Firefighting system for photovoltaic modules installed on roofs

Abstract

Firefighting system for a photovoltaic module (03) installed on a roof (02) of a building (01), comprising - a storage tank (04) in the attic of the building (01), which has at least one foam agent chamber (17), a water chamber (18) filled with water and a pressure agent chamber (16); - a mixing unit (19) which is connected to the chambers (16, 17, 18) of the storage container (04) and provides a fire-fighting foam to a supply line (06) upon supply of foam agent, water and pressure medium; - an outlet line (07) which is fed by the supply line (06), has numerous outlet openings (12) and is positioned above the photovoltaic module (03) mounted on the roof (02) in such a way that the fire-fighting foam emerging from the outlet openings (12) automatically flows downwards over the entire width of the photovoltaic module (03); - at least two trigger elements (08, 09), of which a first (08) is positioned inside the building and a second (09) outside the building (01), wherein the trigger elements are accessible for actuation by an operator and positioned away from the storage container (04), wherein upon actuation of at least one trigger element the foam agent, water and pressure medium are fed from the storage container (04) to the mixing unit (19) in order to generate the fire-fighting foam, and wherein the trigger elements are mechanically actuated switches and / or comprise an electrical control.

Description

[0001] The invention relates to a firefighting system for photovoltaic modules installed on roofs. Photovoltaic modules are used in so-called solar systems to generate electrical power. To ensure high levels of solar radiation, photovoltaic modules are often installed on the roofs of buildings. However, in the event of a fire in the photovoltaic modules, this also makes extinguishing efforts more difficult, and the fire can therefore quickly spread to the entire building. Furthermore, there is an increased risk for firefighters during extinguishing operations during a conventional firefighting operation, because high electrical voltages can be present at the solar system.

[0002] DE 10 2011 053 616 B4 discloses a device for monitoring critical temperature developments in solar systems with photovoltaic modules. For this purpose, a large number of temperature sensors are distributed throughout the solar system to provide sufficiently reliable information about the presence of a critical condition within the system. When a temperature threshold is reached, a signal is sent to an analysis and control unit. This device does not allow for immediate firefighting.

[0003] DE 20 2010 014 995 U1 describes a fire extinguishing system for a house roof with or without a solar energy system. The system has a triggering device designed to move a hose coupling and at least a section of an extinguishing line from a resting state to an operating state, thus facilitating the establishment of a connection between the extinguishing line and an extinguishing agent source. Once activated, a fire blanket rolls from a folded position and spreads out over the entire solar panel or roof surface. After being filled with extinguishing agent, the fire blanket falls onto the entire fire surface, thereby preventing air from reaching the fire. The extinguishing agent exits holes in the ceiling and flows through the gaps between the solar modules to the fire site. This system is complex in design and prone to error in use.

[0004] DE 10 2010 050 589 A1 describes a device for fire protection of a roof-mounted solar collector system. A fire protection device is located between solar modules and a roof on which the solar modules are arranged. The fire protection device comprises a pipe network with several water outlets, which are electrically connected to a control unit for opening. Furthermore, a temperature sensor can be attached to at least one solar module. The fire protection device can be controlled externally using a control module connected to the control unit.

[0005] BRANDSCHUTZ KNOPF, http: / / www.brandschutzknopf.de / loeschverfahren / kompakt-schaum / brandschutzphotovoltaik-loeschanlage / , describes in "Fire Protection Photovoltaic Extinguishing System," pages 1-4, a photovoltaic extinguishing system that includes one or more compressed air cylinders, a compact foam container, and a control valve. The photovoltaic extinguishing system is triggered via a pressurized trigger line laid beneath the solar panels. This trigger line triggers the extinguishing process via a control valve when a defined temperature is exceeded due to an increase in pressure. A foaming unit is mounted above the solar panels, to which a water-foam mixture is fed, forming a compact foam.

[0006] Based on the prior art, it is an object of the present invention to provide an improved firefighting system which, in the event of a fire on photovoltaic modules, enables safe firefighting, remains permanently ready for use, does not require complicated electronics and, in the event of an emergency, also protects the firefighting forces from excessive danger from electrical voltages.

[0007] This object is achieved by a fire-fighting system according to the appended claim 1.

[0008] The firefighting system according to the invention is particularly, but not exclusively, suitable for fighting fires on photovoltaic modules installed on roofs. In any case, at least parts of the firefighting system are mounted on the outer skin of the roof of a building, as will be explained below. The firefighting system initially has a storage tank that contains at least one foam agent chamber, one water chamber, and one pressurized agent chamber. In the simplest case, the pressurized agent chamber is filled with compressed air, for example in the form of a compressed air cylinder, which thus forms a component of the storage tank. Alternatively, other gases can be used as pressurized agents, such as compressed nitrogen or carbon dioxide. Water is stored in the water chamber.The foam agent chamber contains a foam agent which, when mixed with the water and the pressure agent, forms a firefighting or extinguishing foam that is preferably non-electrically conductive or only slightly electrically conductive. Such foam agents are known to those skilled in the art.

[0009] The firefighting system also features a mixing unit connected to the chambers of the storage tank. When foam agent, water, and pressurized fluid are added, the firefighting foam is delivered to a supply line. In the simplest case, the mixing unit is a mixing valve or a section of the supply line.

[0010] An outlet line, fed by the supply line, is another component of the firefighting system. The outlet line is positioned above the photovoltaic modules mounted on the roof of the building and has numerous outlet openings arranged in such a way that the firefighting foam emerging from the outlet openings automatically flows downwards across the entire width of the photovoltaic modules.

[0011] Finally, the firefighting system has at least two trigger elements, which are accessible to an operator and positioned away from the storage tank. When at least one trigger element is activated, the foam agent, water, and pressurized agent are fed from the storage tank to the mixing unit to generate the firefighting foam. Activating the trigger element, for example, opens the pressurized agent chamber, allowing the pressurized agent to expel the foam agent and water.

[0012] A key advantage of the firefighting system is that photovoltaic modules or similar roof-mounted components can be extinguished quickly and safely in the event of a fire. This effectively protects both these components and the building on which they are mounted. The use of firefighting foam also interrupts the photovoltaic modules' power production in the event of a fire, because sunlight can no longer reach the photovoltaic modules once the firefighting foam has spread over them. This facilitates the deployment of firefighters, who no longer have to fear the danger of electrical shock.

[0013] The fire suppression system is generally suitable for firefighting on a wide variety of roof systems and, in the event of a fire, also serves to extinguish or preventively protect the roof structure. The fire suppression system thus provides a significant increase in safety and shortens the time required to start firefighting. Thus, the fire suppression system increases the overall safety of the building in which it is deployed.

[0014] In a preferred embodiment of the firefighting system, the outlet pipe is made of a fire-resistant material, such as steel. This prevents damage to the outlet pipe in the event of a fire, thus preserving the functionality of the firefighting foam. Of course, the outlet pipe can be visually adapted to the roof design, for example, by painting it.

[0015] The outlet duct is preferably attached to the existing photovoltaic module mounts or to the roof with its own mounts. A distance of between 10 and 20 cm is preferably maintained between the outlet duct and the exterior of the roof covering. According to an advantageous embodiment, the outlet openings in the outlet duct are arranged such that the firefighting foam flows downwards along both the top and bottom of the photovoltaic modules. This covers the modules from above and simultaneously prevents the oxygen supply from below, thus extinguishing the fire.

[0016] According to the invention, the storage container is located in the attic of the building. This creates only a slight difference in height between the storage container and the outlet openings, so that only a slight overpressure is required to direct the firefighting foam to the outlet openings. Preferably, the storage container is located at a height less than two meters lower than the outlet openings of the discharge line.

[0017] An advantageous embodiment is characterized by the fact that the supply line runs parallel to the installation lines of the photovoltaic modules in some sections. This allows the existing feedthroughs to also be used for the supply line.

[0018] According to an embodiment not according to the invention, the storage container is a mobile container that is not located in the attic. For example, the storage container can be mounted on a fire department vehicle. In this case, the supply line is installed as a riser on the building and is connected to the mobile container in the event of a fire. However, this increases the time required to extinguish the fire.

[0019] It is advisable for at least one section of the supply line to be made of an electrically insulating material. This ensures that, even in the event of a defect, no electrical voltage is transmitted via the supply line to the storage tank, which could cause damage.

[0020] In an advantageous embodiment, a shut-off valve, which can preferably be manually closed, is installed between the mixing unit and the discharge line. The user can use this shut-off valve to stop an inadvertently triggered firefighting action and interrupt the supply of firefighting foam to the discharge openings.

[0021] According to the invention, the firefighting system has two triggering elements, a first of which is installed inside the building, for example, near the electrical control box of the photovoltaic modules, and a second of which is positioned outside the building to allow firefighters to activate the firefighting system before entering the building. In the simplest case, the triggering elements can be mechanically operated switches that cause the pressure chamber to open. In modified embodiments, the triggering elements can comprise an electrical control system, allowing, for example, remote control via a radio signal or via a data network.

[0022] It is advantageous if the firefighting foam generated in the mixing unit is electrically non-conductive. This further prevents further damage that could be caused by short circuits.

[0023] A further developed embodiment of the fire-fighting system includes a fire sensor that sends a trigger signal to the trigger unit upon detection of a fire in the solar panel. This allows fire-fighting to be activated automatically if necessary.

[0024] Further advantages and details of the invention will become apparent from the following description of preferred embodiments, with reference to the drawings. Fig. 1 a simplified overview of a building with a roof and a fire-fighting system according to the invention attached thereto; Fig. 2 a simplified plan view of an outflow line arranged above photovoltaic modules; Fig. 3 a detailed view of a supply line with shut-off valve; Fig. 4 a detailed view of a storage tank of the fire fighting system.

[0025] In Fig. Figure 1 shows a highly simplified schematic diagram of a firefighting system according to the invention, which is installed in a building 01. The building 01 has a roof 02, on which several photovoltaic modules 03 are mounted, which provide electrical power when exposed to sunlight. The firefighting system has a storage tank 04, which is located in the attic and whose structure with respect to Fig. 4 is described in more detail below. The storage container 04 is connected to a supply line 06 in order to be able to provide firefighting foam to an outlet line 07 in the event of activation. The outlet line 07 extends on the outside of the roof 02 above the photovoltaic modules 03. To activate the provision of firefighting foam, a first trigger element 08 arranged in the building or a second trigger element 09 attached to the outside of the building 01 must be actuated.

[0026] Fig. Figure 2 shows a top view of the photovoltaic modules 03 mounted on the roof. The discharge line 07 runs across the entire width of the photovoltaic modules 03 and is attached to brackets 11. The discharge line 07 has numerous discharge openings 12 from which the firefighting foam emerges and then flows downwards across the entire width of the photovoltaic modules 03 to cover them and extinguish a fire. The shape of the discharge openings 12 can be adapted to the firefighting foam and the desired distribution.

[0027] Fig. Figure 3 shows a detailed drawing of a section of the supply line 06. To ensure electrical isolation between the discharge line 07 and the storage tank 04, at least one section 13 of the supply line 06 is made of electrically insulating material. Furthermore, a shut-off valve 14 is provided in the supply line 06, which can be used to interrupt the supply of firefighting foam.

[0028] Fig.Figure 4 shows a simplified schematic diagram of the storage tank 04. This comprises at least three chambers, namely a pressurized medium chamber 16, a foam agent chamber 17, and a water chamber 18. A mixing unit 19 is also provided, which is connected to the chambers of the storage tank 04. In the simplest case, the mixing unit 19 can be integrated into the storage tank 04 or enclosed in the supply line. When foam agent, water, and pressurized medium are supplied to the mixing unit 19, fire-fighting foam is formed, which is fed to the supply line 06 and then fed to the discharge line 07. The first and / or second trigger element serve to activate the fire-fighting system, for example by opening the pressurized medium chamber 16, so that the water from the water chamber 18 is mixed with the foam agent from the foam agent chamber 17 and expelled. Reference symbol 01 Building 02 Roof 03 Photovoltaic modules 04 Storage container 05 - 06 Supply line 07 Outlet line 08 first trigger element 09 second trigger element 10 - 11 holders 12 outlet openings 13 electrically insulating section of the supply line 14 Shut-off valve 15 - 16 Pressure medium chamber 17 Foam chamber 18 Water chamber 19 Mixing unit

Claims

[1] Firefighting system for a photovoltaic module (03) installed on a roof (02) of a building (01), comprising - a storage tank (04) in the attic of the building (01), which has at least one foam agent chamber (17), a water chamber (18) filled with water and a pressure agent chamber (16); - a mixing unit (19) which is connected to the chambers (16, 17, 18) of the storage container (04) and provides a fire-fighting foam to a supply line (06) upon supply of foam agent, water and pressure medium; - an outlet line (07) which is fed by the supply line (06), has numerous outlet openings (12) and is positioned above the photovoltaic module (03) mounted on the roof (02) in such a way that the fire-fighting foam emerging from the outlet openings (12) automatically flows downwards over the entire width of the photovoltaic module (03); - at least two trigger elements (08, 09), of which a first (08) is positioned inside the building and a second (09) outside the building (01), wherein the trigger elements are accessible for actuation by an operator and positioned away from the storage container (04), wherein upon actuation of at least one trigger element the foam agent, water and pressure medium are fed from the storage container (04) to the mixing unit (19) in order to generate the fire-fighting foam, and wherein the trigger elements are mechanically actuated switches and / or comprise an electrical control. [2] Firefighting system according to claim 1, characterized by that the outlet line (07) is made of a fireproof material. [3] Firefighting system according to claim 1 or 2, characterized bythat the outlet openings (12) in the outlet line (07) are arranged in such a way that the fire-fighting foam runs downwards both on the top and on the bottom of the photovoltaic module (03). [4] Firefighting system according to one of claims 1 to 3, characterized by that the storage tank (04) is positioned in the attic of the building (01) at a height less than two meters lower than the outlet openings (12) of the outlet line (07). [5] Firefighting system according to one of claims 1 to 4, characterized by that at least one section (13) of the supply line (06) consists of an electrically insulating material. [6] Firefighting system according to one of claims 1 to 5, characterized by that a shut-off valve (14) is inserted between the mixing unit (19) and the outlet line (07), which is preferably manually lockable. [7] Firefighting system according to one of claims 1 to 6, characterized by that the firefighting foam produced in the mixing unit (19) is electrically non-conductive. [8] Firefighting system according to one of claims 1 to 7, characterized by that it comprises a fire sensor which, upon detection of a fire on the photovoltaic module (03), delivers a trigger signal to the trigger elements (08, 09).

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