Gas fuel-air mixer with high mixing uniformity

Abstract

A gas fuel-air mixer includes an outer shell, an inner shell, and a fuel chamber rib. The outer shell includes an air inlet and a fuel inlet. The air inlet is configured to receive air. The air inlet has an air outlet. The fuel inlet has a fuel inlet configured to receive fuel. The inner shell includes an inner shell inlet, which is configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and provide a gas fuel-air mixture. The inner shell and the outer shell cooperate to define a fuel inlet collection chamber and a fuel inlet concentrating chamber. The fuel inlet collection chamber is configured to receive fuel from the fuel inlet, and the fuel inlet concentrating chamber is configured to receive fuel from the fuel inlet collection chamber and provide the fuel to the inner shell inlet.

Description

[0001] Cross-references to Related Patent Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 057,414, filed on July 28, 2020, entitled “GASEOUS FUEL-AIR MIXER WITH HIGHERMIXTURE UNIFORMITY,” the contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates generally to gaseous fuel-air mixers for internal combustion engines.

[0004] background

[0005] For an internal combustion engine with a turbocharger, fuel is mixed with air at an introduction point upstream of the turbocharger's compressor inlet. This introduction can cause the fuel's pressure to drop. Different fuels have different pressure drops between their supply pressure (e.g., upstream of the introduction point) and the pressure of the fuel when mixed with the air upstream of the compressor inlet. When this pressure drop exceeds a threshold (e.g., when the supply pressure is significantly greater than the pressure of the fuel when mixed with the air upstream of the compressor inlet, etc.), the internal combustion engine may not be able to burn the fuel optimally (e.g., due to de-rating, etc.). Additionally or alternatively, introducing the fuel into the air may not result in ideal mixing of the fuel and air. As a result, fuel bubbles may be dispersed in the airstream. Due to the different density of fuel compared to air, these fuel bubbles may undesirably impact downstream components, such as the compressor impeller (e.g., due to fatigue).

[0006] In order for an engine to achieve the same power output when using a fuel with a relatively low calorific value as when using a fuel with a higher calorific value, a larger volume of the fuel with a relatively low calorific value must be consumed than the fuel with a higher calorific value. To ensure ideal combustion of the fuel in a system with an internal combustion engine and to account for the pressure drop in the system, the fuel supply pressure may be increased. In some cases, the fuel supply pressure cannot be increased ideally (e.g., due to cost, feasibility, etc.), making ideal combustion of the fuel difficult or impossible.

[0007] Overview

[0008] In one set of embodiments, a gas fuel-air mixer includes an outer shell, an inner shell, and a fuel chamber rib. The outer shell includes an air inlet and a fuel inlet. The air inlet is configured to receive air. The air inlet has an air outlet. The fuel inlet has a fuel inlet configured to receive fuel. The inner shell includes an inner shell inlet, which is configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and provide a gas fuel-air mixture. The inner shell cooperates with the outer shell to define a fuel inlet collection chamber and a fuel inlet concentration chamber, the fuel inlet collection chamber being configured to receive fuel from the fuel inlet, and the fuel inlet concentration chamber being configured to receive fuel from the fuel inlet collection chamber and provide fuel to the inner shell inlet. The fuel chamber rib is coupled to at least one of the outer shell or the inner shell. The fuel chamber rib is disposed within at least one of the fuel inlet collection chamber or the fuel inlet concentration chamber.

[0009] In some embodiments, at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered on a central axis; the fuel inlet collecting chamber extends annularly around the central axis; and the fuel chamber rib extends within the fuel inlet collecting chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet collecting chamber.

[0010] In some embodiments, the fuel inlet concentrating chamber extends annularly around the central axis; and the fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

[0011] In some embodiments, the outer shell is integrally formed with the inner shell.

[0012] In some embodiments, the fuel chamber ribs are integrally formed with the outer shell and the inner shell.

[0013] In some embodiments, the fuel chamber ribs are integrally formed with the outer shell.

[0014] In some embodiments, the fuel chamber ribs are integrally formed with the inner shell.

[0015] In another set of embodiments, a gas fuel-air mixer includes an outer shell, an inner shell, and a fuel chamber rib. The outer shell includes an air inlet and a fuel inlet. The air inlet is configured to receive air. The air inlet has an air outlet. The fuel inlet has a fuel inlet configured to receive fuel. The inner shell includes an inner shell inlet, which is configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and provide a gas fuel-air mixture. The inner shell cooperates with the outer shell to define a fuel inlet collection chamber and a fuel inlet concentration chamber, the fuel inlet collection chamber being configured to receive fuel from the fuel inlet, and the fuel inlet concentration chamber being configured to receive fuel from the fuel inlet collection chamber and provide fuel to the inner shell inlet. The fuel chamber rib is coupled to the outer shell. The fuel chamber rib is disposed in the fuel inlet collection chamber and the fuel inlet concentration chamber. The fuel chamber rib is in confronting relation with a portion of the inner shell.

[0016] In some embodiments, at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered on a central axis; the fuel inlet collecting chamber extends annularly around the central axis; and the fuel chamber rib extends within the fuel inlet collecting chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet collecting chamber.

[0017] In some embodiments, the fuel inlet concentrating chamber extends annularly around the central axis; and the fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

[0018] In some embodiments, the fuel chamber ribs are integrally formed with the outer shell.

[0019] In some embodiments, the inner shell further comprises an inner shell inlet body having a groove; and the fuel chamber rib is positioned within the groove.

[0020] In some embodiments, the fuel inlet is centered on a fuel inlet central axis; and the fuel chamber rib is disposed along the fuel inlet central axis.

[0021] In some embodiments, the inner housing includes an inner housing inlet body; and a portion of the air outlet is disposed within a portion of the inner housing inlet body.

[0022] In another set of embodiments, a gas fuel-air mixer includes an outer shell, an inner shell, and a fuel chamber rib. The outer shell includes an air inlet and a fuel inlet. The air inlet is configured to receive air. The air inlet has an air outlet. The fuel inlet has a fuel inlet configured to receive fuel. The inner shell includes an inner shell inlet, which is configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and provide a gas fuel-air mixture. The inner shell cooperates with the outer shell to define a fuel inlet collection chamber and a fuel inlet concentration chamber, the fuel inlet collection chamber being configured to receive fuel from the fuel inlet, and the fuel inlet concentration chamber being configured to receive fuel from the fuel inlet collection chamber and provide fuel to the inner shell inlet. The fuel chamber rib is coupled to the inner shell. The fuel chamber rib is disposed within the fuel inlet concentration chamber. The fuel chamber rib is in a facing relationship with a portion of the outer shell.

[0023] In some embodiments, at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered on a central axis; the fuel inlet concentrating chamber extends annularly around the central axis; and the fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

[0024] In some embodiments, the fuel chamber ribs are integrally formed with the inner shell.

[0025] In some embodiments, the fuel inlet is centered on a fuel inlet central axis; and the fuel chamber rib is disposed along the fuel inlet central axis.

[0026] In some embodiments, the inner housing includes an inner housing inlet body; and a portion of the air outlet is disposed within a portion of the inner housing inlet body.

[0027] In some embodiments, the fuel inlet is centered on a fuel inlet central axis; the air outlet is centered on an air inlet central axis; and the fuel inlet central axis intersects the air inlet central axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The details of one or more implementations are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of the present disclosure will become apparent from the description, drawings, and claims, in which:

[0030] Figure 1A is a schematic block diagram of an example internal combustion engine system having a gaseous fuel-air mixer;

[0031] Figure 1B is a schematic block diagram of another example internal combustion engine system having a gaseous fuel-air mixer;

[0032] Figure 2 is a perspective view of an example gaseous fuel-air mixer;

[0033] Figure 3 It is intercepted along plane AA Figure 2 A cross-sectional view of a gas fuel-air mixer;

[0034] Figure 4 It is cut along plane BB Figure 2 A cross-sectional view of a gas fuel-air mixer;

[0035] Figure 5 yes Figure 4 an exploded view of the cross-sectional view shown;

[0036] Figure 6 is a perspective view of another example gas fuel-air mixer;

[0037] Figure 7 It is taken along plane CC Figure 6 A cross-sectional view of a gas fuel-air mixer;

[0038] Figure 8 is a cross-sectional view of yet another example gas fuel-air mixer;

[0039] Figure 9 is a perspective view of yet another example gas fuel-air mixer;

[0040] Figure 10 It is taken along plane DD Figure 9 A cross-sectional view of a gas fuel-air mixer;

[0041] Figure 11 yes Figure 10 an exploded view of the cross-sectional view shown;

[0042] Figure 12 is a perspective view of yet another example gaseous fuel-air mixer; and

[0043] Figure 13 It is taken along plane EE Figure 12 Cross-sectional view of a gas fuel-air mixer.

[0044] It should be appreciated that these drawings are schematic representations for illustrative purposes. The drawings are provided for the purpose of illustrating one or more implementations, with the express understanding that they will not be used to limit the scope or meaning of the claims.

[0045] Detailed description

[0046] The following is a more detailed description of various concepts and implementations related to methods and apparatus for providing a gaseous fuel-air mixer for an internal combustion engine system. The various concepts introduced above and discussed in more detail below can be implemented in any of a variety of ways, as the concepts described are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0047] I. Overview

[0048] Many systems mix air and fuel upstream of the engine. These systems use a mixer that includes internal components that mix the fuel into the air. However, for the combustion of certain fuels (such as natural gas and other fuels with low heating values), these mixers can cause the gaseous fuel-air mixture (e.g., downstream of the mixer) to have an unacceptable amount of swirl. When burning these fuels, this swirl can lead to reduced mixture homogeneity and / or low supply pressure (which can result in a reduced rating of the engine), which is undesirable.

[0049] The implementation described herein relates to an internal combustion engine system that includes a gas fuel-air mixer having fuel chamber ribs that prevent swirl of the fuel before the fuel is introduced into the gas fuel-air mixer along with the air flow. By preventing swirl of the fuel in this manner, the gas fuel-air mixer described herein reduces swirl of the gas fuel-air mixture because the fuel does not impart an unacceptable amount of swirl to the air flow when the fuel is introduced into the air flow. Therefore, the gas fuel-air mixer described herein can provide excellent mixture uniformity and enable the engine to produce maximum power and / or minimum emissions. In addition, the gas fuel-air mixer described herein can enable the engine to burn fuel with a relatively low heating value without causing the engine to be derated, and does not require the use of a boost system or other auxiliary components to avoid derated as in some conventional mixers. Furthermore, the reduced swirl of the gaseous fuel-air mixture provided by the gaseous fuel-air mixer described herein can improve the efficiency of a turbocharger receiving the gaseous fuel-air mixture and can significantly reduce the overall cost of an internal combustion engine system using the gaseous fuel-air mixer described herein, as compared to systems using other conventional mixers.

[0050] II. Example Internal Combustion Engine System

[0051] Figure 1A and Figure 1BAn internal combustion engine system 100 (e.g., a natural gas internal combustion engine system, a lean-burn internal combustion engine system, a biofuel internal combustion engine system, a dual-fuel internal combustion engine system, etc.) is depicted. As explained in greater detail herein, the internal combustion engine system 100 utilizes combustion to generate power. The internal combustion engine system 100 can be implemented, for example, in a generator (e.g., a generator set, a backup generator, etc.), a vehicle (e.g., a commercial vehicle, a construction vehicle, a truck, a tractor-trailer, an automobile, a military vehicle, etc.), a marine vessel (e.g., a ship, a tanker, etc.), and other similar applications. The internal combustion engine system 100 is defined based on output (e.g., power, rating, etc.). For example, the output of the internal combustion engine system 100 can be between 995 kilowatts (kW) and 1540 kW, inclusive. In other embodiments, the output of the internal combustion engine system 100 can be between 1740 kW and 2088 kW, inclusive. However, the output of the internal combustion engine system 100 may be other values ​​such that the internal combustion engine system 100 is customized for the target application.

[0052] The internal combustion engine system 100 includes an air source 102 (eg, an air box, an air inlet, etc.) The air source 102 receives air from the ambient environment surrounding the internal combustion engine system 100 and provides air to the internal combustion engine system 100 for combustion.

[0053] The internal combustion engine system 100 also includes a fuel source 104 (e.g., a fuel tank, a fuel supply, a pipeline, a power grid infrastructure, a landfill, etc.). The fuel source 104 stores fuel for combustion (e.g., natural gas, gaseous fuel, lean burn gas, propane, liquid propane, liquid natural gas, hexane, biogas, etc.). In some embodiments, as Figure 1B As shown, the internal combustion engine system 100 also includes a blower 106 (eg, a compressor, a fuel pump, a rotary pump, a positive displacement pump, etc.) The blower 106 draws fuel from the fuel source 104 via a fuel conduit.

[0054] The internal combustion engine system 100 further includes a fuel control valve 105 (e.g., a solenoid valve, an electronically controllable valve, etc.). The fuel control valve 105 is fluidly coupled to the fuel source 104 via a conduit and is configured to receive fuel from the fuel source 104. In embodiments that do not include the blower 106, as shown in FIG. Figure 1A As shown, the fuel control valve 105 receives fuel from the fuel source 104. In an embodiment including a blower 106, as shown in FIG. Figure 1B As shown, fuel control valve 105 receives fuel from blower 106 .

[0055] The fuel control valve 105 is operable between an open position and a closed position. In the closed position, fuel flow through the fuel control valve 105 is prohibited (e.g., blocked, etc.) by the fuel control valve 105. Between the open and closed positions, fuel flow through the fuel control valve 105 is restricted. In the open position, fuel flow through the fuel control valve 105 is unrestricted.

[0056] In some embodiments, the internal combustion engine system 100 further includes a connection point 107 (e.g., a customer connection point). The connection point 107 is configured to connect an auxiliary fuel conduit between the fuel source 104 and the fuel control valve 105. The connection point 107 can receive fuel from the fuel source 104 (e.g., as a fuel output, etc.) or can provide fuel to the fuel control valve 105 (e.g., as a supplement or replacement for the fuel source 104, etc.). In embodiments where the internal combustion engine system 100 does not include the blower 106, as shown in FIG. Figure 1A As shown, fuel source 104 provides fuel to connection point 107 , which in turn provides fuel to fuel control valve 105 .

[0057] The internal combustion engine system 100 also includes a gas fuel-air mixer 108 (e.g., a manifold, etc.). The gas fuel-air mixer 108 is fluidly coupled to the air source 102 via a conduit and is configured to receive air from the air source 102 via the conduit. Similarly, the gas fuel-air mixer 108 is fluidly coupled to the fuel control valve 105 via a conduit and is configured to receive fuel from the fuel control valve 105 via the conduit. Importantly, the air and fuel are separated before being received by the gas fuel-air mixer 108. As explained in more detail herein, the mixing of the air and fuel within the gas fuel-air mixer 108 allows the operation of the internal combustion engine system 100 to be more ideal than other systems without the gas fuel-air mixer 108. In embodiments where the internal combustion engine system 100 includes the blower 106, as Figure 1B As shown, the gas fuel-air mixer 108 receives fuel from the blower 106 .

[0058] The fuel has an upstream fuel pressure upstream of the gas fuel-air mixer 108 (e.g., downstream of the blower 106, downstream of the connection point 107, etc.). As used herein, "upstream fuel pressure" refers to the fuel pressure between the blower 106 and the gas fuel-air mixer 108 and / or the fuel pressure between the connection point 107 and the gas fuel-air mixer 108, unless otherwise indicated.

[0059] In some embodiments, the internal combustion engine system 100 includes a sensor 109 (eg, a pressure sensor, a differential pressure sensor, a temperature sensor, a flow sensor, etc.). In embodiments where the internal combustion engine system 100 does not include the blower 106, Figure 1A As shown, sensor 109 measures the upstream fuel pressure downstream of fuel source 104 and upstream of gas fuel-air mixer 108 (e.g., downstream of connection point 107 and upstream of fuel control valve 105, etc.). In embodiments where internal combustion engine system 100 includes blower 106, as shown in FIG. Figure 1B As shown, sensor 109 measures the upstream fuel pressure downstream of blower 106 and upstream of gas fuel-air mixer 108. In embodiments where internal combustion engine system 100 includes sensor 109, internal combustion engine system 100 may also include a controller that receives the upstream fuel pressure and utilizes the upstream fuel pressure to control internal combustion engine system 100.

[0060] The internal combustion engine system 100 also includes a turbocharger 110. The turbocharger 110 includes a compressor 111. The compressor 111 is fluidly coupled to the gaseous fuel-air mixer 108 and is configured to receive a gaseous fuel-air mixture from the gaseous fuel-air mixer 108. As explained in greater detail herein, the compressor 111 is configured to compress the gaseous fuel-air mixture (e.g., increase the pressure of the gaseous fuel-air mixture, etc.) in order to increase the output and / or efficiency (e.g., input to output, etc.) of the internal combustion engine system 100.

[0061] The fuel has a downstream fuel pressure downstream of the gas fuel-air mixer 108 and upstream of the compressor 111. As used herein, "downstream fuel pressure" refers to the fuel pressure between the gas fuel-air mixer 108 and the compressor 111, unless otherwise indicated. In some embodiments, the pressure drop of the fuel is determined by comparing the upstream fuel pressure of the fuel downstream of the connection point 107 and upstream of the gas fuel-air mixer 108 with the downstream fuel pressure of the fuel downstream of the gas fuel-air mixer 108 and upstream of the compressor 111. In some embodiments, the pressure drop of the fuel is determined by comparing the upstream fuel pressure of the fuel downstream of the blower 106 and upstream of the gas fuel-air mixer 108 with the downstream fuel pressure of the fuel downstream of the gas fuel-air mixer 108 and upstream of the compressor 111. As explained in more detail herein, the gas fuel-air mixer 108 is configured to minimize these pressure drops, so that certain fuels that experience larger pressure drops in other systems and are therefore undesirable in these other systems can be ideally used in the internal combustion engine system 100 (e.g., having a pressure drop of 25 millibars, etc.).

[0062] In some embodiments, the internal combustion engine system 100 includes a sensor 112 (e.g., a pressure sensor, a differential pressure sensor, a temperature sensor, a flow sensor, etc.) that measures a downstream fuel pressure of the fuel downstream of the gaseous fuel-air mixer 108 and upstream of the compressor 111. The internal combustion engine system 100 includes a controller that receives the downstream fuel pressure and uses the downstream fuel pressure to control the internal combustion engine system 100.

[0063] Internal combustion engine system 100 also includes a throttle valve 113. Throttle valve 113 is fluidly coupled to compressor 111 and is configured to receive a gaseous fuel-air mixture from compressor 111. Throttle valve 113 is operable between an open position and a closed position. In the closed position, the flow of the gaseous fuel-air mixture through throttle valve 113 is prohibited (e.g., blocked, etc.). Between the open and closed positions, the flow of the gaseous fuel-air mixture through throttle valve 113 is restricted. In the open position, the flow of the gaseous fuel-air mixture through throttle valve 113 is unrestricted.

[0064] The internal combustion engine system 100 also includes an internal combustion engine 114. The internal combustion engine 114 is fluidically coupled to the throttle valve 113 and is configured to receive a gaseous fuel-air mixture from the throttle valve 113. The internal combustion engine 114 includes various components, such as cylinders, pistons, a lubricant (e.g., oil, etc.) system, a coolant system, a cylinder block, a cylinder head, and other similar components. The gaseous fuel-air mixture is combusted within the internal combustion engine 114, and the internal combustion engine 114 generates an output for the internal combustion engine system 100. For example, the internal combustion engine 114 may include a drive shaft connected to a rotor, a transmission, or other components for transmitting the output from the internal combustion engine system 100 to another system that utilizes the power.

[0065] In some embodiments, the internal combustion engine system 100 further includes a charge air cooler 115. The charge air cooler 115 is configured to cool air from the compressor 111 before the air is provided to the internal combustion engine 114. In some embodiments, the charge air cooler 115 is disposed downstream of the throttle valve 113 (e.g., between the throttle valve 113 and the internal combustion engine 114, etc.). In some embodiments, the charge air cooler 115 is disposed upstream of the throttle valve 113 (e.g., between the compressor 111 and the throttle valve 113, etc.).

[0066] Internal combustion engine 114 generates exhaust gas. Turbocharger 110 includes turbine 116. Turbine 116 is fluidly coupled to internal combustion engine 114 and is configured to receive exhaust gas from internal combustion engine 114. Turbine 116 utilizes energy within the exhaust gas (e.g., exhaust gas pressure, exhaust gas velocity, etc.) and transfers this energy (e.g., via a connecting shaft, etc.) to compressor 111 to compress the gaseous fuel-air mixture. In this way, turbocharger 110 utilizes energy from the output of internal combustion engine 114 to increase the energy provided to the input of internal combustion engine 114, thereby increasing the efficiency and / or output of internal combustion engine system 100.

[0067] The internal combustion engine system 100 also includes an exhaust outlet 118 (e.g., a muffler, downpipe, chimney, etc.). The exhaust outlet 118 is fluidly coupled to the turbine 116 and is configured to receive exhaust gas from the turbine 116. In some embodiments, the exhaust outlet 118 provides the exhaust gas directly to the atmosphere. In other embodiments, the exhaust outlet 118 provides the exhaust gas to an exhaust aftertreatment system (e.g., a selective catalytic reduction (SCR) system, etc.) and from there to the atmosphere.

[0068] The turbocharger 110 also includes a wastegate 119 (e.g., a purge valve, a blowoff valve, etc.). The wastegate 119 is configured to selectively facilitate bypassing of exhaust gas from between the internal combustion engine 114 and the turbine 116, around the turbine 116, to the exhaust outlet 118. Thus, the wastegate 119 can protect the turbocharger 110 from undesirable pressurization of the exhaust gas within the turbine 116.

[0069] In some embodiments, as Figure 1B As shown, in addition to the fuel source 104, the internal combustion engine system 100 also includes a secondary fuel source 120 (e.g., a fuel tank, a fuel supply, a pipeline, a power grid infrastructure, a landfill, etc.). The secondary fuel source 120 stores fuel for combustion (e.g., natural gas, gaseous fuel, lean burn gas, propane, liquid propane, liquid natural gas, hexane, biogas, etc.). In some applications, the fuel stored by the secondary fuel source 120 is different from the fuel stored by the fuel source 104. For example, the secondary fuel source 120 may store biogas, and the fuel source 104 may store natural gas.

[0070] In embodiments where the internal combustion engine system 100 includes a blower 106 and a secondary fuel source 120 in addition to the fuel source 104, as shown in FIG. Figure 1BAs shown, the blower 106 draws fuel from the secondary fuel source 120 via a secondary fuel conduit. In these embodiments, the internal combustion engine system 100 includes a fuel selector valve 122 (e.g., a solenoid valve, an electronically controllable valve, a three-way valve, a ball valve, etc.). The fuel selector valve 122 is fluidly coupled to the fuel source 104 and the secondary fuel source 120 and is configured to receive fuel from the fuel source 104 and / or a secondary fuel from the secondary fuel source 120. A connection point 107 may be provided between the fuel selector valve 122 and the blower 106.

[0071] The fuel selector valve 122 is operable between an open position and a closed position. In the closed position, the flow of the secondary fuel through the fuel selector valve 122 is prohibited (e.g., blocked, etc.) by the fuel selector valve 122 (e.g., the blower 106 receives only fuel from the fuel source 104 and does not receive any secondary fuel from the secondary fuel source 120, etc.). Between the open and closed positions, the flow of fuel through the fuel selector valve 122 is restricted (e.g., the blower 106 receives fuel from the fuel source 104 and the secondary fuel source 120, etc.). In the open position, the flow of the secondary fuel from the secondary fuel source 120 through the fuel selector valve 122 is unrestricted. In some embodiments, the fuel selector valve 122 is a three-way valve (e.g., a mixer valve, a 270° ball valve, a 180° ball valve, etc.) configured to simultaneously open / close the flow of fuel from both the fuel source 104 and the secondary fuel source 120.

[0072] In some embodiments, the internal combustion engine system 100 does not include a turbocharger 110 . In these embodiments, the gaseous fuel-air mixture is provided directly from the gaseous fuel-air mixer 108 to the internal combustion engine 114 .

[0073] III. Example Gaseous Fuel-Air Mixer

[0074] Figure 2 and Figure 3 The gas fuel-air mixer 108 is depicted in greater detail according to various embodiments. The gas fuel-air mixer 108 includes a housing 200 (e.g., a casing, etc.). In some embodiments, the housing 200 is a single-piece structure (e.g., integrally formed, a unitary structure, etc.). For example, the housing 200 can be formed by casting, three-dimensional (3D) printing, selective laser sintering, welding, or other similar processes.

[0075] The housing 200 includes an air inlet 202 (e.g., an inlet portion, etc.). The air inlet 202 is fluidly coupled to a conduit and is configured to receive air from the air source 102 via the conduit. The housing 200 also includes an air inlet coupler 204 (e.g., a rib, a ring, etc.). The air inlet coupler 204 extends around the air inlet 202 and facilitates coupling the housing 200 to a conduit that provides air from the air source 102 to the air inlet 202. For example, the conduit can be disposed within the air inlet 202 and secured to the housing 200 by a clamp (e.g., a band clamp, etc.) disposed around the air inlet coupler 204. In various embodiments, the housing 200 is coupled to the conduit such that a substantially fluid-tight seal is formed between the housing 200 and the conduit (e.g., allowing less than 1% of the mass air flow to pass through the conduit).

[0076] and flows between the housing 200, etc.).

[0077] The air intake 202 includes an air inlet 206 that receives air from a conduit. The air intake 202 also includes an air outlet 208 that provides air from the air intake 202. In some embodiments, at least one of the air inlet 206 or the air outlet 208 (e.g., the air inlet 206 but not the air outlet 208, the air outlet 208 but not the air inlet 206, both the air inlet 206 and the air outlet 208, etc.) is centered about an inlet central axis 210. For example, in embodiments where the air inlet 206 is circular and the air inlet 206 is centered about the air inlet central axis 210, the air inlet central axis 210 coincides with the center of the circle along which the air inlet 206 extends.

[0078] Air intake 202 also includes an air intake body 212 (eg, a wall, etc.) extending between air intake 206 and air outlet 208 . Air intake body 212 is configured such that all air received by air intake body 212 from air intake 206 is provided to air outlet 208 .

[0079] The air intake body 212 defines an air intake body chamber 213 (e.g., a void, a cavity, etc.). In various embodiments, the air intake body 212 is configured such that the cross-sectional area of ​​the air intake body chamber 213 (e.g., along a plane orthogonal to the air intake central axis 210, etc.) decreases at least partially along the air intake central axis 210 from the air inlet 206 to the air outlet 208. In these embodiments, the velocity of the air can be increased due to the air intake body 212 (e.g., the velocity of the air entering the air inlet 206 is lower than the velocity of the air exiting the air outlet 208, etc.).

[0080] Furthermore, the air inlet body 212 can be configured such that the rate of change in the shape and / or size of the air inlet body chamber 213 changes (e.g., decreases, etc.) along the air inlet central axis 210 from the air inlet 206 to the air outlet 208. In various embodiments, the air inlet body 212 is configured such that the cross-sectional dimension of the air inlet body chamber 213 decreases at a higher rate near the air inlet 206 than near the air outlet 208. Still further, the air inlet body 212 can be configured such that the rate of change in the shape and / or size of the air inlet body chamber 213 gradually decreases along the air inlet central axis 210 from the air inlet 206 to the air outlet 208. As a result, the air inlet body chamber 213 can have a cross-sectional shape that is a partial hyperbola along a plane that coincides with the air inlet central axis 210. In some embodiments, the air inlet body 212 can be generally shaped as a frustum of a hyperbolic hyperboloid of revolution (e.g., a circular hyperboloid) and converge toward the air inlet central axis 210. For example, the diameter of the air inlet body chamber 213 can gradually decrease from the air inlet 206 to the air outlet 208, such that the air inlet body 212 is used to funnel (e.g., direct, focus, etc.) air to the air outlet 208. In some embodiments, the air inlet 206 and the air outlet 208 are both circular, and the diameter of the air inlet 206 is greater than the diameter of the air outlet 208.

[0081] Housing 200 also includes a fuel inlet 214 (e.g., an inlet portion, etc.). Fuel inlet 214 is fluidly coupled to the conduit and is configured to receive fuel from fuel source 104 via the conduit (e.g., after flowing through blower 106, after flowing through connection point 107, etc.). Housing 200 also includes a fuel inlet coupler 216 (e.g., a rib, a ring, etc.). Fuel inlet coupler 216 extends around fuel inlet 214 and facilitates coupling housing 200 to a conduit that provides fuel from fuel source 104 to fuel inlet 214. For example, the conduit may be disposed within fuel inlet 214 and secured to housing 200 via a clamp (e.g., a band clamp, etc.) disposed around fuel inlet coupler 216. In various embodiments, housing 200 is coupled to the conduit such that a substantially fluid-tight seal is formed between housing 200 and the conduit (e.g., allowing less than 1% of the mass of the fuel flow to flow through the conduit between the conduit and housing 200, etc.).

[0082] The fuel inlet 214 includes a fuel inlet 218 that receives fuel from a conduit. The fuel inlet 218 is centered about a fuel inlet central axis 220. For example, in embodiments where the fuel inlet 218 is circular, the fuel inlet central axis 220 coincides with the center of the circle along which the fuel inlet 218 extends.

[0083] The fuel inlet central axis 220 may intersect the air inlet central axis 210. The fuel inlet central axis 220 may be separated from the air inlet central axis 210 by a separation angle α, measured along a plane along which both the fuel inlet central axis 220 and the air inlet central axis 210 lie. In various embodiments, α is substantially equal to (e.g., within 5%, etc.) 90° (e.g., 86°, 87°, 90°, 91°, 93°, etc.). In some embodiments, α is approximately (e.g., within 5%, etc.) between 60° (e.g., 58°, 60°, 62°, etc.) and 90° (e.g., 88°, 90°, 92°, etc.). In some embodiments, α is approximately (e.g., within 5%, etc.) between 45° (e.g., 43°, 45°, 47°, etc.) and 60° (e.g., 58°, 60°, 62°, etc.). In some embodiments, α is approximately (e.g., within 5% of a deviation, etc.) between 60° (e.g., 58°, 60°, 62°, etc.) and 90° (e.g., 88°, 90°, 92°, etc.). In some embodiments, α is approximately (e.g., within 5% of a deviation, etc.) between 0° (e.g., 0°, etc.) and 180° (e.g., 171°, 180°, 189°, etc.). In some embodiments, α is less than 0° (e.g., -20°, -50°, -90°, etc.). In some embodiments, α is greater than 180° (e.g., 200°, 220°, 270°, etc.).

[0084] The fuel inlet 214 also includes a fuel inlet body 222 (e.g., a wall, etc.) that extends from the fuel inlet 218 toward the air inlet central axis 210. As explained in more detail herein, the fuel inlet body 222 cooperates with other components of the gas fuel-air mixer 108 to ensure that all fuel received by the fuel inlet 218 is provided from the fuel inlet 214.

[0085] The fuel inlet body 222 includes a fuel inlet collecting wall 224. The fuel inlet collecting wall 224 extends about the fuel inlet central axis 220. The fuel inlet collecting wall 224 receives fuel from the fuel inlet 218 and distributes the fuel within the fuel inlet 214 and about the fuel inlet central axis 220. In various embodiments, the fuel inlet collecting wall 224 is at least partially annular.

[0086] The fuel inlet body 222 also includes a fuel inlet concentrating wall 226. The fuel inlet concentrating wall 226 is adjacent to the fuel inlet collecting wall 224. The fuel inlet concentrating wall 226 extends about the air inlet central axis 210. A portion of the fuel inlet concentrating wall 226 is separated from the air inlet 202 by the air inlet body 212. As described in more detail herein, the fuel inlet concentrating wall 226 receives fuel from the fuel inlet collecting wall 224 and provides fuel out of the fuel inlet 214 and about the air inlet central axis 210. In various embodiments, the fuel inlet concentrating wall 226 is at least partially annular.

[0087] The housing 200 further includes a housing outer wall 227. The housing outer wall 227 is adjacent to the fuel inlet collecting wall 224. Furthermore, the housing outer wall 227 extends around the air inlet central axis 210. In various embodiments, the housing outer wall 227 is at least partially annular.

[0088] The gas fuel-air mixer 108 also includes an inner shell 228 (e.g., a housing, etc.). In some embodiments, the inner shell 228 is a single-piece structure (e.g., integrally formed, integrally constructed, machined from a solid body, etc.). For example, the inner shell 228 can be formed by casting, 3D printing, selective laser sintering, or other similar processes.

[0089] Inner shell 228 includes an inner shell inlet 230 (eg, an inlet portion, etc.). In some embodiments, inner shell inlet 230 includes an inner shell inlet inlet 232 that receives air from air inlet 202 and fuel from fuel inlet 214 .

[0090] like Figure 3 As shown, a portion of air inlet 202 extends into inner shell inlet 230. Thus, inner shell inlet inlet 232 is positioned upstream of air outlet 208. As explained in more detail herein, this arrangement enables air inlet body 212 to separate air (e.g., within air inlet 202, etc.) from fuel (e.g., within inner shell inlet 230, etc.) near air outlet 208. In other embodiments, air inlet 202 does not extend into inner shell inlet 230.

[0091] Inner casing inlet 230 also includes an inner casing inlet outlet 234 that provides air and fuel from inner casing inlet 230. At least one of inner casing inlet inlet 232 or inner casing inlet outlet 234 (e.g., inner casing inlet inlet 232 but not inner casing inlet outlet 234, inner casing inlet outlet 234 but not inner casing inlet inlet 232, both inner casing inlet inlet 232 and inner casing inlet outlet 234, etc.) is centered about inner casing inlet central axis 236. For example, in embodiments where inner casing inlet inlet 232 is circular and inner casing inlet inlet 232 is centered about inner casing inlet central axis 236, inner casing inlet central axis 236 coincides with the center of the circle along which inner casing inlet inlet 232 extends.

[0092] like Figure 3 As shown, inner shell inlet central axis 236 is coincident with air inlet central axis 210. In other words, inner shell inlet inlet 232 and / or inner shell inlet outlet 234 are centered about air inlet central axis 210, and air inlet 206 and / or air inlet outlet 208 are centered about inner shell inlet inlet 232. However, in other embodiments, inner shell inlet central axis 236 is different from air inlet central axis 210. For example, inner shell inlet central axis 236 may be spaced apart from and / or angled relative to air inlet central axis 210. For example, inner shell inlet central axis 236 may not be coincident with air inlet central axis 210.

[0093] In various embodiments, inner casing inlet 230 is substantially frusto-conical and converges toward inner casing inlet central axis 236. For example, the diameter of inner casing inlet 230 can gradually decrease from inner casing inlet inlet 232 to inner casing inlet outlet 234, such that inner casing inlet 230 functions to funnel (e.g., direct, focus, etc.) the air and fuel mixture to inner casing inlet outlet 234. In some embodiments, the velocity of the air and fuel mixture can be increased by inner casing inlet 230 (e.g., the velocity of the air at air outlet 208 is lower than the velocity of the air and fuel mixture exiting inner casing inlet outlet 234, etc.). In some embodiments, both inner casing inlet inlet 232 and inner casing inlet outlet 234 have circular cross-sections, and the diameter of inner casing inlet inlet 232 is greater than the diameter of inner casing inlet outlet 234.

[0094] Inner shell inlet 230 also includes an inner shell inlet body 238 (e.g., a wall, etc.) extending between inner shell inlet inlet 232 and inner shell inlet outlet 234. Inner shell inlet body 238 is configured such that all air received from air inlet 202 and all fuel received from fuel inlet 214 is provided to inner shell inlet outlet 234.

[0095] Inner casing inlet body 238 defines an inner casing inlet body chamber 239 (e.g., a void, a cavity, etc.). In various embodiments, inner casing inlet body 238 is configured such that the shape and / or size of inner casing inlet body chamber 239 (e.g., along a plane orthogonal to inner casing inlet central axis 236, etc.) decreases at least partially along inner casing inlet central axis 236 from inner casing inlet inlet 232 to inner casing inlet outlet 234. In these embodiments, the velocity of the air can be increased due to inner casing inlet body 238 (e.g., the velocity of the air at air outlet 208 is lower than the velocity of the air and fuel mixture exiting inner casing inlet outlet 234, etc.).

[0096] Furthermore, the inner shell inlet body 238 can be configured such that the rate of change in the shape and / or size of the inner shell inlet body chamber 239 changes (e.g., decreases, etc.) along the inner shell inlet central axis 236 from the inner shell inlet inlet 232 to the inner shell inlet outlet 234. In various embodiments, the inner shell inlet body 238 is configured such that the size of the inner shell inlet body chamber 239 decreases at a higher rate near the inner shell inlet inlet 232 than near the inner shell inlet outlet 234. Further, the inner shell inlet body 238 can be configured such that the rate of change in the shape and / or size of the inner shell inlet body chamber 239 gradually decreases along the inner shell inlet central axis 236 from the inner shell inlet inlet 232 to the inner shell inlet outlet 234. Thus, the inner shell inlet body chamber 239 can have a partially hyperbolic cross-sectional shape along a plane coinciding with the inner shell inlet central axis 236. In some embodiments, inner casing inlet body 238 can be substantially shaped as a frustum of a hyperbolic hyperboloid of revolution (e.g., a circular hyperboloid) and converge toward inner casing inlet central axis 236. For example, the diameter of inner casing inlet body chamber 239 can gradually decrease from inner casing inlet inlet 232 to inner casing inlet outlet 234, such that inner casing inlet body 238 functions to funnel (e.g., direct, focus, etc.) the air and fuel mixture through a funnel-shaped opening to inner casing inlet outlet 234. In some embodiments, both inner casing inlet inlet 232 and inner casing inlet outlet 234 are circular, and the diameter of inner casing inlet inlet 232 is greater than the diameter of inner casing inlet outlet 234.

[0097] The inner casing 228 also includes an inner casing output 240 (e.g., a body, etc.). The inner casing output 240 is fluidly coupled to the inner casing inlet 230 and is configured to receive air and fuel from the inner casing inlet 230. The inner casing output 240 is fluidly coupled to a conduit, such as a conduit extending between the gas fuel-air mixer 108 and the compressor 111, and is configured to provide the air and fuel received from the inner casing inlet 230 to the conduit.

[0098] As explained in greater detail herein, inner housing output 240 also facilitates coupling of inner housing 228 to outer housing 200 such that a substantially fluid-tight seal exists between inner housing 228 and outer housing 200. Inner housing output 240 includes an inner housing divider wall 242 extending radially outward (e.g., away from inner housing inlet central axis 236, etc.) from inner housing inlet 230. In various embodiments, inner housing divider wall 242 is at least partially annular.

[0099] The inner housing output end 240 further includes an inner housing outer wall 244 that is adjacent to the inner housing divider wall 242 and separated from the inner housing inlet 230 by the inner housing divider wall 242. In various embodiments, the inner housing outer wall 244 is at least partially annular.

[0100] In various embodiments, inner housing outer wall 244 is separated from inner housing inlet body 238 by a gap. This gap can receive a portion of a conduit coupled to inner housing 228. For example, an end of a conduit coupled to inner housing 228 can be positioned within inner housing 228 and disposed between inner housing outer wall 244 and inner housing inlet body 238.

[0101] Inner shell outer wall 244 includes an inner shell coupling surface 246 and an inner shell coupling flange 248 adjacent inner shell coupling surface 246. When outer shell 200 is coupled to inner shell 228, inner shell coupling surface 246 is in facing relationship with outer shell coupling surface 252 of outer shell outer wall 227, and inner shell coupling flange 248 is in facing relationship with outer shell coupling flange 250. Outer shell 200 may also be coupled to inner shell 228 in other arrangements.

[0102] When the outer shell 200 is coupled to the inner shell 228, a small gap (e.g., less than 5 mm, less than 2 mm, less than 1 mm, less than 0.5 mm, less than 0.25 mm, etc.) exists between the inner shell coupling surface 246 and the outer shell coupling surface 252. This small gap facilitates displacement of the outer shell 200 relative to the inner shell 228. In this manner, the inner shell 228 can be inserted into or removed from the outer shell 200.

[0103] A sealing member 254 (e.g., an O-ring, a gasket, a liquid sealant, etc.) is positioned between the inner shell coupling surface 246 and the outer shell coupling surface 252. The sealing member 254 can facilitate establishing a substantially fluid-tight seal between the inner shell coupling surface 246 and the outer shell coupling surface 252. The sealing member 254 can be positioned (e.g., received, located, etc.) within a recess (e.g., a cavity, a seat, etc.) formed in the inner shell coupling surface 246 and / or the outer shell coupling surface 252. In some embodiments, the sealing member can be included between the outer shell outer wall 227 and the inner shell coupling flange 248.

[0104] The gas fuel-air mixer 108 also includes a band clamp 256 (e.g., a V-band clamp, a Marmon clamp, etc.). The band clamp 256 interfaces with both the inner shell coupling flange 248 and the outer shell coupling flange 250 to couple the outer shell 200 to the inner shell 228. Specifically, tightening the band clamp 256 toward the inner shell inlet centerline 236 causes the inner shell coupling flange 248 and the outer shell coupling flange 250 to be drawn closer together, ultimately coupling the outer shell 200 to the inner shell 228. In some embodiments, the band clamp 256 is replaced or supplemented by a bolted connection (e.g., between the inner shell coupling flange 248 and the outer shell coupling flange 250, etc.).

[0105] In some embodiments, the gas fuel-air mixer 108 does not include the band clamp 256, but instead includes another mechanism (e.g., bolts, welds, threads, etc.) for coupling the inner shell coupling flange 248 to the outer shell coupling flange 250. For example, the inner shell coupling flange 248 may be welded or bolted to the outer shell coupling flange 250.

[0106] In some embodiments, the inner shell 228 further includes an inner shell coupler (e.g., a rib, a ring, etc.). The inner shell coupler extends around the inner shell outer wall 244 and facilitates coupling the inner shell 228 to a conduit that receives air and fuel from the gas fuel-air mixer 108. For example, the conduit can be disposed around the inner shell 228 and secured to the inner shell 228 by a clamp (e.g., a band clamp, etc.) disposed around the inner shell coupler. In various embodiments, the inner shell 228 is coupled to the conduit such that a substantially fluid-tight seal is formed between the inner shell 228 and the conduit (e.g., allowing less than 1% by mass of the gas fuel-air flow to flow through the conduit between the conduit and the inner shell 228, etc.).

[0107] The inner housing output end 240 further includes an inner housing outlet 260. The inner housing outlet 260 is adjacent to the inner housing outer wall 244. The inner housing outlet 260 is centered about an inner housing outlet central axis 262. For example, in an embodiment where the inner housing outlet 260 is circular, the inner housing outlet central axis 262 coincides with the center of the circle along which the inner housing outlet 260 extends.

[0108] like Figure 3 As shown, inner casing outlet central axis 262 coincides with inner casing inlet central axis 236. However, in other embodiments, inner casing outlet central axis 262 is different from inner casing inlet central axis 236. For example, inner casing outlet central axis 262 can be spaced apart from and / or angled relative to inner casing inlet central axis 236.

[0109] When inner shell 228 is coupled to outer shell 200, fuel outlet 264 of fuel inlet 214 is defined between air inlet body 212 and inner shell inlet body 238. In operation, fuel flows from a conduit into fuel inlet 218. The fuel then flows into a fuel inlet collection chamber 266 (e.g., a void, cavity, etc.). Fuel inlet collection chamber 266 is defined by fuel inlet collection wall 224, inner shell divider wall 242, and inner shell inlet 230. Fuel inlet collection chamber 266 is at least partially annular and extends along fuel inlet collection wall 224.

[0110] Fuel flows from fuel inlet collection chamber 266 into fuel inlet concentrating chamber 268 (e.g., a gap, cavity, etc.). Fuel inlet concentrating chamber 268 is defined between fuel inlet concentrating wall 226, air inlet body 212, and inner shell inlet body 238. Inner shell inlet body 238 includes a lobe 270 (e.g., an end, etc.). Fuel flows along lobe 270 within fuel inlet concentrating chamber 268. Fuel inlet concentrating wall 226 is defined by a first radius of curvature, and lobe 270 is defined by a second radius of curvature.

[0111] In various embodiments, the protrusion 270 and the fuel inlet concentrating wall 226 are configured such that the first radius of curvature is substantially equal (e.g., within 5%, equal, etc.) to the second radius of curvature. In these embodiments, the width of the fuel inlet concentrating chamber 268 (e.g., the distance between the protrusion 270 and the fuel inlet concentrating wall 226, etc.) is substantially constant along the length of the fuel inlet concentrating chamber 268 (e.g., the distance between the fuel inlet collecting chamber 266 and the fuel outlet 264, etc.). Furthermore, this provides the gas fuel-air mixer 108 with a lower pressure drop (e.g., the difference between the air pressure upstream of the gas fuel-air mixer 108 and the pressure of the air and fuel mixture downstream of the gas fuel-air mixer 108, etc.) than other mixers that pass fuel through chambers of significantly different widths. In some cases, the increased difference in chamber widths in these other mixers can result in increased backpressure in these mixers, which is undesirable. In some embodiments, the radius of curvature of the protrusion 270 and / or the radius of curvature of the fuel inlet concentrating wall 226 is selected to minimize fuel pressure drop while providing excellent mixture uniformity at the periphery of the air flow.

[0112] The fuel exits the fuel inlet concentrating chamber 268 via the fuel outlet 264. The fuel flows from the fuel outlet 264 into the inner casing inlet body 238. The fuel is evenly distributed around the air within the inner casing inlet body 238, and the fuel and air are propelled through the inner casing inlet body 238 into a conduit downstream of the gas fuel-air mixer 108.

[0113] like Figure 2 and Figure 3As shown, the gas fuel-air mixer 108 further includes at least one fuel chamber rib 272. The fuel chamber rib 272 protrudes across the fuel inlet collecting chamber 266 to prevent fuel from flowing (e.g., allowing less than 5% of the mass of fuel to flow, etc.) from one side (e.g., left side, right side, front side, rear side, etc.) of the fuel chamber rib 272 within the fuel inlet collecting chamber 266 to the other side (e.g., right side, left side, rear side, front side, etc.) of the fuel chamber rib 272. The fuel chamber rib 272 also protrudes across the fuel inlet concentrating chamber 268 to prevent fuel from flowing (e.g., allowing less than 25% of the mass of fuel to flow, etc.) from one side (e.g., left side, right side, front side, rear side, etc.) of the fuel chamber rib 272 within the fuel inlet concentrating chamber 268 to the other side (e.g., right side, left side, rear side, front side, etc.) of the fuel chamber rib 272. In this manner, the fuel chamber ribs 272 reduce swirl of the fuel (e.g., about the air inlet central axis 210, etc.) within the fuel inlet collecting chamber 266 and the fuel inlet concentrating chamber 268. By reducing swirl of the fuel, the fuel chamber ribs 272 reduce swirl imparted by the fuel exiting the fuel outlet 264 on the air within the inner casing inlet body 238, and thus reduce swirl of the air and fuel within the inner casing inlet body 238 and within the conduit downstream of the gas fuel-air mixer 108.

[0114] In some embodiments, as Figure 4 As shown, the gas fuel-air mixer 108 includes only one of the fuel chamber ribs 272. In these embodiments, the fuel chamber rib 272 can be located diametrically opposite the fuel inlet 218. In other words, the fuel chamber rib 272 can be located along the fuel inlet central axis 220 and spaced 180° apart from the fuel inlet 218. This arrangement can be beneficial because the fuel chamber rib 272 evenly distributes the fuel, and the cost of the gas fuel-air mixer 108 associated with the fuel chamber rib 272 is minimized.

[0115] The gas fuel-air mixer 108 may include more than one fuel chamber rib 272. For example, the gas fuel-air mixer 108 may include two, three, four, five, six, seven, eight, or more fuel chamber ribs 272. The fuel chamber ribs 272 may be evenly angularly spaced about at least one of the air inlet central axis 210, the inner casing inlet central axis 236, or the inner casing outlet central axis 262. For example, the gas fuel-air mixer 108 may include three fuel chamber ribs 272 that are angularly spaced 120° apart from adjacent fuel chamber ribs 272.

[0116] In various embodiments, the fuel chamber rib 272 protrudes across the fuel inlet collecting chamber 266 to inhibit fuel flow (e.g., allowing less than 1% of the mass of fuel to flow, etc.) from one side (e.g., left side, right side, front side, rear side, etc.) of the fuel chamber rib 272 to the other side (e.g., right side, left side, rear side, front side, etc.) of the fuel chamber rib 272 within the fuel inlet collecting chamber 266. The fuel chamber rib 272 also protrudes across the fuel inlet concentrating chamber 268 to inhibit fuel flow (e.g., allowing less than 5% of the mass of fuel to flow, etc.) from one side (e.g., left side, right side, front side, rear side, etc.) of the fuel chamber rib 272 to the other side (e.g., right side, left side, rear side, front side, etc.) of the fuel chamber rib 272 within the fuel inlet concentrating chamber 268.

[0117] By reducing turbulence of the air and fuel within the conduit downstream of the gas fuel-air mixer 108, the gas fuel-air mixer 108 has a lower pressure drop (e.g., the difference between the pressure of the air upstream of the gas fuel-air mixer 108 and the pressure of the air and fuel mixture downstream of the gas fuel-air mixer 108, etc.) than other mixers that do not include the fuel chamber ribs 272. This reduction in pressure drop enables the internal combustion engine system 100 to burn fuels (e.g., low heating value fuels, natural gas, fuels with a heating value of less than 450 British thermal units per standard cubic foot of gas, etc.) that cannot be burned in an engine system that does not include a mixer with the fuel chamber ribs 272 without de-rating the engine system or installing a boost system or other components (e.g., a larger fuel control valve, a larger diameter conduit structure, etc.), which are undesirable.

[0118] Furthermore, the reduction in swirl of the air and fuel provided to the compressor 111, and the increased uniformity of the air and fuel mixture, can provide the turbocharger 110 with several advantages over turbochargers in other systems that do not include the fuel plenum ribs 272. For example, the reduction in swirl can provide increased efficiency of the turbocharger 110 compared to turbochargers in other systems that do not include the fuel plenum ribs 272 due to reduced resistance to the movement of the impeller within the compressor 111. Furthermore, the service life of components of the turbocharger 110 can be extended compared to components in turbochargers in other systems that do not include the fuel plenum ribs 272 because the reduction in swirl provides more uniform loading (e.g., aerodynamic loading, etc.) on components within the turbocharger 110.

[0119] In some embodiments, the fuel chamber rib 272 protrudes across the fuel inlet collecting chamber 266 to allow less than 5% (e.g., 1%, 2%, etc.) of the mass of the fuel within the fuel inlet collecting chamber 266 to flow from one side of the fuel chamber rib 272 to the other side of the fuel chamber rib 272. In these embodiments, the fuel chamber rib 272 may also protrude across the fuel inlet concentrating chamber 268 to allow less than 15% (e.g., 10%, 5%, etc.) of the mass of the fuel within the fuel inlet concentrating chamber 268 to flow from one side of the fuel chamber rib 272 to the other side of the fuel chamber rib 272.

[0120] In some embodiments, as Figure 2-Figure 5 As shown, fuel chamber rib 272 is integrally formed with outer shell 200. Fuel chamber rib 272 can be integrally formed with fuel inlet collecting wall 224 and fuel inlet concentrating wall 226. When outer shell 200 is coupled to inner shell 228, fuel chamber rib 272 is in a facing relationship with inner shell inlet body 238 and inner shell divider wall 242. Specifically, the profile of fuel chamber rib 272 matches the profile of inner shell inlet body 238 and inner shell divider wall 242. In some embodiments, when outer shell 200 is coupled to inner shell 228, fuel chamber rib 272 abuts at least one of inner shell inlet body 238 and inner shell divider wall 242.

[0121] In various embodiments, the inner housing inlet body 238 includes at least one slot 274 (eg, channel, groove, etc.). Figure 4 and Figure 5 As shown. When the inner shell 228 is inserted into the outer shell 200, the groove 274 receives the fuel chamber rib 272. The groove 274 extends through the protrusion 270. In some embodiments, the groove 274 extends along an axis parallel to at least one of the air inlet central axis 210, the inner shell inlet central axis 236, or the inner shell outlet central axis 262. As a result of this alignment, the groove 274 can receive the fuel chamber rib 272 without the outer shell 200 rotating relative to the inner shell 228. However, in other embodiments, the groove 274 receives the fuel chamber rib 272 through rotation of the outer shell 200 relative to the inner shell 228 (e.g., when the groove 274 is at least partially bent along the inner shell inlet body 238, etc.). In some embodiments, the number of grooves 274 is equal to the number of fuel chamber ribs 272.

[0122] Figure 6 and Figure 7 The gas fuel-air mixer 108 is depicted in an embodiment in which each fuel chamber rib 272 is integrally formed with the inner shell 228, rather than as in the embodiment of FIG. Figure 2-Figure 5 As shown, the fuel cell ribs 272 are integrally formed with the outer shell 200. In these embodiments, each fuel cell rib 272 may be integrally formed with the inner shell inlet body 238 and the inner shell divider wall 242.

[0123] When the outer shell 200 is coupled to the inner shell 228, each fuel chamber rib 272 is in facing relationship with the fuel inlet collecting wall 224 and the fuel inlet concentrating wall 226. Figure 6 As shown, this arrangement is facilitated in part by each fuel chamber rib 272 extending at least partially along the protrusion 270.

[0124] In some embodiments, outer shell 200 includes at least one slot 274. For example, each slot 274 can be formed in at least one of fuel inlet collecting wall 224 or fuel inlet concentrating wall 226. As described herein, when outer shell 200 is coupled to inner shell 228, each slot 274 receives one of fuel chamber ribs 272.

[0125] Figure 8 The gas fuel-air mixer 108 is depicted in an embodiment in which each fuel chamber rib 272 includes an outer shell rib 800 and an inner shell rib 802. Each outer shell rib 800 is integrally formed with the outer shell 200, and each inner shell rib 802 is integrally formed with the inner shell 228. Each outer shell rib 800 is integrally formed with the fuel inlet collecting wall 224 and / or the fuel inlet concentrating wall 226. Each inner shell rib 802 is integrally formed with the inner shell inlet body 238. For example, each inner shell rib 802 may be integrally formed with the protrusion 270.

[0126] When outer shell 200 is coupled to inner shell 228, each outer shell rib 800 is aligned with one of inner shell ribs 802 and cooperates with inner shell rib 802 to function as one of fuel cell ribs 272 as described herein. For example, when outer shell 200 is coupled to inner shell 228, each outer shell rib 800 may abut one of inner shell ribs 802 such that a substantially fluid-tight seal is formed between outer shell rib 800 and inner shell rib 802 (e.g., allowing less than 5% by mass of fuel to flow, etc.).

[0127] Figures 9-11 The gas fuel-air mixer 108 is depicted in an embodiment in which each fuel chamber rib 272 is integrally formed only with the inner shell inlet body 238. When the outer shell 200 is coupled to the inner shell 228, each fuel chamber rib 272 is in facing relation with the fuel inlet collecting wall 226. In various embodiments, when the outer shell 200 is coupled to the inner shell 228, each fuel chamber rib 272 is not opposed to the fuel inlet collecting wall 224. Figure 11 As shown, this arrangement is facilitated in part by each fuel chamber rib 272 extending at least partially along protrusion 270 .

[0128] Figures 9-11The illustrated gaseous fuel-air mixer 108 includes five fuel chamber ribs 272. In some embodiments, each of the five fuel chamber ribs 272 is angularly spaced approximately 72 degrees apart from adjacent fuel chamber ribs 272. In this manner, fuel flow can be evenly distributed among the five channels formed between adjacent pairs of fuel chamber ribs 272, thereby reducing swirl imparted by the fuel on the gaseous fuel-air mixture.

[0129] Figure 12 and Figure 13 The gas fuel-air mixer 108 is depicted in an embodiment in which each fuel chamber rib 272 is integrally formed only with the fuel inlet collecting wall 226. When the outer shell 200 is coupled to the inner shell 228, each fuel chamber rib 272 is in facing relation with the protrusion 270. In various embodiments, each fuel chamber rib 272 is separate from the fuel inlet collecting wall 224, such that fuel flow between the fuel inlet collecting wall 224 and the inner shell inlet body 238 is not impeded by at least one fuel chamber rib 272.

[0130] Figure 12 and Figure 13 The illustrated gaseous fuel-air mixer 108 includes seven fuel chamber ribs 272. In some embodiments, each of the seven fuel chamber ribs 272 is angularly spaced approximately 51 degrees apart from adjacent fuel chamber ribs 272. In this manner, fuel flow can be evenly distributed among the seven channels formed between adjacent pairs of fuel chamber ribs 272, thereby reducing swirl imparted by the fuel on the gaseous fuel-air mixture.

[0131] IV. Manufacturing of Gas Fuel-Air Mixer

[0132] In various embodiments, the various components of the gas fuel-air mixer 108 (e.g., the outer shell 200, the inner shell 228, etc.) are assembled by additive manufacturing. For example, the gas fuel-air mixer 108 can be assembled using 3D printing, selective laser sintering, or other similar processes. In these embodiments, the gas fuel-air mixer 108 is configured such that in various embodiments, several components of the gas fuel-air mixer 108 are formed integrally. The components of the gas fuel-air mixer 108 can be "integrally formed" when the components of the gas fuel-air mixer 108 are formed and joined together as part of a single manufacturing step. The components of the gas fuel-air mixer 108 can also be "integrally formed" when the components of the gas fuel-air mixer 108 are formed and joined together using multiple manufacturing steps (e.g., machining and subsequent welding, machining and subsequent chemical bending, etc.).

[0133] When two components are "integrally formed," the two components form a single piece or unitary structure that cannot be disassembled without at least partially destroying one or both of the components. For example, when components of the gas fuel-air mixer 108 are integrally formed, the components of the gas fuel-air mixer 108 are: (i) inseparable from one another (e.g., one component of the gas fuel-air mixer 108 cannot be separated from the gas fuel-air mixer 108 without destroying the gas fuel-air mixer 108, etc.); (ii) formed integrally from one another (e.g., the components of the gas fuel-air mixer 108 are formed simultaneously, the components of the gas fuel-air mixer 108 are formed as a single component in a single process, etc.); and (iii) no gaps or joints exist along boundaries between adjacent components of the gas fuel-air mixer 108 (e.g., multiple components that share a boundary, etc.). In some embodiments, the gas fuel-air mixer 108 is constructed entirely of stainless steel (e.g., 316 stainless steel, etc.). In other embodiments, the gaseous fuel-air mixer 108 is constructed entirely of aluminum or steel.

[0134] In embodiments where the components of the gaseous fuel-air mixer 108 are integrally formed, the components do not have any internal joints (e.g., joints between multiple parts of the component, etc.) that create leak paths for air and / or fuel. Consequently, air and fuel cannot leak from the components of the gaseous fuel-air mixer 108. This can reduce warranty costs associated with the internal combustion engine system 100 compared to other mixers that have multiple internal joints that create leak paths. Over time, these leak paths can lead to leakage of air and / or fuel, making these other systems less desirable.

[0135] Furthermore, in embodiments where the components of the gas fuel-air mixer 108 are integrally formed, the part count (e.g., bill of materials item count, inventory item count, etc.) of the components of the gas fuel-air mixer 108 is lower than other conventional mixers because the components are integrally formed.

[0136] Each of the fuel chamber ribs 272, protrusions 270, fuel inlet concentrating wall 226, and other components of the gas fuel-air mixer 108 can be configured to have a target geometry when assembled via additive manufacturing. For example, one fuel chamber rib 272 can have a first cross-sectional shape (e.g., an airfoil, a teardrop, etc.), and another fuel chamber rib 272 can have a second cross-sectional shape (e.g., a square, a triangle, a circle, an ellipse, etc.) that is different from the first cross-sectional shape. By selecting an appropriate cross-sectional shape for each component of the gas fuel-air mixer 108 based on predetermined design and / or performance parameters, a target swirl of the gas fuel-air mixture and / or a pressure drop across the gas fuel-air mixer 108 can be achieved. Furthermore, when the components of the gas fuel-air mixer 108 are integrally formed, the mass of the gas fuel-air mixer 108 can be significantly less than that of a conventional mixer due to the elimination of a large number of fasteners (e.g., bolts, etc.) and the increased material thickness of the fasteners used in conventional mixers.

[0137] V. Operation of the Example Embodiment

[0138] Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of what may be claimed, but rather as descriptions of features that are peculiar to a particular implementation. Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations. Furthermore, although features may be described as working in certain combinations, or even initially claimed as such, in some cases, one or more features from the claimed combination may be cut out of the combination, and the claimed combination may point to a sub-combination or a variant of the sub-combination.

[0139] As used herein, the terms "substantially," "substantially," "approximately," and similar terms are intended to have a broad meaning consistent with common and accepted usage by persons of ordinary skill in the art to which the subject matter of this disclosure relates. Those skilled in the art who review this disclosure should understand that these terms are intended to allow description of certain features described and claimed without limiting the scope of those features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations to the subject matter described and claimed are considered to be within the scope of the invention as set forth in the appended claims.

[0140] As used herein, the terms "coupled" and "coupled" refer to the joining of two components directly or indirectly to one another. Such joining may be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved by the two components, or the two components and any additional intermediate components, being integrally formed as a single unitary body with one another, or by the two components, or the two components and any additional intermediate components, being attached to one another.

[0141] As used herein, the term "fluid coupling" or the like refers to two components or objects having a passage formed between the two components or objects through which a fluid, such as air, fuel, a gaseous fuel-air mixture, etc., can flow, with or without intervening components or objects. Examples of fluid couplings or structures for achieving fluid communication may include pipes, channels, or any other suitable means for achieving fluid flow from one component or object to another.

[0142] It is important to note that the construction and arrangement of the various systems shown in the various example implementations are merely illustrative and not restrictive in nature. All changes and modifications that come within the spirit and / or scope of the described implementations are intended to be protected. It should be understood that some features may not be required, and implementations lacking various features may be considered to be within the scope of this disclosure, which is defined by the claims that follow. When the language "a portion" is used, the item can include a portion and / or the entire item unless specifically stated to the contrary.

[0143] In addition, in the context of a list of elements, the term "or" is used in its inclusive sense (rather than its exclusive sense), so that when used to connect a list of elements, the term "or" refers to one, some, or all of the elements in the list. Unless otherwise specifically stated, conjunction language such as the phrase "at least one of X, Y, and Z" is understood together with the context in which it is typically used to express an item, term, or the like, and can be X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Therefore, unless otherwise indicated, such conjunction language is generally not intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0144] In addition, unless otherwise indicated, the value ranges used herein (e.g., W1 to W2, etc.) include their maximum and minimum values ​​(e.g., W1 to W2 includes W1 and includes W2, etc.). In addition, the value ranges (e.g., W1 to W2, etc.) do not necessarily require that intermediate values ​​be included in the value range (e.g., W1 to W2 may only include W1 and W2, etc.), unless otherwise indicated.

Claims

1. A gas fuel-air mixer comprising: A housing, comprising: an air inlet defining an air inlet central axis and configured to receive air, the air inlet having an air outlet, and - a fuel inlet having a fuel inlet configured to receive fuel; an inner shell including an inner shell inlet configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and to provide a gaseous fuel-air mixture, the inner shell cooperating with the outer shell to define a fuel inlet collecting chamber and a fuel inlet concentrating chamber, the fuel inlet collecting chamber configured to receive fuel from the fuel inlet, the fuel inlet concentrating chamber configured to receive fuel from the fuel inlet collecting chamber and provide fuel to the inner shell inlet; and a fuel chamber rib coupled to at least one of the outer shell or the inner shell, the fuel chamber rib being disposed within at least one of the fuel inlet collecting chamber or the fuel inlet concentrating chamber, The fuel chamber rib extends in a direction parallel to a central axis of the air inlet to define a first channel and a second channel in at least one of the fuel inlet collecting chamber or the fuel inlet concentrating chamber.

2. The gas fuel-air mixer according to claim 1, wherein: at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered about a central axis; The fuel inlet collection chamber extends annularly around the central axis; and The fuel chamber rib extends within the fuel inlet collecting chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet collecting chamber.

3. The gas fuel-air mixer according to claim 2, wherein: The fuel inlet concentration chamber extends annularly around the central axis; and The fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

4. The gas fuel-air mixer according to any one of claims 1 to 3, wherein: The outer shell is integrally formed with the inner shell.

5. The gas fuel-air mixer according to claim 4, wherein The fuel chamber rib is integrally formed with the outer shell and the inner shell.

6. The gas fuel-air mixer according to any one of claims 1 to 3, wherein: The fuel chamber rib is integrally formed with the outer shell.

7. The gas fuel-air mixer according to any one of claims 1 to 3, wherein: The fuel chamber rib is integrally formed with the inner shell.

8. A gas fuel-air mixer comprising: A housing, comprising: an air inlet defining an air inlet central axis and configured to receive air, the air inlet having an air outlet, and - a fuel inlet having a fuel inlet configured to receive fuel; an inner shell including an inner shell inlet configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and to provide a gaseous fuel-air mixture, the inner shell cooperating with the outer shell to define a fuel inlet collecting chamber and a fuel inlet concentrating chamber, the fuel inlet collecting chamber configured to receive fuel from the fuel inlet, the fuel inlet concentrating chamber configured to receive fuel from the fuel inlet collecting chamber and provide fuel to the inner shell inlet; and a fuel chamber rib coupled to the outer shell, the fuel chamber rib being disposed in the fuel inlet collecting chamber and the fuel inlet concentrating chamber, the fuel chamber rib being in confronting relation with a portion of the inner shell, The fuel chamber rib extends in a direction parallel to a central axis of the air inlet to define a first channel and a second channel in at least one of the fuel inlet collecting chamber or the fuel inlet concentrating chamber.

9. The gas fuel-air mixer of claim 8, wherein: at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered about a central axis; The fuel inlet collection chamber extends annularly around the central axis; and The fuel chamber rib extends within the fuel inlet collecting chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet collecting chamber.

10. The gas fuel-air mixer of claim 9, wherein: The fuel inlet concentration chamber extends annularly around the central axis; and The fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

11. The gas fuel-air mixer according to claim 8, wherein The fuel chamber rib is integrally formed with the outer shell.

12. The gas fuel-air mixer according to any one of claims 8 to 11, wherein: The inner shell further comprises an inner shell inlet body having a groove; and The fuel chamber rib is positioned within the groove.

13. A gas fuel-air mixer according to any one of claims 8 to 11, wherein: The inner shell includes an inner shell inlet body; and A portion of the air outlet is disposed within a portion of the inner casing inlet body.

14. A gas fuel-air mixer comprising: A housing, comprising: an air inlet defining an air inlet central axis and configured to receive air, the air inlet having an air outlet, and - a fuel inlet having a fuel inlet configured to receive fuel; an inner shell including an inner shell inlet configured to receive air from the air outlet and fuel from the fuel inlet, respectively, and to provide a gaseous fuel-air mixture, the inner shell cooperating with the outer shell to define a fuel inlet collecting chamber and a fuel inlet concentrating chamber, the fuel inlet collecting chamber configured to receive fuel from the fuel inlet, the fuel inlet concentrating chamber configured to receive fuel from the fuel inlet collecting chamber and provide fuel to the inner shell inlet; and a fuel chamber rib coupled to the inner shell, the fuel chamber rib being disposed within the fuel inlet concentration chamber, the fuel chamber rib being in confronting relationship with a portion of the outer shell, The fuel chamber rib extends in a direction parallel to a central axis of the air inlet to define a first channel and a second channel in at least one of the fuel inlet collecting chamber or the fuel inlet concentrating chamber.

15. The gas fuel-air mixer of claim 14, wherein: at least one of the air inlet, the fuel inlet, or the inner shell inlet is centered about a central axis; The fuel inlet concentration chamber extends annularly around the central axis; and The fuel chamber rib extends within the fuel inlet concentrating chamber to prevent fuel from flowing between the outer shell and the inner shell within the fuel inlet concentrating chamber.

16. The gas fuel-air mixer according to claim 14, wherein The fuel chamber rib is integrally formed with the inner shell.

17. A gas fuel-air mixer according to any one of claims 14 to 16, wherein: The inner shell includes an inner shell inlet body; and A portion of the air outlet is disposed within a portion of the inner casing inlet body.

18. A gas fuel-air mixer according to any one of claims 14 to 16, wherein: The fuel inlet is centered on the fuel inlet central axis; The air outlet is centered on the central axis of the air inlet; and The fuel inlet central axis intersects the air inlet central axis.

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