How to install a fiber optic grating fire alarm system for tunnel fire temperature sensing cables

Fiber optic temperature sensor, Intelligent monitoring system, Distributed fiber optic manufacturer in China

Tunnel fiber optic grating temperature sensing detection device
The fiber optic grating temperature detection device is installed on the top of the vehicle tunnel and laid longitudinally along the tunnel, with a fire alarm positioning accuracy of no more than 10 meters. There are two sets of fiber optic grating signal processors installed in the central equipment room, which are interconnected with the fire alarm controller in the central control room through a bus for alarm information transmission. The fiber optic grating fire alarm system consists of a fiber optic grating temperature detection device (including temperature sensing components, connecting optical cables and junction boxes), a transmission optical cable, and a signal processing unit.

A linear temperature sensing cable is installed in the cable channel, which is laid above the power cable support in a sine wave manner. The fire detection zone of the side section cable channel is set at 100 meters, and the fire detection zone of the shield section cable channel is set at 200 meters.

Cross River Tunnel

Automatic linkage mode of tunnel fire alarm system
1) After the judgment of the automatic fire alarm program, the fire information obtained through the dual fire detection devices installed in the vehicle tunnel will be uploaded to the central control room fire automatic alarm controller and the central computer network through the working well fire automatic alarm controller. The subsystems of fire protection, ventilation, lighting, traffic monitoring, equipment monitoring, video monitoring, and emergency broadcasting will be linked to enter the fire operation mode.

2) The intelligent evacuation lighting indication system is implemented by the lighting profession, and the interface with the tunnel fire alarm system is on the communication interface of the intelligent evacuation lighting control host in the tunnel management center. In case of a fire, the fire alarm controller sends an alarm address to the intelligent evacuation lighting host and receives feedback signals. When a communication failure occurs, a fault alarm signal is sent to the central control room duty room.

3) The dual-use smoke exhaust fan is controlled by the regular equipment monitoring system. When the fire alarm host receives an alarm signal from a two-point detector in the same area or a manual alarm signal, it starts the corresponding control module, and sends instructions directly to the equipment monitoring system through a hard wire to start the corresponding fan for smoke exhaust.

4) The fire alarm controller in the central control room is equipped with fire hydrant pump, water spray pump, foam pump, smoke control fan, smoke exhaust fan direct start and stop control buttons and status display lights.

5) Upload fire alarm information through networking with the Shanghai urban fire automatic alarm system.

Analysis of alarm relationship between dual fire detection devices and automatic linkage scheme of fire automatic alarm system
1) Simultaneous alarm of dual wavelength flame detection device and fiber optic grating detection device

(1) The single point dual wavelength flame detection device and the fiber grating detection device give an alarm at the same time, link the sound and light in the corresponding area, confirm the fire alarm and automatically link the alarm to the deluge valve group and foam valve group [7] whose dual wavelength is adjacent, simultaneously start the spray pump and foam pump, and the action signal of the pressure switch is fed back to the fire alarm controller.

(2) When the multi-point dual wavelength flame detection device and the grating fiber detection device alarm at the same time, the system automatically selects the fire alarm point reported by the dual wavelength flame detection device closest to the grating fiber alarm point, and links the two adjacent groups of deluge valves and foam valves of the dual wavelength flame detection device.

2) Dual wavelength flame detection device and manual alarm button alarm simultaneously

The dual wavelength flame detection device and the manual alarm button within two positions adjacent to the alarm dual wavelength flame detection device in the same channel give an alarm at the same time, and the automatic linkage alarm for the deluge valve group and foam valve group adjacent to the dual wavelength. At the same time, the spray pump and the foam pump are started, and the action signal of the pressure switch is fed back to the fire alarm controller.

3) Fiber optic grating detection device and manual alarm button alarm simultaneously

The fiber grating detection device and the manual alarm buttons in the two fire compartments adjacent to the alarm fiber grating detection device in the same channel give alarm at the same time, the automatic linkage alarm fiber grating detection device corresponds to the deluge valve group and foam valve group in the two fire compartments adjacent to the alarm fiber grating detection device, and simultaneously start the spray pump and foam pump, and the action signal of the pressure switch is fed back to the fire alarm controller.

4) When dual wavelength flame detectors and grating fiber optic detection devices alarm separately, there is no linkage.

5) Automatic fire alarm system.