Fuel gas supply system

Abstract

This invention provides a fuel gas supply device that achieves a compact structure, vibration resistance, and energy efficiency while increasing power output by incorporating multiple injectors. [Solution] The fuel gas supply device 24 includes a high-pressure pipe 28 for supplying high-pressure fuel gas, a first injector 36 communicating with the high-pressure pipe 28 and ejecting high-pressure fuel gas at a first flow rate, a first ejector 38 that uses the jet of the first injector 36 to send off-gas to the fuel cell, a second injector 40 communicating with the high-pressure pipe 28 and ejecting high-pressure fuel gas at a second flow rate greater than the first flow rate, and a second ejector 42 that uses the jet of the second injector 40 to send off-gas to the fuel cell, wherein the second ejector 42 is positioned closer to the first axis along the center of the high-pressure pipe 28 than the first ejector 38.

Description

【Technical Field】 【0001】 The present disclosure relates to a fuel gas supply device that supplies fuel gas to a fuel cell. 【Background Art】 【0002】 In recent years, in order to enable more people to access affordable, reliable, sustainable, and advanced energy, research and development on fuel cells that contribute to energy efficiency have been conducted. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent No. 5594162 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 By the way, in the technology related to fuel cells, it is a problem to achieve both high output, compact size, and improved durability. 【0005】 The present disclosure aims to achieve compact structure and durability against vibration when increasing the output by mounting a plurality of injectors in a fuel gas supply device in order to solve the above problems. Subsequently, it contributes to energy efficiency. 【Means for Solving the Problems】 【0006】 A first aspect of the present disclosure is a fuel gas supply device for supplying fuel gas to a fuel cell, comprising: a high-pressure pipe for supplying high-pressure fuel gas; a first injector communicating with the high-pressure pipe and ejecting the high-pressure fuel gas at a first flow rate; a first ejector utilizing the jet of the first injector to send off-gas back to the fuel cell; a second injector communicating with the high-pressure pipe and ejecting the high-pressure fuel gas at a second flow rate greater than the first flow rate; and a second ejector utilizing the jet of the second injector to send the off-gas back to the fuel cell, wherein the second ejector is positioned closer to a first axis along the center of the high-pressure pipe than the first ejector. 【0007】 A second aspect of the present disclosure is a fuel gas supply device for supplying fuel gas to a fuel cell, comprising: a first injector for ejecting high-pressure fuel gas at a first flow rate; a first ejector for sending off-gas to the fuel cell using the jet of the first injector; a second injector for ejecting the high-pressure fuel gas at a second flow rate greater than the first flow rate; a second ejector for sending the off-gas back to the fuel cell using the jet of the second injector; and a junction connected downstream of the first ejector and the second ejector. The fuel gas supply device comprises a confluence section having a first opening into which the jet from the first ejector flows, a second opening into which the jet from the second ejector flows, a confluence passage extending in the direction of extension of the first and second ejectors for confluence of the fuel gas flowing out from the first and second openings, and a bent section provided downstream of the confluence passage and bent toward the fuel cell, wherein the first opening is located closer to the inner circumference of the bent section and the second opening is located closer to the outer circumference of the bent section. [Effects of the Invention] 【0008】 The fuel gas supply device disclosed herein contributes to increasing the output, improving durability, and miniaturizing the fuel cell. [Brief explanation of the drawing] 【0009】 [Figure 1] Figure 1 is a diagram showing the configuration of the fuel gas supply system of the fuel cell system according to this embodiment. [Figure 2] Figure 2 is a plan view showing the fuel gas supply device according to this embodiment attached to the stack case of the fuel cell. [Figure 3] Figure 3 is a schematic cross-sectional view of the fuel gas supply device shown in Figure 2. [Figure 4] Figure 4 is an explanatory diagram showing the arrangement of the flow paths of the fuel gas supply device in Figure 2, with the first and second injectors removed. [Figure 5] Figure 5 is an exploded perspective view showing the connection structure between the injector unit and the first and second ejectors. [Modes for carrying out the invention] 【0010】 As shown in Figure 1, the fuel cell system 10 of this embodiment includes a fuel gas supply system 14 that supplies hydrogen gas as fuel gas to the anode of the fuel cell 12 (also called a fuel cell stack). The fuel gas supply system 14 has a fuel gas circulation path 16 that supplies fuel gas (off-gas) discharged from the fuel cell 12 back to the fuel cell 12. 【0011】 The circulation path 16 is equipped with, in order from the anode outlet 12a of the fuel cell 12, a gas-liquid separator 18, a purge valve 22, a check valve 23, and a fuel gas supply device 24. The gas-liquid separator 18 separates the liquid phase water contained in the off-gas. The gas-liquid separator 18 is equipped with a drain valve 20. When the drain valve 20 opens at a predetermined timing, the water collected in the gas-liquid separator 18 is discharged into the exhaust passage 26. The purge valve 22 opens when the concentration of impurity gases increases or when the pressure in the circulation path 16 increases, etc., and discharges the off-gas into the exhaust passage 26. 【0012】 The circulation path 16 branches into a low-flow path 16a and a high-flow path 16b upstream of the fuel gas supply device 24. Check valves 23 are installed in both the low-flow path 16a and the high-flow path 16b. The low-flow path 16a is connected to the first ejector 38 and serves as the path for flowing off-gas when the fuel cell 12 is operating at low power. 【0013】 The high-flow path 16b is connected to the second ejector 42 and, together with the low-flow path 16a, serves as a path for flowing off-gas when the fuel cell 12 is operating at high power. The check valve 23 prevents the propagation of negative pressure between the first ejector 38 and the second ejector 42, preventing interference between their operations. In one non-limiting embodiment, the low-flow path 16a, the high-flow path 16b, and the check valve 23 may be included in the fuel gas supply device 24. 【0014】 The fuel gas supply device 24 includes a high-pressure pipe 28, a shut-off valve 30, a pressure sensor 31, a filter 32, a branch section 34, a first injector 36, a first ejector 38, a second injector 40, and a second ejector 42. The high-pressure pipe 28 is connected to a gas tank that stores high-pressure fuel gas. High-pressure hydrogen gas, for example, at a pressure of several MPa to tens of MPa, flows through the high-pressure pipe 28. 【0015】 The high-pressure piping 28 is equipped with a shut-off valve 30, a pressure sensor 31, and a filter 32. The shut-off valve 30 shuts off the supply of fuel gas to the circulation path 16 when the fuel cell 12 is shut down or for other reasons. The pressure sensor 31 is connected to the high-pressure piping 28 via a sensor support 28b. The pressure sensor 31 detects the internal pressure of the high-pressure piping 28. The filter 32 is located downstream of the shut-off valve 30 and the pressure sensor 31 and removes foreign matter from the high-pressure fuel gas. 【0016】 The branch portion 34 is a flow path member attached to the downstream side of the high-pressure pipe 28. The branch portion 34 guides the high-pressure fuel gas to the first injector 36 and the second injector 40 through a plurality of branched flow paths (described later). The first injector 36 includes one injector unit 44 and can eject the high-pressure fuel gas at a first flow rate toward the first ejector 38. The first injector 36 and the first ejector 38 cause the supply of new fuel gas and the circulation of the off-gas (fuel gas) in the circulation path 16 when the fuel cell 12 is operated at a low output. 【0017】 The second injector 40 includes a plurality (for example, three) of injector units 44. The second injector 40 can eject the high-pressure fuel gas at a second flow rate greater than the first flow rate toward the second ejector 42. The second injector 40 and the second ejector 42 cause the supply of new fuel gas and the circulation of the off-gas in the circulation path 16 when the fuel cell 12 is operated at a high output. 【0018】 Hereinafter, the configuration of the fuel gas supply device 24 will be described in more detail. 【0019】 As shown in FIG. 2, the fuel gas supply device 24 is disposed, for example, on the side portion of the stack case 46 of the fuel cell 12. The fuel gas supply device 24 includes an ejector housing 48 that houses the first ejector 38 and the second ejector 42, and the ejector housing 48 and the high-pressure pipe 28 are fixed to the stack case 46 through a fastening member 50 such as a bolt. A second pipe 52 that forms a part of the circulation path 16 extending from the gas-liquid separator 18 is connected to the lower portion of the ejector housing 48. 【0020】 From the tip side of the ejector housing 48, a second pipe 52 that forms part of the circulation path 16 extends into the stack case 46 of the fuel cell 12. Also, the first injector 36 and the second injector 40 are connected to the base end side of the ejector housing 48. The first injector 36 and the second injector 40 are sandwiched and supported between the first plate 34d and the second plate 58, and are connected to the ejector housing 48 via the second plate 58. 【0021】 Also, a high-pressure pipe 28 is connected to the base end sides of the first injector 36 and the second injector 40 via the first plate 34d. A horizontally extending portion of the high-pressure pipe 28 is fixed to the stack case 46 by a fastening member 50 such as a bolt. Since the first plate 34d and the second plate 58 that support the first injector 36 and the second injector 40 are not fixed to the stack case 46, the reaction force during injection of the first injector 36 and the second injector 40 is mainly received by the high-pressure pipe 28 fixed to the stack case 46. 【0022】 The high-pressure pipe 28 includes a straight portion 28a that extends linearly in the horizontal direction, a sensor port 28b, and a downstream end portion 28c. The straight portion 28a is fixed to the stack case 46 by a fastening member 50. The straight portion 28a is a portion that serves as a fulcrum for receiving vibrations caused by injection of the first injector 36 and the second injector 40. The central axis of the straight portion 28a is referred to as the first axis in this specification. 【0023】 The sensor port 28b branches upward and extends from the straight portion 28a. A pressure sensor 31 is attached to the sensor port 28b. The downstream end portion 28c bends from the straight portion 28a near the sensor port 28b and extends obliquely downward. Therefore, the downstream end portion 28c is inclined with respect to the first axis. A branch portion 34 is connected to the downstream end portion 28c. The filter 32 is disposed at the downstream end portion 28c and is sandwiched and held between the branch portion 34 and the sensor port 28b. 【0024】 As shown in Figure 3, the branch portion 34 is integrally formed with the first plate 34d. The first plate 34d has a main surface perpendicular to the extending direction of the downstream end 28c and supports the base end sides of the first injector 36 and the second injector 40. The first plate 34d has a plurality of first column portions 34e extending toward the tip side at its peripheral edge. The first column portions 34e have a threaded structure through which fastening members such as bolts pass and are connected to second column portions 58a extending from the second plate 58. 【0025】 As shown in Figure 4, the branch section 34 comprises a first flow channel section 34a, a second flow channel section 34b, a third flow channel section 34c, a first connection section 34f, a second connection section 34g, a third connection section 34h, and a fourth connection section 34i. The first flow channel section 34a extends perpendicularly toward the base end from the first plate 34d and is connected to the downstream end section 28c. The first flow channel section 34a extends linearly coaxially with the downstream end section 28c. 【0026】 The second channel section 34b and the third channel section 34c extend in a direction parallel to the main surface of the first plate 34d and are formed to bulge out toward the base end of the first plate 34d (see Figure 3). The second channel section 34b extends from the first channel section 34a in a direction perpendicular to the first channel section 34a. The central axis of the second channel section 34b extends in a substantially horizontal direction. The third channel section 34c intersects with the second channel section 34b and extends diagonally upward. The central axis of the third channel section 34c extends at an angle of 60° with respect to the central axis of the second channel section 34b. 【0027】 The first connection section 34f, the second connection section 34g, the third connection section 34h, and the fourth connection section 34i have flow paths that penetrate the first plate 34d in the thickness direction and extend toward the second plate 58. These flow paths communicate with the second flow path section 34b or the third flow path section 34c. The inner diameters of the flow paths of the first connection section 34f, the second connection section 34g, the third connection section 34h, and the fourth connection section 34i are sized to accommodate the introduction port 44a of the injector unit 44. Parts of the first connection section 34f, the second connection section 34g, the third connection section 34h, and the fourth connection section 34i extend outwards in a short, cylindrical shape toward the tip side of the first plate 34d. 【0028】 The first connection point 34f is the part to which the injector unit 44 of the first injector 36 is connected. The second connection point 34g, the third connection point 34h, and the fourth connection point 34i are to which the injector unit 44 of the second injector 40 is connected, respectively. 【0029】 The first connection part 34f, the second connection part 34g, and the third connection part 34h are arranged in a straight line along the third flow channel section 34c. The first connection part 34f is located near the end of the third flow channel section 34c, furthest from the first flow channel section 34a. Therefore, the first connection part 34f is located at the part furthest from the first axis of the high-pressure piping 28. 【0030】 The second connection portion 34g is positioned next to the first connection portion 34f. The third connection portion 34h is provided at or near the intersection of the third flow channel portion 34c and the second flow channel portion 34b. By arranging the first connection portion 34f, the second connection portion 34g, and the third connection portion 34h in a straight line in this way, the shape of the third flow channel portion 34c can be made straight, thereby simplifying the manufacturing process. 【0031】 The fourth connection section 34i extends from the second flow path section 34b. The fourth connection section 34i may be arranged coaxially with the first flow path section 34a. The second connection section 34g, the third connection section 34h, and the fourth connection section 34i are positioned closer to the first axis of the high-pressure piping 28 than the first connection section 34f, and are connected to the high-pressure piping 28 via a shorter path than the first connection section 34f. As a result, the injector unit 44 of the second injector 40 is connected to the high-pressure piping 28 via a shorter path than the injector unit 44 of the first injector 36. 【0032】 Furthermore, the second connection part 34g, the third connection part 34h, and the fourth connection part 34i are arranged in a positional relationship that forms the vertices of an equilateral triangle on the main surface of the first plate 34d. This highly symmetrical arrangement can suppress variations in the ejection characteristics of the three injector units 44 included in the second injector 40. In addition, the two injector units 44 included in the second injector 40 and the injector units 44 of the first injector 36 are arranged in a straight line. All injector units 44 are arranged aligned on the same plane. 【0033】 As shown in Figure 5, the injector unit 44 comprises an introduction port 44a, a base step portion 44b, an ejection port 44c, and a tip step portion 44d. The injector unit 44 used in the first injector 36 and the injector unit 44 used in the second injector 40 are identical parts and have the same structure. 【0034】 The introduction port 44a is inserted into the first connector 34f, second connector 34g, third connector 34h, or fourth connector 34i shown in Figures 3 and 4 so as to be displaceable in the axial direction. The radial displacement of the introduction port 44a is restricted by the first connector 34f, second connector 34g, third connector 34h, or fourth connector 34i. A packing (not shown) is attached to the outer circumference of the introduction port 44a, sealing the gap between the first connector 34f, second connector 34g, third connector 34h, or fourth connector 34i and the introduction port 44a. 【0035】 A first vibration damping plate 54 is attached to the base step portion 44b. As shown in Figure 5, the first vibration damping plate 54 is a plate-shaped member made of an elastic material having a plurality of first holes 54a through which the introduction port 44a can be inserted. The base end side of the first vibration damping plate 54 is joined to the first plate 34d. As shown in Figure 3, the first vibration damping plate 54 restricts the displacement of the injector unit 44 in the base end direction by contacting the base step portion 44b. The injector unit 44 is supported by the first plate 34d via the first vibration damping plate 54. By integrating the first vibration damping plate 54 with multiple injector units 44, vibrations generated in individual injector units 44 can be dispersed over a wide area, and resonance can also be prevented. 【0036】 The tip of the injector unit 44 is supported by a second vibration damping plate 56 and a second plate 58. The second plate 58 is a plate-shaped member with a planar shape similar to that of the first plate 34d. Multiple second column portions 58a are formed at predetermined locations on the periphery of the second plate 58, extending toward the first plate 34d. The second column portions 58a are connected to the first column portion 34e of the first plate 34d. 【0037】 The second plate 58 is provided with a through hole 58b and three connecting tubes 58c. The through hole 58b penetrates the second plate 58. The through hole 58b is located on the extension of the first connecting portion 34f and receives the ejection port 44c of the injector unit 44 connected to the first connecting portion 34f. The base end of the first nozzle 60 of the first ejector 38 is inserted into the through hole 58b. 【0038】 As shown in Figure 3, the ejection port 44c of the injector unit 44 of the first injector 36 is inserted into the first nozzle 60. The ejection port 44c of the injector unit 44 is inserted so as to be displaceable in the direction of the injection axis relative to the first nozzle 60. The gap between the inner surface of the first nozzle 60 and the outer surface of the ejection port 44c is sealed with a packing or the like. 【0039】 As shown in Figures 3 and 5, the connecting cylinder 58c of the second plate 58 is a cylindrical portion extending toward the base end. A flow path communicating with the second nozzle 66 of the second ejector 42 is formed inside the connecting cylinder 58c. The ejection port 44c of the injector unit 44 of the second injector 40 is inserted into the connecting cylinder 58c. The connecting cylinder 58c accommodates the ejection port 44c so that it can be displaced in the axial direction of the injector unit 44. The gap between the inner circumferential surface of the connecting cylinder 58c and the outer circumferential surface of the ejection port 44c is sealed with a packing or the like. 【0040】 The second vibration damping plate 56 shown in Figures 3 and 5 is a plate-shaped member made of an elastic material and has four second holes 56a through which the ejection ports 44c of the four injector units 44 pass. The front end surface of the second vibration damping plate 56 is joined to the second plate 58. The second vibration damping plate 56 is positioned between the second plate 58 and the front step portion 44d of the injector unit 44, restricting the displacement of the injector unit 44 toward the front end. The second vibration damping plate 56 dampens vibrations during ejection from the injector unit 44. By integrating the second vibration damping plate 56 with multiple injector units 44, vibrations generated in individual injector units 44 can be dispersed over a wide area, preventing the occurrence of resonance. 【0041】 The tip of the second plate 58 is connected to the first ejector 38 and the second ejector 42. The first ejector 38 has a first nozzle 60, a first body 62, and a first diffuser 64. The first nozzle 60 is attached to the second plate 58 and is positioned downstream of the first injector 36. The first nozzle 60 is connected to the injector unit 44 of the first injector 36. The first nozzle 60 injects high-pressure fuel gas at a first flow rate, which is ejected from one injector unit 44, into the first ejector 38. The first nozzle 60 has a constricted portion 60a that narrows towards the tip. An opening 60b for ejecting high-pressure fuel gas is formed at the tip of the constricted portion 60a. The central axes of the constricted portion 60a and the opening 60b are coaxial with the injection axis of the first injector 36. 【0042】 The opening 60b opens into the first main body 62. A circulation path 16 is connected to the side of the first main body 62. The first nozzle 60 protrudes into the interior of the first main body 62. A first diffuser 64 is positioned at the tip of the first nozzle 60. The first main body 62 forms a first annular flow path 62a around the gap between the first nozzle 60 and the first diffuser 64. One end of the circulation path 16 opens into the first annular flow path 62a. The first diffuser 64 is tapered, with its inner diameter gradually increasing as it moves downstream. The central axis of the first diffuser 64 is the first injection axis, which is the center of the injection of the first ejector 38. The first injection axis is coaxial with the central axis of the first nozzle 60 and the ejection axis of the first injector 36. 【0043】 The second ejector 42 includes a second nozzle 66, a second body 68, and a second diffuser 70. The second nozzle 66 is located downstream of the three injector units 44 and is attached to the tip side of the second plate 58. The second nozzle 66 has a conical flow path 66a that is formed in a conical shape to merge the high-pressure fuel gas injected from the multiple injector units 44. The diameter of the conical flow path 66a decreases as it moves away from the second injector 40. 【0044】 The conical flow path 66a has the largest inner diameter at its base end, and the inner diameter at the base end is large enough to accommodate the ejection ports 44c of the three injector units 44. The second nozzle 66 can inject the second flow rate of high-pressure fuel gas injected from the three injector units 44 into the second ejector 42. 【0045】 The second axis along the center of the conical flow path 66a is parallel to the axial direction of the injector unit 44 included in the second injector 40. Furthermore, the central axis of the conical flow path 66a is equidistant from the three injector units 44, and the three injector units 44 are positioned at a central location where they are equally spaced (120°) apart in the circumferential direction. This arrangement reduces the difference in ejection capacity when the injector units 44 are operated individually. Therefore, the second nozzle 66 enables a rotation operation that sequentially deactivates some of the injector units 44, contributing to the extended lifespan of the second injector 40. 【0046】 The second nozzle 66 further has an ejection hole 66b that communicates with the tip of the conical flow path 66a. The ejection hole 66b extends at an inclination with respect to the second axis of the conical flow path 66a. The ejection hole 66b injects high-pressure fuel gas toward the second diffuser 70. The direction of extension of the ejection hole 66b coincides with the second injection axis of the second diffuser 70. 【0047】 The second main body 68 forms a second annular flow path 68a that surrounds the gap between the second nozzle 66 and the second diffuser 70. One end of the circulation path 16 opens to the second annular flow path 68a. The second diffuser 70 is a tapered flow path whose inner diameter gradually widens towards the downstream. The average flow path cross-sectional area of ​​the second diffuser 70 is larger than that of the first diffuser 64, allowing the fuel gas in the circulation path 16 to flow more efficiently when a larger flow rate of high-pressure fuel gas is injected. 【0048】 The first ejector 38 and the second ejector 42 generate axial reaction forces as high-pressure fuel gas is injected. The second ejector 42 generates a larger reaction force than the first ejector 38 because its flow rate and velocity are greater. These reaction forces are transmitted as vibrations to various parts of the fuel gas supply device 24, potentially increasing the frequency of maintenance and reducing durability by loosening bolts that secure the fuel gas supply device 24 to the stack case 46. 【0049】 Therefore, in this embodiment, the fuel gas supply device 24 has made the angle between the second injection axis of the second ejector 42 and the first axis of the high-pressure pipe 28 smaller than the angle between the first injection axis of the first ejector 38 and the first axis of the high-pressure pipe 28. As a result, the reaction force of the second ejector 42 can be effectively absorbed by the high-strength high-pressure pipe 28, and the generation of vibration is suppressed. 【0050】 Furthermore, the second ejector 42 is positioned closer to the extension of the first axis of the high-pressure piping 28 than the first ejector 38, and is connected to the second plate 58 at a position closer to the first axis. This suppresses the torque generated by the reaction force of the second ejector 42, which generates a larger reaction force, and further effectively suppresses vibrations in the fuel gas supply device 24. 【0051】 Furthermore, the large and heavy second injector 40 and second ejector 42 are positioned below the small and light first injector 36 and first ejector 38. This configuration lowers the center of gravity and effectively suppresses vibrations. 【0052】 A confluence section 72 is connected downstream of the first ejector 38 and the second ejector 42. The confluence section 72 has a confluence passage 72a and a bend 72b. The confluence passage 72a extends in the direction of the extension of the first ejector 38 and the second ejector 42 and decreases in diameter towards the downstream side. That is, the flow path cross-sectional area gradually decreases as you move from the first opening 72d and the second opening 72e toward the bend 72b. The bend 72b is located downstream of the confluence passage 72a and bends toward the fuel cell 12. From the downstream side of the bend 72b, an outlet passage 72c extends toward the interior of the stack case 46. 【0053】 The jet from the first ejector 38 flows into the confluence section 72 through the first opening 72d, and the jet from the second ejector 42 flows into the confluence section 72 through the second opening 72e. The first opening 72d is located closer to the inner circumference of the bent section 72b, and the second opening 72e is located closer to the outer circumference of the bent section 72b. 【0054】 The fuel gas flowing out from the first ejector 38 mainly flows along the inner wall adjacent to the first opening 72d and bends on the inner circumference side (the side with a smaller radius of curvature) of the bend 72b. Similarly, the fuel gas flowing out from the second ejector 42 mainly flows along the inner wall adjacent to the second opening 72e and flows along the outer circumference side (the side with a larger radius of curvature) of the bend 72b. As a result, the fuel gas flowing out from the second ejector 42, which has a high flow velocity and flow rate, flows closer to the outer circumference with a larger radius of curvature at the bend 72b, thus suppressing pressure loss. 【0055】 Furthermore, even if the fuel gas injection timing of the first ejector 38 and the second ejector 42 overlaps, the flow of fuel gas injected inside the confluence section 72 prevents collision and suppresses an increase in pressure loss. Therefore, the fuel gas supply device 24 can suppress variations in the pressure and flow rate of the fuel gas supplied to the fuel cell 12 due to pressure loss. 【0056】 With regard to the above embodiments, the following additional information is disclosed. 【0057】 (Note 1) This disclosure relates to a fuel gas supply device (24) for supplying fuel gas to a fuel cell (12), comprising: a high-pressure pipe (28) for supplying high-pressure fuel gas; a first injector (36) communicating with the high-pressure pipe and ejecting the high-pressure fuel gas at a first flow rate; a first ejector (38) utilizing the jet of the first injector to send off-gas to the fuel cell; a second injector (40) communicating with the high-pressure pipe and ejecting the high-pressure fuel gas at a second flow rate greater than the first flow rate; and a second ejector (42) utilizing the jet of the second injector to send off-gas to the fuel cell, wherein the second ejector is positioned closer to a first axis along the center of the high-pressure pipe than the first ejector. 【0058】 The fuel gas supply system described above suppresses vibrations during fuel gas injection by positioning the second ejector, which experiences significant vibration during fuel gas injection, close to the first axis of the high-pressure piping. As a result, the fuel gas supply system prevents loosening of its components due to vibration, resulting in superior durability. 【0059】 (Note 2) The fuel gas supply device described in Appendix 1 may have an angle between the second injection axis of the second ejector and the first axis that is smaller than the angle between the first injection axis of the first ejector and the first axis. This fuel gas supply device has excellent durability because it can suppress vibrations during fuel gas injection. 【0060】 (Note 3) The fuel gas supply device described in Appendix 2 may have the second ejector positioned below the first ejector. By positioning the large and heavy second ejector lower, this fuel gas supply device can increase its resistance to vibration and has excellent durability. 【0061】 (Note 4) The fuel gas supply device described in Appendix 1 has a branch section (34) that connects the high-pressure piping to the first injector and the second injector, and the second injector may be connected to the high-pressure piping via a shorter path than the first injector. This fuel gas supply device can connect the second injector, which has a large flow rate, to the high-pressure piping via a short path, and can effectively prevent vibration caused by the injection of the second injector. 【0062】 (Note 5) The fuel gas supply device described in Appendix 1 may have, in which the first injector has one injector unit (44), the second injector has a plurality of the injector units, and the second ejector has a second nozzle (66) that merges the jets of the plurality of the injector units. This fuel gas supply device can handle high output with one type of injector unit. 【0063】 (Note 6) The fuel gas supply device described in Appendix 5 may have the injector unit of the first injector and a portion of the injector unit included in the second injector arranged in a straight line. This fuel gas supply device can be made compact by arranging the first injector and the second injector at the shortest possible distance from each other. 【0064】 (Note 7) The fuel gas supply device described in Appendix 5, wherein the second nozzle is provided with a conical flow path (66a) formed in a conical shape that decreases in diameter as it moves away from the second injector, and the plurality of injector units included in the second injector may be arranged at equal distances with respect to a second axis along the center of the conical flow path and at equal intervals in the circumferential direction. This fuel gas supply device can suppress variations in flow rate and flow velocity when each injector is operated individually by making the distance between each injector unit included in the second injector and the confluence equal. 【0065】 (Note 8) The fuel gas supply device described in Appendix 5 is such that the injector unit of the first injector and the plurality of injector units of the second injector are arranged on the same plane, and all of the injector units are supported by a first vibration damping plate (54) and a second vibration damping plate (56) made of an integrally formed elastic member. This fuel gas supply device can disperse and suppress vibrations during injection of each injector unit and prevent resonance. 【0066】 (Note 9) A fuel gas supply device for supplying fuel gas to another fuel cell according to the present disclosure, comprising: a first injector for ejecting high-pressure fuel gas at a first flow rate; a first ejector for supplying off-gas to the fuel cell using the jet of the first injector; a second injector for ejecting the high-pressure fuel gas at a second flow rate greater than the first flow rate; a second ejector for supplying the off-gas to the fuel cell using the jet of the second injector; and a confluence section (72) connected downstream of the first ejector and the second ejector, wherein The confluence section includes a first opening (72d) into which the jet from the first ejector flows, a second opening (72e) into which the jet from the second ejector flows, a confluence passage (72a) extending in the direction of the extension of the first and second ejectors to confluence the fuel gas flowing out from the first and second openings, and a bent section (72b) provided downstream of the confluence passage and bent toward the fuel cell, wherein the first opening is located closer to the inner circumference of the bent section, and the second opening is located closer to the outer circumference of the bent section. This fuel gas supply device can reduce the pressure loss of the second ejector. Furthermore, even if the injection timing of the first injector and the injection timing of the second injector overlap, jet collisions are prevented, and variations in the pressure and flow rate of the fuel gas supplied to the fuel cell due to pressure loss can be suppressed. 【0067】 (Note 10) The fuel gas supply device described in Appendix 9, wherein the flow path cross-sectional area of ​​the merging passage may gradually decrease as it moves from the first opening and the second opening toward the bent portion. This fuel gas supply device can prevent collision between the jet from the first ejector and the jet from the second ejector. 【0068】 (Note 11) The fuel gas supply device described in Appendix 9, wherein the first opening may be located above the second opening. 【0069】 While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols] 【0070】 12…Fuel cell 16…Circulation pathway 24…Fuel gas supply system 28…High-pressure piping 34...Branching section 36...First injector 38...First ejector 40...Second injector 42...Second ejector 44...Injector unit 54...First vibration damping plate 56...Second vibration damping plate 60b…Opening 66…Second nozzle 66a...Conical channel 72...Confluence 72a…merging passage 72b…bending part 72d...First opening 72e...Second opening

Claims

[Claim 1] A fuel gas supply device that supplies fuel gas to a fuel cell, High-pressure piping for supplying high-pressure fuel gas, A first injector is connected to the high-pressure piping and ejects the high-pressure fuel gas at a first flow rate, A first ejector that uses the jet of the first injector to deliver off-gas to the fuel cell, A second injector, which is in communication with the high-pressure piping and injects the high-pressure fuel gas at a second flow rate greater than the first flow rate, The system includes a second ejector that uses the jet of the second injector to deliver the off-gas to the fuel cell, The second ejector is positioned closer to the first axis along the center of the high-pressure piping than the first ejector, The first injection axis of the first ejector and the second injection axis of the second ejector approach each other as they move downstream, and furthermore, A fuel gas supply device having a confluence section connected downstream of the first ejector and the second ejector, which narrows in diameter as it extends downstream. [Claim 2] A fuel gas supply device according to claim 1, A fuel gas supply device in which the angle between the second injection axis and the first axis of the second ejector is smaller than the angle between the first injection axis and the first axis of the first ejector. [Claim 3] A fuel gas supply device according to claim 2, The second ejector is a fuel gas supply device positioned below the first ejector. [Claim 4] A fuel gas supply device according to claim 1, It has a branch section that connects the high-pressure piping to the first injector and the second injector, A fuel gas supply device in which the second injector is connected to the high-pressure piping via a shorter path than the first injector. [Claim 5] A fuel gas supply device for supplying fuel gas to a fuel cell, High-pressure piping for supplying high-pressure fuel gas, A first injector is connected to the high-pressure piping and ejects the high-pressure fuel gas at a first flow rate, A first ejector that uses the jet of the first injector to deliver off-gas to the fuel cell, A second injector, which is in communication with the high-pressure piping and injects the high-pressure fuel gas at a second flow rate greater than the first flow rate, The system includes a second ejector that uses the jet of the second injector to deliver the off-gas to the fuel cell, The first injector has one injector unit, The second injector has a plurality of the injector units, The second ejector is a fuel gas supply device having a second nozzle that merges the jets of a plurality of injector units. [Claim 6] A fuel gas supply device according to claim 5, A fuel gas supply device in which the injector unit of the first injector and a portion of the injector unit included in the second injector are arranged in a straight line. [Claim 7] A fuel gas supply device according to claim 5, The second nozzle is provided with a conical channel formed in a conical shape that decreases in diameter as it moves away from the second injector. A fuel gas supply device in which a plurality of injector units included in the second injector are arranged at equal distances with respect to a second axis along the center of the conical flow path and at equal intervals in the circumferential direction. [Claim 8] A fuel gas supply device according to claim 5, The injector unit of the first injector and the plurality of injector units of the second injector are arranged in the same plane. A fuel gas supply device in which all of the injector units are supported by a first vibration damping plate and a second vibration damping plate made of an integrally formed elastic member. [Claim 9] A fuel gas supply device that supplies fuel gas to a fuel cell, A first injector that ejects high-pressure fuel gas at a first flow rate, A first ejector that uses the jet of the first injector to deliver off-gas to the fuel cell, A second injector that injects the high-pressure fuel gas at a second flow rate greater than the first flow rate, A second ejector that uses the jet of the second injector to send the off-gas to the fuel cell, The system includes a confluence connected downstream of the first ejector and the second ejector, The aforementioned confluence section is, The first opening into which the jet from the first ejector flows, The second opening into which the jet from the second ejector flows, A confluence passage extending in the direction of extension of the first ejector and the second ejector, which combines the fuel gas flowing out from the first opening and the second opening, A bent section is provided downstream of the aforementioned confluence passage and is bent toward the fuel cell, A fuel gas supply device in which the first opening is located closer to the inner circumference of the bent portion, and the second opening is located closer to the outer circumference of the bent portion. [Claim 10] A fuel gas supply device according to claim 9, The fuel gas supply device wherein the merging passage has a flow path cross-sectional area that gradually decreases as it moves from the first opening and the second opening toward the bent portion. [Claim 11] A fuel gas supply device according to claim 9, The first opening is located above the second opening in the fuel gas supply device.

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