Injector with variable nozzle structure

Abstract

An ejector has a variable nozzle structure and is installed in a fuel cell recirculation line to supply new hydrogen gas and recirculation gas. The ejector includes a first housing having a first hole through which hydrogen gas is supplied and a port through which hydrogen gas is discharged, a second housing disposed in the first housing and having a second hole into which hydrogen gas flowing through the first hole flows, and a poppet valve passing through a third hole defined in one side of the second housing. The poppet valve is configured to adjust an area of a space opened by the port through which hydrogen gas is discharged. Hydrogen gas flowing into the second housing moves to the port by being discharged through a space between the other side of the second housing opposite to the one side and the poppet valve.

Description

Technical Field

[0001] The present invention relates to an injector having a variable nozzle structure, which is capable of changing the flow rate of hydrogen discharged from the injector according to the flow rate of hydrogen supplied to the injector. Background Technology

[0002] A hydrogen supply system is configured to receive high-pressure hydrogen from a hydrogen tank and reduce its pressure to the level required by the fuel cell stack. The primary functions of the hydrogen supply system are to adequately supply the hydrogen needed by the fuel cell stack, recycle unreacted hydrogen, and remove impurities from the fuel cell stack to improve hydrogen purity. To produce the maximum output required by the fuel cell stack, the hydrogen supply system should supply an amount of hydrogen equal to or greater than the amount corresponding to the maximum output. To recycle unreacted gases, the hydrogen supply system should use recirculation components such as blowers or injectors to recirculate the unreacted gases.

[0003] A blower can be used as a means of recirculating hydrogen. Blowers are motor-based components and require actuators. Actuators are expensive, and bearings or other components are highly susceptible to corrosion from the condensate in the recirculated gas.

[0004] Using injectors instead of blowers simplifies the technology for hydrogen recirculation. To ensure recirculation performance in the low-output stage and maximum supply performance in the high-output stage, methods such as increasing the pressure at the injector tip or using two injectors are employed.

[0005] However, increasing the pressure at the hydrogen supply end makes it difficult to ensure the airtightness of the hydrogen supply end and maintain internal pressure performance. Furthermore, the method of using two injectors has disadvantages in terms of overall encapsulation due to the increased size of the hydrogen supply system.

[0006] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The object of the present invention is to provide an injector having a variable nozzle structure, which can change the flow rate of hydrogen discharged from the injector according to the flow rate of hydrogen supplied to the injector.

[0008] A variable nozzle structure injector, installed in a fuel cell recirculation line according to an embodiment of the invention, is used to supply fresh hydrogen and recirculated gas. The injector with the variable nozzle structure includes: a first housing in which hydrogen is supplied through a first orifice and discharged through an orifice; a second housing disposed within the first housing and having a second orifice through which hydrogen flows into the second orifice; and a lift valve passing through a third orifice defined on one side (i.e., the first side) of the second housing. The lift valve is configured to adjust the area of ​​the opening of the orifice from which hydrogen is discharged. Hydrogen flowing into the second housing is discharged through the space between the other side of the second housing opposite to the first side (i.e., the second side) and the lift valve, thus moving to the orifice.

[0009] As an example, the lift valve includes a first region passing through a third orifice and a second region adjacent to a second side of the second housing. Hydrogen gas is discharged through the space between the second region and the second housing.

[0010] As an example, an injector with a variable nozzle structure includes a damage-resistant member disposed on the surface of a second region of a lift valve to contact a second housing. The damage-resistant member contacts or separates from the second housing depending on the pressure exerted on the lift valve by the hydrogen flowing into the second housing.

[0011] As an example, as the pressure applied to the lift valve increases, the lift valve moves away from the orifice. As the lift valve moves away from the orifice, the distance between the second region and the second housing increases.

[0012] As an example, the first region of the lift valve extends in the direction from the second region toward the orifice.

[0013] As an example, the cross-sectional area of ​​the second region increases as it moves away from the point connected to the first region.

[0014] As an example, a protrusion is provided on the inner surface of the second housing, protruding toward the lift valve, and a spring is provided between the protrusion and the third hole.

[0015] As an example, the injector with a variable nozzle structure also includes a guide member disposed on the surface of the lift valve to guide the position of the lift valve within the second housing. The guide member is positioned between the spring and the third hole.

[0016] As an example, there are multiple first holes and multiple second holes, and a flow path is provided to connect the first holes and the second holes.

[0017] As an example, the first and second holes are defined to overlap in a direction perpendicular to the direction in which the lift valve extends, such that hydrogen gas passing through the first hole flows into the second hole.

[0018] As an example, an airtight component is provided between the third hole and the lift valve.

[0019] As an example, the first housing is inserted into a fourth hole in the third housing to which hydrogen is supplied.

[0020] Based on the flow rate of hydrogen supplied to the injector, the injector according to embodiments of the present invention can automatically change the flow rate of hydrogen discharged from the injector. Specifically, the injector with a variable nozzle structure according to embodiments of the present invention may include a housing with a two-stage structure and can automatically control the flow rate of hydrogen discharged through the orifice of the first housing according to the flow rate of hydrogen flowing into the second housing to provide a hydrogen supply that meets the output requirements of the fuel cell system.

[0021] According to an embodiment of the invention, the flow direction of the fluid (hydrogen) is the same as the pressurization direction of the lift valve. Furthermore, the volume of the space between the second housing and the first region of the lift valve remains unchanged. The lift valve thus moves stably. Additionally, a guide member can be provided in the first region to aid in the stable movement of the lift valve.

[0022] According to an embodiment of the present invention, the supplied hydrogen is supplied to the first hole of the first housing and the second hole of the second housing, and enters the second housing, which serves as a high-pressure section, through a flow path, thereby eliminating concerns about hydrogen leakage into the first or third housing, which serves as a relatively low-pressure section. Therefore, the phenomenon of hydrogen leaking from the high-pressure section to the low-pressure section, which could damage the fuel cell stack, can be prevented.

[0023] It should be understood that the terms "vehicle" or "of vehicles" or other similar terms used herein include motor vehicles in general. Such motor vehicles may include passenger vehicles including SUVs, buses, trucks, and various commercial vehicles; watercraft including various boats and vessels; and aircraft. Such motor vehicles may also include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle combining gasoline and electric power.

[0024] The above and other features of the present invention will be discussed below. Attached Figure Description

[0025] The above and other features of the invention will now be described in detail with reference to specific embodiments illustrated in the accompanying drawings, which are given below by way of illustration only and are therefore not intended to limit the invention, wherein:

[0026] Figure 1It is a view illustrating the basic structure of the fuel supply and recirculation system in a fuel cell system.

[0027] Figure 2 This is a view illustrating an injector with a variable nozzle structure according to an embodiment of the present invention.

[0028] Figure 3 It means to explain along Figure 2 A view of the surface cut off by line A-A' of the injector shown.

[0029] Figure 4 This is a view illustrating an injector with a variable nozzle structure according to another embodiment of the present invention.

[0030] It should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present simplified representations of various preferred features illustrating the basic principles of the invention. Specific design features of the invention, such as specific dimensions, orientations, positions, and shapes, as disclosed herein, will be determined in part by the particular intended application and environment of use.

[0031] In the accompanying drawings, reference numerals throughout the multiple figures indicate the same or equivalent parts of the invention. Detailed Implementation

[0032] The advantages and features of the present invention, as well as methods of implementing them, should become apparent from the embodiments described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms. These embodiments are provided merely to complete the disclosure of the inventive concept and to fully inform those skilled in the art of the scope of the invention. The invention is defined only by the scope of the claims. Throughout this specification, the same reference numerals refer to the same parts.

[0033] Furthermore, in this specification, the use of terms such as "first," "second," etc., to distinguish components whose names have the same relationship is not necessarily limited to the order described below. When we describe components, devices, elements, etc., of the present invention as having a purpose or performing an operation or function, such component, device, or element should be considered herein as "configured" to satisfy that purpose or perform that operation or function.

[0034] The present invention is described in detail below. Furthermore, while the foregoing has illustrated and described embodiments of the invention, the invention can be used in various other combinations, variations, and environments. In other words, changes or modifications can be made within the scope of the inventive concept disclosed herein, within the scope of equivalents to the disclosure, and / or within the scope of the technology or knowledge in the art. The described embodiments explain the manner in which the technical idea of ​​the invention is implemented. Various changes are also possible in the specific fields and uses of the invention. Therefore, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Furthermore, the appended claims should be interpreted as including other embodiments.

[0035] Figure 1 It is a view illustrating the basic structure of the fuel supply and recirculation system in a fuel cell system.

[0036] Reference Figure 1 The hydrogen supply system can perform the fuel supply process of supplying hydrogen to the fuel cell stack 30 and the process of recirculating unreacted hydrogen in the fuel cell stack 30. The hydrogen supply system may include: a hydrogen supply line 11 connected to a hydrogen storage tank 10; a hydrogen recirculation line 13 through which unreacted hydrogen is recirculated in the fuel cell stack 30; an injector 20 installed at the junction of the stack inlet 30a and the hydrogen recirculation line 13 to pump and supply fresh and recirculated hydrogen to the anode of the fuel cell stack 30; a stack inlet-side pressure sensor 15 installed on the stack inlet 30a to measure hydrogen and air pressure; a regulator 16 installed on the hydrogen supply line 11, etc.

[0037] Injector 20 receives hydrogen that has been depressurized via high-pressure regulator 16, injects the supplied compressed hydrogen through a nozzle to create a vacuum, and thereby draws in exhaust gases from fuel cell stack 30 to recycle the hydrogen. In other words, injector 20 can supply all newly supplied hydrogen and unreacted hydrogen in fuel cell stack 30. Injector 20 can use the pressure at the downstream end of high-pressure regulator 16 to inject a jet through a nozzle to generate the momentum required for recirculation during fuel supply. The specific construction of injector 20 will be described below.

[0038] Figure 2 This is a view illustrating an injector with a variable nozzle structure according to an embodiment of the present invention.

[0039] Reference Figure 2The injector 20 may include a first housing 100, a second housing 200, a lift valve 300, a damage-resistant member 400, a spring 500, and a guide member 600. The second housing 200 may be disposed within the first housing 100, and the spring 500 and the guide member 600 may also be disposed within the first housing 100. The pressure applied to the lift valve 300 may vary depending on the flow rate of hydrogen flowing into the second housing 200. The flow rate of hydrogen discharged from the injector 200 may be adjusted as the lift valve 300 moves according to the pressure applied to it.

[0040] Orifice 105 and first orifice 110 may be defined in first housing 100, orifice 105 being a channel for discharging hydrogen to the outside of injector 20, and first orifice 110 being configured to supply hydrogen to second housing 200. A plurality of first orifices 110 may be formed in first housing 100. Orifice 105 and lift valve 300 are components configured to regulate the flow rate of discharged hydrogen, wherein the flow rate of hydrogen discharged through orifice 105 can be controlled when lift valve 300 moves in the horizontal direction.

[0041] A second orifice 210 may be defined in a second housing 200, configured to allow hydrogen gas supplied through a first orifice 110 of the first housing 100 to flow into the second housing 200. Multiple second orifices 210 may be formed in the second housing 200. Hydrogen gas passing through the first orifice 110 may flow into the second orifice 210 through a flow path 50 connecting the first orifice 110 and the second orifice 210. Hydrogen gas passing through the second orifice 210 may flow into the second housing 200. The first orifice 110 and the second orifice 210 may be defined to overlap in a direction perpendicular to the extension direction of the lift valve 300. In this case, the extension direction of the lift valve 300 may represent the horizontal direction in the figure and the direction from the lift valve 300 toward the orifice 105. The flow path 50 may be formed in the same number as the first orifice 110 and the second orifice 210.

[0042] The lift valve 300, passing through the third hole 205 therein, can be defined on one side (i.e., the first side) of the second housing 200, and the other side of the second housing 200 opposite to that side (i.e., the second side) can be opened. One side (i.e., the first side) of the second housing 200 can represent an area closer to the orifice 105 than the other side.

[0043] The lift valve 300 can adjust the area of ​​the space opened by the orifice 105 for discharging hydrogen. Instead of being a component inserted into the orifice 105 to completely close it, the lift valve 300's end can partially close the orifice 105. In other words, if the flow rate of hydrogen supplied to the second housing 200 is low and the pressure applied to the lift valve 300 is low, the lift valve 300 may not move and hydrogen may be discharged through the partially closed orifice 105. The lift valve 300 may include a first region 310 through a third hole 205 in the second housing 200 and a second region 320 adjacent to the other side of the second housing 200. The first region 310 of the lift valve 300 may extend from the second region 320 toward the orifice 105. The cross-sectional area of ​​the second region 320 may be equal to or greater than the cross-sectional area of ​​the first region 310. The cross-sectional area of ​​the second region 320 may increase as the second region 320 moves away from the point connected to the first region 310.

[0044] Hydrogen gas flowing into the second housing 200 can be discharged into the space between the second region 320 of the lift valve 300 and the other side of the second housing 200. In other words, the second region 320 can be used to partially close the other open side (i.e., the second side) of the second housing 200. A damage prevention member 400 can be disposed on the surface 321 of the second region 320 of the lift valve 300. When the second region 320 of the lift valve 300 directly contacts the other side of the second housing 200, the damage prevention member 400 can prevent damage to the lift valve 300 or the second housing 200. In other words, the damage prevention member 400 can physically contact the other side (i.e., the second side) of the second housing 200. Depending on the pressure applied to the lift valve 300 by the hydrogen gas flowing into the second housing 200, the damage prevention member 400 can contact or separate from the other side of the second housing 200.

[0045] A protrusion 250 protruding toward the lift valve 300 can be provided on the inner surface of the second housing 200. A spring 500 can be provided between the protrusion 250 and one side (i.e., the first side) of the second housing 200 or between the third hole 205. Furthermore, a guide member 600 can be provided, disposed on the surface of the lift valve 300 to guide the position of the lift valve 300 within the second housing 200. The spring 500 can be configured to surround the surface of the lift valve 300. The spring 500 can be configured to surround the surface of the first region 310 of the lift valve 300. The spring 500 can be disposed in the space between the protrusion 250 and the guide member 600. One end of the spring 500 can contact the protrusion 250 and the other end of the spring 500 can contact the guide member 600. The lift valve 300 can move according to the pressure applied to the lift valve 300 by the spring 500, and the anti-damage member 400 can contact or separate from the other side of the second housing 200 according to the movement of the lift valve 300. In other words, the spring 500 can move the lift valve 300 according to the pressure applied to the lift valve 300.

[0046] The guide member 600 can guide the position of the lift valve 300 within the internal space of the second housing 200. The lift valve 300 can ideally be positioned at the center of the internal space of the second housing 200. Therefore, the guide member 600 can be disposed on the surface of the first region 310 of the lift valve 300 to guide its position. The guide member 600 can be disposed between the spring 500 and the third hole 205.

[0047] An airtight component 700 may be disposed between the third hole 205 of the second housing 200 and the lift valve 300. Specifically, the airtight component 700 may be disposed to prevent hydrogen leakage between the third hole 205 and the first region 310 of the lift valve 300. The airtight component 700 may be disposed on a surface of the second housing 200 exposed by the third hole 205.

[0048] The injector 20 may include a third housing 800 defining the shape of its outer surface. A fourth hole (not shown) into which the first housing 100 is inserted may be defined in the third housing 800. The third housing 800 may be a component that receives hydrogen from a high-pressure regulator or a fuel cell stack.

[0049] According to an embodiment of the present invention, the flow direction of the fluid (hydrogen) is the same as the pressurization direction of the lift valve 300. Furthermore, the volume of the space between the second housing 200 and the first region 310 of the lift valve 300 remains unchanged, allowing the lift valve 300 to move stably. Additionally, a guide member 600 may be disposed in the first region 310 to assist in the stable movement of the lift valve 300.

[0050] According to an embodiment of the invention, friction between the first region 310 of the lift valve 300 and the second housing 200 occurs only in the airtight member 700 when the lift valve 300 moves. Therefore, friction between the lift valve 300 and the second housing 200 can be minimized, which is advantageous in terms of the mobility of the lift valve 300.

[0051] Figure 3 It means to explain along Figure 2 The view of the surface intercepted by line A-A' shown.

[0052] refer to Figure 2 and Figure 3 A first housing 100 may be disposed within a third housing 800, and a second housing 200 may be disposed within the first housing 100. A plurality of first holes 110 may be defined within the first housing 100, and a plurality of second holes 210 may be defined within the second housing 200. The number of flow paths 50 connecting the first holes 110 and the second holes 210 may be the same as the number of first holes 110 and second holes 210 formed. Hydrogen gas flowing into the third housing 800 may flow into the second housing 200 sequentially through the first holes 110, the flow paths 50, and the second holes 210. The hydrogen gas flowing into the second housing 200 may move a lift valve 300, and through the movement of the lift valve 300, the hydrogen gas may be discharged into the space between the lift valve 300 and the other side (i.e., the second side) of the second housing 200. The hydrogen gas discharged into the space between the lift valve 300 and the other side of the second housing 200 may be discharged through an orifice 105 defined in the first housing 100.

[0053] According to an embodiment of the present invention, the supplied hydrogen gas is supplied to the second housing 200 through the first hole 110 of the first housing 100, the second hole 210 of the second housing 200, and the flow path 50, thereby eliminating concerns about hydrogen gas leakage into the first housing 100 or the third housing 800, which are relatively low-pressure sections. Therefore, it is possible to prevent hydrogen gas from leaking from the high-pressure section to the low-pressure section and damaging the fuel cell stack.

[0054] Figure 4 This is a view illustrating an injector with a variable nozzle structure according to another embodiment of the present invention. For simplicity, descriptions of repeated content are omitted.

[0055] Figure 4 This is used to illustrate that the flow rate of hydrogen entering the second housing 200 is higher than... Figure 2 A view of the situation. (Refer to...) Figure 4When the flow rate of hydrogen into the second housing 200 increases, the pressure applied to the lift valve 300 increases. As the pressure applied to the lift valve 300 increases, the lift valve 300 can move away from the orifice 105. When the lift valve 300 moves away from the orifice 105, the distance between the anti-damage member 400 and the other side of the second housing 200 increases. Furthermore, the amount of hydrogen discharged between the second region 320 of the lift valve 300 and the other side of the second housing 200 can increase. Additionally, when the amount of hydrogen flowing into the second housing 200 increases, the lift valve 300, which blocks the orifice 105, can move away from the orifice 105. Therefore, the flow rate of hydrogen discharged through the orifice 105 can increase.

[0056] According to an embodiment of the present invention, the fuel cell system operates under various output conditions. First, in the low output range, the area of ​​the hydrogen discharge orifice 105 should be small to improve the injector's intake performance. In the high output range, the area of ​​the orifice 105 should be large to prevent insufficient flow. In the low output range, due to the low pressure at the injector tip, the force pushing the lift valve 300 is weak, resulting in a small movement of the lift valve. Therefore, since the area blocking the orifice 105 at the end of the lift valve 300 is large, the area where hydrogen can move is relatively small. However, if the fuel cell system output is high, the pressure at the injector tip increases, and the force of the hydrogen pushing the lift valve 300 increases. Therefore, the amount of movement of the lift valve 300 becomes larger. Consequently, the area blocking the orifice 105 at the end of the lift valve 300 decreases, making the area where hydrogen can move relatively large. In other words, the flow rate of hydrogen discharged through the orifice 105 of the first housing 100 can be automatically controlled according to the flow rate of hydrogen flowing into the second housing 200. Implement injectors that can provide the amount of hydrogen supplied to match the output required by the fuel cell system.

[0057] As described above, embodiments of the present invention have been described with reference to the accompanying drawings. However, those skilled in the art will understand that the invention can be implemented in other specific forms without altering its technical concept or essential characteristics. Therefore, it should be understood that the above embodiments are illustrative in all respects and not restrictive.

Claims

1. An ejector having a variable nozzle structure, the ejector being installed in a fuel cell recirculation line to supply new hydrogen and recirculated gas, the ejector comprising: a first housing having a first hole through which hydrogen is supplied and a port through which hydrogen is discharged; a second housing provided in the first housing, the second housing having a second hole into which hydrogen flowing through the first hole flows; and a poppet valve provided in the second housing and passing through a third hole defined on one side of the second housing and configured to adjust an area of a space opened by the port through which hydrogen is discharged, wherein hydrogen flowing into the second housing moves along a space between the second housing and the poppet valve to the other side of the second housing opposite to the one side, is discharged through a space between the other side of the second housing opened and the poppet valve, then moves along a space between the first housing and the second housing to the one side of the second housing, and further moves to the port. 2.The ejector of claim 1, wherein the poppet valve including a first area passing through the third hole and a second area adjacent to the other side of the second housing, and wherein hydrogen is discharged through a space between the second area and the second housing.

3. The injector of claim 2, further comprising: a damage prevention member provided on a surface of the second area of the poppet valve to contact the second housing, wherein the damage prevention member contacts or separates from the second housing according to a pressure applied to the poppet valve from hydrogen flowing into the second housing. 4.The ejector of claim 3, wherein as the pressure applied to the poppet valve increases, the poppet valve moves in a direction away from the port, and wherein as the poppet valve moves in the direction away from the port, a distance between the second area and the second housing increases. 5.The ejector of claim 2, wherein the first area of the poppet valve extends in a direction from the second area toward the port. 6.The ejector of claim 5, wherein as the second area moves away from a point connected to the first area, a cross-sectional area of the second area increases. 7.The ejector of claim 1, wherein a protrusion protruding toward the poppet valve is provided on an inner surface of the second housing, and wherein a spring is provided between the protrusion and the third hole. 8.The ejector of claim 7, further comprising: a guide member provided on a surface of the poppet valve to guide a position of the poppet valve in the second housing, wherein the guide member is provided between the spring and the third hole. 9.The ejector of claim 1, wherein, a plurality of first holes and a plurality of second holes are defined, and wherein a flow path connecting the first holes and the second holes is provided. 10.The ejector of claim 9, wherein the first holes and the second holes are defined to overlap in a direction perpendicular to a direction in which the poppet valve extends, so that hydrogen passing through the first holes flows into the second holes.

11. The injector of claim 1, wherein Airtight members are provided between the third hole and the poppet.

12. The injector of claim 1, wherein The first housing is inserted into a fourth hole defined in a third housing to which hydrogen gas is supplied.

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