JPH07122918B2 - Fire alarm equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fire alarm system suitable for a place having a plenum chamber (filling chamber) for air conditioning on the ceiling of a building, The fire detection operation was performed quickly and without delay, and even if the plenum chamber was divided into multiple compartments by partitions, a small number of fire detectors were used to detect the fire sharply. We propose a fire alarm system.

(Prior Art) In recent years, in a high-rise building or a building such as a so-called intelligent building, a large room in which the number of indoor columns is small and the floor area is wide is often provided.

In addition, in such a building, in order to effectively use a large floor area and to freely change the floor plan in the room, an intake port is provided in the ceiling, and the air in the room is sucked into the ceiling from the intake port. A so-called plenum chamber system is used in which the sucked exhaust gas is guided from an exhaust duct to an air conditioner through an opening of a charging chamber provided in the ceiling.

By the way, in such a building, the fire detector is provided on the ceiling surface of the room, as in a conventional building.

(Problems to be solved by the invention) However, in the plenum chamber method, smoke caused by a fire inside the room is sucked into the compartment above the ceiling through the intake port near the fire point and detected by the fire detector. It takes a considerable amount of time to start, and there is a problem that the detection of a fire is delayed.

It is also possible to detect a fire by providing a fire detector on the slab surface of each compartment divided by beams on the ceiling.

However, in this case, since a fire detector must be provided for each compartment that is divided by a partition for each compartment, there is a drawback that a large number of fire detectors are required.

(Means for Solving Problems) The present invention has a problem that a fire detector provided on a ceiling surface of a building having ventilation equipment of a plenum chamber method delays detection of a fire occurring in a room, and However, when it is installed in the ceiling, the problem of the above-mentioned fire alarm system that a partition must be equipped with a fire detector must be solved, and the fire detection can be performed sharply and adjacent to each other. The equipment location of the detectors was examined so that the fire detection action in the two compartments being operated can be sensitively performed by a single fire detector. Compartment
The ceiling ₂ divided into R ₁ and R ₂ is used as a part of the exhaust duct of the air conditioning equipment, and the partition 5 separating the adjacent compartments R ₁ and R ₂ is provided with a communication port 9. The fire alarm system is provided with a fire detector near the communication port 9, and the fire detector is used to monitor both compartments R ₁ and R ₂ .

(Operation) The smoke of the fire generated in the room is stored in each of the compartments in the ceiling 2
R _1, rising to R _2, will penetrate partially the compartment R _1, R _2, these constituting the inside duct 7 of the exhaust duct.

In this exhaust process, near the through-hole 9 provided in the partition 5 between the adjacent compartments R ₁ and R ₂ , smoke reaches an early stage and becomes a high concentration, so that fire detection in the vicinity of the through-hole 9 may occur. , Is extremely advantageous.

That is, the smoke generated in the room enters the compartment R ₂ near the fire point F at an early stage, and the compartment R ₁ far from the fire point F is mainly divided into the partition 5 from the compartment R ₂ on the near side. It seems that the smoke passing through the through hole 9 is supposed to enter.

Such a phenomenon shows substantially the same tendency when the air conditioning equipment is operating and when it is not operating.

(Example) Next, one Example of this invention is described.

In order to investigate the suitable equipment position of the fire detector installed in the ceiling for fire alarm in the plenum chamber system, FIG. 2 is a plan view and FIG. 1 is a view taken along the line AA of FIG. The following experiment was conducted in the room 1 and the ceiling 2 shown in the drawings.

The attic 2 is formed by the ceiling 3 of the room 1 and the slab 4, and is divided into left and right compartments R ₁ and R ₂ by a partition 5 for supporting the slab 4, for example.

The ceiling 3 is provided with a plurality of slit-shaped intake ports 6, and an exhaust fan 8 is provided at a discharge end portion 7c of a duct 7 which has openings 7a and 7b in the respective compartments R ₁ and R _2. The general exhaust system is a plenum chamber.

Then, the partition 5 is provided with a communication port 9 so that both compartments
R ₁ and R ₂ are ventilated from each other through this communication port 9.

For fire detection, the conventional fire detectors S ₁ and S ₂ installed on the ceiling 3 (corresponding to a normal room other than the plenum chamber method) are installed, and the fire detectors attached to the slab 4
P _3, P _4, and, in particular, in this experiment, and be performed by the fire detector P _1, P ₂ that equipment near the communication port 9, both of sensors, the smoke density, the light projecting portion A smoke-sensing type was used in which the amount of light received by the corresponding light-receiving unit was expressed by the extinction rate% / m / m.

The fire was generated by burning a predetermined amount of smoke fragments at a fire point F.

The smoke generated at the fire point F reaches the ceiling 3, enters the compartments R ₁ and R ₂ from the intake port 6, and passes from the compartment R ₂ near the fire point F to the communication port 9 of the partition 5. Flow into the section chamber R ₁ , enter the duct 7 through the openings 7a and 7b, and are exhausted to the outside of the room.

The experimental results are shown in FIG.

(1) Contrast with conventional ventilation equipment and plenum chamber method When there is no plenum chamber, fire detectors S ₁ and S ₂ installed on the ceiling 3 are used for detection.
Detected concentration 5.0,5.0 when the fire detectors P ₁ and P ₂ are installed near the communication port 9 of the plenum chamber type partition 5.
(The position far from the fire point F) and 4.6,5.5 (the position near the fire point F) are the values of S ₁ and S ₂ installed on the ceiling 3 6.5,2.5 (the fire point F)
77 to 200% (positions far from the fire point F) and 30 to 78% compared to 15.0, 7.0 (positions far from the fire point F)
(Close to the fire point F).

When installed on the ceiling 3, there is a problem that the detection of the fire detector S ₁ distant from the fire point F becomes slow during air conditioning operation, whereas the detection concentration when installed near the communication port 9 is Regardless of the stop and operation of the equipment and the distance from the fire point F, the detected concentration is high and stable.

(2) Detection position in plenum chamber method Detection concentration when fire detectors P ₃ and P ₄ are installed on slab 4.
For 0,0.7 (position far from the fire point F) and 4.0,6.0 (position near the fire point F), the above-mentioned values 5.0,5.0 and 4.6,5.5 provided near the communication port 9 are 225 ~ 714% (positions far from the fire point F) and 115-92% (positions close to the fire point F).

As described above, in the conventional case in which the fire detectors P ₃ and P ₄ are provided on the slab 4, the detected concentration at the position far from the fire point F is extremely low, and therefore, in each of the compartments R ₁ and R ₂ . Detection must be done.

In comparison with this, the detected concentration near the communication port 9 of the partition 5 of both compartments R ₁ and R ₂ shows a high detected concentration regardless of the distance from the fire point F, and further, Stop,
The detected concentration is stable in any operation.

From these facts, it was found that when performing fire detection near the communication port 9, either _{one of} the fire detectors P ₁ or P ₂ should be installed.

Further, as described above, the detected concentration detected near the communication port 9 is sufficiently higher than that detected by the slab 4, and is particularly high at the fire point F far from the detection position. It is a value.

As a specific example of the installation position of the fire detector P ₁ or P ₂ in the above embodiment, a. A fire detector is provided in the communication port 9.

b. Those provided on the side of the communication port 9.

c. The one provided on the upper surface of the ceiling 3 of the compartment R ₁ or R ₂ near the communication port 9.

Each of these can be used.

(Effect of the invention) As described above, the fire alarm system according to the present invention has the partition 5
The attic ₂ divided into a plurality of compartments R ₁ and R ₂ by
In a fire alarm system in a place used as a part of an exhaust duct of an air conditioner, a partition 5 that separates adjacent compartments R ₁ and R ₂ is provided with a communication port 9, and this communication port 9
A fire detector installed near the
It is configured to monitor R ₁ and R ₂ , and the smoke generated inside the room enters the compartment R ₂ near the fire point F early and enters the compartment R ₁ far from the fire point F. Means that the smoke mainly flows from the above-mentioned compartment R ₂ on the near side through the through-hole 9 of the partition 5, and when passing through this through-hole 9, the smoke detector near the through-hole 9 detects a high level of smoke. A concentration of smoke is detected.

Therefore, regardless of the position of the fire point F, a single fire detector installed near the communication port 9 of the partition 5 can always detect a high concentration at an early stage, and the accuracy of fire notification in the plenum chamber system can be improved. Is improved.

Moreover, since a plurality of compartments can be monitored by a single fire detector, it is possible to construct an inexpensive and highly reliable fire alarm system.

[Brief description of drawings]

1 shows an embodiment of the present invention, FIG. 1 is a view taken along the line AA in FIG. 2, FIG. 2 is a plan view of the plenum chamber type ceiling, and FIG. 3 is experimental data. Is. 1 ... Room, 2 ... Attic, 3 ... Ceiling, 4 ... Slab,
5 ... Partition, 6 ... Intake port, 7 ... Duct, 7a, 7b ...
… Aperture, 7c …… Discharge end, 8 …… Exhaust fan, 9 ……
Communication port, R ₁ , R ₂ …… Division room, P ₁ , P ₂ , P ₃ , P ₄ , S ₁ , S ₂ …… Fire detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidenori Miyamoto, 4-7-3 Kudan-minami, Chiyoda-ku, Tokyo No. 4 Minami Kogyo Kogyo Co., Ltd. (72) Koji Tanaka 4--7, 9th Dan, Chiyoda-ku, Tokyo No.3 Nomi Disaster Prevention Industry Co., Ltd.

Claims (4)

[Claims] 1. An attic that is divided into a plurality of compartments by a partition is used as a part of an exhaust duct of an air conditioner, and a partition that separates adjacent compartments is provided with a communication port. A fire alarm system characterized in that a fire detector is provided in the vicinity of the communication port, and the fire detector is configured to monitor both compartments. 2. The fire alarm system according to claim 1, wherein the fire detector is provided in the communication port. 3. The fire alarm system according to claim 1, wherein the fire detector is provided on a side of the communication port. 4. The fire alarm system according to claim 1, wherein the fire detector is provided on the upper surface of the compartment ceiling near the communication port.