WO2014020082A1

WO2014020082A1 - Cooling of the main lines of a firefighting installation

Info

Publication number: WO2014020082A1
Application number: PCT/EP2013/066125
Authority: WO
Inventors: Dirk Sprakel; Max Lakkonen
Original assignee: Fogtec Brandschutz Gmbh & Co. Kg
Priority date: 2012-08-02
Filing date: 2013-07-31
Publication date: 2014-02-06
Also published as: DE102012023198A1

Abstract

Method for cooling main lines of a firefighting installation 2, comprising receiving an alarm signal, activating a volumetric flow of extinguishing fluid in the main line 3 in response to the received alarm signal in such a way that extinguishing fluid flows as a cooling medium through the main lines 3 for a defined waiting time and, after the waiting time has elapsed, opening at least one zone valve 10.

Description

Cooling of mains of a firefighting system

The subject matter relates to a method of cooling

Mains of a firefighting system as well as a

Fire fighting system.

Firefighting systems are usually made of piping, pumps, valves and extinguishing nozzles. The pumps are connected to piping and with the aid of the piping, the pumps can pump extinguishing fluid to the extinguishing nozzles. In large firefighting systems are individual

Firefighting areas formed by so-called area valves. Range valves connect one

Main extinguishing fluid line (main) with one

Subdistribution (area lines), where pipelines of the subdistribution are usually connected to extinguishing nozzles. Thus, a plurality of extinguishing nozzles can be assigned to a range valve, wherein the extinguishing nozzles each cover a common area together, so that a fire in this area can be controlled by these extinguishing nozzles. If the corresponding area valve opens, the area lines and extinguishing nozzles of this area are also displayed

Exposing fluid applied and discharged extinguishing fluid. The use of area valves prevents fire in the event of fire extinguishing fluid through all extinguishing nozzles of the

Firefighting system is deployed. It will

ensures that only in those areas where a fire actually exists, extinguishing fluid out

can. For this purpose, the area valves or the Actuators or the solenoid valves by appropriate

Controlled control signals, wherein the control signals are such that the range valves are opened, in which the fire is located.

The range valves are usually opened by servomotors. The servomotors usually open and close the ball valves of the valves, the opening and closing usually lasting several seconds, sometimes up to one minute. Also solenoid valves can be used.

Particularly in the area of tunnels, firefighting is an enormously important safety feature. If trucks, cars, trains or other vehicles in tunnels are not cleared quickly enough, it can lead to catastrophic consequences. In addition, in tunnels, the heat in the area of a fire is enormous. This enormous heat build-up in tunnels can lead to temperatures of more than 800 ° C, even more than 1000 ° C, even before firefighting has been started

that may cause severe damage to the main, divisional, or divisional piping.

Also, an evacuation of persons under the

Self-rescue or alien rescue, e.g. be required by the fire department from the fire areas before a

Firefighting takes place. In this case, the

Activation of firefighting and the discharge of cooling extinguishing fluid eg extinguishing water deliberately delayed and an enormous heat development in the area of the main line as well as the area management accepted. Therefore, in known firefighting systems, the enormous heat development is problematic, especially if one

Fire fighting due to a very large area to be monitored and thus a detection delay is to be made possible or an evacuation possibility before the

Application of extinguishing liquid should be possible.

From DE 10 2010 011 763 AI is known, thereby cooling the area valves and area lines

ensure that some area valves are opened in a pre-alarm and thus extinguishing fluid is discharged before the actual fire fighting, which, however, is independent of the position of the fire and only the cooling of the area lines used.

For this reason, the object of the object to provide a fire fighting available, which efficiently prevents or reduces the damage of mains and divisional line by heat development.

This object is achieved in one aspect by a method for cooling mains of a fire fighting system comprising the steps of receiving an alarm signal, activating a circulation of extinguishing fluid, in particular one

Volumetric flow of the extinguishing fluid in the main line such that extinguishing fluid flows as a cooling medium through the main line for a defined waiting time and after the lapse of the waiting period opening at least one area valve. It has been recognized that before an effective

Firefighting can be started, in some cases a waiting period must be accepted in order to Evacuation measures. Depending on the spatial conditions and the existing escape routes, this waiting time can be between 1 minute and 60 minutes, for example.

During the waiting period, an enormous heat development can already occur, especially in the case of main ducts installed on the ceilings of tunnels. To counteract this heat, it is suggested that at a

Alarm signal or pre-alarm signal a circulation of

Extinguishing liquid in the main line is made possible.

For this purpose, the main line is preferably installed annularly at least in parts, such that a circulation through this annular part is possible. Preferably, the main line is a closed ring with a

Löschtluidzuleitung, which is preferably powered by a pump. It is also possible to apply a first end of the main line with extinguishing fluid and to let emerge at a second end of the extinguishing fluid from the main line. Then there would be no closed, but an open system.

A circulation may e.g. through at least one

Circulation pump can be enabled. Also, for example, a circulation direction may be determined, particularly by using one circulation pump for each direction of the ring of the main pipe. The circulation direction can be selected, for example, depending on the detected fire. In particular, the direction of circulation may be chosen, in which the extinguishing fluid has a shorter path or a longer path through the main line to the source of the fire. Depending on the heat distribution along the main line, which is detected eg by appropriate sensors, the feeding of the main line with extinguishing fluid for the purpose of Circulation on one side or the other makes sense.

During circulation, preferably all range valves are closed.

It is also possible that while waiting

and / or at least one for a pre-alert

Valve valve is at least partially opened. In particular, a partial opening of area valves makes it possible to flow even small amounts of extinguishing fluid in the area lines and thus to cause cooling of the area line. As already explained above, circulation can take place in a closed ring or an open line.

Circulation thus means a volume flow of the extinguishing fluid in the main line. The function of the circulation is the cooling of the main line by the extinguishing fluid.

The main line is formed at rest preferably as a wet system. That means that in the main line

Extinguishing fluid is stored at static pressure. In case of fire, the extinguishing fluid, such as water, mixed with additives added water, foam or the like, heated enormously, which can lead to a necessarily preventing bursting of the main line. Therefore, the main line is cooled by the objective circulation of the extinguishing fluid. In this case, it is possible that the extinguishing fluid flowing in the main line is cooled by suitable measures. For this purpose, for example, a heat exchanger can be connected to the main line. A heat exchanger can be used to cool the extinguishing fluid circulating in a loop.

Once a range valve is opened, quench fluid flows through the main line to the range valve. The

Division lines can be designed as dry systems. This means that no extinguishing fluid is stored in them. As a result, these lines are usually not damaged so quickly by heat, because in them the

Extinguishing fluid can not expand and can lead to bursting of the line. Empty lines can withstand heat for longer than with extinguishing fluid, e.g. Water, filled

Cables. But in order to cool these lines, a partial opening of a range valve may be required. Then a small amount of extinguishing fluid can already be during the

Wait time to flow through the area line to the extinguishing nozzles and thus cool the area line.

In order to also cool a range valve and the stub line between the main line and the area valve, it is also proposed that in the area of a range valve, a nozzle is arranged, which can be opened. This can

preferably a temperature-controlled nozzle. This nozzle can e.g. then open when the area valve or the

Sting line is heated strongly. The extinguishing fluid exiting the nozzle may cool the range valve. The volume flow of the extinguishing fluid in the stub can be used to cool the

Stub line can be used. After the at least partial opening of a range valve, the extinguishing fluid through the circulation pump or an additional pump (eg, a high-pressure pump), in the Main line and the corresponding area line and to the extinguishing nozzles to be pumped. Also, it is possible that the

High pressure pump is used to the extinguishing fluid

circulate. Then you can do without an additional pump. Again, a pump may be installed on a supply line of the main line, in particular the ring of the main line. Again, it is possible to choose in which direction the fluid is pumped, depending on the position of the fire and the open area valve. For this, e.g. in the ring for each direction downstream of the supply line, a valve may be provided. In particular, the valve can be opened, the distance is the smallest to the open area valve. Also, both valves can be opened, which leads to the fact that in the case of fire fighting extinguishing fluid flows through the entire main line and not, as in the use of only one valve, essentially only

upstream of the opened range valve.

The circulation can take place with the existing in the main extinguishing fluid. Then, a heat exchanger is advantageous to cool the quenching fluid during circulation. Also can be included in the circulation volume of the fluid tank. As a result, the heat capacity can be significantly increased. In a circulation through an open at one end line, a fluid reservoir is preferably provided, which provides the necessary for cooling fluid.

In particular in railway tunnels or road tunnels, it may happen that persons have to be evacuated from the endangered area before the actual firefighting by discharging extinguishing fluid. For self-rescue or for

Fremdrettung are so-called self-rescue phases or Provision is made for emergency recovery phases, which can last between 1 minute and 60 minutes or more. These phases should be taken into account in the waiting period. A timer actuator may be provided in a control device at which the waiting time is adjustable. Also, a manual termination of the

Waiting time be possible. For example, can be activated by the fire department firefighting in which manually the

Circulation is ended and the range valves associated with the fire are opened. For this purpose, a high pressure pump can be activated manually or automatically. Also, a video surveillance may be provided, by which the fire or rescue teams can see when the circulation or fire fighting is activated. The circulation can also be activated manually.

In the area of the fire is over a range valve a

Variety of extinguishing nozzles acted upon with extinguishing fluid to combat the fire or at least to cool the corresponding area. Extinguishing nozzles can be formed as Lögebebeldüsen. However, sprinkler nozzles and foam nozzles are also possible.

In general, it is not necessary for the actual firefighting to open all area valves, because then

in particular, too large an amount of extinguishing fluid escapes from the extinguishing nozzles. Rather, it is necessary for firefighting regularly only to apply the extinguishing nozzles with extinguishing fluid, which are located in the immediate vicinity of the fire zone. For trains, for example, it is usually the case that only one wagon burns, whereas the other wagons are not affected. So it would be one

Waste of resources when all extinguishing nozzles in Extinguishing fluid would be applied to firefighting, as then extinguishing fluid would be applied in areas where there is no fire. This would be highly problematic, since the amount of extinguishing fluid is often limited and then extinguishing fluid would not be used exclusively for fire fighting, but would be wasted in other areas.

However, to locate the fire, it takes some time. Furthermore, the startup of the pumps, in particular a high-pressure pump requires a certain amount of time. Finally, the evacuation requires a certain waiting time. During this time, the heat is great, causing damage to the

Main lines and / or area lines could arise. In order to counteract these damages, it is proposed that at least one of them already receive upon receiving the fire signal

Circulation pump is activated. The circulation pump may be dimensioned such that it promotes the amount of ^{'extinguishing} fluid that is sufficient to cool the main line down so that no damage occurs and there is no evaporation of the extinguishing fluid in the main line. The

Circulation pump can also be realized by the existing pump. Thus, the high pressure pump or a booster pump can also be used to operate the circulation.

As soon as the fire has been localized and a fire zone has been detected and the waiting time for the evacuation has also ended or is ended manually, at least one area valve can be opened. It is proposed that only those area valves are opened, which can be assigned to the fire zone, so that the extinguishing fluid is discharged only in the fire zone. A pressure drop only occurs in the area of the fire zone associated extinguishing nozzles instead. Before the expiry of the waiting period and a range valve can be at least partially opened. Since the extinguishing fluid pressure during the

Circulation is less than the operating pressure emits even a small amount of quenching fluid from the extinguishing nozzles on the range valves. Also, an intermittent opening and closing of the area valves can take place in order to allow only a short time flow of extinguishing fluid in the area lines, but which is sufficient to cool them.

According to one embodiment, it is proposed that all the area valves associated with the detected fire zone be completely opened. The complete opening of the zone valves, which are assigned to the fire zone, results in that the extinguishing fluid is spread in the fire zone to the maximum extent and thus the fire can be fought with all available extinguishing fluid. Since the area valves not associated with the fire zone are closed, no extinguishing fluid is wasted and the discharged extinguishing fluid is discharged only in the area of the fire zone.

A fire-fighting system is usually designed as a wet system if it is to cover large areas. This means that the main lines are at rest, at least up to the area valves with extinguishing fluid applied. Thus, in the activation case, the extinguishing fluid is very quickly brought to the extinguishing nozzles, since immediately after the opening of the area valves, the extinguishing fluid through the

Range valves can flow over the pipes to the extinguishing nozzles. To prevent leaks in the main strand of the

To detect piping system at rest, is the extinguishing fluid at rest at a static pressure applied. The static pressure is, for example, less than 20 bar, for example, less than 5 bar or 2.5 bar. The static pressure can also be the hydrostatic pressure

correspond .

Once the alarm signal (or pre-alarm signal) has been received, a volume flow can be used to circulate the extinguishing fluid. This volume flow can be through a

Pre-activation pressure to be generated on one of the pumps. While circulation does not increase the pressure in the line, a pre-activation pressure is necessary to activate the circulation at the pump. The pre-activation pressure is higher than the static pressure. Preferably, the

Pre-activation pressure between 2.5 and 100 bar, more preferably between 1 and 150 bar. The preactivation pressure causes the quench fluid to circulate throughout the main conduit. The one caused by the pre-activation pressure

Volume flow is chosen so that the amount of quenching fluid circulating through the main conduit is just sufficient to sufficiently cool the main conduits and avoid evaporation of the quenching fluid. In addition, the

Pre-activation pressure less than the operating pressure. When Voraktivierungsdruck flows at least partially open area valves even a small amount of extinguishing fluid through the extinguishing nozzle.

According to one exemplary embodiment, it is proposed that the after-waiting or manually opened range valves be subjected to extinguishing fluid at an operating pressure which is higher than the static pressure. The moment the

Range valves associated with the fire zone are open (or are being opened) and the wait time is over actual firefighting. At this moment, a high pressure must be applied to the extinguishing nozzles. Therefore, it is proposed that an operating pressure is then generated with which the

Range valves and the extinguishing nozzles are acted upon. The operating pressure is usually higher than the static pressure. The operating pressure may, for example, be above 2.5 bar, preferably above 40 bar, particularly preferably above 80 bar. Of the

Operating pressure, for example, be chosen so that the extinguishing nozzles an extinguishing mist of fine fluid droplets

deploy. The extinguishing mist serves to the fire room with

Apply extinguishing mist and cool down sufficiently so that the fire is effectively combated. It is also possible to apply the extinguishing fluid through special nozzles, generators or rotors as extinguishing foam. Again, an operating pressure is necessary. Also, sprinkler nozzles may be provided, e.g. with a lower operating pressure than

Fog nozzles can be operated.

Another aspect is a fire fighting system with a preferably annularly formed main supply line for supplying a plurality of area valves with extinguishing fluid, wherein the plurality of area valves in one

Fire fighting are arranged, the

Area valves in each case at least one extinguishing nozzle head

assigned via the main supply line, the

Extinguishing fluid is applied to the area valve and a pipeline connected thereto in the event of fire, detection means for receiving an alarm signal, control means for activating a circulation of the extinguishing fluid in the main line in

In response to the received alarm signal, such that

Extinguishing fluid flows as a cooling medium through the main line. It is understood that when erasing, extinguishing nozzles or extinguishing fluid is mentioned, always their property to

Fire fighting is meant. Whether a fire is actually extinguished, depends regularly on the source of the fire, so that only a fight is possible, either to a

Damming the fire or even extinguishing it. Thus, the firefighting, firefighting nozzles or firefighting fluid could be discussed.

Subsequently, the object is determined by a

Embodiments drawing showing explained. In the drawing show:

Fig. 1 is a schematic view of a

Fire-fighting system in a tunnel with a rail vehicle in which a circulation is activated;

Fig. 2, the fire-fighting system of FIG. 1 in the

Rail vehicle in the area of the fire zone is deleted.

Fig. 1 shows a fire-fighting system 2, which is preferably arranged in a tunnel 4. In the tunnel 4, a train 5 can drive. In the tunnel 4 are at intervals to each other

Fire fighting areas 20 arranged. The

Fire fighting areas 20 may be arranged, for example, at intervals of a few kilometers to each other. The length of the firefighting areas can correspond approximately to the length of the turn 5, for example several 100 meters,

for example 900 meters. Road tunnels usually do not have their own firefighting area, but the Tunnel is equipped over its entire length for fire fighting.

Associated with a firefighting area are a receiver 6 for receiving arm signals. Besides, one is

Control device 8 is provided, which is in operative connection with the receiver 6 and is also adapted to control a pump 9 and arranged on area valves 10 actuators. The control device 8 is also adapted to drive circulation pumps 9a, 9b.

In addition, the control device 8 can control directional valves IIa, IIb. The circulation pumps 9a, 9b may also, unlike those shown, be arranged in a bypass of the main line, so that they do not constitute a flow resistance in the case of fire fighting. Also, the

Main pump 9 are used to cause the circulation in the main line 3. But then preferably one end of the main supply line 3 is open and only one of the directional valves IIa, IIb opened.

The main pump 9 is connected via a supply line 3a with a

Main supply line 3 and the area valves 10

connected . The main supply line 3 is annular closed in the example shown, so that a circulation of

Extinguishing liquid in the main supply line 3 is possible. Not shown is a heat exchanger, which is used for cooling the circulating in the main supply line fluid. A heat exchanger is preferably in the range of

Directional valves arranged. Also not shown is that an extinguishing agent supply is integrated into the circulation circuit. In this case, via a suitable valve control in the case of circulation, the main supply line with an inlet and a

Outlet of the supply to be connected, so that the

Extinguishing agent supply is also circulated. As a result, the heat capacity can be increased.

In the main supply line 3, the circulation pumps 9a, 9b are arranged. Depending on which of the

Circulation pumps 9a, 9b is activated, the circulation in the main supply line 3 is clockwise or

counter-clockwise. However, only one circulation pump 9a, 9b can be used.

In the case of fire fighting the circulation pumps 9a, 9b are either via a not shown piping / valves

bridged, or the circulation pumps 9a, 9b represent only a low flow resistance for by the pump 9 via the supply line 3a fed extinguishing agent.

Each individual area valve 10 has a sub-distribution with at least one pipeline, at the end of a

Plurality of extinguishing nozzles 12 is provided. The extinguishing nozzles 12 are preferably extinguishing spray nozzles for discharging a finely distributed extinguishing mist. The extinguishing nozzles 12 may also be formed as sprinkler nozzles, deluge or foam generators. Further, a plurality of fire detectors 16 are provided in a fire fighting area 20. The fire detectors 16 are connected to a fire panel 14. By means of Fire alarm panel 14, a fire signal can be transmitted to the receiver 6. Also, only a single one can

Fire alarm line (e.g., a fire alarm cable) over the entire length to be monitored.

In FIG. 1, it can be seen that a plurality of extinguishing nozzles 12a are connected to a range valve 10a via pipelines

are connected. A range valve 10 may also be located remotely from the firefighting area, in which case the piping to the extinguishing nozzles is longer. Also can one

Area valve 10 may be arranged protected in a housing. In addition, a fire detector 16a is the corresponding one

Area associated with the area valve 10a. Thus, an area valve 10a, the piping connected thereto, the extinguishing nozzles 12a and the fire detector 16a form a first zone and the respective area valves 10b, 10c, 10d and 10e with the respective piping and extinguishing nozzles 12b, 12c, 12d, 12e and the fire detectors 16b. 16c, 16d, 16e each a further zone.

With the help of arranged on the area valves 10

Actuators can the range valves 10 open and to drive. It is also possible that the range valves 10 are only partially opened. This is especially true

useful if during the waiting period and / or during the

Pre-activation pressure even small amounts of extinguishing fluid to flow through the area lines to cool them. The opening of the area valves 10 is controlled by the control device 8. Further, the control device 8 controls the pump 9, so that the pump 9, the area valves 10 on the

Main supply line 3 with extinguishing fluid at a static pressure, a pre-activation pressure and an operating pressure can apply. The static pressure is preferably below 5 bar, but may also be higher, the pre-activation pressure is for example between 1 and 10 bar, and the operating pressure is preferably between 2.5 and 100 bar. The operating pressure is high enough that the extinguishing fluid exits from the extinguishing nozzles 12, for example as a finely divided mist.

In the train 5, a fire 18 can be detected. Once the train stops, people have to be evacuated. In this case, no fire fighting should take place. Therefore, the fire fighting by fully opening the

Range valves 10 and activating the operating pressure for a certain waiting time suppressed. The fire 18 can increase in the waiting time. This causes the

Fire fighting area 20 is heated enormously. In the area of the fire 18, temperatures of more than 1000 ° C. may arise, in particular at the tunnel ceiling, which may lead to the main line 3 and the extinguishing fluid contained therein being strongly heated. This may lead to a bursting of the main line 3, according to which a fire fighting is impossible and people are at risk.

To prevent this, as soon as the alarm signal has been received in the receiver 6, this alarm signal for

Activation of the control device 8 used. The

Control device 8 receives the alarm signal and activates one of the pumps 9a, 9b for the duration of the waiting time such that the main supply line 3 is supplied with extinguishing fluid at a pre-activation pressure. Further, the control device 8 controls the servomotors on the valves IIa, IIb such that these two valves 11 are opened. In addition, an at least partial opening of the

Area valves in the area of the fire take place in order to cool the area lines during the waiting period. Depending on the position of the fire, either the pump 9a or the pump 9b is activated, and thus the direction of circulation is determined. A valve 11c to the pump 9 is closed. The valve 11c may also be a check valve.

The result is that during the waiting time already present in the main line 3 extinguishing fluid through the

Pre-activation pressure circulates in this. The main line 3 is in this case a closed ring. That by the

Main line 3 flowing through the extinguishing fluid leads to a

Cool it so that damage is avoided.

If the extinguishing fluid flows past the heat exchanger, not shown, it is also cooled.

During the entire waiting time, an attempt is made to locate the fire 18 by means of the fire detectors 16, so that a fire zone can be determined. The fire detectors 16 can, for example, a temperature profile as well as a

Measure flue gas development and according to the

Temperature profiles as well as the flue gas development

Determine if the fire zone is in your area. The corresponding status data are received by the fire detectors 16 and transmitted to the fire panel 14. The fire panel 14 evaluates the results and determines a fire zone. In the case shown in Fig. 2, the fire zone in the region of the area valve 10 b, the extinguishing nozzles 12 b and the

Fire detector 16b. A fire zone can also have several Extend areas is limited in the present case, however, limited to only one area. The

Fire alarm panel 14 reports the detected fire zone to the receiver. 6

In the meantime, the waiting time, e.g. can be monitored by the controller 8 and e.g. 5 minutes, expired. The control device 8 deactivates after the waiting time, the previously activated circulation pump 9a, 9b. In addition, the valve 3a is opened.

The receiver 6 controls the control device 8 such that it controls the servomotor on the range valve 10b such that the range valve 10b, in the area of which the fire has been located, is completely opened. In parallel, the control device 8 controls the pump 9, the

Main supply line 3 with extinguishing fluid at one

Operating pressure, preferably at more than 50 bar to apply.

Depending on the position of the fire area, one of the valves IIa, IIb is closed and another valve IIa, IIb is opened. Also both valves 11 can remain open, then extinguishing fluid flows from both sides to the range valve 10b. The Strömungsguerschnitt is doubled in this case from the pump to the range valve 10b.

Through the opened area valve 10b, the extinguishing fluid flows and is discharged through the extinguishing nozzles 12b. During firefighting, the fire can spread to other areas

propagate. Therefore, it is proposed to constantly fire monitor and, if necessary, change the area of loading by opening other area valves.

As can be seen in FIG. 2, extinguishing fluid flows

exclusively from the extinguishing nozzles 12b and the extinguishing nozzles 12a, 12c, 12d, and 12e bring no extinguishing fluid. As can also be seen in FIG. 2, the discharge of the extinguishing fluid through the extinguishing nozzles 12b is sufficient to adequately control the fire 18 in the fire zone. The extinguishing fluid is used exclusively for fire fighting and no extinguishing fluid is wasted for areas where no fire was detected.

It goes without saying that in the case of a detected fire, the fire zone must not only be restricted to the area directly affecting the fire 18, but can also be extended to neighboring areas. The fire zone could also be present on the range valves 10a and 10c

be extended, which also meant that the extinguishing nozzles 12a and 12c, which are arranged immediately adjacent to the fire 18, Ausschfluid ausbrächten.

By means of the subject firefighting system, it is possible, during a waiting period, which can be used for evacuation, the main line against excessive heat too

protect and thus prevent damage. It is also achieved that once a fire zone has been detected, the fire is effectively combated with extinguishing fluid and no

Extinguishing fluid is wasted.

Claims

claims

Method for cooling main lines of a

Firefighting system (2) with,

Receiving an alarm signal,

Activating a volume flow of extinguishing fluid in the main conduit (3) in response to the received

Alarm signal, such that extinguishing fluid flows as a cooling medium through the main lines (3) for a defined waiting time and after the lapse of the waiting period

Opening at least one area valve (10).

A method according to claim 1, characterized in that the waiting time may depend on the spatial

Conditions and existing escape routes between 1 minute and 30 minutes.

A method according to claim 1 or 2, characterized in that a fire zone is detected and that after the waiting time all of the detected fire zone associated area valves (10) are fully opened.

Method according to one of claims 1 to 3, characterized in that a circulation direction is determined, in particular by using one each

Circulation pump (9a, 9b) for each direction of the ring of the main line (3). Method according to one of claims 1 to 4, characterized in that when receiving the alarm signal at least one circulation pump (9a, 9b) is activated.

Method according to one of claims 1 to 5, characterized in that at least one area valve (10) is at least partially opened during the waiting time.

Method according to one of claims 1 to 6, characterized in that in response to the received

Alarm signal the extinguishing fluid is applied with a pre-activation pressure which is higher than a static pressure.

Method according to one of claims 1 to 7, characterized in that after the waiting time, the opened area valves (10) with extinguishing fluid at a

Operating pressure to be applied which is higher than the pre-activation pressure and / or the static pressure.

Firefighting system with,

a main supply line (3) for supplying a plurality of area valves (10) with extinguishing fluid, the plurality of area valves (10) being disposed in a fire fighting area,

wherein the area valves (10) in each case at least one extinguishing nozzle head (12) is assigned, via the

Main supply line (3), the area valve (10) and a pipe connected thereto in the event of fire is treated with extinguishing fluid,

Detection means (6) for receiving an alarm signal, control means (8) for activating a volume flow of the extinguishing fluid in the main supply line (3) in Response to the received alarm signal, such that extinguishing fluid as the cooling medium through the

Main supply line (3) flows.