JP2021005498A - Gas-liquid separator - Google Patents

Abstract

To construct a gas-liquid separator that can be miniaturized without degrading the water separation performance of water-containing gas.SOLUTION: A gas-liquid separator includes, in a housing H, a gas-liquid separation unit 3 that separates water from water-containing gas, and a water storage unit 4 that stores the water separated by the gas-liquid separation unit 3. The gas-liquid separation unit 3 includes a tubular separation space T along the horizontal central axis X, an introductory pipe 1 that supplies hydrous gas, a collision wall 21 of the inner wall of the separation space T, and a drain opening 22 that sends out water and dehydrated gas obtained by separating water. The collision wall 21 is formed in a region shorter than the total length of the separation space T in the direction along the central axis X, such that a confluence space is formed between the end portion of the collision wall 21 in the extending direction and the end wall at a position facing the end wall, and a drain opening 22 is formed at the bottom of the confluence space.SELECTED DRAWING: Figure 3

Description

The present invention relates to a gas-liquid separator technique used to separate water from gas discharged from the anode of a fuel cell.

As a gas-liquid separator having the above configuration, Patent Document 1 describes a technique for a gas-liquid separator having a gas-liquid separator main body having a water storage unit at a lower portion and an inlet and an outlet at a position higher than the water storage unit. Is described.

The gas-liquid separator described in Patent Document 1 is provided with a vertical wall-shaped collision wall inside the main body of the gas-liquid separator and at an intermediate position between the inlet and the outlet, and rebounds upward from the water storage portion. It has a board. From this configuration, the water-containing gas introduced from the inlet collides with the collision wall to separate the water contained in the gas, and the separated water is stored in the storage unit. Then, the gas from which the water is separated is discharged from the outlet.

JP-A-2017-147159

In a fuel cell, power generation is realized by supplying hydrogen gas to the anode side and air containing oxygen to the cathode side. In addition, the anode-off gas discharged from the anode side of the fuel cell contains unreacted hydrogen and water, and in the fuel cell, the anode-off gas is reduced to the anode side in order to reuse the unreacted hydrogen gas. A gas-liquid separator is provided in the reducing flow path to separate and remove water contained in the reduced anode off-gas.

The gas-liquid separator of Patent Document 1 receives the anode off-gas discharged horizontally from the fuel cell stack into the main body from the introduction port, and causes the anode-off gas to collide with the plate-shaped collision wall inside the main body. The flow velocity is reduced, the water contained in the anode off-gas is separated as the flow velocity decreases, and then the water contained in the anode off-gas is separated by utilizing the change in the gas flow when passing through the lower end of the collision wall. It is further separated.

Further, in the gas-liquid separator of Patent Document 1, the outlet is arranged at a relatively high position so that water in the gas can be separated when the anode-off gas flows through the outlet. As described above, the gas-liquid separator of Patent Document 1 has a configuration in which the anode off-gas received from the introduction port flows in the horizontal direction and collides with the vertical wall-shaped collision wall, so that a part of the anode off gas hits the collision wall. Since it may flow without collision, improvement in separation performance was desired. In particular, since the lead-out portion is formed at a high position, the size of the gas-liquid separator is increased, and there is room for improvement.

Further, a gas-liquid separator provided with an on-off valve (drainage valve in Patent Document 1) for forming a drainage channel for discharging water from the water storage section (reservoir section in Patent Document 1) and opening and closing this drainage channel. Considering this, in order to suppress the inconvenience that the anode off gas containing unreacted hydrogen is discharged after the on-off valve is opened and the water is discharged, it is conceivable to form the drainage channel with a small diameter like an orifice.

However, in the case where a drainage channel having a small diameter is formed, when the fuel cell vehicle (FCV) is stopped in a cold region and the power generation of the fuel cell is stopped, the water freezes inside the drainage channel, and this It was a hindrance to the power generation of the fuel cell later. Therefore, when stopping the power generation of the fuel cell in a cold region, not only the process of opening the on-off valve to discharge the water in the storage section but also the hydrogen-free gas etc. is supplied to the inside of the gas-liquid separator. The process of removing water droplets inside the gas-liquid separator was also performed by scavenging. However, even if water is discharged and scavenging is performed, it is difficult to eliminate the phenomenon that water droplets remain on the inner surface of the gas-liquid separator.

For this reason, there is a demand for a gas-liquid separator capable of miniaturization without deteriorating the water separation performance of the water-containing gas.

The characteristic configuration of the gas-liquid separator according to the present invention is provided on the housing, the gas-liquid separator provided inside the housing to separate water from the water-containing gas, and the bottom of the housing in the direction in which gravity acts. A water storage unit for storing water separated by the gas-liquid separation unit, and a tubular separation space in which the gas-liquid separation unit extends along the central axis of a lateral posture with respect to the direction in which gravity acts. An introduction pipe that supplies a water-containing gas to the separation space, and a predetermined width extending from the inner wall of the separation space in the direction of the central axis, and extending from the first end wall of the separation space along the central axis. The introduction pipe has at least one collision wall to be discharged, water separated from the water-containing gas in the separation space, and a drain opening to send out the dehydrated gas separated from the water, and the introduction pipe has the water-containing gas on the central axis. The supply direction is set so as to rotate around the collision wall, and the collision wall is formed with an extension length shorter than the total length of the separation space in the direction along the central axis, so that the end of the collision wall in the extension direction is formed. A confluence space is formed between the portion and the second end wall formed at a position facing the first end wall, and the drain opening is formed at the bottom of the confluence space.

According to this characteristic configuration, when the water-containing gas is supplied from the introduction pipe to the gas-liquid separation part, it turns around the central axis so as to collide with the collision wall inside the separation space, and is along the central axis. And move. As a result, when the water-containing gas collides with the collision wall, the water contained in the water-containing gas is separated, and the separated water and the dehydrated gas separated by water pass through the end of the collision wall in the extending direction. Reach the confluence space. Then, the water and the dehydrated gas are sent downward from the drain opening at the bottom of the confluence space, the water falls into the water storage portion and is collected, and the dehydrated gas is discharged from the housing.
That is, in this configuration, since the collision walls are arranged in a posture of extending laterally, for example, the dimensions can be reduced in the vertical direction as compared with the case where a plurality of collision walls are arranged vertically. Moreover, when the water-containing gas is sent laterally, the water-containing gas is swirled around the central axis and collides with multiple collision walls, so that the water separation performance is improved and the dimensions can be reduced in the lateral direction. Will also be realized.
As a result, a gas-liquid separator capable of miniaturization without deteriorating the water separation performance of the water-containing gas was constructed.

As another configuration, the inner wall on the bottom side of the separation space may be formed in an inclined posture in which the inner wall is lowered from the first end wall toward the drain opening.

According to this, the water separated from the water-containing gas in the separation space flows by its own weight toward the drain opening along the inner wall on the bottom side, and water droplets do not remain inside the separation space.

As another configuration, when the collision wall has a plurality of the collision walls, the water-containing gas supplied to the separation space is sequentially guided to the collision wall on the downstream side in the turning direction on the central axis. A posture in a directional view is set, and the upper surface on the opposite side of the direction in which gravity acts may be formed in the plurality of collision walls in an inclined posture that becomes lower as the position closer to the confluence space.

According to this, the hydrous gas supplied to the separation space swirls around the central axis in a state of sequentially contacting a plurality of collision walls. Further, since the upper surface of the plurality of collision walls opposite to the direction in which gravity acts is formed in a lower inclined posture as the position closer to the confluence space, the upper surface of the collision walls is formed when the fuel cell power generation is stopped. Even if the water droplets remain in the adhered state, the water droplets on the upper surface flow toward the confluence space and can be collected in the water storage portion through the drain opening.

As another configuration, the drain opening may have a slit-shaped portion which is an opening extending in a direction along the central axis.

According to this, since the drain opening has a slit-shaped portion, the gas-liquid separator is provided in the fuel cell vehicle (FCV), and the gas-liquid separator is provided as in the case where the fuel cell vehicle is stopped on a slope. Even in a sloping situation, the water in the separation space can be reliably discharged.

As another configuration, a communication portion that communicates in the thickness direction of the collision wall may be formed at the base end portion of the collision wall on the inner wall side of the separation space.

According to this, the water droplets remaining in the separation space can flow through the communication portion of the collision wall, and the inconvenience of the water droplets remaining in the separation space can be eliminated.

It is a perspective view of the gas-liquid separator which was partially cut out. It is a front view of the gas-liquid separator. FIG. 2 is a sectional view taken along line III-III of FIG. It is a top view of the gas-liquid separator which was partially cut out. It is a vertical cross-sectional view of a gas-liquid separation part. It is a vertical sectional view of a gas-liquid separator. It is a cross-sectional view which shows the shape of a drain opening. It is sectional drawing of the gas-liquid separation part of another embodiment (a).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
1 to 6 show a gas-liquid separator A that separates water contained in an anode off gas (an example of a water-containing gas) discharged from the anode side of a fuel cell mounted on a fuel cell vehicle (FCV). There is. The gas-liquid separator A includes an introduction pipe 1, a discharge port 2, a gas-liquid separation unit 3, and a water storage unit 4 in the housing H. Further, an electromagnetic on-off valve 5 for controlling the discharge of water stored in the water storage unit 4 is provided outside the H of the housing.

In a fuel cell, power generation is realized by humidifying and supplying an anode gas (fuel gas) containing hydrogen gas to the anode side and supplying a cathode gas (oxidizing agent gas) containing oxygen and air to the cathode side. .. The reason for humidifying the anode gas is to wet the anode side of the fuel cell.

Since power generation is performed in this way, the anode off gas (an example of a hydrous gas) discharged from the anode side includes unreacted hydrogen gas and water. In the fuel cell, a gas-liquid separator A is provided in the reduction path for returning the anode off-gas to the anode side in order to reuse unreacted hydrogen gas as a part of the anode gas supplied to the anode side.

That is, the gas-liquid separator A is supplied with the anode-off gas as the water-containing gas, so that the water contained in the anode-off gas is separated and collected in the water storage unit 4, and the water is separated and the anode-off gas is used as the dehydrated gas. Is discharged from the discharge port 2. The anode-off gas discharged in this way is supplied to the anode side of the fuel cell to realize the reuse of unreacted hydrogen gas.

[Housing, inlet, outlet]
As shown in FIGS. 1 to 3 and 6, the housing H includes an upper flange portion 11f of an upper housing 11 having an introduction pipe 1, a discharge port 2, and a gas-liquid separation portion 3, a water storage portion 4, and an electromagnetic on-off valve. It has a structure in which the lower flange portion 15f of the lower housing 15 having the 5 is fastened with a plurality of fastening bolts 6. The upper flange portion 11f and the lower flange portion 15f may be fastened by other means such as welding by ultrasonic waves.

The upper housing 11 and the lower housing 15 are formed of a resin material, and when the upper housing 11 and the lower housing 15 are fastened together, an internal space S is formed between them. The upper housing 11 and the lower housing 15 may be made of a metal such as aluminum.

As shown in FIG. 3, a gas-liquid separation portion 3 is formed in the separation space T separated from the internal space S in the upper housing 11. Details of the gas-liquid separation unit 3 will be described later.

As shown in FIGS. 1 to 6, the separation space T is a space formed inside the bulging portion 12 that bulges upward in the upper housing 11 and is integrally formed. The separation space T extends along a central axis X (an axis virtualized at the center of the separation space T) that is in a sideways posture with respect to the direction in which gravity acts. The bulging portion 12 is formed with a tubular introduction pipe 1 that intersects the central axis X and extends in the horizontal direction so as to communicate with the separation space T. The separation space T is formed in the bulging portion 12 between the outer wall 12W (an example of the first wall portion) and the closing plate 13 (an example of the second wall portion) located at a position facing the outer wall 12W (an example of the first wall portion). ..

The introduction pipe 1 has an introduction path 1R for sending the anode off gas inside, and the supply direction by the introduction pipe 1 is set so as to send the anode off gas in the horizontal direction above the separation space T. Due to this setting of the supply direction, as shown by the arrow in FIG. 3, the anode off gas swirls counterclockwise around the central axis X in the separation space T.

As shown in FIGS. 1 and 6, the closing plate 13 (an example of the end wall) is detachably fixed by a plurality of screws 13a at a position of the bulging portion 12 that closes the side opening 12a of the separation space T. ing. Although the closing plate 13 is made of a resin material, it may be made of a metal such as aluminum. Further, the closing plate 13 is not limited to being fixed by a plurality of screws 13a, and may be fixed by ultrasonic waves or the like. When fixed in this way, the obstruction plate 13 is not removable.

As shown in FIGS. 3 and 4, the discharge port 2 is formed in the internal space S of the bulging portion 12. The discharge port 2 is arranged at a position lower than the introduction pipe 1 in a posture orthogonal to the extension direction of the introduction pipe 1. The position of the discharge port 2 is not limited to a position lower than the introduction pipe 1, but is preferably a position lower than the introduction pipe 1.

[Housing, water storage]
As shown in FIGS. 3 and 6, the lower housing 15 is integrally formed with a bottom wall portion 16 having a central portion projecting downward, and a mortar-shaped portion 16 having a large depression toward the center on the inner surface side of the bottom wall portion 16. The water storage unit 4 is configured in the space. The internal space S is a combination of the space above the water storage unit 4 and the space excluding the separation space T of the upper housing 11.

As shown in FIGS. 1, 2, and 6, a drainage block 17 projecting laterally is integrally formed at the lower end of the bottom wall portion 16. Inside the drainage block 17, a drainage channel 17a communicating with the bottom of the water storage section 4 is formed, and on the outer surface of the drainage block 17, a drainage pipe 17b for discharging water from the drainage channel 17a is formed. ing. Further, the drainage block 17 is provided with an electromagnetic on-off valve 5 for controlling the discharge of water flowing through the drainage flow path 17a.

In addition, in order to suppress the discharge of the anode off gas containing unreacted hydrogen when the electromagnetic on-off valve 5 is opened and the water of the water storage unit 4 is discharged, and to enable the discharge of a constant flow rate, the drainage flow path 17a is provided. It is formed with a small diameter like an orifice.

As shown in FIG. 6, the solenoid on-off valve 5 has a valve body 5a held at a position where the drainage flow path 17a is blocked by a spring-forced force, and an electromagnetic wave that operates the valve body 5a against the spring-forced force by energization. It includes a solenoid 5b and a resin or rubber sealing film 5c that abuts on the outer end of the drainage channel 17a.

From this configuration, when the electromagnetic solenoid 5b is not driven, the valve body 5a is held in the closed position by the spring urging force, and the seal film 5c closes the outlet of the drainage flow path 17a, so that water is stored in the water storage unit 4. To. On the other hand, when the electromagnetic solenoid 5b is driven, the seal film 5c separates from the outlet of the drainage flow path 17a as the valve body 5a operates, and the water in the water storage unit 4 moves from the drainage flow path 17a to the drainage pipe 17b. It flows and is discharged to the outside.

[Gas-liquid separation part]
As shown in FIGS. 3, 5, and 6, the introduction path 1R of the introduction pipe 1 communicates with a portion of the separation space T that is connected to the outer wall 12W (one end side in the direction along the central axis X). ing. In the separation space T, a portion facing the outer wall 12W is open to the side, and this open portion is closed by the closing plate 13. In this way, the block plate 13 is arranged at a position facing the outer wall 12W. The introduction pipe 1 is formed in a posture orthogonal to the central axis X.

The gas-liquid separation unit 3 includes a plurality of collision walls 21. That is, the collision wall 21 projects from the outer wall 12W of the separation space T in the direction of the central axis X with a predetermined width, and extends along the central axis X in the region of the separation space T in the direction along the central axis X. It is formed with an extension length shorter than the total length. Further, a merging space Ta is formed between the end portions of the plurality of collision walls 21 in the extending direction and the closing plate 13, and a drain opening 22 is formed at the bottom of the merging space Ta.

As shown in FIG. 3, a plurality of directional views along the central axis X so that the anode off gas (hydrous gas) supplied to the separation space T is sequentially guided to the collision wall 21 on the downstream side in the turning direction. The posture of the collision wall 21 is set.

Assuming that the inner surface of the bottom of the separation space T and the upper surface of the collision wall 21 are in a horizontal posture in the gas-liquid separator A having this configuration, the power generation by the fuel cell is stopped and the anode off gas is gas. In a situation where the fuel is not supplied to the liquid separator A, it is conceivable that water droplets adhere to and remain on the upper surfaces of the plurality of collision walls 21.

In order to eliminate such inconvenience, as shown in FIGS. 5 and 6, the inner wall 12b on the bottom side of the separation space T and the upper surface of the plurality of collision walls 21 on the opposite side in the direction in which gravity acts are formed. , The merging space Ta is formed in an inclined posture that becomes lower toward a position closer to the drain opening 22. The angle at which the inner wall 12b of the separation space T is inclined is set to about 8 ° with respect to the horizontal, but it may be any angle.

As a result, even when water droplets adhere to the inner wall 12b on the bottom side of the separation space T and the upper surfaces of the plurality of collision walls 21, these water droplets flow toward the confluence space Ta and drain the bottom of the separation space T. It is discharged downward from the opening 22 and collected in the water storage unit 4.

As shown in FIG. 7, the drain opening 22 is arranged at the bottom of the merging space Ta at the bottom of the separation space T with the opening body 22a extending in the circumferential direction of the merging space Ta in a positional relationship adjacent to each other. It has a slit-shaped portion 22b formed in a direction extending along the central axis X between the pair of collision walls 21.

[Separation of water by gas-liquid separator and action / effect of embodiment]
From such a configuration, as shown in FIGS. 3 and 6, in the gas-liquid separation unit 3, the anode off gas from the introduction pipe 1 was supplied to the outer end side of the upper housing 11 in the lateral direction with respect to the separation space T. In this case, the anode off gas moves in the direction of the obstruction plate 13 on the opposite side of the supply position while rotating around the central axis X inside the separation space T.

Further, as the anode off-gas swirls inside the separation space T, the anode off-gas comes into contact with the plurality of collision walls 21 in a sequential manner. Due to this contact, the water contained in the anode off gas becomes water droplets on the surface of the collision wall 21. Further, even if the anode off gas does not come into contact with the collision wall 21, it becomes water droplets due to the centrifugal force due to turning and the change in the direction of motion.

A part of the anode off-gas finally collides with the inner surface of the closing plate 13, and the closing plate 13 changes the flow direction of the anode off-gas downward, so that the flow velocity is greatly reduced, and the closing plate 13 The water contained in the anode off-gas also separates and becomes water droplets at this site. As shown in FIGS. 5 and 6, of the side openings 12a, the opening side inner wall 12c located on the bottom side is formed in an inclined posture that becomes lower toward the position closer to the drain opening 22, so that the closing plate 13 Water droplets formed on the inner surface of the water also flows toward the drain opening 22.

Then, the water flowing into the confluence space Ta and the dehydrated anode off gas are discharged from the drain opening 22, and the water is stored in the water storage section 4 below the drain opening 22. On the other hand, the dehydrated anode off gas that has passed through the drain opening 22 flows toward the discharge port 2 at a position higher than the drain opening 22 in the internal space S, and is discharged from the discharge port 2. When water is contained in the anode off gas flowing toward the discharge port 2, when it flows upward in the internal space S, it is separated by its weight and collected in the water storage unit 4.

In this way, in the gas-liquid separator A, the anode off gas is not simply moved in the lateral direction (horizontal direction), but is brought into contact with the plurality of collision walls 21 by swirling around the central axis X in the lateral posture, resulting in efficiency. It enables the separation of water. Therefore, for example, it is possible to reduce the dimensions in the vertical direction as compared with the case where a plurality of collision walls 21 are arranged vertically, and it is also possible to reduce the dimensions in the horizontal direction, resulting in overall miniaturization. Has been realized.

In this gas-liquid separator A, the amount of water stored in the water storage unit 4 is estimated by a control device such as an ECU from the amount of power generated by the fuel cell, and when the amount of water estimated in this way requires discharge, the control device. Controls the opening of the electromagnetic on-off valve 5 to discharge water. A gas-liquid separator A may be configured to include a sensor that detects the amount of water stored in the water storage unit 4 and open the electromagnetic on-off valve 5 based on the detection result of this sensor.

If water remains in the drainage channel 17a when the fuel cell vehicle stops in a cold region and the power generation by the fuel cell is stopped, the water freezes inside the drainage channel 17a, and thereafter. It was also considered that the fuel cell would hinder power generation. In order to eliminate such inconvenience, when the power generation of the fuel cell is stopped in a cold region, the electromagnetic on-off valve 5 is opened to discharge the water of the water storage unit 4.

In particular, since the inner wall 12b on the bottom side of the separation space T and the upper surfaces of the plurality of collision walls 21 are in an inclined posture, and the inner wall 12c on the opening side is formed in an inclined posture on the bottom side of the side opening 12a, power is generated. Even if water droplets adhere to a plurality of collision walls 21 or the like in the separation space T at the time of stopping, the water droplets can be discharged to the drain opening 22 by their own weight before the temperature of the gas-liquid separator A drops below the freezing point. It is possible. Since the water discharged from the drain opening 22 is discharged to the outside from the water storage unit 4, the inconvenience of freezing the water inside the drainage channel 17a does not occur.

[Another Embodiment]
The present invention may be configured as follows in addition to the above-described embodiment (those having the same functions as those in the embodiment are designated by the same number and reference numeral as those in the embodiment).

(A) As shown in FIG. 8, a communication hole 21a (an example of the communication portion) penetrating in the thickness direction of the collision wall 21 is formed at the base end portion of the collision wall 21 on the inner wall side of the separation space T. By forming the communication hole 21a in the collision wall 21 in this way, the water droplets remaining inside the separation space T flow into the communication hole 21a to facilitate discharge.

In this other embodiment (a), the communication hole 21a is shown as the communication portion, but for example, a notched space (not shown) in which a part of the collision wall 21 is cut out can be formed as the communication portion. .. As described in the embodiment, since the plurality of collision walls 21 are formed in an inclined posture in which the position closer to the confluence space Ta is lower, the collision wall 21 can be discharged even if water droplets are present on the upper surface of the collision wall 21. However, the water can be discharged more satisfactorily by forming the communication hole 21a and the notch space.

(B) A water-repellent resin material is used as the material of the housing H, or a water-repellent paint is applied to the inner surface of the housing H. As a result, the phenomenon of water droplets remaining inside the housing is suppressed, and the inconvenience of the water droplets freezing inside the drainage channel 17a is suppressed.

(C) The position supplied from the introduction pipe 1 to the separation space T may be set to the lower side, contrary to the embodiment. In this case, the direction in which the anode off-gas turns is set to be opposite to that in the embodiment. Even if the introduction direction is set in this way, the anode off-gas can be swirled around the central axis X, and water can be separated satisfactorily.

(D) The discharge port 2 is formed as a vertically facing opening so as to discharge the anode off gas upward. By forming in this way, it can be expected that the water contained in the anode off-gas is separated by gravity when the anode off-gas flows upward.

The present invention can be used in a gas-liquid separator that separates water from the gas discharged from the anode of a fuel cell.

1 Introduction pipe 3 Gas-liquid separation part 4 Water storage part 12W External wall (first end wall)
13 Closure plate (second end wall)
21 Collision wall 21a Communication hole (communication part)
22 Drain opening 22b Slit-shaped part H Housing T Separation space Ta Confluence space X Central axis

Claims (5)

With the housing
A gas-liquid separation unit provided inside the housing to separate water from the water-containing gas,
It is provided at the bottom of the housing in the direction in which gravity acts, and is provided with a water storage unit for storing water separated by the gas-liquid separation unit.
From the tubular separation space in which the gas-liquid separation portion extends along the central axis of the lateral posture with respect to the direction in which gravity acts, the introduction pipe for supplying the water-containing gas to the separation space, and the inner wall of the separation space. At least one collision wall that projects in the direction of the central axis with a predetermined width and extends from the first end wall of the separation space along the central axis, water separated from the water-containing gas in the separation space, and It has a drain opening, which sends out the dehydrated gas separated by water.
The supply direction of the introduction pipe is set so as to swirl the hydrous gas around the central axis, and the collision wall is formed in a direction along the central axis with an extension length shorter than the total length of the separation space. As a result, a merging space is formed between the end portion of the collision wall in the extending direction and the second end wall formed at a position facing the first end wall, and the merging space is formed at the bottom of the merging space. A gas-liquid separator in which the drain opening is formed. The gas-liquid separator according to claim 1, wherein the inner wall on the bottom side of the separation space is formed in an inclined posture in which the inner wall is lowered from the first end wall toward the drain opening. When the collision wall has a plurality of collision walls, the posture in the directional view along the central axis so that the collision wall sequentially guides the water-containing gas supplied to the separation space to the collision wall on the downstream side in the turning direction. Is set,
The gas-liquid separator according to claim 1 or 2, wherein the upper surface of the plurality of collision walls, which is opposite to the direction in which gravity acts, is formed in an inclined posture in which the upper surface becomes lower toward a position closer to the confluence space. The gas-liquid separator according to any one of claims 1 to 3, wherein the drain opening has a slit-shaped portion which is an opening extending in a direction along the central axis. The gas-liquid separation according to any one of claims 1 to 4, wherein a communication portion communicating with the thickness direction of the collision wall is formed at a base end portion of the separation space of the collision wall on the inner wall side. vessel.

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