EP2186546B1 - Inert gas fire extinguisher for reducing the risk of and extinguishing fires in a protected area - Google Patents

Abstract

The fire extinguisher (100) has a pressure reducing device (6) including parallel branches (21, 31, 41) with respective pressure reducing units (22, 32, 42). The branches are connected to a high pressure collecting line (3) and a low-pressure extinguishing line (4) via respective controllable valves (23, 33, 43). Each pressure reducing unit reduces a high input pressure to a low output pressure according to a preset pressure reducing characteristic. The extinguishing line is connected with an extinguishing nozzle (5) via the pressure reducing device. An independent claim is also included for an inertization method for reducing the risk of fire and for extinguishing fire in a protected space.

Description

The invention relates to an inert gas fire extinguishing system for reducing the risk and extinguishing fires in a shelter, wherein the Inertgasfeuerlöschanlage has at least one high-pressure gas storage, in which an oxygen-displacing gas is stored under high pressure, the high-pressure gas storage is connected via a quick opening valve with a manifold, and wherein an extinguishing line is further provided, which is connected on the one hand via a pressure reducing device to the manifold and on the other hand with extinguishing nozzles.

Such an inert gas fire extinguishing system is known in principle from the prior art. For example, in the German patent application DE 198 11 851 A1 describes an inert gas fire extinguishing system which is designed to lower the oxygen content in an enclosed space (hereinafter "shelter") to a certain basic inerting level and, in the event of a fire, to further lower the oxygen content rapidly to a certain full inertization level, thus effectively extinguishing one in the Protective space to allow broken fire, while the space required for inert gas tabs, in which an oxygen-displacing gas is stored under high pressure, can be kept small.

The basic principle of the inert gas fire extinguishing technology is based on the recognition that in closed rooms, which are only occasionally entered by humans or animals and whose facilities react sensitively to the influence of water, the risk of fire thereby it can be counteracted that the oxygen concentration in the affected area is lowered to a value of, for example, about 12% by volume on average. With such a (reduced) oxygen concentration, most flammable materials can no longer ignite. Accordingly, the main area of application of inert gas extinguishing technology is also computerized areas, electrical sheep and distribution rooms, enclosed facilities as well as storage areas with high-quality assets. The extinguishing effect resulting from this process is based on the principle of oxygen displacement. Normal ambient air is known to be 21% by volume of oxygen, 78% by volume of nitrogen and 1% by volume of other gases. To extinguish, by introducing an oxygen displacing gas, such as nitrogen, the oxygen content in the room atmosphere of the enclosed space is reduced. It is known that an extinguishing effect already starts when the oxygen content drops below about 15% by volume. Depending on the combustible materials present in the shelter, further lowering of the oxygen content may be required to the 12 vol% already mentioned as an example.

By the term "base inertization level" as used herein is meant a reduced oxygen level compared to the oxygen level of normal ambient air, however, this reduced level of oxygen does not present any hazard to persons or animals, thus still providing the shelter with ease (ie, without special protective measures such as oxygen masks ). The basic inerting level corresponds, for example, to an oxygen content in the protected space of 15% by volume, 16% by volume or 17% by volume.

On the other hand, the term "full inertization level" is to be understood as meaning a further reduced oxygen content in comparison to the oxygen content of the basic inertization level, in which the flammability of most materials has already been reduced to such an extent that they can no longer be ignited. Depending on the fire load present in the affected shelter, the full inertization level is typically about 11% to 12% oxygen concentration by volume.

For example, from the publication DE 198 11 851 A1 According to known multistage inerting process, in which a gradual reduction of the oxygen content is made, an "inert gas extinguishing technology" is used, in which by flooding a fire-prone or in fire room by oxygen-displacing gases such as carbon dioxide, nitrogen, noble gases or mixtures From this, the oxygen content in the shelter is first lowered to a certain lowering level (basic inerting level) of, for example, 16% by volume, in the event of a fire or if necessary a further lowering of the oxygen content to a certain full inerting level of, for example, 12% by volume or under it is made. In such a two-stage inerting method for lowering the oxygen content to the first subsidence level (bottom inertization level), an inert gas generator such as a nitrogen generator is used as the inert gas source, the number of high-pressure gas storage tanks required for full inertization in which the oxygen displacing gas or gas can be achieved Gas mixture (hereinafter also simply called "inert gas") is stored in compressed form, can be kept as small as possible.

In the practical application of the above-described and per se known two-stage inertization method, however, it has proved to be problematic in certain cases that the inerting of the protection space for setting a predetermined reduction level, such as the basic or Vollinertisierungsniveaus, not carried out in accordance with a preestablished event sequence can. In particular, in presently known multistage inert gas fire extinguishing systems, it is not considered that it may be desirable to carry out a stepwise inerting of a protected space, ie a stepwise setting of predefined lowering levels corresponding to different event sequences, whereby these event sequences can be adapted to particular conditions. In a multi-stage inerting process, as for example from the document DE 198 11 851 A1 In particular, in the introduction of inert gas into the room atmosphere of the shelter for setting a certain Absenkungsniveaus no difference is made, whether in the room atmosphere, a basic or Vollinertisierungsniveau is set. In other words, regardless of which subsidence level is to be set in the shelter, inerting of the shelter occurs according to one and the same inertization curve in the known methods.

The term "inerting curve" as used herein means the time course of the oxygen content during the introduction of oxygen-displacing gas (inert gas) into the room atmosphere of the protective space.

Due to this limitation is an inert gas fire extinguishing system, as described for example in the document DE 198 11 851 A1 is described, not or only conditionally as

Multi-range fire extinguishing system suitable because the inerting is not adaptable to the individual shelters. In particular, it is not considered that, for example, in the case of differently dimensioned shelters, an inert gas quantity introduced at maximum per unit of time for inerting should be adapted to the corresponding shelter. In particular, the available pressure relief and the compressive strength of the space envelope determine the maximum permissible amount of inert gas introduced into the protected area per unit of time. This maximum allowable amount of inert gas introduced into the shelter per unit of time ultimately sets the event sequence in the inertization of the shelter, i. the inertisation curve to be used for the room.

When using an inert gas fire extinguishing system as a multi-zone system, in which therefore a preventive fire protection or fire extinguishing for several shelters provided by one and the same inert gas fire extinguishing system, thus the problem arises that regardless of which of the multiple shelters is to flood with an oxygen-displacing gas, the inerting of the shelter is carried out according to one and the same event sequence. Thus, in conventional multi-range fire extinguishing systems, a shelter having a relatively small volume of space is supplied with the same amount of oxygen displacing gas per unit time as a shelter having a relatively large volume of space. Since the amount of inert gas which can be supplied by the inert-gas fire extinguishing system per unit of time depends, in particular, on the existing pressure relief measures of the respective protective rooms, this means that under certain circumstances the inerting of a protected area may be much slower than would actually be possible.

Based on this problem, the invention has for its object, an inert gas fire extinguishing system, as for example, from the publication. DE 198 11 851 A1 It is known to further develop to the effect that the inerting of a shelter, ie the setting of a lowering level in the room atmosphere of the shelter, according to different event sequences can be done.

To achieve this object, an inert gas fire extinguishing system of the aforementioned type is proposed according to the invention, in which the pressure reducing device has at least two parallel branches, each with a pressure reducing device, each parallel branch is connectable via a controllable valve to the manifold and the extinguishing line, and wherein each pressure reducing device is designed, to reduce a high input pressure to a low output pressure according to a known pressure reduction characteristic. As used herein, the terms "inlet pressure" and "outlet pressure" respectively mean the hydrostatic pressure of the medium (the oxygen displacing gas) applied to the inlet side and outlet side of the corresponding pressure reducing device.

The advantages that can be achieved with the solutions according to the invention are obvious. The fact that the pressure reduction device, via which the extinguisher with extinguishing nozzles connected to the high-pressure manifold (manifold) is connected, several if necessary via the control of appropriate valves switchable parallel branches, in each of which a pressure reduction device is arranged with known pressure reduction characteristic can be on simple Way to be adapted by the appropriate control of the parallel branches associated valves with the pressure reduction device to be made pressure reduction to the respective application. Thus, it is conceivable, for example, for a pressure reduction device to be provided in a first of the at least two parallel branches, the pressure reduction characteristic of which has a significantly higher gradient than the pressure reduction characteristic of a pressure reduction device provided in a second parallel branch. By using the pressure reducing device of the first of the at least two parallel branches in this pressure reducing example, it is possible to increase the amount of oxygen displacing gas supplied from the inert gas fire extinguishing system per unit time compared to a case where the pressure reducing device of the second parallel branch is used to reduce the pressure becomes. In this way, with one and the same inert gas fire extinguishing system during flooding of a protected area, the event sequence can be varied as needed and, for example, adapted to the pressure relief provided for the protected area to be flooded.

The term "pressure reduction characteristic" as used herein means the dependence of the output pressure of a pressure reducing device on the input pressure. It is therefore an input pressure-output pressure characteristic. The pressure reduction characteristic of a pressure reduction device is particularly important with regard to the temporal evolution of the oxygen content in the shelter during the inertization, wherein this temporal evolution of the oxygen content is also referred to herein as "inerting".

Accordingly, it can be seen that a Mehrbreichs inert gas fire extinguishing system can be provided with the solution according to the invention, wherein the amount of oxygen-displacing gas supplied by the inert gas fire extinguishing system to a protective space per unit time is adaptable to, for example, the pressure relief available for the corresponding space.

In addition, the solution according to the invention also makes it possible that, in the case of a multistage inerting method, the respective subsidence levels, such as, for example, the basic or the full inertization level, are respectively set correspondingly to different inertization curves.

In a preferred further development of the solution according to the invention, the inert-gas fire-extinguishing system accordingly also has a control device for automatically carrying out a multi-stage inerting process, in which the oxygen content in the protective space is first lowered to a first lowering level (such as a basic inerting level) and if required, for example in case of fire, is then further lowered to one or step by step to a plurality of predetermined lowering levels. Preferably, in this development, the control device is designed to control the valves of the pressure reduction device such that - to set the corresponding Absenkungsniveaus - the oxygen content in the shelter is reduced in accordance with a predetermined inerting.

This development thus makes it possible that, in the case of a multi-stage inerting method, the inerting to be made for setting the respective lowering levels takes place automatically in accordance with different event sequences adapted to the lowering levels.

In an implementation of the last-mentioned further development, it is preferred if the control device is designed, on the one hand, to actuate the valves of the pressure reduction device in such a way that only one first parallel branch of the at least two parallel branches is connected to the high-pressure manifold (collecting manifold) for reducing the oxygen content to a first lowering level. and the extinguishing line is connected, and in that the control device is, on the other hand, designed to control the valves of the pressure reduction device such that only a second parallel branch of the at least two parallel branches is connected to the high-pressure manifold and the extinguishing line, in order to lower the oxygen content further to a second setback level, wherein the pressure reduction characteristic the pressure reducing means arranged in the first parallel branch is different from the pressure reducing characteristic of the pressure reducing means arranged in the second parallel branch. In this realization of the solution according to the invention, it is thus conceivable that for the second parallel branch, via which the high-pressure manifold and the low-pressure extinguishing line are then connected to each other, if the oxygen content in the shelter from an already set first Absenkdungsniveau to a predetermined second lowering level is further reduced, a pressure reduction characteristic is selected, which - compared to the steepness of the pressure reduction characteristic of the pressure reducer used in the first parallel branch - has a relatively large slope. By so selecting the pressure reduction characteristics of the at least two pressure reducing means, the lowering of the oxygen content in the shelter from the first lowering level to the second lowering level is faster than lowering the oxygen content from, for example, the normal level to the first lowering level.

In a two-stage inerting process, in which the first reduction level, for example, the Grundinertisierungsniveau and the second reduction level, for example, the Vollinertisierungsniveau, in this preferred implementation of inert gas fire extinguishing system according to the invention can ensure that, for example, in case of fire, the reduction of the oxygen content of the Grundinertisierungsniveau to the Vollinertisierungsniveau possible done quickly. Preferably, however, the pressure reduction devices used for the inertization should be designed with regard to their pressure reduction characteristics such that the maximum permissible amount of oxygen-displacing gas supplied per unit time is not exceeded in order to meet in particular the requirements of effective pressure relief during flooding Protective space care and counteract possible damage to the space envelope.

As an alternative to the last-mentioned embodiment, it is naturally also conceivable for the control region to be designed to control the valves of the pressure reduction device in such a way that only a first parallel branch of the at least two parallel branches of the pressure reduction device is provided for lowering the oxygen content to the first lowering level is connected to the high pressure manifold and the low pressure extinguishing line, wherein the Control device is further configured, for further lowering the oxygen content to a second lowering level, such as the Vollinertisierungsniveau to control the valves of the pressure reducing device such that the first parallel branch and a second parallel branch of the at least two parallel branches are connected to the manifold and the extinguishing line. In this embodiment, it is entirely conceivable, in contrast to the previously described embodiment, that the pressure reduction characteristics of the pressure reduction devices arranged in the first and the second parallel branches are identical.

By further reducing both the first and the second parallel branches of the pressure reduction device to connect the manifold to the quench line for further decreasing the oxygen content to the second recession level, it is achieved that lowering the oxygen content to the second descent level compared to lowering the oxygen content to the first Lowering level can be performed much faster. Accordingly, the further reduction to the second subsidence level occurs according to an inertization curve, which is steeper compared to the inertization curve, which is decisive in lowering the oxygen content to the first subsidence level. As with the embodiment described above, it is preferred that even with the reduction of the oxygen content to the second lowering level per unit time the shelter supplied amount of oxygen-displacing gas does not exceed the maximum allowable flow, the space for the protection in particular with regard to given pressure relief is given.

The solution according to the invention is not limited to a pressure reducing device which has only two parallel branches. In particular, for applications in which an inerting of the shelter in more than two steps (lowering levels) is performed, the pressure reduction device should have a correspondingly higher number of parallel branches. Thus, for example, it is conceivable that the inert gas fire extinguishing system initially lowers the oxygen content in the shelter to a base inerting level, and in the event of a fire (or at bedtime) in the shelter, the oxygen content is further lowered from the base inerting level to a lower level of subsidence and for a predetermined level Time is kept continuously at this subsidence level, wherein the oxygen content is then lowered from this subsidence level further to a Vollinertisierungsniveau if a fire after a predetermined time has not extinguished. In order to achieve that, in such a (three-stage) inerting of the shelter in setting the respective lowering levels (Grundinertisierungsniveau, Abenkungsniveau, Vollinertisierungsniveau) for each reduction to be performed, the event flow and in particular the inerting curve can be customized, it is preferred if the pressure reduction device of Inertgas fire extinguishing system according to the invention comprises at least three parallel branches, each with a pressure reducing device, each parallel branch via a controllable valve to the manifold and the extinguishing line is connected, and wherein each pressure reducing device is designed according to a known pressure reduction characteristic to reduce a high inlet pressure to a low outlet pressure. In this preferred embodiment of the inert gas fire extinguishing system it is further preferred, if the control device is designed to control the valves of the pressure reduction device such that only a third parallel branch of the at least three is to lower the oxygen content from the second lowering level to a third lowering level (such as the Vollinertisierungsniveau) Parallel branches is connected to the manifold and the extinguishing line.

Accordingly, with the solution according to the invention, it is possible to use different pressure reduction measures for each inertization stage (for each reduction level) in order to be able to individually adjust the amount of oxygen-displacing gas supplied to the protection space per unit time during the setting of the respective suspension level, so that the Lowering of the oxygen content to the individual lowering levels can be carried out according to different inerting curves. This is particularly advantageous when different amounts of oxygen displacing gas are necessary to set the individual subsidence levels, i. when the distance between the corresponding lowering levels is different.

At present, in the inert gas fire extinguishing technique pressure reducing devices are usually used to lower a relatively high inlet pressure (for example, 300 bar) to an outlet pressure of, for example, 60 bar on average. A pressure reducing device, which is designed in the form of a pressure diaphragm, has a pressure reduction characteristic, in which the output pressure is proportional to the input pressure. When the quick-opening valves are opened in the inert gas fire extinguishing system, this flows under high pressure in the at least one high-pressure gas storage stored oxygen-displacing gas in the high-pressure manifold (manifold), wherein subsequently adjusting itself in the manifold high gas pressure using the pressure reduction device is reduced to an operating pressure of, for example, 60 bar. Accordingly, the extinguishing pipe can be designed as a low-pressure line, while a high-pressure manifold is to be selected for the manifold.

It should be noted that during the inerting of the protective space, the initially high pressure in the high-pressure manifold drops relatively quickly when at least one high-pressure gas reservoir connected to the collecting line via an opened quick-opening valve is emptied. Comes as Druckreduzierungseinrichtung a pressure diaphragm, i. a throttle disk with a bore for use, the inerting curve at the beginning of the inerting process, a high pressure peak, which decreases in proportion to the pressure in the manifold relatively quickly. Such a pressure peak at the beginning of the inerting process, however, is problematic in view of a pressure relief to be provided in the shelter because the pressure relief at the maximum occurring, per unit time of the room atmosphere of the shelter supplied amount of oxygen displacing gas is adjusted.

Accordingly, it is preferred if in the inert gas fire extinguishing system according to the invention at least a part of the pressure reduction devices has a pressure reduction characteristic in which the output pressure does not exceed a predetermined pressure value independently of the applied input pressure over a predetermined pressure range (working range). As a pressure reducing device, which has a linear pressure reduction characteristic, for example, a pressure reducer, which ensures despite different pressures on the input side (input pressure) that on the output side, a certain output pressure is not exceeded. It is conceivable that a pressure reduction device designed as a pressure reducer has an example spring-loaded membrane, the pressure acting on the output side of this membrane. The diaphragm should also be mechanically coupled to a valve to make the valve the more closed the higher the pressure on the output side increases. When reaching a (adjustable) maximum output pressure, the valve should completely shut off the gas flow.

The solution according to the invention is not limited to an inert gas fire extinguishing system which has only one high-pressure gas storage. In a preferred embodiment The inert gas fire extinguishing system comprises at least two high-pressure gas reservoirs which can be connected to the collecting line via a quick-opening valve, with each high-pressure gas accumulator being assigned a parallel branch with a pressure reducing device. This assignment is made such that when opening the quick opening valve of a high-pressure gas storage of at least two high-pressure gas automatically the valves of the pressure reducing device are controlled such that only the one high-pressure gas accumulator associated parallel branch is connected to the extinguishing line and the manifold.

Accordingly, it should be noted that the inert gas fire extinguishing system according to the invention is designed to carry out an inerting process, in which the oxygen content in the shelter is first lowered to a certain, first lowering level and maintained at this first lowering level, and in the event of a fire in the shelter (or at Demand), the oxygen content in the shelter is further lowered from the first descent level to a particular second descent level. With the inerting system according to the invention, it can be achieved that the lowering of the oxygen content in the protection space to the first lowering level corresponding to a first inertization curve, which is predetermined by a pressure reduction characteristic of a first pressure reduction device, and that the further lowering of the oxygen content in the shelter to the second lowering level in accordance with a second inerting curve, which is predetermined by a pressure reduction characteristic of a second pressure reducing device.

To realize this previously mentioned inerting method, it is preferred if in the shelter, preferably continuously, with the aid of a detector at least one fire characteristic is measured to determine whether there is a fire in the shelter or if a fire already broken out in the shelter due to a carried out inerting already extinguished again. However, the measurement of the fire parameter does not have to be continuous, but it is also conceivable that at predetermined times or depending on certain predetermined events, such a measurement takes place. The measurement of the fire parameter is preferably carried out by means of a detector for detecting a fire characteristic, which emits a corresponding signal to the control device in the event of fire, in which preferably automatically an inerting of the protective space by controlling the corresponding Quick opening valves and valves of the pressure reducing device is made.

In a preferred realization of the solution according to the invention, it is provided that the detection of a fire parameter takes place with the aid of an aspiratively operating system in which the room air of the protective room is taken from representative air samples and supplied to the detector for fire characteristics.

The term "fire characteristic" is understood to mean physical quantities which are subject to measurable changes in the ambient air of an incipient fire, for example the ambient temperature, the proportion of solid or liquid or gas in the ambient air (formation of smoke in the form of particles or aerosols or steam) or the ambient radiation. For example, it is conceivable for representative air samples to be taken by means of an aspiratively operating fire detection system of the room air to be monitored and fed to a fire characteristic detector which emits a corresponding signal to the control device in the event of fire.

An aspirative fire detection device is to be understood as a fire detection device which sucks, for example via a pipeline or duct system at a multiplicity of locations within the protection space, a representative subset of the room air of the protected space to be monitored and then feeds this subset to a measuring chamber with the detector for detecting a fire parameter , In particular, it would be conceivable that this detector for detecting a fire parameter is designed in such a way to output a signal which also makes possible a quantitative statement with regard to the fire parameters present in the sucked subset of the ambient air. Thus, it would be possible to record the time course of the fire or the time course of the development of the fire, so as to determine the effectiveness of setting and holding the different levels of reduction in the shelter. In particular, it would be possible to obtain a statement as to which required amount of inert gas still has to be supplied to the protective space for extinguishing the fire.

The invention is not limited only to the previously described inert gas fire extinguishing systems; Rather, it also relates to an inertization process preferably carried out with the inert gas fire extinguishing system according to the invention for reducing the risk and for extinguishing fires in a shelter. In this inertization method, in a first method step, the oxygen content in the protective space is lowered to a specific first lowering level. This is done by preferably controlled introduction of an oxygen-displacing gas (inert gas), which is stored in at least one high-pressure gas storage under high pressure or is provided by a nitrogen generator. Subsequently, the oxygen content in the shelter - possibly by controlled tracking of inert gas or by continuous introduction of further inert gas - held at or below the first lowering level. In the event of a fire in the shelter or as needed, the oxygen content in the shelter is then further lowered from the first descent level to a particular second descent level. According to the invention, in the inertization method it is provided that the lowering of the oxygen content in the protective space to the first lowering level corresponding to a first inertization curve, which is predetermined by a pressure reduction characteristic of a first pressure reducing device, which is arranged in a first parallel branch, and that the further lowering of the oxygen content in Protection space to the second lowering level is carried out according to a second inertization curve, which is predetermined by a pressure reduction characteristic of a second pressure reducing device, which is arranged in a second parallel branch.

Of course, it is also conceivable that, if necessary, a further reduction of the oxygen content in the shelter from the second subsidence level to a certain third subsidence level.

The inertization process according to the invention can be carried out in particular by an inert gas fire extinguishing system which, as described above, has a pressure reduction device with at least two parallel branches, and in which the oxygen-displacing gas is stored under high pressure up to, for example, 300 bar in high pressure gas reservoirs (such as steel tanks). Before the oxygen-displacing gas is introduced into the protective space, this initially high accumulator pressure is reduced to a working pressure of preferably a maximum of 60 bar by a pressure-reducing device arranged in a first parallel branch of the pressure-reducing device. The pressure reduction device arranged in the first parallel branch comprises a diaphragm with a pre-defined diaphragm opening, which is calculated for example by means of suitable software, in order to reduce the pressure.

It is known that with the emptying of the high-pressure gas storage, the storage pressure in the extinguishing agent containers and thus also the inlet pressure applied to the pressure-reducing device arranged in the first parallel branch sinks. Also, the working pressure behind the orifice of the pressure reducing device, i.e., the pressure decreases. the outlet pressure of the arranged in the first parallel branch Druckreduzierungseinrichtun.

With the sinking pressures in the high-pressure gas storage or behind the orifice of the pressure-reducing device arranged in the first parallel branch, the mass / volume flow introduced into the protected area also reduces in the case of oxygen-displacing gas. In order to introduce a defined amount of oxygen-displacing gas in a predetermined time in the protection area, so care must be taken that at the beginning of the flooding a correspondingly high mass / volume flow is present, this present at the beginning of flooding high mass / volume flow of the with the emptying of the high-pressure gas storage decreasing Be \ Torratungsdruck ablängt. The problem, however, is that the high mass / volume flow present at the beginning of the flooding exposes the protected area to corresponding loads due to overpressure, turbulence, etc.

With the solution according to the invention, it is possible that in a particularly easy to implement yet effective manner, the mass / volume flow over the available time can be evened out to prevent pressure and flow peaks at the beginning of the flooding and thus the necessary protective measures in the protected area (eg pressure relief opening area) to a minimum.

For example, it is possible with the inventive solution that the supply of oxygen-displacing gas is activated in one step, this supply is combined with a gradual switching behind the extinguishant supply arranged parallel branches of the pressure reducing device - and thus of pressure reducing devices, for example in the form of orifices. In this way it is achieved that the oxygen-displacing gas flows at the beginning of the flooding at high supply pressure through a small diaphragm cross-section and with decreasing supply pressure through a stepwise enlarged diaphragm cross-section. Thus, the volume flow peak occurring in conventional extinguishing systems is capped at the beginning of the flooding, whereby the resulting safety measures can be reduced.

The connection of the individual parallel branches of the pressure reducing device, and thus the connection of the individual pressure reducing devices, for example in the form of orifices can be done in addition, wherein at certain (predetermined) times another parallel branch is added in the extinguishing agent flow and the aperture cross sections of coming to reduce the pressure used Add pressure reduction devices. Alternatively, it is of course also conceivable that parallel branches of the pressure reducing device, in which pressure reducing devices with different sized aperture (or more generally expressed with different pressure reduction characteristics) for the different times and switched off again.

More generally, therefore, the invention also relates to an inerting method for reducing the risk and extinguishing fires in a shelter in which a high pressure oxygen displacing gas is first reduced to a working pressure and then introduced into the shelter to reduce the oxygen content in the shelter to lower to a certain lowering level, wherein for reducing the pressure of the oxygen-displacing gas stored under high pressure, a first pressure reducing device is used, through which already at the beginning of lowering the oxygen content, the oxygen displacing gas flows, and wherein at least to further reduce the pressure of the stored under high pressure oxygen-displacing gas a second pressure reducing device is used, through which the oxygen-displacing gas flows only after a predetermined time after the beginning of the lowering.

In the following, exemplary embodiments of the inert gas fire extinguishing system according to the invention will be described in more detail with reference to the accompanying drawings.

Fig. 1

eine schematische Ansicht einer ersten beispielhaften Ausführungsform der erfindungsgemäßen Inertgasfeuerlöschanlage;

Fig. 2

eine schematische Ansicht einer weiteren beispielhaften Ausführungsform der erfindungsgemäßen Inertgasfeuerlöschanlage;

Fig. 3a

den zeitlichen Verlauf der Sauerstoffkonzentration in einem Schutzraum bei Anwendung eines mit Hilfe einer Ausführungsform der erfindungsge- mäßen Inertgasfeuerlöschanlage durchgeführten Inertisierungsverfahrens;

Fig. 3b

den zeitlichen Verlauf eines quantitativen Messwertes einer Brandkenngrö- ße bzw. des Rauchpegels in einem Schutzraum, in welchem die Sauerstoff- konzentration gemäß dem in Fig. 3a gezeigten Kurvenverlauf mit Hilfe ei- ner bevorzugten Ausführungsform der erfindungsgemäßen Inertgasfeuerlö- schanlage abgesenkt wird;

Fig. 4a

den zeitlichen Verlauf der Sauerstoffkonzentration in einem Schutzraum bei der Anwendung einer Ausführungsform der erfindungsgemäßen Inert- gasfeuerlöschanlage zur Durchführung eines mehrstufigen Inertisierungs- verfahrens, wobei bereits während der Reduzierung des Sauerstoffgehaltes auf ein erstes Absenkungsniveau der Brand erloschen ist;

Fig. 4b

den zeitliche Verlauf des quantitativen Messwertes einer Brandkenngröße bzw. des Rauchpegels in einem Schutzraum, in welchem die Sauerstoffkon- zentration gemäß dem in Fig. 4a gezeigten Kurvenverlauf mit Hilfe einer bevorzugten Ausführungsform der erfindungsgemäßen Inertgasfeuerlö- schanlage abgesenkt wird; und

Fig. 5

eine schematische Ansicht einer weiteren beispielhaften Ausführungsform der erfindungsgemäßen Inertgasfeuerlöschanlage, die in Gestalt einer Mehrbereichsanlage ausgeführt ist.

It shows:

Fig. 1

a schematic view of a first exemplary embodiment of the inert gas fire extinguishing system according to the invention;

Fig. 2

a schematic view of another exemplary embodiment of the inert gas fire extinguishing system according to the invention;

Fig. 3a

the time course of the oxygen concentration in a protective space when using an inertization process carried out with the aid of an embodiment of the inert gas fire extinguishing system according to the invention;

Fig. 3b

the time course of a quantitative measured value of a fire parameter or the smoke level in a shelter in which the oxygen concentration according to the in Fig. 3a shown curve curve is lowered by means of a preferred embodiment of the inert gas fire extinguishing system according to the invention;

Fig. 4a

the time course of the oxygen concentration in a shelter in the application of an embodiment of the inert gas fire extinguishing system according to the invention for carrying out a multi-stage inerting process, already during the reduction of the oxygen content to a first lowering level of the fire is extinguished;

Fig. 4b

the temporal course of the quantitative measured value of a fire parameter or the smoke level in a shelter, in which the oxygen concentration in accordance with the in Fig. 4a shown curve profile is lowered by means of a preferred embodiment of the inert gas fire extinguishing system according to the invention; and

Fig. 5

a schematic view of another exemplary embodiment of the inert gas fire extinguishing system according to the invention, which is designed in the form of a multi-range system.

Fig. 1 1 shows a schematic view of a first preferred embodiment of the inert gas fire extinguishing system 100 according to the invention. The inert gas fire extinguishing system 100 has a total of 5 high-pressure gas storages 1a, 1b, 1c, 2a, 2b which are each designed, for example, as commercially available 200 bar or 300 bar high-pressure gas cylinders. It would also be conceivable to use one or more high-pressure gas storage containers, for example in the form of high-pressure gas storage tubes, instead of high-pressure gas cylinders. In the high-pressure gas reservoirs 1a, 1b, 1c, 2a, 2b, an oxygen-displacing gas or gas mixture, consisting for example of nitrogen, carbon dioxide and / or noble gas, is stored under high pressure.

In the illustrated embodiment, the inert gas fire extinguishing system 100, the high-pressure gas storage 1a, 1b, 1c, 2a, 2b in two groups consisting of the high-pressure gas storage 1a, 1b, 1c and the high-pressure gas storage 2a, 2b divided. The division of the high-pressure gas storage 1a, 1b, 1c and 2a, 2b in high-pressure gas storage batteries has the advantage that not all high-pressure gas storage 1a, 1b, 1c, 2a, 2b at the same time, but in a multi-stage inert gas fire extinguishing system for setting a certain Absenkungsniveaus in the room atmosphere of a shelter only the high-pressure gas storage 1a, 1b, 1c and 2a, 2b can be used.

Each high-pressure gas storage 1a, 1b, 1c, 2a, 2b is connected to a high-pressure manifold 3 via a quick opening valve 11a, 11b, 11c, 12a, 12b. If necessary, the respective quick-opening valves 11a, 11b, 11c, 12a, 12b can be controlled by a control device 7 via corresponding control lines 13a, 13b in order to connect the associated high-pressure gas reservoir 1a, 1b, 1c, 2a, 2b to the high-pressure manifold 3.

The high-pressure manifold 3 is connected to a pressure reducing device 6. The object of the pressure reducing device 6 is to reduce the oxygen displacing gas flowing into the high pressure manifold 3 under high pressure after opening at least one quick opening valve 11a, 11b, 11c, 12a, 12b to a predetermined operating pressure of, for example, 60 bar. Accordingly, there is at the input side of the pressure reducing device 6, a relatively high gas pressure, which is reduced by means of pressure reducing means 22, 32 to the low operating pressure. The output side of the pressure reduction device 6 is connected to a low-pressure extinguishing line 4, via which the oxygen-displacing gas throttled down in the pressure reduction device 6 to an operating pressure determined by the pressure reduction devices 22, 32 is supplied to the protective space 10. As schematically in Fig. 1 illustrated, the low-pressure extinguishing line 4 opens in the shelter 10 via a plurality of extinguishing nozzles. 5

According to the invention, the pressure reducing device 6 at least two, in the embodiment according to Fig. 1 exactly two parallel branches 21, 31. In each parallel branch 21, 31, one of the already mentioned pressure reducing devices 22, 32 is arranged. By way of corresponding controllable by means of the control device 7 valves 23, 33, the individual pressure reducing means 22, 32 of the respective parallel branches 21, 31 on the one hand to the high-pressure manifold 3 and on the other hand with the Low pressure extinguishing line 4 connectable. Although in the illustration according to Fig. 1 the respective valves 23, 33 are arranged between the high-pressure manifold 3 and the corresponding pressure-reducing device 22, 32, it is of course also conceivable that the valves 23, 33 are present between the corresponding pressure-reducing devices 22, 32 and the low-pressure extinguishing line 4.

For controlling the respective valves 23, 33 of the pressure reducing device 6 corresponding control lines 24, 34 are provided, via which control commands from the control device 7 to the valves 23, 33 can be transmitted. Furthermore, the control device 7 is connected via control lines 13a and 13b to the already mentioned quick-opening valves 11a, 11b, 11c, 12a, 12b of the high-pressure gas reservoirs 1a, 1b, 1c, 2a, 2b in order to supply, if necessary, the quick-opening valves 11a, 11b, 11c, 12a, 12b associated high-pressure gas storage 1a, 2b, 1c, 2a, 2b to connect with either the high-pressure manifold 3 can.

At the in Fig. 1 In the illustrated embodiment of the inert gas fire extinguishing system 100, the pressure reduction devices 22, 32 provided in the two parallel branches 21, 31 can each have, for example, different pressure reduction characteristics. For example, it is conceivable that the pressure reduction device 22 arranged in the first parallel branch 21 is designed as a pressure reducer with a pressure reduction characteristic constant over a defined pressure range. If therefore the valve 23 is opened to flood the protective space 10 with the aid of the control device 7 and the valve 33 arranged in the second parallel branch 31 flows, if at least one quick-opening valve 11a, 11b, 11c, 12a, 12b has been opened with the aid of the control device 7 - The present in the high-pressure manifold 3 under high pressure oxygen displacement gas through the first parallel branch 21 of the pressure reduction device 6 to the low-pressure extinguishing line 4 and from there via the extinguishing nozzles 5 in the shelter 10. Since arranged in the first parallel branch 21 pressure reduction device 22 at according to the exemplary embodiment Fig. 1 has a constant pressure reduction characteristic is - if the valve 23 is opened and the valve 33 is closed - the protective space 10 per unit time, a constant amount of oxygen-displacing gas supplied. In the case of the supply of inert gas via the first parallel branch 21 of the pressure reduction device 6, therefore, the inertization curve runs in a straight line. The steepness of the (rectilinear) Inertisierungskurve is on the one hand by the volume of space of the enclosed shelter 10 and on the other hand by the reduced by means of the pressure reducing device 22 (constant) operating pressure at the output of the pressure reducing device 6 dependent. Depending on which pressure value, for example, the pressure reduction device 22 designed as a pressure reducer reduces the high pressure present in the high-pressure manifold 3, the straight-line inerting curve runs more or less steeply.

The pressure reduction device 32 arranged in the second parallel branch 31 can, for example, likewise be designed as a pressure reducer, which therefore supplies a constant outlet pressure over a certain working range independently of the inlet pressure. It is preferably provided that the pressure reduction characteristic curve of the pressure reduction device 32 arranged in the second parallel branch 31 is designed differently from the pressure reduction characteristic line of the pressure reduction device 22 arranged in the first parallel branch 21. Thus, it is conceivable, for example, that the pressure reduction device 32 arranged in the second parallel branch is designed to provide a constant outlet pressure that is greater in comparison with the reduced pressure present at the outlet of the pressure reduction device 22 arranged in the first parallel branch 21. In this way, it is possible that the oxygen-displacing gas is supplied with different volume flows to the shelter 10 by a suitable control of the valves 23, 33. With regard to a necessary pressure relief, the maximum volume flow supplied to the protection space 10 should be matched to the maximum permissible amount of inert gas that can be supplied to the protection space 10 per unit time.

As in Fig. 1 the inert gas fire extinguishing system 100 according to the invention is further equipped with a fire detection system, which has at least one fire characteristic quantity sensor 9. This fire characteristic quantity sensor 9 is connected in the illustrated embodiment via a control line to the control device 7. With the help of the fire detection system is checked continuously or at predetermined times or events, whether in the room air of the enclosed space 10 a fire has broken out. When a fire parameter is detected, the fire characteristic variable sensor 9 sends a corresponding signal to the control device 7. The control device 7 then preferably automatically initiates the inerting of the enclosed space 10.

The inertization method that can be implemented with the aid of the control device 7 is subsequently used in conjunction with FIGS FIGS. 3a, 3b and 4a, 4b described.

Of the Fig. 1 It can also be seen that the inert gas fire extinguishing system 100 according to the embodiment shown by way of example is also equipped with a sensor 8 for detecting the oxygen concentration in the room atmosphere of the protective space 10. The measured values taken by the sensor 8 continuously or at predetermined times or events are fed to the control device 7 via a corresponding data line. In this way, it is possible that with the aid of the control device 7, the oxygen concentration in the shelter 10 at a predetermined lowering level can be maintained by possibly required tracking of oxygen-displacing gas within a certain control range.

In Fig. 2 a further embodiment of the inert gas fire extinguishing system 100 according to the invention is shown. The structure corresponds to the in Fig. 2 shown inert gas fire extinguishing system 100 substantially the previously with reference to Fig. 1 described plant; with the exception that in Fig. 2 In the embodiment shown, the pressure reduction device 6 has a total of three parallel branches 21, 31 and 41, each having a pressure reduction device 22, 32, 42. Each parallel branch 21, 31, 41 of the pressure reducing device 6 is connected via a corresponding controllable by the control device 7 valve 23, 33, 43 with the high-pressure manifold 3 and the low-pressure extinguishing line 4 connectable.

Preferably, in the in Fig. 2 illustrated embodiment, the individual pressure reducing means 22, 32, 42 different pressure reduction characteristics. By either by controlling the valves 23, 33, 43 selectively either one of the three parallel branches 21, 31, 41, or two of the three parallel branches 21, 31, 41, or all three parallel branches 21, 31, 41 simultaneously with the high pressure On the one hand and the low-pressure extinguishing line 4 are connected on the other hand, the inerting of the shelter 10 can be carried out according to a total of six different inerting curves.

The in the FIGS. 1 and 2 illustrated pressure reducing means 21, 31, 41 may be formed as a pressure reducer having a constant, straight-line pressure reduction characteristic at least over a certain input pressure range, so that - regardless of the input pressure (pressure in the high-pressure manifold 3) - a constant output pressure unit is provided. If the pressure reduction takes place only with a pressure reducer, then the inertization curve assumes a straight course with a certain slope, the slope of the inertization curve can be influenced by varying the amount of oxygen displacing gas flowing through the pressure reducing device 6 per unit time.

On the other hand, it is of course also conceivable, however, that at least some of the pressure reduction devices 22, 32, 42 used in the pressure reduction device 6 are designed as pressure diaphragms, wherein a pressure reduction takes place by a change in cross section by means of a throttle plate with a bore of a specific diameter. The size of the bore is adapted to the inert gas fire extinguishing system according to the intended use. A pressure reduction device, in which the pressure reduction takes place with the aid of a pressure diaphragm, has a curved pressure reduction characteristic, which is dependent on the course of the inlet pressure (pressure in the high-pressure manifold 3) and thus pressure peaks, in particular immediately after opening one of the quick-opening valves 11a, 11b , 11c, 12a, 12b.

If the inerting of the protective space 10 takes place via a pressure reduction device, which has the pressure reduction of a pressure diaphragm, the inerting curve assumes an arcuate development.

Although in the FIGS. 1 and 2 schematically shown embodiments of the inert gas fire extinguishing system 100 according to the invention are shown as a single-area extinguishing systems, of course, the use as a multi-range fire extinguishing system is conceivable. For this purpose, it is only necessary to provide, for example downstream of the pressure reduction device 6 corresponding multi-range valves, of which lead low-pressure extinguishing pipes to the respective shelters. The controller 7 controls the multi-range valves accordingly to connect certain low pressure purge lines to the output of the pressure reducing device 6.

The following is with reference to the FIGS. 3a, b and 4a, b a described with the inert gas fire extinguishing system according to the invention 100 inerting process described.

Fig. 3a and Fig. 3b show in each case the oxygen concentration and the quantitative measured value of a detected with the help of the fire characteristics sensor 9 fire characteristic or the smoke level in the shelter 10, wherein with the aid of an inert gas fire extinguishing system 100 according to the present invention, a multi-stage inerting process is performed. The representations in the FIGS. 3a and 3b It can be seen that until the time t ₀ in the shelter 10, an oxygen concentration of about 21 vol .-% is present and thus corresponds to the oxygen concentration of the normal ambient air.

At the time t ₀ , the inerting of the protective space 10 begins by continuously supplying an oxygen-displacing gas until the time t _{1 of} the room atmosphere of the enclosed space 10. The representation in Fig. 3a It can be seen that in the time interval t ₀ - t _1, the inerting curve is rectilinear and relatively flat. This curve shape of the inertization curve is possible, for example, by connecting a first of the at least two parallel branches 21, 31, 41 of the pressure reduction device 6 to the high-pressure manifold 3 and the low-pressure extinguishing line 4, in which first parallel branch 21 a pressure reduction device 22 designed as a pressure reducer is provided.

At time t ₁ , the oxygen content in the enclosed space 10 is reduced to a first subsidence level of, for example, 15.9 vol%. At this first lowering level, the oxygen content is maintained until time t ₂ . This is preferably done by continuously measuring the oxygen concentration in the shelter 10 with the help of the oxygen sensor 8, and by introducing oxygen displacing gas or fresh air into the shelter in a controlled manner. The term "maintaining the oxygen concentration at your particular subsidence level" is understood to mean maintaining the oxygen concentration within a certain control range, ie, within a range defined by upper and lower thresholds. The maximum amplitude of the oxygen concentration in this control range is adjustable in advance and is for example 0.1 to 0.4 vol .-%.

In the in Fig. 3a shown scenario is at the time t ₀ a fire alarm of the in the FIGS. 1 and 2 shown fire characteristic detector 9 delivered to the control device 7, which controls the implementation of the inerting, ie the lowering of the oxygen content to the first lowering level. Specifically, at this point in time t _0, the smoke level or the quantitative measured value of the fire parameter, which is detected continuously or at predefined times by the fire characteristic detector 9, has exceeded a first threshold value (alarm threshold 1) Fig. 3b can be seen. In response to this fire alarm, the oxygen content in the shelter is reduced from the original 21 vol% to the first descent level. The first subsidence level (subsidence level 1) corresponds to the one in Fig. 3a illustrated curve of an oxygen concentration of about 15.9 vol .-%. As the timing of the Fig. 3a can be seen, the lowering of the oxygen content to the first lowering level within a relatively long period of time (t ₁ - t ₀ ), since during the inerting, ie during the lowering of the oxygen content to the first lowering level, already an active fire fighting takes place.

By continuously monitoring the fire development in the shelter 10 during the lowering of the oxygen content to the first subsidence level, it can be determined whether the fire has already completely extinguished during the subsidence.

In the in the FIGS. 3a and 3b In the scenario shown, the fire could not be completely extinguished until the time t ₂ , as the development of the fire parameters in accordance with Fig. 3b can be seen. Rather, in the illustrated scenario, the quantitative value of the fire parameter increases steadily in the room air of the shelter 10, in spite of the reduction of the oxygen content to the first lowering level. This is an indication that despite the reduced oxygen content of the fire in the shelter 10 is not extinguished.

If, what in the in the FIGS. 3a and 3b shown scenario, after expiration of a first predetermined time .DELTA.T1, ie at time t _2, the quantitative measured value of the fire characteristic exceeds a second predetermined alarm threshold, it is assumed that the fire is not extinguished, so that the output at time t ₀ Fire alarm is confirmed once again. The confirmation of the fire alarm at time t ₂ causes the oxygen concentration in the shelter 10 to be lowered relatively rapidly from the first descent level (eg, 15.9 vol% oxygen) to a second descent level. This is done by rapidly introducing a certain amount of oxygen-displacing gas (inert gas), so that relatively quickly after the operation of the fire alarm at time t _2, the oxygen concentration has reached the second lowering level in the amount of, for example, 13.8 vol .-% oxygen. The comparison of the inerting curve in the time intervals t ₀ - t ₁ and t ₂ - t ₃ shows that when lowering the oxygen content to the second lowering level, the inerting curve is also rectilinear, but a significantly larger slope compared to the inerting curve in the time interval between t ₀ and t ₁ .

The slope of the inerting curve is increased in the illustrated embodiment, for example, by a second parallel branch 31 is switched on in the pressure reduction device 6 in addition to the first parallel branch 21, in which a pressure reduction device 32 is arranged in the form of a pressure reducer. In contrast to the pressure reducing device 22, which is arranged in the first parallel branch 21 of the pressure reducing device 6, however, the pressure reducing device 32 of the second parallel branch 31 is preferably designed to deliver a higher outlet pressure, so that the inerting curve is steeper in the lowering to the second lowering level ,

The associated curve of the Fig. 3b It can be seen that the reintroduction of inert gas for adjusting the second lowering level has not led to a complete containment of the fire in the shelter cracked. Although the quantitative measured value of the fire parameter initially shows a stagnation in a time window ΔT2, which means that the spread of the fire in the shelter could at least be suppressed, the smoke level or the quantitative measured value of the fire parameter increases again after a certain time and exceeds even the alarm threshold 3, at which a main alarm is triggered. The exceeding of the alarm threshold 3 takes place at the in Fig. 3b illustrated scenario at time t ₄ .

Reconfirming the fire alarm at time t ₄ causes the oxygen content in the shelter to be lowered further from the second descent level to the full inertization level, this time by introducing as fast as possible a corresponding amount of oxygen displacing gas into the space atmosphere of the shelter. Specifically, for this purpose, at least two parallel branches 21, 31 are simultaneously opened in the pressure reduction device 6, in order to thus enable the largest possible inert gas throughput through the pressure reduction device 6. Since the pressure reducing devices 22, 32 used for pressure reduction are each designed as pressure reducers, the inerting curve again assumes a rectilinear course when lowering the oxygen content from the second lowering level to the third lowering level (full inerting level), although the gradient of the inerting curve is again is increased.

The Vollinertisierungsniveau is preferably set such that it corresponds to an oxygen concentration, which is below the ignition limit of existing materials in the shelter (fire load). By setting the Vollinertisierungsniveaus in the shelter so the fire is completely extinguished by oxygen deprivation, at the same time a re-ignition of the materials in the shelter is effectively prevented.

The curve of the Fig. 3b It can be seen that after setting the Vollinertisierungsniveaus (at time t ₅ ), the quantitative measurement of the fire characteristic decreases continuously, which means that the fire is extinguished or extinguished. The full inertization level should be maintained at least until the temperature in the shelter has dropped below the critical limit of ignition of the material. However, it would also be conceivable that the Vollinertisierungsniveau is held until emergency services have arrived and taken by means of a manual release, for example, the inert gas fire extinguishing system from its automatic fire extinguishing mode.

In carrying out the inertization process, as exemplified by the FIGS. 3a and 3b is shown, the Vollinertisierungsniveau is thus set via two intermediate stages, namely the first and the second lowering level. In this case, a different pressure reduction measure is used for each intermediate stage, which is ultimately reflected in the curve of the inerting curve.

In the FIGS. 4a and 4b another scenario is presented in which the reduction of the oxygen content from originally 21% by volume to the first subsidence level (for example 15.9% by volume) is carried out according to a rectilinear inertization curve which deliberately has such a low slope that only after a relatively long time, the oxygen content in the shelter is lowered to the first lowering level. Due to the slow introduction of the oxygen-displacing gas into the shelter no special pressure relief measures must be provided. Furthermore, during the lowering of the oxygen content, the fire development or fire extinguishment can be observed very accurately.

At the in Fig. 4 The scenario shown is the curve of the Fig. 4b It can be seen that after the fire alarm is released at time t _0, the quantitative measured value of the fire parameter first stagnates and then continuously decreases, which is an indication of this is that the fire in the shelter has gone out. At time t ₁ , the quantitative measured value of the fire parameter falls below the first alarm threshold, as a result of which the introduction of oxygen-displacing gas for setting the first lowering level can be set. Accordingly, the solution according to the invention enables a needs-based adaptation of the amount of inert gas used for deletion.

In Fig. 5 is a schematic view of another exemplary embodiment of the inert gas fire extinguishing system 100 according to the invention, this time the inert gas fire extinguishing system 100 is designed in the form of a multi-range system, with which a preventive fire protection or fire extinguishing for a total of two shelters 10-1 and 10-2 of one and the same Inertgasfeuerlöschanlage 100 is provided.

As already mentioned, it is problematic in conventional multi-range fire extinguishing systems that regardless of which of the shelters is to flood with an oxygen-displacing gas, the inerting of the shelter is carried out according to one and the same event sequence. Thus, in conventional multi-range fire extinguishing systems, a shelter having a relatively small volume of space is supplied with the same amount of oxygen displacing gas per unit time as a shelter having a relatively large volume of space. Since the amount of inert gas which can be supplied by the inert-gas fire extinguishing system per unit of time depends, in particular, on the existing pressure relief measures of the respective protective rooms, this means that under certain circumstances the inerting of a protected area may be much slower than would actually be possible.

With the solution according to the invention, which in an exemplary embodiment in Fig. 5 is shown is achieved in a particularly easy to implement yet effective manner that a preventive fire protection or fire extinction for several shelters 10-1, 10-2 with one and the same inert gas fire extinguishing system 100 can be achieved, with a fire or if needed in the With regard to one of the multiple shelters 10-1, 10-2 inertization to be initiated is adaptable to the respective shelter. In particular, it is taken into account here that, for example, in the case of differently dimensioned shelters, an inert gas quantity introduced at maximum per unit of time for inerting is adapted to the corresponding shelter. As already indicated at the outset, in particular the available pressure relief and the compressive strength of the space envelope determined the maximum permissible amount of inert gas introduced per unit of time into the protected space. This maximum allowed, per unit of time in the Protected space introduced inert gas ultimately sets the event sequence in the inerting of the shelter, ie the applicable for the room inerting curve.

In the Fig. 5 schematically illustrated multigrade fire extinguishing system 100 substantially corresponds to the single-range fire extinguishing system, which previously with reference to the representation in Fig. 1 has been described. In detail, the multi-range fire extinguishing system 100 according to Fig. 5 a plurality of high-pressure gas storage 1a, 1b, 1c, 2a, 2b, which in turn may each be designed, for example, as commercially available 200-bar or 300-bar high-pressure gas cylinders, and in which an oxygen-displacing gas or gas mixture is stored under high pressure. Each high-pressure gas storage 1a, 1b, 1c, 2a, 2b can be connected to a high-pressure collecting pipe 3 via a quick-opening valve 11a, 11b, 11c, 12a, 12b which can be activated by a control device 7. The high-pressure manifold 3 is connected to a pressure reducing device 6, which at least two, in the embodiment according to Fig. 5 exactly two parallel branches 21, 31 has. In each parallel branch 21, 31, one of the already mentioned pressure reducing devices 22, 32 is arranged. The individual pressure reducing devices 22, 32 of the respective parallel branches 21, 31 can be connected to the high-pressure manifold 3 on the one hand and to a low-pressure extinguishing line 4 connected to the output side of the pressure reduction device 6 via corresponding valves 23, 33 that can be controlled by the control device 7.

Unlike the in Fig. 1 schematically illustrated single-range fire extinguishing system divides at the in Fig. 5 illustrated multi-range fire extinguishing system 100 connected to the output side of the pressure reducing device 6 low-pressure extinguishing line 4 in two parallel branches 4-1 and 4-2, each parallel branch 4-1, 4-2 in one of the two shelters 10-1, 10- 2 in each case via a plurality of extinguishing nozzles 5 opens. Each parallel branch 4-1, 4-2 of the low-pressure extinguishing line 4 can be connected to the low-pressure extinguishing line 4 and thus to the outlet side of the pressure-reducing device 6 via a range valve 41, 42 that can be activated by the control device 7.

At the in Fig. 5 illustrated embodiment of the multi-zone fire extinguishing system 100, the provided in the two parallel branches 21, 31 of the pressure reduction device 6 pressure reduction devices 22, 32 each have a adapted to one of the two shelters 10-1, 10-2 pressure reduction characteristic. For example, it is conceivable that the pressure reduction device arranged in the first parallel branch 21 22 has adapted to the maximum allowable load of the first shelter 10-1 pressure reduction characteristic. Accordingly, when the first protective space 10-1 is flooded with the aid of the control device 7, the valve 23 is opened and the valve 33 arranged in the second parallel branch 31 closes, if at least one quick-opening valve 11a, 11b, 11c, 12a flows with the aid of the control device 7 12b, the oxygen-displacing gas present in the high-pressure manifold 3 is passed through the first parallel branch 21 of the pressure-reducing device 6 to the low-pressure extinguishing line 4. Assuming that the area valve associated with the first protective chamber 10-1 is opened with the aid of the control device 7 41 is opened and the second protection chamber, 10-2 associated area valve 42 is closed, flows in the first parallel branch 21 of the pressure reducing device 6 pressure-reduced gas via the parallel branch 4-1 and the extinguishing nozzles 5 in the first shelter 10-1.

Since the pressure reduction device 22 arranged in the first parallel branch 21 has a pressure reduction characteristic adapted to the maximum permissible load of the first protection space 10-1, the inerting of the first protection space 10-1 takes place in accordance with an event sequence which can be specifically adapted to the first protection space 10-1.

Since the pressure reduction device 32 arranged in the second parallel branch 31 of the pressure reduction device 6 can correspondingly have a pressure reduction characteristic adapted to the maximum permissible load of the second protection space 10-2 so that, if required, the inerting of the second protection space 10-2 according to one to the second protection space 10-2 customizable event sequence can be done.

Claims (14)

1. An inert gas fire extinguisher (100) for reducing the risk of and extinguishing fires in a protected room (10, 10-1, 10-2), wherein the inert gas fire extinguisher (100) comprises at least one high-pressure gas tank (1a, 1b, 1c; 2a, 2b) in which an oxygen-displacing gas is stored under high pressure, wherein the high-pressure gas tank (1a, 1b, 1c; 2a, 2b) is connectable to a collecting line (3) via a quick-release valve (11a, 11b, 11c; 12a, 12b), and wherein an extin-guishing line (4, 4-1, 4-2) is further provided which is connected on one side to the collecting line (3) via a pressure-reducing device (6) and on the other side to extinguishing nozzles (5),
   characterized in that
   the pressure-reducing device (6) comprises at least two parallel branches (21, 31, 41), each having a pressure-reducing unit (22, 32, 42), wherein each parallel branch (21, 31, 41) is connectable to the collecting line (3) and the extinguishing line (4, 4-1, 4-2) via a controllable valve (23, 33, 43), and wherein each pressure-reducing unit (22, 32, 42) is designed to reduce a high input pressure to a low output pressure according to a preset pressure-reducing characteristic.
2. The inert gas fire extinguisher (100) according to claim 1,
   wherein a control device (7) is further provided to automatically effect a multistage inerting process in which the oxygen content in the protected room (10, 10-1, 10-2) is first lowered to a first reduced level and then further lowered as needed to another preset reduced level or successively to multiple preset reduced levels, wherein the control device (7) is designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to set the reduced level such that the oxygen content in the protected room (10, 10-1, 10-2) reduces in accordance with a preset inerting curve.
3. The inert gas fire extinguisher (100) according to claim 2,
   wherein the control device (7) is designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to lower the oxygen content to the first reduced level such that only one first parallel branch (21; 31) of the at least two parallel branches (21, 31, 41) is connected to the collecting line (3) and the extinguishing line (4, 4-1, 4-2), and
   wherein the control device (7) is further designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to further lower the oxygen content to a second reduced level such that only one second parallel branch (31; 21) of the at least two parallel branches (21, 31, 41) is connected to the collecting line (3) and the extinguishing line (4, 4-1, 4-2),
   wherein the pressure-reducing characteristic of the pressure-reducing unit (22) arranged in the first parallel branch (21) differs from the pressure-reducing characteristic of the pressure-reducing unit (32) arranged in the second parallel branch (31).
4. The inert gas fire extinguisher (100) according to claim 2,
   wherein the control device (7) is designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to lower the oxygen content to the first reduced level such that only one first parallel branch (21) of the at least two parallel branches (21, 31, 41) is connected to the collecting line (3) and the extinguishing line (4, 4-1, 4-2), and
   wherein the control device (7) is further designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to further lower the oxygen content to a second reduced level such that the first parallel branch (21) and a second parallel branch (31) of the at least two parallel branches (21, 31, 41) are connected to the collecting line (3) and the extinguishing line (4, 4-1, 4-2).
5. The inert gas fire extinguisher (100) according to any one of claims 2 to 4,
   wherein the pressure-reducing device (6) comprises at least three parallel branches (21, 31, 41) each having a pressure-reducing unit (22, 32, 42), wherein each parallel branch (21, 31, 41) is connectable to the collecting line (3) and the extinguishing line (4, 4-1, 4-2) via a controllable valve (23, 33, 43), and wherein each pressure-reducing unit (22, 32, 42) is designed to reduce a high input pressure to a low output pressure according to a preset pressure-reducing characteristic, and
   wherein the control device (7) is designed to control the valves (23, 33, 43) of the pressure-reducing device (6) to lower the oxygen content from the second reduced level to a third reduced level such that only one third parallel branch (41) of the at least three parallel branches (21, 31, 41) is connected to the collecting line (3) and the extinguishing line (4, 4-1, 4-2).
6. The inert gas fire extinguisher (100) according to any one of the preceding claims,
   wherein at least some of the pressure-reducing units (22, 32, 42) exhibit a pressure-reducing characteristic with which, irrespective of a set input pressure, the output pressure does not exceed a predefined pressure value.
7. The inert gas fire extinguisher (100) according to any one of the preceding claims,
   wherein at least some of the pressure-reducing units (22, 32, 42) exhibit a pressure-reducing characteristic with which the output pressure is proportionally dependent on the input pressure.
8. The inert gas fire extinguisher (100) according to any one of the preceding claims,
   wherein at least some of the pressure-reducing units (22, 32, 42) exhibit a pressure-reducing characteristic with which, irrespective of a set input pressure, the output pressure assumes a predefinable constant pressure value over at least a specific range of pressure.
9. The inert gas fire extinguisher (100) according to any one of the preceding claims which comprises at least two high-pressure gas tanks (1a, 1b, 1c; 2a, 2b) which are connectable to a collecting line (3) via a quick-release valve (11a, 11b, 11c; 12a, 12b), wherein a parallel branch having a pressure-reducing unit (22, 32, 42) is allocated to each high-pressure gas tank (1a, 1b, 1c; 2a, 2b) such that when the quick-release valve (11a, 11b, 11c; 12a, 12b) of one high-pressure gas tank (1a, 1b, 1c; 2a, 2b) of the at least two high-pressure gas tanks (1a, 1b, 1c; 2a, 2b) opens, the valves (23, 33, 43) automatically control the pressure-reducing device (6) such that only the parallel branch (21, 31, 41) allocated to the one high-pressure gas tank (1a, 1b, 1c; 2a, 2b) is connected to the extinguishing line (4, 4-1, 4-2) and the collecting line (3).
10. An inerting method for reducing the risk of and extinguishing fires in a protected room (10, 10-1, 10-2) in which an oxygen-displacing gas stored under high pressure is first reduced to a working pressure and subsequently introduced into the protected room (10, 10-1, 10-2) so as to lower the oxygen content in the protected room (10, 10-1, 10-2) to a specific reduced level,
    characterized in that
    a first pressure-reducing unit (22; 32) arranged in a first parallel branch (21; 31) is used to reduce the pressure of the oxygen-displacing gas stored under high pressure, and through which the oxygen-displacing gas flows as soon as the oxygen content begins to be lowered; and that
    at least one second pressure-reducing unit (32; 22) arranged in a second parallel branch (31; 21) is further used to reduce the pressure of the oxygen-displacing gas stored under high pressure, and through which the oxygen-displacing gas only flows after a predefined period of time has passed since the oxygen content began to be lowered.
11. The inerting method according to claim 10,
    wherein the first pressure-reducing unit (22; 32) is a pressure aperture exhibiting a first aperture cross-section, and wherein the second pressure-reducing unit (22; 32) is a pressure aperture exhibiting a larger aperture cross-section than the first aperture cross-section.
12. The inerting method according to claim 10 or 11,
    wherein after the predefined time set for reducing the pressure has passed, the oxygen-displacing gas flows through both the first pressure-reducing unit (22; 32) as well as through the at least one second pressure-reducing unit (32; 22).
13. The inerting method according to any one of claims 10 to 12, wherein the inerting method comprises the following steps:

    a) lowering the oxygen content in the protected room (10) to a specific first reduced level;

    b) maintaining the oxygen content in the protected room (10) at or below the first reduced level; and

    c) in the event of a fire in the protected room (10) or if otherwise needed, the oxygen content in the protected room (10) is further lowered from the first reduced level to a specific second reduced level,

    wherein the lowering of the oxygen content in the protected room (10) to the first reduced level ensues in accordance with a first inerting curve which is predetermined by a pressure-reducing characteristic of the first pressure-reducing unit (22; 32), and wherein the further lowering of the oxygen content in the protected room (10) to the second reduced level ensues in accordance with a second inerting curve which is predetermined by a pressure-reducing characteristic of the second pressure-reducing unit (32; 22).
14. The inerting method according to claim 13,
    wherein at least one fire parameter is measured in the protected room (10, 10-1, 10-2), preferably continuously, in order to determine the presence of fire in said protected room (10, 10-1, 10-2).

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