Fuel cell module

Abstract

To improve water leakage prevention performance in fuel cell modules. [Solution] The gas-liquid separator GLS includes a first communication port CH1 through which first and second generated water flows from a first space S1 into a water storage tank WT, a second communication port CH2 through which first and second generated water flows from a second space S2 into a water storage tank WT, a first plate portion that surrounds the first communication port CH1 and extends from the first communication port CH1 to the bottom side inside the water storage tank WT, and a second plate portion that surrounds the second communication port CH2 and extends from the second communication port to the bottom side inside the water storage tank.

Description

Technical Field

[0001] The present invention relates to a fuel cell module.

Background Art

[0002] As a fuel cell module, there is one provided with a diluter into which an oxidant gas, a hydrogen gas, and generated water discharged from a fuel cell flow, and the inflowing hydrogen gas and oxidant gas are discharged to the outside from a discharge port, and a water storage tank for storing the generated water flowing in from the diluter through a communication port. As a related technique, there is Patent Document 1.

[0003] By the way, when the fuel cell module is mounted on a moving body, when the moving body accelerates or turns, the water level in the water storage tank may rise due to the inertial force applied to the generated water in the water storage tank, causing the water surface in the water storage tank to tilt or ripple. Further, when the water level in the water storage tank rises, there is a risk that the generated water in the water storage tank may flow back to the diluter through the communication port, or the generated water that has flowed back to the diluter may leak to the outside through the discharge port.

[0004] Therefore, as another fuel cell module, there is one provided with a plate portion extending from the communication port to the bottom side in the water storage tank, which suppresses the rise and ripple of the water surface of the generated water in the water storage tank when the moving body accelerates or turns. According to another fuel cell module, since it is possible to suppress the backflow of the generated water from the water storage tank to the diluter when the moving body accelerates or turns, it is possible to suppress an increase in the generated water in the diluter, and it is possible to suppress the leakage of the generated water in the diluter to the outside through the discharge port. As a related technique, there is Patent Document 2.

[0005] However, in the above fuel cell module and the above another fuel cell module, when the amount of generated water discharged from the fuel cell is relatively large, the generated water tends to remain in the diluter. Therefore, when the moving body accelerates or turns, the generated water in the diluter may leak to the outside through the discharge port.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-135996 [Patent Document 2] Japanese Patent Publication No. 2023-106000 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] One aspect of the present invention is to improve the water leakage prevention performance in fuel cell modules. [Means for solving the problem]

[0008] A fuel cell module according to one embodiment of the present invention comprises a fuel cell, a gas-liquid separator having a fuel cell, a diluent into which oxidant gas and first generated water discharged from the fuel cell flow in a first space, hydrogen gas and second generated water discharged from the fuel cell flow in a second space, and the hydrogen gas flowing into the second space is discharged to the outside from an outlet together with the oxidant gas through the first space, and a water storage tank for storing the first and second generated water, wherein the gas-liquid separator comprises at least one first communication port for allowing the first and second generated water to flow from the first space into the water storage tank, at least one second communication port for allowing the first and second generated water to flow from the second space into the water storage tank, a first plate portion surrounding the first communication port and extending from the first communication port to the bottom side inside the water storage tank, and a second plate portion surrounding the second communication port and extending from the second communication port to the bottom side inside the water storage tank.

[0009] Thus, since the configuration includes at least one first communication port and at least one second communication port, the amount of generated water flowing from the diluent to the storage tank can be increased compared to a configuration with only one communication port. This reduces the amount of generated water remaining in the diluent, thereby suppressing leakage of generated water from the diluent to the outside through the outlet.

[0010] Furthermore, because the configuration includes a first plate section and a second plate section, it is possible to suppress the rise in the water level of the generated water in the water storage tank when the moving body is accelerating or turning, compared to a configuration that does not include the first plate section and the second plate section. As a result, backflow of generated water from the water storage tank to the diluent can be suppressed when the moving body is accelerating or turning, thereby suppressing the increase in generated water in the diluent and preventing the generated water in the diluent from leaking to the outside through the outlet.

[0011] Furthermore, the gas-liquid separator is provided between the first space and the second space and includes a partition plate that allows the hydrogen gas to accumulate in the second space, and the second communication port may be provided near the partition plate.

[0012] This prevents the generated water near the second communication port from being stirred up or blown away by the oxidizing gas flowing into the first space, and makes it easier for the generated water in the second space to flow into the water storage tank through the second communication port. As a result, the amount of generated water remaining in the diluent can be reduced, and leakage of generated water from the diluent to the outside through the outlet can be further suppressed.

[0013] Furthermore, the gas-liquid separator may be provided in the first space and include a stirring plate for stirring the oxidizing agent gas flowing into the first space, and the first communication port may be provided near the stirring plate on the side opposite to the side into which the oxidizing agent gas flows, with the stirring plate in between.

[0014] This prevents the generated water near the first communication port from being stirred up or blown away by the oxidizing gas flowing into the first space, and makes it easier for the generated water in the first space to flow into the water storage tank through the first communication port. As a result, the amount of generated water remaining in the diluent can be reduced, and leakage of generated water from the diluent to the outside through the outlet can be further suppressed.

[0015] Furthermore, the distance between the first and second plate portions may be less than or equal to a predetermined distance.

[0016] As a result, compared to the case where the distance between the first and second plates is longer than a predetermined distance, fluctuations in the water level of the generated water in the first and second plates during acceleration or rotation of the moving body can be suppressed. This further suppresses the backflow of generated water from the water storage tank to the diluent, and further suppresses the leakage of generated water from the diluent to the outside through the outlet.

[0017] Furthermore, the inner diameter of the second plate portion may be smaller than the inner diameter of the first plate portion.

[0018] As a result, compared to the case where the inner diameter of the second plate is greater than or equal to the inner diameter of the first plate, fluctuations in the water level of the generated water in the first plate during acceleration or rotation of the moving body can be suppressed. This further suppresses backflow of generated water from the water storage tank to the diluent, and further suppresses leakage of generated water from the diluent to the outside through the outlet.

[0019] Furthermore, the first plate portion may extend from the first communication port toward the ceiling inside the diluent and have an opening toward the discharge port.

[0020] Thereby, by applying the oxidant gas flowing into the first space to the first plate portion on the side opposite to the opening portion, the oxidant gas can be agitated. In addition, it is possible to suppress the generated water near the opening portion from being lifted up or blown away by the oxidant gas flowing into the first space, and it is possible to easily allow the generated water in the first space to flow into the water storage tank through the first communication port. Therefore, the amount of generated water in the diluter can be reduced, and it is possible to further suppress the generated water in the diluter from leaking to the outside through the discharge port.

[0021] Further, the opening portion may be provided at a position lower than the discharge port.

[0022] Thereby, even if the generated water flows back from the water storage tank to the diluter through the opening portion, it is difficult for the generated water to enter the discharge port, so that it is possible to suppress the generated water from leaking to the outside through the discharge port.

Advantages of the Invention

[0023] According to the present invention, it is possible to improve the water leakage prevention performance in the fuel cell module.

Brief Description of the Drawings

[0024] [Figure 1] It is a diagram showing an example of the fuel cell module of the embodiment. [Figure 2] It is a perspective view of the gas-liquid separator. [Figure 3] It is a diagram schematically showing the states of the oxidant gas, the first generated water, the hydrogen gas, and the second generated water flowing in the gas-liquid separator. [Figure 4] It is a diagram schematically showing the states of the oxidant gas and the hydrogen gas flowing in the diluter. [Figure 5] It is a diagram schematically showing the states of the water surfaces in the first plate portion and the second plate portion. [Figure 6] It is a diagram showing the first and second plate portions in Modified Example 1. [Figure 7] It is a diagram showing the first plate portion in Modified Example 2. [Modes for carrying out the invention]

[0025] In the fuel cell module of the embodiment, when the fuel cell stack generates electricity, an oxidizer gas containing unreacted oxygen (cathode-off gas), hydrogen gas containing unreacted hydrogen (anode-off gas), and generated water are discharged from the fuel cell stack. For example, when a fuel cell module is installed in an industrial vehicle such as a forklift that is also used indoors, in addition to diluting the hydrogen to below a standard concentration before exhaust, a water storage structure may be required to prevent the generated water from leaking outside the industrial vehicle. This is because, unlike passenger cars which are mainly used outdoors, flooding the interior of an industrial vehicle could impair the convenience of the user.

[0026] To prevent water leakage during power generation, it is necessary to, for example, prevent leakage due to the undulation of generated water caused by acceleration, deceleration, and turning during operation; separate and store the generated water discharged simultaneously with oxidizer gas and hydrogen gas during power generation; store all the generated water discharged until the hydrogen in the fuel tank is used up; accommodate space saving (as described later, the smaller the capacity of the water storage tank, the more disadvantageous it becomes in terms of generated water leakage); and achieve cost reduction (simple structure).

[0027] When diluting hydrogen, it is necessary to achieve, for example, reducing the concentration from 70% to 100% to a few percent (4% to 8%), to cope with intermittent hydrogen gas emissions (diluting the remaining hydrogen gas before the next emission (for example, after several tens of seconds)), to conserve space (as described later, the smaller the capacity of the diluent, the smaller the hydrogen gas buffer area becomes, which is disadvantageous for dilution), and to reduce costs (simple structure).

[0028] In the fuel cell module of this embodiment, the structure of the gas-liquid separator has been devised to meet the various requirements mentioned above, particularly to improve the water leakage prevention performance.

[0029] Figure 1 shows an example of a fuel cell module according to an embodiment.

[0030] The fuel cell module (FCM) shown in Figure 1 is mounted on vehicles such as forklifts, towing tractors, or automated guided vehicles (AGVs), or on aircraft such as drones. Hereinafter, the vehicle or aircraft on which the fuel cell module (FCM) is mounted will be referred to as the mobile body M. The fuel cell module (FCM) also supplies power to a load Lo mounted on the mobile body M. Load Lo is, for example, an inverter circuit or electrical equipment for driving a driving motor or an aircraft motor. In this embodiment, the fuel cell module (FCM) may refer to the fuel cell module (FCM) before it is mounted on the mobile body M, or to the fuel cell module (FCM) after it has been mounted on the mobile body M.

[0031] Furthermore, the fuel cell module (FCM) comprises a main unit, the fuel cell stack (FCS), and several types of auxiliary equipment for generating power for the fuel cell stack (FCS).

[0032] In other words, the fuel cell module (FCM) includes, as electrical auxiliary equipment, a DC-DC converter (CNV) and an energy storage device (B).

[0033] Furthermore, the fuel cell module (FCM) is equipped with cooling system auxiliary components such as a radiator (R) and a water pump (WP).

[0034] Furthermore, the fuel cell module (FCM) is equipped with hydrogen gas system auxiliary components such as a fuel tank (HT), injector (INJ), hydrogen gas separator (HGS), hydrogen circulation pump (HP), and gas-liquid separator (GLS).

[0035] Furthermore, the fuel cell module (FCM) is equipped with auxiliary oxidizer gas system components such as an air compressor (ACP) and an air pressure regulating valve (ARV).

[0036] Furthermore, the fuel cell module (FCM) is equipped with a control device (Cnt), among other things.

[0037] A fuel cell stack (FCS) consists of multiple fuel cell cells connected in series with each other. It generates electricity through an electrochemical reaction between hydrogen gas (as the anode gas) and oxygen (as the cathode gas, e.g., air) containing an oxidizing gas. The fuel cell cells are, for example, polymer electrolyte fuel cells (PEFCs).

[0038] The DC-DC converter (CNV) converts the voltage output from the fuel cell stack (FCS) to a predetermined voltage. The power output from the DC-DC converter (CNV) is supplied to various auxiliary equipment and loads (Lo).

[0039] Energy storage device B is composed of a lithium-ion battery or lithium-ion capacitor and is connected between the DC-DC converter CNV and the load Lo. If the supplied power, which is the difference between the power output from the DC-DC converter CNV and the total power supplied to each auxiliary device, is greater than the required power requested from outside the fuel cell module FCM (for example, a control unit not shown that controls the operation of load Lo), then the required power is supplied to load Lo, and the surplus power is supplied to energy storage device B. When power is supplied from the DC-DC converter CNV to energy storage device B, energy storage device B is charged and its charge rate (the ratio of remaining capacity to the full charge capacity of energy storage device B [%]) increases. Also, when regenerative power supplied from load Lo to the fuel cell module FCM is supplied to energy storage device B, energy storage device B is charged and its charge rate increases. Furthermore, if the supplied power is less than the required power, that supplied power is supplied to load Lo, and the deficit is supplied from energy storage device B to load Lo. When power is supplied from energy storage device B to load Lo, energy storage device B is discharged and its charge level decreases.

[0040] The radiator R exchanges heat between the coolant discharged from the fuel cell module (FCM) and the outside air.

[0041] The water pump (WP) supplies the cooling water, which has been heated by the radiator (R), to the fuel cell stack (FCS).

[0042] The fuel tank (HT) is a storage container for hydrogen gas. The hydrogen gas stored in the fuel tank (HT) is supplied to the fuel cell stack (FCS) via the injector (INJ).

[0043] The injector (INJ) regulates the flow rate of hydrogen gas supplied to the fuel cell stack (FCS).

[0044] The hydrogen gas separator HGS separates the hydrogen gas containing unreacted hydrogen discharged from the fuel cell stack FCS from the first generated water produced in the fuel cell stack FCS. A portion of the separated hydrogen gas and the first generated water are sent to the gas-liquid separator GLS, and the remaining hydrogen gas is sent to the hydrogen circulation pump HP.

[0045] The hydrogen circulation pump (HP) resupplies the hydrogen gas received from the hydrogen gas separator (HGS) to the fuel cell stack (FCS).

[0046] The air compressor (ACP) compresses the oxidizer gas supplied from outside the fuel cell module (FCM) and delivers it to the fuel cell stack (FCS).

[0047] The air pressure regulating valve (ARV) adjusts the pressure and flow rate of the oxidizer gas supplied to the fuel cell stack (FCS).

[0048] The control device Cnt, for example, is composed of a microcomputer and controls the operation of each auxiliary device to control the power generation of the fuel cell stack FCS. For example, the control device Cnt changes the target power generation power according to the charge level of the energy storage device B, and controls the operation of each auxiliary device so that the power generation power of the fuel cell stack FCS follows the target power generation power through PI (Proportional-Integral) control or the like.

[0049] The gas-liquid separator GLS comprises a diluent DIL and a water storage tank WT. While there is flexibility in the shape of the housings constituting the diluent DIL and water storage tank WT, allowing for various design modifications, they can be, for example, roughly rectangular. Similarly, the materials used for the housings constituting the diluent DIL and water storage tank WT also offer flexibility, allowing for various design modifications, but they can be, for example, stainless steel (iron with added chromium, nickel, molybdenum, etc.), carbon fiber reinforced plastics (CFRP), or polypropylene. Furthermore, while there are no particular limitations on the placement of the gas-liquid separator GLS within the fuel cell module FCM, it is desirable to place the GLS below the fuel cell stack FCS to minimize the size of the fuel cell module FCM.

[0050] The diluter DIL receives unreacted hydrogen gas and first-generation water discharged from the fuel cell stack FCS via the hydrogen gas separator HGS, and unreacted oxidizer gas and second-generation water discharged from the fuel cell stack FCS via the air pressure regulating valve ARV. The diluter DIL also dilutes the hydrogen gas with the oxidizer gas (mixing the hydrogen gas and oxidizer gas) and discharges it to the outside, and sends the first-generation water and second-generation water to the water storage tank WT. The hydrogen gas and oxidizer gas after dilution (mixing) will be referred to as "dilution gas" below. When the first-generation water and second-generation water are not distinguished, they will simply be referred to as "generation water" below.

[0051] The water storage tank WT stores the generated water sent from the diluent DIL. Furthermore, the tank may be configured to allow the generated water stored in the water storage tank WT to be drained through an unillustrated drain port at the bottom of the water storage tank WT, for example, during maintenance of the fuel cell module FCM.

[0052] Figure 2 is a perspective view of the gas-liquid separator GLS. The X, Y, and Z axes in Figure 2 and Figures 3-7 (described later) are shown to define the direction and orientation of the gas-liquid separator GLS. The X, Y, and Z axes are orthogonal to each other, forming a right-handed system. Furthermore, the aspect ratios and relative sizes of the components of the gas-liquid separator GLS and diluent DIL shown in Figures 2-7 are schematic representations and do not necessarily match the aspect ratios and relative sizes of the components of the actual manufactured gas-liquid separator GLS and diluent DIL. Also, for explanatory purposes, the relative sizes of the components may be exaggerated in some cases. Additionally, the positive X-axis side of the gas-liquid separator GLS (diluent DIL and water storage tank WT) shown in Figure 2 is omitted to show the interior of the gas-liquid separator GLS. In Figures 3-7, some surfaces are also omitted when showing the interior. Furthermore, in the example shown in Figure 2, the diluent DIL and the water storage tank WT are formed as a single unit, and the bottom of the diluent DIL and the top of the water storage tank WT are made of a common material.

[0053] The gas-liquid separator GLS shown in Figure 2 comprises a partition plate PP, an outlet OL, a stirring plate SP, a first communication port CH1, a second communication port CH2, a first plate section WB1, and a second plate section WB2.

[0054] The partition plate PP is formed to extend from the bottom (negative Z-axis side of the diluent DIL) to the ceiling (positive Z-axis side of the diluent DIL) near the center of the diluent DIL. In the example shown in Figure 2, the partition plate PP is formed in a roughly rectangular plate shape, and there are gaps between the positive Z-axis side, positive X-axis side, and negative X-axis side of the diluent DIL and the partition plate PP. The shape of the partition plate PP is not particularly limited as long as it allows the diluent gas to move between the first space S1 and the second space S2, which will be described later.

[0055] The outlet OL is formed to extend from inside the diluent DIL, through the positive Y-axis side of the diluent DIL, and out of the diluent DIL. In the example shown in Figure 2, the outlet OL is formed in a roughly cylindrical shape, with the inlet side of the outlet OL, where the dilution gas enters, located inside the diluent DIL, and the outlet side of the outlet OL, where the dilution gas exits, located outside the diluent DIL.

[0056] The stirring plate SP is formed between the partition plate PP and the outlet OL, extending from the bottom to the ceiling inside the diluent DIL. In the example shown in Figure 2, the stirring plate SP is formed in a substantially rectangular plate shape, and there are gaps between the positive Z-axis side, positive X-axis side, and negative X-axis side inside the diluent DIL and the stirring plate SP. The shape of the stirring plate SP is not particularly limited as long as it is a shape that can stir the oxidizing gas flowing into the first space S1.

[0057] The first communication port CH1 is a through-hole located at the bottom of the diluent DIL (or the ceiling of the water storage tank WT). In the example shown in Figure 2, the first communication port CH1 is located near the stirring plate SP between the stirring plate SP and the outlet OL, but the location of the first communication port CH1 is not particularly limited as long as it is located at the bottom of the diluent DIL in the first space S1 described later. Also, in the example shown in Figure 2, the shape of the first communication port CH1 is approximately circular, but it may also be approximately rectangular and is not particularly limited. Furthermore, the size of the first communication port CH1 is not particularly limited, but the larger it is, the easier it is for the generated water to flow from the diluent DIL to the water storage tank WT, but the easier it is for the generated water to leak from the water storage tank WT to the diluent DIL, so it is desirable to set the size to an optimal size considering these factors.

[0058] The second communication port CH2 is a separate through-hole from the first communication port CH1 and is located at the bottom of the diluent DIL (or the ceiling of the water storage tank WT). In the example shown in Figure 2, the second communication port CH2 is located near the partition plate PP between the partition plate PP and the negative Y-axis side of the diluent DIL, but the location of the second communication port CH2 is not particularly limited as long as it is located at the bottom of the diluent DIL in the second space S2 described later. Also, in the example shown in Figure 2, the shape of the second communication port CH2 is approximately circular, but it may also be approximately rectangular and is not particularly limited. Furthermore, the size of the second communication port CH2 is not particularly limited, but the larger it is, the easier it is for the generated water to flow from the diluent DIL to the water storage tank WT, but the easier it is for the generated water to leak from the water storage tank WT to the diluent DIL, so it is desirable to set the size to an optimal size considering these factors.

[0059] Furthermore, when the dilution unit DIL and the water storage tank WT are configured as separate units, the first communication port CH1 is provided at a position opposite the bottom of the dilution unit DIL and the ceiling of the water storage tank WT, respectively, and similarly, the second communication port CH2 is provided at a position opposite the bottom of the dilution unit DIL and the ceiling of the water storage tank WT, respectively.

[0060] The first plate portion WB1 is a baffle plate for suppressing the undulation of the generated water in the water storage tank WT, and is formed to surround the first communication port CH1 and extend from the first communication port CH1 to the bottom side (negative Z-axis side) of the water storage tank WT. In the example shown in Figure 2, the first plate portion WB1 is formed in a substantially cylindrical shape, with the inlet side of the first plate portion WB1 into which the generated water enters connected to the first communication port CH1, and the outlet side of the first plate portion WB1 out into the water storage tank WT. There is also a gap between the outlet side of the first plate portion WB1 and the bottom of the water storage tank WT.

[0061] The second plate WB2, like the first plate WB1, is a baffle plate for suppressing the undulation of the generated water in the water storage tank WT, and is formed to surround the second communication port CH2 and extend from the second communication port CH2 to the bottom of the water storage tank WT. In the example shown in Figure 2, the second plate WB2 is formed in a roughly cylindrical shape, with the inlet side of the second plate WB2 into which the generated water enters connected to the second communication port CH2, and the outlet side of the second plate WB2 out which the generated water exits located inside the water storage tank WT. There is also a gap between the outlet side of the second plate WB2 and the bottom of the water storage tank WT.

[0062] Furthermore, the first plate section WB1 and the second plate section WB2 have the function of adjusting the water level of the generated water stored in the water storage tank WT.

[0063] Figure 3 schematically shows the flow of oxidant gas, first generated water, hydrogen gas, and second generated water within the gas-liquid separator GLS. Figure 4 schematically shows the flow of oxidant gas and hydrogen gas within the diluent DIL. Solid arrows indicate oxidant gas, dashed arrows indicate first generated water, dashed arrows indicate hydrogen gas, and double dashed arrows indicate second generated water. The entire space within the diluent DIL is divided into a first space S1 (upward-sloping shaded area) and a second space S2 (downward-sloping shaded area) by a partition plate PP. That is, hydrogen gas accumulates in the second space S2 due to the partition plate PP located between the first space S1 and the second space S2. The shaded area in Figure 3 shows the generated water stored in the water storage tank WT.

[0064] The oxidant gas discharged from the fuel cell stack FCS and flowing into the first space S1 is agitated by contact with the stirring plate SP. A portion of the agitated oxidant gas then contacts the partition plate PP and remains in the first space S1, while the remaining oxidant gas flows into the second space S2 through the gap between the partition plate PP and the wall or ceiling inside the diluent DIL.

[0065] Furthermore, the hydrogen gas discharged from the fuel cell stack FCS and flowing into the second space S2 is diluted by the oxidizer gas in the second space S2. As the diluted gas strikes the partition plate PP, some of the diluted gas remains in the second space S2, while the remaining diluted gas flows into the first space S1 through the gap between the partition plate PP and the wall or ceiling inside the diluter DIL.

[0066] Furthermore, the dilution gas that flows from the second space S2 to the first space S1 is further diluted by the oxidizer gas remaining in the first space S1 before being discharged to the outside through the outlet OL. In this way, the hydrogen gas discharged from the fuel cell stack FCS is diluted in the second space and then further diluted in the first space, thus improving the dilution performance.

[0067] Furthermore, the first generated water discharged from the fuel cell stack FCS and flowing into the first space S1 is agitated by hitting the stirring plate SP. A portion of the agitated first generated water flows into the second space S2 through the gap between the partition plate PP and the wall inside the diluent DIL, while the remaining first generated water hits the partition plate PP and remains in the first space S1.

[0068] Furthermore, the second generated water discharged from the fuel cell stack FCS and flowing into the second space S2 flows to the water storage tank WT via the second communication port CH2 together with the first generated water, while the remainder flows into the first space through the gap between the partition plate PP and the wall inside the diluent DIL, and then flows to the water storage tank WT via the first communication port CH1 together with the first generated water.

[0069] Thus, the fuel cell module FCM of this embodiment is configured to have at least a first communication port CH1 and a second communication port CH2, which allows for an increase in the amount of generated water flowing from the diluent DIL to the water storage tank WT compared to a configuration with only one communication port. This reduces the amount of generated water remaining in the diluent DIL, thereby suppressing leakage of generated water from the diluent DIL to the outside through the outlet OL.

[0070] Furthermore, as shown in Figure 4, since the first communication port CH1 is located near the stirring plate SP, the first communication port CH1 can be placed in a location where the oxidizing gas accumulates (a location where the wind force (flow velocity) of the oxidizing gas is relatively small). This prevents the generated water near the first communication port CH1 from being blown away or stirred up by the oxidizing gas flowing into the first space S1, and makes it easier for the generated water in the first space S1 to flow to the water storage tank WT via the first communication port CH1. As a result, the amount of generated water remaining in the diluent DIL can be reduced, and leakage of generated water from the diluent DIL to the outside via the outlet OL can be further suppressed.

[0071] Furthermore, as shown in Figure 4, since the second communication port CH2 is provided near the partition plate PP, the second communication port CH2 can be provided in a location where the oxidizing gas accumulates (a location where the wind force (flow velocity) of the oxidizing gas is relatively small). This suppresses the generated water near the second communication port CH2 from being blown away or stirred up by the oxidizing gas flowing into the second space S2, and makes it easier for the generated water in the second space S2 to flow to the water storage tank WT via the second communication port CH2. As a result, the amount of generated water remaining in the diluent DIL can be reduced, and leakage of generated water from the diluent DIL to the outside via the outlet OL can be further suppressed.

[0072] Furthermore, multiple first communication openings CH1 may be provided in the first space S1. In this case, multiple first communication openings CH1 may be configured so that each of the multiple first communication openings CH1 is connected to a first plate section WB1, or one first plate section WB1 may be connected to each of the multiple first communication openings CH1.

[0073] Furthermore, multiple second communication openings CH2 may be provided in the second space S2. In this case, if multiple second communication openings CH2 are provided, the configuration may be such that each of the multiple second communication openings CH2 is connected to a second plate section WB2, similar to the case where multiple first communication openings CH1 are provided, or the configuration may be such that one second plate section WB2 is connected to each of the multiple second communication openings CH2.

[0074] Furthermore, the size of the inner diameter of the first communication port CH1 and the second communication port CH2 is not particularly limited.

[0075] Increasing the number of first and second communication ports CH1 and CH2, or increasing the inner diameter of the first and second communication ports CH1 and CH2, can increase the amount of generated water flowing from the diluent DIL to the water storage tank WT. However, depending on the capacity of the water storage tank WT, generated water may easily flow back from the water storage tank WT to the diluent DIL. Therefore, it is desirable to set the number and inner diameter of the first and second communication ports CH1 and CH2 to appropriate values, taking into consideration parameters such as the capacity of the water storage tank WT.

[0076] Here, we assume that when the moving object M is moving with positive or negative acceleration, or when the moving object M is turning to the right or left (hereinafter referred to as "when the moving object M is accelerating or turning"), an inertial force acts on the generated water in the water storage tank WT in addition to atmospheric pressure, causing the water surface of the generated water in the water storage tank WT to tilt. Note that when the moving object M is stationary or moving at a constant speed, it is referred to as "when the moving object M is not accelerating or turning". Furthermore, when the moving body M is not accelerating or rotating, if the water level of the generated water in the water storage tank WT rises above the negative Z-axis ends of the first plate section WB1 and the second plate section WB2, the air in the space (hereinafter referred to as space A) enclosed by the ceiling and walls of the water storage tank WT, the outer side surface of the first plate section WB1, the outer side surface of the second plate section WB2, and the water level of the generated water leaks into the diluent DIL through air holes (not shown) provided in the ceiling of the water storage tank WT, so that the heights of the water level of the generated water in the first plate section WB1, the water level of the generated water in the second plate section WB2, and the water level of the generated water in space A become equal.

[0077] Figure 5(a) schematically shows the water surface α in the first plate section WB1, the water surface β in the second plate section WB2, and the water surface γ in space A when the moving body M is not accelerating and not rotating.

[0078] As shown in Figure 5(a), when the moving body M is not accelerating or rotating, atmospheric pressure is applied to the generated water in space A, the generated water in the first plate section WB1, and the generated water in the second plate section WB2, respectively, so the heights of the water surfaces α, β, and γ become equal to each other.

[0079] Figure 5(b) schematically shows the state of water surfaces α, β, and γ when the moving body M is accelerating or turning. It is assumed that when the moving body M is accelerating or turning, the generated water in space A tilts, closing the air holes and sealing space A.

[0080] As shown in Figure 5(b), when the moving body M is accelerating or turning, the generated water in the first plate section WB1 and the generated water in the second plate section WB2 are subjected to a resultant force of gravity and inertia in addition to atmospheric pressure. Therefore, the inclinations of the water surfaces α and β coincide with the direction perpendicular to the direction of the resultant force of gravity and inertia. Consequently, the height of the water surface β relative to the bottom of the water storage tank WT decreases by a predetermined value Δh1 minutes compared to the height of the water surface β when the moving body M is not accelerating or turning, and the height of the water surface α relative to the bottom of the water storage tank WT increases by a predetermined value Δh1 minutes compared to the height of the water surface α when the moving body M is not accelerating or turning. Since space A is sealed, the height of the water surface γ is the same as the height of the water surface γ when the moving body M is not accelerating or turning.

[0081] Furthermore, when the surface of the generated water is tilted, the axis of rotation of the water surface changes position according to the length of the rotation direction of the generated water surface subjected to atmospheric pressure. The shorter the length of the rotation direction of the generated water surface subjected to atmospheric pressure, the lower the water surface of the generated water becomes. For example, as shown in Figure 5(b), when the gas-liquid separator GLS is not equipped with the first plate section WB1 and the second plate section WB2, the axis of rotation of the water surface of the generated water is axis a, and the length of the rotation direction of the water surface of the generated water is equal to the length of the dashed line. On the other hand, the lengths of the rotation direction of water surfaces α and β are equal to the lengths of the dashed lines, and the length of the dashed lines is shorter than the length of the dashed line. Therefore, the axis of rotation of the tilt of water surfaces α and β is axis b, which is in a different position from axis a, and the heights of water surfaces α and β (heights of the dashed lines relative to the bottom of the water storage tank WT) are lower than the water surface heights when the gas-liquid separator GLS is not equipped with the first plate section WB1 and the second plate section WB2 (heights of the dashed lines relative to the bottom of the water storage tank WT).

[0082] As a result, when the gas-liquid separator GLS is equipped with a first plate section WB1 and a second plate section WB2, it is possible to suppress the backflow of generated water from the water storage tank WT to the diluent DIL when the mobile body M is accelerating or turning, compared to when the gas-liquid separator GLS is not equipped with a first plate section WB1 and a second plate section WB2.

[0083] Furthermore, it is desirable that the lengths of the first plate section WB1 and the second plate section WB2 be set considering the maximum inclination angles of the water surface α and water surface β during acceleration or rotation of the mobile body M, in order to suppress the backflow of generated water from the water storage tank WT to the diluent DIL.

[0084] Figure 5(c) schematically shows the state of water surfaces α, β, and γ when the moving body M is accelerating or turning. It is assumed that when the moving body M is accelerating or turning, the generated water in space A tilts, closing the air holes and sealing space A. Also, the distance between the first plate WB1 and the second plate WB2 shown in Figure 5(c) is shorter than the distance between the first plate WB1 and the second plate WB2 shown in Figure 5(b).

[0085] As shown in Figure 5(c), the water level β relative to the bottom of the water storage tank WT is lower by a predetermined value Δh2 than the water level β when the mobile body M is not accelerating or turning, and the water level α relative to the bottom of the water storage tank WT is higher by a predetermined value Δh2 than the water level β when the mobile body M is not accelerating or turning. Since space A is sealed, the water level γ is the same as the water level γ when the mobile body M is not accelerating.

[0086] Furthermore, the lengths of the water surfaces α and β in the rotational direction shown in Figure 5(c) coincide with the length of the dashed line, and the length of the dashed line is shorter than the length of the single dashed line shown in Figure 5(b). Therefore, the axis of rotation of the inclination of the water surfaces α and β is axis c, which is in a different position from axis b, and the heights of the water surfaces α and β shown in Figure 5(c) (heights of the dashed line relative to the bottom of the water storage tank WT) are lower than the heights of the water surfaces α and β shown in Figure 5(b) (heights of the dashed line relative to the bottom of the water storage tank WT). In other words, the predetermined value Δh2 < predetermined value Δh1.

[0087] Thus, the shorter the distance between the first plate section WB1 and the second plate section WB2, the lower the water levels α and β can be when the moving body M is accelerating or turning, thereby further suppressing the backflow of generated water from the water storage tank WT to the diluent DIL.

[0088] In other words, the distance between the first plate section WB1 and the second plate section WB2 shown in Figure 5(c) is set to be less than or equal to a predetermined distance, and the predetermined distance is defined as the minimum distance between the first plate section WB1 and the second plate section WB2 when, for example, the first communication opening CH1 is provided in the first space S1 and the second communication opening CH2 is provided in the second space S2.

[0089] Figure 5(d) schematically shows the state of water surfaces α, β, and γ when the moving body M is accelerating or turning. It is assumed that when the moving body M is accelerating or turning, the generated water in space A tilts, closing the air holes and sealing space A. The distance between the first plate WB1 and the second plate WB2 shown in Figure 5(d) is the same as or approximately the same as the distance between the first plate WB1 and the second plate WB2 shown in Figure 5(b). The inner diameter of the first plate WB1 shown in Figure 5(d) is the same as the inner diameter of the first plate WB1 shown in Figure 5(b), and the area of ​​water surface α shown in Figure 5(d) is the same as the area of ​​water surface α shown in Figure 5(b). Furthermore, the inner diameter of the second plate portion WB2 shown in Figure 5(d) is smaller than the inner diameter of the second plate portion WB2 shown in Figure 5(b), and the area of ​​the water surface β shown in Figure 5(d) is smaller than the area of ​​the water surface β shown in Figure 5(b). Also, the inner diameter of the second plate portion WB2 shown in Figure 5(d) is smaller than the inner diameter of the first plate portion WB1 shown in Figure 5(d), and the area of ​​the water surface β shown in Figure 5(d) is smaller than the area of ​​the water surface α shown in Figure 5(d).

[0090] As shown in Figure 5(d), the water level β relative to the bottom of the water storage tank WT drops by a predetermined value Δh3 from the water level β when the moving body M is not accelerating or turning, and the water level α relative to the bottom of the water storage tank WT rises by a predetermined value Δh4 from the water level β when the moving body M is not accelerating or turning. At this time, the volume fluctuation of the generated water in the first plate section WB1 and the volume fluctuation of the generated water in the second plate section WB2 are equal due to the balance of forces due to gravity, so the water level fluctuation of the smaller water level β (predetermined value Δh3) is greater than the water level fluctuation of the larger water level α (predetermined value Δh4). Furthermore, since the area of ​​water surface α shown in Figure 5(d) is the same as the area of ​​water surface α shown in Figure 5(b), and the area of ​​water surface β shown in Figure 5(d) is smaller than the area of ​​water surface β shown in Figure 5(b), the amount of water level fluctuation (predetermined value Δh3) of water surface β shown in Figure 5(d) is greater than the amount of water level fluctuation (predetermined value Δh1) of water surface β shown in Figure 5(b), and the amount of water level fluctuation (predetermined value Δh4) of water surface α shown in Figure 5(d) is smaller than the amount of water level fluctuation (predetermined value Δh1) of water surface α shown in Figure 5(b). Note that since space A is sealed, the height of water surface γ is the same as the height of water surface γ when the moving body M is not accelerating and not turning.

[0091] In this way, by making the area of ​​the water surface where the water level falls during acceleration or turning of the mobile body M smaller than the area of ​​the water surface where the water level rises during acceleration or turning of the mobile body M, the amount of water level fluctuation on the side where the water level falls can be increased, and the amount of water level fluctuation on the side where the water level rises can be decreased. As a result, the water level α shown in Figure 5(d) can be made lower than the water level α shown in Figure 5(b), and the water level β shown in Figure 5(d) can be made lower than the water level β shown in Figure 5(b), so the rise in the water level of the generated water in the water storage tank WT during acceleration or turning of the mobile body M can be further suppressed.

[0092] Furthermore, the inner diameters of the first plate section WB1 and the second plate section WB2 may be set such that the area of ​​the water surface on the side where the water level rises during acceleration or rotation of the mobile body M is larger than the area of ​​the water surface on the side where the water level falls during acceleration or rotation of the mobile body M. With this configuration, the amount of water level fluctuation on the side where the water level falls can be increased, while the amount of water level fluctuation on the side where the water level rises can be decreased. However, as mentioned above, a configuration with a larger inner diameter of the plate section makes it easier for the generated water to flow back from the water storage tank WT to the diluent DIL, so a configuration with a smaller inner diameter of the plate section may be more effective from the viewpoint of suppressing the backflow of generated water.

[0093] In this way, when the mobile body M is accelerating or turning, the rise in the water level of the generated water in the water storage tank WT can be suppressed, and thus the backflow of generated water from the water storage tank WT to the diluent DIL can be suppressed.

[0094] Furthermore, as shown in Figure 2, if the first plate section WB1 on the side closer to the outlet OL is the plate section where the water level rises when the moving body M is accelerating or turning, as shown in Figure 5(d), the inner diameter of the second plate section WB2 may be smaller than the inner diameter of the first plate section WB1, or the inner diameter of the first plate section WB1 may be larger than the inner diameter of the second plate section WB2. This further suppresses the backflow of generated water from the water storage tank WT to the diluent DIL.

[0095] Furthermore, the inner diameters of the first plate section WB1 and the second plate section WB2 may be set such that the area of ​​the water surface on the side where the water level rises increases when the moving body M is accelerating or turning, and the area of ​​the water surface on the side where the water level falls decreases when the moving body M is accelerating or turning. With this configuration, the amount of water level fluctuation on the side where the water level falls can be increased, and the amount of water level fluctuation on the side where the water level rises can be decreased.

[0096] Figure 5(e) schematically shows the state of water surfaces α, β, and γ when the moving body M is accelerating or turning. It is assumed that when the moving body M is accelerating or turning, the generated water in space A tilts, closing the air holes and sealing space A.

[0097] The distance between the first plate section WB1 and the second plate section WB2 shown in Figure 5(e) shall be shorter than the distance between the first plate section WB1 and the second plate section WB2 shown in Figure 5(b). Furthermore, the inner diameter of the second plate section WB2 shown in Figure 5(e) shall be smaller than the inner diameter of the second plate section WB2 shown in Figure 5(b).

[0098] In this way, by shortening the distance between the first plate section WB1 and the second plate section WB2 and reducing the inner diameter of the second plate section WB2, the heights of the water surface α and water surface β can be further reduced when the moving body M is accelerating or turning, thereby further suppressing the backflow of generated water from the water storage tank WT to the diluent DIL. Alternatively, the distance between the first plate section WB1 and the second plate section WB2 may be shortened and the inner diameter of the first plate section WB1 may be increased. Or, the distance between the first plate section WB1 and the second plate section WB2 may be shortened, the inner diameter of the second plate section WB2 may be reduced, and the inner diameter of the first plate section WB1 may be increased.

[0099] In other words, since the fuel cell module FCM of this embodiment is configured to include a first plate portion WB1 and a second plate portion WB2, it is possible to suppress the rise in the water level of the generated water in the water storage tank WT when the mobile body M is accelerating or turning, compared to a configuration that does not include the first plate portion WB1 and the second plate portion WB2. As a result, backflow of generated water from the water storage tank WT to the diluent DIL when the mobile body M is accelerating or turning can be suppressed, thereby suppressing the increase in generated water in the diluent DIL and preventing the generated water in the diluent DIL from leaking to the outside through the outlet OL.

[0100] Furthermore, by shortening the distance between the first plate section WB1 and the second plate section WB2, or by changing the inner diameter of the first plate section WB1 and the second plate section WB2, the water level of the generated water in the first plate section WB1 and the second plate section WB2 during acceleration or rotation of the moving body M can be lowered. This further suppresses the backflow of generated water from the water storage tank WT to the diluent DIL, thereby further suppressing the increase in generated water in the diluent DIL and further suppressing the leakage of generated water from the diluent DIL to the outside through the outlet OL.

[0101] It should be noted that the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention.

[0102] <Example 1> In the above embodiment, the first plate portion WB1 and the second plate portion WB2 are each formed in a cylindrical shape, but the shape of the first plate portion WB1 and the second plate portion WB2 is not particularly limited as long as they have the function of adjusting the water level of the generated water. For example, as shown in Figure 6, the first plate portion WB1 and the second plate portion WB2 may each be composed of two plate-shaped members. It is assumed that the positive X-axis end of the first plate portion WB1, the negative X-axis end of the first plate portion WB1, the positive X-axis end of the second plate portion WB2, and the negative X-axis end of the second plate portion WB2 are each connected to the wall inside the water storage tank WT.

[0103] Even with this configuration, backflow of generated water from the water storage tank WT to the diluent DIL during acceleration or rotation of the mobile body M can be suppressed, thereby reducing the increase in generated water in the diluent DIL and improving the leak prevention performance of the gas-liquid separator GLS.

[0104] <Modification 2> Alternatively, as shown in Figure 7, the first plate portion WB1 may be formed to extend from the first communication port CH1 to the bottom side of the water storage tank WT, and also to extend from the first communication port CH1 to the ceiling side of the diluent DIL. In the example shown in Figure 7, the Z-axis positive end of the first plate portion WB1 is connected to the ceiling of the diluent DIL, but there may be a gap between the Z-axis positive end of the first plate portion WB1 and the ceiling of the diluent DIL. If there is a gap between the Z-axis positive end of the first plate portion WB1 and the ceiling of the diluent DIL, it is desirable that the Z-axis positive end of the first plate portion WB1 be closed.

[0105] Furthermore, the first plate section WB1 has an opening H in the portion of the section that extends from the first communication port CH1 towards the ceiling inside the diluent DIL, and that is in contact with the bottom inside the diluent DIL. The generated water in the first space S1 flows to the water storage tank WT via the opening H, the first communication port CH1, and the first plate section WB1. In the example shown in Figure 7, the opening H is provided on the outlet OL side and not on the partition plate PP side. In this configuration, the portion of the first plate section WB1 that extends from the first communication port CH1 towards the ceiling inside the diluent DIL, on the partition plate PP side, can stir the oxidizer gas and the first generated water discharged from the fuel cell stack FCS and flowing into the first space S1. As a result, as shown in Figure 7, the stirring plate SP can be omitted, thereby reducing the manufacturing cost of the fuel cell module FCM.

[0106] Furthermore, in the example shown in Figure 7, the shape of the first plate WB1 is a roughly cylindrical shape, but it is not particularly limited to a roughly rectangular prism shape or other shapes. Also, the first plate WB1 extending from the first communication port CH1 towards the ceiling inside the diluent DIL may be composed of two plate-shaped members, as shown in Figure 6. When the first plate WB1 is composed of a roughly rectangular prism shape or two plate-shaped members, the oxidizer gas discharged from the fuel cell stack FCS and flowing into the first space S1 can be efficiently stirred, thereby improving the dilution performance in the diluent DIL.

[0107] Furthermore, it is desirable that the opening H be located lower than the outlet OL. By positioning the opening H lower than the outlet OL, even if the generated water flows back from the water storage tank WT to the diluent DIL through the opening H, it is possible to prevent the generated water from entering the outlet OL, thereby preventing the generated water from leaking outside the diluent DIL. [Explanation of symbols]

[0108] FCM Fuel Cell Module M Mobile object Lo load FCS Fuel Cell Stack HT fuel tank INJ Injector HP Hydrogen Circulation Pump HGS Hydrogen Gas Separator ACP Air Compressor ARV Air Pressure Regulating Valve GLS gas liquid separator DIL Diluent WT Water storage tank OL outlet PP partition plate SP stirring plate CH1 1st communication port CH2 2nd communication port WB1 1st plate part WB2 2nd plate part R Radiator WP Water Pump CNV DC-DC converter B Energy storage device Cnt control unit

Claims

1. Fuel cells and A gas-liquid separator having a diluent into which the oxidizing agent gas and first generated water discharged from the fuel cell flow into a first space, the hydrogen gas and second generated water discharged from the fuel cell flow into a second space, and the hydrogen gas that has flowed into the second space is discharged to the outside from an outlet together with the oxidizing agent gas through the first space, and a water storage tank for storing the first and second generated waters, Equipped with, The aforementioned gas-liquid separator is, At least one first communication port for allowing the first and second generated waters to flow from the first space into the water storage tank, At least one second communication port for allowing the first and second generated waters to flow from the second space into the water storage tank, A first plate portion surrounds the first communication opening and extends from the first communication opening to the bottom side inside the water storage tank, A second plate portion surrounds the second communication opening and extends from the second communication opening towards the bottom of the water storage tank, A fuel cell module equipped with the following features.

2. A fuel cell module according to claim 1, The gas-liquid separator is provided between the first space and the second space and includes a partition plate that allows the hydrogen gas to accumulate in the second space. The second communication opening is provided near the partition plate. Fuel cell module.

3. A fuel cell module according to claim 1, The gas-liquid separator is provided in the first space and includes a stirring plate for stirring the oxidizing gas flowing into the first space. The first communication port is located near the stirring plate, on the side opposite to the side into which the oxidizing agent gas flows, with the stirring plate in between. Fuel cell module.

4. A fuel cell module according to claim 1, The distance between the first and second plate portions is less than or equal to a predetermined distance. Fuel cell module.

5. A fuel cell module according to claim 1 or claim 4, The inner diameter of the second plate portion is smaller than the inner diameter of the first plate portion. Fuel cell module.

6. A fuel cell module according to claim 1, The first plate portion extends from the first communication port toward the ceiling inside the diluent and has an opening toward the discharge port. Fuel cell module.

7. A fuel cell module according to claim 6, The aforementioned opening is located at a lower position than the aforementioned discharge port. Fuel cell module.

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