JP2009245768A - Fuel cell power generating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generating apparatus discharging exhaust gas without forming white plume with simple constitution in collecting reaction produced water and combustion produced water in exhaust gas by a water collecting apparatus and discharging separated exhaust gas to the outside. <P>SOLUTION: The fuel cell power generating apparatus includes a fuel reforming apparatus; a fuel cell body; the water collecting apparatus for collecting reaction produced water and combustion produced water; an exhaust heat utilizing heat exchanger for recovering waste heat ejected from the fuel cell body, to an external heat utilization facility; and an air-cooled waste heat treating facility for radiating exhaust heat other than the exhaust heat recovered to the heat utilization facility, to the outside. The fuel cell power generating apparatus is constituted such that the exhaust gas discharged from the water collecting apparatus 5 of the fuel cell power generating apparatus body 20 is mixed with outlet air of the air-cooled exhaust heat treating facility 8 and discharged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell power generator that obtains electrical energy by an electrochemical reaction.

A fuel cell power generator is a fuel cell body that introduces fuel gas and air to generate power by an electrochemical reaction, a fuel reformer that reforms raw fuel into a hydrogen-rich fuel gas, and a fuel cell body A battery cooling water system that plays a role in maintaining a predetermined operating temperature, a water recovery device that recovers reaction product water generated in the fuel cell main body as a result of power generation and combustion product water generated in the fuel reformer, and heat generated by power generation It is composed of a heat exchanger using exhaust heat that takes out the outside, and other auxiliary equipment and control equipment.
Among these, there are various types of fuel cells incorporated into the fuel cell main body, which are classified according to the type of electrolyte used. For example, phosphoric acid fuel cells using phosphoric acid as an electrolyte are well known. ing. Natural gas is generally used as a raw fuel for obtaining fuel gas to be supplied to the fuel electrode of the fuel cell body. The introduced raw fuel is mixed with steam and sent to a fuel reformer, where it is reformed into a hydrogen-rich fuel gas by a steam reforming reaction. In the fuel cell main body, hydrogen of the fuel gas is supplied to the fuel electrode, and oxygen of the reaction air is supplied to the air electrode, whereby an electrochemical reaction occurs and electric energy is obtained, and at the same time, reaction product water is generated. This reaction product water is recovered by the water recovery device together with the combustion product water contained in the exhaust gas discharged from the heating burner of the fuel reformer, purified and returned to the battery cooling water system again for the steam reforming reaction. Recycled as water vapor.

A cooling plate is incorporated in the fuel cell body, and the fuel cell body is maintained at a predetermined operating temperature by circulatingly supplying battery cooling water. The heat generated in the fuel cell body is taken out by the battery cooling water, sent to the user via the heat exchanger, and used. The heat not used by the heat exchanger is radiated to the outside by the exhaust heat treatment apparatus. Although there are several types of exhaust heat treatment apparatuses used, air-cooled coolers are often used for reasons such as easy maintenance.
As described above, in this type of fuel cell power generation device, the reaction product water generated in the fuel cell main body and the combustion product water generated in the fuel reformer are recovered by the water recovery device, and thus are discharged from the water recovery device. The exhaust gas is saturated with water. Therefore, when the exhaust gas in the water saturation state is discharged to the outside and cooled by the outside air having a lower temperature, the water vapor in the exhaust gas becomes white smoke. Although the white smoke of exhaust gas is not a fatal defect for a fuel cell power generation device, it may be regarded as a problem depending on the installation location of the device, and various fuel cell power generation devices having a function of suppressing white smoke are also various. It is disclosed.
For example, in the apparatus of Patent Document 1, a heater is installed to heat exhaust gas, thereby reducing the amount of water and suppressing white smoke. Moreover, in the apparatus of patent document 2, the exhaust heater heated with sunlight is provided, exhaust gas is heated, the moisture content is lowered | hung and white smoke generation is suppressed. Further, in the devices of Patent Document 3 and Patent Document 4, exhaust gas is mixed with ventilation of the package type fuel cell power generation device and exhausted to reduce the amount of water and suppress white smoke.
Moreover, in the apparatus of patent document 5, exhaust gas is cooled with the supplementary water supplied to a battery cooling water system, a water | moisture content is removed, and white smoke is prevented. Moreover, in the apparatus of patent document 6, exhaust gas is heated with the blowdown water of the water vapor separator of a battery cooling water system, the moisture content is lowered | hung and white smoke generation is suppressed. In addition, in the device of Patent Document 7, a heat exchanger for heating the exhaust gas is provided in the water recovery device, and the exhaust gas is heated by heating with this heat exchanger, and the amount of moisture is reduced to suppress white smoke. ing. In the apparatus of Patent Document 8, white smoke is prevented by changing the area of the exhaust gas discharge port to adjust the flow velocity.
Japanese Unexamined Patent Publication No. 7-169498 JP-A-8-236133 JP-A-8-293316 JP-A-9-223510 JP-A-11-102720 Japanese Patent Laid-Open No. 2001-185199 Japanese Patent Laid-Open No. 2002-100382 Japanese Unexamined Patent Publication No. 2005-222892

As described above, in the fuel cell power generation device, the reaction product water generated in the fuel cell main body and the combustion product water generated in the fuel reformer are recovered and reused by the water recovery device, and the water-saturated exhaust gas is generated. Although it is discharged from the water recovery unit, if this water-saturated exhaust gas is released into the atmosphere, water vapor in the exhaust gas will become white smoke, which may be considered a problem depending on the installation location. It is. As described above, a number of measures have already been used as described above. However, there are advantages and disadvantages, and a fuel cell power generation device that can easily prevent white smoke is desired.
The present invention has been made in view of the current state of the art, and an object of the present invention is to recover and reuse reaction product water and combustion product water in exhaust gas by a water recovery device. An object of the present invention is to provide a fuel cell power generation apparatus that discharges separated exhaust gas to the outside without exhausting the exhaust gas with a simple configuration.

In the present invention, in order to achieve the above object,
A fuel reformer for reforming raw fuel to obtain a hydrogen-rich fuel gas, a fuel cell main body for generating power by introducing the fuel gas and reaction air, exhaust air discharged from the fuel cell main body, and the fuel A water recovery device that recovers moisture contained in the flue gas discharged from the reformer, and battery cooling water discharged through the cooling plate provided in the fuel cell main body to external heat utilization equipment In a fuel cell power generator equipped with an exhaust heat utilization heat exchanger to be recovered and an air-cooled exhaust heat treatment facility for dissipating exhaust heat other than the exhaust heat recovered to the external heat utilization facility,
The exhaust gas exhausted from the water recovery device is configured to be exhausted by mixing with the outlet air of the air-cooled exhaust heat treatment facility. For example, the air cooling outlet provided with an exhaust fan is provided at the exhaust port of the water recovery device. It is supposed to be connected to the outlet of the type waste heat treatment equipment. Alternatively, the exhaust port of the water recovery device is provided close to the outlet of the air-cooled exhaust heat treatment facility provided with the exhaust fan.

  As described above, the fuel reformer, the fuel cell main body, the water recovery device that recovers the moisture contained in the exhaust air and the combustion exhaust gas, and the exhaust that recovers the heat of the discharged battery cooling water to an external heat utilization facility. In a fuel cell power generation apparatus equipped with a heat-use heat exchanger and an air-cooled exhaust heat treatment facility for dissipating exhaust heat other than the exhaust heat collected in this external heat-use facility, the outlet air of the air-cooled exhaust heat treatment facility The flow rate is sufficiently larger than the flow rate of the exhaust gas discharged from the water recovery apparatus, and the temperature is higher than that of the exhaust gas. Therefore, as in the present invention, if the exhaust gas discharged from the water recovery device is configured to be mixed and discharged with the outlet air of the air-cooled exhaust heat treatment facility, the exhaust gas is diluted with hot outlet air, Since the moisture in the exhaust gas sufficiently falls below the saturation state, white smoke is suppressed. In particular, the exhaust port of the water recovery device is connected to the outlet of the air-cooled exhaust heat treatment facility equipped with the exhaust fan, or the exhaust port of the water recovery device is connected to the outlet of the air-cooled exhaust heat treatment facility equipped with the exhaust fan. If it is provided close to the outlet, the exhaust gas can be easily diluted, and the exhaust gas can be prevented from becoming white smoke.

The best embodiment of the fuel cell power generator of the present invention is:
A fuel reformer for reforming raw fuel to obtain a hydrogen-rich fuel gas, a fuel cell main body for generating power by introducing the fuel gas and reaction air, exhaust air discharged from the fuel cell main body, and the fuel A water recovery device that recovers moisture contained in the flue gas discharged from the reformer, and battery cooling water discharged through the cooling plate provided in the fuel cell main body to external heat utilization equipment In a fuel cell power generation apparatus comprising an exhaust heat utilization heat exchanger to be recovered and an air-cooled exhaust heat treatment facility for dissipating exhaust heat other than the exhaust heat recovered to the external heat utilization facility, the exhaust of the water recovery device The outlet is connected to the outlet of the air-cooled exhaust heat treatment facility equipped with an exhaust fan, and the exhaust gas discharged from the water recovery device is mixed with the outlet air of the air-cooled exhaust heat treatment facility and discharged. In the embodiment.
In addition, instead of the above embodiment, the water recovery device has an exhaust port close to the outlet of an air-cooled exhaust heat treatment facility equipped with an exhaust fan, and the exhaust gas discharged from the water recovery device is air-cooled exhaust heat treatment It is also good as an embodiment configured to be mixed and discharged with the outlet air of the facility.

FIG. 1 is a basic system diagram of a first embodiment of the fuel cell power generator of the present invention, and FIG. 2 is a side view of the first embodiment. In FIG. 1, 1 is a fuel cell main body, 2 is a fuel reformer, and 3 and 4 are a water vapor separator and a heat exchanger constituting a battery cooling water system. 5 is a water recovery device, 6 and 7 are heat exchangers, 8 is an air-cooled exhaust heat treatment device, and 11, 12, 14, and 15 are pumps.
When the raw fuel is reformed into hydrogen-rich fuel gas by the fuel reformer 2 and then supplied to the fuel electrode of the fuel cell main body 1, and simultaneously the reaction air is supplied to the other air electrode of the fuel cell main body 1. Electrochemical reaction takes place and electric energy is obtained. At the same time, reaction product water is generated along with the electrochemical reaction, and is contained and discharged in the exhaust gas from the air electrode. Further, since the exhaust gas from the fuel electrode of the fuel cell main body 1 contains hydrogen gas that has not been used for the electrochemical reaction, it is sent to the burner of the fuel reformer 2 in order to make effective use of this. The reforming reaction is promoted by mixing and burning with combustion air. Therefore, the combustion exhaust gas discharged from this burner contains combustion product water.
The exhaust gas from the air electrode containing the reaction product water and the combustion exhaust gas of the fuel reformer 2 containing the combustion product water are sent to the water recovery device 5 and cooled to recover the product water. The recovered water is sent to the steam separator 3 and used again as battery cooling water. In the fuel cell power generator of this embodiment, as shown in FIG. 2, the exhaust pipe 21 that exhausts exhaust gas from the water recovery device 5 of the fuel cell power generator main body 20 to the outside is the air of the air-cooled exhaust heat treatment device 8. It is connected to the outlet duct 8a and is characterized in that the exhaust gas from the water recovery device 5 is mixed with the exhaust of the air-cooled exhaust heat treatment device 8 and discharged. In the fuel cell power generator configured as described above, the exhaust gas discharged from the exhaust pipe 21 is in a water saturated state, but is mixed with a large amount of high-temperature outlet air in the air outlet duct 8a of the air-cooled exhaust heat treatment apparatus 8. As a result, the water is sufficiently diluted to fall below the saturated state, so that white smoke of the gas released to the outside is prevented.

FIG. 3 is a side view of a second embodiment of the fuel cell power generator of the present invention. The feature of the present embodiment is that the outlet of the exhaust pipe 21 for discharging the exhaust gas to the outside from the water recovery device 5 of the fuel cell power generator main body 20 is close to the outlet of the air outlet duct 8b of the air-cooled exhaust heat treatment device 8. It is to be arranged. Also in this configuration, the exhaust gas from the water recovery device 5 is mixed with the exhaust of the air-cooled exhaust heat treatment device 8 and discharged, so that the exhaust gas discharged from the exhaust pipe 21 is the air of the air-cooled exhaust heat treatment device 8. Since it is mixed with a large amount of outlet air discharged from the outlet duct 8b and diluted, the water content is not saturated. Therefore, the white smoke of the emitted gas to the outside is suppressed.

  FIG. 4 is a side view of a third embodiment of the fuel cell power generator of the present invention. The feature of this embodiment is that an air-cooled exhaust heat treatment device 8A is installed vertically, an outlet of an exhaust cylinder 22 that exhausts exhaust gas from the water recovery device 5 of the fuel cell power generator main body 20 to the outside, an air-cooled exhaust The outlet of the air outlet duct 8c of the heat treatment apparatus 8A is disposed relatively close to each other. With such a configuration, as in the first and second embodiments, white smoke of the exhaust gas from the water recovery device 5 is suppressed, and furthermore, the installation area of the air-cooled exhaust heat treatment device 8A is reduced. The battery power generator is also small and compact.

  As described above, in the fuel cell power generator of the present invention, the proportion of moisture contained in the exhaust gas discharged from the water recovery device 5 is reduced, and white smoke of the exhaust discharged to the outside is suppressed. It is widely used as a fuel cell power generator for various uses.

Basic system diagram of the first embodiment of the fuel cell power generator of the present invention 1 is a side view of a first embodiment of a fuel cell power generator according to the present invention. Side view of the second embodiment of the fuel cell power generator of the present invention Side view of the third embodiment of the fuel cell power generator of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell main body 2 Fuel reformer 3 Steam separator 4 Heat exchanger 5 Water recovery device 8 Air-cooled exhaust heat treatment device 8A Air-cooled exhaust heat treatment device 8a, 8b, 8c Air outlet duct (air-cooled exhaust heat treatment device)
20 Fuel Cell Power Generator Main Body 21 Exhaust Pipe (Fuel Cell Power Generator Main Body)
22 Exhaust tube (fuel cell generator main unit)

Claims (3)

A fuel reformer for reforming raw fuel to obtain a hydrogen-rich fuel gas, a fuel cell main body for generating power by introducing the fuel gas and reaction air, exhaust air discharged from the fuel cell main body, and the fuel A water recovery device that recovers moisture contained in the flue gas discharged from the reformer, and battery cooling water discharged through the cooling plate provided in the fuel cell main body to external heat utilization equipment In a fuel cell power generator equipped with an exhaust heat utilization heat exchanger to be recovered and an air-cooled exhaust heat treatment facility for dissipating exhaust heat other than the exhaust heat recovered to the external heat utilization facility,
An exhaust gas discharged from the water recovery device is configured to be discharged with being mixed with outlet air of the air-cooled exhaust heat treatment facility. 2. The fuel cell power generator according to claim 1, wherein an exhaust port of the water recovery device is connected to an outlet of the air-cooled exhaust heat treatment facility provided with an exhaust fan. 2. The fuel cell power generator according to claim 1, wherein an exhaust port of the water recovery device is provided close to an outlet of the air-cooled exhaust heat treatment facility including an exhaust fan.

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