JP5545760B2 - Fireproof design method and building - Google Patents

Description

  The present invention relates to a fireproof design method and a building.

  Conventionally, the fire resistance performance verification method of the Ministry of Construction Notification No. 1433 of 2000 was known as a fire resistance performance verification method (hereinafter referred to as “notification verification method”) (see Non-Patent Document 1). In this notification verification method, first, a target room (single room or multiple rooms assuming simultaneous combustion) is set, and the duration of a fire occurring indoors is calculated. After that, for the main structural parts facing the target room, the limit time that can maintain the fire resistance required for each main structural part (non-damage, heat insulation, flame resistance), that is, the possessed fire resistance time for each member Calculate. And if the possessed fireproof time of the main structural part is equal to or longer than the fire duration time, it is determined that the performance is satisfied. This verification is performed for all the main structural parts constituting the building.

Explanation of 2001 fire resistance verification method and calculation examples and explanations, Ministry of Land, Infrastructure, Transport and Tourism Housing Bureau Building Guidance Division

  By the way, in the notification verification method, since the knowledge about the combustion rate reduction is insufficient, the fire room temperature is calculated without considering the reduction of the combustion rate in order to give a safety evaluation.

  However, in practice, in a room with few openings, the amount of inflow of air (oxygen) necessary for combustion is small, and combustibles in the room do not necessarily burn completely. In such a case, in the notification verification method, the combustion rate becomes higher than the actual one, and the fire room temperature rise coefficient is calculated to be higher. Therefore, there is a problem that the fire resistance specification of the member becomes heavy and the cost becomes high.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fireproof design method and a building that can reduce the cost for fireproof processing while ensuring necessary fireproof performance. .

  The invention according to claim 1 is a fireproof design method for performing fireproof design of a target room, and it is assumed that the combustible material stored in the target room and the interior building material (hereinafter referred to as a stored combustible material) are completely combusted. The ratio of the actual calorific value to the calorific value of the case is used as the combustion rate, and the total effective heat value and effective heat rate of the stored combustibles are calculated using the combustion rate, and the total effective heat value and effective heat rate are calculated. Calculate the indoor fire duration and fire temperature rise coefficient, calculate the fire temperature rise coefficient near the member in the target room, and for the members constituting the target room, the fire temperature rise coefficient and the fire temperature rise near the member The indoor fire possession fireproof time is calculated using a coefficient, and the target room is designed such that the duration time of the indoor fire is equal to or less than the indoor fire possession fireproof time.

According to the first aspect of the present invention, the total effective heat generation amount and effective heat generation rate of the combustibles stored in the target room are calculated using the combustion rate, and the indoor fire is continued using the total effective heat generation amount and effective heat generation rate. By calculating the time and fire temperature rise coefficient, it is possible to calculate the indoor fire duration and fire temperature rise coefficient that suit the actual situation. In particular, the fire temperature increase coefficient can be reduced as compared with the prior art.
Therefore, even if the thickness of the fireproof coating and the size and strength of the structural member are reduced, appropriate fire resistance can be ensured, so that the cost for fireproof treatment can be reduced while ensuring the necessary fireproof performance.

  The invention according to claim 2 is characterized in that a reduced model of the target chamber is manufactured, a fire experiment is performed with the reduced model, and a burning rate of the reduced model is set as a burning rate of the target chamber.

  According to the invention of claim 2, the combustion rate of the reduced model is set as the combustion rate of the target chamber. Therefore, since it is not necessary to manufacture a full-scale model and perform a fire experiment, the cost for the fire experiment can be reduced.

  The invention according to claim 3 preliminarily performs a fire experiment on a plurality of chambers having different characteristics using a reduced model to obtain each combustion rate, and approximates the target chamber from among the plurality of chambers. A chamber having the characteristics to be selected is selected, and the combustion rate of the selected chamber is used.

  According to the invention of claim 3, the combustion rates of a plurality of chambers having different characteristics are obtained in advance, a chamber having characteristics approximating to the target chamber is selected from the plurality of chambers, and the chambers of the selected chambers are selected. Burning rate was used. Therefore, since the number of fire experiments can be greatly reduced, the cost for fire experiments can be greatly reduced.

  The invention described in claim 4 is characterized by comprising a chamber that is fireproofed based on the fireproof design method described above.

  According to the invention which concerns on Claim 4, since the thickness of a fireproof coating and the size and intensity | strength of the structural member of a building can be reduced, it is possible to reduce a construction cost or to ensure a large effective area in a building. It becomes.

  According to the present invention, the total effective heat generation amount and effective heat generation rate of the combustibles stored in the target room are calculated using the combustion rate, and the duration of the indoor fire and the fire are calculated using the total effective heat generation amount and effective heat generation rate. By calculating the temperature rise coefficient, it is possible to calculate the indoor fire duration and the fire temperature rise coefficient that match the actual situation. In particular, the fire temperature increase coefficient can be reduced as compared with the prior art. Therefore, even if the thickness of the fireproof coating and the size and strength of the structural member are reduced, appropriate fire resistance can be ensured, so that the cost for fireproof treatment can be reduced while ensuring the necessary fireproof performance.

It is a block diagram of the design system which performs the fireproof design method concerning one embodiment of the present invention. It is a flowchart which shows operation | movement of the design system which concerns on the said embodiment. It is a perspective view of the reduction model for creating the map used for the fireproof design method concerning the embodiment. It is the front view of a division model used for the experiment which creates the above-mentioned map, a transverse section, and a longitudinal section. It is a figure which shows the result of the experiment which produces the said map.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a design system 1 that executes a fireproof design method according to an embodiment of the present invention.
The design system 1 is for performing fireproof design based on basic building information, and includes an input device 2, a display device 3, an arithmetic processing device 4, and a storage device 5.
The input device 2 is a device that inputs information to the arithmetic processing device 4, and is configured by a keyboard, a mouse, and the like. The display device 3 is a device that displays information input from the input device 2 or information output from the arithmetic processing device 4, and is, for example, a monitor. The storage device 5 is a device that stores various information, and is, for example, a hard disk.
The arithmetic processing unit 4 reads out a program stored in the storage unit 5 and develops and executes it on an OS (Operating System) that performs operation control.

  Specifically, the arithmetic processing device 4 calculates | requires the continuation time of an indoor fire, a fire temperature rise coefficient, and a member vicinity fire temperature rise coefficient for every room of a building. And, for the members that make up each room, calculate the indoor fire holding fire resistance time using the fire temperature rise coefficient and the fire temperature rise coefficient near the member, so that the duration of the indoor fire is less than the indoor fire holding fire time, Design the target room.

FIG. 2 is a flowchart showing an operation for designing the target room.
In step S <b> 1, room conditions such as a fire prevention section, a floor area and a ceiling height of the target room, and a position and shape of the opening of the target room are input to the arithmetic processing unit 4 using the input device 2. This input value is stored in the RAM of the arithmetic processing unit 4.

In step S2, the arithmetic processing unit 4 calculates the effective opening factor f _op and the combustion type control factor χ.
Specifically, the effective opening factor f _op is calculated according to the equation (1) based on the shape of the opening of the target chamber.

Here, A _op is the area of each opening, and H _op is the dimension (opening length) from the upper end to the lower end of each opening.

However, when the opening is sufficiently small, the effective opening factor f _op may be calculated according to the following equation (2) based on the shape of the room, following the notification verification method.

Here, _Ar is the floor area in the target room, and _Hr is the average height from the floor to the ceiling of the target room.

  Similarly to the notification verification method, the combustion type control factor χ is calculated according to the following equation (3).

Here, A _fuel is the total surface area of the combustibles stored in the room.
The following can be said about the combustion type control factor χ.
That is, when a sufficient amount of air is supplied to the combustible material at the time of a fire, the effective opening factor f _op becomes large with respect to the combustible material surface area A _fuel , so that it becomes fuel-dominated combustion, and the combustion-type governing factor The value of χ increases.

On the other hand, when a sufficient amount of air is not supplied to the combustible material at the time of the fire, the effective opening factor f _op becomes small with respect to the combustible material surface area A _fuel , so that the combustion is controlled by ventilation and the combustion type control factor χ The value of becomes smaller.
Specifically, the case where χ exceeds 0.1 is defined as fuel-dominated combustion, the case where it is 0.081 or less is defined as ventilation-dominated combustion, and the case where χ exceeds 0.081 and is less than 0.1. Intermediate combustion is assumed.

  Next, in step S3, it is determined by the arithmetic processing unit 4 whether or not the structure is such that the combustion rate decreases in the event of a fire. Specifically, it is determined whether or not both the following expressions (4) and (5) are satisfied.

  If this determination is Yes, since the opening is sufficiently small and ventilation-dominated combustion, it is determined that there is a possibility that the combustion rate may decrease, and the process proceeds to step S4, and this determination is No Then, the process proceeds to step S10.

In step S4, the arithmetic processing unit 4, determine the nominal heat release rate _{q b} and the maximum heat release rate _{q bmax.}
The nominal heat release rate q _b, assuming storage combustibles target chamber is completely burned, a heat generation rate, which has been calculated based on the surface area and fired dominant factor storage combustibles chi. The heat generation rate is represented by the amount of heat generated per second. Specifically, according to the following equation (6), calculating the nominal heat release rate q _b.

The maximum heat generation rate q _bmax is an upper limit value of the heat generation rate determined based on the ventilation amount calculated from the opening factor (opening area and opening height). Specifically, the maximum heat generation rate q _bmax is calculated according to the following formula (7).

In step S5, the processing unit 4 calculates the combustion rate phi _b. That is, the storage device 5 stores a plurality of maps according to the room characteristics. The arithmetic processing unit 4 reads out a map corresponding to the characteristics of the target room from the plurality of maps, and obtains the combustion rate φ _b corresponding to the nominal heat generation rate q _b and the maximum heat generation rate q _bmax according to this map.

In step S6, the total effective calorific value _{Qr, eff} of the combustible material in the verification target room is calculated according to the equation (8).

Here, q _l is a calorific value per 1 m ² of the floor area of the target room, and q _f is a surface area 1 m ^{2 of the} building material for interior of the target room facing the walls, floor, and ceiling. The calorific value per 1 mm thickness. Also, A _f is the surface area of each part of each type of interior building materials of the target chamber, d _f is the thickness of the interior building materials of the target chamber.
Further, f _a is a heat penetration coefficient, and the subscript a means a room adjacent to the target room.

In step S7, the effective heat generation amount (effective heat generation rate) qb _{, eff} per second of the combustible material in the verification target chamber is obtained according to the equation (9).

In addition, in accordance with the equation (10), determine the duration _{t f} of indoor fire.

  In step S8, the fire temperature increase coefficient α is obtained according to equation (11).

Here, A _C, the walls of the target chamber, a floor, the surface area of each ceiling, I _h, the walls of the target chamber, the floor is the thermal inertia of each ceiling.

In step S9, the near-member fire temperature increase coefficient α ₁ is obtained for the uncoated steel frame and the wooden column or beam according to the equation (12).

  Here, z is the height of the member from the floor.

In step S10, the indoor fire duration t _f , the fire temperature increase coefficient α, and the near-member fire temperature increase coefficient α _l are calculated according to the conventional notification verification method.
In step S11, the indoor fire possession fireproof time t _fr is calculated for each member of the target room according to the conventional notification verification method.

In step S12, it is determined whether or not the indoor fire possession fireproof time t _{fr for} each member is equal to or longer than the indoor fire duration t _f . If this determination is Yes, the process ends. If the determination is No, the process returns to Step S1 to change the design of the floor area, ceiling height, opening, etc. of the fire room, or to change the fire resistance performance of the member. Change the amount of combustibles according to the interior material and application.
Thus, each step is repeated until it is determined that the indoor fire possession fireproof time t _fr for each member in the target room is equal to or longer than the indoor fire duration t _f .

Next, a procedure for creating a map indicating the relationship between the combustion rate φ _b and the nominal heat generation rate q _b / maximum heat generation rate q _bmax stored in the storage device 5 will be described.

  Build a full-scale model of the same shape and size as the target room, conduct a fire experiment, and create a map. However, if a full-scale model of the target room cannot be constructed, a reduced model in which the target room is reduced is constructed, and a fire experiment is performed using the reduced model.

FIG. 3 is a perspective view of a reduced model for a fire experiment.
The width of the target room is W _r , the depth is D _r , the room height is H _r , the floor area is _Ar , the reduced model width is W _rm , the depth is D _rm , the room height is H _rm , and the floor area is _Arm . Each dimension of the experimental model is set to S (0 <S <1) times as large as each dimension of the examination target room.

Here, because the actual target room has columnar irregularities on the wall surface, the entrance protrudes outward from the room, or the planar shape is a complex polygonal shape instead of a rectangle, the target room is reduced. It may be difficult to build a model. In this case, the average value of the width of the target room is W _A , the average value of the depth is D _A , and the width W _rm and the depth D _rm of the reduced model are set as shown in Expression (13) and Expression (14), respectively. .

Then, the following formula (15) is established for the floor area A _rm of the reduced model.

Further, when the opening factor of the target room is f _op and the effective opening factor of the reduced model is f _opm , the following equation (16) is established.

In the fire experiment, the fuel supply amount per unit time and the heat generation rate are measured for the above reduced model.
The amount of fuel supply per unit time is measured by the following method. When the fuel is gas or liquid, the flow rate of the fuel is measured with a flow meter, for example. When the fuel is solid, for example, a decrease in the weight of the fuel is measured using a load cell.
Further, the heat generation rate is measured using the oxygen consumption method, and the measured heat generation rate is set as an effective heat generation rate q _{m, eff} .

Further, the nominal heat generation rate q _m in this reduced model is obtained by multiplying the fuel supply amount per unit time by the unit weight heat generation amount during complete combustion.
Further, the maximum heat generation rate q _mmax in this reduced model is _obtained using the above-described equation (7).
Then, a value obtained by dividing the effective heat generation rate q _{m, eff} by the nominal heat generation rate q _m is defined as a combustion rate φ _b, and a map showing a correspondence relationship between q _m / q _mmax and the combustion rate φ _b is created.

Actually, in order to create a map showing the relationship between the nominal heat generation rate q _m / maximum heat generation rate q _mmax and the combustion rate φ _b , Experiments 1 to 3 were performed using a compartment model.
FIG. 4 is a front view, a transverse sectional view, and a longitudinal sectional view of the compartment model used in Experiments 1 to 3.
The compartment model is box-shaped and has an opening on one side. Inside this model are 12 K-type thermocouples. The compartment models in Experiments 2 and 3 were 1/2 the size of Experiment 1.

Walls, floors, and ceilings (hereinafter referred to as “peripheral walls”) were produced by attaching a ceramic fiber board to a base of an iron plate having a thickness of 3 mm or a calcium silicate plate having a thickness of 5 mm.
A gas burner using propane as fuel was installed in the center of the floor.
Table 1 shows the dimensions of the compartment model in Experiments 1 to 3.

In Experiments 1 and 2, fuels corresponding to 50%, 75%, and 100% of the maximum heat generation rate _qmmax were supplied. In Experiment 3, fuel corresponding to 60%, 90%, 110%, 120%, and 130% of the maximum heat generation rate _qmmax was supplied.
Table 2 shows the maximum heat generation rate q _mmax and the nominal heat generation rate q _m of Experiments 1 to 3.

The fuel was supplied by using a mass flow controller in Experiment 1 and in Experiments 2 and 3 by manually controlling the flow rate while measuring the flow rate with a mass flow meter.
Then, the temperature in the compartment is measured by a K-type thermocouple, and the heat generation rate is obtained by the oxygen consumption method. The measured value of the heat generation rate is defined as effective heat generation rate q _{m, eff} .
Since the aperture is small, the amount of smoke to be analyzed is small, and it is necessary to consider the influence of measurement errors (span drift) of the gas analyzer. Therefore, the smoke concentration measurement value was corrected using the fresh air concentration measured before and after the experiment and during the experiment.

The experimental results of Experiments 1 to 3 are shown in FIG.
FIG. 5 is an example of a graph visualizing a map showing the relationship between the combustion rate φ _b and the nominal heat generation rate q _m / maximum heat generation rate q _mmax .

The vertical axis of the graph of FIG. 5 is the combustion rate φ _b , and the horizontal axis is q _m / q _mmax .
When q _m / q _mmax is 0.6 or less, the combustion rate φ _b is 0.9 to 1.0. This is a state in which sufficient air for the supplied fuel to burn completely flows from the opening, and the supplied fuel is actually almost completely burned.
When q _m / q _mmax exceeds 0.6, the combustion rate φ _b decreases. That is, the air flowing in from the opening is gradually reduced, and the supplied fuel is not completely burned.

According to this experiment, in all experiments, a decrease in the combustion rate φ _b was observed as the nominal heating rate q _m increased. Therefore, it is understood that the total effective calorific value Q _r with the combustion rate phi _{b, eff} and the effective heating rate q _b, be calculated _eff is extremely effective. Further, it can be seen that the burning rate φ _b is almost the same value even if the scale of the model is different, and even if the reduced model is used, the same experimental result as that of the full-scale model can be obtained.

According to this embodiment, there are the following effects.
(1) the total effective calorific value _{Q r,} such as housing combustibles target chamber with the combustion _{rate, eff} and the effective heating rate _{q b, eff} calculated, and these total effective calorific value _{Q r, eff} and the effective heating rate q _{b, eff} by calculating the duration t _f and fire temperature increase coefficient alpha of indoor fires using, can calculate the duration of an indoor fire to the circumstances t _f and fire temperature increase coefficient alpha. In particular, the fire temperature increase coefficient α can be reduced.
Therefore, even if the thickness of the fireproof coating and the size and strength of the structural member are reduced, appropriate fire resistance can be ensured, so that the cost for fireproof treatment can be reduced while ensuring the necessary fireproof performance.

(2) a combustion rate phi _b of the miniature and the combustion rate phi _b of the target chamber. Therefore, since it is not necessary to manufacture a full-scale model and perform a fire experiment, the cost for the fire experiment can be reduced.

(3) advance, characteristics may be stored in the storage device 5 seeking combustion rate phi _b of different chambers, to select a chamber having a characteristic approximate to the target chamber from among the plurality of chambers, the selection The combustion rate φ _b of the chamber was read from the storage device 5 and used. Therefore, since the number of fire experiments can be greatly reduced, the cost for fire experiments can be greatly reduced.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Design system 2 ... Input device 3 ... Display apparatus 4 ... Arithmetic processing device 5 ... Memory | storage device

Claims (4)

A fireproof design method for performing fireproof design of a target room,
Using the combustion rate as the ratio of the actual calorific value to the calorific value when the combustible material stored in the target room is assumed to burn completely, the total effective heat value and effective heat rate of the stored combustible material are calculated using the combustion rate. ,
Calculate the indoor fire duration and fire temperature rise coefficient using the total effective heat value and effective heat generation rate,
Calculate the near-member fire temperature rise coefficient in the target room,
For the members constituting the target room, the indoor fire holding fire resistance time is calculated using the fire temperature increase coefficient and the vicinity fire temperature increase coefficient,
The fireproof design method, wherein the target room is designed so that a duration time of the indoor fire is equal to or less than a fireproof time possessed by the indoor fire.   The fireproof design method according to claim 1, wherein a reduced model of the target chamber is manufactured, a fire experiment is performed with the reduced model, and a combustion rate of the reduced model is set as a combustion rate of the target chamber. For a plurality of chambers with different characteristics in advance, a fire experiment is performed using a reduced model, and each combustion rate is obtained,
The fireproof design method according to claim 1 or 2, wherein a chamber having characteristics approximating to the target chamber is selected from the plurality of chambers, and a combustion rate of the selected chamber is used.   A building comprising a room fireproofed based on the fireproof design method according to claim 1.

Images