Gas-liquid separator

Abstract

To improve gas-liquid separation performance by a gas-liquid separator.SOLUTION: A gas-liquid separator includes a container which has an upper part, a bottom part and a side part connecting the upper part and the bottom part, and forms a gas-liquid separation chamber for separating a gas-liquid two-phase flow into a gas phase and a liquid phase. The side part has a first side part and a second side part opposite to each other, and the container has an inflow port that is provided in the upper part and to which the gas-liquid two-phase flow flows, and an outflow port that is provided on the first side part and from which the gas phase separated by the gas-liquid separation chamber flows. The gas-liquid separator further includes a flow channel formation part for forming an inclined flow channel extending obliquely below so that the gas-liquid two-phase flow having flown from the inflow port collides with the second side part below the outflow port.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a gas-liquid separator. [Background technology]

[0002] Conventionally, there has been known a gas-liquid separation device that includes a container having an inlet for a gas-liquid mixture provided at an upper portion, a liquid reservoir provided at a lower portion, and a gas outlet provided on a side wall, and that includes a baffle plate inside the container that shields the gas outlet from the inlet for the gas-liquid mixture (see, for example, Patent Document 1). In the device described in Patent Document 1, the baffle plate has an inclined portion so that the area of ​​the opening at the bottom of the baffle plate is large. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-29718 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as described in the above Patent Document 1, it is difficult to sufficiently improve gas-liquid separation performance by simply increasing the area of ​​the opening at the bottom of the baffle plate to reduce the gas flow rate. [Means for solving the problem]

[0005] One aspect of the present invention is a gas-liquid separator including a container having an upper portion, a bottom portion, and a side portion connecting the upper portion and the bottom portion, and forming a gas-liquid separation chamber for separating a gas-liquid two-phase flow into a gas phase and a liquid phase, the side portion having a first side portion and a second side portion opposed to each other, the container having an inlet provided in the upper portion and through which the gas-liquid two-phase flow flows in, and an outlet provided in the first side portion and through which the gas phase separated in the gas-liquid separation chamber flows out. The gas-liquid separator further includes a flow path forming portion that forms an inclined flow path extending obliquely downward so that the gas-liquid two-phase flow flowing in from the inlet collides with the second side portion below the outlet. Effect of the Invention

[0006] According to the present invention, the gas-liquid separation performance of the gas-liquid separator can be sufficiently improved. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a schematic overall configuration of a fuel cell stack 100 to which a gas-liquid separator according to an embodiment of the present invention is attached. [Diagram 2] 1 is a circuit diagram showing a schematic configuration of a main part of a fuel cell system to which a gas-liquid separator according to an embodiment of the present invention is applied; [Diagram 3] FIG. 2 is a perspective view of a gas-liquid separator according to an embodiment of the present invention. [Figure 4] FIG. 4 is a rear view of the gas-liquid separator of FIG. 3. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4 . [Figure 6] 4 is a perspective view of a lower vessel constituting the gas-liquid separator of FIG. 3, as viewed obliquely from above. [Figure 7] FIG. 4 is a plan view of a lower vessel constituting the gas-liquid separator of FIG. 3 . [Figure 8] 4 is a perspective view of a flow path forming member that constitutes the gas-liquid separator of FIG. 3. [Figure 9A] FIG. 2 is a diagram showing an example of a flow of fuel exhaust gas in a gas-liquid separator according to an embodiment of the present invention. [Figure 9B] FIG. 4 is a diagram showing another example of the flow of fuel exhaust gas in the gas-liquid separator according to the embodiment of the present invention. [Figure 10] FIG. 6 is a diagram showing a modification of FIG. 5 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 10. A gas-liquid separator according to an embodiment of the present invention is applied to a fuel cell system having a fuel cell. The fuel cell system is mounted on, for example, a vehicle and generates electric power for driving the vehicle. The fuel cell system has a fuel cell stack configured by stacking a plurality of power generation cells. The gas-liquid separator according to the present embodiment is attached to such a fuel cell stack.

[0009] FIG. 1 is a perspective view showing a schematic overall configuration of a fuel cell stack 100 to which a gas-liquid separator 10 according to this embodiment is attached. For convenience, the three mutually orthogonal axial directions shown in the figure are defined below as the front-rear direction, the left-right direction, and the up-down direction, and the configuration of each part will be described according to these definitions. The downward direction in the up-down direction corresponds to the direction of gravity. The front-rear direction and the left-right direction correspond to, for example, the front-rear direction and the left-right direction of a vehicle. However, the front-rear direction and the left-right direction do not have to coincide with the front-rear direction and the left-right direction of a vehicle.

[0010] As shown in Fig. 1, the fuel cell stack 100 has a cell stack 110, end plates 120 arranged at both front and rear ends of the cell stack 110, and a case 130 surrounding the cell stack 110, and has a generally rectangular parallelepiped shape as a whole. Part A of Fig. 1 shows a cutaway view of a portion of the case 130. As shown in part A of Fig. 1, the cell stack 110 is formed by stacking a plurality of power generating cells 111 (for convenience, only a single power generating cell 111 is shown) in the front-rear direction.

[0011] The power generating cell 111 has an electrode assembly 112 having an assembly including an electrolyte membrane and an electrode, and separators 113 arranged on both the front and rear sides of the electrode assembly 112 and sandwiching the electrode assembly 112. The electrode assembly 112 and the separators 113 are arranged alternately in the front-rear direction. The separator 113 has a pair of front and rear thin metal plates with a corrugated cross section, and is integrally formed by joining the outer peripheries of the pair of thin plates. A cooling flow path through which a cooling medium (e.g., water) flows is formed inside the pair of thin plates, and the power generating surface of the power generating cell 111 is cooled by the flow of the cooling medium.

[0012] The separator 113 on the front side of the electrode assembly 112 is, for example, an anode side separator (anode separator), and an anode flow path through which a fuel gas containing hydrogen flows is formed between the anode separator 113 and the electrode assembly 112. The separator 113 on the rear side of the electrode assembly 112 is, for example, a cathode side separator (cathode separator), and a cathode flow path through which an oxidant gas containing oxygen flows is formed between the cathode separator 113 and the electrode assembly 112.

[0013] The electrode assembly 112 has a membrane electrode assembly and a resin frame that supports the periphery of the membrane electrode assembly. The membrane electrode assembly has an electrolyte membrane, an anode electrode provided on the front surface of the electrolyte membrane, and a cathode electrode provided on the rear surface of the electrolyte membrane. The electrolyte membrane is, for example, a solid polymer electrolyte membrane. The anode electrode is an electrode catalyst layer formed on the front surface of the electrolyte membrane and serves as a reaction field for the electrode reaction, and a gas diffusion layer that diffuses and supplies a fuel gas is provided on the front surface of the electrode catalyst layer. The cathode electrode is an electrode catalyst layer formed on the rear surface of the electrolyte membrane and serves as a reaction field for the electrode reaction, and a gas diffusion layer that diffuses and supplies an oxidant gas is provided on the rear surface of the electrode catalyst layer.

[0014] At the anode electrode, the fuel gas (hydrogen) supplied via the anode flow channel and the gas diffusion layer is ionized by the action of a catalyst and passes through the electrolyte membrane to move to the cathode electrode side. The electrons generated at this time pass through an external circuit and are extracted as electrical energy. At the cathode electrode, the oxidant gas (oxygen) supplied via the cathode flow channel and the gas diffusion layer reacts with the hydrogen ions guided from the anode electrode and the electrons that have moved from the anode electrode to generate water. The generated water provides an appropriate humidity to the electrolyte membrane, and excess water is discharged to the outside of the electrode assembly 112.

[0015] The front end plate 120 has through holes 121-126 that penetrate the end plate 120 in the front-rear direction. The through holes 121-123 are arranged at the left end of the end plate 120 with their positions vertically offset, and the through holes 124-126 are arranged at the right end of the end plate 120 with their positions vertically offset. Note that in FIG. 1, the lowermost through hole 126 on the right side is shown in a state covered by the flange portion 11a of the gas-liquid separator 10.

[0016] Fuel gas is supplied to the inside of the cell stack 110 via through-hole 121, oxidant gas is supplied via through-hole 124, and a cooling medium is supplied via through-hole 125. From the cell stack 110, the cooling medium is discharged via through-hole 122, oxidant exhaust gas is discharged via through-hole 123, and fuel exhaust gas is discharged via through-hole 126. The oxidant exhaust gas is the oxidant gas after a portion has been used at the cathode electrode, and is a two-phase gas-liquid flow containing moisture. The fuel exhaust gas is the fuel gas after a portion has been used at the anode electrode, and is a two-phase gas-liquid flow containing moisture.

[0017] Fig. 2 is a circuit diagram showing a schematic configuration of the main components of the fuel cell system 200, particularly the flow of fuel gas. As shown in Fig. 2, the fuel cell system 200 has a supply flow path PA1 that guides the fuel gas to the fuel cell stack 100 via a through hole 121, a discharge flow path PA2 that guides the fuel exhaust gas from the fuel cell stack 100 to a drainage pipe L1 via a through hole 126, and a circulation flow path PA3 that guides (recirculates) the fuel gas separated from the fuel exhaust gas to the supply flow path PA1.

[0018] The supply flow path PA1 includes a tank 201 that stores high-pressure fuel gas, a pair of injectors 202, 203 that inject the fuel gas supplied from the tank 201, and an ejector 204 that is interposed between the injectors 202, 203 and the through-hole 121 of the fuel cell stack 100. The discharge flow path PA2 includes a gas-liquid separator 10 connected to the through-hole 126 of the fuel cell stack 100 via a pipe L2, a drain valve 205 connected to the gas-liquid separator 10 via a pipe L3, and a purge valve 206 connected to the gas-liquid separator 10 via a pipe L4. The circulation flow path PA3 includes a pipe L5 that connects the gas-liquid separator 10 and the ejector 204. The driving of the injectors 202, 203 and the opening and closing operations of the drain valve 205 and the purge valve 206 are controlled by a controller (not shown).

[0019] Although detailed illustration is omitted, the ejector 204 has a nozzle portion, a suction portion, a junction portion, and a diffuser portion. The fuel gas injected from the injectors 202 and 203 passes through a small-diameter nozzle portion and then flows into the diffuser portion via the junction portion. At this time, the ejector 204 draws in the fuel gas from the pipe L5 via the suction portion. The drawn in fuel gas merges with the fuel gas that passed through the nozzle portion at the junction portion, and is made into a uniform flow in the diffuser portion, and is then supplied to the fuel cell stack 100 via the through-hole 121.

[0020] The gas-liquid separator 10 has an inlet 11 through which the fuel exhaust gas flows in, an outlet 12 through which the fuel gas separated in the gas-liquid separator 10 flows out, a drain port 13 through which water separated in the gas-liquid separator 10 is discharged, and an outlet port 14 through which the fuel exhaust gas is discharged. As shown in Fig. 1, the gas-liquid separator 10 is disposed behind the right end of the fuel cell stack 100 in a state in which it protrudes downward below the bottom surface of the fuel cell stack 100. Note that in a rear region AR1 of the fuel cell stack 100 on the left side of the gas-liquid separator 10, a fuel injection unit (not shown) in which injectors 202, 203 and an ejector 204 are integrated is disposed.

[0021] Fig. 3 is a perspective view of the gas-liquid separator 10. As shown in Fig. 3, the inlet 11 is provided at the top of the gas-liquid separator 10, and the outlet 13 is provided at the bottom. The outlet 12 and the discharge port 14 are provided at the middle of the gas-liquid separator 10 in the height direction.

[0022] A flange portion 11a is provided around the inlet 11. A front end surface of the flange portion 11a is a mounting surface, and the flange portion 11a is attached to the rear end surface of the fuel cell stack 100 (FIG. 1) by bolts via the mounting surface. A flange portion 12a is provided around the outlet 12. A rear end surface of the flange portion 12a is a mounting surface, and an end of a circulation pipe connected to an ejector 204 is attached to the flange portion 12a via the mounting surface. A flange portion 13a is provided around the drain port 13. A right end surface of the flange portion 13a is a mounting surface, and a drain valve 205 is attached to the flange portion 13a via the mounting surface. A flange portion 14a is provided around the outlet 14. An upper end surface of the flange portion is a mounting surface, and a purge valve 206 is attached to the flange portion 14a via the mounting surface.

[0023] Fig. 4 is a rear view (view from behind) of the gas-liquid separator 10, and Fig. 5 is a cross-sectional view of the main parts of the gas-liquid separator 10 taken along line VV in Fig. 4. As shown in Figs. 4 and 5, the gas-liquid separator 10 has a lower container 20 having an open upper surface and a generally concave shape extending downward, and an upper container 30 having an open lower surface and a generally concave shape extending upward. The length of the lower container 20 and the upper container 30 in the front-rear direction is longer than the length in the left-right direction, and the gas-liquid separator 10 is formed to be elongated in the front-rear direction. The lower container 20 and the upper container 30 are formed by resin molding using resin as a constituent material.

[0024] FIG. 6 is a perspective view of the lower container 20 as viewed obliquely from above. FIG. 6 also shows a flow path forming member 40 housed inside the lower container 20. As shown in FIG. 6, a flange portion 21 having a substantially rectangular frame shape is provided at the upper end of the lower container 20. A plurality of screw holes 21a are opened in the flange portion 21 over its entire circumference. As shown in FIG. 3, a flange portion 31 having a substantially rectangular frame shape is provided at the lower end of the upper container 30 in correspondence with the flange portion 21. A plurality of through holes are opened in the flange portion 31 in correspondence with the positions of the screw holes 21a. A bolt 21b inserted through a through hole in the flange portion 31 is screwed into the screw hole 21a, thereby fastening the upper container 30 and the lower container 20 together.

[0025] As shown in Fig. 5, a recess 31a is provided around the entire circumference of the lower end surface of the flange portion 31 of the upper container 30, and a seal material 39 is arranged along the recess 31a. As shown in Fig. 6, the lower end surface of the seal material 39 abuts on the upper end surface of the flange portion 21. As shown in Fig. 5, the upper end surface of the lower container 20 and the lower end surface of the upper container 30 both extend in a substantially horizontal direction. By fastening the lower container 20 and the upper container 30 via the seal material 39, an internal space SP0 that is sealed off from the outside is formed inside the lower container 20 and the upper container 30. At this time, the lower container 20 and the upper container 30 collectively constitute a container CA that forms the internal space SP.

[0026] 4 and 5, the lower container 20 has front, rear, left and right side walls 22 extending in the up-down direction, i.e., a front wall 221, a rear wall 222, a left wall 223 and a right wall 224, and a bottom wall 23. The rear wall 222 has an upper rear wall 222a extending downward from the flange portion 21, an inclined rear wall 222b extending forward from a lower end of the upper rear wall 222a at a downward slope, and a lower rear wall 222c extending downward from a front end of the inclined rear wall 222b.

[0027] The bottom wall 23 slopes downward from the lower end of the front wall 221 and the lower end of the rear wall 222 (lower rear wall 222c) to the center in the front-rear direction, and a storage chamber SP1 in which water separated from the exhaust fuel gas is stored is formed in the lower part of the internal space SP0. The front-rear center part of the bottom wall 23 is the lowermost part 23a of the lower container 20. A flange part 13a in which the drainage port 13 is opened is provided to the right of this lowermost part 23a. The storage chamber SP1 communicates with the external space of the gas-liquid separator 10 via the drainage port 13.

[0028] The upper container 30 has front, rear, left and right side walls 32 extending in the up-down direction, i.e., a front wall 321, a rear wall 322, a left wall 323 and a right wall 324, and an upper wall 33. As shown in Figures 3 and 4, the right wall 324 has a right rear surface portion 324a extending in the left-right direction at the center in the front-rear direction. Similarly, the left wall 323 has a left rear surface portion 323a extending in the left-right direction at the center in the front-rear direction.

[0029] More specifically, the right wall 324 extends rearward from the right end of the front wall 321, then bends at a right angle to the left in the center of the front-rear direction to extend a predetermined length (right rear portion 324a), and further extends rearward from the left end of the right rear portion 324a. The left wall 323 extends rearward from the left end of the front wall 321, then bends at a right angle to the right in the center of the front-rear direction to extend a predetermined length (left rear portion 323a), and further extends rearward from the right end of the left rear portion 323a. Therefore, the left-right length of the upper wall 33 forward of the left rear portion 323a and the right rear portion 324a is longer than the left-right length of the upper wall 33 rearward of the left rear portion 323a and the right rear portion 324a.

[0030] 5, the upper wall 33 has a front upper wall 331 extending rearward substantially horizontally from the upper end of the front wall 321 to the left rear portion 323a and the right rear portion 324a, an inclined upper wall 332 extending rearward from the rear end of the front upper wall 331 at an upward gradient, and a rear upper wall 333 extending substantially horizontally from the upper end of the inclined upper wall 332 to the upper end of the rear wall 322. Thus, the heights of the left wall 323 and the right wall 324 gradually increase from the intermediate portion in the front-rear direction toward the rear, and the upper end of the rear wall 322 is located higher than the upper end of the front wall 321.

[0031] As shown in Figs. 4 and 5, a substantially circular opening is provided in the rear upper wall 333, and a substantially cylindrical pipe section 34 extends upward from the rear upper wall 333 so as to cover the opening. The front end surface of the pipe section 34 is located slightly rearward of the left rear surface section 323a of the left wall 323 and the right rear surface section 324a of the right wall 324. The upper end section of the pipe section 34 is bent forward, and an inlet 11 is provided at the tip end (front end) of the pipe section 34, and a flange section 11a is provided around the inlet 11. The flange section 11a is located above the center section of the upper wall 33 in the front-rear direction. The internal space SP0 of the container CA communicates with the external space of the gas-liquid separator 10 via the pipe section 34 and the inlet 11.

[0032] A substantially circular opening is provided in the rear wall 322, and a substantially cylindrical pipe section 35 is provided to protrude rearward from the rear wall 322 so as to cover this opening. An outlet 12 is provided at the tip (rear end) of the pipe section 35, and a flange section 12a is provided around the outlet 12. The internal space SP0 of the container CA communicates with the external space of the gas-liquid separator 10 via the pipe section 35 and the outlet 12.

[0033] A substantially circular opening is provided at the corner where the rear end of the upper wall 33 (rear upper wall 333) and the upper end of the rear wall 322 intersect, and a substantially cylindrical pipe section 36 is provided obliquely rearward and upward between the pipe sections 34 and 35 so as to cover this opening. An outlet 14 is provided at the tip of the pipe section 36, and a flange section 12a is provided around the outlet 14. The internal space SP0 of the container CA communicates with the external space of the gas-liquid separator 10 via the pipe section 36 and the outlet 14.

[0034] As shown in Figs. 3 to 5, the gas-liquid separator 10 is attached to the fuel cell stack 100 via a bracket 70. The bracket 70 has a substantially U-shaped base portion 71 extending in the left-right direction across the upper wall 33 of the upper container 30 in front of the pipe portion 34, and an inclined portion 72 extending obliquely forward and downward from a lower end portion at the center in the left-right direction of the base portion 71, and is formed by bending a plate member. As shown in Fig. 4, through holes 71a are opened at the lower right end portion, upper right end portion, lower left end portion, and upper left end portion of the base portion 71, respectively. Bolts 73 are inserted from the rear into the through holes 71a at the lower right end portion and the lower left end portion.

[0035] As shown in FIG. 3, both left and right ends of the front surface of the base portion 71 abut against the left rear surface portion 323a of the left wall 323 and the right rear surface portion 324a of the right wall 324. The left rear surface portion 323a and the right rear surface portion 324a are provided with screw holes corresponding to the positions of the through holes 71a (FIG. 4), and the bolts 73 inserted through the through holes 71a are screwed into the screw holes. As shown in FIG. 5, the through holes 72a are opened at the front end portion of the inclined portion 72. The bolts 74 are inserted through the through holes 72a from above, and the bolts 74 are screwed into the bottomed screw holes provided in the upper wall 33 (front upper wall 331). As a result, the bracket 70 is fixed to the left wall 323, the right wall 324, and the upper wall 33 at three points by the bolts 73 and 74.

[0036] 1, the front surface of the upper part of base portion 71 of bracket 70 abuts against the rear end surface of fuel cell stack 100 (end plate 120). Screw holes are provided in the rear surface of fuel cell stack 100 at the positions where bracket 70 abuts. Bolts are inserted from the rear into through holes 71a (FIG. 4) at the upper left and upper right ends of base portion 71, and the bolts screw into the screw holes in the rear surface of fuel cell stack 100.

[0037] As a result, the bracket 70 is fastened to the fuel cell stack 100, and the gas-liquid separator 10 is attached to the fuel cell stack 100 via the bracket 70. At this time, the portion of the gas-liquid separator 10 forward of the pipe portion 34 (part of the upper container 30 and the lower container 20) is located below the fuel cell stack 100. This makes it possible to reduce the amount of protrusion of the gas-liquid separator 10 rearward from the fuel cell stack 100, and the gas-liquid separator 10 can be arranged efficiently. In addition, the gas-liquid separator 10, whose length in the left-right direction is shorter than its length in the front-rear direction, is attached to the lower right end of the fuel cell stack 100. This makes it possible to secure a large amount of space behind and below the fuel cell stack 100, excluding the installation space for the gas-liquid separator 10, and makes it easy to arrange other components around the fuel cell stack 100.

[0038] 7 is a view taken along line VII of FIG. 6 (as viewed from above). As shown in FIGS. 5 to 7, a flow path forming member 40 is disposed in an internal space SP0 of a container CA (upper container 30 is omitted in FIGS. 6 and 7). FIG. 8 is a perspective view showing an overall configuration of the flow path forming member 40. As shown in FIG. 8, the flow path forming member 40 has a cylindrical portion 41 extending in the vertical direction, an inclined portion 42 extending obliquely forward and downward from a lower end of the cylindrical portion 41, and a shielding portion 43 extending in a substantially horizontal direction from a lower end of the inclined portion 42. The cylindrical portion 41, the inclined portion 42, and the shielding portion 43 are integrally molded using resin as a constituent material.

[0039] A groove 411 is provided around the entire outer periphery of the cylindrical portion 41. As shown in Fig. 6, a resilient seal material 412, such as an O-ring, is fitted in the groove 411. Furthermore, a plate-shaped bracket 413 extending in a substantially horizontal direction protrudes from the outer periphery of the cylindrical portion 41 below the groove 411 toward the right and rear. As shown in Figs. 6 and 7, a through hole 413a is opened at the tip of the bracket 413, and a bolt 414 is inserted into the through hole 413a from below.

[0040] The bolt 414 is screwed into a bottomed screw hole (not shown) provided on the lower surface of the upper wall 33 (rear upper wall 333) of the upper container 30. This attaches the flow path forming member 40 to the upper container 30, and the flow path forming member 40 is supported in a suspended state from the upper container 30. At this time, as shown in Fig. 5, the upper end of the cylindrical portion 41 fits into the lower end of the pipe portion 34 via the seal material 412. Therefore, the interior of the pipe portion 34 and the interior of the cylindrical portion 41 are airtightly communicated, and the cylindrical portion 41 forms a vertical flow path PA11 that communicates with the internal passage of the pipe portion 34.

[0041] As shown in FIG. 8, the inclined portion 42 has a substantially plate-shaped bottom wall 421 that is connected to the lower end of the cylindrical portion 41, extends downward from the rear end of the cylindrical portion 41 by a predetermined length, and then extends forward and downward, and a pair of substantially plate-shaped left and right side walls 422 that extend upward from both left and right ends of the bottom wall 421. The intersection between the bottom wall 421 and the side walls 422 is formed in a substantially arc shape, and the inclined portion 42 is formed in a substantially U-shaped cross section. The inclination angle of the bottom wall 421 with respect to the horizontal line is set to a predetermined angle. The predetermined angle is preferably, for example, between 30° and 60°, and as a specific example, the predetermined angle is 45°. The rear end of the side wall 422 is connected to the lower end of the cylindrical portion 41, and an inclined flow path PA12 that is surrounded by the bottom wall 421 and the side walls 422 and is open upward is formed in front of the cylindrical portion 41.

[0042] An upper end surface 422a of the side wall 422 in front of the cylindrical portion 41 extends substantially parallel to the upper wall 33 (rear upper wall 333 in FIG. 5), i.e., substantially horizontally in the front-rear direction. A front end surface 422b of the side wall 422 extends in the up-down direction so as to be substantially parallel to the front wall 221 (FIG. 5) of the lower container 20. An upper end surface 422c of the side wall 422 between the upper end surface 422a and the front end surface 422b extends substantially parallel to the bottom wall 421, slanting forward and downward, and the length from the upper end surface 422c to the bottom wall 421 (the height of the side wall 422) is substantially constant over the entire length of the side wall 422 in the front-rear direction.

[0043] 5, the upper end surface 422c is approximately parallel to the inclined upper wall 332. The circular opening at the upper end of the cylindrical portion 41 forms an inlet (flow path inlet) PAin of the vertical flow path PA11. The approximately rectangular openings on the inner sides of the front end surfaces 422b of the left and right side walls 422 form an outlet (flow path outlet) PAout of the inclined flow path PA12. The area of ​​the flow path outlet PAout is larger than the area of ​​the flow path inlet PAin.

[0044] As shown in FIG. 8, the shielding portion 43 is generally plate-shaped. The shielding portion 43 has an attachment portion 431 joined to the lower end of the inclined portion 42, a front shielding portion 432 extending generally horizontally forward from the attachment portion 431, and a generally plate-shaped rear shielding portion 433 extending rearward from the attachment portion 431. As shown in FIG. 7 and FIG. 8, a narrow through hole 432a is opened in the left-right center and the front-rear center of the front shielding portion 432. A narrow through hole 433a is opened in the left-right center of the rear shielding portion 433 near the attachment portion 431 (the front-rear center of the shielding portion 43). The bottom wall 421 of the inclined portion 42 is located above the through hole 433a.

[0045] 7, the inner edge 21c of the flange portion 21 of the lower container 20 has a protrusion 211 protruding toward the internal space SP0 in correspondence with the position of the screw hole 21a, and the inner edge 21c is formed in an uneven shape. The peripheral portion 434 of the shielding portion 43 is formed in an uneven shape in correspondence with the shape of the inner edge 21c of the flange portion 21, and a gap CL of a predetermined length (shown by hatching for convenience) is provided around the entire circumference between the peripheral portion 434 and the inner edge 21c.

[0046] As shown in Fig. 5, when the container CA is assembled, the shielding portion 43 is located a predetermined height above the lowermost portion 23a of the bottom wall 23. Specifically, the height from the lowermost portion 23a to the shielding portion 43 is ¼ or more of the height from the lowermost portion 23a to the lower surface of the upper wall 33 (front upper wall 331). Within the container CA, a gas-liquid separation chamber SP2 is formed above the storage chamber SP1 via the shielding portion 43. The storage chamber SP1 and the gas-liquid separation chamber SP2 communicate with each other via the through holes 432a, 433a of the shielding portion 43 and the gap CL around the shielding portion 43.

[0047] A blocking plate 50 is attached to the rear wall 322 of the upper container 30. The blocking plate 50 has a support portion 51 extending in the vertical direction along the inner surface of the rear wall 322, and an inclined portion 52 extending from the lower end of the support portion 51 at an inclination forward and downward approximately parallel to the bottom wall 421 of the flow path forming member 40. A through hole is opened in the support portion 51, and a bolt 55 (FIG. 7) passing through the through hole and extending rearward is screwed into a bottomed screw hole provided on the front surface of the rear wall 322, thereby fastening the blocking plate 50 to the upper container 30. The tip of the inclined portion 52 is located between the upper end surface of the flange portion 21 of the lower container 20 and the upper surface of the shielding portion 43. For example, it is located at a vertical intermediate position between the upper end surface of the flange portion 21 and the upper surface of the shielding portion 43.

[0048] The flow of the fuel exhaust gas in the gas-liquid separator 10 configured as above will be described. FIG. 9A is a cross-sectional view of the gas-liquid separator 10 showing the flow of the fuel exhaust gas, and FIG. 9B is a plan view. FIGS. 9A and 9B are based on FIGS. 5 and 7, respectively. As indicated by an arrow A1 in FIG. 9A, the fuel exhaust gas flows into the gas-liquid separator 10 through the inlet 11. The fuel exhaust gas flows downward along the pipe portion 34 (arrow A2), and flows from the inlet Pin into the vertical flow path PA11 inside the cylindrical portion 41 (arrow A3). Since the periphery of the cylindrical portion 41 is sealed with a seal material 412, the fuel exhaust gas does not leak from the periphery of the cylindrical portion 41 to the outlet 12, and the entire amount of the fuel exhaust gas is guided to the vertical flow path PA11.

[0049] The fuel exhaust gas guided to the vertical flow path PA11 flows obliquely forward and downward along the inclined flow path PA12 formed by the inclined portion 42, and then the flow direction is changed to a substantially horizontal direction by the shielding portion 43, and then flows out forward from the flow path outlet PAout. In this manner, liquid water can be separated from the fuel exhaust gas as the flow direction of the fuel exhaust gas changes successively from downward, obliquely downward, and horizontal through the flow paths PA11 and PA12. The separated water flows downward and passes through the through-hole 432a of the shielding portion 43 provided midway along the flow of the fuel exhaust gas or the gap CL around the shielding portion 43, and accumulates in the storage chamber SP1 below the shielding portion 43.

[0050] As indicated by arrow A4 in FIG. 9A, the fuel exhaust gas flowing forward from the flow passage outlet PAout collides with the front wall 221 of the container CA. This separates water from the fuel exhaust gas. Since the area of ​​the flow passage outlet PAout is larger than the area of ​​the flow passage inlet PAin, the flow rate of the fuel exhaust gas decreases, and the kinetic energy of the fuel exhaust gas when colliding with the front wall 221 decreases. This allows the moisture to be efficiently separated from the fuel exhaust gas, and the gas-liquid separation efficiency to be improved. The separated water passes through the through-hole 432a or the gap CL and accumulates in the storage chamber SP1, becoming stored water.

[0051] A shielding portion 43 is provided above the storage chamber SP1. This can prevent the fuel exhaust gas from colliding with the water surface SF1 of the stored water and disturbing (blowing up) the water surface SF1. As a result, it is possible to prevent a part of the stored water from being re-entered into the fuel exhaust gas, thereby preventing gas-liquid separation from being disturbed, and stable gas-liquid separation can be performed.

[0052] The fuel exhaust gas that collides with the front wall 221 passes through the right and left sides of the side wall 422 of the inclined portion 42 and flows backward in the gas-liquid separation chamber SP2, as shown by the arrow A5 in FIG. 9B. At this time, the fuel exhaust gas collides with the convex portions 211 protruding from the left and right side walls 22. The fuel exhaust gas that has passed through the right side of the side wall 422 and the fuel exhaust gas that has passed through the left side collide with each other behind the lower end portion (attachment portion 431) of the inclined portion 42, that is, below the inclined portion 42. This causes turbulence in the flow of the fuel exhaust gas, and the water can be separated well from the fuel exhaust gas. The separated water passes through the through hole 433a or the gap CL below the inclined portion 42 and accumulates in the storage chamber SP1.

[0053] As shown in FIG. 9A, the fuel exhaust gas that flows to the rear of the inclined portion 42 flows upward in the rear space of the inclined portion 42 toward the outlet 12 (arrow A6). In this case, the flow velocity of the fuel exhaust gas is low, so that water can be separated well from the fuel exhaust gas. The separated water passes through the through hole 433a or the gap CL and accumulates in the storage chamber SP1. At the rear of the inclined portion 42, when the vehicle accelerates or runs on an incline, the fuel exhaust gas may flow (run up) along the rear wall 222 as shown by the arrow A7. This flow is blocked by the blocking plate 50. This makes it possible to prevent the fuel exhaust gas containing moisture from reaching the outlet 12. Due to the above-mentioned flow of the fuel exhaust gas, the fuel exhaust gas (fuel gas) from which moisture has been sufficiently removed can be discharged from the gas-liquid separator 10 through the outlet 12 and returned to the ejector 204 (FIG. 2) (arrow A8).

[0054] According to this embodiment, the following advantageous effects can be obtained. (1) The gas-liquid separator 10 is provided with a container CA having an upper wall 33, a bottom wall 23, and side walls 22, 32 connecting the upper wall 33 and the bottom wall 23, and forming a gas-liquid separation chamber SP2 that separates a gas-liquid two-phase flow into a gas phase and a liquid phase (FIGS. 4 and 5). The side walls 22, 32 have front walls 221, 321 and rear walls 222, 322 that face each other (FIG. 5). The container CA has an inlet 11 provided at the tip of a pipe section 34 provided integrally with the upper wall 33, through which the gas-liquid two-phase flow flows in, and an outlet 12 provided in the rear wall 322, through which the gas phase (fuel gas) separated in the gas-liquid separation chamber SP2 flows out (FIG. 5). The gas-liquid separator 10 further includes a flow path forming member 40, particularly an inclined portion 42, which forms an inclined flow path PA12 extending obliquely downward so that the fuel exhaust gas, which is a gas-liquid two-phase flow flow that flows in from the inlet 11, collides with the front wall 221 below the outlet 12 (FIG. 5).

[0055] According to this configuration, the fuel exhaust gas flowing along the inclined flow path PA12 collides with the front wall 221, and water is separated from the fuel exhaust gas. Therefore, it is possible to improve the gas-liquid separation performance compared to a configuration in which the flow path area is simply increased to reduce the flow rate. Furthermore, the gas-liquid separator 10 has a simple configuration in which the flow path forming member 40 is simply disposed in the container CA, and the gas-liquid separator 10 can be configured compactly.

[0056] (2) A shielding portion 43 is further provided to separate the space SP0 in the container CA into a storage chamber SP1 in which the water separated in the gas-liquid separation chamber SP2 is stored, and a gas-liquid separation chamber SP2 above the storage chamber SP1, which are in communication with each other via the gap CL and through-holes 432a, 433a (FIG. 5). The shielding portion 43 extends in a substantially horizontal direction below the inclined portion 42 (FIG. 5). This makes it possible to prevent the water separated from the fuel exhaust gas from being reentered into the fuel exhaust gas, and allows efficient gas-liquid separation.

[0057] (3) The flow path forming member 40 has a cylindrical portion 41 that extends in the vertical direction and communicates with the inlet 11, and an inclined portion 42 that is connected to the lower end of the cylindrical portion 41 and extends obliquely toward the front wall 221 (FIGS. 5 and 8). The cross-sectional shape of the inclined portion 42 is generally concave with an open upper space (FIG. 8). By opening the cross-sectional shape of the inclined portion 42 in this manner, the pressure of the exhaust fuel gas flowing along the inclined flow path PA12 decreases, and water can easily be separated from the exhaust fuel gas.

[0058] (4) A gap CL is provided between the peripheral portion 434 of the shielding portion 43 and the side wall 22 (FIG. 7). This allows the water separated from the exhaust fuel gas to be quickly guided to the storage chamber SP1 through the gap CL.

[0059] (5) The shielding portion 43 is provided with through-holes 432a, 433a penetrating the shielding portion 43 (FIG. 8). This makes it possible to prevent water separated from the exhaust fuel gas from remaining on the shielding portion 43.

[0060] (6) The shielding portion 43 is fixed to the lower end of the inclined portion 42 (FIG. 8). This makes it possible to easily support the shielding portion 43 within the container CA.

[0061] (7) The exhaust duct is further provided with a blocking plate 50 that extends obliquely downward from the rear wall 322 below the outlet 12 and blocks the fuel exhaust gas that reaches the outlet 12 (FIG. 5). This makes it possible to prevent the fuel exhaust gas containing moisture that rises along the rear wall 222 from flowing out of the outlet 12 when the vehicle accelerates or runs on an incline, and thus allows for sufficient gas-liquid separation performance to be exhibited.

[0062] The above embodiment can be modified in various ways. Some modified examples will be described below. FIG. 10 is a diagram showing a modified example of FIG. 5. In FIG. 10, the configuration of the shielding portion 43 of the flow path forming member 40 is different from that of FIG. 5. That is, as shown in FIG. 10, the shielding portion 43 is not generally horizontal as a whole, but the front end portion 436 and the rear end portion 437 are each formed to be inclined upward from the central portion 438 in the front-rear direction. The through holes 432a, 433a are provided in the central portion 438.

[0063] This makes it possible to prevent the stored water in the storage chamber SP1 from flowing through the gap CL and through-holes 432a, 433a into the gas-liquid separation chamber SP2 above the shielding portion 43 when the vehicle is tilted, for example, while traveling up a slope. In addition, the water that falls onto the upper surfaces of the front end portion 436 and the rear end portion 437 is guided along the inclined surface to the through-holes 432a, 433a in the central portion 438. This makes it possible to smoothly guide the water separated in the gas-liquid separation chamber SP2 into the storage chamber SP1.

[0064] In the above embodiment, the container CA is composed of the lower container 20 with an open top and the upper container 30 with an open bottom, but the container may have any configuration as long as it has an upper portion (upper wall), a bottom portion (bottom wall), and a side portion (side wall) and forms a gas-liquid separation chamber that separates the gas-liquid two-phase flow into a gas phase and a liquid phase. The separated gas phase may be other than fuel gas, and the separated liquid phase may be other than water. In the above embodiment, the pipe portion 34 is protruded upward from the upper wall 33, and the inlet 11 is provided at the tip of the pipe portion 34, but the configuration of the upper portion where the inlet is provided is not limited to this. In the above embodiment, the drain port 13 is provided on the side of the bottom wall 23, but the configuration of the bottom portion where the liquid phase outlet is provided is not limited to this.

[0065] In the above embodiment, the rear wall 322 (first side) of the container CA is provided with the outlet 12 through which the fuel gas separated in the gas-liquid separation chamber SP2 flows out, and the flow path forming member 40 is provided so that the fuel exhaust gas collides with the front wall 221 (second side) facing the rear wall 322, but the configuration of the flow path forming part is not limited to the above. In other words, the flow path forming part may have any configuration as long as it forms an inclined flow path extending obliquely downward so that the gas-liquid two-phase flow flowing in from the inlet collides with the second side below the outlet.

[0066] In the above embodiment, the space inside the container CA, i.e., the internal space SP0, is separated into the storage chamber SP1 and the gas-liquid separation chamber SP2 by the shielding portion 43 (shielding plate) provided integrally with the inclined portion 42, but the configuration of the shielding plate is not limited to the above. The shielding plate may be provided separately from the flow path forming portion (inclined portion 42) that forms the inclined flow path, and may not be fixed to the lower end of the inclined portion. In the above embodiment, the flow path forming member 40 has a cylindrical portion 41 (tubular portion) and an inclined portion 42, but the configuration of the tubular portion may be any as long as it extends in the vertical direction and communicates with the inlet. In the above embodiment, the inclined portion 42 is configured to have a substantially U-shaped cross section, but the cross-sectional shape of the inclined portion may be other than U-shaped as long as it is configured to have a substantially concave cross section.

[0067] In the above embodiment, the storage chamber SP1 and the gas-liquid separation chamber SP2 communicate with each other through the gap CL provided between the peripheral portion 434 of the shielding portion 43 and the side wall 22 (side portion) and the through holes 432a, 433a provided in the shielding portion 43, but the configuration of the opening that communicates the storage chamber and the gas-liquid separation chamber is not limited to the above. In the above embodiment, the blocking plate 50 is attached to the rear wall 322, but the configuration of the blocking portion is not limited to the above.

[0068] In the above embodiment, an example has been described in which the gas-liquid separator 10 is applied to a fuel cell system mounted on a vehicle, but the gas-liquid separator of the present invention can be applied to fuel cell systems mounted on moving bodies other than vehicles, such as aircraft and ships, robots, and various industrial machines. It can also be applied to systems other than fuel cell systems.

[0069] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other.

[0070] 10 gas-liquid separator, 11 inlet, 12 outlet, 20 lower container, 22 side wall, 23 bottom wall, 30 upper container, 32 side wall, 40 flow path forming member, 41 cylindrical portion, 42 inclined portion, 43 shielding portion, 50 weir stopper plate, 221 front wall, 322 rear wall, CL gap, PA12 inclined flow path, SP0 internal space, SP1 storage chamber, SP2 gas-liquid separation chamber

Claims

1. A gas-liquid separator comprising a container having a top, a bottom, and a side portion connecting the top and the bottom, and forming a gas-liquid separation chamber for separating a gas-liquid two-phase flow into a gas phase and a liquid phase, The side portion has a first side portion and a second side portion opposed to each other, The container comprises: an inlet provided in the upper portion and into which the gas-liquid two-phase flow flows; an outlet provided in the first side portion, through which the gas phase separated in the gas-liquid separation chamber flows out; The gas-liquid separator further comprises a flow path forming portion that forms an inclined flow path extending diagonally downward so that the gas-liquid two-phase flow flowing in from the inlet collides with the second side portion below the outlet.

2. 2. The gas-liquid separator according to claim 1, The space within the container is further divided into a storage chamber in which the liquid phase separated in the gas-liquid separation chamber is stored and the gas-liquid separation chamber above the storage chamber, the space being in communication with each other through an opening. The gas-liquid separator according to claim 1, wherein the shielding plate is disposed below the flow path forming portion and extends in a substantially horizontal direction.

3. The gas-liquid separator according to claim 2, The flow path forming portion is A cylindrical portion extending in a vertical direction and communicating with the inlet; an inclined portion connected to a lower end of the cylindrical portion and extending obliquely toward the second side portion, A gas-liquid separator, wherein the cross-sectional shape of the inclined portion is a generally concave shape with an open upper space.

4. The gas-liquid separator according to claim 2, A gas-liquid separator, wherein the opening is formed by a gap provided between a peripheral portion and the side portion of the shielding plate.

5. The gas-liquid separator according to claim 2, The gas-liquid separator according to claim 1, wherein the opening is a through hole penetrating the shielding plate.

6. The gas-liquid separator according to any one of claims 2 to 5, The gas-liquid separator according to claim 1, wherein the shielding plate is fixed to a lower end of the flow path forming portion.

7. 2. The gas-liquid separator according to claim 1, A gas-liquid separator further comprising a damming portion extending obliquely downward from the first side portion below the outlet and damming the gas-liquid two-phase flow reaching the outlet.

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