WO2019204832A1

WO2019204832A1 - Automatic fire suppression system for internal combustion device

Info

Publication number: WO2019204832A1
Application number: PCT/US2019/028836
Authority: WO
Inventors: Klaus Meiler
Original assignee: Key Safety Systems, Inc.
Priority date: 2018-04-18
Filing date: 2019-04-24
Publication date: 2019-10-24

Abstract

Provided is a fire suppression system for use in conjunction with an internal combustion device (1) such as an internal combustion engine, water heater or air heater (1) that may be part of a motor vehicle. The fire suppression system is compact and can be mounted as a kit (34) on combustion devices in existing vehicles. The fire suppression system includes one or more fire suppression vessels (4) which may be in the form of an inflator or gas generator such as used in conjunction with air bags. The fire suppression vessels (4) act automatically responsive to a sensor (6, 19, 25, 35) signal and direct an extinguishing material such as a gas or solid particles or liquid, through a valve (12) and into the combustion device.

Description

Automatic Fire Suppression System for Internal Combustion Device

FIELD OF THE INVENTION

[0001] The present invention provides an automatic fire suppression system for an internal combustion device and a method for its operation. The internal combustion device of the invention may be a combustion heater, a combustion engine, or other combustion devices.

BACKGROUND ART

[0002] Fire suppression devices and vessels for vehicles are known and actually required by safety regulations of some countries for public transport vehicles.

[0003] In the case of vehicles having an internal combustion device such as a combustion heater, the vehicle may be equipped with an alarm system, e.g. providing the driver with a warning signal, in the event of excess temperature in the engine compartment and in each compartment where a combustion heater is located. In addition to the alarm systems, some vehicles may be equipped with a fire suppression system in the engine compartment and in each compartment where a combustion heater is located.

[0004] Typically, fires involve a chemical reaction between oxygen and a fuel which is raised to its ignition temperature by heat. In general, suppression or extinguishment of fires has involved one or more of the following procedures: removing the oxygen, reducing the temperature in the environment of the fire, physically separating the oxygen from the fuel and/or interruption of the chemical reactions of the components. A number of means of accomplishing the foregoing methods are known. Physical agents operate primarily on heat absorption and chemical agents operate primarily by removing free radicals from the flames and the combustion system. Among the agents employed are water, carbon dioxide, dry chemicals and Halon halocarbons.

[0005] Internal combustion engines require a specific fuel-to-air ratio to work properly. Air enters the engine through the intake that leads to the combustion chambers (cylinders). Changes in the fuel-to-air ratio create ignition hazards by elevating engine operating temperatures, creating sparks and causing over-speed and runaway engines. In particular, increasing the fuel-to-air ratio causes pre-ignition within internal combustion engines, which causes damaging pressure surges and higher engine surface and exhaust system temperatures. Furthermore, a fuel-rich condition in an engine can result in incomplete combustion, and the uncombusted fuel exiting the cylinders and entering the exhaust system, can ignite due to the hot engine surface. Over-speed occurs when flammable vapors and gases in the intake air cause engines to ran faster than designed, which causes overheating and risk of auto-ignition.

[0006] A known patent literature, GB 1,399,749, discloses an automatic fire extinguishing system which enables extinguishant to be discharged, substantially simultaneously, at a number of different points in an area to be protected. Such a system requires electrical connections between the different points. The system comprises at least two self-contained extinguishers each of which includes a container for holding extinguishant under pressure and having a normally closed extinguishant discharging opening, detecting means on the extinguisher and electrical signaling means. Automatic operation of any one of the extinguishers in response to a local rise in ambient temperature automatically causes operation of all the other extinguishers protecting the area, thus the whole area is almost instantaneously saturated with extinguishant such as an extinguishing fluid.

[0007] A liquid fuel burner in combination with flame extinguishing means is disclosed in GB 1,205,018. A container comprising a flame extinguishing medium is mounted in fixed relation to the burner and is connected to said burner by means of a conduit tube. In case of an abnormal operating condition of the burner, a pressure is applied directly on the flame extinguishing medium to be discharged along said conduit tube into the burner. The extinguishing medium may be any fluid, i.e. liquid, gas or powder.

[0008] A fire extinguishing system for a cookstove is known from US

4,834,188, wherein the fire suppression vessel is mounted above a hood positioned over the cookstove for automatically extinguishing stove fires. The fire suppression vessel is connected to a pair of nozzles within the hood to dispense fire suppressant over the cookstove when there is a fire on the stove.

[0009] US 2016/0193489 discloses fire extinguishing equipment having a pipe coiled in a flat state above a pack of Lithium batteries. The walls of the pipe can be opened by the heat of a possible fire to release a fire suppression agent. [0010] EP 3002516 Al discloses a heater having an automatic fire suppression vessel which extinguishes flames. A temperature detection unit monitors the temperature of the lower portion of the combustion tank and the hollow part of the air tank of the heater. When the temperature reaches a preset temperature value or higher, the detection signal is transferred to the fire suppression vessel which operates by reversely rotating the wick driving shaft such that the wick is lowered and flame is extinguished.

[0011] The Japanese patent publications JP 2002295985A and JPH03155875A refer to automatic fire extinguishing by means of diffusing a fire suppression agent to the fire generating position or in the neighborhood of the extinguisher when the detected temperature exceeds a preset value.

[0012] WO 2016/060990, in the name of the present applicant, discloses a fire extinguishing system comprising an automatic fire suppression vessel in combination with a vehicle engine. The fire suppression vessel is arranged in an engine compartment of a vehicle and in case of sensing a fire or a fire condition, an activation signal is generated to activate a gas generator and to dispense fire suppression agent on the engine external surface. The fire suppression vessel comprises a gas generator containing pressurized gas, which is connected to a hose that contains a powder fire suppression agent. The gas released from the gas generator pushes the powder agent outside the hose. The device is installed in the engine area of a vehicle.

[0013] The known prior art documents concerning the field of the present invention refer to automatic fire extinguishing by means of diffusing a fire suppression vessel in the close ambient/space of the extinguishing appliance or releasing the fire suppressant directly onto devices reaching too high temperature during their operation. The known fire extinguishing systems are big and require adapting the vehicle to house the fire extinguishing system. A further problem with the known fire suppression systems is that they may damage the combustion device when suppressing the fire.

OBJECTS OF THE INVENTION

[0014] It is therefore an object of this invention to provide a fire suppression system for an internal combustion device which is compact and can be mounted as a kit on extinguishing combustion devices in existing vehicles. [0015] A further object of this invention is to provide a known type of internal combustion device, in particular an air heater or a water heater for auto vehicles, with a fire suppression vessel device without requiring substantial modification of the internal combustion device or of the vehicle.

[0016] An additional aim of this invention is to provide a compact automatic fire extinguishing device, which can be easily installed in any type of vehicle in combination with an internal combustion device where only limited space is available. A still further object is to provide a method for automatic fire suppression in an internal combustion chamber, which can be carried out in a simple and effective way.

SUMMARY OF THE INVENTION

[0017] The above identified aims are achieved by the fire suppression system of claim 1 and by the method of claim 13. The preferred embodiments of the fire suppression system are further defined in dependent claims. In a preferred embodiment of the present invention the combustion device is an air heater or a water heater and in other embodiments the combustion device is a combustion engine or other internal combustion device. In the following, the wording“fire suppression” is used to refer to both the extinguishing of a fire and the prevention of a fire, e.g. by drastically cooling a part of an internal combustion device to prevent a fire.

[0018] The present invention provides a fire suppression system for an internal combustion device, which allows the automatic release of a fire suppressant in the interior of the combustion device when required, e.g. when an activation signal is received. The system comprises a fire suppression vessel connected to the interior of an internal combustion device having at least one air inlet and preferably a sensor. The sensor may be a sensor for detecting an ongoing fire and/or a sensor for detecting anomalies in operating conditions of the internal combustion device, which could generate inflammation or explosion of the device.

[0019] More particularly, the invention comprises a fire suppression system for an internal combustion device comprising a fire suppression device capable of delivering a fire suppression agent from a fire suppression vessel, an internal combustion device wherein said fire suppression vessel is connected to an air inlet of the combustion device for introducing a fire suppressant into the combustion device when the fire suppression vessel is activated.

[0020] The objects of the present invention can be achieved in conjunction with various types of internal combustion devices. Internal combustion devices particularly suited to benefit from aspects of the present invention, may be selected from an internal combustion heater and an internal combustion engine. Preferably, the internal combustion heater is selected from an air heater and a water heater for use in automotive.

[0021] Any type of fire suppression device that is suitable to deliver a (high velocity) stream of a fire suppression agent can be used in the present invention.

According to an aspect of the present invention the fire suppression device may include a vessel comprising a container containing a fire suppression agent and having an outlet for said fire suppression agent. The vessel is normally closed and is opened upon activation of the fire suppression vessel, e.g. by an activation/alarm signal of the sensor.

[0022] In a preferred embodiment, the fire suppression device includes a fire suppression vessel which is an inflator suitable for air bags; typically, such a vessel contains a highly pressurized gas in a reduced volume, the gas in the present case being a fire suppression gas. Inflators for air bags are also known as gas generators; in the present invention, preferred inflators, or gas generators, contain a pressurized gas, preferably a cold gas such as a gas stored at the local temperature. The use of an inflator for air bags as the vessel containing a fire suppression agent is particularly advantageous in that the inflator has a reduced volume and can therefore be fitted to the combustion heater without having to modify the vehicle space that houses the heater. Thus, the combustion heater may be sold with one or more fire suppression vessels already attached to the heater’s body; a preferred way for the attachment of the inflators-fire suppression vessels to the heater’s body is by means of a bracket that supports one or two inflators.

[0023] According to another aspect of the present invention, the fire suppression vessel may be a container connected to at least one inflator or gas generator, wherein said container comprises a fire suppression agent and the inflator contains a gas that will feed the fire suppression agent to the combustion device.

[0024] According to the present invention the terms“container“ and “conduit tube” include any geometrical form capable of housing a fire extinguishing material. By means of example the following terms are mentioned without any limitation of the scope of the present invention: cylindrical container, canister, vial, enclosure, conduit, tube, hose, sock and pocket.

[0025] An automatic fire suppression vessel particularly suitable when the suppression agent is a powder is described in WO 2016/060990, which is incorporated herein for reference purposes.

[0026] The fire suppression agent or material useful in the present invention includes any known type of fire suppression agent in any form selected from gas, powder and liquid. Preferably, the fire suppression agent is a gas. In some embodiments, the gas may be nitrogen but other suitable gases are used in other embodiments. For exemplary purposes, fire suppression agents used in WO 2016/060990 are mentioned here. When the suppression agent is a gas, the gas may be stored as compressed gas in a vessel or gas generator.

[0027] According to an aspect of the present invention, the fire suppression device includes a vessel connected to the combustion device by means of a T-manifold comprising a one-way valve in order to avoid the backflow of the pressurized fire extinguishing material but other devices for connecting the fire suppression vessel to the combustion device such as a three-way valve, are used in other embodiments. The fire suppression vessel can be connected to an air inlet of the combustion device. The air inlet may be the inlet for the combustion air. When the combustion device has an internal space between the combustion chamber and the outer shell of the combustion device, the fire suppression agent may be provided to said space. When the combustion device is an internal combustion engine or heater, the fire suppression vessel may be connected to the combustion air inlet of the engine or heater. When the combustion device is an internal combustion air heater, the fire suppression vessel can also be connected to an internal space between the combustion chamber and the outer shell of the combustion heater where air is heated prior to be sent to the interior of the vehicle.

[0028] The internal combustion device preferably comprises in a way known in the art, at least one sensor for monitoring the operating conditions of the inner combustion device. The sensor may be a fire sensor, a heat sensor, a smoke sensor, a crash sensor, or a combination of two or more of said sensors. When anomalies in the operating conditions are detected by the sensor, the automatic fire suppression vessel of the fire suppression device is activated by an activation signal and fire suppression agent is released from the fire suppression vessel and propelled, preferably at a high speed, into the combustion device.

[0029] The automatic fire suppression system of the present invention may comprise more than one automatic fire suppression vessel in combination with an inner combustion device in order to enhance the fire suppression efficiency of the system. In this event the fire suppression vessels may be the same or different types. Additional fire suppression vessels may be provided outside to provide the combustion device with suppression agent, as disclosed in WO’990, previously cited.

[0030] When more than one fire suppression vessel is used in the system of the present invention, two of them can be arranged to feed a fire suppression agent to the same air inlet of the internal combustion device and can be activated at the same time or with time shifts, i.e. at different times in function of the seriousness of the anomalies detected by the sensor, which may result in fire or explosion.

[0031] For illustrative purpose, in case the fire suppression system comprises an internal combustion heater, the fire suppression device may include more than one fire suppression vessel in combination with the heater. In case of using an internal combustion air heater with a combustion chamber and an air chamber surrounding the combustion chamber, the fire suppression vessels may be arranged on the air chamber and/or on the combustion air inlet. Accordingly, the system of the invention may include an automatic fire suppression vessel connected to the combustion air inlet of the combustion heater and, in case of an air heater, another fire suppression vessel may be connected to the air chamber of the combustion air heater. When the automatic fire suppression vessels are activated by a signal generated by a sensor of the system of the present invention, the valve connecting the fire suppression vessel and the heater is opened and the fire suppression agent is released from the fire suppression vessels and enters the combustion heater. In this manner, when both extinguishers are activated of a same air heater, the combustion air flow to the combustion chamber is blocked, for example, the oxygen supply to the combustion chamber may be stopped, and the space between the combustion chamber and the outer shell of the air heater, i.e. the air heating chamber, is also directly cooled. More particularly, the fire suppression agent released form the fire suppression vessel is connected to the combustion air inlet, enters the combustion air inlet of the heater air conduit blocking thereby the air flow to the combustion chamber, while the fire suppression agent released from the other fire suppression vessel, arranged on the combustion air heater and connected to the internal space between the combustion chamber and the outer shell of the air heater, thereby causes a direct cooling of the surface of the combustion chamber.

[0032] The intensity of the technical effects, i.e. the effects for avoiding or suppressing fire and explosion, may also depend on the type of the fire extinguishing material. When multiple fire suppression vessels are used in the system of the present invention, they can comprise different type of fire suppression agents.

[0033] It can be appreciated by the skilled person that the automatic fire suppression system of the present invention may be used in conjunction with any known internal combustion device with the same improved fire extinguishing result without requiring structural modifications of the combustion device or the automatic fire suppression vessel used, apart for those required for making a connection.

[0034] The fire suppression system of the present invention can be easily installed in any vehicle using an internal combustion device, particularly an internal combustion heater for air or water.

[0035] The present invention also provides a method of preventing or extinguishing fire in an internal combustion device by means of using the fire suppression system.

[0036] A method of the present invention may comprise the following steps:

monitoring the operating conditions of the internal combustion device by means of at least one sensor;

activating at least one fire suppression vessel by an activation signal of the sensor when the sensor detects by said monitoring of a), anomalies in the operating conditions of the combustion device; and

directing an amount of fire suppression agent from the at least one fire suppression vessel to the internal part of the combustion device. [0037] The monitoring of the operating conditions of the internal combustion device is carried out by at least one sensor as previously specified. When the sensor or sensors generate a signal in case of anomalies in the operating conditions of the inner combustion device, at least one fire suppression vessel is activated and a sufficient amount of fire suppression agent is directed to at least the internal part of the combustion device.

[0038] The fire suppression vessel can be activated by means of an activation signal of the sensor, which acts on a valve that connects the fire suppression vessel to the internal combustion device. The valve may advantageously be a one-way valve in order to avoid the backflow of the pressurized fire extinguishing material. Upon activation of the fire suppression vessel the valve is opened and a sufficient amount of fire extinguishing material is directed from the fire suppression vessel through the valve to extinguish the fire in the combustion device. In embodiments in which other valves are used, such as when the valve is a 3 -way valve, other fluid flow through the valve may be stopped at this time.

[0039] According to the method of the present invention, in step a) the at least one temperature which can be monitored may be the temperature of the combustion chamber, the temperature of the warm air within the combustion device or the temperature of the hot air leaving the combustion device.

[0040] According to the present invention, in step b) of the method, the term“anomalies in the operating conditions of the internal combustion device” may mean a fire or hazardous conditions which might cause fire or explosions. In a preferred aspect of the present invention, in step b) of the method the fire suppression vessel is activated when the temperature monitored in step a) exceeds a threshold value set in a control unit.

[0041] The present invention also contemplates the detection, in any of various suitable matters known in the art, of other operating conditions of the combustion device which might indicate conditions that could generate fire or explosions, e.g. the pressure in the combustion device exceeds a preset value.

[0042] The method of the present invention provides fast and improved fire suppression in any type of internal combustion device. The following internal combustion devices which may benefit from the fire suppression method and device of the present invention are presented for exemplary but not limitative purposes: internal combustion engine, internal combustion air heater and internal combustion water heater.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The foregoing and other features and aspects of the present invention will become more apparent from the following description of the preferred embodiment illustrated in the accompanying drawing, wherein:

Figure 1 shows a schematic representation of a fire suppression system comprising one fire suppression vessel and an internal combustion air heater;

Figure 2 shows a schematic representation of a fire suppression system comprising two fire suppression vessels and an internal combustion air heater;

Figure 3 shows a schematic illustration of a fire suppression system comprising a fire suppression vessel and an internal combustion water heater;

Figure 4 is a perspective view in partial cross-section showing a fire suppression system and an internal combustion water heater;

Figure 5 is a perspective view in partial cross-section showing a fire suppression system and an internal combustion air heater;

Figure 6 schematically shows two fire suppression vessels in conjunction with an internal combustion device;

Figure 7 is a perspective view showing a fire suppression vessel coupled to an internal combustion device; and

Figure 8 shows a schematic illustration of an automatic fire suppression system comprising an automatic fire extinguisher and an internal combustion engine.

DETAILED DESCRIPTION OF THE INVENTION

[0044] Figure 1 schematically represents a fire suppression system comprising an internal combustion air heater 1 and one, preferably automatic, fire suppression vessel 4. The air heater 1 comprises a combustion chamber 5, a blower motor with a control unit 10, a hot air blower wheel 7, a combustion air blower wheel 8, sensor 6, glow plug 9 heat exchanger 11, a fresh air intake A, a hot air output B, combustion gas/air intake C, fuel supply line D and exhaust gas outlet E. Sensor 6 may be any of various suitable types of sensors for sensing anomalies such as but not limited to an overheat sensor and a flame sensor. The fire suppression device includes fire suppression vessel 4 connected to the combustion air intake conduit C of the air heater 1, e.g. through valve 12 which may be a three-way valve as illustrated. In other embodiments, the fire suppression vessel 4 is connected to the combustion air intake conduit C of the air heater through a T-manifold including a valve 12 which is a one-way valve to avoid the backflow of the pressurized fire extinguishing material. In the fire suppression system shown in Figure 1 the temperature of the internal space 20 between the combustion chamber 5 and the outer shell 13 of the air heater 1 is continuously or periodically monitored by means of sensor 6. When the sensor 6 detects a temperature exceeding a preset threshold value, for example, the automatic fire suppression vessel 4 is actuated by means of opening the valve 12. Upon activation of the valve 12 of fire suppression vessel 4, the fire suppression agent flows from the automatic fire suppression vessel 4, through the combustion air intake conduit C, then enters the combustion chamber 5 and blocks the combustion air supply 22 to the air heater 1 causing thereby the cooling of the combustion chamber 5 and the air heater 1. The fire suppression agent is preferably a gas, e.g. a gas commonly used in the art for fire suppression but in other embodiments, the fire suppression agent may be solid particles or liquid or any of various other known types of fire suppression agents. When the fire suppression agent is a gas, the gas may be nitrogen but other suitable gases are used in other embodiments.

[0045] The fire suppression vessel 4 may be a container connected to at least one inflator or gas generator, wherein the container comprises a fire suppression agent and the inflator contains a gas or fluid that will feed the fire suppression agent to the combustion device. The inflator may be a source of high pressure fluid connected directly or indirectly to at least one container or tube containing the fire suppression agent.

[0046] Figure 2 shows another embodiment of the present invention, wherein the automatic fire suppression system shown in Figure 1 comprises a further fire suppression vessel 4’ connected to the outer shell 13 of the internal combustion air heater 1 and in fluid communication with internal space 20 through inlet port 29, in order to feed fire suppression agent to the internal space 20 between the combustion chamber 5 and the outer shell 13. This further fire suppression vessel 4’ is connected to the internal space 20 inside outer shell 13 by means of valve 12' which may be a one way valve but other valves may be used. In the system of the present invention, both automatic fire suppression vessels 4 and 4’ can be activated at the same time or with a time shift, i.e. at different times depending on the seriousness of the anomalies detected by the sensor 6.

[0047] According to another embodiment, the internal combustion device may be provided with two or more fire suppression vessels 4 on the combustion air intake conduit C and/or coupled to internal space 20 through the outer shell 13 of the internal combustion heater.

[0048] Figure 3 and Figure 4 schematically represent another embodiment of the fire suppression system of the present invention comprising an internal combustion water heater 2 and one, preferably automatic, fire suppression vessel 4. The water heater 2 comprises an outer shell 13, a combustion chamber 5 being a combustion water heater, a blower motor with a control unit 15, a combustion air fan 24, an evaporator 14, a sensor 6, an internal temperature sensor 19, a heat exchanger 11, combustion air intake conduit C, combustion air source 22, fuel supply line D, water intake I, water heater chamber 28, warm water outlet J and exhaust gas outlet E. Sensor 6 may preferably be an overheat sensor. Cold water 26 is fed to the heater by a pump 21; warm water 27 is produced during combustion of the mixture of fuel and air in the combustion chamber 5. The mixture is ignited by a glow plug 9 and the heat generated by combustion is transmitted to the water, circulating around the combustion chamber 5 in water heater chamber 28, by a heat- exchanger 11. Heated water 27 is conducted out of the water heater 2 through line J, while exhaust gas escapes through line E. The temperature of the combustion chamber 5 is monitored by sensor 6, while the temperature within the water heater chamber 28 is monitored by sensor 19. When sensors 6, 19 detect a temperature exceeding a preset threshold value, the fire suppression vessel 4 is actuated by means of acting on valve 12. Valve 12 opens to enable the fire suppression agent released from the fire suppression vessels 4, to flow through the combustion air intake conduit C and when valve 12 is a three-way valve such as illustrated, it may also block the combustion air intake and combustion air source 22. In other embodiments, valve 12 may be a one-way valve used in conjunction with a T-manifold. The fire suppression agent enters the water heater 2 causing thereby the cooling of the combustion chamber 5 as well as the water heater 2 itself.

[0049] The system is thus an automatic system activated responsive to at least one sensor, and in addition to the sensors 6, 19 described above, other heat sensors or smoke sensors may be used. In some embodiments, other sensors 25, 35 such as visual sensors, crash sensors or other suitable sensors may be used for detecting various adverse conditions. The sensors may be sensors 25 directly coupled to the internal combustion device or remote sensors 35 positioned at other locations within a motor vehicle, for example, and may be used to activate the fire suppression system responsive to various other sensed adverse conditions.

[0050] Figure 3 schematically shows fire suppression vessel 4 coupled by means of valve 12, to combustion air intake C. Although not shown in Figure 4, it should be understood that fire suppression vessel 4 can be connected to combustion air intake conduit C to block combustion air source 22, as shown schematically in figure 3 or fire suppression vessel 4 can be connected to combustion air intake conduit C by way of a one-way valve in conjunction with a T-manifold. The water heater 2 may be provided with two or more fire suppression vessels 4 on the combustion air intake conduit C, in some embodiments.

[0051 ] Figure 5 shows an embodiment of the present invention in which combustion chamber 5 is a hot air heater, and in which the fire suppression vessel 4 is used. In Figure 5, the air which is to be cooled, enters at intake port A, is heated within an internal chamber that surrounds combustion chamber 5 and exits as hot air 30 at outlet port B. The air is heated within internal space 20 which may include fins to increase surface area. Fire suppression vessel 4 is connected to combustion air intake conduit C through a T-manifold including a valve 12, which may be a one-way valve, but in other embodiments, valve 12 may be a three-way valve that blocks combustion air source 22 from passing through air intake conduit C. As in the other embodiments, valve 12 is operable responsive to a sensor such as sensor 6 although other sensor arrangements such as described above, may be used in other embodiments.

[0052] Figure 6 shows an assembly including two fire suppression vessels, fire suppression vessel 4 and fire suppression vessel 4’, coupled together and to bracket 33 to form a kit 34 that may be joined to outer shell 13 of an internal combustion device 35. Figure 6 shows outer shell 13 and a fresh air intake A, a hot air output B, combustion air intake C, fuel supply line D and exhaust gas outlet E. As indicated by the dashed lines, fire suppression vessel 4 may be coupled to air intake conduit C such as by way of valve 12, not shown in Figure 6, but as described above and fire suppression vessel 4’ may be coupled to an internal air or water heating chamber such as internal space 20 or water heater chamber 28, through a further conduit such as through inlet port 29.

[0053] Figure 7 shows another perspective of fire suppression vessel 4’ coupled to an internal space of outer shell 13 through inlet port 29. Fire suppression vessel 4’ may be fixedly attached to the outer shell 13 and may also be coupled to a further fire suppression vessel by way of bracket 33, but various other suitable means of physically coupling the fire suppression vessels to the internal combustion devices may be used in other embodiments.

[0054] A further embodiment of the fire suppression system of the present invention is shown in Figure 8, wherein the internal combustion device is an internal combustion engine 3. The fire suppression system shown in Figure 8 comprises an internal combustion engine 3, a fire suppression vessel 4 and a sensor 17 positioned on or nearby the combustion chamber 16 of the internal combustion engine 3. The fire suppression vessel 4 is connected to the air inlet F of the internal combustion engine 3 through valve 12. The connection may be through use of a T-manifold including a one-way valve 12 as described above, or in which valve 12 is a three-way valve as illustrated. In operation, air flowing through conduit F is mixed with fuel supplied through conduit G and the air-fuel mixture is introduced into the combustion chamber 16 of the internal combustion engine 3 where the air-fuel mixture is ignited by the spark plug 18 located in the cylinder head of the engine 3. During combustion, high temperature and pressure is generated within the combustion chamber 16. The exhaust gas generated by combusting the air- fuel mixture is exhausted from the chamber 16 through exhaust gas conduit H.

[0055] The operating conditions of the internal combustion engine 3 and, in particular, the combustion chamber 16 of the internal combustion engine 3, are monitored by said sensor 17. In case anomalies are detected in the operating conditions, such as fire or temperature exceeding a preset threshold value, the automatic fire suppression vessel 4 is activated by acting on the valve 12 connecting the fire suppression vessel 4 to the air inlet F of the engine 3. Upon activation of the fire suppression vessel 4, the fire suppression agent enters the internal part of the internal combustion engine 3 from the fire suppression vessel 4 and through valve 12, thereby blocking the air supply for combustion in the combustion chamber 16, thus blocking the heat generation process in the engine 3 and cooling the combustion chamber as well as the engine 3.

[0056] The intensity of the cooling effect obtained by the system of the present invention may depend also on the type of the suppression agent used in the fire suppression vessels. Various degrees of cooling may be achieved

[0057] The fire suppression system of the present invention allows preventing and extinguishing fires and explosions in an internal combustion device, such as an internal combustion heater and an internal combustion engine. This advantageous effect is reached by the present invention without the structural modification of components of the fire suppression system of the present invention.

Claims

1 . A fire suppression system for a combustion device (1, 2, 3) having an air inlet (C), said system comprising an internal combustion device (5) and at least one fire suppression vessel (4) capable of delivering a fire suppression agent, said fire suppression vessel (4) connected to a space internal to said combustion device (1, 2, 3) for introducing a fire suppression agent into the combustion device (1, 2, 3) when the fire suppression system is activated.

2. The fire suppression system of claim 1, wherein the internal combustion device (1, 2,

3) comprises a combustion heater (1, 2) or a combustion engine (3).

3. The fire suppression system of claim 2, wherein said combustion heater is selected from an air heater (1) and a water heater (2).

4. The fire suppression system of any claim 1, wherein said fire suppression vessel (4) is connected to a combustion air inlet (C) supplying air to a combustion chamber (5) of the combustion device.

5. The fire suppression system of claim 1, wherein said fire suppression vessel (4) is connected to a space (20) between the combustion chamber (5) and an outer shell (13) of the combustion device (1), said space (20) comprising a fluid heating space, said fluid preferably being air.

6. The fire suppression system of claim 1, wherein the fire suppression vessel (4) is connected to the air inlet (C) by a T-manifold comprising a one-way valve (12) for the introduction of the fire suppression agent.

7. The fire suppression system of claim 1, wherein the fire suppression agent is selected from an agent in the form of gas, solid particles or liquid.

8. The fire suppression system of claim 7, wherein the fire suppression agent is a pressurized gas in said fire suppression vessel (4).

9. The fire suppression system of claim 1, wherein the fire suppression vessel (4)

comprises at least one inflator or gas generator for air bags, which contains the fire suppression agent therein.

10. The fire suppression system of claim 9, wherein the inflator is a source of high

pressure fluid connected directly or indirectly to at least one container or tube comprising the fire suppression agent.

1 1 . The fire suppression system of claim 1, wherein said system is an automatic system comprising fire detection means including at least one sensor (5, 19, 25, 35) preferably selected from heat sensors, smoke sensors, visual sensors and a crash sensor, said fire suppression system being activated responsive to said at least one sensor.

12. A method of suppressing fire in an internal combustion device (1, 2, 3) by means of the fire suppression system of any of claims 1-11, said method comprising the steps of:

a) monitoring operating conditions of the internal combustion device (1, 2, 3) by means of at least one sensor (6, 19);

b) activating at least one fire suppression vessel (4) by means of an activation signal of the sensor (6, 19) when the sensor (6, 19) detects by said monitoring of a), anomalies in the operating conditions of the combustion device (1); and c) directing an amount of fire suppression agent from the fire suppression vessel (4) to an air inlet (C) of the combustion device.

13. The method of claim 12, wherein in step a) temperature is monitored, said

temperatures selected from the temperature of the combustion chamber (5), the temperature of the warm air within the combustion device and the temperature of the hot air (E) leaving the combustion device (1) and wherein in step b) the fire suppression vessel (4) is activated when the temperature monitored in step a) exceeds a pre-determined threshold value.

14. The method of claim 13, wherein said fire suppression vessel (4) is an inflator for air bags.

15. The method of claim 13, wherein the internal combustion device (1) is an internal combustion air heater and two fire suppression vessels (4, 4”) are connected to said air heater.

16. The method of claim 13, wherein two said fire suppression vessels (4, 4”) are

connected to said internal combustion device (1) including a first fire suppression vessel (4) coupled to an internal combustion chamber (5) and a second fire suppression vessel (4’) coupled to an internal space (20) outside said internal combustion chamber (5) and inside an outer shell (13) of said internal combustion device (1).

17. The method of claim 13, wherein said directing an amount of fire suppression agent from the fire suppression vessel (4) to an air inlet (C) of the combustion device (1) further includes preventing other fluid flow (22) through said air inlet.

18. The method of claim 18, wherein said directing an amount of fire suppression agent from the fire suppression vessel (4) to an air inlet (C) of the combustion device (1) and said preventing other fluid flow (22) through said air inlet (C) is carried out by automatically adjusting a valve (12) responsive to said sensor (6, 19) detecting said anomalies.