JP2005198703A - Disaster protection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disaster protection structure to resolve a contradiction of a smoke discharging capacity and a risk of the spread of a fire maintaining the protection of a smoke discharger (continuous smoke discharging) as a precondition. <P>SOLUTION: The disaster protection structure comprises a multilayered structure 4 which forms a life space and a smoke discharging network which is disposed in many layers in the multilayered structure 4. The smoke discharging network is formed by a smoke discharging duct 6, the smoke discharger 8 which is disposed in the smoke discharging duct 6 and a cooling structure 17 which refrigerates a flow of smoke flowing in the smoke discharging duct 6 and forms a dam of the heat in the duct. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a disaster prevention structure, and more particularly to a deep-type underground disaster prevention structure.

  Advances in the technology of super-high-rise construction methods and deep construction methods will realize the creation of large-scale vertical spatial structures, especially underground (underground) spaces. Known disaster prevention systems are considered ineffective against disasters that occur in large underground spaces. There are many types of alarms and a large number of alarm devices, and it is difficult for a person or a computer to quickly and accurately determine a disaster situation from various alarm contents of many alarm devices. The operation of the smoke detector at the combustible storage location does not necessarily indicate a fire, and the smoke detector signal of the smoke detector where there is no combustible or power supply is not likely to be based on malfunction, If a thermal sensor is working with the sensor, there is a high possibility of arson. It is difficult for a person or a computer to determine whether or not the arson is arson.

  Recognition of smoke behavior is important for proper evacuation and fire fighting activities. In a deep underground structure, it is difficult to predict the behavior, and it is difficult to predict the extent of damage (fire spread). If a measure is taken against the current situation estimated by a person or a computer, the effect is difficult to predict or counter-effective. A plurality of ducts are connected to one exhaust fan, and the plurality of ducts branch in a mesh shape. Furthermore, one room and another room are connected by doors, and the open / close state of the door and damper is changed. Has an unpredictable impact on the entire facility and is likely to have adverse effects. In deep subways and complex deep structures, it is difficult for evacuees to confirm their current location, and evacuation routes are not well recognized. The evacuees in the underground structure are more likely to get lost in the evacuation route filled with the smoke flow flowing upward. Confusion at the time of evacuation makes priority evacuation of vulnerable people difficult. Thus, known disaster prevention systems are powerless with respect to underground structures.

  The underground space is getting deeper and more complex. It is difficult to urgently escape from such underground space. When the actual evacuation speed at the time of a fire is slower than the assumed evacuation speed, it is difficult to prevent the evacuee from getting caught in the smoke because the installed smoke evacuation capability is not in time. When the actual evacuation time is longer than the assumed evacuation time, the generated smoke diffuses and flows out into the evacuation route. It is difficult or impossible to take retreat behavior in such a situation. If the diffusion space is maintained at room temperature in a situation where chemicals are diffusing, chemicals with a molecular weight or specific gravity greater than air will normally be discharged by a smoke evacuator located at the upper part. The smoke effect is thin.

There is a contradiction between smoke emission and fire spread. A fire damper (thermal fuse damper) is installed at the entrance of the smoke exhaust duct. When the temperature of the smoke exhaust duct exceeds the specified temperature, the fire damper is closed. The closing of the fire damper protects the smoke exhauster associated with the smoke exhaust duct from heat. Such suppression of smoke exhaustion is contrary to the purpose of providing a smoke exhaust duct. Good smoke evacuation promotes the introduction of fresh air, increases the spread of fire, creates a spark and increases the number of new fire sources. If the fire damper is activated, smoke must be exhausted by the smoke evacuator in the room where the fire damper is not activated. Such flue gas has the following problems.
(1) Since the smoke is not exhausted from the generation source, the smoke exhaust efficiency is reduced.
(2) Exhausting the source smoke through another room promotes the diffusion of the smoke and invites the smoke to adjacent rooms.
(3) If all the fire dampers are closed, the smoke exhausting ability will be significantly reduced, and fire fighting activities will be hindered. When the fire has progressed sufficiently and the fire spread area has increased, all the fire dampers may be in operation.

  In order to resolve such contradictory problems, it is important to continuously exhaust the smoke from the fire source or in the vicinity of the smoke exhauster. As a result, the temperature of the fire source rises and the exhaust temperature rises. In this way, the smoke evacuator and the fireproof damper operate inconsistently with each other. Failure of the smoke exhauster due to high heat must be avoided in terms of disaster prevention. A driver (eg, an electric motor) that drives a smoke evacuator has a portion (transistor, excitation coil) that fails due to high heat. Due to the high heat, the part of the smoke evacuator is deformed, the lubricant is denatured and the rotating shaft or bearing is seized, resulting in wiring failure such as loss of function due to overheating of the motor and wiring burnout.

  It is important to reconsider the importance of disaster prevention shelters, which are temporary evacuation facilities. A heat-insulating double-structured shelter is known from Patent Document 1 described later. A shelter having a cooling structure is known from Patent Document 2 described later. A shelter with a temporary evacuation structure for coping with hot air generation is known from Patent Document 3 listed later. A shelter in which a plurality of evacuation exits are arranged is known from Patent Document 4 described later.

  Disaster prevention system consists of shelter, smoke duct net arrangement, numerous thermometers / smoke detectors, measuring instruments, electrical drive sources that drive sprinklers, and many different measurement signals It is a collection of complicated equipment systems such as computers that centrally control the opening and closing of many smoke exhaust ducts and the opening and closing of many fire doors, and communication systems for evacuation guidance. In the event of a fire associated with an earthquake, it is expected that some or all of the control systems of such complex and intertwined devices will be disabled.

  It is difficult to predict the extent of damage. It is difficult for a computer to predict proper opening / closing control of dampers interposed at many positions in a smoke exhaust duct connected like a mesh. Computers installed in intelligently sophisticated and safe protected locations are useless if the communication line is interrupted.

  It is required to resolve the contradiction between smoke emission and fire spread. It is particularly important to ensure smoke emission.

Patent No. 3018402 JP-A-11-141173 JP 2000-34848 Japanese Patent No. 2926470

The subject of this invention is providing the disaster prevention structure which solves the contradiction of smoke exhaustion and fire spreadability.
Another object of the present invention is to provide a disaster prevention structure that solves the contradiction between smoke emission and fire spread on the premise of ensuring smoke emission (constant smoke emission).

  The disaster prevention structure by this invention is comprised from the multilayer structure (4) which forms a living space, and the flue gas network arrange | positioned in multilayer form in the multilayer structure (4). The flue gas network cools the flue gas flowing in the flue gas duct (6), the flue gas machine (8) interposed in the flue gas duct (6), and the flue gas duct (6). ) And a cooling structure that forms a thermal dam. [Multilayer structure (4) has a particularly high disaster prevention effect in that it is an underground and underground underground multilayer structure].

  Fires that occur in deeply built high-rise structures such as high-rise buildings and subway stations cause a great deal of damage to many people due to harmful chemical substances including heat and smoke. A high-rise structure that forms a chimney creates a smoke stream and extends the spread of fire to a higher layer. The smoke exhaust duct that is netted in the structure creates a high-speed high-temperature smoke stream for exhaust smoke, and promotes the spread of fire, but the smoke exhaust duct cannot be eliminated. In the present invention, the smoke flow flowing in the smoke exhaust duct is cooled, and the high-rise building in which the smoke exhaust duct is netted is converted into a refrigerator as a whole. Most of the heat is concentrated in the smoke exhaust duct by the smoke exhauster, its cooling efficiency is high, and its cooling effect is great. A temperature drop shows the best effect of preventing fire spread. Cooling is extremely effective in that the smoke evacuator itself can be protected. The flow of smoke that is cooled and flows into the duct cools the duct itself, protects the smoke exhauster, secures smoke exhaustion, and eliminates the contradiction between smoke exhaustion and fire spread. Smoke emission is primarily important, and it is necessary to protect the smoke evacuator. The smoke evacuator sends a high-temperature smoke stream downstream. In order to reduce the spread of fire, it is necessary to cool the smoke stream, and in order to protect the smoke evacuator, the cooling of the smoke stream is secondarily important.

  The cooling structure is formed of a damper (17) disposed in the smoke exhaust duct (6) on the upstream side of the smoke exhauster (8). The damper (17) forms a throttle (21) that restricts the upstream smoke flow when the temperature of the smoke flow rises above a specified temperature. The aperture is rapidly cooled by adiabatic expansion, has the effect of confining heat to the fire source side, and suppresses the increase in fire spread. The substance ignites above a certain level. Such confinement causes the fire source material to burn out more quickly and the thermal power to decay due to lack of oxygen, but the temperature of the smoke stream downstream of the throttling is rapidly cooled and its flame spread is reduced, and the smoke is expelled quickly. Is done. In this way, the damper forms a thermal dam.

  The cooling structure is formed by a water source (22) arranged in the multilayer structure (4) and a water supply pipe (23) for introducing water from the water source (22) into the smoke exhaust duct (6). The water supply pipe (22) is formed of a plurality of branch pipes (24). The plurality of branch pipes (24) form an opening row having a plurality of openings (29) that respectively open into the smoke exhaust duct (6). The opening row has a wide opening area on the upstream side and a narrow opening area on the downstream side. Such distribution cools the smoke stream on the higher temperature side more rapidly and effectively suppresses the spread of fire to the vicinity.

  The opening row includes a more upstream opening and a downstream opening. The cross-sectional area of the upstream opening of the opening row is wider than the cross-sectional area of the downstream opening of the opening row. Such distribution cools the smoke stream on the higher temperature side more rapidly and effectively suppresses the spread of fire to the vicinity.

  The plurality of branch pipes (23) form an opening row having a plurality of openings (29) that respectively open into the smoke exhaust duct (6). The plurality of openings (29) are arranged in a direction substantially perpendicular to the flow direction of the smoke flow. In the opening row, the opening area is widely distributed on the center side of the smoke exhaust duct (6), and the opening area is narrowly distributed on the wall surface side of the smoke exhaust duct (6). A smoke stream with a higher flow rate is cooled more quickly.

  The plurality of branch pipes (23) form an opening row having a plurality of openings (29) that respectively open into the smoke exhaust duct (6). The opening (29) includes a first type opening and a second type opening. Both the first type opening and the second type opening extend from the wall surface toward the center. The first type opening extends longer from the wall surface toward the center than the second type opening, and the lateral width of the first type opening is narrower than the lateral width of the second type opening. The diffusibility of the flow near the center where the flow velocity is faster is promoted, and the cooling efficiency is high.

  The cross-sectional area of the opening (29) through which the water supply pipe opens in the smoke exhaust duct (6) is variable. The cross-sectional area varies more widely when the smoke flow temperature is higher. The adiabatic expansion effect is increased. Changing the opening position in response to the temperature change enhances the cooling effect.

  The cooling structure forms a heat exchanger which is arranged in the smoke exhaust duct (6) upstream from the smoke exhauster (8). The heat exchanger has a heat absorber (36) thermally bonded to the smoke flow, and transfers heat of the heat absorber (36) to the outside of the smoke exhaust duct (6) to radiate heat outside the smoke exhaust duct (6). It is formed from the radiator (38) which carries out. Heat exchange is activated and the effect of preventing the spread of fire is further promoted.

  The disaster prevention structure according to the present invention overcomes the contradiction between smoke emission and fire spreadability, and can effectively prevent the spread of fire by converting the structure, particularly a deep structure, into a refrigerator as a whole. The flow of smoke that is cooled and flows into the duct cools the duct itself, protects the smoke exhauster, secures smoke exhaustion, and eliminates the contradiction between smoke exhaustion and fire spread. Smoke emission is primarily important, and it is necessary to protect the smoke evacuator. The smoke evacuator sends a high-temperature smoke stream downstream. In order to reduce the spread of fire, it is necessary to cool the smoke stream, and in order to protect the smoke evacuator, the cooling of the smoke stream is secondarily important.

  The realization state of the disaster prevention structure according to the present invention will be described in detail corresponding to the drawings. As shown in FIG. 1, the deep underground structure 1 is supported on a rock mass or a rock mass equivalent structure 2. The deep underground structure 1 is formed of a ground life layer 3, an underground life layer 4, and a shelter arrangement layer 5, and is built on the bedrock 2. It is particularly preferable that the shelter 10 constructed as a large mass object is disposed on the lower side of the underground living layer 4 while being joined to the lowest layer region of the deep underground structure 1.

  The underground living layer 4 is multi-layered. A large number of horizontal smoke exhaust duct lines 6 are arranged vertically and horizontally or in a net shape in a large number of layers of the underground living layer 4. The horizontal smoke exhaust duct line 6 of each layer is connected to a plurality of vertical common smoke exhaust duct lines 7. The horizontal smoke exhaust duct line 6 is equipped with a smoke exhauster 8 interposed. Smoke and harmful gas (hereinafter referred to as smoke flow) in the horizontal smoke exhaust duct line 6 are sent to the vertical common smoke exhaust duct line 7 by the smoke exhauster 8. The uppermost end of the vertical common smoke exhaust duct line 7 is connected to a large smoke exhauster 11 installed on the ground. Each of the smoke evacuator 8 and the large smoke evacuator 11 has a built-in blower blade.

  The smoke evacuator 8 and the large smoke evacuator 11 discharge the smoke flow gas generated globally or locally in the underground life layer 4 to the atmosphere. It is desirable to attach to the large smoke evacuator 11 a cyclone that removes smoke particles and a smoke gas detoxification device (not shown) that detoxifies the combustion of harmful gases. The situation detection sensor unit 12 is arranged at a plurality of appropriate locations. The situation detection sensor unit 12 is installed in the smoke exhauster 8, in the vicinity of the smoke exhauster 8, or in a ceiling portion of each level. The situation detection sensor unit 12 forms a temperature sensor (not shown), a smoke detection sensor (not shown), a smoke flow gas flow rate sensor (not shown), and other sensors (example: flow rate sensor). More preferably, the situation detection sensor unit 12 is interposed in the vertical common smoke exhaust duct line 7 in correspondence with the position of each level.

  The shelter 10 is formed with an escape entrance hatch 13 and an elevator unit passing hatch 14 through which the elevator unit of the elevator can enter and exit. The escape entrance hatch 13 is preferably arranged at a plurality of locations on the ceiling surface, cylindrical side surface, vertical side surface, and tunnel facing surface toward the escape tunnel of the shelter 10. A computer 15 for disaster prevention system is stored in the shelter 10. The detection signals output by the situation detection sensor units 12 are transmitted to the disaster prevention system computer 15 by wire 16 or wirelessly. The disaster prevention system computer 15 analyzes the detection signal and performs group control of a large number of smoke evacuators 8.

The method for lowering the temperature of the smoke flow according to the present invention realizes the contradiction between the smoke exhaustibility and the fire spreadability described above in the following three ways.
(1) Flow velocity method (2) Vaporization method (3) Heat exchange method Hereinafter, each method will be described in detail.

Flow velocity method:
As shown in FIG. 2, an open / close damper 17 is rotatably disposed in the smoke flow path 16 in the horizontal smoke exhaust duct line 6. The open / close damper 17 is supported by a pivot 18 at the center of rotation. The pivot 18 is supported on the opposite side wall of the horizontal smoke exhaust duct line 6. The pivot 18 is rotated to the operating position shown in the figure by a command from the disaster prevention computer 15. The opening / closing damper 17 is prevented from further rotation by the stopper 19. The opening / closing damper 17 is provided with a smoke flow passage 21 in a central region. The open / close damper 17 is disposed on the upstream side of the smoke evacuator 8. The position Pu indicates the upstream side that coincides with the fire source existence side. The position Pd indicates the downstream side that coincides with the smoke emission side. When the upstream smoke flow temperature detected by the situation detection sensor unit 12 becomes higher than the specified temperature, the disaster prevention system computer 15 transmits a signal for operating the open / close damper 17 to the operating position. The output shaft of an operating motor (not shown) is coupled to the pivot 18. The operating position is defined as a position where the smoke flow cross-sectional area of the open / close damper 17 is smaller than the smoke flow cross-sectional area before operation.

The energy of the smoke flow is approximately expressed by the following equation.
Total energy per unit mass = U + PV + gZ + v · v / 2
U: Internal energy P: Pressure V: Volume g: Gravity acceleration Z: Height v: Speed The sum of the internal energy U and the pressure energy PV is a custom called enthalpy. This enthalpy can be regarded as a function of temperature T, and in an ideal gas,
h = (Cv + R) T
Cv: Constant volume specific heat R: Expressed by gas constant. The above-described formula is represented by the following formula.
Total energy per unit mass = h (T) + gZ + v · v / 2

The total energy of the fluid is preserved. Increasing the potential energy gZ or increasing the kinetic energy (increasing the flow velocity v) decreases the enthalpy h. It is difficult to increase Z on the building structure. The flow rate of the fluid passing through the horizontal smoke exhaust duct line 6 is represented by ρSv (ρ; density, S: flow path cross-sectional area). A decrease in the flow passage cross-sectional area S in a range that does not significantly affect the ability of the smoke evacuator 8 preserves the exhaust flow rate. Therefore, the flow velocity v is increased, and the temperature T is lowered by energy conservation. The relationship between the temperature Tu at the upstream position Pu and the temperature Td at the downstream position Pd is expressed by the following equation.
Td <Tu
Such a temperature drop protects the smoke exhauster 8 located on the downstream side, does not require activation of a damper that stops the upstream flow, can continue the smoke exhaust, Conflicts can be resolved. The damper forms a thermal dam.

  The driving force for rotating the open / close damper 17 is replaced with the above-described motor, and a bimetal that is deformed by raising and lowering the temperature is used. The smoke flow passage 21 can be formed of a porous plate.

Vaporization method:
As shown in FIG. 3, the underground living layer 4 is equipped with a water source 22 that supplies fire-extinguishing water to the fire-extinguishing sprinkler. The distribution water supply pipe 23 is connected to the water source 22. The distribution water supply pipe 23 forms a number of branch pipe branches 24. Each end of the branch pipe branch 24 is formed as an opening 25 that opens in a flow path in the duct. A water supply valve 26 is interposed in the common pipe portion of the distribution water supply pipe 23. The opening / closing force of the water supply valve 26 can be obtained from the rotational energy of a windmill (not shown) that converts the velocity energy of the smoke flow. Such conversion makes it possible to use a part of the energy of the smoke evacuator 8 as the opening / closing force of the water supply valve 26. Such a windmill is installed in the far flow path 16. The water source 22 is equipped on a plurality of middle floors as a large number of water tanks for storing domestic water such as drinking water and non-drinking water.

  A large amount of fire-fighting water or water from the water source 22 released from the sprinkler that starts operation in the event of a fire is sprayed into the horizontal smoke exhaust duct line 6 from a number of openings 25 via distribution water supply pipes 23. The Such water evaporates in response to the heat of the smoke flow in the horizontal smoke exhaust duct line 6 and the temperature of the smoke flow drops rapidly due to the loss of heat of vaporization. The net-formed horizontal smoke exhaust duct line 6 and the vertical common smoke exhaust duct line 7 extend in the vertical and horizontal directions, and the smoke flow therein transports heat extensively. The temperature of the smoke stream drops rapidly, and heat at a temperature above the ignition point and the hot stream that causes the smoke exhauster to fail are not transported extensively. The exhaust of the smoke stream facilitates the introduction of fresh air into the room containing the fire source, and the temperature around the fire source temporarily rises, but the hot gas around the fire source is in the horizontal flue duct line 6 And is quickly cooled in the horizontal smoke exhaust duct line 6. In this way, smoke emission is promoted, fire spread is suppressed, and the smoke exhauster is protected.

FIG. 4 shows a realization that improves the cooling efficiency of the vaporization method. In FIG. 4 represented by a plane cross section, the duct bottom surface 27 appears. The upstream point and the downstream point of the smoke stream 28 sucked by the smoke exhauster (shown) are represented by Pu and Pd. A large number of jet outlets 29 from which water jets from the duct bottom surface 27 toward the duct upper surface (ceiling surface) are arranged side by side at appropriate intervals from the upstream side to the downstream side. The jet stream is jetted in a direction generally orthogonal to the smoke stream. The upstream outlet 29 corresponds to a wider opening area, and the downstream outlet 29 corresponds to a narrower opening area. Generally, the jet outlet 29 has a wider opening area distribution on the more upstream side, and the jet outlet 29 has a narrower opening area distribution on the further downstream side. When all the spouts 29 are formed in the same opening area, the distribution density of the spouts 29 is higher on the upstream side, and the distribution density of the spouts 29 is lower on the further downstream side. FIG. 5 shows the opening area per unit length, and the horizontal axis shows the flow direction position coordinate x of the horizontal smoke exhaust duct line 6 or the vertical common smoke exhaust duct line 7 from the upstream side to the downstream side. The axis indicates the area S per unit length.
S = S (x)
In the example shown,
dS / dx <0, in particular dS / dx = constant <0
In this way, the temperature of the smoke stream, which is higher on the upstream side, drops more rapidly, and the cooling efficiency with a certain total amount of water is designed to be higher.

FIG. 6 shows another realization that improves the cooling efficiency of the vaporization method. In FIG. 6 represented by a plane cross section, a duct bottom surface 27 appears. The upstream point and the downstream point of the smoke stream 28 sucked by the smoke exhauster (shown) are represented by Pu and Pd. A number of jet outlets 29 through which water jets from the duct bottom surface 27 toward the duct top surface (ceiling surface) are arranged side by side in a direction orthogonal to the smoke flow direction. The jet stream is jetted in a direction generally orthogonal to the smoke stream. The jet outlet 29 closer to the center corresponds to a wider opening area, and the jet outlet 29 farther from the center (closer to the duct wall) corresponds to a smaller opening area. Generally, the jet outlet 29 closer to the center has a wider opening area distribution, and 29 farther from the center has a narrower opening area distribution. When all the spouts 29 are formed in the same opening area, the distribution density of the spouts 29 is high on the side closer to the center (center, center line), and the distribution of the spouts 29 on the side farther from the center. The density is low. FIG. 7 shows the opening area per unit length, and the horizontal axis shows the flow direction orthogonal position coordinate y of the horizontal smoke exhaust duct line 6 or the vertical common smoke exhaust duct line 7 in the direction orthogonal to the smoke flow. The vertical axis indicates the area S per unit length.
S = S (y), in particular, (S−a) ² + (y−b) ² = constant. Such an area distribution is represented by a circle. On the other hand, the area per unit length is narrow near the side wall and near the other side wall, and the area per unit length is wide on the center line side.
dS / dy> 0, y <b
dS / dy <0, y> b
Functional circles can be replaced by ellipses, parabolas, other curves, or straight lines.

  When the smoke evacuator operates effectively and the high-temperature smoke stream is sucked at a high speed, the smoke stream becomes turbulent near the wall surface and its residence time is long. Designing a large jet outlet area in a wall area with a long residence time (low flow speed) and a narrow jet nozzle area in a wall area having a high flow speed has a high cooling efficiency with a constant amount of jet water. This mode of realization is the same as the mode of realization described above in that the contradiction between smoke emission and fire spreadability is resolved.

FIG. 8 shows still another realization that improves the cooling efficiency of the vaporization method. A duct side surface 31 appears in FIG. The upstream point and the downstream point of the smoke stream 28 sucked by the smoke exhauster (shown) are represented by Pu and Pd. A large number of jet outlets 29 through which water jets from the duct ceiling surface 32 (or the bottom surface) toward the duct bottom surface 27 are arranged side by side at appropriate intervals in the smoke flow direction. The jet stream is jetted in a direction generally orthogonal to the smoke stream. FIG. 8 shows three jet outlets 29-1, 2, 3 having different jet nozzle cross-sectional areas. The cross-sectional area of the spout 29-1 is wider than the cross-sectional area of the spout 29-2, and the cross-sectional area of the spout 29-2 is wider than the cross-sectional area of the spout 29-2. The height position of the lower end of the jet outlet 29-1 having a wider cross-sectional area is higher than the center line L (further far from the center line L). The height position of the lower end of the ejection port 29-3 having the smallest cross-sectional area is closest to the center line L. The height position of the lower end of the outlet 29-3 having the smallest cross-sectional area does not exceed the center line L. FIG. 9 shows the height position of the ejection port 29. The horizontal axis indicates the jet nozzle area S, and the vertical axis indicates the height position H.
H = H (S), especially H = kS + a, H> 0 (H = 0 at the center line position)
dH / dS> 0

  The larger amount of jet water jetted from the jet outlet 29-1 having a larger cross-sectional area diffuses more toward the center line L, and the smaller quantity jetted from the jet port 29-3 having a smaller cross-sectional area. More water is injected into the center line L. Such adjustment of the cross-sectional area and the height position makes the amount of water injected in the entire area in the horizontal smoke exhaust duct line 6 uniform, and the cooling efficiency is high with a constant amount of ejected water. This mode of realization is the same as the mode of realization described above in that the contradiction between smoke emission and fire spreadability is resolved. Since the diffusion rate in the flow direction is higher than the diffusion rate in the direction orthogonal to the flow direction, the interval in the flow direction of the jet outlet is preferably designed to be larger than the interval in the orthogonal direction of the jet port. The spout 29-3 is suitable for the arrangement in the orthogonal direction, and the spout 29-1 is suitable for the arrangement in the flow direction.

  FIG. 10 shows still another realization that improves the cooling efficiency of the vaporization method. In this realization, the arrangement of a large number of jets is not considered, and the cross-sectional area of one jet is shown. In FIG. 8, the duct bottom surface 27 (or the duct side surface 31) appears. The upstream point and the downstream point of the smoke stream 28 sucked by the smoke exhauster (shown) are represented by Pu and Pd. The spout 29 is open at the duct bottom surface 27. The cross-sectional area of the spout 29 can be changed by the open / close door 33. The jet water flow is jetted in a direction substantially orthogonal to the smoke flow. The open / close door 33 is formed of a stretchable material that deforms and particularly expands and contracts in response to a temperature change such as bimetal. It expands expansively or expansively at high temperatures and contracts contractively at low temperatures. The outlet 29 having the maximum cross-sectional area is represented by a dotted line. The minimum cross-sectional area of the jet outlet 29 is zero. The cross-sectional area of the two-dot chain line indicates the opening area that is not shielded by the open / close door 33.

  FIG. 11 shows still another realization that improves the cooling efficiency of the vaporization method. The duct side surface 31 appears in FIG. 11 represented by the front cross section. The upstream point and the downstream point of the smoke stream 28 sucked by the smoke exhauster (shown) are represented by Pu and Pd. Water is ejected from the duct side surface 31 toward the opposite side surface. The jet stream is jetted in a direction generally orthogonal to the smoke stream. The lower end of the spout 29 extends from the ceiling surface 32 to near the center line L. The cross-sectional area of the spout 29 can be changed by the open / close door 34. The open / close door 34 is given a lifting force by a stretchable material 35 that deforms and expands and contracts in response to a temperature change such as bimetal. The stretchable material expands or expands at a high temperature and contracts at a low temperature. The lower end of the open / close door 34 does not exceed the center line L. The open / close door 34 rises (moves) toward the ceiling surface 32 by the stretchable material that expands due to the high temperature of the smoke flow 28, and increases the effective sectional area of the jet outlet 29. The cross-sectional area of the jet outlet 29 at a low temperature is zero. In this realization state, the height of the effective opening position of the jet outlet 29 opening in the smoke flow path is variable.

Heat exchange method:
FIG. 12 shows an implementation of the heat exchange method. A number of plate-like heat absorbers 36 of the heat exchanger are interposed at appropriate positions of the horizontal smoke exhaust duct line 6, particularly at the upstream side of the smoke exhauster (not shown). The heat of the smoke stream 28 is transferred to the heat absorber 36 when the smoke stream passes through the surface of the heat absorber 36 at high speed. The heat transmitted to the heat absorber 36 is transmitted through the heat conducting duct 37 and is released from a heat radiator 38 such as a fin. The heat exchanger is formed as a collection of heat absorbing plates.

A heat transfer corresponding to the heat transfer coefficient α (w / m ² / K) occurs between the solid surface and the fluid. Although the heat transfer coefficient varies depending on the substance and conditions, when the flow in the pipe is an air flow, α is 50 (w / m ² / K) (6 (w / m ² / K in free flow). )). Due to the heat absorption of the heat absorbing plate, the smoke flow 28 loses the following heat quantity ΔQ.
ΔQloss (J) = αSw (Tg−Tw) Δx / v
Tg; smoke flow temperature Tw: endothermic plate temperature Sw: total area of the endothermic plate v: smoke flow velocity Δx: length in the flow direction The length in the flow direction of the differential heat absorption plate is represented by L, and the heat exchanger 36 absorbs heat. The heat loss amount Q of the smoke flow 28 is expressed by the following equation.
Qloss (J) = (1 / v) · ∫ ₀ ^L αSw (Tg (x) −Tw (x)) dx
By actively cooling the radiator 37, the heat absorption amount Q can be increased by decreasing Tw and increasing (Tg (x) −Tw (x)).

  It is expected that it is impossible to control the opening and closing of the damper by computer instructions. Control that opens or closes when the temperature rises, and opens or closes when the temperature drops due to a material that deforms due to heat (example: expansion-deformed metal multilayer plate, shape memory alloy) enhances the protection of the smoke evacuator and spreads fire It is effective in reducing In order to start a mechanical structure such as opening / closing of a damper by thermal fluctuation, in addition to the above-described heat-deformable substance, a mechanical part in which a part that melts by heat is incorporated is effectively used. It is effective for the seal portion to melt and flow a smoke stream.

FIG. 1 is a cross-sectional view showing a realization of a disaster prevention structure according to the present invention. FIG. 2 is a cross-sectional view showing a realization state of the cooling structure (thermal dam). FIG. 3 is a cross-sectional view showing another embodiment of the cooling structure. FIG. 4 is a cross-sectional view showing a further embodiment of the cooling structure. FIG. 5 is a cross-sectional view showing the opening area portion distribution. FIG. 6 is a cross-sectional view showing a further embodiment of the cooling structure. FIG. 7 is a cross-sectional view showing another opening area portion distribution. FIG. 8 is a cross-sectional view showing a further embodiment of the cooling structure. FIG. 9 is a cross-sectional view showing still another opening area portion distribution. FIG. 10 is a cross-sectional view showing another embodiment of the cooling structure. FIG. 11 is a cross-sectional view showing a further embodiment of the cooling structure. FIG. 12 is a cross-sectional view showing a further embodiment of the cooling structure.

Explanation of symbols

4 ... multilayer structure 6 ... smoke exhaust duct 8 ... smoke exhauster 17 ... damper 21 ... throttle 22 ... water source 23 ... water supply pipe 24 ... branch pipe 29 ... opening 36 ... heat absorber 38 ... heat radiator

Claims (13)

A multilayer structure that forms a living space;
Comprising a flue gas network arranged in multiple layers in the multilayer structure,
The flue gas network is
A flue duct,
A smoke exhauster interposed in the smoke exhaust duct;
A disaster prevention structure comprising: a cooling structure that cools a flow of smoke flowing in the smoke exhaust duct and forms a thermal dam in the smoke exhaust duct. The whole or part of the multilayer structure is in the ground. The smoke evacuator
A first smoke evacuator disposed upstream of the smoke stream;
A second smoke evacuator disposed downstream of the first smoke evacuator,
The disaster prevention structure according to claim 1, wherein the thermal dam is disposed on the downstream side of the first smoke exhauster and is disposed on the upstream side of the second smoke exhauster. The disaster prevention structure according to claim 1, wherein the mechanical start-up for cooling the cooling structure is performed by a heat fluctuation-resistant substance. The cooling structure is
A damper disposed in the smoke exhaust duct upstream from the smoke exhauster,
The disaster prevention structure according to claim 1, wherein the damper forms a throttle that restricts the upstream side of the smoke flow when the temperature of the smoke flow rises to a specified temperature or higher. The cooling structure is
A water source arranged in the multilayer structure;
The disaster prevention structure according to claim 1, further comprising a water supply pipe that introduces water from the water source into the smoke exhaust duct. The water supply pipe includes a plurality of branch pipes,
The plurality of branch pipes form an opening row having a plurality of openings that respectively open into the smoke exhaust duct, and the opening row has a wide distribution of opening areas on the upstream side, and further on the downstream side. The disaster prevention structure according to claim 6, wherein the opening area is narrowly distributed. The opening row includes a more upstream opening and a downstream opening;
The cross-sectional area of the said upstream opening is wider than the cross-sectional area of the downstream opening of the said opening row | line | column. The water supply pipe includes a plurality of branch pipes,
The plurality of branch pipes form an opening row having a plurality of openings that respectively open into the smoke exhaust duct, and the plurality of openings are arranged in a direction substantially perpendicular to the flow direction of the smoke flow,
The disaster prevention structure according to claim 6, wherein the opening row has an opening area widely distributed on the center side of the smoke exhaust duct and a narrow opening area on the wall surface side of the smoke exhaust duct. The water supply pipe includes a plurality of branch pipes,
The plurality of branch pipes form an opening row having a plurality of openings that respectively open into the smoke exhaust duct,
The opening includes a first type opening and a second type opening,
Both the first type opening and the second type opening extend from the wall surface toward the center,
The first type opening extends longer from the wall surface toward the center than the second type opening, and the lateral width of the first type opening is narrower than the lateral width of the second type opening. Construction. The cross-sectional area of the opening which the said water supply pipe opens in the said smoke exhaust duct is variable, and when the said smoke flow temperature is higher, the said cross-sectional area changes more widely. The disaster prevention structure according to claim 11, wherein the position of the opening changes corresponding to a change in temperature. The cooling structure is
A heat exchanger disposed in the smoke exhaust duct upstream from the smoke exhauster,
The heat exchanger is
An endothermic body thermally bonded to the smoke stream;
The disaster prevention structure according to claim 1, further comprising a radiator that transmits heat of the heat absorber to the outside of the smoke exhaust duct and dissipates the heat outside the smoke exhaust duct.

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