Design of fire extinguishing systems based on ESMI FX NET equipment.

Design of fire extinguishing systems based on ESMI FX NET equipment.

Equipment with the ESMI brand has long been known on the Russian market. Addressable analog fire alarm and fire safety automation control systems are successfully used at facilities of various sizes and purposes: office and business centers, museums and universities, industrial enterprises and hydroelectric power plants.
Automatic fire detection is one of the fundamental points that determine the efficiency of the system as a whole. The earlier and more reliably a fire is detected, the less damage will be done and the greater the chances of evacuating people in time, preventing their death. Currently, the highest quality of detection in the world is offered by addressable analogue systems. The main advantage of these systems is the intelligent algorithms for assessing the situation embedded in them, allowing for the detection of a fire at an early stage, while cutting off false alarms.
ESMI FX NET equipment belongs to this class of equipment. The addressable-analog fire alarm control and monitoring devices (AAFCMD) of the FX NET/RU series have passed all the necessary tests for compliance with the Technical Regulations on Fire Safety (Federal Law of 22.07.2008 No. 123-FZ). At the same time, a unified fire alarm control system can be built on the basis of the FX NET/RU series devices. According to certain algorithms, after a fire is detected, commands are generated for the supply and exhaust ventilation and air conditioning systems, notification and evacuation control, smoke protection and, of course, the fire extinguishing system.
Currently, the following types of fire extinguishing systems are used:
— gas fire extinguishing;
— powder fire extinguishing;
— aerosol fire extinguishing;
— water and foam fire extinguishing.
In this article, we will consider options for constructing automatic fire extinguishing systems based on devices of the FX NET/RU series for gas, powder and aerosol types of installations.

Gas fire extinguishing
Gas fire extinguishing units (GFU) are divided into centralized (gas fire extinguishing stations) and modular. In this case, modules, batteries or isothermal tanks are used in units for storing gas fire extinguishing agents (GFEA). GFEA themselves can also be of different types, which determines the method of monitoring the safety of GFEA: by weight or by pressure.
Modular GFU unit (Fig. 1). In such units, the modules are located either in the protected room itself or in close proximity to it.
FX NET/RU series APPKUP performs:
generating a command for automatic start-up of the fire extinguishing system upon detection of a fire from two or more automatic or one manual fire alarm (MA) located in the protected premises;
counting down the start-up delay, set individually for each direction of the PT;
remote start-up of the system by directions;
switching on the «Gas leave», «Gas do not enter», «Automation is off» board;
disabling and restoring the automatic start-up mode;
monitoring the safety of the GFFS and the displacer gas;
automatic switching of power supply circuits from the main power supply input to the backup one when the voltage at the main input disappears, followed by switching to the main power supply input when the voltage at it is restored;
automatic monitoring of all lines for serviceability.

Algorithm of installation operation
Monitoring the safety of gas-fired heating systemsis performed by a pressure or weight sensor, depending on the type of GFTS, with a malfunction indication on the FX NETRU series APPKUP at the duty station.
Enabling/disabling the automatic start mode of the GPT in the direction
The automatic start mode of the GPT in the direction is disabled when the door to the protected room is opened. Door contacts are connected via addressable control modules. In this case, closing the door itself does not lead to the restoration of automation (mandatory).
When the automatic start mode is disabled, the «Automatic system disabled» sign is turned on at the protected room and the indication on the FX NET/RU series APPKUP at the duty station is turned on.
The automatic start mode is restored by the automatic system restore button, connected via addressable control modules.

Start of the GPT unit in the direction, when the automatic start mode is enabled.
The command to start the fire extinguishing unit in automatic mode is generated upon detection of a fire using two or more automatic PI or one manual PI.
Automatic start procedure:
The delay countdown for starting the gas-fired heating system is started (the delay duration is set during programming).
The «Gas leave» signs located in the protected room are switched on.
When the delay countdown is complete, the «Gas do not enter» signs located above the doors to the protected room are switched on.
The gas-fired heating system modules are started.
When confirmation of the GFTS start-up is received from the pressure/weight sensor, the «Gas Leave» sign turns off, and the «Fire Extinguishing Enabled» indicator turns on at the duty station on the FX NET/RU series APPKUP.
If there is no confirmation of the GFTS start-up within the set time, the «Gas Not Supplied» indicator turns on at the duty station.
During the start-up delay countdown, the automatic start-up of the GPT can be interrupted. To do this, it is necessary to disable the automatic start-up mode.
If the automatic start mode in a given direction is disabled, the GPT modules will not start. In this case, the start can be performed either by restoring the automatic mode or by pressing the remote start button.
The start pulse will be issued after the set delay of the automatic or remote start has expired.

Remote start of the GPT in a direction
Remote start is performed by a remote start button installed near the protected room (an address button or a button connected via an addressable control module).
After pressing the button, the system will start the remote start procedure of the gas turbine module. It is similar to the automatic start procedure except for the following:
The duration of the remote start delay may differ from the duration of the automatic start delay (set independently).
The gas turbine module will start even if the automatic start mode is disabled (the «Automatic off» sign is on);
During the remote start delay countdown (if provided), the GPT start can be interrupted. To do this, open the door to the protected room or reset the «Fire» signal.

Installation of a centralized GPTdiffers in that the cylinder batteries (isothermal tank) are placed in a special room — a gas fire extinguishing station (Fig. 2), where the distribution devices (RD) are also located. The protected rooms are located at a sufficient distance from the location of the GFFS, and it is more expedient to connect fire alarms, panels and other devices located in the protected room to one loop, and devices that issue commands to start the cylinder batteries and RD, to another loop

The number of GFFS in installations of this type must be sufficient to extinguish any of the protected premises, while different numbers of cylinder banks are launched for different directions. The safety of GFFS is monitored using a pressure or weight sensor installed on the cylinder banks. The number of distribution devices corresponds to (or exceeds) the number of protected premises, and the GFFS launch control in a direction is performed using a control system installed after the switchgear.
In the case of using an isothermal tank, the launch command is issued either by time or by information from level sensors, depending on the type of equipment used.

Powder and aerosol fire extinguishing
The main differences in the control of powder and aerosol fire extinguishing installations (Fig. 3) from the control of GPT installations are as follows:
Most of them do not provide the ability to monitor the safety of the GFTS, sometimes it is possible to monitor the propellant gas, therefore this control is not carried out in all cases;
Modular type installations (can be with a distribution pipeline);
A large number of powder modules is often required, therefore a large number of control signals is required;
Aerosol installations require sequential startup of modules at a certain interval.

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