HYDROGEN-POWERED RAIL VEHICLE WITH AN AIR CONDITIONING DEVICE

Description

[0001] The invention relates to a rail vehicle according to the preamble of claim 1, and a method according to the preamble of claim 8.

[0002] Rail vehicles (trains) that are not connected to overhead lines are typically powered or supplied by a diesel engine. The interior of the rail vehicle also needs to be heated and / or cooled.

[0003] Heating is typically provided by means of the waste heat from the diesel engine during operation or by auxiliary heaters with direct diesel combustion to generate heat when the rail vehicle is stationary.

[0004] Typically, cooling is achieved by using the mechanical and / or electrical energy provided by the diesel engine to operate a refrigeration unit while the train is in motion, or to operate refrigeration units powered by smaller auxiliary units while the rail vehicle is stationary.

[0005] However, the combustion of diesel fuel is associated with significant carbon dioxide emissions. Therefore, with a view to decarbonizing the transport sector, alternative propulsion systems to diesel-powered vehicles are being investigated. In particular, diesel-powered trains could be replaced by hydrogen-powered trains. A well-known example of a hydrogen-powered train is the Mireo Plus H, manufactured by Siemens Mobility GmbH. In this system, hydrogen is carried in pressurized tanks and converted into electrical energy by a fuel cell. The generated electrical energy is stored in a battery, which powers the train's drive motor. However, the aim is to minimize the amount of electrical energy used for air conditioning in the train, so as not to reduce its range.

[0006] EP 3 690 354 A1 discloses a rail vehicle with a device for air conditioning a passenger cabin of the hydrogen-powered rail vehicle, wherein the device comprises a pressure tank for storing hydrogen, a fuel cell for providing electrical energy by means of the stored hydrogen and a piping system for the hydrogen as well as an adsorber and a desorber for hydrogen.

[0007] The present invention is based on the objective of providing a device for improved air conditioning of a hydrogen-powered vehicle, in particular for a hydrogen-powered rail vehicle.

[0008] The problem is solved by a rail vehicle with a device having the features of independent claim 1 and by a method having the features of independent claim 8. Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0009] The rail vehicle according to the invention is equipped with a device for air conditioning a passenger cabin of the hydrogen-powered rail vehicle. The device comprises a pressure tank for storing hydrogen, a fuel cell for providing electrical energy using the stored hydrogen, and a piping system for the hydrogen, as well as an adsorber and a desorber for hydrogen, wherein the piping system is configured to guide the hydrogen from the pressure tank through the adsorber and / or through the desorber before it is supplied to the fuel cell. The device is characterized in that it includes a buffer tank for intermediate storage of the hydrogen, wherein the buffer tank is arranged downstream of the adsorber or desorber and upstream of the fuel cell with respect to the piping system.

[0010] A hydrogen-powered vehicle within the meaning of the present invention is a vehicle whose drive is at least partially, and in particular completely, hydrogen-based.

[0011] Air conditioning, as defined in the present invention, is the heating and / or cooling of at least one passenger cabin of the vehicle. In particular, the air conditioning is used when the vehicle is stationary. The system is designed to cool an interior space, namely a passenger cabin of a rail vehicle. The cooling can also be used for air conditioning or temperature control of an energy storage device, especially one or more accumulators, as well as for temperature control of other systems, such as inverters and / or converters, within the vehicle. For this purpose, the vehicle can include a cooling duct system.

[0012] Adsorption by means of the adsorber or desorption by means of the desorber can occur as physical adsorption (physisorption) and / or as chemical adsorption (chemisorption). In other words, adsorption and desorption are understood here to mean either physisorption and / or chemisorption. Preferably, only physisorption takes place.

[0013] According to the present invention, the device is configured to pass the hydrogen through the adsorber and / or desorber before its use in the fuel cell. The adsorber and desorber are connected in parallel with respect to the piping system. In other words, according to the present invention, the hydrogen is passed through the adsorber and / or desorber before its use in the fuel cell.

[0014] The adsorber and / or desorber provided according to the invention utilizes a portion of the pressure energy of the hydrogen stored in the pressure tank to provide heat via the adsorber and / or cooling via the desorber. In this process, the hydrogen is at least partially adsorbed within the adsorber (adsorption) by at least some of the pressure energy. This releases heat, which can be used to heat the vehicle. At lower pressures, heat can be used to desorb the hydrogen within the desorber (desorption). This heat absorption thus generates cooling, which can be used to cool the vehicle.

[0015] The present invention thus allows at least some of the pressure energy from the vehicle's pressure tank to be used for air conditioning the vehicle before its expansion to the significantly lower pressure level typically found at the fuel station, and thus at least partially recovered. This advantageously improves the energy efficiency of a vehicle according to the invention. In particular, the invention increases the range of hydrogen-powered rail vehicles.

[0016] A significant advantage of the present invention is that the pressure energy of the hydrogen in the pressure tanks is partially used for air conditioning, i.e. for cooling and / or heating, before the hydrogen expands to the pressure level of the fuel cell (operating pressure of the fuel cell), instead of dissipating this pressure energy - as in the prior art - in an isenthalpic expansion.

[0017] Thus, the cooling of a passenger cabin using a conventional refrigeration unit can be partially replaced by cooling according to the invention via hydrogen desorption in the desorber. This, in particular, increases the range of a rail vehicle according to the invention.

[0018] Furthermore, cooling and / or heating are possible when the fuel cell is stationary and without consuming electrical or material energy. Advantageously, the air conditioning can operate independently of driving or fuel cell operation, meaning that simultaneous operation of the air conditioning system via adsorption and / or desorption and the fuel cell is not required. However, simultaneous operation can be provided. By implementing the air conditioning system via adsorption / desorption, cooling and / or heating can also be provided when the fuel cell is not in operation.Depending on the duration of the vehicle's or fuel cell's standstill and the resulting required amounts of thermal energy, for example for air conditioning a passenger cabin during a standstill of the vehicle, an additional buffer tank for the hydrogen at low pressure level or at the pressure level of the operating pressure of the fuel cell is advantageously used.

[0019] The invention thus enables, through the adsorber and the desorber, the advantageous partial use of the pressure energy of hydrogen for cooling and / or heating the rail vehicle.

[0020] The method according to the invention is designed for air conditioning a hydrogen-powered rail vehicle according to the invention, wherein, for heating a passenger cabin of the rail vehicle, the hydrogen is routed via the adsorber to the fuel cell, and for cooling the passenger cabin, the hydrogen is routed via the desorber to the fuel cell. The method is characterized in that the hydrogen is temporarily stored by means of a buffer tank after the adsorber or after the desorber and before being routed to the fuel cell.

[0021] By passing the hydrogen through the adsorber, it is partially adsorbed at a high pressure level, for example, in the range of 30 bar to 100 bar, releasing heat which is at least partially used for heating. Passing the hydrogen through the desorber, it is partially desorbed at a low pressure level, for example, in the range of 5 to 30 bar, releasing cold which is at least partially used for cooling. Here, cold is released or generated because heat is required for hydrogen desorption, which is drawn from the passenger cabin. This cools the passenger cabin. The hydrogen is then directed to the fuel cell, for example, to power the vehicle, where intermediate storage in a buffer tank is also provided upstream of the fuel cell.Therefore, the hydrogen does not need to be directed directly from the adsorber and / or from the desorber to the fuel cell.

[0022] The inventive method offers equivalent and equivalent advantages and / or embodiments to the rail vehicle according to the invention.

[0023] According to an advantageous embodiment of the invention, the piping system comprises at least one three-way valve by means of which the hydrogen can be switched to the adsorber and / or to the desorber.

[0024] Advantageously, the switchable three-way valve allows the hydrogen to be directed to the adsorber or the desorber, or in parallel to both the adsorber and the desorber. This advantageously allows heat to be provided for heating and / or cooling (through heat absorption) of the vehicle, particularly its interior.

[0025] It is particularly preferred if the device includes a control unit, wherein the control unit is configured to switch at least the three-way valve.

[0026] In an advantageous further development of the invention, the control unit is configured to switch the three-way valve in such a way that the hydrogen is directed to the adsorber for the purpose of heating an interior space and / or a component of the vehicle.

[0027] This process causes the hydrogen to be at least partially adsorbed within the adsorber, at least partially using its pressure energy and releasing heat. The heat released through adsorption is then used to heat the vehicle.

[0028] According to an advantageous embodiment of the invention, the control unit is designed to switch the three-way valve in such a way that the hydrogen is directed to the desorber for the purpose of cooling an interior space and / or a component of the vehicle.

[0029] This process causes the hydrogen within the desorber to be at least partially desorbed at a lower pressure than in the adsorber, although this requires heat. The heat required for desorption is drawn from the vehicle's interior or the vehicle component. In other words, this generates cold, thus providing cooling for the interior or the component.

[0030] In an advantageous embodiment of the invention, the adsorber is formed by means of a first container and the desorber by means of a second container, wherein the containers each comprise an adsorber material for adsorption or desorption of the hydrogen.

[0031] The two containers advantageously allow for alternating and therefore continuous operation. Adsorption and desorption can thus occur alternately within the two containers. The containers can, in turn, comprise several sub-containers.

[0032] Furthermore, the temperature for heat absorption and heat release can advantageously be set by specifying the adsorbent material used within the adsorber and desorber, respectively, and the associated pressure levels for adsorption and desorption. Typically, the pressure level of the hydrogen within the adsorber is higher than within the desorber. The hydrogen is thus adsorbed under high pressure in the adsorber, where, according to the invention, the pressure energy of the hydrogen stored in the pressure tank is used, and desorbed under lower pressure, for example, 10 bar, within the desorber. Heat is generated or provided through adsorption, and cooling is generated or provided through desorption.

[0033] According to an advantageous embodiment of the invention, the adsorbent material comprises a solid, in particular a metal hydride.

[0034] The adsorber for adsorption and the desorber for desorption of hydrogen can be made of different materials. Furthermore, the adsorber material within the adsorber and the desorber can be the same material. It is particularly advantageous for the adsorber material within the adsorber and / or desorber to be a solid comprising one or more metal hydrides. The temperature level for heating and / or cooling can advantageously be adjusted by using appropriate materials and the respective pressure level. In particular, when metal hydrides are used as a solid, at least a chemical reaction occurs, i.e., chemical adsorption / desorption.

[0035] The rail vehicle device includes a buffer tank for intermediate storage of the hydrogen, wherein the buffer tank is arranged downstream of the adsorber or desorber and upstream of the fuel cell with respect to the piping system.

[0036] In other words, the hydrogen is advantageously temporarily stored by means of a buffer tank after the adsorber and / or after the desorber and before being fed into the fuel cell.

[0037] The buffer tank and its arrangement advantageously enable the air conditioning system to operate independently of the fuel cell. After its use for air conditioning, the hydrogen is temporarily stored within the buffer tank at a low pressure, for example 10 bar, for its later use in the fuel cell.

[0038] According to an advantageous embodiment of the invention, the hydrogen is stored inside the pressure tank at a pressure in the range of 300 bar to 400 bar, in particular at 350 bar.

[0039] This advantageously provides a preferred storage method for the hydrogen.

[0040] In an advantageous embodiment of the invention, the hydrogen is supplied to the adsorber and / or desorber at a pressure in the range of 30 bar to 100 bar.

[0041] Advantageously, the hydrogen still possesses sufficient pressure energy for its adsorption in the adsorber. The aforementioned advantageous pressure level in the range of 30 to 100 bar can be achieved by means of a pressure reducer. Using the pressure reducer, the pressure of the hydrogen within the pressure tank can be reduced from 300 to 400 bar (high pressure) to a pressure in the range of 30 to 100 bar (medium pressure). The pressure reducer is specifically designed as an expansion valve.

[0042] According to an advantageous embodiment of the invention, the hydrogen is temporarily stored within the buffer tank at a pressure in the range of 5 bar to 15 bar (low pressure), in particular at 10 bar.

[0043] This advantageously allows the hydrogen to be temporarily stored within the pressure tank at the operating pressure of the fuel cell. Furthermore, the technical requirements for the buffer tank are lower than those for the pressure tank due to the reduced pressure level. Typically, the fuel cell operates at a pressure of approximately 10 bar. Therefore, the hydrogen can advantageously be supplied directly to the fuel cell without further pressure reduction. Alternatively or additionally, further pressure reduction can be achieved by means of a pressure reducer installed upstream of the fuel cell.

[0044] Further advantages, features, and details of the invention will become apparent from the exemplary embodiments described below and from the drawings. These show, schematically: Figure 1 shows a device according to the prior art; and Figure 2 shows a device according to an embodiment of the present invention.

[0045] Similar, equivalent or equivalent elements may be provided with the same reference symbols in one or more of the figures.

[0046] The Figure 1 schematically illustrates a device for a hydrogen-powered vehicle according to the state of the art.

[0047] The device comprises a pressure tank 2, a pressure reducer 3 (expansion valve), and a fuel cell 5. The electrical energy generated by the fuel cell 5 using hydrogen is used to power the vehicle. The device can only heat the vehicle using the waste heat from the fuel cell 5. Cooling is not possible with the known device shown and must be achieved, for example, using other known electrically operated refrigeration units.

[0048] The hydrogen is typically stored at high pressure in pressure tank 2. For use in the fuel cell 5, it is conveyed from pressure tank 2 to the fuel cell 5 via a piping system, through expansion valve 3. Expansion valve 3 is necessary because the operating pressure of the fuel cell is significantly lower than the storage pressure of the hydrogen in pressure tank 2. According to the current state of the art, the pressure energy of the hydrogen is lost during its expansion and is not utilized further. In other words, the pressure energy is dissipated according to the current state of the art.

[0049] The Figure 2 Illustrates a device 1 according to an embodiment of the present invention.

[0050] A hydrogen-powered rail vehicle, in particular a train, according to an embodiment of the present invention, comprises the device 1.

[0051] The device 1 comprises a pressure tank 2, an expansion valve 3, and a fuel cell 5. Furthermore, the device 1 comprises two three-way valves 4, an adsorber 41, a desorber 42, and a buffer tank 6. The aforementioned components of the device 1 are fluidically connected to one another via a hydrogen piping system 25.

[0052] Hydrogen is stored in the pressure tank 2. Preferably, the hydrogen is stored at a pressure of 350 bar. The pressure of the stored hydrogen is reduced by means of the expansion valve 3, preferably to a pressure in the range of 30 to 100 bar. The hydrogen is thus stored at high pressure and subsequently reduced to an intermediate pressure by means of the expansion valve 3. This intermediate pressure is even higher than the operating pressure (low pressure) of the fuel cell 5. The operating pressure of the fuel cell 5 is, for example, 10 bar.

[0053] After its expansion by means of the expansion valve 3, the hydrogen is directed via one of the three-way valves 4 to the adsorber 41 and / or to the desorber 42.

[0054] Within the adsorber 41, hydrogen is at least partially adsorbed under a higher pressure, for example in the range of 30 to 100 bar. This adsorption is achieved, for example, by an adsorption material, which in particular comprises a metal hydride. The pressure energy of the hydrogen after the expansion valve 3 is at least partially used for adsorption. The adsorption releases heat (symbolized by arrow 410; heating), which can be used to heat an interior space and / or a component of a hydrogen-powered vehicle, in particular a rail vehicle, comprising the device 1. Preferably, the vehicle is a rail vehicle and the heated interior space is a passenger cabin. Since the pressure in the adsorber 41 is even higher than the operating pressure of the fuel cell 5, the pressure energy is at least partially utilized, in contrast to the prior art, namely in particular for heating the interior space.The pressure energy is thus at least partially used for the adsorption of hydrogen and therefore for heat generation. Through the adsorption of the hydrogen, for example, its pressure is reduced from the range of 30 to 100 bar to a pressure of 10 bar.

[0055] Hydrogen is desorbed within the desorber 42. For this process, heat must be supplied at low pressure. This heat is preferably provided, at least in part, by the heat from a passenger cabin, for example, in summer, of a rail vehicle. This advantageously cools the interior or the vehicle component, in particular the passenger cabin. The heat supply for hydrogen desorption within the desorber 42 is indicated by arrow 420 (cooling). Furthermore, the aforementioned heat can be provided by a battery or accumulator intended for storing the electrical energy of the fuel cell 5. Thus, the battery or accumulator can be cooled alternatively or additionally to the interior.

[0056] The heat dissipation 410 and / or the heat input 420 can each be carried out by means of heat exchangers and a corresponding piping system for air, water and / or another cooling medium, for example propane or a fluoroketone.

[0057] After the adsorber 41 or the desorber 42, the hydrogen is combined again into a mass flow via the piping system 25 and by means of the three-way valves 4, and directed either directly to the fuel cell 5 or to the buffer tank 6 for intermediate storage. The buffer tank 6 decouples the operation of the air conditioning system from the operation of the fuel cell 5. This is particularly advantageous for rail vehicles or trains, as it allows the air conditioning to operate independently of the train's movement. Subsequently, the hydrogen from the buffer tank 6 and / or directly after the adsorber 41 and / or desorber 42 is converted into electrical energy in the fuel cell 5, which is used, at least partially, to power the vehicle comprising the device 1. Furthermore, the waste heat from the fuel cell 5 can also be used for heating.

[0058] The adsorber 41 and the desorber 42 are connected in parallel with respect to the hydrogen mass flow rate and within the power system 25. This parallel connection is made possible by the two three-way valves 4. This allows the hydrogen to be directed through the adsorber and / or desorber. The three-way valves 4 can be switched or controlled by a control unit (not shown) of the device or vehicle.

[0059] Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples. Reference symbol list

[0060] 1 Device 2 Pressure tank 3 Expansion valve 4 Three-way valve 5 Fuel cell 6 Buffer tank 25 Piping system 41 Adsorber 42 Desorber 410 Heater 420 Cooling

Claims

1. Rail vehicle having a device (1) for air-conditioning a passenger cabin of the hydrogen-powered rail vehicle, wherein the device (1) comprises a pressure tank (2) for storing hydrogen, a fuel cell (5) for providing electrical energy by means of the stored hydrogen, and a line system (25) for the hydrogen, and also an adsorber (41) and a desorber (42) for hydrogen, wherein the line system (25) is designed to conduct the hydrogen from the pressure tank (2) through the adsorber (41) and / or through the desorber (42) before it is fed to the fuel cell (5), characterized in that the device (1) comprises a buffer tank (6) for buffer storage of the hydrogen, wherein the buffer tank (6) is arranged downstream of the adsorber (41) or desorber (42) and upstream of the fuel cell (5) with respect to the line system (25).

2. Rail vehicle according to Claim 1, characterized in that the line system (25) comprises at least one three-way valve (4), by means of which the hydrogen can be conducted switchably to the adsorber (41) and / or to the desorber (42).

3. Rail vehicle according to Claim 2, characterized in that the device (1) comprises a control unit, wherein the control unit is designed to switch at least the three-way valve (4).

4. Rail vehicle according to Claim 3, characterized in that the control unit is designed to switch the three-way valve (4) for heating the passenger cabin in such a way that the hydrogen is conducted to the adsorber (41).

5. Rail vehicle according to Claim 3 or 4, characterized in that the control unit is designed to switch the three-way valve (4) for cooling the passenger cabin in such a way that the hydrogen is conducted to the desorber (42).

6. Rail vehicle according to one of the preceding claims, characterized in that the adsorber (41) is formed by means of a first container and the desorber (42) is formed by means of a second container, wherein the containers each comprise an adsorber material for adsorption or desorption of the hydrogen.

7. Rail vehicle according to Claim 6, characterized in that the adsorber material comprises a solid, in particular metal hydrides.

8. Method for air-conditioning a hydrogen-powered rail vehicle according to one of the preceding claims, wherein, for heating a passenger cabin of the rail vehicle, the hydrogen is conducted to the fuel cell (5) via the adsorber (41), and, for cooling the passenger cabin, the hydrogen is conducted to the fuel cell (5) via the desorber (42), characterized in that the hydrogen is buffer-stored by means of a buffer tank (6) downstream of the adsorber (41) or downstream of the desorber (42) and before it is conducted into the fuel cell (5).

9. Method according to Claim 8, characterized in that the hydrogen is stored within the pressure tank (2) at a pressure in the range from 300 bar to 400 bar, in particular at 350 bar.

10. Method according to either of Claims 8 or 9, characterized in that the hydrogen is fed to the adsorber (41) and / or desorber (42) at a pressure in the range from 30 bar to 100 bar.

11. Method according to one of Claims 8 to 10, characterized in that the hydrogen is buffer-stored within the buffer tank (6) at a pressure in the range from 5 bar to 15 bar, in particular at 10 bar.