A method for fire prevention in a storage unit and a storage unit employing said method

Abstract

A method for preventing fire in a storage unit (1) comprising a housing (10), defining a chamber, and a ventilation unit (6); the method comprising the steps of refrigerating (610) goods located in the chamber using the ventilation unit (6); sensing (310) one or more of heat and gas using a sensing device (31) located in the chamber; sending (311) a signal from the sensing device (31) to a control unit (32), the control unit (32) being associated with the ventilation unit (6) and comprising a signal processing device (33); processing (330) the signal using the signal processing device (33) to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped; triggering (320) the ventilation unit (6) using the control unit (32) when the predetermined threshold is reached or overstepped; and when the ventilation unit (6) is triggered, stopping (611) the supply of cooled air into the chamber; and supplying (621) gas into the chamber using the ventilation unit.

Description

[0001] A method for fire prevention in a storage unit and a storage unit employing said method

[0002] Technical field

[0003] The present invention relates to a method for fire prevention in a storage unit and a storage unit employing said method.

[0004] Background Art

[0005] Cold stores or cool stores are refrigeration rooms or buildings designed for the storage of goods in a cooled environment. Cold stores are often located near shipping ports used for import and export of goods needing refrigeration, such as food and food stuff.

[0006] In recent years there has been some catastrophic fires on ships related to the import and export of electric cars. Also, fire in parking garages caused by electric vehicles has been more prevalent with the increased interest in electric cars. The fire related to electric bikes and electric scooter has also been increasing in past years.

[0007] When a fire occurs inside electric vehicles, such as electric cars, electric scooters or e-bikes, it occurs in the battery of the vehicle. This is due to too high ambient temperatures and eventually wrong voltage and a chemical process very quickly generating heat, which can result in fires and release of toxic gases from a battery, e. g. hydrochloric acid and other acids released from thermal runaway. Latter acid is corrosive and dangerous for human beings. The battery fire process is called "thermal runaway" because the fire itself generates heat and very important also oxygen, such that the fire can spread to nearby material.

[0008] The higher ambient temperature the higher is the likelihood for a sudden fire in a battery of an electric vehicle. Therefore, electric vehicles should be stored in temperature controlled areas to mitigate the risk of a fire breaking out in such a vehicle. The problem is that once fire in a battery of electric vehicle occurs, it cannot be fought by firefighting methods like water and foam. Therefore, the fire continues until all flammable material has been consumed.

[0009] Summary of the invention

[0010] With this background it is an object of the present invention to alleviate the risk of fire in a storage unit storing batteries for electric vehicles and / or electric vehicles containing batteries.

[0011] This is achieved with a method for preventing fire in a storage unit, wherein the storage unit comprises a housing, defining a chamber, and a ventilation unit; the method comprising the steps of: refrigerating goods using the ventilation unit by supplying cooled air through a first inlet into the chamber; sensing one or more of heat and gas using a sensing device, the sensing device being located in the chamber; sending a signal from the sensing device to a control unit the control unit being associated with the ventilation unit and the control unit comprising a signal processing device; processing the signal using the signal processing device to determine whether a predetermined threshold related to the sensed one or more of heat, and gas is reached or overstepped; triggering the ventilation unit using the control unit when it is determined that the predetermined threshold is reached or overstepped; and when the ventilation unit is triggered: stopping the supply of cooled air into the chamber through the first inlet; and supplying gas into the airtight chamber through a second inlet using the ventilation unit.

[0012] Refrigerating the stored goods permanently using the ventilation unit reduces the likelihood for a fire in a lithium battery during storage of both electric vehicles containing batteries or solely the batteries of electric vehicles. A cooled environment during storage is also suitable for other goods, such as food and foodstuff.

[0013] Heat and gas, such as smoke gases and / or toxic gases, are common signs of fire. Sensing heat enables early alarming of the control unit independent of the goods about a fire outbreak. Sensing for gas, besides heat in the storage unit, enables fire detection in batteries to be done even more reliably, as toxic gasses, e.g., hydrochloric acid and other acids released from thermal runaway, are released during a fire in batteries. The invention is thus specifically suitable to store goods and prevent fire in goods containing batteries.

[0014] Supplying a gas into the storage unit through a second inlet removes oxygen from the atmosphere around the goods. Without oxygen fire cannot spread. In case of a lithium battery, only that one battery "melts" instead of the fire consuming all stored goods and potentially the entire storage unit. By stopping the air supply through a first inlet more oxygen is prevented from entering into the storage unit.

[0015] In an embodiment a gas selected from the group consisting of: helium, neon, argon, krypton, xenon, radon, nitrogen and combinations thereof is supplied into the chamber through the second inlet, when triggered by the control unit.

[0016] Helium, neon, argon, krypton, xenon, and radon are noble gasses, also called inert gasses. These gasses can be injected into the atmosphere surrounding the stored goods when heat or gasses are detected in the storage unit. When injected into the atmosphere, noble gasses remove the oxygen from the atmosphere. Without oxygen potential fire cannot spread in the cargo. The same is the case, when injecting nitrogen into the atmosphere surrounding the goods.

[0017] In an embodiment one or more of heat, hydrochloric acid, and other acids released from thermal runaway is sensed by the sensing device.

[0018] When a fire occurs inside lithium batteries it can result in the release of toxic gases. Examples of these toxic gases are hydrochloric acid and other acids released from thermal runaway. They are corrosive and dangerous for human beings. Sensing for these toxic gases specifically reduces the risk of damage, both in the storage unit, as well as on the people handling the stored goods. In principle, such a thermal runaway starts at a temperature of between 90 and 105 degrees Celsius and is once started irreversible or unstoppable. Therefore, it is desired to keep the batteries and thus the chamber cooled to temperatures as far below 90 degrees as Celsius possible. On the other hand, very cold batteries tend to easier go into thermal runaway in case of a fire. Also, the lower the temperature to be kept in the chamber, the more expensive the cooling becomes. Therefore, keeping the batteries and thus the chamber cooled at too low temperatures is not desirable either.

[0019] In an embodiment cooled air is supplied by the ventilation unit into the chamber through the first inlet, such that a temperature of the air in the storage unit stays at a temperature of between 10 and 20 degrees Celsius, of between 12 and 18 degrees Celsius, of between 14 and 17 degrees Celsius or of between 15 and 16 degrees Celsius.

[0020] Alternatively, cooled air is supplied by the ventilation unit into the chamber through the first inlet, such that a temperature of the air in the storage unit stays at a temperature less than 20 degrees Celsius, less than 16 degrees Celsius, less than 15 degrees Celsius, less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degree Celsius, or of between 5 and 25 degrees Celsius, between 12 and 25 degrees Celsius, between 12 and 16 degrees Celsius, or between 15 and 16 degrees Celsius.

[0021] To prevent fires in lithium batteries temperatures of lower degrees are desirable, as the ambient temperature has a decisive influence on the likelihood of a sudden fire occurring in lithium batteries. Other temperatures may also be able to achieve the desired effect.

[0022] In an embodiment the predetermined threshold for triggering the ventilation unit when sensing heat is a temperature of the air in the housing. The temperature of the air in the housing as a threshold may be measured in a suitable unit, such as degrees Celsius. Exemplary appropriate thresholds may be 20 degrees Celsius, 16 degrees Celsius, 15 degrees Celsius, 12 degrees, 5 degrees or 1 degree Celsius. However other temperatures may also be suitable thresholds.

[0023] In an embodiment the predetermined threshold for triggering the ventilation unit when sensing gas is a predetermined amount of the sensed gas in the air in the housing. A predetermined amount of the sensed gas may be measured in a suitable unit of volume, such as ml / m3, ppm or in percent of the total volume of air in the housing.

[0024] In an embodiment one or more of heat, gas, and a person being present in a vicinity of the sensing device is detected by the sensing device employing Al. Using an Al sensor may detect a sudden fire within the stored goods earlier than traditional sensors. Using sensors based on Al may assure the safety of the personnel in the storage unit. By sensing a person in the vicinity of the sensor, when a fire breaks out, the person may be warned. The person is then able to remove themselves from the situation, before being damaged. By sensing a person in a vicinity of the sensor, it may also be possible to alert help early, if the person is not able to remove themselves from the situation. Furthermore, sensing a person in a vicinity of the sensor allows to delay the supply of a gas through the second inlet until the person is in safety. With an on-premises server, heat and gas detection may be performed in real time. The Al may operate based on image recognition. It may be trained based on pictures from similar situations, where fire in lithium batteries occurred in similar spaces, e.g., closed storage facilities, cargo vessels or parking spaces, with the sensing device being located for example beneath the battery. An Al based image sensing device may be a lidar or a camera.

[0025] In an embodiment, the method comprises the step of retrofitting at least the ventilation unit, the sensing device, and the control unit are retrofitted to the storage unit.

[0026] Thereby it becomes possible to also prevent fires in storage units that are not originally build with a ventilation unit, sensing device, and control unit according to the invention.

[0027] In a second aspect there is provided a storage unit for storing batteries, the storage unit comprising a housing defining a chamber, at least one ventilation unit having a first and a second inlet, the ventilation unit is configured to supply cooled air through the first inlet into the chamber; a sensing device located in the chamber and configured to sense one or more of heat and gas; and a control unit, associated with the sensing device and the ventilation unit, the control unit comprising a signal processing device, the signal processing device being configured to receive a signal from the sensing device and to process the received signal to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, and the control unit being configured to trigger the ventilation unit when it is determined that the predetermined threshold is reached or overstepped; wherein the ventilation unit further comprises a gas source and is configured to supply gas through the second inlet into the chamber when triggered by the control unit; and wherein the ventilation unit further is configured to stop supplying air through the first inlet into the chamber when triggered by the control unit.

[0028] The storage unit may be part of a bigger storage facility. The storage unit may alternatively be a storage building configured to store entire cars.

[0029] There is preferably provided one ventilation unit for every ventilation zone. The separation into different ventilation zones allows for the stored goods to be treated differently in terms of temperature, ventilation air amounts, and / or composition of the air or gas used for ventilation. In this manner it becomes simple to store different types of refrigerated goods, as the climate in the ventilation zone can be adjusted. The storage unit is suitable for different goods and can be used for storage of different goods simultaneously. The ventilation unit is provided with a first inlet, allowing air supply into the housing. The ventilation unit is provided with a second inlet connected to a pure gas source, allowing gas supply into the housing when the ventilation unit is triggered by the control unit.

[0030] In an embodiment the goods are batteries of electric vehicles and / or goods with batteries. Fire in storage units may be related to the increased demand of electric vehicles, such as electric cars, scooters, or bikes. These fires may be related specifically to the batteries in these electric vehicles. The sudden fires may also occur in any other goods containing such batteries.

[0031] In an embodiment at least a part of the housing is provided with a support surface.

[0032] The support surface may comprise throughgoing ventilation openings allowing ventilation of the storage unit. For the sake of simplicity and to allow even ventilation, draining etc. the openings in the support surface may be distributed substantially evenly, but more complex configurations are also possible. The support surface may be part of one or more platforms. By arranging goods on platforms, and the possibility of arranging the platforms on the storage unit in a highly compact manner results in a significant improvement of the capacity of the storage unit. The platforms may be loaded with any type of commodities, but with the ventilation openings of the support surface, allowing for air circulation needed for controlling temperature and the atmosphere surrounding the stored goods, platforms may specifically suited for cargo needing refrigeration under storage, such as goods with batteries, for example electric vehicles, but also food and foodstuff. The support surface may be provided with a grating. This makes it efficient, reliable and relatively cheap, as gratings are a standard commodity and therefore available all over the world. It may be used to keep the goods elevated above the housing surface so that air may circulate through the stored goods.

[0033] In a preferred embodiment of the storage unit, the ventilation unit is configured to supply a gas selected from the group consisting of: helium, neon, argon, krypton, xenon, radon, nitrogen and combinations thereof into the chamber through the second inlet, when triggered by the control unit.

[0034] In a preferred embodiment of the storage unit, the sensing device is configured to sense one or more of heat, hydrochloric acid, and other acids released from thermal runaway.

[0035] In a preferred embodiment of the storage unit, the ventilation unit is configured to supply cooled air is supplied by the ventilation unit into the chamber through the first inlet, such that a temperature of the air in the storage unit stays at a temperature of between 10 and 20 degrees Celsius, of between 12 and 18 degrees Celsius, of between 14 and 17 degrees Celsius or of between 15 and 16 degrees Celsius.

[0036] In a preferred embodiment of the storage unit, the ventilation unit is configured to supply cooled air at a temperature of less than 20 degrees Celsius, less than 16 degrees Celsius, less than 15 degrees Celsius, less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degrees Celsius, or of between 5 and 25 degrees Celsius, between 12 and 25 degrees Celsius, between 12 and 16 degrees Celsius, or between 15 and 16 degrees Celsius, into the chamber.

[0037] In a preferred embodiment of the storage unit, the predetermined threshold for triggering the ventilation unit when sensing heat is a temperature of the air in the storage unit.

[0038] In a preferred embodiment of the method, the predetermined threshold for triggering the ventilation unit when sensing gas is a predetermined amount of the sensed gas in the air in the storage unit.

[0039] In a preferred embodiment of the storage unit, the sensing device is configured to employ Al to detect one or more of heat, gas, and a person present in a vicinity of the sensing device.

[0040] In an embodiment, the storage unit may be retrofitted with the ventilation system, the sensing device and / or the control unit.

[0041] In a third aspect there is provided a method for providing a storage unit according to the invention, the method comprising: providing a storage unit, and retrofitting the storage unit with a ventilation system and a sensing device.

[0042] In an embodiment, the method further comprises retrofitting the storage unit with a control unit.

[0043] Other embodiments and further advantages will be apparent from the subsequent detailed description and drawings.

[0044] Brief Description of Drawings

[0045] Fig. 1 illustrates a perspective cross-section of an embodiment of a storage unit,

[0046] Fig. 2 illustrates a cross-section of an embodiment of a storage unit,

[0047] Fig. 3 illustrates a front-view of an embodiment platform,

[0048] Fig. 4 illustrates schematically a fire prevention device, and

[0049] Fig. 5 illustrates schematically steps of a method of preventing fire in a storage unit according to the invention.

[0050] Detailed Description In the following detailed description, preferred embodiments of the present invention will be described.

[0051] Fig. 1 shows an example of a storage unit 1 according to the invention. The storage unit 1 has four walls 12, a floor 100 and a roof 13 defining a chamber. One or more of the walls 12 may have a door to access the chamber. Goods that require cooling during storage may be placed in the storage unit 1. The goods may be placed on the floor 100 of the storage unit 1. The floor 100 of the storage unit 1 may be provided with a support surface 11. The support surface 11 may comprise through- going ventilation openings allowing for even ventilation.

[0052] In an embodiment the storage unit 1 may be of such size, that the unit can store electric vehicles in it. In another embodiment, the storage unit 1 may be of such size, that the unit is intended to store the batteries of electric vehicles. In another embodiment, the storage unit 1 may be of such size, that the unit is intended to store batteries by themselves. In another embodiment, the storage unit 1 may be of such size, that the unit is intended to store goods of any feasible type containing batteries.

[0053] In an embodiment, the goods may be stored on platforms 9. In this embodiment the support surface 11 is part of one or more platforms 9. The support surface 11 may in practice be formed either by a platform 9 or by the floor itself. In another embodiment, the support surface 11 may also be formed by racks that are located within the storage unit 1. These racks may especially be suitable for a storage unit 1 intended to store the batteries of electric vehicles or smaller electric vehicles, such as electric scooters. The support surface 87 may thus take up the whole floor or platform 9 or only a part of the floor or platform 9.

[0054] Storing the goods on platforms 9 is especially advantageous if the storage unit 1 is located near a harbour. When located near a harbour the storage unit 1 may store goods for intercontinental transport by oversea vessels. Storing the goods on platforms 9 allows for a more continuous workload for personnel in a harbour. Instead of having to transport the goods into the storage unit, such as onto a vessel, one-by-one, the goods can be arranged on the platforms 9 on shore before storage and the loaded platforms 9 may be directly taken into the storage unit, such as onto the vessel.

[0055] An example of such a platform 9 is shown in Fig. 3. The upper surface 91 of the platform 9 may be in the form of a grate. It is, however, also possible to use a grid-like structure with bars crossing each other, a perforated plate or the like.

[0056] In the embodiment shown, the platform 9 is downwards open and resting on four legs 92. In this way the platform 9 is kept elevated above the surface on which it rests.

[0057] In the storage unit 1 the legs 92 provide a space between the floor of the storage unit and the surface of the platform 9, and this space allows very efficient ventilation where air / gas is also able to be distributed underneath the stored goods so that ventilation is performed in an even manner. By providing the upper surface 91 of the platform 9 with a support surface 11, the air / gas may circulate through the stored goods, providing a more even ventilation.

[0058] The platform 9 shown in Fig. 3 is of a both simple and open structure and therefore easy to maintain. If using platforms of a more complex or closed design, they may advantageously be separable, for instance by attaching grates constituting the upper and lower surfaces to a frame by means of bolts or other fastening means such as latches or spring locks.

[0059] When transporting the loaded platforms on a vessel for intercontinental transportation it may be advantageous that the cargo / goods is / are secured. This particularly applies when transporting cars, and the platforms may therefore comprise at least one fastening device for securing a cargo item to the upper surface 91.

[0060] As shown in Fig. 2, a ventilation unit 6 comprising ventilating fans and air conditioning equipment 64 provided at one side of the storage unit. The air conditioning equipment 64 is supplemented with a gas source 63 at the same side of the storage unit. The gas source 63 may be provided at the other side of the storage unit in another embodiment of the invention. The gas source 63 is provided for use when an artificial atmosphere, like nitrogen, is used by the ventilation unit 6 instead of or as a supplement to ambient air. Ambient air is taken into the storage unit through a first inlet 61, where it is cooled or heated, if necessary, by the air conditioning equipment 64. From here the air is led into the storage unit. The first inlet 61 may comprise ventilating fans to distribute the air in the storage unit. The air in the storage unit 1 may be mixed with other gasses, which may be supplied from the gas source 63 through a second inlet 62 into the storage unit. The second inlet 62 may comprise an injection nozzle to inject the gas into the storage unit. While Fig. 2 shows the first 61 and the second inlet 62 as two separate inlet openings in the storage unit, it shall be understood that 'inlet' does not refer to openings in the wall or walls of the storage unit. 'Inlet' rather refers to an intake into the ventilation unit. In other words, the first and second inlet are meant to let at least two different gasses, such as nitrogen, or gas mixtures, such as air, into the ventilation unit from two different sources. In one embodiment, as seen in Fig. 2, the first inlet 61 takes ambient air into the ventilation unit and the ventilation unit comprises ventilating fans to lead ambient air into the storage unit. The second inlet 62 is connected to a gas source 63, and the ventilation unit comprises injection nozzles to lead a gas, i.e., nitrogen, into the storage unit. In another embodiment, the ventilation unit may lead the air from the first inlet and the gas from the second inlet into the storage unit through the same inlet opening 66, such as illustrated in Fig. 2.

[0061] The air or air mixture is distributed into the storage unit. The outlet opening 65 is located in the storage unit, such that the air or air mixture moves through the stored goods, while moving from the inlet opening 66 to the outlet opening 65. In Fig. 2 the outlet opening 65 is located in the wall opposite of the wall in which the inlet opening 66 is located. The air or air mixture flows through an outlet opening 65 and is eventually blown out by ventilation equipment 67, which may include a heat exchanger and / or a gas recovery unit.

[0062] Only a single set of ventilation units has been described, but in other embodiments several sets may be employed depending amongst others on the size and capacity of the storage unit, on the demands for ventilation and conditioning of the atmosphere, and on the capacity of the units employed. Moreover, the storage unit may be divided into several individually climate-controlled storage compartments, which may have access doors between them. It is further possible that not all but only some of the cargo compartments are climate-controlled cargo compartments.

[0063] There may be multiple inlet openings 66 in each storage unit and / or climate-controlled storage compartment to assure sufficient ventilation and supply of inert gas when necessary. There may be inlet openings supplying each 10x10 m space of a storage unit with ventilation and / or inert gas independent of the sizing of the storage unit or storage compartment. Other distances, such as every 5x5 m or every 15x15 m, may also be possible.

[0064] Fig. 2 illustrates a storage unit with several individually climate-controlled storage compartments. In this embodiment the storage unit has the dimension of for example a parking garage, in which electric vehicles can be stored. Each floor 100, 200, 300, 400 constitutes an individually climate-controlled storage compartment.

[0065] In the example of Fig. 2 the illustrated ventilation unit 6 is employed to control the atmosphere of the first floor 100 of the storage unit. In this storage unit the first inlet 61 and the second inlet 62 lead respectively the air and gas into a ventilation duct from which the mixture is lead into the floor 100 through a single inlet opening 66. Further ventilation units may be employed to control the atmosphere of each other floor 200, 300, 400 respectively.

[0066] Alternatively, a bigger storage facility may comprise one or more individual storage units according to an embodiment of the present invention. It is also possible to use an uneven number of conditioning and ventilating units, where one conditioning unit works with two or more ventilating units or vice versa.

[0067] When storing electric vehicles and / or the batteries of electric vehicles, it is appreciated, that in the ventilation zone in which the electric vehicles and / or batteries are located during storage, the air circulating through the storage unit may be cooled to around 0 degrees Celsius at all times. A cooled ambient air reduces the risk of sudden fire in the batteries of electric cars. However, other, higher, temperatures are possible, such as between 10 and 20 degrees Celsius, of between 12 and 18 degrees Celsius, of between 14 and 17 degrees Celsius or of between 15 and 16 de- grees Celsius, or such as 20 degrees, 16 degrees, 15 degrees, 12 degrees or 5 degrees Celsius, to reduce the risk already.

[0068] The possibility of multiple ventilation zones in the same storage unit allows for the storage of different goods, even though the stored goods may require different cooling or heating during the storage compared to electric vehicles or batteries thereof.

[0069] Depending on the goods, not all ventilation zones of a storage unit and / or not all cargo compartments need be cooled. It is therefore appreciated, that the different ventilation zones of a storage unit may each have their own ventilation unit 6, which can be controlled independent of the other ventilation units.

[0070] Referring to Fig. 4, the ventilation unit 6 is further associated with a control unit 32, which is located within the storage unit. The ventilation unit 6 and the control unit 32 may be able to communicate with each other via a wired or a wireless communication.

[0071] The control unit 32 is responsible for triggering heating or cooling of the incoming air to a predetermined temperature, and the optional addition of gas to the air, before the air circulates through the housing of the storage unit. Thereby, the control unit 32 control the air circulated through the stored goods. The control unit is further associated with a sensing device 31. The sensing device 31 is configured to sense heat and gas. The sensing device 31 comprises one or more sensors 34 for sensing for heat and gas. The sensing device 31 and the control unit 32 may be connected by a wired or a wireless signal communication. The sensing device 31 and the control unit 32 may be separate units as shown in Fig. 4, or they may be integrated into one unit.

[0072] The sensing device 31 may be a traditional sensor, such as a smoke alarm, or a sensor based on Al. The sensing device 31 may be located underneath the stored goods at a floor of the storage unit. Alternatively, or additionally, the sensing device 31 may be located above the stored goods at a roof of the storage unit. The goods are placed on the respective support surface 11 of the storage unit. This may either be the floor of the storage unit and / or platforms. The sensing device 31 is configured to sense heat and gas and to transmit signals with the recorded sensing data to the control unit 32. In the control unit 32, the sensing data received from the sensing device 31 is processed by a signal processing device 33.

[0073] The sensing device 31 may be based on artificial intelligence, Al. Using an Al sensor may detect a sudden fire of stored goods within such a storage unit earlier than traditional sensors. Sensing devices 31 based on artificial intelligence may be trained to recognise patterns quickly. A sensing device 31 based on Al may be trained with images and / or heat data of burning vehicle batteries or other batteries of electric vehicles, such as electric bikes or scooters, taken and / or measured from the same position as the sensing device assumes in the storage unit in relation to the stored goods. This may be under the goods, above the goods and / or next to the stored goods. With a sensing device 31 based on Al, the sensing device 31 may be operating based on image recognition. Besides the sensor(s) 34 for sensing for heat and gas, the sensing device 31 may further comprise an optional image sensing device 35, such as a lidar or a camera. An Al based sensing device 31 may be trained to recognise the signs of fire or smoke formation based on pictures from similar situations. When comprising an image sensor device 31, an Al based sensing device 31 may be trained to recognise the signs of fire or smoke formation in an image taken or generated by the image sensor device 35 based on pictures from similar situations. Similar situations could be burning goods, especially electric vehicles, where a sudden fire occurred in a battery. The Al based sensing device 31 may be located underneath the stored goods, above the goods and / or on the walls of the housing 10 next to the goods of a storage unit such as to enable surveillance from more than one side or from all sides. By quickly recognising the signs of a fire, a unit with the sensing device 31 based on Al can react quickly to prevent the sudden fire from spreading, for instance by triggering an alarm. This may further alleviate the need for guards doing fire bills, which may in any event be insufficient for efficient fire prevention especially in large storage facilities. This may also alleviate the need for fire bills, when the storage unit is a small part of a bigger storage facility, that otherwise does not require fire bills. Using a sensing device 31 based on Al may assure the safety of the personnel in and / or around the storage unit. By sensing a person in the vicinity of the sensing device 31, when a fire breaks out, the person may be warned. The person is then able to remove themselves from the situation, before being damaged. By sensing a person in a vicinity of the sensing device 31, it may also be possible to alert help early, if the person is not able to remove themselves from the situation. An Al based sensing device 31 may be trained to recognise the presence of a person based on pictures from similar situations. When comprising an image sensor device 35, an Al based sensing device 31 may be trained to recognise the presence of a person in an image taken by the image sensor device 35 based on pictures from similar situations, such as pictures of persons on a cargo ship, in a parking garage or in other similar structures to the storage unit.

[0074] The signal processing device 33 determines whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, by comparing the data received from the sensing device 31 with said predetermined threshold. There may be a predetermined threshold when sensing for heat. There may be another predetermined threshold when sensing for gas. When sensing for heat, the threshold may relate to a temperature in the storage unit. When storing the batteries of electric vehicles or electric vehicles containing batteries this threshold may be 20 degrees Celsius, 16 degrees Celsius, 15 degrees Celsius, 12 degrees Celsius, or 5 degrees Celsius or 1 degree Celsius. However, it is appreciated that other thresholds are possible. Likewise, different thresholds may be suitable for different goods. For instance, a threshold of 15 degrees Celsius would be suitable when storing bananas. When sensing for gas, the threshold may be related to the volume or amount of a gas sensed in the storage unit compared to the remaining air in the storage unit.

[0075] When the predetermined threshold is overstepped, the control unit 32 triggers the ventilation unit. When the ventilation unit, which is provided with a gas source 63, is triggered it will supply a gas through the second inlet 62 into the storage unit. When triggered, the ventilation unit 6 will stop the air supply through the first inlet 61 into the storage unit. Thereby the oxygen is removed from the atmosphere in the storage unit. Suitable gasses may be noble gasses (inert gasses) or nitrogen. Without oxygen a fire cannot spread within the storage unit. In case of a battery, the battery having caught fire will "melt", but the fire will be isolated, and no damage will be done to the rest of the electric cars, or the rest of the batteries, or the surrounding goods or people.

[0076] After the ventilation unit is triggered to supply a gas through the second inlet into the storage unit, the gas is constantly supplied to minimize the risk of a fire restarting. Gas loss is measure with a sensing device in the storage unit to assure that sufficient gas is supplied. In one embodiment, this may be done, by the sensing device measuring 02 and nitrogen. Thereby, more nitrogen can be supplied, in case the 02 percentage in the atmosphere of the storage unit increases. To measure 02 in a room filled with nitrogen, as done in this embodiment, the sensing device may be located a few centimetres above ground. For example, a 1520 cm distance from the ground would be suitable for this embodiment. Other locations for the sensing device are in other embodiments also suitable. The gas supply may manually be turned off and the air supply may be manually turned on again, after the ventilation unit was triggered. This is to assure, that the storage unit may be entered without putting people at risk.

[0077] While only one sensing device 31 is described above, there may be other embodiments, where multiple sensing devices 31 are connected to one or more control unit(s) 32.

[0078] Also, a combination of one or more sensing devices 31 based on Al and one or more traditional sensing devices 31 may be employed. In an alternative embodiment, different ventilation zones may be employed and suitable for different stored goods, and different thresholds when sensing for heat and gas may be suitable for different stored goods. For instance, one sensing device 31 may be located underneath each electric vehicle in the storage unit. This provides the most reliable detection of early fire signs in the storage unit. At least one sensing device 31 based on Al may be employed to assure the safety of the personnel working in and / or around the storage unit in case of a potential fire.

[0079] In another embodiment the invention relates to a method for preventing fire in a storage unit, such as the storage unit seen in Fig. 1 and Fig. 2, which structural and functional features have been described in some detail above. Referring to Fig. 5, the goods in the storage unit are refrigerated 610 by using the ventilation unit. Hereby, air is getting cooled down by the ventilation unit and distributed into the housing of the storage unit through a first inlet. Meanwhile a sensing device 31 is used to sense 310 heat and / or gas in the storage unit. The sensing device 31 sends 311 a signal to a control unit 32.

[0080] The control unit 32 is associated with the ventilation unit responsible for supplying air into the housing of the storage unit through the first inlet. The control unit 32 comprises a signal processing unit 33. The signal processing unit is responsible for processing 330 the signals received from the sensing device 31. When processing the signals, the signal processing unit 33 compares the data received from the sensing device 31 with a predetermined threshold. A predetermined threshold when sensing for heat is established based on the goods, that stored in the storage unit. Another predetermined threshold when sensing for gas is also established.

[0081] When one or both thresholds are reached or overstepped the control unit 32 triggers 320 the ventilation unit. When the threshold is not reached or overstepped, it is understood that the control unit 32 does not trigger the ventilation unit. The sensing device 31 records data continuously and sends the data to the control unit 32 continuously. Therefore, the control unit 32 will trigger the ventilation unit very quickly after a threshold is reached or overstepped.

[0082] Reaching or overstepping the threshold is a sign of fire. When the ventilation unit is triggered, the ventilation unit 6 supplies 621 a gas through the second inlet 62 into the housing of the storage unit. Simultaneously the ventilation unit stops 611 the air supply through the first inlet 61. The gas is supplied, and the air supply is removed in order to remove any oxygen from the atmosphere in the storage unit. Removing oxygen from the atmosphere in the storage unit removes the possibility of a potential fire spreading within the storage unit. The storage unit according to the invention may be a newbuilt storage unit fitted with at least the ventilation unit, the sensing device, and the control unit as described above.

[0083] It is also feasible that at least the ventilation unit, the sensing device, and / or the control unit as described above may be retrofitted to an already existing storage unit. When retrofitting, the storage unit may as a part of retrofitting the ventilation unit be provided with piping for supplying a gas, such as nitrogen. The piping for supplying a gas, such as nitrogen, may be identical to and arranged parallel to any already existing piping for conducting or supplying CO2. Alternatively, any already existing piping for conducting or supplying CO2 may also be used as the piping for supplying a gas, such as nitrogen.

[0084] Variations of the abovementioned embodiments are possible within the scope of the appended patent claims.

Claims

P A T E N T C L A I M S1. A method for preventing fire in a storage unit (1), wherein the storage unit (1) comprises a housing (10), defining a chamber, and a ventilation unit (6); the method comprising the steps of: refrigerating (610) goods using the ventilation unit (6) by supplying cooled air through a first inlet (61) into the chamber; sensing (310) one or more of heat and gas using a sensing device (31), the sensing device (31) being located in the chamber; sending (311) a signal from the sensing device (31) to a control unit (32), the control unit (32) being associated with the ventilation unit (6) and the control unit (32) comprising a signal processing device (33); processing (330) the signal using the signal processing device (33) to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped; triggering (320) the ventilation unit (6) using the control unit (32) when it is determined that the predetermined threshold is reached or overstepped; and when the ventilation unit (6) is triggered: stopping (611) the supply of cooled air into the chamber through the first inlet (61); and supplying (621) gas into the chamber through a second inlet (62) using the ventilation unit.

2. A method according to claim 1, wherein a gas selected from the group consisting of: helium, neon, argon, krypton, xenon, radon, nitrogen and combinations thereof is supplied by the ventilation unit (6) comprising at least one gas source (63) into the chamber through the second inlet (62), when triggered by the control unit (32).

3. A method according to any preceding claim, wherein one or more of heat, hydrochloric acid, and other acids released from thermal runaway is sensed by thesensing device (31).

4. A method according to any preceding claim, wherein cooled air is supplied by the ventilation unit (6) into the chamber through the first inlet (61), such that a temperature of the air in the storage unit stays at a temperature of between 10 and 20 degrees Celsius, of between 12 and 18 degrees Celsius, of between 14 and 17 degrees Celsius or of between 15 and 16 degrees Celsius, or such that a temperature of the air in the storage unit stays at a temperature of less than 20 degrees Celsius, less than 16 degrees Celsius, less than 15 degrees Celsius, less than 12 degrees Celsius, preferably less than 5 degrees Celsius, most preferably less than 1 degree Celsius.

5. A method according to any preceding claim, wherein the predetermined threshold for triggering the ventilation unit (6): when sensing heat is a temperature of the air in the housing (10), when sensing gas is a predetermined amount of the sensed gas in the air in the housing.

6. A method according to any preceding claim, wherein one or more of: heat, gas, and a person being present in a vicinity of the sensing device (31) is detected by the sensing device (31) employing Al.

7. A method according to any preceding claim, and further comprising the step of retrofitting the ventilation unit (6), the sensing device (31) and the control unit (32) to the storage unit (1).

8. A storage unit (1) for batteries, the storage unit comprising: a housing (10) defining a chamber,at least one ventilation unit (6) having a first and a second inlet (61,62), the ventilation unit is configured to supply cooled air through the first inlet (61) into the chamber; a sensing device (31) located in the chamber and configured to sense one or more of heat and gas; and a control unit (32), associated with the sensing device (31) and the ventilation unit (6), the control unit (32) comprising a signal processing device (33), the signal processing device (33) being configured to receive a signal from the sensing device (31) and to process the received signal to determine whether a predetermined threshold related to the sensed one or more of heat and gas is reached or overstepped, and the control unit (32) being configured to trigger the ventilation unit (6) when it is determined that the predetermined threshold is reached or overstepped; wherein the ventilation unit (6) further comprises a gas source (63) and is configured to supply gas through the second inlet (62) into the chamber when triggered by the control unit (32); and the ventilation unit (6) is further configured to stop supplying air through the first inlet (61) into the chamber when triggered by the control unit (32).

9. A storage unit according to claim 8, wherein at least a part of the housing (10) is provided with a support surface (11).

10. A storage unit according to anyone of claims 8-9, wherein the storage unit stores batteries for electric vehicles and / or electric vehicles containing batteries.

11. A storage unit according to anyone of claims 8-10, wherein the ventilation system (6), the sensing device (31) and / or the control unit (32) are retrofitted to the storage unit.

12. A method for providing a storage unit according to any one of claims 1-10, the method comprising: providing a storage unit, and retrofitting the storage unit with a ventilation system (6) and a sensing device (31).

13. A method according to claim 12 and further comprising retrofitting the storage unit with a control unit (32).

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