MXPA97003958A - Method and apparatus for the detection and prevention of danger of fu - Google Patents

Abstract

A new method and apparatus for the detection of fire hazard and prevention or extinction of fire is described, based on the activation of a plurality of nozzles, based on the activation of a plurality of independently operable nozzles, which discharge cooling agent / Fire extinguisher in a pre-programmed time pattern, after the automatic detection of the impact imposed on the vehicles. The extinguishing agent is preferably CO2 already provided in the vehicle, and applied as a refrigerant in the air conditioning system of the vehicle.

Description

METHOD AND APPARATUS FOR THE DETECTION AND PREVENTION OF FIRE HAZARD DESCRIPTION OF THE INVENTION The present invention relates to an automatic detection of fire hazard and to the fire prevention / extinguishing system, particularly for vehicles provided with an internal combustion engine. Automotive vehicles that have engines of the type mentioned above, involved in accidents and exposed to violent impact (shock) have a tendency to catch fire during or just after accidents. This is especially the case for injection engines where the feed pump continues to provide fuel under pressure, thus representing a great danger to the occupants of the vehicle. The use of portable fire extinguishers to extinguish a fire in the engine compartment is a risky task and also gives time that involves the exposure of people to smoke and flames for people who open the engine compartment (chamber) and It also allows the entry of air under the cube inside the engine compartment, thus promoting a diffusion of fire.

REF: 24826 Consequently, several systems based on an automatic fire detection and extinction have been recently developed and described in various patent / patent applications. Thus, the French patent FR 2674441 describes a system based on the use of HALON 13-01 as an extinguishing agent that is located in a pressure vessel in the engine chamber (compartment), which is activated by an impact detectors. frontal or lateral, or by supplementary smoke and / or flame detectors. A system of pipes and nozzles provides with the above detection, the automatic discharge of HALON, directly to the engine compartment, and simultaneously provides the shutdown of the fuel pump. German patent DE 4223293 Al describes a fire protection system, combined, for personal vehicles and trucks (trucks) based on the detection of fire and the use of C02 as a fire extinguishing agent. The disadvantages related to the installation / use of these and other known systems of extinction, are the need to move bulky containers and auxiliary equipment (detectors, sensors, transducers) in the engine chamber that lacks free space and, in addition, increasing the weight and consequently the costs of the detection and extinction system. In addition, the patent RU 2008046 describes another system for extinguishing fire, based on the discharge of cooling fluid from the radiator (water) or a mixture of ethylene glycol for extinguishing the fire, aided by a pressurized propellant, for example C02 gaseous. The claimed advantage of the subject of interest described is to avoid the special "bulky" containers of the extinguishing agents in the vehicles. However, the use of cooling water as an extinguishing agent gives a poor extinguishing efficiency, limited capacity (leaks and losses due to direct side-by-side steam formation) and is definitely not applicable for fire prevention purposes. Accordingly, an object of the present invention is to provide an automatic system for fire extinguishing, new, and improved, which ensures increased safety for the occupants of motor vehicles, in case of accidents by means of fire extinguishing agents. , preventively applied, immediately after impact detection.

Still another object of the present invention is to provide a new detection system that responds (reacts) fast, which reduces the number of components / parts applied, and thus reduces the weight and costs of the installed detection and extinguishing system. Still another object of the present invention is to provide a method and means for a differential (delayed) release of the extinguishing agent (fluid), which is of the environmentally acceptable (benign) type and preferably already installed / applied for other purposes (functions) in the vehicle. These and other objects and features of the present invention are met by the provision of a method and assembly (means) for the detection of a fire hazard situation and the prevention / extinction of fire as defined in appended claims 1-10 . According to the invention, a new system that responds quickly for the detection / prevention / extinction of fire, is developed based on a preferred embodiment of the system on the application of C02 as an extinguishing agent, which is already installed as a refrigerant in the air conditioning circuit. air of the vehicle, and where the detection of fire is directly linked to the detection of frontal, lateral and / or posterior impact, and to the activation of the protection system by the vehicle's airbag. The apparent advantage of using C02 as an agent for the prevention of fire in connection with a vehicle that is involved in an accident, is a combination of the following characteristics: cooling the entire engine compartment below the ignition temperature, - the prolonged contact with cooling agent due to the partial formation of CO 2 adhering snow, and then the sublimation providing CO2 in gaseous form, and finally an efficient reduction of the 02 content in the closed / encapsulated chambers / compartments, below the concentration required for ignition (oxidation reaction). The invention will be more readily understood and apparent from the following description of the preferred embodiments and the mode of operation of the system, as illustrated in the accompanying drawings, Figures 1-3, where: Figure 1 is a schematic side view of a vehicle housing the components of the automatic system for the detection of fire hazard and the prevention / extinction of fire, Figure 2 illustrates schematically in a diagrammatic form, the system and its operably linked components, applicable according to the present invention, Figure 3 shows a cross section of a test apparatus, used in the extinction tests.

With reference to Figure 1, schematically showing in a cross-sectional view an automotive vehicle comprising a conventionally located front engine chamber 4 housing the vehicle engine (not shown in the Figure) and a fuel tank 1, located on the back, the number 2 describes a container (reservoir) containing, by way of example, liquid C02 as an agent for extinguishing fire. Pressure sensors 6 (impact) strategically located on expected impact sites and levels as a front impact detector 6 ', the side impact detector 6' 'and the rear impact detector 6' '', respectively, are operably linked by transmission lines / signaling 17 ', 11' ', 11' '' to a processing / address unit 8 that provides the directional signal through the transmission lines 16 ', 16' ', 16' '' to manipulate the aperture / closing of the valves 9 ', 9' ', 9' '' for the access of the extinguishing agent to a group of independently operable nozzles 3 ', 3' ', 3' '', where the latter is located in the chamber 4 of engine, and in addition to the nozzles 3 'which ensure the release of the agent on the fuel tank 1 and also, preferably retarded for a predetermined period of time which allows the passengers to leave the vehicle, also unloading towards the cabin 5 through of the nozzles 3 ''. Said delayed release can be achieved by a time delay circuit in the processing / steering unit 8 which ensures that the extinguishing agent is discharged according to the previously programmed pattern. This previously programmed pattern may also include a control of the duration of the discharge of the extinguishing agent at each nozzle site. Alternatively, time delay elements and / or flow restrictors may be provided in the lines supplying the extinguishing agent in the nozzles. Advantageously, the applied sensors / detectors 6 are identical to the deployed / applied sensors, in connection with the release / activation of the installed airbag (s) 7, for the protection of the occupants of the front seat in the vehicle. According to a preferred embodiment of the system, the pressurized container 2 represents an integral part of the air conditioning circuit using C02 as a refrigerant. As shown in Figure 2, which schematically illustrates the connection between the present fire prevention / extinguishing system and the installed installation of air conditioning in the form of a block diagram, the impact detectors 6 are connected through a line of transmission / signal 15 to a valve 9, coupled to the pressurized vessel 2, which is an integral part of a (transcritical) vapor compression cycle compensating vessel (receiver), further comprising a compressor 10, a gas cooler 11, a moderate or throttle valve 13 and an evaporator 14, connected in series in a closed circuit. The valve can advantageously be operated by solenoid when electronic sensors are used, but the valve can also be operated by hydraulic or pneumatic means. After the detection of an impact, the sensor or sensors transmit a signal through the transmission / signal line 15 to the valve 9, which will be opened so that the pressurized C02 flows through the conduit 12 towards the effective fire sites, as shown in this embodiment - fuel tank 1, engine chamber 4 and cabin 5. Thus, there is no need for additional impact sensors or a bulky special container for the fire extinguishing agent. A simple adaptation of the compensating vessel (receiver) 2 through the provision of an extra valve 9 and the connecting line, will eliminate the installation of a new vessel for fire extinguishing purposes.

Example A fire extinguishing test was performed in a container provided with closed side walls , a lower section 25, partially open, and a perforated upper plate with some small holes 21, as shown in cross-sectional view according to Figure 3.

The container was of a similar size to that of an engine chamber in an average personal car, for example, 0.5 meters high, 0.72 meters wide and 1.12 meters long. The internal volume of the vessel was approximately 400 liters. A nozzle device 23 with three openings, each of a diameter of 1 millimeter, was centrally placed in the lower part of the upper plate. A container 24 with a diameter of 0.19 meters and a height of 0.075 meters was placed centrally in the bottom of the container. Before the extinction tests were carried out, it was observed that 0.2 liters of gasoline were able to ignite for approximately 10 minutes. The extinguishing equipment comprised pressurized C02 expelled through the nozzle device. The capacity of the extinguishing equipment was approximately 60 grams of C02 per second. Four extinguishing tests were carried out, where the extinguishing agent was expelled through the nozzles after the fire was allowed to ignite for about one minute. The time of extinction of the fire was less than 5 seconds in all the tests that were carried out.

In each extinction test, less than 300 grams of C02 were consumed. Using pressurized C02 that is already installed in a car with an air conditioning circuit that applies C02 as a refrigerant, there will usually be approximately 2 kilograms of C02 available for extinction purposes. In this way, it should therefore be ensured that there is sufficient amount of CO2 available to extinguish a possible fire in the engine chamber, in addition to possible fires elsewhere in the automobile. According to another aspect of the invention of the present system, the presence of a C02 compensating container already installed in the air conditioning circuit allows the possible in situ provision of a softer fire extinguishing agent to be applied in the cabin. Thus, for example, an additional container (not shown in the Figures) containing a mixture of nitrogen and argon gases, and which is connected to the C02 container can be installed in the cabinet so that by means of the coordinated "spill" of Some C02 after impact detection in this gas mixture, a special agent known as INERGEN® or similar agents can be provided in situ to avoid the shock treatment (cooling) of the occupants of the vehicle, and even the danger of suffocation by using pure C02. The scope of the present invention described and exemplified in the above manner in the preferred embodiments is not limited to these examples. The described inventive principle of automatic fire hazard detection and fire extinguishing system can also be applied, for example, in battery-powered vehicles, and a combination of automatic, semi-automatic or even manual means for activation / deactivation of the system, it is possible within the framework of the present invention.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content is claimed as follows:

Claims (10)

1. A method for the automatic detection of a fire hazard and the method for the prevention or extinction of fire, particularly in automotive vehicles provided with combustion engines, the method comprising the steps of the automatic detection of impact imposed on vehicles involved in a collision by means of sensing sensors' impact and the discharge of the extinguishing agent through the nozzles, by operation of the valve means in conjunction with one or more outputs of a reservoir of the extinguishing agent, characterized by a plurality of independently operable nozzles, distributed through different parts of the vehicle, discharging fire cooling / extinguishing agent in a pre-programmed time pattern.

2. A method for the automatic detection of a fire hazard and a method for the prevention or extinction of fire, characterized in that the extinguishing agent is C02 already provided in the vehicle in a container, and applied as a refrigerant in the air conditioning system of the vehicle, and because the exit or exits of the container of the extinguishing agent, ensures the discharge of the container as C02 in substantially liquid phase, the outlets being arranged in / near the bottom of the container.

3. A method for the automatic detection of a fire hazard and a method for the prevention or extinction of fire, characterized in that the activation of the fire cooling / extinguishing nozzle located in the vehicle engine chamber, is initiated simultaneously with the activation of the bag or air bags that protect the occupants of the vehicle.

4. The method according to claim 1, 2 or 3, characterized in that the activation of the fire extinguishing nozzles located in the vehicle cabin is delayed for a predetermined period of time, compared to the impact detection.

5. The method according to any of the preceding claims, characterized in that the fire extinguishing agent is of the INERGEN® type, provided in situ by the addition of C02 from the air conditioning system of the vehicle to a vessel containing the N2 mixture. and argon, before the release of the resulting gas mixture into the vehicle cabin.

6. An apparatus for the automatic detection of fire hazard and the elimination of fire in automotive vehicles, comprising one or more impact sensor detectors, a processing / steering unit for activating the valve means in conjunction with one or more outputs of a extinguishing agent container, connected via pipe and nozzles to the engine chamber, and possibly to the fuel tank and cabin, characterized in that the impact sensor or sensors and the steering unit are parts of the fuel detection system. impact and activation, for the release of the bag or air bags.

7. The apparatus according to claim 6, characterized in that the outlet or exits of the extinguishing agent container are located in / near the bottom of the container.

8. The apparatus according to claim 6 or 7, characterized in that the extinguishing agent is a refrigerant applied in the air conditioning circuit of the vehicle.

9. The apparatus according to claim 6, 7 or 8, characterized in that the extinguishing agent is C02.

10. The apparatus according to claim 6, characterized in that the container of the extinguishing agent contains C02, and in that the apparatus further comprises an additional container containing a mixture of nitrogen and argon gases, and connected to the extinguishing agent container, by means of which ensures the on-site provision of INERGEN® gas applicable for extinguishing the fire in the cabin.