JP7013944B2 - Fuel cell system with cooling mechanism - Google Patents

Description

The present invention relates to a fuel cell system including a cooling mechanism.

In the fuel cell system, a cooling mechanism is used to reduce the temperature of the fuel cell whose temperature rises due to operation. The cooling mechanism includes a radiator for heat dissipation, a circulation flow path for circulating a refrigerant such as antifreeze and cooling water between the fuel cell and the radiator, and a temperature sensor for detecting the temperature of the refrigerant cooled by the radiator.

In the cooling mechanism of the fuel cell system, as shown in Patent Document 1, a bypass path may be provided in order to circulate at least a part of the refrigerant without passing through a radiator. In this case, a diversion valve is provided at the branch portion to the bypass path to switch between the flow path to the radiator and the bypass path, or to distribute the refrigerant to both channels at a predetermined ratio. By controlling this shunt valve, the temperature of the refrigerant supplied to the fuel cell is controlled to be appropriate for the operation of the fuel cell.

Japanese Unexamined Patent Publication No. 2008-300068

A fuel cell system equipped with such a cooling mechanism is an excellent one that appropriately controls the temperature of the fuel cell, but it appropriately detects the amount of cooling by the radiator and controls the distribution ratio of the refrigerant to the bypass flow path. In that respect, further improvement was required.

In particular, when the fuel cell system is mounted on a large vehicle, the cooling capacity of the radiator is increased, so the refrigerant cooled through the radiator and the bypass flow path at the temperature warmed by the fuel cell are used. There is a high demand for proper control of the diversion ratio with the passing refrigerant.

The present invention is based on these problems and can be realized in the following aspects.

As one embodiment, a fuel cell system with a cooling mechanism is provided. This fuel cell system is equipped with a cooling mechanism. The cooling mechanism includes a radiator that cools the refrigerant; a refrigerant discharge flow path that connects the refrigerant discharge port of the fuel cell to the refrigerant inlet of the radiator; and a refrigerant that connects the refrigerant outlet of the radiator to the refrigerant supply port of the fuel cell. A circulation flow path; a bypass flow path that connects the refrigerant discharge flow path and the refrigerant circulation flow path by bypassing the radiator; a bypass flow path provided at one end of the bypass flow path and discharged by the refrigerant discharge flow path. A diversion valve that adjusts the ratio of the refrigerant flowing through the radiator and the refrigerant flowing through the bypass flow path among the refrigerants; the pipe pass flow path and the refrigerant circulation flow downstream of the refrigerant outlet of the radiator. It is equipped with a temperature sensor provided at a position separated by a predetermined distance or more on the upstream side from the confluence with the road. Such a fuel cell system controls the ratio of the diversion valve by the temperature of the refrigerant detected by the temperature sensor.

In this fuel cell system, the temperature sensor is provided on the downstream side of the refrigerant outlet of the radiator and at a position separated by a predetermined distance or more on the upstream side from the confluence of the bypass flow path and the refrigerant circulation flow path. The temperature sensor is not easily affected by the temperature of the refrigerant flowing through the bypass flow path, and can appropriately detect the temperature of the refrigerant cooled by the radiator.

The schematic block diagram which shows the fuel cell system of 1st Embodiment centering on a cooling mechanism. An explanatory diagram illustrating the relationship between the two radiators and the bypass flow path in the first embodiment. The explanatory view which shows an example of the temperature distribution of the radiator return flow path in 1st Embodiment. Explanatory drawing which shows an example of the temperature distribution in the radial direction of the cooling water in the pipe of a radiator return flow path. Explanatory drawing which shows the point of temperature measurement in a radiator return flow path. Explanatory drawing which shows an example of the temperature distribution in the flow path direction of the radiator return flow path at each point shown in FIG. The schematic block diagram which shows the fuel cell system of 2nd Embodiment centering on a cooling mechanism. An explanatory diagram illustrating a desirable relationship between an inlet and an outlet of cooling water when the flow path in the radiator is horizontal. An explanatory diagram illustrating a desirable relationship between an inlet and an outlet of cooling water when the flow path in the radiator is vertical.

A1. Hardware configuration of the embodiment:
As shown in FIG. 1, the fuel cell system 10 of the first embodiment includes a fuel cell 20 that generates power by being supplied with a fuel gas and an oxidizing agent gas, and a cooling mechanism 30 that circulates cooling water as a refrigerant in the fuel cell 20. It includes a control unit 80 and the like that control the fuel cell 20 and the cooling mechanism 30. The fuel cell 20 is mounted on a vehicle, and the generated electric power is supplied to a motor for driving the vehicle or the like. Since the configuration for supplying fuel gas or the like to the fuel cell 20 to generate power and the power system for appropriately supplying the power generated by the fuel cell 20 to the load are well known, the illustration and description thereof are omitted. ..

The cooling mechanism 30 includes a battery-side discharge flow path 32 and a radiator-side discharge flow path 33 constituting the refrigerant discharge flow path, a battery-side circulation flow path 31 constituting the refrigerant circulation flow path, a radiator return flow path 34, and a bypass flow path 40. , Cooling water pump 51, diversion valve 52, first and second temperature sensors 61, 62, first and second radiators 71, 72, first and second fans 73 for cooling the first and second radiators 71 and 72. , 74 and the like. The cooling water, which is a refrigerant, is pumped by the cooling water pump 51 in the cooling mechanism 30 and circulates between the cooling passages in the fuel cell 20 and the first and second radiators 71 and 72.

One end of the battery side discharge flow path 32 is connected to the cooling water discharge port 22 of the fuel cell 20, and the other end of the battery side discharge flow path 32 is connected to the radiator side discharge flow path 33 and the bypass flow path by the flow dividing valve 52. It is connected to 40. The radiator side discharge flow path 33 is connected to the first and second radiators 71 and 72 at the confluence point GP1. The merging point GP1 is a merging point to which the pipes from the flow path inlet sides of the first and second radiators 71 and 72 are connected, and the cooling water flowing through the divergence valve 52 and the radiator side discharge flow path 33 is this. It flows from the confluence GP1 to the radiators 71 and 72.

The cooling water that has flowed into the first and second radiators 71 and 72 passes through the cooling flow path inside the radiator and flows out from the flow path outlet side of each radiator 71 and 72. One end of the radiator return flow path 34 is connected to the confluence GP2 to which the piping from the flow path outlet side is connected. The other end of the radiator return flow path 34 is connected to the confluence point GP3 with the bypass flow path 40. A battery-side circulation flow path 31 connected to the cooling water supply port 21 of the fuel cell 20 is also connected to the confluence GP3, and the cooling water from the first and second radiators 71 and 72 passes through the bypass flow path 40. It merges with the flowing cooling water and flows from the confluence point GP3 into the cooling water supply port 21 of the fuel cell via the battery-side circulation flow path 31. Such a flow of cooling water is created by the cooling water pump 51.

The diversion valve 52 provided at the connection point of the battery side discharge flow path 32, the radiator side discharge flow path 33, and the bypass flow path 40 allows the cooling water from the battery side discharge flow path 32 to be bypassed to the radiator side discharge flow path 33 side. It is configured as an electric three-way valve that distributes to the flow path 40 side. The shunt valve 52 changes the opening degree of the internal valve in response to a command from the control unit 80, and the ratio of the cooling water flowing to the radiator side discharge flow path 33 side, that is, the first and second radiators 71 and 72 side. And the ratio of the cooling water flowing to the bypass flow path 40 side are adjusted. The shunt valve 52 is of a type driven by a motor, but it can also be configured by using an actuator of another type such as a solenoid.

The control unit 80 is a signal from a first temperature sensor 61 that detects the water temperature T1 of the cooling water in the radiator return flow path 34, a second temperature sensor 62 that detects the temperature T2 of the cooling water in the battery side discharge flow path 32, and the like. Is input to control the drive amount of the cooling water pump 51, the opening degree of the shunt valve 52, and the air flow amount of the first and second fans 73 and 74 for cooling the first and second radiators 71 and 72. The control of the diversion valve 52 by the control unit 80 will be described later. Although the control unit 80 also controls the fuel cell 20, a control ECU or the like for the fuel cell 20 may be provided separately from the control unit 80 to exchange necessary data by communication or the like.

FIG. 2 is an explanatory diagram illustrating the relationship between the two radiators and the bypass flow path in the first embodiment. The flow of the cooling water will be collectively described with reference to FIG. The cooling water F1 flowing from the cooling water discharge port 22 of the fuel cell 20 to the battery side discharge flow path 32 is diverted by the flow dividing valve 52 and heads for the first and second radiators 71 and 72 via the radiator side discharge flow path 33. It is divided into the cooling water F2 and the cooling water Fb flowing through the bypass flow path 40. The cooling water F2 flowing through the radiator side discharge flow path 33 toward the radiator side branches at the confluence GP1, and becomes the cooling water F11 flowing through the first radiator 71 and the cooling water F12 flowing through the second radiator 72. The cooling water cooled by the first and second radiators 71 and 72 and whose temperature has dropped is merged at the confluence point GP2. The cooling water F3 after merging flows through the radiator return flow path 34 and merges with the cooling water Fb flowing through the bypass flow path 40 at the merging point GP3. The cooling water F4 merged at the confluence point GP3 is pumped by the cooling water pump 51 and supplied to the cooling water supply port 21 of the fuel cell 20 through the battery-side circulation flow path 31. The radiator return flow path 34 is provided with a first temperature sensor 61 at a position W separated from the position R of the confluence GP3 by a predetermined distance L.

A2. Control of shunt valve:
In the above-mentioned cooling water flow, while the fuel cell 20 is normally operated, the cooling water is used to cool the fuel cell 20 and raises the temperature. Therefore, the cooling water discharge port 22 discharges the battery side. The cooling water toward the shunt valve 52 via the path 32 is heated by the heat generated by the fuel cell 20, and is cooled by the first and second radiators 71 and 72. On the other hand, since the fuel cell 20 is cold at the time of starting the fuel cell 20, the ratio of supplying the cooling water to the first and second radiators 71 and 72 to cool the fuel cell 20 is reduced, and the water temperature of the cooling water drops too much. The time required for warming up the fuel cell 20 is shortened by avoiding the above.

Therefore, the control unit 80 detects the temperature T2 of the cooling water passing through the battery side discharge flow path 32, that is, the temperature of the fuel cell 20 by the second temperature sensor 62, and cools by the first and second radiators 71 and 72. The temperature T1 of the cooling water is detected by the first temperature sensor 61, and the temperature of the cooling water supplied to the fuel cell 20 via the battery-side circulation flow path 31 is set in an appropriate range so that the temperature of the cooling water is within an appropriate range. By passing through the opening degree, that is, the bypass flow path 40, the ratio of the cooling water that is not cooled by the first and second radiators 71 and 72 is controlled. Assuming that the shunt valve 52 is controlled to a predetermined opening and 100 · α% (0 ≦ α ≦ 1) of the cooling water F1 passes through the bypass flow path 40, the water temperature Th after merging at the merging point GP3. Follows the following equation (1), ignoring the temperature change in the flow path.
Th = T2 ・ α + T1 ・ (1-α)… (1)
The control unit 80 controls the opening degree of the flow dividing valve 52 so that the water temperature Th of the cooling water supplied to the fuel cell 20 is in an appropriate temperature range when viewed from the current operating state of the fuel cell 20. Of course, the control unit 80 also controls the driving amount of the cooling water pump 51, that is, the supply amount of the cooling water, the rotation speeds of the first and second fans 73, 74, that is, the cooling capacity of the cooling mechanism 30 and the like. Then, the water temperature Th of the cooling water supplied to the fuel cell 20 is controlled within an appropriate range.

In the first embodiment, the radiator return flow path 34 has a slight uphill slope from the confluence GP2 to the confluence GP3, as shown in FIG. Generally, when the high-temperature cooling water comes into contact with the cooling water having a lower temperature, it stays upward due to the difference in specific gravity and is difficult to descend. The backflow of the cooling water to the radiator return flow path 34 can be reduced. By reducing the backflow, the distance L at which the arrangement of the first temperature sensor 61 should be separated from the confluence GP3 can be reduced, which can contribute to the miniaturization of the cooling mechanism 30.

A3. Placement of temperature sensor:
FIG. 3 is an explanatory diagram showing an example of the form of the radiator return flow path 34 in the first embodiment and the temperature distribution in the same flow path. The radiator return flow path 34 is a pipe connecting the confluence point GP2 and the confluence point GP3. As illustrated in FIG. 3, in the first embodiment, the radiator return flow path 34 is changed from the confluence point GP2 to the confluence point GP3. It is an uphill slope. Further, the lower part of FIG. 3 shows an example of the water temperature of the cooling water in the radiator return flow path 34, with the merging point GP2 as the position R, the merging point GP3 as the position B, and the first temperature sensor 61 as the position W.

The graph WTC of FIG. 3 shows an example of a case where the fuel cell 20 is operated and the temperature of the cooling water discharged from the fuel cell 20 rises constantly to reach the temperature T2. Further, it is assumed that the flow dividing valve 52 divides about half (α = 0.5) of the cooling water flowing through the battery side discharge flow path 32 into the bypass flow path 40. As shown in the figure, at the position B of the confluence GP3, the cooling water having a temperature T2 flows from the bypass flow path 40, and the cooling water after being cooled to the temperature T1 is flown from the first and second radiators 71 and 72. Is flowing in. In this case, the temperature Th of the cooling water at the confluence GP3 is according to the above equation (1).
Th = 0.5 ・ T2 + 0.5 ・ T1
Will be. At the confluence point GP3, the cooling water from the two flow paths merges, so that some of the cooling water that has passed through the bypass flow path 40 flows back to the radiator return flow path 34 side to some extent. Therefore, the influence of the cooling water having the temperature T2 flowing back from the bypass flow path 40 extends from the position B of the confluence GP3 to a predetermined range in the upstream direction in the radiator return flow path 34. However, since the cooling water flows from the first and second radiators 71 and 72 to the fuel cell 20 side, the backflowing cooling water does not enter beyond a certain distance, and the range of its influence is limited. It will be something like that.

In the present embodiment, the first temperature sensor 61 avoids the range in which the influence of the cooling water at the temperature T2 extends from the confluence GP3, and specifically, the first temperature sensor 61 is separated from the confluence GP3 by 50 mm or more upstream and the confluence GP2. It is provided at the position W on the downstream side. Therefore, the first temperature sensor 61 detects the temperature of the cooling water cooled by the first and second radiators 71 and 72 accurately or by suppressing the influence of the temperature of the cooling water flowing through the bypass flow path 40. be able to. Therefore, the control unit 80 can appropriately control the opening degree of the flow dividing valve 52 by knowing the temperature T1 of the cooling water cooled by the first and second radiators 71 and 72. Similarly, the rotation speeds of the first and second fans 73 and 74 and the rotation speeds of the cooling water pump 51, that is, the cooling capacity can be appropriately controlled. In the present embodiment, the position W of the first temperature sensor 61 is set to be 50 mm or more upstream from the position B of the confluence GP3, but this distance generally has a correlation with the inner diameter of the flow path and the flow rate. In this embodiment, it was found that the steady flow rate of the cooling water pump 51 should be arranged upstream by about 1.5 to 2 times or more the inner diameter of the pipe.

In the present embodiment, the tip of the first temperature sensor 61 is arranged so that the temperature sensitive portion is located substantially in the center of the pipe of the radiator return flow path 34. This situation is shown in FIG. FIG. 4 schematically shows a 4-4 cross section in FIG. 3, and shows an example of the radial temperature distribution of the cooling water at this position W. In FIG. 4, it is shown that the higher the hatching is, the higher the temperature is. However, the actual temperature distribution is not divided as shown in FIG. 4, and is distributed without boundaries. Such a temperature distribution is caused by the fact that the water temperatures of both the cooling waters flowing from the first radiator 71 and the second radiator 72 do not match at the confluence GP2. Moreover, since the two pipes from the first and second radiators 71 and 72 are joined in a plane in a substantially horizontal direction, a temperature distribution is generated in a substantially horizontal direction in the present embodiment.

As described above, if the temperature in the radiator return flow path 34 is not uniform, the detection of the water temperature by the first temperature sensor 61 may be inaccurate. Therefore, the radial temperature distribution in the radiator return flow path 34 was examined. FIG. 5 is an explanatory diagram showing the radial position of the temperature measurement point in the radiator return flow path 34. The measurement was performed with the center of the pipe as the measurement point C0 and the points separated from this point C0 by 7.5 mm in the vertical, right, and left directions as points C1, C2, C3, and C4. For the measurement, a thermocouple having a small diameter that does not obstruct the flow of cooling water was used instead of a sensor housed in a pipe having a predetermined diameter having corrosion resistance in consideration of durability, such as the first temperature sensor 61. FIG. 6 shows an example of the temperature distribution. In this example, the diversion valve 52 is closed and the cooling water does not join from the bypass flow path 40. As shown in the figure, the diameter in the radiator return flow path 34 at any of the position B of the merging point GP3, the position W separated from the merging point GP3 position B by 50 mm or more in the upstream direction, and the position R of the merging point GP2. The temperature distribution was uneven in the direction. In the figure, “● Ave” is an example of the average value of the temperatures detected at each measurement point C0 to C5. At the position W separated from the position B of the confluence GP3 in the upstream direction by 50 mm or more, the detected value at the point C0 of the center was within the predetermined allowable range ΔT with respect to the average value Ave. Therefore, the first temperature sensor 61 is attached to the radiator return flow path 34 so that the temperature sensing portion serves as the radial center of the piping of the radiator return flow path 34.

B. Second embodiment:
FIG. 7 is a schematic configuration diagram showing the fuel cell system 10A of the second embodiment centered on the cooling mechanism 30A. As shown in the figure, the second embodiment differs from the first embodiment in that only the first radiator 71 is used as the radiator. Therefore, in the second embodiment, the second fan 74 is also not used. Also, there are no confluence points GP1 and GP2. In the following description, for convenience of explanation, the elbow provided at the position where the flow path from the shunt valve 52 is connected to the inlet of the first radiator 71 is referred to as a connection point GP4, and the outlet of the first radiator 71 returns the radiator. The elbow provided at the location connected to the flow path 34 may be referred to as a connection point GP5.

Even in the second embodiment configured in this way, the first temperature sensor 61 is separated from the confluence point GP3 of the radiator return flow path 34 and the bypass flow path 40 by 50 mm or more on the upstream side, and is on the downstream side of the connection point GP5. It is provided at the position of. Therefore, as in the first embodiment, the temperature of the cooling water after being cooled by the first radiator 71 is not affected by the temperature of the cooling water flowing through the bypass flow path 40, or is sufficiently affected by the temperature. It can be suppressed and detected. Therefore, the control unit 80 can appropriately grasp the state of the cooling mechanism 30A according to the temperature of each cooling water detected by the first temperature sensor 61 and the second temperature sensor 62, and can appropriately grasp the state of the cooling mechanism 30A, such as the diversion valve 52 of the cooling mechanism 30A. It can be controlled properly.

C1. Other embodiments:
Although some embodiments have been described above, the embodiment of the cooling mechanism is not limited to the configuration disclosed as the first and second embodiments. For example, the radiator may be configured to include three or more radiators. Further, the heat exchange piping inside the radiator may be horizontal piping or vertical piping. FIG. 8 is an explanatory diagram illustrating a desirable relationship between an inlet and an outlet of cooling water when the flow path in the radiator is in the horizontal direction. Further, FIG. 9 is an explanatory diagram illustrating a desirable relationship between the inlet and the outlet of the cooling water when the flow path for heat exchange in the radiator is in the vertical direction. As shown in the figure, in the case of the horizontal pipe (FIG. 8), the cooling water distribution manifold 75L is provided along the vertical direction on one side of the radiator 79 in the horizontal direction. Cooling water enters the cooling water distribution manifold 75L from the cooling water inlet 76i provided slightly above the center thereof, and while exchanging heat through a plurality of horizontal pipes, the cooling water merges provided at the other end. Meet at the manifold 75R. The combined cooling water exits from the cooling water outlet 76o provided slightly above the center of the cooling water confluence manifold 75R, and flows through the radiator return flow path 34.

When the radiator 79 is used alone as in the example shown as the second embodiment, the first temperature sensor 61 may be provided in the cooling water confluence manifold 75R of the radiator 79. Even in this case, it is sufficient that the cooling mechanism 30A illustrated in FIG. 7 or the like is separated from the confluence GP3 by 50 mm or more on the upstream side. In this case, it is more preferably installed vertically downward from the cooling water outlet 76o. By doing so, even if the high-temperature cooling water flowing back from the confluence GP3 accidentally reaches the cooling water confluence manifold 75R and invades from the cooling water outlet 76o, the high-temperature cooling water easily moves upward. The possibility that the first temperature sensor 61 outputs an erroneous detection result to the control unit 80 due to such accidental intrusion of high temperature cooling water can be reduced.

The case of the radiator 79 of the vertical pipe will be described with reference to FIG. In the case of the radiator 79, a cooling water distribution manifold 77u is provided along the horizontal direction on one side of the radiator 79 in the vertical direction. The cooling water distribution manifold 77u is provided at the other end while cooling water enters from the cooling water inlet 78i provided in the center thereof and exchanges heat through a plurality of vertically provided passages. It merges with the cooling water merging manifold 77d. The combined cooling water exits from the cooling water outlet 78o provided at substantially the center of the cooling water confluence manifold 77d, and flows through the radiator return flow path 34.

When the radiator 79 is used alone as in the example shown as the second embodiment, the first temperature sensor 61 may be provided in the cooling water confluence manifold 77d of the radiator 79. Even in this case, it is sufficient that the cooling mechanism 30A illustrated in FIG. 7 or the like is separated from the confluence GP3 by 50 mm or more on the upstream side. In this case, it is more preferably installed at a position horizontally separated from the cooling water outlet 78o. By doing so, even if the high-temperature cooling water flowing back from the confluence GP3 accidentally reaches the cooling water confluence manifold 77d, the high-temperature cooling water easily moves upward, so that the first temperature sensor 61 can be used. Due to such accidental intrusion of high temperature cooling water, the possibility of outputting an erroneous detection result to the control unit 80 can be reduced.

Although some embodiments have been shown above, they can be implemented in various embodiments other than these embodiments. These fuel cell systems are not limited to in-vehicle devices, and may be stationary. Further, the vehicle is not limited to a normal four-wheeled vehicle, but can also be used for a large bus or the like. When using a high-power fuel cell system such as such a large bus, it is expected that the cooling mechanism will be large and equipped with multiple radiators, so the temperature of the cooling water cooled by the radiator should be measured accurately. Is important. According to the methods shown in these embodiments, the temperature of the cooling water cooled by the radiator can be accurately detected in the cooling mechanism when there is a bypass flow path with a simple configuration.

Further, in these embodiments, cooling water is used as the refrigerant, but antifreeze liquid other than water and other liquids may be used. Further, the cooling water pump 51 may be provided on the battery side discharge flow path 32 side. Further, it is also possible to use a plurality of cooling water pumps 51. If necessary, cooling water pumps may be provided in each of the bypass flow path 40 and the radiator side discharge flow path 33. The cooling mechanism may also cool other members other than the fuel cell that generates heat. For example, it may be applied to a cooling mechanism such as a boost converter provided in a power supply line of a fuel cell or an inverter for driving a motor or the like. The flow dividing valve 52 may be provided at the confluence point GP3. Further, the cooling water pump 51 may be provided in the battery side discharge flow path 32.

GP1 to GP3 ... Confluence point GP4, GP5 ... Connection point 10,10A ... Fuel cell system 20 ... Fuel cell 21 ... Cooling water supply port 22 ... Cooling water discharge port 30, 30A ... Cooling mechanism 31 ... Battery side circulation flow path 32 ... Battery side discharge flow path 33 ... Radiator side discharge flow path 34 ... Radiator return flow path 40 ... Bypass flow path 51 ... Cooling water pump 52 ... Divergence valve 61 ... First temperature sensor 62 ... Second temperature sensor 71 ... First radiator 72 ... 2nd radiator 73 ... 1st fan 74 ... 2nd fan 75L ... Cooling water distribution manifold 75R ... Cooling water confluence manifold 76i ... Cooling water inlet 76o ... Cooling water outlet 77d ... Cooling water confluence manifold 77u ... Cooling water distribution manifold 78i ... Cooling water inlet 78o ... Cooling water outlet 79 ... Radiator 80 ... Control unit

Claims (1)

A fuel cell system with a cooling mechanism
The cooling mechanism is
With a radiator that cools the refrigerant,
A refrigerant discharge flow path connecting the refrigerant discharge port of the fuel cell to the refrigerant inlet of the radiator,
A refrigerant circulation flow path connecting the radiator's refrigerant outlet to the fuel cell's refrigerant supply port,
A bypass flow path that connects the refrigerant discharge flow path and the refrigerant circulation flow path by bypassing the radiator.
A flow dividing valve provided at one end of the bypass flow path and adjusting the ratio of the refrigerant flowing through the radiator and the refrigerant flowing through the bypass flow path among the refrigerants discharged by the refrigerant discharge flow path.
Provided at a position downstream of the refrigerant outlet of the radiator, upstream from the confluence of the bypass flow path and the refrigerant circulation flow path, at a position 1.5 times or more the inner diameter of the refrigerant circulation flow path. With the temperature sensor
Equipped with
A fuel cell system that controls the ratio of the diversion valve by the temperature of the refrigerant detected by the temperature sensor.

Images