Method for diagnosing fuel gas supply device, control device, computer program, computer readable medium, fuel gas supply device, and vehicle

Abstract

A method (100) of diagnosing a fuel gas supply device (1, 1 ') is disclosed. The fuel gas supply device (1, 1 ') comprises a pressure tank (3), a fuel pressure reducer (6, 6'), a first conduit assembly (C1) connecting an inlet (9) of the fuel pressure reducer (6, 6 ') to the pressure tank (3), and a second conduit assembly (c2) connecting an outlet (9') of the fuel pressure reducer (6, 6 ') to a propulsion system (60). The method (100) comprises the steps of: obtaining (110) pressure data at a plurality of consecutive times, where the pressure data represents a pressure in the second conduit assembly (c2) during a zero flow condition across the fuel pressure reducer (6, 6 '); and diagnosing (130) the operating performance of the fuel pressure reducer (6, 6 ') by analyzing the obtained pressure data. The disclosure also relates to a control device (21), a computer program, a computer readable medium (200), a fuel gas supply device (1, 1 ') and a vehicle (2).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method of diagnosing a fuel gas supply arrangement, wherein the fuel gas supply arrangement is configured to supply fuel gas to a propulsion system of a vehicle. The present disclosure further relates to a control device for a fuel gas supply arrangement, a computer program, a computer readable medium, a fuel gas supply arrangement for a vehicle, and a vehicle comprising a fuel gas supply arrangement. BACKGROUND

[0002] Fuel gas is any of a variety of fuels that are gaseous at normal ambient temperature and pressure conditions. Many fuel gases consist of hydrocarbons (methane, butane or propane or mixtures thereof). Some examples of different types of fuel gas are compressed natural gas (CNG), liquefied natural gas (LNG) and hydrogen (H2).

[0003] Natural gas consists mainly of methane and can be found on oil deposits or can be collected from renewable energy sources in which it is referred to as biogas. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, food waste, landfill or waste water treatment plants. Compressed natural gas (CNG) is a term used to describe natural gas, biogas or mixtures thereof that is compressed in a pressure tank. Compressed natural gas can be stored at a pressure of about 180-200 bar at a fully charged pressure tank and can be reduced to approximately 15 bar, which is generally considered to be the empty system of a vehicle propelled by the gas.

[0004] The term “liquefied natural gas (LNG)” is used to describe natural gas, biogas or mixtures thereof in liquid form. For convenience and safety of storage or transportation, natural gas, biogas or mixtures thereof is usually liquefied by being cooled into liquid form. Liquefied natural gas is usually stored in a pressure tank of a fuel gas supply arrangement of a vehicle at cryogenic temperatures, such as at a temperature of about -130 degrees Celsius. In this way, the gas can be stored in liquid form at a relatively low pressure, which in turn allows more gas to be accommodated in the pressure tank at a lower pressure. Such pressure tanks can also be referred to as cryogenic tanks, as such pressure tanks are constructed to store fuel gas in liquid form at cryogenic temperatures.

[0005] In systems operating with liquefied natural gas, the fuel gas is usually heated by a heat exchanger arranged on or near the pressure tank, so that the propulsion system can be fed with a less cold gas fuel. That is, the propulsion system and components arranged between the pressure tank and the internal combustion engine are sensitive to low temperatures.

[0006] Hydrogen (H2) is a zero-emission fuel when combusted with oxygen and can be produced from a variety of resources, making hydrogen a promising alternative fuel for the future. Hydrogen can also be used to generate electricity in a fuel cell, where the electricity is used to power a vehicle in one or more electric machines of the vehicle. However, challenges related to production, storage, refueling infrastructure, and vehicle costs remain to be solved to facilitate wider adoption. Due to the physical properties of hydrogen, storing this hydrogen in a vehicle presents challenges. The volumetric energy density of hydrogen is low, requiring efficient storage methods to maintain sufficient fuel to meet realistic vehicle driving ranges. One method of storing hydrogen on a vehicle is in high pressure tanks, typically at pressures of 350-700 bar. The tanks are designed to be robust to safely contain the high pressure hydrogen gas.

[0007] As indicated above, fuel gas is typically stored in the pressure tank of a vehicle at a pressure range of approximately 15-700 bar. However, the fuel systems of the propulsion system, such as the injection system of an internal combustion engine and the fuel management system of a fuel cell, are typically designed to operate at a pressure of about 5-9 bar. Therefore, the pressure of the fuel gas from the pressure tank must be reduced before the gas reaches the propulsion system of the vehicle. This is typically achieved using one or more fuel pressure reducers, also referred to as pressure regulators or simply regulators.

[0008] Such fuel pressure reducers are used to regulate the higher pressure range of the pressure tank to a lower preset pressure. The fuel pressure reducer can be seen as acting as a dedicated valve. The fuel pressure reducer is subjected to high pressure on one side, referred to as the upstream side, while the other side, also referred to as the downstream side, contains a lower pressure. Typically, the fuel pressure reducer comprises a valve comprising a valve member, a valve seat, and a spring connected to the valve member. Furthermore, the fuel pressure reducer typically comprises a piston or diaphragm connected to the valve member and to a chamber connected to the downstream side of the fuel pressure reducer. The valve member moves relative to the valve seat between an open position and a closed position depending on the movement of the diaphragm or piston. When the pressure in the downstream chamber drops below the preset pressure, the valve member moves towards the open position by the biasing force of the spring to allow more gas to flow into the downstream side of the fuel pressure reducer. If the downstream pressure reaches above the preset pressure, the valve member moves towards the closed position by the pressure acting on a specific area of the diaphragm or piston.

[0009] As understood from the above, the spring force and the surface area influence the preset pressure. When no flow occurs, a balance is reached between the upstream pressure, the downstream pressure, and the force exerted by the spring. When gas in the downstream volume is consumed or removed, this balance is broken, causing the valve to be moved by the upstream pressure, which in turn opens the valve. This action refills the downstream gas volume until the force balance is re-established. In steady flow conditions, this means that the valve of the fuel pressure reducer maintains a certain degree of opening, creating a restriction orifice of a certain size.

[0010] If the flow increases or decreases, the force balance is disturbed and the fuel pressure reducer adjusts the orifice size between the valve member and the valve seat until balance is regained. In the absence of flow, the fuel pressure reducer closes, pressing the valve piston onto its corresponding seat to prevent pressure from increasing above the preset pressure.

[0011] If a leak occurs in the valve, the pressure in the downstream volume will increase and the push force on the diaphragm or piston will increase until the leak stops. The fuel gas supply typically includes a pressure relief valve (PRV) designed to automatically release gas if the pressure at the downstream side of the fuel pressure reducer exceeds a pressure limit, thereby protecting the system from potential damage due to overpressure. The pressure relief valve does this by opening when the internal force generated by the pressure overcomes the force applied by a spring or similar mechanism that keeps the valve closed.

[0012] The pressure relief valve can also be referred to as a safety valve, release valve, safety release valve, pressure safety valve (PSV), or overflow valve. Regardless of the term used, the main function remains the same, i.e. to provide a safety mechanism that mitigates the risk of system failure due to excessive pressure.

[0013] If a severe leak occurs on the fuel pressure reducer, the pressure relief valve (PRV) can open, thereby releasing gas to the atmosphere. Typically, the fuel pressure reducer is heated by the engine coolant to offset the cold generated by the expanding gas.

[0014] During the service life of the fuel pressure reducer, as debris flows through the valve member and valve seat, it can cause slight scratches, dents, and similar damage on the sealing surfaces of the valve member and valve seat. These irregularities can cause slight leakage through the seat during periods of zero flow, such as when the engine is off.

[0015] As these leaks gradually increase, the pressure during the closed period also rises over time, exerting greater force on the valve member. These amplified forces can deform the sealing surfaces of the valve member and / or valve seat. Furthermore, if the supply pressure is too high, the fuel injectors of the engine's fuel injection system can become inoperable, which leads to a vehicle stoppage, also known as a vehicle outage (VOR) situation.

[0016] In the long term, if the wear and leakage of the fuel pressure reducer is not addressed, the fuel pressure reducer can start leaking to such an extent that it starts releasing gas through the pressure relief valve (PRV). Due to the Joule-Thomson effect, the fuel pressure reducer will absorb the cold from the expanding gas. However, if this happens at engine shutdown, and thus not being heated by the coolant, this cooling effect can cause the O-ring to drop below its design temperature. This can impair the functionality of the fuel pressure reducer, resulting in a free flow of gas. This can either permanently damage the downstream components or the fuel pressure reducer itself, potentially causing them to burst in the worst case, or gradually deplete the fuel gas in the line over time, through the safety relief valve. Both cases can result in a vehicle stall.

[0017] Furthermore, releasing fuel gas into the surrounding environment can result in adverse effects on the environment. Many gaseous fuels contain potent greenhouse gases. As an example, methane is a potent greenhouse gas and is a more potent greenhouse gas than carbon dioxide due to its greater global warming potential. Compared to carbon dioxide, atmospheric methane has a relatively short lifetime with a half-life of about 7 years. However, this methane is more efficient at capturing heat in the atmosphere. Thus, a given amount of methane has a global warming potential of about 84 times that of carbon dioxide over a 20-year period, and about 28 times over a 100-year period.

[0018] Furthermore, due to the flammability of the fuel gas, releasing the fuel gas into the surrounding environment can cause safety issues. SUMMARY

[0019] It is an object of the present invention to overcome or at least alleviate at least some of the above-mentioned problems and drawbacks.

[0020] According to a first aspect of the present invention, the object is achieved by a method of diagnosing a fuel gas supply arrangement, wherein the fuel gas supply arrangement is configured to supply a fuel gas to a propulsion system of a vehicle. The fuel gas supply arrangement comprises a pressure tank configured to store the fuel gas, a fuel pressure reducer, a first conduit assembly connecting an inlet of the fuel pressure reducer to the pressure tank, and a second conduit assembly connecting an outlet of the fuel pressure reducer to the propulsion system. The method comprises the steps of: - obtaining pressure data at a plurality of consecutive time instances, wherein the pressure data is representative of a pressure in the second conduit assembly during a zero-flow condition across the fuel pressure reducer, and - diagnosing an operational performance of the fuel pressure reducer by analyzing the obtained pressure data.

[0021] Thereby, a method is provided which is able to provide a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner. This is because the step of obtaining pressure data representative of the pressure in the second conduit assembly during the zero-flow condition across the fuel pressure reducer at a plurality of consecutive time instances can be indicative of whether the pressure in the second conduit assembly develops over time during the zero-flow condition across the fuel pressure reducer.

[0022] Such a development of the pressure in the second conduit assembly can clearly be indicative of the operational performance of the fuel pressure reducer and whether the valve member or valve seat of the fuel pressure reducer has suffered from wear. Moreover, by diagnosing the operational performance of the fuel pressure reducer via analyzing the obtained pressure data, the diagnosis can be indicative of how the pressure in the second conduit assembly can develop to form a basis for an accurate recommendation of when to schedule shop repair for maintenance or replacement of the fuel pressure reducer.

[0023] Furthermore, the pressure data can be obtained in a simple and effective manner, e.g. by using input from a pressure sensor configured to obtain the current pressure in the second conduit assembly. Thereby, the method is able to provide a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner as explained above.

[0024] In addition, a method is provided which has conditions for avoiding leakage of fuel gas from a fuel gas supply device, e.g. via its pressure release valve. As a further result, a method is provided which has conditions for reducing the environmental impact of a vehicle comprising the fuel gas supply device and conditions for improving the operational safety of the vehicle.

[0025] Furthermore, a method is provided which has conditions for avoiding vehicle standstill caused by a malfunctioning fuel pressure reducer.

[0026] Hence, a method is provided which overcomes or at least alleviates at least some of the above-mentioned problems and disadvantages. Thereby, the above-mentioned objects are achieved.

[0027] Optionally, the step of obtaining pressure data comprises: - obtaining the pressure data at a plurality of consecutive time instances such that at least several of the plurality of consecutive time instances occur at different operational instances of the vehicle.

[0028] Thereby, a reliable diagnosis of the operational performance of the fuel pressure reducer can be further ensured. This is because the pressure data obtained at different operational instances of the vehicle can give a clear indication of how the pressure in the second conduit assembly develops. As a further result, the diagnosis can be indicative of how the pressure in the second conduit assembly can develop in a more reliable manner to form a basis for a more accurate recommendation of when to schedule shop repair for maintenance or replacement of the fuel pressure reducer.

[0029] Optionally, the step of obtaining pressure data comprises: - obtaining pressure data at a plurality of consecutive time instances such that at least several of the plurality of consecutive time instances occur within a respective time period between start-up of the vehicle and start-up of the propulsion system.

[0030] Thereby, a reliable diagnosis of the operational performance of the fuel pressure reducer can be further ensured. This is because the pressure data obtained during the respective time period between start-up of the vehicle and start-up of the propulsion system can ensure that the obtained pressure data is accurate and representative of the current operational state of the fuel pressure reducer without any disturbance from flow transients. Furthermore, the pressure data obtained during the time period between start-up of the vehicle and start-up of the propulsion system can be indicative of a leak occurring over time even more slowly than a leak that can be monitored immediately after shutting down the propulsion system, for example. In addition, due to these features, the pressure data can be obtained in a consistent manner, wherein the obtained pressure data is collected under similar instances, which provides conditions for a reliable diagnosis of the operational performance of the fuel pressure reducer.

[0031] As referred to herein, the start-up of the propulsion system can correspond to the point in time at which a fuel consumption phase of the propulsion system is initiated. In embodiments in which the propulsion system comprises an internal combustion engine, the start-up of the propulsion system can comprise starting of the internal combustion engine, as referred to herein. In embodiments in which the propulsion system comprises a fuel cell, the start-up of the propulsion system can comprise starting a fuel supply phase to the fuel cell, as referred to herein.

[0032] Optionally, the step of diagnosing the operational performance of the fuel pressure reducer comprises: - estimating a remaining operational lifetime of the fuel pressure reducer based on the obtained pressure data.

[0033] Thereby, an even more accurate advice on when to schedule an in-plant repair for maintenance or replacement of the fuel pressure reducer can be provided.

[0034] Optionally, the step of estimating the remaining operational lifetime comprises: - estimating at least one of a remaining time until a predetermined pressure is reached in the second conduit assembly, a remaining distance of travel, a remaining number of operational instances, and a remaining amount of fuel supplied to the propulsion system.

[0035] Thereby, an even more accurate advice on when to schedule an in-plant repair for maintenance or replacement of the fuel pressure reducer can be provided. This is because the analysis of the obtained pressure data can be indicative of how the pressure in the second conduit assembly can develop, thereby also being indicative of at least one of a remaining time until a predetermined pressure is reached in the second conduit assembly, a remaining distance of travel, a remaining number of operational instances, and a remaining amount of fuel supplied to the propulsion system.

[0036] According to some embodiments, at least one of the remaining time, the remaining driving distance, the remaining number of operational instances, and the remaining amount of fuel supplied to the propulsion system can be included in the output of the suggestion of when to schedule the in-plant service for maintenance or replacement of the fuel pressure reducer. Thus, according to such embodiments, the user of the vehicle can plan such in-plant service in a more simple and convenient way.

[0037] Optionally, the fuel gas supply arrangement comprises a pressure release valve configured to release gas from the second conduit assembly when a pressure in the second conduit assembly exceeds a pressure limit, wherein the pressure limit is higher than the predetermined pressure. Thereby, it can be further ensured that the suggestion of when to schedule the in-plant service for maintenance or replacement of the fuel pressure reducer is performed before a case where the operational performance of the fuel pressure reducer has deteriorated to a point where the pressure release valve releases gas from the second conduit assembly. Thus, in this way, a method is provided with improved conditions for avoiding leakage of fuel gas from the fuel gas supply arrangement. As a further result, a method is provided with improved conditions for reducing the environmental impact of a vehicle comprising the fuel gas supply arrangement and with improved conditions for improving the operational safety of the vehicle.

[0038] Optionally, the method comprises: - scheduling the in-plant service based on the estimated remaining operational lifetime of the fuel pressure reducer.

[0039] Thereby, a method is provided which is able to provide an accurate suggestion of when to schedule the in-plant service for maintenance or replacement of the fuel pressure reducer. As a further result, a method is provided with conditions for reducing the environmental impact of a vehicle comprising the fuel gas supply arrangement and with conditions for improving the operational safety of the vehicle.

[0040] Optionally, the fuel gas supply arrangement comprises a pressure release valve configured to release gas from the second conduit assembly when a pressure in the second conduit assembly exceeds a pressure limit, and wherein the method comprises: - setting a fault indicator for the pressure release valve in case the data indicates that the pressure in the second conduit assembly is at a plurality of consecutive time instances within a predetermined pressure range below the pressure limit without any further pressure increase.

[0041] Thereby, the fault indicator can be set in a reliable manner to indicate that the pressure relief valve needs maintenance or replacement. This is because in case the data indicates that the pressure in the second conduit assembly is within the predetermined pressure range at a plurality of consecutive time instances without any further pressure increase, it can be determined that the pressure relief valve opens at too low pressure. A further result of these features, the leakage of fuel gas from the fuel gas supply device can be further avoided. Thus, a method is provided which has improved conditions for reducing the environmental impact of a vehicle comprising a fuel gas supply device and for improving the safety of the operation of the vehicle.

[0042] According to a second aspect of the present application, the object is achieved by a control device for a fuel gas supply device, wherein the fuel gas supply device is configured to supply fuel gas to a propulsion system of a vehicle, the fuel gas supply device comprising a pressure tank configured to store fuel gas, a fuel pressure reducer, a first conduit assembly connecting an inlet of the fuel pressure reducer to the pressure tank, a second conduit assembly connecting an outlet of the fuel pressure reducer to the propulsion system, and the control device, wherein the control device is configured to: obtain pressure data at a plurality of consecutive time instances, wherein the pressure data is representative of the pressure in the second conduit assembly during zero flow conditions across the fuel pressure reducer, and diagnose an operational performance of the fuel pressure reducer by analyzing the obtained pressure data.

[0043] Thereby, a control device is provided which is able to provide a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner. This is because the obtained pressure data, which is representative of the pressure in the second conduit assembly during zero flow conditions across the fuel pressure reducer at a plurality of consecutive time instances, can be indicative of whether the pressure in the second conduit assembly develops over time during zero flow conditions across the fuel pressure reducer.

[0044] This development of the pressure in the second conduit assembly can clearly be indicative of the operational performance of the fuel pressure reducer and whether the valve member or valve seat of the fuel pressure reducer has suffered from wear. Moreover, by diagnosing the operational performance of the fuel pressure reducer by analyzing the obtained pressure data, the diagnosis can be indicative of how the pressure in the second conduit assembly can develop to form a basis for an accurate recommendation when to schedule a shop visit for maintenance or replacement of the fuel pressure reducer.

[0045] Moreover, the pressure data can be obtained in a simple and effective manner, e.g. by using an input from a pressure sensor configured to obtain a current pressure in the second conduit assembly. Thereby, the control device is able to provide a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner as explained above.

[0046] Further, a control device is provided having a condition for avoiding leakage of fuel gas from a fuel gas supply device, e.g. via its pressure release valve. As a further consequence, a control device is provided having a condition for reducing the environmental impact of a vehicle comprising the fuel gas supply device and a condition for improving the operational safety of the vehicle.

[0047] Further, a control device is provided having a condition for avoiding vehicle immobilization caused by a malfunctioning fuel pressure reducer.

[0048] Hence, a control device is provided which overcomes or at least reduces at least some of the above-mentioned problems and drawbacks. Thereby, the above-mentioned objects are achieved.

[0049] It should be appreciated that the various embodiments described with respect to the method can all be combined with the control device as described herein. That is, the control device according to the second aspect of the present disclosure can be configured to perform any of the method steps of the method according to the first aspect of the present disclosure.

[0050] According to a third aspect of the present disclosure, the object is achieved by a computer program comprising instructions for causing the control device according to the second aspect of the present disclosure to perform the steps of the method according to the first aspect of the present disclosure. Thereby, a computer program is provided which provides a condition for overcoming or at least reducing at least some of the above-mentioned drawbacks. Thereby, the above-mentioned objects are achieved.

[0051] According to a fourth aspect of the present disclosure, the object is achieved by a computer readable medium having stored thereon the computer program according to the third aspect of the present disclosure. Thereby, a computer readable medium is provided which provides a condition for overcoming or at least reducing at least some of the above-mentioned drawbacks. Thereby, the above-mentioned objects are achieved.

[0052] According to a fifth aspect of the present disclosure, the object is achieved by a fuel gas supply device for a vehicle, wherein the fuel gas supply device is configured to supply fuel gas to a propulsion system of the vehicle. The fuel gas supply device comprises a pressure tank configured to store fuel gas, a fuel pressure reducer, a first conduit assembly connecting an inlet of the fuel pressure reducer to the pressure tank, a second conduit assembly connecting an outlet of the fuel pressure reducer to the propulsion system, and a control device configured to: - obtain pressure data at a plurality of consecutive time instants, wherein the pressure data is representative of a pressure in the second conduit assembly during a zero flow condition across the fuel pressure reducer, and - diagnose an operational performance of the fuel pressure reducer by analyzing the obtained pressure data.

[0053] Thereby, a fuel gas supply device is provided which is able to provide a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner. This is because the obtained pressure data, which is representative of the pressure in the second conduit assembly during the zero flow condition across the fuel pressure reducer at a plurality of consecutive time instants, can be indicative of whether the pressure in the second conduit assembly during the zero flow condition across the fuel pressure reducer evolves over time.

[0054] Further, a fuel gas supply device is provided which has conditions for avoiding leakage of fuel gas from the fuel gas supply device, e.g. through its pressure release valve. As a further result, a fuel gas supply device is provided which has conditions for reducing the environmental impact of a vehicle comprising the fuel gas supply device and conditions for improving the operational safety of the vehicle.

[0055] Further, a fuel gas supply device is provided which has conditions for avoiding vehicle immobilization caused by a malfunctioning fuel pressure reducer.

[0056] Hence, a fuel gas supply device is provided which overcomes or at least reduces at least some of the above-mentioned problems and drawbacks. Thereby, the above-mentioned objects are achieved.

[0057] According to a sixth aspect of the present invention, the object is achieved by a vehicle comprising a propulsion system, wherein the vehicle comprises a fuel gas supply device according to the fifth aspect of the present invention, and wherein the fuel gas supply device is configured to supply fuel gas to the propulsion system of the vehicle.

[0058] As the vehicle comprises a fuel gas supply device according to the fifth aspect of the present invention, a vehicle is provided which overcomes or at least reduces at least some of the above-mentioned problems and drawbacks. Thereby, the above-mentioned objects are achieved.

[0059] Optionally, the vehicle is a heavy road vehicle, such as a truck or a bus. Thereby, a heavy road vehicle is provided which has at least some of the above-mentioned advantages.

[0060] Further features and advantages of the present invention will become apparent from the detailed description of the application and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0061] The various aspects of the present invention, including its particular features and advantages, will be readily appreciated by those skilled in the art from the following detailed description, considered in connection with the accompanying drawings, from which: Figure 1A vehicle according to some embodiments is schematically illustrated, Figure 2 A vehicle according to some embodiments is schematically illustrated, Figure 1 A propulsion system of the illustrated vehicle and a fuel gas supply arrangement according to some further embodiments, Figure 3 A vehicle according to some embodiments is schematically illustrated, Figure 1 A propulsion system of the illustrated vehicle and a fuel gas supply arrangement according to some further embodiments, Figure 4 A method of diagnosing a fuel gas supply arrangement of a vehicle is schematically illustrated, and Figure 5 A computer readable medium according to some embodiments is illustrated. DETAILED DESCRIPTION

[0062] Aspects of the present application will now be described more fully. Identical reference numerals are used throughout the specification to refer to the same or like parts. For the sake of clarity, well-known functions or constructions will not be described in detail.

[0063] Figure 1 A vehicle 2 according to some embodiments is schematically illustrated. According to the illustrated embodiment, the vehicle 2 is a truck, i.e. a type of heavy road vehicle and a type of heavy commercial vehicle. According to further embodiments, the vehicle 2 can be another type of heavy or lighter type of manned or unmanned vehicle for land- or water-based propulsion, such as a lorry, a bus, a construction vehicle, a tractor, a car, a boat, a ship, etc., as referred to herein.

[0064] The vehicle 2 comprises a propulsion system 60. According to the illustrated embodiment, the propulsion system 60 of the vehicle 2 comprises a combustion engine 5. Alternatively or additionally, the propulsion system 60 can comprise one or more electric propulsion motors. The propulsion system 60 is configured to provide power to the vehicle 2 via wheels 47 of the vehicle 2.

[0065] The vehicle 2 comprises a fuel gas supply arrangement 1 configured to supply fuel gas to the propulsion system 60 of the vehicle 2, as further explained herein. The fuel gas supply arrangement 1 comprises a pressure tank 3 configured to contain pressurized fuel gas. The pressure tank 3 can be configured to store fuel gas at a pressure in the range of 15-700 bar. The pressure tank 3 can also be referred to as a pressure vessel, a pressure container, a pressurized storage tank, etc. In Figure 1 The fuel gas supply arrangement 1 of the vehicle 2 is illustrated as comprising one pressure tank 3 in the illustrated embodiment. However, the fuel gas supply arrangement 1 of the vehicle 2 can comprise more than one pressure tank 3.

[0066] Figure 2 A vehicle according to some embodiments is schematically illustrated, Figure 1The propulsion system 60 of the exemplified vehicle 2 and the fuel gas supply arrangement 1. In the following, reference is made to both simultaneously if not otherwise indicated Figure 1 and Figure 2 .

[0067] As mentioned above, according to the exemplified embodiment, the propulsion system 60 comprises an internal combustion engine 5. For the sake of brevity and clarity, the internal combustion engine 5 is in some places herein referred to as “engine 5”.

[0068] The engine 5 is configured to operate using fuel gas from the pressure tank 3. As used herein, the expression “fuel gas” can encompass any type of fuel that is gaseous at ordinary ambient temperature and pressure conditions and that can be stored in the pressure tank 3 under pressure and that can be combusted in the internal combustion engine 5 to produce useful work. Examples of such gaseous fuels are compressed natural gas (CNG), liquefied natural gas (LNG), liquefied petroleum gas (LPG), hydrogen (H2), biogas, and synthetic gas.

[0069] According to the exemplified embodiment, the internal combustion engine 5 is a four-stroke internal combustion engine. The engine 5 can be a so-called Otto engine (also known as a spark-ignition engine) comprising an ignition device, such as a spark plug, configured to ignite an air-fuel mixture in a combustion chamber of the engine 5. Before the air enters the combustion chamber of the engine 5, the fuel gas can be mixed with the air by a plurality of fuel injectors of a fuel injection system 4 of the engine.

[0070] According to further embodiments, the engine 5 can employ compression-ignition operation. In other words, the engine 5 can be a compression-ignition engine. According to such embodiments, a small amount of liquid fuel, such as diesel or diesel-like fuel, can be used as a pilot for initiating combustion, while the majority of the released energy comes from the combustion of fuel gas supplied to the engine 5 via the fuel gas supply arrangement 1. These types of engines can also be referred to as Bi-fuel engines, dual fuel engines, etc.

[0071] The engine 5 further comprises a cooling system 32. The cooling system 32 comprises coolant channels, a coolant pump configured to pump a coolant, such as a water / glycol mixture, through the cooling system 32, and a radiator 34 configured to radiate heat from the cooling system 32 to the surroundings.

[0072] According to further embodiments, the propulsion system 60 of the vehicle 2 can comprise a fuel cell, wherein the fuel cell is configured to generate electric power using oxygen and hydrogen stored in the pressure tank 3, and wherein the electric power is used to power the vehicle 2 using one or more electric propulsion motors of the vehicle 2.

[0073] The fuel gas supply arrangement 1 comprises a fuel pressure reducer 6. As explained further below, the fuel pressure reducer 6 is configured to reduce the pressure of the fuel gas supplied from the pressure tank 3 before the fuel gas is supplied to the propulsion system 60 of the vehicle 2. In embodiments in which the propulsion system 60 of the vehicle 2 comprises an engine 5, the fuel pressure reducer 6 is configured to reduce the pressure of the fuel gas supplied from the pressure tank 3 before the fuel gas is supplied to the fuel injection system 4 of the engine 5. In embodiments in which the propulsion system 60 of the vehicle 2 comprises a fuel cell, the fuel pressure reducer 6 can be configured to reduce the pressure of the fuel gas supplied from the pressure tank 3 before the fuel gas is supplied to the fuel management system of the fuel cell. The fuel pressure reducer 6 can also be referred to as a pressure regulator, a fuel gas pressure regulator, or simply as a regulator.

[0074] The fuel pressure reducer 6 comprises an inlet 9 and a first conduit assembly cl, wherein the inlet 9 of the fuel pressure reducer 6 is connected to the pressure tank 3 via the first conduit assembly cl. In other words, the first conduit assembly cl connects the inlet 9 of the fuel pressure reducer 6 to the pressure tank 3.

[0075] The fuel gas supply arrangement 1 further comprises a valve vl arranged on, at, or in the region of the pressure tank 3. The valve vl is controllable to an open state in which a fluid connection between the pressure tank 3 and the inlet 9 of the fuel pressure reducer 6 is open. Further, the valve vl is controllable to a closed state in which the valve vl closes the connection between the pressure tank 3 and the inlet 9 of the fuel pressure reducer 6.

[0076] The fuel pressure reducer 6 further comprises an outlet 9’ and a second conduit assembly c2. According to the illustrated embodiment, the outlet 9’ of the fuel pressure reducer 6 is connected to the fuel injection system 4 of the engine 5. In other words, according to the illustrated embodiment, the second conduit assembly c2 connects the outlet 9’ of the fuel pressure reducer 6 to the fuel injection system 4 of the engine 5. In embodiments in which the propulsion system 60 of the vehicle 2 comprises a fuel cell, the outlet 9’ of the fuel pressure reducer 6 can be connected to the fuel management system of the fuel cell.

[0077] According to the illustrated embodiment, the fuel pressure reducer 6 comprises a valve member 11 and a valve seat 12. The valve member 11 is movably arranged relative to the valve seat 12 to control the flow of fuel gas from the inlet 9 to the outlet 9’ of the fuel pressure reducer 6, as explained in more detail below.

[0078] Valve member 11 and valve seat 12 separate the fuel pressure regulator 6 into an upstream portion 26 connected to the inlet 9 of the fuel pressure regulator 6 and a downstream portion 26' connected to the outlet 9' of the fuel pressure regulator 6. According to the illustrated embodiment, the fuel pressure regulator 6 includes a control volume 14 connected to the downstream portion 26' of the fuel pressure regulator 6 and a diaphragm 13 including a surface forming a defining surface of the control volume 14. The diaphragm 13 may also be referred to as a membrane.

[0079] Furthermore, the fuel pressure regulator 6 also includes a spring member 15. The spring member 15 is operatively connected to the diaphragm 13 and the valve member 11. The spring member 15 is configured to bias the valve member 11 relative to the valve seat 12 toward the open position. This bias direction is... Figure 2 The downward direction corresponds to the schematic diagram. When the valve member 11 is in the open position relative to the valve seat 12, the fluid connection between the upstream portion 26 and the downstream portion 26' of the fuel pressure regulator 6 is opened via a throttling orifice formed between the valve member 11 and the valve seat 12.

[0080] When the vehicle 2, including the engine 5 and the fuel gas supply device 1, is started for operation, valve v1 can be controlled to open. In this way, pressurized fuel gas can flow from the pressure tank 3 through the first conduit assembly c1 into the inlet 9 of the fuel pressure regulator 6 and from the upstream portion 26 of the fuel pressure regulator 6 through a throttle orifice formed between the valve member 11 and the valve seat 12 into the downstream portion 26' of the fuel pressure regulator 6, and from this downstream portion into the second conduit assembly c2 through the outlet 9' of the fuel pressure regulator 6. If the propulsion system 60 is deactivated, such as when the engine 5 is stopped, the propulsion system 60 of the vehicle 2 does not consume fuel gas, therefore, the pressure in the downstream portion 26' of the fuel pressure regulator 6 and the second conduit assembly c2 increases.

[0081] The increased pressure is transmitted to the control volume 14, which forces the diaphragm 13 to move in the direction that compresses the spring member 15 and causes the valve member 11 to move toward the closed state. Figure 2 In the schematic diagram, this direction corresponds to the upward direction. In the closed state, valve member 11 abuts against valve seat 12, which closes the fluid connection between the upstream portion 26 and the downstream portion 26' of the fuel pressure regulator 6, thereby also closing the fluid connection between the inlet 9 and the outlet 9' of the fuel pressure regulator 6. Figure 2 In the illustration, valve member 11 is shown in the closed position relative to valve member 11.

[0082] according to Figure 2In the exemplified embodiment, the fuel pressure reducer 6 is a so-called balanced fuel pressure reducer 6, which means that the fuel pressure reducer 6 comprises a second control volume 16 fluidly connected to a downstream portion 26’ of the fuel pressure reducer 6. A portion of the valve member 11 is arranged in a cylindrical portion of the second control volume 16 such that this portion of the valve member 11 is subjected to the current pressure in the downstream portion 26’ of the fuel pressure reducer 6. The pressure acting on this portion of the valve member 11 biases the valve member 11 towards the closed position. However, the surface area of this portion of the valve member 11 is smaller than the surface area of the diaphragm 13. Thus, in total, when the pressure in the downstream portion 26’ of the fuel pressure reducer 6 increases above the set pressure and the spring member 15 becomes compressed, the valve member 11 moves towards the closed position.

[0083] As understood from the above description, the surface area of the diaphragm 13, the surface area of this portion of the valve member 11 and the stiffness / spring constant of the spring member 15 determine the set pressure of the fuel pressure reducer 6. Thus, the set pressure of the fuel pressure reducer 6 corresponds to the pressure level at the downstream portion 26’ of the fuel pressure reducer 6 at which the valve member 11 moves to the closed position. By way of example only, the set pressure of the fuel pressure reducer 6 can be in the range of 5-9 bar.

[0084] According to a further embodiment, the fuel pressure reducer 6 can comprise a piston instead of the diaphragm 13, wherein the piston is operatively connected to the valve member 11 and the control volume 14 to obtain the above described functionality.

[0085] During use, the sealing surfaces of the valve member 11 and the valve seat 12 can suffer from wear, which can result in leakage of fuel gas past the valve member 11 and the valve seat 12 even though the valve member 11 is moved to the closed position relative to the valve seat 12. Such leakage will increase the pressure in the downstream portion 26’ of the fuel pressure reducer 6 and in the first conduit assembly cl connected to the outlet 9’ of the fuel pressure reducer 6. Due to the increased pressure acting on the diaphragm 13, the increased pressure increases the contact force between the valve member 11 and the valve seat 12. Thus, the fluid connection between the upstream portion 26 and the downstream portion 26’ of the fuel pressure reducer 6 can become closed, but at a higher pressure at the downstream portion 26’ of the fuel pressure reducer 6. The increased contact force obtained between the valve member 11 and the valve seat 12 can damage the valve member 11 and / or the valve seat 12.

[0086] The fuel gas supply device 1 also includes a pressure relief valve 7. The pressure relief valve 7 is configured to discharge gas from the second conduit assembly c2 when the pressure in the second conduit assembly c2 exceeds a pressure limit. By way of example only, the pressure limit could be approximately 12 bar. The pressure limit is set to a pressure higher than the set pressure of the fuel pressure regulator 6, and therefore also higher than the normal operating pressure of the propulsion system 60 of the vehicle 2. The pressure relief valve 7 may also be referred to as a safety valve, relief valve, safety relief valve, pressure relief valve (PSV), and overflow valve.

[0087] The fuel gas supply device 1 according to the illustrated embodiment further includes a first pressure sensor s1 and a second pressure sensor s2, the first pressure sensor being configured to provide pressure data representing the current pressure in the first conduit assembly c1, and the second pressure sensor providing pressure data representing the current pressure in the second conduit assembly c2.

[0088] In addition, according to Figure 2 In the illustrated embodiment, the fuel gas supply device 1 includes a low-pressure valve 8. The low-pressure valve 8 is controllable to a closed state and an open state. In the closed state, the low-pressure valve 8 prevents the flow of fuel gas between the outlet 9' of the fuel pressure regulator 6 and the propulsion system 60 of the vehicle 2. In the open state, the low-pressure valve 8 allows the flow of fuel gas between the outlet 9' of the fuel pressure regulator 6 and the propulsion system 60 (engine 5) of the vehicle 2. The low-pressure valve 8 can be controlled to a closed state when the propulsion system 60, the engine 5 of the propulsion system 60, or the vehicle 2 including the propulsion system 60 is deactivated, and can be controlled to an open state when the propulsion system 60, the engine 5 of the propulsion system 60, or the vehicle 2 including the propulsion system 60 is started.

[0089] according to Figure 2 In the illustrated embodiment, each of the first pressure sensor s1, fuel pressure regulator 6, pressure relief valve 7, second pressure sensor s2, and low-pressure valve 8 is arranged in a so-called gas panel 10. According to another embodiment, at least the fuel pressure regulator 6 and possibly the pressure relief valve 7 may be arranged in the gas panel 10. The gas panel 10 includes a coolant passage 36' arranged to have thermal contact with the fuel pressure regulator 6 and the pressure relief valve 7.

[0090] As explained above, the fuel pressure regulator 6 is configured to reduce the pressure supplied from the pressure tank 3 to a set pressure below the pressure supplied from the pressure tank 3. The fuel pressure regulator 6 is cooled due to the expansion of fuel gas within it. Therefore, coolant from the engine 5 is pumped through the coolant passage 36' via the conduit assembly 36 to heat the fuel pressure regulator 6 during operation.

[0091] like Figure 2The fuel gas supply device 1 comprises, as exemplified, a control device 21. The control device 21 is operatively connected to the second pressure sensor s2. Further, according to the exemplified embodiment, the control device 21 is also operatively connected to the first pressure sensor s1, the valve v1 and the low pressure valve 8. However, according to further embodiments, as mentioned herein, the control device 21 can be operatively connected to the second pressure sensor s2 only.

[0092] According to embodiments herein, the control device 21 is configured to obtain pressure data at a plurality of consecutive time instants, wherein the pressure data is representative of the pressure in the second conduit assembly c2 during zero flow conditions across the fuel pressure reducer 6. Further, the control device 21 is configured to diagnose the operational performance of the fuel pressure reducer 6 by analyzing the obtained pressure data. Thereby, a control device 21 is provided which is able to perform a reliable diagnosis of the operational performance of the fuel pressure reducer in a simple and effective manner. This is because the obtained pressure data, which is representative of the pressure in the second conduit assembly during zero flow conditions across the fuel pressure reducer 6 at a plurality of consecutive time instants, can be indicative of whether the pressure in the second conduit assembly c2 develops over time during zero flow conditions across the fuel pressure reducer 6. Such a development of the pressure in the second conduit assembly c2 can clearly be indicative of the operational performance of the fuel pressure reducer 6 and whether the valve member 11 or the valve seat 12 of the fuel pressure reducer 6 has suffered from wear.

[0093] Further, by diagnosing the operational performance of the fuel pressure reducer 6 by analyzing the obtained pressure data, the diagnosis can be indicative of how the pressure in the second conduit assembly c2 can develop to form a basis for accurate recommendations when to schedule shop repairs for maintenance or replacement of the fuel pressure reducer 6, as explained in more detail below.

[0094] According to the exemplified embodiment, the control device 21 is configured to obtain the pressure data by inputting data from the second pressure sensor s2 at a plurality of consecutive time instants. As mentioned herein, the plurality of consecutive time instants can comprise at least two time instants, or at least five time instants. Further, the plurality of consecutive time instants can comprise consecutive time instants occurring at different operational instances of the vehicle 2. In other words, the control device 21 can be configured to obtain the pressure data at a plurality of consecutive time instants such that at least several of the plurality of consecutive time instants occur at different operational instances of the vehicle 2.

[0095] One operational instance of the vehicle 2 can comprise one or more of a start-up of the vehicle 2, the propulsion system 60, the engine 5 of the propulsion system 60, a start of the engine 5 of the propulsion system 60, an operational phase of the engine 5 of the propulsion system 60, a shut-down of the engine 5 of the propulsion system 60, and a deactivation of one or more of the vehicle 2, the propulsion system 60, the engine 5 and the fuel gas supply device 1.

[0096] As used herein, the expression "zero flow condition" means that no fuel gas, or at least substantially no fuel gas, is flowing through the valve member 11 and the valve seat 12 of the fuel pressure reducer 6.

[0097] Furthermore, the plurality of consecutive instants can comprise consecutive instants occurring during the respective time period between the start of the vehicle 2 and the start of the propulsion system 60. In other words, the control device 21 can be configured to obtain pressure data at a plurality of consecutive instants such that at least several instants of the plurality of consecutive instants occur during the respective time period between the start of the vehicle 2 and the start of the propulsion system 60.

[0098] According to these embodiments, the control device 21 can be configured to control the valve vl to the open state at the start of the vehicle 2. As explained above, when the valve vl is controlled to the open state, pressurized fuel gas can flow from the pressure tank 3 via the first conduit assembly cl into the inlet 9 of the fuel pressure reducer 6 and from the upstream portion 26 of the fuel pressure reducer 6 through the orifice formed between the valve member 11 and the valve seat 12 into the downstream portion 26' of the fuel pressure reducer 6 and from this downstream portion via the outlet 9' of the fuel pressure reducer 6 into the second conduit assembly c2. If the engine 5 is in a standstill state, the propulsion system 60 of the vehicle 2 does not consume fuel gas, therefore, the pressure in the downstream portion 26' of the fuel pressure reducer 6 and in the second conduit assembly c2 increases.

[0099] When the pressure in the downstream portion 26' of the fuel pressure reducer 6 and in the second conduit assembly c2 reaches the set pressure, as explained above, the valve member 11 moves relative to the valve seat 12 to the closed position and a zero flow condition is obtained across the fuel pressure reducer 6 when the pressure in the downstream portion 26' of the fuel pressure reducer 6 and in the second conduit assembly c2 reaches the set pressure.

[0100] According to these embodiments, therefore, the control device 21 can be configured to obtain pressure data shortly after the valve vl has been controlled to the open state. As Figure 1 As indicated, according to the illustrated embodiments, the control device 21 is configured to control the valve vl between an open state and a closed state.

[0101] By obtaining pressure data at a plurality of consecutive instants during these types of instances, the operational performance of the fuel pressure reducer 6 can be diagnosed in a simple, efficient and reliable manner. The obtained pressure data obtained at the plurality of consecutive instants can be saved in a memory, such as a memory comprised in the control device 21. The pressure data can be represented by a list of pressure values obtained at the plurality of consecutive instants.

[0102] According to some embodiments, the control device 21 can be configured to estimate a remaining operational lifetime of the fuel pressure reducer 6 based on the obtained pressure data. This estimation can be performed by comparing the pressure data obtained at a plurality of consecutive time instants to identify whether the pressure in the second conduit assembly c2 evolves over time and analyzing a rate of change of the pressure in the second conduit assembly c2 between the plurality of consecutive time instants.

[0103] Further, according to some embodiments, the control device 21 can be configured to estimate at least one of a remaining time until a predetermined pressure is reached in the second conduit assembly c2, a remaining distance of travel, a remaining number of operational instances and a remaining amount of fuel supplied to the propulsion system 60 of the vehicle 2. Such estimation can be based on saved historical driving data of the vehicle 2 and saved historical fuel consumption of the vehicle 2.

[0104] The predetermined pressure can be set to a level lower than the pressure limit of the pressure release valve 7 and higher than the set pressure of the fuel pressure reducer 6. In other words, according to such embodiments, the pressure limit of the pressure release valve 7 is higher than the predetermined pressure.

[0105] The control device 21 can be configured to set a fault indicator based on the diagnosis of the operational performance of the fuel pressure reducer 6. In more detail, the fault indicator can indicate at least one of a remaining time until a predetermined pressure is reached in the second conduit assembly c2, a remaining distance of travel, a remaining number of operational instances and a remaining amount of fuel supplied to the propulsion system 60 of the vehicle 2. The fault indicator can be output in a driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, e.g. on a display arranged in the driver environment 55. Alternatively, the fault indicator can be output to an external device, such as to an external diagnostic tool or the like. Figure 2 The driver environment 55 of the vehicle 2 is schematically indicated.

[0106] According to some embodiments, the control device 21 is configured to schedule a shop visit based on the estimated remaining operational lifetime of the fuel pressure reducer 6. According to such embodiments, the scheduled shop visit can be output in a driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, e.g. on a display arranged in the driver environment 55. Alternatively, the scheduled shop visit can be output to an external device, such as to an external diagnostic tool or the like.

[0107] Furthermore, according to some embodiments, the control device 21 is configured to provide a fault indicator for the pressure relief valve 7 when the data indicates that the pressure in the second conduit assembly c2 is within a predetermined pressure range below the pressure limit for multiple consecutive moments without any further increase in pressure. This is because in this case, i.e., when the data indicates that the pressure in the second conduit assembly c2 is within a predetermined pressure range for multiple consecutive moments without any further increase in pressure, the pressure relief valve 7 can be indicated to have malfunctioned and open when the pressure in the second conduit assembly c2 is too low, i.e., it opens at a pressure below the set pressure limit of the pressure relief valve 7.

[0108] The fault indicator for the pressure relief valve 7 can be output in the driver environment 55 of the vehicle 2, which includes the fuel gas supply device 1, for example, on a display arranged in the driver environment 55. Alternatively, the fault indicator for the pressure relief valve 7 can be output to an external device, such as an external diagnostic tool.

[0109] according to Figure 3 In the illustrated embodiment, the second pressure sensor s2 is positioned between the outlet 9' of the fuel pressure reducer 6 and the low-pressure valve 8. However, according to another embodiment, the second pressure sensor s2 can be arranged downstream of the low-pressure valve 8, i.e., between the low-pressure valve 8 and the propulsion system 60 of the vehicle 2. According to such an embodiment, the control device 21 can be configured to control the low-pressure valve 8 to the open state before pressure data is obtained at multiple consecutive moments.

[0110] Figure 1 An illustrative example Figure 3 The illustrated vehicle 2 has a propulsion system 60 and a fuel gas supply device 1' according to some other embodiments. Figure 2 The fuel gas supply device 1' of the illustrated embodiment includes a reference Figure 1 The fuel gas supply device 1 described herein shares the same features, functions, and advantages; some differences are noted below. Similar features, functions, and advantages will not be further explained herein. Figure 3 As indicated, vehicle 2 may include, according to Figure 3 The fuel gas supply device 1' of the illustrated embodiment.

[0111] according to Figure 3 In the illustrated embodiments, the fuel gas supply device 1' includes a so-called "unbalanced" fuel pressure regulator 6'. Also in these embodiments, the fuel pressure regulator 6' may be referred to as a pressure regulator, fuel gas pressure regulator, or simply a regulator.

[0112] according to Figure 3The fuel pressure reducer 6' of the exemplified embodiment of the fuel gas supply device 1' lacks the second control volume and a portion of the valve member 11' is instead facing the upstream portion 26 of the fuel pressure reducer 6'. Apart from this, the fuel pressure reducer 6' operates according to Figure 2 the fuel pressure reducer 6 in the same way as explained above. Figure 3

[0113] However, since the fuel pressure reducer 6' lacks the second control volume and a portion of the valve member 11' is instead facing the upstream portion 26 of the fuel pressure reducer 6', the outlet pressure, i.e. the pressure in the downstream portion 26' of the fuel pressure reducer 6', and thus the pressure in the second conduit assembly c2, is affected by changes in the inlet pressure, i.e. by the pressure in the upstream portion 26 of the fuel pressure reducer 6'. Figure 2

[0114] According to these embodiments, the control device 21 is thus configured to obtain pressure data representative of the pressure in the first conduit assembly cl during zero flow conditions across the fuel pressure reducer 6' at a plurality of successive time instants and to diagnose the operational performance of the fuel pressure reducer 6' by analysing this pressure data together with pressure data representative of the pressure in the second conduit assembly c2. According to these embodiments, the control device 21 can be configured to compare the pressure data of the second conduit assembly c2 with the pressure data of the first conduit assembly cl and can adjust the diagnosis based on the difference between the pressure data of the first conduit assembly cl and the pressure data of the second conduit assembly c2.

[0115] Also in the exemplified embodiment, the control device 21 can be configured to obtain pressure data representative of the pressure in the first conduit assembly cl during zero flow conditions across the fuel pressure reducer 6 at a plurality of successive time instants. In these embodiments, the obtained pressure data of the first conduit assembly cl can be used for statistics and / or for adapting or adjusting the diagnosis of the fuel pressure reducer 6. Figure 2 According to these embodiments, the control device 21 is thus configured to obtain pressure data representative of the pressure in the first conduit assembly cl during zero flow conditions across the fuel pressure reducer 6' at a plurality of successive time instants and to diagnose the operational performance of the fuel pressure reducer 6' by analysing this pressure data together with pressure data representative of the pressure in the second conduit assembly c2. According to these embodiments, the control device 21 can be configured to compare the pressure data of the second conduit assembly c2 with the pressure data of the first conduit assembly cl and can adjust the diagnosis based on the difference between the pressure data of the first conduit assembly cl and the pressure data of the second conduit assembly c2.

[0116] Figure 3 and Figure 2 ​​​The exemplified embodiments, the fuel gas supply 1, 1' comprises only one fuel pressure reducer 6, 6'. However, according to further embodiments, the fuel gas supply 1, 1' can comprise two fuel pressure reducers arranged in series, i.e. with the outlet of the first fuel pressure reducer connected to the inlet of the second fuel pressure reducer. Such an arrangement of two fuel pressure reducers can be advantageous when the pressure tank 3 of the fuel gas supply 1, 1' is configured to contain fuel gas at high pressure, such as in a hydrogen gas system where the pressure in the pressure tank 3 can be about 700 bar. By arranging two fuel pressure reducers in series, the pressure can be reduced in two steps, which reduces the pressure difference between the upstream part and the downstream part of each fuel pressure reducer.

[0117] In embodiments where the fuel gas supply 1, 1' comprises two fuel pressure reducers arranged in series, one of the fuel pressure reducers can be a balanced fuel pressure reducer, such as the one described with reference to Figure 3 The other one of the fuel pressure reducers can be a non-balanced fuel pressure reducer, such as the one described with reference to Figure 4 The fuel pressure reducer 6'. Generally, according to the above, the first fuel pressure reducer is the balanced fuel pressure reducer 6 and the second fuel pressure reducer is the non-balanced fuel pressure reducer 6'.

[0118] In embodiments where the fuel gas supply 1, 1' comprises a first fuel pressure reducer and a second fuel pressure reducer arranged in series, the control device 21 can be configured to obtain pressure data at a plurality of consecutive time instants, where the pressure data is representative of the pressure between downstream of the first fuel pressure reducer and upstream of the second fuel pressure reducer during zero flow conditions across the fuel pressure reducers. The control device 21 can be configured to diagnose the operational performance of the first fuel pressure reducer by analyzing this pressure data. Furthermore, the control device 21 can be configured to obtain pressure data upstream of the first fuel pressure reducer and can adjust or adapt the diagnosis based on this pressure data.

[0119] Furthermore, in embodiments where the fuel gas supply 1, 1' comprises a first fuel pressure reducer and a second fuel pressure reducer arranged in series, the control device 21 can be configured to obtain pressure data at a plurality of consecutive time instants, where the pressure data is representative of the pressure downstream of the second fuel pressure reducer during zero flow conditions across the fuel pressure reducers. The control device 21 can be configured to diagnose the operational performance of the second fuel pressure reducer by analyzing this pressure data. Also in these embodiments, the control device 21 can be configured to obtain pressure data upstream of the second fuel pressure reducer and can adjust or adapt the diagnosis based on this pressure data.

[0120] Figure 2 A method 100 of diagnosing a fuel gas supply of a vehicle is schematically exemplified. The fuel gas supply can be according to any of the embodiments described above.Figure 3 The fuel gas supply device 1 of the illustrated embodiment, or the vehicle 2 according to Figure 1 The fuel gas supply device 1’ of the illustrated embodiment, and the vehicle can be according to Figures 1 to 4 The vehicle 2 according to the illustrated embodiment. Thus, in the following, if not otherwise indicated, reference is made to Figure 4 .

[0121] The method is a method 100 of diagnosing a fuel gas supply device 1, 1’, wherein the fuel gas supply device 1, 1’ is configured to supply fuel gas to a propulsion system 60 of a vehicle 2. The fuel gas supply device 1, 1’ comprises a pressure tank 3 configured to store fuel gas, a fuel pressure reducer 6, 6’, a first conduit assembly cl connecting an inlet 9 of the fuel pressure reducer 6, 6’ to the pressure tank 3, and a second conduit assembly c2 connecting an outlet 9’ of the fuel pressure reducer 6, 6’ to the propulsion system 60. The method 100 comprises the steps of: - obtaining 110 pressure data at a plurality of consecutive time instants, wherein the pressure data is representative of a pressure in the second conduit assembly c2 during zero flow conditions across the fuel pressure reducer 6, 6’, and - diagnosing 130 an operational performance of the fuel pressure reducer 6, 6’ by analyzing the obtained pressure data.

[0122] The step of obtaining 110 pressure data at a plurality of consecutive time instants can be performed using input from a pressure sensor s2 configured to sense a current pressure in the second conduit assembly c2.

[0123] Further, as Figure 4 indicated, the method 100 can comprise the step of: - saving 120 the pressure data obtained at a plurality of consecutive time instants into a memory.

[0124] Thus, the step of diagnosing 130 an operational performance of the fuel pressure reducer 6, 6’ can be performed by analyzing data stored in the memory. The memory can be a memory of the control device 21 or a memory of an external device or system.

[0125] Further, as Figure 4 indicated, the method 100 can comprise the step of: - outputting 141 data representative of a diagnosis of the operational performance of the fuel pressure reducer 6, 6’ into a driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, 1’ and / or to an external device, such as to an external diagnostic tool.

[0126] The data representative of a diagnosis of the operational performance of the fuel pressure reducer 6, 6’ can be outputted in the form of a fault indicator of the fuel pressure reducer 6, 6’.

[0127] As Figure 4 indicated, the step of obtaining 110 pressure data can comprise: - obtaining 112 pressure data at a plurality of consecutive time instants, such that at least several of the plurality of consecutive time instants occur at different operating instances of the vehicle 2.

[0128] According to some embodiments, the step of obtaining 112 pressure data can be performed such that each of the plurality of consecutive time instants occurs at a single operating instance of the vehicle 2.

[0129] Further, as Figure 4 indicated, the step of obtaining 110 pressure data can - comprise obtaining 114 pressure data at a plurality of consecutive time instants, such that at least several of the plurality of consecutive time instants occur during a respective time period between start-up of the vehicle 2 and start-up of the propulsion system 60.

[0130] According to some embodiments, the step of obtaining 114 pressure data can be performed such that each of the plurality of consecutive time instants occurs during the time period between start-up of the vehicle 2 and start-up of the propulsion system 60.

[0131] Further, as Figure 4 indicated, the step of diagnosing 130 operational performance of the fuel pressure reducer 6, 6’ can comprise: - estimating 131 a remaining operational lifetime of the fuel pressure reducer 6, 6’ based on the obtained pressure data.

[0132] Further, as Figure 4 indicated, the method 100 can comprise the step of: - outputting 143 data representative of the remaining operational lifetime of the fuel pressure reducer 6, 6’ into a driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, 1’ and / or to an external device, such as to an external diagnostic tool.

[0133] As Figure 4 indicated, the step of estimating 131 a remaining operational lifetime can comprise: estimating 132 at least one of a remaining time until a predetermined pressure is reached in the second conduit assembly c2, a remaining distance of travel, a number of remaining operating instances, and a remaining amount of fuel supplied to the propulsion system 60 of the vehicle 2.

[0134] Further, as Figure 4 indicated, the method 100 can comprise the step of: - output 145 data representative of at least one of the remaining time, the remaining driving distance, the remaining number of operating instances and the remaining amount of fuel supplied to the propulsion system 60 of the vehicle 2 into the driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, 1’ and / or to an external device, such as to an external diagnostic tool.

[0135] According to some embodiments, the fuel gas supply device 1, 1’ comprises a pressure release valve 7 configured to vent gas from the second conduit assembly c2 when the pressure in the second conduit assembly c2 exceeds a pressure limit. According to such embodiments, the pressure limit can be higher than a predetermined pressure.

[0136] According to Figure 4 The illustrated embodiment, the method 100 comprises: - scheduling 135 an in-plant repair based on the estimated remaining operating life of the fuel pressure reducer 6, 6’.

[0137] Further, as Figure 4 Indicated, the method 100 can comprise the step of: - outputting 147 data representative of the scheduled in-plant repair of the fuel pressure reducer 6, 6’ into the driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, 1’ and / or to an external device, such as to an external diagnostic tool.

[0138] According to some embodiments, the fuel gas supply device 1, 1’ comprises a pressure release valve 7 configured to vent gas from the second conduit assembly c2 when the pressure in the second conduit assembly c2 exceeds a pressure limit, and wherein the method 100 comprises: - setting 137 a fault indicator for the pressure release valve 7 in case the data indicate that the pressure in the second conduit assembly c2 is at a plurality of consecutive time instances within a predetermined pressure range below the pressure limit without any further pressure increase.

[0139] Further, as Figure 5 Indicated, the method 100 can comprise the step of: - outputting 149 - data representative of the fault indicator of the pressure release valve 7 into the driver environment 55 of the vehicle 2 comprising the fuel gas supply device 1, 1’ and / or to an external device, such as to an external diagnostic tool.

[0140]

[0140] Any of the fault indicators described herein can be represented by a specific fault code. The fault indicator / indicators can be saved into a memory and / or can be output to and / or on a further device, such as an external diagnostic tool, and / or can be output in the driver environment 55 of the vehicle 2.

[0141] It should be appreciated that the various embodiments described with respect to the method 100 can all be combined with the control device 21 as described herein. That is, the control device 21 can be configured to perform any of the method steps 110, 112, 114, 120, 130, 131, 132, 135, 137, 141, 143, 145, 147, and 149 of the method 100.

[0142] Figure 5 A computer readable medium 200 comprising instructions which, when executed by a computer, cause the computer to carry out the method 100 according to some embodiments of the present disclosure is exemplified. According to some embodiments, the computer readable medium 200 comprises a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method 100 according to some embodiments. The computer can be comprised in the control device 21.

[0143] The skilled person will appreciate that the method 100 of diagnosing a fuel gas supply arrangement 1, 1’ of a vehicle 2 can be implemented by programmed instructions. These programmed instructions are typically constituted by a computer program which, when executed in the control device 21, ensures that the control device 21 performs the desired control, such as the method steps 110, 112, 114, 120, 130, 131, 132, 135, 137, 141, 143, 145, 147, and 149 described herein. The computer program is typically part of a computer program product comprising a suitable digital storage medium on which the computer program is stored, such as Figure 2 The computer readable medium 200 exemplified. In other words, the computer program product can be the computer readable medium 200 and the computer program can be stored in the computer readable medium 200.

[0144] The control device 21 can comprise a computer which can take the form of substantially any suitable type of hardware or hardware / firmware device implemented using processing circuitry, such as for example but not limited to a processor, a central processing unit (CPU), a controller, an arithmetic logic unit (ALU), a digital signal processor, a circuit for digital signal processing (digital signal processor, DSP), a microcomputer, a field programmable gate array (FPGA), a system on chip (SoC), a programmable logic unit, a microprocessor, an application specific integrated circuit, or any other device capable of electronically executing operations in a defined manner, or other processing logic which can interpret and execute instructions. The expression “computer” used herein can represent processing circuitry comprising a plurality of processing circuits, such as any one, some or all of the processing circuits mentioned above.

[0145] The control device 21 can also comprise a memory unit, wherein the computer can be connected to the memory unit, which can provide the computer with stored program code and / or stored data, e.g. that the computer can need to enable it to perform calculations. The computer can also be adapted to store partial results or final results of calculations in the memory unit. The memory unit can comprise a physical device for temporarily or permanently storing data or programs, i.e. sequences of instructions. According to some embodiments, the memory unit can comprise an integrated circuit comprising transistors based on silicon. In different embodiments, the memory unit can comprise, e.g., a memory card, a flash memory, a USB memory, a hard disk, or another similar volatile or non-volatile storage unit for storing data, such as, e.g., a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), an EEPROM (Electrically Erasable PROM), etc.

[0146] The control device 21 is connected to components of the vehicle 2 and / or the fuel gas supply device 1, 1’ for receiving and / or sending input and output signals. These input and output signals can comprise waveforms, pulses, or other properties that the input signal receiving devices can detect as information and can be converted into signals that can be processed by the control device 21. These signals can then be supplied to the computer. One or more output signal sending devices can be arranged to convert the results of calculations from the computer into output signals for transmission to other parts of the vehicle control system and / or to one or more components for which the signals are intended. Each of the connections for receiving and sending input and output signals to the respective components of the vehicle 2 and / or the fuel gas supply device 1, 1’ can take the form of one or more of a cable, a data bus (e.g. a CAN (Controller Area Network) bus, a MOST (Media Oriented Systems Transport) bus, or some other bus configuration), or a wireless connection.

[0147] In the illustrated embodiment, the fuel gas supply device 1, 1’ of the vehicle 2 comprises the control device 21, but alternatively, it can be implemented, in whole or in part, in two or more control devices, two or more control devices, or two or more control units.

[0148] Control systems in modern vehicles typically comprise a communication bus system comprising one or more communication buses for connecting a plurality of electronic control units (ECUs) or controllers to various components on the vehicle. Such control systems can comprise a large number of control units, and it is noted that specific functions can be shared between two or more of them. Thus, as the skilled person will certainly appreciate, vehicles and engines of the type with which this concerns are typically provided with significantly more control devices than Figure 3 and Figure 5 depicted in Fig. 1.

[0149] The computer readable medium 200 can for example be provided in the form of a data carrier carrying computer program code for performing at least some of the method steps 110, 112, 114, 120, 130, 131, 132, 135, 137, 141, 143, 145, 147 and 149 according to some embodiments of the method 100 when loaded into one or more computers of the control device 21. The data carrier can be for example a CD ROM disc (such as ​ as shown) or a ROM (Read-Only Memory), a PROM (Programmable Read-Only memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), a hard disk, a memory stick, an optical storage device, a magnetic storage device, or any other appropriate medium including a disk or tape that can hold machine readable data in a non-transitory fashion, such as magnetic disks or tapes. Thus, in some embodiments, the computer readable medium 200 can be a non-transitory computer readable medium, such as a tangible electronic, magnetic, optical, infrared, electromagnetic, and / or semiconductor system, apparatus, and / or device. The computer readable medium 200 can also be provided as a computer program code on a server and can be downloaded to the control device 21 remotely, e.g. over the Internet or an intranet connection or via other wired or wireless communication systems.

[0150] It is to be understood that the above description is illustrative of various example embodiments and that the present application is defined by the appended independent claims only. Those skilled in the art will recognize modifications or alterations to the example embodiments which fall within the scope of the present application as defined by the appended independent claims. The modifications or alterations can be made in light of the above detailed description of the example embodiments and the independent claims and will be understood by skilled artisans to which the example embodiments pertain.

[0151] As used herein, the terms “comprising” or “comprises” are open-ended, and include one or more stated features, elements, steps, components or functions but do not preclude the presence or addition of one or more other features, elements, steps, components, functions or groups thereof.

Claims

1. A method (100) for diagnosing a fuel gas supply device (1, 1'), wherein the fuel gas supply device (1, 1') is configured to supply fuel gas to a propulsion system (60) of a vehicle (2), the fuel gas supply device (1, 1') comprising: - Pressure tank (3), the pressure tank being configured to store the fuel gas. - Fuel pressure regulator (6, 6') - First conduit assembly (c1), which connects the inlet (9) of the fuel pressure regulator (6, 6') to the pressure tank (3), and - Second conduit assembly (c2), which connects the outlet (9') of the fuel pressure reducer (6, 6') to the propulsion system (60). And the method (100) described therein includes the following steps: - Pressure data (110) is acquired at multiple consecutive moments, wherein the pressure data represents the pressure in the second conduit assembly (c2) during zero-flow conditions on the fuel pressure regulator (6, 6'), and - Diagnose the operational performance of the fuel pressure regulator (6, 6') by analyzing the obtained pressure data (130).

2. The method (100) according to claim 1, wherein the step of obtaining the pressure data (110) comprises: - The pressure data (112) is obtained at multiple consecutive moments, such that at least some of the multiple consecutive moments occur at different operating instances of the vehicle (2).

3. The method (100) according to claim 1 or 2, wherein the step of obtaining the pressure data (110) comprises: - The pressure data (114) is obtained at multiple consecutive moments, such that at least some of the multiple consecutive moments occur during a corresponding time period between the start of the vehicle (2) and the start of the propulsion system (60).

4. The method (100) according to any one of the preceding claims, wherein the step of diagnosing (130) the operational performance of the fuel pressure regulator (6, 6') comprises: - Estimate the remaining operating life of the fuel pressure regulator (6, 6') based on the obtained pressure data (131).

5. The method (100) of claim 4, wherein the step of estimating (131) the remaining operating life comprises: - Estimate (132) at least one of the remaining time before the predetermined pressure is reached in the second conduit assembly (c2), the remaining travel distance, the remaining number of operation instances, and the remaining amount of fuel supplied to the propulsion system (60).

6. The method (100) according to claim 5, wherein the fuel gas supply device (1, 1') includes a pressure relief valve (7) configured to discharge gas from the second conduit assembly (c2) when the pressure in the second conduit assembly (c2) exceeds a pressure limit, wherein the pressure limit is higher than the predetermined pressure.

7. The method (100) according to any one of claims 4 to 6, wherein the method (100) comprises: - Arrange for (135) to be brought in for maintenance based on the estimated remaining operating life of the fuel pressure regulator (6, 6').

8. The method (100) according to any one of the preceding claims, wherein the fuel gas supply device (1, 1') includes a pressure relief valve (7) configured to discharge gas from the second conduit assembly (c2) when the pressure in the second conduit assembly (c2) exceeds a pressure limit, and wherein the method (100) comprises: - When the data indicates that the pressure in the second conduit assembly (c2) is within a predetermined pressure range below the pressure limit at multiple consecutive moments without any further pressure increase, a fault indicator (137) is set for the pressure relief valve (7).

9. A control device (21) for a fuel gas supply device (1, 1'), wherein the fuel gas supply device (1, 1') is configured to supply fuel gas to a propulsion system (60) of a vehicle (2), the fuel gas supply device (1, 1') comprising: - Pressure tank (3), the pressure tank being configured to store the fuel gas. - Fuel pressure regulator (6, 6') - First conduit assembly (c1), which connects the inlet (9) of the fuel pressure regulator (6, 6') to the pressure tank (3). - Second conduit assembly (c2), which connects the outlet (9') of the fuel pressure reducer (6, 6') to the propulsion system (60), and - Control device (21). The control device (21) is configured to: - Pressure data is acquired at multiple consecutive moments, wherein the pressure data represents the pressure in the second conduit assembly (c2) during zero-flow conditions across the fuel pressure reducer (6, 6'), and - The operational performance of the fuel pressure regulator (6, 6') is diagnosed by analyzing the obtained pressure data.

10. A computer program comprising instructions for causing a control device (21) according to claim 9 to perform the steps of the method (100) according to any one of claims 1 to 8.

11. A computer-readable medium (200) having a computer program according to claim 10 stored thereon.

12. A fuel gas supply device (1, 1') for a vehicle (2), wherein the fuel gas supply device (1, 1') is configured to supply fuel gas to a propulsion system (60) of the vehicle (2), the fuel gas supply device (1, 1') comprising: - Pressure tank (3), the pressure tank being configured to store the fuel gas. - Fuel pressure regulator (6, 6') - First conduit assembly (c1), which connects the inlet (9) of the fuel pressure regulator (6, 6') to the pressure tank (3). - Second conduit assembly (c2), which connects the outlet (9') of the fuel pressure reducer (6, 6') to the propulsion system (60), and - The control device (21) according to claim 9.

13. A vehicle (2) including a propulsion system (60), wherein the vehicle (2) includes a fuel gas supply device (1, 1') according to claim 12, and wherein the fuel gas supply device (1, 1') is configured to supply fuel gas to the propulsion system (60) of the vehicle (2).

14. The vehicle (2) according to claim 13, wherein the vehicle (2) is a heavy road vehicle, such as a truck or a bus.

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