JP7332991B2 - Electrochemical hydrogen compressor - Google Patents

Description

The present invention has an electrolyte membrane and electrodes (anode and cathode), and hydrogen supplied to the anode is ionized by passing an electric current, moves to the cathode, and outputs hydrogen at the cathode to obtain electricity at high pressure. It relates to a chemical hydrogen compressor (EHC). The present invention also relates to an electrochemical hydrogen compressor using a solid polymer membrane (PEM: Polymer Electrolyte Membrane) as an electrolyte membrane.

Such an electrochemical hydrogen compressor has been conventionally proposed (see Patent Document 1, for example).
In the conventional electrochemical hydrogen compressor 100 (see Patent Document 1) shown in FIG. In the bubbler 52, the temperature of the liquid storage section 52A is adjusted by the bubbler chiller 72, and the saturated vapor of the stored liquid-phase water is vaporized. The hydrogen and water vapor introduced from the hydrogen pipe 58 move to the gas storage portion 52B and are supplied as humidified hydrogen to the anode 54A of the hydrogen compressor 54 (cell) via the hydrogen introduction passage 60 .
At the anode 54A, hydrogen is ionized by applying electric power, the ionized hydrogen permeates the electrolyte membrane 54B, moves to the cathode 54C side, and returns to hydrogen at the cathode 54C. Compressed hydrogen containing water (exhaust gas from the cathode) is sent from the cathode 54</b>C to the water separator 56 via the cathode discharge passage 66 .
Here, the temperature of the cell 54 composed of the anode 14A, the electrolyte membrane 54B, and the cathode 54C is controlled by a cell chiller 74. As shown in FIG.

In the water separator 56, water is separated from the cathode exhaust gas, which is high-pressure compressed hydrogen, and the high-pressure compressed hydrogen is delivered to the compressed hydrogen output line 64, for example, to fill a fuel cell vehicle (not shown) with hydrogen. be done. On the other hand, the separated water is sent to the cathode discharge water circulation path 68, decompressed by the decompression valve V1, and supplied (returned) to the bubbler 52 as liquid-phase water. In bubbler 52, water is stored in liquid storage portion 52A, and hydrogen dissolved in water is released to gas storage portion 52B.
The anode off-gas (including water vapor and hydrogen) that has not moved from the anode 54A to the cathode 54C is supplied again to the anode 54A via the anode off-gas passage 62 and the hydrogen introduction passage 60 (off-gas circulation system).

However, in the conventional electrochemical hydrogen compressor, the cells or electrolyte membranes exposed to the low pressure side and the high pressure side are also required to satisfy the standard as a pressure vessel. It is required to satisfy the standard that it can withstand four times the pressure. Therefore, when used for filling hydrogen in a fuel cell vehicle (when high-pressure hydrogen of 80 MPa is required), it is necessary to clear the hard standard that the cell or electrolyte membrane must be four times the pressure (320 MPa can be safely operated). there were.
Further, as shown in FIG. 7, in the conventional electrochemical hydrogen compressor, the offgas circulation system (anode offgas passage 62, hydrogen introduction passage 60, pump P2, valve V2) and the cathode are provided outside the cell or stack of cells. Since the discharge water circulation path 68 is provided, it is difficult to stack or densely arrange a plurality of cells, a large space is required, and each cell, the off-gas circulation system and/or the cathode discharge water circulation system are separated. The layout was difficult to prevent interference between
Furthermore, in the conventional electrochemical hydrogen compressor, at least two high-precision chillers must be prepared for cell cooling and bubbler temperature control, and there is a problem that the manufacturing cost rises.

Japanese Patent No. 6795439

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-described problems of the prior art, and an object of the present invention is to provide an electrochemical hydrogen compressor that does not require application of standards as a pressure device to the electrolyte membrane.

The electrochemical hydrogen compressor (40) of the present invention includes a plurality of cells (1) configured by sandwiching an electrolyte membrane (1B: polymer electrolyte membrane: PEM) between an anode (1A) and a cathode (1C). a cell casing (11) containing a cell (1) of ; a water separator (2); a water separator casing (12) containing the water separator (2); a bubbler (3); Having a bubbler casing (13) that houses (3),
A cell casing (11) containing a cell (1), a water separator casing (12) containing a water separator (2), and a bubbler casing (13) containing a bubbler (3) are integrated. is bound to
A water separator (2) is provided above the cell casing (11), and the compressed hydrogen of the cathode (1C) is supplied to the inner space of the water separator (2) together with water (water vapor),
Water is stored in the internal space of the water separator (2), a cup float (25) is arranged,
A water drop pipe (26) is provided to communicate the center of the internal space of the water separator (2) and the bubbler (3), and the water drop pipe (26) passes through the water separator casing (12). and communicates with the bubbler (3).

In the present invention, the cup float (25) arranged in the internal space of the water separator (2) has a rod-shaped portion (25B), and the tip (lower end) of the rod-shaped portion (25B) has a valve body (25C). provided,
The upper end (26A) of the water descending pipe (26) is open below the internal space of the water separator (2), and the valve body (25C) provided on the cup float (25) can be seated. It preferably constitutes a seat.

In the present invention, a hydrogen gas flow path (4) having a portion formed by connecting ports and grooves in a plurality of cells (1) housed in a cell housing outer shell (11: cell casing) is provided. ,
A mixture of hydrogen and water vapor generated in the bubbler (3) is supplied to the cell (1) through the hydrogen gas flow path (4), and the anode (1A) of the cell (1) is supplied through the hydrogen gas flow path (4). ) is preferably returned to the bubbler (3).

In addition, in the present invention, a heat tube (5) connecting the bubbler (3) and the cell (1) is provided, and one end of the heat tube (5) is installed as a heat tube heat receiving part (5A) in a distributed manner (solid heat transfer ) and connected (solid connection) to each of the plurality of cells (1), and the other end of the heat tube (5) is connected to the liquid phase region (3B) of the bubbler (3) as a heat tube heat radiation part (5B). Immersion is preferred.

According to the electrochemical hydrogen compressor (40) of the present invention having the above configuration, hydrogen gas is supplied to the bubbler (3), and the hydrogen gas supplied into the bubbler (3) entrains water vapor to produce hydrogen gas. It flows through the gas channel (4) and is supplied to the anode (1A) of the cell (1). The supplied hydrogen is ionized, permeates through a solid polymer membrane (1B: PEM), which is an electrolyte membrane, and moves to the cathode (1C) side. It is then converted back to hydrogen and compressed at the cathode (1C). Compressed hydrogen is sent to a water separator (2), water is separated, and high-pressure hydrogen gas is filled in a hydrogen container (for example, a hydrogen filling tank of an FCV).
In the present invention, the cell (1) is integrally configured with the bubbler (3) and the water separator (2), and the plurality of cells (1) is a pressure vessel-like cell housing portion outer shell (11: for cell Casing), the electrolyte membrane (1B: solid polymer membrane: PEM) does not meet the criteria for a pressure vessel (quadruple pressure criteria). Therefore, for example, when used for hydrogen charging of a fuel cell vehicle (when high-pressure hydrogen of 80 MPa is required), the cell housing portion integrally configured with the bubbler casing (13) and the water separator casing (12) If the outer shell (11) satisfies the quadruple pressure standard (if it can be safely operated even at 320 MPa), the cell (1) housed in the cell housing part outer shell (11) or its electrolyte membrane (1B: A solid polymer membrane (PEM) does not need to satisfy the standard for a pressure vessel (standard for quadruple pressure: 320 MPa, for example).
Since the pressure vessel can be protected by providing a low-voltage circuit protection mechanism such as a check valve, the electrolyte membrane (1B) does not need to meet the standards for a pressure vessel. Even if the electrolyte membrane (1B) is slightly damaged, there is no need to replace the entire cell (1), and there is no need to stop the operation of the electrochemical hydrogen compressor (40) for cell replacement.

In the present invention, the mixture of hydrogen and water vapor generated in the bubbler (3) has a portion formed by connecting ports and grooves in a plurality of cells (1) housed in a cell casing (11). It is supplied to the cell (1) through the hydrogen gas flow path (4), and the off-gas generated at the anode (1A) of the cell (1) is returned to the bubbler (3) through the hydrogen gas flow path (4). With this configuration, the offgas can be circulated within the bubbler casing (13) and the cell containing portion outer shell (11) without constructing an offgas circulation system outside the cell (1) or cell stack.
Therefore, even if a plurality of cells (1) are stacked or densely arranged, there is no fear of interfering with the off-gas circulation system. It can be placed (accommodated).
Therefore, a large space is not required for arranging a plurality of cells (1), and there is no need to consider a layout for preventing interference between each cell (1) and the off-gas circulation system.

Here, as in the present invention, the cell (1) is integrally configured with the bubbler (3) and the water separator (2), and the plurality of cells (1) is a pressure vessel-like cell container outer shell The electrochemical hydrogen compressor (40) housed in (11: cell casing) has not been proposed in the past. Then, in the electrochemical hydrogen compressor (40) of the present invention, the function of separating the compressed hydrogen and water (water vapor) of the cathode (1C) and returning the separated water to the bubbler (3) for reuse. A water separator (2) having
On the other hand, in the present invention, a water separator (2) is provided above the outer shell (11) of the cell housing part, and the compressed hydrogen of the cathode (1C) is supplied to the inner space of the water separator 2 together with water (water vapor). , Water is stored in the inner space of the water separator (2), a cup float (25) is arranged, and a water drop that communicates the central part of the inner space of the water separator (2) and the bubbler (3) If a water drop pipe (26) is provided, and the water drop pipe (26) penetrates the water separator casing (12) and communicates with the bubbler (3), water will flow from the cathode 1C of the cell 1 The hydrogen that has moved to the separator 2 floats in the water inside the water separator (2) through the cup float (25), and the high-pressure hydrogen gas moves to the water remover (18).

In the present invention, the cup float (25) arranged in the internal space of the water separator (2) has a rod-shaped portion (25B), and the tip (lower end) of the rod-shaped portion (25B) has a valve body (25C). is provided, the upper end (26A) of the water descending pipe (26) is open below the inner space of the water separator (2), and the valve body (25C) provided on the cup float (25) is seated. If a valve seat that can be attached is configured, when the cup float (25) floats due to the buoyancy caused by the water in the water separator (2), the valve body (25C) provided in the cup float (25) will open as a valve. It is separated from the upper end opening (26A) of the water descending pipe (26) which is a seat. The water in the water separator 2 descends in the water descending pipe 26 and is returned to the bubbler (3) side.
On the other hand, when the amount of water in the water separator (2) decreases, the cup float (25) descends and the valve body (25C) sits on the upper end opening (26A) of the water descending pipe (26), which is the valve seat. put on and close. In that state, the water in the water separator (2) stays in the water separator (2) without descending to the bubbler (3) side.
That is, the water in the water separator (2) is returned to the bubbler (3) through the water drop pipe (26) that communicates the center of the internal space of the water separator (2) with the bubbler (3). Unlike the prior art, there is no need to form a separate water circulation system outside the cell stack. In addition, since there is no need to form a water circulation system outside the cell stack, the cells can be easily integrated and the layout can be facilitated.
Furthermore, since the cup float (25) has an opening (25D) at the bottom and the internal space is an open space, there is no pressure difference between the inside and outside of the cup float (25) even under high pressure. Therefore, even if the cup float (25) with a thin outer shell is installed in the water separator (2) under high pressure environment, it will not be crushed.

Further, in the present invention, the bubbler (3) and the cell (1) are connected by a heat tube (5), and one end of the heat tube (5) is provided with a plurality of heat tube heat receiving parts (5A) distributedly (solid heat transfer). is connected (solid connection) to each of the plurality of cells (1), and the other end of the heat tube (5) is immersed in the liquid phase region (3B) of the bubbler (3) as a heat tube heat radiation part (5B). Then, the heat amount in the cell (1) is transferred to the heat tube heat receiving part (5A) which is installed in a plurality of distributed (solid heat transfer), and the heat amount is transferred to the heat tube through the heat receiving part (5A) of the heat tube (5). It is transmitted to the pure water in (5) to vaporize the pure water into steam, and the steam moves in the heat tube (5) and is administered to the liquid phase region (3B) of the bubbler (3), The cell (1) can be self-cooled depending on the operating conditions. Therefore, cell (1) does not need to be equipped with a high quality chiller.
Further, in the present invention, the bubbler casing (13) is provided with fins (6), and the blower (7) blows hot air or cold air toward the fins (6), thereby enabling temperature adjustment of the bubbler (3). . Alternatively, the temperature of the bubbler (3) can be adjusted by providing a heater mechanism (8) for heating the bubbler (3) and/or a cooler mechanism for cooling the bubbler (3). Furthermore, the temperature of the bubbler (3) can be adjusted by adjusting the temperature of the hydrogen supplied to the bubbler with the temperature controller (9). Therefore, in the present invention, it is not necessary to provide a chiller, which is a high-quality device, for adjusting the temperature of the bubbler (3).

1 is an explanatory diagram showing an embodiment of an electrochemical hydrogen compressor of the present invention; FIG. It is an explanatory view showing a water separation device in an embodiment. It is an explanatory view showing a bubbler in an embodiment. FIG. 4 is an explanatory view schematically showing cooling of cells by a heat tube; FIG. 4 is an explanatory diagram showing a mechanism for heating the bubbler at startup; FIG. 2 is an explanatory view similar to FIG. 1 and specifically shows a mode in which cells are stacked in the embodiment. FIG. 2 is an explanatory diagram showing a conventional electrochemical hydrogen compressor; It is explanatory drawing which shows the modification of a cup float.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG.
In FIG. 1, the electrochemical hydrogen compressor 40 according to the illustrated embodiment includes a plurality of cells 1 (see FIG. 2: in FIG. 1, cells are indicated only by lead lines and reference numeral 1) (or cell stacks), It has a cell casing 11 containing a cell 1, a water separator 2, a water separator casing 12 containing the water separator 2, a bubbler 3, and a bubbler casing 13 containing the bubbler 3. .
The cell casing 11 that houses the cell 1, the water separator casing 12 that houses the water separator 2, and the bubbler casing 13 that houses the bubbler 3 are, for example, bolts 14 (in FIG. shown).

For example, about 40 cells 1 are accommodated in the cell casing 11 . Although not shown in FIG. 1, the cell 1 has an anode 1A, which is an electrode, a cathode 1C, and a polymer electrolyte membrane 1B (PEM), which is an electrolyte membrane. are sandwiched to form a cell 1.
Each cell 1 is configured to have a function of pressurizing hydrogen gas up to about 80 MPa. In the illustrated embodiment, the high pressure of 80 MPa, for example, is not obtained by connecting a plurality of cells in series and pressurizing each cell by several MPa. are laminated (for example, 40 pieces).

As described above with reference to FIG. 7, in the prior art, the cell or electrolyte membrane exposed to the low pressure side and the high pressure side is required to satisfy the hard criteria as a pressure vessel. For example, the electrolyte membrane had to clear the standard of four times the pressure (for example, the standard that an electrochemical chamber hydrogen compressor used in a filling machine filled with 80 MPa high-pressure gas can operate safely even at 320 MPa).
In the illustrated embodiment, the cells 1 are configured integrally with the bubbler 3 and the water separator 2, and the plurality of cells 1 are housed in a pressure container-like cell casing 11 (cell housing portion outer shell). Therefore, the standard (quadruple pressure standard) as a pressure vessel is not applied to the electrolyte membrane 1B (proton polymer membrane: PEM) itself. Therefore, if the cell casing 11 satisfies the quadruple pressure standard (if the cell casing 11 can be safely operated even at 320 MPa), for example, when it is used for hydrogen filling of a fuel cell vehicle (when high-pressure hydrogen of 80 MPa is required), ), the cell 1 or the solid polymer membrane 1B (PEM) accommodated in the cell casing 11 is not required to satisfy the standard (quadruple pressure standard) as a pressure vessel. Also, since it can be protected by providing a low-pressure circuit protection mechanism (not shown) such as a check valve, the solid polymer membrane 1B (PEM) does not require the standard as a pressure vessel.
Therefore, the solid polymer membrane 1B (PEM) is required only to be airtight, and does not need to have a pressure resistance that can withstand a standard of four times the pressure.

In the illustrated embodiment, the cell 1 or the solid polymer membrane 1B (PEM) does not need to satisfy a strict standard such as quadruple pressure, so the bubbler 3 (the bubbler casing 13 containing the bubbler), the water separator 2 ( If the cell casing 11 integrated with the water separator casing 12) that accommodates the solid polymer membrane 1B (PEM) is slightly damaged, if it satisfies the criteria as a pressure vessel If the cell 1 as a whole exhibits the function of compressing hydrogen, a check valve (not shown) is arranged on the anode 1A side without replacing the damaged cell 1, and hydrogen and water are discharged. You can configure it so that it can continue to operate.

In FIG. 1, the hydrogen supplied from the hydrogen supply source via the pipe 15 and the temperature control device 9 is supplied to the bubble generator 16 (see FIG. 3: not shown in FIG. 1) in the bubbler 3. . A pipe 28 from a water supply source with a water circulation pump 33 interposed joins the pipe 15 .
Hydrogen supplied from the hydrogen supply source through the flow path 15 floats as a large amount of bubbles in the water (pure water) stored in the liquid phase region 3B of the bubbler 3, entraining water vapor. do. The mixed gas of hydrogen and water vapor flows from the vapor phase region 3A of the bubbler 3 through the hydrogen gas channel 4 (hydrogen gas channel 4 on the left side in FIG. 1) and is supplied to the anode 1A (FIG. 2) of the cell 1. be. Reference numeral 29 indicates a gas pump.
Although not clearly shown, a hydrogen gas flow path 4 is formed by connecting ports and grooves in a plurality of cells 1 accommodated in the cell casing 11 .
Hydrogen supplied to the anode 1A of the cell 1 is ionized, permeates the electrolyte membrane 1B (proton polymer membrane: PEM) (Fig. 2), moves to the cathode 1C (Fig. 2) side, returns to hydrogen, and is compressed. It is sent to the water separator 2 in the state where it is separated from the water.
On the other hand, the hydrogen that has not moved to the cathode 1C side flows through the hydrogen gas channel 4 (the hydrogen gas channel 4 on the right side in FIG. 1) as off gas and is returned to the bubbler 3 .
In FIG. 1, the flow path of the hydrogen gas flow path 4 toward the anode 1A side and the flow path returning from the anode 1A side are symbolically shown as a single thick pipe. The hydrogen gas flow path 4 directed to the anode 1A side and the hydrogen gas flow path 4 returning from the anode 1A side are branched and merged as many as necessary according to the number of the cells 1. FIG.

In FIG. 1, the hydrogen that has moved to the cathode 1C (FIG. 2) side flows through the water separator 2, which will be described later with reference to FIG. Moisture is removed by Reference numeral 19 denotes a gas pump for sending high-pressure hydrogen in the water separator 2 to the water remover 18 .
Hydrogen from which moisture has been removed is filled into a high-pressure hydrogen container (for example, a hydrogen container for a fuel cell vehicle) via, for example, a hydrogen filling device (dispenser) (not shown).
The moisture remover 18 is constructed by, for example, filling a cartridge with an adsorbent (such as zeolite). The adsorbent is periodically replaced or regenerated directly to the vacuum pump 20 as shown in FIG.
In FIG. 1, the moisture remover 18 communicates through a pipe 21 with an adsorbent regeneration pump 20 (vacuum pump: not shown). After the adsorbent of the water removing device 18 has sufficiently adsorbed water, the vacuum pump 20 is operated to vacuum dry the adsorbent of the water removing device 18 through the pipe 21 to remove the water from the adsorbent. to play. After regenerating the adsorbent, the on-off valve 22 is opened, the pipe 21 is communicated with the outside air through the pipe 23, and the vacuum state is released.

As described above, the cell casing 11, the water separator casing 12, and the bubbler casing 13 are integrally connected by bolts 14 in the illustrated embodiment.
The water separator 2 and the bubbler 3 are communicated with each other by a water descending pipe 26, and the cell 1 and the bubbler 3 are connected by a hydrogen gas flow path 4, a heat tube 5 and the like.
The water separator 2 will be described later with reference to FIG. Also, the bubbler 3 will be described later with reference to FIG.

Next, the water separator 2 will be described with reference to FIG. In addition, illustration of the cell casing 11 is omitted in FIG.
In FIG. 2, water (indicated by hatching) is stored in the internal space of the water separator 2, and the cup float 25 is floating. The cup float 25 has an outer edge 25A protruding downward in FIG. 2, and has a rod-like portion 25B extending downward in FIG. A valve body 25C is formed at the tip (lower end) of the bar-shaped portion 25B. The cup float 25 has an open shape with an opening 25D below, and the internal space of the cup float 25 is an open space.
The center of the internal space of the water separator 2 and the bubbler 3 (see FIGS. 1 and 3; not shown in FIG. 2) are communicated by a water drop pipe 26 . The water descending pipe 26 penetrates the water separator 2 and the bottom of the water separator casing 12 and extends downward (on the side of the bubbler 3 not shown in FIG. 2) to communicate with the bubbler 3 . The upper end portion 26A of the water descending pipe 26 is open below the internal space of the water separator 2, and constitutes a valve seat on which the valve body 25C formed in the cup float 25 can be seated. The valve body 25C of the cup float 25 and the upper end opening 26A of the water descending pipe 26 constitute a valve mechanism (needle valve) having a function of opening and closing the upper end opening 26A.

As described with reference to FIG. 1, the cells 1 are arranged in the area below the water separator 2 in FIG. The hydrogen supplied to the anode 1A of the cell 1 and moved to the cathode 1C side through the electrolyte membrane 1B is transferred from the cell 1 side to the inner space of the water separator 2 along with water (water vapor) through the path 27 as high-pressure compressed hydrogen. supplied. Water is necessary for the electrolyte membrane 1B such as a polymer electrolyte membrane (PEM). Water permeates through the electrolyte membrane 1B and accumulates on the cathode 1C side, so water is accumulated on the water separator 2 side.
The cup float 25 is configured so that all of the hydrogen that has moved from the cathode 1C of the cell 1 to the water separator 2 floats in the water and moves into the internal space of the cup float 25, and the cell 1 operates. As long as the hydrogen moves to the cathode 1C through the cup float 25, the hydrogen moves to the inner space of the cup float 25.

In FIG. 2, the reason why the cup float 25 having the opening 25D at the bottom and the inner space forming an open space is used is that the float having no opening and having a closed inner space can operate under high pressure ( For example, it is because it cannot withstand 80 MPa). In a normal float whose internal space is a closed space, since the internal space is at normal pressure, the float collapses due to the pressure difference with the internal space in a high-pressure environment. On the other hand, if the outer shell of the float is made thick so as not to collapse under the pressure difference, the float will not float on the water (cathode water) in the water separator 2 .
On the other hand, the cup float 25 in the illustrated embodiment has an opening 25D at the bottom and the internal space is an open space. 2, the pressure differential mentioned above does not exist. Therefore, even if the outer shell of the cup float 25 is thin, the cup float 25 will not be crushed.

When the cup float 25 is floated by the water in the water separation device 2, the valve body 25C provided on the cup float 25 is moved to the upper end opening 26A of the water descending pipe 26, which is the valve seat. Open the valve away from The water in the water separator 2 flows down through the water descending pipe 26 from the upper end opening 26A and is returned to the bubbler 3 side.
When the amount of water in the water separator 2 decreases, the cup float 25 descends, the valve body 25C sits on the upper end opening 26A of the water lowering pipe 26, which is the valve seat, and the upper end opening 26A is closed. . Since the upper end opening 26A of the water descending pipe 26 is closed, the water in the water separator 2 stays in the water separator 2 without descending to the bubbler side.

In FIG. 2, the high-pressure hydrogen gas that floats in the water of the water separator 2 from the cell 1 side, reaches the inner space of the cup float 25, and accumulates there, flows into the cup float 25 as indicated by an arrow H2 in FIG. move outside the Water is separated when the high-pressure hydrogen floats in the water of the water separator 2 from the cell 1 side and moves through the path leading to the inner space of the cup float 25 and the path indicated by the arrow H2. The high-pressure hydrogen gas that has moved to the outside of the cup float 25 flows through the pipe 17 via the gas pump 19 and moves to the water removing device 18 .
Here, even if the high-pressure hydrogen gas that has moved to the outside of the cup float 25 via the water in the cup float 25 entrains moisture, the higher the pressure, the drier the hydrogen gas tends to be. Even if it is carried along, it will be removed by the moisture adsorption removal device 18, so there is no problem.

The position of the cup float 25 is included so that all of the hydrogen that has moved from the cathode 1C of the cell 1 to the water separator 2 moves into the inner space of the cup float 25 . Unless the entire amount of hydrogen that has moved to the water separator 2 enters the internal space of the cup float 25, hydrogen will flow into the cup float 25 after the cup float 25 descends (after the valve body 25C is closed). If hydrogen does not enter the cup float 25, the cup float 25 will not float, and the upper end opening 26A of the water descending pipe 26 will not be opened.
Moreover, if the cup float 25 is left for a long period of time, water will replace the inside of the cup float 25 and the cup float 25 will sink. However, in the illustrated embodiment, since hydrogen from the cathode 1C continues to enter the interior space of the cup float 25, hydrogen is always supplied to the interior space, and the cup float 25 can be prevented from sinking.
As described above, since the entire amount of hydrogen that has moved to the water separator 2 side enters the inner space of the cup float 25, if the water in the water separator 2 increases, the cup float 25 will surely move. Since the state of floating on the water is maintained, a situation in which the upper end opening 26A of the water descending pipe 26 is not opened can be prevented.

Here, pure water stored in the bubbler 3 shown in FIG. However, as described above, if the cup float 25 can be kept floating on the water, the water in the water separator 2 surely flows through the water descending pipe 26 and into the bubbler 3 . This keeps water circulating between the bubbler 3 , the cell 1 and the water separator 2 .
Therefore, there is no need to form a separate water circulation system outside the cell 1 or the cell stack as in the prior art, and the cells can be easily integrated and the layout can be simplified.
In the illustrated embodiment, water separates from the hydrogen gas in the water separator 2 and returns to the bubbler 3 , continuously circulating between the bubbler 3 , the cell 1 and the water separator 2 . However, as described above with reference to FIG. is not returned to bubbler 3. When it is necessary to replenish the amount of water removed by the water removing device 18, the water circulation pump 33 is driven in FIG. water supply. Such water supply can also be performed periodically.

In FIG. 2, when there is no more water on the cathode side, the electrolyte membrane 1B (solid polymer membrane: PEM, FIG. 2) dries and the resistance in the PEM increases. And as the resistance of the PEM increases, the efficiency of hydrogen transfer in the PEM decreases. Therefore, it is preferable to always keep water on the cathode side.
In the illustrated embodiment, the hydrogen moved to the water separation device 2 is arranged so as to always float toward the inner space of the cup float 25, and the valve body 25C provided in the cup float 25 serves as a water drop pipe. Water remains in the water separation device 2 even if the valve seat formed by the upper end opening 26A of the valve 26 is seated. Although not clearly shown, as long as water remains in the water separator 2, water is always retained on the cathode side.

Next, referring to FIG. 3, the bubbler 3 will be described.
In FIG. 3, the bubbler 3 is configured as a water pan or a drain pan, the upper region is a gas phase region 3A (region where a mixture of hydrogen and steam is stored), and the lower region is a liquid phase region 3B (water is stored).
A bubble generator 16 (vaporizer) is arranged in the liquid phase region 3B of the bubbler 3, and hydrogen is supplied to the bubble generator 16 through a pipe 15 in which a temperature control device 9 is interposed.
The air bubble generator 16 may be of any type such as a stone type, a mesh type, or a natural evaporation type, and other types of air bubble generators may also be used.

As described above with reference to FIG. 2, a water drop pipe 26 extends from the water separator 2 to the bubbler 3 to return the water in the water separator 2 (FIGS. 1 and 2) to the bubbler 3. It is
In FIG. 3, when the hydrogen temperature-controlled by the temperature control device 9 is supplied to the bubble generator 16, a large amount of hydrogen bubbles are jetted out into the water (pure water) stored in the bubbler 3. Water vapor moves together with hydrogen to the vapor phase region 3A of the bubbler 3 (arrow AB). Then, the mixture of hydrogen and water vapor is supplied to the anode 1A (FIG. 2) of the cell 1 via the gas pump 29 through the hydrogen gas channel 4 (hydrogen gas channel 4 on the left side in FIG. 3) ( Arrow A1). As described above, the hydrogen gas flow path 4 is configured by communicating the ports and grooves in the plurality of cells 1 .
The off-gas in the anode 1A contains hydrogen gas and water vapor that have not moved to the cathode 1C side, and the off-gas is transferred to the gas phase region of the bubbler 3 by the hydrogen gas flow path 4 (the hydrogen gas flow path 4 on the right side in FIG. 3). 3A (returns: arrow A2).
Therefore, the off-gas can be circulated in the bubbler casing 13 and the cell casing 11 (see FIG. 1) without forming an off-gas circulation system outside the cell 1 or the cell stack, and a plurality of cells 1 can be stacked. Alternatively, even if they are densely arranged, interference with the off-gas circulation system is prevented. In this case, a large space is not required for arranging the plurality of cells 1, and there is no need to consider a layout for preventing interference between each cell 1 and the off-gas circulation system.

In the conventional technology, the cells are cooled by a chiller, but in the illustrated embodiment, the cells 1 are cooled by heat tubes 5 arranged from the bubbler 3 to the cells 1 (a plurality of cell groups). Cooling of the cells by the heat tube 5 will be described with reference to FIG.
As schematically shown in FIG. 4, the heat tube 5 connects the bubbler 3 and the cell 1 (in the actual machine, each of the plurality of cells 1 in the casing 11). One end of the heat tube 5 is dispersedly installed (solid heat transfer) as a heat tube heat receiving portion 5A and connected (solid connection) to each of the plurality of cells 1, and the other end of the heat tube 5 is a heat tube heat radiating portion. It is immersed in the liquid phase region 3B of the bubbler 3 as 5B. For simplicity of illustration only a single cell 1 is shown in FIG.
The heat tube 5 is made of copper and has a double tube structure of an inner tube 5C and an outer tube 5D. The inner tube 5C and the outer tube 5D are in communication at the heat tube heat receiving portion 5A and the heat tube heat radiating portion 5B. . The double tube of the heat tube 5 is filled with pure water and has a function of transferring heat at high speed. By utilizing the high heat transfer characteristics of the heat tube 5, heat generated in the cell 1 can be discharged into the bubbler 3 when current is passed through the electrolyte membrane 1B (PEM, FIG. 2).

When the cells 1 are cooled by the heat tubes 5, the amount of heat generated in the cells 1 is transferred to the heat receiving portions 5A of the heat tubes 5, which are installed in multiple locations (solid heat transfer). is transmitted to the pure water in the heat tube 5 via the heat tube 5, and the pure water absorbs heat of vaporization and immediately vaporizes. The vaporized water vapor flows through the inner tube 5C of the heat tube 5 at high speed (arrow F1), reaches the heat radiation portion 5B immersed in the liquid phase region 3B of the bubbler 3 in the heat tube 5, and is Vaporization heat is applied to the pure water stored in the bubbler 3 .
When the amount of heat is applied to the pure water in the bubbler 3, the water vapor that has flowed through the inner tube 5C of the heat tube 5 is condensed into pure water, and the pure water flows through the outer tube 5D of the heat tube 5 again into the heat tube 5. It flows toward the heat-receiving portion 5A (arrow F2), and is vaporized again by the heat of the cell 1 at the heat-receiving portion 5A. The cell 1 is continuously cooled by circulating pure water or water vapor in the inner tube 5C and the outer tube 5D of the heat tube 5 .

Here, the heat transfer by the heat tube 5 between the cell 1 and the pure water in the bubbler 3 depends on the temperature difference between the (heat receiving) temperature in the cell 1 and the pure water (radiating) temperature in the bubbler 3 .
The electrolyte membrane 1B (polymer electrolyte membrane: PEM) or cell 1 has an optimum operating temperature, and in order to properly operate the electrochemical hydrogen compressor 40, the electrolyte membrane 1B (polymer electrolyte membrane: PEM) or cell 1 the temperature should be adjusted. Also, in order to prevent dew condensation within the cell 1, the temperature of the cell 1 must be set higher than the pure water within the bubbler 3 by a predetermined temperature (for example, about 5.degree. C.). Since there is this temperature difference to be set, heat can be transferred from the cell 1 to the bubbler 3 via the heat tube 5 .
Here, in the system in which the bubbler 3 and the cell 1 are connected by the heat tube 5, for example, by controlling the temperature of the hydrogen supplied to the bubbler 3, or by heating and cooling the bubbler 3 (the bubbler 3 and the cell 1 are connected by the heat tube 5), the temperature of the bubbler 3 and the temperature of the cell 1 can be controlled appropriately.
That is, the cell 1 and the bubbler 3 are heat-exchanged by the heat tube 5, and the cell 1, the bubbler 3, and the heat tube 5 work in a chain reaction, so that temperature control can be easily and accurately performed. Therefore, the cell 1 can be stably cooled without requiring a special control device. And there is no need to equip the cell 1 with a high quality chiller.

Referring to FIG. 6, the structure of the electrochemical compressor 40 described with reference to FIGS. 1-5, but equipment not explicitly shown in FIGS. 1-5 will be described.
In FIG. 6, four cells are shown inside the casing, and the electrolyte membranes of the respective cells are indicated by reference numerals 1B-1 to 1B-4. In a real machine, the number of cells is much higher than four.
In FIG. 6, below each of the electrolyte membranes 1B-1 to 1B-4 is an anode (1A-1 to 1A-4: symbols are not shown in FIG. 6 to avoid complication of the illustration), and the electrolyte membrane Above each of 1B-1 to 1B-4 is a cathode (1C-1 to 1C-4: symbols are not shown in FIG. 6 to avoid complication of illustration). The four cells are partitioned by an insulator IS, which is indicated by a thick dotted line in FIG.
Power is supplied to the four cells from a power supply PS via conductors generally designated EC.

In FIG. 6, the hydrogen gas humidified by the hydrogen bubbles BH of the bubble generator 16 of the bubbler 3 is sucked by the circulation pump PB as indicated by the arrow ABH, and enters the hydrogen gas flow path 4I on the left side of FIG. Dispensed. Hydrogen flowing through the hydrogen gas flow path 4I is supplied to the anodes 1A-1 to 1A-4 (not shown) of each cell together with water vapor. Then, they become hydrogen ions, permeate electrolyte membranes 1B-1 to 1B-4, and return to hydrogen at cathodes 1C-1 to 1C-4 (not shown). The high-pressure hydrogen from the cathodes 1C-1 to 1C-4 moves to the water separator 2 via hydrogen paths 42, 42 (only two paths are shown in FIG. 6, but more paths are provided in the actual machine). In FIG. 6, the high pressure hydrogen traveling to the water separator 2 is represented as an upward arrow in the hydrogen path 42 .
A hydrogen gas flow path 4I that supplies hydrogen and water vapor to the anodes 1A-1 to 1A-4 of each cell passes through a hydrogen gas flow path 4H extending in the horizontal direction (horizontal direction in FIG. 6). After reaching the right hydrogen gas channel 4O, the offgas from the anodes 1A-1 to 1A-4 returns to the bubbler 3 via the hydrogen gas channels 4H and 4O.

The high-pressure hydrogen gas that has moved from the cathodes 1C-1 to 1C-4 to the water separator 2 via the hydrogen path 42 moves inside the water separator 2 as bubbles H ₂ and arrows AH ₂ and flows through the pipe 17. , is sent to the moisture remover 18 (FIG. 1). The water separated from the high-pressure hydrogen gas in the water separator 2 flows through the water descending pipe 26 and is returned to the bubbler 3 .
The bubbler 3 is provided with a heat tube 5, and the heat tube 5 is as described above with reference to FIGS.

In FIG. 6, a conditioning port CP is formed in the water separation casing 12, and oxygen is supplied to the electrolyte membranes 1B-1 to 1B-4 through the conditioning port CP during maintenance of the electrochemical compressor. is configured to In FIG. 6, it seems that the conditioning port CP communicates with the hydrogen path 42, but the conditioning port CP does not communicate with the hydrogen path 42, and the cathodes 1C1 to 1C4 of each cell are connected via flow paths (not shown). communicates with
Before the operation of the electrochemical compressor, oxygen is supplied from the conditioning port CP and hydrogen is supplied from the bubbler 3, so that 2H ₂ +O ₂ →2H ₂ O+ A reaction called electricity occurs, which improves the state of the electrolyte membranes 1B-1 to 1B-4.

In the illustrated embodiment, in order to heat the cell 1 at the time of start-up, for example, as shown in FIG. At times, the blower 7 blows hot air onto the fins 6 (arrow H). As a result, the bubbler 3 is heated, the water in the bubbler 3 is also heated, and the heated water heats the cell 1 to a suitable temperature through the heat tube 5 .
On the other hand, when cold air is blown to the fins 6 of the bubbler casing 13 by the blower 7, the temperature of the bubbler 3 is lowered, and the temperature of the water in the bubbler 3 is also lowered. 1 to a suitable temperature.

Further, as a mechanism for heating the bubbler 3, as shown in FIG. You can
On the other hand, as a mechanism for cooling the bubbler 3, a cooler (not shown) for cooling the bubbler can be used.
Mechanisms other than those shown may be selected to heat or cool the bubbler 3 .
Furthermore, the temperature of the water in the bubbler 3 is adjusted by adjusting the temperature of the hydrogen supplied to the bubbler 3 through the pipe 15 (FIGS. 1 and 3) with the temperature control device 9 (FIGS. 1 and 3). to adjust the cell 1 to a suitable temperature.
Since such a configuration can be adopted, in the illustrated embodiment, there is no need to provide a chiller, which is a high-quality device, for adjusting the temperature of the bubbler 3 .

Although not clearly shown in FIG. 7, in the prior art, a tube is used to connect the bubbler and the cell. Therefore, if the tube is not specially covered and insulated, dew condensation will occur, which will adversely affect the cell. And when connecting the bubbler and the cell with a tube that is not insulated with a special coating, the temperature of the bubbler, the cell, the space between them, and the tube must be controlled to prevent condensation in the tube.
On the other hand, in the illustrated embodiment, the heat tube 5 has a portion in which a plurality of distributed (solid heat transfer) heat receiving portions 5A of the heat tube are connected (solid connection) to each cell 1. The hydrogen channel 4 through which the supplied mixture of hydrogen and steam flows has a layout (path) different from that of the heat tube 5, and the gas (the mixture of hydrogen and steam) flowing through the hydrogen channel 4 is , the hydrogen passage 4 and the heat tube 5 do not condense. That is, the pure water, which is the coolant flowing through the heat tube 5 , does not contact the gas flowing through the hydrogen flow path 4 and does not exchange heat. Therefore, there is no need for temperature control to prevent condensation or heat insulation with a special coating as in the prior art.
And there is no need to use high-quality equipment for temperature control of pablas and chillers.

In the illustrated embodiment, as shown in FIG. 2, the cup float 25 of the water separator 2 has a rod-shaped portion 25B at the center, and a valve body 25C is formed at the tip (lower end) of the rod-shaped portion 25B. It is The valve main body 25C of the cup float 25 and the upper end opening 26A of the water descending pipe 26 constitute a needle valve having a function of opening and closing the upper end opening 26A. However, the needle valve for opening and closing the upper end opening 26A of the cup float 25 and the water descending pipe 26 can be modified in various ways in addition to the configuration shown in FIG.
An example of such a variant is shown in FIG.
In FIG. 8, the cup float generally indicated by reference numeral 125 includes a rod-shaped portion 125B, a valve body 125C, a rod 125R, and a float portion 125P. More specifically, in the inner space of the water separator 2, a fulcrum 125S is provided in the vicinity of the water descending pipe 26, and a rod 125R rotatable relative to the fulcrum 125S is rotatably pivoted in the direction of arrow RA. supported. A float portion 125P is fixed to the opposite end (the right end in FIG. 8) of the rod 125R to the starting point 125 of the rod 125R. An outer edge portion 125A is formed on the side of the float portion 125P, and an opening portion 125D is formed below.
A rotatable universal joint 125F is interposed approximately in the center of the rod 125R, and a rod-shaped portion 125B is pivotally supported so as to be rotatable in the direction marked SA. A valve body 125C is provided on the opposite side of the rod-shaped portion 125 to the universal joint 125F, and the valve body 125C and the upper end opening 26A of the water descending pipe 26 constitute a needle valve having a function of opening and closing the upper end opening 26A. are doing. In other words, the rod-shaped portion 125B is not provided on the float portion 125P, but the rod-shaped portion 125B is provided at a location separated from the float portion 125P.

Buoyancy is applied to the float portion 125P of the cup float 125 by the water in the water separator 2, and when the float portion 125P floats, the rod 125R rotates in the counterclockwise direction of the arrow RA in FIG. 8, and the rod portion 125B rises. Then, the valve main body 125C is separated from the upper end opening 26A of the water descending pipe 26, which is the valve seat, and the valve is opened. The water in the water separator 2 flows down through the water descending pipe 26 from the upper end opening 26A and is returned to the bubbler 3 side.
On the other hand, when the amount of water in the water separator 2 decreases, the float portion 125P descends, the rod 125R rotates in the clockwise direction of arrow RA in FIG. It sits on the upper end opening 26A of a certain water descending pipe 26, and the upper end opening 26A is closed. Therefore, the water in the water separator 2 does not descend to the bubbler side and stays in the water separator 2 .
Except for the points described above, the configuration and effects of the cup float 125 shown in FIG. 8 are the same as those of the cup float 25 shown in FIG.

The electrochemical hydrogen compressor 40 according to the illustrated embodiment having the above-described configuration has a high degree of freedom in layout, and does not require a special device outside the cell stack for circulating hydrogen and water within the device. It does not require expensive equipment and the cell temperature can be easily controlled.
It should be noted that the illustrated embodiment is merely an example and is not intended to limit the technical scope of the present invention.

1 Cell 1A Anode 1B Electrolyte membrane (solid polymer membrane: PEM)
1C Cathode 2 Water separator 3 Bubbler 3A Gas phase region 3B Liquid phase region 4 Hydrogen gas channel 5 Heat tube 5A Heat tube heat receiving portion 5B Heat tube heat radiating portion 11 Casing for cell (outer shell of cell containing portion)
12 Casing for water separator 13 Casing for bubbler 25, 125 Cup float 25A, 125A Outer edge 25B, 125B (of cup float) Rod-shaped portions 25C, 125C Valve bodies 25D, 125D Opening 26 (of cup float) Water dropping pipe 26A Upper end 40 (of water dropping pipe) Electrochemical type hydrogen compressor

Claims (2)

A cell casing containing a plurality of cells each having an electrolyte membrane sandwiched between anodes and cathodes, a water separator, a water separator casing containing the water separator, a bubbler, and a bubbler having a bubbler casing containing
The cell casing containing the cells, the water separator casing containing the water separator, and the bubbler casing containing the bubbler are integrally joined,
A water separation device is provided above the cell casing , and the compressed hydrogen of the cathode is supplied to the inner space of the water separation device together with water,
Water is stored in the internal space of the water separator, a cup float is arranged,
Electrochemical hydrogen, characterized in that a water drop pipe is provided that communicates between the central part of the inner space of the water separator and the bubbler, and the water drop pipe penetrates the casing for the water separator and communicates with the bubbler. compressor. The cup float arranged in the internal space of the water separation device has a rod-shaped portion, and the tip of the rod-shaped portion is provided with a valve body,
2. An electrochemical hydrogen compressor according to claim 1, wherein the upper end of said water descending pipe is open below the internal space of the water separator and constitutes a valve seat on which a valve body provided on the cup float can be seated.

Images