JPH11204123A - Water treating apparatus for fuel cell power generating facilities - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water treatment apparatus for fuel cell power generating facilities in which no cooler for cooling water to be treated is required at a pre-stage of an ion-exchange resin and an exhaust heat recovery quantity is large. SOLUTION: Water 9 to be treated, which is composed of recovery water 7A from an exhaust gas cooler 7 combined with blow-down water 8 from a gas-liquid separator 4, is supplied to a heat-resistant type ion-exchange resin 13. The heat-resistant type ion-exchange resin 13 can be operated at temperatures of at least 90 deg.C is adapted to subject the water 9 to be treated as it is not cooled but kept at a high temperature for treatment with super pure water, and then to supply resultant supplementary water 15 to the gas- liquid separator 4. Since a cooler at the front stage of the heat resistant type ion exchange resin 13 is not required, it is possible to reduce the initial cost, and furthermore, since no cooling is conducted, exhaust heat recovery quantity is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water treatment device for a fuel cell power generation facility.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a block diagram showing a flow of water treatment in a conventional water treatment device for a fuel cell power generation facility shown in Japanese Patent Application Publication No. H10-207, in which 1 is a reformer that generates hydrogen by reacting fuel and steam, and 2 is a reformer. A fuel cell for obtaining DC power from hydrogen in the hydrogen-rich reformed gas generated in the reformer 1 and oxygen in the air, 3 for combustion air 3A to the reformer 1 and reaction for the fuel cell 2 Air blower for supplying air 3B, 4
Is a gas-liquid separator that collects heat generated when the fuel cell 2 generates power, generates steam using the heat, and supplies steam to the reformer 1 and the waste heat utilization facility 5. A battery cooling water circulation pump that sends cooling water, 7 is an exhaust gas cooler that cools the combustion exhaust gas 1A from the reformer 1 and the air electrode off-gas 2A from the fuel cell 2 to obtain recovered water 7A, and 8 is a gas-liquid separator 4 is blowdown water for maintaining water quality, 9 is treated water obtained by combining recovered water 7A and blowdown water 8, 10
Denotes a water pump, 11 denotes a water cooler for cooling the water 9 to a predetermined temperature, and 12 denotes an ion for ion-exchanging the water 9 cooled by the water cooler 11 to obtain ultrapure water. The exchange resin enables operation in a low temperature range of 40 ° C. or less.
Reference numeral 14 denotes a high-pressure pump that sends the replenishment water 15 that has become ultrapure water to the gas-liquid separator 4.

Next, the operation will be described. The reformer 1 produces a hydrogen-rich reformed gas using hydrocarbons such as natural gas and steam as raw materials. This reformed gas is supplied to the fuel electrode side of the fuel cell 2. On the other hand, reaction air 3B is supplied from the air blower 3 to the air electrode side of the fuel cell 2, and DC power is generated. Since the battery reaction is an exothermic reaction, pressurized water is supplied from the gas-liquid separator 4 to the fuel cell 2 by the battery cooling water circulation pump 6 to be cooled. At this time, the gas-liquid separator 4 has excess heat, and the heat is taken out of the fuel cell system 2 as steam, and is used by the exhaust heat utilization equipment 5.

Further, the combustion exhaust gas 1A from the reformer 1 and the air electrode off-gas 2A from the fuel cell 2 are supplied to an exhaust gas cooler 7A.
To sufficiently condense the water in the exhaust gas. The condensed water is supplied to the water treatment device as recovered water 7A. The water treatment apparatus is an apparatus that treats the water 9 to be treated including the recovered water 7A into ultrapure water, and uses the ion exchange resin 12 that operates in a low temperature range (40 ° C. or lower). The water temperature of the water 9 to be treated is about 50 ° C. to 80 ° C., and is cooled to a temperature of 40 ° C. or lower by the water cooler 11 before being supplied to the ion exchange resin 12 operating in a low temperature range. Ion exchange resin 1
The ultrapure water made in 2 is supplied with high pressure pump 14
5 is supplied to the gas-liquid separator 4.

[0005]

In the conventional water treatment apparatus for a fuel cell power generation facility, since ultrapure water is obtained by using the ion exchange resin operating in the low temperature region as described above, it is sent to the ion exchange resin. The temperature of the water to be treated had to be lowered to a temperature suitable for the ion exchange resin, and it was necessary to provide a water cooler before the ion exchange resin. In addition, by providing a water cooler to be treated, heat exchange is performed here,
There is a problem that the amount of exhaust heat recovery decreases. The present invention has been made in order to solve the above-mentioned problems, and makes it unnecessary to cool the water to be treated to be sent to the ion exchange resin, thereby eliminating the need for installing a water cooler in front of the ion exchange resin. It is another object of the present invention to obtain a water treatment apparatus for a fuel cell power generation facility having a large amount of waste heat recovery.

[0006]

A water treatment apparatus for a fuel cell power generation facility according to the present invention uses a high-temperature ion exchange resin as an ion exchange resin for treating water to be treated. Furthermore, it has a heating deaerator for heating and degassing the carbon dioxide gas in the recovered water by the heat of the blowdown water. Further, it has an air deaerator for sending air to degas carbon dioxide gas in the recovered water. Furthermore, it has a heat recovery unit that recovers heat from blowdown water to makeup water.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 1 of the present invention. In the drawing, reference numeral 1 denotes a reaction between a hydrocarbon gas such as natural gas and steam. A reformer that generates hydrogen and obtains a hydrogen-rich reformed gas is a fuel cell that obtains a DC power by reacting hydrogen in the reformed gas generated in the reformer 1 with oxygen in the air. , Water-cooled. 3 is an air blower that sends combustion air 3A to the reformer 1 and sends reaction air 3B to the fuel cell 2. 4 collects heat generated in the fuel cell 2 and generates steam using the heat to reform. -Liquid separator for supplying steam to the steam generator 1 and the waste heat utilization equipment 5, 6 for a battery cooling water circulation pump for sending cooling water to the fuel cell 2, 7 for the combustion exhaust gas 1A from the reformer 1, and for the fuel cell 2 This is an exhaust gas cooler that cools the air electrode off-gas 2A to obtain recovered water 7A.

[0008] Reference numeral 8 denotes blowdown water which is sent to water treatment to maintain the water quality of the gas-liquid separator 4, 9 denotes water to be treated which is a combination of the recovered water 7A and blowdown water 8, and 10 denotes water to be treated. The water supply pump 13 is a heat-resistant ion exchange resin that obtains ultrapure water by subjecting the water 9 to be subjected to ion exchange treatment. In this specification, a heat-resistant ion exchange resin is at least 90 ° C.
An anion exchanger having a plurality of hydrocarbon groups is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 4-34941. 14 is a make-up water 15 which has been treated and turned into ultrapure water.
Is a high-pressure pump that sends the gas to the gas-liquid separator 4.

Next, the operation will be described. Hydrocarbon such as natural gas and steam from the gas-liquid separator 4 are supplied to the reformer 1 and heated using these as raw materials to generate hydrogen,
A hydrogen-rich reformed gas is obtained. The reformed gas is supplied to the fuel electrode side of the fuel cell 2 and the reaction air 3B is supplied from the air blower 3 to the air electrode side of the fuel cell 2 to generate DC power. Since the reaction in the fuel cell 2 is an exothermic reaction, pressurized water is sent from the gas-liquid separator 4 to the fuel cell 2 by the cell cooling water circulation pump 6 and cooled. At this time, heat is left in the gas-liquid separator 4, and the heat is taken out of the fuel cell 2 system as steam and is used in the exhaust heat utilization equipment 5.

Further, a combustion exhaust gas 1A from a burner section (not shown) for heating a raw material for obtaining a reformed gas in the reformer 1 and an air electrode off-gas 2A from a fuel cell 2
Is sufficiently cooled by the exhaust gas cooler 7 to condense the moisture in the exhaust gas. This condensed water is supplied to the water treatment device as recovered water 7A. On the other hand, in order to maintain the water quality of the gas-liquid separator 4, a part of the water is sent to the water treatment as blowdown water 8. The to-be-processed water 9 obtained by combining the recovered water 7A and the blowdown water 8 is sent to the heat-resistant ion exchange resin 13 by the water supply pump 10 to perform ion exchange processing. The water temperature of the water to be treated 9 is 50 ° C.
The temperature is about ８０80 ° C., but is within the operable temperature since the heat-resistant ion exchange resin 13 is used. Therefore,
A device such as the water cooler 11 in FIG. 5 is unnecessary, and the water 9 can be directly sent to the heat-resistant ion exchange resin 13 without cooling without being cooled. The ultrapure water produced by the ion exchange treatment is supplied to the gas-liquid separator 4 as the makeup water 15 by the high-pressure pump 14. Thus, the heat-resistant ion exchange resin 1
3 can be operated at a high temperature, so that a water cooler to be treated becomes unnecessary and the initial cost is reduced, and since the makeup water can be supplied to the gas-liquid separator at a high temperature, the amount of waste heat recovery increases. As a result, the exhaust heat recovery efficiency of the fuel cell power generation equipment is increased.

Embodiment 2 FIG. 2 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 2 of the present invention. In the drawing, reference numeral 16 denotes a heating deaerator using heat of blowdown water 8, 16A
Is a steam discharge section, which sends recovered water 7A and blowdown water 8 to a heating and deaerator 16 and sends water to be treated 9 from the heating and deaerator 16 to a heat-resistant ion exchange resin 13 by a water supply pump 10. Has become. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

Next, the operation will be described. The recovered water 7A from the exhaust gas cooling device 7 is sent to the heating and degassing device 16, and the blowdown water 8 is supplied to the heating and degassing device 16 to serve as a heat source for heating and degassing. The flow rate of the blowdown water 8 is adjusted so that the water temperature becomes about ℃ (the water temperature may be raised to, for example, 100 ℃, depending on the heat resistance of the heat-resistant ion exchange resin 13). In the heating deaerator 16, the generated steam is transferred to the steam discharge section 16.
By bringing the recovered water 7A into gas-liquid contact when releasing it to the atmosphere through A, the degassing effect is enhanced. The deaerated recovered water 7A and blowdown water 8 are combined to treat water 9
Send out as. Although the water 9 to be treated has a water temperature of about 90 ° C., it is treated with the heat-resistant ion exchange resin 13 as it is. The operation is the same as that of the first embodiment, and the description is omitted. In this embodiment, since the carbon dioxide gas dissolved in the recovered water 7A is degassed by utilizing the heat of the blowdown water 8, the load on the heat-resistant ion exchange resin 13 is reduced, and the water treatment for the fuel cell power generation equipment is performed. The operating costs of the device are reduced.

Embodiment 3 FIG. 3 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 3 of the present invention. In the drawing, reference numeral 17 denotes an air deaerator using air from the air blower 3; 17
A is an air discharging portion, and 3C is deaeration air supplied from the air blower 3 to the air deaerator 17. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

Next, the operation will be described. The recovered water 7A from the exhaust gas cooling device 7 is sent to the air deaerator 17 and the air for deaeration 3C is sent from the air blower 3 to the air deaerator 17. When the supplied deaeration air 3C is discharged into the atmosphere through the air discharge part 17A, the deaeration effect is improved by bringing the recovered water 7A into gas-liquid contact. For example, by feeding recovered water 7A from one side and degassing air 3C from the other into a space filled with flocculent material or small granular solids, the contact area between the two can be increased. Further, the blowdown water 8 is supplied to the air deaerator 17, and the treated water 9 having a water temperature of about 50 ° C. to 60 ° C. is sent to the heat-resistant ion exchange resin 13 together with the deaerated recovered water 7A. To process. Other operations are the same as those in the first embodiment, and a description thereof will not be repeated. In this embodiment, the air blower 3
Since the carbon dioxide dissolved in the recovered water is degassed by using the degassing air 3C, the load on the heat-resistant ion exchange resin 13 is reduced, and the operating cost is reduced.

Embodiment 4 FIG. 4 is a block diagram showing a flow of water treatment in a water treatment apparatus for a fuel cell power generation facility according to Embodiment 4 of the present invention. In the drawing, reference numeral 18 denotes a blow for recovering heat from blowdown water 8 to makeup water 15. It is a down water heat recovery unit. The makeup water 15 treated with the heat-resistant ion exchange resin 13 is supplied to a blowdown water heat recovery unit 18.
After recovering heat from the blowdown water 8 having a high temperature of about 170 ° C., the heat is supplied to the gas-liquid separator 4. Blowdown water 8
Is supplied to the air deaerator 17 via the blowdown water heat recovery unit 18. Other configurations are the same as those in the third embodiment, and a description thereof will be omitted. In this embodiment, the load on the heat-resistant ion exchange resin 13 is reduced by degassing the recovered water 7A, and the amount of exhaust heat recovered is increased by recovering heat from blowdown water to makeup water.

[0016]

As described above, according to the water treatment apparatus for a fuel cell power generation facility according to the present invention, since the water to be treated is treated by using a heat-resistant ion exchange resin, the water to be treated is heated to a high temperature. The treatment can be carried out as it is, and therefore, a water cooler to be treated becomes unnecessary, and the initial cost is reduced, and the amount of exhaust heat recovery is increased to increase the efficiency of exhaust heat recovery. Furthermore, the load on the ion exchange resin is reduced by degassing the carbon dioxide gas in the recovered water using the heat of the blowdown water, or by degassing the carbon dioxide gas in the recovered water using air, Operating costs are reduced. Further, the heat recovery from the blowdown water to the makeup water increases the waste heat recovery amount.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 3 of the present invention.

FIG. 4 is a block diagram showing a flow of water treatment in a water treatment device for a fuel cell power generation facility according to Embodiment 4 of the present invention.

FIG. 5 is a block diagram showing a flow of water treatment in a conventional water treatment device for a fuel cell power generation facility.

[Explanation of symbols]

1 reformer, 1A flue gas, 2 fuel cell, 2A
Air electrode off gas, 3C deaeration air, 4 gas-liquid separator,
7 Exhaust gas cooler, 7A recovered water, 8 blowdown water, 9 treated water, 13 heat-resistant ion exchange resin, 15
Makeup water, 16 heating deaerator, 17 air deaerator,
18 Blowdown water heat recovery unit.

Claims (4)

[Claims] 1. A reformer for producing a reformed gas containing hydrogen by reacting a fuel and steam, and a water-cooled fuel for producing a direct current by reacting hydrogen in the reformed gas with oxygen in the air. A battery, a gas-liquid separator for supplying steam to the reformer and cooling water to the fuel cell, and cooling water collected by cooling combustion exhaust gas from the reformer and air electrode off-gas from the fuel cell. For fuel cell power generation equipment having an exhaust gas cooler for obtaining, water to be treated combining the blowdown water from the gas-liquid separator and the recovered water from the exhaust gas cooler was subjected to ion exchange treatment with an ion exchange resin. A water treatment apparatus for supplying fuel water, wherein a heat-resistant ion exchange resin is used as the ion exchange resin. 2. A heating and degassing device for heating and degassing carbon dioxide gas in recovered water by the heat of blowdown water, and the blowdown water and the recovered water are sent to the heating and degassing device. The water treatment device for a fuel cell power generation facility according to claim 1, wherein 3. The water treatment apparatus for a fuel cell power generation facility according to claim 1, further comprising an air deaerator for degassing carbon dioxide gas in the recovered water by sending air. 4. To make-up water supplied to a fuel cell power generation facility,
The water treatment apparatus for a fuel cell power generation facility according to claim 3, further comprising a heat recovery unit that recovers heat from the blowdown water.