JPH11102720A - Fuel cell power generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell power generating device capable of preventing the generation of the white smoke of water vapor when plant exhaust gas is exhausted to the atmosphere. SOLUTION: A fuel cell, a reformer, an exhaust heat recovery device, and an exhaust gas condenser 4 are connected through a gas flow path. The reformer has a burner and a reforming pipe. The exhaust gas condenser 4 uses secondary cooling water as a low-temperature side fluid, and has a chimney 6 for exhausting plant exhaust gas. A condensing device 5 is installed between the condenser 4 and the chimney 6. The condensing device 5 is connected to a supply route of make-up water 14, so that the make-up water 14 supplied to a cell cooling water line 13 is used as the low-temperature side fluid for condensing. A reservoir tank 15 is arranged in the supply route of the make-up water 14 between the condensing device 5 and the cell cooling water line 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell power generator provided with equipment necessary for power generation of a fuel cell, and more particularly to a fuel cell power generator having an improved exhaust gas exhaust system for a plant.

[0002]

2. Description of the Related Art A fuel cell is a power generation device that directly converts chemical energy of fuel into electric energy by reacting hydrogen generated from a raw fuel such as natural gas and methanol with oxygen in the air. Because it does not undergo heat energy or kinetic energy processes, it has low pollution and high power generation efficiency can be expected even on a small scale.

A general fuel cell is a reformer for producing hydrogen by a reforming reaction by adding steam to a hydrocarbon-based fuel, and an apparatus for supplying and recovering steam required in the reforming process. In order to maintain the reaction conditions and increase the plant efficiency, a fuel cell power generator is configured together with a plurality of heat exchangers and the like provided in a gas or cooling water flow path.

[0004] By the way, a relatively small-capacity fuel cell power generation facility installed in a place where there is a demand for electricity or heat is called an on-site fuel cell, but a normal on-site fuel cell seems to be convenient for installation. The fuel cell power generator is configured as a package-type fuel cell power generator in which a fuel cell body, other devices, piping, and the like are housed in a package.

An example of an exhaust system conventionally used in such a package type fuel cell power generator will be described with reference to FIG. That is, this exhaust system is configured by connecting the fuel cell 2, the reformer 1, the exhaust heat recovery device 3, and the exhaust gas condenser 4 through a gas flow path. The illustration of the reaction gas supply path to the fuel cell 2, the cell cooling water path, and the heat exchangers and the like appropriately arranged in various places is omitted.

[0006] Both electrodes of the fuel cell 2 are an anode 2a and a cathode 2b, respectively. Reformer 1
Has a burner 1b to which the anode exhaust gas 7 from the anode electrode 2a and the air 9 are supplied, and a reforming tube 1c heated by the burner 1b. The exhaust gas condenser 4 is connected to a chimney 6 for discharging the plant exhaust gas 11 using the secondary cooling water 12 as a low-temperature fluid.

In one example of the exhaust system described above, when the fuel cell 2 generates electric energy by the reaction between hydrogen generated by the reformer 1 and oxygen in the air, water is generated as a by-product. The generated water is mixed into the anode exhaust gas 7 containing unreacted hydrogen from the anode electrode 2a and mixed into the exhaust air 8 from the cathode electrode 2b and discharged.

Then, the anode exhaust gas 7 is sent to the reformer 1, and is supplied as fuel to a burner 1b for generating a high-temperature gas in order to promote a reforming reaction which is an endothermic reaction. Air 9 for combustion is also added to the burner 1b. The combustion gas generated in the burner 1b contains a large amount of water vapor for hydrogen combustion. After transferring heat for the reforming reaction to the reforming pipe 1c, the exhaust heat recovery device 3 is used as the reformer exhaust gas 10. Since it passes, the wetness is high.

Furthermore, the reformer exhaust gas 1 having a high wetness
0 and the exhaust air 8 containing water vapor from the cathode 2 b are sent to the exhaust gas condenser 4 and condensed using the secondary cooling water 12 to collect condensed water. The gas after water recovery is
As the plant exhaust gas 11, it is continuously released into the atmosphere via the chimney 6.

[0010]

However, unrecovered water exists in the above-mentioned plant exhaust gas 11 in a saturated state. For this reason, when the plant exhaust gas 11 discharged from the chimney 6 is cooled by the atmosphere and a condensation phenomenon occurs,
From the outside, it will be observed as steam white smoke.
This phenomenon tends to be remarkable in winter when the atmospheric temperature is low.However, such noticeable steam white smoke is not preferable from the viewpoint of landscape, especially when installed in urban areas, and is mistaken as a fire Could be done.

The present invention has been proposed to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a fuel cell capable of preventing generation of steam white smoke when discharging plant exhaust gas to the atmosphere. An object of the present invention is to provide a power generator.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a reformer for reforming raw fuel to obtain hydrogen, and a method for producing hydrogen from the reformer and oxygen in air. A fuel cell having a fuel cell that obtains electric energy by reacting with a fuel cell and a reaction gas path and a cooling water path have the following technical features.

That is, the first aspect of the present invention is a first condensing means for condensing and recovering water from the exhaust gas of the reformer and the exhaust air of the fuel cell, and discharging the water as plant exhaust gas. Second condensing means for further condensing and recovering water from the plant exhaust gas discharged from the means. According to the first aspect of the present invention, since water is condensed and recovered by the second condensing means with respect to the plant exhaust gas whose water is condensed and recovered by the first condensing means, water vapor in the plant exhaust gas is reduced. Also, even when cooled by the atmosphere, the generation of white steam is prevented.

According to a second aspect of the present invention, in the fuel cell power generator according to the first aspect, the low-temperature side fluid of the second condensing means is makeup water to a cooling water path of the fuel cell. And According to the second aspect of the present invention, since the make-up water used as the low-temperature side fluid of the second condensing means has a low water temperature, it is possible to efficiently condense and recover water even with a small flow rate.

According to a third aspect of the present invention, in the fuel cell power generator according to the first aspect, the second condensing means is constituted by a heat pipe. According to the third aspect of the present invention, water is condensed and recovered by the heat pipe with respect to the plant exhaust gas in which water is condensed and recovered by the first condensing means. Even when cooled, generation of steam white smoke is prevented.

According to a fourth aspect of the present invention, in the fuel cell power generator according to the third aspect, the reformer, the fuel cell,
The reaction gas path, the cooling water path, the first condensing unit and the second condensing unit are housed in a package, and the package is provided with a ventilation fan, and the heat pipe is located near the ventilation fan. And a radiation fin is provided at a position corresponding to the airflow of the ventilation fan in the heat pipe. According to the fourth aspect of the present invention, since the heat transfer efficiency is improved by disposing the heat radiation fins in the airflow of the ventilation fan, the heat radiation effect can be significantly improved.

According to a fifth aspect of the present invention, in the fuel cell power generator according to the first aspect, an exhaust duct is provided in the first condensing means, and an inner surface of the exhaust duct has a heat transfer function of the second condensing means. Surface. According to the fifth aspect of the present invention, the device can be simplified by configuring the inner surface of the exhaust duct as a heat transfer surface for condensation.

According to a sixth aspect of the present invention, there is provided a condensing means for condensing and recovering water from the exhaust gas from the reformer and the exhaust air from the fuel cell, and discharging the condensed water as plant exhaust gas. And heating means for heating. In the sixth aspect of the present invention, the exhaust gas from which water has been condensed and recovered by the condensing means is released to the atmosphere after being reheated by the heating means to reduce the partial pressure of water vapor. Then, the transition from saturated condensation of water due to cooling in the atmosphere to the generation of steam white smoke is temporally alleviated, and the plant exhaust gas is rapidly diffused into the atmosphere. Can be.

According to a seventh aspect of the present invention, in the fuel cell power generator according to the sixth aspect, an exhaust duct is provided in the condensing means, and an inner surface of the exhaust duct is a heat transfer surface of the heating means. And According to the seventh aspect of the present invention, the apparatus can be simplified by configuring the inner surface of the exhaust duct as a heat transfer surface for heating.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the related art shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

(1) First Embodiment (Configuration) An embodiment corresponding to the first and second aspects of the present invention will be described with reference to FIG. That is, in the present embodiment, the condenser 5 is provided between the exhaust gas condenser 4 and the chimney 6. The condenser 5 is connected to a supply path of the makeup water 14 so that the makeup water 14 injected into the battery cooling water system 13 can be used as a low-temperature fluid for condensation. A reservoir tank 15 as a water storage tank is provided in a supply path of the makeup water 14 between the condenser 5 and the battery cooling water system 13.

(Operation) In the present embodiment having the above configuration, the reformer exhaust gas 10 and the exhaust air 8 of the battery are condensed in the exhaust gas condenser 4 to recover water. The plant exhaust gas 11 from the exhaust gas condenser 4 is further condensed using low-temperature make-up water 14 in the condenser 5, and the uncondensed water is recovered in the exhaust gas condenser 4. Therefore, the plant exhaust gas 1 discharged from the chimney 6
The steam in 1 is reduced, and the generation of steam white smoke is prevented even when cooled by the atmosphere.

The supply amount of the make-up water 14 to the battery cooling water system 13 is adjusted in the reservoir tank 15 by absorbing temporal fluctuations.
4 can be flowed continuously.

(Effects) According to the present embodiment as described above, since the white steam generated from the plant exhaust gas 11 is suppressed, the landscape is not spoiled, and there is no possibility of being mistaken as a fire. Further, since the make-up water 14 used in the battery cooling water system 13 has a low water temperature, the water can be condensed and recovered even if the flow rate is small, and efficient condensation can be realized. Further, since the supply water 14 can be continuously supplied by using the reservoir tank 15, it is possible to uniformly and stably suppress steam white smoke.

(2) Second Embodiment (Configuration) An embodiment corresponding to the third and fourth aspects of the present invention will be described with reference to FIG. First, in the present embodiment, similarly to a general package type fuel cell power generator, a motor room ventilation system and a fuel handling flammable gas are used in order to maintain the temperature of a device or a measuring instrument in the package at a normally operable temperature. A plurality of ventilation fans 17 for forced ventilation represented by a room ventilation system are provided.

As in the first embodiment, a condensing device 5 is provided between the exhaust gas condenser 4 and the chimney 6. The condenser 5 is constituted by a heat pipe 16 through which a refrigerant circulates, and the heat pipe 16 is extended to a position corresponding to the ventilation fan 17. further,
In the vicinity of the ventilation fan 17 in the heat pipe 16, cooling can be performed by the airflow of the ventilation fan 17.
The radiation fin 16a is provided.

(Operation) In the present embodiment having the above-described configuration, the reformer exhaust gas 10 and the exhaust air 8 of the battery are condensed in the exhaust gas condenser 4 to recover water. The plant exhaust gas 11 from the exhaust gas condenser 4 is
In the condenser 5, the water is further condensed by the refrigerant circulating through the heat pipe 16, and the uncondensed water is recovered in the exhaust gas condenser 4. For this reason, the steam in the plant exhaust gas 11 discharged from the chimney 6 is reduced, and the generation of white steam is suppressed even when cooled by the atmosphere.

(Effects) According to the present embodiment as described above, since the white steam generated from the plant exhaust gas 11 is suppressed, the landscape is not impaired as in the first embodiment. There is no risk of being mistaken for a fire. In addition, since the heat radiation of the refrigerant is performed by the heat radiation fins 16 in the airflow by the ventilation fan 17, the heat transfer efficiency is good and the heat radiation effect can be greatly improved. Furthermore, since the ventilation fan 17 is used for ventilation inside the package, existing devices can be used, and manufacturing costs can be reduced.

(3) Third Embodiment (Configuration) An embodiment corresponding to the invention described in claim 5 is as follows:
This will be described with reference to FIG. That is, in the present embodiment, instead of providing the condenser 5 as in the first embodiment between the exhaust gas condenser 4 and the chimney 6, the inner surface of the exhaust duct 18 connected to the chimney 6 By configuring the make-up water 14 as a heat transfer surface of a condenser circulating as a low-temperature fluid, the plant exhaust gas 11 passing through the exhaust duct 18 is
This is configured to be condensed by the makeup water 14.
The other configuration is the same as that of the first embodiment.

(Operation) In the present embodiment having the above configuration, the reformer exhaust gas 10 and the exhaust air 8 of the battery are condensed in the exhaust gas condenser 4 to recover water. The plant exhaust gas 11 from the exhaust gas condenser 4 and the chimney 6 is supplied to the makeup water 14
, And the uncondensed water is recovered in the exhaust gas condenser 4. For this reason, the steam in the plant exhaust gas 11 discharged from the exhaust duct 18 is reduced, and the generation of steam white smoke is suppressed even when cooled by the atmosphere.

(Effects) According to the present embodiment as described above, the same effects as those of the first embodiment can be obtained, and the inner surface of the exhaust duct 18 is configured as a heat transfer surface of the condenser. Thus, the apparatus can be simplified. In addition, by connecting the exhaust duct 18 having the above configuration to the chimney 6 of the exhaust gas condenser 4, the present invention can be easily applied to existing facilities.

(4) Fourth Embodiment (Configuration) An embodiment corresponding to the invention described in claim 6 is
This will be described with reference to FIG. That is, in the present embodiment, the heater 19 is provided between the exhaust gas condenser 4 and the chimney 6. The secondary cooling water 12 used as the low-temperature fluid of the exhaust gas condenser 4 is used as the secondary cooling water 12 in the heater 19 so that the secondary cooling water 12 can be used as the heating fluid.
Distribution channels are connected.

(Operation) In the present embodiment having the above-described configuration, the reformer exhaust gas 10 and the exhaust air 8 of the battery are condensed in the exhaust gas condenser 4 to recover water. The plant exhaust gas 11 from the exhaust gas condenser 4 is reheated by the heat energy of the secondary cooling water 12 in the heater 19, and is discharged from the chimney 6 after the partial pressure of steam is reduced. For this reason, the transition from saturated condensation of water to generation of steam white smoke due to cooling in the atmosphere after release to the atmosphere is temporally mitigated.
Is rapidly diffused into the atmosphere, so that the generation of white smoke can be suppressed.

(Effects) According to the present embodiment as described above, since the white steam generated from the plant exhaust gas 11 is suppressed, the landscape is not spoiled, and there is no possibility of being mistaken as a fire. Also, for heating the plant exhaust gas 11,
Since the secondary cooling water 12 used in the exhaust gas condenser 4 is used, efficient heat utilization is possible.

(5) Fifth Embodiment (Configuration) An embodiment corresponding to the seventh aspect of the present invention is
This will be described below with reference to FIG. That is, in the present embodiment, instead of providing the heater 19 between the exhaust gas condenser 4 and the chimney 6 as in the fourth embodiment, the inner surface of the exhaust duct 18 connected to the chimney 6 By forming the secondary cooling water 12 as a heat transfer surface of a heater that circulates as a heating fluid, the plant exhaust gas 11 passing through the exhaust duct 18 can be heated by the secondary cooling water 12.

(Operation) In the present embodiment having the above-described configuration, the reformer exhaust gas 10 and the exhaust air 8 of the battery are condensed in the exhaust gas condenser 4 to recover water. In the process of passing through the exhaust duct 18, the plant exhaust gas 11 from the exhaust gas condenser 4 and the chimney 6 is reheated by the thermal energy of the secondary cooling water 12, and is released after the partial pressure of steam is reduced. Therefore, the white steam can be suppressed in the same manner as in the fourth embodiment.

(Effects) According to the present embodiment as described above, the same effects as those of the fourth embodiment can be obtained, and the inner surface of the exhaust duct 18 is configured as a heat transfer surface of a heater. Thus, the apparatus can be simplified.
In addition, by connecting the exhaust duct 18 having the above configuration to the chimney 6 of the exhaust gas condenser 4, the present invention can be easily applied to existing facilities.

(6) Other Embodiments The present invention is not limited to the above-described embodiment. For example, in the second embodiment, ventilation for cooling the heat pipe 16 is performed. Instead of forced cooling by the fan 17, it is also possible to use outside air as a low heat source. Further, the present invention is effective for a package type fuel cell power generator, but is not necessarily limited thereto.

[0039]

As described above, according to the present invention,
It is possible to provide a fuel cell power generation device capable of preventing generation of steam white smoke when discharging plant exhaust gas to the atmosphere.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a conventional exhaust system of a fuel cell power generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reformer 2 ... Fuel cell 2a ... Anode 2b ... Cathode 3 ... Exhaust heat recovery device 4 ... Exhaust gas condenser 5 ... Condenser 6 ... Chimney 7 ... Anode exhaust 8 ... Battery exhaust air 9 ... Air 10 ... Reformer exhaust gas 11 ... Plant exhaust gas 12 ... Secondary cooling water 13 ... Battery cooling water system 14 ... Make-up water 15 ... Reservoir tank 16 ... Heat pipe 16a ... Radiation fin 17 ... Ventilation fan 18 ... Exhaust duct 19 ... Heater

Claims (7)

[Claims] 1. A reformer for reforming a raw fuel to obtain hydrogen,
In a fuel cell power generation apparatus having a fuel cell that obtains electric energy by reacting hydrogen from the reformer with oxygen in the air, and a reaction gas path and a cooling water path, the exhaust gas of the reformer and the fuel First condensing means for condensing and recovering water from the exhaust air of the battery and discharging it as plant exhaust gas; and second condensing means for further condensing and recovering water from the plant exhaust gas discharged from the first condensing means. A fuel cell power generator, comprising: 2. The fuel cell power generator according to claim 1, wherein the low temperature side fluid of the second condensing means is makeup water to a cooling water path of the fuel cell. 3. The fuel cell power generator according to claim 1, wherein said second condensing means is constituted by a heat pipe. 4. The package according to claim 1, wherein the reformer, the fuel cell, the reaction gas path, the cooling water path, the first condensing means and the second condensing means are housed in a package, and the package has ventilation. 4. A fan is provided, wherein the heat pipe is extended near the ventilation fan, and a radiation fin is provided at a position corresponding to an airflow of the ventilation fan in the heat pipe. Fuel cell power plant. 5. The fuel cell power generator according to claim 1, wherein an exhaust duct is provided in the first condensing means, and an inner surface of the exhaust duct is a heat transfer surface of the second condensing means. . 6. A reformer for reforming a raw fuel to obtain hydrogen,
A fuel cell that obtains electric energy by reacting hydrogen from the reformer with oxygen in the air, and a fuel cell power generator having a reaction gas path and a cooling water path of the fuel cell; A fuel cell power generator comprising: a condensing unit that condenses and recovers water from exhaust gas and exhaust air of the fuel cell and discharges it as plant exhaust gas; and a heating unit that heats the plant exhaust gas discharged from the condensing unit. . 7. The fuel cell power generator according to claim 6, wherein an exhaust duct is provided in the condensing means, and an inner surface of the exhaust duct is a heat transfer surface of the heating means.