WO2010007759A1 - Fuel cell system - Google Patents

Fuel cell system Download PDF

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Publication number
WO2010007759A1
WO2010007759A1 PCT/JP2009/003290 JP2009003290W WO2010007759A1 WO 2010007759 A1 WO2010007759 A1 WO 2010007759A1 JP 2009003290 W JP2009003290 W JP 2009003290W WO 2010007759 A1 WO2010007759 A1 WO 2010007759A1
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WO
WIPO (PCT)
Prior art keywords
heat medium
fuel cell
heat
path
temperature
Prior art date
Application number
PCT/JP2009/003290
Other languages
French (fr)
Japanese (ja)
Inventor
中村彰成
行正章典
小原英夫
浦田隆行
Original Assignee
パナソニック株式会社
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Application filed by パナソニック株式会社 filed Critical パナソニック株式会社
Priority to JP2010520765A priority Critical patent/JPWO2010007759A1/en
Publication of WO2010007759A1 publication Critical patent/WO2010007759A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
    • H01M8/04037—Electrical heating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04313—Processes for controlling fuel cells or fuel cell systems characterised by the detection or assessment of variables; characterised by the detection or assessment of failure or abnormal function
    • H01M8/0432—Temperature; Ambient temperature
    • H01M8/04358—Temperature; Ambient temperature of the coolant
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
    • H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
    • H01M8/04746—Pressure; Flow
    • H01M8/04768—Pressure; Flow of the coolant
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to a configuration of a fuel cell system.
  • the fuel cell system generates electricity by an electrochemical reaction between fuel gas and oxidant gas supplied to the fuel cell from outside, collects the heat generated by the reaction, stores it as hot water, and stores this hot water to the outside.
  • This system is used effectively for heat supply.
  • Such a fuel cell system is grid-connected to a grid power source, and the power generated by the fuel cell or the like and the power from the grid power source are supplied to an external power load (for example, household power load).
  • the fuel cells that make up the fuel cell system have a slow output change (following) speed due to load fluctuations of the external power load, so the total power consumption of all devices that receive power supply from the cogeneration system is output from the cogeneration system. If the output power is lower than the output power, surplus power is generated, and a reverse power flow to the system power supply occurs.
  • a fuel cell system is known in which surplus power is converted into heat by a heater and used effectively (see, for example, Patent Document 1).
  • FIG. 7 is a schematic diagram showing a schematic configuration of the fuel cell system disclosed in Patent Document 1.
  • the fuel cell system 200 disclosed in Patent Document 1 includes a fuel cell 201, a cooling water channel 202, a heat exchanger 203, a hot water tank 204, a hot water channel 205, and heating elements 206 and 207. It has.
  • a cooling water channel 202 is connected to the fuel cell 201, and a hot water channel 205 is connected to the hot water tank 204.
  • the heat exchanger 203 is configured so that the heat exchanger 203 can exchange heat between the cooling water flowing through the cooling water flow path 202 and the hot water flowing through the hot water flow path 205. It is provided so as to straddle.
  • the cooling water channel 202 is provided with a cooling water pump 208, while the warm water channel 205 is provided with an exhaust heat recovery water pump 209. Furthermore, heating elements 206 and 207 are provided in the cooling water passage 202 and the hot water passage 205, respectively.
  • the conventional fuel cell system has a (cooling) water tank that stores cooling water flowing through the cooling water flow path, and the water tank is located downstream of the heat exchanger in order to efficiently recover heat.
  • a (cooling) water tank that stores cooling water flowing through the cooling water flow path, and the water tank is located downstream of the heat exchanger in order to efficiently recover heat.
  • JP 2006-12564 A Japanese Laid-Open Patent Publication No. 2004-213985
  • the hot water flowing through the hot water flow path 205 is changed into the cooling water rapidly heated by the heat exchanger 203, and in some cases, the boiling cooling water and
  • the hot water heated excessively than usual and overheated may be supplied to the hot water tank 204.
  • the hot water that has been overheated is stored in the hot water storage tank, when the hot water in the hot water storage tank 204 is supplied to the outside, the temperature is reduced to the optimum temperature desired by the user even if the temperature is lowered by mixing with city water. Does not decrease, hot hot water is supplied, and the user may be burned.
  • the present invention has been made in view of the above-described problems of the prior art, and the heat medium exemplified by the cooling water or the like for cooling the fuel cell has a surplus power heater that causes the cooling water to flow from the surplus power heater due to a sudden fluctuation in surplus power. Even if gas is generated from the cooling water as described above, the heat exchange in the heat exchanger is more stable than before due to rapid heating, excessive temperature rise, and in some cases boiling.
  • a first object is to provide a fuel cell system that can be used.
  • the present invention provides a second heat medium exemplified by the warm water by suppressing the supply of the heat medium that has been heated rapidly, and in some cases, the boiled heat medium to the heat exchanger.
  • a second object of the present invention is to provide a fuel cell system that can be operated safely while suppressing the supply to a heat accumulator exemplified by the hot water storage tank while the temperature is raised.
  • a fuel cell system includes a fuel cell, a first heat medium path through which a first heat medium that cools the fuel cell flows, and a second heat medium.
  • a second heat medium path that flows, the first heat medium that is provided across the first heat medium path and the second heat medium path, and flows through the first heat medium path;
  • a heat exchanger for exchanging heat with the second heat medium flowing through the second heat medium path, and heating the first heat medium that has cooled the fuel cell before flowing into the heat exchanger
  • a surplus power heater that consumes surplus power of the fuel cell, and a tank that is provided in the first heat medium path and stores the first heat medium, wherein the tank is heated by the surplus power heater.
  • the first heat medium and the first heat medium in the tank are mixed.
  • the first heat medium heated by the surplus power heater is excessively heated, or in some cases, boiling, so that dissolved oxygen in the cooling water is vaporized, Even if gas is generated by steaming, the possibility that the flow rate of the first heat medium becomes unstable due to gas retention in the first heat medium path is suppressed, and the heat exchanger is stable with the second heat medium. Heat exchange takes place. Further, the first heat medium that has been heated rapidly, and in some cases, the first heat medium that has boiled is mixed with the first heat medium in the tank, whereby the temperature is leveled in the tank. Since the heat medium is supplied to the heat exchanger, it is possible to reduce the possibility that the temperature of the second heat medium that has passed through the heat exchanger is excessively increased.
  • the surplus power heater is provided in the first heat medium path, and the first heat medium heated by the surplus power heater flows into the tank. May be.
  • the surplus power heater may be provided in the tank.
  • the tank may be open to the atmosphere.
  • the tank may be provided with a depressurizer.
  • a portion of the first heat medium path between the surplus power heater and the tank is configured to be horizontal or ascending in the flow of the first heat medium. It may be.
  • the first temperature detector provided on the downstream side of the heat exchanger in the first heat medium path and the first heat detector flow through the second heat medium flow path.
  • a first flow rate regulator that adjusts the flow rate of the two heat mediums and a first controller that controls the first flow rate regulator based on the temperature detected by the first temperature detector may be provided.
  • the first temperature detector provided on the downstream side of the heat exchanger in the first heat medium path, and after cooling the fuel cell, the surplus power heater
  • a second temperature detector for detecting a temperature of the first heat medium before being heated
  • a second flow rate regulator for adjusting a flow rate of the first heat medium flowing through the first heat medium path
  • a second controller for controlling the second flow rate regulator such that a detected temperature of the second temperature detector is lower than an average temperature of the detected temperature of the first temperature detector and the boiling point of the first heat medium; May be provided.
  • the fuel cell system of the present invention even if the first heat medium heated suddenly by the surplus electric power heater or, in some cases, the first heat medium boils due to a rapid fluctuation of the surplus power, By collecting the generated gas such as water vapor in the tank, gas retention in the first heat medium path is suppressed, and heat exchange in the heat exchanger can be stably performed. Moreover, by mixing with the 1st heat medium in a tank, the temperature rise of the 1st heat medium supplied to a heat exchanger is suppressed, and the 2nd heat medium after passing a heat exchanger can overheat. Is reduced.
  • FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention.
  • FIG. 2 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention.
  • FIG. 3 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention.
  • FIG. 4 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 4 of the present invention.
  • FIG. 5 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention.
  • FIG. 6 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 6 of the present invention.
  • FIG. 7 is a schematic diagram showing a schematic configuration of the fuel cell system disclosed in Patent Document 1. As shown in FIG.
  • FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention.
  • a fuel cell system 100 As shown in FIG. 1, a fuel cell system 100 according to Embodiment 1 of the present invention includes a fuel cell 1, a surplus power heater 2, a first heat medium tank 3, a heat exchanger 4, and a controller 10. Yes.
  • a fuel gas supply device (not shown) and an oxidant gas supply device (not shown) are connected to the fuel cell 1, and a fuel gas and an oxidant gas (reacted by these) supplied from these supply devices. Electricity and heat are generated by electrochemical reaction of gas).
  • the fuel cell 1 is provided with a first heat medium flow path 21 through which the first heat medium flows in order to recover exhaust heat generated by the electrochemical reaction.
  • the downstream end of the first heat medium forward path 51 a is connected to the inlet of the first heat medium flow path 21 in the fuel cell 1, and the upstream end of the first heat medium forward path 51 a is the primary flow of the heat exchanger 4. Connected to the exit of the path 22.
  • the inlet of the primary flow path 22 of the heat exchanger 4 is connected to the downstream end of the first heat medium return path 51b, and the upstream end of the first heat medium return path 51b is connected to the first heat medium in the fuel cell 1.
  • the outlet of the medium channel 21 is connected.
  • the first heat medium path 51 includes the first heat medium forward path 51a, the first heat medium return path 51b, the first heat medium flow path 21, and the primary flow path 22.
  • a second pump (second flow regulator) 7 capable of adjusting the flow rate is provided in the middle of the first heat medium forward path 51a, and the surplus power heater 2 is disposed in the middle of the first heat medium return path 51b.
  • a first heat medium tank 3 for storing a first heat medium (here, cooling water) are provided in this order.
  • the surplus power heater 2 is configured such that surplus power out of the power generated by the fuel cell 1 is energized and heats the first heat medium flowing through the first heat medium forward path 51a.
  • the 2nd flow regulator of this invention although the pump which can adjust flow volume is used here, it is not limited to this, You may use flow regulators, such as a pump and a flow control valve.
  • the second heat medium forward path 52a and the second heat medium return path 52b are connected to the secondary flow path 23 of the heat exchanger 4, and the second heat medium forward path 52a and the second heat medium return path 52b are connected.
  • route 52 comprised from the secondary flow path 23 is connected with the hot water storage tank 5 as a heat storage device.
  • the downstream end of the second heat medium return path 52 b is connected to the inlet of the secondary flow path 23 of the heat exchanger 4, and the upstream end is connected to the lower end of the hot water storage tank 5.
  • the upper end of the hot water storage tank 5 is connected to the downstream end of the second heat medium forward path 52 a, and the upstream end is connected to the outlet of the secondary flow path 23 of the heat exchanger 4.
  • a first pump (first flow rate regulator) 6 capable of adjusting the flow rate is provided in the middle of the second heat medium return path 52b.
  • the pump which can adjust flow volume is used here as a 1st flow regulator of this invention, it is not limited to this, You may use flow regulators, such as a pump and a flow control valve.
  • the hot water storage tank 5 is formed so as to extend in the vertical direction, and a water supply path 53 for supplying city water is connected to the lower end of the hot water storage tank 5. Is connected to a hot water supply passage 54 for supplying hot water to the user.
  • the hot water supply channel 54 is connected to a heat load that uses the hot water (not shown). Examples of the thermal load include hot water supply equipment, heating equipment, and air conditioning equipment.
  • the first heat medium recovered from the exhaust heat of the fuel cell 1 flows through the first heat medium return path 51b of the first heat medium path 51 and is supplied to the primary flow path 22 in the heat exchanger 4. .
  • the first heat medium supplied to the primary flow path 22 is supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 in the heat exchanger 4 while flowing through the primary flow path 22 of the heat exchanger 4.
  • the second heat medium is subjected to heat exchange and cooled.
  • the cooled first heat medium flows through the first heat medium forward path 51 a and is supplied to the inlet of the first heat medium flow path 21 of the fuel cell 1.
  • the second heat medium (here, hot water) supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 of the heat exchanger 4 flows through the secondary flow path 23 of the heat exchanger 4. In the meantime, it is heated by the first heat medium flowing through the primary flow path 22.
  • the heated second heat medium flows through the second heat medium return path 52 b and is supplied to the upper end portion of the hot water storage tank 5.
  • the hot water storage tank 5 stores water having a low temperature close to the city water temperature in the lower part, and stores a second heat medium heated by the heat exchanger 4 from the upper part. It becomes a hot water storage tank.
  • the first heat medium recovered from the exhaust heat of the fuel cell 1 is further heated by the surplus power heater 2 if surplus power is generated while flowing through the first heat medium return path 51b of the first heat medium path 51. Is done.
  • the flow direction of the first heat medium and the second heat medium (the direction indicated by the arrow in FIG. 1) is the flow direction during power generation, and the flow of the second heat medium during the warm-up operation of the fuel cell 1. The direction is the opposite direction.
  • an input terminal (not shown) of the DC / DC converter 8 is connected to an output terminal (not shown) of the fuel cell 1 by appropriate wiring.
  • the DC / DC converter 8 is configured to boost DC power generated in the fuel cell 1 to a predetermined voltage.
  • an input terminal (not shown) of the inverter 9 is connected to an output terminal of the DC / DC converter 8 by an appropriate wiring.
  • the inverter 9 is configured to convert the DC power boosted by the DC / DC converter 8 into AC power.
  • the surplus power heater 2 is connected to an output terminal (not shown) of the inverter 9 by appropriate wiring.
  • a system power supply 12 is connected to the output terminal of the inverter 9 through a system interconnection point 11. That is, the output power of the fuel cell 1 and the power from the system power supply 12 are grid-connected at the grid connection point 11.
  • the surplus power heater 2 is connected to the output terminal of the inverter 9 here, the invention is not limited to this, and it may be connected to the output terminal of the DC / DC converter 8.
  • the external power load 14 is connected to the grid connection point 11 by appropriate wiring.
  • the external power load 14 is assumed to be a power consuming device used in a general household.
  • a current detector 13 is provided between the grid connection point 11 and the inverter 9.
  • the current detector 13 detects the amount of current supplied from the system power supply 12, and the detected current value is output to the controller 10.
  • the current detector 13 is composed of a current sensor such as a current transformer.
  • the current detector 13 detects the magnitude of the current as the magnitude of the electric power, and detects the direction of the current, thereby generating a reverse power flow. Is detected.
  • a current sensor using a shunt resistor a clamp type AC current sensor that clamps a current transformer on a system wire, and detects current from a secondary winding current proportional to the primary current, AC current An AC ammeter or the like that directly measures can be used.
  • the DC power boosted by the DC / DC converter 8 is converted to AC power by the inverter 9 and supplied to the external power load 14 while being connected to the system power supply 12. Then, the current detector 13 detects the power supplied from the system power supply 12, and the detected power is output to the controller 10.
  • the controller 10 is configured by a computer such as a microcomputer, and includes an arithmetic processing unit composed of a CPU, a storage unit (internal memory) composed of a semiconductor memory, and a clock unit (not shown) having a calendar function. Have.
  • the arithmetic processing unit reads out a predetermined control program stored in the storage unit and executes it to perform various controls relating to the fuel cell system.
  • the arithmetic processing unit detects whether or not reverse power flow has occurred based on the direction of the current detected by the current detector 13, and according to the current value detected by the current detector 13.
  • the arithmetic processing unit of the controller 10 controls the amount of power supplied to the surplus power heater 2 so that the current detected by the current detector 13 does not flow to the system power supply 12. That is, the fuel cell system 100 is provided with, for example, a voltage regulator (a voltage converter capable of adjusting the output voltage: not shown) that controls the supply voltage to the surplus power heater 2, and this voltage regulator The power consumption of the surplus power heater 2 is adjusted by adjusting the output voltage.
  • the controller 10 controls the amount of power supplied to the surplus power heater 2 by controlling the output voltage of the voltage regulator.
  • the controller means not only a single controller but also a group of controllers that execute control of the fuel cell system in cooperation with a plurality of controllers. For this reason, the controller 10 does not need to be composed of a single controller, and a plurality of controllers may be arranged in a distributed manner so that they cooperate to control the fuel cell system 100. .
  • a fuel gas and an oxidant gas are respectively supplied to an anode and a cathode (not shown) of the fuel cell 1 from a fuel gas supply device and an oxidant gas supply device, and electric power and heat are generated by an electrochemical reaction.
  • the electric power (DC power) generated in the fuel cell 1 is boosted by the DC / DC converter 8, and the boosted DC power is supplied to the inverter 9.
  • the supplied DC power is converted into AC power, and power is supplied to the external power load 14 while being connected to the system power supply 12.
  • the heat (exhaust heat) generated in the fuel cell 1 is recovered by the first heat medium supplied to the first heat medium flow path 21.
  • the first heat medium that has recovered the exhaust heat of the fuel cell 1 flows out to the first heat medium return path 51b, flows through the first heat medium return path 51b, and returns to the first heat medium tank 3.
  • the first heat medium returned to the first heat medium tank 3 is mixed with the first heat medium in the first heat medium tank 3, and the temperature is leveled.
  • the first heat medium supplied into the first heat medium tank 3 further flows through the first heat medium return path 51 b and is supplied to the primary flow path 22 of the heat exchanger 4.
  • the first heat medium supplied to the primary flow path 22 of the heat exchanger 4 flows from the lower end of the hot water storage tank 5 to the secondary flow of the heat exchanger 4 while flowing through the primary flow path 22 of the heat exchanger 4. Heat is exchanged with the second heat medium supplied to the passage 23 to be cooled.
  • the cooled first heat medium flows through the first heat medium forward path 51 a and is supplied to the inlet of the first heat medium flow path 21 of the fuel cell 1.
  • the second heat medium supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 of the heat exchanger 4 is heated while flowing through the secondary flow path 23 of the heat exchanger 4.
  • the heated second heat medium flows through the second heat medium forward path 52 a and returns to the upper end portion of the hot water storage tank 5.
  • the second heat medium returned to the hot water storage tank 5 is supplied to the heat load through the hot water supply channel 54 according to demand, and used as hot water by the user.
  • city water is supplied from the water supply path 53 under the control of the controller 10.
  • the flow rate of the first heat medium flowing through the first heat medium path 51 is adjusted by the second pump 7 based on a control signal from the controller 10, and similarly, the second heat medium path 52.
  • the flow rate of the second heat medium flowing therethrough is adjusted by the first pump 6 based on a control signal from the controller 10.
  • the high-temperature first heat medium is supplied (returned) to the first heat medium tank 3, so that the inside of the first heat medium tank 3 It is mixed with the first heat medium, and the temperature of the first heat medium is leveled in the first heat medium tank 3. Accordingly, the first heat medium is suppressed from being excessively heated or boiled in the primary flow path 22 of the heat exchanger 4 to be supplied, so that the first heat medium flow of the fuel cell 1 is suppressed. Supply of the first heat medium that has been overheated to the path 21 is suppressed, and temperature fluctuations in the fuel cell 1 can be suppressed.
  • the first heat medium is rapidly heated by the surplus electric power heater 2 and, in some cases, is boiled, whereby dissolved oxygen in the first heat medium is vaporized, water vapor is generated, and the gas is Although generated, the generated gas is collected in the first heat medium tank 3. For this reason, it can suppress that the produced
  • the first heat medium circulates stably, the heat exchanger 4 can stably exchange heat, and the inside of the fuel cell 1 can be kept at an appropriate temperature.
  • the second pump 7 may be disposed at any location in the first heat medium path 51. Therefore, in the present embodiment, the second pump 7 is provided in the first heat medium path 51a downstream of the heat exchanger 4, but this is merely an example and is not limited to this example. Absent. However, it is more preferable that the second pump 7 is provided in the first heat medium path 51 downstream from the first heat medium tank 3 or the first heat medium path 51 upstream from the surplus power heater 2. This is for suppressing the gas generated by the rapid heating of the surplus power heater 2 from clogging the second pump 7 (so-called gas biting).
  • the second pump 7 is disposed at the first heat medium path 51 (first heat medium forward path 51a) downstream of the first heat medium tank 3 rather than the first heat medium path 51 upstream of the surplus power heater 2. ) Is more preferable. This is because the first heat medium may be heated while passing through the fuel cell 1 and the dissolved oxygen may vaporize, so the second pump 7 is disposed in the first heat medium path 51 upstream from the surplus power heater 2. If installed, there is a possibility of gas biting. On the other hand, when the second pump 7 is provided in the first heat medium path 51 (first heat medium forward path 51 a) downstream from the first heat medium tank 3, it is generated from the first heat medium while passing through the fuel cell 1. This is because the gas is collected in the first heat medium tank 3 so that the possibility of gas biting in the second pump 7 is suppressed.
  • FIG. 2 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention.
  • the fuel cell system 100 according to Embodiment 2 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 1, but the first heat medium path 51 The difference is that the first temperature detector 15 is provided in the first heat medium forward path 51a (downstream of the heat exchanger 4 in the first heat medium path 51).
  • the first temperature detector 15 is provided on the downstream side of the second pump 7 in the first heat medium forward path 51a.
  • the first temperature detector 15 is configured to detect the temperature of the first heat medium that flows through the first heat medium forward path 51 a and is supplied to the first heat medium flow path 21 of the fuel cell 1.
  • the detected temperature is output to the controller (first controller) 10.
  • the controller 10 is configured as an example of the first controller of the present invention.
  • the present invention is not limited to this, and the first controller is controlled separately from the controller 10 by a controller (computer). It may be configured.
  • the first temperature detector 15 is provided with the first heat medium. It is more preferable that the forward path 51a is provided at a position near the downstream end of the first heat medium forward path 51a.
  • Controller 10 controls first pump 6 based on the temperature detected by first temperature detector 15. Specifically, the amount of operation of the first pump 6 is adjusted so that the temperature detected by the first temperature detector 15 becomes a predetermined temperature (for example, 60 ° C.), and the second heat medium path 52. The flow rate of the second heat medium flowing therethrough is controlled.
  • a predetermined temperature for example, 60 ° C.
  • the controller 10 when the detected temperature of the first temperature detector 15 reaches 62 ° C., which is higher than a predetermined temperature, the controller 10 outputs a control signal for increasing the operation amount to the first pump 6.
  • the first pump 6 increases its operation amount to increase the flow rate of the second heat medium.
  • the controller 10 controls the first pump 6 to reduce the operation amount.
  • the flow rate of the second heat medium is decreased.
  • the amount of heat recovered from the second heat medium in the secondary flow path 23 in the heat exchanger 4 is reduced, and the temperature of the first heat medium can be raised.
  • a temperature detector 210 is provided between the heating element 206 and the heat exchanger 203 in the cooling water flow path 202 (downstream of the heating element 206 in the cooling water flow path 202). It is disclosed that the operation amount of the heat recovery water pump 209 is controlled based on the temperature detected by the temperature detector 210. Since the fuel cell cannot adjust the amount of power generation following the rapid fluctuation of the electric power load, the sudden fluctuation of surplus power occurs. For this reason, in the fuel cell system 200 disclosed in Patent Document 1, the temperature of the cooling water heated by the heating element 206 also varies abruptly due to a rapid variation in surplus power supplied to the heating element 206. If the operation amount is controlled by following the temperature fluctuation of the exhaust heat recovery water pump 209, the temperature of the cooling water flowing into the fuel cell 201 may not be stabilized.
  • the temperature detector 210 is provided between the heating element 206 and the heat exchanger 203 in the cooling water flow path 202, the fuel cell system 200 is supplied to the fuel cell 201. In order to detect the exact temperature of the cooling water, it is necessary to further provide a temperature detector, and the cost of the fuel cell system cannot be reduced.
  • the first heat medium tank 3 is provided on the downstream side of the surplus power heater 2, the first heat that has fluctuated in temperature due to sudden fluctuations in surplus power.
  • the medium is supplied into the first heat medium tank 3, and the temperature fluctuation is alleviated by the first heat medium stored in the first heat medium tank 3.
  • the heat exchanger 4 since the heat exchanger 4 is provided on the downstream side of the first heat medium tank 3, the temperature fluctuation of the first heat medium is further alleviated.
  • the first temperature detector 15 is provided on the downstream side of the heat exchanger 4 in the first heat medium path 51. For this reason, even if the surplus electric power fluctuates rapidly, the first heat medium flowing through the first heat medium forward path 51a is more relaxed by the first heat medium tank 3 and the heat exchanger 4, Control of the operation amount of the first pump 6 based on the temperature detected by the first temperature detector 15 can be stably performed. As a result, the temperature of the cooling water flowing into the first heat medium flow path 21 of the fuel cell 1 is more stable than before even if the surplus power suddenly varies.
  • the temperature detected by the first temperature detector 15 with a simple configuration. Therefore, by controlling the operation amount of the first pump 6, the heat exchange amount in the heat exchanger 4 can be adjusted, and the temperature of the first heat medium can be adjusted stably. Moreover, the temperature in the fuel cell 1 can be stably adjusted by adjusting the temperature of the first heat medium stably.
  • FIG. 3 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention.
  • the fuel cell system 100 according to Embodiment 3 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 2, but the first heat medium path 51 includes The difference is that the second temperature detector 16 is provided in the one heat medium forward path 51a.
  • the second temperature detector 16 is provided on the upstream side of the surplus power heater 2 in the first heat medium return path 51b.
  • the second temperature detector 16 is configured to detect the temperature of the first heat medium discharged from the first heat medium flow path 21 of the fuel cell 1, and the detected temperature is the controller (first 2 controller) 10.
  • the controller 10 is configured as an example of the second controller.
  • the present invention is not limited to this, and the second controller is configured by a controller (computer) that is independent from the controller 10. Also good.
  • the second temperature detector 16 is provided with the first heat medium return path. It is preferable to be provided at a position near the upstream end of 51b.
  • the controller 10 controls the operation amount of the second pump 7 based on the temperatures detected by the first and second temperature detectors 15 and 16. Specifically, the controller 10 detects that the temperature detected by the second temperature detector 16 is the temperature detected by the first temperature detector 15 (for example, 60 ° C.) and the boiling point of the first heat medium 100 ° C.
  • the operation amount of the second pump 7 (including the first pump 6 in this case) is controlled so as to be a predetermined temperature (for example, 70 ° C.) lower than the average of 80 ° C. In this case, when the temperature detected by the second temperature detector 16 rises above the predetermined temperature, the amount of heat generated by the fuel cell 1 is increased, so the amount of operation of the second pump 7 is increased and the first heat medium is increased. In order to reduce the amount of heat generated by the fuel cell 1 when the detected temperature of the second temperature detector 16 decreases and the detected temperature of the second temperature detector 16 decreases. The amount is decreased and the temperature detected by the second temperature detector 16 is increased.
  • the power generation usually generates a heat amount equivalent to a heat amount conversion value of the power generation amount (that is, the heat generation amount of the fuel cell ⁇ the heat amount conversion of the fuel cell power generation amount). Value), the temperature of the first heat medium rises due to this generated heat.
  • the temperature detected by the first temperature detector 15 is 60 ° C. while the surplus power is not generated during operation of the fuel cell system 100, and is detected by the second temperature detector 16.
  • the temperature is 70 ° C., it can be said that the temperature of the first heat medium has increased by 10 ° C. due to the heat generated in the fuel cell 1.
  • the surplus power heater is a resistance heating type heater, since the heat exchange efficiency is almost 100%, “the amount of heat generated by the surplus power heater ⁇ the amount of heat generated from the fuel cell power generation value”, and In the polymer electrolyte fuel cell, considering that “the amount of heat generated by the fuel cell ⁇ the value converted to the amount of power generated by the fuel cell”, “the amount of heat generated by the surplus power heater ⁇ the amount of heat generated by the fuel cell”.
  • the temperature increase of the first heat medium heated by the surplus power heater 2 is expected to further increase by about 10 ° C. compared to the case where the surplus power is zero.
  • the temperature of the first heat medium introduced into the first heat medium tank 3 is about 80 ° C., and the amount of power supplied to the surplus power heater 2 increases rapidly due to fluctuations in power consumption in the external power load 14.
  • the 1st heat carrier is heated until it boils.
  • the first exhaust discharged from the first heat medium flow path 21 of the fuel cell 1 is performed.
  • the temperature of one heat medium is the temperature of the first heat medium (detected by the first temperature detector 15) supplied to the first heat medium flow path 21 of the fuel cell 1.
  • the surplus power heater due to fluctuations in the external power load 14 by controlling the operation amount of the second pump 7 so that the predetermined temperature is lower than the average temperature of the boiling point of the first heat medium. Even if the energization amount of the first heat medium rapidly increases, the temperature of the first heat medium heated by the surplus power heater 2 becomes less than the boiling point, and the boiling of the first heat medium can be stably suppressed.
  • the temperature of the first heat medium is set to an appropriate temperature by suppressing the surplus power heater 2 from heating until the first heat medium boils. It can be kept more stable, and the inside of the fuel cell 1 can be kept at an appropriate temperature.
  • FIG. 4 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 4 of the present invention.
  • the basic configuration of the fuel cell system 100 according to Embodiment 4 of the present invention is the same as that of the fuel cell system 100 according to Embodiment 1, but the first configuration in the first heat medium path 51 is the same.
  • the portion 55 between the surplus power heater 2 and the first heat medium tank 3 in the first heat medium return path 51b is configured such that the direction of the vertical flow of the first heat medium is vertically upward. Different. Specifically, the flow of the first heat medium in the pipe constituting the portion 55 is configured to face upward in the vertical direction.
  • the generated gas is Due to the buoyancy, the portion 55 flows together with the first heat medium without staying in the portion 55 and flows into the first heat medium tank 3. Since the gas flowing into the first heat medium tank 3 is collected in the gap 3a of the first heat medium tank 3, it flows out to the downstream side of the first heat medium tank in the first heat medium return path 51b. There is no. For this reason, the gas generated by the heating of the surplus power heater 2 is more reliably collected in the first heat medium tank 3 without staying in the first heat medium path 51 up to the first heat medium tank 3.
  • the first heat medium flowing through the first heat medium path 51 can be used.
  • the flow rate can be made more stable. Further, since the flow rate of the first heat medium is stabilized, heat exchange with the second heat medium in the heat exchanger 4 is further stabilized, and the temperature of the first heat medium supplied to the fuel cell 1 is further stabilized. Therefore, the temperature in the fuel cell 1 is further stabilized.
  • the portion 55 of the first heat medium return path 51b is configured to flow upward in the vertical direction in the flow of the first heat medium.
  • the portion 55 is horizontal or It does not matter if it is uphill.
  • the “uphill gradient” means that the vertical component of the flow of the first heat medium is not vertically downward in the portion 55.
  • the portion 55 is slanted.
  • the horizontal portion and the vertically upward portion may be mixed, or the horizontal portion and the inclined portion may be mixed.
  • control of the first pump 6 or the second pump 7 as in the fuel cell system in the second or third embodiment is performed on the fuel cell system in the present embodiment. You may comprise so that it may implement.
  • FIG. 5 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention.
  • the fuel cell system 100 according to the fifth embodiment of the present invention has the same basic configuration as the fuel cell system 100 according to the first embodiment, but the surplus power heater 2 is the first heat. The difference is that it is provided inside the medium tank 3 and that the first heat medium tank 3 is provided with a pressure releaser comprising a pressure detector 17, a communication flow path 18, and an on-off valve 19.
  • the surplus power heater 2 is provided inside the first heat medium tank 3 and is configured to heat the first heat medium in the first heat medium tank 3. Further, a water level detector (not shown) is provided inside the first heat medium tank 3, and the detected water level is output to the controller 10. Based on the water level detected by the water level detector, the controller 10 uses the appropriate means (for example, a water replenisher for replenishing the first heat medium to the first heat medium tank 3) to make the surplus power heater 2 the first.
  • the water level of the first heat medium is adjusted so that it is always located below the liquid level of the one heat medium.
  • the surplus power heater 2 when surplus power that is not consumed by the external power load 14 among the power generated by the fuel cell 1 is energized to the surplus power heater 2, the first heat medium in the first heat medium tank 3 is directly heated. Therefore, compared with the configuration in which the surplus power heater 2 is provided in the first heat medium forward path 51a of the first heat medium path 51, there is less heat loss (that is, there is no heat loss in the portion 55 of the third embodiment), and the efficiency is high.
  • the surplus power can be used as thermal energy, and the energy saving property of the fuel cell system 100 can be further improved.
  • the generated gas remains in the gap portion. Since it is collected by 3a, it does not flow out to the first heat medium path 51. For this reason, the flow rate of the first heat medium flowing through the first heat medium path 51 can be made more stable, and the second flow rate in the heat exchanger 4 can be increased by stabilizing the flow rate of the first heat medium. Heat exchange with the heat medium can be performed more stably. And since the temperature of the 1st heat medium supplied to the fuel cell 1 becomes more stable because the heat exchange in the heat exchanger 4 becomes more stable, the temperature in the fuel cell 1 also becomes more stable.
  • a communication flow path 18 is provided in the upper part of the first heat medium tank 3 so as to communicate the air gap 3 a inside the first heat medium tank 3 with the outside air.
  • a valve 19 is provided.
  • a pressure detector 17 is provided on the upper portion of the first heat medium tank 3. The pressure detector 17 is configured to detect the pressure of the gap 3 a of the first heat medium tank 3 and output the detected pressure of the gap 3 a to the controller 10.
  • the controller 10 adjusts the opening / closing of the on-off valve 19 based on the pressure detected by the pressure detector 17. Specifically, the controller 10 opens the valve of the on-off valve 19 when the pressure in the gap 3a becomes lower than a predetermined pressure Pc (for example, the design pressure of the piping that configures the first heat medium path 51).
  • a predetermined pressure Pc for example, the design pressure of the piping that configures the first heat medium path 51.
  • the pressure of the gap 3a is controlled to be lower than the predetermined pressure Pc, and the valve of the on-off valve 19 is controlled to be closed when the pressure of the gap 3a is lower than the predetermined pressure Pc.
  • the pressure release device including the communication flow path 18 and the on-off valve 19 is provided in the first heat medium tank 3, but the present invention is not limited to this, and the communication flow path 18 is simply provided to provide the first heat medium tank 3.
  • the heat medium tank 3 may be open to the atmosphere.
  • the first heating medium is rapidly heated by the surplus power heater 2, and in some cases, gas such as water vapor generated by boiling is collected in the gap 3a, thereby increasing the pressure in the gap 3a.
  • the gap 3a communicates with the outside air, and the pressure of the gap 3a can be made smaller than the predetermined pressure Pc, and the pressure in the first heat medium tank 3 can be reduced.
  • An increase (pressure fluctuation) can be suppressed.
  • the flow rate of the first heat medium flowing through the first heat medium path 51 can be made more stable, By stabilizing the flow rate, heat exchange with the second heat medium in the heat exchanger 4 can be performed more stably. And since the temperature of the 1st heat medium supplied to the fuel cell 1 becomes more stable because the heat exchange in the heat exchanger 4 becomes more stable, the temperature in the fuel cell 1 also becomes more stable.
  • the surplus power heater 2 is directly connected to the first heat medium tank 3 in the first heat medium tank 3. Compared with the configuration in which the surplus power heater 2 is provided in the first heat medium forward path 51a of the first heat medium path 51 in order to heat the heat medium, the heat dissipation loss can be suppressed, and the energy saving performance of the fuel cell system 100 is further improved. be able to.
  • control of the first pump 6 or the second pump 7 as in the fuel cell system in the second embodiment or the third embodiment with respect to the fuel cell system in the present embodiment You may comprise so that it may implement.
  • FIG. 6 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 6 of the present invention.
  • the basic configuration of the fuel cell system 100 according to Embodiment 6 of the present invention is the same as that of the fuel cell system 100 according to Embodiment 5, but the surplus power heater 2 is disposed on the outer surface of the first heat medium tank 3.
  • the first heat medium tank 3 is provided on the bottom outer surface (lower surface) of the first heat medium tank 3 through the bottom of the first heat medium tank 3.
  • the first heat medium is configured to be heated.
  • the surplus power heater 2 is configured to be covered with a heat insulating material.
  • surplus power that is not consumed by the external power load 14 among the power generated by the fuel cell 1 as in the fifth embodiment.
  • the surplus power heater 2 when the surplus power heater 2 is energized, the first heat medium in the first heat medium tank 3 is heated via the bottom of the first heat medium tank 3, so that the surplus power heater 2 is The heat loss is less than the configuration provided in the first heat medium forward path 51a of the medium path 51 (that is, there is no heat loss in the portion 55 of the third embodiment), and the surplus power can be efficiently used as heat energy.
  • the energy saving property of the fuel cell system 100 can be further improved.
  • the surplus power heater 2 is provided on the outer surface of the first heat medium tank 3, particularly on the bottom outer surface (lower surface). Therefore, the first heat in the first heat medium tank 3 is used. Regardless of the height of the medium, the first heat medium can be heated by the surplus power heater 2 from the position facing the first heat medium via the container of the first heat medium tank 3 in between. The heat energy from the power heater 2 can be efficiently transmitted to the first heat medium, and further energy efficiency of the fuel cell system 100 can be improved.
  • the hot water storage tank 5 is connected to the second heat medium path 52 and the hot water is supplied from the hot water storage tank 5 to the heat load.
  • the present invention is not limited to this. It is good also as a structure which supplies hot water directly from the 2 heat-medium path
  • the operation amount of the 1st pump 6 was adjusted based on the temperature detected by the 1st temperature detector 15, it is not limited to this,
  • a 2nd heat medium A temperature detector may be provided in the path 52 and the operation amount of the first pump 6 may be adjusted based on the temperature detected by the temperature detector.
  • water is used as the first heat medium
  • the present invention is not limited to this.
  • an antifreeze liquid may be used.
  • the fuel cell system of the present invention is useful for a fuel cell system that performs an operation of recovering surplus power generated during power generation as heat. It can also be applied to applications such as a cogeneration system that recovers heat generated with power generation using an engine or the like.

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Abstract

Provided is a fuel cell system including: a fuel cell (1); a first thermal medium channel (51) through which a first thermal medium flows for cooling the fuel cell (1); a second thermal medium channel (52) through which a second thermal which has collected heat from the first thermal medium flows; a heat exchanger (4) for heat exchange between the first thermal medium flowing in the first thermal medium channel (51) and the second thermal medium flowing in the second thermal medium channel (52); an excessive power heater (2) which heats the first thermal medium used for cooling the fuel cell (1) before flowing into the heat exchanger (4) so as to consume an excessive power of the fuel cell (1); and a first thermal medium tank (3) arranged on a first thermal medium channel (51) for accumulating the first thermal medium.  The first thermal medium tank (3) is configured so as to mix the first thermal medium heated by the excessive power heater (2) and the first thermal medium in the first thermal medium tank (3).

Description

燃料電池システムFuel cell system
　本発明は、燃料電池システムの構成に関する。 The present invention relates to a configuration of a fuel cell system.
　燃料電池システムは、外部から燃料電池に供給された燃料ガスと酸化剤ガスとの電気化学反応により発電を行い、反応により生じた熱を回収して湯水をして貯え、この湯水を外部への熱供給に有効利用するシステムである。このような燃料電池システムは、系統電源と系統連系されており、燃料電池等で発電した電力と系統電源からの電力が、外部電力負荷（例えば、家庭の使用電力負荷）に供給される。 The fuel cell system generates electricity by an electrochemical reaction between fuel gas and oxidant gas supplied to the fuel cell from outside, collects the heat generated by the reaction, stores it as hot water, and stores this hot water to the outside. This system is used effectively for heat supply. Such a fuel cell system is grid-connected to a grid power source, and the power generated by the fuel cell or the like and the power from the grid power source are supplied to an external power load (for example, household power load).
　ところで、燃料電池システムを構成する燃料電池は、外部電力負荷の負荷変動に対する出力変化（追随）速度が遅いため、コージェネレーションシステムから電力供給を受ける全機器の総消費電力が、コージェネレーションシステムから出力される出力電力を下回る場合、余剰電力が発生し、系統電源への電力の逆潮流が生じる。これを防止するために、余剰電力をヒータで熱に変換して有効利用する燃料電池システムが知られている（例えば、特許文献１参照）。 By the way, the fuel cells that make up the fuel cell system have a slow output change (following) speed due to load fluctuations of the external power load, so the total power consumption of all devices that receive power supply from the cogeneration system is output from the cogeneration system. If the output power is lower than the output power, surplus power is generated, and a reverse power flow to the system power supply occurs. In order to prevent this, a fuel cell system is known in which surplus power is converted into heat by a heater and used effectively (see, for example, Patent Document 1).
　図７は、特許文献１に開示されている燃料電池システムの概略構成を示す模式図である。図７に示すように、特許文献１に開示されている燃料電池システム２００は、燃料電池２０１、冷却水流路２０２、熱交換器２０３、貯湯槽２０４、温水流路２０５、及び発熱体２０６、２０７を備えている。 FIG. 7 is a schematic diagram showing a schematic configuration of the fuel cell system disclosed in Patent Document 1. As shown in FIG. As shown in FIG. 7, the fuel cell system 200 disclosed in Patent Document 1 includes a fuel cell 201, a cooling water channel 202, a heat exchanger 203, a hot water tank 204, a hot water channel 205, and heating elements 206 and 207. It has.
　燃料電池２０１には、冷却水流路２０２が接続されていて、貯湯槽２０４には、温水流路２０５が接続されている。そして、冷却水流路２０２を通流する冷却水と、温水流路２０５を通流する温水と、の間で熱交換を行えるように、熱交換器２０３は、冷却水流路２０２と温水流路２０５を跨ぐように設けられている。また、冷却水流路２０２には、冷却水ポンプ２０８が設けられていて、一方、温水流路２０５には、排熱回収水ポンプ２０９が設けられている。さらに、冷却水流路２０２及び温水流路２０５には、それぞれ、発熱体２０６、２０７が設けられている。 A cooling water channel 202 is connected to the fuel cell 201, and a hot water channel 205 is connected to the hot water tank 204. The heat exchanger 203 is configured so that the heat exchanger 203 can exchange heat between the cooling water flowing through the cooling water flow path 202 and the hot water flowing through the hot water flow path 205. It is provided so as to straddle. The cooling water channel 202 is provided with a cooling water pump 208, while the warm water channel 205 is provided with an exhaust heat recovery water pump 209. Furthermore, heating elements 206 and 207 are provided in the cooling water passage 202 and the hot water passage 205, respectively.
　このように構成された特許文献１に開示されている燃料電池システム２００では、余剰電力が発生した場合に、発生した余剰電力を発熱体２０６、２０７で消費して熱に変換することにより、系統電源への電力の逆潮流を防止することができる。 In the fuel cell system 200 disclosed in Patent Document 1 configured as described above, when surplus power is generated, the generated surplus power is consumed by the heating elements 206 and 207 and converted into heat. The reverse power flow to the power source can be prevented.
　また、従来の燃料電池システムでは、冷却水流路を通流する冷却水を貯える（冷却）水タンクを有していて、水タンクは、効率的な熱回収を図るために熱交換器の下流側に設けられているのが、一般的である（例えば、特許文献２参照）。 In addition, the conventional fuel cell system has a (cooling) water tank that stores cooling water flowing through the cooling water flow path, and the water tank is located downstream of the heat exchanger in order to efficiently recover heat. Is generally provided (for example, see Patent Document 2).
特開２００６－１２５６４号公報JP 2006-12564 A 特開２００４－２１３９８５号広報Japanese Laid-Open Patent Publication No. 2004-213985
　ところで、一般家庭では、設置されている複数の電化製品が様々なタイミングで使用されるため、電力消費量が大きく変動する。このため、電力負荷が急激に減少した場合に、余剰電力が急激に増加する場合がある。このような場合に、上記特許文献１に開示されている燃料電池システム２００の構成では、余剰電力の急激な増加によって、発熱体２０６で冷却水が急激に加熱され、場合によっては、冷却水が沸騰する可能性がある。 By the way, in a general household, power consumption varies greatly because a plurality of installed appliances are used at various timings. For this reason, when electric power load reduces rapidly, surplus electric power may increase rapidly. In such a case, in the configuration of the fuel cell system 200 disclosed in Patent Document 1, the cooling water is rapidly heated by the heating element 206 due to a sudden increase in surplus power. There is a possibility of boiling.
　冷却水の急激な加熱により、冷却水中の溶存酸素等が気化したガスや、冷却水の沸騰によって生成された水蒸気等のガスが、冷却水流路２０２（例えば、熱交換器２０３）に溜まり、安定した冷却水の循環が維持できなくなる可能性がある。 Gases such as dissolved oxygen in the cooling water vaporized due to rapid heating of the cooling water and water vapor generated by boiling of the cooling water accumulate in the cooling water flow path 202 (for example, the heat exchanger 203) and are stable. It may become impossible to maintain the circulation of the cooling water.
　そして、安定した冷却水の循環が維持されなくなると、熱交換器２０３での安定した熱交換ができなくなり、燃料電池２０１の温度が上昇して、燃料電池２０１内を適正な温度に保つことができなくなるという問題があった。 If stable cooling water circulation is not maintained, stable heat exchange in the heat exchanger 203 cannot be performed, the temperature of the fuel cell 201 rises, and the inside of the fuel cell 201 can be maintained at an appropriate temperature. There was a problem that it was impossible.
　また、冷却水が急激に加熱され、場合によっては、沸騰すると、温水流路２０５を通流する温水が、熱交換器２０３で急激に加熱された冷却水、場合によっては、沸騰した冷却水と熱交換することで、通常よりも過剰に加熱され、過昇温した温水が、貯湯槽２０４に供給されるおそれがあった。過昇温した温水が貯湯槽に貯えられると、貯湯槽２０４内の温水が外部に供給される場合、市水と混合して温度低下を図っても使用者の所望する最適な温度にまで温度が低下せず、高温の温水が供給されて、使用者が火傷する可能性がある。 In addition, when the cooling water is heated suddenly and, in some cases, boiled, the hot water flowing through the hot water flow path 205 is changed into the cooling water rapidly heated by the heat exchanger 203, and in some cases, the boiling cooling water and By exchanging heat, the hot water heated excessively than usual and overheated may be supplied to the hot water tank 204. When the hot water that has been overheated is stored in the hot water storage tank, when the hot water in the hot water storage tank 204 is supplied to the outside, the temperature is reduced to the optimum temperature desired by the user even if the temperature is lowered by mixing with city water. Does not decrease, hot hot water is supplied, and the user may be burned.
　本発明は、上記従来技術の課題を鑑みてなされたものであり、燃料電池を冷却する上記冷却水等に例示される熱媒体が、余剰電力の急激な変動により、余剰電力ヒータで冷却水が急激に加熱され、過昇温したり、場合によっては、沸騰したりすることで、上述のように冷却水よりガスが生成しても、熱交換器での熱交換を従来よりも安定して行える燃料電池システムを提供することを第１の目的とする。また、本発明は、急激に加熱された熱媒体、場合によっては、沸騰した熱媒体が熱交換器に供給されるのを抑制することにより、上記温水に例示される第２熱媒体が、過昇温した状態で、上記貯湯タンクに例示される蓄熱器に供給されるのを抑制し、安全に運転することができる燃料電池システムを提供することを第２の目的とする。 The present invention has been made in view of the above-described problems of the prior art, and the heat medium exemplified by the cooling water or the like for cooling the fuel cell has a surplus power heater that causes the cooling water to flow from the surplus power heater due to a sudden fluctuation in surplus power. Even if gas is generated from the cooling water as described above, the heat exchange in the heat exchanger is more stable than before due to rapid heating, excessive temperature rise, and in some cases boiling. A first object is to provide a fuel cell system that can be used. In addition, the present invention provides a second heat medium exemplified by the warm water by suppressing the supply of the heat medium that has been heated rapidly, and in some cases, the boiled heat medium to the heat exchanger. A second object of the present invention is to provide a fuel cell system that can be operated safely while suppressing the supply to a heat accumulator exemplified by the hot water storage tank while the temperature is raised.
　以上のような課題を解決するために、本発明に係る燃料電池システムは、燃料電池と、前記燃料電池を冷却する第１熱媒体が通流する第１熱媒体経路と、第２熱媒体が通流する第２熱媒体経路と、前記第１熱媒体経路と前記第２熱媒体経路とに跨がって設けられ、前記第１熱媒体経路を通流する前記第１熱媒体と、前記第２熱媒体経路を通流する前記第２熱媒体との間で熱交換するための熱交換器と、前記燃料電池を冷却した前記第１熱媒体を前記熱交換器に流入するまでに加熱し、前記燃料電池の余剰電力を消費する余剰電力ヒータと、前記第１熱媒体経路に設けられ、前記第１熱媒体を貯えるタンクと、を備え、前記タンクは前記余剰電力ヒータで加熱された前記第１熱媒体と前記タンク内の前記第１熱媒体とが混合するように構成されている。 In order to solve the above problems, a fuel cell system according to the present invention includes a fuel cell, a first heat medium path through which a first heat medium that cools the fuel cell flows, and a second heat medium. A second heat medium path that flows, the first heat medium that is provided across the first heat medium path and the second heat medium path, and flows through the first heat medium path; A heat exchanger for exchanging heat with the second heat medium flowing through the second heat medium path, and heating the first heat medium that has cooled the fuel cell before flowing into the heat exchanger And a surplus power heater that consumes surplus power of the fuel cell, and a tank that is provided in the first heat medium path and stores the first heat medium, wherein the tank is heated by the surplus power heater. The first heat medium and the first heat medium in the tank are mixed. To have.
　これにより、余剰電力の急激な増加により、余剰電力ヒータで加熱された第１熱媒体が過昇温したり、場合によっては、沸騰したりすることで、冷却水中の溶存酸素が気化したり、水蒸気化によりガスが生成しても、第１熱媒体経路内のガス滞留により第１熱媒体の流量が不安定になる可能性が抑制され、熱交換器において第２の熱媒体との安定した熱交換が行われる。また、急激に加熱された第１熱媒体が、また、場合によっては、沸騰した第１熱媒体がタンク内の第１熱媒体と混合することにより、タンク内で温度が平準化された第１熱媒体が熱交換器に供給されるため、熱交換器を通過した第２熱媒体の温度が過昇温する可能性を低減することができる。 Thereby, due to a sudden increase in surplus power, the first heat medium heated by the surplus power heater is excessively heated, or in some cases, boiling, so that dissolved oxygen in the cooling water is vaporized, Even if gas is generated by steaming, the possibility that the flow rate of the first heat medium becomes unstable due to gas retention in the first heat medium path is suppressed, and the heat exchanger is stable with the second heat medium. Heat exchange takes place. Further, the first heat medium that has been heated rapidly, and in some cases, the first heat medium that has boiled is mixed with the first heat medium in the tank, whereby the temperature is leveled in the tank. Since the heat medium is supplied to the heat exchanger, it is possible to reduce the possibility that the temperature of the second heat medium that has passed through the heat exchanger is excessively increased.
　また、本発明に係る燃料電池システムでは、前記余剰電力ヒータは前記第１熱媒体経路に設けられ、該余剰電力ヒータで加熱された第１熱媒体が前記タンク内に流入するように構成されていてもよい。 In the fuel cell system according to the present invention, the surplus power heater is provided in the first heat medium path, and the first heat medium heated by the surplus power heater flows into the tank. May be.
　また、本発明に係る燃料電池システムでは、前記タンク内に前記余剰電力ヒータが設けられていてもよい。 In the fuel cell system according to the present invention, the surplus power heater may be provided in the tank.
　また、本発明に係る燃料電池システムでは、前記タンクは大気開放されていてもよい。 In the fuel cell system according to the present invention, the tank may be open to the atmosphere.
　また、本発明に係る燃料電池システムでは、前記タンクには圧抜き器が設けられていてもよい。 In the fuel cell system according to the present invention, the tank may be provided with a depressurizer.
　また、本発明に係る燃料電池システムでは、前記第１熱媒体経路の前記余剰電力ヒータと前記タンクとの間の部分は、水平又は前記第１熱媒体の流れにおいて上り勾配になるように構成されていてもよい。 In the fuel cell system according to the present invention, a portion of the first heat medium path between the surplus power heater and the tank is configured to be horizontal or ascending in the flow of the first heat medium. It may be.
　また、本発明に係る燃料電池システムでは、前記第１熱媒体経路の前記熱交換器よりも下流側に設けられた第１温度検出器と、前記第２熱媒体流路を通流する前記第２熱媒体の流量を調整する第１流量調整器と、前記第１温度検出器の検出温度に基づき前記第１流量調整器を制御する第１制御器と、を備えていてもよい。 In the fuel cell system according to the present invention, the first temperature detector provided on the downstream side of the heat exchanger in the first heat medium path and the first heat detector flow through the second heat medium flow path. A first flow rate regulator that adjusts the flow rate of the two heat mediums and a first controller that controls the first flow rate regulator based on the temperature detected by the first temperature detector may be provided.
　さらに、本発明に係る燃料電池システムでは、前記第１熱媒体経路の前記熱交換器よりも下流側に設けられた第１温度検出器と、前記燃料電池を冷却した後、前記余剰電力ヒータで加熱される前の前記第１熱媒体の温度を検出する第２温度検出器と、前記第１熱媒体経路を通流する前記第１熱媒体の流量を調整する第２流量調整器と、前記第２温度検出器の検出温度が前記第１温度検出器の検出温度と前記１熱媒体の沸点との平均温度よりも低くなるように前記第２流量調整器を制御する第２制御器と、を備えていてもよい。 Furthermore, in the fuel cell system according to the present invention, the first temperature detector provided on the downstream side of the heat exchanger in the first heat medium path, and after cooling the fuel cell, the surplus power heater A second temperature detector for detecting a temperature of the first heat medium before being heated, a second flow rate regulator for adjusting a flow rate of the first heat medium flowing through the first heat medium path, and A second controller for controlling the second flow rate regulator such that a detected temperature of the second temperature detector is lower than an average temperature of the detected temperature of the first temperature detector and the boiling point of the first heat medium; May be provided.
　本発明の上記目的、他の目的、特徴、及び利点は、添付図面参照の下、以下の好適な実施態様の詳細な説明から明らかにされる。 The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.
　本発明の燃料電池システムによれば、余剰電力の急激な変動により、余剰電力ヒータで急激に加熱された第１熱媒体、又は場合によっては第１熱媒体が沸騰したような場合でも、沸騰により生成された水蒸気等のガスをタンク内で捕集することにより第１熱媒体経路内のガス滞留が抑制され、熱交換器での熱交換を安定して行える。また、タンク内の第１熱媒体と混合されることで、熱交換器に供給される第１熱媒体の温度上昇が抑制され、熱交換器通過後の第２熱媒体が過昇温する可能性が低減される。 According to the fuel cell system of the present invention, even if the first heat medium heated suddenly by the surplus electric power heater or, in some cases, the first heat medium boils due to a rapid fluctuation of the surplus power, By collecting the generated gas such as water vapor in the tank, gas retention in the first heat medium path is suppressed, and heat exchange in the heat exchanger can be stably performed. Moreover, by mixing with the 1st heat medium in a tank, the temperature rise of the 1st heat medium supplied to a heat exchanger is suppressed, and the 2nd heat medium after passing a heat exchanger can overheat. Is reduced.
図１は、本発明の実施の形態１に係る燃料電池システムの概略構成を示した模式図である。FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention. 図２は、本発明の実施の形態２に係る燃料電池システムの概略構成を示した模式図である。FIG. 2 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention. 図３は、本発明の実施の形態３に係る燃料電池システムの概略構成を示した模式図である。FIG. 3 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention. 図４は、本発明の実施の形態４に係る燃料電池システムの概略構成を示した模式図である。FIG. 4 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 4 of the present invention. 図５は、本発明の実施の形態５に係る燃料電池システムの概略構成を示した模式図である。FIG. 5 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention. 図６は、本発明の実施の形態６に係る燃料電池システムの概略構成を示した模式図である。FIG. 6 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 6 of the present invention. 図７は、特許文献１に開示されている燃料電池システムの概略構成を示す模式図である。FIG. 7 is a schematic diagram showing a schematic configuration of the fuel cell system disclosed in Patent Document 1. As shown in FIG.
　以下、本発明の好ましい実施の形態を、図面を参照しながら説明する。なお、全ての図面において、同一または相当部分には同一符号を付し、重複する説明は省略する。 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.
　（実施の形態１）
　図１は、本発明の実施の形態１に係る燃料電池システムの概略構成を示した模式図である。 (Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 1 of the present invention.
　[燃料電池システムの構成]
　図１に示すように、本発明の実施の形態１に係る燃料電池システム１００は、燃料電池１、余剰電力ヒータ２、第１熱媒体タンク３、熱交換器４、及び制御器１０を備えている。 [Configuration of fuel cell system]
As shown in FIG. 1, a fuel cell system 100 according to Embodiment 1 of the present invention includes a fuel cell 1, a surplus power heater 2, a first heat medium tank 3, a heat exchanger 4, and a controller 10. Yes.
　燃料電池１には、燃料ガス供給装置（図示せず）と酸化剤ガス供給装置（図示せず）が接続されており、これらの供給装置から供給される燃料ガスと酸化剤ガス（これらを反応ガスという）を電気化学反応させることにより、電力と熱を発生する。 A fuel gas supply device (not shown) and an oxidant gas supply device (not shown) are connected to the fuel cell 1, and a fuel gas and an oxidant gas (reacted by these) supplied from these supply devices. Electricity and heat are generated by electrochemical reaction of gas).
　また、燃料電池１には、電気化学反応により発生した排熱を回収するために第１熱媒体が流れる第１熱媒体流路２１が設けられている。 Further, the fuel cell 1 is provided with a first heat medium flow path 21 through which the first heat medium flows in order to recover exhaust heat generated by the electrochemical reaction.
　燃料電池１内の第１熱媒体流路２１の入口には、第１熱媒体往路５１ａの下流端が接続されており、第１熱媒体往路５１ａの上流端は、熱交換器４の一次流路２２の出口に接続されている。また、熱交換器４の一次流路２２の入口には、第１熱媒体復路５１ｂの下流端が接続されており、第１熱媒体復路５１ｂの上流端は、燃料電池１内の第１熱媒体流路２１の出口に接続されている。上記のような構成により、第１熱媒体経路５１は、第１熱媒体往路５１ａ、第１熱媒体復路５１ｂ、第１熱媒体流路２１、及び一次流路２２により構成される。 The downstream end of the first heat medium forward path 51 a is connected to the inlet of the first heat medium flow path 21 in the fuel cell 1, and the upstream end of the first heat medium forward path 51 a is the primary flow of the heat exchanger 4. Connected to the exit of the path 22. The inlet of the primary flow path 22 of the heat exchanger 4 is connected to the downstream end of the first heat medium return path 51b, and the upstream end of the first heat medium return path 51b is connected to the first heat medium in the fuel cell 1. The outlet of the medium channel 21 is connected. With the above configuration, the first heat medium path 51 includes the first heat medium forward path 51a, the first heat medium return path 51b, the first heat medium flow path 21, and the primary flow path 22.
　また、第１熱媒体往路５１ａの途中には、流量調整が可能な第２ポンプ（第２流量調整器）７が設けられていて、第１熱媒体復路５１ｂの途中には、余剰電力ヒータ２と、第１熱媒体（ここでは、冷却水）を貯えるための第１熱媒体タンク３と、がこの順で設けられている。余剰電力ヒータ２は、燃料電池１で発電した電力のうち余剰の電力が通電され、第１熱媒体往路５１ａを通流する第１熱媒体を加熱するように構成されている。なお、本発明の第２流量調整器として、ここでは、流量調節が可能なポンプを用いているが、これに限定されず、ポンプと流量調節弁等の流量調節器を用いてもよい。 A second pump (second flow regulator) 7 capable of adjusting the flow rate is provided in the middle of the first heat medium forward path 51a, and the surplus power heater 2 is disposed in the middle of the first heat medium return path 51b. And a first heat medium tank 3 for storing a first heat medium (here, cooling water) are provided in this order. The surplus power heater 2 is configured such that surplus power out of the power generated by the fuel cell 1 is energized and heats the first heat medium flowing through the first heat medium forward path 51a. In addition, as the 2nd flow regulator of this invention, although the pump which can adjust flow volume is used here, it is not limited to this, You may use flow regulators, such as a pump and a flow control valve.
　また、熱交換器４の二次流路２３には、第２熱媒体往路５２ａと第２熱媒体復路５２ｂとが接続されていて、これらの第２熱媒体往路５２ａ、第２熱媒体復路５２ｂ及び二次流路２３より構成される第２熱媒体経路５２は、蓄熱器としての貯湯タンク５と接続されている。具体的には、熱交換器４の二次流路２３の入口には、第２熱媒体復路５２ｂの下流端が接続されており、その上流端は、貯湯タンク５の下端部に接続されている。貯湯タンク５の上端部には、第２熱媒体往路５２ａの下流端が接続されており、その上流端は、熱交換器４の二次流路２３の出口に接続されている。また、第２熱媒体復路５２ｂの途中には、流量調節可能な第１ポンプ（第１流量調整器）６が設けられている。なお、本発明の第１流量調整器として、ここでは、流量調節が可能なポンプを用いているが、これに限定されず、ポンプと流量調節弁等の流量調節器を用いてもよい。 The second heat medium forward path 52a and the second heat medium return path 52b are connected to the secondary flow path 23 of the heat exchanger 4, and the second heat medium forward path 52a and the second heat medium return path 52b are connected. And the 2nd heat-medium path | route 52 comprised from the secondary flow path 23 is connected with the hot water storage tank 5 as a heat storage device. Specifically, the downstream end of the second heat medium return path 52 b is connected to the inlet of the secondary flow path 23 of the heat exchanger 4, and the upstream end is connected to the lower end of the hot water storage tank 5. Yes. The upper end of the hot water storage tank 5 is connected to the downstream end of the second heat medium forward path 52 a, and the upstream end is connected to the outlet of the secondary flow path 23 of the heat exchanger 4. Further, a first pump (first flow rate regulator) 6 capable of adjusting the flow rate is provided in the middle of the second heat medium return path 52b. In addition, although the pump which can adjust flow volume is used here as a 1st flow regulator of this invention, it is not limited to this, You may use flow regulators, such as a pump and a flow control valve.
　貯湯タンク５は、ここでは、鉛直方向に延びるように形成されていて、貯湯タンク５の下端部には、市水を供給するための水供給路５３が接続されており、貯湯タンク５の上部には、貯湯水を利用者に供給するための貯湯水供給路５４が接続されている。また、貯湯水供給路５４には、貯湯水を利用する熱負荷が接続されている（図示せず）。熱負荷としては、例えば、給湯機器、暖房機器や空調機器が挙げられる。 Here, the hot water storage tank 5 is formed so as to extend in the vertical direction, and a water supply path 53 for supplying city water is connected to the lower end of the hot water storage tank 5. Is connected to a hot water supply passage 54 for supplying hot water to the user. The hot water supply channel 54 is connected to a heat load that uses the hot water (not shown). Examples of the thermal load include hot water supply equipment, heating equipment, and air conditioning equipment.
　これにより、燃料電池１の排熱を回収した第１熱媒体は、第１熱媒体経路５１の第１熱媒体復路５１ｂを通流して、熱交換器４内の一次流路２２に供給される。一次流路２２に供給された第１熱媒体は、熱交換器４の一次流路２２を通流する間に、貯湯タンク５の下端部から熱交換器４内の二次流路２３に供給された第２熱媒体と熱交換して、冷却される。冷却された第１熱媒体は、第１熱媒体往路５１ａを通流して、燃料電池１の第１熱媒体流路２１の入口に供給される。一方、貯湯タンク５の下端部から熱交換器４の二次流路２３に供給された第２熱媒体（ここでは、貯湯水）は、熱交換器４の二次流路２３を通流する間に、一次流路２２を通流する第１熱媒体によって加熱される。加熱された第２熱媒体は、第２熱媒体復路５２ｂを通流して、貯湯タンク５の上端部に供給される。このような構成により、貯湯タンク５は、下部には市水温度に近い温度の低い水が貯えられ、熱交換器４により高温化した第２熱媒体が上部より貯えられる、いわゆる積層沸き上げ型の貯湯タンクとなる。 As a result, the first heat medium recovered from the exhaust heat of the fuel cell 1 flows through the first heat medium return path 51b of the first heat medium path 51 and is supplied to the primary flow path 22 in the heat exchanger 4. . The first heat medium supplied to the primary flow path 22 is supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 in the heat exchanger 4 while flowing through the primary flow path 22 of the heat exchanger 4. The second heat medium is subjected to heat exchange and cooled. The cooled first heat medium flows through the first heat medium forward path 51 a and is supplied to the inlet of the first heat medium flow path 21 of the fuel cell 1. On the other hand, the second heat medium (here, hot water) supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 of the heat exchanger 4 flows through the secondary flow path 23 of the heat exchanger 4. In the meantime, it is heated by the first heat medium flowing through the primary flow path 22. The heated second heat medium flows through the second heat medium return path 52 b and is supplied to the upper end portion of the hot water storage tank 5. With such a configuration, the hot water storage tank 5 stores water having a low temperature close to the city water temperature in the lower part, and stores a second heat medium heated by the heat exchanger 4 from the upper part. It becomes a hot water storage tank.
　なお、燃料電池１の排熱を回収した第１熱媒体は、第１熱媒体経路５１の第１熱媒体復路５１ｂを通流する間に、余剰電力が発生すると、余剰電力ヒータ２によりさらに加熱される。また、上記の第１熱媒体及び第２熱媒体の流動方向（図１に矢印で示す方向）は、発電時における流動方向であり、燃料電池１の暖機運転時には、第２熱媒体の流動方向は、これと逆方向になる。 The first heat medium recovered from the exhaust heat of the fuel cell 1 is further heated by the surplus power heater 2 if surplus power is generated while flowing through the first heat medium return path 51b of the first heat medium path 51. Is done. In addition, the flow direction of the first heat medium and the second heat medium (the direction indicated by the arrow in FIG. 1) is the flow direction during power generation, and the flow of the second heat medium during the warm-up operation of the fuel cell 1. The direction is the opposite direction.
　また、燃料電池１の出力端子（図示せず）には、適宜な配線により、ＤＣ／ＤＣコンバータ８の入力端子（図示せず）が接続されている。ＤＣ／ＤＣコンバータ８は、燃料電池１で発生した直流電力を所定の電圧に昇圧するように構成されている。また、ＤＣ／ＤＣコンバータ８の出力端子には、適宜な配線により、インバータ９の入力端子（図示せず）が接続されている。インバータ９は、ＤＣ／ＤＣコンバータ８で昇圧された直流電力を交流電力に変換するように構成されている。 Further, an input terminal (not shown) of the DC / DC converter 8 is connected to an output terminal (not shown) of the fuel cell 1 by appropriate wiring. The DC / DC converter 8 is configured to boost DC power generated in the fuel cell 1 to a predetermined voltage. Further, an input terminal (not shown) of the inverter 9 is connected to an output terminal of the DC / DC converter 8 by an appropriate wiring. The inverter 9 is configured to convert the DC power boosted by the DC / DC converter 8 into AC power.
　インバータ９の出力端子（図示せず）には、適宜な配線により余剰電力ヒータ２が接続されている。また、インバータ９の出力端子には、系統連系点１１を介して、系統電源１２が接続されている。すなわち、燃料電池１の出力電力と系統電源１２からの電力が、系統連系点１１で系統連系されている。なお、ここでは、余剰電力ヒータ２をインバータ９の出力端子に接続したが、これに限定されず、ＤＣ／ＤＣコンバータ８の出力端子に接続してもよい。 The surplus power heater 2 is connected to an output terminal (not shown) of the inverter 9 by appropriate wiring. A system power supply 12 is connected to the output terminal of the inverter 9 through a system interconnection point 11. That is, the output power of the fuel cell 1 and the power from the system power supply 12 are grid-connected at the grid connection point 11. Although the surplus power heater 2 is connected to the output terminal of the inverter 9 here, the invention is not limited to this, and it may be connected to the output terminal of the DC / DC converter 8.
　系統連系点１１には、適宜な配線により、外部電力負荷１４が接続されている。外部電力負荷１４は、ここでは、一般家庭で使用される電力消費機器を想定している。さらに、系統連系点１１とインバータ９との間には、電流検出器１３が設けられている。 The external power load 14 is connected to the grid connection point 11 by appropriate wiring. Here, the external power load 14 is assumed to be a power consuming device used in a general household. Furthermore, a current detector 13 is provided between the grid connection point 11 and the inverter 9.
　電流検出器１３は、系統電源１２から供給される電流量を検出し、検出した電流値は、制御器１０に出力される。電流検出器１３は、ここでは、カレントトランス等の電流センサで構成されており、電流の大きさを電力の大きさとして検出し、また、電流の向きを検出することで、逆潮流が発生しているかを検出している。なお、電流検出器１３として、例えば、シャント抵抗を用いた電流センサ、カレントトランスを系統電線にクランプし、１次電流に比例した２次巻き線電流から電流検知するクランプ式交流電流センサ、交流電流を直接計測する交流電流計等を使用してもよい。 The current detector 13 detects the amount of current supplied from the system power supply 12, and the detected current value is output to the controller 10. Here, the current detector 13 is composed of a current sensor such as a current transformer. The current detector 13 detects the magnitude of the current as the magnitude of the electric power, and detects the direction of the current, thereby generating a reverse power flow. Is detected. In addition, as the current detector 13, for example, a current sensor using a shunt resistor, a clamp type AC current sensor that clamps a current transformer on a system wire, and detects current from a secondary winding current proportional to the primary current, AC current An AC ammeter or the like that directly measures can be used.
　これにより、ＤＣ／ＤＣコンバータ８で昇圧された直流電力が、インバータ９で交流電力に変換され、系統電源１２と系統連系しながら、外部電力負荷１４に電力が供給される。そして、系統電源１２から供給される電力を電流検出器１３が検出し、検出した電力が制御器１０に出力される。 Thus, the DC power boosted by the DC / DC converter 8 is converted to AC power by the inverter 9 and supplied to the external power load 14 while being connected to the system power supply 12. Then, the current detector 13 detects the power supplied from the system power supply 12, and the detected power is output to the controller 10.
　制御器１０は、マイコン等のコンピュータによって構成されており、ＣＰＵからなる演算処理部、半導体メモリから構成された記憶部（内部メモリ）、及びカレンダー機能を有する時計部（いずれも図示せず）を有している。演算処理部は、記憶部に格納された所定の制御プログラムを読み出し、これを実行することにより、燃料電池システムに関する各種の制御を行う。 The controller 10 is configured by a computer such as a microcomputer, and includes an arithmetic processing unit composed of a CPU, a storage unit (internal memory) composed of a semiconductor memory, and a clock unit (not shown) having a calendar function. Have. The arithmetic processing unit reads out a predetermined control program stored in the storage unit and executes it to perform various controls relating to the fuel cell system.
　また、演算処理部は、電流検出器１３にて検出された電流の向きに基づいて、逆潮流が生じているか否かを検出し、また、電流検出器１３にて検出された電流値に応じて、余剰電力ヒータ２への電力供給量を制御している。具体的には、制御器１０の演算処理部は、電流検出器１３で検出される電流が、系統電源１２へ流れないように、余剰電力ヒータ２への電力供給量を制御している。すなわち、燃料電池システム１００には、例えば、余剰電力ヒータ２への供給電圧を制御する電圧調整器（出力電圧を調整可能な電圧変換器：図示せず）が設けられていて、この電圧調整器の出力電圧を調整することにより、余剰電力ヒータ２の消費電力が調整される。制御器１０は、この電圧調整器の出力電圧を制御することにより、余剰電力ヒータ２への電力供給量を制御する。 Further, the arithmetic processing unit detects whether or not reverse power flow has occurred based on the direction of the current detected by the current detector 13, and according to the current value detected by the current detector 13. Thus, the power supply amount to the surplus power heater 2 is controlled. Specifically, the arithmetic processing unit of the controller 10 controls the amount of power supplied to the surplus power heater 2 so that the current detected by the current detector 13 does not flow to the system power supply 12. That is, the fuel cell system 100 is provided with, for example, a voltage regulator (a voltage converter capable of adjusting the output voltage: not shown) that controls the supply voltage to the surplus power heater 2, and this voltage regulator The power consumption of the surplus power heater 2 is adjusted by adjusting the output voltage. The controller 10 controls the amount of power supplied to the surplus power heater 2 by controlling the output voltage of the voltage regulator.
　ここで、本明細書において、制御器とは、単独の制御器だけでなく、複数の制御器が協働して、燃料電池システムの制御を実行する制御器群をも意味する。このため、制御器１０は、単独の制御器から構成される必要はなく、複数の制御器が分散配置され、それらが協働して燃料電池システム１００を制御するように構成されていてもよい。 Here, in this specification, the controller means not only a single controller but also a group of controllers that execute control of the fuel cell system in cooperation with a plurality of controllers. For this reason, the controller 10 does not need to be composed of a single controller, and a plurality of controllers may be arranged in a distributed manner so that they cooperate to control the fuel cell system 100. .
　[燃料電池システムの動作]
　次に、本実施の形態１に係る燃料電池システムの動作について、図１を参照しながら説明する。 [Operation of fuel cell system]
Next, the operation of the fuel cell system according to Embodiment 1 will be described with reference to FIG.
　まず、燃料電池１の図示されないアノード及びカソードに、燃料ガス供給装置及び酸化剤ガス供給装置から、それぞれ、燃料ガス及び酸化剤ガスが供給され、電気化学反応により、電力と熱が発生する。燃料電池１で発生した電力（直流電力）は、ＤＣ／ＤＣコンバータ８で昇圧され、昇圧された直流電力は、インバータ９に供給される。インバータ９では、供給された直流電力を交流電力に変換され、系統電源１２と系統連系しながら、外部電力負荷１４に電力が供給される。 First, a fuel gas and an oxidant gas are respectively supplied to an anode and a cathode (not shown) of the fuel cell 1 from a fuel gas supply device and an oxidant gas supply device, and electric power and heat are generated by an electrochemical reaction. The electric power (DC power) generated in the fuel cell 1 is boosted by the DC / DC converter 8, and the boosted DC power is supplied to the inverter 9. In the inverter 9, the supplied DC power is converted into AC power, and power is supplied to the external power load 14 while being connected to the system power supply 12.
　一方、燃料電池１で発生した熱（排熱）は、第１熱媒体流路２１に供給された第１熱媒体により回収される。燃料電池１の排熱を回収した第１熱媒体は、第１熱媒体復路５１ｂに流出し、該第１熱媒体復路５１ｂを通流して、第１熱媒体タンク３に戻る。第１熱媒体タンク３に戻った第１熱媒体は、第１熱媒体タンク３内の第１熱媒体と混合され、温度が平準化される。そして、第１熱媒体タンク３内に供給された第１熱媒体は、さらに、第１熱媒体復路５１ｂを通流して、熱交換器４の一次流路２２に供給される。 Meanwhile, the heat (exhaust heat) generated in the fuel cell 1 is recovered by the first heat medium supplied to the first heat medium flow path 21. The first heat medium that has recovered the exhaust heat of the fuel cell 1 flows out to the first heat medium return path 51b, flows through the first heat medium return path 51b, and returns to the first heat medium tank 3. The first heat medium returned to the first heat medium tank 3 is mixed with the first heat medium in the first heat medium tank 3, and the temperature is leveled. The first heat medium supplied into the first heat medium tank 3 further flows through the first heat medium return path 51 b and is supplied to the primary flow path 22 of the heat exchanger 4.
　熱交換器４の一次流路２２に供給された第１熱媒体は、熱交換器４の一次流路２２を通流する間に、貯湯タンク５の下端部から熱交換器４の二次流路２３に供給された第２熱媒体と熱交換して、冷却される。冷却された第１熱媒体は、第１熱媒体往路５１ａを通流して、燃料電池１の第１熱媒体流路２１の入口に供給される。 The first heat medium supplied to the primary flow path 22 of the heat exchanger 4 flows from the lower end of the hot water storage tank 5 to the secondary flow of the heat exchanger 4 while flowing through the primary flow path 22 of the heat exchanger 4. Heat is exchanged with the second heat medium supplied to the passage 23 to be cooled. The cooled first heat medium flows through the first heat medium forward path 51 a and is supplied to the inlet of the first heat medium flow path 21 of the fuel cell 1.
　一方、貯湯タンク５の下端部から熱交換器４の二次流路２３に供給された第２熱媒体は、熱交換器４の二次流路２３を通流する間に、加熱される。加熱された第２熱媒体は、第２熱媒体往路５２ａを通流して、貯湯タンク５の上端部に戻る。貯湯タンク５に戻った第２熱媒体は、需要に応じて、貯湯水供給路５４を通流して熱負荷に供給され、利用者にお湯として使用される。また、貯湯タンク５内の第２熱媒体が減少すると、制御器１０の制御により、水供給路５３から市水が供給される。 On the other hand, the second heat medium supplied from the lower end of the hot water storage tank 5 to the secondary flow path 23 of the heat exchanger 4 is heated while flowing through the secondary flow path 23 of the heat exchanger 4. The heated second heat medium flows through the second heat medium forward path 52 a and returns to the upper end portion of the hot water storage tank 5. The second heat medium returned to the hot water storage tank 5 is supplied to the heat load through the hot water supply channel 54 according to demand, and used as hot water by the user. In addition, when the second heat medium in the hot water storage tank 5 decreases, city water is supplied from the water supply path 53 under the control of the controller 10.
　なお、第１熱媒体経路５１を通流する第１熱媒体は、制御器１０からの制御信号に基づいて、第２ポンプ７により、その流量が調整され、同様に、第２熱媒体経路５２を通流する第２熱媒体は、制御器１０からの制御信号に基づき、第１ポンプ６により、その流量が調整される。 Note that the flow rate of the first heat medium flowing through the first heat medium path 51 is adjusted by the second pump 7 based on a control signal from the controller 10, and similarly, the second heat medium path 52. The flow rate of the second heat medium flowing therethrough is adjusted by the first pump 6 based on a control signal from the controller 10.
　ところで、外部電力負荷１４で消費される電力が、燃料電池１で発電された電力よりも小さい場合、余剰電力が発生する。この余剰電力は、上述したように、余剰電力ヒータ２に供給され、第１熱媒体復路５１ｂを通流する第１熱媒体が加熱される。そして、特に、外部電力負荷１４で消費される消費電力量が急激に減少した場合、余剰電力が急激に増加し、余剰電力ヒータ２で第１熱媒体が急激に加熱され、場合によっては、沸騰する（又は、沸騰に近い温度までに加熱される）可能性がある。 Incidentally, when the power consumed by the external power load 14 is smaller than the power generated by the fuel cell 1, surplus power is generated. As described above, the surplus power is supplied to the surplus power heater 2, and the first heat medium flowing through the first heat medium return path 51b is heated. In particular, when the amount of power consumed by the external power load 14 decreases rapidly, the surplus power increases rapidly, and the first heat medium is rapidly heated by the surplus power heater 2, and in some cases boiling (Or heated to a temperature close to boiling).
　このような場合においても、本実施の形態１に係る燃料電池システム１００では、高温の第１熱媒体が第１熱媒体タンク３に供給される（戻る）ため、第１熱媒体タンク３内の第１熱媒体と混合され、第１熱媒体タンク３内で第１熱媒体の温度の平準化がされる。これにより、熱交換器４の一次流路２２に過昇温したり、もしくは沸騰したりして、第１熱媒体が供給されることが抑制されるので、燃料電池１の第１熱媒体流路２１に過昇温した第１熱媒体が供給されるのが抑制され、燃料電池１内の温度変動を抑制することができる。 Even in such a case, in the fuel cell system 100 according to the first embodiment, the high-temperature first heat medium is supplied (returned) to the first heat medium tank 3, so that the inside of the first heat medium tank 3 It is mixed with the first heat medium, and the temperature of the first heat medium is leveled in the first heat medium tank 3. Accordingly, the first heat medium is suppressed from being excessively heated or boiled in the primary flow path 22 of the heat exchanger 4 to be supplied, so that the first heat medium flow of the fuel cell 1 is suppressed. Supply of the first heat medium that has been overheated to the path 21 is suppressed, and temperature fluctuations in the fuel cell 1 can be suppressed.
　また、熱交換器４の一次流路２２に急激に加熱された第１熱媒体、場合によっては、沸騰した第１熱媒体が供給されることが抑制されるので、熱交換器４で熱交換される第２熱媒体が過剰に加熱されるのが抑制される。このため、過昇温した第２熱媒体が貯湯タンク５に供給されるのが抑制される。 Moreover, since it is suppressed that the 1st heat medium heated suddenly to the primary flow path 22 of the heat exchanger 4, and the 1st heat medium which boiled depending on the case are supplied, heat exchange with the heat exchanger 4 is carried out. Excessive heating of the second heat medium to be performed is suppressed. For this reason, it is suppressed that the 2nd heat medium which carried out excessive temperature rise is supplied to the hot water storage tank 5.
　さらに、第１熱媒体が余剰電力ヒータ２で急激に加熱され、場合によっては、沸騰されることにより、第１熱媒体中の溶存酸素が気化したり、水蒸気が生成したりして、ガスが生成されるが、この生成されたガスは、第１熱媒体タンク３で捕集される。このため、生成されたガスが、熱交換器４の一次流路２２に流入し、一次流路内に溜まることを抑制することができ、従来よりも、より安定した第１熱媒体の循環を維持することができる。また、第１熱媒体が安定して循環することにより、熱交換器４で安定して熱交換ができ、燃料電池１内を適切な温度に保つことができる。なお、熱交換器４でのガスの滞留を抑制するという意味においては、第２ポンプ７の配設位置は、第１熱媒体経路５１のいずれの箇所であっても構わない。従って、本実施の形態においては、第２ポンプ７を、熱交換器４の下流の第１熱媒体経路５１ａに設けているが、これは、例示に過ぎず、本例に限定されるものではない。ただし、第２ポンプ７は、第１熱媒体タンク３より下流の第１熱媒体経路５１、または余剰電力ヒータ２より上流の第１熱媒体経路５１に設けられることがより好ましい。これは、余剰電力ヒータ２の急激な加熱により生成したガスが第２ポンプ７に詰まること（いわゆる、ガス噛みの発生）を抑制するためである。 Furthermore, the first heat medium is rapidly heated by the surplus electric power heater 2 and, in some cases, is boiled, whereby dissolved oxygen in the first heat medium is vaporized, water vapor is generated, and the gas is Although generated, the generated gas is collected in the first heat medium tank 3. For this reason, it can suppress that the produced | generated gas flows into the primary flow path 22 of the heat exchanger 4, and accumulates in a primary flow path, and can circulate the 1st heat carrier more stably than before. Can be maintained. In addition, since the first heat medium circulates stably, the heat exchanger 4 can stably exchange heat, and the inside of the fuel cell 1 can be kept at an appropriate temperature. In addition, in the meaning of suppressing gas stagnation in the heat exchanger 4, the second pump 7 may be disposed at any location in the first heat medium path 51. Therefore, in the present embodiment, the second pump 7 is provided in the first heat medium path 51a downstream of the heat exchanger 4, but this is merely an example and is not limited to this example. Absent. However, it is more preferable that the second pump 7 is provided in the first heat medium path 51 downstream from the first heat medium tank 3 or the first heat medium path 51 upstream from the surplus power heater 2. This is for suppressing the gas generated by the rapid heating of the surplus power heater 2 from clogging the second pump 7 (so-called gas biting).
　また、第２ポンプ７の配設位置は、余剰電力ヒータ２より上流の第１熱媒体経路５１よりも、第１熱媒体タンク３より下流の第１熱媒体経路５１（第１熱媒体往路５１ａ）に設けることがより好ましい。これは、第１熱媒体は、燃料電池１を通過する間に加熱され溶存酸素が気化する可能性があるため、余剰電力ヒータ２より上流の第１熱媒体経路５１に第２ポンプ７を配設すると、ガス噛みする可能性がある。一方、第２ポンプ７を、第１熱媒体タンク３より下流の第１熱媒体経路５１（第１熱媒体往路５１ａ）に設けると、燃料電池１を通過した間に第１熱媒体より生成したガスは、第１熱媒体タンク３に補集されるので、第２ポンプ７でのガス噛みの可能性が抑制されるからである。 Further, the second pump 7 is disposed at the first heat medium path 51 (first heat medium forward path 51a) downstream of the first heat medium tank 3 rather than the first heat medium path 51 upstream of the surplus power heater 2. ) Is more preferable. This is because the first heat medium may be heated while passing through the fuel cell 1 and the dissolved oxygen may vaporize, so the second pump 7 is disposed in the first heat medium path 51 upstream from the surplus power heater 2. If installed, there is a possibility of gas biting. On the other hand, when the second pump 7 is provided in the first heat medium path 51 (first heat medium forward path 51 a) downstream from the first heat medium tank 3, it is generated from the first heat medium while passing through the fuel cell 1. This is because the gas is collected in the first heat medium tank 3 so that the possibility of gas biting in the second pump 7 is suppressed.
　（実施の形態２）
　図２は、本発明の実施の形態２に係る燃料電池システムの概略構成を示す模式図である。 (Embodiment 2)
FIG. 2 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 2 of the present invention.
　図２に示すように、本発明の実施の形態２に係る燃料電池システム１００は、実施の形態１に係る燃料電池システム１００と基本的構成は同じであるが、第１熱媒体経路５１の第１熱媒体往路５１ａ（第１熱媒体経路５１の熱交換器４の下流側）に第１温度検出器１５が設けられている点が異なる。 As shown in FIG. 2, the fuel cell system 100 according to Embodiment 2 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 1, but the first heat medium path 51 The difference is that the first temperature detector 15 is provided in the first heat medium forward path 51a (downstream of the heat exchanger 4 in the first heat medium path 51).
　具体的には、第１温度検出器１５は、第１熱媒体往路５１ａにおける第２ポンプ７の下流側に設けられている。そして、第１温度検出器１５は、第１熱媒体往路５１ａを通流し、燃料電池１の第１熱媒体流路２１に供給される第１熱媒体の温度を検出するように構成されており、検出した温度は、制御器（第１制御器）１０に出力される。なお、ここでは、制御器１０を本発明の第１制御器の一例として構成したが、これに限定されず、制御器１０とは、別途独立した制御器（コンピュータ）によって、第１制御器が構成されてもよい。また、燃料電池１（正確には、第１熱媒体流路２１）内に供給される第１熱媒体の温度をより正確に検出する観点から、第１温度検出器１５は、第１熱媒体往路５１ａの中でも第１熱媒体往路５１ａの下流端に近い位置に設けられることがより好ましい。 Specifically, the first temperature detector 15 is provided on the downstream side of the second pump 7 in the first heat medium forward path 51a. The first temperature detector 15 is configured to detect the temperature of the first heat medium that flows through the first heat medium forward path 51 a and is supplied to the first heat medium flow path 21 of the fuel cell 1. The detected temperature is output to the controller (first controller) 10. Here, the controller 10 is configured as an example of the first controller of the present invention. However, the present invention is not limited to this, and the first controller is controlled separately from the controller 10 by a controller (computer). It may be configured. Further, from the viewpoint of more accurately detecting the temperature of the first heat medium supplied into the fuel cell 1 (more precisely, the first heat medium flow path 21), the first temperature detector 15 is provided with the first heat medium. It is more preferable that the forward path 51a is provided at a position near the downstream end of the first heat medium forward path 51a.
　制御器１０は、第１温度検出器１５で検出された温度に基づき、第１ポンプ６を制御する。具体的には、第１温度検出器１５で検出される温度が、所定の温度（例えば、６０℃）になるように、第１ポンプ６の操作量を調整して、第２熱媒体経路５２を通流する第２熱媒体の流量を制御する。 Controller 10 controls first pump 6 based on the temperature detected by first temperature detector 15. Specifically, the amount of operation of the first pump 6 is adjusted so that the temperature detected by the first temperature detector 15 becomes a predetermined temperature (for example, 60 ° C.), and the second heat medium path 52. The flow rate of the second heat medium flowing therethrough is controlled.
　例えば、第１温度検出器１５の検出温度が、所定の温度より高い６２℃になった場合には、制御器１０は、第１ポンプ６に操作量を増加させる制御信号を出力する。第１ポンプ６は、制御器１０からの制御信号が入力されると、その操作量を増加させて、第２熱媒体の流量を増加させる。これにより、熱交換器４において二次流路２３内の第２熱媒体より回収される熱量が大きくなって、第１熱媒体の温度を下げることができる。一方、第１温度検出器１５の検出温度が、例えば、所定の温度より低い５８℃になった場合には、制御器１０は、第１ポンプ６を制御して、その操作量を減少させて、第２熱媒体の流量を減少させる。これにより、熱交換器４において二次流路２３内の第２熱媒体より回収される熱量が小さくなって、第１熱媒体の温度を上げることができる。 For example, when the detected temperature of the first temperature detector 15 reaches 62 ° C., which is higher than a predetermined temperature, the controller 10 outputs a control signal for increasing the operation amount to the first pump 6. When the control signal from the controller 10 is input, the first pump 6 increases its operation amount to increase the flow rate of the second heat medium. Thereby, the amount of heat recovered from the second heat medium in the secondary flow path 23 in the heat exchanger 4 is increased, and the temperature of the first heat medium can be lowered. On the other hand, when the detected temperature of the first temperature detector 15 becomes 58 ° C., which is lower than a predetermined temperature, for example, the controller 10 controls the first pump 6 to reduce the operation amount. The flow rate of the second heat medium is decreased. Thereby, the amount of heat recovered from the second heat medium in the secondary flow path 23 in the heat exchanger 4 is reduced, and the temperature of the first heat medium can be raised.
　ところで、上記特許文献１には、冷却水流路２０２における発熱体２０６と熱交換器２０３との間（冷却水流路２０２の発熱体２０６の下流側）に温度検知器２１０が設けられていて、排熱回収水ポンプ２０９の操作量を温度検知器２１０の検知した温度に基づいて制御することが開示されている。燃料電池は、電力負荷の急激な変動に追随して発電量を調整することができないため、余剰電力の急激な変動が生じる。このため、特許文献１に開示されている燃料電池システム２００では、発熱体２０６に供給される余剰電力の急激な変動によって、発熱体２０６で加熱される冷却水の温度も急激に変動するので、排熱回収水ポンプ２０９をその温度変動に追随してその操作量を制御すると、燃料電池２０１に流入する冷却水の温度が安定しないおそれがある。 By the way, in Patent Document 1, a temperature detector 210 is provided between the heating element 206 and the heat exchanger 203 in the cooling water flow path 202 (downstream of the heating element 206 in the cooling water flow path 202). It is disclosed that the operation amount of the heat recovery water pump 209 is controlled based on the temperature detected by the temperature detector 210. Since the fuel cell cannot adjust the amount of power generation following the rapid fluctuation of the electric power load, the sudden fluctuation of surplus power occurs. For this reason, in the fuel cell system 200 disclosed in Patent Document 1, the temperature of the cooling water heated by the heating element 206 also varies abruptly due to a rapid variation in surplus power supplied to the heating element 206. If the operation amount is controlled by following the temperature fluctuation of the exhaust heat recovery water pump 209, the temperature of the cooling water flowing into the fuel cell 201 may not be stabilized.
　また、特許文献１に開示されている燃料電池システム２００では、冷却水流路２０２における発熱体２０６と熱交換器２０３との間に温度検知器２１０が設けられているため、燃料電池２０１に供給される冷却水の正確な温度を検知するために、さらに温度検知器を設ける必要があり、燃料電池システムの低コスト化を図ることができない。 Further, in the fuel cell system 200 disclosed in Patent Document 1, since the temperature detector 210 is provided between the heating element 206 and the heat exchanger 203 in the cooling water flow path 202, the fuel cell system 200 is supplied to the fuel cell 201. In order to detect the exact temperature of the cooling water, it is necessary to further provide a temperature detector, and the cost of the fuel cell system cannot be reduced.
　しかしながら、本実施の形態２に係る燃料電池システム１００では、余剰電力ヒータ２の下流側に第１熱媒体タンク３が設けられているため、余剰電力の急激な変動により、温度変動した第１熱媒体は、第１熱媒体タンク３内に供給され、第１熱媒体タンク３に貯えられている第１熱媒体によりその温度変動が緩和される。また、本実施の形態２に係る燃料電池システム１００では、第１熱媒体タンク３の下流側に熱交換器４が設けられているため、第１熱媒体の温度変動はさらに緩和される。 However, in the fuel cell system 100 according to Embodiment 2, since the first heat medium tank 3 is provided on the downstream side of the surplus power heater 2, the first heat that has fluctuated in temperature due to sudden fluctuations in surplus power. The medium is supplied into the first heat medium tank 3, and the temperature fluctuation is alleviated by the first heat medium stored in the first heat medium tank 3. Further, in the fuel cell system 100 according to the second embodiment, since the heat exchanger 4 is provided on the downstream side of the first heat medium tank 3, the temperature fluctuation of the first heat medium is further alleviated.
　そして、本実施の形態２に係る燃料電池システム１００では、第１温度検出器１５が第１熱媒体経路５１の熱交換器４の下流側に設けられている。このため、余剰電力の急激な変動が生じても、第１熱媒体タンク３及び熱交換器４により、第１熱媒体往路５１ａを通流する第１熱媒体は、温度変動がより緩和され、第１温度検出器１５の検出温度に基づく第１ポンプ６の操作量の制御を安定して行うことができる。その結果、余剰電力の急激な変動が生じても、燃料電池１の第１熱媒体流路２１に流入する冷却水の温度が従来よりも安定する。 In the fuel cell system 100 according to the second embodiment, the first temperature detector 15 is provided on the downstream side of the heat exchanger 4 in the first heat medium path 51. For this reason, even if the surplus electric power fluctuates rapidly, the first heat medium flowing through the first heat medium forward path 51a is more relaxed by the first heat medium tank 3 and the heat exchanger 4, Control of the operation amount of the first pump 6 based on the temperature detected by the first temperature detector 15 can be stably performed. As a result, the temperature of the cooling water flowing into the first heat medium flow path 21 of the fuel cell 1 is more stable than before even if the surplus power suddenly varies.
　このように、本実施の形態２に係る燃料電池システム１００では、実施の形態１に係る燃料電池システム１００の作用効果に加えて、簡素な構成で、第１温度検出器１５で検出された温度に基づき、第１ポンプ６の操作量を制御することにより、熱交換器４での熱交換量を調整し、第１熱媒体の温度を安定して調整することができる。また、第１熱媒体の温度が安定して調整されることにより、燃料電池１内の温度を安定して調整することができる。 Thus, in the fuel cell system 100 according to the second embodiment, in addition to the operational effects of the fuel cell system 100 according to the first embodiment, the temperature detected by the first temperature detector 15 with a simple configuration. Therefore, by controlling the operation amount of the first pump 6, the heat exchange amount in the heat exchanger 4 can be adjusted, and the temperature of the first heat medium can be adjusted stably. Moreover, the temperature in the fuel cell 1 can be stably adjusted by adjusting the temperature of the first heat medium stably.
　（実施の形態３）
　図３は、本発明の実施の形態３に係る燃料電池システムの概略構成を示す模式図である。 (Embodiment 3)
FIG. 3 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 3 of the present invention.
　図３に示すように、本発明の実施の形態３に係る燃料電池システム１００は、実施の形態２に係る燃料電池システム１００と基本的構成は同じであるが、第１熱媒体経路５１の第１熱媒体往路５１ａに第２温度検出器１６が設けられている点が異なる。 As shown in FIG. 3, the fuel cell system 100 according to Embodiment 3 of the present invention has the same basic configuration as the fuel cell system 100 according to Embodiment 2, but the first heat medium path 51 includes The difference is that the second temperature detector 16 is provided in the one heat medium forward path 51a.
　具体的には、第２温度検出器１６は、第１熱媒体復路５１ｂにおける余剰電力ヒータ２の上流側に設けられている。そして、第２温度検出器１６は、燃料電池１の第１熱媒体流路２１から排出される第１熱媒体の温度を検出するように構成されており、検出した温度は、制御器（第２制御器）１０に出力される。なお、ここでは、制御器１０を第２制御器の一例として構成したが、これに限定されず、制御器１０とは、別途独立した制御器（コンピュータ）によって、第２制御器が構成されてもよい。また、燃料電池１（正確には、第１熱媒体流路２１）から排出される第１熱媒体の温度をより正確に検出する観点から、第２温度検出器１６は、第１熱媒体復路５１ｂの上流端に近い位置に設けられることが好ましい。 Specifically, the second temperature detector 16 is provided on the upstream side of the surplus power heater 2 in the first heat medium return path 51b. The second temperature detector 16 is configured to detect the temperature of the first heat medium discharged from the first heat medium flow path 21 of the fuel cell 1, and the detected temperature is the controller (first 2 controller) 10. Here, the controller 10 is configured as an example of the second controller. However, the present invention is not limited to this, and the second controller is configured by a controller (computer) that is independent from the controller 10. Also good. Further, from the viewpoint of more accurately detecting the temperature of the first heat medium discharged from the fuel cell 1 (more precisely, the first heat medium flow path 21), the second temperature detector 16 is provided with the first heat medium return path. It is preferable to be provided at a position near the upstream end of 51b.
　制御器１０は、第１及び第２温度検出器１５、１６で検出された温度に基づき、第２ポンプ７の操作量を制御する。具体的には、制御器１０は、第２温度検出器１６で検出される温度が、第１温度検出器１５で検出された温度（例えば、６０℃）と、第１熱媒体の沸点１００℃と、の平均である８０℃よりも、低い所定温度（例えば、７０℃）になるように、第２ポンプ７（ここでは、第１ポンプ６を含む）の操作量を制御している。この場合、第２温度検出器１６の検出温度が上記所定温度よりも上昇すると、燃料電池１の生成熱の回収量を増加させるため、第２ポンプ７の操作量を増大させて第１熱媒体の流量を増加させ、第２温度検出器１６の検出温度を低下させ、第２温度検出器１６の検出温度が低下すると燃料電池１の生成熱の回収量を低減させるため、第２ポンプの操作量を減少させ、第２温度検出器１６の検出温度を上昇させる。 The controller 10 controls the operation amount of the second pump 7 based on the temperatures detected by the first and second temperature detectors 15 and 16. Specifically, the controller 10 detects that the temperature detected by the second temperature detector 16 is the temperature detected by the first temperature detector 15 (for example, 60 ° C.) and the boiling point of the first heat medium 100 ° C. The operation amount of the second pump 7 (including the first pump 6 in this case) is controlled so as to be a predetermined temperature (for example, 70 ° C.) lower than the average of 80 ° C. In this case, when the temperature detected by the second temperature detector 16 rises above the predetermined temperature, the amount of heat generated by the fuel cell 1 is increased, so the amount of operation of the second pump 7 is increased and the first heat medium is increased. In order to reduce the amount of heat generated by the fuel cell 1 when the detected temperature of the second temperature detector 16 decreases and the detected temperature of the second temperature detector 16 decreases. The amount is decreased and the temperature detected by the second temperature detector 16 is increased.
　ところで、燃料電池１が固体高分子形燃料電池の場合、発電により、通常、発電量の熱量換算値と同等の熱量を生成する（すなわち、燃料電池の生成熱量≒燃料電池の発電量の熱量換算値）が、この生成熱により、第１熱媒体の温度が上昇する。例えば、上述したように燃料電池システム１００を運転中に、余剰電力が生じていない状態で、第１温度検出器１５で検出された温度が６０℃であり、第２温度検出器１６で検出された温度が７０℃である場合、燃料電池１での生成熱により、第１熱媒体が１０℃だけ温度上昇したといえる。 By the way, when the fuel cell 1 is a polymer electrolyte fuel cell, the power generation usually generates a heat amount equivalent to a heat amount conversion value of the power generation amount (that is, the heat generation amount of the fuel cell≈the heat amount conversion of the fuel cell power generation amount). Value), the temperature of the first heat medium rises due to this generated heat. For example, as described above, the temperature detected by the first temperature detector 15 is 60 ° C. while the surplus power is not generated during operation of the fuel cell system 100, and is detected by the second temperature detector 16. When the temperature is 70 ° C., it can be said that the temperature of the first heat medium has increased by 10 ° C. due to the heat generated in the fuel cell 1.
　このような燃料電池システム１００の運転中に上述の同じ発電量で、かつ、外部電力負荷１４での電力消費が突然停止した場合、燃料電池１で発電した全発電量が、余剰電力ヒータ２に通電される。ここで、例えば、余剰電力ヒータが抵抗加熱型のヒータである場合、電熱交換効率はほぼ１００％であるため、「余剰電力ヒータの発熱量≒燃料電池の発電量の熱量換算値」となり、さらに、固体高分子形燃料電池では、「燃料電池の生成熱量≒燃料電池の発電量の熱量換算値」であることを考慮すると、「余剰電力ヒータの発熱量≒燃料電池の生成熱量」となる。従って、余剰電力ヒータ２で加熱された第１熱媒体の温度上昇は、余剰電力が０の場合に比べて、さらに、約１０℃の温度上昇が見込まれる。このため、第１熱媒体タンク３に導入される第１熱媒体の温度は、約８０℃となり、外部電力負荷１４における電力消費の変動により余剰電力ヒータ２への通電量が急激に上昇しても、第１熱媒体が沸騰するまで加熱されるのが抑制される。これにより、第１熱媒体経路５１を通流する第１熱媒体流量がより安定し、燃料電池１に流入する第１熱媒体の温度を適切な温度で安定して保つことができ、また、燃料電池１内を適切な温度で保つことができる。 When the fuel cell system 100 operates in the same manner as described above and the power consumption at the external power load 14 suddenly stops, the total power generated by the fuel cell 1 is transferred to the surplus power heater 2. Energized. Here, for example, when the surplus power heater is a resistance heating type heater, since the heat exchange efficiency is almost 100%, “the amount of heat generated by the surplus power heater ≈ the amount of heat generated from the fuel cell power generation value”, and In the polymer electrolyte fuel cell, considering that “the amount of heat generated by the fuel cell≈the value converted to the amount of power generated by the fuel cell”, “the amount of heat generated by the surplus power heater≈the amount of heat generated by the fuel cell”. Accordingly, the temperature increase of the first heat medium heated by the surplus power heater 2 is expected to further increase by about 10 ° C. compared to the case where the surplus power is zero. For this reason, the temperature of the first heat medium introduced into the first heat medium tank 3 is about 80 ° C., and the amount of power supplied to the surplus power heater 2 increases rapidly due to fluctuations in power consumption in the external power load 14. Moreover, it is suppressed that the 1st heat carrier is heated until it boils. Thereby, the flow rate of the first heat medium flowing through the first heat medium path 51 is more stable, the temperature of the first heat medium flowing into the fuel cell 1 can be kept stable at an appropriate temperature, The inside of the fuel cell 1 can be kept at an appropriate temperature.
　このように、本実施の形態３に係る燃料電池システム１００では、実施の形態２に係る燃料電池システム１００の作用効果に加えて、燃料電池１の第１熱媒体流路２１から排出される第１熱媒体の温度（第２温度検出器１６で検出される温度）を、燃料電池１の第１熱媒体流路２１に供給される第１熱媒体の温度（第１温度検出器１５で検出される温度）と第１熱媒体の沸点の平均温度よりも低い、所定の温度になるように、第２ポンプ７の操作量を制御することにより、外部電力負荷１４の変動により余剰電力ヒータへの通電量が急激に上昇しても、余剰電力ヒータ２で加熱された第１熱媒体の温度は、沸点未満となり、安定的に第１の熱媒体の沸騰を抑制することができる。 Thus, in the fuel cell system 100 according to the third embodiment, in addition to the operational effects of the fuel cell system 100 according to the second embodiment, the first exhaust discharged from the first heat medium flow path 21 of the fuel cell 1 is performed. The temperature of one heat medium (the temperature detected by the second temperature detector 16) is the temperature of the first heat medium (detected by the first temperature detector 15) supplied to the first heat medium flow path 21 of the fuel cell 1. The surplus power heater due to fluctuations in the external power load 14 by controlling the operation amount of the second pump 7 so that the predetermined temperature is lower than the average temperature of the boiling point of the first heat medium. Even if the energization amount of the first heat medium rapidly increases, the temperature of the first heat medium heated by the surplus power heater 2 becomes less than the boiling point, and the boiling of the first heat medium can be stably suppressed.
　また、本実施の形態３に係る燃料電池システム１００では、余剰電力ヒータ２で第１熱媒体が沸騰するまで加熱されるのが抑制されることにより、第１熱媒体の温度を適切な温度でより安定して保つことができ、また、燃料電池１内を適切な温度でより保つことができる。 Moreover, in the fuel cell system 100 according to Embodiment 3, the temperature of the first heat medium is set to an appropriate temperature by suppressing the surplus power heater 2 from heating until the first heat medium boils. It can be kept more stable, and the inside of the fuel cell 1 can be kept at an appropriate temperature.
　（実施の形態４）
　図４は、本発明の実施の形態４に係る燃料電池システムの概略構成を示す模式図である。 (Embodiment 4)
FIG. 4 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 4 of the present invention.
　図４に示すように、本発明の実施の形態４に係る燃料電池システム１００は、実施の形態１に係る燃料電池システム１００と基本的構成は同じであるが、第１熱媒体経路５１における第１熱媒体復路５１ｂの余剰電力ヒータ２と第１熱媒体タンク３との間の部分５５が、第１熱媒体の鉛直方向の流れの向きが、鉛直上向きになるように構成されている点が異なる。具体的には、部分５５を構成する配管における第１熱媒体の流れが、鉛直方向上向きになるよう構成されている。 As shown in FIG. 4, the basic configuration of the fuel cell system 100 according to Embodiment 4 of the present invention is the same as that of the fuel cell system 100 according to Embodiment 1, but the first configuration in the first heat medium path 51 is the same. The portion 55 between the surplus power heater 2 and the first heat medium tank 3 in the first heat medium return path 51b is configured such that the direction of the vertical flow of the first heat medium is vertically upward. Different. Specifically, the flow of the first heat medium in the pipe constituting the portion 55 is configured to face upward in the vertical direction.
　これにより、余剰電力の急激な増加により、第１熱媒体が余剰電力ヒータ２で急激に加熱され、場合によっては、沸騰して、水蒸気等のガスが生成しても、生成したガスは、ガスの浮力により、部分５５に滞留することなく、第１熱媒体とともに部分５５を通流して、第１熱媒体タンク３に流入する。そして、第１熱媒体タンク３に流入したガスは、第１熱媒体タンク３の空隙部３ａに捕集されるので、第１熱媒体復路５１ｂの第１熱媒体タンクの下流側に流出することがない。このため、余剰電力ヒータ２の加熱により発生したガスが第１熱媒体タンク３に至るまでの第１熱媒体経路５１内に滞留することなく、より確実に第１熱媒体タンク３に捕集することができるため、本実施の形態４に係る燃料電池システム１００では、実施の形態１に係る燃料電池システム１００の作用効果に加えて、第１熱媒体経路５１を通流する第１熱媒体の流量をより安定にすることができる。また、第１熱媒体の流量が安定することにより、熱交換器４での第２熱媒体との熱交換がより安定し、燃料電池１に供給される第１熱媒体の温度がより安定するため、燃料電池１内の温度もより安定する。 Accordingly, even if the first heat medium is rapidly heated by the surplus power heater 2 due to a sudden increase in surplus power and, in some cases, boiles and generates a gas such as water vapor, the generated gas is Due to the buoyancy, the portion 55 flows together with the first heat medium without staying in the portion 55 and flows into the first heat medium tank 3. Since the gas flowing into the first heat medium tank 3 is collected in the gap 3a of the first heat medium tank 3, it flows out to the downstream side of the first heat medium tank in the first heat medium return path 51b. There is no. For this reason, the gas generated by the heating of the surplus power heater 2 is more reliably collected in the first heat medium tank 3 without staying in the first heat medium path 51 up to the first heat medium tank 3. Therefore, in the fuel cell system 100 according to the fourth embodiment, in addition to the operational effects of the fuel cell system 100 according to the first embodiment, the first heat medium flowing through the first heat medium path 51 can be used. The flow rate can be made more stable. Further, since the flow rate of the first heat medium is stabilized, heat exchange with the second heat medium in the heat exchanger 4 is further stabilized, and the temperature of the first heat medium supplied to the fuel cell 1 is further stabilized. Therefore, the temperature in the fuel cell 1 is further stabilized.
　なお、本実施の形態においては、第１熱媒体復路５１ｂの部分５５を第１熱媒体の流れにおいて、鉛直方向上向きに流れるように構成したが、これに限定されず、部分５５が、水平または上り勾配であれば構わない。なお、ここでいう「上り勾配」とは、部分５５において第１熱媒体の流れの鉛直方向成分が鉛直下向きにならないように構成されていることを指し、具体的には、部分５５は、斜めに傾斜していてもよく、また、水平部分と鉛直方向上向きの部分とが混在する構成としてもよく、また、水平部分と斜めに傾斜する部分とが混在する構成であっても構わない。 In the present embodiment, the portion 55 of the first heat medium return path 51b is configured to flow upward in the vertical direction in the flow of the first heat medium. However, the present invention is not limited to this, and the portion 55 is horizontal or It does not matter if it is uphill. Here, the “uphill gradient” means that the vertical component of the flow of the first heat medium is not vertically downward in the portion 55. Specifically, the portion 55 is slanted. Further, the horizontal portion and the vertically upward portion may be mixed, or the horizontal portion and the inclined portion may be mixed.
　また、上述においては説明しなかったが、本実施の形態の燃料電池システムに対して、実施の形態２や実施の形態３における燃料電池システムのような第１ポンプ６又は第２ポンプ７の制御を実施するように構成しても構わない。 Although not described above, the control of the first pump 6 or the second pump 7 as in the fuel cell system in the second or third embodiment is performed on the fuel cell system in the present embodiment. You may comprise so that it may implement.
　（実施の形態５）
　図５は、本発明の実施の形態５に係る燃料電池システムの概略構成を示す模式図である。 (Embodiment 5)
FIG. 5 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 5 of the present invention.
　図５に示すように、本発明の実施の形態５に係る燃料電池システム１００は、実施の形態１に係る燃料電池システム１００と基本的構成は同じであるが、余剰電力ヒータ２が第１熱媒体タンク３内部に設けられている点と、第１熱媒体タンク３に、圧力検出器１７、連通流路１８、及び開閉弁１９からなる圧抜き器が設けられている点が異なる。 As shown in FIG. 5, the fuel cell system 100 according to the fifth embodiment of the present invention has the same basic configuration as the fuel cell system 100 according to the first embodiment, but the surplus power heater 2 is the first heat. The difference is that it is provided inside the medium tank 3 and that the first heat medium tank 3 is provided with a pressure releaser comprising a pressure detector 17, a communication flow path 18, and an on-off valve 19.
　具体的には、余剰電力ヒータ２は、第１熱媒体タンク３の内部に設けられていて、第１熱媒体タンク３内の第１熱媒体を加熱することができるように構成されている。また、第１熱媒体タンク３の内部には、水位検出器（図示せず）が設けられていて、検出した水位を制御器１０に出力している。制御器１０は、水位検出器で検出された水位に基づいて、適宜な手段（例えば、第１熱媒体の第１熱媒体タンク３への補給する水補給器）により、余剰電力ヒータ２が第１熱媒体の液面下に常に位置するように、第１熱媒体の水位を調整している。 Specifically, the surplus power heater 2 is provided inside the first heat medium tank 3 and is configured to heat the first heat medium in the first heat medium tank 3. Further, a water level detector (not shown) is provided inside the first heat medium tank 3, and the detected water level is output to the controller 10. Based on the water level detected by the water level detector, the controller 10 uses the appropriate means (for example, a water replenisher for replenishing the first heat medium to the first heat medium tank 3) to make the surplus power heater 2 the first. The water level of the first heat medium is adjusted so that it is always located below the liquid level of the one heat medium.
　これにより、燃料電池１で発電した電力のうち外部電力負荷１４で消費されない余剰の電力が、余剰電力ヒータ２に通電されると、直接第１熱媒体タンク３内の第１熱媒体が加熱されるため、余剰電力ヒータ２を第１熱媒体経路５１の第１熱媒体往路５１ａに設ける構成よりも、放熱ロスが少なく（つまり、実施の形態３の部分５５における放熱ロスがなく）、効率よく余剰電力を熱エネルギーとして利用することができ、燃料電池システム１００の省エネルギー性をより高めることができる。 Thus, when surplus power that is not consumed by the external power load 14 among the power generated by the fuel cell 1 is energized to the surplus power heater 2, the first heat medium in the first heat medium tank 3 is directly heated. Therefore, compared with the configuration in which the surplus power heater 2 is provided in the first heat medium forward path 51a of the first heat medium path 51, there is less heat loss (that is, there is no heat loss in the portion 55 of the third embodiment), and the efficiency is high. The surplus power can be used as thermal energy, and the energy saving property of the fuel cell system 100 can be further improved.
　また、余剰電力の急激な増加により、第１熱媒体が余剰電力ヒータ２で急激に加熱され、場合によっては、沸騰して、水蒸気等のガスが生成しても、生成したガスは、空隙部３ａに捕集されるため、第１熱媒体経路５１には流出しない。このため、第１熱媒体経路５１を通流する第１熱媒体の流量をより安定にすることができ、また、第１熱媒体の流量が安定することにより、熱交換器４での第２熱媒体との熱交換がより安定して行うことができる。そして、熱交換器４での熱交換がより安定することにより、燃料電池１に供給される第１熱媒体の温度がより安定するため、燃料電池１内の温度もより安定する。 In addition, even if the first heat medium is rapidly heated by the surplus power heater 2 due to a sudden increase in surplus power and, in some cases, boiles and generates a gas such as water vapor, the generated gas remains in the gap portion. Since it is collected by 3a, it does not flow out to the first heat medium path 51. For this reason, the flow rate of the first heat medium flowing through the first heat medium path 51 can be made more stable, and the second flow rate in the heat exchanger 4 can be increased by stabilizing the flow rate of the first heat medium. Heat exchange with the heat medium can be performed more stably. And since the temperature of the 1st heat medium supplied to the fuel cell 1 becomes more stable because the heat exchange in the heat exchanger 4 becomes more stable, the temperature in the fuel cell 1 also becomes more stable.
　また、第１熱媒体タンク３の上部には、第１熱媒体タンク３内部の空隙部３ａと外気を連通する連通流路１８が設けられていて、該連通流路１８の途中には、開閉弁１９が設けられている。さらに、第１熱媒体タンク３の上部には、圧力検出器１７が設けられている。圧力検出器１７は、第１熱媒体タンク３の空隙部３ａの圧力を検出し、検出した空隙部３ａの圧力を制御器１０に出力するように構成されている。そして、制御器１０は、圧力検出器１７で検出した圧力に基づき、開閉弁１９の弁の開閉を調節している。具体的には、制御器１０は、空隙部３ａの圧力が、所定の圧力Ｐｃ（例えば、第１熱媒体経路５１を構成する配管の設計圧力より低い圧力になると、開閉弁１９の弁を開き、空隙部３ａの圧力が、所定の圧力Ｐｃより小さくなるように制御する。そして、空隙部３ａの圧力が、所定の圧力Ｐｃより小さくなると、開閉弁１９の弁を閉じるように制御する。なお、ここでは、連通流路１８、及び開閉弁１９を備える圧抜き器を第１熱媒体タンク３に設ける構成としたが、これに限定されず、単に、連通流路１８を設けて、第１熱媒体タンク３を大気開放する構成としてもよい。 In addition, a communication flow path 18 is provided in the upper part of the first heat medium tank 3 so as to communicate the air gap 3 a inside the first heat medium tank 3 with the outside air. A valve 19 is provided. Furthermore, a pressure detector 17 is provided on the upper portion of the first heat medium tank 3. The pressure detector 17 is configured to detect the pressure of the gap 3 a of the first heat medium tank 3 and output the detected pressure of the gap 3 a to the controller 10. The controller 10 adjusts the opening / closing of the on-off valve 19 based on the pressure detected by the pressure detector 17. Specifically, the controller 10 opens the valve of the on-off valve 19 when the pressure in the gap 3a becomes lower than a predetermined pressure Pc (for example, the design pressure of the piping that configures the first heat medium path 51). The pressure of the gap 3a is controlled to be lower than the predetermined pressure Pc, and the valve of the on-off valve 19 is controlled to be closed when the pressure of the gap 3a is lower than the predetermined pressure Pc. Here, the pressure release device including the communication flow path 18 and the on-off valve 19 is provided in the first heat medium tank 3, but the present invention is not limited to this, and the communication flow path 18 is simply provided to provide the first heat medium tank 3. The heat medium tank 3 may be open to the atmosphere.
　これにより、余剰電力ヒータ２で第１熱媒体が急激に加熱され、場合によっては、沸騰することにより生成した水蒸気等のガスを空隙部３ａで捕集することで、空隙部３ａの圧力が上昇しても、開閉弁１９の弁を開けることにより、空隙部３ａと外気とが連通し、空隙部３ａの圧力を所定の圧力Ｐｃより小さくすることができ、第１熱媒体タンク３内の圧力上昇（圧力変動）を抑制することができる。また、第１熱媒体タンク３内の圧力上昇を抑制することにより、第１熱媒体経路５１を通流する第１熱媒体の流量をより安定にすることができ、また、第１熱媒体の流量が安定することにより、熱交換器４での第２熱媒体との熱交換がより安定して行うことができる。そして、熱交換器４での熱交換がより安定することにより、燃料電池１に供給される第１熱媒体の温度がより安定するため、燃料電池１内の温度もより安定する。 As a result, the first heating medium is rapidly heated by the surplus power heater 2, and in some cases, gas such as water vapor generated by boiling is collected in the gap 3a, thereby increasing the pressure in the gap 3a. Even so, by opening the valve of the on-off valve 19, the gap 3a communicates with the outside air, and the pressure of the gap 3a can be made smaller than the predetermined pressure Pc, and the pressure in the first heat medium tank 3 can be reduced. An increase (pressure fluctuation) can be suppressed. Moreover, by suppressing the pressure rise in the first heat medium tank 3, the flow rate of the first heat medium flowing through the first heat medium path 51 can be made more stable, By stabilizing the flow rate, heat exchange with the second heat medium in the heat exchanger 4 can be performed more stably. And since the temperature of the 1st heat medium supplied to the fuel cell 1 becomes more stable because the heat exchange in the heat exchanger 4 becomes more stable, the temperature in the fuel cell 1 also becomes more stable.
　このように、本実施の形態５に係る燃料電池システム１００では、実施の形態１に係る燃料電池システム１００の作用効果に加えて、余剰電力ヒータ２が直接第１熱媒体タンク３内の第１熱媒体を加熱するため、余剰電力ヒータ２を第１熱媒体経路５１の第１熱媒体往路５１ａに設ける構成よりも、放熱ロスを抑制することができ、燃料電池システム１００の省エネルギー性をより高めることができる。 As described above, in the fuel cell system 100 according to the fifth embodiment, in addition to the operational effects of the fuel cell system 100 according to the first embodiment, the surplus power heater 2 is directly connected to the first heat medium tank 3 in the first heat medium tank 3. Compared with the configuration in which the surplus power heater 2 is provided in the first heat medium forward path 51a of the first heat medium path 51 in order to heat the heat medium, the heat dissipation loss can be suppressed, and the energy saving performance of the fuel cell system 100 is further improved. be able to.
　なお、上述においては説明しなかったが、本実施の形態の燃料電池システムに対して、実施の形態２や実施の形態３における燃料電池システムのような第１ポンプ６または第２ポンプ７の制御を実施するように構成しても構わない。 Although not described above, the control of the first pump 6 or the second pump 7 as in the fuel cell system in the second embodiment or the third embodiment with respect to the fuel cell system in the present embodiment. You may comprise so that it may implement.
　（実施の形態６）
　図６は、本発明の実施の形態６に係る燃料電池システムの概略構成を示す模式図である。 (Embodiment 6)
FIG. 6 is a schematic diagram showing a schematic configuration of a fuel cell system according to Embodiment 6 of the present invention.
　本発明の実施の形態６に係る燃料電池システム１００は、実施の形態５に係る燃料電池システム１００と基本的構成は同じであるが、余剰電力ヒータ２が、第１熱媒体タンク３の外面に設けられている点が異なる。具体的には、図６に示すように、第１熱媒体タンク３の底外面（下面）に設けられていて、第１熱媒体タンク３の底部を介して、第１熱媒体タンク３内の第１熱媒体を加熱するように構成されている。なお、第１熱媒体タンク３の底外面より第１熱媒体タンク３内の第１熱媒体を加熱するよう構成されているため、余剰電力ヒータ２から周囲の外気への放熱量等を抑制するために、余剰電力ヒータ２を断熱材で覆うよう構成することが好ましい。 The basic configuration of the fuel cell system 100 according to Embodiment 6 of the present invention is the same as that of the fuel cell system 100 according to Embodiment 5, but the surplus power heater 2 is disposed on the outer surface of the first heat medium tank 3. Different points are provided. Specifically, as shown in FIG. 6, the first heat medium tank 3 is provided on the bottom outer surface (lower surface) of the first heat medium tank 3 through the bottom of the first heat medium tank 3. The first heat medium is configured to be heated. In addition, since it is comprised so that the 1st heat medium in the 1st heat medium tank 3 may be heated from the bottom outer surface of the 1st heat medium tank 3, the amount of heat dissipation from the surplus electric power heater 2 to the surrounding outside air, etc. are suppressed. Therefore, it is preferable that the surplus power heater 2 is configured to be covered with a heat insulating material.
　このような構成とすることにより、本実施の形態６に係る燃料電池システム１００では、上記実施の形態５と同様に、燃料電池１で発電した電力のうち外部電力負荷１４で消費されない余剰の電力が、余剰電力ヒータ２に通電されると、第１熱媒体タンク３の底部を介して、第１熱媒体タンク３内の第１熱媒体が加熱されるため、余剰電力ヒータ２を第１熱媒体経路５１の第１熱媒体往路５１ａに設ける構成よりも、放熱ロスが少なく（つまり、実施の形態３の部分５５における放熱ロスがなく）、効率よく余剰電力を熱エネルギーとして利用することができ、燃料電池システム１００の省エネルギー性をより高めることができる。また、本実施の形態６においては、余剰電力ヒータ２を第１熱媒体タンク３の外面のうち、特に、底外面（下面）に設けているため、第１熱媒体タンク３内の第１熱媒体の高さに関らず、第１熱媒体タンク３の容器を間に介して、第１熱媒体と対向する位置から第１熱媒体を余剰電力ヒータ２で加熱することができるため、余剰電力ヒータ２からの熱エネルギーを効率よく第１熱媒体に伝達することができ、燃料電池システム１００の更なるエネルギー効率を向上させることができる。なお、上述においては説明しなかったが、本実施の形態の燃料電池システムに対して、実施の形態２や実施の形態３における燃料電池システムのような第１ポンプ６または第２ポンプ７の制御を実施するように構成しても構わない。 By adopting such a configuration, in the fuel cell system 100 according to the sixth embodiment, surplus power that is not consumed by the external power load 14 among the power generated by the fuel cell 1 as in the fifth embodiment. However, when the surplus power heater 2 is energized, the first heat medium in the first heat medium tank 3 is heated via the bottom of the first heat medium tank 3, so that the surplus power heater 2 is The heat loss is less than the configuration provided in the first heat medium forward path 51a of the medium path 51 (that is, there is no heat loss in the portion 55 of the third embodiment), and the surplus power can be efficiently used as heat energy. The energy saving property of the fuel cell system 100 can be further improved. In the sixth embodiment, the surplus power heater 2 is provided on the outer surface of the first heat medium tank 3, particularly on the bottom outer surface (lower surface). Therefore, the first heat in the first heat medium tank 3 is used. Regardless of the height of the medium, the first heat medium can be heated by the surplus power heater 2 from the position facing the first heat medium via the container of the first heat medium tank 3 in between. The heat energy from the power heater 2 can be efficiently transmitted to the first heat medium, and further energy efficiency of the fuel cell system 100 can be improved. Although not described in the above, the control of the first pump 6 or the second pump 7 as in the fuel cell system in the second or third embodiment with respect to the fuel cell system in the present embodiment. You may comprise so that it may implement.
　なお、上記実施の形態１～５においては、第２熱媒体経路５２に貯湯タンク５を接続し、貯湯タンク５から熱負荷に貯湯水を供給する構成としたが、これに限定されず、第２熱媒体経路５２から直接熱負荷に貯湯水を供給する構成としてもよい。 In the first to fifth embodiments, the hot water storage tank 5 is connected to the second heat medium path 52 and the hot water is supplied from the hot water storage tank 5 to the heat load. However, the present invention is not limited to this. It is good also as a structure which supplies hot water directly from the 2 heat-medium path | route 52 to a heat load.
　また、上記実施の形態２及び３においては、第１温度検出器１５で検出された温度に基づき、第１ポンプ６の操作量を調整したが、これに限定されず、例えば、第２熱媒体経路５２に温度検出器を設けて、該温度検出器で検出された温度に基づいて、第１ポンプ６の操作量を調整してもよい。 Moreover, in the said Embodiment 2 and 3, although the operation amount of the 1st pump 6 was adjusted based on the temperature detected by the 1st temperature detector 15, it is not limited to this, For example, a 2nd heat medium A temperature detector may be provided in the path 52 and the operation amount of the first pump 6 may be adjusted based on the temperature detected by the temperature detector.
　さらに、第１熱媒体として、水を用いたが、これに限定されず、例えば、不凍液を用いてもよい。 Furthermore, although water is used as the first heat medium, the present invention is not limited to this. For example, an antifreeze liquid may be used.
　上記説明から、当業者にとっては、本発明の多くの改良や他の実施形態が明らかである。従って、上記説明は、例示としてのみ解釈されるべきであり、本発明を実行する最良の態様を当業者に教示する目的で提供されたものである。本発明の要旨を逸脱することなく、その構造及び／又は機能の詳細を実質的に変更できる。また、上記実施形態に開示されている複数の構成要素の適宜な組合せにより種々の発明を形成できる。 From the above description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the scope of the invention. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.
　本発明の燃料電池システムは、発電時に発生した余剰電力を熱として回収する運転を行なう燃料電池システム等に有用である。また、エンジン等を用いた発電とともに発生する熱を回収するコージェネレーションシステム等の用途にも応用できる。 The fuel cell system of the present invention is useful for a fuel cell system that performs an operation of recovering surplus power generated during power generation as heat. It can also be applied to applications such as a cogeneration system that recovers heat generated with power generation using an engine or the like.
１　燃料電池
２　余剰電力ヒータ
３　第１熱媒体タンク
４　熱交換器
５　貯湯タンク
６　第１ポンプ（第１流量調整器）
７　第２ポンプ（第２流量調整器）
８　　ＤＣ／ＤＣコンバータ
９　インバータ
１０　制御器
１１　系統連系点
１２　系統電源
１３　電流検出器
１４　外部電力負荷
１５　第１温度検出器
１６　第２温度検出器
１７　圧力検出器
１８　連通流路
１９　開閉弁
２１　第１熱媒体流路
２２　一次流路
２３　二次流路
５１　第１熱媒体経路
５１ａ　第１熱媒体往路
５１ｂ　第１熱媒体復路
５２　第２熱媒体経路
５２ａ　第２熱媒体往路
５２ｂ　第２熱媒体復路
５３　水供給路
５４　貯湯水供給路
５５　部分
１００　燃料電池システム
２００　燃料電池システム
２０１　燃料電池
２０２　冷却水流路
２０３　熱交換器
２０４　貯湯槽
２０５　温水流路
２０６　発熱体
２０７　発熱体
２１０　温度検知器 DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Surplus electric power heater 3 1st heat medium tank 4 Heat exchanger 5 Hot water storage tank 6 1st pump (1st flow regulator)
7 Second pump (second flow regulator)
8 DC / DC converter 9 Inverter 10 Controller 11 System connection point 12 System power supply 13 Current detector 14 External power load 15 First temperature detector 16 Second temperature detector 17 Pressure detector 18 Communication channel 19 On-off valve 21 First heat medium flow path 22 Primary flow path 23 Secondary flow path 51 First heat medium path 51a First heat medium forward path 51b First heat medium return path 52 Second heat medium path 52a Second heat medium forward path 52b Second heat medium Return path 53 Water supply path 54 Hot water supply path 55 Portion 100 Fuel cell system 200 Fuel cell system 201 Fuel cell 202 Cooling water flow path 203 Heat exchanger 204 Hot water storage tank 205 Hot water flow path 206 Heating element 207 Heating element 210 Temperature detector

Claims (8)

  1. 　燃料電池と、
    　前記燃料電池を冷却する第１熱媒体が通流する第１熱媒体経路と、
    　第２熱媒体が通流する第２熱媒体経路と、
    　前記第１熱媒体経路を通流する前記第１熱媒体と、前記第２熱媒体経路を通流する前記第２熱媒体との間で熱交換するための熱交換器と、
    　前記燃料電池を冷却した前記第１熱媒体を前記熱交換器に流入するまでに加熱し、前記燃料電池の余剰電力を消費する余剰電力ヒータと、
    　前記第１熱媒体経路に設けられ、前記第１熱媒体を貯えるタンクと、を備え、
    　前記タンクは前記余剰電力ヒータで加熱された前記第１熱媒体と前記タンク内の前記第１熱媒体とが混合するように構成されている、燃料電池システム。     A fuel cell;
    A first heat medium path through which a first heat medium for cooling the fuel cell flows;
    A second heat medium path through which the second heat medium flows;
    A heat exchanger for exchanging heat between the first heat medium flowing through the first heat medium path and the second heat medium flowing through the second heat medium path;
    Heating the first heat medium that has cooled the fuel cell before flowing into the heat exchanger, and surplus power heater that consumes surplus power of the fuel cell;
    A tank provided in the first heat medium path and storing the first heat medium;
    The fuel cell system, wherein the tank is configured to mix the first heat medium heated by the surplus power heater and the first heat medium in the tank.
  2. 　前記余剰電力ヒータは前記第１熱媒体経路に設けられ、該余剰電力ヒータで加熱された第１熱媒体が前記タンク内に流入するように構成されている、請求項１に記載の燃料電池システム。 2. The fuel cell system according to claim 1, wherein the surplus power heater is provided in the first heat medium path, and the first heat medium heated by the surplus power heater is configured to flow into the tank. .
  3. 　前記タンク内に前記余剰電力ヒータが設けられている、請求項１に記載の燃料電池システム。 The fuel cell system according to claim 1, wherein the surplus power heater is provided in the tank.
  4. 　前記タンクは大気開放されている、請求項１に記載の燃料電池システム。 The fuel cell system according to claim 1, wherein the tank is open to the atmosphere.
  5. 　前記タンクには圧抜き器が設けられている、請求項１に記載の燃料電池システム。 The fuel cell system according to claim 1, wherein the tank is provided with a depressurizer.
  6. 　前記第１熱媒体経路の前記余剰電力ヒータと前記タンクとの間の部分は、水平又は前記第１熱媒体の流れにおいて上り勾配になるように構成されている、請求項２に記載の燃料電池システム。 3. The fuel cell according to claim 2, wherein a portion of the first heat medium path between the surplus power heater and the tank is configured to be horizontal or ascending in the flow of the first heat medium. system.
  7. 　前記第１熱媒体経路の前記熱交換器よりも下流側に設けられた第１温度検出器と、
    　前記第２熱媒体流路を通流する前記第２熱媒体の流量を調整する第１流量調整器と、
    　前記第１温度検出器の検出温度に基づき前記第１流量調整器を制御する第１制御器と、を備える、請求項１に記載の燃料電池システム。     A first temperature detector provided downstream of the heat exchanger in the first heat medium path;
    A first flow controller for adjusting a flow rate of the second heat medium flowing through the second heat medium flow path;
    The fuel cell system according to claim 1, further comprising: a first controller that controls the first flow rate regulator based on a temperature detected by the first temperature detector.
  8. 　前記第１熱媒体経路の前記熱交換器よりも下流側に設けられた第１温度検出器と、
    　前記燃料電池を冷却した後、前記余剰電力ヒータで加熱される前の前記第１熱媒体の温度を検出する第２温度検出器と、
    　前記第１熱媒体経路を通流する前記第１熱媒体の流量を調整する第２流量調整器と、
    前記第２温度検出器の検出温度が前記第１温度検出器の検出温度と前記１熱媒体の沸点との平均温度よりも低くなるように前記第２流量調整器を制御する第２制御器と、を備える、請求項１に記載の燃料電池システム。     A first temperature detector provided downstream of the heat exchanger in the first heat medium path;
    A second temperature detector for detecting a temperature of the first heat medium after being cooled by the surplus power heater after cooling the fuel cell;
    A second flow rate regulator for adjusting a flow rate of the first heat medium flowing through the first heat medium path;
    A second controller for controlling the second flow rate regulator such that the detected temperature of the second temperature detector is lower than the average temperature of the detected temperature of the first temperature detector and the boiling point of the first heat medium; The fuel cell system according to claim 1, comprising:
PCT/JP2009/003290 2008-07-14 2009-07-14 Fuel cell system WO2010007759A1 (en)

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