Patent Description:
A fuel cell system includes a fuel cell stack in which a plurality of fuel cell units are stacked. The fuel cell unit has an electrolyte film intervening between a fuel electrode and an air electrode. In the fuel cell unit, a fuel electrode gas containing hydrogen is supplied to the fuel electrode and air is supplied to the air electrode (oxidant electrode), whereby an electrochemical reaction occurs to generate electricity.

<CIT> describes a fuel cell propulsion system for submarine and <CIT> a power system for an unmanned surface vehicle.

A fuel cell system is sometimes used as a power source or the like in a boat moving on the sea, for example. The fuel cell system is installed on a deck of the boat, for example. In such a case, when an ambient temperature drops at the time of halting of the fuel cell, there is a possibility that cooling water used for cooling the fuel cell freezes.

In order to prevent freezing of the cooling water, heating by using a heater has been conventionally performed. However, in such a case, power consumption is large and many devices are necessary.

Under the circumstances stated above, it has been conventionally difficult to perform antifreeze of cooling water easily and efficiently.

Therefore, the problem to be solved by the present invention is to provide a fuel cell system which can perform antifreeze of cooling water easily and efficiently.

A fuel cell system of an embodiment includes a fuel cell section, and has: a cooling water circulation system in which cooling water circulates via the fuel cell section; a heat exchange system to perform heat exchange between seawater and the cooling water circulating in the cooling water circulation system; and a control section to control the heat exchange. The control section heats the cooling water by the heat exchange when a temperature regarding the cooling water circulation system is equal to or lower than a first threshold value and a temperature of the seawater used for the heat exchange in the heat exchange system is equal to or higher than a second threshold value which is higher than the first threshold value.

<FIG> is a diagram schematically illustrating an entire configuration of a fuel cell system according to a first embodiment.

The fuel cell system of this embodiment includes a fuel cell section <NUM> as illustrated in <FIG>. Further, the fuel cell system has a cooling water circulation system S1, a heat exchange system S2, and a control section <NUM>. The fuel cell system of this embodiment is used as a power source or the like in a boat moving on the sea, for example, and installed on a deck of the boat. Each part constituting the fuel cell system will be described in sequence.

First, an example of the fuel cell section <NUM> constituting the fuel cell system will be described by using <FIG> and <FIG>.

<FIG> is a perspective view schematically illustrating an entire configuration of the fuel cell section in the first embodiment. <FIG> is a cross-sectional view illustrating in enlargement a part of a cross-section of the fuel cell section in the first embodiment. In <FIG>, a y-axis runs along a vertical direction, a z-axis runs along a first horizontal direction, and an x-axis runs along a second horizontal direction which is orthogonal to the first horizontal direction. <FIG> shows a part of a cross-section corresponding to a horizontal surface (xz-surface) in <FIG>.

The fuel cell section <NUM> has a fuel cell stack <NUM>, as illustrated in <FIG>. The fuel cell stack <NUM> includes a plurality of fuel cell units <NUM> and a plurality of separators <NUM>, the fuel cell units <NUM> and the separators <NUM> being stacked alternately in a stack direction. The fuel cell stack <NUM> intervenes between a pair of fastening plates <NUM> (end plates) in the stack direction, and the pair of fastening plates <NUM> are fastened by using a fastening member (not shown) such as a tie rod and a band.

In the fuel cell stack <NUM>, the fuel cell unit <NUM> is a polyelectrolyte type fuel cell unit, and includes a polyelectrolyte film <NUM>, a fuel electrode <NUM>, and an air electrode <NUM> as illustrated in <FIG>. The fuel cell unit <NUM> is a film/electrode joined body in which the polyelectrolyte film <NUM> intervenes between the fuel electrode <NUM> and the air electrode <NUM>.

The polyelectrolyte film <NUM> is constituted by a fluorine-based polymeric material which has a sulfonic acid group, for example. The fuel electrode <NUM> and the air electrode <NUM> are constituted by a platinum catalyst being supported by a carbon black support, for example.

In the fuel cell stack <NUM>, the separator <NUM> is constituted by a porous body formed of a conductive material. In the separator <NUM>, a fuel electrode gas flow path F121 and an air electrode gas flow path F122 are formed.

The fuel electrode gas flow path F121 is formed on a surface of a fuel electrode <NUM> side in the separator <NUM>. The fuel electrode gas flow path F121 is formed to run along the vertical direction (y-axis direction) and a fuel electrode gas to be supplied to the electrode <NUM> of the fuel cell unit <NUM> flows therein. The fuel electrode gas flow paths F121 are plurally provided, a plurality of the fuel electrode gas flow paths F121 being provided with an interval in the second horizontal direction (x-axis direction).

The air electrode gas flow path F122 is formed on a surface of an air electrode <NUM> side in the separator <NUM>. The air electrode gas flow path F122 is formed to run along the second horizontal direction (x-axis direction) which is orthogonal to the first horizontal direction (z-axis direction) along the stack direction, and an air electrode gas to be supplied to the air electrode <NUM> of the fuel cell unit <NUM> flows therein. The air electrode gas flow paths F122 are provided plurally, though not illustrated, a plurality of the air electrode gas flow paths F122 being provided with an interval in the first horizontal direction (y-axis direction).

The cooling water circulation system S1 is configured so that cooling water CW circulates via the fuel cell section <NUM>, as illustrated in <FIG>.

Here, the cooling water circulation system S1 has a cooling water pump P1. The cooling water pump P1 is installed in order to supply the cooling water CW to the fuel cell section <NUM>.

The cooling water CW is pure water, for example, and is supplied from up above in the vertical direction (y-axis direction) and discharged downward in the fuel cell section <NUM>. More specifically, the cooling water CW flows into the inside of a micropore of the separator <NUM> constituted of the porous body. The cooling water CW is supplied at a pressure lower than a pressure of the fuel electrode gas and a pressure of the air electrode gas. Thereby, generated water generated by an electricity generation reaction in the fuel cell section <NUM> and condensate water condensed inside the fuel cell section <NUM> can be removed to the outside of the fuel cell section <NUM> and cooling by humidification and latent heat of vaporization of the polyelectrolyte film <NUM> can be performed.

The heat exchange system S2 is provided in order to perform heat exchange between seawater SW and the cooling water CW circulating in the cooling water circulation system S1, as illustrated in <FIG>.

Here, the heat exchange system S2 has a seawater heat exchanger <NUM> and a seawater pump P2. The seawater heat exchanger <NUM> is installed in order to perform heat exchange between the seawater SW and the cooling water CW circulating in the cooling water circulation system S1. The seawater pump P2 is installed in order to supply the seawater SW to the seawater heat exchanger <NUM>. The heat exchange system S2 is a seawater circulation system, and is configured so that the seawater SW pumped up from the sea (not shown) by using the seawater pump P2 returns to the sea after passing through the seawater heat exchanger <NUM>.

The control section <NUM> is provided in order to control heat exchange between the seawater SW and the cooling water CW, as illustrated in <FIG>. Though not shown, the control section <NUM> includes an arithmetic unit (not shown) and a memory device (not shown), and is configured so that the arithmetic unit performs arithmetic processing by using a program which the memory device stores. In the control section <NUM>, temperature data or the like detected by temperature sensors T11, T12a, T12b, and T21a is input as input signals, and the control section <NUM> outputs control signals obtained by performing arithmetic processing based on the input signals to respective sections, to thereby controls actions of the respective sections.

Here, the control section <NUM> controls heat exchange between the seawater SW and the cooling CW so that a temperature of the fuel cell section <NUM> becomes a temperature designated in advance. For example, in a case where the fuel cell section <NUM> is normally operated, if a temperature of the cooling water CW for cooling the fuel cell section <NUM> is equal to or larger than a value designated in advance, the control section <NUM> controls heat exchange between the seawater SW and the cooling water CW so that the seawater SW cools the cooling water CW.

Further, in this embodiment, the control section <NUM> is configured to heat the cooling water CW by using heat of the seawater SW when an antifreeze operation to prevent freezing of the cooling water CW is carried out. More specifically, the control section <NUM> heats the cooling water CW by increasing a heat exchange amount by heat exchange when a temperature regarding the cooling water circulation system S1 is equal to or lower than a first threshold value TH1 and when a temperature of the seawater SW used for heat exchange in the heat exchange system S2 is equal to or higher than a second threshold value TH2 which is higher than the first threshold value TH1 (TH1 < TH2).

The first threshold value TH1 is <NUM> to <NUM>, for example, and the control section <NUM> determines whether or not the temperature is equal to or lower than the first threshold value TH1, based on the temperature data measured by the temperature sensor T11 which detects the temperature of the fuel cell section <NUM>. Further, the second threshold value TH2 is <NUM> to <NUM>, for example, and the control section <NUM> determines whether or not the temperature is equal to or higher than the second threshold value TH2, based on the temperature data measured by the temperature sensor T21a which detects the temperature of the seawater SW pumped up by the seawater pump P2.

The control section <NUM> drives at least one of the cooling water pump P1 and the seawater pump P2 to thereby increase the heat exchange amount by heat exchange. In other words, the control section <NUM> increases a discharge amount of at least one of the cooling water pump P1 and the seawater pump P2, to thereby increase the heat exchange amount by heat exchange between the cooling water CW and the seawater SW.

At this time, the control section <NUM> controls at least one action of the cooling water pump P1 and the seawater pump P2 so that a temperature difference between a cooling water inflow temperature regarding the cooling water CW flowing into the seawater heat exchanger <NUM> and a cooling water outflow temperature regarding the cooling water CW flowing out of the seawater heat exchanger <NUM> becomes a set temperature difference set in advance. The cooling water inflow temperature is measured by the temperature sensor T12a, and the cooling water outflow temperature is measured by the temperature sensor T12b. The control section <NUM> performs control so that the heat exchange amount by heat exchange between the cooling water CW and the seawater SW becomes larger as the temperature difference between the cooling water inflow temperature and the cooling water outflow temperature is largely apart from the set temperature difference set in advance.

As described above, in the fuel cell system of this embodiment, when there is a possibility that the cooling water CW freezes, the cooling water CW is heated by using heat of the seawater SW which has a higher temperature than the cooling water CW. Therefore, this embodiment is able to perform antifreeze of the cooling water CW easily and efficiently.

In the fuel cell system of this embodiment, in order to improve a power generation performance, it is necessary to decrease a proton resistance of the polyelectrolyte film <NUM> by increasing a water content of the polyelectrolyte film <NUM> since the fuel cell unit <NUM> is the polyelectrolyte type (internally humified type) fuel cell unit. Therefore, the cooling water CW is supplied, not only for cooling, but also to humidify the polyelectrolyte film. Thus, the cooling water CW is preferably pure water which does not have an adverse effect on the fuel cell unit <NUM>, and it is not suitable to use antifreeze liquid which has an adverse effect on the fuel cell unit <NUM>. Therefore, when the fuel cell unit <NUM> is the polyelectrolyte type fuel cell unit, it is preferable to perform antifreeze of the cooling water CW by heating the cooling water CW by the seawater SW which has the temperature higher than that of the cooling water CW, as in this embodiment.

<FIG> is a diagram schematically illustrating an entire configuration of a fuel cell system according to a second embodiment.

As illustrated in <FIG>, in the fuel cell system of this embodiment, a configuration of a heat exchange system S2 is different from that of the first embodiment (see <FIG>). This embodiment is the same as the first embodiment except for the point above and a point related thereto. Therefore, overlapping explanation will be properly omitted.

In this embodiment, the heat exchange system S2 includes a heat exchange medium circulation system S21 and a seawater circulation system S22.

In the heat exchange system S2, the heat exchange medium circulation system S21 is configured so that a heat exchange medium PW to perform heat exchange between cooling water CW and the heat exchange medium PW circulates therein. The heat exchange medium circulation system S21 has a primary heat exchanger <NUM> and a heat exchange medium pump P3. The primary heat exchanger <NUM> is installed in order to perform heat exchange between the heat exchange medium PW and the cooling water CW. The heat exchange medium pump P3 is installed in order to provide the heat exchange medium PW to the primary heat exchanger <NUM>. The heat exchange medium PW is water, for example.

In the heat exchange system S2, the seawater circulation system S22 has a seawater exchanger <NUM> and a seawater pump P2. The seawater heat exchanger <NUM> is installed in order to perform heat exchange between seawater SW and the heat exchange medium PW circulating in the heat exchange medium circulation system S21. The seawater pump P2 is installed in order to provide the seawater SW to the seawater heat exchanger <NUM>. The seawater circulation system S22 is configured so that the seawater SW pumped up from the sea (not shown) by using the seawater pump P2 returns to the sea after passing through the seawater exchanger <NUM>.

A control section <NUM> is configured to heat the cooling water CW by using heat of the seawater SW in order to prevent freezing of the cooling water CW, similarly to the first embodiment. In other words, the control section <NUM> heats the cooling water CW by increasing a heat exchange amount by heat exchange when a temperature regarding the cooling water circulation system S1 is equal to or lower than a first threshold value TH1 and when a temperature of the seawater SW used for heat exchange in the heat exchange system S2 is equal to or higher than a second threshold value TH2 which is higher than the first threshold value TH1 (TH1 < TH2), similarly to the first embodiment.

In this embodiment, the control section <NUM> drives at least one of a cooling water pump P1, the seawater pump P2, and the heat exchange medium pump P3 to thereby increase the heat exchange amount by heat exchange. In other words, the control section <NUM> increases a discharge amount of at least one of the seawater pump P2 and the heat exchange medium pump P3 to thereby increase the heat exchange amount by heat exchange between the heat exchange medium PW and the seawater SW. Further, by increasing the discharge amount of at least one of the cooling water pump P1 and the heat exchange medium pump P3, the control section <NUM> increases the heat exchange amount by heat exchange between the cooling water CW and the heat exchange medium PW. As described above, in this embodiment, freezing of the cooling water CW is prevented by performing heat exchange between the cooling water CW and the seawater SW via the heat exchange medium PW.

At this time, the control section <NUM> controls at least one action of the cooling water pump P1, the seawater pump P2, and the heat exchange medium pump P3 so that a temperature difference between a heat exchange medium inflow temperature regarding the heat exchange medium PW flowing into the seawater heat exchanger <NUM> and a heat exchange medium outflow temperature regarding the heat exchange medium PW flowing out of the seawater heat exchanger <NUM> becomes a set temperature difference set in advance. The heat exchange medium inflow temperature is measured by a temperature sensor T12a, and the heat exchange medium outflow temperature is measured by a temperature sensor T12b. The control section <NUM> performs control so that the heat exchange amount by heat exchange between the heat exchange medium PW and the seawater SW becomes larger as the temperature difference between the heat exchange medium inflow temperature and the heat exchange medium outflow temperature is largely apart from the set temperature difference set in advance.

As described above, in the fuel cell system of this embodiment, freezing of the cooling water CW is prevented by performing heat exchange between the cooling water CW and the seawater SW via the heat exchange medium PW. Therefore, this embodiment is able to perform antifreeze of the cooling water CW easily and efficiently. Note that in this embodiment, in a case where the heat exchange medium PW is pure water, even if the primary heat exchanger <NUM> is broken to cause mixing of the heat exchange medium PW with the cooling water CW, the fuel cell section <NUM> is not damaged. In the case of the first embodiment, there is a possibility that the seawater heat exchanger <NUM> is broken to cause mixing of the seawater SW with the cooling water CW, thereby damaging the fuel cell section <NUM>. This embodiment has an effect on decreasing the above-described possibility.

<FIG> is a diagram schematically illustrating an entire configuration of a fuel cell system according to a third embodiment.

As illustrated in <FIG>, in the fuel cell system of this embodiment, a heat exchange system S2 includes a heat exchange medium circulation system S21 and a seawater circulation system S22, similarly to the second embodiment (see <FIG>). However, this embodiment is different from the second embodiment (see <FIG>) in a part of a configuration of the heat exchange medium circulation system S21 and the seawater circulation system S22. This embodiment is the same as the second embodiment except for the point described above and a point related thereto. Therefore, overlapping explanation will be properly omitted.

In this embodiment, the heat exchange medium circulation system S21 further has, as illustrated in <FIG>, a heat source <NUM> (first heat source), a seawater heat exchanger bypass flow path BP1 (first seawater heat exchanger bypass flow path), a seawater heat exchanger bypass valve BV1 (first seawater heat exchanger bypass valve), and a seawater heat exchanger inlet valve V1.

In the heat source <NUM>, a heat exchange medium PW discharged from a primary heat exchanger <NUM> flows. The heat source <NUM> is, for example, a storage battery storing electric power generated in a fuel cell section <NUM>. The heat source <NUM> may be a device such as an inverter, a refrigeration cycle condenser, and a heat exchanger of a cooling medium (chiller).

The seawater heat exchanger bypass flow path BP1 is configured so that the heat exchange medium PW flowing out of the heat source <NUM> takes a detour around a seawater heat exchanger <NUM> and flows into the primary heat exchanger <NUM>.

The seawater heat exchanger bypass valve BV1 is provided in the seawater heat exchanger bypass flow path BP1.

The seawater heat exchanger inlet valve V1 is provided on a downstream side of an entrance of the seawater heat exchanger bypass flow path BP1 and on an upstream side of the seawater heat exchanger <NUM>, in a flow path of the heat exchange medium PW flowing from the heat source <NUM> into the seawater heat exchanger <NUM>.

In this embodiment, a temperature sensor T12a for measuring a heat exchange medium inflow temperature is installed on an upstream side of the entrance of the seawater heat exchanger bypass flow path BP1 in a flow of the heat exchange medium PW.

Further, in this embodiment, a temperature sensor T21b for measuring a seawater inflow temperature regarding seawater SW flowing into the seawater heat exchanger <NUM> is installed between the seawater heat exchanger <NUM> and a seawater pump P2.

Additionally, in this embodiment, a control section <NUM> further controls an action of the seawater heat exchanger bypass valve BV1 and an action of the seawater heat exchanger inlet valve V1 to thereby adjust heat exchange between cooling water CW and the seawater SW which is performed via the heat exchange medium PW.

More specifically, in an activation operation of a fuel cell section <NUM>, the control section <NUM> opens the seawater heat exchanger bypass valve BV1 and closes all the seawater heat exchanger inlet valves V1 when driving of a heat exchange medium pump P3 is started. Thereafter, when a temperature measured by a temperature sensor T11 detecting a temperature of the fuel cell section <NUM> rises to an operating temperature (for example, <NUM> to <NUM>) of the fuel cell section <NUM>, the control section <NUM> closes all the seawater heat exchanger bypass valves BV1 and opens the seawater heat exchanger inlet valve V1. Thereby, the activation operation of the fuel cell section <NUM> can be finished promptly.

In implementation of an antifreeze operation, in a case where a measured temperature t12a of the temperature sensor T12a is equal to or higher than a measured temperature t21b of the temperature sensor T21b (t21a ≥ t21b), the control section <NUM> opens the seawater heat exchanger bypass valve BV1 and closes all the seawater heat exchanger inlet valves V1. Thereby, the heat exchange medium PW flows to the primary heat exchanger <NUM> by the heat exchange medium pump P3 through the seawater heat exchanger bypass flow path BP1 without running through the seawater heat exchanger <NUM>.

Meanwhile, in implementation of the antifreeze operation, in a case where the measured temperature t12a of the temperature sensor T12a is lower than the measured temperature t21b of the temperature sensor T21b (t21a < t21b), the control section <NUM> closes all the seawater heat exchanger bypass valves BV1 and opens the seawater heat exchanger inlet valve V1. Thereby, the heat exchange medium PW flows to the primary heat exchanger <NUM> by the heat exchange medium pump P3 through the seawater heat exchanger <NUM> without running through the seawater heat exchanger bypass flow path BP1.

As described above, in the fuel cell system of this embodiment, similarly to the second embodiment, freezing of the cooling water CW is prevented by performing heat exchange between the cooling water CW and the seawater SW via the heat exchange medium PW. Therefore, this embodiment is able to perform antifreeze of the cooling water CW easily and efficiently.

Further, in this embodiment, since the action of the seawater exchanger bypass valve BV1 and the action of the seawater heat exchanger inlet valve V1 are controlled in the activation operation of the fuel cell section <NUM>, as described above, the activation operation can be finished promptly.

Further, in this embodiment, since heat of the heat source <NUM> is properly used as described above in implementation of the antifreeze operation, antifreeze can be performed effectively.

<FIG> is a diagram schematically illustrating an entire configuration of a fuel cell system according to a fourth embodiment.

As illustrated in <FIG>, in the fuel cell system of this embodiment, similarly to the third embodiment (see <FIG>), a heat exchange system S2 includes a heat exchange medium circulation system S21 and a seawater circulation system S22. However, in this embodiment, a part of a configuration of the seawater circulation system S22 is different from that of the third embodiment (see <FIG>). This embodiment is the same as the third embodiment except for the point described above and a point related thereto. Therefore, overlapping explanation will be properly omitted.

In this embodiment, the seawater circulation system S22 further has, as illustrated in <FIG>, a heat source <NUM> (second heat source), a seawater heat exchanger bypass flow path BP2 (second seawater heat exchanger bypass flow path), and a seawater heat exchanger bypass valve BV2 (second seawater heat exchanger bypass valve).

In the heat source <NUM>, seawater SW discharged from a seawater pump P2 flows. The heat source <NUM> is a device such as a refrigeration cycle condenser and a heat exchanger of a cooling medium (chiller).

The seawater heat exchanger bypass flow path BP2 is configured so that the seawater SW flowing out of the heat source <NUM> flows taking a detour around a seawater heat exchanger <NUM>.

The seawater heat exchanger bypass valve BV2 is provided in the seawater heater exchanger bypass flow path BP2.

Further, in this embodiment, a temperature sensor T21b for measuring a seawater inflow temperature regarding the seawater SW flowing into the seawater heat exchanger <NUM> is installed between an entrance of the seawater heat exchanger bypass flow path BP2 and the seawater heat exchanger <NUM>.

Additionally, in this embodiment, a control section <NUM> further controls an action of the seawater heat exchanger bypass valve BV2 to thereby adjust heat exchange between cooling water CW and the seawater SW which is performed via a heat exchange medium PW.

More specifically, in implementation of a normal operation of a fuel cell section <NUM>, the control section <NUM> increases a discharge amount of the seawater pump P2 and opens the seawater heat exchanger bypass valve BV2 when a measured temperature t21b of the temperature sensor T21b is higher than a set temperature (for example, <NUM> to <NUM>) set in advance. Thereby, even in a case where a temperature of the seawater SW flowing out of the heat source <NUM> by heat exchange in the heat source <NUM> is higher than a set temperature, it is possible to properly keep a heat exchange amount in the seawater heat exchanger <NUM>. It is possible to prevent an increase in a load of the pump due to flowing of an excessive flow amount to the seawater heat exchanger <NUM> and it is possible to optimize the heat exchange amount.

In implementation of an antifreeze operation, the control section <NUM> makes all the seawater heat exchanger bypass valves BV2 closed, in principle. Then, in a case where a measured temperature t12a of a temperature sensor T12a is equal to or lower than a measure temperature t21b of the temperature sensor T21b (t12a ≤ t21b), the control section <NUM> continues driving of the seawater pump P2 until a measured temperature t11 of a temperature sensor T11 becomes equal to or higher than a set temperature (for example, <NUM>) at which cooling water CW does not freeze.

In a case where the measured temperature t12a of the temperature sensor T12a is higher than the measured temperature t21b of the temperature sensor T21b (t12a > t21b), the control section <NUM>, though driving the seawater pump P2, opens a seawater heater exchanger bypass valve BV1 and closes a seawater heat exchanger inlet valve V1. In other words, in the seawater exchanger <NUM>, heat exchange between the heat exchange medium PW and the seawater SW is not performed.

In a case where the measured temperature t21b (temperature of the heat exchange medium PW flowing out of the heat source <NUM>) measured by the temperature sensor T21b is higher than a set temperature set in advance, the control section <NUM> increases a flow amount of the seawater pump P2 and controls an action of the seawater heat exchanger bypass valve BV2 so that the measured temperature t21b becomes the set temperature.

As described above, in the fuel cell system of this embodiment, similarly to the third embodiment, freezing of the cooling water CW is prevented by performing heat exchange between the cooling water CW and the seawater SW via the heat exchange medium PW. Therefore, this embodiment is able to perform antifreeze of the cooling water CW easily and efficiently.

Further, in this embodiment, in implementation of the normal operation of the fuel cell section <NUM>, an action of the seawater pump P2 and the action of the seawater heater exchanger bypass valve BV2 are controlled, as described above. Therefore, as described above, it is possible to properly keep the heat exchange amount in the seawater heat exchanger <NUM>.

Further, in this embodiment, since heat of the heat source <NUM> is properly used in implementation of the antifreeze operation as described above, antifreeze can be performed effectively.

In this embodiment, similarly to the third embodiment (see <FIG>), a case is described where the heat exchange medium circulation system S21 has the heat source <NUM>, the seawater heat exchanger bypass flow path BP1, the seawater heat exchanger bypass valve BV1, and the seawater heat exchanger inlet valve V1, but the configuration is not limited to the above. The heat exchange medium circulation system S21 is not necessarily required to be provided with the heat source <NUM>, the seawater heat exchanger bypass flow path BP1, the seawater heat exchanger bypass valve BV1, and the seawater heat exchanger inlet valve V1.

While certain embodiments have been described above, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions.

Claim 1:
A fuel cell system including a fuel cell section, the fuel cell system comprising:
a cooling water circulation system in which cooling water circulates via the fuel cell section;
a heat exchange system for performing heat exchange between seawater and the cooling water circulating in the cooling water circulation system; and
a control section for controlling the heat exchange, wherein
the control section heats the cooling water by the heat exchange when a temperature regarding the cooling water circulation system is equal to or lower than a first threshold value and a temperature of the seawater used for the heat exchange in the heat exchange system is equal to or higher than a second threshold value which is higher than the first threshold value.