Liquid-gas separator assembly and method of delivering wastewater

Abstract

Liquid-gas (LG) separator assemblies for separating air and water in a fuel cell system (FCS) exhaust stream, methods of making / using such assemblies, and FCS-driven vehicles equipped with such assemblies are presented. The LG separator assembly includes a quick connect (QC) fitting having a fitting body having a first open end coupled to an exhaust pipe of the FCS to receive an exhaust flow discharged from the FCS. The LG separator unit has a separator body with opposing open ends, with a first open end coupled to a second open end of the fitting body to releasably couple to and receive an exhaust flow from the exhaust pipe through the QC fitting. The LG separator unit extracts liquid water entrained in the exhaust stream, ejects the extracted water through a water nozzle located within the separator body, and discharges the remaining exhaust stream through a second end of the separator body.

Description

Technical Field

[0001] The present disclosure generally relates to electrochemical fuel cell systems for converting hydrogen-rich fuel into electricity. More specifically, aspects of the present disclosure relate to apparatus for separating water from air in an FCS exhaust stream. Background Art

[0002] The motor vehicles currently produced, such as modern cars, are initially equipped with a powertrain that operates to drive the vehicle and provide power for the vehicle's onboard electronics. For example, in automotive applications, the vehicle powertrain is typically represented by a prime mover that transmits drive torque to the vehicle's final drive system (e.g., differential, axle, corner module, wheel, etc.) through an automatic or manually shifted power transmission. Automobiles have historically been powered by reciprocating piston internal combustion engine (ICE) components because they are easily available, relatively inexpensive, lightweight, and highly efficient overall. As some non-limiting examples, such engines include compression ignition (CI) diesel engines, spark ignition (SI) gasoline engines, two-stroke, four-stroke, and six-stroke architectures, and rotary engines. On the other hand, hybrid electric vehicles and all-electric vehicles (collectively referred to as "electrically powered vehicles") utilize alternative energy sources to drive the vehicle, thereby minimizing or eliminating reliance on fossil fuel-based engines to provide traction.

[0003] Hybrid electric and all-electric powertrains employ a variety of architectures, some of which utilize a fuel cell system (FCS) to generate the electricity needed to power the vehicle's electric traction motor. A fuel cell is an electrochemical device that generally consists of an anode electrode that receives hydrogen (H2), a cathode electrode that receives oxygen (O2), and an electrolyte barrier interposed between the anode and cathode electrodes. An electrochemical reaction is induced to oxidize hydrogen molecules on the anode side of the FCS—the hydrogen is catalytically split in a half-cell oxidation reaction—to produce free electrons (-) and free protons (H+). The free hydrogen protons travel through the electrolyte to the cathode, where these protons react with oxygen and electrons to form stack reaction byproducts. However, the free electrons from the anode cannot travel through the electrolyte; these electrons are redirected to a load, such as the vehicle's traction motor and accessories, before being sent to the cathode.

[0004] Fuel cell architectures commonly used in automotive applications contain a semipermeable polymer electrolyte membrane (also known as a "proton exchange membrane" or "PEM") to provide ion transport between the anode and cathode. Proton exchange membrane fuel cells (PEMFCs) typically employ a solid polymer electrolyte (SPE) proton conducting membrane, such as a perfluorosulfonic acid membrane, which, in addition to facilitating proton conduction, separates product gases and provides electrical insulation of the electrodes. The anode and cathode typically include finely dispersed catalytic particles (e.g., platinum) supported on carbon particles and mixed with an ionomer. For some fuel cell manufacturing processes, this catalytic mixture can be deposited on the sides of the membrane to form an anode layer and a cathode layer. The combination of the anode catalyst layer, the cathode catalyst layer, and the electrolyte membrane defines a membrane electrode assembly (MEA), in which the anode catalyst and the cathode catalyst are supported on opposite sides of the ion-conducting solid polymer membrane.

[0005] In order to generate the electricity required to power a motor vehicle, many fuel cells are usually combined in series or in parallel into a fuel cell stack to achieve higher output voltages and allow for stronger current consumption. For example, a typical fuel cell stack for an automobile may have more than two hundred stacked cells. These fuel cell stacks receive a reactant gas as a cathode input, typically a metered flow of ambient air or concentrated gaseous oxygen forced through the stack by a compressor. During normal operation, the stack does not consume a quantifiable mass of oxygen; some residual oxygen is output as a cathode exhaust gas, which may include water as a byproduct of the stack. The fuel cell stack also receives hydrogen or a hydrogen-rich reactant gas as an anode input that flows into the anode side of the stack. For proper fuel cell stack operation, the distribution of hydrogen within the anode flow channel is generally kept substantially constant. Exhaust generated as a byproduct of fuel cell operation may include water vapor, liquid water, air, and negligible levels of waste hydrogen and waste nitrogen. In some operating modes, waste hydrogen can be reused and recycled back into the fuel cell stack so that the anode gas is evenly distributed to achieve a calibrated stack output load. In addition, the fuel cell stack may be operated in such a manner as to maintain the MEA in a moist state in which the gas supplied to the fuel cell stack is moistened with waste water to prevent the MEA from drying out. Summary of the invention

[0006] Described below is a liquid-gas (LG) separator assembly for separating air and water in the exhaust flow of a fuel cell system, a method for manufacturing and using such a separator assembly, and an FCS-powered vehicle equipped with such a separator assembly. In one example, a passive separator assembly is proposed, which can extract liquid water entrained in the exhaust flow of the fuel cell system and transport the extracted water for on-board storage or off-board discharge. The LG separator assembly can be a two-part structure, which is mainly composed of a quick-connect (QC) fitting that can be releasably mounted on the open end of the FCS exhaust pipe and a liquid-gas separator unit rigidly mounted on the QC fitting. For a three-part structure, the liquid-gas separator assembly can be mainly composed of a QC fitting, a separator unit, and a flexible water pipe that is fluidly connected to a water nozzle extending from the separator unit. The QC fitting may include a retaining ring spring and an annular gasket for friction fit and thereby fluid sealing to the open end of the FCS exhaust pipe. On the other hand, the separator unit can be crimped, clamped, or otherwise rigidly fixed to the open end of the QC fitting. During stationary operation of the vehicle, FCS exhaust flows from the exhaust pipe, passes through the QC fitting, and is fed into the open proximal (top) end of the separator unit. The separator unit may be a spiral-type water separator that utilizes the centripetal force and surface friction of an internal spiral ramp enclosed within a cylindrical body to force entrained liquid water into an axially elongated water nozzle inside the separator unit. The extracted water is discharged through the separator unit's water nozzle and into the water pipe, while excess exhaust gas is discharged through the open distal (bottom) end of the separator unit.

[0007] Ancillary benefits of at least some of the disclosed concepts include lightweight and inexpensive assemblies for passively separating water from exhaust gases without the use of moving parts or active electronic components. Other ancillary benefits may include a gas-liquid separator assembly with universal connectors and ports that can be expanded to nearly any FCS architecture, for example, for conveying water away from a vehicle. The use of quick-connect fittings allows the user to quickly attach or detach the separator assembly to or from a fuel cell system without the use of tools, welding, adhesives, fasteners, or brackets. In addition, the use of a compact separator unit and flexible fluid hoses helps to simplify component integration while minimizing component packaging requirements.

[0008] Various aspects of the present disclosure relate to a passive separator assembly for extracting entrained water from exhaust gas discharged from a fuel cell system, including automotive and non-automotive fuel cell system (FCS) applications. In one example, a liquid-gas separator assembly for a fuel cell system is provided. The LG separator assembly can be a two-piece structure with a quick-connect fitting and an LG separator unit, or a three-piece structure that also includes a flexible water tube. The QC fitting has a fitting body with opposing open ends, wherein the first end is securely connected to the open end of the FCS exhaust pipe to receive the exhaust flow discharged from the FCS. The LG separator unit has a separator body with opposing open ends, wherein the first open end is connected to the second open end of the fitting body, thereby releasably connecting the LG separator assembly to the exhaust pipe of the FCS and receiving the exhaust flow from the exhaust pipe through the QC fitting. The LG separator unit is structurally configured to extract liquid water entrained in the exhaust flow, spray the extracted water through a water nozzle extending axially within the separator body, and discharge the remaining exhaust flow through the second open end of the separator body.

[0009] Additional aspects of the present disclosure relate to an electrically driven vehicle having an electrified powertrain including a traction motor powered by a fuel cell system employing any of the disclosed separator assemblies. As used herein, the terms "vehicle" and "motor vehicle" may be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger vehicles (ICE, HEV, FEV, fully and partially autonomous driving, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road vehicles (ORV) and all-terrain vehicles (ATV), motorcycles, agricultural equipment, marine vessels, aircraft, etc. For non-automotive applications, the disclosed concepts may be implemented for all logically related uses, including stand-alone power stations, portable power packs, backup generator systems, pumping equipment, residential, commercial and industrial uses, electric vehicle charging stations (EVCS), etc.

[0010] In an example, an electrically driven vehicle includes a body having a passenger compartment, a plurality of wheels mounted to the body (e.g., by corner modules coupled to a unibody or non-load-bearing body chassis), and other standard original equipment. The electrified powertrain includes one or more on-board traction motors that operate alone (e.g., for an FEV powertrain) or in combination with an internal combustion engine assembly (e.g., for an HEV powertrain) to selectively drive one or more wheels to propel the vehicle. A resident FCS mounted on the vehicle oxidizes a hydrogen-based fuel to generate an FCS voltage to power the electrified powertrain (directly or through a traction battery pack). The FCS includes a fuel cell stack, an exhaust manifold that collects exhaust and byproducts from the cells in the fuel cell stack, and exhausts the exhaust from the FCS through an exhaust pipe.

[0011] Continuing with the discussion of the previous example, the vehicle is also equipped with a liquid-gas separator assembly that passively separates entrained water from the discharged FCS exhaust flow. The separator assembly includes a QC fitting made of a hollow body having longitudinally spaced and opposing open ends. The first open end of the QC fitting body is physically mounted on the exhaust pipe of the FCS and fluidly sealed to the exhaust pipe of the FCS, thereby receiving the exhaust flow discharged from the FCS. The separator assembly also includes a LG separator unit, which is made of an elongated separator body having longitudinally spaced and opposing open ends. The first open end of the separator body is physically mounted on the second open end of the fitting body and fluidly sealed to the second open end of the fitting body, thereby releasably connecting the LG separator unit to the FCS exhaust pipe and receiving the exhaust flow passing through the QC fitting therefrom. The LG separator unit is structurally configured to passively extract liquid water entrained in the exhaust gas flow, spray the extracted water through a hollow cylindrical water nozzle that extends axially through the center of the separator body and protrudes from its second open end, and discharge the remaining exhaust gas flow through this second open end.

[0012] Aspects of the present disclosure also relate to manufacturing workflow processes, system control logic, and computer readable media (CRM) for manufacturing and / or using any disclosed separator assembly. In an example, a method for manufacturing a liquid-gas separator assembly for a fuel cell system is presented. The representative method includes, in any order and in any combination of any of the options and features disclosed above and below: manufacturing, retrieving, and / or inputting (collectively referred to as "receiving") a quick-connect fitting having a fitting body with opposing first and second open QC ends; connecting the first open QC end of the fitting body to the FCS exhaust pipe, thereby receiving an exhaust flow discharged from the FCS; receiving a liquid-gas separator unit having a separator body, the separator body having opposing first and second open LG ends; connecting the first LG open end of the separator body to the second open QC end, thereby releasably connecting the LG separator unit to the FCS exhaust pipe and receiving the exhaust flow therefrom through the QC fitting, the LG separator unit being configured to extract liquid water entrained in the exhaust flow, spraying liquid water through a water nozzle extending axially in the separator body, and discharging the exhaust flow through the second open LG end.

[0013] For any of the disclosed assemblies, vehicles, and methods, the separator body may include a proximal (first) internal fluid chamber adjacent to the top (first) open end of the separator body, a distal (second) internal fluid chamber adjacent to the bottom (second) open end of the separator body, and a spiral ramp between and axially separating the two internal fluid chambers. As a further option, the water nozzle may include a hollow cylinder coaxially aligned with the opposite open ends of the separator body; in this case, the spiral ramp may be adjacent to the hollow cylinder of the water nozzle and axially surround the hollow cylinder. The hollow cylinder of the water nozzle may have longitudinally spaced opposite open ends that are concentrically aligned with the two open ends of the separator body, such as so that the flow-restricted volume of the exhaust gas flow pushes the extracted water through the water nozzle.

[0014] For any of the disclosed assemblies, vehicles, and methods, the LG separator unit may also include a dam wall that protrudes axially from the end of the spiral ramp and extends radially inward from the inner surface of the separator body. In this case, the water nozzle may include a fluid port that extends laterally through the hollow cylinder and is aligned with the radially inner end of the dam wall, such as so that the dam wall impedes the flow of liquid water down the spiral ramp and directs water into the fluid port. It may be desirable that the LG separator unit - separator body, water nozzle, spiral ramp, dam wall, etc. - is integrally formed as a single, one-piece structure (e.g., injection molded from polypropylene (PP)). To help minimize or eliminate back pressure within the FCS exhaust pipe, the opening diameter of the open end of the LG separator body may be approximately equal to or greater than the pipe diameter of the FCS exhaust pipe. In this case, the water nozzle that may be concentrically aligned with the open end of the separator body may have a nozzle diameter that is less than the diameter of the FCS exhaust pipe.

[0015] For any disclosed assembly, vehicle, and method, the QC fitting may include a spring and a seal, both of which are physically attached to the fitting body. The spring and the seal are cooperatively configured to friction fit the QC fitting onto the FCS exhaust pipe. On the other hand, the second (bottom) open end of the fitting body can be inserted into the top (first) open end of the separator body and crimped or clamped to the top (first) open end of the separator body. As a further option, the QC fitting can be a twist lock QC fitting, a Luer lock QC fitting, a ball-sleeve QC fitting, a cam lock QC fitting, and / or a friction fit QC fitting. It may be desirable that the liquid-gas separator assembly is characterized by a lack of electrical components and is mainly composed of a QC fitting and a LG separator unit. As a further option, the LG separator assembly may also include a flexible water pipe, which is connected to the open (bottom) end of the water nozzle to divert the extracted water away from the FCS. In this case, the LG separator assembly is characterized by a lack of electrical components and a lack of moving parts, and may be mainly composed of a QC fitting, a LG separator unit, and a flexible water pipe.

[0016] The present invention provides the following technical solutions:

[0017] 1. A gas-liquid separator assembly for a fuel cell system (FCS), the FCS comprising a fuel cell stack and an FCS exhaust pipe fluidly connected to the fuel cell stack and configured to discharge an exhaust flow from the FCS, the gas-liquid separator assembly comprising:

[0018] a quick connect (QC) fitting having a fitting body with opposed first and second open QC ends, the first open QC end of the fitting body being configured to couple to the FCS exhaust pipe to receive an exhaust flow discharged from the FCS; and

[0019] A liquid-gas (LG) separator unit having a separator body having first and second opposed open LG ends, the first LG open end of the separator body being coupled to the second open QC end so as to be releasably coupled to the FCS exhaust pipe and receive the exhaust flow therefrom through the QC fitting, the LG separator unit being configured to extract liquid water entrained in the exhaust flow, spray the liquid water through a water nozzle extending axially within the separator body, and discharge the exhaust flow through the second open LG end.

[0020] 2. A liquid-gas separator assembly according to Option 1, wherein the separator body includes a first internal fluid chamber adjacent to the first LG opening end, a second internal fluid chamber adjacent to the second LG opening end, and a spiral ramp inserted between the first and second internal fluid chambers and separating the first and second internal fluid chambers.

[0021] 3. A liquid-gas separator assembly according to Option 2, wherein the water nozzle includes a hollow cylinder coaxially aligned with the first and second LG opening ends of the separator body, and the spiral ramp is adjacent to and spirally surrounds the hollow cylinder of the water nozzle.

[0022] 4. The gas-liquid separator assembly of claim 3, wherein the hollow cylindrical body of the water nozzle has opposing first and second open nozzle ends that are concentrically aligned with the first and second LG open ends of the separator body.

[0023] 5. A gas-liquid separator assembly according to Option 3, wherein the LG separator unit further comprises a dam wall protruding from the end of the spiral ramp and extending radially inward from the inner surface of the separator body, and wherein the water nozzle comprises a fluid port extending laterally through the hollow cylinder and aligned with the radially inward end of the dam wall.

[0024] 6. The gas-liquid separator assembly according to claim 5, wherein the LG separator unit including the separator body, the water nozzle, the spiral ramp and the dam wall is integrally formed as a single-piece structure.

[0025] 7. A gas-liquid separator assembly according to Option 1, wherein the FCS exhaust pipe has a pipe diameter, the first LG open end of the separator body has a first diameter, and the second LG open end has a second diameter, and the first diameter and the second diameter are approximately equal to or greater than the pipe diameter.

[0026] 8. The gas-liquid separator assembly of claim 7, wherein the water nozzle is concentrically aligned with the first LG open end and the second LG open end and has a nozzle diameter that is smaller than a tube diameter of the FCS exhaust pipe.

[0027] 9. A gas-liquid separator assembly according to Option 1, wherein the QC fitting includes a spring and a seal, which are attached to the fitting body and cooperatively configured to friction fit the QC fitting onto the FCS exhaust pipe, and wherein the second open QC end of the fitting body is crimped to the first LG open end of the separator body.

[0028] 10. The gas-liquid separator assembly of Option 1, wherein the QC fitting is a twist-lock QC fitting, a Luer-lock QC fitting, a ball-and-socket QC fitting, a cam-lock QC fitting, or a friction-fit QC fitting.

[0029] 11. The gas-liquid separator assembly according to claim 1, wherein the gas-liquid separator assembly is characterized by lacking electrical components and consisting primarily of a QC fitting and a LG separator unit.

[0030] 12. The gas-liquid separator assembly of claim 1, further comprising a flexible water tube coupled to the open nozzle end of the water nozzle to convey the extracted liquid water away from the FCS.

[0031] 13. A gas-liquid separator assembly according to Option 12, wherein the gas-liquid separator assembly is characterized by having no electrical components and mainly consisting of QC fittings, LG separator units and flexible water pipes.

[0032] 14. A motor vehicle comprising:

[0033] Car body;

[0034] a plurality of wheels attached to the vehicle body;

[0035] an electric motor attached to the vehicle body and configured to drive one or more wheels to propel the motor vehicle;

[0036] a fuel cell system (FCS) attached to the vehicle body and operable to power the electric motor, the FCS comprising a fuel cell stack and an FCS exhaust conduit fluidly connected to the fuel cell stack to exhaust an exhaust flow from the FCS; and

[0037] A passive liquid-gas separator assembly comprising:

[0038] a quick connect (QC) fitting having a hollow fitting body with longitudinally spaced and opposed first and second open QC ends, the first open QC end of the fitting body physically mounted on and fluidly sealed to the FCS exhaust pipe to receive an exhaust flow discharged from the FCS; and

[0039] A liquid-gas (LG) separator unit having an elongated separator body having first and second longitudinally spaced apart and opposed open LG ends, the first LG open end of the separator body being physically mounted on and fluidly sealed to the second open QC end, thereby releasably coupling the LG separator unit to an FCS exhaust pipe and receiving an exhaust flow therefrom through a QC fitting, the LG separator unit being configured to extract liquid water entrained in the exhaust flow, spray the liquid water through a hollow cylindrical water nozzle extending axially through the center of the separator body and protruding from the second open LG end, and discharge the exhaust flow through the second open LG end of the separator body.

[0040] 15. A method of manufacturing a gas-liquid separator assembly for a fuel cell system (FCS), the FCS comprising a fuel cell stack and an FCS exhaust conduit fluidly connected to the fuel cell stack and configured to exhaust an exhaust stream from the FCS, the method comprising:

[0041] receiving a quick connect (QC) fitting having a fitting body with opposed first and second open QC ends;

[0042] coupling the first open QC end of the fitting body to the FCS exhaust pipe to receive the exhaust flow from the FCS;

[0043] receiving a liquid-gas (LG) separator unit having a separator body with opposed first and second open LG ends; and

[0044] The LG separator unit is releasably coupled to the FCS exhaust pipe by coupling the first LG open end to the second open QC end of the separator body and receiving the exhaust flow therefrom through the QC fitting, the LG separator unit being configured to extract liquid water entrained in the exhaust flow, spray the liquid water through a water nozzle extending axially within the separator body, and discharge the exhaust flow through the second open LG end.

[0045] 16. A method according to Option 15, wherein the separator body includes a first internal fluid chamber adjacent to the first LG open end, a second internal fluid chamber adjacent to the second LG open end, and a spiral ramp inserted between the first and second internal fluid chambers and separating the first and second internal fluid chambers.

[0046] 17. A method according to option 16, wherein the water nozzle includes a hollow cylinder coaxially aligned with the first and second LG open ends of the separator body, and the spiral ramp is adjacent to and spirally surrounds the hollow cylinder of the water nozzle.

[0047] 18. A method according to Option 17, wherein the LG separator unit also includes a dam wall, which extends radially within the separator body and protrudes from the end of the spiral ramp, and wherein the water nozzle includes a fluid port extending laterally through the hollow cylinder and aligned with the radially inward end of the dam wall.

[0048] 19. A method according to Option 15, wherein the FCS exhaust pipe has a pipe diameter, the first LG open end and the second LG open end of the separator body have corresponding first diameters and second diameters, and the water nozzle has a nozzle diameter, and wherein the first diameter and the second diameter are approximately equal to or greater than the pipe diameter, and the nozzle diameter is smaller than the pipe diameter.

[0049] 20. The method of claim 15, further comprising coupling a flexible water tube to an open nozzle end of the water nozzle to convey the extracted liquid water away from the FCS.

[0050] The above overview does not represent every embodiment or every aspect of the present disclosure. On the contrary, the foregoing overview only provides an outline of some novel concepts and features set forth herein. When combined with the accompanying drawings and the appended claims, the above-mentioned features and advantages of the present disclosure and other features and accompanying advantages will become apparent from the following detailed description of the illustrated examples and representative modes for performing the present disclosure. In addition, the present disclosure expressly includes any and all combinations and sub-combinations of the elements and features presented above and below. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is an elevational perspective view of a representative motor vehicle with a schematic illustration of a rechargeable energy storage system (RESS) including a traction battery pack and a fuel cell system for operating an electric motor of an electrified powertrain in accordance with aspects of the disclosed concepts.

[0052] Figure 2is a perspective view of a representative passive type liquid-gas separator assembly for a fuel cell system in accordance with aspects of the disclosed concepts.

[0053] Figure 3 yes Figure 2 A partially exploded front perspective view of a representative gas-liquid separator assembly.

[0054] Figure 4 yes Figure 2 A cross-sectional elevation view of a representative gas-liquid separator assembly.

[0055] The present disclosure is susceptible to various modifications and alternative forms, and some representative embodiments of the present disclosure are shown in the accompanying drawings by way of example and will be described in detail herein. However, it should be understood that the novel aspects of the present disclosure are not limited to the specific forms shown in the drawings listed above. On the contrary, the present disclosure encompasses all modifications, equivalents, combinations, arrangements, groupings, and substitutions that fall within the scope of the present disclosure, such as those covered by the appended claims. DETAILED DESCRIPTION

[0056] The present disclosure may take many different forms of embodiments. Representative embodiments of the present disclosure are shown in the accompanying drawings and will be described in detail herein, and it should be understood that these embodiments are provided as examples of the disclosed principles, rather than limitations on the broad aspects of the present disclosure. In this regard, elements and limitations that are described, for example, in the abstract, introduction, overview, illustrations, and detailed description sections, but not explicitly set forth in the claims, should not be incorporated into the claims individually or collectively by implication, inference, or otherwise. In addition, statements of "first", "second", "third", etc. in the specification or claims are not themselves used to establish order or numerical limitations; unless otherwise specifically stated, these names can be used to facilitate reference to similar features in the specification and drawings and to distinguish between similar elements in the claims.

[0057] For the purposes of this detailed description, unless expressly denied: the singular includes the plural and vice versa; the words "and" and "or" are both conjunctions and disjunctions; the words "any" and "all" each mean "any and all"; the words "include," "contain," "includes," "have," and the like each mean "including but not limited to." In addition, approximate words such as "approximately," "almost," "substantially," "roughly," "approximately," and the like may each be used herein to mean, for example, "at, approximately, or nearly at..." or "within 0-5% of..." or "within acceptable manufacturing tolerances," or any logical combination thereof. Finally, directional adjectives and adverbs, such as front, rear, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, front, rear, left, right, and the like, may be with respect to a motor vehicle, such as the forward direction of travel of a motor vehicle when the vehicle is operably oriented on a level running surface.

[0058] Referring now to the drawings, in which like reference numerals refer to like features throughout the several views, Figure 1 A representative automobile is shown, generally indicated at 10 and depicted herein for purposes of discussion as a sedan-type fuel cell electric vehicle (FCEV). The illustrated automobile 10 - also referred to herein as a "motor vehicle" or simply "vehicle" - is merely an exemplary application in which various aspects of the present disclosure may be practiced. Likewise, the incorporation of the inventive concepts into the illustrated proton exchange membrane fuel cell (PEMFC) system should be understood as a non-limiting implementation of the disclosed features. Therefore, it should be understood that aspects and features of the present disclosure may be applied to other fuel cell system (FCS) architectures, incorporated into any logically related type of vehicle, and implemented for automotive and non-automotive applications alike. In addition, only selected components of the motor vehicle, fuel cell system, and LG separator assembly are illustrated and described in greater detail herein. However, the vehicles, systems, and assemblies discussed below may include many additional and alternative features and other available peripheral components for performing the various methods and functions of the present disclosure.

[0059] Enclosed within a body 12 of the automobile 10 is a representative fuel cell system 14 for powering a prime mover, such as a motor-generator unit (MGU) 16 , which is operable to drive any one or more of the vehicle's wheels 18 . Figure 1 The proton exchange membrane fuel cell system 14 is equipped with one or more fuel cell stacks 20, each fuel cell stack 20 consisting of a plurality of PEM-type fuel cells 22 stacked on each other and electrically connected in series or in parallel. In the illustrated structure, each fuel cell 22 is a multi-layered structure having an anode side 24 and a cathode side 26, which are separated by a proton conductive perfluorosulfonic acid membrane 28. An anode diffusion medium layer 30 is disposed on the anode side 24 of the PEMFC 22, and an anode catalyst layer 32 is interposed between the membrane 28 and the corresponding diffusion medium layer 30 and operably connects the membrane 28 and the corresponding diffusion medium layer 30. Juxtaposed in a relative spaced relationship with the anode layers 30 and 32 is a cathode diffusion medium layer 34, which is disposed on the cathode side 26 of the PEMFC 22. A cathode catalyst layer 36 is interposed between the membrane 28 and the corresponding diffusion medium layer 34 and operably connects the membrane 28 and the corresponding diffusion medium layer 34. The two catalyst layers 32 and 36 cooperate with the membrane 28 to define, in whole or in part, a membrane electrode assembly (MEA) 38 .

[0060] Diffusion media layers 30 and 34 are porous structures that provide fluid inlet delivery to and fluid exhaust delivery from MEA 38. An anode flow field plate (or "first plate") 40 is disposed on anode side 24 in adjacent relationship to anode diffusion media layer 30. Similarly, a cathode flow field plate (or "second plate") 42 is disposed on cathode side 26 in adjacent relationship to cathode diffusion media layer 34. Coolant flow channels 44 pass through each flow field plate 40 and 42 to allow cooling fluid to flow through fuel cell 22. Fluid inlets and headers direct hydrogen-rich fuel and oxidant to corresponding channels in anode flow field plate 40 and cathode flow field plate 42. The central active area of ​​anode plate 40 facing proton conducting membrane 28 can be fabricated with an anode flow field consisting of serpentine flow channels for distributing hydrogen gas on opposite faces of membrane 28. MEA 38 and plates 40, 42 can be stacked together between stainless steel clamps and single end plates (not shown). These clamps can be electrically insulated from the end plates by gaskets or dielectric coatings. The fuel cell system 14 may also employ anode recirculation, wherein anode recirculation gas is supplied from an exhaust manifold or header through an anode recirculation line for recirculating hydrogen back to the anode side 24 input to conserve hydrogen in the stack 20 .

[0061] A hydrogen (H2) inlet flow - whether gaseous, concentrated, entrained or otherwise - is delivered from a hydrogen source (e.g., a fuel storage tank 46) to the anode side 24 of the fuel cell stack 20 via a fluid injector 47 connected to a (first) fluid inlet conduit or hose 48. The anode exhaust leaves the stack 20 via a (first) fluid exhaust conduit or hose 50. Although shown on the anode side of the stack, a compressor or pump 52 forces a cathode inlet flow (e.g., ambient air and / or concentrated gaseous oxygen (O2)) to the cathode side 26 of the stack 20 via a (second) fluid intake line or manifold 54. The cathode exhaust is output from the stack 20 via a (second) fluid exhaust conduit or hose 56. Flow control valves, flow restrictors, filters, and other available devices for regulating fluid flow may be provided by the stack 20. Figure 1 The PEMFC system 14 is implemented as shown in FIG. The power generated by the fuel cell stack 20 and output by the fuel cell system 14 may be transmitted for storage in an onboard traction battery pack 82 within a rechargeable energy storage system (RESS) 80 .

[0062] Figure 1The fuel cell system 14 may also include a thermal subsystem that is operable to control the temperature of the fuel cell stack 20 during pre-conditioning, running-in, and post-conditioning. According to the example shown, the cooling fluid pump 58 pumps the cooling fluid through the coolant loop 60 to the fuel cell stack 20 and into the coolant channel 44 in each cell 22. The radiator 62 and the optional heater 64 fluidly connected in the coolant loop 60 are used to maintain the cell stack 20 at the desired operating temperature. The fuel cell conditioning system can be equipped with various sensing devices for monitoring the progress of system operation and fuel cell running-in. For example, the (first) temperature sensor 66 monitors the temperature value of the coolant at the coolant inlet of the fuel cell stack 20, and the (second) temperature sensor 68 measures the temperature value of the coolant at the coolant outlet of the fuel cell stack 20. The electrical connector or cable 74 connects the fuel cell stack 20 to the electrical load 76, which can be used to draw current from each cell 22 in the fuel cell stack 20. The voltage / current sensor 70 is operable to measure, monitor, or otherwise detect the fuel cell voltage and / or current across the fuel cell 22 in the cell stack 20.

[0063] A programmable electronic control unit (ECU) 72 helps control the operation of the fuel cell system 14. As an example, the ECU 72 receives a temperature signal T1 from the temperature sensors 66, 68 indicating the operating temperature of the fuel cell stack 20; the ECU 72 may be programmed to responsively issue a command signal C1 to adjust the operation of the stack 20. Figure 1 The ECU 72 also receives a voltage signal V1 from the voltage sensor / current 70 ; the ECU 72 may be programmed to responsively issue a command signal C2 to adjust the operation of the hydrogen source (eg, fuel tank 46 ) and / or compressor / pump 52 , thereby adjusting the electrical output of the stack 20 . Figure 1 ECU 72 is also shown receiving coolant temperature signal T2 from sensor 66 and / or 68; ECU 72 may be programmed to responsively issue command signal C3 to adjust operation of the fuel cell's thermal system. N can be received by the ECU 72, and the additional control command C N The ECU 72 may issue a command signal to transfer the evolving hydrogen gas and liquid H2O from the cathode side 26 through the fluid exhaust conduit 56 to the storage tank 78 ( Figure 1 ), where hydrogen and water from the cathode combine with depleted hydrogen exhausted from the anode through fluid exhaust conduit / hose 50.

[0064] Continue to refer Figure 1, the traction battery pack 82 of the RESS 80 can include an array of rechargeable lithium-based (secondary) battery modules 84. Aspects of the disclosed concepts can be similarly applied to other electrical storage unit architectures, including electrical storage unit architectures that employ nickel metal hydride (NiMH) batteries, solid-state (SS) batteries, lithium metal and lithium sulfur batteries, or other applicable types of rechargeable electric vehicle batteries (EVBs). Each battery module 84 can include a series of electrochemical battery cells, such as soft-pack lithium-ion (Li-ion) or lithium-ion polymer battery cells 86. A single battery module 84 can be represented by a group of 10-45 lithium-ion battery cells, which are stacked side by side, facing each other and connected in parallel or in series to store and supply electrical energy. Although described as a silicon-based lithium-ion "soft pack battery" battery pack, the battery cell 86 can be suitable for other structures, including cylindrical structures and square structures. In order to increase the voltage output of the vehicle FCS, a corresponding DC-DC boost converter (DC CON) 193 can be electrically inserted between the fuel cell stack 20 and the RESS 80.

[0065] During operation of the motor vehicle 10, the vehicle's fuel cell system 14 produces exhaust that may contain liquid water, humidified air with entrained water vapor, low levels of waste hydrogen, and other non-toxic trace elements. For certain vehicle configurations, these byproducts of FCS operation are exhausted from the vehicle; when the vehicle is stationary, liquid water entrained in the FCS exhaust stream may spray onto the road surface and may coalesce into puddles. While some FCEV architectures can recycle metered wastewater back to the FCS, for example, to humidify the battery stack, or store the wastewater in an onboard tank, such as for drinking, most architectures do not provide for the use of auxiliary devices to transport the wastewater away from the vehicle. Those vehicles that are equipped with hardware for managing FCS wastewater typically employ expensive and complex electromechanical devices or bulky mechanical devices that require moving parts and a large amount of packaging space.

[0066] Described below is a lightweight and compact liquid-gas (LG) separator assembly for extracting liquid water from the exhaust gas of a fuel cell system and delivering the extracted water for onboard storage or off-board discharge. Figure 2 An example of a system-integrated passive LG separator assembly 200 is shown for separating exhaust water in a fuel cell system, such as Figure 1The proton exchange membrane FCS14 of the present invention and the water extracted from the FCS are discharged, for example, the water is discarded from the vehicle 10. According to the illustrated example, the separator assembly 200 can be a two-part structure, which includes: a quick connect (QC) fitting 202, which is operably attached to the open end of the FCS exhaust pipe 208, and a liquid-gas separator unit 204, which is operably attached to the QC fitting 202 on the side opposite to the exhaust pipe 208. For a three-part configuration, the separator assembly 200 can also include a flexible water tube 206, which is operably attached to the separator unit 204 on the side opposite to the QC fitting 202. When integrated into the motor vehicle 10, the two-part design of the separator assembly 200 can be inserted between the exhaust hoses 50, 52 and the tank 78, for example, using a manifold connector (not shown) to combine the anode and cathode exhaust from the respective sides of the battery pack 20. On the other hand, a three-part variation of the separator assembly 200 may replace the reservoir 78 and thereby allow liquid water to drain from the vehicle body 12. It should be appreciated that the separator assembly 200 may be packaged in a manner relative to the vehicle body 12. Figure 1 Other locations of FCS14 and can be Figure 2 The components shown may be composed of more, fewer or alternative components.

[0067] The quick connect fittings 202 enable an assembly line operator or system user to quickly attach or remove the LG separator assembly 200 to or from a fuel cell system, e.g., without the use of tools, welding, adhesives, fasteners, or brackets. Figure 3 and Figure 4 As shown, the QC fitting 202 is made of an annular fitting body 210 having a hollow core inserted between an open top end 211 (a first open end) that is longitudinally spaced and opposite an open bottom end 213 (a second open end). The open top end 211 of the QC fitting body 210 is securely coupled to the open end of the FCS exhaust tube 208 and, in doing so, receives exhaust gas discharged from the FCS. It is contemplated that the QC fitting 202 may take on several form factors, including a twist lock QC fitting, a luer lock QC fitting, a ball-and-socket QC fitting, a cam lock QC fitting, and / or a friction fit QC fitting, the latter of which is shown in the figures and described in further detail below.

[0068] According to the example shown in the figure, Figure 2-Figure 4The QC fitting 204 of FIG. 2 employs a spring element (e.g., a U-shaped retaining ring spring 212) and a sealing element (e.g., an annular gasket seal 214) that are operably attached to a QC fitting body 210 and cooperatively configured to sealingly engage and friction fit the QC fitting 202 onto the end of an FCS exhaust pipe 208. The retaining ring spring 212 is shown mounted to the outer diameter (OD) surface of the fitting body 210 near its top end 211, and when the QC fitting 202 is pressed onto the exhaust pipe 208, the retaining ring spring 212 slides onto and presses against the outer diameter surface of the exhaust pipe 208. In contrast, the gasket seal 214 is shown mounted inside the fitting body 210, adjacent its inner surface near the open bottom end 213; when the pipe 208 slides downward into the QC fitting body 210, the gasket seal 214 presses against the inner diameter (ID) surface of the exhaust pipe 208. It may be advantageous to manufacture the QC fitting body 210 as a one-piece construction from a deep drawn material, such as stainless steel sheet.

[0069] LG separator unit 204 is located downstream of QC fitting 202 in flow, inserted inline between exhaust pipe 208 and water pipe 206, and is structurally configured to extract liquid water from the exhaust stream discharged from the FCS, for example, without the use of any moving parts or electronic components. Figure 3 and Figure 4 As shown, the separator unit 204 is made of an elongated cylindrical separator body 216 having an open top end 215 (first open end) longitudinally spaced and opposite an open bottom end 217 (second open end). The open top end 215 of the LG separator body 216 is securely coupled to the open bottom end 213 of the QC fitting body 210, such as via crimping, clamping, threading, or interference fit, and in doing so receives exhaust gas discharged from the FCS through the QC fitting 202. It is contemplated that the LG separator unit 204 can take on a myriad of form factors, including tubular (centrifugal) air-water separators and ramp (centripetal) air-water separators, the latter of which are shown in the drawings and described in further detail below.

[0070] According to the example shown in the figure, Figure 2-Figure 4 The LG separator unit 204 includes a top (first) internal fluid chamber 221 adjacent to the open top end 215 of the separator body 216 and facing the FCS exhaust pipe 208. A bottom (second) internal fluid chamber 223 is also disposed within the separator unit 204 adjacent to the bottom open end 217 of the separator body 216 and facing the water pipe 206. A spiral ramp 218 is interposed between and separates the two longitudinally spaced internal fluid chambers 221, 223 contained in the separator body 216. Although not limiting in itself, the spiral ramp 218 may be a right-handed cylindrical spiral with a single spiral turn (in Figure 4 As another option, the total volume of the top fluid chamber 221 can be less than the total volume of the bottom fluid chamber 223.

[0071] The water nozzle 220 extends axially through the center of the LG separator unit body 216, and the liquid water extracted by the separator unit 204 is discharged from the separator body 216 through the water nozzle 220. To simplify design and manufacturing, the water nozzle 220 can be a hollow right cylindrical body coaxially aligned with the opposite open ends 215, 217 of the LG separator body 216, such as Figure 4 The hollow cylindrical nozzle 220 has opposing top (first) and bottom (second) open nozzle ends 225 and 227, respectively, which are concentrically aligned with the top and bottom open ends 215 and 217 of the separator body 216. Although not required per se, the topmost proximal end 225 of the water nozzle 220 can be surrounded by and substantially coplanar with the top end 215 of the LG separator body 216, while the bottommost distal end 227 of the water nozzle 220 can protrude axially beyond the bottom end 217 of the body 216. It is contemplated that the water nozzle 216 can take on alternative lengths, diameters, and shapes without departing from the intended scope of the present disclosure.

[0072] For example, using centripetal force and surface friction, the spiral ramp 218 extracts liquid water from the FCS exhaust stream and directs the extracted water to the water nozzle 220 inside the LG separator unit 204. The spiral ramp 218 projects inwardly from the ID surface of the separator body 216, abuts against the OD surface of the cylindrical water nozzle 220 and wraps spirally around it. Protruding axially upward at an oblique angle from the bottom-most end of the spiral ramp 218 is a dam wall (shown in FIG. Figure 4 222 in the figure), which extends radially inward from the ID surface of the separator body 216. The fluid port (shown as Figure 4 229 in the figure) extends transversely through the cylindrical wall of the water nozzle 220 and is aligned with the radially innermost end of the dam wall 222. With this arrangement, the dam wall 222 blocks the liquid water flowing down the spiral ramp 218 and guides the flowing water into the fluid port 229. It may be desirable that the LG separator unit 204, including the separator body 216, the spiral ramp 218, the water nozzle 220 and the dam wall 222, are integrally formed as a single one-piece structure (e.g., injection molded from polypropylene (PP)).

[0073] During operation of the LG separator assembly 200, the topmost proximal end of the water tube 206 is pressed onto or otherwise fluidly coupled with the bottom end 227 of the water nozzle 220. If the separator unit 204 and the QC fitting are not preassembled as a single unit, the top end 215 of the LG separator unit body 216 is securely coupled to the open bottom end 213 of the QC fitting 202. The QC fitting 202 is then pressed onto the FCS exhaust pipe 208 and thereby releasably coupled to the FCS exhaust pipe 208, so that the LG separator unit 204 receives the exhaust flow exiting the FCS through the QC fitting 202. For other quick-connect form factors, the top section of the fitting can be rigidly attached to the exhaust pipe, the bottom end of the fitting can be rigidly attached to the separator unit, and the two mating sections releasably mate with each other. When the FCS is in operation, the LG separator unit 204 extracts liquid water entrained in the exhaust flow, sprays the extracted water through the water nozzle 220, and discharges the remaining exhaust flow through the open bottom end 217 of the separator unit 204. The top end 225 of the central water nozzle 220 can be open so that the exhaust flow of the flow-restricted volume flows downward into the nozzle 220 and pushes the extracted water out through the bottom end 227 of the nozzle 220 and into the water pipe 206.

[0074] To help minimize or eliminate undesirable back pressure within the FCS exhaust pipe 208, the inner (first) body diameter D of the open top end 215 of the separator body 216 is B1 and the inner (second) body diameter D of the bottom open end 217 of the separator body 216 B2 Can be greater than or equal to the inner diameter D of the exhaust pipe 208 P1 According to the example shown, the inner diameter D of the top end 215 and the bottom end 217 of the separator body 216 is B1 , D B2 are substantially equal to each other and are both larger than the inner diameter D of the exhaust pipe 208 P1 As a further option, the central water nozzle 220 may have a nozzle inner diameter D N1 , which is smaller than the inner diameter D of the exhaust pipe 208 P1 and smaller than the inner body diameter D B1 , D B2 To minimize system cost, size, and complexity, the gas-liquid separator assembly 200 may lack electrical components and the LG separator unit 204 may lack moving parts. Likewise, the gas-liquid separator assembly 200 may consist essentially of the QC fitting 202 and the LG separator unit 204 (i.e., for a two-part structure), or may consist essentially of the QC fitting 202, the LG separator unit 204, and the flexible water pipe 206 (i.e., for a three-part structure).

[0075] Various aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise configuration and composition disclosed herein; any and all modifications, variations and modifications apparent from the foregoing description are within the scope of the present disclosure as defined by the appended claims. Furthermore, the present concept expressly includes any and all combinations and sub-combinations of the foregoing elements and features.

Claims

1. A gas-liquid separator assembly for a fuel cell system (FCS), the FCS comprising a fuel cell stack and an FCS exhaust pipe fluidly connected to the fuel cell stack and configured to discharge an exhaust flow from the FCS, the gas-liquid separator assembly comprising: a quick connect (QC) fitting having a fitting body with opposed first and second open QC ends, the first open QC end of the fitting body being configured to couple to the FCS exhaust pipe to receive an exhaust flow discharged from the FCS; and A liquid-gas (LG) separator unit having a separator body having first and second opposed open LG ends, the first LG open end of the separator body being coupled to the second open QC end so as to be releasably coupled to the FCS exhaust pipe and receive the exhaust flow therefrom through the QC fitting, the LG separator unit being configured to extract liquid water entrained in the exhaust flow, spray the liquid water through a water nozzle extending axially within the separator body, and discharge the exhaust flow through the second open LG end.

2. The gas-liquid separator assembly of claim 1 , wherein the separator body comprises a first internal fluid chamber adjacent to the first LG open end, a second internal fluid chamber adjacent to the second LG open end, and a spiral ramp interposed between and separating the first and second internal fluid chambers.

3. The gas-liquid separator assembly of claim 2, wherein the water nozzle comprises a hollow cylinder coaxially aligned with the first and second LG open ends of the separator body, and the spiral ramp abuts and spirally surrounds the hollow cylinder of the water nozzle.

4. The gas-liquid separator assembly of claim 3, wherein the hollow cylindrical body of the water nozzle has opposing first and second open nozzle ends concentrically aligned with first and second LG open ends of the separator body.

5. The gas-liquid separator assembly of claim 3, wherein the LG separator unit further comprises a dam wall projecting from a terminal end of the spiral ramp and extending radially inward from an inner surface of the separator body, and wherein the water nozzle comprises a fluid port extending transversely through the hollow cylinder and aligned with a radially inward end of the dam wall.

6. The liquid-gas separator assembly according to claim 5, wherein: The LG separator unit including the separator body, the water nozzle, the spiral ramp and the dam wall is integrally formed as a one-piece structure.

7. The gas-liquid separator assembly of claim 1, wherein the FCS exhaust tube has a tube diameter, the first LG open end of the separator body has a first diameter, and the second LG open end has a second diameter, the first and second diameters being approximately equal to or greater than the tube diameter.

8. The gas-liquid separator assembly of claim 7, wherein the water nozzle is aligned concentrically with the first LG open end and the second LG open end and has a nozzle diameter that is smaller than a tube diameter of the FCS exhaust pipe.

9. The gas-liquid separator assembly of claim 1 , wherein the QC fitting comprises a spring and a seal attached to the fitting body and cooperatively configured to friction fit the QC fitting onto the FCS exhaust pipe, and wherein the second open QC end of the fitting body is crimped to the first LG open end of the separator body.

10. The gas-liquid separator assembly of claim 1, wherein the QC fitting is a twist-lock QC fitting, a Luer-lock QC fitting, a ball-and-socket QC fitting, a cam-lock QC fitting, or a friction-fit QC fitting.

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