JP2010045012A - Fuel-cell power generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel-cell power generation device that achieves reduction in cost required for exhaust-heat treatment by reducing the number of cooling devices. <P>SOLUTION: The fuel-cell power generation device includes: a recovered-water circulation passage 20 that circulates recovered water to a recovered-water generating device 21 for recovering moisture in exhaust gas, discharged from a fuel cell 2 as recovered water, and is provided with a recovered-water circulation pump 23 halfway in the recovered-water circulation passage; a cooling device 25 for cooling the recovered water circulating in the recovered-water circulation passage 20; a fuel-cell cooling-water circulation passage 1 that circulates first cooling water to the fuel cell 2 and is provided with a cooling heat exchanger 6 halfway in the fuel-cell cooling-water circulation passage; and an exhaust-heat recovery passage for supplying the heat of the first cooling water to an external heat demand. The fuel-cell power generation device is configured to supply the heat of the first cooling water extracted from the cooling heat exchanger 6 to the external heat demand via the exhaust-heat recovery passage and to discharge the excessive heat to the outside in the cooling device 25 via the recovered-water circulation passage 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell power generator configured to be able to use exhaust heat of a fuel cell.

  A fuel cell power generator is a power generator that directly converts the binding energy between hydrogen obtained by reforming natural gas and oxygen in the air into electric energy. Such a fuel cell power generator uses a fuel cell in which a plurality of unit cells each composed of an electrolyte layer and an anode electrode and a cathode electrode sandwiching the electrolyte layer are stacked. Since the fuel cell generates heat with power generation, it is maintained at the power generation optimum temperature by flowing cooling water.

  An example of a conventional fuel cell power generation device will be described with reference to FIG. 5. Reference numeral 1 in the figure denotes a fuel cell cooling water circulation path, which is a first cooling water circulation path for cooling the fuel cell 2. The fuel cell cooling water circulation path 1 includes a fuel cell 2, a heater 3, a water vapor separator 4, a battery cooling water circulation pump 5, a cooling heat exchanger 6, a battery cooling water temperature sensor 8, a battery cooling water adjusting valve 9, and these It has piping connecting each component. The cooling heat exchanger 6 and the battery coolant adjustment valve 9 are provided in a bypass path that returns to the battery coolant circulation pump 5.

  In the fuel cell cooling water circulation path 1, the first cooling water is caused to flow into the operating fuel cell 2, and the amount of heat generated by the power generation from the fuel cell 2 is taken to lower the temperature of the fuel cell 2. The first cooling water flowing out from the fuel cell 2 is heated to a high temperature, and this high temperature first cooling water passes through the heater 3 and flows into the water vapor separator 4 to be cooled, and the battery cooling water circulation is performed. It is returned to the fuel cell 2 by the pump 5. At this time, part of the water passes through the bypass path, is cooled by the cooling heat exchanger 6, and returned to the fuel cell 2. And by adjusting the opening degree of the battery cooling water adjustment valve 9 according to the detection value of the battery cooling water temperature sensor 8, and adjusting the flow rate of the first cooling water cooled by the cooling heat exchanger 6, The temperature of the first cooling water in the fuel cell cooling water circulation path 1 is adjusted to a predetermined temperature.

  In the figure, reference numeral 70 denotes a second cooling water circulation path, which is a second cooling water circulation path for cooling the first cooling water. The second cooling water circulation path 70 includes a second cooling water circulation pump 11, an exhaust heat recovery heat exchanger 71, a cooling device 73, adjustment valves 74 and 75, and pipes connecting the respective components.

  In the second cooling water circulation path 70, a part or all of the second cooling water whose temperature is increased by exchanging heat with the first cooling water via the cooling heat exchanger 6 is converted into the exhaust heat recovery heat exchanger 71 and / or Alternatively, after passing through the cooling device 73, the second cooling water circulation pump 11 is pumped to the cooling heat exchanger 6 and circulates in the second cooling water circulation path 70. The flow rate of the second cooling water flowing through the exhaust heat recovery heat exchanger 71 and the cooling water flowing through the bypass not passing through the exhaust heat recovery heat exchanger 71 are adjusted by adjusting the opening of the adjustment valve 74. The flow rate of the second cooling water flowing through the cooling device 73 and the flow rate of the cooling water flowing through the bypass not passing through the cooling device 73 are adjusted by adjusting the flow rate of the adjusting valve 75 and the opening degree of the adjusting valve 75. Thus, the temperature of the cooling water circulating through the second cooling water circulation path 70 is maintained at a predetermined temperature.

  In the figure, reference numeral 80 denotes a recovered water circulation path, which is a recovered water circulation path recovered from the exhaust gas discharged from the fuel cell 2. The recovered water circulation path 80 includes a recovered water generating device 21, a recovered water circulating pump 23, an exhaust heat recovery heat exchanger 72, a cooling device 25, an adjustment valve 76, and pipes connecting the respective components.

  The recovered water recovered by the recovered water generating device 21 is pumped to the exhaust heat recovery heat exchanger 72 by the recovered water circulation pump 23, passes through the exhaust heat recovery heat exchanger 72, and a part or all of the recovered water is recovered. It passes through the cooling device 25 and is sent to the recovered water generation device 21 again. That is, by adjusting the opening of the adjustment valve 76, the flow rate of the recovered water flowing through the cooling device 25 and the flow rate of the cooling water flowing through the bypass not passing through the cooling device 25 are adjusted, and the recovered water generating device 21. The temperature of the recovered water is maintained at a predetermined temperature.

  Further, in the second cooling water circulation path 70, high-temperature water of about 85 ° C. to 94 ° C. is obtained by exchanging heat with the second cooling water passing through the second cooling water circulation path 70 via the exhaust heat recovery heat exchanger 71. Similarly, in the recovered water circulation path 80, heat is exchanged with the recovered water passing through the recovered water circulation path 80 via the exhaust heat recovery heat exchanger 72, so that about 40 ° C. to The low-temperature water of 50 ° C. can be stably generated, and the generated high-temperature water and low-temperature water are provided to the user's use of hot water and the recovered exhaust heat is effectively used.

  As described above, the conventional fuel cell power generation device shown in FIG. 5 includes the cooling devices 25 and 73 in the second cooling water circulation path 70 and the recovered water circulation path 80, respectively. Water circulating through each circulation path is cooled, and the temperature is individually controlled.

  Patent Document 1 listed below includes a fuel cell, a reformer, a heat exchanger for low-temperature water that exchanges heat discharged from the fuel cell and the reformer with cooling water having different temperature levels, and a heat exchanger for low-temperature water. Cooling water with different temperature levels in the low-temperature water heat exchanger and the high-temperature water heat exchanger is collectively cooled by an air-cooling fan when performing heat treatment of the fuel cell power generator equipped with the high-temperature water heat exchanger. Circulates and cools the low-temperature water cooler and the high-temperature water cooler in the air-cooled cooler, and passes the cooling air in the air-cooled cooler from the low-temperature water cooler side to the high-temperature water cooler side. Cooling is disclosed.

JP 2002-280033 A

  In the conventional fuel cell power generator as shown in FIG. 5, since the cooling device is arranged in each circulation path in order to control the water temperature circulating through the two cooling water systems, the cost of the device and the man-hours for the regular maintenance are reduced. It increased in cost and labor, and the occupied space required for installation also increased.

  Moreover, in the said patent document 1, the cooler for low-temperature water and high-temperature water use in the air-cooling type cooler which cools the cooling water from which the temperature level in a heat exchanger for low-temperature water and a heat exchanger for high-temperature water differs collectively with an air-cooling fan Each unit is circulated through a cooler and cooled by a single cooling device, but low-temperature water and high-temperature water are simultaneously cooled, so the amount of water to be cooled increases, so the output of the cooling device is increased. There is a problem that the operation cost is high. In addition, if the temperature difference between the high-temperature water and the low-temperature water is large, the temperature may not be sufficiently cooled or excessively cooled, making temperature control difficult.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel cell power generation apparatus that can reduce the number of cooling apparatuses and reduce the cost required for exhaust heat treatment.

In order to solve the above problems, a fuel cell power generator according to the present invention includes a fuel cell (2) that generates electricity by electrochemically reacting fuel gas and air.
The recovered water is circulated to the recovered water generating device (21) that recovers the moisture in the exhaust gas discharged from the fuel cell (2) as recovered water, and a recovered water circulation pump (23) is provided in the middle thereof. A recovered water circulation path (20);
A cooling device (25) for cooling the recovered water flowing through the recovered water circulation path (20);
A fuel cell cooling water circulation path (1) in which the first cooling water is circulated to the fuel cell (2) and a cooling heat exchanger (6) is provided in the middle thereof;
An exhaust heat recovery path for supplying heat of the first cooling water to an external heat demand,
The heat of the first cooling water taken out from the cooling heat exchanger (6) is supplied to the external heat demand via the exhaust heat recovery path, and the surplus is supplied to the recovered water circulation path (20 ) Through the cooling device (25) to be discharged to the outside.

  According to the fuel cell power generator of the present invention, the heat of the first cooling water taken out from the cooling heat exchanger is supplied to the external heat demand to recover the exhaust heat discharged from the fuel cell, and the surplus amount The heat is discharged outside in the cooling device via the recovered water circulation path. Therefore, the first cooling water for cooling the fuel cell can be actively cooled while recovering and effectively using the exhaust heat of the fuel cell, and the fuel cell can be stably operated without lowering the power generation efficiency. can do. And since the exhaust heat discharged from the fuel cell contained in the first cooling water and the recovered water is cooled by the cooling device installed in the recovered water circulation path, it is not necessary to provide a plurality of cooling devices, and the entire device is made smaller. In addition, the running cost and maintenance man-hour of the cooling device can be reduced.

A first preferred embodiment of the fuel cell power generator of the present invention is as shown in FIGS.
Heat exchange with the first cooling water via the cooling heat exchanger (6), and a second cooling water circulation path (10) through which the second cooling water for cooling the first cooling water circulates,
A first relay pipe (31) branched and extended from the recovered water circulation path via the adjustment valve (32) is connected to the second cooling water circulation path (10),
The second relay pipe (33) branched and extended from the second cooling water circulation path (10) is connected to the downstream side of the adjustment valve (32) of the recovered water circulation path (20).

  According to this aspect, since the recovered water having a low temperature can be passed through the second cooling water circulation path having a high temperature, the water temperature of the second cooling water circulating in the second cooling water circulation path can be lowered. Further, since the same amount of the second cooling water as the recovered water returned to the second cooling water circulation path through the first relay pipe is returned to the recovered water circulation path through the second relay pipe and cooled by the cooling device, With the configuration, the first cooling water for cooling the fuel cell can be maintained at the set temperature by controlling the temperature of the second cooling water. The second cooling water circulation path quickly absorbs temperature fluctuations of the second cooling water because the low temperature recovered water flows in from the first relay pipe and the high temperature second cooling water flows out from the second relay pipe. Can be kept at the set temperature.

The fuel cell power generator of the present invention is the above first aspect.
The second cooling water circulation path (10) includes second cooling water temperature detecting means (16),
The degree of opening of the adjustment valve (32), the recovered water circulation pump so that the temperature of the second cooling water detected by the second cooling water temperature detecting means (16) falls within a predetermined set range. By controlling at least one selected from the output of (23) and the output of the cooling device (25), the amount of water and / or the water temperature passing through the first relay pipe (31) is adjusted. Preferably it is.

  According to this aspect, when the temperature of the second cooling water detected by the second cooling water temperature detecting means is too high, the amount of water passing through the first relay pipe is increased and / or the output of the cooling device is increased. If the water temperature is too low and the temperature is too low, the amount of water passing through the first relay pipe is reduced and / or the output of the cooling device is lowered to increase the water temperature, thereby circulating the second cooling water circulation path. The temperature of the second cooling water can be adjusted, whereby the temperature of the cooling water passing through the cooling water circulation path can also be adjusted.

The fuel cell power generator of the present invention is the above first aspect.
The second relay pipe (33) includes second relay pipe cooling water temperature detecting means (15),
The degree of opening of the adjustment valve (32), so that the temperature of the second cooling water detected by the second relay pipe cooling water temperature detecting means (15) becomes a value within a predetermined setting range; By controlling at least one selected from the output of the recovered water circulation pump (23) and the output of the cooling device (25), the amount of water and / or the water temperature passing through the second relay pipe (33) is adjusted. It is preferable to be configured.

  According to this aspect, when the temperature of the second cooling water detected by the second relay pipe cooling water temperature detecting means is too high, the amount of water passing through the second relay pipe is increased and / or the output of the cooling device. If the water temperature is too low, adjust the temperature of the recovered water by reducing the amount of water passing through the second relay pipe and / or increasing the water temperature by reducing the output of the cooling device. can do.

As shown in FIG. 1, the fuel cell power generator of the present invention is the above first embodiment.
An exhaust heat recovery heat exchanger (51) is disposed in a path between the second relay pipe (33) and the first relay pipe (31) of the second cooling water circulation path (10),
The exhaust heat recovery path is configured to extract heat to the outside through heat exchange with the second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (51). It is preferable that

  According to this aspect, since heat is extracted by exchanging heat with the second cooling water, the exhaust heat of the fuel cell can be effectively used. Further, since the amount of heat corresponding to the user's needs can be easily taken out simply by changing the set temperature of the second cooling water, it is possible to stably provide the user with hot water having a desired water temperature. .

As shown in FIG. 2, the fuel cell power generator of the present invention is the above first embodiment.
An exhaust heat recovery heat exchanger (51) is disposed in a path upstream of the path connected to the second relay pipe (33) of the second cooling water circulation path (10),
The exhaust heat recovery path is configured to extract heat to the outside through heat exchange with the second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (51). It is preferable that

  According to this aspect, since heat is extracted by exchanging heat with the second cooling water, the exhaust heat of the fuel cell can be effectively used. Further, since the amount of heat corresponding to the user's needs can be easily taken out simply by changing the set temperature of the second cooling water, it is possible to stably provide the user with hot water having a desired water temperature. . Furthermore, since the second relay pipe is provided on the downstream side of the heat exchanger for exhaust heat recovery, the second cooling water after heat exchange by the heat exchanger for exhaust heat recovery can be introduced into the recovered water circulation path. More heat can be recovered by the heat exchanger for exhaust heat recovery.

A second preferred embodiment of the fuel cell power generator of the present invention is as shown in FIG.
A recovered water bypass path (40) is branched from the recovered water circulation path (20) via an adjustment valve (32) and returned to the recovered water circulation path (20) through the cooling heat exchanger (6). That is.

  According to this aspect, the first cooling water heated by cooling the fuel cell is cooled by heat exchange with the recovered water passing through the recovered water detour path via the cooling heat exchanger and returned to the fuel cell. Therefore, the fuel cell can be continuously cooled. In addition, since the recovered water heated by heat exchange with the first cooling water whose temperature has been increased is cooled by the cooling device, it can be used again for cooling the first cooling water through the recovered water detour path.

The fuel cell power generator of the present invention, in the second aspect,
A bypass recovery water temperature detection means (41) is provided in the recovery water bypass path (40),
The degree of opening of the adjustment valve (32) and the recovered water circulation pump (23) so that the temperature of recovered water detected by the detour recovered water temperature detecting means (41) becomes a value within a predetermined set range. And controlling the amount of water and / or the water temperature passing through the recovered water bypass route (40) by controlling at least one selected from the output of the cooling device (25) and the output of the cooling device (25). preferable.

  According to this aspect, when the temperature of the recovered water detected by the bypass recovery water temperature detecting means is too high, the amount of water passing through the recovery water bypass path is increased and / or the output of the cooling device is increased to increase the water temperature. If it is lowered and is too low, the temperature of the recovered water can be adjusted by decreasing the amount of water passing through the recovered water bypass path and / or increasing the water temperature by decreasing the output of the cooling device.

The fuel cell power generator of the present invention, in the second aspect,
Waste heat recovery heat exchangers (52, 53) are disposed in the fuel cell cooling water circulation path (1) and the recovered water bypass path (40), respectively.
The exhaust heat recovery path includes first cooling water passing through the fuel cell cooling water circulation path (1) via the exhaust heat recovery heat exchanger (52) provided in the fuel cell cooling water circulation path (1). Recovered water passing through the recovered water bypass path (40) via a path for heat exchange to extract heat to the outside and the exhaust heat recovery heat exchanger (53) provided in the recovered water bypass path (40) It is preferable that it is comprised with the path | route which takes heat out and extracts heat | fever outside.

  According to this aspect, since heat is extracted by exchanging heat with the first cooling water and the recovered water, the exhaust heat of the fuel cell can be effectively used. In addition, since the first cooling water and the recovered water have different temperatures, for example, hot water having different temperatures can be recovered simultaneously.

A third preferred embodiment of the fuel cell power generator of the present invention is as shown in FIG.
Second cooling in which a second cooling water is circulated through the cooling heat exchanger (6) to cool the first cooling water, and a second cooling heat exchanger (17) is provided in the middle of the second cooling water. Water circulation path (10);
A recovered water second bypass path (branched from the recovered water circulation path (20) via the regulating valve (32) and returned to the recovered water circulation path (20) through the second cooling heat exchanger (17) ( 45).

  According to this aspect, the first cooling water heated by cooling the fuel cell is cooled by heat exchange with the second cooling water via the cooling heat exchanger and returned to the fuel cell. Can continue to cool. Moreover, since all or a part of the recovered water passing through the recovered water circulation path passes through the recovered water second bypass path, heat is exchanged with the second cooling water via the second cooling heat exchanger. The second cooling water whose temperature has been raised by heat exchange with the first cooling water is cooled and can be used again for cooling the first cooling water. In addition, since the recovered water whose temperature has been raised by heat exchange with the second cooling water is returned to the recovered water circulation path and cooled by the cooling device, it is used again for cooling the second cooling water through the recovered water second bypass path. be able to.

The fuel cell power generator of the present invention, in the third aspect,
Second cooling water temperature detection means (16) is provided in the second cooling water circulation path (10),
The opening degree of the adjustment valve (32), the recovered water circulation pump so that the temperature of the second cooling water detected by the second cooling water temperature detecting means (16) becomes a value within a predetermined setting range. By controlling at least one selected from the output of (23) and the output of the cooling device (25), the water amount and / or the water temperature passing through the recovered water second bypass path (45) are adjusted. It is preferable that

  According to this aspect, when the temperature of the second cooling water detected by the second cooling water temperature detecting means is too high, the amount of water passing through the recovered water second bypass path is increased and / or the cooling device If the water temperature is lowered by increasing the output, and if it is too low, the amount of water passing through the second bypass path of the recovered water is reduced and / or the output of the cooling device is decreased and the water temperature is increased to increase the water temperature. The temperature of the water can be adjusted, whereby the temperature of the first cooling water flowing through the cooling water circulation path can also be adjusted.

The fuel cell power generator of the present invention, in the third aspect,
A second detour recovered water temperature detection means (46) is provided in the recovered water second detour path (45),
The degree of opening of the adjustment valve (32), the recovered water circulation pump () so that the temperature of the recovered water detected by the second detour recovered water temperature detecting means (46) becomes a value within a predetermined setting range. 23) and at least one selected from the output of the cooling device (25) is controlled to adjust the amount of water and / or the water temperature through the recovered water second bypass path (45). It is preferable.

  According to this aspect, when the temperature of the recovered water detected by the second bypass recovery water temperature detection means is too high, the amount of water passing through the recovery water second bypass path is increased and / or the output of the cooling device If the temperature of the recovered water is too low, the amount of water passing through the second bypass route of the recovered water is decreased and / or the output of the cooling device is decreased to increase the temperature of the recovered water. Can be adjusted.

The fuel cell power generator of the present invention, in the third aspect,
Exhaust heat recovery heat exchangers (54, 55) are disposed in the second cooling water circulation path (10) and the recovered water second bypass path (45), respectively.
The exhaust heat recovery path includes second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (54) provided in the second cooling water circulation path (10). A path for extracting heat to the outside through heat exchange and the second bypass path for recovered water (45) via the heat exchanger (55) for exhaust heat recovery provided in the second bypass path for recovered water (45) It is preferable that it is comprised with the path | route which heat-exchanges with the collection | recovery water which passes through, and takes out heat | fever outside.

  According to this aspect, since heat is extracted by exchanging heat with the second cooling water and the recovered water, the exhaust heat of the fuel cell can be effectively used.

1, 3, and 4, the recovered water circulation path (20) includes the recovered water after flowing through the cooling device (25) and the cooling device (25). The recovered water temperature detecting means (27) for detecting the water temperature of the water and the flow ratio adjusting valve for adjusting the flow rate ratio of the recovered water to be passed through the cooling device (25) and the recovered water to bypass the cooling device (25) (26)
The output of the recovered water circulation pump (23) and the flow rate ratio adjusting valve (26) so that the temperature of the recovered water detected by the recovered water temperature detecting means (27) becomes a value within a predetermined setting range. It is preferable that at least one of the opening degree and the output of the cooling device (25) is controlled.

As shown in FIG. 2, the fuel cell power generator of the present invention
The recovered water circulation path (20) includes a recovered water cooling heat exchanger (28) and recovered water temperature detecting means for detecting the temperature of the recovered water after flowing through the recovered water cooling heat exchanger (28). (27)
The cooling device (25) is disposed in the refrigerant circulation path (60) of the recovered water cooling heat exchanger (28),
The output of the recovered water circulation pump (23), the recovered water cooling heat exchanger so that the temperature of the recovered water detected by the recovered water temperature detecting means (27) becomes a value within a predetermined set range. It is preferable to be configured to control at least one of the flow rate of the refrigerant passing through (28) and the output of the cooling device (25).

  According to each aspect described above, the recovered water flowing through the recovered water circulation path can be maintained at a predetermined temperature. Further, the temperature fluctuation of the recovered water can be quickly and automatically reduced, and it can be stably operated without lowering the generation efficiency of the recovered water generating device.

  According to the fuel cell power generation device of the present invention, the first cooling water for cooling the fuel cell can be actively cooled while recovering and effectively using the exhaust heat of the fuel cell, and the power generation efficiency of the fuel cell can be improved. It is possible to drive stably without lowering. And since the exhaust heat discharged from the fuel cell contained in the first cooling water and the recovered water can be cooled by the cooling device installed in the recovered water circulation path, it is not necessary to provide a plurality of cooling devices and can be further downsized. Furthermore, the running cost and maintenance man-hour of the cooling device can be reduced.

1 is a configuration diagram of a first embodiment of a fuel cell power generator of the present invention. FIG. It is a block diagram of 2nd Embodiment of the fuel cell power generator of this invention. It is a block diagram of 3rd Embodiment of the fuel cell power generator of this invention. It is a block diagram of 4th Embodiment of the fuel cell electric power generating apparatus of this invention. It is a block diagram of the conventional fuel cell power generator.

(First embodiment)
FIG. 1 is a block diagram showing a first embodiment of a fuel cell power generator of the present invention. As shown in FIG. 1, the fuel cell power generator of this embodiment includes a fuel cell cooling water circulation path 1, a second cooling water circulation path 10, a recovered water circulation path 20, a first relay pipe 31, a second relay pipe 33, and a control. Part 100a.

  The fuel cell cooling water circulation path 1 is a first cooling water circulation path for cooling the fuel cell 2, and includes a fuel cell 2, a heater 3, a water vapor separator 4, a battery cooling water circulation pump 5, a cooling heat exchanger 6, The battery cooling water temperature sensor 8, the battery cooling water adjustment valve 9, and piping connecting these components are provided.

  That is, the heater 3, the water vapor separator 4, the battery cooling water circulation pump 5, and the battery cooling water temperature sensor 8 are arranged from the upstream side in the pipe 1 a extending from the cooling water outflow side 2 a of the fuel cell 2. The cooling water introduction side 2b is connected. Further, the pipe between the battery cooling water circulation pump 5 and the battery cooling water temperature sensor 8 is branched to extend the bypass pipe 1b, and is connected between the water vapor separator 4 and the battery cooling water circulation pump 5. The bypass pipe 1b is provided with a cooling heat exchanger 6 and a battery coolant adjustment valve 9 from the upstream side.

  In the fuel cell cooling water circulation path 1, the first cooling water is caused to flow into the operating fuel cell 2, and the amount of heat generated by the power generation from the fuel cell 2 is taken to lower the temperature of the fuel cell 2. The first cooling water flowing out from the fuel cell 2 is heated to a high temperature, and the high temperature first cooling water passes through the heater 3 and flows into the water vapor separator 4. The water vapor separator 4 is a device for separating water vapor from the cooling water heated to high temperature by exhaust heat from the fuel cell, and the vaporized first cooling water (water vapor) is separated here. The water vapor separated by the water vapor separator 4 is introduced into a reformer (not shown) or the like and used for a steam reforming reaction or the like. A part of the cooling water separated by the water vapor separator 4 is further cooled by the cooling heat exchanger 6 through the bypass pipe 1 b and flows into the fuel cell 2 again. At that time, the flow rate of the first cooling water cooled by the cooling heat exchanger 6 is adjusted by adjusting the opening of the battery cooling water adjustment valve 9 according to the detection value of the battery cooling water temperature sensor 8. The water temperature of the first cooling water in the fuel cell cooling water circulation path 1 is adjusted to a predetermined temperature. Note that, when the fuel cell 2 is started, if the first cooling water flowing into the fuel cell 2 is at a low temperature, the output efficiency of the fuel cell 2 at the time of startup is lowered. For this reason, the heater 3 is provided for warming the cooling water flowing into the fuel cell 2 at the time of startup, and is often stopped during the steady operation.

  The second cooling water circulation path 10 exchanges heat with the first cooling water flowing through the fuel cell cooling water circulation path 1 via the cooling heat exchanger 6 to cool the first cooling water. This is a circulation path of the second cooling water serving as a refrigerant, and connects the cooling heat exchanger 6, the exhaust heat recovery heat exchanger 51, the second cooling water temperature sensor 16, the cooling water circulation pump 11, and these components. It has piping.

  That is, in the pipe 10a extending from the second cooling water outflow side 6a of the cooling heat exchanger 6, the exhaust heat recovery heat exchanger 51, the second cooling water temperature sensor 16, and the cooling water circulation pump 11 are respectively provided from the upstream side. It arrange | positions and is connected to the 2nd cooling water introduction side 6b of the heat exchanger 6 for cooling. Further, the second relay pipe 33 provided with the second relay pipe cooling water temperature sensor 15 branches and extends to the pipe between the cooling heat exchanger 6 and the exhaust heat recovery heat exchanger 51, and is recovered. It is connected to the water circulation path 20. A first relay pipe 31 extending from the recovered water circulation path 20 described later is connected to the pipe between the exhaust heat recovery heat exchanger 51 and the second cooling water temperature sensor 16.

  In the heat exchanger 51 for exhaust heat recovery, the amount of heat of the second cooling water whose temperature has been raised by heat exchange with the first cooling water is given to external water or the like that is the refrigerant of the heat exchanger 51 for exhaust heat recovery to Collect etc.

  The recovered water circulation path 20 is a circulating path of recovered water recovered from the exhaust gas discharged from the fuel cell 2, and includes a recovered water generation device 21, a recovered water circulation pump 23, a first adjustment valve 32, a second adjustment valve 26, an air The fin cooler 25, the recovered water temperature sensor 27, and piping connecting the above-described components are provided.

  A fuel cell off-gas exhaust path 7 extending from the cathode electrode of the fuel cell 2 is connected to the upper part of the recovered water generating device 21, and exhaust gas such as cathode off gas is introduced into the recovered water generating device 21. Although not specifically shown, in the case of a fuel cell power generator further provided with a reformer, the burner combustion exhaust gas path extending from the burner portion of the reformer is connected so that the burner combustion exhaust gas is introduced. It is configured. In addition, a sprinkler 22 is arranged in the upper part of the recovered water generating device 21, and the exhaust gas introduced into the recovered water generating device 21 is sprinkled with recovered water from the sprinkler 22 to cool and cool the moisture. It is configured to condense. In addition, a decarbonation tower is disposed below the sprinkler 22, where the moisture water recovered from the exhaust gas is decarboxylated and recovered as recovered water in the recovery tank at the bottom. The gas component in the exhaust gas is exhausted from the upper part of the recovered water generation device 21 to the outside of the system.

  A pipe 20a extending from the bottom (recovery tank) of the recovered water generation device 21 includes a recovered water circulation pump 23, a first adjustment valve 32, a second adjustment valve 26, an air fin cooler 25, and a recovered water temperature sensor 27 from the upstream side. They are respectively arranged and connected to the sprinkler 22 at the top of the recovered water generator 21.

  Further, the first relay pipe 31 extends through the first adjustment valve 32, and the pipe between the heat exchanger 51 for exhaust heat recovery in the second cooling water circulation path 10 and the second cooling water temperature sensor 16 as described above. Connected to. The first adjustment valve 32 can adjust the opening degree in the direction of the first relay pipe 31 between 0 to 100%, and the air fin cooler 25 direction as the opening degree in the direction of the first relay pipe 31 increases. It is comprised so that the opening degree of the valve connected to this piping may become small.

  The second adjustment valve 26 is connected to a bypass pipe 20b that is branched and extended from the upstream pipe of the air fin cooler 25, and adjusts the opening degree of each opening valve of the second adjustment valve 26. Thus, the flow rate of the recovered water that flows to the air fin cooler 25 and the flow rate ratio of the recovered water that flows while bypassing the air fin cooler 25 are adjusted.

  The control unit 100a receives the temperature measurement value from the second relay pipe cooling water temperature sensor 15, the second cooling water temperature sensor 16, and the recovered water temperature sensor 27, and the output value of the recovered water circulation pump 23, and receives the second cooling water circulation. The first adjustment valve 32, so that the temperature of the second cooling water flowing through the path 10, the temperature of the recovered water flowing through the second relay pipe 33, and the temperature of the recovered water flowing through the recovered water circulation path 20 are within the set range. An output signal is transmitted to the second adjustment valve 26, the recovered water circulation pump 23, and the air fin cooler 25.

  Next, the control performed by the control unit 100a will be described.

  The detection value of the second cooling water temperature sensor 16 is sent to the control unit 100a and compared with the upper limit value stored in advance in the control unit 100a. When the detected value is larger than the set value, the first adjustment valve 32 is opened in a direction in which the flow rate of the recovered water flowing from the recovered water circulation path 20 through the first relay pipe 31 into the second cooling water circulation path 10 is increased. When the detected value of the second cooling water temperature sensor 16 is smaller than the set value, the command to adjust the degree is flowed from the recovered water circulation path 20 into the second cooling water circulation path 10 through the first relay pipe 31. A command to adjust the opening degree of the first adjustment valve 32 in a direction to decrease the flow rate of the recovered water is transmitted to the first adjustment valve 32. Since the temperature of the recovered water in the recovered water tank of the recovered water generating device 21 provided in the recovered water circulation path 20 is lower than the temperature of the second cooling water circulating in the second cooling water circulation path 10, the second cooling of the recovered water is performed. The temperature of the second cooling water can be adjusted by adjusting the amount of inflow into the water circulation path 10. Even when the opening of the first adjustment valve 32 in the direction of the first relay pipe 31 reaches 100%, such as when there is little demand for hot water taken out from the heat exchanger 51 for exhaust heat recovery, the second cooling water When the detected value of the water temperature sensor 16 is larger than the set value stored in the control unit 100a, a command to increase the output is transmitted to the recovered water circulation pump 23, the flow rate of recovered water sent from the recovered water circulation pump 23 is increased, The flow rate of the recovered water flowing into the second cooling water circulation path 10 from the recovered water circulation path 20 is increased.

  The detection value of the second relay pipe cooling water temperature sensor 15 is sent to the control unit 100a and compared with the upper limit value stored in advance in the control unit 100a. When the detected value is larger than the upper limit value, a command to increase the output of the recovered water circulation pump 23 of the recovered water circulation path 20 is issued. When the detected value of the second relay pipe cooling water temperature sensor 15 is lower than the upper limit value, A command to lower the output of the recovered water circulation pump 23 in the water circulation path 20 is transmitted to the recovered water circulation pump 23. In the second relay pipe 33, the second cooling water having the same flow rate as that flowing into the second cooling water circulation path 10 from the recovered water circulation path 20 through the first relay pipe 31 passes through the second relay pipe 33 and is second. Since it recirculates from the cooling water circulation path 10 to the recovered water circulation path 20, the temperature of the second cooling water and the recovered water can be adjusted by adjusting the output of the recovered water circulation pump 23.

  Further, the detected value of the recovered water temperature sensor 27 is sent to the control unit 100a and compared with the upper limit value stored in advance in the control unit 100a. When the detected value is larger than the upper limit value, a command for adjusting the opening degree of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the air fin cooler 25, and when the detected value is smaller than the set value. Sends a command to the second adjustment valve 26 to adjust the opening of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the sprinkler 22 by bypassing the air fin cooler 25. Further, when the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even when the opening degree of the second adjustment valve 26 in the direction of the air fin cooler 25 becomes 100%, the control unit 100a outputs to the air fin cooler 25. Is transmitted, the output of the air fin cooler 25 is increased, the recovered water in the recovered water circulation path 20 is actively cooled, and the temperature of the recovered water in the recovered water circulation path 20 detected by the recovered water temperature sensor 27 is detected. Is controlled to a predetermined temperature. If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even if the output of the air fin cooler 25 is increased to the upper limit, a command to increase the output of the recovered water circulation pump 23 is transmitted to the recovered water circulation pump 23. The amount of recovered water in the air fin cooler 25 is increased.

  Next, the case where intermediate temperature water (about 65 ° C.) or high temperature water (about 85 ° C.) is taken out from the heat exchanger 51 for exhaust heat recovery of the fuel cell power generator of the above embodiment will be described with an example.

  When taking out the medium temperature water of about 65 ° C. from the heat exchanger 51 for exhaust heat recovery, the control unit 100a opens the first adjustment valve 32 so that the temperature detected by the second cooling water temperature sensor 16 becomes 65 ° C. Control. If the detected value of the second cooling water temperature sensor 16 is 65 ° C. or higher even when the opening of the first adjustment valve 32 toward the first relay pipe 31 reaches 100%, the recovered water circulation pump of the recovered water circulation path 20 The output of 23 is increased and the flow rate of the cooling water flowing into the first relay pipe 31 is increased. Further, in the second cooling water circulation path 10, the same amount of the second cooling water that has flowed into the first relay pipe 31 as the recovered water in the recovered water circulation path 20 flows out to the recovered water circulation path 20 via the second relay pipe 33. To do. Therefore, the temperature of the cooling water in the recovered water circulation path 20 rises. Therefore, when the detection value of the second relay pipe cooling water temperature sensor 15 reaches 75 ° C., the rotation speed of the recovered water circulation pump 23 is increased to increase the flow rate of the recovered water, and the temperature of the cooling water sent to the air fin cooler 25 is adjusted. Lower.

  When high temperature water of about 85 ° C. is taken out from the heat exchanger 51 for exhaust heat recovery, the control unit 100a opens the first adjustment valve 32 so that the detected value of the second cooling water temperature sensor 16 becomes 85 ° C. The set value related to the opening of the first adjustment valve 32 is changed so as to be controlled. Further, when the detection of the second relay pipe cooling water temperature sensor 15 is 95 ° C. or higher, the control unit 100a changes the set value for the recovered water circulation pump 23 so as to perform control to increase the output of the recovered water circulation pump 23. To do. Except for changing these set values, the same control is performed as when medium-temperature water is taken out.

  As described above, it is possible to stably provide hot water having a water temperature according to the needs of the user only by changing the set temperature with respect to the temperature detected by each of the temperature sensors 15 and 16. In addition, when controlling the temperature of the cooling water, the air fin cooler 73 can be made unnecessary as compared with the conventional fuel cell power generator shown in FIG. Maintenance costs can be reduced.

  In this embodiment, an example in which an air fin cooler is used as a cooling device has been shown and described. Needless to say, a cooling device other than an air fin cooler can be used.

(Second Embodiment)
A fuel cell power generator according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as the said 1st Embodiment, and the description is abbreviate | omitted.

  In this embodiment, the second cooling water circulation path 10 is connected to the pipe 10a extending from the second cooling water outflow side 6a of the cooling heat exchanger 6 to the exhaust heat recovery heat exchanger 51, the backflow prevention valve 19, from the upstream side, A second cooling water temperature sensor 16 and a cooling water circulation pump 11 are arranged and connected to the second cooling water introduction side 6 b of the cooling heat exchanger 6. A second relay pipe 33 provided with a second relay pipe cooling water temperature sensor branches and extends in the pipe between the exhaust heat recovery heat exchanger 51 and the backflow prevention valve 19, and the recovered water circulation path 20 is extended. Connected to. A first relay pipe 31 extending from the recovered water circulation path 20 is connected to the pipe between the exhaust heat recovery heat exchanger 51 and the backflow prevention valve 19.

  Further, the recovered water circulation path 20 is connected to a pipe 20a extending from the bottom (recovery tank) of the recovered water generating device 21, from the upstream side, the recovered water circulation pump 23, the first adjustment valve 32, the recovered water cooling heat exchanger 28, the recovery Water temperature sensors 27 are respectively arranged and connected to a watering device above the recovered water generation device 21.

  The air fin cooler 25 and the refrigerant circulation pump 61 are disposed in the refrigerant circulation path 60 of the refrigerant of the recovered water cooling heat exchanger 28 (hereinafter referred to as recovered water refrigerant), and the recovered water cooling heat exchanger 28 is The recovered water and the recovered water refrigerant are exchanged with each other through the heat exchanger to cool the recovered water. The recovered water refrigerant whose temperature has been raised by heat exchange with the recovered water is cooled by the air fin cooler 25 and introduced into the recovered water cooling heat exchanger 28 again.

  The control unit 100b in the fuel cell power generator receives the temperature measurement values from the second relay pipe cooling water temperature sensor 15, the second cooling water temperature sensor 16, and the recovered water temperature sensor 27, and the output value of the recovered water circulation pump 23. The temperature of the second cooling water flowing through the second cooling water circulation path 10, the temperature of the recovered water flowing through the second relay pipe 33, and the temperature of the recovered water flowing through the recovered water circulation path 20 are within the set range. An output signal is transmitted to the first adjustment valve 32, the recovered water circulation pump 23, and the air fin cooler 25.

  Next, the control performed by the control unit 100b will be described.

  The detection value of the second coolant temperature sensor 16 is sent to the control unit 100b and compared with the upper limit value stored in advance in the control unit 100b. When the detected value is larger than the upper limit value, the opening degree of the first adjustment valve 32 in the direction of increasing the flow rate of the recovered water flowing from the recovered water circulation path 20 through the first relay pipe 31 into the second cooling water circulation path 10. If the detected value is smaller than the set value, the flow rate of the recovered water flowing from the recovered water circulation path 20 through the first relay pipe 31 to the second cooling water circulation path 10 is decreased. A command for adjusting the opening degree of the first adjustment valve 32 is transmitted to the first adjustment valve 32. And even if the opening degree of the first adjustment valve 32 toward the first relay pipe 31 reaches 100%, the detected value of the second cooling water temperature sensor 16 is larger than the set value stored in the control unit 100b. Transmits a command to increase the output to the recovered water circulation pump 23, increases the flow rate of the recovered water sent from the recovered water circulation pump 23, and sets the flow rate of the recovered water flowing into the second cooling water circulation path 10 from the recovered water circulation path 20. increase.

  The detection value of the second relay pipe cooling water temperature sensor 15 is sent to the control unit 100b and compared with the upper limit value stored in advance in the control unit 100b. When the detected value is larger than the upper limit value, a command to increase the output of the recovered water circulation pump 23 of the recovered water circulation path 20 is issued. When the detected value is less than the upper limit value, the output of the recovered water circulation pump 23 of the recovered water circulation path 20 is decreased. The command is transmitted to the recovered water circulation pump 23.

  Further, the detected value of the recovered water temperature sensor 27 is sent to the control unit 100b and compared with the upper limit value stored in advance in the control unit 100b. When the detected value is larger than the upper limit value, a command to increase the output of the air fin cooler 25 is transmitted to the air fin cooler 25, and when the detected value is equal to or lower than the upper limit value, a command to decrease the output of the air fin cooler 25 is transmitted. . That is, by adjusting the temperature of the recovered water refrigerant flowing through the refrigerant circulation path 60, the temperature of the recovered water in the recovered water circulation path 20 detected by the recovered water temperature sensor 27 is controlled to be a predetermined temperature. If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even if the output of the air fin cooler 25 is increased to the upper limit, a command to increase the output of the recovered water circulation pump 23 is transmitted to the recovered water circulation pump 23. The processing amount of recovered water in the recovered water cooling heat exchanger 28 is increased.

  In this embodiment, since the first relay pipe 31 is arranged downstream of the exhaust heat recovery heat exchanger 51, the second water after the heat exchange with the exhaust heat recovery heat exchanger 51 is provided in the recovered water circulation path 20. Cooling water can be introduced, and more exhaust heat can be recovered by the exhaust heat recovery heat exchanger 51. Further, since the second cooling water after heat exchange is passed through the recovered water circulation path 20 by the heat exchanger 51 for exhaust heat recovery, lower temperature recovered water can be returned and the load on the air fin cooler 25 is further reduced. it can.

  In addition, since the exhaust gas contains carbon dioxide and the like, the recovered water that circulates through the recovered water circulation path 20 is often acidic. However, in this embodiment, since the recovered water does not flow into the refrigerant flow path of the air fin cooler 25, it is necessary to configure the air fin cooler 25. A copper-based material can be used as the constituent material. For this reason, the cooling efficiency of the air fin cooler 25 can be increased, and the cost required for cooling the recovered water can be further reduced.

(Third embodiment)
A third embodiment of the fuel cell power generator of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as the said 1st Embodiment, and the description is abbreviate | omitted.

  In this embodiment, a heat exchanger for exhaust heat recovery from the upstream side is connected to a bypass pipe 1b in which a pipe between a battery cooling water circulation pump 5 and a battery cooling water temperature sensor 8 in the fuel cell cooling water circulation path 1 extends. 52, a cooling heat exchanger 6 and a battery cooling water adjusting valve 9 are respectively arranged and connected to a pipe between the water vapor separator 4 and the battery cooling water circulation pump 5 in the fuel cell cooling water circulation path 1.

  The cooling heat exchanger 6 is provided with a recovered water bypass path 40 that branches from the recovered water circulation path 20 via the first adjustment valve 32 and returns to the recovered water circulation path 20 through the cooling heat exchanger 6. ing. That is, part or all of the recovered water circulating through the recovered water circulation path 20 can be used as the refrigerant of the first cooling water. A bypass recovery water temperature sensor 41 and a waste heat recovery heat exchanger 53 are respectively arranged on the downstream side of the cooling heat exchanger 6 of the recovered water bypass path 40, and the first adjustment valve of the recovered water circulation path 20. 32 is connected to the downstream side.

  In the heat exchanger for exhaust heat recovery 52, the heat quantity of the first cooling water that has received the power generation calorific value during cooling of the fuel cell 2 and raised the temperature is used as external water that is the refrigerant of the heat exchanger for exhaust heat recovery 52 or the like. Give it to collect hot water.

  In the cooling heat exchanger 6, the amount of heat obtained by subtracting the amount of heat recovered by the exhaust heat recovery heat exchanger 52 from the amount of heat generated by the fuel cell 2 is recovered water (hereinafter referred to as the recovered water bypass route 40). In this case, it can be given to the detoured water by heat exchange with the detoured water.

  In the heat exchanger for exhaust heat recovery 53, the amount of heat of detour recovered water whose temperature has been raised by heat exchange with the first cooling water in the cooling heat exchanger 6 is the refrigerant of the heat exchanger for exhaust heat recovery 53. Give hot water to external water. The amount of heat recovered here is equal to or less than the amount of heat obtained by subtracting the amount of heat recovered by the exhaust heat recovery heat exchanger 52 from the amount of heat generated by the fuel cell 2. Also low temperature hot water is recovered.

  The control unit 100c in the fuel cell power generation apparatus receives the temperature measurement values from the detour recovery water temperature sensor 41 and the recovery water temperature sensor 27 and the output value of the recovery water circulation pump 23, and flows out from the cooling heat exchanger 6. An output signal is transmitted to the first adjustment valve 32, the recovered water circulation pump 23, and the air fin cooler 25 so that the temperature of the bypass recovered water falls within the set range.

  Next, the control performed by the control unit 100c will be described.

  The detection value of the bypass recovery water temperature sensor 41 is sent to the control unit 100c and compared with the upper limit value stored in advance in the control unit 100c. When the detected value is larger than the set value, a command to adjust the opening of the first adjustment valve 32 in the direction to increase the flow rate of the recovered water flowing through the recovered water bypass path 40, and conversely, the detected value is the set value. If smaller, the command to adjust the opening degree of the first adjustment valve 32 in a direction to decrease the flow rate of the recovered water flowing through the recovered water bypass path 40 is transmitted to the first adjustment valve 32. And even if the opening degree of the first adjustment valve 32 in the direction of the recovered water bypass path 40 reaches 100%, if the detected value is larger than the set value stored in the control unit 100c, it is output to the recovered water circulation pump 23. To increase the flow rate of the recovered water flowing from the recovered water circulation path 20 through the recovered water bypass path 40 by increasing the flow rate of the recovered water sent from the recovered water circulation pump 23.

  Further, the detected value of the recovered water temperature sensor 27 is sent to the control unit 100c and compared with the upper limit value stored in advance in the control unit 100c. When the detected value is larger than the upper limit value, a command for adjusting the opening degree of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the air fin cooler 25, and when the detected value is smaller than the set value. Sends a command to the second adjustment valve 26 to adjust the opening of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the sprinkler 22 by bypassing the air fin cooler 25. If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even when the opening of the second adjustment valve 26 in the direction of the air fin cooler 25 becomes 100%, the control unit 100c outputs to the air fin cooler 25. Send a command to increase If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even if the output of the air fin cooler 25 is increased to the upper limit, a command to increase the output of the recovered water circulation pump 23 is transmitted to the recovered water circulation pump 23. The amount of recovered water in the air fin cooler 25 is increased.

  According to this embodiment, hot water or the like in different temperature ranges can be obtained simultaneously. Further, as in the above embodiment, the air fin cooler 73 can be dispensed with when controlling the temperature of the cooling water as compared with the conventional fuel cell power generator shown in FIG. As a result, maintenance costs can be reduced.

(Fourth embodiment)
A fuel cell power generator according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as the said 1st Embodiment, and the description is abbreviate | omitted.

  In this embodiment, the second cooling water circulation path 10 is connected to the pipe 10a extending from the second cooling water outflow side 6a of the cooling heat exchanger 6 to the exhaust heat recovery heat exchanger 54, the second cooling use from the upstream side. A heat exchanger 17, a second cooling water temperature sensor 16, and a cooling water circulation pump 11 are arranged and connected to the second cooling water introduction side 6 b of the cooling heat exchanger 6.

  The second cooling heat exchanger 17 branches from the recovered water circulation path 20 via the first adjustment valve 32, passes through the second cooling heat exchanger 17 and returns to the recovered water circulation path 20. A detour path 45 is arranged. That is, a part or all of the recovered water circulating through the recovered water circulation path 20 can be used as the refrigerant for the second cooling water. A second bypass recovery water temperature sensor 46 and an exhaust heat recovery heat exchanger 55 are arranged in the pipe 45a downstream of the second cooling heat exchanger 17 of the recovered water second bypass path 45, respectively. The recovered water circulation path 20 is connected to the downstream side of the first adjustment valve 32.

  In the heat exchanger for exhaust heat recovery 54, the amount of heat of the second cooling water raised by heat exchange with the first cooling water is given to external water or the like as the refrigerant of the heat exchanger for exhaust heat recovery 54 to Collect etc.

  In the second cooling heat exchanger 17, the amount of heat obtained by subtracting the amount of heat recovered by the exhaust heat recovery heat exchanger 54 from the amount of generated heat generated by the fuel cell 2 flows through the recovered water second bypass path 45. Heat is exchanged with the recovered water (hereinafter referred to as “second detour recovery water”) to give the second detour recovery water.

  In the heat exchanger 55 for exhaust heat recovery, the heat amount of the second detour recovery water that has been heated by heat exchange with the second cooling water in the second cooling heat exchanger 17 is used as the heat exchanger 55 for exhaust heat recovery. The hot water is collected by supplying it to external water, which is the refrigerant. The amount of heat recovered here is equal to or less than the amount of heat obtained by subtracting the amount of heat recovered by the exhaust heat recovery heat exchanger 54 from the amount of generated heat generated by the fuel cell 2. Relatively low temperature hot water is also recovered.

  The control unit 100d in the fuel cell power generator receives the temperature measurement values from the second cooling water temperature sensor 16, the second detour recovery water temperature sensor 46 and the recovery water temperature sensor 27, and the output value of the recovery water circulation pump 23. Then, an output signal is transmitted to the first adjustment valve 32, the recovered water circulation pump 23, and the air fin cooler 25 so that the temperatures of the second cooling water and the second bypass recovery water fall within the set range.

  Next, control performed by the control unit 100d will be described.

  The detection value of the second coolant temperature sensor 16 is sent to the control unit 100d and compared with the upper limit value stored in advance in the control unit 100d. When the detected value is larger than the set value, a command to adjust the opening of the first adjustment valve 32 in a direction to increase the flow rate of the recovered water flowing through the recovered water second bypass path 45, and conversely, the detected value is When it is smaller than the set value, a command to adjust the opening of the first adjustment valve 32 in a direction to decrease the flow rate of the recovered water flowing through the recovered water second bypass path 45 is transmitted to the first adjustment valve 32. And even if the opening degree of the first adjustment valve 32 in the direction of the recovered water second bypass path 45 reaches 100%, the detected value of the second cooling water temperature sensor 16 is more than the set value stored in the control unit 100d. If larger, a command to increase the output is transmitted to the recovered water circulation pump 23, the flow rate of recovered water sent from the recovered water circulation pump 23 is increased, and the recovered water flowing into the recovered water second bypass path 45 from the recovered water circulation path 20 Increase the flow rate.

  The detection value of the second detour recovery water temperature sensor 46 is sent to the control unit 100d and compared with the upper limit value stored in advance in the control unit 100d. When the detected value is larger than the upper limit value, an instruction to increase the output of the recovered water circulation pump 23 is transmitted to the recovered water circulation pump 23. When the detected value is equal to or lower than the upper limit value, an instruction to decrease the output of the recovered water circulation pump 23 is transmitted. .

  The detected value of the recovered water temperature sensor 27 is sent to the control unit 100d and compared with the upper limit value stored in advance in the control unit 100d. When the detected value is larger than the upper limit value, a command for adjusting the opening degree of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the air fin cooler 25, and when the detected value is smaller than the set value. Sends a command to the second adjustment valve 26 to adjust the opening of the second adjustment valve 26 in a direction to increase the flow rate of the recovered water sent to the sprinkler 22 by bypassing the air fin cooler 25. If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even when the opening degree of the second adjustment valve 26 in the direction of the air fin cooler 25 becomes 100%, the control unit 100d outputs to the air fin cooler 25. Send a command to increase If the detected value of the recovered water temperature sensor 27 exceeds a predetermined temperature even if the output of the air fin cooler 25 is increased to the upper limit, a command to increase the output of the recovered water circulation pump 23 is transmitted to the recovered water circulation pump 23. The amount of recovered water in the air fin cooler 25 is increased.

  According to this embodiment, hot water or the like in different temperature ranges can be obtained simultaneously. Further, as in the above-described embodiment, the air fin cooler 73 can be dispensed with when controlling the temperature of the cooling water as compared with the conventional fuel cell power generator shown in FIG. As a result, maintenance costs can be reduced.

1: Fuel cell cooling water circulation path 2: Fuel cell 3: Heater 4: Steam separator 5: Battery cooling water circulation pump 6: Cooling heat exchanger 7: Fuel cell off-gas exhaust path 8: Battery cooling water temperature sensor 9: Battery cooling Water adjustment valve 10: Cooling water circulation path 11: Cooling water circulation pump 15: Relay pipe cooling water temperature sensor 16: Cooling water temperature sensor 17: Second cooling heat exchanger 19: Backflow prevention valve 20: Recovered water circulation path 21: Recovered water Generator 22: Sprinkler 23: Recovery water circulation pump 25: Air fin cooler 26: Second adjustment valve 27: Recovery water temperature sensor 28: Recovery water cooling heat exchanger 31: First relay pipe 32: First adjustment valve 33 : Second relay pipe 40: recovered water bypass path 41: bypass recovered water temperature sensor 45: recovered water second bypass path 46: second bypass recovered water temperature sensors 51 to 55: heat exchange for exhaust heat recovery 60: refrigerant circulation path 61: coolant circulation pump 100a to 100d: control unit

Claims (15)

In a fuel cell power generator having a fuel cell (2) for generating electricity by electrochemically reacting fuel gas and air,
The recovered water is circulated to the recovered water generating device (21) that recovers the moisture in the exhaust gas discharged from the fuel cell (2) as recovered water, and a recovered water circulation pump (23) is provided in the middle thereof. A recovered water circulation path (20);
A cooling device (25) for cooling the recovered water flowing through the recovered water circulation path (20);
A fuel cell cooling water circulation path (1) in which the first cooling water is circulated to the fuel cell (2) and a cooling heat exchanger (6) is provided in the middle thereof;
An exhaust heat recovery path for supplying heat of the first cooling water to an external heat demand,
The heat of the first cooling water taken out from the cooling heat exchanger (6) is supplied to the external heat demand via the exhaust heat recovery path, and the surplus is supplied to the recovered water circulation path (20 ) Through the cooling device (25) to be discharged to the outside. Heat exchange with the first cooling water via the cooling heat exchanger (6), and a second cooling water circulation path (10) through which the second cooling water for cooling the first cooling water circulates,
A first relay pipe (31) branched and extended from the recovered water circulation path via the adjustment valve (32) is connected to the second cooling water circulation path (10),
The second relay pipe (33) branched and extended from the second cooling water circulation path (10) is connected to the downstream side of the adjustment valve (32) of the recovered water circulation path (20). The fuel cell power generator described in 1. The second cooling water circulation path (10) includes second cooling water temperature detecting means (16),
The degree of opening of the adjustment valve (32), the recovered water circulation so that the temperature of the second cooling water detected by the second cooling water temperature detecting means (16) is a value within a predetermined setting range. By controlling at least one selected from the output of the pump (23) and the output of the cooling device (25), the amount of water and / or the water temperature passing through the first relay pipe (31) is adjusted. The fuel cell power generator according to claim 2. The second relay pipe (33) includes second relay pipe cooling water temperature detecting means (15),
The degree of opening of the adjustment valve (32) so that the temperature of the second cooling water detected by the second relay pipe cooling water temperature detecting means (15) is a value within a predetermined setting range; By controlling at least one selected from the output of the recovered water circulation pump (23) and the output of the cooling device (25), the amount of water and / or the water temperature passing through the second relay pipe (33) is adjusted. The fuel cell power generator according to claim 2 or 3, wherein An exhaust heat recovery heat exchanger (51) is disposed in a path between the second relay pipe (33) and the first relay pipe (31) of the second cooling water circulation path (10),
The exhaust heat recovery path is configured to extract heat to the outside through heat exchange with the second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (51). The fuel cell power generator according to any one of claims 2 to 4, wherein An exhaust heat recovery heat exchanger (51) is disposed in a path upstream of the path connected to the second relay pipe (33) of the second cooling water circulation path (10),
The exhaust heat recovery path is configured to extract heat to the outside through heat exchange with the second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (51). The fuel cell power generator according to any one of claims 2 to 4, wherein   A recovered water bypass path (40) is branched from the recovered water circulation path (20) via an adjustment valve (32) and returned to the recovered water circulation path (20) through the cooling heat exchanger (6). The fuel cell power generator according to claim 1. A bypass recovery water temperature detection means (41) is provided in the recovery water bypass path (40),
The degree of opening of the adjustment valve (32) and the recovered water circulation pump (23) so that the temperature of recovered water detected by the detour recovered water temperature detecting means (41) becomes a value within a predetermined set range. The amount of water and / or the water temperature passing through the recovered water bypass route (40) is controlled by controlling at least one selected from the output of the cooling device (25) and the output of the cooling device (25). 8. The fuel cell power generator according to 7. Waste heat recovery heat exchangers (52, 53) are disposed in the fuel cell cooling water circulation path (1) and the recovered water bypass path (40), respectively.
The exhaust heat recovery path includes first cooling water passing through the fuel cell cooling water circulation path (1) via the exhaust heat recovery heat exchanger (52) provided in the fuel cell cooling water circulation path (1). Recovered water passing through the recovered water bypass path (40) via a path for heat exchange to extract heat to the outside and the exhaust heat recovery heat exchanger (53) provided in the recovered water bypass path (40) The fuel cell power generator according to claim 7 or 8, comprising a path for exchanging heat with the heat and extracting heat to the outside. Second cooling in which a second cooling water is circulated through the cooling heat exchanger (6) to cool the first cooling water, and a second cooling heat exchanger (17) is provided in the middle of the second cooling water. Water circulation path (10);
A recovered water second bypass path (branched from the recovered water circulation path (20) via the regulating valve (32) and returned to the recovered water circulation path (20) through the second cooling heat exchanger (17) ( 45). The fuel cell power generator according to claim 1, further comprising: Second cooling water temperature detection means (16) is provided in the second cooling water circulation path (10),
The opening degree of the adjustment valve (32), the recovered water circulation pump so that the temperature of the second cooling water detected by the second cooling water temperature detecting means (16) becomes a value within a predetermined setting range. By controlling at least one selected from the output of (23) and the output of the cooling device (25), the water amount and / or the water temperature passing through the recovered water second bypass path (45) are adjusted. The fuel cell power generator according to claim 10. A second detour recovered water temperature detection means (46) is provided in the recovered water second detour path (45),
The degree of opening of the adjustment valve (32), the recovered water circulation pump () so that the temperature of the recovered water detected by the second detour recovered water temperature detecting means (46) becomes a value within a predetermined setting range. 23) and at least one selected from the output of the cooling device (25) is controlled to adjust the amount of water and / or the water temperature through the recovered water second bypass path (45). The fuel cell power generator according to claim 10. Exhaust heat recovery heat exchangers (54, 55) are disposed in the second cooling water circulation path (10) and the recovered water second bypass path (45), respectively.
The exhaust heat recovery path includes second cooling water passing through the second cooling water circulation path (10) via the exhaust heat recovery heat exchanger (54) provided in the second cooling water circulation path (10). A path for extracting heat to the outside through heat exchange and the second bypass path for recovered water (45) via the heat exchanger (55) for exhaust heat recovery provided in the second bypass path for recovered water (45) The fuel cell power generator according to any one of claims 10 to 12, wherein the fuel cell power generator is configured by a path for exchanging heat with recovered water passing through the pipe and extracting heat to the outside. The recovered water circulation path (20) includes the cooling device (25), recovered water temperature detecting means (27) for detecting the temperature of the recovered water after flowing through the cooling device (25), and the cooling device ( 25) a flow rate adjusting valve (26) for adjusting a flow rate ratio between the recovered water to be passed to 25) and the recovered water to bypass the cooling device (25),
The output of the recovered water circulation pump (23) and the flow rate ratio adjusting valve (26) so that the temperature of the recovered water detected by the recovered water temperature detecting means (27) becomes a value within a predetermined setting range. The fuel cell power generator according to any one of claims 1 to 13, wherein the fuel cell power generator is configured to control at least one of an opening degree and an output of the cooling device (25). The recovered water circulation path (20) includes a recovered water cooling heat exchanger (28) and recovered water temperature detecting means for detecting the temperature of the recovered water after flowing through the recovered water cooling heat exchanger (28). (27)
The cooling device (25) is disposed in the refrigerant circulation path (60) of the recovered water cooling heat exchanger (28),
The output of the recovered water circulation pump (23), the recovered water cooling heat exchanger so that the temperature of the recovered water detected by the recovered water temperature detecting means (27) becomes a value within a predetermined set range. The fuel cell power generator according to any one of claims 1 to 13, wherein the fuel cell power generator is configured to control at least one of a flow rate of the refrigerant passing through (28) and an output of the cooling device (25). .