Drain valve used in the anode circuit of fuel cell stack

Abstract

This application relates to a drain valve (100) used in the anode circuit of a fuel cell stack, comprising: a valve body (11) in which a nozzle (60) is installed as a fluid inlet for the drain valve (100); a first stationary valve core (300) and a second stationary valve core (310) installed in the valve body (11), the first stationary valve core (300) being closer to the nozzle (60) than the second stationary valve core (310); and in the first stationary valve core (300)... Each of the first and second stationary valve cores (310) has a flow channel formed therein, the flow channels being interconnected and connected to the fluid outlet of the drain valve (100); and a moving valve core (400) is selectively slidably disposed in a mounting hole (302) formed at least in the first stationary valve core (300), the moving valve core (400) having a rod portion (410) and a head (420) located at the free end of the rod portion (410).

Description

Technical Field

[0001] This application generally relates to drain valves, particularly drain or vent valves used in the anode circuit of a fuel cell stack. Background Technology

[0002] In the anode circuit design of fuel cell stacks, vent valves and drain valves are used in the corresponding pipelines. This allows the gas and liquid from the anode gas outlet, separated by a gas-liquid separator, to selectively enter the mixing tank for mixing and discharge, controlled by the vent valves and drain valves respectively. Typically, the vent valve or drain valve includes a moving valve core and a stationary valve core installed within the valve body. As the moving valve core is selectively actuated, the fluid inlet on the valve body communicates with the flow channels in the moving and stationary valve cores, allowing fluids such as gases and liquids to selectively enter these channels and exit through the fluid outlet on the valve body. However, the gas entering the fluid inlet inevitably contains moisture, or the liquid entering the fluid inlet necessarily contains moisture. Therefore, some moisture often remains between the moving valve core and the valve body, and between the moving and stationary valve cores, after the fluid flows through the valve body. When the moving valve core stops actuating, this residual moisture freezes in cold weather, affecting the re-actuation of the moving valve core. Therefore, existing exhaust or drain valves must be equipped with heating elements, such as PTC heating elements, arranged around the valve body, so that when needed, the heating elements are activated first to melt the ice, and then the exhaust or drain valve is activated.

[0003] While the heating element can solve the icing problem, its relatively low power means it takes a certain amount of time to melt the ice, significantly impacting the response time of the exhaust or drain valve. Furthermore, the heating element also increases the complexity of the exhaust or drain valve's structural design and assembly. Utility Model Content

[0004] To address the aforementioned issues, this application aims to propose an improved structural design for a drain valve that can be used as both an exhaust valve and a drain valve in the anode circuit of a fuel cell stack. This drain valve prevents water vapor from accumulating as the fluid passes through, thereby eliminating the need for heating elements in the valve body and reducing the overall valve design and assembly complexity.

[0005] According to one aspect of this application, a drain valve for use in the anode circuit of a fuel cell stack is provided, comprising:

[0006] A valve body, in which a nozzle is installed as the fluid inlet of the discharge valve;

[0007] A first stationary valve core and a second stationary valve core are installed in the valve body. The first stationary valve core is closer to the nozzle than the second stationary valve core. Each of the first and second stationary valve cores has a flow channel formed therein, and these flow channels are interconnected and connected to the fluid outlet of the discharge valve.

[0008] A movable valve core is selectively slidably disposed in a mounting hole formed at least in a first stationary valve core. The movable valve core has a rod portion and a head located at the free end of the rod portion. The rod portion is at least partially inserted into the mounting hole from the end face of the first stationary valve core. The head has a first end face for contacting the orifice of the nozzle and an opposite second end face for contacting the end face of the first stationary valve core. A sealing gasket is disposed between the second end face of the head and the end face of the first stationary valve core. The sealing gasket is pressurized and clamped between the second end face of the head and the end face of the first stationary valve core when the first end face of the head leaves the nozzle.

[0009] Optionally, the end face of the first stationary valve core is mounted against the stepped portion of the valve body around its periphery.

[0010] Optionally, the second end face of the head and the sealing gasket are annular.

[0011] Optionally, an annular flange is formed extending from the end face of the first stationary valve core toward the nozzle, the mounting hole passes through the annular flange, and the annular flange has an annular end face toward the head, and the sealing gasket is selectively pressurized and clamped between the annular end face of the annular flange and the second end face of the head.

[0012] Optionally, the sealing gasket is fixedly disposed on the second end face of the head and / or the annular end face of the annular flange.

[0013] Optionally, an electromagnetic coil is arranged around the outer periphery of the valve body to selectively drive the moving valve core.

[0014] Optionally, a helical spring is located within the mounting hole to provide a restoring force that moves the movable valve core toward the nozzle.

[0015] Optionally, the stem of the moving valve core forms a hollow internal space that extends from the end face of the stem opposite to the head toward the head. The mounting hole has a large-diameter section near the end face of the stationary valve core and a small-diameter section away from the end face of the stationary valve core. The stem of the moving valve core is located in the large-diameter section, and the helical spring is located in the internal space and the small-diameter section.

[0016] Optionally, the mounting hole is formed through the first stationary valve core.

[0017] Alternatively, no heating element may be arranged around the valve body.

[0018] The drain valve with the novel design of this application, when used as a drainage or venting valve in the anode circuit of a fuel cell stack, can minimize the accumulation of water vapor in the fluid in the valve body and eliminate the possibility of icing, thereby eliminating the use of heating elements as in the prior art and simplifying the assembly difficulty of the drain valve. Attached Figure Description

[0019] A more comprehensive understanding of the principles and aspects of this application will be gained from the detailed description below, in conjunction with the accompanying drawings. It should be noted that the scale of the drawings may vary for clarity, but this will not affect the understanding of this application. In the drawings:

[0020] Figure 1 The diagram schematically illustrates a fuel cell stack, and shows an exhaust valve and a drain valve in the form of a drain valve in the anode circuit of the fuel cell stack.

[0021] Figure 2A and 2B This schematically illustrates a prior art drain valve design, wherein the drain valve is in Figure 2A It is shown to be in the open state and in Figure 2B The text appears to be in a closed state.

[0022] Figure 3A and 3B This schematically illustrates a drain valve design according to an embodiment of the present application, wherein the drain valve is in Figure 3A It is shown to be in the open state and in Figure 3B The text appears to be in a closed state; and...

[0023] Figure 4A and 4B This schematically illustrates a drain valve design according to an embodiment of the present application, wherein the drain valve is in Figure 4A It is shown to be in the open state and in Figure 4B It is shown as being in the off state. Detailed Implementation

[0024] In the accompanying drawings of this application, features with the same structure or similar function are represented by the same reference numerals. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Figure 1 A schematic diagram of an example fuel cell stack system according to this application is shown. The fuel cell stack system generally includes a stack 10, a hydrogen subsystem, an air subsystem, a thermal management subsystem in fluid communication with the internal flow channels of the stack 10, an electrical control system, and an exhaust gas discharge subsystem. For example, the stack 10 may be a proton exchange membrane type stack. The stack 10 is provided with an anode gas inlet 11 and an anode gas outlet 12; a cathode gas inlet 13 and a cathode gas outlet 14; and a cooling liquid inlet 15 and a cooling liquid outlet 16. The anode gas inlet 11 and the anode gas outlet 12 are connected to the hydrogen circuit inside the stack 10, the cathode gas inlet 13 and the cathode gas outlet 14 are connected to the air circuit inside the stack 10, and the cooling liquid inlet 15 and the cooling liquid outlet 16 are connected to the cooling liquid circuit inside the stack 10.

[0026] The hydrogen subsystem has a hydrogen supply line L1 and a hydrogen recovery line L2, the former being in fluid communication with the anode gas inlet 11 and the latter being in fluid communication with the anode gas outlet 12. The hydrogen subsystem is configured to supply hydrogen to the anode gas inlet 11 via the hydrogen supply line L1 as needed and to recover excess hydrogen from the anode gas outlet 12 via the hydrogen recovery line L2. The air subsystem has an air supply line L3 and an air collection line L4, the former being in fluid communication with the cathode gas inlet 13 and the latter being in fluid communication with the cathode gas outlet 14. Furthermore, a fluid line L10 can be configured between the air supply line L3 and the air collection line L4, which is in fluid communication with the inlet of the exhaust gas discharge subsystem, and the flow rate and / or pressure of the fluid flowing through the fluid line L10 can be selectively controlled to ensure, for example, during the start-up of the fuel cell stack 10, an air bypass mode as known to those skilled in the art. The air subsystem is configured to supply air to the cathode gas inlet 13 via the air supply line L3 as needed and to collect air from the cathode gas outlet 14 via the air collection line L4. The thermal management subsystem has a liquid supply line L5 in fluid communication with the coolant inlet 15 and a liquid recovery line L6 in fluid communication with the coolant outlet 16. The thermal management subsystem is configured to supply coolant to the coolant inlet 15 via the liquid supply line L5 as needed to absorb heat generated inside the fuel cell stack 10 during operation. The coolant that has absorbed heat is discharged from the coolant outlet 16 via the liquid recovery line L6, cooled by the thermal management system, and can be supplied back to the fuel cell stack 10. This cooling liquid circulation ensures that the temperature of the fuel cell stack 10 does not exceed the specified limits during operation.

[0027] The exhaust gas discharge subsystem can be configured to be fluidly connected to the hydrogen subsystem 20 and the air subsystem 30 via fluid lines, so that excess hydrogen and air can be mixed in the exhaust gas discharge subsystem and discharged to meet the hydrogen emission requirements of the fuel cell stack system.

[0028] The fuel cell stack 10 may be equipped with a DC / DC converter 110, for example. The positive and negative terminals of the current output of the fuel cell stack 10 can be connected to the DC / DC converter 110 through corresponding circuits. The DC / DC converter 110 is configured to adjust the output voltage of the fuel cell stack 10 to a level that matches the load of the fuel cell stack system, thereby meeting the power requirements of the load, when the fuel cell stack 10 is operating and its current output terminals are not yet connected to the DC / DC converter 110. The voltage between the positive and negative terminals can be called the open-circuit voltage. During the start-up process of the fuel cell stack system, it is necessary to avoid the fuel cell stack 10 establishing a high open-circuit voltage prematurely.

[0029] exist Figure 1For simplicity, the electrical control system is not shown. As shown, the hydrogen subsystem generally includes a hydrogen source 21 in the form of a high-pressure hydrogen tank. This hydrogen source 21 is fluidly connected to the anode gas inlet 11 of the fuel cell stack 10 via a hydrogen supply line L1. From the hydrogen source 21 to the anode gas inlet 11, a hydrogen filter 22, a pressure reducing valve 23, a proportional (regulating) valve 24, and an ejector 25 are sequentially arranged in the hydrogen supply line L1. Furthermore, a vapor-liquid separator 26 is provided in the hydrogen recovery line L2, and the hydrogen recovery line L2 is fluidly connected to the low-pressure gas inlet of the ejector 25. The specific construction and operating principle of the hydrogen filter 22, pressure reducing valve 23, proportional (regulating) valve 24, ejector 25, and vapor-liquid separator 26 can be found in existing technology and therefore will not be described in detail here. As shown, the air subsystem 30 generally includes an air compressor 31 for pressurizing and outputting ambient air. The outlet of the air compressor 31 is in fluid communication with the cathode gas inlet 13 of the fuel cell stack 10 via the air supply line L3. An air filter 32 can be installed upstream of the inlet of the air compressor 31 to filter the intake air. Furthermore, an intercooler 33 and an inlet shut-off valve 34 can be sequentially installed in the air supply line L3 from the outlet of the air compressor 31 to the cathode gas inlet 13. An outlet shut-off valve 35 is installed in the air collection line L4, and a back pressure valve 39 is installed downstream of it. In an alternative embodiment (not shown), the back pressure valve 39 can be omitted, and the outlet shut-off valve 35 can be used as the back pressure valve. Additionally, as shown, a bypass valve 36 is installed in the fluid line L10 between the air outlet of the intercooler 33 and the outlet shut-off valve 35 and upstream of the back pressure valve 39. A circulation pump 29 is arranged in the hydrogen return line L2 (as shown). The specific structure and working principle of the air compressor 31, intercooler 33, inlet shut-off valve 34, and outlet shut-off valve 35 can be referred to the existing technology, so they will not be described in detail here.

[0030] The exhaust gas discharge subsystem includes a mixing chamber 61. For example, the outlet of the mixing chamber 61 can be connected to the exhaust gas duct of a motor vehicle. One inlet of the mixing chamber 61 is connected via pipe L7 to the downstream of the gas separation outlet of the vapor-liquid separator 26 in the hydrogen return pipe L2, and a purge valve (or exhaust valve) 27 is provided in pipe L7. Furthermore, another inlet of the mixing chamber 61 is connected via pipe L8 to the downstream of the liquid separation outlet of the vapor-liquid separator 26, and a drain valve 28 is provided in pipe L8. When the fuel cell stack 10 is operating, as the purge valve 27 opens, the gas separated by the vapor-liquid separator 26 (mainly containing hydrogen) in the gas discharged from the anode gas outlet 12 can enter the mixing chamber 61 via pipe L7, mix, and then be discharged. Furthermore, as the purge valve 27 closes, the gas separated by the vapor-liquid separator 26 in the gas discharged from the anode gas outlet 12 can re-enter the ejector 25 via the hydrogen return pipe L2 and be re-supplied to the anode gas inlet 11 of the fuel cell stack 10. As the drain valve 28 selectively opens and closes, the moisture content of the gas supplied to the anode gas inlet 11 of the fuel cell stack 10 via the hydrogen return line L2 and ejector 25 is reduced accordingly. This is because, with the opening of the drain valve 28, the water vapor separated by the vapor-liquid separator 26 in the gas discharged from the anode gas outlet 12 can enter the mixing chamber 61 via the line L8 for mixing and discharge. The air return line L4 of the air subsystem is fluidly connected to another inlet of the exhaust gas discharge subsystem. When the air compressor 31 of the air subsystem is operating, by adjusting the opening of the inlet bypass valve 36, the air flow rate and / or pressure supplied to the cathode gas inlet 13 and entering the mixing chamber 61 can be adjusted to regulate the electrochemical reaction process inside the fuel cell stack 10 and the hydrogen concentration in the exhaust gas, respectively.

[0031] As shown in the figure, the thermal management subsystem generally includes a radiator 41 equipped with a fan, a coolant pump 42, and an expansion tank 43. The radiator 41 is connected to the coolant inlet 15 and coolant outlet 16 of the fuel cell stack 10 via a coolant supply line L5 and a coolant return line L6, respectively. The coolant pump 42 is installed in the coolant supply line L5, and a three-way valve 44 is installed in the coolant return line L6 so that an additional line L11 between the coolant supply line L5 and the coolant return line L6 can be controlled to open or close via the three-way valve 44. As shown in the figure, the coolant supply line L5 and the coolant return line L6 can also be connected to the intercooler 33 of the air subsystem 30 in a manner well known to those skilled in the art. Coolant pump 42 is configured to drive the circulation of coolant in the air subsystem, thermal management subsystem, and fuel cell stack 10. The design of three-way valve 44 and line L11 allows the coolant to operate in the thermal management subsystem 40 in a first and second cycle. In the first cycle, the state of three-way valve 44 allows the coolant entering the fuel cell stack 10 to return to the stack 10 via liquid recovery line L6 and line L11, and then via liquid supply line L5. In the second cycle, the state of three-way valve 44 allows the coolant entering the fuel cell stack 10 to return to the stack 10 via liquid recovery line L6 and a fan-equipped radiator 41, and then via liquid supply line L5. The switching between the first and second cycles depends on the cooling requirements of the fuel cell stack 10 during operation. When the internal temperature of the fuel cell stack 10 is high, the thermal management subsystem 40 can operate in the second cycle mode; when the internal temperature of the fuel cell stack 10 is low, the thermal management subsystem 40 can operate in the first cycle mode. An expansion tank 43 is provided at the inlet of the cooling liquid pump 42 in a manner well known to those skilled in the art, for eliminating air bubbles in the cooling liquid circulated by the thermal management subsystem 40 and ensuring the inlet pressure of the cooling liquid pump 42, etc.

[0032] During operation of the fuel cell stack system, high-pressure hydrogen stored in hydrogen source 21 passes through hydrogen filter 22 and pressure reducing valve 23 to proportional valve 24. After being regulated by proportional valve 24, it is input into anode gas inlet 11 through ejector 25 and enters the stack 10 to participate in the electrochemical reaction. Then, excess hydrogen that has not participated in the electrochemical reaction can be separated from water vapor by vapor separator 26 from anode gas outlet 12 and input back into anode gas inlet 11 through ejector 25 to further enter the stack 10 to participate in the electrochemical reaction. Purge valve 27 and drain valve 28 can be opened or closed intermittently to purge the anode and increase or decrease the hydrogen concentration or water vapor concentration input into anode gas inlet 11 of the stack 10. As air compressor 31 operates, air is drawn in through air filter 32 and pressurized by air compressor 31 before being input into air supply line L3. Intercooler 33 is used to initially cool the air input through air compressor 31. The specific working principles of the fuel cell stack system, such as the implementation of anode purging and cathode purging during stack shutdown, can be found in the knowledge familiar in this field and will not be elaborated here.

[0033] The purge valve 27 (or exhaust valve) and drain valve 28 mentioned above are the drain valves involved in this application.

[0034] Figure 2A and 2B This schematically illustrates a prior art drain valve design, wherein the drain valve is in Figure 2A It is shown to be in the open state and in Figure 2B The nozzle 60 is shown in the closed state. As shown, a movable valve core 30 and a fixed valve core 31 are installed in the valve body 10, and a flow channel (not shown in the figure) is formed in both. The movable valve core 30 is slidably mounted in the valve body 10. For example, an electromagnetic coil 20 is arranged on the outer periphery of the valve body 10. When the electromagnetic coil 20 is energized, it generates an electromagnetic force, causing the movable valve core 30 to move within the valve body 10 against the restoring force of the spring 50, thereby moving the movable valve core 30 from the closed state of the nozzle 60 installed in the valve body 10 (e.g., the nozzle is blocked in the valve body 10). Figure 2B (As shown) switch to the open state that allows fluid to enter the valve body 10 through the nozzle 60 (e.g.) Figure 2A (As shown). Furthermore, when the electromagnetic coil 20 is de-energized, the moving valve core 30 returns to the closed state of blocking the nozzle 60 under the restoring force of the spring 50 (as shown). Figure 2B (As shown).

[0035] It can be seen that there is a small gap s between the outer wall of the moving valve core 30 and the inner wall of the valve body 10. When the drain valve is in the open state, fluid is allowed to enter the interior of the valve body 10 through the nozzle 60 installed in the valve body 10, and then discharged from the outlet of the valve body 10 through the flow channels in the moving valve core 30 and the stationary valve core 31. Water vapor in the fluid flowing through the drain valve inevitably remains in this small gap s. At the same time, since the moving valve core 30 needs to be in the open state ( Figure 2A ) and closed state ( Figure 2B The valve body 10 is constantly driven between the moving valve core 30 and the stationary valve core 31, inevitably resulting in moisture retention. When the drain valve is closed, this retained moisture cannot escape from the valve body 10. This retained moisture will freeze in cold weather and after the fuel cell stack 10 is shut down, affecting the restart of the moving valve core 30 and the cold start sensitivity of the drain valve. Therefore, a heating element 40, such as a PTC heating element, must be installed on the outside of the valve body 10 of the existing drain valve to heat and melt the ice inside the valve body 10 before starting the drain valve.

[0036] To solve the problem of icing Figure 3A and 3B This schematically illustrates a drain valve design according to an embodiment of the present application, wherein the drain valve is in Figure 3A It is shown to be in the open state and in Figure 3B It is shown as being in the off state. Figure 3A and 3B Only the key features of the discharge valve relevant to the technical solution of this application are schematically shown; other features, such as the electromagnetic coil 20, can be found in [the relevant documentation]. Figure 2A and 2B Introduction.

[0037] According to embodiments of this application, such as Figure 3A and 3BAs shown, the drain valve 100 generally includes a valve body 11. A nozzle 60 is fixedly mounted on one side of the valve body 11 as a fluid inlet. A first stationary valve core 300 and a second stationary valve core 310 are fixedly mounted in the valve body 11. The first stationary valve core 300 and the second stationary valve core 310 may be cylindrical. A plurality of flow channels 301 are formed in the first stationary valve core 300, and a plurality of flow channels 311 are also formed in the second stationary valve core 310. Optionally, a gasket (not shown) may be arranged between the first stationary valve core 300 and the second stationary valve core 310, which allows communication between the flow channels 301 and 311. An outlet 12 is formed on the side of the valve body 11 opposite to the nozzle 60, and the outlet 12 communicates with the flow channel 311 of the second stationary valve core 310. A stepped portion 11a is formed in the inner wall of the valve body 11. The end face 300a of the first stationary valve core 300 is mounted against the stepped portion 11a around its periphery, so that if fluid is ejected from the nozzle 60, the ejected fluid will not penetrate into the gap between the outer peripheral wall of the first stationary valve core 300 and the inner wall of the valve body 11.

[0038] According to an embodiment of this application, a mounting hole 302 is formed in the first stationary valve core 300. The mounting hole 302 extends from the end face 300a of the first stationary valve core 300 along the central axis of the first stationary valve core 300 toward the opposite end face 300b, and may extend to the opposite end face 300b or alternatively not extend to the opposite end face 300b. Viewed along the central axis of the first stationary valve core 300, the mounting hole 302 has a large-diameter section 3021 near the end face 300a and a small-diameter section 3022 away from the end face 300a (or near the end face 300b).

[0039] A flange 303 is formed on the end face 300a of the first stationary valve core 300. For example, the flange 303 extends annularly from the end face 300a toward the nozzle 60. The flange 303 is coaxial with the central axis of the first stationary valve core 300. The large-diameter section 3021 of the mounting hole 302 extends to the annular end face 303a of the flange 303. An armature member 400, as a moving valve core, is slidably disposed in the large-diameter section 3021 of the mounting hole 302 along the central axis. The moving valve core 400 may be, for example, an electromagnetic coil 20 disposed outside the valve body 11 (in... Figure 3A and 3B Not shown in the image, but can be referenced. Figure 2A and 2BUnder the influence of electromagnetic force generated by energization, the valve core 400 moves in a direction away from the nozzle 60. The moving valve core 400 has a cylindrical rod 410 and a head 420 located at one end of the rod 410. The rod 410 is inserted into the large-diameter section 3021 of the mounting hole 302, and the diameter of the head 420 is larger than the diameter of the rod 410. The head 420 extends from the flange 303. The rod 410 forms a hollow internal space 430 that extends from the end face of the rod 410 opposite to the head 420 toward the head 420. A helical spring 50 is disposed between the internal space 430 and the small-diameter section 3022 of the mounting hole 302. The helical spring 50 is configured to apply a force to the moving valve core 400, causing it to move toward the nozzle 60. Therefore, the electromagnetic coil 20 externally disposed on the valve body 11 is configured such that the electromagnetic force generated when it is energized can drive the moving valve core 400 to move away from the nozzle 60 against the force of the helical spring 50, and when the electromagnetic coil 20 is de-energized, the moving valve core 400 moves toward the nozzle 60 under the action of the force of the helical spring 50.

[0040] The head 420 has an end face 420a facing the nozzle 60. A sealing gasket 510 is provided on this end face 420a. The head 420 also has an annular end face 420b axially opposite to the end face 420a. This annular end face 420a axially faces the annular end face 303a of the flange 303. According to an embodiment of this application, a sealing gasket 520 is provided between the annular end face 420b of the head 420 and the annular end face 303a of the flange 303. For example, the sealing gasket can be made of an elastic sealing material such as rubber. In one embodiment, the sealing gasket 520 is annular and can be provided on the annular end face 420b of the head 420 and / or the annular end face 303a of the flange 303. Thus, in the event that the electromagnetic coil 20 is de-energized (e.g. Figure 3B As shown), the moving valve core 400 moves toward the nozzle 60 under the force of the helical spring 50 and maintains contact with the orifice of the nozzle 60 with its sealing gasket 510, so that fluid cannot be supplied into the valve body 11 through the nozzle 60. When the electromagnetic coil 20 is energized (e.g., Figure 3A As shown, the moving valve core 400 moves away from the nozzle 60 against the force of the helical spring 50, and the annular sealing gasket 520 is kept tightly clamped between the annular end face 420b and the annular end face 303a. In this way, fluid (such as air, water vapor or water) entering the valve body 11 through the nozzle 60 cannot enter the mounting hole 302 and thus cause fluid residue, but is discharged directly from the outlet 12 through the flow channel 301 of the first stationary valve core 300 and the flow channel 311 of the second stationary valve core 310.

[0041] According to the drain valve design of this application, the sealing gasket 520 is tightly pressed between the head 420 and the flange 303 under the pressure of the fluid entering the valve body 11 through the nozzle 60 and under the action of electromagnetic force, thus preventing any fluid from entering the mounting hole 302 and thus entering the gap between the first stationary valve core 300 and the second stationary valve core 310 and remaining there. Furthermore, because the end face 300a of the first stationary valve core 300 is mounted against the stepped portion 11a of the valve body 11, fluid is prevented from entering the gap between the stationary valve core and the inner wall of the valve body 11 and remaining there. Moreover, because the fluid entering the valve body 11 through the nozzle 60 carries a certain pressure, although there is a certain space between the inner end face 300a of the valve body 11 and the nozzle 60, the volume of this space is large enough that the entering fluid will not remain. As shown in the figure, according to an embodiment of this application, one end of the helical spring 50 contacts the second stationary valve core 310 and the other end contacts the moving valve core 400 via a gasket 51. For example, the gasket 51 can be made of a noise-eliminating material to reduce the noise that may exist during the operation of the drain valve 100.

[0042] Compared to existing technologies, the drain valve design of this application significantly reduces or eliminates icing even in cold seasons because it prevents fluid from remaining inside the valve body 11. Therefore, the heating element required in existing technologies can be eliminated.

[0043] In an alternative embodiment of this application, the mounting hole 302 may also be coaxially formed in the first stationary valve core 300 and the second stationary valve core 310. For example, it may be formed as a blind hole in the second stationary valve core 310, preferably to facilitate the installation of the helical spring 50 without affecting the communication between the flow channels in the two valve cores. Furthermore, the method of fixing the sealing gasket 520 to the respective end face shall be as is known to those skilled in the art.

[0044] Figure 4A and 4B Another embodiment according to this application is illustrated schematically. This embodiment is related to... Figure 3A and 3B The difference in the illustrated embodiment is that a mounting hole 302' is formed in the first stationary valve core 300, which is a blind hole with approximately the same inner diameter. For example, the moving valve core 400 can be linearly slidably mounted in this mounting hole 302', while the rod portion 410 of the moving valve core 400 does not have a hollow internal space 430 (e.g., Figure 3A and 3B As shown), the helical spring 50 is disposed in the mounting hole 302', with one end contacting the second stationary valve core 310 and the other end contacting the end of the rod portion 410 via the washer 51. In addition, regarding... Figure 4A and 4BThe embodiments can be referred to the above embodiments and their modifications.

[0045] Although specific embodiments of this application are described in detail herein, they are provided for illustrative purposes only and should not be construed as limiting the scope of this application. Furthermore, those skilled in the art will understand that the various embodiments described herein can be used in combination with each other. Various substitutions, modifications, and alterations can be conceived without departing from the spirit and scope of this application.

Claims

1. A drain valve (100) used in the anode circuit of a fuel cell stack, characterized in that, include: A valve body (11) in which a nozzle (60) is installed as the fluid inlet of the drain valve (100); A first stationary valve core (300) and a second stationary valve core (310) are installed in the valve body (11). The first stationary valve core (300) is closer to the nozzle (60) than the second stationary valve core (310). A flow channel is formed in both the first stationary valve core (300) and the second stationary valve core (310), and these flow channels are interconnected and connected to the fluid outlet of the drain valve (100). A movable valve core (400) is selectively slidably disposed in mounting holes (302, 302'), which are formed at least in the first stationary valve core (300). The movable valve core (400) has a rod portion (410) and a head (420) located at the free end of the rod portion (410). The rod portion (410) is at least partially inserted into the mounting holes (302, 302') from the end face (300a) of the first stationary valve core (300). The head (420) has an orifice for contacting the nozzle (60). The head (420) has a first end face (420a) and an opposite second end face (420b) for contacting the end face (300a) of the first stationary valve core (300). A sealing gasket (520) is provided between the second end face (420b) of the head (420) and the end face (300a) of the first stationary valve core (300). The sealing gasket (520) is pressurized and clamped between the second end face (420b) of the head (420) and the end face (300a) of the first stationary valve core (300) when the first end face (420a) of the head (420) leaves the nozzle (60).

2. The drain valve (100) according to claim 1, characterized in that, The end face (300a) of the first static valve core (310) is mounted against the stepped portion (11a) of the valve body (11) around its periphery.

3. The drain valve (100) according to claim 2, characterized in that, The second end face (420b) of the head (420) and the sealing gasket (520) are annular.

4. The drain valve (100) according to claim 3, characterized in that, An annular flange (303) is formed extending from the end face (300a) of the first stationary valve core (300) toward the nozzle (60), the mounting holes (302, 302') pass through the annular flange (303), and the annular flange (303) has an annular end face (303a) facing the head (420), and the sealing gasket (520) is selectively pressed and clamped between the annular end face (303a) of the annular flange (303) and the second end face (420b) of the head (420).

5. The drain valve (100) according to claim 4, characterized in that, The sealing gasket (520) is fixedly disposed on the second end face (420b) of the head (420) and / or the annular end face (303a) of the annular flange (303).

6. The drain valve (100) according to claim 5, characterized in that, An electromagnetic coil (20) is arranged on the outer periphery of the valve body (11) to selectively drive the moving valve core (400).

7. The drain valve (100) according to claim 6, characterized in that, A helical spring (50) is located within the mounting holes (302, 302') to provide a restoring force that causes the moving valve core (400) to move toward the nozzle (60).

8. The drain valve (100) according to claim 7, characterized in that, The stem portion (410) of the moving valve core (400) forms a hollow internal space (430) extending from the end face of the stem portion (410) opposite to the head (420) toward the head (420). The mounting hole (302) has a large-diameter section (3021) near the end face (300a) of the stationary valve core (300) and a small-diameter section (3022) away from the end face (300a) of the stationary valve core (300). The stem portion (410) of the moving valve core (400) is located in the large-diameter section (3021), and the helical spring (50) is located in the internal space (430) and the small-diameter section (3022).

9. The drain valve (100) according to claim 8, characterized in that, The mounting hole (302) is formed through the first stationary valve core (300).

10. The drain valve (100) according to any one of claims 1 to 9, characterized in that, No heating element is provided around the valve body (11).

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