EP1779903B1 - Fire extinguishing system utilizing the engine coolant - Google Patents

Description

The invention relates to a device for controlling fires in the engine compartment of a commercial vehicle with the generic features specified in the preamble of claim 1 Art.

A confluence of combustible fuels with heat sources of extremely high temperatures in a confined space may be e.g. in the engine compartment in extreme cases lead to a fire. Fire cases of this kind usually lead to total damage to the affected vehicle and represent a life-threatening situation for drivers and passengers.

From the DE 103 33 382 A1 is a deletion device for commercial vehicles known in the cooling liquid of the extinguishing system is performed as extinguishing liquid with operating air pressure, from existing in the vehicle air tanks to the source of fire. However, a prevailing in the operating pressure is usually too low to achieve an effective nebulization of the extinguishing agent with a corresponding extinguishing effect on the spray nozzles. The cooling liquid is in the cooling system of the motor vehicle under atmospheric pressure and must be compressed, for example for a nebulization as extinguishing agent before the fire on pressure ratios of about 100 - 130 bar. For safety reasons, only a small part of the total existing in the vehicle compressed air supply is available, since the majority of the compressed air supply to maintain the brake system is required.

Object of the present invention is therefore to provide a device to provide in the event of fire, arranged in the engine compartment spray nozzles, extinguishing agent always with the pressure required for the extinguishing operation.

The object is achieved according to the characterizing part of claim 1, characterized in that the pressure source is formed by an electric motor driven pump, the suction side via a line with a built-in case of fire on passage switchable valve with the engine cooling system and the pressure side leading to the spray nozzles Line is connected.

Advantageous details or embodiments of the invention as well as the alternative examples are characterized in the subclaims.

Representative of the inventive use of the invention in commercial vehicles, it is assumed in the further use of a bus. The fire detection system is advantageously able to detect a fire in the engine compartment of the commercial vehicle and display this a control device that automatically triggers the connection of a pump. The fire detection system, however, is e.g. Can also be used in the passenger compartment of the vehicle. The deletion process can initially be initiated unaffected by the reaction possibility of the vehicle driver. The presence of a fire is detected by the at least one sensor arranged in the engine compartment. In the event of a fire, the sensor forwards a signal to a control unit, whereupon it initiates the deletion process. In one embodiment of the invention, the control unit sends e.g. an electrical signal to a switch. The switch closes the circuit between the power source of the pump e.g. the vehicle battery and the pump motor. It is also conceivable that the switch closes the circuit in the electric motor of the pump and thereby the deletion process is triggered. The pump can be driven by the starter instead of by the drive unit of the commercial vehicle. Such a design leads to additional weight and space savings, since it can be used on an already existing in the vehicle unit. At the same time, the starter of a bus has sufficient power reserves for the operation of the extinguishing device.

According to the invention, the ignition of the engine can be switched off with the deletion process. In the event that the driver is no longer able to initiate rescue measures, this ensures that the control unit interrupts the running of the engine and / or initiates the braking process.

The safety of the driver and the passengers can be increased by the fact that when the sensor is triggered by this or the control unit, a signal is sent to the driver. Due to the length of the bus, the position of the driver and the motor are often far from each other. It is conceivable that the driver sits above or in front of the engine, so that a possible smoke formation due to the wind from the driver until very late or not perceived. Against this background, it is preferred that simultaneously with the occurrence of a fire in the engine compartment from the control unit in the cab an alarm is triggered so that the driver can initiate the necessary rescue measures.

In a further advantageous method, the pump can be seen in the flow direction, behind a normally closed valve, hereinafter referred to as shut-off valve, are fed by a second pump disposed in the line with extinguishing agent.

• Fig. 1 ein schematisches erstes Ausführungsbeispiel der Erfindung;
• Fig. 2 ein schematisches zweites Ausführungsbeispiel der Erfindung;
• Fig. 3 ein schematisches drittes Ausführungsbeispiel der Erfindung und
• Fig. 4 ein schematisches viertes Ausführungsbeispiel der Erfindung.

Further features, details and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention and from the drawing. Hereby show:

• Fig. 1 a schematic first embodiment of the invention;
• Fig. 2 a schematic second embodiment of the invention;
• Fig. 3 a schematic third embodiment of the invention and
• Fig. 4 a schematic fourth embodiment of the invention.

Fig. 1 shows a schematic representation of a motor 1, which is connected to an associated cooling system 2. The cooling system 2 comprises a liquid cooler 3, a system of cooling lines 4 and a pump 5. In the present Fig. 1 the pump 5 is shown as a high pressure pump with an associated electric motor 6, the circuit 7 is powered by a vehicle battery 8.

The cooling lines 4 are shown on the basis of arrows as cooling liquid supplying 9 and cooling liquid 10 discharging. The pump 5 is connected to the cooling system 2 via a shut-off valve 11 arranged in the cooling line 9 supplying the cooling liquid. Fig. 1 shows that, according to the invention, an aeration valve 12 actuated by a control device (not shown) can be arranged on an overhead region of the cooling system 2, for example on the liquid cooler 3. Since the cooling system 2 is aerated or vented by opening the venting valve 12, the formation of a vacuum in the cooling system 2 is prevented when pumping the cooling liquid through the downstream pump 5. Destruction of the cooling system 2 is thereby prevented. The vent valve 12 is preferably larger than the check valve 11.

In an extinguishing agent supply line 13, a water jet pump 14 and spray nozzles 15 are arranged. The extinguishing agent supply line 13 opens into a number of spray nozzles 15, which, as in Fig. 1 is shown schematically, are arranged in the engine compartment. Advantageous is that the pressure of the extinguishing agent at the spray nozzles can be constructed by an electric motor driven pump 5, and the pump 5, the extinguishing agent suction side via a line 22 with the built-in, in case of fire on passage switchable shut-off valve 11 can be supplied. On the discharge side, the extinguishing agent can be supplied to the spray nozzles 15 by the pump 5 via the line 13 leading to the spray nozzles 15.

Another advantage is that no additional supply of extinguishing liquid needs to be carried, as according to the invention, depending on the size and weight of the commercial vehicle, a cooling water volume between about 25 and 60 liters is available for extinguishing purposes. The number and position of the spray nozzles 15 are variable as needed to the particularly fire-prone locations in the engine compartment.

Via a device which is arranged in the line 13 which supplies the extinguishing agent to the spray nozzles 15, a fire-fighting additive can be added to the extinguishing agent. In Fig. 1 the supply into the extinguishing agent supply line 13 via a connected to an additional container 16 water jet pump 14, between the pump 5 and the spray nozzles 15. Thus, inter alia, firefighting or fuel fires can be deleted, which can not be controlled solely by nebulization of coolant. The use of a water jet pump 14 proves to be advantageous because it is based on a simple design principle and thus the manufacturing costs for the bus are not excessively increased. Under full power pressure, the additive can be injected from the water jet pump 14 into the extinguishing agent supply line 13, which favors optimal distribution of the additive or the additives in the extinguishing liquid.

The admixture of an additive or an additive combination can take place at any point within the conduit 13 conveying the extinguishing agent. As an additive, for example, film or foaming agents can be used.

Advantageously, the sensor signal can be terminated after a predetermined period of time and repeated as the fire continues. The control unit can be programmed, for example, so that the circuit of the pump 5 is interrupted after a previously determined period of time, for example, about 90 seconds and the, the extinguishing agent promoting pump motor is turned off. Preferably, sensors, lines 13:22 and the controller are designed to be insensitive to heat.

The safety of the vehicle driver increases in that in an additional embodiment of the invention, the control unit can be activated by a signal triggered by the sensor, the signal duration and / or the signal frequency can be controlled by a timer. A resumption of the fire can thus be effectively combated. The consumption of the entire extinguishing agent in the first deletion process is avoided.

As in Fig. 2 2, at least one filter 17 can be arranged in the line 13 supplying the extinguishing agent to the spray nozzles 15, viewed in the direction of flow, behind the shut-off valve 11 which can be switched to passage. Behind the normally closed shut-off valve 11, the extinguishing agent in the leading to the spray nozzles 15 lines 13 can be cleaned. In an advantageous embodiment of the invention can be filtered in this way the extinguishing agent to protect the spray nozzles 15 from contamination. The contamination of the spray nozzles 15 is effectively prevented and thus kept a permanent fire protection.

The spray nozzles 15 may e.g. be provided with sintered screw-in sieves. It is conceivable that the filter or filters 17 are coupled between the pump 5 and the one or more spray nozzles 15. In order to obtain high differential pressures of e.g. 100 bar in front of and behind the filter 17 to be able to withstand high pressure filter can be used. The filter 17 can be placed anywhere within the extinguishing agent feeding line 13, e.g. Arrangements in front of the spray nozzles 15 or in front of the pump 5 are also conceivable. Preferably, the filters 17 are adapted to the type of coolers 3, taking into account that, for example, liquids cooled with plastic coolers are subject to greater contamination than liquids cooled with steel coolers. The filter 17 is a high pressure filter and is positioned between the high pressure pump 5 and the water jet pump 14, in front of the spray nozzles 15.

Fig. 3 shows that in an advantageous embodiment of the invention, the valve 11, which releases the extinguishing agent-carrying line 22, can be arranged on the suction side in front of the low-pressure pump 18. In the line 22, which connects the pump 5 with the switchable on passage check valve 11, a second pump 18 can be arranged on the suction side in front of the pump 5. The extinguishing agent-promoting pump 5 is preferably a high-pressure pump, while the second pump 18 is a low-pressure pump, and can be used to power the high-pressure pump with extinguishing agent. The embodiment of the invention ensures a constant and timely supply of low pressure pump 18 with extinguishing agent. The low-pressure pump 18 can be supplied with extinguishing agent even before the formation of the fire, for example when reaching a predetermined triggering temperature and thus before the connection of the high-pressure pump 5 under the pressure required for fire fighting. In addition, the high-pressure pump 5 can be cleaned by connecting the low-pressure pump 18.

Both pumps 5; 18 will be in Fig. 3 powered by the vehicle battery 8 and are connected in parallel with each other.

Contrary to the illustration in Fig. 1 the shut-off valve 11 arranged on the cooling fluid 9 connects the cooling system 2 not to the high-pressure pump 5 but to the low-pressure pump 18. The latter pump 18 is connected to the high-pressure pump 5 via a connecting line 20, via which the high-pressure pump 5 is supplied with extinguishing agent. Timed after the opening of the supply line 22 releasing shut-off valve 11, which is preferably arranged between the liquid cooler 3 and the low-pressure pump 18, the startup of the pump 5 takes place; 18. In case of failure of the pump 18 can flow through the force of gravity, the extinguishing agent at the opening of the vent valve 12 in the still functioning pump 5 and thus ensure effective fire fighting.

The invention offers the advantage that the low-pressure pump 18 can still be burned before the occurrence of a fire, e.g. from reaching a fixed limit temperature, the high pressure pump 5 feeds with extinguishing liquid, whereby in the high pressure pump 5, a form is established. For the atomization of the extinguishing liquid at the source of pressure conditions up to about 130 bar are conceivable. However, the pressure required for the extinguishing operation is generated according to the invention only when needed and in the respectively required height, so that neither the pump 5 nor the line system 13; 22 permanently high pressure conditions are exposed.

Unlike in Fig. 2 , the filter is 17 in Fig. 3 between the low pressure pump 18 and the high pressure pump 5 is arranged.

In Fig. 4 It is shown that the ventilation valve 12 can be connected to a pressure reducer 21 (not shown) that is acted upon by the operating compressed air system. This will take effect Damage to the cooling system 2 by supplying too high supply pressure avoided. In the Fig. 4 the vent valve 12 and the pressure reducer 21 are arranged on the liquid cooler 3. By variable adjustment of the line pressure by the pressure reducer 21, depending on the severity of the fire in the engine compartment, the consumption of cooling fluid can be controlled. Advantageously, the liquid cooler 3 is acted upon by the operating pressure system with a pressure reduced by the pressure reducer 21 to approximately 1 bar. The extinguishing liquid is thus pressed under pressure into the supply lines 22, which leads to the formation of a pre-pressure in the applied pump 5. To compensate for an overpressure, the additional air valve 12 is provided, which opens automatically when a predetermined pressure is exceeded. Fig. 4 shows

the schematic embodiment according to Fig. 2 with the further difference that the filter 17 is positioned between the shut-off valve 11 and the high-pressure pump 5.

references

1

engine

2

cooling system

3

Chillers

4

cooling line

5

high pressure pump

6

electric motor

7

circuit

8th

vehicle battery

9

Coolant supplying cooling line

10

Coolant-removing cooling line

11

shut-off valve

12

vent valve

13

Extinguishing agent supply line

14

Water jet pump

15

spray nozzles

16

additional container

17

filter

18

Low pressure pump

20

connecting line

21

pressure reducer

22

management

Claims (14)

1. System for extinguishing fires in the engine compartment of a commercial vehicle, in particular of a bus/coach, utilising the coolant from the cooling system (2) of the vehicle engine as the extinguishing agent, which is supplied in the event of a fire by an activated pressure source to spray nozzles (15) located in the engine compartment, whereby a fire is able to be detected by at least one sensor and subsequently a control unit is able to be activated, which then switches a valve (11) that is normally closed to an open position, whereby a line carrying the extinguishing agent from the cooling system to the spray nozzles (15) is released, characterised in that the pressure source is provided by a pump (5) that is driven by an electric motor, whereby this pump is connected on the intake side to the engine cooling system (2) by a line (22) with the built-in valve (11) that can be switched to an open position in the event of a fire and connected on the discharge side to the line (13) leading to the spray nozzles (15).
2. System in accordance with claim 1, characterised in that a second pump (18) is located on the intake side upstream of the pump (5) in the line (22) that connects the pump (5) with the valve (11) that can be switched to an open position.
3. System in accordance with claim 2, characterised in that the valve (11) that can be switched to an open position is located upstream of the second pump (18) in terms of the flow direction.
4. System in accordance with claim 1, characterised in that at least one filter (17) is located downstream in terms of flow direction of the valve (11) that can be switched to an open position in the line (22 or 13) that carries the extinguishing agent to the spray nozzles (15).
5. System in accordance with claim 1, characterised in that an additive is able to be added to the extinguishing agent by means of a device (14) located in the line (13) that carries the extinguishing agent to the spray nozzles (15).
6. System in accordance with claim 1, characterised in that a breather valve (12) that is actuated by the control unit is located in an upper area of the cooling system (2).
7. System in accordance with claim 6, characterised in that a breather valve (12) and a pressure regulator (21) that is subjected to pressure by the operating compressed air system are located on the cooling system (2).
8. Method for extinguishing fires in the engine compartment of a commercial vehicle, in particular of a bus/coach, utilising the coolant from the cooling system (2) of the vehicle engine as the extinguishing agent, which is supplied in the event of a fire by an activated pressure source to spray nozzles (15) located in the engine compartment, whereby a fire is able to be detected by at least one sensor and subsequently a control unit is able to be activated, which then switches a valve (11) that is normally closed to an open position, whereby a line that carries the extinguishing agent from the cooling system to the spray nozzles (15) is released, characterised in that the pressure is built up by a pump (5) that is driven by an electric motor, whereby the extinguishing agent is supplied to the pump (5) on the intake side by means of a line (22) with the built-in valve (11) that can be switched to an open position in the event of a fire and whereby the extinguishing agent is supplied by the pump (5) to the spray nozzles (15) on the discharge side by means of the line (13) that leads to the spray nozzles (15).
9. Method in accordance with claim 8, characterised in that the pump (5) downstream of the valve that is normally closed (11) in terms of flow direction is supplied with extinguishing agent by a second pump (18) located in the line (22).
10. Method in accordance with claim 8, characterised in that the control unit is activated by a signal triggered by the sensor, whereby a timer controls the signal duration and/or signal frequency.
11. Method in accordance with claim 8, characterised in that the extinguishing agent is cleaned downstream of the valve that is normally closed (11) in terms of flow direction by at least one filter (17) located in the line (13) that leads to the spray nozzles (15).
12. Method in accordance with claim 8, characterised in that the ignition of the engine (1) is switched off during the extinguishing process.
13. Method in accordance with claim 8, characterised in that a signal is sent to the driver from the sensor or the control unit when the sensor is activated.
14. Method in accordance with claim 8, characterised in that the sensor signal terminates after a predefined length of time and is repeated if the fire continues.

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