JP6050036B2 - Fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell device with improved power generation efficiency.

  In recent years, as a next-generation energy, a fuel cell module in which a fuel cell capable of obtaining electric power using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air) is stored in a storage container, or a fuel cell Various fuel cell devices in which a module is housed in an outer case have been proposed (see, for example, Patent Document 1).

  In such a fuel cell device, exhaust gas that has not been used for power generation of the fuel cell is combusted, and the temperature of the oxygen-containing gas supplied to the fuel cell is increased by this combustion heat, so that a high-temperature oxygen-containing gas is produced. It has been proposed to supply the fuel cell (see, for example, Patent Document 2).

JP 2007-59377 A JP 2005-166439 A

  By the way, in the fuel cell expected as the next generation energy, further improvement in power generation efficiency is required from the viewpoint of energy saving.

  Therefore, an object of the present invention is to provide a fuel cell device with improved power generation efficiency.

The fuel cell device of the present invention includes a fuel cell that generates electricity with an oxygen-containing gas and fuel, a purification device for purifying exhaust gas discharged from the fuel cell, and a purified exhaust gas discharged from the purification device. A first heat exchanger for exchanging heat of the oxygen-containing gas or fuel supplied to the fuel cell, and heating for further heating the oxygen-containing gas or fuel heat-exchanged in the first heat exchanger A device, a first heat exchanger supply line for supplying the oxygen-containing gas or fuel toward the first heat exchanger, and the oxygen-containing gas heat-exchanged by the first heat exchanger Alternatively, a heating device supply line for supplying fuel to the heating device, a reformer for generating the fuel supplied to the fuel cell by steam reforming, and the purified exhaust gas and water heat Replace it to produce hot water The second heat exchanger and a hot water storage tank for storing hot water generated in the second heat exchanger, and the condensed water generated in the second heat exchanger is converted into the modified water. And a bypass line that connects the first heat exchanger supply line and the heating device supply line, and the bypass line has a three-way valve at a connection with the first heat exchanger supply line. A second temperature sensor for measuring the temperature of the purified exhaust gas discharged from the purification device, and when the temperature measured by the second temperature sensor is equal to or lower than a predetermined temperature, The apparatus includes a control device that controls the three-way valve so that the oxygen-containing gas or fuel flowing through the first heat exchanger supply line flows to the heating device supply line via the bypass line .

The fuel cell device of the present invention, since it is possible to provide a high oxygen-containing gas or the fuel temperature to fuel cells, can be improved fuel cell system of the power generation efficiency.

It is a block diagram which shows an example of a structure of a fuel cell system provided with the fuel cell apparatus of this embodiment. It is an external appearance perspective view which shows the fuel cell module which comprises some examples of the fuel cell apparatus of this embodiment. FIG. 3 is a cross-sectional view of the fuel cell module shown in FIG. 2. It is a conceptual diagram which shows that the 1st heat exchanger and the 2nd heat exchanger are connected to the fuel cell module in the fuel cell apparatus of this embodiment in order. It is a block diagram which shows another example of a structure of a fuel cell system provided with the fuel cell apparatus of this embodiment. It is a block diagram which shows another example of a structure of a fuel cell system provided with the fuel cell apparatus of this embodiment. It is a block diagram which shows another example of a structure of a fuel cell system provided with the fuel cell apparatus of this embodiment.

  FIG. 1 is a configuration diagram illustrating an example of a configuration of a fuel cell system including the fuel cell device of the present embodiment. The fuel cell system shown in FIG. 1 includes a power generation unit that is an example of the fuel cell device of the present embodiment, a hot water storage unit that stores hot water after heat exchange, and a circulation pipe that circulates water between these units. It is composed of

  The power generation unit shown in FIG. 1 includes a cell stack 5 formed by combining a plurality of solid oxide fuel cells having a fuel electrode layer, a solid electrolyte layer, and an air electrode layer, and a fuel supply for supplying raw fuel such as city gas. Means 1, oxygen-containing gas supply means 2 for supplying an oxygen-containing gas to the fuel cells constituting the cell stack 5, a heating device 20 for heating the oxygen-containing gas supplied from the oxygen-containing gas supply means 2, A reformer 3 for steam reforming the raw fuel with the raw fuel and steam, and a purification device 18 for purifying exhaust gas not used for power generation discharged from the cell stack are provided. In the power generation unit shown in FIG. 1, a fuel cell module 4 (hereinafter sometimes referred to as a module) is configured by storing the cell stack 5 and the reformer 3 in a storage container. It is surrounded by a two-dot chain line. Although not shown in the figure, the module 4 is provided with an ignition device for burning fuel gas that has not been used in power generation. Further, in the fuel cell system shown in FIG. 1, an example in which the purification device 18 is provided outside the module 4 is shown, but it can also be provided in the module 4. An oxygen-containing gas supply line that is an oxygen-containing gas supply line supplied by the oxygen-containing gas supply means 2 is indicated by a broken line.

  Further, in the power generation unit shown in FIG. 1, a heat exchanger 8 that is a second heat exchanger that performs heat exchange between exhaust gas (exhaust heat) generated by power generation of the fuel cells constituting the cell stack 5 and water. Water for circulating water, condensed water treatment device 9 for treating condensed water generated in the heat exchanger 8 into pure water, and water treated by the condensed water treatment device 9 (pure water) are stored. A water tank 11 is provided, and the water tank 11 and the heat exchanger 8 are connected by a condensed water supply pipe 10. In addition, depending on the quality of the condensed water produced | generated by the heat exchange in the heat exchanger 8, it can also be set as the structure which does not provide the condensed water processing apparatus 9. FIG. Moreover, when the condensed water processing apparatus 9 has the function to store water, it can also be set as the structure which does not provide the water tank 11. FIG.

  The water stored in the water tank 11 is supplied to the reformer 3 by a water pump 12 provided in a water supply pipe 13 that connects the water tank 11 and the reformer 3.

Further, the power generation unit shown in FIG. 1 converts the DC power generated by the module 4 into AC power, and adjusts the supply amount of the converted electricity to the external load (power conditioner). 6. In addition to an outlet water temperature sensor 14 for measuring the water temperature of water (circulated water flow) provided at the outlet of the heat exchanger 8 and flowing through the outlet of the heat exchanger 8, a controller 7 for controlling the operation of various devices The power generation unit is configured together with a circulation pump 17 that circulates water in the circulation pipe 15. And each apparatus which comprises these electric power generation units can be set as a fuel cell with easy installation, carrying, etc. by accommodating in the exterior case mentioned later. The hot water storage unit includes a hot water storage tank 16 for storing hot water after heat exchange.

  Here, a normal operation method of the fuel cell system shown in FIG. 1 will be described.

  In generating fuel gas necessary for power generation of the cell stack 5, the control device 7 operates the raw fuel supply means 1 and the water pump 12. As a result, raw fuel (natural gas, kerosene, etc.) and water are supplied to the reformer 3, and by performing steam reforming in the reformer 3, a fuel gas containing hydrogen is generated and the fuel cell. Supplied to the fuel electrode side.

  On the other hand, the control device 7 operates the oxygen-containing gas supply means 2 to supply oxygen-containing gas (air) to the air electrode side of the fuel cell. The supply of the oxygen-containing gas will be described later.

  The control device 7 operates an ignition device (not shown) in the module 4 to burn fuel gas that has not been used for power generation of the cell stack 5. Thereby, the temperature in the module (the temperature of the cell stack 5 and the reformer 3) rises, and efficient power generation can be performed.

  Since the exhaust gas generated by the power generation of the cell stack 5 may include unburned fuel gas and carbon monoxide, these exhaust gases are purified by the purification device 18. In addition, as the purification apparatus 18, it can be set as the structure provided with the combustion catalyst in the container, for example.

  The exhaust gas purified by the purification device 18 is supplied to the heat exchanger 8 via a first heat exchanger 19 described later, and is heat-exchanged with water flowing through the circulation pipe 15. Hot water generated by heat exchange in the heat exchanger 8 flows through the circulation pipe 15 and is stored in the hot water storage tank 16. On the other hand, water contained in the exhaust gas discharged from the cell stack 5 by heat exchange in the heat exchanger 8 becomes condensed water and is supplied to the condensed water treatment device 9 through the condensed water supply pipe 10. The condensed water is converted to pure water by the condensed water treatment device 9 and supplied to the water tank 11. The water stored in the water tank 11 is supplied to the reformer 3 by the water pump 12 via the water supply pipe 13. Thus, water self-sustained operation can be performed by effectively using condensed water.

  Subsequently, the module 4 of the present embodiment will be described. 2 and 3 show an example of the module 4 constituting the fuel cell device of the present embodiment, FIG. 2 is an external perspective view showing the module 4, and FIG. 3 is a sectional view of the module 4 shown in FIG. is there.

  In the module 4 shown in FIG. 2, the columnar fuel cells 23 having gas flow paths (not shown) through which the fuel gas flows are arranged in a row in the storage container 22 in an upright manner. The adjacent fuel cells 23 are electrically connected in series via a current collecting member (not shown), and the lower end of the fuel cells 23 is connected to an insulating bonding material (not shown) such as a glass sealant. The cell stack device 21 having two cell stacks 5 fixed to the gas tank 24 is accommodated. At both ends of the cell stack 5, conductive members having electrical lead portions for collecting the electricity generated by the power generation of the cell stack 5 (fuel cell 23) and drawing it out are disposed ( Not shown). The cell stack device 21 is configured by including the above-described members. 2 shows the case where the cell stack device 21 includes two cell stacks 5, the number can be changed as appropriate. For example, even if only one cell stack 5 is provided. Good. In addition, the storage container 22 is provided with an ignition device 30 for burning fuel gas that has passed through a fuel battery cell 23 described later, and a thermocouple 31 for measuring the temperature of the module 4.

In FIG. 2, the fuel battery cell 23 is a hollow flat plate type having a gas flow path through which fuel gas flows in the longitudinal direction, and a fuel electrode layer, a solid electrolyte is formed on the surface of a support having the gas flow path. 1 illustrates a solid oxide fuel cell 23 in which a layer and an oxygen electrode layer are sequentially laminated. The fuel cell 23 may have a gas flow path in which the oxygen-containing gas flows in the longitudinal direction. In this case, the oxygen electrode layer, the solid electrolyte layer, and the fuel electrode layer are sequentially arranged from the inside. The configuration of the module 4 may be changed as appropriate. Furthermore, the fuel cell is not limited to the hollow plate type, and may be a flat plate type or a cylindrical type, for example, and it is preferable to change the shape of the storage container 22 as appropriate.

  Further, in the module 4 shown in FIG. 2, in order to obtain a fuel gas used for power generation of the fuel battery cell 23, a fuel by reforming raw fuel such as city gas supplied through the raw fuel supply pipe 28 is reformed. A reformer 3 for generating gas is disposed above the cell stack 5. The raw fuel supply pipe 28 can be appropriately arranged in accordance with the fuel supply means 1 shown in FIG. In addition, the reformer 3 can have a structure capable of performing steam reforming, which is an efficient reforming reaction, and a reforming unit 26 for vaporizing water and reforming raw fuel into fuel gas. And a reforming unit 25 in which a reforming catalyst (not shown) is disposed. In the reformer 3, partial oxidation reforming may be performed in addition to steam reforming, and a combustion catalyst capable of partial oxidation reforming in addition to steam reforming can be used as the reforming catalyst. . The fuel gas (hydrogen-containing gas) generated by the reformer 3 is supplied to the gas tank 24 through the fuel gas circulation pipe 27 and is supplied from the gas tank 24 to the gas flow path provided in the fuel cell 23. Supplied. Note that the configuration of the cell stack device 21 can be changed as appropriate depending on the type and shape of the fuel cell 23. For example, the reformer 3 can be included in the cell stack device 21.

  FIG. 2 shows a state where a part (front and rear surfaces) of the storage container 22 is removed and the cell stack device 21 stored inside is taken out rearward. Here, in the module 4 shown in FIG. 2, the cell stack device 21 can be slid and stored in the storage container 22.

  The reaction container 22 is disposed between the cell stacks 5 juxtaposed in the gas tank 24 inside the storage container 22 so that the oxygen-containing gas flows from the lower end portion toward the upper end portion of the fuel cell 23. A gas introduction member 29 is disposed.

  As shown in FIG. 3, the storage container 22 constituting the module 4 has a double structure having an inner wall 33 and an outer wall 34, and an outer frame of the storage container 22 is formed by the outer wall 34, and a cell stack is formed by the inner wall 33. A power generation chamber 35 for accommodating the device 21 is formed. Further, in the storage container 22, a reaction gas flow path 40 through which the oxygen-containing gas introduced into the fuel cell 23 circulates between the inner wall 33 and the outer wall 34.

  Here, the storage container 22 is provided with an oxygen-containing gas inlet (not shown) for allowing oxygen-containing gas to flow into the upper end side from the upper portion of the storage container 22 and a flange portion 37, and a fuel at the lower end portion. A reaction gas introduction member 29 provided with a reaction gas outlet 36 for introducing an oxygen-containing gas at the lower end of the battery cell 23 is inserted through the inner wall 33 and fixed. A heat insulating member 37 is disposed between the flange portion 37 and the inner wall 33.

  In FIG. 3, the reaction gas introduction member 29 is disposed so as to be positioned between two cell stacks 5 juxtaposed inside the storage container 22, but is appropriately disposed depending on the number of cell stacks 5. be able to. For example, when only one cell stack 5 is stored in the storage container 22, two reaction gas introduction members 29 can be provided and disposed so as to sandwich the cell stack 5 from both side surfaces.

Further, in the power generation chamber 35, the temperature in the module 4 is maintained at a high temperature so that the heat in the module 4 is extremely dissipated and the temperature of the fuel cell 23 (cell stack 5) is lowered and the power generation amount is not reduced. A heat insulating member 37 is appropriately provided.

  The heat insulating member 37 is preferably disposed in the vicinity of the cell stack 5. In particular, the heat insulating member 37 is disposed on the side surface side of the cell stack 5 along the arrangement direction of the fuel cell 23, and the fuel cell unit on the side surface of the cell stack 5. It is preferable to dispose a heat insulating member 37 having a width equal to or greater than the width along the arrangement direction of 23. In addition, it is preferable to arrange the heat insulating members 37 on both side surfaces of the cell stack 5. Thereby, it can suppress effectively that the temperature of the cell stack 5 falls. Furthermore, the oxygen-containing gas introduced from the reaction gas introduction member 29 can be suppressed from being discharged from the side surface side of the cell stack 5, and the flow of the oxygen-containing gas between the fuel cells 23 constituting the cell stack 5 can be reduced. Can be promoted. In the heat insulating members 37 arranged on both side surfaces of the cell stack 5, the flow of the oxygen-containing gas supplied to the fuel cell 23 is adjusted, and the longitudinal direction of the cell stack 5 and the stacking direction of the fuel cell 23 are adjusted. An opening 38 is provided to reduce the temperature distribution at. Note that the opening 38 may be formed by combining a plurality of heat insulating members 37.

  Further, an exhaust gas inner wall 39 is provided on the inner side of the inner wall 33 along the arrangement direction of the fuel cells 23, and the exhaust gas in the power generation chamber 35 is located between the inner wall 33 and the exhaust gas inner wall 39 from above. The exhaust gas flow path 41 flows downward. The exhaust gas passage 41 communicates with an exhaust hole 45 provided at the bottom of the storage container 22. A heat insulating member 37 is also provided on the exhaust gas inner wall 39 on the cell stack 5 side.

  Thereby, the exhaust gas generated by the operation of the module 4 flows through the exhaust gas passage 41 and is then exhausted from the exhaust hole 45. The exhaust hole 45 may be formed by cutting out a part of the bottom of the storage container 22 or may be formed by providing a tubular member.

  In the module 4, the ignition device 30 for igniting the fuel gas that has passed through the fuel battery cell 23 is positioned between the fuel battery cell 23 and the reformer 3 from the side surface of the storage container 2. Has been inserted. In addition, by igniting the fuel gas that has passed through the fuel cell 23 by the ignition device 30, the temperature in the module 4 can be increased, and the temperature of the fuel cell 23 and the reformer 3 is maintained at a high temperature. can do.

  By the way, when power generation is performed in the fuel battery cell 23, the oxygen-containing gas is supplied from the oxygen-containing gas supply means 2 to the module 4, but when a low-temperature oxygen-containing gas is supplied to the module 4, the temperature in the module 4 is increased. Accordingly, the temperature of the fuel battery cell 23 and the reformer 3 may be lowered, and the power generation efficiency may be lowered.

  Therefore, in the fuel cell device of the present embodiment shown in FIG. 1, the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 between the purification device 18 and the heat exchanger 8 that is the second heat exchanger. A first heat exchanger 19 for exchanging heat between the gas and the purified exhaust gas discharged from the purification device 18 is provided, and a heating device 20 is provided between the first heat exchanger 19 and the module 4. ing.

  FIG. 4 is a conceptual diagram showing a connection state of the module 4, the purification device 18, the first heat exchanger 19, and the second heat exchanger 8. A heat insulating member 37 for maintaining the temperature of the module 1 at a high temperature is provided on the outer periphery of the module 1.

When the fuel cell 3 disposed in the module 4 is a solid oxide fuel cell 3, the temperature in the module 4 becomes as high as about 500 to 800 ° C. and is discharged from the module 4 together. The temperature of the exhaust gas is also high, and further, the temperature of the purified exhaust gas discharged from the purification device 18 is also high.

  Here, in FIG. 4, a purification device 18 for purifying exhaust gas discharged from the module 4 and a purification device 18 are disposed in an exhaust hole (not shown) for exhausting exhaust gas at the bottom of the module 4. The first heat exchanger 19 for exchanging heat between the purified exhaust gas after purification and the oxygen-containing gas supplied to the module 4, and exchanging heat between the exhaust gas passing through the first heat exchanger 19 and water. A second heat exchanger 8 for generating hot water is connected in this order. The second heat exchanger 8 is provided with an inlet 46 to which water having a low temperature is supplied on the lower side, and feeds water generated in the second heat exchanger 8 to the upper side. Outlet 47 is provided.

  On the other hand, the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 passes through the outer surface of the first heat exchanger 8 and then passes through the heating device 20 to introduce the oxygen-containing gas provided at the bottom of the module 4. It is supplied into the module 4 from the section 48.

  Since the temperature of the purified exhaust gas discharged from the purification device 18 is a high temperature of about 250 to 280 ° C. during power generation, the temperature of the oxygen-containing gas supplied to the module 4 using this heat is increased, Furthermore, by further heating the oxygen-containing gas with the heating device 20, it is possible to suppress the temperature of the module 4 from being lowered and to improve the power generation efficiency.

  For example, a heater can be used as the heating device 20. Furthermore, in order to improve heat exchange in the first heat exchanger 18, the oxygen-containing gas supply line may be supplied to the heating device 20 after circulating around the first heat exchanger 18.

  FIG. 5 is a configuration diagram illustrating another example of the configuration of the fuel cell system including the fuel cell device of the present embodiment.

  The fuel cell system shown in FIG. 5 includes a first temperature sensor 49 for measuring the temperature of the oxygen-containing gas flowing through the heating device 20 in addition to the configuration of the fuel cell system shown in FIG.

  If the heating device 20 is operated when the temperature of the oxygen-containing gas supplied to the module 4 is sufficiently high, extra power is consumed, and the degree of improvement in power generation efficiency may be reduced.

  Therefore, the temperature of the oxygen-containing gas that has passed through the heating device 20 is measured by the first temperature sensor 49, and the operation of the heating device 20 is controlled based on the temperature, thereby improving the power generation efficiency. It can be a device.

  Specifically, the temperature information measured by the first temperature sensor 49 is transmitted to the control device 7. Here, when the temperature measured by the first temperature sensor 49 is equal to or lower than the preset lower limit temperature, the control device 7 performs control to operate the heating device 20. Thereby, the temperature of the oxygen-containing gas supplied to the module 4 can be raised.

  On the other hand, when the temperature measured by the first temperature sensor 49 is equal to or higher than a preset upper limit temperature, the control device 7 performs control to stop the operation of the heating device 20. Thereby, efficient operation can be performed.

The preset lower limit temperature in the first temperature sensor 49 can be set as appropriate, for example, between 200 and 300 ° C., and the upper limit temperature can be set as appropriate in the range of 250 to 350 ° C., for example.

  FIG. 6 is a configuration diagram illustrating still another example of the configuration of the fuel cell system including the fuel cell device according to the present embodiment.

  In the fuel cell system shown in FIG. 6, the first heat exchanger supply line connecting the oxygen-containing gas supply means 2 and the first heat exchanger 19, the first heat exchanger 19, and the heating device 20 are provided. A bypass line 52 for connecting a heating device supply line to be connected is provided, and a three-way valve 50 is provided at a connection portion between the bypass line 52 and the first heat exchanger supply line. Further, a second temperature sensor 53 for measuring the temperature of the purified exhaust gas discharged from the purification device 20 is provided. In the fuel cell system shown in FIG. 6, the three-way valve 51 is also provided at the connection between the bypass line 52 and the heating device supply line, and the oxygen-containing gas flowing through the bypass line 52 is subjected to the first heat exchange. It is set as the structure which does not flow to the container 19 side.

  At the time of starting the fuel cell system or when the amount of power generated in the cell stack 5 is small, the temperature of the exhaust gas discharged from the module 4 is low. In this case, the first heat exchanger 19 contains oxygen having a low temperature. When heat exchange is performed with gas, the temperature of the exhaust gas supplied to the second heat exchanger 8 is lowered, and there is a possibility that the amount of condensed water necessary for steam reforming in the reformer 3 cannot be obtained. In addition, heat exchange with the water flowing through the circulation pipe 15 cannot be sufficiently performed, and there is a possibility that a sufficient amount of hot water cannot be generated.

  Therefore, by supplying the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 to the heating device 20 via the bypass line, the temperature of the exhaust gas supplied to the second heat exchanger 8 is lowered. It can suppress and it can suppress that the production amount of condensed water and the production amount of hot water decrease.

  Specifically, the temperature information of the purified exhaust gas measured by the second temperature sensor 53 is transmitted to the control device 7. Here, when the temperature measured by the second temperature sensor 53 is equal to or lower than a predetermined temperature set in advance, the control device 7 supplies the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 to the bypass line. The three-way valves 50 and 51 are controlled so as to be supplied to 52.

  In addition, the predetermined temperature preset in the 1st temperature sensor 53 can be suitably set, for example between 150-200 degreeC.

  In the fuel cell system shown in FIG. 6, the oxygen-containing gas that has flowed through the bypass line 52 does not flow to the first heat exchanger 19 side at the connection portion between the bypass line 52 and the heating device supply line. Although the three-way valve 51 is also provided, for example, instead of the three-way valve 51, a check valve is provided on the first heat exchanger 19 side rather than the connection portion between the bypass line 52 and the heating device supply line. You can also.

  FIG. 7 is a configuration diagram showing still another example of the configuration of the fuel cell system including the fuel cell device of the present embodiment.

  The fuel cell system shown in FIG. 7 includes a hot water tank temperature sensor 54 for measuring the temperature of hot water stored in the hot water storage tank 16 in addition to the fuel cell system shown in FIG. In FIG. 7, only one hot water storage tank temperature sensor 54 is provided so as to measure the temperature of the central portion of the hot water storage tank 16. For example, when measuring the temperature of the hot water storage tank 16, A plurality of tank temperature sensors 54 may be provided to adopt an average value.

  Normally, the hot water storage tank 16 is set so that the amount of hot water stored in the hot water storage tank 16 is constant, and when the amount of hot water used increases, tap water is stored in the hot water storage tank 16. However, in this case, although the amount of water stored in the hot water storage tank 16 is sufficient, the temperature is lowered. Therefore, when the temperature of the hot water stored in the hot water storage tank 16 is lowered, it is supplied from the oxygen-containing gas supply means 2 so that the heat exchange rate in the heat exchanger 8 that is the second heat exchanger does not decrease. It is preferable to supply the oxygen-containing gas to the heating device 20 via a bypass line. Thereby, it can suppress that the temperature of the purification | cleaning waste gas supplied to the heat exchanger 8 falls, and can suppress that the production | generation of the hot water in the heat exchanger 8 falls.

  Specifically, the temperature information measured by the hot water tank temperature sensor 54 is transmitted to the control device 7. Here, when the temperature measured by the hot water storage tank temperature sensor 54 is equal to or lower than a predetermined temperature set in advance, the control device 7 supplies the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 to the bypass line 53. The three-way valves 50 and 51 are controlled so as to be supplied.

  In the example in which the hot water storage tank temperature sensor 54 shown in FIG. 7 is provided in the central portion of the hot water storage tank 16, the predetermined temperature set in advance in the hot water storage tank temperature sensor 54 is appropriately set between, for example, 4 to 30 ° C. be able to.

  Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, in the control by the control device 7, the control of the second temperature sensor 52 and the hot water tank temperature sensor 54 has been described separately, but it is also possible to control them simultaneously. In this case, the control device 7 supplies the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 to the bypass line 53 when the temperature measured by at least one temperature sensor is equal to or lower than the set temperature. What is necessary is just to control the three-way valves 50 and 51 so that it may supply.

  Further, during the stop process of the fuel cell device, the control device 7 controls the three-way valves 50 and 51 so as to supply the oxygen-containing gas supplied from the oxygen-containing gas supply means 2 to the bypass line 53, By controlling the heating device 20 so as not to operate, the temperature in the module 4 can be lowered quickly, and the stop processing time can be shortened.

  Further, by providing a heating device such as a heater in the purification device 18, the temperature of the purified exhaust gas can be improved. Thereby, the heat exchange efficiency in the 1st heat exchanger 19 can be improved, and since it can suppress that the temperature in the module 4 falls, electric power generation efficiency can be improved.

  Specifically, for example, when the temperature measured by the second temperature sensor 53 is lower than a preset lower limit temperature, the control device 7 performs control to operate the heating device provided in the purification device 18. . As a result, the temperature of the purified exhaust gas increases. On the other hand, when the temperature measured by the second temperature sensor 53 is higher than the preset upper limit temperature, the control device 7 performs control to stop the heating device provided in the purification device 18. Thereby, it can suppress that power generation efficiency falls. In addition, in controlling the operation of the heating device provided in the purification device 18, the preset lower limit temperature in the second temperature sensor 53 can be set as appropriate between, for example, 20 to 100 ° C., and the upper limit. The temperature can be appropriately set within a range of 200 to 280 ° C, for example.

  In the above description, the oxygen-containing gas is used, but the same applies to the case of fuel.

2: oxygen-containing gas supply means 4: fuel cell module 7: control device 8: second heat exchanger 18: purification device 19: first heat exchanger 20: heating device 49: first temperature sensors 50, 51 : Three-way valve 52: Bypass line 53: Second temperature sensor 54: Hot water storage tank temperature sensor

Claims (4)

A fuel cell that generates power with an oxygen-containing gas and fuel, a purification device for purifying exhaust gas discharged from the fuel cell, a purified exhaust gas discharged from the purification device, and an oxygen-containing gas supplied to the fuel cell A first heat exchanger for exchanging heat of the gas or fuel, a heating device for further heating the oxygen-containing gas or fuel heat-exchanged in the first heat exchanger, and the first heat A first heat exchanger supply line for supplying the oxygen-containing gas or fuel toward the exchanger, and the oxygen-containing gas or fuel heat-exchanged in the first heat exchanger toward the heating device A heating device supply line for supplying the fuel cell, a reformer for generating the fuel supplied to the fuel cell by steam reforming, and generating heat by exchanging heat between the purified exhaust gas and water A second heat exchanger of Hot water generated in the second heat exchanger and a hot water storage tank for hot water storage, supplies the condensed water generated in the second heat exchanger to said reformer,
With a bypass line connecting the said first heat exchanger supply line the heater supply line, the bypass line is provided with a three-way valve to the connection portion between the first heat exchanger supply lines, the purifier A second temperature sensor for measuring the temperature of the purified exhaust gas discharged further,
When the temperature measured by the second temperature sensor is equal to or lower than a predetermined temperature, the oxygen-containing gas or fuel flowing through the first heat exchanger supply line is caused to flow to the heating device supply line via the bypass line. Thus, a fuel cell device comprising a control device for controlling the three-way valve .   2. The fuel according to claim 1, further comprising a first temperature sensor for measuring a temperature of the oxygen-containing gas or fuel flowing through the heating device between the heating device and the fuel cell. Battery device.   The heating device is operated when a temperature measured by the first temperature sensor is equal to or lower than a predetermined temperature, and when the temperature measured by the first temperature sensor is equal to or higher than a predetermined temperature, the heating device is operated. The fuel cell device according to claim 2, further comprising a control device that performs control to stop the operation. Provided with a hot water storage tank temperature sensor for measuring the temperature of the pre-Symbol hot water storage tank, when the temperature of the hot water in the hot water storage tank as measured by the hot water storage tank temperature sensor is below a predetermined temperature, the first heat exchanger an oxygen-containing gas or the fuel flowing through the vessel feed line of claim 1 to claim 3, characterized in that it comprises a control unit for controlling the three-way valve to flow to the heating device feed line via the bypass line The fuel cell device according to any one of the above.

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