JP2009224121A - Fuel cell power generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generation device capable of simplifying structure of the device and reutilizing condensed water for a long period in a system by efficiently carrying out deionization treatment. <P>SOLUTION: The fuel cell power generation device is provided with a recovery water tank 4 to store condensed water recovered from exhaust gas exhausted from a fuel cell body 1 and/or a reforming device 3, an electric deionization device 10 which has a desalination chamber and a condensing chamber demarcated by an ion exchange film between a positive electrode and a negative electrode and in which an ion exchange resin is filled in the desalination chamber, a treating water supply line L21 which connects the recovery water tank 4 and the desalination chamber of the electric deionization device 10 and in which a first metering pump P1 is installed in-between, and a condensed water supply line L22 which connects the recovery water tank 4 and the condensing chamber of the electric deionization device 10 and in which a second metering pump P2 is installed in-between. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell power generator equipped with an electrical deionization device.

  Fuel cell exhaust gas discharged from the fuel cell main body and combustion exhaust gas discharged from the combustion section of the reformer contain moisture, and water self-sustained within the system of the fuel cell power generation device (accepts supplementary water from outside) In order to maintain a state in which the operation is continued without any trouble, it is a common practice to collect condensed water from fuel cell exhaust gas or combustion exhaust gas and reuse it. Condensed water contains carbonate ions, metal ions eluted from piping, etc., and these ions may adversely affect the electrode catalyst and reforming catalyst. After ion treatment, it is reused.

  As a method for deionizing condensed water, attempts have been made in recent years to deionize condensed water using an electric deionizer.

  The electric deionization apparatus has, for example, a demineralization chamber and a concentration chamber defined by an ion exchange membrane between an anode and a cathode, as disclosed in Patent Document 1 below, and a demineralization chamber Is a water treatment device filled with an ion exchange resin. The ions flowing into the desalting chamber react with the ion exchange resin based on their affinity, concentration and ionic strength, move in the direction of the potential gradient, and reach the ion exchange membrane. The cations permeate the cation exchange membrane and the anions permeate the anion exchange membrane and move to the concentration chamber. Thereby, the condensed water can be separated into deionized water and concentrated water.

  In the deionization process using an electric deionization device, the deionization capacity decreases when the ratio of the amount of water passing through the demineralization chamber and the concentration chamber changes. Furthermore, the ion exchange membrane and ion of the electric deionization device are reduced. Irreversible damage may occur to the exchange resin.

For example, in the following Patent Document 2, a valve and a flow meter are used in combination to control the amount of water supplied to each chamber to be constant.
JP 2003-266075 A Japanese Patent Laid-Open No. 2001-236981

  Even if the water supply flow rate to the demineralization chamber and concentration chamber of the electric deionization device is set to be constant in advance by using a flow control valve, etc., the ion exchange membrane, ion exchange resin, etc. of the electric deionization device Since pressure loss occurs due to clogging of the water, the amount of water supplied to the desalting chamber and the concentration chamber may vary.

  In addition, as in Patent Document 2, when flow control is performed by combining a flow meter and valves, the number of parts increases, so that the equipment cost increases, and the entire apparatus becomes complicated and the maintenance cost increases. was there.

  Accordingly, an object of the present invention is to provide a fuel cell power generator capable of simplifying the device configuration, efficiently deionizing condensed water over a long period of time, and reusing the condensed water in the system.

In order to achieve the above object, a fuel cell power generator of the present invention comprises:
A recovered water tank for storing condensed water recovered from the exhaust gas discharged from the fuel cell main body and / or the reformer;
An electric deionization apparatus having a demineralization chamber and a concentration chamber partitioned by an ion exchange membrane between an anode and a cathode, the demineralization chamber being filled with an ion exchange resin;
A treated water supply line that is connected to the recovered water tank and the demineralization chamber of the electric deionizer, and is provided with a first metering pump;
A concentrated water supply line interfacing with a second metering pump, connecting the recovered water tank and the concentration chamber of the electric deionizer;
It is characterized by providing.

  According to the fuel cell power generator of the present invention, since the metering pumps are arranged in each of the treated water supply line and the concentrated water supply line, pressure loss occurs, and water is supplied to the desalination chamber and the concentration chamber. Even if the flow rate fluctuates, a constant amount of water can always be supplied, so that the ratio of the amount of condensed water supplied to the desalting chamber and the amount of condensed water supplied to the concentrating chamber can be maintained within a preset range. Therefore, the condensed water can be efficiently deionized over a long period of time, and can be suitably used as battery cooling water, reforming water for reforming reaction, and humidifying water for reaction gas of a fuel cell.

  Hereinafter, embodiments of a fuel cell power generator according to the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a fuel cell power generator of the present invention.

  In the figure, reference numeral 1 denotes a fuel cell body, which is a cooling system 1d having an anode electrode 1a and a cathode electrode 1b sandwiching an electrolyte 1c, and a cooling pipe disposed each time a plurality of unit cells made of these are stacked. It consists of and.

A reformed gas supply line L1 extending from the reformer 3 is connected to the reformed gas supply side of the anode electrode 1a. The reformed gas supply line L1 is provided with a reformed gas drain trap Q1, and the reformed gas condensate water supply line L2 extends from the condensate storage part of the reformed gas drain trap Q1 to decarboxylate. It is connected to the device 5.
An anode off-gas discharge line L3 extends from the anode off-gas discharge side of the anode electrode 1a, and the tip side thereof is connected to the combustion fuel supply line L12. Further, an anode offgas drain trap Q2 is disposed in the middle of the anode offgas discharge line L3, and the anode offgas condensed water supply line L4 extends from the condensate storage part of the anode offgas drain trap Q2. 5 is connected.

An air supply line L5 extending from an air supply source is connected to the air supply side of the cathode electrode 1b. The humidifier 2 is disposed in the air supply line L5.
A cathode offgas discharge line L6 extends from the cathode air discharge side of the cathode electrode 1b and is connected to the water tank 4. A cathode offgas heat exchanger Q3 is disposed in the cathode offgas discharge line L6.

A battery coolant supply line L7 extending from the battery coolant tank 12 is connected to the coolant supply side of the cooling system 1d.
A battery cooling water discharge line L8 extends from the cooling water discharge side of the cooling system 1d and is connected to the battery cooling water tank 12.

  The reformer 3 includes a reforming catalyst layer 3a filled with a steam reforming catalyst and a combustion section 3b in which a burner is disposed, and combustion heat and combustion exhaust gas generated when combustion fuel is burned by the burner. Thus, the reforming catalyst layer 3a is heated.

A raw material supply line L9 extending from the raw fuel source and a reforming water supply line L10 extending from the battery cooling water tank 12 are connected to the reforming raw material input side of the reforming catalyst layer 3a.
From the reformed gas discharge side of the reformed catalyst layer 3a, the reformed gas supply line L1 extends and is connected to the anode electrode 1a.

A combustion fuel supply line L12 and a combustion air supply line L11 are connected to the combustion fuel inlet side of the combustion section 3b, and fuel fuel and combustion air are supplied to a burner disposed in the combustion section 3b. It is configured to be able to. The anode offgas discharge line L3 and the raw fuel supply line L9 are connected to the upstream side of the combustion fuel supply line L12.
A combustion exhaust gas line L13 extends from the combustion exhaust gas exhaust side of the combustion section 3b and is connected to the decarbonation device 5. A combustion exhaust gas heat exchanger Q4 is disposed in the combustion exhaust gas line L13.

  The decarbonation device 5 is disposed adjacent to the upper portion of the water tank 4 and communicates via the drain port 6. In the upper part of the decarboxylation device 5, the concentrated gas discharge extending from the reforming gas condensate supply line L 2, the anode off-gas condensate supply line L 4, the combustion exhaust gas line L 13, and the concentration chamber of the electric deionization device 10 described later. Line L24 is connected. Further, an exhaust line L17 extends from the decarboxylation device 5.

  The decarbonation device 5 is not particularly limited, and a device that can degas by condensing condensed water and decarbonation air to diffuse carbon dioxide in the condensed water in the air can be preferably used. The deaeration device having such a configuration includes a deaeration part filled with a SUSCH ring or the like, supplies condensed water to the upper part of the deaeration part, and supplies decarbonation air from the lower part of the deaeration part. Supplying and condensing water by gravity falling, contacting with decarbonation air and decarboxylation treatment, for example, a porous material as disclosed in JP-A-2007-323969 The degassing part in which the inclined plate is arranged is provided, decarbonation air is circulated from the lower side of the inclined plate to the upper side, and condensed water is allowed to flow downward from the upper side of the inclined plate, An example of such a structure that decarboxylates the condensed water is given as an example.

  The water tank 4 is connected to a cathode offgas discharge line L6 and a battery cooling water overflow line L18 extending from the battery cooling water tank 12. A tank water overflow line L19 extends on the side wall of the water tank 4 so that the water level in the tank does not exceed a certain level. Further, a recovered water supply line L20 extends from the lower part of the water tank 4.

  In the recovered water supply line L20, an inlet filter 8 and a metal ion removing device 9 are arranged from the upstream side. And the front-end | tip of a collection | recovery water supply line is to the to-be-processed water supply line L21 connected to the demineralization chamber of the electrical deionization apparatus 10, and the concentrated water supply line L22 connected to the concentration chamber of the electrical deionization apparatus Branched.

  In the fuel cell power generator according to the present invention, a first metering pump P1 is interposed in the treated water supply line L21, and a second metering pump P2 is interposed in the concentrated water supply line L22. Has been.

  The first metering pump P1 and the second metering pump P2 are not particularly limited as long as the flow rate is not affected by fluctuations in back pressure and is excellent in quantification. For example, “Hicera Pump” (manufactured by Iwaki Co., Ltd.) (Trade name), “CCPP” (trade name) manufactured by Nippon Control Industrial Co., Ltd., and the like are preferable examples.

  The inlet filter 8 is not particularly limited as long as it removes impurities such as soot and dust contained in the recovered water collected in the water tank 4, and a metal removal filter, a particulate removal filter, and the like are preferable.

  Preferred examples of the metal ion removing device 9 include metal ion adsorption resins and chelate resins contained in condensed water.

  The electric deionization apparatus 10 is a water treatment apparatus having a demineralization chamber and a concentration chamber partitioned by an ion exchange membrane between an anode and a cathode, and the demineralization chamber is filled with an ion exchange resin. is there. A deionized water supply line L23 extends from the demineralization chamber of the electric deionizer 10 and is connected to the battery cooling water tank 12. Further, a concentrated water discharge line L24 extends from the concentration chamber of the electric deionizer 10 and is connected to the decarboxylation device 5 so that the concentrated water is returned to the upstream side of the water tank 4. Yes.

  Next, the operation of the fuel cell power generator of the present invention will be described.

  In the reformer 3, the raw fuel supplied from the raw fuel supply line L9 is mixed with the reformed water supplied from the reformed water supply line L10, and supplied to the reforming catalyst layer 3a to perform the steam reforming reaction. To produce reformed gas rich in hydrogen. Since the steam reforming reaction is an endothermic reaction, combustion fuel is supplied from the combustion fuel supply line L12 and combustion air from the combustion air supply line L11 to the combustion unit 3b of the reformer 3, and these are combusted. Then, the reforming catalyst layer 3a is heated. At the start of startup of the fuel cell power generator, the raw fuel supplied from the raw fuel supply line L9 is mainly used as the combustion fuel, the combustion state in the combustion section 3b is stabilized, and the reforming catalyst When the layer 3a is sufficiently heated, anode off-gas is mainly used.

  The reformed gas generated by the reformer 3 is supplied to the anode electrode 1a through the reformed gas supply line L1. Condensed water contained in the reformed gas is recovered by the reformed gas drain trap Q1 disposed in the middle of the reformed gas supply line L1, and supplied to the decarbonation device 5 through the reformed gas condensed water supply line L2. Is done.

  In the fuel cell main body 1, the reformed gas supplied to the anode electrode 1a and the air supplied to the cathode electrode 1b are electrochemically reacted at the interface of the electrolyte 1c to generate power, and this generated output is supplied to the power system. .

  The cathode offgas discharged from the cathode electrode 1b is cooled by the cathode offgas heat exchanger Q3 and supplied to the water tank 4 through the cathode offgas discharge line L6 together with the cathode offgas condensed water and the cathode gas.

  The anode off gas discharged from the anode electrode 1a is supplied to the combustion unit 3b through the anode off gas discharge line L3 and used as a combustion fuel. The condensed water contained in the anode off gas is recovered by an anode off gas drain trap Q2 disposed in the middle of the anode off gas discharge line L3, and is supplied to the decarbonation device 5 through the anode off gas condensed water supply line L4.

  The combustion exhaust gas discharged from the combustion unit 3b of the reformer 3 is cooled by the combustion exhaust gas heat exchanger Q4 and supplied to the decarbonation device 5 together with the combustion exhaust gas.

  The condensed water collected in the water tank 4 is subjected to removal of impurities such as soot and dust by the inlet filter 8 and then subjected to metal ion removal processing by the metal ion removal device 9, and then is electrically operated. It is sent to the deionization apparatus 10 and deionized. The deionized water discharged from the demineralization chamber is sent to the battery cooling water tank 12 through the deionized water supply line L23 and used for battery cooling water, humidified water, reformed water, and the like. On the other hand, the concentrated water discharged from the concentration chamber of the electric deionizer 10 is returned to the decarbonator 5 through the concentrated water discharge line L24.

  By the way, if it operates for a long time, a scale will accumulate in piping etc., the filter 8 etc. will be clogged, pressure loss will generate | occur | produce, and the supply flow rate of the water to a desalination chamber and a concentration chamber will change. In the deionization process in the electric deionization apparatus 10, when the balance of the amount of water supplied to the demineralization chamber and the concentration chamber is lost, the demineralization treatment may be insufficiently discharged from the demineralization chamber. There is a risk that the ion load on the fuel cell body 1 and the reformer 3 will increase.

  In the fuel cell power generation device of the present invention, since the metering pumps P1 and P2 are arranged in each of the treated water supply line L21 and the concentrated water supply line L22, pressure loss occurs, and water to the desalination chamber and the concentration chamber Even if the supply flow rate of the water fluctuates, a constant amount of water can always be supplied. As a result, the ratio of the amount of condensed water supplied to the desalting chamber and the amount of condensed water supplied to the concentrating chamber can be maintained within a preset range without any complicated control, and the condensed water can be maintained over a long period of time. It can be efficiently deionized and reused suitably as battery cooling water, reforming water for reforming reaction, or humidifying water for reaction gas of fuel cells.

It is a schematic block diagram of the fuel cell power generator of the present invention.

Explanation of symbols

1: Fuel cell body 1a: Anode electrode 1b: Cathode electrode 1c: Electrolyte 1d: Cooling system 2: Humidifier 3: Reforming device 3a: Reforming catalyst layer 3b: Combustion unit 4: Water tank 5: Decarbonation device 6: Drain port 8: Inlet filter 9: Metal ion removal device 10: Electric deionization device 12: Battery cooling water tank L1: Reformed gas supply line L2: Reformed gas condensed water supply line L3: Anode off-gas discharge line L4: Anode Off-gas condensed water supply line L5: Air supply line L6: Cathode off-gas discharge line L7: Battery cooling water supply line L8: Battery cooling water discharge line L9: Raw fuel supply line L10: Reformed water supply line L11: Combustion air supply line L12 : Combustion fuel supply line L13: Combustion exhaust gas line L17: Exhaust line L18: Battery cooling water overflow line L19: Tan Water overflow line L20: recovered water supply line L21: treated water supply line L22: concentrated water supply line L23: deionized water supply line L24: concentrated water discharge line P1: first metering pump P2: second metering pump Q1: modified Gas drain trap Q2: Anode offgas drain trap Q3: Cathode offgas heat exchanger Q4: Combustion exhaust gas heat exchanger

Claims (1)

A recovered water tank for storing condensed water recovered from the exhaust gas discharged from the fuel cell main body and / or the reformer;
An electric deionization apparatus having a demineralization chamber and a concentration chamber partitioned by an ion exchange membrane between an anode and a cathode, the demineralization chamber being filled with an ion exchange resin;
A treated water supply line that is connected to the recovered water tank and the demineralization chamber of the electric deionizer, and is provided with a first metering pump;
A concentrated water supply line interfacing with a second metering pump, connecting the recovered water tank and the concentration chamber of the electric deionizer;
A fuel cell power generator comprising: