Differential pressure regulator

Abstract

A pressure regulator is disclosed for regulating a pressure difference between a first fluid pressure of a first fluid and a second fluid pressure of a second fluid. The pressure regulator has a valve between a regulator body and a valve member. A valve member is movably disposed within the first longitudinal bore of the regulator body between the first fluid pressure sensing chamber and the second fluid pressure sensing chamber. The first fluid pressure sensing chamber is in fluid communication with the first fluid inlet and the second fluid pressure sensing chamber is in fluid communication with the second fluid port. The valve member is movable between a closed position, in which a cross-sectional flow area through the valve is below a predetermined level, and an open position, in which the cross-sectional flow area through the valve is above the predetermined level.

Description

Technical Field

[0001] The present application relates to an apparatus for regulating a pressure difference between a first fluid and a second fluid, and more particularly, to regulating a pressure difference between a liquid fluid and a gaseous fluid in a dual-fluid system, the dual-fluid system including a dual-fuel system. Background Art

[0002] Hydraulically actuated dual fuel injectors typically use liquid fuel as a hydraulic fluid, and the hydraulically actuated dual fuel injectors can inject gaseous fuel independently and separately from the liquid fuel. The liquid fuel, in its ability to act as a hydraulic fluid, is used to control the movement of the valve member in the dual fuel injector, and also in its ability to act as a sealing fluid, to reduce and ideally prevent the leakage of gaseous fuel from the injector. The pressure difference between the liquid fuel pressure and the gaseous fuel pressure is controlled so that the movement of the valve member is properly controlled and the liquid fuel acts as a fluid seal. The pressure difference between the liquid fuel pressure and the gaseous fuel pressure is sometimes referred to as a bias pressure, or simply a bias pressure. In this article, the bias pressure is more generally defined as the difference between the pressure of a higher viscosity fluid and the pressure of a lower viscosity fluid, for example, the bias pressure can be the difference between the liquid fuel pressure and the gaseous fuel pressure. The preferred bias pressure has a value greater than zero bar, and may also preferably be within a range of these values ​​greater than zero. A smaller bias pressure increases the likelihood of gaseous fuel leaking through the liquid fuel seal and leaking out of the injector because the liquid fuel pressure and the gaseous fuel pressure oscillate during operation. A greater bias pressure may increase the amount of liquid fuel that leaks into the gaseous fuel cavity within the injector, which is subsequently injected into the combustion chamber of the engine.

[0003] Prior art techniques for controlling bias pressure are disclosed in applicant's U.S. Patent No. 6,298,833 B1, issued October 9, 2001 ("the '833 Patent"), which is incorporated herein by reference. In the '833 Patent, several embodiments are discussed relating to two general techniques for controlling bias pressure. Figure 2 B shows such a technique, where the gaseous fuel pressure is used as a reference pressure (in fuel line 242) to adjust the liquid fuel pressure (in seal fluid line 229) supplied to the injection valve (280) to maintain a desired bias pressure between the two fluids supplied to the injection valve. In contrast, in the '833 patent Figure 3 In another fuel regulation technique shown in B, the liquid fluid pressure (in the sealed fluid pipeline 323) is used as a reference pressure to regulate the gas fuel pressure (in the fuel pipeline 343) supplied to the injection valve (280) to maintain a desired bias pressure between the two fluids supplied to the injection valve.

[0004] U.S. Patent No. 6,003,543A, issued on December 21, 1999 and incorporated herein by reference, discloses an electronic gas regulator for an internal combustion engine system having an internal gas chamber and a high-speed solenoid valve that controls the flow of gas into the chamber. A control device, including a microprocessor, receives signals from instruments associated with the engine, including receiving signals from a pressure sensor mounted on the electronic gas regulator to measure the pressure downstream of the valve. The control device generates a pulsed electrical signal having a variable pulse width, a variable pulse frequency, or a variable pulse width and a variable pulse frequency to control the high-speed solenoid valve so that the pressure of the gas downstream of the valve is adjusted toward a set point. There are problems with using high-speed solenoid valves in higher fluid pressure systems. The electromagnetic energy required to directly actuate the electromagnetic coil to overcome the sealing pressure of the high-pressure fluid is very large, and this requires an overly large electromagnetic coil. In some applications, either or both of the electromagnetic energy requirement and the large electromagnetic coil requirement are unacceptable.

[0005] The prior art lacks techniques for pressure regulation in dual fluid systems, where liquid fluid pressure is regulated based on gas fluid pressure. The present apparatus and method provide techniques for improved pressure regulation in dual fuel systems.

[0006] In addition to the benefits and improvements disclosed herein, other objects and other advantages of the present invention will become apparent from the following description in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it is understood that the disclosed embodiments are only illustrative of the present invention, and the present invention can be implemented in various forms. In addition, each of the examples given with respect to the various embodiments of the present invention is intended to be illustrative rather than limiting. Summary of the invention

[0007] An improved pressure regulator is disclosed for regulating a pressure difference between a first fluid pressure of a first fluid and a second fluid pressure of a second fluid. The pressure regulator includes a valve between a regulator body and a valve member. The regulator body includes: a first fluid inlet for a first fluid; a first fluid outlet for the first fluid; a second fluid port for a second fluid; a first longitudinal bore extending between the first fluid inlet and the second fluid port; and an outlet channel extending from the first longitudinal bore to the first fluid outlet. The valve is in fluid communication with the first fluid inlet on the inlet side of the valve, and the valve is in fluid communication with the first fluid outlet on the outlet side of the valve. The valve member is movably disposed in the first longitudinal bore of the regulator body, the valve member being located between a first fluid pressure sensing chamber and a second fluid pressure sensing chamber. The first fluid pressure sensing chamber is in fluid communication with the first fluid inlet, and the second fluid pressure sensing chamber is in fluid communication with the second fluid port. The valve is movable between a closed position and an open position, in which a cross-sectional flow area through the valve is lower than a predetermined level, and in which a cross-sectional flow area through the valve is higher than a predetermined level.

[0008] In an exemplary embodiment, in a closed position, the valve member is movable within an overlap position range, and in an open position, the valve member is movable within a zero overlap position range to maintain a pressure differential between a first fluid and a second fluid within a predetermined range. Within the overlap position range, the first fluid inlet is in fluid communication with an outlet channel in the regulator body through a first matching fit formed between an outer surface of the valve member and a first bore wall of the regulator body. Within the zero overlap position range, the first fluid inlet is in fluid communication with the outlet channel such that as the valve member moves further away from the overlap position range, a cross-sectional flow area through the valve increases.

[0009] In some embodiments, as the valve member moves through the overlap position range, the cross-sectional flow area through the valve can be substantially constant. In some embodiments, at least one of the first longitudinal bore and the valve member is tapered so that as the valve member moves through the overlap position range toward the zero overlap position range, the cross-sectional flow area through the valve increases, wherein the rate of increase of the cross-sectional flow area in the overlap position range is less than the rate of increase of the cross-sectional flow area in the zero overlap position range. In some embodiments, the regulator body has an annular groove in a first bore wall of the regulator body, the outlet channel extends from the annular groove to the first fluid outlet, and in the overlap position range, the first fluid inlet is indirectly fluidly connected to the annular groove through a first matching fitting between the valve member and the regulator body. In the zero overlap position range, the first fluid inlet is directly fluidly connected to the annular groove. In some embodiments, the valve member has a first annular groove in an outer surface of the valve member, a first end of the valve member in the first fluid pressure sensing cavity, a second end in the second fluid pressure sensing cavity, and a first channel extending from the first end of the valve member to the first annular groove, wherein in the overlap position range, the first annular groove is indirectly fluidly connected to the outlet channel through the first matching fitting. In the zero overlap position range, the first annular groove is directly fluidly connected to the outlet channel.

[0010] The valve member of the pressure regulator may further include a second annular groove in an outer surface of the valve member. A second passage extends between the first end of the valve member and the second annular groove, wherein the first fluid ring seal extends between the second annular groove and a bore wall of the regulator body.

[0011] The pressure regulator may have a first fluid inlet connector that is mutually received in the first fluid inlet. The first fluid inlet connector may include a set screw for adjusting the hard stop position of the valve member. The pressure regulator may have a second fluid connector that is mutually received in the second fluid port, and a spring between the second fluid connector and the valve member. The spring may bias the valve member toward an overlapping position range. The second fluid connector may include a set screw for adjusting the preload on the spring. The first fluid inlet and the second fluid port may each have a sealing surface. The sealing surface of the first fluid inlet connector and / or the second fluid connector may be one of a truncated conical surface, a spherical surface, a parabolic surface, an elliptical surface, and a hyperbolic surface.

[0012] In some embodiments, the pressure regulator has a first fluid outlet connector and an annular sealing member, the first fluid outlet connector is received by each other in the first fluid outlet, and the annular sealing member is arranged between the first fluid outlet and the first fluid outlet connector and around the outlet channel of the regulator body, so that the annular sealing member forms a sealing portion between the regulator body and the first fluid outlet connector.

[0013] The valve member moves to adjust the flow of the first fluid between the first fluid inlet and the first fluid outlet by changing the cross-sectional flow area through the valve to maintain the pressure difference within a predetermined range. The valve member can be a stepped valve member, and the first longitudinal hole can be a stepped longitudinal hole. The stepped valve member includes a first valve member portion having a first valve member diameter and a second valve member portion having a second valve member diameter, and the stepped longitudinal hole includes a first longitudinal hole portion having a first longitudinal hole diameter and a second longitudinal hole portion having a second longitudinal hole diameter. The first valve member diameter can be greater than the second valve member diameter, and the first longitudinal hole diameter can be greater than the second longitudinal hole diameter, so that the first part and the second part of the stepped valve member reciprocate in the first part and the second part of the stepped longitudinal hole, respectively.

[0014] In an exemplary embodiment, the valve is a curtain valve. The valve includes a valve gain characterized as a function of the position of the valve member along the longitudinal axis of the longitudinal bore. The curtain valve gain can vary between a closed position of the valve and a fully open position of the valve, in which the cross-sectional flow area through the valve is at a low value, and a fully open position of the valve, in which the cross-sectional flow area through the valve is at a high value. The valve may include a feature for reducing the rate of increase of the valve gain when the valve is opened. The feature may include a tapered matching fit that limits the cross-sectional flow area through the valve. Alternatively or in addition, the curtain valve includes a first annular groove in the valve member and a first annular edge associated with the first annular groove, and the feature may include a first annular edge having a fillet, a bevel, or a chamfer; or the valve includes a second annular groove in the regulator body and a second annular edge associated with the second annular groove, and the feature includes a second annular edge having a fillet, a bevel, or a chamfer. Alternatively or in addition, the curtain valve includes a first annular groove in the valve member, wherein the first annular groove includes a first annular sidewall and a second annular sidewall, and the feature includes a recess in the second annular sidewall; or the curtain valve includes a second annular groove in the regulator body, wherein the second annular groove includes a first annular sidewall and a second annular sidewall, and the feature includes a recess in the second annular sidewall of the second annular groove. The recess may include at least one of a flat surface and a curved surface. In other exemplary embodiments, the valve may be an orifice valve.

[0015] The first fluid may have a higher viscosity than the second fluid, and the first fluid may be liquid and the second fluid may be gaseous, and one or both fluids may be a fuel. The first fluid may have a higher cetane number than the second fluid, and the first fluid may be selected from diesel, dimethyl ether or liquefied petroleum gas; and / or the second fluid may be selected from methane, hydrogen, air, synthesis gas, natural gas or a mixture thereof.

[0016] Objects and advantages associated with an improved pressure regulator for maintaining a pressure differential between a first fluid pressure of a first fluid and a second fluid pressure of a second fluid in a dual fluid system may become apparent upon reference to the examples shown in the accompanying drawings and the examples disclosed in the following written description or the appended claims.

[0017] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constitute a part of this specification, include illustrative embodiments of the present invention, and show various objects and features of the illustrative embodiments. In addition, the drawings are not necessarily drawn to scale, and some features may be exaggerated or reduced relative to other features, or omitted entirely. Unless it is explicitly stated that the drawings are drawn to scale, the drawings should not be considered to be drawn to scale. The embodiments shown are examples only and should not be interpreted as limiting the scope of the present disclosure or the appended claims. In addition, any measurements, specifications, etc. shown in the drawings are intended to illustrate rather than limit. Therefore, the specific structural details and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to adopt the present invention in various ways. In addition, where appropriate, figure marks may be repeated in the drawings to indicate corresponding or similar elements.

[0019] Figure 1 is a schematic diagram of a dual fluid system according to an embodiment.

[0020] Figure 2 yes Figure 1 Schematic diagram of the control mechanism of the two-fluid system.

[0021] Figure 3 yes Figure 1 Schematic cross-section of a rail ejector of a dual-fluid system.

[0022] Figure 4a yes Figure 1 A cross-sectional view of a liquid fluid regulator of a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0023] Figure 4b yes Figure 4a A portion of a liquid fluid regulator is shown in FIG.

[0024] Figure 5 yes Figure 4a A cross-sectional view of a regulator body of a liquid fluid regulator.

[0025] Figure 6 yes Figure 4a A cross-sectional view of a valve component of a liquid fluid regulator.

[0026] Figure 7a yes Figure 4a A cross-sectional view of a liquid fluid regulator shown in an open position.

[0027] Figure 7b yes Figure 7a A portion of a liquid fluid regulator is shown.

[0028] Figure 8 yes Figure 1 A cross-sectional view of an alternative embodiment of a liquid fluid regulator for a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0029] Fig. 9 yes Figure 8 A cross-sectional view of a valve component of a liquid fluid regulator.

[0030] Fig.10 yes Figure 1 A cross-sectional view of an alternative embodiment of a liquid fluid regulator for a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0031] Fig.11 yes Figure 1 A cross-sectional view of an alternative embodiment of a liquid fluid regulator for a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0032] Fig.12 yes Figure 1 A cross-sectional view of an alternative embodiment of a liquid fluid regulator for a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0033] Fig.13 yes Fig.12 A cross-sectional view of a valve component of a liquid fluid regulator.

[0034] Fig.14 yes Figure 1 A cross-sectional view of an alternative embodiment of a liquid fluid regulator for a dual fluid system, the liquid fluid regulator being shown in a closed position.

[0035] Fig.15 yes Fig.14 A cross-sectional view of a regulator body of a liquid fluid regulator.

[0036] Fig.16 yes Fig.14 A cross-sectional view of a valve component of a liquid fluid regulator.

[0037] Fig.17 is a schematic diagram of an engine arrangement showing the distances between the gas rail injectors and the fuel injectors and their corresponding engine cylinders.

[0038] Fig.18 is a schematic diagram of a dual fuel system according to another embodiment.

[0039] Fig.19 is a schematic diagram of a liquid fluid regulator according to another embodiment.

[0040] Fig. 20 is a schematic diagram of a liquid fluid regulator according to another embodiment.

[0041] Fig.21 is a schematic diagram of a liquid fluid regulator according to another embodiment.

[0042] Fig. 22 yes Fig.21 Schematic diagram of a valve component of a liquid fluid regulator.

[0043] Fig.23 yes Fig.21 Schematic diagram of a regulating valve of a liquid fluid regulator, the regulating valve being shown in an open position.

[0044] Fig.24 yes Fig.21 Schematic diagram of the regulating valve of the liquid fluid regulator, with Fig.23 In comparison, the regulating valve is shown in a more open position.

[0045] Fig.25 yes Fig.21 Schematic diagram of the regulating valve of the liquid fluid regulator, with Fig.24 In comparison, the regulating valve is shown in a more open position.

[0046] Fig.26 is a schematic diagram of a liquid fluid regulator according to another embodiment, the liquid fluid regulator being shown in a closed position.

[0047] Fig. 27 yes Fig.26 Schematic diagram of a liquid fuel regulator shown in an open position.

[0048] Fig.28 yes Fig.26 and Fig. 27 A perspective view of a valve component of a liquid fuel regulator. DETAILED DESCRIPTION

[0049] Throughout the specification and claims, the following terms have the meanings explicitly associated herein, unless the context explicitly states otherwise. As used herein, the phrases "in some embodiments," "in an exemplary embodiment," "in an exemplary embodiment," and "in some exemplary embodiments" do not necessarily refer to the same embodiment, but they may refer to the same embodiment. In addition, as used herein, the phrases "in other embodiments," "in other exemplary embodiments," "in another embodiment," and "in some other embodiments" do not necessarily refer to different embodiments, but they may refer to different embodiments. Therefore, as described below, the various embodiments of the present invention can be easily combined without departing from the scope of the present invention.

[0050] The term "and / or" is used herein to mean "one or the other or both". In addition, as used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or", unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on additional factors that are not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of "a", "an", and "the" includes plural references unless the context clearly dictates otherwise. The phrase "the difference between X and Y" should be interpreted as "X minus Y", and "the difference between Y and X" should be interpreted as "Y minus X". The term "substantially" when modifying a parameter with stated limitations should be interpreted to mean that something effectively has the same characteristics as the stated limitations or performs the same function as the stated limitations, and includes the exact stated limitations as well as minor deviations from the stated limitations.

[0051] Although exemplary embodiments are shown in the drawings and described herein, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary implementations and techniques shown in the drawings and described herein. Where examples are listed, it is understood that any combination of alternative examples in the alternative examples is also contemplated. The scope of the present invention is not limited to the specific embodiments disclosed herein, which are intended to be exemplary only and represent the limitations set forth in the published claims arising from this application and the equivalents of those limitations.

[0052] For the purpose of simplifying the present disclosure, in the exemplary embodiments, individual features may be combined together, but this disclosure method should not be interpreted as reflecting an intention that any claimed embodiment requires more features than those explicitly stated in the corresponding claims. Rather, the subject matter of the invention may have less than all the features in a single disclosed exemplary embodiment, or may combine features from different drawings or different embodiments. Therefore, the attached claims are incorporated into the detailed description, with each claim existing independently as a separately disclosed embodiment. However, the present disclosure should also be interpreted as implicitly disclosing any embodiment of any suitable group (i.e., a group of features that are neither contradictory nor mutually exclusive) of one or more features disclosed or claimed, which appear in the present disclosure or the attached claims, and the above-mentioned suitable groups include those groups that may not be explicitly disclosed herein or may not be explicitly disclosed in a single drawing or a single embodiment. On the contrary, the scope of the attached claims does not necessarily include the entire content of the subject matter disclosed herein.

[0053] Referring to the accompanying drawings, first refer to Figure 1 , shows a dual fluid system 10, which, among other functions, regulates the pressure of a first fluid and the pressure differential between the first fluid and the second fluid. The pressure differential is defined herein as the difference between the pressure of the first fluid and the pressure of the second fluid. In an exemplary embodiment, the first fluid is a liquid fluid and the second fluid is a gaseous fluid, more specifically, one or both fluids may be fuels, such as liquid fuels and / or gaseous fuels, respectively; however, in other embodiments, the first fluid and the second fluid may both be liquid fluids, or both the first fluid and the second fluid may both be gaseous fluids. As used herein, a gaseous fuel is any fuel that is in the gas phase (or gaseous state) at standard temperature and standard pressure (STP), wherein standard temperature is defined herein as zero degrees Celsius (0°C) and standard pressure is defined herein as one bar (1 bar) absolute pressure. In some exemplary embodiments, the dual fluid system 10 may be a single fuel system, such as a gaseous fuel system that employs a liquid as a hydraulic fluid in a single fuel injector, or a liquid fuel system such as that employs another fluid as an oxidant or fuel additive in a single fuel injector. In other exemplary embodiments, the dual fluid system 10 may be a dual fuel system that delivers both a liquid fuel and a gaseous fuel to a dual fluid injector, which may then be referred to as a dual fuel injector. Many of the advantages and features of the exemplary system described herein for a dual fluid system that delivers two fluids to a dual fuel injector may also be applicable to a dual fluid system that delivers a single fuel and another fluid to a single fuel injector, or a dual fluid system that delivers two fluids to a dual fluid injector or some other end-use device, in which it is desired to regulate the pressures of two fluids with different viscosities relative to each other.

[0054] The dual fluid system 10 is now described as an exemplary dual fuel system 10 that delivers gaseous fuel to a fuel consumer at a predetermined gas fuel rail pressure and delivers liquid fuel to a fuel consumer at a predetermined liquid fuel rail pressure, which in the illustrated embodiment is a dual fuel injector 20. Although only one dual fuel injector 20 is shown, it is understood that there may be multiple dual fuel injectors. The dual fuel injector 20 is a hydraulically actuated injector that can inject gaseous fuel separately and independently of liquid fuel, and similarly, the hydraulically actuated injector can inject liquid fuel separately and independently of gaseous fuel; however, this is not a requirement of the dual fuel system 10. In the exemplary embodiment, the dual fuel injector 20 injects gaseous fuel and liquid fuel into the combustion chamber of the internal combustion engine, but this is also not a requirement. Liquid fuels such as diesel are fuels that are easier to ignite than some gaseous fuels such as natural gas or hydrogen, and can be used to create a pressure and temperature environment in the combustion chamber suitable for igniting gaseous fuels. Natural gas and hydrogen are disclosed herein as exemplary gaseous fluids; however, any fluid delivered to the injector in gaseous form is similarly contemplated, including but not limited to biogas, methane, hydrogen, natural gas, synthesis gas, air, or a gaseous mixture thereof. Other suitable fuels that are gaseous at standard temperature and standard pressure, but can be in liquid form when used in a high-pressure injection system (e.g., greater than 100 bar) so that the fuel is in liquid form when delivered to the injector of the high-pressure injection system, such as liquefied petroleum gas or dimethyl ether, are also suitable for igniting low cetane gaseous fuels, and can be used as liquid fuels in dual-fuel systems or as fuels in single-fuel systems. In other embodiments, liquids can be used for reasons other than ignition assistance. The dual-fuel system 10 includes a gas fuel system 30 and a liquid fuel system 40.

[0055] The gas fuel system 30 regulates the pressure of the gas fuel from a higher pressure to a predetermined gas fuel rail pressure. The pressurized supply 60 is a higher pressure supply of gas fuel, which in the illustrated embodiment is an accumulator that receives pressurized gas fuel from an upstream source through a conduit 50. For example, the accumulator can receive gas fuel from a heat exchanger that evaporates gas fuel in liquefied form received from a cryogenic pump. The higher pressure of the gas fuel is relative to the downstream pressure of the gas fuel. In other embodiments, the higher pressure supply of gas fuel can be, for example, one or more gas fuel pressurized cylinders - such as compressed natural gas cylinders, which are combined with a compressor to maintain the pressure of the gas fuel delivered from the cylinder to the conduit 70 above the predetermined gas fuel rail pressure. The pressure of the gas fuel in the pressurized supply 60 is referred to herein as the gas fuel supply pressure. The rail injector 110 is fluidly connected to the accumulator 60 through a shut-off valve 85. The control unit 300 ( Figure 2 1 ) commands the shutoff valve 85 to an open position when the internal combustion engine is operating, and commands the shutoff valve 85 to a closed position when the internal combustion engine is shut down to isolate the pressurized supply 60 from the rail injector 110. The control unit 300 commands the rail injector 110 to inject discrete amounts of gaseous fuel into the gaseous fuel rail 120. For purposes of this disclosure, the gaseous fuel rail pressure is the pressure of the gaseous fuel in the gaseous fuel rail 120. In other embodiments, the rail injector 110 may be used as a shutoff valve, so that the shutoff valve 85 is not required. The pressure relief valve 145 is used to selectively discharge gaseous fuel from the gaseous fuel rail 120 when commanded by the control unit 300, such as whenever the gaseous fuel rail pressure rises above a predetermined gaseous fuel discharge pressure, or during shutdown of the internal combustion engine in order to discharge gaseous fuel in the gaseous fuel rail 120, or whenever the system bias pressure is too low or negative. Where gaseous fuel is discharged into conduit 150, the gaseous fuel may optionally pass through a separator 155 which separates any liquid fluid components in the gaseous fuel prior to delivering the gaseous fuel to a discharge processor (not shown). The liquid fluid component may be added to the gaseous fuel within the rail injector 110, as will be explained in greater detail below. The discharge processor may be, for example, a burner (not shown) for burning the discharged gaseous fuel, and / or a device (not shown) for returning the gaseous fuel to a low pressure supply of gaseous fuel, such as a cryogenic storage vessel for maintaining a liquefied supply of the gaseous fuel. In the illustrated embodiment, both the shut-off valve 85 and the pressure relief valve 145 are controlled by the control unit 300 (see Figure 2) controlled solenoid valve, but this is not a requirement. Alternatively, each of valve 85 and valve 145 may be a mechanically actuated valve, or there may be a mechanically actuated valve in addition to valve 85 and valve 145. In the illustrated embodiment, pressure sensor 75 monitors the gaseous fuel pressure in conduit 70 upstream of shutoff valve 85 and represents the gaseous fuel supply pressure in accumulator 60. Alternatively, pressure sensor 75 may be located in accumulator 60 or associated with conduit 50 upstream of accumulator 60. Pressure sensor 125 monitors the gaseous fuel rail pressure in gaseous fuel rail 120. Pressure sensor 75 and pressure sensor 125 emit signals representative of the pressures they monitor, as will be described in more detail below.

[0056] The liquid fuel system 40 pressurizes the liquid fuel from the low-pressure supplier of the liquid fuel and then adjusts the pressure of the pressurized liquid fuel so that the pressure difference between the liquid fuel and the gaseous fuel is within a predetermined range. The liquid fuel is stored in the storage tank 170, where the liquid fuel is generally stored at a pressure equal to or close to atmospheric pressure, which is considered to be a low pressure in the context of this application. The control unit 300 (see Figure 2 ) commands the liquid fuel pump 190 to pressurize the liquid fuel received from the storage tank 170 through the conduit 180, and commands the liquid fuel pump 190 to deliver the pressurized liquid fuel to the liquid fuel rail 220. For the purposes of this disclosure, the liquid fuel rail pressure is the pressure of the liquid fuel in the liquid fuel rail 220. The liquid fuel pump 190 may include an inlet metering valve to help regulate the flow of liquid fuel entering the pump. In other embodiments, there may be a transfer pump (not shown) inside the storage tank 170 to help transfer the liquid fuel to the conduit 180. The pressure relief valve 205 is a pressure activated valve that releases liquid fuel from the liquid fuel rail 220 into the liquid fuel discharge pipe 250 whenever the liquid fuel rail pressure rises above a predetermined liquid fuel release pressure. In other embodiments, the pressure relief valve 205 may be a solenoid activated valve, and the control unit 300 (see Figure 2 ) can command the solenoid-activated valve to open as needed, or there can be a solenoid-activated valve in addition to the mechanically activated pressure relief valve. Figure 2) can command the isolation valve 255 to selectively isolate the liquid fuel regulator 260 from the liquid fuel rail 220. For example, when the internal combustion engine is operated by consuming only liquid fuel, the isolation valve 255 can be commanded to be in a closed position, while the isolation valve is normally in an open position. The liquid fuel regulator 260 is a differential pressure regulator and a back pressure regulator that fluidly delivers liquid fuel from the liquid fuel rail 220 to the liquid fuel discharge pipe 250 based on the gas fuel rail pressure sensed in the conduit 130 so that the pressure difference between the liquid fuel rail pressure and the gas fuel rail pressure is within a predetermined range. The liquid fuel regulator 260 can be a spool type regulator using a needle, or a dome load regulator using a piston, a plunger, a diaphragm, or any combination thereof, for sensing bias pressure and adjusting a valve (not shown) in the liquid fuel regulator that controls the flow of liquid fuel from the liquid fuel rail 220 to the liquid fuel discharge pipe 250. The mating fit between the piston and the bore in which the piston reciprocates or between the plunger and the bore in which the plunger reciprocates can be used to limit leakage of liquid fuel in the liquid fuel rail 220 into the gas fuel rail 120, as will be described in more detail below. The liquid fuel drain 250 also receives liquid fuel from the drain outlet 22 of the dual fuel injector 20 through the conduit 290 and the check valve 285. The dual fuel injector 20, in addition to injecting liquid fuel, also uses liquid fuel as a hydraulic fluid within the injector for controlling the injection valve in the injector. Liquid fuel flows from the liquid fuel rail 220 into the dual fuel injector 20 at the liquid fuel inlet 24. A single fuel injector may have a similar arrangement of liquid fluid inlets 24 and drain outlets 22. During operation of the injector 20, when the injection valve is open, hydraulic fluid is discharged from the injector 20. The liquid in the liquid fuel drain 250 returns to the tank 170 so that the liquid can be re-pressurized by the liquid fuel pump 190. Pressure sensor 245 monitors the liquid fuel discharge pressure in liquid fuel discharge pipe 250, and pressure sensor 225 monitors the liquid fuel rail pressure in liquid fuel rail 220. Pressure sensor 225 and pressure sensor 245 emit signals representative of the pressures they monitor, as described in more detail below. In the illustrated embodiment, pressure sensor 245 provides pressure information about liquid fuel discharge pipe 250, which can be useful for detecting gaseous fuel pressure leaks, where gaseous fuel leaks from dual fuel injector 20 or rail injector 110 or liquid fuel regulator 260 into the liquid fuel. In other embodiments, pressure sensor 245 is not required.

[0057] Now refer to Figure 2, a schematic diagram of the control mechanism of the dual fuel system 10 is shown. The control unit 300 is connected to the shut-off valve 85 by a communication line 310 shown in dashed lines; is connected to the gas fuel discharge valve 145 by a communication line 312 shown in dashed lines; is connected to the isolation valve 255 by a communication line 314 shown in dashed lines; is connected to the liquid fuel pump 190 by a communication line 320 shown in dashed lines; is connected to the pressure sensor 75, the pressure sensor 125, the pressure sensor 225, and the pressure sensor 245 by communication lines 330, 332, 334, and 336 shown in dashed lines, respectively; is connected to the rail injector 110 by a communication line 340 shown in dashed lines; and is connected to the dual fuel injector 20 by communication lines 350 and 352 shown in dashed lines. The dashed communication lines herein represent communication lines that can be connected by wire or wirelessly between each system device and the control unit 300, as appropriate, according to system design preferences. Communication lines 310, 312, and 314 are used to transmit command signals from control unit 300 to solenoid valves 85, 145, and 255, respectively, to command them to enter one of a through (i.e., open) position and a cutoff (i.e., closed) position. Communication line 320 is used to transmit command signals from control unit 300 to liquid fuel pump 190 to pressurize liquid fuel from tank 170. Communication lines 330, 332, 334, and 336 are used to transmit signals generated by corresponding pressure sensors 75, 125, 225, and 245 to control unit 300, which signals represent the pressure measured by the corresponding pressure sensors. In some embodiments, sensors 75, 125, 225, and 245 may also transmit temperature data and / or optical sensor data to control unit 300. The communication line 340 is used to transmit a command signal from the control unit 300 to the rail injector 110 to inject the gaseous fuel from the conduit 100 into the gaseous fuel rail 120. The communication line 350 is used to transmit a command signal from the control unit 300 to the dual fuel injector 20 to inject the liquid fuel, and the communication line 352 is used to transmit a command signal from the control unit 300 to the dual fuel injector to inject the gaseous fuel. The communication lines 310, 312, 314, 320, 330, 332, 334, 336, 340, 350 and 352 can transmit electronic signals and / or photon signals to and / or from the control unit 300, and in an exemplary embodiment, the communication lines 310, 312, 314, 320, 330, 332, 334, 336, 340, 350 and 352 are one or more electrical wires.

[0058] In an exemplary embodiment, the control unit 300 is an electronic controller, which may include hardware components and software components. The hardware components may include digital electronic components and / or analog electronic components. In the embodiments of this article, the control unit 300 includes a processor and a memory for storing and executing programs, and the memory includes one or more permanent memories and temporary memories, such as FLASH, EEPROM and hard disk, and temporary memories such as SRAM and DRAM. As used herein, the terms "algorithm", "module" and "step" refer to processors (shared, dedicated or group) and memories, application specific integrated circuits (ASICs), electronic circuits, combinational logic circuits, and / or other suitable components that provide the functions that execute one or more software programs or firmware programs. The algorithms, modules and steps executed by the control unit 300 are part of the control unit. The control unit 300 may also be referred to as a controller or an electronic controller. The control unit 300 may be programmed with any one of a feedback control algorithm, a feedforward control algorithm and a conversion control algorithm, preferably all of them. Considering first the feedback control algorithm, the control unit 300 may be programmed to receive signals representative of the gaseous fuel rail pressure, determine a measured gaseous fuel rail pressure based on these signals, determine a difference between the measured gaseous fuel rail pressure and a desired gaseous fuel rail pressure, wherein the difference is an error signal, and may be programmed to actuate the rail injector 110 to inject gaseous fuel from the gaseous fuel supplier into the gaseous fuel rail such that the difference is reduced. The desired gaseous fuel rail pressure is primarily determined by engine parameters such as engine speed, engine load, pedal position (for a diesel cycle engine) or throttle position (for an Otto cycle engine), and boost pressure (pressure in the intake manifold in a turbocharged or supercharged engine). A feedforward control algorithm may be used to actively actuate the rail injector 110 to inject a bolus of gaseous fuel into the gaseous fuel rail 120 such that an inflowing bolus of fuel flowing into the gaseous fuel rail matches an expected outflowing bolus of fuel flowing to a fuel consumer, which in the illustrated embodiment is a dual fuel injector 20. The transition control algorithm may be used to determine the amount of gaseous fuel bolus that needs to be injected into the gaseous fuel rail 120 when the desired gaseous fuel rail pressure changes, and may be used to actuate the rail injector 110 to inject the determined amount of gaseous fuel bolus in one or more injections.

[0059] Now refer to Figure 3 The rail injector 110 is described in more detail. In the exemplary embodiment, the rail injector 110 is a hydraulically actuated, outwardly opening gas fuel injector. The rail injector 110 includes a hydraulic fluid inlet 400, a hydraulic fluid outlet 410, a gas fuel outlet 420, an actuation terminal 430, and a gas fuel injection valve 440. Figure 1As seen in the illustrated embodiment, hydraulic fluid inlet 400 is fluidly connected to liquid fuel rail 220, and hydraulic fluid outlet 410 is fluidly connected to liquid fuel drain 250 via check valve 195. Advantageously, gaseous fuel outlet 420 is fluidly connected to gaseous fuel rail 120; and injection valve 440 is fluidly connected to conduit 100, as opposed to how an outwardly opening injector is configured, as will be described in more detail below.

[0060] The liquid fuel rail 220 operates as a hydraulic fluid supply for the rail injectors 110, and the liquid fuel is the hydraulic fluid for the rail injectors. In other embodiments, a separate and distinct hydraulic fluid supply from the liquid fuel rail 220 may be employed to supply the rail injectors 110 with a separate hydraulic fluid (which may also be a liquid fuel, but the liquid fuel comes from a different pumping source). However, employing liquid fuel from the liquid fuel rail 220 as the hydraulic fluid for the rail injectors is advantageous because pressurized liquid fuel is already available, and taking advantage of this reduces system complexity and cost as well as parasitic losses. Alternatively, a second liquid fuel pump may be employed to pressurize the liquid fuel from the liquid fuel rail 220 to a higher pressure and then deliver the higher pressure liquid fuel to the rail injectors 110 as a supply of hydraulic fluid; however, the additional pump also increases system cost and parasitic losses. The input of the second liquid fuel pump may be connected to the liquid fuel rail 220 or the conduit 180, and the output of the second liquid fuel pump is connected to the hydraulic fluid inlet 400 of the rail injectors 110.

[0061] like Figure 2 As shown, the start terminal 430 is connected to the control unit 300 for communication. Figure 3 , the injection valve 440 is the gas fuel inlet of the rail injector 110 and includes a valve member 450 and a valve seat 460. The valve member 450 is slidably received and reciprocatable within a cylindrical bore 470 formed in a rail injector body 480. The valve seat 460 is formed at a distal end of a nozzle 490 of the rail injector body 480. In other embodiments, the nozzle 490 may extend outwardly away from the valve seat 460 to form a tubular shroud surrounding the injection valve 440, in which case the shroud may be considered to be the gas fuel inlet of the rail injector 110 upstream of the injection valve 440. In an exemplary embodiment, the contact surface area between the valve member 450 and the valve seat 460 is annular in shape. The gas fuel conduit 500 delivers the gas fuel from the annular passage 510 to the gas fuel outlet 420. As shown in FIG. Figure 3As shown, the annular passage 510 and the gas fuel conduit 500 are located downstream of the injection valve 440. The cavity 515 allows the diameter of the valve member 450 in the bore 470 to be equal to the inner diameter of the valve seat 460, which improves the ability to open the valve member, as will be described in more detail below. The opening control chamber 520 can be fluidly connected to the hydraulic fluid inlet 400 via the hydraulic fluid conduit 530. The closing control chamber 540 can be fluidly connected to the actuating valve 550 via the hydraulic fluid conduit 560. In the illustrated embodiment, the actuating valve 550 is a three-way actuating valve 550, which, in addition, is fluidly connected to the hydraulic fluid inlet 400 via the hydraulic fluid conduit 530 and is fluidly connected to the hydraulic fluid outlet 410 via the hydraulic fluid conduit 570. In other embodiments, the actuating valve 550 can be a two-way actuating valve, such as disclosed in the applicant's U.S. Patent No. 11,053,866B2 issued on July 6, 2021. Back Figure 3 The bore wall defining the cylindrical bore 470 has an annular groove 585 formed therein, which is in fluid communication with the hydraulic fluid conduit 530 so that a liquid annular seal is formed around the valve member 450, thereby reducing and preferably preventing leakage of gaseous fuel in the annular passage 510 into the closure control chamber 540 and out of the injector when the closure control chamber 540 is at a relatively low pressure during operation. A matching fit 474 formed between the outer surface of the valve member 450 and the bore wall of the rail injector body 480 extends along at least a portion of the bore wall of the cylindrical bore 470. The matching fit 474 is lubricated with hydraulic fluid from the closure control chamber 540 and the annular groove 585, and operates to guide the valve member 450 and control leakage of hydraulic fluid into the annular passage 510. In the illustrated embodiment, the spring 590 is a helical compression spring and is disposed within the closure control chamber 540, and the spring 590 biases the valve member 450 toward the valve seat 460 in the closing direction so that the injection valve 440 is in the closed position. The rail injector 110 may include a threaded surface 493 around the outside of the nozzle 490 so that the rail injector may be connected to the conduit 100, either directly or through a threaded coupling or fitting. In other embodiments, the distal end of the nozzle 490 may protrude outwardly beyond the valve member 450 so that the inner threaded surface of the protrusion may be threadably coupled to the conduit 100 or fitting. In other embodiments, the spring 590 may be disposed in the conduit 100, or in a fitting that connects the conduit 100 to the rail injector 110, or in a protruding distal end of the nozzle 490 so that the spring abuts against a surface 455 of the valve member 450, with the opposite end of the spring being fixed, whereby the spring biases the valve member in a closing direction, the closing direction being referenced to the spring. Figure 3 For upward.

[0062] The operation of rail injector 110 will now be discussed. Actuation valve 550 is operated to fluidly connect closing control chamber 540 to hydraulic fluid inlet 400 or hydraulic fluid outlet 410. Actuation valve 550 is commanded to fluidly connect closing control chamber 540 to hydraulic fluid inlet 400 such that both closing control chamber and opening control chamber 520 contain hydraulic fluid at liquid fuel rail pressure (i.e., at a relatively high pressure) so that injection valve 440 is moved to and maintained in the closed position. The opening force generated by the pressure of the hydraulic fluid in opening control chamber 520 acting on valve member 450 is less than the combined closing force generated by the following factors: (1) the conduit 100 (see FIG. 1 ); Figure 1 ) acting on the valve member 450, (2) pressure of the gas fuel in the closing control chamber 540 acting on the valve member, (3) pressure of the gas fuel in the chamber 515 acting on the valve member, and (4) force generated by the spring 590 acting on the valve member, so that the valve member moves to and is maintained in the closed position. The actuated valve 550 is commanded to fluidly connect the closing control chamber 540 with the hydraulic fluid outlet 410, so that the closing control chamber is cut off from the relatively high pressure hydraulic fluid in the conduit 530 and is instead fluidly connected to the relatively low pressure liquid fuel discharge pipe 250, so that the valve member moves to and is maintained in the open position due to the high pressure of the hydraulic fluid in the opening control chamber 520. The opening force generated by the pressure of the hydraulic fluid in the opening control chamber 520 acting on the valve member 450 is greater than the combined closing force generated by the following factors: (1) the conduit 100 (see Figure 1 ) the pressure of the gas fuel in chamber 515 acting on the valve member 450, (2) the pressure of the gas fuel in chamber 515 acting on the valve member 450, and (3) the force generated by the spring 590 acting on the valve member, so that the valve member is moved to and maintained in the open position.

[0063] Refer again Figure 1 Advantageously, the injection valve 440 is fluidly connected to the conduit 100 and the gas fuel outlet 420 is fluidly connected to the gas fuel rail 120, which is opposite to how outwardly opening injectors are typically configured. That is, when the injection valve 440 is open, gaseous fuel flows from the conduit 100 through the injection valve into the rail injector 110 and then travels through the injector to the gas fuel outlet 420 where the gaseous fuel exits to the gas fuel rail 120. Typically, fluid injected by an outwardly opening injector, or any injector, is contained within the injector and then exits the injector through the injection valve. This typical operation causes problems in the dual fuel system 10. The gas fuel supply pressure in the pressurized supply 60 is greater than the gas fuel rail pressure in the gas fuel rail 120, and may be greater than the liquid fuel rail pressure in the liquid fuel rail 220. The annular groove 585 (see Figure 3) is unable to seal against the (higher) gas fuel supply pressure in conduit 100. By maintaining the gas fuel supply pressure on the opposite side of injection valve 440 as compared to the liquid fuel annular seal in rail injector 110, gas fuel does not leak through the lower pressure hydraulic fluid when the injection valve is in the closed position. Using the gas fuel supply pressure from pressurized supply 60 to hold valve member 450 in the outwardly opening rail injector 110 tightly against valve seat 460 (i.e., in the closed position) is advantageous because this is the highest pressure acting on the rail injector. When liquid fuel is pressurized to a pressure higher than the gas fuel supply pressure using a second liquid fuel pump (not shown), then rail injector 110 may be connected in the reverse configuration, i.e., conduit 100 may be connected to gas fuel outlet 420 (operating as an inlet in this case), and gas fuel rail 120 may be connected to nozzle 490 of the rail injector (operating as an outlet in this case).

[0064] Now refer to Figure 4a , Figure 4b , Figure 5 and Figure 6 , first refer to Figure 4a and Figure 5 The liquid fuel regulator 260 is described in more detail. The liquid fuel regulator 260 includes a regulating valve 800, which is formed between a regulator body 810 and a valve member 1810 (also referred to as a valve core), and the valve member 1810 can slide in a first longitudinal hole 830 formed in the regulator body. The regulating valve 800 is a new type of sliding valve. As used herein, each hole is defined by a hole wall and / or an inner surface in the body, and the hole is formed in the body, and all holes and combinations of holes that allow a fluid such as a liquid fluid or a gas fluid to pass through can also be referred to as a channel or passage for the fluid. Some holes shown as straight are not necessarily straight, and can be formed with curved portions and / or straight portions. The first longitudinal hole 830 defined by a first hole wall 836 of the regulator body 810 having a first diameter 839 extends between a liquid fuel inlet receiver 852 of a liquid fuel inlet 850 and a gas fuel receiver 862 of a gas fuel port 860. The annular groove 845 of the regulator body is formed in the bore wall 836 of the regulator body 810, and is partially defined by an annular sidewall and an annular edge, the annular sidewall including a first groove sidewall 847a closer to the first fluid inlet 850 than the second groove sidewall 847b, the annular edge including a first groove edge 848a closer to the first fluid inlet 850 than the second groove edge 848b, and the annular groove 845 extends substantially radially relative to the longitudinal axis 820 of the regulator body 820. The enlarged second diameter bore portion 900 of the bore 830 serves as a spring retainer, which is provided with a spring retainer when the spring abuts against the annular shelf 920 (see Figure 5 ) is a hard stop position for one end of the spring 910. In the illustrated embodiment, the hole 940 extends radially relative to the longitudinal axis 820 between the inner wall of the annular groove 845 and the liquid fuel outlet receiver 842 of the liquid fuel outlet 840. The gas fuel receiver 862 includes a threaded portion 863 and a sealing surface 960 (at Figure 5 960 is in the form of a truncated cone (i.e., a truncated conical surface); however, in other embodiments, the surface may be a spherical surface, a parabolic surface, an elliptical surface, a hyperbolic surface, and other types of surface shapes. Liquid fuel inlet receiver 852 includes a threaded portion 853 and a sealing surface 950. Liquid fuel outlet receiver 842 includes a threaded portion 843 and a sealing surface 846, which in the illustrated embodiment is a flat annular sealing surface. In other embodiments, it is possible that a different fastening method may be used to fasten the coupler to receiver 862, receiver 852, and receiver 842, respectively, rather than using threaded portion 863, threaded portion 853, and threaded portion 843, such as a nut and bolt fastener, or a nut and threaded boss fastener, or other fastening techniques.

[0065] Reference Figure 4a and Figure 6 Describing the valve member 1810 in more detail, the valve member 1810 may also be referred to as a needle, plunger, or piston. A hole 1830 defined by the annular inner surface of the valve member 1810 extends along the longitudinal axis 1820 from the end 1000 of the valve member 1810 toward the opposite end 1010 of the valve member 1810 and ends before the opposite end 1010 of the valve member 1810; that is, the hole 1830 is a blind hole. The hole 1020 extends generally radially (relative to the longitudinal axis 1820 of the valve member 1810 in the illustrated embodiment) between the annular bore wall of the blind hole 1830 and the inner wall of the first annular groove 1035 formed in the outer surface 1056 of the valve member 1810. Although the hole 1020 is shown as a through-drilled hole, the hole 1020 need not pass from one side of the outer surface 1056 of the valve member 1810 to the other side of the outer surface 1056. In other embodiments, there may be other holes spaced angularly from the bore 1020 relative to the longitudinal axis 1820, including through-bores. In other embodiments, the first annular groove 1035 is not required, so that the bore 1020 extends between the outer surface 1056 of the valve member 1810 and the bore wall of the blind bore 1830. Further reference is made to Figure 4b, a first annular groove 1035 formed in the outer surface 1056 of the valve member 1810 is further defined by first and second annular sidewalls 1037a, 1037b, respectively, and by first and second annular edges 1038a, 1038b, respectively. In the illustrated embodiment, another hole 1040 is shown extending radially between the bore wall of the longitudinal blind bore 1830 and the inner wall of a second annular groove 1045, the second annular groove 1045 being formed in the outer surface 1056 of the valve member 1810, wherein the second annular groove 1045 is positioned further away from the first end 1000 of the valve member 1810 than the first annular groove 1035. Although the hole 1040 is shown as a through-drilled hole, this is not required, and in other embodiments, there may be other holes spaced angularly from the radial hole 1040 relative to the longitudinal axis 1820, including through-drilled holes. In other embodiments, the second annular groove 1045 is not required, so that the hole 1040 extends to the outer surface 1056 of the valve member 1810. The reduced diameter portion 1060 at or near the opposite end 1010 of the valve member 1810 acts as a spring 910 (see Figure 4a ) which radially positions the spring 910 within the enlarged second diameter hole portion 900 of the hole 830 relative to the longitudinal axis 820.

[0066] Refer again Figure 5 , the annular groove 845 in the regulator body 810 is not required, but, in other embodiments, the outlet hole 940 can extend between the hole wall 836 of the hole 830 formed in the regulator body 810 and the liquid fuel outlet receiver 842. Figure 4a , Figure 5 and Figure 6 In those embodiments where the annular groove 845 and the annular groove 1035 are not used, the diameter and position of the outlet hole 940 are such that regardless of the angular orientation of the valve member 1810 about the longitudinal axis 820 within the hole 830, when the hole 1020 of the valve member 1810 overlaps with the outlet hole 940 of the regulator body 810 along the longitudinal axis 820, there is a fluid communication path between the hole 1020 of the valve member 1810 and the outlet hole 940 of the regulator body 810, so that when the valve 800 is opened (which will be explained in more detail below), there will be direct fluid communication between the radial holes 1020 of the valve member 810 and the radial holes 940 of the regulator body 810.

[0067] Now refer to Figure 1 , Figure 4a and Figure 5 , the liquid fuel regulator 260 is connected through the fluid connection, the gas fuel connection 1370 (see Figure 4a ) and the catheter 130 (see Figure 1) is connected, and the gas fuel connector 1370 is threadedly received by the gas fuel receiver 862, so that the sealing surface 1386 of the gas fuel connector abuts against the sealing surface 960 of the gas fuel receiver and fluidly seals with the sealing surface 960 of the gas fuel receiver, thereby forming an annular fluid seal portion 1384. Compared with the sealing surface 960, the sealing surface 1386 is in the form of a mutually engaged and complementary surface. In those applications where high-pressure sealing (for example, greater than 100 bar) is required, the metal-to-metal sealing technology disclosed in the applicant's U.S. patent application with publication number 2017 / 0350357A1 can be used between all components requiring a high-pressure sealing interface. The gas fuel port channel 1380 passes through the gas fuel connector 1370 and is fluidly connected to the second fluid pressure sensing chamber 968 formed in the hole 830 in the regulator body 810, and is connected to the gas fuel rail 120 (see Figure 1 ) fluidly communicates. Although the opposite side of the gas fuel coupling 1370 is not shown, the opposite side can be similar to the male connection type shown or can be a female connection type and, such as through a coupling or fitting, in the illustrated embodiment, connected to and fluidly sealed with the conduit 130, or in other embodiments, the opposite side is directly fluidly sealed with the gas fuel rail 120. The end 1375 of the gas fuel coupling 1370 (see Figure 4a ) includes a recess 1395 that serves as a spring retainer for the spring 910, which radially positions the spring 910 relative to the longitudinal axis 820 of the bore 830 of the regulator body 810. The liquid fuel regulator 260 is connected to the liquid fuel inlet coupling 2370 (see Figure 4a ) is connected to the conduit 230 (see Figure 1 ), the liquid fuel inlet connector 2370 is threadedly received by the liquid fuel inlet receiver 852 so that the sealing surface 2386 of the liquid fuel inlet connector abuts against and fluidly seals with the sealing surface 950 of the liquid fuel regulator body, thereby forming an annular fluid seal portion 2384. Compared with the sealing surface 950, the sealing surface 2386 is in the form of a mutually engaging and complementary surface. The liquid fuel inlet passage 2380 passes through the liquid fuel inlet connector 2370 and the first fluid pressure sensing cavity 958 (see FIG. 1 ) in the hole 1830 of the valve member 1810. Figure 4a ) is fluidly connected to the liquid fuel rail 220 (see Figure 1) fluid communication. Although the opposite side of the liquid fuel inlet coupling 2370 is not shown, the opposite side can be similar to the male connection type shown or can be a female connection type and connected to the conduit 230 and fluidly sealed with the conduit 230, such as by a coupling or fitting. In the exemplary embodiment, the annular fluid seal 1384 and the annular fluid seal 2384 are capable of sealing high pressure fluids, such as 500 bar or even higher fluid pressures. The liquid fuel regulator 260 is connected to the liquid fuel outlet coupling 2470 (see Figure 4a ) is connected to the conduit 240 (see Figure 1 ), the liquid fuel outlet coupling 2470 is threadedly received by the liquid fuel outlet receiver 842 so that when the annular sealing member 2440 is compressed between the liquid fuel outlet coupling 2470 and the annular sealing surface 846 in the liquid fuel outlet receiver 842, an annular fluid seal 2444 is formed. The liquid fuel outlet passage 2480 extends through the liquid fuel outlet coupling 2470 so that the liquid fuel outlet passage 2480 is in fluid communication with the outlet hole 940 in the regulator body 810 and is connected to the liquid fuel discharge pipe 250 (see Figure 1 ) is in fluid communication with the liquid fuel outlet coupling 2470. Although the opposite side of the liquid fuel outlet coupling 2470 is not shown, the opposite side can be similar to the male connection type shown or can be a female connection type and connected to and fluidly sealed with the conduit 240 in the illustrated embodiment, such as by a coupling or fitting, or directly fluidly sealed with the liquid fuel drain 250 in other embodiments. The annular fluid seal 2444 seals against relatively low pressures compared to the sealing pressures at the fluid seals 1384 and 2384 because the liquid fuel outlet passage 2480 is in fluid communication with the liquid fuel drain 250, i.e., the liquid fuel outlet passage 2480 is at a significantly lower pressure than the liquid fluid rail 220 and the gas fluid rail 120.

[0068] Refer again Figure 4a, in the exemplary embodiment, the liquid fuel inlet coupling 2370 includes a set screw 2360, and the gas fuel coupling 1370 includes a set screw 1360. The set screw 2360 adjustably sets the hard stop position of the end 1000 of the valve member 1810, and includes a hollow core such that the liquid fuel inlet passage 2380 extends through the hollow core. In other embodiments, instead of the set screw 2360, the hard stop position of the valve member 1810 can be set by the position of the liquid fuel inlet coupling 2370 or by a shelf (not shown) formed within the hole 830 of the regulator body 810. Before discussing the set screw 1360, it is worth noting that the spring 910 partially determines the pressure difference between the liquid fuel rail pressure in the liquid fuel rail 220 and the gas fuel rail pressure in the gas fuel rail 120. The pressure differential is also determined based on the difference in area between the liquid fuel area of ​​the valve member 1810 exposed to the first fluid pressure sensing cavity 958, on which the liquid fuel acts and generates a liquid fuel force that moves the valve member toward the gas fuel receiver 862, and the gas fuel area of ​​the valve member 1810 exposed to the second fluid pressure sensing cavity 968, on which the gas fuel acts and generates a gas fuel force that moves the valve member toward the liquid fuel inlet receiver 852. The set screw 1360 adjustably preloads the spring 910 against the valve member 1810, thereby providing the ability to adjust the pressure differential between the liquid fuel pressure in the liquid fuel rail 220 and the gas fuel pressure in the gas fuel rail 120. The set screw 1360 has a hollow core, so that the gas fuel port passage 1380 extends through the hollow core. In other embodiments, a fixed preload on the spring 910 can be set by the gas fuel coupling 1370 instead of using the set screw 1360. In other embodiments, spring 910 is not required, such that the bias pressure between the liquid fuel and the gaseous fuel is determined based on the area difference between the liquid fuel area and the gaseous fuel area discussed above.

[0069] Refer again Figure 4a , Figure 5 and Figure 6 , the outer diameter of the valve member 1810 is 1059 (see Figure 6 ) relative to the inner diameter 839 (see Figure 5 ) are sized so that when the valve member 1810 is disposed within the first longitudinal bore 830, the annular mating fit portion 924 and the annular mating fit portion 922 (both see Figure 4a) is formed by the overlap between the outer surface 1056 of the valve member 1810 and the first bore wall 836 of the first longitudinal bore 830. The annular matching fitting portion 822, the annular matching fitting portion 824 and the annular matching fitting portion 924 restrict the flow of liquid fuel from the liquid fuel inlet passage 2380 therebetween. The liquid fuel from the liquid fuel rail 220 flows through the liquid fuel inlet passage 2380 of the liquid fuel inlet connector 2370 and the passage formed by the longitudinal bore 1830 of the valve member and the radial bore 1040 of the valve member, and flows into the second annular groove 1045 of the valve member, wherein the liquid fuel flows around the groove and flows into the annular matching fitting portion 922 and the annular matching fitting portion 924, where the liquid fuel is flow restricted, forming a liquid ring seal portion 825 (see Figure 4a ). The liquid ring seal 825 reduces and preferably prevents the flow of gaseous fuel from the gas fuel port passage 1380 from flowing into the annular groove 845 and out of the liquid fuel regulator 260 through the hole 940 and through the liquid fuel outlet passage 2480. The annular matching fit 922 and the annular matching fit 924 restrict the flow of fluid in all possible positions of the valve member 1810 within the hole 830 during operation. The liquid fuel within the annular matching fit 922 and the annular matching fit 924 also serves to lubricate the wall of the hole 830, thereby improving the ability of the valve member 1810 to move and slide within the hole. The annular matching fit 822 formed between the outer surface 1056 of the valve member 1810 and the bore wall 836 of the first longitudinal bore 830 serves as a valve member guide to improve the radial position of the valve member 1810 and the accuracy of the regulating valve 800, but in other embodiments, the annular matching fit 822 is not required.

[0070] exist Figure 4a , the regulating valve 800 is shown in a closed position, wherein the annular matching fit 824 restricts fluid flow through the regulating valve. The annular matching fit 824 is formed by an overlap between the outer surface 1056 of the valve member 1810 and the hole wall 836 of the hole 830 formed in the regulator body 810. Generally, when the valve member 1810 moves through the overlapping position range defined by the presence of the first annular matching fit 824, the regulating valve 800 has a closed position range, wherein, in the closed position, the cross-sectional flow area through the regulating valve 800 is less than a predetermined level. In an exemplary embodiment, the cross-sectional flow area through the regulating valve 800 is substantially constant within the closed position range, so that the closed position range can actually be referred to as a closed position. When the valve member 1810 moves through the closed position range, the axial length Lm (see Figure 4b ) (relative to the longitudinal axis 820) changes. Figure 4b Shows Figure 4aAn enlarged portion of the regulator 260 is shown, wherein the valve member 1810 is in an overlap position within a range of possible overlap positions, in which the matching fit 824 has a matching fit length Lm. The dashed arrow indicates that fluid flow is delivered through the inlet channel formed by the hole 1830 and the hole 1020 and the annular groove 1035 in the valve member 1810. In the exemplary embodiment, the matching fit 824 provides a constant flow area through the regulating valve when passing through the overlap position range, but this is not a requirement. In the closed position (i.e., within the overlap position range, where the length Lm of the matching fit 824 is greater than zero), the inlet channel formed by the hole 1830 and the hole 1020 and the annular groove 1035 in the valve member 1810 is indirectly fluidly connected to the outlet channel formed by the annular groove 845 and the hole 940 in the regulator body 810 through the matching fit 824. In the illustrated embodiment, when the valve member 1810 is slidably moved to the right, the length Lm of the mating fit portion 824 will decrease so that when the second groove side wall 1037b and the second groove edge 1038b of the groove 1035 (closest to the first groove side wall 847a and the first groove edge 848a of the groove 845) are laterally aligned with the first groove side wall 847a of the groove 845, and then move beyond the first groove side wall 847a of the groove 845, the mating fit portion disappears. Figure 7a and Figure 7b , the regulating valve 800 is shown in an open position, wherein the matching fit 824 is not present, and wherein, in the open position, the cross-sectional flow area through the regulating valve 800 is equal to or above a predetermined level. Generally, the regulating valve 800 has an open position range as the valve member 1810 moves through a zero overlap position range, the zero overlap position being defined by zero overlap between the outer surface 1056 of the valve member 1810 and the portion of the regulator body bore wall 836 of the bore 830 that forms the matching fit 824. In the illustrated embodiment, as the valve member 1810 continues to slidably move to the right, the regulating valve 800 has a variable cross-sectional flow area when open, such that the cross-sectional flow area through the regulating valve 800 changes as the valve member 1810 moves through the open position range, and the cross-sectional flow area through the regulating valve 800 increases as the valve member 1810 moves through the open position range and further away from the closed position. Referring to Figure 7b , the length L1 is the distance between the first groove side wall 1037a and the second groove side wall 847a along the axis 820 (see Figure 4a), the length L2 is the distance between the second groove sidewall 1037b and the first groove sidewall 847a along the axis 820, and the groove width Wg is the width of the annular groove 1035 between the first groove sidewall 1037a and the second groove sidewall 1037b along the axis 820. In the illustrated embodiment, when opened, as the second groove sidewall 1037b of the annular groove 1035 in the valve member 1810 moves further away (i.e., as Figure 7b The first groove sidewall 847a and the first groove edge 848a of the annular groove 845 in the longitudinal hole 830 of the regulator body (marked with the length L2 in the figure) increase the flow area through the regulating valve 800. In the illustrated embodiment, when there is Figure 7b As the slot 1035, whose slot width is represented by Wg, is slidably moved to the right, the length L1 decreases and the flow area of ​​the valve opening (as can be measured by the length L2) increases. The flow area through the regulating valve 800 is relatively significantly larger in any open position than in any closed position. In the open position of the regulating valve 800, the opening 1830 and the opening 1020 and the annular slot 1035 (see FIG. Figure 6 and Figure 7b ) The inlet passage formed in the valve member 1810 is in direct fluid communication with the outlet passage 840 formed in the regulator body 810 by the annular groove 845 and the hole 940. In other embodiments, it is possible that either or both of the valve member 1810 and the first longitudinal hole 830 have a tapered profile so that when the regulating valve 800 is closed, as the valve member 1810 moves toward the open position, the flow area through the matching fitting 824 into the annular groove 845 increases, but the rate of increase is much less than the rate of increase of the flow area in the open position.

[0071] In operation, when the pressure differential between the liquid fuel pressure in the liquid fuel rail 220 and the gaseous fuel pressure in the gaseous fuel rail 120 is too large, the liquid fuel pressure pushes the valve member 1810 in a direction that increases the flow area through the regulating valve 800 to increase the mass flow of the liquid fuel in the liquid fuel rail 210 to the liquid fuel discharge pipe 250. When the pressure differential is too low, the gaseous fuel pressure pushes the valve member 1810 in a direction that decreases the flow area through the regulating valve 800 to decrease the mass flow of the liquid fuel from the liquid fuel rail 220 into the liquid fuel discharge pipe 250.

[0072] Now refer to Figure 8, in another embodiment, a liquid fuel regulator 261 is shown, wherein components similar to the previous embodiment and to all embodiments disclosed herein have similar reference numerals and are not necessarily described in further detail. A liquid fuel inlet receiver 854 is radially positioned in the regulator body 811 relative to the longitudinal axis 820. Liquid fuel inlet coupling 2371 is similar to coupling 2370, except that the liquid fuel inlet coupling 2371 does not have a set screw therein. Set screw 2361 is threadedly received in bore 831 and performs the same Figure 4a 856 extends through the regulator body 811 between the receiver end 855 of the liquid fuel inlet receiver 854 and the first fluid pressure sensing chamber 957, which surrounds the end 1000 of the valve member 1811 (see FIG. 10A ). Fig. 9 ) is located in the hole 830. The hole 856 may include a flow restriction orifice 1856, or may be sized so that the hole 856 functions as a flow restriction orifice. The flow restriction orifice 1856 functions as a low pass filter between the first fluid pressure sensing chamber 957 and the upstream side of the regulating valve 800, whereby a sudden change in the flow through the regulating valve has a delayed effect on the fluid pressure in the first fluid pressure sensing chamber 957, making the transient response of the regulating valve 800 more stable and improved. The first fluid pressure sensing chamber 957 primarily includes an annular portion of the hole 830 adjacent to the fixing screw 2361, and an annular portion of the hole 830 adjacent to the reduced diameter portion 1051 of the valve member 1811; however, other spaces within the valve member 1811 and within the hole 830 that are in fluid communication with the first fluid pressure sensing chamber defined above and that are substantially free of flow restriction, such as the hole 1830, the hole 1030 and the hole 1040, and the second annular groove 1045 (at Fig. 9 830) and may also be considered part of the sensing cavity. Aperture 858 extends radially through the regulator body 811 between the receiver end 855 of the liquid fluid inlet receiver 854 and the longitudinal bore 830, such that the aperture 858 is in fluid communication with the annular groove 1035 and the regulating valve 800. In addition to the fact that the valve member 1811 does not have a bore 1020 extending from the annular groove 1035 to the bore 1830 (see FIG. Figure 6), and includes a reduced diameter portion 1051 at the end 1000 of the valve member 1811 and a portion extending radially from the outer surface of the reduced diameter portion 1051 to the outside of the hole 1030 of the hole 1830, the valve member 1811 is similar to the valve member 1810 (see Figure 6 ). Liquid fuel enters the first fluid pressure sensing chamber 957 radially from the liquid fuel inlet passage 1020 relative to the longitudinal axis 820 and the valve member 1811 (through the hole 856), and radially enters the annular groove 1035 (through the hole 858). Figure 4a ) is that the liquid fuel regulator 261 is more stable under transient conditions when the regulating valve 800 is adjusted. There are two reasons for the improved stability. First, the liquid fuel flowing through the regulating valve 800 from the liquid fuel inlet channel 2380 does not flow through the first fluid pressure sensing chamber 957. Also, the restricting orifice 1856 in the hole 856 between the first fluid pressure sensing chamber 957 and the regulating valve 800 acts as a low pass filter to filter any (higher) high frequency pressure fluctuations in the liquid fuel pressure in the liquid fuel inlet channel 2380. Due to these factors, when the regulating valve 800 overflows fuel from the liquid fuel inlet channel 2380 to the liquid fuel outlet channel 2480, the first fluid pressure sensing chamber 957 is exposed to less liquid fuel pressure fluctuations or noise. Therefore, the valve member 1811 more accurately senses the liquid fuel rail 220 (see Figure 1 ) and the liquid fuel pressure in the gas fuel rail 120 (see Figure 1 ) makes the operation of the liquid fluid regulator 261 more stable under steady-state and transient conditions.

[0073] Now refer to Fig.10 In another embodiment, a liquid fuel regulator 262 is shown. A liquid fuel inlet receiver 854 is radially positioned in the regulator body 812 relative to the longitudinal axis 820. A passage 857 extends through the regulator body 812 between the end 855 of the first fluid inlet receiver 854 and the longitudinal bore 831. In the illustrated embodiment, the passage 857 includes two intersecting bores; however, this is not a requirement, and in other embodiments, the passage 857 may include, for example, only a single bore. The passage 857 may include a flow restriction orifice 1857 (the function of the flow restriction orifice 1857 is the same as that of the flow restriction orifice 1856), or the passage 857 itself may be sized to function as a flow restriction orifice. The passage 857 leads to the bore 831 between the plug 1270 and the cylindrical set screw 2362, so that liquid fuel can flow from the liquid fuel inlet passage 2380 through the passage 857, the bore 831, and the set screw 2362 into the first fluid pressure sensing chamber 957. Similar to the liquid fuel regulator 260 (see Figure 4a) compared to the liquid fuel regulator 262, the liquid fuel regulator 262 has the same characteristics as the liquid fuel regulator 261 (see Figure 8 ), in that stability is improved because the liquid fuel flowing through the regulating valve 800 does not flow through the first fluid pressure sensing chamber 957, and the restricted orifice 1857 acts as a low pass filter to filter the (higher) high frequency pressure fluctuations in the liquid fuel inlet passage 2380. As the liquid fuel enters the first fluid pressure sensing chamber 957 longitudinally along the hole 830 (see Fig.10 ), so liquid fuel regulator 262 can be considered to be even more stable than liquid fuel regulator 261. Figure 8 In the illustrated embodiment of the liquid fuel regulator 261, the liquid fuel radially enters the first fluid pressure sensing chamber 957 along the hole 856, wherein the radial force of the liquid fuel acting on the valve member 1811 may cause the valve member to move radially, which may reduce the ability of the valve member to move longitudinally in response to the pressure difference between the first fluid pressure sensing chamber 957 and the second fluid pressure sensing chamber 968.

[0074] Now refer to Fig.11 In another embodiment, a liquid fuel regulator 263 is shown. The annular mating fitting 822 is sized by the outer diameter of the control valve member 1811 to provide a flow restriction ring 999 between the valve member 1811 and the first longitudinal bore 830, which is similar to Figure 8 The flow restriction orifice 1856 and Fig.10 The restricted flow orifice 1857 in the , operates as a low pass filter between the first fluid pressure sensing chamber 957 and the upstream side of the regulating valve 800. Fig.11 In the illustrated embodiment, the fluid flow through the restrictor ring 999, combined with the position of the valve member 1811, controls the fluid pressure in the first fluid pressure sensing chamber 957. Figure 8 The difference between the regulator body 811 in FIG. 8 is that the hole 856 (between the first fluid inlet receiver 854 and the first fluid pressure sensing chamber 957) is removed. Figure 8 ), and the regulator body 813 and Fig.10 The difference between the regulator body 812 in FIG. 8 is that the hole 857 (between the first fluid inlet receiver 854 and the hole 831) is removed. Fig.10 ).

[0075] Now refer to Fig.12 and Fig.13 In another embodiment, a liquid fuel regulator 264 is shown. The flow restriction orifice 1831 extends between the annular groove 1035 and the hole 1830 of the valve member 1812 and is respectively connected to Figure 8 , Fig.10 and Fig.11The flow restriction orifices 1856 and 1857 and the flow restriction ring 999 in the previous embodiment of the invention similarly act as a low pass filter between the first fluid pressure sensing chamber 957 and the upstream side of the regulating valve 800. Fig.12 In the illustrated embodiment of FIG. 2 , liquid fuel flows from inlet passage 2380 through restricted orifice 1831 and hole 1830 and hole 1030 into first fluid pressure sensing chamber 957. In other embodiments, hole 1830 may operate as a restricted orifice that restricts fluid flow into and out of first fluid pressure sensing chamber 957, and in these embodiments, orifice 1831 does not restrict flow relative to hole 1830. In other embodiments, hole 1030 and hole 1040 (in FIG. 2 ) may be connected to each other. Fig.13 1040) can be a flow restricting orifice, and in these embodiments, hole 1831 does not restrict flow relative to hole 1030 and hole 1040. When hole 1040 is used as a flow restricting orifice, hole 1040 operates as a low pass filter for liquid ring seal 825.

[0076] Now refer to Fig.14 , Fig.15 and Fig.16 In another embodiment, a liquid fuel regulator 265 is shown. The regulator body 814 includes a stepped longitudinal bore 834 (at Fig.15 ), the stepped longitudinal bore 834 has a first diameter portion 834a and a second diameter portion 834b, which receives the stepped valve member 1814, which has a first diameter portion 1814a and a second diameter portion 1814b. In the illustrated embodiment, the diameter 838 of the first diameter portion 834a is larger than the diameter 837 of the second diameter portion 834b, and the diameter 1058 of the first diameter portion 1814a is larger than the diameter 1057 of the second diameter portion 1814b, but in other embodiments that use different liquid fluids instead of liquid fluids and gaseous fluids, it is contemplated that the diameter of the first diameter portion 834a can be smaller than the diameter of the second diameter portion 834b, and the diameter of the first diameter portion 1814a can be smaller than the diameter of the second diameter portion 1814b (to be explained in more detail below). The stepped valve member 1814 is shown as a unitary member; however, in other embodiments, there may be two separate valve members having different diameters that abut each other, for example, the first diameter portion 1814a may be a unitary member and the second diameter portion 1814b may be a unitary member, wherein the first diameter portion 1814a is separate and distinct from the second diameter portion 1814b. Fig.16, the surface area of ​​the second end 1010 of the valve member 1814 is greater than the surface area of ​​the first end 1000 of the valve member 1814, so that when the difference between the first force generated by the gas fuel pressure acting on the second end 1010 and the second force generated by the liquid fuel pressure acting on the first end 1000 is less than or greater than a predetermined value, a force difference is established. In the illustrated embodiment, the surface area difference between the end 1010 and the end 1000 has the same effect as the spring 910 in the previous embodiment; that is, the surface area difference between the end 1010 and the end 1000 of the valve member 1814 determines a predetermined pressure difference between the liquid fuel pressure and the gas fuel pressure, and the liquid fuel regulator 265 is configured to maintain this pressure difference by overflowing the liquid fuel from the liquid fuel inlet passage 2380 to the liquid fuel outlet passage 2480. Generally, the liquid fuel pressure is greater than the gas fuel pressure because the purpose of the liquid fuel is to seal the gas fuel, and in this regard, the surface area of ​​the second end 1010 is greater than the surface area of ​​the first end 1000 so that the predetermined pressure difference between the liquid fuel and the gas fuel (i.e., the system bias pressure) is greater than zero. However, in other embodiments, when the pressure difference between the two liquids is controlled, it is conceivable that the surface area of ​​the second end 1010 can be smaller than the surface area of ​​the first end 1000. The passage 905 delivers the liquid fuel to the liquid ring seal 825 through the flow restriction orifice 1905 (used as a low-pass filter). Generally, any flow restriction orifice in the present disclosure can be replaced by sizing the conduit containing the flow restriction orifice accordingly. The passage 935 is used as a drain to discharge any liquid fuel overflowing from the liquid ring seal 825 or from the matching fitting 922 into the annular cavity 936 (note that when the annular groove 845 and the annular cavity 936 are at the same pressure, no fluid flows through the matching fitting 922). In the illustrated embodiment, the matching fitting 922 is used as a guide bearing for the valve member 1814 and is shown as having no lubrication source, but it is conceivable that in other embodiments, the matching fitting 922 can be lubricated by the liquid fuel supplied by the conduit through the flow restriction orifice.

[0077] Now refer to Fig.17 , shows an internal combustion engine 700 using a dual fuel system 10, wherein the rail injector 110 and the gas fuel rail 120 are shown, while other components of the dual fuel system are not shown. The engine 700 includes six cylinders 710, 720, 730, 740, 750, 760, in which corresponding pistons (not shown) reciprocate and are equipped with dual fuel injectors 712, 722, 732, 742, 752, 762. In other embodiments, the engine 700 may include less than or more than six cylinders. The dual fuel injectors 712, 722, 732, 742, 752, 762 are similar to Figure 12. Each dual fuel injector 712, 722, 732, 742, 752, 762 is connected to the gaseous fuel rail 120 via a corresponding fuel line 716, 726, 736, 746, 756, 766. Fig.17Other fluidic or electrical connections to these injectors are not shown, for example, fluidic connections to the liquid fuel rail 220 and the liquid fuel drain 250, or communication connections to the control unit 300 via the communication lines 350 and 352. In the illustrated embodiment, the fluid passing distance that the gaseous fuel from the rail injector 110 must travel to reach each dual fuel injector 712, 722, 732, 742, 752, 762 is different, but it is not required that all fluid passing distances be different, and in other embodiments, two or more fluid passing distances may be equal. The fluid passing distance D1 is the distance along the gaseous fuel rail 120 between the connection point of the fuel lines 716, 746 to the gaseous fuel rail and the gaseous fuel outlet 420 of the rail injector 110, wherein in the illustrated embodiment, the fuel line 716 and the fuel line 746 are connected at the same longitudinal point along the gaseous fuel rail. It is not required that two or more fuel lines connect at the same longitudinal point along the gas fuel rail 120, and in other embodiments, the longitudinal connection point may be different or unique for each fuel line. Fluid passing distance D2 is the distance along the gas fuel rail 120 between the connection point of fuel lines 726, 756 to the gas fuel rail and the gas fuel outlet 420, wherein in the illustrated embodiment, fuel line 726 and fuel line 756 connect at the same point along the gas fuel rail. Fluid passing distance D3 is the distance along the gas fuel rail 120 between the connection point of fuel lines 736, 766 to the gas fuel rail and the gas fuel outlet 420, wherein in the illustrated embodiment, fuel line 736 and fuel line 766 connect at the same point along the gas fuel rail. Fluid passing distance D4 is the distance along fuel line 716, which in the illustrated embodiment is also equal to the distance along fuel lines 726, 736. It is not required that any of the fuel lines 716, 726, 736, 746, 756, 766 have equal lengths. Fluid passing distance D5 is the distance along fuel line 746, and in the illustrated embodiment, this distance is also equal to the distance along fuel line 756, fuel line 766. The fluid passing distance between the dual fuel injector 712 and the rail injector 110 for fluid passing of gaseous fuel is equal to the sum of distance D1 and distance D4. Similarly, for the dual fuel injector 722, the fluid passing distance is equal to the sum of distance D2 and distance D4. For the dual fuel injector 732, the fluid passing distance is equal to the sum of distance D3 and distance D4. For the dual fuel injector 742, the fluid passing distance is equal to the sum of distance D1 and distance D5. For the dual fuel injector 752, the fluid passing distance is equal to the sum of distance D2 and distance D5. For the dual fuel injector 762, the fluid passing distance is equal to the sum of distance D3 and distance D5.

[0078] Whenever any of the dual fuel injectors 712, 722, 732, 742, 752, 762 is actuated to inject gaseous fuel, a pressure wave characterized by a forward wave valley is generated that travels along the corresponding fuel line 716, 726, 736, 746, 756, 766, toward, into, and along the gaseous fuel rail 120. Similarly, when the rail injector 110 is actuated, a pressure wave characterized by a forward wave peak is generated that travels along the gaseous fuel rail 120. Based on the fluid passing distance between the dual fuel injector and the rail injector, the timing of actuating the rail injector 110 can be coordinated with the timing of actuating each of the dual fuel injectors 712, 722, 732, 742, 752, 762 so that the pressure wave from the rail injector can meet the pressure wave of the dual fuel injector at a selected location between the injection valve 440 of the rail injector and the injection valve (not shown) of the dual fuel injector so that the pressure waves (1) cancel each other and reduce pressure fluctuations along the gas fuel rail 120 or pressure fluctuations within the dual fuel injector, or (2) combine to produce an increased pressure above the average pressure. For example, the pressure waves can meet at the connection point of the corresponding fuel line 716, 726, 736, 746, 756, 766 and the gas fuel rail 120. Alternatively, the pressure waves may meet at a gaseous fuel accumulator (not shown) within the respective dual fuel injectors, such that during injection of the gaseous fuel into the respective cylinders, the pressure change of the gaseous fuel near the injection valve of the dual fuel injector is reduced, or if the peak of the pressure wave from the rail injector 110 reaches the accumulator before the start of injection, the local pressure is increased before injection. When a (higher) average gaseous fuel rail pressure is used, it is advantageous to reduce the gaseous fuel pressure at the injection valve during injection, whereas when a (lower) average gaseous fuel rail pressure is used, it is advantageous to increase the gaseous fuel pressure at the injection valve before injection.

[0079] Gas fuel rail capacity 770( Fig.17 ) is the gaseous fuel volume defined by the gaseous fuel rail 120, fuel lines 716, 726, 736, 746, 756, 766, rail injector 110, and dual fuel injectors 712, 722, 732, 742, 752, 762. Figure 3 In the illustrated embodiment of FIG. 1 , the gaseous fuel volume in the rail injector 110 is the volume downstream of the injection valve 440, including the gaseous fuel annular passage 500 and the gaseous fuel annular passage 510. The gaseous fuel volume in the dual fuel injectors 712, 722, 732, 742, 752, 762 is the volume downstream of the corresponding gaseous fuel injection valve 28 (see FIG. Figure 1 ) upstream of the gas fuel injection valve 28 and the gas fuel inlet 26 (see Figure 1) between the gas fuel rail volume and the gas fuel rail volume, including channels and conduits and other possible volumes such as internal accumulators. Any gas fuel mass flow into and out of the gas fuel rail volume generates a pressure wave that travels through the gas fuel rail volume. For example, whenever any of the dual fuel injectors 712, 722, 732, 742, 752, 762 is actuated to inject gas fuel into the corresponding cylinder, thereby removing a bolus of fuel from the gas fuel rail volume 770, a pressure wave characterized by a forward wave valley is generated, which travels along the corresponding fuel line, toward the gas fuel rail 120, into the gas fuel rail 120, and along the gas fuel rail 120, and into other fuel lines, and reflects on surfaces encountered along the way. Similarly, when the rail injector 110 is actuated to inject gas fuel into the gas fuel rail volume 770, thereby adding a bolus of fuel to the gas fuel rail volume, a pressure wave characterized by a forward wave peak is generated, which travels along the gas fuel rail 120 and into the fuel line. When the engine 700 is operated, a series of continuous rail injector and dual fuel injector pressure waves are generated, and when these waves interact with each other within the gas fuel rail volume, the local pressure therein fluctuates. For example, when the peak of a first pressure wave interacts with the peak of a second pressure wave, the local pressure at the point of interaction increases. When the trough of the first pressure wave interacts with the trough of the second pressure wave, the local pressure at the point of interaction decreases. When the peak of the first wave interacts with the trough of the second wave, the first wave and the second wave will partially or completely cancel each other out, so that the local pressure change will be reduced or eliminated compared to the local pressure change caused by the peak or trough acting alone.

[0080] There are three locations within the gas fuel rail volume 770 where the local pressure has increased temporal significance compared to other locations within the gas fuel rail volume 770. The first location is at each gas fuel injection valve on the upstream side within the corresponding nozzle of the dual fuel injectors 712, 722, 732, 742, 752, 762, which are dual fuel injector locations in this document and where the local pressure has increased significance when the dual fuel injectors are injecting. It is desirable to have a local pressure increase above the average pressure in the gas fuel rail volume 770 at the dual fuel injector locations to increase the injection pressure and therefore the injection rate. The injection rate is determined by the pressure differential within the dual fuel injector and the pressure within the cylinder when the injectors are injecting. Increasing the local pressure at the time of injection also allows the average pressure in the gas fuel rail volume 770 to be reduced while still maintaining the desired injection rate, which reduces the amount of fuel from the cryogenic pump (not shown) to the pressurized supply 60 (see Figure 1) to pump the gas fuel in liquefied form through a heat exchanger (not shown). As an example, if the required local pressure at the first position (dual fuel injector position) is 280 bar to achieve the desired injection rate, the average pressure in the gas fuel rail volume 770 may be 250 bar, and by timing the arrival of the crest of the pressure wave at injection, the local pressure at injection may be increased to 280 bar. For a system where the cryogenic pump (indirectly) pressurizes the gas fuel rail volume 770 to 250 bar instead of 280 bar, the parasitic energy savings are significant, and the reliability cost of such a cryogenic pump is significantly lower than a cryogenic pump that must pressurize to 280 bar. In other embodiments, the required local pressure at the first position may be in the range of 150 bar to 290 bar, and the average pressure in the gas fuel rail volume 770 may be in the range of 160 bar to 350 bar. In other embodiments, the desired local pressure at the first location may be in the range of 150 bar to 470 bar, and the average pressure in the gaseous fuel rail volume 770 may be in the range of 160 bar to 550 bar. As another advantage, the technique allows the internal combustion engine to achieve desired emission targets and efficiency targets at a lower parasitic energy cost.

[0081] The second location where the local pressure has increased temporal significance is the location where the pressure sensor 125 measures the pressure within the gaseous fuel rail volume 770 at the time of the pressure sampling, herein the pressure sensor location. It is desirable for the pressure sensor to sample the actual average pressure in the gaseous fuel rail volume 770 to avoid the delay associated with sampling the local pressure at the second location that has been changed up or down by one or more pressure waves. For example, when the local pressure at the second location has not been changed by one or more pressure waves, then the sampled pressure is the average pressure in the gaseous fuel rail volume 770, and the pressure sensor 125 (see Figure 1 ) can measure the pressure in a sample and send the measured value to the control unit 300 (see Figure 2 ), and the control unit 300 may then use the measurements to control the operation of the dual fuel system and the engine 700. Alternatively, when the local pressure is varied by one or more pressure waves, then to determine the average pressure in the gaseous fuel rail volume 770, the control unit 300 may need to receive multiple measurements from the pressure sensor 125 over multiple sampling periods, and then process these measurements to mathematically determine the average pressure in the gaseous fuel rail volume.

[0082] A third location where the local pressure has increased temporal significance is the outlet of the rail injector 110, herein the rail injector location, and where the local pressure has increased significance as the rail injector injects into the gas fuel rail volume 770. It is desirable that the local pressure at the third location be less than the average pressure in the gas fuel rail volume 770 to reduce the average pressure required in the pressurized supply 60 to inject a bolus of fuel into the gas fuel rail volume. This technique has similar advantages to those associated with the dual fuel injector location, namely energy savings by reducing the work required of the cryogenic pump, increased reliability, and lower cost.

[0083] Actuation of the rail injector 110 is controlled by the control unit 300 to achieve desired local pressure conditions in the first position, the second position, and the third position. For example, the injection timing of the rail injector 110 and the fuel bolus injected by the rail injector can be adjusted to achieve the desired local pressure. For each of the first position, the second position, and the third position, the injection timing of the rail injector 110 and the fuel bolus injected by the rail injector 110 can be determined according to the distance of the rail injector from the first position, the distance of the rail injector from the second position, and the distance of the rail injector from the third position, respectively. In addition, the injection timing of the rail injector 110 and the fuel bolus injected by the rail injector 110 can be determined according to the injection timing of each of the dual fuel injectors 712, 722, 732, 742, 752, 762 or the fuel bolus injected by each of the dual fuel injectors 712, 722, 732, 742, 752, 762, respectively. Additional pressure sensors that sense pressure at the first, second, and third locations may be used to send signals representative of local pressures at the first, second, and third locations to the control unit 300 , and the control unit may use these local pressure measurements to determine injection timing for the rail injector 110 .

[0084] Now refer to Fig.18, shows a dual fluid system 11 according to another embodiment, which, among other functions, regulates the pressure of a first fuel and the pressure differential between a second fuel and the first fuel. An electronic forward pressure regulator 90 regulates the gas fuel rail pressure in a gas fuel rail 120 by varying the flow area through the regulator according to the gas fuel supply pressure in the conduit 100 and the desired gas fuel rail pressure. The electronic forward pressure regulator 90 includes a valve (not shown) having a variable flow area therethrough, and the valve can be balanced relative to the gas fuel supply pressure so that the solenoid for opening the valve to a variable position does not need to resist the entire force of the gas fuel supply pressure acting on the valve, but only needs to resist the spring for biasing the valve to the closed position. This greatly reduces the size of the electromagnet in the pressure regulator 90. In operation, the valve in the pressure regulator 90 can be used to generate a pressure wave similar to the rail injector 110 by opening or closing the valve in a variable manner to produce a pressure wave with a leading wave peak or a leading wave trough in the gas fuel rail 120.

[0085] exist Figure 4a-Figure 7b , Figure 8-Figure 11 , Figure 12-13 and Figure 14-16 In the illustrated embodiment of FIG. 8 , the regulating valve 800 can be described as an edge valve or a curtain valve, wherein the opening of the regulating valve 800 is like a curtain opening for letting light in, and the wider the curtain opens, the more light enters. Figure 4a and Figure 4b (for Figure 8-Figure 11 , Figure 12-13 and Figure 14-16 When the annular side wall 1037b radially overlaps the annular side wall 847a relative to the axis 820, or is on the left side of the annular side wall 847a (i.e., the annular side wall 1037b is closer to the liquid fuel receiver 852 than the annular side wall 847a), the regulating valve 800 can be considered to be closed, so that the matching fitting portion 824 exists, and the liquid fuel rail 220 and the liquid fuel discharge pipe 250 (see Figure 1 ) is restricted by the cross-sectional flow area through the mating fitting 824. Figure 7a and Figure 7b When the annular side wall 1037b moves to the right of the annular side wall 847a along the axis 820 (i.e., the annular side wall 1037b is closer to the gas fuel receiver 862 than the annular side wall 847a), the matching fitting 824 disappears, and the regulating valve 800 can be considered to be open and in one of the multiple open positions, whereby the flow between the liquid fuel rail 220 and the liquid fuel discharge pipe 250 is controlled by the annular surface 849 (see Figure 7b), the annular surface 849 is located between the groove edge 1038b and the groove edge 848a, and as the annular sidewall 1037b moves more and more to the right away from the sidewall 847a, the cross-sectional flow area through the annular surface 849 increases. The valve gain can be defined as the ratio between the cross-sectional flow area through the regulating valve 800 in one of the multiple open positions (defined by the cross-sectional flow area through the surface 849) and the cross-sectional flow area through the regulating valve 800 when closed (defined by the cross-sectional flow area through the matching fitting 824). The valve gain is adjustable in at least a portion of the multiple open positions of the regulating valve 800, wherein the valve gain increases as the flow area through the annular surface 849 increases as the annular sidewall 1037b moves further away from the annular sidewall 847a toward the gas fuel receiver 862. The valve gain of the regulating valve 800 can be characterized as a function of the position of the valve member 1810 along the longitudinal axis 820 of the longitudinal bore 830, wherein the valve gain varies between a closed position of the regulating valve 800, in which the cross-sectional flow area through the regulating valve 800 is at a low value (defined by the cross-sectional flow area through the mating fitting 824), and a fully open position of the regulating valve 800, in which the cross-sectional flow area through the regulating valve 800 is at a high value (defined by the cross-sectional flow area through the annular surface 849). The low value of the cross-sectional flow area through the regulating valve 800 can be a minimum value, and the high value of the cross-sectional flow area can be a maximum value. Likewise, as the valve member 1810 moves from the closed position toward the fully open position, the cross-sectional flow area through the annular surface 849 increases. In an exemplary embodiment, the valve gain function is nonlinear, but this is not a requirement. In some cases, the valve gain may increase significantly as the valve member 1810 travels a relatively short distance along the longitudinal axis 820, such that within the relatively short distance, the magnitude of the first derivative of the valve gain function may have a relatively large value (i.e., the rate of increase of the valve gain of the regulating valve 800 may be excessive relative to the position of the valve member 1810 along the axis 820). Large changes in valve gain within a short distance of the valve member 1810 along the axis 820 may reduce the ability of the regulating valve 800 to ideally regulate the liquid fuel in the liquid fuel rail 220 and the gaseous fuel rail 120 (see Figure 1) and may result in an undesirable response of the control system of the regulating valve 800. For example, the undesirable response of the control system may be an undesirable underdamped response, a slightly stable response, or an unstable response. In these cases, various features in the regulating valve 800 may be employed to reduce the magnitude of the first-order derivative of the valve gain function (particularly within a relatively short travel distance of the valve member 1810 along the longitudinal axis 820, where the valve gain increases significantly), which may have a stabilizing effect on the ability of the regulating valve 800 to regulate the pressure differential. It is worth noting that in those cases where the valve gain in the fully open position is too small or the rate of increase of the valve gain between the closed position and the fully open position is too small, the response of the control system of the regulating valve 800 may be an undesirable overdamped response.

[0086] Reference Fig.19 , now discussing the first feature, which can reduce the rate of increase of the valve gain of the regulating valve 800 when it is opened. The matching fit portion 824b between the outer surface 1056 of the valve member 1810b and the bore wall 836 of the regulator body 810b includes a tapered profile, and at least a portion of the matching fit portion 824b includes a tapered profile, whereby the matching fit portion 824b is a tapered matching fit portion, so that when the valve member 1810 moves to the right along the axis 820, the flow area through the matching fit portion 824b increases. In the illustrated embodiment, the valve member 1810b includes an annular tapered portion 1061 that tapers radially outwardly relative to the axis 820 between the edge 1038b and the edge 1039b. In addition or alternatively, the bore wall 836 may include an annular tapered portion 1062 that tapers radially outwardly relative to the axis 820 between the edge 1039a and the edge 848a. In other embodiments, the mating fitting portion 824b may include one of the annular tapered portion 1061 or the annular tapered portion 1062, but not both. In the illustrated embodiment, when the valve member 1810b moves rightward toward the open position of the regulating valve 800b, the rate of increase of the valve gain is reduced by increasing the cross-sectional flow area through the mating fitting portion 824b. The first feature may be used for all embodiments of the regulating valve 800 disclosed herein.

[0087] Reference Fig. 20, now discuss the second feature, which can reduce the rate of increase of the valve gain of the regulating valve 800 when it is opened. The edge 1038b can be defined by a fillet, a bevel, or a chamfer to introduce a gentle transition between the outer surface 1056 of the valve member 1810c and the annular sidewall 1037b. In the illustrated embodiment, the edge 1038b is a fillet, which can be defined as a circular edge with a radius R1. The radius R1 of the fillet can be selected to correspondingly adjust the rate of increase of the valve gain as the valve member 1810c moves to the right when the regulating valve 800c is opened. In addition or alternatively, the edge 848a can be defined by a fillet, a bevel, or a chamfer to introduce a gentle transition between the hole wall 836 and the annular sidewall 847a. In the illustrated embodiment, the edge 848a is a fillet having a radius R2, which is selected to adjust the rate of increase of the valve gain as the valve member 1810c moves to the right when the regulating valve 800c is opened. In other embodiments of the regulating valve 800c, the edge 1038b may be defined as a radius, bevel, or chamfer, or the edge 848a may be defined as a radius, bevel, or chamfer, but the edge 1038b and the edge 848a are not defined as radiuses, bevels, or chamfers at the same time. In the illustrated embodiment, the rate of increase of the valve gain is reduced by increasing the cross-sectional flow area through the mating fit portion 824c, wherein in the illustrated embodiment, as the valve member 1810c moves rightward toward the open position of the regulating valve 800c, the cross-sectional flow area through the mating fit portion 824c begins to increase as the front portion 1041 of the edge 1038b overlaps the front portion 851 of the edge 848a. In embodiments where one or both of the edge 1038b and the edge 848a are beveled or chamfered, similar to Fig.19 1061 and 1062. The second feature may be used in all embodiments of the regulating valve 800 disclosed herein.

[0088] Now refer to Fig.21 and Fig. 22 Now, the third feature is discussed, which can reduce the rate of increase of the valve gain of the regulating valve 800 when it is opened. The outlet hole 940 extends directly to the hole wall 836 of the regulator body 810d (ie, Figure 4a The annular groove 845 shown in the figure is removed), thereby forming an opening 945 in the hole wall 836. In the exemplary embodiment, the outlet hole 940 is cylindrical, and thus the opening 945 is also cylindrical (at least the projection of the opening 945 along the longitudinal axis of the outlet hole 940 onto a plane at right angles to the longitudinal axis of the outlet hole 940 is cylindrical), but this is not a requirement. Further reference is made to Fig.23In the illustrated embodiment, as the valve member 1810 moves to the right, when the annular groove 1035 overlaps with the opening 945 to form the opening surface 849d, the regulating valve 800d opens, and the cross-sectional flow area through the regulating valve 800d is limited by the opening surface 849d. The regulating valve 800d may be referred to as an orifice valve. Further reference is made to Fig.24 and Fig.25 As the valve member 1810 continues to move to the right, the annular groove 1035 increasingly overlaps with the opening 945, thereby increasing the cross-sectional flow area through the regulating valve 800d defined by the opening surface 849d. When the cross-sectional flow area through the opening surface 849d of the regulating valve 800d increases to exceed a limiting value, which depends on the relative size of the outlet hole 940 or the relative size of other passages upstream of the regulating valve 800d, the flow of liquid fluid through the regulating valve 800d may be affected by the size of the outlet hole 940 or other passages upstream of the regulating valve 800d (such as Fig.21 In contrast, referring back to Figure 7a and Figure 7b In the control valve 800 of FIG. 800 , when the control valve 800 is opened after the matching fitting portion 824 disappears, the cross-sectional flow area through the control valve is limited by the flow area through the annular surface 849, and the flow area through the annular surface 849 is generally larger than the flow area through the annular surface 849 when the control valve 800d is opened. Fig.23 , Fig.24 and Fig.25 The cross-sectional flow area of ​​the opening surface 849d shown in FIG. 8 is such that the rate of increase of the valve gain of the regulating valve 800d is less than the rate of increase of the valve gain of the regulating valve 800. Additionally or alternatively, in other embodiments, the annular groove 1035 may be removed, and the hole 1020 may extend directly to the outer surface 1056 of the valve member 1810, so that when the hole 1020 and the outlet hole 940 overlap, the regulating valve 800d opens. The third feature may be used for all embodiments of the regulating valve 800 disclosed herein.

[0089] Now refer to Fig.26 , Fig. 27 and Fig.28 , now discussing the fourth feature, which can reduce the rate of increase of the valve gain of the regulating valve 800 when it is opened. The valve member 1810e includes a recess 1042 in the annular side wall 1037b, the recess 1042 extending radially inward from the outer surface 1056, and the recess 1042 extends semi-annularly around a portion of the annular side wall 1037b relative to the axis 820. When the semi-annular side wall 1043 of the recess 1042 moves to the right side of the annular side wall 847a of the annular groove 845, the regulating valve 800e opens, thereby defining a semi-annular surface 849e between the edge 1044 of the recess 1042 and the edge 848a of the annular groove 845 (see Fig. 27 Before the annular side wall 1037b moves to the right side of the annular side wall 847a, the cross-sectional flow area of ​​the semi-annular surface 849e is smaller than Figure 7b The value of the cross-sectional flow area of ​​the annular surface 849 shown in FIG. 1 is effective to reduce the rate of increase of the valve gain of the regulating valve 800e compared to the valve gain of the regulating valve 800 when the corresponding valve is opened. Although the recess 1042 is shown as having a substantially square or rectangular shape, this is not a requirement, and in other embodiments, the recess 1042 may have other shapes including one or more curved surfaces and / or one or more inclined surfaces, and the semi-annular surface 849e generally limits the cross-sectional flow area entering the annular groove 845 through the recess 1042. Alternatively or in addition, in other embodiments, the regulating valve 800e may include a recess in the annular sidewall 847a of the regulator body 810e, or one or more recesses in the annular sidewall 1037b and / or the annular sidewall 847a. The fourth feature may be used for all embodiments of the regulating valve 800 disclosed herein. In other embodiments, two or more of the first feature, the second feature, the third feature, and the fourth feature may be combined to reduce the rate of increase of the valve gain of the regulating valve 800.

[0090] While particular elements, embodiments, and applications of the present invention have been shown and described, it will be appreciated that the invention is not limited thereto since modifications may be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the above teachings.

Claims

1. A pressure regulator (260, 261, 262, 263, 264, 265), the pressure regulator (260, 261, 262, 263, 264, 265) being used to adjust a pressure difference between a first fluid pressure of a first fluid and a second fluid pressure of a second fluid, the pressure regulator comprising: a valve (800) between a regulator body (810, 811, 812, 813, 814) and a valve member (1810, 1811, 1812, 1814); The regulator body (810, 811, 812, 813, 814) includes: a first fluid inlet (850), the first fluid inlet (850) being used for the first fluid; A first fluid outlet (840) is provided for the First fluid; a second fluid port (860), the second fluid port (860) being used for the second fluid; a first longitudinal bore (830, 834) defined by a first bore wall (836) in the regulator body, the first longitudinal bore (830, 834) extending between the first fluid inlet (850) and the second fluid port (860); and an outlet passage (940), the outlet passage (940) extending outwardly from the first hole wall (836) to the first fluid outlet (840); The valve (800) is in fluid communication with the first fluid inlet (850) at an inlet side of the valve, and the valve (800) is in fluid communication with the first fluid outlet (840) at an outlet side of the valve (800); The valve member (1810) is movably disposed in the first longitudinal hole (830) of the regulator body (810, 811, 812, 813, 814), the valve member (1810) being located between a first fluid pressure sensing cavity (957, 958) and a second fluid pressure sensing cavity (968), the first fluid pressure sensing cavity (957, 958) being in fluid communication with the first fluid inlet (850), and the second fluid pressure sensing cavity (968) being in fluid communication with the second fluid port (860); Wherein the valve is movable between a closed position in which a cross-sectional flow area through the valve is below a predetermined level and an open position in which a cross-sectional flow area through the valve is above the predetermined level.

2. The pressure regulator according to claim 1, wherein: In the closed position, the valve member (1810) is movable within an overlapping position range, and in the open position, the valve member (181) is movable within a zero overlapping position range to maintain a pressure difference between the first fluid and the second fluid within a predetermined range; within the overlapping position range, the first fluid inlet (850) is fluidically connected to the outlet channel (940) in the regulator body (810, 811, 812, 813, 814) through a first matching fitting portion (824), and the first matching fitting portion (824) is formed between an outer surface (1056) of the valve member (1810) and the first hole wall (836) of the regulator body (810, 811, 812, 813, 814); and within the zero overlapping position range, the first fluid inlet (850) is fluidically connected to the outlet channel (940), so that as the valve member (1810) moves further away from the overlapping position range, the cross-sectional flow area through the valve (800) increases.

3. The pressure regulator according to claim 2, wherein: The cross-sectional flow area through the valve (800) is substantially constant as the valve member (1810) moves through the range of overlapping positions.

4. The pressure regulator according to claim 2 or 3, wherein: At least one of the first longitudinal hole (830) and the valve member (1810) is tapered so that the cross-sectional flow area through the valve (800) increases as the valve member (1810) moves through the overlap position range toward the zero overlap position range, wherein the rate of increase of the cross-sectional flow area within the overlap position range is less than the rate of increase of the cross-sectional flow area within the zero overlap position range.

5. The pressure regulator according to any one of claims 2 to 4, wherein the regulator body (811, 812, 813, 814) further comprises an annular groove (845), wherein the annular groove (845) is in the first hole wall (836) of the regulator body, and the outlet channel (940) extends from the annular groove (845) to the first fluid outlet (840), wherein: Within the overlapping position range, the first fluid inlet (850) is indirectly fluidically connected to the annular groove (845) through the first matching fitting portion (824) between the valve member (1810, 1811, 1812, 1814) and the regulator body (810, 811, 812, 813, 814); and within the zero overlapping position range, the first fluid inlet (850) is directly fluidically connected to the annular groove (845).

6. According to the pressure regulator of any one of claims 2 to 5, the valve member (1810) further comprises a first annular groove (1035) in the outer surface (1056) of the valve member (1810), a first end (1000) of the valve member (1810) in the first fluid pressure sensing chamber (957, 958), a second end in the second fluid pressure sensing chamber (968), and a first channel (1830 / 1020) extending from the first end (1000) of the valve member to the first annular groove (1035), wherein: Within the overlapping position range, the first annular groove (1035) is indirectly fluidically connected to the outlet channel (940) via the first matching fitting portion (824), and within the zero overlapping position range, the first annular groove (1035) is directly fluidically connected to the outlet channel (940).

7. A pressure regulator according to any one of claims 2 to 6, further comprising a first fluid ring seal (825), wherein the first fluid ring seal (825) is between the valve member (1810, 1811, 1812, 1814) and the regulator body (810, 811, 812, 813, 814), and the first fluid ring seal (825) is between the first fluid outlet (840) and the second fluid port (860), and the first fluid ring seal (825) restricts the flow of the second fluid from the second fluid port (860) to the first fluid outlet (840).

8. The pressure regulator of claim 7, further comprising a second passage (1830 / 1040) between the first end (1000) of the valve member (1810) and the first fluid ring seal (825).

9. The pressure regulator according to claim 8, wherein the valve member (1810) further comprises a second annular groove (1045), wherein the second annular groove (1045) is in the outer surface (1056) of the valve member (1810), and the second channel (1830 / 1040) extends between the first end (1000) of the valve member (1810) and the second annular groove (1045), wherein: The first fluid ring seal (825) extends between the second annular groove (1045) and the bore wall (836) of the regulator body (810, 811, 812, 813, 814).

10. The pressure regulator according to any one of claims 2 to 9, wherein the regulator body (810, 811, 812, 813, 814) further comprises an annular groove (845), wherein the annular groove (845) is in the first hole wall (836), and the outlet channel 940 extends from the annular groove (845) to the first fluid outlet (840); the valve member (1810) further comprises a first annular groove (1035) formed in the outer surface (1056) of the valve member (1810), a first end (1000) of the valve member in the first fluid pressure sensing cavity (957, 958), a second end (1010) of the valve member in the second fluid pressure sensing cavity (968), and a channel (1830 / 1020) extending from the first end (1000) of the valve member to the first annular groove (1035); in, Within the overlapping position range, the first annular groove (1035) of the valve member is indirectly fluidically connected to the annular groove (845) of the regulator body through the first matching fitting portion (824), and within the zero overlapping position range, the first annular groove (1035) of the valve member is directly fluidically connected to the annular groove (845) of the regulator body.

11. The pressure regulator according to claim 10, the valve member (1810) further comprising: a second annular groove (1045) in the outer surface (1056) of the valve member between the first fluid outlet (840) and the second fluid port (860), and a second passage (1830 / 1040), the second passage (1830 / 1040) being between the first end (1000) of the valve member (1810) and the second annular groove (1045); Wherein, the first fluid ring seal portion (825) extends between the second annular groove (1045) and the regulator body (810, 811, 812, 813, 814).

12. A pressure regulator according to any one of claims 2 to 11, further comprising a first fluid inlet connector (2370), the first fluid inlet connector (2370) being received mutually in the first fluid inlet, the first fluid inlet connector comprising a fixing screw (2360), the fixing screw (2360) being used to adjust the hard stop position of the valve member (1810).

13. A pressure regulator according to any one of claims 2 to 12, wherein the pressure regulator further comprises a second fluid connector (1370) and a spring (910), wherein the second fluid connector (1370) are received mutually in the second fluid port, the spring (910) is between the second fluid connector (1370) and the valve member (1810), the spring biases the valve member (1810) toward the overlapping position range, and the second fluid connector comprises a fixing screw (1360) for adjusting the preload on the spring (910).

14. The pressure regulator according to any one of claims 2 to 13, wherein: The first fluid inlet (850) includes a sealing surface (950), and the second fluid port (860) includes a sealing surface (960).

15. The pressure regulator according to any one of claims 2 to 14, further comprising: a first fluid inlet coupling (2370, 2371), the first fluid inlet coupling (2370, 2371) comprising a sealing surface (2386), and the first fluid inlet coupling (2370, 2371) being received in the first fluid inlet so that a first seal (2384) is formed between the sealing surface (950) of the first fluid inlet and the sealing surface (2386) of the first fluid inlet coupling (2370, 2371); and A second fluid coupling (1370), the second fluid coupling (1370) including a sealing surface (1386), and the second fluid coupling (1370) is received mutually in the second fluid port so that a second sealing portion (1384) is formed between the sealing surface (960) of the second fluid port and the sealing surface of the second fluid port coupling.

16. The pressure regulator (260, 261, 262, 263, 264, 265) according to claim 15, wherein: The sealing surface (2386) of the first fluid inlet connector (2370, 2371) is one of a truncated conical surface, a spherical surface, a parabolic surface, an elliptical surface and a hyperbolic surface; and / or the sealing surface (1386) of the second fluid connector (1370) is one of a truncated conical surface, a spherical surface, a parabolic surface, an elliptical surface and a hyperbolic surface.

17. A pressure regulator (260, 261, 262, 263, 264, 265) according to any one of claims 2 to 16, the pressure regulator (260, 261, 262, 263, 264, 265) further comprising a first fluid outlet connector (2470) and an annular sealing member (2440), the first fluid outlet connector (2470) being mutually received in the first fluid outlet (840), the annular sealing member (2440) being arranged between the first fluid outlet (840) and the first fluid outlet connector (2470) and surrounding the outlet passage of the regulator body (810, 811, 812, 813, 814), wherein: The annular sealing member (2440) forms a seal (2444) between the regulator body (810, 811, 12, 813, 814) and the first fluid outlet coupling (2470).

18. The pressure regulator (260, 261, 262, 263, 264, 265) according to any one of claims 2 to 17, wherein: The valve member (1810) moves to adjust the flow of the first fluid between the first fluid inlet (850) and the first fluid outlet (840) by changing the cross-sectional flow area through the valve (800) to maintain the pressure differential within a predetermined range.

19. The pressure regulator (265) according to any one of claims 2 to 18, wherein: The valve member (1814) is a stepped valve member (1814; 1814a, 1814b), and the first longitudinal hole (834) is a stepped longitudinal hole (834a, 834b), the stepped valve member includes a first valve member portion (1814a) having a first valve member diameter (1058) and a second valve member portion (1814b) having a second valve member diameter (1057), the stepped longitudinal hole (834) includes a first longitudinal hole portion (834a) having a first longitudinal hole diameter (838) and a second longitudinal hole portion (834b) having a second valve member diameter (1057). The first valve member diameter (1058) is larger than the second valve member diameter (1057), and the first longitudinal hole diameter (838) is larger than the second longitudinal hole diameter (837), so that the first part (1814a) and the second part (1814b) of the stepped valve member (1814) reciprocate in the first part (834a) and the second part (834b) of the stepped longitudinal hole (834), respectively.

20. The pressure regulator of claim 1, wherein: The valve is a curtain valve.

21. The pressure regulator of claim 20, wherein: The valve (800) includes a valve gain, which is characterized as a function of the position of the valve member (1810) along the longitudinal axis (820) of the longitudinal bore (830), wherein the valve gain varies between the closed position of the valve (800) and the fully open position of the valve, wherein the cross-sectional flow area through the valve is at a low value, and the fully open position of the valve, wherein the cross-sectional flow area through the valve is at a high value, and the valve (800) also includes a feature for reducing the rate of increase of the valve gain when the valve is opened.

22. The pressure regulator of claim 21, wherein: The feature includes a tapered mating fit that restricts the cross-sectional flow area through the valve.

23. The pressure regulator of claim 21, wherein: The valve comprises a first annular groove in the valve member and a first annular edge associated with the first annular groove, and the feature comprises the first annular edge having a fillet, bevel or chamfer; or The valve includes a second annular groove in the regulator body and a second annular edge associated with the second annular groove, and the feature includes the second annular edge having a radius, bevel, or chamfer.

24. The pressure regulator of claim 21, wherein: The valve comprises a first annular groove in the valve member, the first annular groove comprising a first annular sidewall and a second annular sidewall, the feature comprising a recess in the second annular sidewall; or The valve includes a second annular groove in the regulator body, the second annular groove including a first annular sidewall and a second annular sidewall, the feature including a notch in the second annular sidewall of the second annular groove.

25. The pressure regulator of claim 24, wherein: The recess includes at least one of a flat surface and a curved surface.

26. The pressure regulator of claim 1, wherein: The valve is an orifice valve.

27. The pressure regulator according to any one of claims 1 to 26, wherein: The first fluid has a higher viscosity than the second fluid.

28. The pressure regulator according to any one of claims 1 to 27, wherein: The first fluid is a liquid and the second fluid is a gaseous state.

29. The pressure regulator according to any one of claims 1 to 28, wherein: The first fluid is a liquid fuel and the second fluid is a gaseous fuel.

30. The pressure regulator according to any one of claims 1 to 29, wherein: The first fluid has a higher cetane number than the second fluid.

31. The pressure regulator according to any one of claims 1 to 30, wherein: The first fluid is selected from diesel, dimethyl ether or liquefied petroleum gas; and / or the second fluid is selected from methane, hydrogen, air, synthesis gas, natural gas or a mixture thereof.

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