JP2010021061A - Fuel cell power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress freezing of water used in a fuel cell power generation system with a simple structure. <P>SOLUTION: The fuel cell power generation system is provided with an enclosure panel 1, a fuel cell 4 housed in the enclosure panel 1, a tank 19 storing water of a heat storing medium by recovering exhausted heat from the fuel cell 4 or the like, a thermometer 21 for measuring a temperature inside the enclosure panel 1, a floor-warming heater 15 for introducing the water stored in the tank 19 and radiating heat, and a controlling unit 2 for controlling a floor-warming heater pump 22 which sends the water to the floor-warming heater 15 based on the temperature inside the enclosure panel 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell power generation system.

  The fuel cell power generation system is a system in which hydrogen, which is a fuel, and oxygen, which is an oxidant, react to directly extract electricity. For this reason, the fuel cell power generation system can extract electric energy with high efficiency. In addition, since the noise is low and no harmful exhaust gas is emitted, it has excellent environmental characteristics. Since hydrocarbon fuels such as city gas, LP gas, and kerosene already have a fuel supply base, fuel cell power generation that generates power from hydrogen obtained from the reforming reaction with steam from such hydrocarbon fuels Development is progressing mainly in the system.

  A relatively small fuel cell power generation system for home use or small business use may be used as a cogeneration system that supplies generated power and exhaust heat generated by power generation. Water is often circulated for the recovery of waste heat.

  In order to demonstrate the superiority as a cogeneration system, it is effective to use more exhaust heat for hot water supply, floor heating, and the like. For this reason, the installation of fuel cell power generation systems in cold regions where a large amount of waste heat is expected to be used, especially in winter, can be expected to operate with high overall efficiency. Many demands are expected.

When installing a fuel cell power generation system in a cold region, it is necessary to ensure that internal devices can perform standby operation for power generation without damaging the devices even when the temperature is below freezing, and that stable power generation can be performed. . When installing a fuel cell power generation system in a cold region, there is a method of circulating water in the cooling system of the fuel cell main body (see, for example, Patent Document 1).
JP 2007-294186 A

  The fuel cell power generation system is required to be as simple as possible in order to improve reliability and reduce costs. However, in a fuel cell power generation system in which hydrogen used for power generation is obtained from a hydrocarbon fuel by a reforming reaction with steam, it is necessary to supply water to the reformer. The water supplied to the reformer does not need to be circulated for reforming, but if it is intended to prevent freezing by circulation, a system for bypassing the reformer and returning the water must be added. For this reason, simplification for realizing low cost is difficult.

  Further, by circulating the cooling water, it is possible to prevent the cooling water from freezing even when the power generation is stopped, but it is not possible to prevent condensation of the control device and the power conversion device. Furthermore, since there are a plurality of cooling water systems that must be prevented from freezing, reliability may be reduced due to complicated control.

  Therefore, an object of the present invention is to suppress freezing of water used in a fuel cell power generation system with a simple configuration.

  In order to achieve the above-described object, the present invention provides a fuel cell power generation system that recovers exhaust heat exhausted from an enclosure panel, a fuel cell power generation device housed in the enclosure panel, and the fuel cell power generation device. A heat storage device for storing heat in a heat storage medium, a temperature sensor for measuring an internal temperature of the enclosure panel inside the enclosure panel, a heat dissipation device capable of dissipating heat stored in the heat storage medium to the inside of the enclosure panel, and the enclosure panel And a control device that controls the heat dissipation device based on an internal temperature.

  According to the present invention, freezing of water used in a fuel cell power generation system can be suppressed with a simple configuration.

  An embodiment of a fuel cell power generation system according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
FIG. 1 is a block diagram of a fuel cell power generation system according to a first embodiment of the present invention.

  The fuel cell power generation system of this embodiment includes a fuel cell power generation device, a hot water storage tank 11, a freeze prevention device, and an enclosure panel 1. The fuel cell power generator includes a reforming device 6, a reforming water pump 7, a fuel cell 4, a power conversion device 3, a cooling water system, an exhaust heat recovery system, and a recovery heater 14. The exhaust heat recovery system includes a hot water pump 12 and two heat exchangers 31 and 32. The hot water tank 11 includes a tank 19, a boiler 16, a floor heating heater valve 23 and a hot water supply valve 17. The power conversion device 3 is connected to the fuel cell 4.

  The freeze prevention device includes a floor heating heater 15, a floor heating heater pump 22, a thermometer 21, and a control device 2. A floor heater heater pipe 25 is routed inside the floor heater 15.

  The fuel cell 4, the reforming device 6, the reforming water pump 7, the cooling water system, the exhaust heat recovery system, the recovery heater 14, the power conversion device 3, and the antifreezing device are housed in the enclosure panel 1 to form a package structure. ing. The hot water tank 11 is provided independently of the enclosure panel 1.

  The reformer 6 generates hydrogen rich gas by a steam reforming reaction using the supplied fuel and the water in the water tank 8 supplied by the reforming water pump 7. The generated hydrogen rich gas is supplied to the fuel cell 4.

  The fuel cell 4 is formed by stacking unit cells including a cathode, an anode, and an electrolyte membrane. The electrolyte membrane is sandwiched between the cathode and the anode. In the fuel cell 4, for example, a cooling water flow path is formed in a separator provided between the unit cells.

  The fuel cell 4 generates electricity using air supplied to the cathode and hydrogen supplied to the anode. The direct current generated by the fuel cell 4 is converted into an alternating current by the power converter 3.

  In the cooling water system, water 18 stored in the water tank 8 is circulated by the cooling water pump 5 through the coolant passage of the fuel cell 4 as cooling water. Further, the water stored in the water tank 8 is sent to the pure water device 9 by the pure water pump 10. The pure water device 9 performs water treatment so that the supplied water has the required low electrical conductivity and removes elution components such as metal ions. The water subjected to the water treatment by the pure water device 9 is sent again to the water tank 8.

  The exhaust heat recovery system guides the water stored in the hot water storage tank 11 to the inside of the enclosure panel 1 by the hot water pump 12, recovers the exhaust heat of the fuel cell power generation system by the heat exchangers 31 and 32, and stores the hot water storage tank 11. It is a system to store in. That is, the exhaust heat recovery system and the hot water storage tank 11 are heat storage devices that recover exhaust heat discharged from the fuel cell power generation device and store it in the heat storage medium. The heat exchangers 31 and 32 of the exhaust heat recovery system include a heat exchanger 31 that exchanges heat with the cooling water system and a heat exchanger 32 that recovers heat generated in the reformer 6. In addition, you may collect | recover waste heat in places other than these.

  The hot water tank 11 is supplied with water from the outside via the water supply valve 20 and stores it in the tank 19. The water stored in the tank 19 is heated by the exhaust heat recovery system. The water stored in the tank 19 is supplied to the outside through the hot water supply valve 17 and used for hot water supply, heating, and the like. When the temperature of the water stored in the tank 19 is low when supplying to the outside, the water is heated by the boiler 16. Further, the water stored in the tank 19 is also supplied to the floor heating heater 15 via the floor heating heater valve 23.

  Further, of the power generated by the fuel cell 4, the portion not consumed outside is consumed by the recovery heater 14. The recovery heater 14 heats the water flowing through the exhaust heat recovery system using this surplus power.

  The thermometer 21 of the freeze prevention device is provided inside the enclosure panel 1. The thermometer 21 measures the temperature inside the enclosure panel 1. When the temperature measured by the thermometer 21 falls below a predetermined temperature at which freezing or condensation may occur, the control device 2 activates the floor heating heater pump 22 to floor heating inside the floor heating heater 15. Hot water stored in the tank 19 is allowed to flow through the heater pipe 25. At this time, the control device 2 may operate the floor heating heater valve 23 as necessary.

  As a result, the heat stored in the hot water tank 11 is dissipated inside the enclosure panel 1. Due to this heat dissipation, the temperature inside the enclosure panel 1 rises, and freezing and condensation of the equipment inside the enclosure panel 1 are suppressed.

  That is, the floor heating heater 15, the floor heating heater pump 22, and the floor heating heater valve 23 are heat radiating devices that can radiate the heat stored in the hot water storage tank 11 to the inside of the enclosure. It is controlled by the control device 2 based on the temperature.

  The system that supplies the reforming water to the reformer 6 does not form a circulation system. For this reason, in the state where the fuel cell 4 is not generating power, the water present in the system that supplies the reforming water to the reformer 6 is stopped. However, in the fuel cell power generation system of the present embodiment, it is possible to prevent the entire interior of the enclosure panel 1 from falling below a predetermined temperature that may cause freezing or condensation. For this reason, even if it is a system that supplies reforming water to the reforming device 6 that does not form a circulation system, a system that bypasses the reforming device 6 and returns the reforming water to the water tank 8 in order to perform circulation operation. The freezing of the water used in the fuel cell power generation system can be suppressed without adding. Therefore, stable operation can be realized.

  Further, in the case of a system in which cooling water is circulated to prevent freezing, the control becomes complicated if there are a plurality of cooling water systems that must be prevented from freezing. However, in the present embodiment, since the entire interior of the enclosure panel 1 is heated, freezing can be suppressed with a simple configuration.

  Furthermore, the hot water tank 11 needs to be provided with a boiler 16 in order to keep the hot water supply temperature at a predetermined temperature or higher. Therefore, when the temperature of the water supplied to the floor heater 15 is low, the control device 2 may activate the boiler 16 to increase the temperature of the water. If it does in this way, the temperature of the water supplied to the floor heater 15 can be kept above a predetermined temperature without providing additional equipment.

  In addition, since the entire interior of the enclosure panel 1 can be prevented from falling below a predetermined temperature that may cause freezing or condensation, it is possible to suppress freezing and condensation from occurring in electrical components such as the power converter 3. it can.

  The threshold temperature at which the control device 2 starts to radiate heat with the floor heater 15 or the like may be a constant value. For example, when the temperature change is abrupt, the threshold temperature may be increased. In this case, even if the heating rate inside the enclosure panel 1 by the floor heater 15 is relatively small, it corresponds to a sudden change in the temperature inside the enclosure panel 1 due to a sudden change in the outside air temperature. The interior of the enclosure panel 1 can be kept at a predetermined temperature or higher.

  Further, a hygrometer may be provided inside the enclosure panel 1 to control the heat dissipation device according to temperature and humidity. Thereby, generation | occurrence | production of condensation can be suppressed more. Moreover, although the hot water storage tank 11 used for hot water supply was demonstrated as an example here as a heat storage apparatus, what is used for a heating system etc. may be used.

  The heat radiating device may be other than the floor heater 15. For example, it may be a pipe that is routed in the vicinity of a device that needs to suppress freezing / condensation such as the power conversion device 3 and the fuel cell 4 and through which water in the tank 19 flows. Furthermore, you may use combining such a thermal radiation apparatus.

[Second Embodiment]
FIG. 2 is a block diagram of a fuel cell power generation system according to a second embodiment of the present invention.

  The fuel cell power generation system according to the present embodiment is different from the first embodiment in that the floor heater 15 is provided in the middle of the exhaust heat recovery system. In the present embodiment, the floor heating heater 15 is inserted into the exhaust heat recovery system on the downstream side of the recovery heater 14. Accordingly, the floor heating heater pump 22 (see FIG. 1) and the floor heating heater valve 23 (see FIG. 1) become unnecessary. The water flowing to the floor heater 15 is driven by the hot water pump 12.

  The control device 2 controls the flow of water to the floor heater 15 by controlling the hot water pump 12. That is, when the temperature measured by the thermometer 21 falls below a predetermined temperature at which freezing or condensation may occur, the control device 2 activates the hot water pump 12 to floor heating inside the floor heating heater 15. Hot water stored in the tank 19 is allowed to flow through the heater pipe 25.

  Even in such a fuel cell power generation system, freezing can be suppressed as in the first embodiment. In the present embodiment, the number of pumps and valves can be reduced as compared with the first embodiment.

  In the exhaust heat recovery system, a valve that bypasses the floor heating heater 15 may be provided on the downstream side of the recovery heater 14. By controlling this valve with the control device 2, when there is no risk of freezing / condensation, water from which the exhaust heat is recovered does not flow to the floor heater 15, and unnecessary heating inside the enclosure panel 1 is suppressed. be able to.

[Other embodiments]
The above-described embodiments are merely examples, and the present invention is not limited to these. Moreover, you may implement combining the characteristic of each embodiment.

1 is a block diagram of a fuel cell power generation system according to a first embodiment of the present invention. It is a block diagram in 2nd Embodiment of the fuel cell power generation system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Enclosure panel, 2 ... Control apparatus, 3 ... Power converter device, 4 ... Fuel cell, 5 ... Cooling water pump, 6 ... Reformer, 7 ... Reformed water pump, 8 ... Water tank, 9 ... Pure water device DESCRIPTION OF SYMBOLS 10 ... Pure water pump, 11 ... Hot water storage tank, 12 ... Hot water pump, 14 ... Recovery heater, 15 ... Floor heater, 16 ... Boiler, 17 ... Hot water supply valve, 18 ... Water, 19 ... Tank, 20 ... Water supply valve, DESCRIPTION OF SYMBOLS 21 ... Thermometer, 22 ... Floor heating heater pump, 23 ... Floor heating heater valve, 25 ... Floor heating heater piping, 31 ... Heat exchanger, 32 ... Heat exchanger

Claims (8)

An enclosure panel;
A fuel cell power generator housed in the enclosure panel;
A heat storage device for recovering exhaust heat discharged from the fuel cell power generation device and storing it in a heat storage medium;
A thermometer for measuring the temperature inside the enclosure panel inside the enclosure panel;
A heat dissipating device capable of dissipating heat stored in the heat storage medium into the enclosure panel;
A control device for controlling the heat dissipation device based on the internal temperature of the enclosure panel;
A fuel cell power generation system comprising:   2. The fuel cell power generation system according to claim 1, wherein the heat dissipation device includes a heat radiator that guides the heat storage medium to the inside of the enclosure panel to dissipate heat.   The fuel cell power generation system according to claim 2, wherein the radiator includes a floor heating heater provided on a floor surface of the enclosure panel.   The said heat radiator is arrange | positioned in the position which can each heat at least one part of the components of the said fuel cell electric power generating apparatus, The piping which the said thermal storage medium flows through is arrange | positioned. The fuel cell power generation system according to claim 3.   The fuel cell power generation according to any one of claims 1 to 4, wherein the control device operates the heat dissipation device when an internal temperature of the enclosure panel becomes a threshold value or less. system.   6. The fuel cell power generation system according to claim 5, wherein the threshold value changes based on a change amount per unit time of the enclosure panel internal temperature.   The fuel according to any one of claims 1 to 6, wherein the heat storage device includes a heating device that heats the heat storage medium, and the control device further controls the heat storage device. Battery power generation system.   The surplus power recovery heater that heats the cooling water using surplus power of the fuel cell power generator is provided, and the control device further controls the surplus power recovery heater. Item 8. The fuel cell power generation system according to any one of Items 7.

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