JP6096709B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system including a solid polymer fuel cell stack.

  In the field of the fuel cell system, a technique for reusing condensed water (drain water) generated by condensing water vapor contained in exhaust gas inside the system in a reforming catalyst, a fuel cell stack, or the like has been proposed. According to such a fuel cell system, it is not necessary to supply water to the reforming catalyst or the fuel cell stack from the outside, so that a water supply facility for supplying water from the outside to the reforming catalyst or the fuel cell stack is unnecessary. Can be.

  By the way, in order to reuse condensed water in a reforming catalyst, a fuel cell stack, or the like, it is necessary to remove impurities from the condensed water. Some water treatment apparatuses that remove this impurity include an ion exchange resin (see, for example, Patent Documents 1 to 5).

  However, in the water treatment apparatus provided with this ion exchange resin, the amount of impurities that can be adsorbed by the ion exchange resin cartridge is limited. For this reason, regular maintenance such as replacement and regeneration of the ion exchange resin cartridge is required, and the maintenance cost increases.

  Thus, an electrodeionization-type water treatment apparatus has been proposed as a technique that eliminates the need for regular maintenance (see, for example, Patent Document 6). This electrodeionization-type water treatment apparatus has an advantage that periodic maintenance is not required because the resin for removing impurities is regenerated by electricity.

  However, in the electrodeionization-type water treatment apparatus, electric power is required to regenerate the resin for removing impurities. Therefore, when the electric power generated in the fuel cell system is used for resin regeneration in the electrodeionization type water treatment device, the power generation efficiency of the fuel cell system is lowered.

  In addition, as another technique regarding the water treatment apparatus, there is one using a distillation membrane described in Patent Documents 7 and 8.

JP2013-243146A Japanese Patent No. 5371554 JP-A-8-17457 Japanese Patent Laid-Open No. 9-231990 JP 2011-29144 A Japanese Patent No. 4461553 Japanese Patent Publication No.49-45461 JP 2011-167628 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell system capable of realizing a reduction in maintenance costs and an improvement in power generation efficiency.

In order to solve the above problems, a fuel cell system according to claim 1 includes a reforming catalyst for steam reforming a raw material gas and a burner for heating the reforming catalyst, and includes a hydrogen gas. Is formed in a cylindrical shape, and a solid polymer fuel cell stack that generates electricity by reacting a fuel gas supplied from the fuel processing device and an oxidizing gas supplied from the outside. In addition, a distillation membrane that forms an exhaust gas flow path through which exhaust gas containing water vapor discharged from at least one of the fuel cell stack and the burner circulates, and is provided annularly around the distillation membrane and permeates the distillation membrane. a heat transfer wall water vapor is formed between the distillation film condensation space to be condensed, said heat transfer hot wall a cooling fluid channel of the cooling fluid flows along with provided annularly around the heat transfer thermal wall A heat exchanger having an outer wall formed therebetween, and condensate recovery for recovering condensate generated in the condensing space and supplying the condensate to at least one of the reforming catalyst and the fuel cell stack -A supply part.

  In this fuel cell system, when the fuel gas and the oxidizing gas are supplied to the fuel cell stack, the fuel gas and the oxidizing gas react in the fuel cell stack to generate electric power. Along with this power generation, exhaust gas containing water vapor is discharged from at least one of the fuel cell stack and the burner, and this exhaust gas is supplied to the heat exchanger. In this heat exchanger, an exhaust gas flow path is formed by a distillation membrane, a condensation space is formed between the distillation membrane and the heat transfer wall, and a cooling fluid is provided between the heat transfer wall and the outer wall. A cooling fluid flow path through which is circulated is formed. Therefore, the water vapor contained in the exhaust gas supplied to the exhaust gas flow path passes through the distillation film and moves to the condensation space, where heat is released on the surface of the heat transfer wall and condensed. And the condensed water (distilled water) produced | generated in the condensation space in this way is collect | recovered by a condensed water collection | recovery / supply part, and is supplied to at least one of a reforming catalyst and a fuel cell stack.

  Thus, according to this fuel cell system, the condensed water is recovered from the exhaust gas discharged from at least one of the fuel cell stack and the burner, and this condensed water is supplied to at least one of the reforming catalyst and the fuel cell stack. This eliminates the need for water supply from the outside to at least one of the reforming catalyst and the fuel cell stack, thus eliminating the need for a water supply facility for supplying water from the outside to at least one of the reforming catalyst and the fuel cell stack. it can.

  Moreover, according to this fuel cell system, as described above, a distillation membrane that does not require replacement or regeneration is used to generate condensed water from water vapor contained in the exhaust gas. Therefore, since regular maintenance for stably generating condensed water can be eliminated, for example, maintenance costs can be reduced as compared with the case of using a water treatment apparatus equipped with an ion exchange resin. it can.

  In addition, since the distilled membrane does not need to be regenerated by electricity, it is possible to avoid using the power generated by the fuel cell system in order to maintain the performance of the distilled membrane. Thereby, the power generation efficiency of the fuel cell system can be improved as compared with, for example, the case of using an electrodeionization type water treatment device.

In addition, the distillation membrane is formed in a cylindrical shape, and the exhaust gas flow path is formed inside thereof. The heat transfer wall is provided in an annular shape around the distillation membrane, and the outer wall is provided with the heat transfer It is provided in an annular shape around the wall.

Therefore, water vapor permeates through the distillation film over the entire circumference of the distillation film formed in a cylindrical shape, and condensed water can be generated from the water vapor over the entire circumference of the heat transfer wall. Thereby, the production | generation efficiency of condensed water can be improved.

Further, as described in claim 2, in the fuel cell system of claim 1, further comprising a hot water storage tank for storing hot water, cooling fluid flowing through the cooling fluid flow path, the cooling and the hot water storage tank It may be hot water circulating water that circulates between the fluid flow paths.

  When configured in this way, the hot water circulating water flowing through the cooling fluid flow path between the heat transfer wall and the outer wall is heated by the heat of the steam moved to the condensing space between the distillation membrane and the heat transfer wall. can do. Thereby, the heat of the exhaust gas discharged from at least one of the fuel cell stack and the burner can be effectively used for heating the hot water stored in the hot water storage tank.

In addition, as described in claim 3 , in the fuel cell system according to claim 1 or 2 , the heat exchanger includes one heat exchanger, and the exhaust gas flow path includes an air electrode of the fuel cell stack and An exhaust gas containing water vapor discharged from both of the burners may be circulated.

  When configured in this manner, condensed water is generated from water vapor contained in the exhaust gas from the air electrode and burner of the fuel cell stack, so that only from one of the air electrode and burner of the fuel cell stack. Compared with the case where the exhaust gas flows through the exhaust gas flow path, the amount of condensed water generated in the condensation space can be increased. In addition, since only one heat exchanger is required, the cost can be reduced.

Moreover, as described in claim 4 , in the fuel cell system according to claim 1 or 2 , the heat exchanger includes a pair of heat exchangers, and the exhaust gas flow path in one of the heat exchangers includes the fuel The exhaust gas containing water vapor discharged from the air electrode of the battery stack may circulate, and the exhaust gas containing water vapor discharged from the burner may flow through the exhaust gas flow path in the other heat exchanger.

  Even in such a configuration, condensed water is generated from water vapor contained in the exhaust gas from the air electrode and burner of the fuel cell stack, so that only from one of the air electrode and burner of the fuel cell stack. Compared with the case where the exhaust gas flows through the exhaust gas flow path, the amount of condensed water generated in the condensation space can be increased.

  Further, since condensed water can be separately generated by both of the pair of heat exchangers, the condensed water can be stably supplied to at least one of the reforming catalyst and the fuel cell stack. Thereby, the stability of the fuel cell system can be ensured.

In addition, as described in claim 5 , in the fuel cell system according to claim 1 or 2 , the heat exchanger includes a pair of heat exchangers, and the exhaust gas passage in one of the heat exchangers includes the fuel Exhaust gas containing water vapor discharged from both the air electrode of the battery stack and the burner circulates, and the exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack passes through the exhaust gas flow path in the other heat exchanger. The exhaust gas that circulates and is discharged from the exhaust gas flow path in the other heat exchanger may be supplied to the burner as burner gas.

  With this configuration, condensed water is generated from the water vapor contained in the exhaust gas from the fuel electrode of the fuel cell stack in addition to the water vapor contained in the exhaust gas from the air electrode and burner of the fuel cell stack. The amount of condensed water produced in the system can be increased.

  Further, since condensed water can be separately generated by both of the pair of heat exchangers, the condensed water can be stably supplied to at least one of the reforming catalyst and the fuel cell stack. Thereby, the stability of the fuel cell system can be ensured.

  Furthermore, since the exhaust gas from which the water vapor has been removed from the exhaust gas flow path in the other heat exchanger is supplied to the burner as burner gas, the content of water vapor contained in the burner gas supplied to the burner can be reduced. it can. Thereby, it is possible to suppress the occurrence of malfunction such as misfire in the burner, and it is not necessary to use an expensive burner gas that can handle burner gas with a high water vapor content.

Further, as described in claim 6 , in the fuel cell system according to claim 1 or 2 , the heat exchanger includes three heat exchangers, and the exhaust gas passage in the first heat exchanger includes: Exhaust gas containing water vapor exhausted from the air electrode of the fuel cell stack circulates, and exhaust gas containing water vapor exhausted from the burner circulates in the exhaust gas flow path in the second heat exchanger, Exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows through the exhaust gas passage in the heat exchanger, and discharged from the exhaust gas passage in the third heat exchanger to the burner. The exhaust gas may be supplied as burner gas.

  Even in this configuration, condensed water is generated from the water vapor contained in the exhaust gas from the fuel electrode of the fuel cell stack in addition to the water vapor contained in the exhaust gas from the air electrode and burner of the fuel cell stack. The amount of condensed water produced in the system can be increased.

  In addition, since condensed water can be separately generated in each of the three heat exchangers, the condensed water can be stably supplied to at least one of the reforming catalyst and the fuel cell stack. Thereby, the stability of the fuel cell system can be ensured.

  Furthermore, since the exhaust gas from the exhaust gas flow path in the third heat exchanger and from which the water vapor has been removed is supplied to the burner as the burner gas, the content of water vapor contained in the burner gas supplied to the burner is reduced. Can do. Thereby, it is possible to suppress the occurrence of malfunction such as misfire in the burner, and it is not necessary to use an expensive burner gas that can handle burner gas with a high water vapor content.

Further, as described in claim 7 , in the fuel cell system according to claim 1 or 2 , as the heat exchanger, the exhaust gas flow path includes both an air electrode of the fuel cell stack and the burner as the heat exchanger. There may be provided at least one of a heat exchanger through which exhaust gas containing water vapor is discharged and a heat exchanger through which exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows through the exhaust gas passage. .

Further, as described in claim 8 , in the fuel cell system according to claim 7 , as the heat exchanger, exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows through the exhaust gas passage. At least a heat exchanger may be provided, and the burner may be supplied with exhaust gas discharged from the exhaust gas passage in the heat exchanger as burner gas.

Further, as described in claim 9 , in the fuel cell system according to claim 1 or 2 , as the heat exchanger, the exhaust gas flow path includes water vapor discharged from the air electrode of the fuel cell stack as the heat exchanger. A heat exchanger through which exhaust gas flows, a heat exchanger through which exhaust gas containing water vapor discharged from the burner flows into the exhaust gas channel, and exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack through the exhaust gas channel You may provide at least one among the heat exchangers which distribute | circulate.

In addition, as described in claim 10 , in the fuel cell system according to claim 9 , as the heat exchanger, exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows through the exhaust gas channel. At least a heat exchanger may be provided, and the burner may be supplied with exhaust gas discharged from the exhaust gas passage in the heat exchanger as burner gas.

  As described above in detail, according to the fuel cell system of the present invention, it is possible to reduce maintenance costs and improve power generation efficiency.

It is a figure showing the whole fuel cell system composition concerning a first embodiment of the present invention. It is a figure which shows the whole structure of the fuel cell system which concerns on 2nd embodiment of this invention. It is a figure which shows the whole structure of the fuel cell system which concerns on 3rd embodiment of this invention. It is a figure which shows the whole structure of the fuel cell system which concerns on 4th embodiment of this invention. It is a longitudinal cross-sectional view of the 1st heat exchanger shown by FIGS.

[First embodiment]
First, a first embodiment of the present invention will be described.

  As shown in FIG. 1, the fuel cell system S1 according to the first embodiment of the present invention includes a desulfurizer 12, a fuel processing device 14, a fuel cell stack 16, a first heat exchanger 18, and a second. The heat exchanger 20, the hot water storage tank 22, and the condensed water collection | recovery and supply part 24 are provided as main structures.

  The desulfurizer 12 is connected to the city gas pipe 26. The desulfurizer 12 adsorbs and removes sulfur compounds contained in the city gas supplied through the city gas pipe 26.

  The fuel processing apparatus 14 includes a reforming catalyst 28, a burner 30, a shift catalyst 32, and a PROX catalyst 34. The reforming catalyst 28 is connected to the desulfurizer 12 via the raw material gas pipe 36. The reforming catalyst 28 is supplied with the city gas from which the sulfur compound is adsorbed and removed by the desulfurizer 12 through the raw material gas pipe 36. The reforming catalyst 28 steam-reforms the city gas (raw material gas) supplied through the raw material gas pipe 36 using the condensed water supplied through the first condensed water supply pipe 104 described later.

  An air gas pipe 40 provided with a first air blower 38 and a burner gas pipe 42 are connected to the burner 30. The burner 30 burns a mixed gas of air gas supplied through the air gas pipe 40 and burner gas supplied through the burner gas pipe 42 to heat the reforming catalyst 28.

  The shift catalyst 32 reacts the carbon monoxide generated in the reforming catalyst 28 with water vapor to convert it into hydrogen and carbon dioxide, thereby reducing the carbon monoxide concentration. A PROX air pipe 44 branched from an oxidizing gas pipe 60 described later is connected to the PROX catalyst 34. Air is supplied to the PROX catalyst 34 through a PROX air pipe 44. The PROX catalyst 34 reacts carbon monoxide and oxygen on a noble metal catalyst to convert them into carbon dioxide, and oxidizes and removes carbon monoxide.

  And in this fuel processing apparatus 14, the fuel gas containing hydrogen gas is produced | generated from the city gas (raw material gas) supplied from the desulfurizer 12 by the above. This fuel gas is supplied to a fuel electrode 54 of the fuel cell stack 16 described later through a fuel gas pipe 46. A bleed air pipe 48 branched from the PROX air pipe 44 is connected to the fuel gas pipe 46, and the air extracted through the bleed air pipe 48 is mixed with the fuel gas flowing through the fuel gas pipe 46. .

  The fuel cell stack 16 is a polymer electrolyte fuel cell stack, and includes a plurality of stacked fuel cells 50. Each fuel cell 50 includes an electrolyte layer 52, and a fuel electrode 54 and an air electrode 56 that are respectively laminated on the front and back surfaces of the electrolyte layer 52.

  Fuel gas is supplied from the fuel processing device 14 to the fuel electrode 54 (anode electrode) through the fuel gas pipe 46. In the fuel electrode 54, as shown by the following formula (1), hydrogen in the fuel gas is decomposed into hydrogen ions and electrons. Hydrogen ions generated at the fuel electrode 54 move to the air electrode 56 through the electrolyte layer 52, and electrons generated at the fuel electrode 54 move to the air electrode 56 through an external circuit.

(Fuel electrode reaction)
H ₂ → 2H ⁺ + 2e ⁻ (1)

  On the other hand, an oxidizing gas (air) is supplied to the air electrode 56 (cathode electrode) through an oxidizing gas pipe 60 provided with a second air blower 58. In this air electrode 56, as shown by the following formula (2), hydrogen ions that have passed through the electrolyte layer 52 and electrons that have passed through the external circuit react with oxygen in the oxidizing gas to generate water. Is done.

(Air electrode reaction)
4H ⁺ + O ₂ + 4e ⁻ → 2H ₂ O (2)

  Then, the electrons move from the fuel electrode 54 to the air electrode 56 in this way, whereby electric power is generated in each fuel cell 50. In addition, each fuel cell 50 generates heat with the above reaction during power generation, and the water generated at the air electrode 56 is steam.

  A drain pot 64 is connected to the fuel electrode 54 via a fuel electrode exhaust pipe 62. In the drain pot 64, water vapor contained in the fuel electrode exhaust gas discharged from the fuel electrode 54 is condensed. One end of a drain water drain pipe 65 is connected to the drain pot 64, and the other end of the drain water drain pipe 65 is connected to a drain water drain pipe 103 of a drain tank 102 described later. When the amount of condensed water stored in the drain pot 64 exceeds the allowable amount, the excess amount of condensed water is discharged to the outside through the drain water drain pipe 65 and the drain water drain pipe 103.

  Further, the above-described burner gas pipe 42 is connected to the drain pot 64. The unreacted hydrogen gas remains in the fuel cell stack 16 in the fuel electrode exhaust gas discharged from the fuel electrode 54 and from which the water vapor has been removed by the drain pot 64, and the fuel electrode exhaust gas containing this unreacted hydrogen gas is The burner gas pipe 42 supplies the burner 30 as burner gas.

  Further, one end of a burner exhaust gas pipe 66 is connected to the burner 30, and one end of an air electrode exhaust gas pipe 68 is connected to the air electrode 56 described above. The other end of the burner exhaust pipe 66 is connected to a first heat exchanger 18 to be described later, and the other end of the air electrode exhaust pipe 68 is connected to a portion of the burner exhaust pipe 66 on the first heat exchanger 18 side. ing.

  The first heat exchanger 18 is an example of the “heat exchanger” in the present invention, and is configured as follows. That is, as shown in FIG. 5, the first heat exchanger 18 includes a distillation membrane 70, an inner tube 72, and an outer tube 74.

  The distillation membrane 70 is formed in a hollow cylindrical shape. The distillation membrane 70 is composed of a porous membrane that allows water vapor to pass therethrough and does not allow liquid to pass through. The distillation membrane 70 is preferably formed of a material that can be adapted to the heat generation temperature of the fuel cell stack 16. Examples of this material include a fluorine-based resin. An exhaust gas flow channel 76 is formed inside the distillation membrane 70, and an inlet portion of the exhaust gas flow channel 76 is connected to a burner exhaust gas pipe 66 shown in FIG.

  Through this exhaust gas flow path 76, exhaust gas (burner exhaust gas and air electrode exhaust gas) containing water vapor discharged from the burner exhaust gas pipe 66 and the air electrode exhaust gas pipe 68 shown in FIG. An exhaust port 78 shown in FIG. 1 is connected to an outlet portion of the exhaust gas flow channel 76, and the exhaust gas from which water vapor has been removed through the exhaust gas flow channel 76 is discharged to the outside from the exhaust port 78.

  The inner tube 72 is formed in a cylindrical shape having a top wall portion 80 and a bottom wall portion 82. The distillation film 70 described above is disposed through the axial core portion of the inner tube 72. The outer periphery of the inner pipe 72 is formed as a heat transfer wall 84 provided in an annular shape around the distillation film 70, and water vapor that has passed through the distillation film 70 is between the heat transfer wall 84 and the distillation film 70. Is formed as a condensing space 86 in which is condensed. Further, a condensed water drain pipe 88 is provided on the bottom wall portion 82 of the inner pipe 72.

  The outer tube 74 is formed in a hollow annular shape, and is arranged coaxially with the distillation membrane 70 and the inner tube 72 described above. The outer tube 74 has a larger outer diameter than the heat transfer wall 84. An inlet pipe 90 is provided on the top wall portion of the outer pipe 74, and an outlet pipe 92 is provided on the bottom wall portion of the outer pipe 74. A first hot water circulating circuit 94 connected to the hot water storage tank 22 shown in FIG. 1 is connected to the inlet pipe 90 and the outlet pipe 92.

  Further, the outer peripheral portion of the outer pipe 74 is formed as an outer wall 96 provided in an annular shape around the heat transfer wall 84, and the hot water storage shown in FIG. 1 is provided between the outer wall 96 and the heat transfer wall 84. A hot water circulating water flow path 98 through which hot water circulating water (heat recovery water) supplied from the tank 22 circulates is formed. The hot water circulating water is circulated between the hot water circulating water flow path 98 and the hot water storage tank 22 shown in FIG. The hot water storage circulating water flow path 98 is an example of the “cooling fluid flow path” in the present invention, and the hot water storage circulating water flowing through the hot water storage circulating water flow path 98 is an example of the “cooling fluid” in the present invention.

  In the first heat exchanger 18, the water vapor contained in the exhaust gas in the exhaust gas flow channel 76 passes through the distillation membrane 70 in a state where the hot water circulating water flows through the hot water storage water flow channel 98, and the condensation space 86. The water vapor that has moved to the condensation space 86 releases heat on the surface of the heat transfer wall 84 and is condensed. Further, the condensed water (distilled water) generated in the condensed space 86 in this manner is drained through the condensed water drain pipe 88.

  An inlet portion of a drain tank 102 is connected to the condensed water drain pipe 88 via a condensed water recovery pipe 100 shown in FIG. The drain tank 102 stores the condensed water generated by the first heat exchanger 18 and recovered through the condensed water recovery pipe 100. When the amount of condensed water stored in the drain tank 102 exceeds the allowable amount, the excess amount of condensed water is discharged from the drain tank 102. A first condensed water supply pipe 104 connected to the above-described reforming catalyst 28 is connected to the outlet portion of the drain tank 102.

  The first condensed water supply pipe 104 is provided with a first pump 106, and a second condensed water supply pipe 110 provided with a second pump 108 is branched from the first condensed water supply pipe 104. ing. The second condensed water supply pipe 110 is provided with a second heat exchanger 20, and the second heat exchanger 20 is connected to a second hot water storage water circulation circuit 112 connected to the hot water storage tank 22 described above. ing. In the second heat exchanger 20, heat is exchanged between the condensed water flowing through the second condensed water supply pipe 110 and the hot water circulating water flowing through the second hot water circulating circuit 112. Is deprived of heat by the hot water circulating water and cooled.

  A cooling circuit 114 penetrating the fuel cell 50 of the fuel cell stack 16 is connected to the second condensed water supply pipe 110 downstream of the second heat exchanger 20. An outlet side (downstream side) of the cooling circuit 114 is connected to a downstream side portion of the second pump 108 in the second condensed water supply pipe 110.

  The condensed water recovery pipe 100, the drain tank 102, the first pump 106, the second pump 108, the first condensed water supply pipe 104, the second condensed water supply pipe 110, the second heat exchanger 20, and the cooling circuit 114 described above. Constitutes a condensed water recovery / supply unit 24.

  In the condensed water recovery / supply unit 24, the condensed water generated in the condensing space 86 (see FIG. 5) of the first heat exchanger 18 is recovered in the drain tank 102 through the condensed water recovery pipe 100, and this drain tank. A part of the condensed water recovered in 102 is supplied to the reforming catalyst 28 through the first condensed water supply pipe 104 in accordance with the operation of the first pump 106, and is used as steam for steam reforming by the reforming catalyst 28. Used. On the other hand, another part of the condensed water collected in the drain tank 102 is supplied to the second heat exchanger 20 through the second condensed water supply pipe 110 in accordance with the operation of the second pump 108, and this second heat exchanger 20 is cooled. Further, the condensed water cooled by the second heat exchanger 20 is supplied to the fuel cell 50 through the cooling circuit 114, and the fuel cell 50 is cooled.

  Next, the operation and effect of the fuel cell system S1 according to the first embodiment will be described.

  As described above in detail, in the fuel cell system S1 according to the first embodiment, the fuel gas is supplied from the fuel processing device 14 to the fuel electrode 54 of the fuel cell stack 16, and the second air blower 58 is activated. When the oxidizing gas is supplied from the oxidizing gas pipe 60 to the air electrode 56 of the fuel cell stack 16, the fuel gas and the oxidizing gas react in the fuel cell stack 16 to generate power. With this power generation, the air electrode exhaust gas is discharged from the air electrode 56 of the fuel cell stack 16, and the burner exhaust gas is discharged from the burner 30 of the fuel processing device 14. These exhaust gases contain water vapor and are supplied to the first heat exchanger 18 through the air electrode exhaust pipe 68 and the burner exhaust pipe 66.

  In the first heat exchanger 18, as shown in FIG. 5, an exhaust gas flow path 76 is formed by the distillation membrane 70, and a condensing space 86 is formed between the distillation membrane 70 and the heat transfer wall 84. Between the heat transfer wall 84 and the outer wall 96, a hot water circulating water flow path 98 through which the hot water circulating water flows is formed. Therefore, the water vapor contained in the exhaust gas supplied to the exhaust gas flow path 76 passes through the distillation film 70 and moves to the condensation space 86, and is condensed by releasing heat on the surface of the heat transfer wall 84.

  The condensed water (distilled water) thus generated in the condensing space 86 is recovered in the drain tank 102 shown in FIG. 1, and a part of the condensed water recovered in the drain tank 102 is The water is supplied to the reforming catalyst 28 through the single condensed water supply pipe 104, and is used as steam for steam reforming by the reforming catalyst 28. On the other hand, the other part of the condensed water collected in the drain tank 102 is supplied to the second heat exchanger 20 through the second condensed water supply pipe 110 and cooled in the second heat exchanger 20. Further, the condensed water cooled by the second heat exchanger 20 is supplied to the fuel cell 50 through the cooling circuit 114, and the fuel cell 50 is cooled.

  As described above, according to the fuel cell system S1 according to the first embodiment, the condensed water is recovered from the exhaust gas discharged from the air electrode 56 and the burner 30 of the fuel cell stack 16, and the condensed water is used as the reforming catalyst 28 and The fuel cell stack 16 is supplied. Accordingly, the exhaust gas discharged from the air electrode 56 and the burner 30 of the fuel cell stack 16 is effective for generating steam for steam reforming in the reforming catalyst 28 and cooling water for cooling the fuel cell 50. It can be used for.

  Further, as described above, the condensed water is recovered from the exhaust gas discharged from the fuel cell stack 16 and the burner 30, and this condensed water is supplied to the reforming catalyst 28 and the fuel cell stack 16, so that the reforming catalyst 28 is externally supplied. In addition, water supply to the fuel cell stack 16 is unnecessary. This eliminates the need for a water supply facility for supplying external water to the reforming catalyst 28 and the fuel cell stack 16.

  Moreover, according to the fuel cell system S1, as described above, the distillation membrane 70 (see FIG. 5) that does not require replacement or regeneration is used to generate condensed water from the water vapor contained in the exhaust gas. Therefore, since regular maintenance for stably generating condensed water can be eliminated, for example, maintenance costs can be reduced as compared with the case of using a water treatment apparatus equipped with an ion exchange resin. it can.

  Moreover, since the distillation membrane 70 does not need to be regenerated by electricity, it is possible to avoid using the electric power generated in the fuel cell system S1 in order to maintain the performance of the distillation membrane 70. Thereby, the power generation efficiency of the fuel cell system S1 can be improved as compared with, for example, the case of using an electrodeionization type water treatment device.

  Furthermore, according to the fuel cell system S1, the exhaust gas flow path 76 (see FIG. 5) of the first heat exchanger 18 is exhausted from both the air electrode 56 and the burner 30 of the fuel cell stack 16 and contains water vapor. Therefore, condensed water can be generated from water vapor contained in the exhaust gas from the air electrode 56 and the burner 30 of the fuel cell stack 16. As a result, the exhaust gas from only one of the air electrode 56 and the burner 30 of the fuel cell stack 16 is generated in the condensation space 86 shown in FIG. The amount of condensed water produced can be increased.

  Further, according to the fuel cell system S1, only one first heat exchanger 18 is provided, and the fuel cell stack 16 is provided in the exhaust gas flow path 76 (see FIG. 5) of the first heat exchanger 18. The exhaust gas containing water vapor discharged from both the air electrode 56 and the burner 30 flows. Therefore, since only one first heat exchanger 18 is required, the cost can be reduced.

  Further, as shown in FIG. 5, the distillation film 70 provided in the first heat exchanger 18 is formed in a cylindrical shape, and an exhaust gas flow channel 76 is formed inside thereof, and a heat transfer wall 84 is formed. Is provided in an annular shape around the distillation film 70, and the outer wall 96 is provided in an annular shape around the heat transfer wall 84. Therefore, the water vapor passes through the distillation film 70 over the entire circumference of the distillation film 70 formed in a cylindrical shape, and condensed water can be generated from the water vapor over the entire circumference of the heat transfer wall 84. Thereby, the production | generation efficiency of condensed water can be improved.

  Further, as shown in FIG. 1, the fuel cell system S1 is provided with a hot water storage tank 22 for storing hot water, and the hot water circulating water supplied from the hot water storage tank 22 is heat transfer shown in FIG. The hot water circulating water flow path 98 formed between the wall 84 and the outer wall 96 is circulated. Therefore, this hot water circulating water can be heated by the heat of the steam that has moved to the condensing space 86 between the distillation membrane 70 and the heat transfer wall 84. Thereby, the heat of the exhaust gas discharged from the fuel cell stack 16 and the burner 30 shown in FIG. 1 can be effectively used for heating the hot water stored in the hot water storage tank 22.

  Then, the modification of 1st embodiment is demonstrated.

  In the first embodiment described above, the exhaust gas discharged from both the air electrode 56 and the burner 30 of the fuel cell stack 16 is circulated through the exhaust gas flow path 76 (see FIG. 5) of the first heat exchanger 18. The exhaust gas discharged from only one of the air electrode 56 and the burner 30 of the fuel cell stack 16 may be circulated. In this case, the exhaust gas that is not circulated through the exhaust gas flow path 76 among the exhaust gas discharged from the air electrode 56 and the burner 30 of the fuel cell stack 16 may be discharged to the outside.

  Even in such a configuration, in the fuel cell system including the polymer electrolyte fuel cell stack 16, the exhaust gas discharged from either the air electrode 56 or the burner 30 of the fuel cell stack 16 is converted into condensed water. Can be effectively utilized for the generation of

  In the first embodiment described above, the condensed water generated by the first heat exchanger 18 and stored in the drain tank 102 is supplied to both the reforming catalyst 28 and the fuel cell stack 16, and the reforming catalyst This is used for both steam reforming at 28 and cooling of the fuel cell 50. However, the condensed water stored in the drain tank 102 is supplied only to one of the reforming catalyst 28 and the fuel battery cell 50, and among steam reforming in the reforming catalyst 28 and cooling of the fuel battery cell 50. It may be used only for either of these.

  In the first embodiment described above, the hot water circulating water supplied from the hot water storage tank 22 is used as an example of the cooling fluid for generating condensed water in the first heat exchanger 18, but other than the hot water circulating water is used. Cooling water may be used. Further, as a cooling fluid for generating condensed water in the first heat exchanger 18, for example, a gas such as an oxidizing gas supplied to the air electrode 56 through the oxidizing gas pipe 60, and other gases and liquids are appropriately used. May be.

  In the first embodiment described above, as shown in FIG. 5, the distillation film 70 is formed in a cylindrical shape, and the inside of the cylindrical distillation film 70 is formed as an exhaust gas flow path 76. ing. However, the distillation membrane 70 may be formed in a shape other than a cylindrical shape, for example, constituting only a part of the circumferential direction in the tubular body forming the exhaust gas flow channel 76. Further, the heat transfer wall 84 and the outer wall 96 may also have a shape other than an annular shape, such as a flat plate shape or an arc shape, as long as the condensing space 86 and the hot water circulating water channel 98 (cooling fluid channel) can be formed. It may be formed by.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  The structure of the fuel cell system S2 according to the second embodiment shown in FIG. 2 is changed as follows with respect to the fuel cell system S1 according to the first embodiment described above (see FIG. 1). In the second embodiment, the same reference numerals are used for the same structures as those in the first embodiment, and the description thereof is omitted.

  The fuel cell system S2 according to the second embodiment includes a pair of first heat exchangers 18A and 18B instead of the above-described first heat exchanger 18 (see FIG. 1). The pair of first heat exchangers 18A and 18B is an example of the “heat exchanger” in the present invention, and has the same configuration as the first heat exchanger 18 (see FIG. 5).

  The inlet part of the exhaust gas flow path 76 (see FIG. 5) in one first heat exchanger 18A is connected to the air electrode exhaust gas pipe 68, and the exhaust gas flow path 76 in this one first heat exchanger 18A includes The exhaust gas discharged from the air electrode 56 of the fuel cell stack 16 and containing water vapor flows.

  On the other hand, the inlet part of the exhaust gas flow path 76 (see FIG. 5) in the other first heat exchanger 18B is connected to the burner exhaust gas pipe 66, and the exhaust gas flow path in the other first heat exchanger 18B. In 76, the exhaust gas containing water vapor | steam discharged | emitted from the burner 30 distribute | circulates.

  An exhaust port 78 shown in FIG. 2 is connected to an outlet portion of the exhaust gas passage 76 (see FIG. 5) in the pair of first heat exchangers 18A and 18B, and water vapor passes through the exhaust gas passages 76. The removed exhaust gas is discharged from the exhaust port 78 to the outside.

  Further, the inlet pipe 90 and the outlet pipe 92 (see FIG. 5) in the pair of first heat exchangers 18A and 18B are respectively provided with first hot water circulation circuits 94A and 94B connected to the hot water storage tank 22 shown in FIG. It is connected. And hot water circulating water circulates between the hot water circulating water flow path 98 (refer FIG. 5) in a pair of 1st heat exchanger 18A, 18B, and the hot water storage tank 22 shown by FIG.

  Further, the condensate drain pipes 88 (see FIG. 5) in the pair of first heat exchangers 18A and 18B are connected to the inlet portions of the drain tank 102 via the condensate recovery pipes 100A and 100B shown in FIG. Has been. The drain tank 102 stores condensed water generated by the pair of first heat exchangers 18A and 18B and recovered through the condensed water recovery pipes 100A and 100B, respectively.

  In this fuel cell system S2, the condensed water recovery pipes 100A and 100B, the drain tank 102, the first pump 106, the second pump 108, the first condensed water supply pipe 104, the second condensed water supply pipe 110, the second heat The exchanger 20 and the cooling circuit 114 constitute a condensed water recovery / supply unit 24.

  Also with the fuel cell system S2 according to the second embodiment, condensed water can be generated from water vapor contained in the exhaust gas from the air electrode 56 and the burner 30 of the fuel cell stack 16. As a result, the exhaust gas from only one of the air electrode 56 and the burner 30 of the fuel cell stack 16 is generated in the condensation space 86 shown in FIG. The amount of condensed water produced can be increased.

  In addition, when the pair of first heat exchangers 18A and 18B is provided as in the fuel cell system S2, the pair of first heat exchangers 18A and 18B can separately generate condensed water. Therefore, the condensed water can be stably supplied to the reforming catalyst 28 and the fuel cell stack 16. Thereby, stability of fuel cell system S2 is securable.

  The fuel cell system S2 according to the second embodiment may be configured to include only one of the pair of first heat exchangers 18A and 18B.

[Third embodiment]
Next, a third embodiment of the present invention will be described.

  The structure of the fuel cell system S3 according to the third embodiment shown in FIG. 3 is changed as follows with respect to the fuel cell system S1 (see FIG. 1) according to the first embodiment described above. In the third embodiment, the same reference numerals are used for the same structures as in the first embodiment, and the description thereof is omitted.

  The fuel cell system S3 according to the third embodiment includes a pair of first heat exchangers 18A and 18B instead of the first heat exchanger 18 (see FIG. 1). The pair of first heat exchangers 18A and 18B is an example of the “heat exchanger” in the present invention, and has the same configuration as the first heat exchanger 18 (see FIG. 5).

  The inlet portion of the exhaust gas flow path 76 (see FIG. 5) in one first heat exchanger 18A is connected to the burner exhaust gas pipe 66. The other end of the air electrode exhaust gas pipe 68 is connected to a portion of the burner exhaust gas pipe 66 on the first heat exchanger 18A side. Then, exhaust gas including water vapor discharged from the air electrode 56 and the burner 30 of the fuel cell stack 16 flows through the exhaust gas flow path 76 in the first heat exchanger 18B.

  On the other hand, the inlet part of the exhaust gas flow path 76 (see FIG. 5) in the other first heat exchanger 18B is connected to the fuel electrode exhaust gas pipe 62, and the exhaust gas flow in the other first heat exchanger 18B. Exhaust gas containing water vapor discharged from the fuel electrode 54 of the fuel cell stack 16 flows through the path 76.

  Further, an exhaust port 78 shown in FIG. 3 is connected to the outlet of the exhaust gas flow path 76 (see FIG. 5) in one first heat exchanger 18A. The exhaust gas that has passed through the exhaust gas flow path 76 and from which the water vapor has been removed is discharged from the exhaust port 78 to the outside.

  On the other hand, the burner gas pipe 42 is connected to the outlet of the exhaust gas flow path 76 (see FIG. 5) in the other first heat exchanger 18B. Unreacted hydrogen gas remains in the fuel cell stack 16 in the fuel electrode exhaust gas from which the water vapor has been removed by the distillation membrane 70 (see FIG. 5) of the other first heat exchanger 18B discharged from the fuel electrode 54. The fuel electrode exhaust gas containing unreacted hydrogen gas is supplied as burner gas to the burner 30 through the burner gas pipe 42.

  Further, the inlet pipe 90 and the outlet pipe 92 (see FIG. 5) in the pair of first heat exchangers 18A and 18B are respectively provided with first hot water circulation circuits 94A and 94B connected to the hot water storage tank 22 shown in FIG. It is connected. And hot water circulating water circulates between the hot water circulating water flow path 98 (refer FIG. 5) in a pair of 1st heat exchanger 18A, 18B, and the hot water storage tank 22 shown by FIG.

  Moreover, the inlet part of the drain tank 102 is connected to the condensed water drain pipe 88 (refer FIG. 5) in one 1st heat exchanger 18A via the condensed water collection | recovery pipe | tube 100A shown by FIG. On the other hand, the inlet part of the drain tank 122 is connected to the condensed water drain pipe 88 (refer FIG. 5) in the other 1st heat exchanger 18B via the condensed water collection | recovery pipe | tube 100B shown by FIG. . The drain tank 122 stores condensed water that is generated in the other first heat exchanger 18B and recovered through the condensed water recovery pipe 100B.

  When the amount of condensed water stored in the drain tank 122 exceeds the allowable amount, the excess amount of condensed water is discharged from the drain tank 122. The outlet portion of the drain tank 122 is connected to the inlet portion of the drain tank 102 described above via a drain water drain pipe 123. And in this drain tank 102, the condensed water each produced | generated by a pair of above-mentioned 1st heat exchanger 18A, 18B is stored.

  In the distillation membrane method, the volatile component contained in the exhaust gas from the fuel electrode 54 has the property of volatilizing with the water vapor. For example, ammonia that may be contained in the exhaust gas from the fuel electrode 54 in a relatively large amount. As for the raw water, if the pH of the raw water is 6 or less, it is shown that ammonia does not enter the permeate side (Chemical Engineering Papers Vol.19 No.2 (1993)). Transmission characteristics of non-volatile components, Kurokawa et al.).

  In this fuel cell system S3, the condensed water recovery pipes 100A and 100B, the drain tank 102, the first pump 106, the second pump 108, the first condensed water supply pipe 104, the second condensed water supply pipe 110, the second heat The exchanger 20, the cooling circuit 114, the drain tank 122, and the drain water drain pipe 123 constitute a condensed water recovery / supply unit 24.

  According to the fuel cell system S3 according to the third embodiment, in addition to the water vapor contained in the exhaust gas from the air electrode 56 and the burner 30 of the fuel cell stack 16, it is contained in the exhaust gas from the fuel electrode 54 of the fuel cell stack 16. Since condensed water is also generated from the generated steam, the amount of condensed water generated in the system can be increased.

  In addition, since the fuel cell system S3 includes the pair of first heat exchangers 18A and 18B as in the second embodiment, the pair of first heat exchangers 18A and 18B are separately provided. Condensed water can be generated. Thereby, since condensed water can be stably supplied to the reforming catalyst 28 and the fuel cell stack 16, the stability of the fuel cell system S3 can be ensured.

  Further, according to this fuel cell system S3, the burner 30 is supplied with the exhaust gas discharged from the exhaust gas flow path 76 (see FIG. 5) in the other first heat exchanger 18B and from which the water vapor has been removed as the burner gas. The content of water vapor contained in the burner gas supplied to the burner 30 can be reduced. Thereby, while malfunctions, such as misfire, can be suppressed in the burner 30, it is not necessary to use the expensive thing which can respond to burner gas with much water vapor | steam content as the burner 30, Therefore The cost can be reduced that much. .

  In addition, fuel cell system S3 which concerns on this 3rd embodiment may be set as the structure provided only with 1st heat exchanger 18B among a pair of above-mentioned 1st heat exchangers 18A and 18B.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described.

  The structure of the fuel cell system S4 according to the fourth embodiment shown in FIG. 4 is changed as follows with respect to the fuel cell system S2 (see FIG. 2) according to the second embodiment described above. Note that in the fourth embodiment, the same structures as those in the above-described second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The fuel cell system S4 according to the fourth embodiment includes a first heat exchanger 18C in addition to the two first heat exchangers 18A and 18B described above. The three first heat exchangers 18A, 18B, and 18C are examples of the “heat exchanger” in the present invention, and have the same configuration as the above-described first heat exchanger 18 (see FIG. 5).

  The inlet portion of the exhaust gas flow path 76 (see FIG. 5) in the first first heat exchanger 18A is connected to the air electrode exhaust gas pipe 68, and the exhaust gas flow path 76 in the first first heat exchanger 18A. In this case, exhaust gas containing water vapor discharged from the air electrode 56 of the fuel cell stack 16 circulates.

  Moreover, the inlet part of the exhaust gas flow path 76 (see FIG. 5) in the second first heat exchanger 18B is connected to the burner exhaust gas pipe 66, and the exhaust gas flow path 76 in the other first heat exchanger 18B. The exhaust gas containing water vapor discharged from the burner 30 circulates.

  Furthermore, the inlet of the exhaust gas flow path 76 (see FIG. 5) in the third first heat exchanger 18C is connected to the fuel electrode exhaust gas pipe 62, and the exhaust gas flow in the third first heat exchanger 18C. Exhaust gas containing water vapor discharged from the fuel electrode 54 of the fuel cell stack 16 flows through the path 76.

  Exhaust ports 78 shown in FIG. 4 are connected to the outlets of the exhaust gas passages 76 (see FIG. 5) in the first and second first heat exchangers 18A and 18B. The exhaust gas that has passed through and from which the water vapor has been removed is discharged from the exhaust port 78 to the outside.

  On the other hand, the burner gas pipe 42 is connected to the outlet of the exhaust gas flow path 76 (see FIG. 5) in the third first heat exchanger 18C. Unreacted hydrogen gas remains in the fuel cell stack 16 in the fuel electrode exhaust gas from which the water vapor has been removed by the distillation film 70 (see FIG. 5) of the third first heat exchanger 18C discharged from the fuel electrode 54. The fuel electrode exhaust gas containing unreacted hydrogen gas is supplied to the burner 30 through the burner gas pipe 42 as burner gas.

  Further, the inlet pipe 90 and the outlet pipe 92 (see FIG. 5) in the three first heat exchangers 18A, 18B, and 18C have first hot water circulation circuits 94A and 94B connected to the hot water storage tank 22 shown in FIG. , 94C are connected to each other. And the hot water circulating water circulates between the hot water circulating water flow path 98 (refer FIG. 5) in these three 1st heat exchangers 18A, 18B, and 18C and the hot water storage tank 22 shown by FIG.

  Further, the condensed water drain pipe 88 (see FIG. 5) in the first and second first heat exchangers 18A and 18B is connected to the inlet of the drain tank 102 via the condensed water recovery pipes 100A and 100B shown in FIG. Each part is connected. The drain tank 102 stores condensed water generated by the first and second first heat exchangers 18A and 18B and recovered through the condensed water recovery pipes 100A and 100B, respectively.

  On the other hand, the inlet part of the drain tank 122 is connected to the condensed water drain pipe 88 (see FIG. 5) in the third first heat exchanger 18C via the condensed water recovery pipe 100C shown in FIG. Yes. In this drain tank 122, the condensed water produced | generated in the above-mentioned 3rd 1st heat exchanger 18C and collect | recovered through the condensed water collection | recovery pipe | tube 100C is stored.

  When the amount of condensed water stored in the drain tank 122 exceeds the allowable amount, the excess amount of condensed water is discharged from the drain tank 122. The outlet portion of the drain tank 122 is connected to the inlet portion of the drain tank 102 described above via a drain water drain pipe 123. And in this drain tank 102, the condensed water each produced | generated by the above-mentioned three 1st heat exchanger 18A, 18B, 18C is stored.

  As described in the third embodiment, in the distillation membrane system, the volatile component contained in the exhaust gas from the fuel electrode 54 has a characteristic of volatilizing with the water vapor. As for ammonia that may be contained in a relatively large amount, it has been shown that if the pH of the raw water is 6 or less, there is no mixing of ammonia into the permeation side (Chemical Engineering Papers Vol. 19 No. 2 (1993 )), Permeability characteristics of volatile and non-volatile components in membrane distillation, Kurokawa et al.).

  In this fuel cell system S4, the condensed water recovery pipes 100A, 100B, 100C, the drain tank 102, the first pump 106, the second pump 108, the first condensed water supply pipe 104, the second condensed water supply pipe 110, the first The two heat exchanger 20, the cooling circuit 114, the drain tank 122, and the drain water drain pipe 123 constitute a condensed water recovery / supply unit 24.

  According to the fuel cell system S4 according to the fourth embodiment, in addition to the water vapor contained in the exhaust gas from the air electrode 56 and the burner 30 of the fuel cell stack 16, it is contained in the exhaust gas from the fuel electrode 54 of the fuel cell stack 16. Since condensed water is also generated from the generated steam, the amount of condensed water generated in the system can be increased.

  Further, when the three first heat exchangers 18A, 18B, and 18C are provided as in the fuel cell system S4, condensed water is separately supplied to each of the three first heat exchangers 18A, 18B, and 18C. Therefore, the condensed water can be stably supplied to the reforming catalyst 28 and the fuel cell stack 16. Thereby, stability of fuel cell system S4 is securable.

  Further, according to the fuel cell system S4, the burner 30 is supplied with the exhaust gas discharged from the exhaust gas flow path 76 (see FIG. 5) in the third first heat exchanger 18C and from which the water vapor has been removed as the burner gas. Therefore, the content of water vapor contained in the burner gas supplied to the burner 30 can be reduced. Thereby, while malfunctions, such as misfire, can be suppressed in the burner 30, it is not necessary to use the expensive thing which can respond to burner gas with much water vapor | steam content as the burner 30, Therefore The cost can be reduced that much. .

  In addition, fuel cell system S4 which concerns on this 4th embodiment is set as the structure provided with only any one among the above-mentioned three 1st heat exchangers 18A, 18B, and 18C, or only any one. Also good.

  Moreover, the modification applicable to 2nd thru | or 4th embodiment among the some modifications in the above-mentioned 1st embodiment may be employ | adopted as a modification of 2nd thru | or 4th embodiment.

  The first to fourth embodiments of the present invention have been described above. However, the present invention is not limited to the above, and various modifications can be made without departing from the spirit of the present invention. Of course there is.

S1, S2, S3, S4 ... Fuel cell system, 12 ... Desulfurizer, 14 ... Fuel treatment device, 16 ... Fuel cell stack, 18, 18A, 18B, 18C ... First heat exchanger (an example of heat exchanger), DESCRIPTION OF SYMBOLS 20 ... 2nd heat exchanger, 22 ... Hot water storage tank, 24 ... Condensate collection | recovery and supply part, 26 ... City gas pipe, 28 ... Reforming catalyst, 30 ... Burner, 32 ... Shift catalyst, 34 ... PROX catalyst, 36 ... Source gas pipe, 38 ... first air blower, 40 ... air gas pipe, 42 ... burner gas pipe, 44 ... PROX air pipe, 46 ... fuel gas pipe, 48 ... bleed air pipe, 50 ... fuel cell, 52 ... electrolyte layer 54 ... Fuel electrode, 56 ... Air electrode, 58 ... Second air blower, 60 ... Oxidizing gas pipe, 62 ... Fuel electrode exhaust pipe, 64 ... Drain pot, 65 ... Drain water drain pipe, 66 ... Burner exhaust pipe, 68 ... Air electrode exhaust pipe, 7 ... Distillation membrane, 72 ... Inner pipe, 74 ... Outer pipe, 76 ... Exhaust gas flow path, 78 ... Exhaust port, 80 ... Top wall part, 82 ... Bottom wall part, 84 ... Heat transfer wall, 86 ... Condensation space, 88 ... Condensate drain pipe, 90 ... inlet pipe, 92 ... outlet pipe, 94, 94A, 94B, 94C ... first hot water circulating circuit, 96 ... outer wall, 98 ... hot water circulating water flow path (an example of cooling fluid flow path), 100, 100A, 100B, 100C ... Condensate recovery pipe, 102 ... Drain tank, 103 ... Drain water drain pipe, 104 ... First condensed water supply pipe, 106 ... First pump, 108 ... Second pump, 110 ... Second condensed water Supply pipe, 112 ... second hot water circulating circuit, 114 ... cooling circuit, 122 ... drain tank, 123 ... drain water drain pipe

Claims (10)

A fuel treatment apparatus that has a reforming catalyst for steam reforming the raw material gas and a burner for heating the reforming catalyst, and generates a fuel gas containing hydrogen gas;
A polymer electrolyte fuel cell stack for generating electric power by reacting a fuel gas supplied from the fuel processor and an oxidizing gas supplied from the outside;
A distillation membrane that is formed in a cylindrical shape and forms an exhaust gas passage through which exhaust gas containing water vapor discharged from at least one of the fuel cell stack and the burner circulates, and is annularly provided around the distillation membrane wherein the heat transfer wall water vapor passing through the distillation membrane is formed between the distillation film condensation space which is condensed, cooled fluid flow path through which a cooling fluid flows with provided annularly around the heat transfer thermal wall with A heat exchanger having an outer wall formed between the heat transfer wall and
A condensed water recovery / supply unit for recovering the condensed water generated in the condensed space and supplying the condensed water to at least one of the reforming catalyst and the fuel cell stack;
A fuel cell system comprising: It further includes a hot water storage tank for storing hot water,
The cooling fluid that circulates through the cooling fluid channel is hot water circulating water that circulates between the hot water storage tank and the cooling fluid channel.
The fuel cell system according to claim 1. One heat exchanger,
In the exhaust gas flow path, exhaust gas containing water vapor discharged from both the air electrode and the burner of the fuel cell stack flows.
The fuel cell system according to claim 1 or 2. A pair of the heat exchangers;
In the exhaust gas passage in one of the heat exchangers, exhaust gas containing water vapor discharged from the air electrode of the fuel cell stack flows,
In the exhaust gas flow path in the other heat exchanger, exhaust gas containing water vapor discharged from the burner flows.
The fuel cell system according to claim 1 or 2 . A pair of the heat exchangers;
In the exhaust gas passage in one of the heat exchangers, exhaust gas containing water vapor discharged from both the air electrode and the burner of the fuel cell stack flows,
In the exhaust gas passage in the other heat exchanger, exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows,
Exhaust gas discharged from the exhaust gas flow path in the other heat exchanger is supplied to the burner as burner gas.
The fuel cell system according to claim 1 or 2 . Comprising three heat exchangers,
In the exhaust gas flow path in the first heat exchanger, exhaust gas containing water vapor discharged from the air electrode of the fuel cell stack flows,
In the exhaust gas flow path in the second heat exchanger, exhaust gas containing water vapor discharged from the burner flows,
In the exhaust gas passage in the third heat exchanger, exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows,
Exhaust gas discharged from the exhaust gas flow path in the third heat exchanger is supplied to the burner as burner gas.
The fuel cell system according to claim 1 or 2 . As the heat exchanger,
A heat exchanger through which exhaust gas containing water vapor discharged from both the air electrode and the burner of the fuel cell stack flows into the exhaust gas flow path, and water vapor discharged from the fuel electrode of the fuel cell stack to the exhaust gas flow path Comprising at least one of the heat exchangers through which exhaust gas containing flows,
The fuel cell system according to claim 1 or 2 . As the heat exchanger,
At least a heat exchanger through which exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows in the exhaust gas flow path,
Exhaust gas discharged from the exhaust gas flow path in the heat exchanger is supplied to the burner as burner gas.
The fuel cell system according to claim 7 . As the heat exchanger,
A heat exchanger through which exhaust gas containing water vapor exhausted from the air electrode of the fuel cell stack flows through the exhaust gas channel, a heat exchanger through which exhaust gas exhausted from the burner and containing water vapor flows through the exhaust gas channel, and Comprising at least one of heat exchangers in which exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows in the exhaust gas flow path,
The fuel cell system according to claim 1 or 2 . As the heat exchanger,
At least a heat exchanger through which exhaust gas containing water vapor discharged from the fuel electrode of the fuel cell stack flows in the exhaust gas flow path,
Exhaust gas discharged from the exhaust gas flow path in the heat exchanger is supplied to the burner as burner gas.
The fuel cell system according to claim 9 .

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