in a rich space of a tunnel vault to form an independent smoke exhaust channel, when a fire disaster occurs, a plurality of smoke exhaust valves near the fire accident point are opened to carry out key smoke exhaust, and a smoke exhaust fan discharges smoke out of a tunnel through the smoke exhaust channel, so that the smoke is controlled in a certain range at the upstream and downstream of a fire source.
The tunnel of the key smoke exhaust system is adopted, the smoke exhaust valve close to the vertical shaft is large in air quantity of the smoke exhaust fan, the smoke layer is thin, air in the tunnel is easily sucked out of the smoke exhaust valve, a sucking-through phenomenon occurs, and smoke exhaust efficiency is reduced. The suction through phenomenon is that air at the lower layer of the smoke is directly sucked out through the smoke due to the overlarge flow speed of the smoke outlet. The key smoke exhaust fan is arranged in the smoke exhaust shaft at the end part of the tunnel, the smoke exhaust port closer to the shaft is larger in suction force of the smoke exhaust fan, and the smoke thermal buoyancy at the smoke exhaust port closer to the fire source is larger, so that the suction air quantity at the smoke exhaust ports at different positions is uneven. Because the distribution rule of suction force and heat floating force is opposite, the coupling acting force of the suction force and the heat floating force is not equal at each smoke outlet, so that the suction through phenomenon is easy to occur at the smoke outlet in the key smoke discharging mode. After the suction through phenomenon occurs, a large amount of air is directly sucked out from the smoke outlet, so that the smoke discharging efficiency of the smoke discharging system is greatly reduced, and meanwhile, the thickness of the smoke layer near the smoke outlet is increased, so that the escape of people is not facilitated.
Aiming at the phenomenon, in order to ensure that the smoke is in a layered state and the smoke turbulence phenomenon does not occur in the smoke discharging process, a good escape environment is created for internal personnel and vehicles, a large amount of smoke is discharged from a smoke outlet near a fire source as much as possible, the spreading range of the smoke is controlled, and the occurrence of the suction through phenomenon is restrained. The current measures are optimized by changing the opening strategy of the smoke discharging valve, namely, the smoke discharging valve closest to the smoke discharging vertical shaft is closed, and meanwhile, one smoke discharging valve is opened on the other side of the fire source to solve the problem of insufficient smoke discharging efficiency. The optimized smoke exhaust valve opening strategy is implemented (2 fire sources are opened on the left side close to the vertical shaft side, and 4 fire sources are opened on the right side), so that the suction phenomenon of the smoke exhaust valve can be effectively improved, the spreading distance of smoke is reduced, and the smoke exhaust efficiency is improved.
However, for very long urban underground tunnels, the key smoke evacuation system has the following problems: 1) When a fire disaster happens in a tunnel truly, the position of a fire source is uncertain, the distance between the fire source and a vertical shaft is also uncertain, different smoke exhaust valve opening strategies cannot be formulated for each fire disaster situation, and smoke exhaust efficiency cannot be accurately and definitely improved; 2) In the existing smoke discharging system design, after a fire disaster occurs, the area of each smoke discharging valve opened at the upstream and downstream of the fire source is consistent, but smoke is continuously subjected to heat exchange with a ceiling and a wall surface in the process of longitudinally spreading along a tunnel, the temperature and the flow speed of the smoke in the longitudinal direction are not consistent, the smoke discharging amount and the smoke discharging efficiency of each smoke discharging port are not the same, the possibility of the occurrence of the suction phenomenon of a fan end far away from the fire source is high, and therefore, a method and a device capable of judging the occurrence of the suction phenomenon and simultaneously inhibiting the suction phenomenon and effectively improving the smoke discharging efficiency are necessary to be developed, so that the spreading of the smoke is effectively controlled, and people in the fire disaster working condition are evacuated.
The existing patents related to the aspect of tunnel smoke discharge mostly take the improvement of smoke discharge efficiency by improving the ventilation and smoke discharge mode of the tunnel as the research direction, but the improvement of a smoke discharge valve during key smoke discharge is seldom carried out, the suction effect is restrained, and the smoke discharge efficiency is improved. In the patent (patent number: 202010522535.0), a tunnel smoke exhaust system is provided, a smoke exhaust efficiency lifting device is additionally arranged in a smoke exhaust air duct, smoke exhaust power is increased under the condition of not changing the section of a tunnel, and smoke exhaust efficiency is improved compared with the existing smoke exhaust system. However, the probability of suction through is greater without considering the increase of the smoke discharging power. Chinese patent (patent number: 201910619971.7) discloses an auxiliary device for preventing smoke from being sucked through in a tunnel vertical shaft, wherein a conical baffle is arranged at the bottom opening of the tunnel vertical shaft and is downwards in a herringbone opening, and the angle of the baffle is adjusted by sensing the temperature of smoke through a sensor so as to inhibit the natural smoke-discharging air sucking through problem of the vertical shaft. The invention mainly aims at the chimney effect of natural smoke exhaust of the vertical shaft, changes the tunnel structure and increases the uncertainty of tunnel fire.
Disclosure of Invention
The invention aims to solve the existing technical problems and provide a method and a device for inhibiting the suction-through phenomenon of a smoke valve during tunnel key smoke discharge. The intelligent linkage control method can judge the opening size of the smoke valve of the suction-through effect on the heavy-point smoke discharging system according to the fire occurrence position of the tunnel and the temperature of the smoke layer of the smoke outlet, and realize intelligent linkage control.
The technical scheme adopted by the invention is as follows:
a method and a device for restraining a smoke exhaust valve from sucking through a tunnel key smoke exhaust are provided, and the key smoke exhaust system of the tunnel comprises a tunnel main body, an independent smoke exhaust duct, a normally closed electric smoke exhaust valve, a smoke exhaust vertical shaft, a fan and an intelligent control system.
Furthermore, the top of the tunnel main body is provided with an independent smoke exhaust duct connected with the tunnel main body, and the tunnel main body can be provided with an interval key smoke exhaust system according to actual engineering.
Further, a smoke exhaust axial flow fan is arranged in a smoke exhaust shaft at the tail end of the key smoke exhaust system in the smoke exhaust section, and the independent smoke exhaust channels are exhausted to accelerate smoke generated by a fire disaster to be sucked into the independent smoke exhaust air channels.
Further, the independent exhaust flue is provided with a plurality of smoke outlets which are uniformly distributed along the longitudinal direction of the tunnel, and the smoke outlets are all provided with automatic smoke discharging fireproof valves. The normally closed electric smoke exhaust valve with a allowance in a 'back' opening mode replaces the traditional smoke exhaust valve, the normally closed electric smoke exhaust valve is arranged at a smoke exhaust port reserved at an independent smoke exhaust channel of a tunnel and a roof of a vehicle tunnel, the smoke exhaust valve is provided with an independent smoke exhaust valve actuating mechanism, and the opening gear of each smoke exhaust valve can be freely adjusted to change the effective smoke exhaust area of the smoke exhaust valve.
Further, the normally closed type electric smoke exhaust valve comprises a fixed shell, telescopic blades are arranged on the inner wall of the fixed shell, four blades are connected with a smoke exhaust valve actuating mechanism at the outer wall of the fixed shell through bearings respectively, a turbine is connected with the outer side of the smoke exhaust valve actuating mechanism to form transmission fit with the blades, the motor is connected with a motor arranged in the smoke exhaust valve actuating mechanism, the motor is connected with a PLC (programmable logic controller) and a wireless signal receiver through a signal wire, the smoke exhaust valve actuating mechanism can drive the smoke exhaust valve to shrink and expand, and the smoke exhaust valve actuating mechanism is used for controlling the opening positions of the smoke exhaust valve blades in multiple gears and is connected with the output end of the PLC.
Further, the intelligent control system comprises a fire alarm system, and a wind speed detection device, a temperature detection device, a data acquisition device and a control terminal which are in one-to-one correspondence with the smoke outlets.
Further, the intelligent control system is used for receiving the feedback signal and controlling the normally closed electric smoke exhaust valve and the start and stop of the smoke exhaust axial flow fan.
Further, the fire alarm system comprises a fire detector arranged at the roof of the vehicle tunnel, and is connected with the control terminal to feed back fire signals and control a preset smoke exhaust valve and a smoke exhaust fan which correspond to the detected fire source.
Further, the wind speed detection device is arranged right above the smoke outlet and used for measuring the smoke speed flowing out of the smoke outlet, and the temperature detection device is arranged at the bottom of the smoke outlet and jointly acts on the occurrence of the phenomena of sensing fire smoke and sucking through.
Further, the wind speed detection device and the temperature detection device are connected with the data acquisition device and transmitted to the control terminal, and the wind speed detection device and the temperature detection device are respectively connected with the signal input end of the PLC through signal wires.
Further, in the hydrodynamic force, the relationship between the inertial force and the buoyancy is expressed by the froude number Fr, and if the inertial force acts more, the larger the Fr value, the more intense the blending, whereas if the buoyancy is larger, the smaller the Fr value. Therefore, hinkley proposes that the criterion number froude can be used to determine whether the blending state under the smoke layer is severe, i.e. froude can be used as a reference value for determining whether the smoke layer with important smoke is sucked through.
Further, the Froude number at the moment of the suction through can be expressed as Fr c . According to Morgan et al, fr when the smoke evacuation valve is located at the tunnel transverse center c 1.5, the opening rate of the smoke exhaust valve is controlled to be alpha through a feedback regulating system, and the following relational expression is satisfied:
in the formula u V The speed (m/s) of the smoke flowing out through the smoke discharging valve port; a is the area of the smoke outlet (m) 2 ) The method comprises the steps of carrying out a first treatment on the surface of the d is a rowThe thickness (m) of the flue gas layer below the flue gas valve; delta T is the difference (K) between the temperature of the flue gas layer and the ambient temperature; t (T) 0 Is the ambient temperature (K); g is gravity acceleration (m/s) 2 )。
Further, a temperature detection device is arranged in the vertical direction below the smoke exhaust valve, smoke is judged to be sucked through the smoke exhaust valve when the temperature difference between the uppermost measuring point and the lowermost measuring point reaches delta T (delta T is less than 40 ℃), the temperature below the ceiling starts to rise along with the continuous development of the smoke, and the thickness of the smoke layer is the height of the measuring point, which is closest to the ceiling and reaches delta T, of the temperature difference.
Further, the PLC obtains the smoke discharging area when critical penetration is performed according to the actually detected temperature and wind speed and a pre-stored temperature-smoke layer thickness relational expression; and then calculating the opening rate alpha of the smoke exhaust valve according to the actual engineering smoke exhaust port area and the ratio of the two, and feeding back and adjusting the valve gear regulator through the signal output end.
Further, the gear regulator is provided with a three-gear switch, according to the calculated value, when the smoke exhaust valve opening rate is 60% < alpha <90%, the gear is regulated to a first gear, when the smoke exhaust valve is closed by one fourth, when the smoke exhaust valve opening rate is 40% < alpha <60%, the gear is regulated to a second gear, when the smoke exhaust valve is closed by one half, and when the smoke exhaust valve opening rate is alpha <40%, the gear is regulated to a third gear, and when the smoke exhaust valve is closed by three quarters. The gear regulator sets threshold values, all of which are regulated by calculating minimum values. And according to the feedback signal received by the temperature measurement system, adjusting the opening rate of the smoke exhaust valve until the measured temperature difference is lower than delta T, and stopping when no suction through occurs.
Further, the specific implementation steps are as follows:
s1, firstly, judging the specific position of a fire disaster according to a signal sent by a fire disaster alarm, and transmitting the specific position back to a control center to start an emergency plan;
s2, starting a smoke exhaust fan in a vertical shaft of the fire disaster occurrence position control unit according to the alarm signal, and starting normally closed electric smoke exhaust valves corresponding to the number of smoke exhaust strategy groups to carry out key smoke exhaust;
s3, starting an intelligent control system, wherein a wind speed detector and a temperature detector corresponding to the smoke exhaust valve start to work, and judging whether suction penetration occurs according to the temperature below the smoke exhaust valve;
s4, the control system feeds back parameters, and when the smoke exhaust valve is found to be in a penetration state, the formula (1) is executed, the opening rate of the smoke exhaust valve is calculated, the opening gear of the smoke exhaust valve is automatically controlled according to the opening rate range, the opening size of the smoke exhaust valve is changed, the penetration phenomenon is restrained, the temperature in a tunnel is reduced, and the smoke exhaust efficiency is improved.
The invention has the following advantages:
(1) Through carrying out intelligent monitoring to the tunnel that adopts key to discharge fume, formulate reasonable exhaust valve and fan and open the tactics to reform into the normal close type electric exhaust valve of the mode of opening of "back" shape that has the surplus with traditional exhaust valve, set up the effective smoke discharging area of each exhaust valve of multispeed switch control, judge the emergence of inhaling through the wind speed and the temperature sensor that confirm the conflagration position and discharge fume the mouth below, thereby change the rate of opening of different position exhaust valve, restrain the suction through of key exhaust fume tunnel discharge fume mouth, and let more flue gas follow the discharge fume mouth that is close from the fire source and discharge fume efficiency, control the flue gas in the shorter distance, be favorable to the safe evacuation of tunnel conflagration personnel.
(2) The device is simple, the engineering cost is low, the tunnel structure is not required to be changed, the negative influence on the tunnel is avoided, the device is easy to realize, the smoke discharging efficiency of the tunnel adopting the key smoke discharging mode can be effectively improved, and the smoke spreading is controlled.
(3) The invention is not limited to inhibiting the suction through of the smoke exhaust valve, and can further judge the optimal opening strategy in different conditions of fire through numerical simulation so as to optimize the smoke exhaust strategy of the key smoke exhaust tunnel.
Drawings
Fig. 1 is a schematic structural diagram of a tunnel key smoke exhaust system according to an embodiment of the present invention.
Fig. 2 is a three-dimensional view of a top smoke evacuation valve of the tunnel key smoke evacuation system according to the embodiment of the invention.
Fig. 3 is a top view of a top smoke evacuation valve of the tunnel key smoke evacuation system of the present invention.
Fig. 4 is a simplified schematic diagram of a smoke evacuation valve in an important smoke evacuation mode according to example 1 of the present invention.
Fig. 5 is a graph showing the temperature distribution pattern of the example 2 of the present invention when the suction is detected, and the temperature distribution pattern after the opening rate of the smoke exhaust valve is adjusted according to the method of the present invention.
Fig. 6 shows the smoke concentration field when the suction through is detected in example 2 of the present invention, and the smoke concentration field after the opening rate of the smoke valve is adjusted according to the method of the present invention.
Fig. 7 is a graph showing the change of smoke discharging efficiency of the right side smoke outlet of the fire source according to example 2 of the present invention.
Fig. 8 is a control flow chart of the tunnel key smoke exhaust system of the invention.
Reference numerals illustrate:
1-a vehicle tunnel; 2-independent smoke exhaust air duct; 3-a smoke discharging vertical shaft; 4-an axial flow fan; 5-a fan switch controller; 6, a smoke outlet; 7-a fire source; 8-a temperature measurement system below the smoke outlet; 9-a wind speed measuring system at the smoke outlet; 10-a data collector; 11-a control terminal; 12-a normally closed electric smoke exhaust valve; 13-fume valve blades; 14-a smoke exhaust valve actuating mechanism; 15-a smoke discharge valve fixed shell; 16-a turbine; 17-an electric motor; 18-a valve gear regulator; 19-a PLC controller; 20-wireless signal receiver.
Detailed Description
The following description of specific embodiments, objects and effects of the present invention will be further illustrated by reference to the accompanying drawings and examples, which are intended to be illustrative of the present invention and not limiting in scope.
Example 1:
as shown in fig. 1, a method and a device for inhibiting the suction through phenomenon of a smoke exhaust valve in a tunnel key smoke exhaust are provided, the key smoke exhaust system of the tunnel key smoke exhaust comprises a tunnel main body 1, an independent smoke exhaust duct 2, a normally closed electric smoke exhaust valve 12, a smoke exhaust vertical shaft 3, an axial flow fan 4 and an intelligent control system, wherein a fire source is arranged at the middle position of a vehicle tunnel 1, a smoke exhaust strategy is formulated to open the left smoke exhaust valve and the right smoke exhaust valve respectively, the axial flow fan 4 in the vertical shafts 3 on two sides is opened to perform key smoke exhaust, a temperature measuring system 8 and an air speed measuring system 9 are arranged at each smoke exhaust port, the temperature measuring system 8 can measure the temperature below the smoke exhaust ports from top to bottom equidistantly, and the air speed measuring system 9 measures the smoke speed flowing out of the smoke exhaust ports.
When a fire disaster occurs, the smoke spreads to two sides, a fire alarm sends out a signal, an emergency plan is started, and the normally closed electric smoke discharging valve L 3 、L 2 、L 1 、R 1 、R 2 、R 3 The smoke valve actuator 14 is fully in a normal open mode by remote control, as shown in fig. 2 and 3, and the corresponding temperature measuring system 8 and wind speed measuring system 9 are activated. The data collector 10 collects real-time data and transmits the data to the control terminal 11, and feeds back the data to the wireless signal receiver 20 and the input end of the PLC 19 in the smoke exhaust valve actuator 14 of the smoke exhaust port according to the fire occurrence position determined by the alarm signal, and the smoke exhaust valve L near the fire source end 1 、R 1 The blades of the smoke exhaust valve are contracted through the bearing, and the residual area of the smoke exhaust valve is opened, so that more smoke is exhausted from the smoke exhaust port near the fire source.
Meanwhile, the flow speed of the remote smoke exhaust valve is influenced by the wind speed of the smoke exhaust fan, so that a certain pressure difference is generated between the inside of the smoke exhaust duct and the inside of the vehicle tunnel. The relative variation of the static pressure along the tunnel is small, so that the flow velocity distribution of the smoke exhaust valve is mainly related to the pressure distribution in the smoke exhaust duct. The tunnel system of the key smoke discharging mode is simplified according to the hydrodynamics, as shown in fig. 4, a control energy equation is established for each section of the smoke discharging valve at the downstream section of the fire source to study the pressure and flow velocity distribution in the smoke discharging channel, and the relative static pressure value at each smoke discharging valve is represented according to the local resistance xi and the along-path resistance coefficient gamma of each section:
the minimum static pressure value when the smoke exhaust valve is fully opened can be equivalent to the resistance value of the smoke exhaust valve, and the relation between the ratio of the minimum static pressure value and the relative static pressure value and the opening rate of the smoke exhaust valve can be obtained:
effective smoke discharging area A and smoke discharging through smoke discharging valveThe relation of the static pressure P of the flue gas in the flue can be obtained, when the area of the smoke outlet is reduced, the resistance at the smoke outlet is increased, the pressure loss is balanced, and the flow velocity v in the flue is effectively increased 1 While reducing the flow velocity v of the flue gas below the flue gas outlet 0 Thereby inhibiting the occurrence of disturbance phenomenon of the smoke layer and achieving the purpose of improving the smoke discharging efficiency.
At this time, the PLC controller 19 obtains the smoke discharge area at the time of critical penetration according to the actually detected temperature and wind speed and the pre-stored temperature-smoke layer thickness relational expression; then, according to the actual engineering smoke outlet area, the opening rate alpha of the smoke outlet valve is controlled according to the ratio of the two, and the following formula is satisfied:
and the corresponding gear is adjusted by the gear adjuster 18 of the feedback adjusting valve through the signal output end according to the range of the opening rate of the smoke exhaust valve, and the opening rate of the smoke exhaust valve is adjusted until the measured temperature difference is lower than delta T and the smoke exhaust valve stops when no more suction occurs according to the feedback signal received by the temperature measuring system 8.
Example 2:
the following is a practical verification performed in connection with a special city underground road engineering using key smoke evacuation, as shown in fig. 1. The smoke discharging modes when fire disaster occurs in the tunnel are divided into two modes, namely a one-way smoke discharging mode of only starting a smoke discharging fan in a vertical shaft close to one side of a fire source and a two-way smoke discharging mode of controlling smoke by the smoke discharging fans in the vertical shafts on two sides of the fire source. When the position of the fire source is deviated to one shaft position, the one-way smoke discharging mode is higher than the two-way smoke discharging mode in smoke discharging efficiency, and the one-way smoke discharging mode is adopted; when the fire source is positioned in the middle of the two shafts, a bidirectional smoke discharging mode can be adopted.
When the tunnel fire disaster adopts key smoke discharge, the air quantity is too large to cause the smoke penetration, the smoke layer below the smoke discharge port is sucked, the air is directly sucked into the smoke discharge port, the smoke discharge efficiency is reduced, and the smoke penetration phenomenon is more obvious as the smoke discharge air quantity is larger. This embodiment will be achieved by establishing 1:1, observing the penetration and smoke spreading distance of a smoke outlet, measuring the smoke generation amount and the smoke discharge amount to calculate the smoke discharge efficiency, analyzing the change of the smoke discharge efficiency when the invention is adopted, and further verifying the effect of the invention by combining the drawing.
In order to verify the design scheme of ventilation and smoke exhaust of the invention, 1 is established according to actual engineering: and 1, a physical model, taking bidirectional smoke exhaust as an example to carry out numerical simulation calculation. The tunnel is shown in figure 1, the tunnel model is 400m long, 13m wide, 9m high, 6.5m clear height of the traffic lane, wherein the height of the smoke exhaust interlayer is 2m, the size of the smoke outlet of the vertical shaft is 6m multiplied by 5m, the vertical shaft 1 and the vertical shaft 2 are fixed air volume fans, and the smoke exhaust amount is 180m 3 The fire source size is 2m multiplied by 2m, the fire source is positioned in the middle position of two vertical shafts, the designed maximum fire source power is 50MW, the smoke outlet distance is 60m, and the maximum opening area is 8m 2 The method comprises the steps of carrying out a first treatment on the surface of the The two-way smoke exhaust strategy is adopted, and the smoke exhaust valve is opened in a mode of 3 groups from top to bottom. The wall surface is an adiabatic boundary condition during simulation, the tunnel entrance is a free boundary, and the simulation environment temperature is 20 ℃.
As shown in fig. 5, a temperature distribution rule diagram of a smoke outlet closest to a smoke exhaust fan side in a tunnel is provided, and fig. 5 (a) is a temperature distribution rule diagram when a smoke exhaust valve is fully opened, so that due to the fact that the designed air quantity of the smoke exhaust fan is large and the thickness of a smoke layer is thin, a part of air below the smoke exhaust valve is directly sucked, is exhausted through the smoke outlet, a obvious concave area is formed below the smoke outlet, and the thickness of the smoke layer below the smoke outlet can reach a critical suction through thickness h according to a temperature field c . At this time, the smoke outlet L is calculated according to formula (1) 3 、R 3 As shown in fig. 5 (b), the opening rate α=50%; the smoke penetration effect of the smoke outlet is basically eliminated by observing the temperature field, the smoke layers are uniformly distributed, and the temperature of the smoke in the tunnel is obviously reduced. As can be seen from fig. 6, the diffusion distance of the smoke in the whole tunnel is shortened from 373m to 320m, which shows that the invention effectively reduces the spreading distance of the smoke and is beneficial to people evacuation in fire environment.
As the smoke generated by the tunnel fire disaster has a plurality of components, and in the process of flowing the smoke to the smoke outlet, the smoke layer at the smoke outlet is caused to scratch fresh air by mechanical smoke discharged from the tunnel, and the smoke quality generation amount and the smoke discharge amount are difficult to measureTherefore, when the smoke discharging efficiency of the tunnel key smoke discharging system is studied, the smoke generating amount of the fire source and the smoke discharging amount of the smoke outlet are generally characterized as CO generated by the fire source 2 Quantity and exhaust port discharged CO 2 The amount, therefore, of smoke extraction efficiency of the tunnel-focused smoke extraction system can be expressed as:
wherein: η is the smoke discharging efficiency of the smoke discharging system,%;CO exhausted by smoke exhausting system 2 Amount, kg/s; />CO generated for fire source 2 Amount, kg/s; />CO discharged for the ith smoke outlet 2 The amount is kg/s.
The combustible material used in the numerical simulation of this example was polyurethane (chemical formula C 6.3 H 7.1 O 2.1 N 1.0 ) The heat value is 25649J/g, and the calculated CO is 5MW fire unit time 2 The amount of produced (C) was 4.131kg/s. Because the smoke outlets and the center of the fire source are symmetrically distributed and the smoke discharging effect is basically symmetrically distributed, the CO discharged from the smoke outlet on one side of the fire source is measured 2 The fume extraction efficiency of the quantitative calculation is shown in table 1. By adopting the method, the smoke can be discharged from the smoke outlet close to the fire source preferentially, and the smoke discharging efficiency close to the smoke outlet of the fire source is improved, so that the total smoke discharging efficiency is effectively improved, and the spread of the smoke is controlled.
TABLE 1
Claims (6)
1. A device that is used for tunnel key to discharge fume to restrain exhaust valve to inhale and wear phenomenon, its characterized in that: comprises a tunnel main body, an independent exhaust flue, a normally closed electric smoke exhaust valve and an intelligent control system;
the top of the tunnel main body is provided with independent smoke exhaust air channels connected with the tunnel main body, a plurality of smoke exhaust ports which are uniformly arranged are arranged at the independent smoke exhaust air channels along the longitudinal direction of the tunnel main body, and the smoke exhaust ports are provided with automatic smoke exhaust fireproof valves; the normally closed electric smoke exhaust valve with a allowance in a 'back' opening mode is arranged at a smoke exhaust port reserved at an independent smoke exhaust channel of a tunnel and a roof of a vehicle tunnel, the smoke exhaust valve is provided with an independent smoke exhaust valve executing mechanism, and the opening gear of each smoke exhaust valve is freely adjusted to change the effective smoke exhaust area of the smoke exhaust valve; the intelligent control system comprises a fire alarm system, and an air speed detection device, a temperature detection device, a data acquisition device and a control terminal which are in one-to-one correspondence with the smoke outlets, and is used for receiving feedback signals and controlling the normally closed electric smoke exhaust valve and the start and stop of the smoke exhaust axial flow fan.
2. The method and the device for inhibiting the suction through phenomenon of a smoke valve for key smoke extraction of a tunnel according to claim 1, wherein the method is characterized in that: the normally closed electric smoke exhaust valve comprises a fixed shell, telescopic blades are mounted on the inner wall of the fixed shell, four blades are connected with a smoke exhaust valve actuating mechanism at the outer wall of the fixed shell through bearings respectively, a turbine is connected with the outer side of the smoke exhaust valve actuating mechanism to form transmission fit with the blades, the motor is connected with a motor arranged in the smoke exhaust valve actuating mechanism, the motor is connected with a PLC (programmable logic controller) and a wireless signal receiver through a signal wire, the smoke exhaust valve can be driven to shrink and expand, the smoke exhaust valve actuating mechanism is provided with a valve gear regulator for controlling the opening position of the smoke exhaust valve blades in multiple gears, and the smoke exhaust valve actuating mechanism is connected with the output end of the PLC.
3. The method and the device for inhibiting the suction through phenomenon of a smoke valve for key smoke extraction of a tunnel according to claim 1, wherein the method is characterized in that: the air speed detection device is arranged right above the smoke outlet and used for measuring the speed of smoke flowing out of the smoke outlet, and the temperature detection device is arranged at the bottom of the smoke outlet and jointly acts on the induction of fire smoke and the occurrence of the suction through phenomenon; the wind speed detection device and the temperature detection device are connected with the data acquisition device and transmitted to the control terminal, and the wind speed detection device and the temperature detection device are respectively connected with the signal input end of the PLC through signal wires.
4. A device for inhibiting smoke valve penetration of tunnel key smoke according to claim 3, wherein: and the opening rate of the smoke exhaust valve is controlled to be alpha through a feedback regulating system, so that the following relational expression is satisfied:
in the formula u V The speed (m/s) of the smoke flowing out through the smoke discharging valve port; a is the area of the smoke outlet; d is the thickness of the flue gas layer below the smoke exhaust valve; delta T is the difference between the temperature of the flue gas layer and the ambient temperature; t (T) 0 Is ambient temperature; g is gravitational acceleration.
5. The device for inhibiting smoke valve penetration of tunnel emphasis smoke according to claim 4, wherein: the PLC obtains the smoke discharging area when in critical penetration according to the actually detected temperature and wind speed and a pre-stored temperature-smoke layer thickness relational expression; then according to the actual engineering smoke outlet area, calculating the opening rate alpha of the smoke outlet valve according to the ratio of the two, and feeding back and adjusting the valve gear regulator through the signal output end; the gear regulator is provided with a three-gear switch, according to the calculated value, when the smoke exhaust valve opening rate is 60% < alpha <90%, the gear is regulated to a first gear, the smoke exhaust valve is closed by one fourth, when the smoke exhaust valve opening rate is 40% < alpha <60%, the gear is regulated to a second gear, the smoke exhaust valve is closed by one half, when the smoke exhaust valve opening rate is alpha <40%, the gear is regulated to a third gear, and the smoke exhaust valve is closed by three quarters; the gear regulator sets threshold values, and the threshold values are regulated by calculating the minimum value; and according to the feedback signal received by the temperature measurement system, adjusting the opening rate of the smoke exhaust valve until the measured temperature difference is lower than delta T, and stopping when no suction through occurs.
6. The device for inhibiting the suction through of a smoke valve for a tunnel key smoke according to claim 5, wherein the device comprises the following specific implementation steps:
s1, firstly, judging the specific position of a fire disaster according to a signal sent by a fire disaster alarm, and transmitting the specific position back to a control center to start an emergency plan;
s2, starting a smoke exhaust fan in a vertical shaft of the fire disaster occurrence position control unit according to the alarm signal, and starting normally closed electric smoke exhaust valves corresponding to the number of smoke exhaust strategy groups to carry out key smoke exhaust;
s3, starting an intelligent control system, wherein a wind speed detector and a temperature detector corresponding to the smoke exhaust valve start to work, and judging whether suction penetration occurs according to the temperature below the smoke exhaust valve;
s4, the control system feeds back parameters, and when the smoke exhaust valve is found to be in a penetration state, the formula (1) is executed, the opening rate of the smoke exhaust valve is calculated, the opening gear of the smoke exhaust valve is automatically controlled according to the opening rate range, the opening size of the smoke exhaust valve is changed, the penetration phenomenon is restrained, the temperature in a tunnel is reduced, and the smoke exhaust efficiency is improved.
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| CN202211106321.0A CN116575966A (en) | 2022-09-11 | 2022-09-11 | Method and device for inhibiting smoke valve penetration phenomenon of tunnel key smoke discharge |
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| CN202211106321.0A CN116575966A (en) | 2022-09-11 | 2022-09-11 | Method and device for inhibiting smoke valve penetration phenomenon of tunnel key smoke discharge |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117328922A (en) * | 2023-11-17 | 2024-01-02 | 中交第二公路勘察设计研究院有限公司 | Tunnel ventilation and smoke exhaust system and method for providing airflow with smoke guide included angle |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117328922A (en) * | 2023-11-17 | 2024-01-02 | 中交第二公路勘察设计研究院有限公司 | Tunnel ventilation and smoke exhaust system and method for providing airflow with smoke guide included angle |
| CN117328922B (en) * | 2023-11-17 | 2024-04-02 | 中交第二公路勘察设计研究院有限公司 | Tunnel ventilation and smoke exhaust system and method for providing airflow with smoke guide included angle |
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