JPH07122919B2 - 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 (charge chamber) for air conditioning in the ceiling of a building. We propose a fire alarm system that is devised so that the detected concentration is high enough for fire alarm.

(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 such a building, as illustrated in FIG. 6, the ceiling space 1 is formed as a charging chamber, the ceiling 2 is provided with an intake port 3 and an air outlet 4, and conditioned air is supplied from the air outlet 4. The air is supplied to the room 5, and the air in the room 5 is sucked from the intake port 3 to the ceiling space 1 which is a replenishment chamber, and the exhaust duct opening (not shown) arranged in the ceiling space 1 is shown. It is a structure in which it is discharged to the outside by an exhaust fan of the air conditioning equipment via the.

In the case of such a plenum chamber system, when a fire occurs at the fire point F, smoke is diluted and diffused by the air blown out from the air outlet 4, and as a result, the fire detector installed on the lower surface of the ceiling 2 The smoke detection density detected by S is about 4.5% / m when expressed by the extinction ratio, which is about 20% / m when the air conditioning equipment is stopped as shown in Fig. 7.
It decreases to 1/4.

Then, as shown in FIGS. 6 and 7, the air outlet 4
Is formed by an elongated slit line, the air blown from the slit line becomes an air curtain, and the smoke at the fire point F tends to be blocked from reaching below the fire detector S. The detected concentration is low.

Generally, it is standard to install one fire detector S per 150 m ^{2 of} room area.

However, in the case of the plenum chamber method, the detected concentration is lowered as described above, so the notification may be delayed with one standard per 150 m ² above, so that the notification should be made without error. Is the warning area per
It must be smaller than the above 150m ² .

(Problems to be Solved by the Invention) In the case of the plenum chamber method, as described above, the warning area becomes smaller than in the case of the normal air conditioning method, and a large number of fire detectors must be installed.

Since a sprinkler is also installed on the ceiling surface, it is not preferable to install many fire detectors in addition to it.

For this reason, it is possible to install a fire detector in the ceiling, but when the air conditioning equipment is stopped, it is difficult to enter smoke from the intake port, which is a narrow slit, and the fire alarm is delayed, which is not practical.

(Means for Solving Problems) The present invention relates to a plenum chamber-type ventilation system that solves the above-mentioned conventional problems and provides a fire notification without delay, and a fire designed to monitor a large area. This is to propose a notification facility, in which a ceiling 6 and an intake port 7 communicating with the ceiling 8 are provided, and the air in the room 9 is guided from the intake 7 to the ceiling 8 and the air In a fire alarm system provided in a building exhausted by an exhaust duct facing the ceiling 8 above, an illumination lamp fitting 10 provided in the ceiling 6 is provided with a recess P that is recessed above the ceiling 6. , This recess P
In the fire alarm system, a communication port 13 that connects the room 9 and the ceiling 8 is provided, and a fire detector S is provided above the communication port 13.

(Operation) The smoke of the fire generated in the room 9 flows along the lower surface of the ceiling 6, and a part of the smoke gathers in the recess P that is recessed above the ceiling 6.

Since the recessed portion P is provided with the communication port 13 that communicates with the attic 8, the collected smoke is constantly discharged upward from the communication port 13 and is installed near the communication port 13 above the fire detector. S will sense a high detected concentration of smoke.

If the recess P is simply formed, the initial low concentration of smoke accumulates, and the high temperature causes the recess P to become a kind of hot zone. Due to the existence of the zone, it is impossible to enter the recess P, and even if a fire detector is provided in the recess P,
Not enough information is given.

However, in the present invention, since the smoke collected in the recessed portion P is constantly discharged to the upper ceiling 8 by the communication port 13, the hot zone does not occur, and the high-density smoke that has passed through the communication port 13 is generated. Touches the fire detector S, and the fire alarm is given without delay.

(Example) Next, an example of the present invention will be described.

Fig. 1 is a perspective view of equipment for performing fire alarms in the plenum chamber system without delay, Fig. 2 is a plan view seen from the ceiling, and Fig. 3 is a bottom view seen from the inside. FIG. 4 shows a view taken along the line AA of FIG.

A slit-shaped intake port 7 is provided in the ceiling 6, and a ceiling back 8 is divided into compartments by partitions such as beams supporting a slab (not shown), and exhaust fans are exhausted from the respective compartments via exhaust ducts. The room 9 is evacuated by the above, and the ceiling 6 is provided with a blow-out port (not shown) so that air-conditioned air is supplied to the room 9 to constitute a general plenum chamber type air conditioning equipment. There is.

A lighting fixture 10 is attached to the ceiling 6 by fitting.

In this illuminating light fixture 10, a reflector 12 to which the fluorescent lamps 11 and 11 are attached is formed as a recessed portion P that is recessed upward from the ceiling 6, and this recessed portion P has a space above the ceiling. The slit-shaped communication ports 13, 13 communicating with 8 are provided, and the fire detector mounting base 14 in front view is attached to the reflector 12 so as to be located above the communication port 13, and the fire detector mounting base 14 is installed. On the underside of 14,
The fire detector S is attached.

The communication ports 13 and 13 of the illustrated example are formed by forming a rectangular inspection port 15 provided in the reflection plate 12 into a slit shape by closing the central portion thereof with a plate 16 provided directly below the fire detector S,
The plate 16 is attached to the reflection plate 12 by the rails 17 and 17 provided on the reflection plate 12, and the plate 1 is guided by the rails 17 and 17.
By removing 6 from above the inspection port 15, the fire detector S can be inspected from this inspection port 15.

In this way, the recessed portion P that is recessed above the ceiling 6 is formed, and the recessed portion P is provided with the communication port 13 that communicates between the room 9 and the back of the ceiling 8. Some of the smoke generated by the fire from the intake port 7 of the ceiling 6 to the ceiling 8
Smoke that has invaded into the ceiling 6 and flows along the ceiling 6 gathers in the recess P, reaches the lower side of the fire detector mounting base 14 through the communication port 13, and is detected by the fire detector S to be attached to the fire detector. Through the side openings 18, 18 of the gantry 14 will be pulled out to the attic 8.

In order to test the smoke detection state according to the present invention,
As shown in the figure, a fire detector C was provided above the intake port 7, which is generally considered to be a passage for smoke, for comparison.

Each of the fire detectors S and C used was a smoke-sensing type that represents smoke density and the amount of light received by the light-receiving unit corresponding to the light-projecting unit by the extinction rate% / m per 1 m.

The fire decided to burn a certain amount of smoke fragments.

The experimental results are shown in FIG.

(1) Comparison between the case of above the intake port and this invention.

When the fire detector C is provided above the air intake port 7 of the ceiling 6, it is 2. to 4.0% / m, including the case where the air conditioner is operated, stopped, and whether the light is turned on or not. Lowest first
Even if a seed fire detector is used, the fire cannot be detected.

On the other hand, in the case of the present invention in which the fire detector S is located above the communication port 13 provided in the recessed portion P, 6.5-
9.0% / m, which is 3.25 times to 2.2 times that of the conventional case
The detection concentration is 5 times higher.

In the case of the above-described embodiment of the present invention, the smoke of the fire rises toward the ceiling 6, flows along the lower surface of the ceiling 6, and part of the smoke enters the recessed portion P which is recessed from the lower surface and located above. ,
The smoke collected in the recess P is constantly discharged to the ceiling 8 through the communication port 13.

Therefore, the smoke flowing on the lower surface of the ceiling 6 constantly enters the recess P, and the dense smoke that flows in from the recess P passes through the communication port 13 from the recess P and the fire detector S.
A fire was sensed by touching the, and thus, a high detection concentration as described above was detected.

Since the communication port 13 is provided in the recessed portion P, there is a phenomenon in which the smoke accumulated in the recessed portion P forms a kind of hot zone and the hot zone hinders the inflow of smoke later. I have lost it.

(2) Regarding the operation or stop of the air conditioning equipment in the case of the present invention.

The concentration is 6.5 to 7.0% / m when the air conditioning equipment is stopped, while it is slightly higher at 9.0% / m during operation.

It is probable that the amount of smoke passing through the communication port 13 increased due to the forced ventilation in the plenum chamber system, and the detected temperature became higher.

(3) Turning on or off the illumination in the case of the present invention.

It was 7.0% / m when the light was off and 7.0% / m when the air was off (both when the air conditioning was stopped).

(Effects of the Invention) As described above, the fire alarm system according to the present invention has the ceiling 6
An air intake 7 communicating with the ceiling 8 is provided, and the air in the room 9 is guided from the intake 7 to the ceiling 8 and is provided in a building where the air is exhausted by an exhaust duct facing the ceiling 8. In the fire alarm system, a recess P that is recessed upward from the ceiling 6 is formed in the lighting fixture 10 provided on the ceiling 6, and the recess P is formed.
Is provided with a communication port 13 that communicates between the room 9 and the ceiling 8 and a fire detector S is provided above the communication port 13, and the rising smoke is generated along the lower surface of the ceiling 6. A part of it spreads out and is recessed from the lower surface, and partly enters the recessed portion P located at a position above.

Therefore, the smoke that has spread to the lower surface of the ceiling 6 constantly flows into the recessed portion P, and the high-density smoke that flows in later comes into contact with the fire detector S from the recessed portion P through the communication port 13,
High concentrations are detected without delay.

In this way, even if the fire point is distant, a wide range of fires will be detected, and in the plenum chamber method, a single fire detector will provide a larger area than conventional alarm equipment. I was able to monitor it.

Since the fire detector S is provided on the backside 8 of the ceiling and is not exposed on the lower surface of the ceiling 6, there is no possibility that the fire detector S will interfere with the attachment of the sprinkler to the lower surface of the ceiling 6, and the fire alarm S The equipment can be well designed and well designed.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a perspective view of a fire alarm system, and FIG. 2 is a plan view seen from the back of the ceiling.
3 is a bottom view seen from the inside of the room, and FIG. 4 is A- in FIG.
FIG. 5 is an experimental view, and FIGS. 6 and 7 are front views showing respective states of fire detection in the conventional fire alarm equipment. 1,8 …… Attic, 2,6 …… Ceiling, 3,7 …… Intake port, 4 ……
Air outlet, 5,9 …… Indoor, 10 …… Lighting fixture, 11
...... Fluorescent lamp, 12 ...... Reflector, 13 ...... Communication port, 14 …… Fire sensor mounting base, 15 …… Inspection port, 16 …… Plate, 17 …… Rail, S, C …… Fire Sensor, F ... Fire point, P ... Recessed part

Front page continued (72) Inventor Hidenori Miyamoto 4-7-3 Kudan-minami, Chiyoda-ku, Tokyo Noh Mi Bi Kogyo Kogyo Co., Ltd. (72) Koji Tanaka 4--7-3 Kudanminami, Chiyoda-ku, Tokyo Noh Within Bi Mihatsu Kogyo Co., Ltd.

Claims (3)

[Claims] 1. A ceiling is provided with an intake port communicating with the back of the ceiling, and indoor air is introduced from the intake port to the back of the ceiling, and the air is exhausted by an exhaust duct facing the back of the ceiling. In the fire alarm equipment, the lighting fixtures provided on the ceiling are provided with a recessed portion that is recessed above the ceiling, and the recessed portion is provided with a communication port that communicates between the interior and the ceiling, Fire alarm equipment, which is equipped with a fire detector above the communication port. 2. The fire alarm system according to claim 1, wherein the lighting fixture has a fire detector mounting base at a position above the communication port. 3. The fire alarm equipment according to claim 1 or 2, wherein the lighting fixture is provided with an inspection port for inspecting the fire detector.