Ejector and fuel cell system having ejector

Abstract

To provide an ejector capable of appropriately coping with pressure abnormality of a working fluid at an early stage, and a fuel cell system having the ejector.SOLUTION: When the pressure of the first operating fluid 55c is abnormal, the outer nozzle 55 and the inner nozzle 56 move in the rear end direction against the biasing force of the spring 81 to close the first operating fluid feed port 51 at the closing portion PA on the outer peripheral surface 55a of the outer nozzle 55. The pressure receiving portion 82 receives the pressure of the first operating fluid WF1 in the rear end direction against the biasing force of the spring 81 on the rear end side of the inflow port WF1.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an ejector that generates negative pressure by flowing a working fluid and causes a target fluid to flow by the action of the negative pressure, and a fuel cell system having the ejector. [Background technology]

[0002] Patent Document 1 discloses an ejector that draws in a target fluid (hydrogen off-gas) by using negative pressure generated by a working fluid (hydrogen gas) injected from an outer nozzle and an inner nozzle, and discharges a mixed fluid (mixed gas) of the injected working fluid and the drawn-in target fluid from a discharge port via a diffuser. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-56365 Summary of the Invention [Problem to be solved by the invention]

[0004] In an ejector such as that disclosed in Patent Document 1, if a failure (abnormality) occurs in a component located upstream of the outer nozzle in the flow of the working fluid, causing an abnormality in the pressure of the working fluid, high-pressure working fluid may flow into the fuel cell, causing a malfunction in the fuel cell. Therefore, it is desirable to respond appropriately to the abnormality in the pressure of the working fluid as soon as possible.

[0005] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide an ejector that can respond promptly and appropriately to pressure abnormalities in the working fluid, and a fuel cell system having this ejector. [Means for solving the problem]

[0006] One aspect of the present disclosure made to solve the above problems is an ejector comprising: a main casing; an outer nozzle disposed within the main casing for injecting a first working fluid; an inner nozzle disposed inside the outer nozzle for injecting a second working fluid; and a first working fluid supply port for supplying the first working fluid into the main casing, wherein the outer nozzle is an ejector having an inlet for allowing the first working fluid to flow into the outer nozzle; the outer nozzle has a biasing member for biasing the outer nozzle and the inner nozzle toward their tip ends; and when a pressure abnormality occurs in which the pressure of the first working fluid is greater than a maximum value within an operating range, the outer nozzle moves toward the rear end against the biasing force of the biasing member, and the outer nozzle blocks the first working fluid supply port, or the inner nozzle moves toward the rear end against the biasing force of the biasing member, and the inner nozzle blocks the inlet.

[0007] According to this aspect, when the pressure of the first working fluid is abnormal, the first working fluid supply port is blocked by the outer nozzle, or the inlet is blocked by the inner nozzle, so that the first working fluid with abnormal pressure can be prevented from flowing downstream of the ejector, thereby making it possible to respond promptly and appropriately to the pressure abnormality of the first working fluid.

[0008] In the above aspect, it is preferable that the outer nozzle has a pressure-receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rearward end against the biasing force of the biasing member, and that in the event of the pressure abnormality, the first working fluid supply port is blocked by a portion of the outer peripheral surface of the outer nozzle that is forward of the inlet.

[0009] According to this aspect, when the pressure of the first working fluid becomes abnormal, the outer surface of the outer nozzle blocks the first working fluid supply port, thereby more reliably preventing the first working fluid with abnormal pressure from flowing downstream of the ejector.

[0010] In the above aspect, there are a seal member disposed between the inner peripheral surface of the main body casing and the outer peripheral surface of the outer nozzle, and a tip-side seal member groove formed for disposing the seal member on the tip side of the outer peripheral surface of the outer nozzle with respect to the inlet. When the amount of movement of the outer nozzle and the inner nozzle in the rear end direction during abnormal pressure is A, the distance between the rear end side end of the first working fluid supply port and the tip side end of the tip-side seal member groove is B, the distance between the tip side end of the tip-side seal member groove and the tip side end of the outer peripheral surface of the outer nozzle is C, and the diameter of the first working fluid supply port is D, it is preferable to satisfy the relationship of B < A and (A - B + D) < C.

[0011] <​​​​​​​​​​

[0014] In the above aspect, it is preferable that the inner nozzle has a protrusion on its outer peripheral surface, and that the protrusion is located forward of the inlet when the pressure of the first working fluid is normal and within a usable pressure range, and that the inner nozzle moves rearward and blocks the inlet with the protrusion when the pressure is abnormal.

[0015] According to this aspect, when the pressure of the first working fluid is abnormal, the inlet is blocked by the protrusion of the inner nozzle, so that the first working fluid with abnormal pressure can be more reliably prevented from flowing downstream of the ejector.

[0016] Another aspect of the present disclosure made to solve the above problems is an ejector having a main body casing, an outer nozzle arranged in the main body casing and spraying a first working fluid, an inner nozzle arranged inside the outer nozzle and spraying a second working fluid, and a first working fluid supply port for supplying the first working fluid into the main body casing, wherein the outer nozzle has an inlet for causing the first working fluid to flow into the inside of the outer nozzle, a first flow path through which the first working fluid flows is formed between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle, and a second flow path through which the second working fluid flows is formed inside the inner nozzle, the outer nozzle has a pressure receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rear end against the biasing force of the biasing member; when the pressure of the first working fluid is within a normal pressure range, the first working fluid supply port is connected to the first flow path, and the first working fluid flows through the first flow path; when the pressure of the first working fluid is abnormal, and the pressure is higher than the maximum value of the usage range, the outer nozzle and the inner nozzle move rearward against the biasing force of the biasing member, and the first working fluid supply port is connected to a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path.

[0017] According to this aspect, since the flow path through which the first working fluid flows is different between the first flow path and the third flow path when the pressure of the first working fluid is normal and when it is abnormal, the way the pressure of the fluid is transmitted to the downstream side of the ejector is different. Therefore, by measuring the outlet pressure of the ejector, an abnormal pressure of the first working fluid can be detected early. In this way, it is possible to appropriately respond to an abnormal pressure of the first working fluid at an early stage.

[0018] In the above aspect, it is preferable that the cross-sectional area of the third flow path is larger than the cross-sectional area of the first flow path.

[0019] According to this aspect, the flow rate of the first working fluid is larger in the third flow path than in the first flow path. Therefore, the outlet pressure of the ejector rises earlier when the pressure of the first working fluid is abnormal and it flows through the third flow path than when the pressure of the first working fluid is normal and it flows through the first flow path. Therefore, by measuring the outlet pressure of the ejector, an abnormal pressure of the first working fluid can be detected early.

[0020] In the above aspect, it has a seal member disposed between the outer peripheral surface of the outer nozzle and the inner peripheral surface of the main body casing, and a tip-side seal member arrangement portion formed for arranging the seal member on the tip side of the outer peripheral surface of the outer nozzle rather than the inlet side. When the amount of movement of the outer nozzle and the inner nozzle in the rear end direction during the abnormal pressure is A, and the distance between the rear end side end portion of the first working fluid supply port and the tip side end portion of the tip-side seal member arrangement portion is E, it is preferable to satisfy the relationship E < A.

[0021] According to this aspect, when the pressure of the first working fluid is abnormal, the outer nozzle and the inner nozzle move in the rear end direction, and more reliably, the first working fluid supply port communicates with the third flow path, and the first working fluid supplied from the first working fluid supply port can flow into the third flow path. Therefore, it is possible to more reliably make the way the pressure of the fluid is transmitted to the downstream side of the ejector different between when the pressure of the first working fluid is normal and when it is abnormal. Therefore, it is possible to more reliably detect an abnormal pressure of the first working fluid at an early stage by measuring the outlet pressure of the ejector.

[0022] In the above aspect, it is preferable that the outer nozzle is attached to the main casing via a sealing member at a tip portion of the inner circumferential surface of the casing that is further tip-side than the first working fluid supply port on the inner circumferential surface of the main casing, and that the outer nozzle is attached to the main casing via a sealing member at a rear portion of the inner circumferential surface of the casing that is further rear-side than the first working fluid supply port on the inner circumferential surface of the main casing, and that the inner diameter of the rear portion of the inner circumferential surface of the casing is larger than the inner diameter of the tip portion of the inner circumferential surface of the casing.

[0023] According to this aspect, the pressure-receiving area of ​​the pressure-receiving portion can be increased. Therefore, in the event of a pressure abnormality in the first working fluid, the outer nozzle and the inner nozzle move toward the rear end more quickly due to the load received by the pressure-receiving portion, against the biasing force of the biasing member. Therefore, the pressure abnormality in the first working fluid can be detected more quickly.

[0024] Another aspect of the present disclosure made to solve the above problems is a fuel cell system having an ejector, the ejector having a main casing, an outer nozzle arranged in the main casing and spraying a first working fluid, an inner nozzle arranged inside the outer nozzle and spraying a second working fluid, and a first working fluid supply port for supplying the first working fluid into the main casing, the outer nozzle having an inlet for allowing the first working fluid to flow into the outer nozzle, a first flow path for the first working fluid to flow between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle, and a second flow path for the second working fluid to flow inside the inner nozzle, the outer nozzle having an urging member for urging the outer nozzle and the inner nozzle toward their forward ends, the outer nozzle having a pressure of the first working fluid to be directed rearward against the urging force of the urging member on the rear end side of the inlet and a pressure receiving section that receives pressure toward the first working fluid, and when the pressure of the first working fluid is within a normal pressure range, the first working fluid supply port is connected to the first flow path, and the first working fluid flows through the first flow path, and when the pressure of the first working fluid is abnormal, and the pressure of the first working fluid is higher than the maximum value of the usage range, the outer nozzle and the inner nozzle move toward the rear end against the biasing force of the biasing member, and the first working fluid supply port is connected to a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path. The fuel cell system has a pressure measuring section that measures the pressure of the fluid downstream of the outer nozzle, and a determining section that determines whether the pressure abnormality has occurred based on the measurement value of the pressure measuring section, and the determining section determines that the pressure abnormality has occurred when the amount of change per unit time of the measurement value of the pressure measuring section exceeds a predetermined amount.

[0025] According to this aspect, an abnormality in the pressure of the first working fluid can be quickly detected based on the amount of change per unit time in the pressure of the fluid downstream of the outer nozzle.

[0026] Another aspect of the present disclosure made to solve the above problems is a fuel cell system having an ejector, the ejector having a main casing, an outer nozzle arranged in the main casing and spraying a first working fluid, an inner nozzle arranged inside the outer nozzle and spraying a second working fluid, and a first working fluid supply port for supplying the first working fluid into the main casing, the outer nozzle having an inlet for causing the first working fluid to flow into the outer nozzle, a first flow path for the first working fluid to flow between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle, and a second flow path for the second working fluid to flow inside the inner nozzle, the outer nozzle having an urging member for urging the outer nozzle and the inner nozzle toward their tip ends, the outer nozzle having a rear end side relative to the inlet, which is configured to apply a pressure of the first working fluid to the rear end side of the outer nozzle against the urging force of the urging member. and a pressure receiving section that receives pressure toward the end direction, and when the pressure of the first working fluid is within a normal pressure range and is within a usage range, the first working fluid supply port is connected to the first flow path, and the first working fluid flows through the first flow path, and when the pressure of the first working fluid is abnormal and is greater than the maximum value of the usage range, the outer nozzle and the inner nozzle move toward the rear end against the biasing force of the biasing member, and the first working fluid supply port is connected to a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path.The fuel cell system is characterized by having a pressure measuring section that measures the pressure of the fluid downstream of the outer nozzle, and a judgment section that judges whether the pressure abnormality has occurred based on the measurement value of the pressure measuring section, and the judgment section judges that the pressure abnormality has occurred when the measurement value of the pressure measuring section is greater than a predetermined value.

[0027] According to this aspect, an abnormality in the pressure of the first working fluid can be quickly detected based on the value of the pressure of the fluid downstream of the outer nozzle. [Effects of the Invention]

[0028] The ejector and fuel cell system having the ejector of the present disclosure can quickly and appropriately respond to pressure abnormalities in the working fluid. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic configuration diagram of a fuel cell system according to a first embodiment. [Figure 2] FIG. 2 is a front cross-sectional view of the ejector of the first embodiment. [Figure 3] FIG. 2 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in the ejector of the first embodiment, showing the state when the pressure of the first working fluid is normal. [Figure 4] FIG. 2 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in the ejector of the first embodiment, showing a state where the pressure of the first working fluid is abnormal. [Figure 5] FIG. 10 is a schematic configuration diagram of a fuel cell system according to a second embodiment. [Figure 6] FIG. 10 is a front cross-sectional view of an ejector according to a second embodiment. [Figure 7] FIG. 10 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in the ejector of the second embodiment, showing the state when the pressure of the first working fluid is normal. [Figure 8] FIG. 10 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in the ejector of the second embodiment, showing a state in which the pressure of the first working fluid is abnormal. [Figure 9] 6 is a diagram showing an example of behavior of the outlet pressure of the ejector when the pressure of the first working fluid is abnormal. FIG. [Figure 10] FIG. 10 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in an ejector according to a third embodiment, showing the state when the pressure of the first working fluid is normal. [Figure 11] FIG. 10 is a side view of the inner nozzle of the third embodiment. [Figure 12] FIG. 12 is a view of the inner nozzle of the third embodiment as seen from the left side of FIG. [Figure 13] FIG. 10 is a top view of the inner nozzle of the third embodiment. [Figure 14] FIG. 10 is an enlarged view of an outer nozzle, an inner nozzle, and their surrounding areas in the ejector of the third embodiment, showing a state where the pressure of the first working fluid is abnormal. [Figure 15] FIG. 11 is a top view of an inner nozzle of a modified example of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] An embodiment of an ejector and a fuel cell system having the ejector of the present disclosure will be described. In the following description, "upstream" means upstream in the flow of a fluid, and "downstream" means downstream in the flow of a fluid.

[0031] [First embodiment] First, the first embodiment will be described.

[0032] <Outline of the fuel cell system> FIG. 1 shows a schematic diagram of a fuel cell system 1 according to this embodiment. This fuel cell system 1 is mounted on an electric vehicle and is used to supply power to its drive motor (not shown). The fuel cell system 1 includes a fuel cell (FC) 11. The fuel cell 11 generates power by receiving a supply of fuel gas (hydrogen gas) and oxidant gas (air). The power generated by the fuel cell 11 is supplied to the drive motor (not shown) via an inverter (not shown).

[0033] On the anode side of fuel cell 11, there are provided a hydrogen supply passage 12 as a fuel supply passage for supplying hydrogen gas to fuel cell 11, a hydrogen circulation passage 13 as a fuel circulation passage for circulating fuel off-gas (hydrogen off-gas) discharged from fuel cell 11 to hydrogen supply passage 12, and an ejector 14 provided at the connection between hydrogen supply passage 12 and hydrogen circulation passage 13. Hydrogen gas flows into hydrogen supply passage 12 from a hydrogen tank 15.

[0034] In the hydrogen supply passage 12 upstream of the ejector 14, a hydrogen pressure sensor 16, a pressure reducing valve 17, and a hydrogen pressure sensor 18 are provided, in that order from the upstream side (i.e., the hydrogen tank 15 side). The high-pressure hydrogen gas flowing from the hydrogen tank 15 is reduced in pressure by the pressure reducing valve 17, and then the pressure of the hydrogen gas is adjusted by the ejector 14. Furthermore, the hydrogen pressure sensor 16 detects the pressure of the hydrogen gas on the inlet side of the pressure reducing valve 17, while the hydrogen pressure sensor 18 detects the pressure of the hydrogen gas on the outlet side of the pressure reducing valve 17.

[0035] Furthermore, first injector 19A and second injector 19B, which are electromagnetic valves for injecting hydrogen gas from hydrogen tank 15, are provided in hydrogen supply passage 12 upstream of ejector 14 and downstream of hydrogen pressure sensor 18. The inlet sides of injectors 19A, 19B are connected in parallel to hydrogen tank 15 via hydrogen supply passage 12. The outlet sides of injectors 19A, 19B are connected via hydrogen supply passage 12 to two different nozzles 55, 56 (see FIG. 2, etc.) provided in ejector 14. Note that linear solenoid valves may be provided instead of first injector 19A and second injector 19B.

[0036] A gas-liquid separator 20 for separating gas and liquid is provided in the hydrogen circulation passage 13. The gas-liquid separator 20 separates moisture from the hydrogen off-gas, directs only the hydrogen off-gas toward the ejector 14, and discharges the moisture to the outside via a discharge passage 21. The discharge passage 21 is provided with an exhaust / drain valve 22 made of an electromagnetic valve.

[0037] On the other hand, on the cathode side of the fuel cell 11, there are provided an air supply passage 31 as an oxidant gas supply passage for supplying air to the fuel cell 11, and an air discharge passage 32 for discharging air off-gas discharged from the fuel cell 11. An air pump 33 is provided in the air supply passage 31 for adjusting the amount of air supplied to the fuel cell 11. An air pressure sensor 34 is provided in the air supply passage 31 downstream of the air pump 33. The air pressure sensor 34 detects the pressure of the air supplied to the fuel cell 11. Downstream of the air pressure sensor 34, a motor-driven on-off valve 36 supplies and cuts off air. An intercooler 37 for cooling the air discharged from the air pump 33 is also provided in the air supply passage 31. A motor-driven flow rate adjustment valve 35 is provided in the air discharge passage 32.

[0038] An air bypass passage 38 is provided on the cathode side of the fuel cell 11. A motor-driven bypass valve 39 is provided in this air bypass passage 38. When it is desired to cause the fuel cell 11 to generate electricity, the on-off valve 36 is opened and the bypass valve 39 is closed. When it is desired to cause the fuel cell 11 not to generate electricity but to drive the air pump 33, the on-off valve 36 is closed and the bypass valve 39 is opened.

[0039] In the above configuration, hydrogen gas from the hydrogen tank 15 flows through the hydrogen supply passage 12 and is supplied to the fuel cell 11 via the pressure reducing valve 17, the injectors 19A and 19B, and the ejector 14. The hydrogen gas supplied to the fuel cell 11 is used to generate electricity in the fuel cell 11 and then discharged from the fuel cell 11 as hydrogen off-gas to the hydrogen circulation passage 13. The discharged hydrogen off-gas is separated from moisture in the gas-liquid separator 20 and then circulated to the hydrogen supply passage 12 via the ejector 14. At this time, negative pressure is generated in the ejector 14 by the hydrogen gas flowing through the ejector 14, and the hydrogen off-gas is drawn into the ejector 14 by the negative pressure, where it is mixed with the hydrogen gas and circulated to the hydrogen supply passage 12.

[0040] As shown in Fig. 1, the fuel cell system 1 further includes a controller 40. The controller 40 controls the injectors 19A, 19B to adjust the flow rate (amount of hydrogen) of hydrogen gas flowing to the ejector 14. The controller 40 controls the exhaust drain valve 22 to adjust the exhaust drain from the discharge passage 21. On the other hand, the controller 40 controls the air pump 33 and the on-off valve 36 to adjust the flow rate of air supplied to the fuel cell 11. The controller 40 also controls the flow adjustment valve 35 to adjust the discharge flow rate of air off-gas from the air discharge passage 32.

[0041] The controller 40 receives detection signals from the hydrogen pressure sensor 16, the hydrogen pressure sensor 18, and the air pressure sensor 34. The controller 40 also receives voltage and current values ​​related to power generation by the fuel cell 11. The controller 40 also receives detection signals from a pressure sensor 91, which will be described later. The controller 40 is equipped with a central processing unit (CPU) and memory, and controls the injectors 19A, 19B, the air pump 33, etc., based on a predetermined control program stored in the memory in order to control the amount of hydrogen and air supplied to the fuel cell 11.

[0042] In this embodiment, the fuel cell system 1 has a pressure sensor 91 that measures the pressure of hydrogen gas (more specifically, a mixed gas of hydrogen gas and hydrogen off-gas) at a position downstream of the ejector 14 (more specifically, an outer nozzle 55 described later). The pressure sensor 91 is an example of the "pressure measurement unit" of the present disclosure.

[0043] <Ejector Overview> Next, an overview of the ejector 14 will be described.

[0044] 2, the ejector 14 has a main body casing 41. The main body casing 41 is formed in a tubular shape for allowing the working fluid (i.e., hydrogen gas) and the target fluid (i.e., hydrogen off-gas) to flow therethrough.

[0045] The main casing 41 is provided with a first working fluid supply port 51, a second working fluid supply port 52, a target fluid supply port 53, a negative pressure generating chamber 54, an outer nozzle 55, an inner nozzle 56, a diffuser 57, a discharge port 58, and a plug 59.

[0046] 3, the first working fluid supply port 51 is a supply port through which the first working fluid WF1 sent from the first injector 19A (see FIG. 1) is supplied into the main casing 41, and supplies the first working fluid WF1 to an inlet 55c (described later) provided in the outer nozzle 55, and is connected to a first flow path 61, which is a flow path through which the first working fluid WF1 flows, in the gap between an inner circumferential surface 55b of the outer nozzle 55 and an outer circumferential surface 56a of the inner nozzle 56. The second working fluid supply port 52 is a supply port through which the second working fluid WF2 sent from the second injector 19B (see FIG. 1) is supplied into the main casing 41, and is connected to a second flow path 62, which is a flow path through which the second working fluid WF2 flows inside the inner nozzle 56.

[0047] 2, the target fluid supply port 53 is a supply port through which the target fluid is supplied, and is connected to the negative pressure generating chamber 54. The negative pressure generating chamber 54 is a space portion for generating negative pressure by the working fluid.

[0048] The outer nozzle 55 and the inner nozzle 56 are each formed in a substantially cylindrical shape and are made of stainless steel, resin, etc. The inner nozzle 56 is provided inside the outer nozzle 55. In this embodiment, the inner nozzle 56 is press-fitted and fixed into the outer nozzle 55.

[0049] The outer nozzle 55 is disposed inside the main casing 41 and sprays the first working fluid WF1 supplied from the first working fluid supply port 51. The outer nozzle 55 has an inlet 55c that allows the first working fluid WF1 to flow into the inside of the outer nozzle 55.

[0050] 3, the outer nozzle 55 is provided with a flow rate restricting section 71 at its tip end that restricts the cross-sectional area of ​​the flow path (so that the cross-sectional area of ​​the flow path is smaller than that of portions other than the tip end). In this embodiment, the outer nozzle 55 is provided with a tip-side O-ring groove 55d in which an O-ring 83 is disposed, on its outer peripheral surface 55a, closer to the tip than an inlet 55c. The outer nozzle 55 is also provided with a rear-side O-ring groove 55e in which an O-ring 84 is disposed, on its outer peripheral surface 55a, closer to the rear than a pressure-receiving section 82, which will be described later. The outer nozzle 55 is attached to the main casing 41 via the O-ring 83 and the O-ring 84.

[0051] Each of O-ring 83 and O-ring 84 is an example of a "sealing member" in the present disclosure. Further, tip-side O-ring groove 55d is an example of a "tip-side sealing member groove" in the present disclosure.

[0052] The inner nozzle 56 is disposed within the outer nozzle 55 and injects the second working fluid WF2 supplied from the second working fluid supply port 52.

[0053] The flow rate restricting portion 71, which is the tip of the outer nozzle 55, and the tip 72 of the inner nozzle 56 are disposed in the negative pressure generating chamber 54. The flow rate restricting portion 71 and the tip 72 are the downstream end portions (left side in FIG. 2) of the outer nozzle 55 and the inner nozzle 56, respectively, and are portions where the inner diameter is narrowed to a minimum.

[0054] 2, the diffuser 57 is a flow path that communicates with the negative pressure generating chamber 54, sucks in the target fluid by using the negative pressure generated by the working fluid, merges the target fluid with the working fluid, and sends it out to the discharge port 58. The discharge port 58 is a portion that discharges the working fluid and the target fluid that have flowed through the diffuser 57 to the outside. In addition, a plug 59 is attached inside the main casing 41 to close an opening on the rear end side of the main casing 41 (i.e., on the opposite side from the discharge port 58).

[0055] Here, as an example, as shown in Figures 2 and 3, the outer nozzle 55, inner nozzle 56, and diffuser 57 are arranged in a coaxial positional relationship (i.e., a positional relationship in which their respective axes coincide).

[0056] The ejector 14 configured in this manner generates negative pressure in the negative pressure generating chamber 54 by the first working fluid WF1 and the second working fluid WF2, which are supplied from the first working fluid supply port 51 and the second working fluid supply port 52 and sprayed from the inner nozzle 56 and the outer nozzle 55, and this negative pressure causes the target fluid to be sucked into the negative pressure generating chamber 54 from the target fluid supply port 53. The ejector 14 then flows the target fluid together with the working fluid to the diffuser 57 and discharges it from the discharge port 58 toward a supply destination (for example, the fuel cell 11).

[0057] More specifically, the first working fluid WF1 supplied to the first working fluid supply port 51 flows to the outer nozzle 55, is injected from the first flow path 61 into the negative pressure generating chamber 54, flows through the diffuser 57, and is discharged from the discharge port 58. Meanwhile, the second working fluid WF2 supplied to the second working fluid supply port 52 flows to the inner nozzle 56, is injected from the second flow path 62 into the negative pressure generating chamber 54, flows through the diffuser 57, and is discharged from the discharge port 58.

[0058] This flow of working fluid generates negative pressure in the negative pressure generating chamber 54, and the target fluid supplied to the target fluid supply port 53 is sucked into the negative pressure generating chamber 54 by this negative pressure, flows through the diffuser 57 together with the working fluid, is mixed with the working fluid, and is discharged from the discharge port 58.

[0059] <Response to pressure abnormalities in the first working fluid> In the event of a failure (i.e., a malfunction) of a component (e.g., the pressure reducing valve 17) located upstream of the outer nozzle 55, hydrogen gas with an abnormal pressure flows from the pressure reducing valve 17 to the first injector 19A, causing a pressure abnormality in the first working fluid WF1 supplied from the first injector 19A to the inlet 55c of the outer nozzle 55 via the first working fluid supply port 51. In this case, high-pressure first working fluid WF1 may flow from the ejector 14 into the fuel cell 11, causing a malfunction in the fuel cell 11. For this reason, it is desirable to take appropriate measures promptly to deal with the pressure abnormality of the first working fluid WF1.

[0060] Therefore, in this embodiment, the structures of the outer nozzle 55 and the inner nozzle 56 are devised so that an appropriate response can be made promptly to the abnormality in the pressure of the first working fluid WF1.

[0061] Specifically, as shown in FIGS. 2 to 4, the ejector 14 has a spring 81 that biases the outer nozzle 55 and the inner nozzle 56 toward their distal ends (i.e., toward the left in FIGS. 2 to 4). The spring 81 is provided between the rear end 73 of the inner nozzle 56 and the plug 59. The spring 81 biases the inner nozzle 56 toward its distal end, and also biases the outer nozzle 55 toward its distal end via the inner nozzle 56. The spring 81 is an example of a "biasing member" in the present disclosure.

[0062] The outer nozzle 55 also has a pressure-receiving portion 82 at a position on the outer peripheral surface 55a rearward of the inlet 55c (i.e., to the right in Figures 2 to 4). The pressure-receiving portion 82 is formed by a surface (i.e., a surface formed in the up-down direction in Figures 2 to 4) that is perpendicular or substantially perpendicular to the axial direction of the outer nozzle 55 (i.e., the left-right direction in Figures 2 to 4).

[0063] The pressure receiving portion 82 receives the pressure of the first working fluid WF1 supplied from the first working fluid supply port 51 in the direction toward the rear end against the biasing force of the spring 81.

[0064] At this time, the biasing load (i.e., spring load) of the spring 81 is set to be greater than the load received by the pressure receiving portion 82 when the pressure of the first working fluid WF1 is normal (i.e., the load received when the maximum operating pressure is applied), but smaller than the load received by the pressure receiving portion 82 when the pressure of the first working fluid WF1 is abnormal. Here, "when the pressure of the first working fluid WF1 is normal" means when the pressure of the first working fluid WF1 is within a pressure value within the normal operating range. Furthermore, "when the pressure of the first working fluid WF1 is abnormal" means when the pressure of the first working fluid WF1 is at a pressure value (i.e., abnormal pressure) greater than the maximum value within the normal operating range (i.e., the maximum operating pressure).

[0065] More specifically, the biasing load of the spring 81 is set so that (maximum usable pressure of the first working fluid WF1 × pressure-receiving area of ​​the pressure-receiving section 82) < (biased load of the spring 81) < (abnormal pressure of the first working fluid WF1 × pressure-receiving area of ​​the pressure-receiving section 82).

[0066] In this embodiment, when the pressure of the first working fluid WF1 becomes abnormal, as shown in FIG. 4, the outer nozzle 55 and the inner nozzle 56 move toward the rear end against the biasing force of the spring 81, and block the first working fluid supply port 51 at the blocking area PA, which is the part of the outer surface 55a of the outer nozzle 55 that is closer to the tip than the inlet 55c (more specifically, closer to the tip than the tip-side O-ring groove 55d).

[0067] In this way, the biasing load of the spring 81 is smaller than the load received by the pressure-receiving portion 82 when the pressure of the first working fluid WF1 is abnormal, and therefore, when the pressure of the first working fluid WF1 is abnormal, the load received by the pressure-receiving portion 82 causes the outer nozzle 55 and the inner nozzle 56 to move toward the rear end against the biasing force of the spring 81. Furthermore, the first working fluid supply port 51 is blocked by the blocking portion PA on the outer peripheral surface 55a of the outer nozzle 55, so the area of ​​the passage through which the first working fluid WF1 flows can be reduced and the first working fluid WF1 with an abnormal pressure can be prevented from flowing downstream of the ejector 14. In this way, it is possible to respond promptly and appropriately to a pressure abnormality in the first working fluid WF1.

[0068] Also, for example, in order to prevent the first working fluid WF1 with abnormal pressure (i.e., high pressure) from flowing into the fuel cell 11 due to a failure of the pressure reducing valve 17 or the like, it is conceivable to provide a relief valve (not shown) between the ejector 14 and the fuel cell 11 located downstream of the ejector 14. In this case, when the pressure of the first working fluid WF1 is abnormal, the area of the passage through which the first working fluid WF1 flows can be reduced as described above, and the flow of the first working fluid WF1 with abnormal pressure downstream of the ejector 14 can be suppressed. Therefore, the size of the relief valve can be reduced, and the fuel cell system 1 can be miniaturized.

[0069] More specifically, each dimension is set as follows. First, let the amount of movement of the outer nozzle 55 and the inner nozzle 56 in the rear end direction when the pressure of the first working fluid WF1 is abnormal be A. Also, regarding the axial direction (the left - right direction in FIG. 3) of the outer nozzle 55 and the inner nozzle 56, let the distance between the rear - end - side end portion 51a of the first working fluid supply port 51 and the front - end - side end portion 55da of the front - end - side O - ring groove 55d when the pressure of the first working fluid WF1 is normal be B. Also, regarding the axial direction of the outer nozzle 55 and the inner nozzle 56, let the distance between the front - end - side end portion 55da of the front - end - side O - ring groove 55d and the front - end - side end portion 55aa of the outer peripheral surface 55a of the outer nozzle 55 (i.e., the length of the closed portion PA) be C. Also, let the diameter of the first working fluid supply port 51 be D. And at this time, the relationship B < A and (A - B+D) < C is satisfied.

[0070] As a result, when the pressure of the first working fluid WF1 becomes abnormal, the outer nozzle 55 and the inner nozzle 56 move toward the rear end, and the first working fluid supply port 51 can be blocked between the tip end 55aa of the outer peripheral surface 55a of the outer nozzle 55 and the tip end 55da of the tip O-ring groove 55d (i.e., the blocked portion PA). Therefore, when the pressure of the first working fluid WF1 becomes abnormal, the first working fluid WF1 with abnormal pressure can be more reliably prevented from flowing downstream of the ejector 14. Note that the tip end 55aa is a boundary portion on the outer peripheral surface 55a of the outer nozzle 55 between a portion where the outer diameter of the outer nozzle 55 is constant (i.e., the blocked portion PA) and a portion where the outer diameter of the outer nozzle 55 gradually decreases toward the tip end (i.e., the flow rate restricting portion 71).

[0071] The outer nozzle 55 is attached to the main casing 41 via an O-ring 83 at a casing inner peripheral surface front end portion 41aa, which is located further forward than the first working fluid supply port 51 on the inner peripheral surface 41a of the main casing 41. The outer nozzle 55 is attached to the main casing 41 via an O-ring 84 at a casing inner peripheral surface rear end portion 41ab, which is located further rearward than the first working fluid supply port 51 on the inner peripheral surface 41a of the main casing 41. An inner diameter D2 of the casing inner peripheral surface rear end portion 41ab is larger than an inner diameter D1 of the casing inner peripheral surface front end portion 41aa.

[0072] This increases the pressure-receiving area of ​​the pressure-receiving portion 82, whose outer diameter is approximately equal to the inner diameter D2 of the casing inner peripheral surface rear end portion 41ab. Therefore, when the pressure of the first working fluid WF1 becomes abnormal, the outer nozzle 55 and the inner nozzle 56 move toward the rear end more quickly due to the load received by the pressure-receiving portion 82, against the biasing force of the spring 81. Therefore, the outer peripheral surface 55a of the outer nozzle 55 can more quickly block the first working fluid supply port 51, thereby preventing the first working fluid WF1 with an abnormal pressure from flowing downstream of the ejector 14.

[0073] Second Embodiment Next, a second embodiment will be described, but a description of the points in common with the first embodiment will be omitted and only the points that differ from the first embodiment will be described.

[0074] <Outline of the fuel cell system> 5, the fuel cell system 1 in this embodiment includes a determination unit 92 that determines whether or not the pressure of the first working fluid WF1 is abnormal, based on the measurement value of the pressure sensor 91, as will be described in detail later. In the example shown in FIG. 1, the determination unit 92 is provided as part of the controller 40, but is not limited to this and may be provided separately from the controller 40.

[0075] <Ejector Overview> In this embodiment, as shown in FIGS. 6 to 8 , a third flow path 63 is formed between the inner circumferential surface 41 a of the main body casing 41 and the outer circumferential surface 55 a of the outer nozzle 55. A tip-side O-ring arrangement portion 55 f in which an O-ring 83 is arranged is formed on the outer circumferential surface 55 a of the outer nozzle 55, closer to the tip of the inlet 55 c. The tip-side O-ring arrangement portion 55 f is formed to protrude from the outer circumferential surface 55 a toward the inner circumferential surface 41 a of the main body casing 41. This leaves a gap between the outer circumferential surface 55 a, which is closer to the tip of the tip-side O-ring arrangement portion 55 f, and the inner circumferential surface 41 a of the main body casing 41, and this gap forms the third flow path 63. The tip-side O-ring arrangement portion 55 f is an example of a “tip-side seal member arrangement portion” of the present disclosure.

[0076] <Detection of abnormal pressure in the first working fluid> In this embodiment, as shown in FIG. 7, when the pressure of the first working fluid WF1 is normal, the first working fluid supply port 51 communicates with the first flow path 61, and the first working fluid WF1 flows through the first flow path 61. On the other hand, as shown in FIG. 8, when the pressure of the first working fluid WF1 is abnormal, the outer nozzle 55 and the inner nozzle 56 move in the rear end direction against the biasing force of the spring 81, and the first working fluid supply port 51 communicates with the third flow path 63, and the first working fluid WF1 flows through the third flow path 63. And the flow path cross-sectional area CA3 of the third flow path 63 is larger than the flow path cross-sectional area CA1 of the first flow path 61. Note that the flow path cross-sectional area CA3 of the third flow path 63 is, for example, seven times the size of the flow path cross-sectional area CA1 of the first flow path 61.

[0077] In this way, since the flow path through which the first working fluid WF1 flows is different between the first flow path 61 and the third flow path 63 when the pressure of the first working fluid WF1 is normal and when it is abnormal, the way the pressure of the fluid is transmitted to the downstream side of the ejector 14 is different. Specifically, the flow rate of the first working fluid WF1 is larger in the third flow path 63 than in the first flow path 61. Therefore, the outlet pressure of the ejector 14 rises earlier when the pressure of the first working fluid WF1 is abnormal and the first working fluid WF1 flows through the third flow path 63 than when the pressure of the first working fluid WF1 is normal and the first working fluid WF1 flows through the first flow path 61. Therefore, by measuring the change (i.e., rise) in the outlet pressure of the ejector 14 by the pressure sensor 91, an abnormal pressure of the first working fluid WF1 can be detected at an early stage. In this way, an appropriate response can be made to the abnormal pressure of the first working fluid WF1 at an early stage.

[0078] More specifically, the respective dimensions are set as follows. First, let the amount of movement of the outer nozzle 55 and the inner nozzle 56 in the rear end direction when the pressure of the first working fluid WF1 is abnormal be A. Also, regarding the axial direction (the left-right direction in FIG. 7) of the outer nozzle 55 and the inner nozzle 56, let the distance between the rear end side end portion 51a of the first working fluid supply port 51 and the front end side end portion 55fa of the front end side O-ring arrangement portion 55f when the pressure of the first working fluid WF1 is normal be E. And at this time, the relationship of E < A is satisfied.

[0079] As a result, when the pressure of the first working fluid WF1 is abnormal, the outer nozzle 55 and the inner nozzle 56 move toward the rear end, allowing the first working fluid WF1 supplied from the first working fluid supply port 51 to flow into the third flow path 63. Therefore, when the pressure of the first working fluid WF1 is abnormal, the fluid pressure is more reliably transmitted to the downstream side of the ejector 14 earlier than when the pressure is normal. Therefore, by measuring the increase in the outlet pressure of the ejector 14, the pressure abnormality of the first working fluid WF1 can be more reliably detected early.

[0080] Furthermore, the inner diameter D2 of the casing inner circumferential surface rear end portion 41ab is larger than the inner diameter D1 of the casing inner circumferential surface front end portion 41aa.

[0081] This increases the pressure-receiving area of ​​the pressure-receiving portion 82, whose outer diameter is approximately equal to the inner diameter D2 of the casing inner circumferential surface rear end portion 41ab. Therefore, when an abnormality in the pressure of the first working fluid WF1 occurs, the outer nozzle 55 and the inner nozzle 56 move toward the rear end more quickly due to the load received by the pressure-receiving portion 82, against the biasing force of the spring 81. Therefore, an abnormality in the pressure of the first working fluid WF1 can be detected more quickly.

[0082] In this embodiment, as shown in Figure 9, in the event of a failure, i.e., when the pressure of the first working fluid WF1 is abnormal, the slope of the increase in the outlet pressure of the ejector 14 (i.e., the amount of change (amount of increase) per unit time) is larger than in a conventional ejector (i.e., an ejector in which the outer nozzle 55 does not have a pressure-receiving portion 82), and the time required to detect the pressure abnormality of the first working fluid WF1 can also be shortened.

[0083] In this way, since the outlet pressure of the ejector 14 rises in the event of a failure, it is possible to determine whether or not a pressure abnormality has occurred in the first working fluid WF1 based on the slope of the rise in the outlet pressure of the ejector 14. Therefore, the determination unit 92 determines that a pressure abnormality has occurred in the first working fluid WF1 when the amount of change per unit time in the measurement value of the pressure sensor 91 exceeds a predetermined amount. Note that the "predetermined amount" is, for example, 1.1 times the amount of change per unit time in the measurement value of the pressure sensor 91 when the pressure of the first working fluid WF1 is normal.

[0084] Alternatively, the determination unit 92 may determine that a pressure abnormality has occurred in the first working fluid WF1 when the measurement value of the pressure sensor 91 is greater than a predetermined value (for example, the system abnormality detection pressure Pfail in FIG. 9). The system abnormality detection pressure Pfail is set to, for example, a value 1.1 times the system operation upper limit pressure Pmax. The system operation upper limit pressure Pmax is the maximum value of the outlet pressure of the ejector 14 when the pressure of the first working fluid WF1 is normal.

[0085] Third Embodiment Next, a third embodiment will be described, but a description of the points common to the first and second embodiments will be omitted and only points different from the first and second embodiments will be described.

[0086] In this embodiment, when the pressure of the first working fluid WF1 becomes abnormal, the inner nozzle 56 moves toward the rear end against the biasing force of the spring 81, and the inner nozzle 56 closes the inlet 55c of the outer nozzle 55. Note that in this embodiment, the inner nozzle 56 is not press-fitted and fixed to the outer nozzle 55, and is therefore movable relative to the outer nozzle 55.

[0087] 10 to 14, the inner nozzle 56 is provided on its outer circumferential surface 56a with protrusions 56b that protrude radially outward (in the vertical direction in FIG. 10) of the inner nozzle 56. As shown in FIGS. 11 and 12, two protrusions 56b are provided in the circumferential direction of the inner nozzle 56. As shown in FIG. 10, when the pressure of the first working fluid WF1 is normal, the protrusions 56b are located closer to the front end than the inlet 55c of the outer nozzle 55 (to the left in FIG. 10).

[0088] At this time, the first working fluid WF1 is able to flow through the areas where no protrusions 56b are provided (that is, the areas between the two protrusions 56b in the circumferential direction of the inner nozzle 56).

[0089] 10 and 14, a clearance δ (i.e., a gap) is provided between the inner circumferential surface 55b of the outer nozzle 55 and the outer circumferential surface 56a of the inner nozzle 56. The size of this clearance δ is set to a value that does not affect the flow rate when the central axes of the outer nozzle 55 and the inner nozzle 56 are misaligned, and is set to a value that allows the inner nozzle 56 to move relative to the outer nozzle 55 when an abnormality occurs in the pressure of the first working fluid WF1.

[0090] When the pressure of the first working fluid WF1 becomes abnormal, the pressure of the first working fluid WF1 acts on the pressure-receiving portion 101 at the rear end portion 73 of the inner nozzle 56 via the clearance δ between the inner circumferential surface 55b of the outer nozzle 55 and the outer circumferential surface 56a of the inner nozzle 56. As a result, as shown in Fig. 14 , the outer nozzle 55 does not move, but the inner nozzle 56 moves toward the rear end, and the inlet 55c of the outer nozzle 55 is blocked by the protrusion 56b of the inner nozzle 56.

[0091] In this way, when the pressure of the first working fluid WF1 becomes abnormal, the protrusion 56b of the inner nozzle 56 blocks the inlet 55c of the outer nozzle 55, thereby more reliably preventing the first working fluid WF1 with abnormal pressure from flowing downstream of the ejector 14.

[0092] The outer shape of the protrusion 56b of the inner nozzle 56 is formed, for example, in a quadrilateral (e.g., rectangular) shape when viewed from above as shown in Fig. 13, but as a modified example, it may be formed in an elliptical shape when viewed from above as shown in Fig. 15. Furthermore, the number of protrusions 56b provided may be one, or three or more.

[0093] It should be noted that the above-described embodiments are merely examples and do not limit the present disclosure in any way. It goes without saying that various improvements and modifications are possible within the scope of the gist of the present disclosure.

[0094] For example, the pressure sensor 91 may be provided inside the ejector 14. In this case, it is conceivable that the pressure sensor 91 is provided at a position downstream of the outer nozzle 55 inside the ejector 14.

[0095] Furthermore, in the event of a pressure abnormality, the blocked portion PA on the outer peripheral surface 55a of the outer nozzle 55 is not limited to blocking the entire first working fluid supply port 51, but may reduce the area of ​​the passage through which the first working fluid WF1 flows by blocking a portion of the first working fluid supply port 51. Similarly, in the event of a pressure abnormality, the protrusion 56b of the inner nozzle 56 is not limited to blocking the entire inlet 55c of the outer nozzle 55, but may reduce the area of ​​the passage through which the first working fluid WF1 flows by blocking a portion of the inlet 55c of the outer nozzle 55. [Explanation of symbols]

[0096] 1. Fuel cell system 11 Fuel Cell (FC) 12 Hydrogen supply passage 13 Hydrogen circulation passage 14 Ejector 16 Hydrogen pressure sensor 17 Pressure reducing valve 18 Hydrogen pressure sensor 19A First injector 40 Controller 41 Main casing 41a Inner surface 41aa Casing inner surface tip portion 41ab Rear end portion of inner circumferential surface of casing 51 First working fluid supply port 51a Rear end 52 Second working fluid supply port 53 Target fluid supply port 54 Negative pressure generating chamber 55 outer nozzle 55a Outer surface 55aa Tip end 55b Inner surface 55c inlet 55d Tip side O-ring groove 55da Tip end 55e Rear end O-ring groove 55f Tip side O-ring placement section 55fa Tip end 56 Inner nozzle 56a Outer surface 56b Protrusion 57 Diffuser 58 Outlet 59 Plug 61 First Channel 62 Second Channel 63 Third Channel 73 Rear end 81 Spring 82 Pressure receiving part 83 O-ring 84 O-ring 91 Pressure Sensor 92 Judgment section 101 Pressure receiving part WF1 First working fluid WF2 Second working fluid PA occlusion site A Travel amount B distance C distance D diameter E distance D1 (inner diameter of the tip of the inner periphery of the casing) D2 (inner diameter of rear end of inner periphery of casing) CA1 (first channel) cross-sectional area CA3 (third channel) cross-sectional area Pfail System abnormality detection pressure δ clearance

Claims

1. A main body casing; an outer nozzle disposed in the main casing and configured to inject a first working fluid; an inner nozzle disposed inside the outer nozzle and configured to inject a second working fluid; a first working fluid supply port that supplies the first working fluid into the main body casing, The outer nozzle includes an inlet for allowing the first working fluid to flow into the outer nozzle. In the ejector, a biasing member that biases the outer nozzle and the inner nozzle toward their distal ends, When the pressure of the first working fluid is abnormal and is greater than the maximum value of the operating range, the outer nozzle moves toward the rear end against the biasing force of the biasing member, and the outer nozzle closes the first working fluid supply port; or the inner nozzle moves toward the rear end against the biasing force of the biasing member, and the inner nozzle closes the inlet; An ejector characterized by:

2. The ejector of claim 1, the outer nozzle includes a pressure receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rear end against the biasing force of the biasing member, when the pressure abnormality occurs, the first working fluid supply port is blocked by a portion of the outer peripheral surface of the outer nozzle that is further toward the tip side than the inlet; An ejector characterized by:

3. The ejector according to claim 1 or 2, a seal member disposed between an inner peripheral surface of the main body casing and an outer peripheral surface of the outer nozzle; a tip-side seal member groove formed in the outer peripheral surface of the outer nozzle on the tip side of the inlet for disposing the seal member; and A is the amount of movement of the outer nozzle and the inner nozzle toward the rear end when the pressure abnormality occurs, and a distance between a rear end of the first working fluid supply port and a front end of the front seal groove is defined as B; a distance between a tip end of the tip end seal groove and a tip end of the outer peripheral surface of the outer nozzle is defined as C; When the diameter of the first working fluid supply port is D, The relationship B<A and (A-B+D)<C is satisfied. An ejector characterized by:

4. The ejector of claim 3, The outer nozzle is the valve is attached to the main casing via a seal member at a tip end portion of the inner circumferential surface of the main casing that is located tip-side with respect to the first working fluid supply port, the pump is attached to the main body casing via a seal member at a rear end portion of the inner circumferential surface of the main body casing that is located rearward of the first working fluid supply port, the inner diameter of the rear end portion of the inner circumferential surface of the casing is larger than the inner diameter of the front end portion of the inner circumferential surface of the casing; An ejector characterized by:

5. The ejector of claim 1, The inner nozzle has a protrusion on its outer circumferential surface, the protrusion is located closer to the front end than the inlet when the pressure of the first working fluid is normal and within a usable pressure range, When the pressure abnormality occurs, the inner nozzle moves toward the rear end and closes the inlet with the protrusion. An ejector characterized by:

6. A main body casing; an outer nozzle disposed in the main casing and configured to inject a first working fluid; an inner nozzle disposed inside the outer nozzle and configured to inject a second working fluid; a first working fluid supply port that supplies the first working fluid into the main body casing, the outer nozzle includes an inlet through which the first working fluid flows into the outer nozzle; a first flow path through which the first working fluid flows is formed between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle; A second flow path through which the second working fluid flows is formed inside the inner nozzle. In the ejector, a biasing member that biases the outer nozzle and the inner nozzle toward their distal ends, the outer nozzle includes a pressure receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rear end against the biasing force of the biasing member, When the pressure of the first working fluid is within a normal pressure range, the first working fluid supply port is in communication with the first flow path, and the first working fluid flows through the first flow path; when a pressure abnormality occurs in which the pressure of the first working fluid is greater than the maximum value of the operating range, the outer nozzle and the inner nozzle move toward the rear end against the biasing force of the biasing member, the first working fluid supply port communicates with a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path; An ejector characterized by:

7. The ejector of claim 6, a cross-sectional area of ​​the third flow path is larger than a cross-sectional area of ​​the first flow path; An ejector characterized by:

8. The ejector according to claim 6 or 7, a seal member disposed between an outer peripheral surface of the outer nozzle and an inner peripheral surface of the main body casing; a tip-side seal member placement portion formed on the outer peripheral surface of the outer nozzle on the tip side of the inlet, for placing the seal member therein; A is the amount of movement of the outer nozzle and the inner nozzle toward the rear end when the pressure abnormality occurs, and When the distance between the rear end of the first working fluid supply port and the front end of the front end seal member arrangement portion is E, Satisfy the relationship E<A, An ejector characterized by:

9. The ejector of claim 8, The outer nozzle is the valve is attached to the main casing via a seal member at a tip end portion of the inner circumferential surface of the main casing that is located tip-side with respect to the first working fluid supply port, the pump is attached to the main body casing via a seal member at a rear end portion of the inner circumferential surface of the main body casing that is located rearward of the first working fluid supply port, the inner diameter of the rear end portion of the inner circumferential surface of the casing is larger than the inner diameter of the front end portion of the inner circumferential surface of the casing; An ejector characterized by:

10. In a fuel cell system having an ejector, The ejector is A main body casing; an outer nozzle disposed in the main casing and configured to inject a first working fluid; an inner nozzle disposed inside the outer nozzle and configured to inject a second working fluid; a first working fluid supply port that supplies the first working fluid into the main body casing, the outer nozzle includes an inlet through which the first working fluid flows into the outer nozzle; a first flow path through which the first working fluid flows is formed between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle; A second flow path through which the second working fluid flows is formed inside the inner nozzle, a biasing member that biases the outer nozzle and the inner nozzle toward their distal ends, the outer nozzle includes a pressure receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rear end against the biasing force of the biasing member, When the pressure of the first working fluid is within a normal pressure range, the first working fluid supply port is in communication with the first flow path, and the first working fluid flows through the first flow path; When a pressure abnormality occurs in which the pressure of the first working fluid is greater than the maximum value of the operating range, the outer nozzle and the inner nozzle move toward the rear end against the biasing force of the biasing member, the first working fluid supply port communicates with a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path, The fuel cell system includes: a pressure measuring unit for measuring a pressure of the fluid downstream of the outer nozzle; a determination unit that determines whether or not the pressure is abnormal based on the measurement value of the pressure measurement unit, the determination unit determines that the pressure is abnormal when a change in the value measured by the pressure measurement unit per unit time exceeds a predetermined amount; A fuel cell system having an ejector characterized by:

11. In a fuel cell system having an ejector, The ejector is A main body casing; an outer nozzle disposed in the main casing and configured to inject a first working fluid; an inner nozzle disposed inside the outer nozzle and configured to inject a second working fluid; a first working fluid supply port that supplies the first working fluid into the main body casing, the outer nozzle includes an inlet through which the first working fluid flows into the outer nozzle; a first flow path through which the first working fluid flows is formed between an inner circumferential surface of the outer nozzle and an outer circumferential surface of the inner nozzle; A second flow path through which the second working fluid flows is formed inside the inner nozzle, a biasing member that biases the outer nozzle and the inner nozzle toward their distal ends, the outer nozzle includes a pressure receiving portion, located rearward of the inlet, that receives the pressure of the first working fluid toward the rear end against the biasing force of the biasing member, When the pressure of the first working fluid is within a normal pressure range, the first working fluid supply port is in communication with the first flow path, and the first working fluid flows through the first flow path; When a pressure abnormality occurs in which the pressure of the first working fluid is greater than the maximum value of the operating range, the outer nozzle and the inner nozzle move toward the rear end against the biasing force of the biasing member, the first working fluid supply port communicates with a third flow path formed between the inner peripheral surface of the main casing and the outer peripheral surface of the outer nozzle, and the first working fluid flows through the third flow path, The fuel cell system includes: a pressure measuring unit for measuring a pressure of the fluid downstream of the outer nozzle; a determination unit that determines whether or not the pressure is abnormal based on the measurement value of the pressure measurement unit, the determination unit determines that the pressure is abnormal when the measurement value of the pressure measurement unit is greater than a predetermined value; A fuel cell system having an ejector characterized by:

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