Rail vehicle for firefighting

Abstract

The invention relates to a rail vehicle (1) for firefighting having a traction system (5) and a liquid tank (2) for storing a fire extinguishant (16), a cooling circuit being arranged to cool components (11, 15, 30) of the traction system (5), the cooling circuit comprising a heat exchanger (18) for dissipating heat to the fire extinguishant (16). The rail vehicle (1) therefore remains ready for operation even after firefighting has been carried out for a lengthy period. The as yet unused fire extinguishant (16) absorbs the thermal energy generated by the traction system (5).

Description

Technical area

[0001] The invention relates to a rail vehicle for firefighting using extinguishing devices arranged on the rail vehicle for dispensing an extinguishing agent, with a traction system and a liquid tank for storing the extinguishing agent. The invention also relates to a method for operating the rail vehicle. State of the art

[0002] A rail vehicle for firefighting is known from WO 2018 / 137871 A1. This rail vehicle is intended in particular for firefighting and rescuing people in a tunnel. The rail vehicle comprises a liquid tank for storing an extinguishing agent used in firefighting. The rail vehicle can be moved along a track by means of a traction system.

[0003] WO 2018 / 210526 A2 describes a rail vehicle whose traction drive comprises an electric motor supplied by an electrical energy storage device located on board the rail vehicle. Devices and methods for fire prevention and fire extinguishing of the energy storage device and the power converter provided for controlling the electric motor are disclosed. These devices include, in particular, a tank with a dielectric fluid, which is arranged above the energy storage device and is connected to a dielectric circuit, which serves to regulate the temperature of the components—i.e., the battery cells—of the energy storage device, via an extinguishing line that can be shut off with a controllable valve, and a compensating line. Description of the invention

[0004] The invention is based on the object of improving a rail vehicle of the type mentioned above so that safe operation is possible at high ambient temperatures over a longer period of use. Furthermore, it is an object of the invention to provide a corresponding method for operating the rail vehicle.

[0005] According to the invention, these objects are achieved by the features of independent claims 1 and 10. Dependent claims specify advantageous embodiments of the invention.

[0006] A cooling circuit is provided to cool components of the traction system, wherein the cooling circuit includes a heat exchanger for dissipating heat to the extinguishing agent. The extinguishing agent thus fulfills an additional function as a thermal mass for cooling the traction system. High ambient temperatures occur during firefighting, particularly in a tunnel. Heat dissipation to the environment is then only possible to a limited extent. With the present invention, the rail vehicle remains operational even after extended firefighting. The unused extinguishing agent absorbs the thermal energy generated by the traction system. The cooling effect is facilitated by a high thermal mass and a relatively good specific heat capacity of the extinguishing agent. In this way, failure of temperature-sensitive components of the traction system is reliably avoided.Even with a reduced or significantly warmed-up extinguishing agent supply, the invention significantly extends the possible operating time.

[0007] In an advantageous development, the heat exchanger is located at least partially within the liquid tank. The extinguishing agent thus remains in the tank and does not need to be routed to an external heat exchanger.

[0008] It is advantageous if the heat exchanger includes pipes, which are arranged, in particular, in a groove in the liquid tank. A cooling medium from the cooling circuit flows through the pipes. The temperature of the cooling medium is higher than the temperature of the extinguishing agent, so that thermal energy is transferred to the extinguishing agent. The energy exchange is optimized by appropriate sizing and material selection of the pipes.

[0009] With the improved design of the liquid tank, the extinguishing agent collects in the groove where the pipes are located. In this case, a thermally effective residual mass of the extinguishing agent is permanently available. Cooling is then maintained even when the amount of extinguishing agent intended for extinguishing has been used up.

[0010] In an advantageous embodiment of the invention, the traction system comprises an electric motor and power electronics, wherein the power electronics are equipped with cooling elements of the cooling circuit. In particular, traction converters and, if applicable, auxiliary converters are cooled.

[0011] A further improvement involves the traction system incorporating an electric storage system, which is equipped with cooling elements for the cooling circuit. This allows thermally sensitive electric storage devices such as lithium-ion batteries to be operated safely. This allows the rail vehicle to be driven purely electrically, even when there is no power supply from an overhead line.

[0012] For transfers and operations at lower ambient temperatures, the cooling circuit is best equipped with an air cooler. This prevents the extinguishing agent from heating up even when air cooling is available.

[0013] It is advantageous if the air cooler is integrated into the cooling circuit via switchable valves. The valves are automatically operated by a control device depending on the ambient temperature.

[0014] The application possibilities are expanded when a first car houses the liquid tank and a second car coupled to the first car houses the traction system. This rail vehicle, consisting of several cars, is suitable for carrying large quantities of extinguishing agent while ensuring sufficient traction.

[0015] A further development of this invention provides for the coupling of the carriages by means of a coupling device comprising connecting lines of the cooling circuit. During the coupling process, the cooling circuit lines are connected along with the various supply and control lines.

[0016] In the method according to the invention for operating the rail vehicle, the heat exchanger in the cooling circuit is activated by a control device when a predetermined temperature threshold is reached. Activation is advantageously achieved by automatically controlling directional control valves arranged in the cooling circuit. This ensures that temperature-sensitive components of the traction system remain below a permissible temperature. Short description of the drawings

[0017] The invention is explained below by way of example with reference to the accompanying figures. They show schematically: Fig. 1 Rail vehicle in a side view Fig. 2 Rail vehicle with several cars Fig. 3 Block diagram Description of the embodiments

[0018] The Fig. 1 The rail vehicle 1 shown comprises a liquid tank 2 supported on a vehicle frame 3. The vehicle frame 3 can be moved on a track 6 on rail bogies 4 by means of a traction system 5. A driver's cab 7 with a driver's station is arranged at each end of the rail vehicle 1. According to the invention, the traction system 5 comprises a cooling circuit with a cooling medium for cooling temperature-sensitive components. In a diesel drive, for example, electronic components of an engine control system or other control devices must be protected from thermal failure. If necessary, the engine block is also cooled by means of the cooling circuit.

[0019] Preferably, the rail vehicle 1 is electrically powered. For this purpose, a pantograph 8 is arranged on the roof of the rail vehicle 1. This pantograph supplies an electric motor 9 with electrical energy from an overhead line 12 via a transformer unit 10 and power electronics 11. The power electronics 11 includes, for example, a traction converter 13 and various additional devices 14, such as an auxiliary converter.

[0020] It is advisable to install an electrical storage unit 15 to maintain the electric traction drive for the duration of a work or firefighting operation in the absence of the overhead line 12. The cooling circuit cools, in particular, the traction converter 11, the auxiliary devices 14, and, if applicable, the electrical storage unit 15.

[0021] For firefighting, the rail vehicle 1 carries a large quantity of extinguishing agent 16 in the liquid tank 2. This is preferably water. Various extinguishing devices 17 are arranged for dispensing the extinguishing agent 16. If necessary, the water stored in the liquid tank 2 is mixed with a separately carried extinguishing additive before dispensing.

[0022] According to the invention, the cooling circuit comprises a heat exchanger 18, which is designed to transfer heat to the extinguishing agent 16. In an embodiment not shown, the extinguishing agent 16 is guided to the heat exchanger 18 via pipes or hoses. Fig. 1 The variant shown is that pipes 19 of the heat exchanger 18 are arranged in the liquid tank 2. The heat transferred from the cooling medium of the cooling circuit to the extinguishing agent 16 in the tank 2 depends on the effective heat transfer area, the average temperature difference, and the heat transfer coefficient of the pipes 19.

[0023] The Fig. 2 The illustrated rail vehicle 1 comprises three coupled wagons 20, 21, 22. A first wagon 20 is designed as a tank wagon and contains the liquid tank 2. A second wagon 21 is coupled to it as a railcar. This wagon includes the pantograph 8, which supplies the traction system 5 via the transformer unit 10. On the other end, the tank wagon 20 is coupled to a third wagon 22, which is designed as another railcar. Via an on-board power line 23, the pantograph 8 supplies additional drive units of the traction system 5 via another transformer unit 10. The circuit is closed via grounding modules 24.

[0024] Optionally, the tanker 20 is also equipped with its own drive to enable it to move independently when uncoupled or to achieve greater traction of the rail vehicle 1. The two railcars 21, 22 are equipped with two two-axle bogies. Preferably, the tanker 20 comprises two three-axle bogies to allow for a large-volume liquid tank (e.g., 50,000 liters of storage capacity) with limited axle loading. At least 5,000 liters of extinguishing agent 16 are carried to ensure the cooling of the components of the traction system 5 according to the invention during an extinguishing operation.

[0025] In Fig. 3 The traction system 5 with two cooling circuits of the three-part rail vehicle 1 is shown schematically. In simplified form, this diagram also applies to the rail vehicle 1 in Fig. 1 , where only one cooling circuit is provided.

[0026] In the center, the liquid tank 2 containing the extinguishing agent 16 is shown. A heat exchanger 18 is arranged within it for each railcar 21, 22. Each heat exchanger 18 is an element of a separate cooling circuit. The respective cooling circuit comprises a circulation pump 25, switchable directional control valves 26, and cooling elements 27 for cooling temperature-sensitive components. The cooling circuit also includes connecting pipes and hoses. A cooling medium, for example, water mixed with antifreeze, circulates through the associated cooling circuit by means of the respective circulation pumps 25.

[0027] The directional control valves 26 are controlled by a control device 28. An air cooler 29, preferably located on the roof of the respective railcar 21, 22, can be connected to each cooling circuit. The respective air cooler 29 is used during transfer trips and during work operations with low ambient temperatures to dissipate heat into the environment. In this operating mode, with an optimized design of the respective air cooler 29, no additional heat is dissipated to the extinguishing agent 16. The supply and discharge lines of the respective heat exchanger 18 then remain blocked by the corresponding switching position of the directional control valves 26.

[0028] In the example shown, each railcar 21, 22 comprises two drive units, each with an electric motor 9 and associated power electronics 11. The electrical storage unit 15 is located in one of the cars 21, 22. This allows the rail vehicle 1 to continue to be operated electrically when there is no power from the overhead line 12. The cooling elements 27 of the associated cooling circuit are located in a housing for the respective power electronics 11 and in a housing for the electrical storage unit 15. A heat sink through which the cooling medium flows is provided, for example, as the cooling element 27. To absorb heat, the respective heat sink is thermally contacted with a temperature-sensitive electrical component of the power electronics 11. This efficient cooling ensures a long service life of the components.

[0029] A motor-generator unit is located in the other railcar 23. This provides an emergency supply of electrical energy to the rail vehicle 1 via a generator 31 driven by a diesel engine 30, if needed. Preferably, the motor-generator unit is also equipped with a cooling element 27 of the associated cooling circuit.

[0030] The three carriages 20, 21, and 22 are coupled by means of coupling devices 32. The power line 23 and the cooling circuit lines are connected to these coupling devices 32. Advantageously, connections for bus lines are also provided for transmitting control signals between the control device 28 and the directional control valves 26.

[0031] For example, in the event of a fire in a tunnel, the operating temperature of rail vehicle 1 reaches 60°Celsius. To ensure functional integrity, a maximum temperature of 55°C is specified for the cooling medium circulating in the cooling circuit for the power electronics 11. The current temperature of the cooling medium is continuously reported to the control device 28 via temperature sensors 33. In addition, an external sensor 34 reports the ambient temperature. Depending on the temperature conditions, cooling is achieved via the air coolers 29, the heat exchangers 18, or through combined operation of both cooling devices 18, 29.

[0032] During an extinguishing operation, the extinguishing agent 16 is consumed, so that the thermal mass in the liquid tank 2 decreases. In order to maintain the cooling function for as long as possible, it is advisable to form a groove 35 in the liquid tank 2 in which any remaining extinguishing agent 16 collects. An outlet 36 for conveying the extinguishing agent 16 to the extinguishing devices 17 is arranged above the groove 35. The pipes 19 of the heat exchangers 18 are arranged in the groove 35 so that the residual thermal mass of the extinguishing agent 16 can continue to absorb heat from the cooling circuits. In this way, a particularly long service life of the rail vehicle 1 at high ambient temperatures is possible without risking thermal failure of individual components.

Claims

1. A rail vehicle (1) for firefighting by means of extinguishing systems (17) arranged on the rail vehicle (1) to apply the extinguishing agent (16) with a traction system (5) and a liquid tank (2) for storing the extinguishing agent (16), wherein a cooling circuit is arranged for cooling components (11, 15, 30) of the traction system (5) and the cooling circuit comprises a heat exchanger (18) for transferring heat to the extinguishing agent (16).

2. A rail vehicle (1) according to claim 1, characterised in that the heat exchanger (18) is arranged at least partially within the liquid tank (2).

3. A rail vehicle (1) according to claim 2, characterised in that the heat exchanger (18) comprises pipes (19) which are arranged, in particular, in a bead (35) of the liquid tank (2).

4. A rail vehicle (1) according to one of the claims 1 to 3, characterised in that the traction system (5) comprises an electric motor (9) and power electronics (11), and in that the power electronics (11) are equipped with cooling elements (27) of the cooling circuit.

5. A rail vehicle (1) according to one of the claims 1 to 4, characterised in that the traction system (5) comprises an electrical storage unit (15), and in that the electrical storage unit (15) is equipped with cooling elements (27) of the cooling circuit.

6. A rail vehicle (1) according to one of the claims 1 to 5, characterised in that the cooling circuit comprises an air cooler (29) for transferring heat.

7. A rail vehicle (1) according to claim 6, characterised in that the air cooler (29) is integrated into the cooling circuit via switchable valves (26).

8. A rail vehicle (1) according to one of the claims 1 to 7, characterised in that a first wagon (20) comprises the liquid tank (2) and in that a second wagon (21) coupled to the first wagon (20) comprises the traction system (5).

9. A rail vehicle (1) according to claim 8, characterised in that the wagons (20, 21) are coupled by means of a coupling device (32) comprising connecting pipes of the cooling circuit.

10. A method for operating a rail vehicle (1) according to one of the claims 1 to 9, characterised in that the heat exchanger (18) in the cooling circuit is activated by means of a control device (28) from a predefined temperature threshold onwards.

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