Valve set for conducting and conditioning a gaseous fuel

Abstract

The present invention relates to a valve set for conducting and conditioning a gaseous fuel, in particular hydrogen, comprising: an inlet for receiving a pressurised gaseous fuel from a fuel store; an outlet for conveying a pressurised gaseous fuel to a fuel injector; a shut-off valve, which is fluidically connected to the inlet and is used for selectively blocking or allowing the conveying of the gaseous fuel flowing in from the inlet to the outlet; a gas metering valve, which is fluidically connected in series with the shut-off valve and is used for regulating (preferably with regard to pressure and amount) a flow of the gaseous fuel flowing in via the inlet and guiding it to the outlet; and a bleed valve, which is used, in an open state, to reduce the pressure prevailing at the outlet to a predetermined level, in particular to depressurise the outlet, wherein the shut-off valve, in a de-energised state, is closed and blocks a fluid line, and the bleed valve is open in a de-energised state. Preferably, the gas metering valve may be closed in a de-energised state.

Description

[0001] 01189-24 La / Se

[0002] Liebherr-Components Deggendorf GmbH DE - 94469 Deggendorf

[0003] Valve block for passing and conditioning a gaseous fuel

[0004] The present invention relates to a valve block for passing and conditioning a gaseous fuel and a device for injecting a gaseous fuel with such a valve block.

[0005] To protect the environment, there are increasing efforts to develop alternative fuel strategies that focus on reducing CO2 emissions. A particular focus has shifted to further developing the existing combustion engine, for example, replacing the diesel fuel used with "green" fuels, such as hydrogen in the gas phase. For rapid dissemination and acceptance, these new engines must deliver the same or better performance than conventional engine generation (e.g., diesel engines), both in steady-state and transient / dynamic operation.

[0006] In recent years, conventional internal combustion engines have been dominated by liquid gasoline-based fuels (mainly gasoline and diesel). Many experiments have been conducted in the field of internal combustion engines using gaseous fuels such as compressed natural gas (CNG) or liquefied petroleum gas (LPG), including their associated injection systems. However, in these cases, series production of internal combustion engines uses a multi-point indirect injection (MPI) system, in which the gas is injected into the engine's intake manifold at low pressure, typically < 10 bar. With this technology, the injection pressure is nearly constant and does not require rapid pressure changes.

[0007] However, new research into internal combustion engines powered by gaseous fuels (CNG or H2) aimed at optimizing engine performance shows that direct injection technology (i.e., feeding the gaseous fuel directly into the combustion chamber of an engine cylinder) offers advantages for both performance and efficiency. To enable precise metering of the desired fuel quantity, the injection system requires highly dynamic pressure control capabilities, which were not necessary with MPI technology, where the gaseous fuel is continuously delivered to the injectors at a constant pressure of approximately 10 bar or less.

[0008] The present invention proposes an effective solution for improved implementation of pressure dynamics and control for both PFI (port-to-port fuel injection) and direct injection, while also integrating essential safety functions. The more compact design allows for better use of the already limited installation space and reduces the number of required components.

[0009] Since gas injection (typically H2) is currently a technology that is not yet used in series production, no solutions are known on the market that meet both the requirements for the dynamics of pressure control and the integration of essential safety features.

[0010] A prior art implementation corresponds in its basic design to the illustration in Fig. 1. Here, pressure control is carried out by two distinct components. While it was previously common practice to provide a single pressure control valve between the gas storage unit and the distribution unit, capable of converting the gas pressure provided by the gas storage unit to a specific, variable output pressure as required, a different approach is now being pursued in the state of the art.

[0011] The plan is to use a pressure control unit and a flow control valve located downstream of it. The gaseous fuel (or liquid fuel in the reservoir), compressed at very high pressure (up to 350 bar) in a gas reservoir, is first reduced to a steady, constant intermediate pressure level (e.g., in the range of 50 to 60 bar) via the pressure control unit. Only downstream of this is the pressure adjusted to the actually required pressure in the distribution unit (e.g., to a value in the range of 10 to 60 bar) using the flow control valve.

[0012] The advantage of separating the function into two different components (pressure control unit and flow control valve) according to the invention is that the downstream volume (control volume) can be reduced by appropriately arranging the flow control valve. This then leads to a reduction in the deviations between a desired target pressure value in the distribution unit and a prevailing actual pressure value, since a faster change of the prevailing pressure value in the distribution unit is possible.

[0013] The pressure value feeding the injectors is the result of the flow balance between the flow entering the control volume (rail + lines + injectors) and the flow leaving the control volume (engine demands). The time required to empty the control volume is proportional to the size of the control volume. Minimizing the control volume also minimizes the system's response time, allowing for very fast pressure control.

[0014] A disadvantage of the implementation known from Fig. 1 is that a large number of distributed components are required for the safe operation of such an injection and the knowledge about the state of the gaseous fuel can be improved for an even more precise injection via the at least one fuel injector.

[0015] An improved implementation in this regard is achieved with a device that has all the features of claim 1. Advantageous embodiments of the present invention can be found in the dependent claims.

[0016] According to the invention, a valve block is provided for the passage and conditioning of a gaseous fuel, in particular hydrogen, comprising an inlet for receiving a pressurized gaseous fuel from a fuel reservoir, an outlet for forwarding a pressurized gaseous fuel to a fuel injector, a shut-off valve fluidically connected to the inlet and serving to selectively block or allow the gaseous fuel flowing in from the inlet to the outlet, a gas metering valve fluidically connected in series with the shut-off valve and serving to regulate a flow of the gaseous fuel flowing in via the inlet (preferably with regard to pressure and quantity) and to direct it to the outlet, and a vent valve which, in an open state, serves to reduce the pressure prevailing at the outlet to a predetermined level.In particular, to depressurize the outlet, wherein the shut-off valve is closed in a de-energized state and blocks a fluid line, and the vent valve is open in a de-energized state. Preferably, the gas metering valve can be closed in a de-energized state.

[0017] The valve block claimed according to the invention combines a plurality of previously distributed functions and therefore represents a significant simplification in the design of a fuel injection system for gaseous fuel.

[0018] In addition to the gas metering valve, which adjusts or regulates the flow of gaseous fuel toward the outlet (toward the downstream fuel injector), the valve block contains a shut-off valve and a vent valve. In a de-energized state, the shut-off valve isolates the fluid connection from the valve block inlet (which is typically connected to a gaseous fuel tank) to downstream components, whereas in a de-energized state, the vent valve lowers the valve block outlet (which is typically connected to a distribution unit / rail or directly to a fuel injector) to a predetermined level, e.g., by coupling the outlet to the ambient pressure via a vent line.

[0019] In this way, in addition to the flow control of the gaseous fuel provided by the gas metering valve, it ensures that in the event of a sudden failure of the power supply to the valve block, the valve block ensures that a downstream fluidically connected distribution unit / rail or a connected fuel injector is immediately vented. Given the very high pressures prevailing there, this represents a significant improvement in safety, which can also be achieved with a single component implemented by the valve block.

[0020] The shut-off valve can be located at the inlet of the valve block and serves to maintain safety in the event of a deactivation or emergency stop of an engine equipped with a fuel supply system that includes the valve block. The shut-off valve thus interrupts the fluid connection to an upstream fuel tank and allows the system downstream of the valve block to be vented. It is advantageous if this shut-off valve is leak-free throughout its entire service life, as this is the only way to reliably shut off the fuel tank.

[0021] The gas metering valve can be a proportional flow control valve whose primary function is to regulate the downstream flow of the gaseous fuel. Typically, a distribution unit / rail or fuel injector is connected directly downstream of the valve block, which is supplied with the gaseous fuel conditioned by the gas metering valve.

[0022] The vent valve is fluidically coupled to the outlet of the valve block and serves to vent the gaseous fuel from a region downstream of the valve block. For this purpose, it has a vent line that is fluidically connected to the outlet of the valve block when required in order to reduce the high pressure prevailing there to a predetermined level. In particular, it can be provided that the vent line is connected to the ambient air so that when the vent line is fluidically connected to the outlet of the valve block, the pressure prevailing at the outlet is reduced to the ambient pressure. The venting of the downstream components at the outlet of the valve block is necessary for safety reasons and is carried out every time an engine that has a fuel supply device with such a valve block is stopped.Of course, venting also takes place if such an engine has to stop in an emergency.

[0023] According to an optional development of the present invention, it can be provided that the vent valve is fluidically connected to the outlet via a line which runs inside the valve block and / or outside the valve block.

[0024] Accordingly, to achieve the advantages of the invention, it is irrelevant whether the valve block has a line inside it that fluidically connects the vent valve to the outlet or whether the outlet is fluidically connected to the vent valve via a connecting element arranged externally to the valve block. It can therefore also be provided that the vent valve has a connection arranged in the valve block that can be connected to the outlet via an external connecting line.

[0025] According to a further optional development of the present invention, it can be provided that the valve block further comprises a pressure and / or temperature sensor for detecting the pressure and / or temperature of the gaseous fuel in an inlet region of the valve block, in particular at the inlet. This pressure and / or temperature sensor serves to detect the pressure and temperature in an inlet region of the valve block in order to determine the quantity and pressure of the gaseous fuel to be dispensed. As a rule, an engine control unit (or an electrical control unit) is used, which receives and processes the detected values ​​for the pressure and temperature in the inlet region of the valve block and, based on these values, controls the gas metering valve accordingly.Furthermore, by recording the pressure and / or temperature values ​​at the inlet area of ​​the valve block, the system's condition and the risk of exceeding safety-critical limits can be monitored. For example, abnormally low pressure values ​​can indicate that the pressure control valve, typically located upstream of the valve block and used to maintain a constant pressure level as the fuel tank level decreases, is defective.

[0026] According to a further advantageous implementation of the present invention, it can be provided that the valve block further comprises a pressure and / or temperature sensor for detecting the pressure and / or the temperature of the gaseous fuel in an outlet region of the valve block, in particular at the outlet.

[0027] By measuring pressure and / or temperature at an outlet area of ​​the valve block, it can be determined whether the valve block is functioning properly.

[0028] Furthermore, by directly connecting a downstream distribution unit, such as a rail, the temperature and / or pressure sensors typically found there can be dispensed with, as the values ​​measured there would generally match those at the outlet of the valve block. This reduces the number of required components, as it is no longer necessary to provide corresponding sensors in the distribution unit (or rail), thus also eliminating the need for separate cabling to those sensors. It is now only necessary to connect the valve block with its sensors, which significantly reduces the wiring and assembly effort.

[0029] Of course, this is also advantageous if the at least one fuel injector arranged downstream of the valve block is connected directly to the valve block without the presence of an intermediate distribution unit (or rail). There are implementations in which a separate connecting line to the valve block is provided for each of the multiple fuel injectors, so that each of the multiple fuel injectors can be supplied with a corresponding amount of gaseous fuel tailored to it. A common distribution unit to which multiple fuel injectors are connected then no longer exists. For this implementation, too, it is advantageous to know the pressure and temperature of the gaseous fuel that is released via the respective fuel injector for outflow, since this can advantageously be used to adjust the opening time of a respective fuel injector.

[0030] According to a further advantageous modification of the present invention, it can be provided that the valve block further comprises a safety valve which is fluidically connected on the inlet side to the inlet and on the outlet side to a low-pressure side or the vent line of the vent valve and serves to establish a fluid connection between the inlet side and the outlet side when a pressure threshold value on the inlet side is exceeded in order to reduce the pressure on the inlet side.

[0031] Typically, this safety valve can be a mechanical relief valve to prevent excessive pressure at the inlet of the valve block from occurring, which could lead to damage to the valve block or adjacent components. To prevent such a situation, the safety valve connects the inlet to the vent line of the vent valve if the pressure at the inlet exceeds a predetermined pressure threshold.

[0032] According to the invention, it can be provided that all valves are mounted on a common base and arranged rigidly relative to one another. The valve block is therefore a single component that has several valves, which can be controlled via a common control connection. Therefore, an electronic control unit (e.g., an engine control unit) no longer needs to be wired separately to each of the several valves present in the valve block; instead, it is sufficient for the wiring to be connected to the valve block. This leads to a significant reduction in installation effort, since valves that were previously typically arranged in a distributed manner are now centrally consolidated in the valve block.

[0033] According to the invention, it can further be provided that the vent valve is fluidly connected on the inlet side to the outlet of the valve block and is fluidly connected on the outlet side to a low-pressure region, in particular to the ambient air. The vent valve therefore serves to reduce the pressure at the outlet of the valve block to a specific pressure value when required. For example, in a fuel supply system, it is typically necessary to evacuate components that are under high pressure relatively quickly in the event of an emergency stop or when the fuel supply line is deactivated, so that they no longer pose a danger. Maintenance personnel or the like generally assume that a resting state or a deactivated engine no longer contains any components that are under pressure and that could pose a danger.However, this would be the case if an attempt to repair the valve block revealed that it was still under high pressure.

[0034] The invention further relates to a device for injecting a gaseous fuel, in particular hydrogen, which comprises a valve block according to one of the preceding variants, at least one fuel injector which is arranged downstream of the valve block and serves to introduce the gaseous fuel into a combustion chamber, and an electronic control unit which is designed to control the valves of the valve block, preferably as a function of at least one temperature and / or pressure value of the gaseous fuel in the inlet area and / or in the outlet area, which value is detected in the valve block.

[0035] This makes it clear that the valve block according to the invention can also be used in conjunction with a device for injecting a gaseous fuel, as the valve block particularly demonstrates its advantages in this context. The valve block according to the invention not only conditions the fuel to the downstream components (distribution unit / rail and fuel injector), but also contains essential safety functions, such as the vent valve, which significantly simplifies and improves the entire device for injecting a gaseous fuel.

[0036] Furthermore, the device can comprise a distribution unit, in particular a rail, which is fluidly connected to the at least one fuel injector for introducing the gaseous fuel into a combustion chamber, preferably with the distribution unit being arranged downstream of the valve block and the at least one fuel injector being arranged downstream of the distribution unit. The distribution unit serves to receive a gaseous fuel under a certain pressure, so that several fuel injectors connected to the distribution unit can introduce it into a combustion chamber.

[0037] If several fuel injectors or all fuel injectors of an engine are connected to the same distribution unit, this is also referred to as a common rail.

[0038] According to the present invention, it can further be provided that the distribution unit extends directly from the valve block without the presence of a connecting line arranged between the distribution unit and the valve block. A connecting line connecting the outlet of the valve block to a distribution unit is not necessarily required.

[0039] Alternatively, according to the invention, it is also possible for the distribution unit to be connected to the valve block via a connecting line, which can be rigid or flexible. By arranging a connecting line between the distribution unit and the valve block, an optimal arrangement position can be found for both the distribution unit and the valve block, which do not have to be in close proximity to each other.

[0040] The present invention further relates to an engine with a device according to one of the preceding variants, in particular an internal combustion engine, fuel cell, or gas turbine. Although the invention is primarily explained with reference to a hydrogen internal combustion engine, the possible uses of the present invention are not limited thereto. Thus, the valve block or the device for injecting a gaseous fuel can also be used in conjunction with a gas turbine or a fuel cell.

[0041] Furthermore, according to an optional modification, it can be provided that the valve block is arranged no further than 2 m from the center of gravity of the engine, preferably wherein the valve block is attached to an engine housing.

[0042] This advantageously results in the fluid space downstream of the valve block, which is to be supplied with a gaseous fuel, having a limited volume, so that this can be easily controlled. If the valve block is arranged further away from it, the control volume downstream of the valve block becomes too large, so that, particularly in the case of relatively large changes in demand with regard to the pressure of the gaseous fuel, these changes are no longer feasible. According to an advantageous development of the present invention, it can be provided that the engine is an internal combustion engine that uses gaseous hydrogen as fuel to drive the engine, which is fed to the inlet of the valve block at a predetermined pressure level.

[0043] Typically, gaseous fuel is only converted into gas after it has been removed from a fuel tank, as storing it in liquid form takes up less space. Regardless of the form in which the fuel is stored, the problem with the fuel tank is that as the fuel level drops, the pressure of the fuel stored therein also drops. To avoid having to work with a varying fuel pressure level, a pressure control valve is typically installed downstream of the fuel tank. This valve keeps the fuel removed from the fuel tank at a constant pressure level. This simplifies further processing of the fuel, as the downstream components do not have to work with a varying pressure level of the gaseous fuel.

[0044] The invention further relates to a work machine with a valve block according to one of the preceding variants, a device according to one of the preceding variants and / or a motor according to one of the preceding variants.

[0045] Further features, details, and advantages of the invention will become apparent from the following description of the figures. These show:

[0046] Fig. 1 : a schematic diagram of a device known from the prior art for injecting a gaseous fuel,

[0047] Fig. 2: a schematic diagram of a valve block according to the invention for

[0048] Injection of a gaseous fuel,

[0049] Fig. 3: a schematic diagram of a valve block according to the invention for

[0050] Injection of a gaseous fuel, Fig. 4: a schematic diagram of an embodiment of a device according to the invention for injecting a gaseous fuel,

[0051] Fig. 5: a schematic diagram of a further embodiment of a device according to the invention for injecting a gaseous fuel,

[0052] Fig. 6: a schematic diagram of another embodiment of a device according to the invention for injecting a gaseous fuel, and

[0053] Fig. 7: a schematic diagram of a further embodiment of a device according to the invention for injecting a gaseous fuel.

[0054] Fig. 1 shows a prior art device for supplying a gaseous fuel. Starting from a reservoir 3 or tank, the fuel, present in gaseous form at the outlet of the reservoir 3, is introduced into the distribution unit 14, so that the injectors 5 connected to it can discharge the gaseous fuel at a desired pressure level.

[0055] Connected to the outlet of accumulator 3 is a pressure control unit 16, which delivers the fuel at a constant, steady-state pressure. This pressure is, for example, in the range of approximately 60 bar and thus significantly below the pressure level prevailing in accumulator 3 of approximately 350 bar. Downstream of the pressure control unit 16, a flow control valve 18 is connected via a fluid connection. This valve, separate from the pressure control unit 16, has the task of generating the variable pressure levels to be set in the distribution unit 14.

[0056] To the right of the accumulator 3, you can see the pressure P plotted over time t, which decreases as the fill level of the accumulator 3 decreases. The pressure control unit 16 has the task of bringing the fuel originating from the accumulator 3 to a constant, stationary pressure level. The fuel at this constant, stationary pressure level is then fed via the fluid connection to the flow control valve 18, which is typically arranged in the area of ​​the distributor unit 14. This reduces the control volume to which a variable pressure of fuel must be applied. Finally, implementations are conceivable in which, for example, the control volume to the distributor unit 14 and the injectors 5 connected to it can be reduced. The flow control valve 18 is designed to output the desired, variable pressure values ​​that should prevail in the distributor unit 14 based on the constant, stationary output pressure of the pressure control unit 16.

[0057] To the right of the pressure control unit 16, the output pressure level P plotted against time t is shown. This pressure level is fed from the pressure control unit 16 via the fluid line to the flow control valve 18. The flow control valve 18 maintains a constant fuel pressure level—independent of the fill level of the accumulator 3—from which the desired pressure setpoints are set.

[0058] Below the distribution unit 14, a graphic representation can be seen that shows the pressure P prevailing in the distribution unit 14 over time t. The solid line in this representation describes the actual fuel pressure, whereas the dashed line indicates the target fuel pressure.

[0059] Furthermore, it can be seen that the first zone 21, which defines the supply area of ​​the fuel without load-dependent, variable pressure fluctuations, contains not only the accumulator 3 of the device, but also the pressure control unit 16 and part of the fluid connection 17.

[0060] The second zone 22, which designates the components with the control volume of a varying pressure and the quantity of gaseous fuel to be controlled, is smaller, since large portions of the fluid connection arranged upstream of the flow control valve 18 are subjected to a constant, steady-state fuel pressure. The small control volume also results in improved response to a varied pressure in the distribution unit 14.

[0061] The electronic control unit 13 is connected to a temperature sensor 19, which measures the temperature in the distribution unit 14. Furthermore, the electronic control unit 13 is also connected to a pressure sensor 20, which detects the pressure prevailing in the distribution unit 14. It can be provided that the flow control valve 18 or the injectors 5 connected to the distribution unit 14 are controlled depending on the pressure and / or temperature in the distribution unit 14.

[0062] The second zone 22 defines the engine compartment of a vehicle, whereas the first zone 21 describes the fuel supply area of ​​a vehicle. By arranging the flow control valve 18 in or near the engine compartment and the pressure control unit 16 at a remote position, the advantages described above can be achieved.

[0063] Fig. 2 shows a schematic diagram of a valve block 1 according to the invention for injecting a gaseous fuel, together with a distributor unit 14 arranged downstream therefrom and at least one fuel injector 5. An inlet 2 of the valve block 1 can be seen, which serves to connect the fluid line from the pressure regulating valve 16. This inlet 2 is connected to a shut-off valve 6, which can selectively close or open the inlet 2 of the valve block 1 to components arranged downstream therefrom. A gas metering valve 7, which serves to condition the gaseous fuel, is connected via a connecting line in series with the shut-off valve. Furthermore, a vent valve 8 is provided in the valve block 1, which serves to selectively connect an outlet 4 of the valve block 1 to a low-pressure region in order to reduce a high pressure prevailing at the outlet 4.The low-pressure range to which the vent valve 8 is connected via a vent line (or a low-pressure line) can also be represented by the ambient pressure. Thus, when the vent valve 8 is actuated, the pressure at the outlet 4 of the valve block 1 can be reduced to the ambient pressure.

[0064] For the purposes of the present invention, it is irrelevant whether the vent valve is connected to the outlet 4 via a line running inside the valve block 1 or whether this occurs via a line provided externally to the valve block 1. Fig. 2 shows the externally running line, whereas subsequent figures of the present invention also show the implementation with an internal line running inside the valve block.

[0065] Downstream of the valve block 1, a distributor unit 14 is arranged, from which at least one fuel injector branches off to introduce fuel into a combustion chamber of an internal combustion engine. Furthermore, a pressure and / or temperature sensor 12 is provided on the distributor unit 14 to detect the pressure and / or temperature of the gaseous fuel present in the distributor unit 14. Analogous to Fig. 1, the value(s) detected in this way are transmitted to an engine control unit 13, which controls the valve block 1 and the at least one fuel injector 5 in response thereto.

[0066] The valve block 1 further comprises a pressure and / or temperature sensor 10 which determines the pressure or temperature of the gaseous fuel introduced at the inlet 2 of the valve block 1 at the inlet area of ​​the valve block 1.

[0067] The connection between the valve block 1 and the downstream distribution unit 14 can be implemented via a flexible hose in order to decouple vibrations emanating from the engine compartment to the upstream components such as the pressure control unit 16 and accumulator 3.

[0068] Fig. 3 shows a further embodiment of the present invention, wherein the valve block 1 now, in deviation from the illustration in Fig. 2, has an internal line 9 which connects the vent valve 8 to the outlet 3 of the valve block 1.

[0069] Fig. 4 shows a further embodiment of the present invention, wherein in a device for supplying a gaseous fuel into a combustion chamber of an internal combustion engine, the distributor unit 14 is arranged directly at the outlet of the valve block 1. It can be seen that no line is provided between the distributor unit 14 and the outlet 3 of the valve block 1 or the gas metering valve 7, so that the control volume to be regulated downstream of the valve block 1 is reduced and can be determined in a simple manner. For the sake of clarity, the connection of the distributor unit 14 to the vent valve 8 is not shown. As already explained above, this can either be implemented inside the valve block 1 or via a separate line on the outside of the valve block 1.

[0070] Fig. 5 shows a further embodiment of a device according to the invention for supplying a gaseous fuel into a combustion chamber of an internal combustion engine, in which it is graphically illustrated that the valve block 1 is to be arranged in a certain spatial proximity to the engine. Reference numeral 24 indicates the center of gravity of such an engine, from which the valve block 1 may only be arranged a maximum of 2 m. If this is not the case, this leads to an unfavorably long connecting line between the valve block 1 and the distributor unit 14 or an injector 5, which increases the control volume and no longer enables satisfactory dynamic pressure control.

[0071] The circle shown in Fig. 5 with the radius indicated therein corresponds in reality to a sphere which defines the permissible arrangement space for the valve block 1. An arrangement within this sphere, or no further than 2 m from the center of gravity 24 of the engine, is considered particularly advantageous, since in this case a downstream control volume can still be regulated with a high degree of dynamics with regard to pressure changes in the gaseous fuel. Fig. 6 shows a further embodiment of a valve block 1 according to the invention, in which, in addition to the components already discussed in more detail above, a safety valve 12, typically a mechanical safety valve, is arranged in the valve block in order to counteract any pressure overload which may occur at the inlet 2.The safety valve 12 is designed to connect the inlet 2 to the vent line 23 (which is coupled to a low-pressure range, such as ambient pressure) when a certain pressure threshold is exceeded at the inlet 2. The safety valve 12 thus ensures that the pressure at the inlet 2 of the valve block 1 does not exceed the predetermined pressure threshold. This ensures that the valve block 1 only operates within the pressure range for which it is designed.

[0072] Fig. 7 shows a further embodiment of the present invention, in which the valve block 1 has, in addition to the shut-off valve 6, the gas metering valve, the vent valve 8, the pressure and / or temperature sensor 10 at the inlet area, a further pressure and / or temperature sensor 11 at the outlet area.

[0073] Furthermore, the present implementation also does not have a distribution unit 14 arranged between the fuel injector 5 and the outlet 3 of the valve block 1. Rather, the plurality of fuel injectors 5 are connected to the valve block 1 by a respective fuel connecting line, so that the respective fuel quantity with the associated pressure for each of the plurality of fuel injectors 5 is output from the valve block 1. The control volume located downstream of the valve block 1 can then be further reduced, resulting in an even better dynamic adjustment capability of the pressure of the gaseous fuel.

[0074] 1 valve block

[0075] 2 entrance

[0076] 3 fuel storage

[0077] 4 Exit

[0078] 5 Fuel injector

[0079] 6 Shut-off valve

[0080] 7 Gas dosing valve

[0081] 8 vent valve

[0082] 9 Management

[0083] 10 Pressure and / or temperature sensor at the input

[0084] 11 Pressure and / or temperature sensor at the output

[0085] 12 Safety valve

[0086] 13 electronic control unit

[0087] 14 Distribution unit / Rail

[0088] 15 Connecting line between valve block and distribution unit

[0089] 16 Pressure control unit

[0090] 17 Fluid connection

[0091] 18 Flow control valve

[0092] 19 Temperature sensor

[0093] 20 pressure sensor

[0094] 21 Zone 1

[0095] 22 Zone 2

[0096] 23 Ventilation line

[0097] 24 Center of gravity of the engine

Claims

Valve block for passing and conditioning a gaseous fuel Claims 1. Valve block (1) for passing and conditioning a gaseous fuel, in particular hydrogen, comprising: an inlet (2) for receiving a pressurized gaseous fuel from a fuel reservoir (3), an outlet (4) for forwarding a pressurized gaseous fuel to a fuel injector (5), a shut-off valve (6) fluidically connected to the inlet (2) and serving to selectively block or allow the gaseous fuel flowing in from the inlet (2) to the outlet (4), a gas metering valve (7) fluidically connected in series with the shut-off valve (6) and serving to regulate a flow of the gaseous fuel flowing in via the inlet and to direct it to the outlet (4), and a vent valve (8) which, in an open state, serves to reduce the pressure prevailing at the outlet (4) to a predetermined level,in particular to depressurise the outlet (4), wherein the shut-off valve (6) is closed in a de-energised state, and the vent valve (8) is open in a de-energised state, preferably wherein the gas dosing valve (7) is closed in a de-energised state.

2. Valve block (1) according to the preceding claim 1, wherein the vent valve (8) is fluidically connected to the outlet (4) via a line (9) which runs inside the valve block (1) and / or outside the valve block (1).

3. Valve block (1) according to one of the preceding claims, further comprising a pressure and / or temperature sensor (10) for detecting the pressure and / or the temperature of the gaseous fuel in an inlet region of the valve block (1), in particular at the inlet (2).

4. Valve block (1) according to one of the preceding claims, further comprising a pressure and / or temperature sensor (11) for detecting the pressure and / or the temperature of the gaseous fuel in an outlet region of the valve block (1), in particular at the outlet (4).

5. Valve block (1) according to one of the preceding claims, further comprising a safety valve (12) which is fluidically connected on the inlet side to the inlet (2) and on the outlet side to a low-pressure side of the vent valve (8) and serves to establish a fluid connection between the inlet side and the outlet side when a pressure threshold value on the inlet side is exceeded in order to reduce the pressure on the inlet side.

6. Valve block (1) according to one of the preceding claims, wherein all valves are mounted on a common base and arranged rigidly to one another.

7. Valve block (1) according to one of the preceding claims, wherein the vent valve (8) is fluidically connected on the inlet side to the outlet (4) and is fluidically connected on the outlet side to a low-pressure region, in particular to the ambient air.

8. Device for injecting a gaseous fuel, in particular hydrogen, comprising: a valve block (1) according to one of the preceding claims, at least one fuel injector (5) which is arranged downstream of the valve block (1) and serves to introduce the gaseous fuel into a combustion chamber, and an electronic control unit (13) which is designed to control the valves of the valve block (1), preferably as a function of at least one temperature and / or pressure value of the gaseous fuel in the inlet area and / or in the outlet area which is detected in the valve block (1).

9. Device according to claim 8, further comprising a distributor unit (14), in particular a rail, which is fluidically connected to the at least one fuel injector (5) for introducing the gaseous fuel into a combustion chamber, preferably wherein the distributor unit (14) is arranged downstream of the valve block (1) and the at least one fuel injector (5) is arranged downstream of the distributor unit (14).

10. Device according to one of the preceding claims 8 or 9, wherein the distributor unit (14) extends directly from the valve block (1) without the presence of a connecting line arranged between the distributor unit (14) and the valve block (1).

11. Device according to one of the preceding claims 8 or 9, wherein the distributor unit (14) is connected to the valve block (1) via a connecting line (15) which is designed to be rigid or flexible.

12. Engine with a device according to one of the preceding claims 8-11, in particular internal combustion engine, fuel cell or gas turbine.

13. Engine according to the preceding claim 12, wherein the valve block (1) is arranged no further than 2 m from the center of gravity of the engine, preferably wherein the valve block (1) is attached to an engine housing.

14. Engine according to one of the preceding claims 12 or 13, wherein the engine is an internal combustion engine which uses gaseous hydrogen as fuel for driving the engine, which hydrogen is supplied at a predetermined pressure level to the inlet (2) of the valve block (1).

15. Working machine with a valve block (1) according to one of the preceding claims 1-7, a device according to one of the preceding claims 7-11 and / or a motor according to one of the preceding claims 12-14.

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