Apparatus and method for pressure protection in a gaseous fuel system

Abstract

A gaseous fuel system supplying a gaseous fuel to a fuel consumer includes a storage vessel storing the gaseous fuel as a compressed gas at a storage pressure; a pressure regulating apparatus including at least one stage of pressure regulation for regulating the gaseous fuel received from the storage vessel to a delivery pressure supplied to the fuel consumer; an excess flow valve downstream from a first stage of pressure regulation; and a pressure relief valve downstream from the excess flow valve. The pressure relief valve opens when a pressure across the pressure relief valve rises above a trigger pressure and the excess flow valve limits or reduces a flow rate of the gaseous fuel when the flow rate through the excess flow valve rises above a trigger flow rate.

Description

APPARATUS AND METHOD FOR PRESSURE PROTECTION IN A GASEOUS FUEL SYSTEMTechnical Field

[0001] The present application relates to an apparatus and method for pressure protection, and more particularly in protecting downstream components from an overpressure situation.Background

[0002] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the invention.

[0003] Gaseous fuel systems can store gaseous fuel as a compressed gas in a pressurized tank at an elevated pressure. In an exemplary embodiment, such as a hydrogen supply system for a fuel cell application, the hydrogen can be stored at a storage pressure as high as 700 bar. The gaseous fuel system down regulates the storage pressure of the gaseous fuel from the tank before delivering it to a downstream consumer, such as delivering hydrogen to a fuel cell stack. The delivery pressure of hydrogen to the fuel cell stack is typically regulated to be between a range of 3 to 6 bar, although other operational pressures are contemplated. The fuel cell stack is particularly sensitive to an overpressure situation and in the event a pressure regulator of the gaseous fuel system is damaged and loses its ability to regulate the delivery pressure of hydrogen, the fuel cell stack can also become irreparably damaged. It is known to employ safety devices associated with the tank to protect against overtemperature situations. For example, a pressure relief device can vent gaseous fuel from the tank in the event of an overtemperature event.

[0004] The state of the art is lacking in techniques for pressure protection in a gaseous fuel system, and more particularly in protecting downstream components from an overpressure situation.Summary

[0005] An improved gaseous fuel system supplying a gaseous fuel to a fuel consumer includes a storage vessel storing the gaseous fuel as a compressed gas at a storage pressure; a pressure regulating apparatus including at least one stage of pressure regulation for regulating the gaseous fuel received from the storage vessel to a delivery pressure of the gaseous fuel supplied to the fuel consumer; an excess flow valve downstream from a first stage of pressure regulation of the pressure regulating apparatus; and a pressure relief valve downstream from the excess flow valve. The pressure relief valve opens when a pressure across the pressure relief valve rises above a trigger pressure and the excess flow valve limits or reduces a flow rate of the gaseous fuel when the flow rate through the excess flow valve rises above a trigger flow rate. In some embodiments, a pressure of the gaseous fuel received by the pressure regulating apparatus is substantially the storage pressure.

[0006] In an exemplary embodiment, the pressure regulating apparatus includes a first pressure regulator providing the first stage of pressure regulation for regulating a pressure of the gaseous fuel received from the storage vessel to the delivery pressure of the gaseous fuel. In some embodiments, the first pressure regulator and the excess flow valve are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

[0007] In another exemplary embodiment, the pressure regulating apparatus includes a first pressure regulator providing the first stage of pressure regulation for regulating a pressure of the gaseous fuel received from the storage vessel to an intermediate pressure of the gaseous fuel; and a second pressure regulator providing a second stage of pressure regulation for regulating the intermediate pressure to the delivery pressure of the gaseous fuel. In some embodiments, the excess flow valve is downstream from the second stage of pressure regulation. The gaseous fuel system can include one or more additional components downstream of any one of the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors. In some embodiments, the first pressure regulator and the second pressure regulator are a unitary component; or the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and thepressure relief valve are a unitary component; or the second pressure regulator and the excess flow valve are a unitary component; or the second pressure regulator and the pressure relief valve are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, and the excess flow valve are a unitary component; or the first pressure regulator, the second pressure regulator, and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

[0008] In some embodiments, the excess flow valve is upstream of the second stage of pressure regulation. The gaseous fuel system can include one or more additional components downstream of any one of the first pressure regulator, the excess flow valve, the second pressure regulator, and the pressure relief valve, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors. In some embodiments, the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and the second pressure regulator are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the excess flow valve and the second pressure regulator are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; or the second pressure regulator and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, and the pressure relief valve are a unitary component; or the excess flow valve, the second pressure regulator, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

[0009] In some embodiments, the excess flow valve and the pressure relief valve are upstream of the second stage of pressure regulation. The gaseous fuel system can include one or more additional components downstream of any one of the first pressure regulator, the excess flow valve, the pressure relief valve, and the second pressure regulator, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors,solenoid valves, and temperature sensors. In some embodiments, the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the first pressure regulator and the second pressure regulator are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; or the excess flow valve and the second pressure regulator are a unitary component; or the pressure relief valve and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the second pressure regulator are a unitary component; or the excess flow valve, the pressure relief valve, and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, the pressure relief valve, and the second pressure regulator are a unitary component.

[0010] In some embodiments, the excess flow valve is downstream from a last stage of pressure regulation of the at least one stage of pressure regulation of the pressure regulating apparatus. Similarly, the pressure relief valve can be downstream from a last stage of pressure regulation of the at least one stage of pressure regulation of the pressure regulating apparatus. In some embodiments, the storage pressure decreases from 700 bar as the fuel consumer consumes the gaseous fuel. In some embodiments, a pressure of the gaseous fuel at an upstream side of the excess flow valve is within a range of 4 bar and 50 bar. In other embodiments, a pressure of the gaseous fuel at an upstream side of the excess flow valve is within a range of 15 bar and 35 bar. In some embodiments, a delivery pressure of the gaseous fuel is within a range of 3 bar and 25 bar. In other embodiments, a delivery pressure of the gaseous fuel is within a range of 5 bar and 15 bar. In some embodiments, a trigger mass flow rate for the excess flow valve is between a range of 2 grams per second and 10 grams per second. In other embodiments, a trigger mass flow rate for the excess flow valve is between a range of 3 grams per second and 5 grams per second. The excess flow valve can limit a mass flow of the gaseous fuel when the pressure relief valve is opened, such that a pressure rise in the delivery pressure above the predetermined value due to mass flow through the pressure relief valve is below a second predetermined value. The gaseous fuel system can further include one or more components upstream of the first pressure regulator, the one or more components selected from the group consisting of check valves, compressors, excess flow valves, filters, manual valves, pressure reducing valves, pressure regulators, pressure relief valves, pressure sensors, solenoid valves, temperature sensors.Brief Description of the Drawings

[0011] The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate specific embodiments of the apparatus, systems, and methods and, together with the general description above, and the detailed description of the specific embodiments, serve to explain the principles of the apparatus, systems, and methods.

[0012] FIG. 1 is a schematic view of a gaseous fuel system including an excess flow valve downstream from a first pressure regulator and a pressure relief valve downstream from the excess flow valve according to an embodiment.

[0013] FIG. 2 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 1 and illustrating a unitary component including the first pressure regulator and the excess flow valve according to an embodiment.

[0014] FIG. 3 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 1 and illustrating a unitary component including the first pressure regulator and the pressure relief valve according to an embodiment.

[0015] FIG. 4 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 1 and illustrating a unitary component including the excess flow valve and the pressure relief valve according to an embodiment.

[0016] FIG. 5 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 1 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the pressure relief valve according to an embodiment.

[0017] FIG. 6 is a schematic view of a gaseous fuel system including an excess flow valve downstream from a first pressure regulator and a second pressure regulator, and a pressure relief valve downstream from the excess flow valve according to an embodiment.

[0018] FIG. 7 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator and the second pressure regulator.

[0019] FIG. 8 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator and the excess flow valve.

[0020] FIG. 9 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator and the pressure relief valve.

[0021] FIG. 10 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the second pressure regulator and the excess flow valve.

[0022] FIG. 11 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the second pressure regulator and the pressure relief valve.

[0023] FIG. 12 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the excess flow valve and the pressure relief valve.

[0024] FIG. 13 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator, the second pressure regulator, and the excess flow valve.

[0025] FIG. 14 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator, the second pressure regulator, and the pressure relief valve.

[0026] FIG. 15 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the pressure relief valve.

[0027] FIG. 16 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the second pressure regulator, the excess flow valve, and the pressure relief valve.

[0028] FIG. 17 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 6 and illustrating a unitary component including the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve.

[0029] FIG. 18 is a schematic view of a gaseous fuel system including an excess flow valve downstream from a first pressure regulator, a second pressure regulator downstream from the excess flow valve, and a pressure relief valve downstream from the second pressure regulator according to an embodiment.

[0030] FIG. 19 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator and the excess flow valve.

[0031] FIG. 20 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator and the second pressure regulator.

[0032] FIG. 21 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator and the pressure relief valve.

[0033] FIG. 22 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the excess flow valve and the second pressure regulator.

[0034] FIG. 23 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the excess flow valve and the pressure relief valve.

[0035] FIG. 24 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the second pressure regulator and the pressure relief valve.

[0036] FIG. 25 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the second pressure regulator.

[0037] FIG. 26 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the pressure relief valve.

[0038] FIG. 27 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator, the second pressure regulator, and the pressure relief valve.

[0039] FIG. 28 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the excess flow valve, the second pressure regulator, and the pressure relief valve.

[0040] FIG. 29 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 18 and illustrating a unitary component including the first pressure regulator, the excess flow valve, the second pressure regulator, and the pressure relief valve.

[0041] FIG. 30 is a schematic view of a gaseous fuel system including an excess flow valve downstream from a first pressure regulator, and a pressure relief valve and a second pressure regulator downstream from the excess flow valve according to an embodiment.

[0042] FIG. 31 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator and the excess flow valve.

[0043] FIG. 32 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator and the pressure relief valve.

[0044] FIG. 33 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator and the second pressure regulator.

[0045] FIG. 34 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the excess flow valve and the pressure relief valve.

[0046] FIG. 35 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the excess flow valve and the second pressure regulator.

[0047] FIG. 36 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the pressure relief valve and the second pressure regulator.

[0048] FIG. 37 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the pressure relief valve.

[0049] FIG. 38 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator, the excess flow valve, and the second pressure regulator.

[0050] FIG. 39 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator, the pressure relief valve, and the second pressure regulator.

[0051] FIG. 40 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the excess flow valve, the pressure relief valve, and the second pressure regulator.

[0052] FIG. 41 is a schematic view of a gaseous fuel system similar to the gaseous fuel system of FIG. 30 and illustrating a unitary component including the first pressure regulator, the excess flow valve, the pressure relief valve, and the second pressure regulator.

[0053] FIG. 42 is a schematic view of a unitary component including a first pressure regulator, an excess flow valve, a second pressure regulator, and a pressure relief valve according to an embodiment.

[0054] FIG. 43 is a schematic view of an excess flow valve according to an embodiment.Detailed Description

[0055] Referring to FIG. 1, there is shown gaseous fuel system 10 according to an embodiment. Storage vessel 20 stores gaseous fuel as compressed gas. As used herein, a gaseous fuel is defined as any fuel that is in the gaseous state (phase) at standard temperature and pressure, which in the context of this application is a temperature of zero (0) degrees Celsius (°C) and an absolute pressure of one hundred (100) kilopascals (kPa), respectively. Examples of gaseous fuels include ammonia, biogas, butane, ethane, hydrogen, liquefied petroleum gas, methane, natural gas, and propane. In exemplary embodiments the gaseous fuel can be hydrogen, or mixtures of hydrogen with one or more other gaseous fuels. In exemplary embodiments storage vessel 20 is a pressurized tank in the form of a cylinder. In some embodiments storage vessel 20 is pressurized to a storage pressure of 700 bar, although both higher pressures and lower pressure are contemplated. First pressure regulator 30 fluidly receives the gaseous fuel from storage vessel 20 and down regulates or reduces the storage pressure to a delivery pressure. As used herein, a pressure reducing valve can be considered a type of pressure regulator. Pressure regulators including pressure reducing valves reduce a pressure of a fluid from a higher pressure to a lower pressure, some of these pressure regulators can more accurately regulate the lower pressure around a setpoint value compared to the pressure-reducing- valve-type of pressure regulator. The pressure regulation can include feedback mechanisms. In some embodiments, first pressure regulator 30 regulates the delivery pressure around the setpoint value. Insome embodiments first pressure regulator 30 reduces the storage pressure around the setpoint value. Excess flow valve 40 is a protection device that triggers once a predetermined flow rate (also called a trigger flow rate or a trigger mass flow) through it is reached and limits or shuts off the mass flow of the gaseous fuel therethrough. Limiting the mass flow of the gaseous fuel can mean reducing a rate of increase of the mass flow, stopping the mass flow from rising further, or reducing the mass flow. In some embodiments, excess flow valve 40 reduces the flow rate to a residual mass flow when triggered. The residual mass flow can be less than 50% of the trigger mass flow, or less than 25% of the trigger mass flow, or less than 10% of the trigger mass flow, or less than 5% of the trigger mass flow, or even less than 1% of the trigger mass flow. In some embodiments, excess flow valve 40 shuts off the mass flow of the gaseous fuel once the trigger flow rate is reached and essentially becomes a fluid open-circuit. Excess flow valve 40 is essentially a fluid short-circuit before it is triggered such that there is negligible pressure drop across the excess flow valve whereby fuel consumer 60, with respect to the embodiment of FIG. 1, is substantially supplied the gaseous fuel at the delivery pressure determined by first pressure regulator 30 when the flow rate through the excess flow valve is less than the trigger flow rate. In an exemplary embodiment fuel consumer 60 is a fuel cell stack and the gaseous fuel is hydrogen, and the fuel cell stack converts the gaseous fuel into electrical energy that is employed to power an electric motor. In other embodiments, fuel consumer 60 is an internal combustion engine that combusts the gaseous fuel in combustion chambers.

[0056] Pressure relief valve 50 limits the delivery pressure of the gaseous fuel supplied to fuel consumer 60, which is downstream from the pressure relief valve and excess flow valve 40. For example, pressure relief valve 50 can be configured to trigger when the delivery pressure rises above a trigger pressure such that when the delivery pressure is below the trigger pressure the pressure relief vale is substantially a fluid open-circuit, and when the delivery pressure rises above the trigger pressure the pressure relief valve opens, substantially becoming a fluid short-circuit providing an exit path for the gaseous fuel away from fuel consumer 60, thereby reducing the delivery pressure below the trigger pressure. In the illustrated embodiment of FIG. 1, the pressure across pressure relief valve 50 is the delivery pressure. In some embodiments the gaseous fuel is vented to atmosphere when pressure relief valve 50 opens. In some embodiments the gaseous fuel is vented into a secondary storage vessel when pressure relief valve 50 opens, particularly but not essentially when excess flow valve 40 becomes a fluid open-circuit when triggered or reduces the mass flow to a low value or to the residual mass flow.

[0057] An outlet pressure of first pressure regulator 30 can rise above the setpoint value when the first pressure regulator is damaged or functioning atypically such as when there is a manufacturing defect. The outlet pressure of first pressure regulator 30 is the delivery pressure to fuel consumer 60 in the embodiment of FIG. 1. Fuel consumer 60 can be damaged when the delivery pressure is allowed to rise above a maximum allowable value tolerated by the fuel consumer. Accordingly, pressure relief valve 50 opens before the delivery pressure reaches the trigger pressure of the pressure relief valve, which is less than the maximum allowable value tolerated by fuel consumer 60, to provide a relief path or a vent path for the gaseous fuel away from the fuel consumer. As the mass flow through the pressure relief valve 50 begins to increase a pressure drop can develop across the pressure relief valve whereby the delivery pressure continues to rise, although at a slower rate than when the pressure relief valve was closed. Simultaneously, the mass flow through excess flow valve 40 increases as the gaseous fuel vents through pressure relief valve 50, and when the trigger flow rate is reached the excess flow valve triggers thereby constraining the mass flow of the gaseous fuel and maintaining the delivery pressure below the maximum allowable value tolerated by fuel consumer 60.

[0058] By configuring the excess flow valve 40 downstream from first pressure regulator 30 the excess flow valve has an activation curve that is flatter and narrower compared to if the excess flow valve is configured upstream of the first pressure regulator. The activation curve can be defined as the trigger flow rate of excess flow valve 40 as a function of the fluid pressure at the inlet of the excess flow valve. For example, in some embodiments the storage pressure upstream of first pressure regulator 30 can vary between 700 bar and 20 bar, whereas the delivery pressure can vary between 6 and 3 bar. When excess flow valve 40 is configured upstream of first pressure regulator 30, it is designed to operate in a pressure range of a first differential pressure (which in the example above is 700 - 20 = 680 bar), whereas if the excess flow valve is configured downstream of the first pressure regulator it can be designed to operate in a pressure range of a second differential pressure (which in the example above is 6 - 3 = 3 bar), where the second differential pressure is less than the first differential pressure. Excess flow valve 40 can be made smaller and can be more accurately triggered at a desired trigger flow rate by configuring the excess flow valve downstream of first pressure regulator 30 (where it can experience the second differential pressure), compared to configuring the excess flow valve upstream of the first pressure regulator (where it experiences the first differential pressure). Similarly, the size of pressure relief valve 50 can be optimized, and particularly reducedin size since it is not required to vent as much of the gaseous fuel, when excess flow valve 40 is configured downstream of first pressure regulator 30 compared to when excess flow valve 40 is placed upstream of the first pressure regulator. The second differential pressure can be a function of the application. In some embodiments, the second differential pressure is less than or equal to 350 bar. In some embodiments, the second differential pressure is less than or equal to 200 bar. In some embodiments, the second differential pressure or the delivery pressure is less than or equal to 100 bar. In some embodiments, the second differential pressure is less than or equal to 75 bar. In some embodiments, the second differential pressure is less than or equal to 50 bar. In some embodiments, the second differential pressure is less than or equal to 25 bar. In some embodiments, the second differential pressure is less than or equal to 10 bar. In some embodiments, the second differential pressure is less than or equal to 5 bar. In some embodiments, the second differential pressure is less than or equal to 2.5 bar. Now considering the delivery pressure, in some embodiments, the delivery pressure is less than or equal to 350 bar. In some embodiments, the delivery pressure is less than or equal to 200 bar. In some embodiments, the delivery pressure is less than or equal to 100 bar. In some embodiments, the delivery pressure is less than or equal to 75 bar. In some embodiments, the delivery pressure is less than or equal to 50 bar. In some embodiments, the delivery pressure is less than or equal to 25 bar. In some embodiments, the delivery pressure is less than or equal to 10 bar. In some embodiments, the delivery pressure is less than or equal to 5 bar. In some embodiments, the delivery pressure is less than or equal to 2.5 bar. In an exemplary embodiment, the delivery pressure is 12 + / - 2 bar, whereby the second differential pressure is 4 bar.

[0059] Referring now to FIGS. 2 to 5, there are shown alternative embodiments of gaseous fuel systems that are similar to gaseous fuel system 10 seen in FIG. 1 and like parts in these and all other embodiments have like reference numerals and only differences are discussed. With reference first to FIG. 2, gaseous fuel system 11 includes unitary component 71 that integrates first pressure regulator 30 and excess flow valve 40 in a single component. In some embodiments, a unitary component is defined to be a component that has a single body enclosing sub-components (for example, first pressure regulator 30 and excess flow valve 40 seen in FIG. 2). In some embodiments, a unitary component is defined to be a component that has sub-components that fastened together (for example, first pressure regulator 30 and excess flow valve 40 seen in FIG. 2). Typically, in a unitary component where sub-components fasten together any interconnecting piping between the sub-components is reduced and preferably eliminated compared to when the sub-components are notfastened together (in this circumstance each sub-component can be considered a unitary component individually). In some embodiments, a unitary component is defined to be a component that has both the features of sub-components within a single body and sub-components that fastened together. A sub-component can either provide a single function or can provide a plurality of functions. As used herein, a unitary component provides a plurality of functions. Each gaseous fuel system application has its own particular requirements, and in some circumstances, there can be advantages to integrating various sub-components into a unitary component. Reducing the overall footprint of the gaseous fuel system is a packaging advantage achieved by integrating sub-components together. There can be performance enhancements when sub-components are more closely interconnected as they are in a unitary component. In the embodiment of FIG. 2, for example, excess flow valve 40 can respond more quickly to flow changes emanating from pressure regulator 30, compared to a similar excess flow valve seen in FIG. 1, and accordingly can be made to trigger sooner when the trigger flow rate out of first pressure regulator 30 is reached. In some applications, it may be desired to employ a preexisting unitary component that is available off-the-shelf. Referring again to FIG. 2, connection 34 fluidly connects first pressure regulator 30 with excess flow valve 40 internally within unitary component 71. Connection 34 preferably is an internal fluid connection, although this is not a requirement and in other embodiments connection 34 can include a portion that is external to unitary component 71, whereby such a connection can be described as an external fluid connection. Similarly, all internal fluid connections within unitary components disclosed herein can also include a portion that is external to the respective fluid connection in other embodiments. For the unitary components disclosed herein that include multiple internal connections, other embodiments are contemplated that encompass all the combinations and permutations of internal and external connections. With reference to FIG. 3, gaseous fuel system 12 includes unitary component 72 that integrates first pressure regulator 30 and pressure relief valve 50 in a single component. With reference to FIG. 4, gaseous fuel system 13 includes unitary component 73 that integrates excess flow valve 40 and pressure relief valve 50 in a single component. With reference to FIG. 5, gaseous fuel system 14 includes unitary component 74 that integrates first pressure regulator 30, excess flow valve 40, and pressure relief valve 50 in a single component. In other embodiments, gaseous fuel systems 10, 11, 12, 13, and 14 and all other gaseous fuel systems disclosed herein can employ one or more additional components upstream of first pressure regulator 30. For example, the one or more additional components can include check valves, compressors, excess flow valves, filters, manual valves, pressure reducing valves, pressure regulators, pressure relief valves, pressure sensors,solenoid valves, temperature sensors. In some embodiments, some of the additional components are integrated into supply vessel 20. In some embodiments there are a plurality of supply vessels 20, such as a plurality of pressurized tanks.

[0060] Referring now to FIG. 6, there is shown gaseous fuel system 100 that is similar to gaseous fuel system 10 seen in FIG. 1 and includes a second pressure regulator 35 between first pressure regulator 30 and excess flow valve 40. First pressure regulator 30 down regulates or reduces the storage pressure of the gaseous fuel from supply vessel 20 to an intermediate pressure, and second pressure regulator 35 down regulates or reduces the intermediate pressure of the gaseous fuel to the delivery pressure. The operating region of the activation curve of excess flow valve 40 in gaseous fuel system 100 can be made even flatter and narrower, compared to the operating region of excess flow valve 40 of gaseous fuel system 10 seen in FIG. 1, by further down regulating or reducing the fluid pressure seen at the inlet of the excess flow valve. Considering now the intermediate pressure, in some embodiments, the intermediate pressure is less than or equal to 350 bar. In some embodiments, the intermediate pressure is less than or equal to 200 bar. In some embodiments, the intermediate pressure is less than or equal to 100 bar. In some embodiments, the intermediate pressure is less than or equal to 75 bar. In some embodiments, the intermediate pressure is less than or equal to 50 bar. In some embodiments, the intermediate pressure is less than or equal to 25 bar. In some embodiments, the intermediate pressure is less than or equal to 10 bar. In some embodiments, the intermediate pressure is less than or equal to 5 bar. In some embodiments, the intermediate pressure is less than or equal to 2.5 bar. In an exemplary embodiment, the storage pressure is 700 bar when storage vessel 20 is fdled, the intermediate pressure is 25 + / - 5 bar, and the delivery pressure is 12 + / - 2 bar.

[0061] Referring now to FIGS. 7 to 17, there are shown alternative embodiments of gaseous fuel systems that are similar to gaseous fuel system 100 seen in FIG. 6. The gaseous fuel systems of FIGS. 7 to 17 include respective unitary components that integrate various sub-components. With reference first to FIG. 7, gaseous fuel system 101 includes unitary component 171 that integrates first pressure regulator 30 and second pressure regulator 35 in a single component. With reference to FIG. 8, gaseous fuel system 102 includes unitary component 172 that integrates first pressure regulator 30 and excess flow valve 40 in a single component. With reference to FIG. 9, gaseous fuel system 103 includes unitary component 173 that integrates first pressure regulator 30 and pressure relief valve50 in a single component. With reference to FIG. 10, gaseous fuel system 104 includes unitary component 174 that integrates second pressure regulator 35 and excess flow valve 40 in a single component. With reference to FIG. 11, gaseous fuel system 105 includes unitary component 175 that integrates second pressure regulator 35 and pressure relief valve 50 in a single component. With reference to FIG. 12, gaseous fuel system 106 includes unitary component 176 that integrates excess flow valve 40 and pressure relief valve 50 in a single component. With reference to FIG. 13, gaseous fuel system 107 includes unitary component 177 that integrates first pressure regulator 30, second pressure regulator 35, and excess flow valve 40 in a single component. With reference to FIG. 14, gaseous fuel system 108 includes unitary component 178 that integrates first pressure regulator 30, second pressure regulator 35, and pressure relief valve 50 in a single component. With reference to FIG. 15, gaseous fuel system 109 includes unitary component 179 that integrates first pressure regulator 30, excess flow valve 40, and pressure relief valve 50 in a single component. With reference to FIG. 16, gaseous fuel system 110 includes unitary component 180 that integrates second pressure regulator 35, excess flow valve 40, and pressure relief valve 50 in a single component. With reference to FIG. 17, gaseous fuel system 111 includes unitary component 181 that integrates first pressure regulator 30, second pressure regulator 35, excess flow valve 40, and pressure relief valve 50 in a single component.

[0062] Referring now to FIG. 18, there is shown gaseous fuel system 200 that is similar to gaseous fuel system 100 seen in FIG. 6 except excess flow valve 40 is configured between the first pressure regulator 30 and second pressure regulator 35 in gaseous fuel system 200. Apart from physical damage due to an impact, the probability of first pressure regulator 30 getting damaged is typically greater than the probability of second pressure regulator 35 getting damaged since the first pressure regulator (being upstream of the second pressure regulator) is exposed to greater inlet pressures that exert greater stresses on the component, even when these greater stresses are considered during the design stage. For example, material defects can more readily lead to component failure when these defects are exposed to greater stresses. For this reason, there can be advantages in configuring excess flow valve 40 closer to the component that is more likely to fail since the excess flow valve can be more quickly triggered when failure occurs, although this configuration is not a requirement. In the illustrated embodiment of FIG. 18, pressure relief valve 50 remains downstream from second pressure regulator 35, which is advantageous when the intermediate pressure between the first and second pressure regulators 30 and 35, respectively is above the maximum allowablevalue tolerated by fuel consumer 60, such that in the event second pressure regulator 35 gets damaged or behaves atypically whereby its outlet pressure rises towards the intermediate pressure, the pressure relief valve protects fuel consumer 60 by clamping the delivery pressure below the intermediate pressure.

[0063] Referring now to FIGS. 19 to 29, there is shown alternative embodiments of gaseous fuel systems that are similar to gaseous fuel system 200 seen in FIG. 18. The gaseous fuel systems of FIGS. 19 to 29 include respective unitary components that integrate various sub-components. With reference first to FIG. 19, gaseous fuel system 201 includes unitary component 271 that integrates first pressure regulator 30 and excess flow valve 40 in a single component. With reference to FIG. 20, gaseous fuel system 202 includes unitary component 272 that integrates first pressure regulator 30 and second pressure regulator 35 in a single component. With reference to FIG. 21, gaseous fuel system 203 includes unitary component 273 that integrates first pressure regulator 30 and pressure relief valve 50 in a single component. With reference to FIG. 22, gaseous fuel system 204 includes unitary component 274 that integrates excess flow valve 40 and second pressure regulator 35 in a single component. With reference to FIG. 23, gaseous fuel system 205 includes unitary component 275 that integrates excess flow valve 40 and pressure relief valve 50 in a single component. With reference to FIG. 24, gaseous fuel system 206 includes unitary component 276 that integrates second pressure regulator 35 and pressure relief valve 50 in a single component. With reference to FIG. 25, gaseous fuel system 207 includes unitary component 277 that integrates first pressure regulator 30, excess flow valve 40, and second pressure regulator 35 in a single component. With reference to FIG.26, gaseous fuel system 208 includes unitary component 278 that integrates first pressure regulator 30, excess flow valve 40, and pressure relief valve 50 in a single component. With reference to FIG.27, gaseous fuel system 209 includes unitary component 279 that integrates first pressure regulator 30, second pressure regulator 35, and pressure relief valve 50 in a single component. With reference to FIG. 28, gaseous fuel system 210 includes unitary component 280 that integrates excess flow valve 40, second pressure regulator 35, and pressure relief valve 50 in a single component. With reference to FIG. 29, gaseous fuel system 211 includes unitary component 281 that integrates first pressure regulator 30, excess flow valve 40, second pressure regulator 35, and pressure relief valve 50 in a single component.

[0064] Referring now to FIG. 30, there is shown gaseous fuel system 300 that is similar to gaseous fuel system 200 seen in FIG. 18 except pressure relief valve 50 is configured between the first pressure regulator 30 and second pressure regulator 30, downstream from excess flow valve 40. This configuration of pressure relief valve 50 can be advantageous to protect not only fuel consumer 60 but also second pressure regulator 35 from excessive pressure when the intermediate pressure between the first and second pressure regulators rises above its setpoint when first pressure regulator 30 gets damaged. Preferably, the intermediate pressure is less than the maximum allowable value tolerated by fuel consumer 60 in applications employing gaseous fuel system 300.

[0065] Referring now to FIGS. 31 to 40, there is shown alternative embodiments of gaseous fuel systems that are similar to gaseous fuel system 300 seen in FIG. 30. The gaseous fuel systems of FIGS. 31 to 40 include respective unitary components that integrate various sub-components. With reference first to FIG. 31, gaseous fuel system 301 includes unitary component 371 that integrates first pressure regulator 30 and excess flow valve 40 in a single component. With reference to FIG. 32, gaseous fuel system 302 includes unitary component 372 that integrates first pressure regulator 30 and pressure relief valve 50 in a single component. With reference to FIG. 33, gaseous fuel system 303 includes unitary component 373 that integrates first pressure regulator 30 and second pressure regulator 35 in a single component. With reference to FIG. 34, gaseous fuel system 304 includes unitary component 374 that integrates excess flow valve 40 and pressure relief valve 50 in a single component. With reference to FIG. 35, gaseous fuel system 305 includes unitary component 375 that integrates excess flow valve 40 and second pressure regulator 35 in a single component. With reference to FIG. 36, gaseous fuel system 306 includes unitary component 376 that integrates pressure relief valve 50 and second pressure regulator 35 in a single component. With reference to FIG. 37, gaseous fuel system 307 includes unitary component 377 that integrates first pressure regulator 30, excess flow valve 40, and pressure relief valve 50 in a single component. With reference to FIG. 38, gaseous fuel system 308 includes unitary component 378 that integrates first pressure regulator 30, excess flow valve 40, and second pressure regulator 35 in a single component. With reference to FIG. 39, gaseous fuel system 309 includes unitary component 379 that integrates first pressure regulator 30, pressure relief valve 50, and second pressure regulator 35 in a single component. With reference to FIG. 40, gaseous fuel system 310 includes unitary component 380 that integrates excess flow valve 40, pressure relief valve 50, and second pressure regulator 35 in a single component. With reference to FIG. 41, gaseous fuel system 311 includes unitary component 381 thatintegrates first pressure regulator 30, excess flow valve 40, pressure relief valve 50, and second pressure regulator 35 in a single component.

[0066] An exemplary unitary component 400 is illustrated in FIG. 42 according to an embodiment. Unitary component 400 is similar to unitary component 281 seen in the gaseous fuel system 211 of FIG. 29, where excess flow valve 40 is configured between first pressure regulator 30 and second pressure regulator 35 and pressure relief valve 50 is configured downstream from pressure regulator 35, and only the differences are discussed. Unitary component 400 includes body 405 having fluid inlet 401 and fluid outlet 402. Filter 410 is in fluid communication with fluid inlet 401 for filtering debris from the fluid stream entering unitary component 400 to protect downstream components both within unitary component 400 and downstream from fluid outlet 402. Shut-off valve (SOV) 420 is in fluid communication with filter 410 to fluidly receive filtered fluid, particularly the gaseous fuel such as hydrogen from an upstream supply, such as supply vessel 20 seen in FIG. 29. Bleed valve 430 is in parallel with shut-off valve 420 and can act as a bypass around the shut-off valve. Ports 440, 442, and 444 can each accommodate external components, such as pressure sensors and / or temperature sensors. The term “and / or” is used herein to mean “one or the other or both”. Port 440 fluidly accesses the upstream side of filter 410 near fluid inlet 401. Port 442 fluidly accesses the downstream side of filer 410 upstream of shut-off valve 420. Port 444 fluidly accesses the downstream side of shut-off valve 420 upstream of first pressure regulator 30. In some embodiments any one of ports 440, 442, and 444 are optional, and each port can either not be included in unitary component 400 or can be blocked with a plug that fluidly seals the port. Intermediate pressure (IP) service valve 450 can be employed to fluidly access an intermediate pressure zone between first pressure regulator 30 and second pressure regulator 35. In the illustrated embodiment, IP service valve 450 fluidly accesses the intermediate pressure zone downstream from excess flow valve 40. In other embodiments, IP service valve 450 can fluidly access both sides of excess flow valve 40, or just the upstream side of excess flow valve 40, in the intermediate pressure zone. Alternatively, or additionally, there can be a second IP service valve that fluidly access the upstream side of excess flow valve 40 in the intermediate pressure zone. The IP service valve 450 can be used to drain the intermediate pressure zone of fluid to reduce the intermediate pressure for servicing. Port 446 (which is also optional in other embodiments like ports 440, 442, and 444) can be employed for an external pressure sensor and / or temperature sensor to measure the pressure and / or the temperature in the intermediate pressure zone, or for other types of components. Low pressure (LP) service valve 460can be employed to fluidly access a low-pressure zone downstream from second pressure regulator 35 upstream of fluid outlet 402. The LP service valve 460 can be used to drain the low-pressure zone of fluid to reduce the pressure for servicing. In some embodiments, the low-pressure zone is at the delivery pressure. Port 448 (which is also optional in other embodiments like ports 440, 442, 444, and 446) can be employed for an external pressure sensor and / or temperature sensor to measure the pressure and / or the temperature in the low-pressure zone (near fluid outlet 402), or for other types of components.

[0067] In other embodiments, the gaseous fuel systems disclosed herein can employ one or more additional components downstream of any one of first pressure regulator 30, second pressure regulator 35, excess flow valve 40, and pressure relief valve 50. For example, the one or more additional components can include, but are not limited to, check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors.

[0068] Referring now to FIG. 43, excess flow valve 500 is illustrated according to an embodiment, which can be employed as excess flow valve 40 in the previous embodiments of the gaseous fuel systems disclosed herein. Fluid inlet 520 and fluid outlet 530 are formed in body 510 where bore 540 extends between the fluid inlet and the fluid outlet. Within bore 540 there is retainer 550 that retains valve member 570. Valve 560 is formed between annular surface 575 of valve member 570 and valve seat 580 in body 510. In the illustrated embodiment annular surface 575 and valve seat 580 each have a frustoconical shape, although this is not a requirement and in other embodiments annular surface 575 can have a hyperbolic, parabolic, or spherical shape. Valve 560 is in an open position when annular surface 575 is spaced apart from valve seat 580. Valve 560 is in a closed position when annular surface 575 abuts valve seat 580. Fluid enters excess flow valve 500 through fluid inlet 510, flows through hollow retainer 550, valve member 570, and valve 560 and exits through fluid outlet 530. Valve member 570 is biased by spring 590 to the open position, and fluid flow from fluid inlet 520 to fluid outlet 530 biases the valve member to the closed position. Valve member 570 is hollow whereby fluid flows through the interior of retainer 550 into and through an interior of valve member 570 and exits the interior of valve member 570 radially through holes 572 into chamber 542 between distal end 574 of valve member 570 and a distal end 545 of an inner surface of bore 540. When the mass flow of fluid through excess flow valve 500 reaches the trigger flow rate (that is, the differential pressure across valve member 570 creates a force greater than theforce of spring 590), valve member 570 moves downwards (with respect to the illustrated embodiment) such that annular surface 575 of the valve member abuts valve seat 580 placing valve 560 in the closed position, thus cutting off the mass flow of the fluid through valve 560. Bypass passage 576 through distal end 574 of valve member 570 allows the residual mass flow of fluid when valve 560 is in the closed position.

[0069] Several advantages are obtained by configuring excess flow valve downstream of first pressure regulator 30 and configuring pressure relief valve 50 downstream from excess flow valve 40. The configuration allows for a flat activation curve for excess flow valve 40, or operation within a flat and narrow region of the activation curve of the excess flow valve. The configuration allows for pressure relief valve 50 to be size and cost reduced since it only needs to accommodate the lower maximum flow rate defined by excess flow valve 40. The configuration also allows for a safer system since excess flow valve 40 can be configured to trigger a small amount above the normal maximum flow rate. The system is safer for two reasons. First, in the event of a damaged pressure regulator (either first pressure regulator 30 or second pressure regulator 40) upstream of excess flow valve 40, the excess flow valve will limit the flow rate of gaseous fuel allowing lower venting gas flow rates through pressure relief valve 50 and thus lower rates of gas discharged to the environment, which is a safety improvement, and lower the delivery pressure supplied to downstream components (such as fuel consumer 60) for a given same sized pressure relief valve, thus reducing the risk of them being damaged. Second, in the event of a fuel line being severed downstream of the pressure regulators and excess flow valve 40, the excess flow valve will reduce and preferably prevent excess flow across a broader range of inlet pressures. In contrast, if the excess flow valve was upstream of the pressure regulators, where the pressure is substantially high it is likely not possible for the excess flow valve to activate until the pressure was reduced enough, due to the choked flow condition caused by the gas regulation being limited by the regulator.

[0070] In other embodiments, the unitary components disclosed herein can employ one or more additional components downstream of any one of first pressure regulator 30, second pressure regulator 35, excess flow valve 40, and pressure relief valve 50. For example, the one or more additional components can include check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors. Additionally, in some embodiments, the unitary components herein can include one or more service ports.

[0071] While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, that the invention is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings.

Claims

ClaimsWe claim:

1. A gaseous fuel system supplying a gaseous fuel to a fuel consumer comprising: a storage vessel storing the gaseous fuel as a compressed gas at a storage pressure; a pressure regulating apparatus including at least one stage of pressure regulation for regulating the gaseous fuel received from the storage vessel to a delivery pressure of the gaseous fuel supplied to the fuel consumer; an excess flow valve downstream from a first stage of pressure regulation of the pressure regulating apparatus; and a pressure relief valve downstream from the excess flow valve; wherein the pressure relief valve opens when a pressure across the pressure relief valve rises above a trigger pressure and the excess flow valve limits or reduces a flow rate of the gaseous fuel when the flow rate through the excess flow valve rises above a trigger flow rate.

2. The gaseous fuel system as claimed in claim 1, wherein a pressure of the gaseous fuel received by the pressure regulating apparatus is substantially the storage pressure.

3. The gaseous fuel system as claimed in claim 1, wherein the pressure regulating apparatus comprises a first pressure regulator providing the first stage of pressure regulation for regulating a pressure of the gaseous fuel received from the storage vessel to the delivery pressure of the gaseous fuel.

4. The gaseous fuel system as claimed in claim 3, wherein the first pressure regulator and the excess flow valve are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; orthe first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

5. The gaseous fuel system as claimed in claim 1, wherein the pressure regulating apparatus comprises a first pressure regulator providing the first stage of pressure regulation for regulating a pressure of the gaseous fuel received from the storage vessel to an intermediate pressure of the gaseous fuel; and a second pressure regulator providing a second stage of pressure regulation for regulating the intermediate pressure to the delivery pressure of the gaseous fuel.

6. The gaseous fuel system as claimed in claim 5, wherein the excess flow valve is downstream from the second stage of pressure regulation.

7. The gaseous fuel system as claimed in claim 6, wherein the gaseous fuel system comprises one or more additional components downstream of any one of the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors.

8. The gaseous fuel system as claimed in claim 6, wherein the first pressure regulator and the second pressure regulator are a unitary component; or the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the second pressure regulator and the excess flow valve are a unitary component; or the second pressure regulator and the pressure relief valve are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; orthe first pressure regulator, the second pressure regulator, and the excess flow valve are a unitary component; or the first pressure regulator, the second pressure regulator, and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

9. The gaseous fuel system as claimed in claim 5, wherein the excess flow valve is upstream of the second stage of pressure regulation.

10. The gaseous fuel system as claimed in claim 9, wherein the gaseous fuel system comprises one or more additional components downstream of any one of the first pressure regulator, the excess flow valve, the second pressure regulator, and the pressure relief valve, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors.

11. The gaseous fuel system as claimed in claim 9, wherein the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and the second pressure regulator are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the excess flow valve and the second pressure regulator are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; orthe second pressure regulator and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, and the pressure relief valve are a unitary component; or the excess flow valve, the second pressure regulator, and the pressure relief valve are a unitary component; or the first pressure regulator, the second pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component.

12. The gaseous fuel system as claimed in claim 5, wherein the excess flow valve and the pressure relief valve are upstream of the second stage of pressure regulation.

13. The gaseous fuel system as claimed in claim 12, wherein the gaseous fuel system comprises one or more additional components downstream of any one of the first pressure regulator, the excess flow valve, the pressure relief valve, and the second pressure regulator, the one or more additional components can be selected from the group consisting of check valves, filters, manual valves, pressure sensors, solenoid valves, and temperature sensors.

14. The gaseous fuel system as claimed in claim 12, wherein the first pressure regulator and the excess flow valve are a unitary component; or the first pressure regulator and the pressure relief valve are a unitary component; or the first pressure regulator and the second pressure regulator are a unitary component; or the excess flow valve and the pressure relief valve are a unitary component; orthe excess flow valve and the second pressure regulator are a unitary component; or the pressure relief valve and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, and the pressure relief valve are a unitary component; or the first pressure regulator, the excess flow valve, and the second pressure regulator are a unitary component; or the excess flow valve, the pressure relief valve, and the second pressure regulator are a unitary component; or the first pressure regulator, the excess flow valve, the pressure relief valve, and the second pressure regulator are a unitary component.

15. The gaseous fuel system as claimed in claim 1, wherein the excess flow valve is downstream from a last stage of pressure regulation of the at least one stage of pressure regulation of the pressure regulating apparatus.

16. The gaseous fuel system as claimed in claim 1, wherein the pressure relief valve is downstream from a last stage of pressure regulation of the at least one stage of pressure regulation of the pressure regulating apparatus.

17. The gaseous fuel system as claimed in claim 1, wherein the storage pressure decreases from 700 bar as the fuel consumer consumes the gaseous fuel.

18. The gaseous fuel system as claimed in claim 1, wherein a pressure of the gaseous fuel at an upstream side of the excess flow valve is within a range of 4 bar and 50 bar.

19. The gaseous fuel system as claimed in claim 1, wherein a pressure of the gaseous fuel at an upstream side of the excess flow valve is within a range of 15 bar and 35 bar.

20. The gaseous fuel system as claimed in claim 1, wherein a delivery pressure of the gaseous fuel is within a range of 3 bar and 25 bar.

21. The gaseous fuel system as claimed in claim 1, wherein a delivery pressure of the gaseous fuel is within a range of 5 bar and 15 bar.

22. The gaseous fuel system as claimed in claim 1, wherein a trigger mass flow rate for the excess flow valve is between a range of 2 grams per second and 10 grams per second.

23. The gaseous fuel system as claimed in claim 1, wherein a trigger mass flow rate for the excess flow valve is between a range of 3 grams per second and 5 grams per second.

24. The gaseous fuel system as claimed in claim 1, wherein the excess flow valve limits a mass flow of the gaseous fuel when the pressure relief valve is opened, whereby a pressure rise in the delivery pressure above the predetermined value due to mass flow through the pressure relief valve is below a second predetermined value.

25. The gaseous fuel system as claimed in claim 1, further comprising one or more components upstream of the first pressure regulator, the one or more components selected from the group consisting of check valves, excess flow valves, filters, manual valves, pressure reducing valves, pressure regulators, pressure relief valves, pressure sensors, solenoid valves, temperature sensors.

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