JP7765267B2 - gas liquid separator - Google Patents

Description

The present invention relates to a gas-liquid separator.

Patent Document 1 describes, for example, a gas-liquid separator that separates water contained in anode off-gas discharged from the anode of a fuel cell.

In the gas-liquid separator of Patent Document 1, a gas-liquid separation section is formed by arranging multiple collision walls extending vertically inside a bulging wall formed on the upper surface of the housing, and an inlet is formed to supply water-containing gas horizontally to the collision walls of this gas-liquid separation section.

In the gas-liquid separator of Patent Document 1, the multiple collision walls that make up the gas-liquid separation section are made up of multiple vertically elongated plate-shaped members that are arranged at set intervals within an annular region in a plan view. A water-containing gas is supplied so as to swirl within the inner region of the annular region, creating a swirl flow, and water separation is achieved through collision between the water-containing gas and the collision walls.

JP 2019-155334 A

This type of gas-liquid separator is placed near the vehicle's fuel cell. For example, if the fuel cell has end plates placed at both ends of multiple stacked fuel cell cells, the gas-liquid separator will be supported by the end plates.

The end plates of fuel cells are equipped with pipes and valves for supplying fuel gas and oxidizing gas, so if the gas-liquid separator is positioned with these in mind, it is expected that it will be difficult to position the inlet for introducing the water-containing gas horizontally at the top of the housing, as in Patent Document 1.

In particular, in fuel cells with multiple fuel cells, the stacking direction of the fuel cells can be vertical, left-right, or front-to-back. Therefore, depending on the relationship between the placement of the gas-liquid separator relative to the end plate and the position where the water-containing gas is discharged from the end plate, it is necessary to design the inlet to be positioned away from the collision wall, such as at the bottom of the housing, or to be positioned vertically relative to the housing.

Furthermore, in a gas-liquid separation section that separates water by bringing the water-containing gas into contact with a collision wall, as described in Patent Document 1, it is preferable to create a swirl flow that causes the water-containing gas to flow horizontally and swirl, in order to improve gas-liquid separation performance.

For these reasons, there is a demand for a gas-liquid separator that allows greater freedom in the placement of the inlet and allows the water-containing gas introduced through the inlet to flow horizontally to separate the gas and liquid.

A characteristic configuration of a gas-liquid separator according to the present invention includes a housing, an inlet formed in the housing, a flow path that communicates with the inlet and allows a water-containing gas supplied from the inlet to flow in a vertical direction, a gas flow converting unit that converts the flow of the water-containing gas flowing through the flow path from a vertical direction to a horizontal direction, and a gas-liquid separating unit that separates water from the water-containing gas by sequentially bringing the water-containing gas supplied from the gas flow converting unit into the housing into contact with a plurality of separation blades , wherein the gas-liquid separating unit is located at a position higher than the inlet and A flow path member having a vertically long orientation and having the flow path formed therein is disposed in the internal space of the housing, and the water-containing gas introduced into the inlet is sent vertically upward through the flow path, and the gas flow conversion unit is composed of a horizontally oriented guide surface formed on the inner surface of the upper wall of the housing so as to cause the water-containing gas sent further vertically upward from the upper end of the flow path member to flow horizontally, and a guide unit at the upper end of the flow path member that guides the water-containing gas in a direction toward the separation blades of the gas-liquid separation unit .

According to this characteristic configuration, the water-containing gas introduced from the inlet flows vertically in the flow path, and this vertical flow is converted into a horizontal flow by the gas flow converter before being supplied to the gas-liquid separation section. In the gas-liquid separation section, the water-containing gas flows horizontally and sequentially comes into contact with the separation blades, thereby making it possible to create, for example, a swirl flow, thereby achieving efficient gas-liquid separation.
According to this, the water-containing gas introduced from the inlet is sent vertically upward through the flow path of the flow path member, which is oriented vertically long. The gas flow conversion section is composed of a horizontally oriented guide surface formed on the inner surface of the upper wall of the housing and a guide section at the upper end of the flow path member that guides the water-containing gas toward the gas-liquid separation section. Therefore, the water-containing gas sent further vertically upward from the upper end of the flow path member is sent horizontally along the horizontally oriented guide surface on the inner surface of the upper wall of the housing and is also sent in the direction toward the gas-liquid separation section by the guide section at the upper end of the flow path member, and the water-containing gas sent in this manner comes into contact with the separation blades of the gas-liquid separation section, achieving gas-liquid separation.
Therefore, the position of the inlet is no longer restricted to the upper part of the housing of the gas-liquid separator, and the freedom of the placement position of the inlet is improved, while a gas-liquid separator is configured in which the water-containing gas introduced from the inlet flows horizontally against the separation blades to perform gas-liquid separation.

In addition to the above configuration, the flow path member may be integrally formed with a holder that is held on the inner surface of the housing.

For example, when assembling a gas-liquid separator, by supporting a holder on the inner surface of the housing, it is possible to support the flow path member relative to the housing via the holder. As a result, the flow path member can be fixed to the housing in a positioned state without welding or gluing it to the inner surface of the housing, allowing the water-containing gas to flow appropriately.

FIG. 2 is a perspective view showing an end plate and a gas-liquid separator of the fuel cell. FIG. 2 is a longitudinal sectional front view of the gas-liquid separator. FIG. 2 is a cross-sectional plan view of a gas-liquid separation section of the gas-liquid separator. FIG. 2 is a cross-sectional plan view of the bottom of the gas-liquid separator. FIG. 2 is a perspective view showing a flow path member and a holder. FIG. 10 is a perspective view of a gas-liquid separator according to another embodiment (a). FIG. 10 is a partially cutaway perspective view of a gas-liquid separator according to another embodiment (a). FIG. 10 is a cross-sectional view of the upper part of the cylindrical body of another embodiment (a). FIG. 10 is a perspective view of a cylindrical body according to another embodiment (a). FIG. 10 is a partially cutaway perspective view of a gas-liquid separator according to another embodiment (b). FIG. 10 is a partially cutaway front view of a gas-liquid separator according to another embodiment (b). FIG. 10 is a perspective view of a guide member according to another embodiment (b).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Basic configuration]
1 shows a gas-liquid separator A provided on the outer surface of an end plate 2 of a fuel cell 1 mounted on a fuel cell vehicle (FCV). The gas-liquid separator A is configured to separate water contained in anode off-gas (an example of a water-containing gas) supplied via an inlet path 3, discharge the dehydrated gas from which the water has been separated via an outlet path 4 (to be combined with the anode gas and returned to the fuel cell 1), and discharge the separated water from the bottom.

The fuel cell 1 has multiple fuel cell cells 1a stacked on top of each other, with end plates 2 made of a metal material such as aluminum positioned at both ends in the stacking direction. Only one of the pair of end plates 2 is shown in Figure 1, and anode gas (hydrogen gas) is supplied to the fuel cell cells 1a from the area where this end plate 2 is positioned, and anode off-gas reacted in the fuel cell cells 1a is discharged. Similarly, cathode gas (air) is supplied to the fuel cell cells 1a from the area where this end plate 2 is positioned, and cathode off-gas reacted in the fuel cell 1a is discharged.

As shown in Figures 1 to 4, gas-liquid separator A is provided with a resin housing 10, a gas-liquid separation section As that separates water from anode off-gas, and a water storage section At that collects the water separated in the gas-liquid separation section As. The bottom of the housing 10 is equipped with an electromagnetic on-off valve 5 that opens and closes a discharge flow path 19 extending from the water storage section At. The housing 10 also has an internal space that extends vertically along a central axis (not shown) of its vertical position. This vertical direction does not strictly mean only the direction parallel to the direction of gravity, but also includes directions in which the vertical relationship can be determined based on the direction of gravity.

This gas-liquid separator A has an inlet 14 formed in the housing 10, through which anode off-gas is introduced from the inlet passage 3, and an outlet 15 through which the anode off-gas from which water has been removed is discharged. The inlet 14 is located at a lower position than the gas-liquid separation unit As, and the gas-liquid separator A has a flow path member 6 that circulates the anode off-gas supplied from the inlet 14 up to the position of the gas-liquid separation unit As, and a gas flow conversion unit Au that discharges the anode off-gas from this flow path member 6 horizontally toward the gas-liquid separation unit As.

The flow path member 6 forms a flow path V through which the anode off-gas supplied from the inlet 14 flows vertically. Furthermore, in the gas-liquid separation unit As, a swirl flow is created around the central axis by the anode off-gas supplied horizontally, perpendicular to the central axis of the vertical position of the housing 10. However, this horizontal direction does not necessarily mean the horizontal direction in the strict sense; it may be any direction that indicates the gas flow necessary to create the swirl flow in the gas-liquid separation unit As.

[Gas-liquid separator]
2, the gas-liquid separator A has a housing 10 made of an upper housing 11 made of resin and a lower housing 12 made of resin, and an upper flange 11a integrally formed with the upper housing 11 and a lower flange 12a integrally formed with the lower housing 12 are fastened together with a plurality of fastening bolts 13. The cross sections of the upper housing 11 and the lower housing 12 (cross sections as viewed in a direction along the central axis) are molded to have approximately the same shape.

As shown in Figures 1 to 3, a gas-liquid separation unit As is disposed inside the upper housing 11, and an exhaust port 15 is formed that opens horizontally to a protrusion 11b that protrudes upward from the top surface of the upper housing 11. The gas-liquid separation unit As has a separation space within the upper housing 11 that is partitioned by a partition wall 16 extending downward from the underside of the top wall 11c of the upper housing 11 and the inner wall of the upper housing 11, and is equipped with a plurality of plate-shaped separation blades 17 that extend vertically downward from the underside of the top wall 11c relative to this separation space. As shown in Figure 3, the multiple separation blades 17 are disposed in an annular region C that is annular in plan view.

As shown in Figure 3, multiple separation blades 17 are arranged at set intervals in an annular region C that is circular in plan view, and the multiple separation blades 17 are oriented in a way that guides the anode off-gas supplied horizontally from the gas flow conversion unit Au toward the center of the separation space.

In this gas-liquid separator A, as shown in Figure 2, the lower end of the partition wall 16 protrudes downward from the lower end of the multiple separation blades 17, preventing the gas in the separation space from short-circuiting and flowing to the exhaust port 15.

The water storage space At is located in a water storage space formed at the bottom of the lower housing 12. As shown in Figures 2 and 4, a filter 18 is located in the water storage space. The filter 18 has a mesh portion 18b on the inner periphery of a frame portion 18a that is annular in plan view. Furthermore, the aforementioned electromagnetic on-off valve 5 is provided to open and close the outer end of the discharge flow path 19 that communicates with the lower end of the water storage space. This electromagnetic on-off valve 5 is configured to maintain a closed state when not energized, and to open the discharge flow path 19 to discharge water when energized.

[Gas-liquid separator: flow path member]
5, the flow path member 6 is disposed inside the housing 10 in a vertical orientation such that the cross section of the flow path is U-shaped. The flow path member 6 is integrally formed with an annular holder 7 that is held on the inner surface of the housing 10. The flow path member 6 and the holder 7 are integrally formed from a resin material.

As shown in Figures 2 to 5, the flow path member 6 has the opening edge of the vertically open area positioned close to (or in contact with) the vertical inner surface 10s of the housing 10, thereby forming a flow path space 6a between the flow path member 6 and the inner surface of the housing 10, and this flow path space 6a forms a flow path V that allows the anode off-gas to circulate vertically.

The holder 7 is annular in plan view and fits along the inner surface of the housing 10. As shown in Figure 2, a portion of the lower part of the holder 7 is fitted into the inner periphery of the lower housing 12, and is held at the boundary between the upper housing 11 and the lower housing 12. This holding determines the position of the flow path member 6 inside the housing 10.

The length of the flow path member 6 in the vertical direction is determined so that it extends from a position adjacent to the inside of the inlet 14 to a position close to the inner surface (lower surface) of the top wall 11c of the upper housing 11. In addition, an inlet surface 6b is formed at the lower end of the flow path member 6, which guides the anode off-gas supplied from the inlet 14 into the flow path space 6a (flow path V).

The upper end of this flow path member 6 forms an upper end opening 6c that opens upward, and a guide portion 6d that guides the anode off-gas from this upper end opening 6c to the separation blades 17 of the gas-liquid separation section As.

In particular, in this gas-liquid separator A, the gas flow conversion section Au is composed of a horizontal guide surface 11d formed on the inner surface (lower surface) of the upper wall 11c of the upper housing 11 to guide the anode off-gas discharged upward from the upper end opening 6c of the flow path member 6 in a horizontal direction, and a horizontal guide section 6d at the upper end of the flow path member 6 that guides the anode off-gas to the gas-liquid separation section As (see Figure 2).

With this configuration, the anode off-gas supplied to the inlet 14 is sent upward (vertically upward) along the flow path space 6a from the lower inlet surface 6b in the flow path V of the flow path member 6 inside the housing 10, and is then sent from the upper end of the flow path member 6 toward the gas-liquid separation unit As by the gas flow conversion unit Au.

In addition, in the gas flow conversion unit Au, the anode off-gas sent upward from the upper end opening 6c of the flow path member 6 is sent horizontally by the guide portion 6d at the upper end of the flow path member 6 in a direction toward one of the separation blades 17 of the gas-liquid separation unit As (the direction indicated by the arrow in Figure 3).

The direction in which the anode off-gas is sent is the direction that creates a swirl flow in the separation space of the gas-liquid separation section As, and the multiple separation blades 17 are arranged in an orientation that extends vertically in the annular region C. Therefore, the anode off-gas swirls as a swirl flow by sequentially coming into contact with the multiple separation blades 17 so that it rotates clockwise when viewed from the direction shown in Figure 3. As this swirl continues, the anode off-gas moves downward, separating the water from it. The separated water is stored in the water storage section At, and the anode off-gas from which the water has been separated passes below the lower end of the partition wall 16 before being discharged from the outlet 15.

[Effects of the embodiment]
The outer surface of the end plate 2 is provided with pipes for supplying and discharging cathode gas (air) in addition to the inlet passage 3 and outlet passage 4 described above for supplying and discharging anode off-gas, and is also provided with valves for controlling the flow of these gases and supports a humidifier for humidifying the cathode gas, etc., so there are limitations on the arrangement of the gas-liquid separator A.

From the perspective of shortening the length of piping and protecting the gas-liquid separator A, it is effective and desirable to position the gas-liquid separator A inside the outer edge of the end plate 2 when viewed in a direction perpendicular to the plate surface of the end plate 2.

Taking these issues into consideration, it may be necessary to design the inlet 14 so that it is positioned lower than the gas-liquid separation section As within the housing 10. The configuration of the above embodiment makes it possible to effectively separate the water contained in the anode off-gas, even when the inlet 14 is positioned lower than the gas-liquid separation section As.

In particular, in the gas-liquid separator A shown in the embodiment, the flow path member 6 is provided in the internal space of the housing 10 via the holder 7. This allows the flow path member 6 to be positioned in the appropriate position and orientation without welding or bonding the flow path member 6 or holder 7 to the housing 10, allowing the anode off-gas introduced from the inlet 14 to be sent upward, and the gas flow conversion section Au converts the flow to a horizontal direction and supplies it to the gas-liquid separation section As.

Furthermore, because the gas flow conversion unit Au is composed of a guide surface 11d formed on the inner surface of the upper wall 11c of the housing 10 and a guide portion 6d formed at the upper end of the flow path member 6, there is no need to use a special component for the gas flow conversion unit Au. The anode off-gas is accurately sent horizontally from the gas flow conversion unit Au configured in this way toward one of the multiple separation blades 17, creating a swirl flow and achieving good water separation.

[Another embodiment]
The present invention may be configured as follows in addition to the above-described embodiment (common numbers and symbols are used to designate components having the same functions as those in the embodiment).

(a) As shown in Figures 6 and 7, a gas-liquid separation unit As is disposed inside the upper housing 11 that constitutes the housing 10, and an inlet 14 is formed in a vertically upward orientation relative to the upper wall 11c of the upper housing 11. A flow path V is provided that communicates with the inlet 14, passes through the upper wall 11c in a vertical orientation, and sends anode off-gas (an example of a water-containing gas) from above to below. A gas flow conversion unit Au is also provided inside the upper housing 11, converting the anode off-gas flowing through the flow path V into a horizontal direction.

In this alternative embodiment (a), as shown in Figures 6 to 9, a circular sleeve 11s that protrudes downward is formed on the underside of the top wall 11c of the upper housing 11, and a gas-liquid separation section As is provided in the separation space inside a cylindrical body 21 that fits into this sleeve 11s. The cylindrical body 21 also has a flat partition wall 16 oriented along the vertical direction, multiple separation blades 17, and an inclined surface 21a that functions as a gas flow conversion section Au.

In other words, a separation space is formed between the partition wall 16 of the cylindrical body 21 and the outer wall of the cylindrical body 21, and multiple separation blades 17 are arranged inside this separation space. The inclined surface 21a is formed in an inclined position with respect to the flow path V so that the anode off-gas supplied to the inlet 14 is supplied horizontally by the gas flow conversion unit Au toward the separation blades 17.

In this alternative embodiment (a), as shown in Figure 8, multiple separation vanes 17 are arranged in an annular region C that is a plate extending vertically and is annular in plan view. An inclined surface 21a serving as a gas flow conversion section Au is formed at a position included in the annular region in plan view. As a result, the anode off-gas that flows vertically through the flow path V from the inlet 14 and is supplied to the cylindrical body 21 is guided horizontally by contacting the inclined surface 21a, and becomes a swirl flow by sequentially contacting the multiple separation vanes 17. The flow moves downward as it swirls, enabling efficient water separation.

In addition, in this alternative embodiment (a), the water storage section At formed inside the lower housing 12 may be provided with a filter 18, as in the embodiment.

(b) As shown in Figures 10 to 12, a gas-liquid separation unit As is disposed inside the upper housing 11 that constitutes the housing 10, as in the previously described alternative embodiment (a). An inlet 14 is formed in a vertically upward orientation relative to the upper wall 11c of the upper housing 11. A flow path V is formed that communicates with the inlet 14 and passes through the upper wall 11c in a vertical orientation to send anode off-gas (an example of a water-containing gas) from above to below. The upper housing 11 is also provided with a gas flow conversion unit Au that converts the anode off-gas flowing through this flow path V to a horizontal direction.

In this alternative embodiment (b), a separation space is formed by a partition wall 16 extending downward from the underside of the upper wall 11c of the upper housing 11 and the inner wall of the upper housing 11, and in this separation space, multiple plate-shaped separation blades 17 extending downward from the underside of the upper wall 11c are formed in annular region C.

A fitting cylindrical portion 11e that protrudes downward and is coaxial with the flow path V is formed on the underside of the upper wall 11c of the upper housing 11. A guide member 25 that fits into this fitting cylindrical portion 11e is provided, and this guide member 25 is provided with a gas flow conversion portion Au. In other words, the guide member 25 includes an inlet cylindrical portion 25a that fits into the fitting cylindrical portion 11e, an exhaust opening 25b that is oriented perpendicular to the flow path V, and a guide surface 25c (an example of an inclined surface) that is oriented inclined with respect to the flow path V so as to guide the anode off-gas supplied to the inlet cylindrical portion 25a to the exhaust opening 25b. This guide surface 25c constitutes the gas flow conversion portion Au.

As a result, a guide member 25 is attached to the underside of the upper wall 11c of the upper housing 11, and anode off-gas is introduced from the inlet 14 into the flow path V from top to bottom. This anode off-gas comes into contact with the guide surface 25c inside the guide member 25, changing its flow direction to horizontal. As it comes into contact with multiple separation blades 17 in succession, it becomes a swirl flow, which moves downward as it swirls, enabling good water separation.

As a variation of this alternative embodiment (b), it is also possible to construct the gas flow conversion unit Au by not forming a guide surface 25c inside, but instead using a guide member 25 that is a curved pipe that sends the anode off-gas supplied to the inlet tube portion 25a out through the discharge opening 25b.

(c) A cylindrical member can also be used as the flow path member 6 shown in the embodiment. Furthermore, in a configuration using a cylindrical member for the flow path member 6 in this manner, by bending the upper end of the cylindrical member, it is possible to configure the gas flow conversion unit Au so that the anode off-gas is supplied to the gas-liquid separation unit As from a horizontal direction. It is also conceivable to configure the gas flow conversion unit Au by forming a guide surface on the inner surface of the upper housing 11 that is inclined with respect to the central axis of the housing 10.

(d) Instead of using a holder 7 to hold the flow path member 6 (including the cylindrical member described in alternative embodiment (c)) inside the housing 10 as shown in the embodiment, it is also possible to employ a configuration in which, for example, the upper end of the flow path member 6 is fitted into the inner surface of the upper housing 11, or the lower end of the flow path member 6 is fitted into the inner surface of the lower housing 12.

The present invention can be used in gas-liquid separators.

6 Flow path member 6d Guide portion 7 Holder 10 Housing 11c Upper wall 11d Guide surface 14 Inlet 17 Separation blade 21a Inclined surface 25c Guide surface (inclined surface)
As: Gas-liquid separation section Au: Gas flow conversion section C: Annular region V: Flow path

Claims (2)

Housing and
an inlet formed in the housing;
a flow path that communicates with the inlet and allows the water-containing gas supplied from the inlet to flow in a vertical direction;
a gas flow conversion unit that converts the flow of the water-containing gas flowing through the flow path from a vertical direction to a horizontal direction;
a gas-liquid separation unit that separates water from the water-containing gas by sequentially bringing the water-containing gas supplied from the gas flow conversion unit into the housing into contact with a plurality of separation blades ,
the gas-liquid separation unit is disposed at a position higher than the inlet,
A gas-liquid separator in which a flow path member elongated in the vertical direction and having the flow path formed therein is disposed in the internal space of the housing, and the water-containing gas introduced into the inlet is sent vertically upward through the flow path, and the gas flow conversion unit is configured to have a horizontal guide surface formed on the inner surface of the upper wall of the housing so as to cause the water-containing gas sent further vertically upward from the upper end of the flow path member to flow horizontally, and a guide unit at the upper end of the flow path member that guides the water-containing gas in a direction toward the separation blades of the gas-liquid separation unit . 2. The gas-liquid separator according to claim 1 , wherein the flow path member is integrally formed with a holder that is held on the inner surface of the housing.