CN212907813U

CN212907813U - Fuel circulation pump, fuel gas supply system, and fuel cell system

Info

Publication number: CN212907813U
Application number: CN202022064548.6U
Authority: CN
Inventors: 孔丽超; 王飞; 廖至钢; 赵猛; 刘杨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2021-04-06
Anticipated expiration: 2030-09-18

Abstract

The present application provides a fuel circulation pump for a fuel cell system to deliver fuel gas. The fuel circulation pump includes a discharge valve that is switchable between an open state and a closed state, the discharge valve being in the closed state when liquid accumulated in a fuel delivery chamber is not higher than a predetermined threshold, the discharge valve being switched to the open state by the liquid to discharge a part of the liquid accumulated in the fuel delivery chamber out of the fuel circulation pump without discharging fuel gas when the liquid accumulated in the fuel delivery chamber is higher than the predetermined threshold. The fuel circulation pump can reduce waste of fuel gas, maintain stable pressure of the anode side and ensure safe and reliable operation of a fuel cell system. The present application also provides a fuel gas supply system for a fuel cell system and a fuel cell system.

Description

Fuel circulation pump, fuel gas supply system, and fuel cell system

Technical Field

The present application relates to the field of fuel cell systems, and more particularly to a fuel circulation pump for a fuel cell system, and a fuel gas supply system and a fuel cell system including such a fuel circulation pump.

Background

Fuel cell systems that generate electricity by an electrochemical reaction of a fuel gas and an oxidizing gas are increasingly used to provide electric power, particularly in the field of electric vehicles. During operation of the fuel cell system, product water, unconsumed fuel gas (e.g., hydrogen), and byproducts (e.g., nitrogen) may accumulate at the output of the anode side of the fuel cell stack. Unconsumed fuel gas is generally recirculated back to the fuel gas injection device by a fuel circulation pump to be supplied again to the fuel cell stack, thereby improving the operating efficiency of the fuel cell system.

A fuel circulation pump generally includes a housing defining a fuel delivery chamber and a fuel delivery mechanism disposed in the housing for flowing fuel gas in the fuel delivery chamber. The recycle stream, which includes product water, unconsumed fuel gas and byproducts, is first passed through a water separation device before entering the fuel circulation pump to remove the product water in the recycle stream. However, since it is difficult for the water separation device to completely remove the water in the recirculation flow, water may still accumulate in the fuel delivery chamber of the fuel circulation pump as the fuel circulation pump is operated for a long period of time. The accumulation of water in the fuel delivery chamber creates resistance to the operation of the fuel delivery mechanism, thereby resulting in a reduction in the operating efficiency of the fuel circulation pump.

Conventional fuel circulation pumps include an electrically controlled valve in communication with the fuel delivery chamber for draining liquid accumulated in the fuel delivery chamber out of the fuel circulation pump. The electrically controlled valve opens when water in the fuel delivery chamber accumulates to a certain amount so that the accumulated water is discharged out of the fuel circulation pump, for example into a vent pipe of the fuel cell system, under the pressure of the fuel gas. However, with the conventional fuel circulation pump using the electrically controlled valve, the fuel gas is discharged from the electrically controlled valve together with water during the water discharge, which results in a waste of the fuel gas and thus a reduction in the fuel utilization efficiency of the fuel cell system. On the other hand, the discharge of the fuel gas from the electrically controlled valve also causes fluctuations in the pressure on the anode side of the fuel cell stack, which may reduce the performance of the fuel cell. On the other hand, when the fuel gas is discharged into the exhaust pipe of the fuel cell system, the concentration of the fuel gas in the exhaust pipe becomes large. Because of the presence of oxygen in the exhaust pipe, there are safety-related risks (e.g. explosion in the exhaust pipe). In still another aspect, the electrically controlled valve is complicated in structure, thereby increasing the manufacturing cost and the assembly difficulty of the fuel circulation pump.

Therefore, there is a pressing need for improvements to existing fuel circulation pumps.

SUMMERY OF THE UTILITY MODEL

The present application is directed to an improved fuel circulation pump that overcomes at least one of the shortcomings of the prior fuel circulation pumps.

According to an aspect of the present application, there is provided a fuel circulation pump for a fuel cell system to deliver a fuel gas, including:

a housing defining a fuel delivery chamber; and

a fuel delivery mechanism provided in the housing for delivering a fuel gas;

characterized in that the fuel circulation pump further comprises a discharge valve in communication with the fuel delivery chamber, the discharge valve being switchable between an open state and a closed state, the discharge valve being in the closed state when the liquid accumulated in the fuel delivery chamber is not above a predetermined threshold, the discharge valve being switched to the open state under the action of the liquid to discharge a portion of the liquid accumulated in the fuel delivery chamber out of the fuel circulation pump without discharging the fuel gas when the liquid accumulated in the fuel delivery chamber is above the predetermined threshold.

Preferably, the discharge valve comprises:

a valve body including a valve cavity, an inlet passage communicating with the fuel delivery chamber to receive liquid, and a discharge passage communicable with the inlet passage and for discharging liquid out of the fuel circulation pump;

a valve piston disposed within the valve chamber and reciprocally movable within the valve chamber; and

a biasing member disposed within the valve chamber to apply a pushing force to the valve piston.

Preferably, the valve piston maintains the inlet passage separate from the discharge passage against the action of the weight of the liquid under the thrust of the biasing member when the liquid accumulated in the fuel delivery chamber is not above the predetermined threshold, and moves into communication with the inlet passage and the discharge passage against the action of the thrust of the biasing member under the action of the weight of the liquid when the liquid accumulated in the fuel delivery chamber is above the predetermined threshold.

Preferably, the biasing member is in the form of a spring having one end abutting the valve piston and the other end abutting the valve body.

Preferably, the biasing member is in the form of a spring having one end abutting the valve piston and the other end abutting a spring seat mounted to the valve body, the spring seat being capable of adjusting the thrust exerted by the biasing member on the valve piston.

Preferably, the spring seat is configured to set the thrust force exerted by the biasing member on the valve piston such that the discharge valve is in the closed state when the liquid accumulated in the fuel delivery chamber is not above a further threshold value, and the discharge valve switches to the open state under the action of the liquid when the liquid accumulated in the fuel delivery chamber is above the further threshold value, wherein the further threshold value is different from the predetermined threshold value.

Preferably, the valve body is formed integrally with the housing of the fuel circulation pump.

Preferably, the valve body is formed separately from the housing of the fuel circulation pump, and the discharge valve is detachably mounted to the fuel circulation pump.

Preferably, the fuel gas is hydrogen and the liquid is water.

According to another aspect of the present application, there is provided a fuel gas supply system for a fuel cell system, characterized by comprising:

a fuel gas injection device;

a water separation device; and

the above-described fuel circulation pump, which is provided between the water separation device and the fuel gas injection device.

According to still another aspect of the present application, there is provided a fuel cell system characterized by comprising the above-described fuel circulation pump or the above-described fuel gas supply system.

In the fuel circulation pump according to the present application, there is always liquid in the drain valve to provide a seal between the fuel gas in the fuel delivery chamber and the environment of the fuel circulation pump, so that the fuel gas does not escape via the drain valve during the liquid being drained out of the fuel circulation pump. This can reduce waste of the fuel gas, maintain the pressure of the anode side stable, and ensure safe and reliable operation of the fuel cell system.

Drawings

The above-described and other aspects of the present application will be more fully understood and appreciated in view of the accompanying drawings. It should be noted that the figures are merely schematic and are not drawn to scale. In the drawings:

fig. 1 schematically shows a fuel gas supply system for a fuel cell system;

FIG. 2 is a schematic cross-sectional view of a fuel circulation pump according to a preferred embodiment of the present application; and

fig. 3A and 3B are schematic enlarged views of the water discharge valve of the fuel circulation pump shown in fig. 2, in which the discharge valve is in a closed state in fig. 3A, and in which the discharge valve is in an open state in fig. 3B.

Detailed Description

Exemplary embodiments of the present application are described in detail below with reference to examples. It should be understood by those skilled in the art that these exemplary embodiments are not meant to limit the present application in any way. Furthermore, the features in the embodiments of the present application may be combined with each other without conflict. In the different drawings, the same or similar components are denoted by the same reference numerals, and other components are omitted for the sake of brevity, but this does not indicate that the fuel circulation pump of the present application may not include other components. It should be understood that the dimensions, proportions and numbers of elements in the drawings are not intended to limit the present application.

Fuel cell systems, such as Proton Exchange Membrane Fuel Cells (PEMFCs), may be used in vehicles to provide electrical power to drive motors to provide power or to cause on-board systems to perform various functions. Fig. 1 schematically shows a part of a fuel cell system, which may include a fuel cell stack 1 and a fuel gas supply system 9. As shown in fig. 1, the fuel cell stack 1 includes an anode side 3 and a cathode side 5. A fuel gas (e.g., hydrogen) from the fuel source 7 is supplied to an input 13 of the anode side 3 through a fuel gas injection device 11 of the fuel gas supply system 9. Typically, excess fuel gas is provided to the input 13 of the anode side 3 to ensure that sufficient fuel gas is available to all cells in the fuel cell stack 1. During operation of the fuel cell system, product water, unconsumed fuel gas (e.g. hydrogen) and by-products (e.g. nitrogen) may accumulate at the output 15 of the anode side 3.

With continued reference to fig. 1, a recirculation loop 17 of the fuel gas supply system 9 may be provided between the output 15 of the anode side 3 and the fuel gas injection device 11 to recirculate unconsumed fuel gas back to the fuel gas injection device 11. The fuel gas injection device 11 mixes unconsumed fuel gas with fuel gas from the fuel source 7 and supplies it again to the input 13 of the anode side 3. The recirculation circuit 17 generally comprises a water separation device 19 connected to the output 15 of the anode side 3 and a fuel circulation pump 100 connected between the water separation device 19 and the fuel gas injection device 11. The water separation device 19 receives a recycle stream 23 (i.e., a fluid mixture including product water, unconsumed fuel gas (e.g., hydrogen), and byproducts (e.g., nitrogen) from the output 15 of the anode side 3) and removes the product water from the recycle stream 23. The water removed by the water separation device 19 can be discharged out of the water separation device 19 through a discharge channel (as indicated by the dashed arrow 25), for example into an exhaust pipe of the fuel cell system. The water-removed recirculation flow 23 is sent to the fuel gas injection device 11 by the fuel circulation pump 100 to be mixed with the fuel gas from the fuel source 7 and supplied again to the input end 13 of the anode side 3, thereby avoiding waste of the fuel gas and improving the utilization efficiency of the fuel gas.

Although the recirculation stream 23 first passes through the water separation device 19 to remove product water in the recirculation stream 23 before entering the fuel circulation pump 100, water may still accumulate in the fuel circulation pump 100 as the fuel circulation pump 100 runs for a long period of time due to the difficulty of the water separation device 19 to completely remove water in the recirculation stream 23. The accumulation of water in the fuel circulation pump 100 may cause a reduction in the operating efficiency of the fuel circulation pump 100. As described in the background section, the use of electrically controlled valves in existing fuel circulation pumps to drain accumulated water out of the fuel circulation pump presents a number of problems: on the one hand, during the draining, the fuel gas is discharged from the electrically controlled valve together with water, which results in a waste of the fuel gas and thus a reduction in the fuel utilization efficiency of the fuel cell system; on the other hand, the discharge of the fuel gas from the electrically controlled valve also causes fluctuations in the pressure on the anode side of the fuel cell stack, which may reduce the performance of the fuel cell; on the other hand, when the fuel gas is discharged into the exhaust pipe of the fuel cell system, the concentration of the fuel gas in the exhaust pipe becomes large, and there is a risk associated with safety (for example, explosion occurs in the exhaust pipe) due to the presence of oxygen in the exhaust pipe; in yet another aspect, the electrically controlled valve is complex and costly.

To overcome at least one of the drawbacks of the existing fuel circulation pumps, the present application proposes a new type of fuel circulation pump 100.

As shown in fig. 2, the fuel circulation pump 100 may include a casing 101 and a fuel delivery mechanism 103 provided in the casing 101 for delivering fuel gas (e.g., hydrogen gas). The fuel delivery mechanism 103 may include an impeller 105 and a motor 107 for driving the impeller 105 in rotation. The housing 101 may define a fuel delivery chamber 109 for delivering fuel gas and a motor chamber 111 for housing a rotor 113 of the motor 107. The impeller 105 may be disposed in the fuel delivery chamber 109 and rotated by a rotor 113 of the motor 107 via a shaft 115 to cause the fuel gas to flow within the fuel delivery chamber 109. Correspondingly, the housing 101 may further define an inlet (not shown) and an outlet (not shown) communicating with the fuel delivery chamber 109 for inlet and outlet of fuel, respectively, wherein the inlet is for connection with the outlet of the water separation device 19 and the outlet is for connection with the fuel gas injection device 11. In this way, the fuel circulation pump 100 can pump the recirculation flow 23 passing through the water separation device 19 to the fuel gas injection device 11.

In the embodiment shown in fig. 2, the housing 101 of the fuel circulation pump 100 is a split structure, and includes a main body 101a, a cover 101b, and a motor housing 101 c. The body 101a and the cover 101b define a fuel delivery chamber 109, and the motor housing 101c defines a motor chamber 111. A stator (not shown) of the motor 107 may be mounted to the motor housing 101c to surround the rotor 113. The rotating shaft 115 of the rotor 113 is rotatably supported by

bearings

117 and 119, and protrudes through the main body 101a into the fuel delivery chamber 109 to be coupled to the impeller 105 and drive the impeller 105 to rotate. The body 101a, cover 101b and motor housing 101c may be manufactured in a manner known in the art and may be fixedly connected by a connection means known in the art. Sealing

members

121 and 123, such as O-rings, may be provided between the body 101a, the cover 101b, and the motor housing 101c to form a hermetic seal to prevent fuel gas from leaking and exploding.

With continued reference to fig. 2, the fuel circulation pump 100 may further include a drain valve 125, and the drain valve 125 may be in communication with the fuel delivery chamber 109 for draining liquid (typically water) accumulated in the fuel delivery chamber 109 out of the fuel circulation pump 100. In the embodiment shown in fig. 2, a drain valve 125 is provided in the cover 101b at the bottom 109a of the fuel delivery chamber 109. With further reference to fig. 3A and 3B, the vent valve 125 is switchable between an open state (fig. 3B) and a closed state (fig. 3A). Specifically, when the liquid accumulated in the fuel delivery chamber 109 (as indicated by the dark regions W) is not higher than (does not exceed) the predetermined threshold, the discharge valve 125 is in the closed state, and when the liquid accumulated in the fuel delivery chamber 109 is higher than (exceeds) the predetermined threshold, the discharge valve 125 is switched to the open state by the liquid to discharge a part of the liquid accumulated in the fuel delivery chamber 109 out of the fuel circulation pump 100 without discharging the fuel gas (as indicated by the dark regions G). The predetermined threshold may correspond to an amount of liquid that accumulates in the fuel delivery chamber 109 that may impede the rotation of the impeller 105. In contrast to electrically controlled valves, the control logic is simplified because the drain valve 125 can switch between the open and closed states directly depending on the amount of liquid accumulated in the fuel delivery chamber 109.

One preferred version of the discharge valve 125 is described in detail below. As shown in fig. 3A and 3B, the discharge valve 125 may include a valve body 129. The valve body 129 may include a valve cavity 127, an inlet passage 127a communicating with the fuel delivery chamber 109 to receive liquid, and a discharge passage 127b communicable with the inlet passage 127a and for discharging liquid out of the fuel circulation pump 100. The discharge valve 125 may further include a valve piston 131 disposed within the valve chamber 127 and capable of reciprocating within the valve chamber 127, and a biasing member 133 disposed within the valve chamber 127 to apply a thrust force to the valve piston 131. As shown in fig. 3A, when the liquid accumulated in the fuel delivery chamber 109 is not higher than the predetermined threshold, the valve piston 131 keeps the inlet passage 127a isolated from the discharge passage 127b against the action of the weight of the liquid under the urging force of the biasing member 133. At this time, the drain valve 125 is in a closed state, and the liquid accumulated in the fuel delivery chamber 109 cannot be discharged out of the fuel circulation pump 100 through the drain valve 125. As shown in fig. 3B, when the liquid accumulated in the fuel delivery chamber 109 is higher than a predetermined threshold, the valve piston 131 moves against the urging force of the biasing member 133 under the weight of the liquid to communicate the intake passage 127a with the discharge passage 127B. At this time, the drain valve 125 is in an open state, and a portion of the liquid accumulated in the fuel delivery chamber 109 is discharged out of the fuel circulation pump 100 via the drain passage 127B (as indicated by an arrow 137 in fig. 3B). When the liquid accumulated in the fuel delivery chamber 109 decreases to not higher than the predetermined threshold, the valve piston 131 returns to the closed state against the action of the weight of the liquid under the thrust force of the biasing member 133, again isolating the intake passage 127a from the discharge passage 127 b. In this way, liquid is always present in the valve cavity 127 of the drain valve 125 to provide a seal between the fuel gas in the fuel delivery chamber 109 and the environment of the fuel circulation pump 100 so that fuel gas does not escape via the drain valve 125 during the time that liquid is being drained out of the fuel delivery chamber 109. This can reduce the waste of the fuel gas, thereby maintaining the pressure of the anode side stable and ensuring safe and reliable operation of the fuel cell system. On the other hand, the discharge valve 125 is simple in structure and easy to assemble, thereby reducing the manufacturing cost and the assembly difficulty of the fuel circulation pump.

In the embodiment shown in fig. 3A and 3B, the biasing member 133 is in the form of a spring having one end abutting the valve piston 131 and the other end abutting a spring seat 135 mounted to the valve body 129. The spring seat 135 can adjust the thrust force that the biasing member 133 applies to the valve piston 131. For example, the urging force exerted by the biasing member 133 against the valve piston 131 can be adjusted by changing the height of the spring seat 135. The provision of spring seat 135 may provide a number of advantages. On the one hand, as the discharge valve 125 operates for a long time, the biasing member 133 may be aged, and its thrust force applied to the valve piston 131 may be changed. In this case, the urging force exerted by the biasing member 133 on the valve piston 131 can be adjusted by adjusting the spring seat 135 so that the valve piston 131 can still isolate the intake passage 127a from the discharge passage 127b against the urging force of the liquid under the urging force of the biasing member 133 when the liquid accumulated in the fuel delivery chamber 109 is not higher than the predetermined threshold, and move against the urging force of the biasing member 133 under the urging force of the liquid to communicate the intake passage 127a with the discharge passage 127b when the liquid accumulated in the fuel delivery chamber 109 is higher than the predetermined threshold. This makes it possible to keep fuel gas from escaping via the drain valve 125 during the time that liquid is being drained out of the fuel delivery chamber 109. On the other hand, the thrust force that the biasing member 133 applies to the valve piston 131 may be adjusted by the adjustment spring seat 135 such that: when the liquid accumulated in the fuel delivery chamber 109 is not higher than another threshold value different from (greater than or less than) the predetermined threshold value, the discharge valve 125 is in a closed state, and when the liquid accumulated in the fuel delivery chamber 109 is higher than the other threshold value, the discharge valve 125 is switched to an open state by the weight of the liquid to discharge a part of the liquid without discharging the fuel gas. In this way, a user may be enabled to control the amount of water accumulated in the fuel delivery chamber 109 by simply adjusting the spring seat 135 according to various operating conditions, thereby ensuring efficient operation of the fuel circulation pump 100. It should be appreciated that in other embodiments, one end of the biasing member 133 may abut the valve piston 131 and the other end may abut directly against the valve body 129.

In the embodiment shown in fig. 3A and 3B, the valve body 129 of the discharge valve 125 may be integrally formed with the casing 101 of the fuel circulation pump 100, for example, with the main body 101a or the cover 101B. This facilitates assembly of the fuel circulation pump 100 and reduces the occupied space of the fuel circulation pump 100. In other partial embodiments, the valve body 129 of the discharge valve 125 may also be formed separately from the casing 101 of the fuel circulation pump 100, and the discharge valve 125 is detachably mounted to the fuel circulation pump 100.

It should be understood that the drain valve 125 may also take other suitable forms, as long as it is capable of being in a closed state when the liquid accumulated in the fuel delivery chamber 109 is not above a predetermined threshold, and switching to an open state under the action of the liquid to drain a portion of the liquid accumulated in the fuel delivery chamber 109 out of the fuel circulation pump 100 without draining fuel gas when the liquid accumulated in the fuel delivery chamber 109 is above the predetermined threshold.

The fuel circulation pump 100 according to the present application always has liquid present in the drain valve 125 to provide a seal between the fuel gas in the fuel delivery chamber 109 and the environment of the fuel circulation pump 100 so that fuel gas does not escape via the drain valve 125 during the liquid being drained out of the fuel circulation pump 100. This can reduce waste of the fuel gas, maintain the pressure of the anode side stable, and ensure safe and reliable operation of the fuel cell system.

The present application is described in detail above with reference to specific embodiments. It is to be understood that both the foregoing description and the embodiments shown in the drawings are to be considered exemplary and not restrictive of the application. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit of the application, and these changes and modifications do not depart from the scope of the application.

Claims

1. A fuel circulation pump (100) for a fuel cell system for delivering a fuel gas, comprising:

a housing (101), the housing (101) defining a fuel delivery chamber (109); and

a fuel delivery mechanism (103) provided in the housing (101) for delivering a fuel gas;

characterized in that the fuel circulation pump (100) further comprises a discharge valve (125), the discharge valve (125) being in communication with the fuel delivery chamber (109), the discharge valve (125) being switchable between an open state and a closed state, the discharge valve (125) being in the closed state when the liquid accumulated in the fuel delivery chamber (109) is not higher than a predetermined threshold, the discharge valve (125) being switched to the open state under the action of the liquid to discharge a portion of the liquid accumulated in the fuel delivery chamber (109) out of the fuel circulation pump (100) without discharging the fuel gas when the liquid accumulated in the fuel delivery chamber (109) is higher than the predetermined threshold.

2. The fuel circulation pump (100) of claim 1, wherein the drain valve (125) comprises:

a valve body (129), the valve body (129) comprising a valve cavity (127), an inlet passage (127a) communicating with the fuel delivery chamber (109) to receive liquid, and a discharge passage (127b) communicable with the inlet passage (127a) and for discharging liquid out of the fuel circulation pump (100);

a valve piston (131) disposed within the valve chamber (127) and reciprocally movable within the valve chamber (127); and

a biasing member (133) disposed within the valve chamber (127) to apply a thrust force to the valve piston (131).

3. The fuel circulation pump (100) of claim 2, wherein the valve piston (131) keeps the inlet passage (127a) isolated from the discharge passage (127b) against the action of the thrust of the biasing member (133) when the liquid accumulated in the fuel delivery chamber (109) is not above the predetermined threshold, and wherein the valve piston (131) moves against the action of the thrust of the biasing member (133) under the action of the thrust of the liquid to place the inlet passage (127a) in communication with the discharge passage (127b) when the liquid accumulated in the fuel delivery chamber (109) is above the predetermined threshold.

4. A fuel circulation pump (100) according to claim 3, wherein the biasing member (133) is in the form of a spring, one end of which abuts the valve piston (131) and the other end of which abuts the valve body (129).

5. A fuel circulation pump (100) according to claim 3, wherein the biasing member (133) is in the form of a spring having one end abutting the valve piston (131) and the other end abutting a spring seat (135) mounted to the valve body (129), the spring seat (135) being capable of adjusting the thrust exerted by the biasing member (133) on the valve piston (131).

6. The fuel circulation pump (100) of claim 5, wherein the spring seat (135) is configured to set the thrust exerted by the biasing member (133) on the valve piston (131) such that the drain valve (125) is in the closed state when the liquid accumulated in the fuel delivery chamber (109) is not above a further threshold value, and the drain valve (125) switches to the open state under the action of the liquid when the liquid accumulated in the fuel delivery chamber (109) is above the further threshold value, wherein the further threshold value is different from the predetermined threshold value.

7. The fuel circulation pump (100) of any one of claims 2-6, characterized in that:

the valve body (129) is formed integrally with the housing (101) of the fuel circulation pump (100); or

The valve body (129) is formed separately from the housing (101) of the fuel circulation pump (100), and the discharge valve (125) is detachably mounted to the fuel circulation pump (100).

8. The fuel circulation pump (100) of claim 1, wherein the fuel gas is hydrogen and the liquid is water.

9. A fuel gas supply system (9) for a fuel cell system, characterized in that the fuel gas supply system (9) comprises:

a fuel gas injection device (11);

water separation means (19); and

the fuel circulation pump (100) of any one of claims 1 to 8, the fuel circulation pump (100) being disposed between the water separation device (19) and the fuel gas injection device (11).

10. A fuel cell system characterized by comprising the fuel circulation pump (100) according to any one of claims 1 to 8 or the fuel gas supply system (9) according to claim 9.