JP5269446B2 - Method for starting fuel cell power generator and fuel cell power generator - Google Patents

Description

  The present invention relates to a method for starting a fuel cell power generation apparatus and a fuel cell power generation apparatus that reduce a load on a water treatment apparatus.

  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 the operation state, the condensed water is collected from the exhaust gas, and deionized in a water treatment device such as an ion exchange resin or an electric deionizer and reused. Is generally done.

By the way, the condensed water may be eluted from a pipe and mixed with metal ions. For this reason, in order to reduce the load applied to the water treatment apparatus, for example, as disclosed in Patent Documents 1 and 2 below, before supplying condensed water to the water treatment apparatus, a metal ion adsorption resin such as a chelate resin is used. Attempts have been made to reduce or remove metal ions by passing condensed water through the filled metal ion removing means.
JP-A-9-161833 JP 2005-347231 A

  If water is retained in the metal ion removing means for a long time, the metal ions may be desorbed from the resin once adsorbed with the metal ions. For this reason, if the fuel cell power generation device is stopped while the condensed water in the metal ion removal means remains, the water discharged from the metal ion removal means immediately after the start of the fuel cell power generation device contains a large amount of metal ions. There is a risk that water containing a large amount of metal ions will flow into the water treatment device, increasing the load on the subsequent water treatment device, and metal ions will precipitate as fine particles and accumulate in the water treatment device. There was a risk of obstructing the flow.

  Accordingly, an object of the present invention is to provide a method of starting a fuel cell power generator and a fuel cell power generator that reduce the load on the water treatment device.

In order to achieve the above object, a method for starting a fuel cell power generator according to the present invention includes a reforming catalyst layer that steam-reforms hydrocarbons to produce a hydrogen-containing gas, and a combustion that supplies reaction heat to the reforming catalyst layer. A reformer having a section, a fuel cell main body that generates power by reaction with the hydrogen-containing gas and the oxidant gas, and condensate is recovered from the exhaust gas of the combustion section and the fuel cell main body to store the condensed water And a water treatment system having a metal ion removing means for removing metal ions contained in the condensed water stored in the water tank and a water treatment device for deionizing the condensed water from which the metal ions have been removed. A method for starting a fuel cell power generator, wherein water was passed through the metal ion removing means when the fuel cell power generator was started up, and the fuel cell power generator was staying in the metal ion removing means while the fuel cell power generator was stopped. Delay Water, the metal ion removing means electric conductivity of water to be discharged from the implement draining step of draining out the water treatment system until the following 20 [mu] S / cm, after which the water passing through the metal ion removing means It introduce | transduces into the said water treatment apparatus, It is characterized by the above-mentioned.

Further, the fuel cell power generator of the present invention includes a reforming catalyst layer that steam-reforms hydrocarbons to generate a hydrogen-containing gas, and a reforming device that includes a combustion section that supplies reaction heat to the reforming catalyst layer, A fuel cell body that generates power by reaction with the hydrogen-containing gas and the oxidant gas, a water tank that collects and stores condensed water from the exhaust gas of the combustion section and the fuel cell body, and metal ions contained in the condensed water Metal ion removing means for removing water, a condensed water feed line connecting the water tank and the metal removing means, a water treatment device for deionizing the condensed water from which metal ions have been removed, and the metal ion removing A demetallized ion water feed line that connects the means and the water treatment device, a drain line that drains the water that has passed through the metal ion removal unit, and water that has passed through the metal ion removal unit Includes a switching valve composed of one or more flow is switched to the drainage line, the switching valve, until the electric conductivity of water to be discharged from the metal ion removal means is less than 20 [mu] S / cm, the It is configured to open to the drainage line side.

  According to the present invention, when the fuel cell power generation device is started, water is passed through the metal ion removal means, and the retained water that has been retained in the metal ion removal means during the stop of the fuel cell power generation device is Since the water is discharged outside the water treatment system, it is possible to prevent water having a high metal ion concentration from being introduced into the water treatment apparatus. Further, the metal ions can be deposited as fine particles and can be prevented from being deposited in the water treatment apparatus. For this reason, the load concerning a water treatment apparatus can be reduced and the replacement cycle of a water treatment apparatus can be lengthened.

And the said drainage process is implemented until the electrical conductivity of the water discharged | emitted from the said metal ion removal means becomes 20 microsiemens / cm or less . Since the electrical conductivity increases when the concentration of metal ions is high, according to this aspect, it is possible to more reliably prevent water having a high metal ion concentration from being introduced into the electrodeionization apparatus.

  In the present invention, the draining step is preferably carried out until water having a volume of at least twice the volume of the metal removing means is drained out of the water treatment system. By draining water having a volume more than twice the volume of the metal removing means out of the system, it is possible to more effectively prevent water having a high metal ion concentration from being introduced into the electrodeionization apparatus.

  In the present invention, it is preferable that the water drained out of the water treatment system from the metal removing unit is returned to the upstream side of the metal ion removing unit. According to this aspect, since the water drained from the metal removing means is reused, the amount of drainage can be reduced, and it becomes easy to maintain water independence in the system.

  According to the present invention, it is possible to prevent water having a high metal ion concentration from being introduced into the water treatment apparatus, and thus the load on the water treatment apparatus can be reduced. For this reason, the replacement cycle of the water treatment apparatus can be prolonged, and the maintenance cost can be reduced.

  Hereinafter, embodiments of a fuel cell power generator according to the present invention will be described with reference to the drawings. In FIG. 1, the schematic block diagram of 1st embodiment of the fuel cell electric power generating apparatus of this invention is shown.

  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 condensed water supply line L2 extends from the condensed water storage part of the reformed gas drain trap Q1, It is connected to a decarboxylation device 5.
An anode off gas discharge line L3 extends from the anode off gas discharge side of the anode electrode 1a and is connected to a combustion unit 3b provided in the reformer 3. The anode off-gas drain line L3 is provided with an anode off-gas drain trap Q2, and the anode off-gas condensate supply line L4 extends from the condensed water storage part of the anode off-gas drain trap Q2. It is linked to.

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 is composed of a reforming catalyst layer 3a and a combustion unit 3b.
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.

An anode offgas discharge line L3 extending from the offgas discharge side of the anode electrode 1a and a combustion air supply line L11 extending from the combustion air source are connected to the combustion fuel inlet side of the combustion section 3b.
From the combustion exhaust gas discharge side of the combustion unit 3b, a combustion exhaust gas line L12 extends and is connected to the decarbonation device 5. A combustion exhaust gas heat exchanger Q4 is disposed in the combustion exhaust gas line L12.

  The decarbonation device 5 is disposed adjacent to the upper portion of the water tank 4 and communicates via the drain port 6. The above-described reformed gas condensate supply line L2, anode off-gas condensate supply line L4, and combustion exhaust gas line L12 are connected to the upper portion of the decarboxylation device 5. Further, an exhaust line L <b> 17 extends from the upper part of 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.

  Connected to the water tank 4 are the cathode offgas discharge line L6 described above and the 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. A recovered water supply line L <b> 20 extends from the lower part of the water tank 4 and is connected to the battery cooling water tank 12.

  In the recovered water supply line L20, a recovered water pump P1, an inlet filter 8, a metal ion removing device 9, an on-off valve V1, and a water treatment device 10 are arranged from the upstream side.

  In the fuel cell power generation device of the present invention, the pipe between the metal ion removing device 9 and the on-off valve V1 of the recovered water supply line L20 branches, and the drain line L21 provided with the drain valve V2 extends. .

  In this embodiment, the on-off valve V1 and the drain valve V2 constitute a “switching valve” in the present invention. However, the switching valve can also be configured by a single switching valve provided at a branch portion between the recovered water supply line L20 and the drainage line L21.

  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.

  Examples of the metal ion removing device 9 include a metal ion removing cylinder filled with a metal ion adsorption resin. Examples of the metal ion adsorption resin include a cation exchange resin and a chelate resin, and a chelate resin is preferable. Since the chelate resin can selectively capture metal ions by chelate bonds, the metal ions in the condensed water can be efficiently reduced. Examples of the chelating resin include “Amberlite IRC748” (trade name, manufactured by Rohm and Haas).

  The water treatment device 10 is not particularly limited as long as it is a device that deionizes the recovered water collected in the water tank 4, and examples thereof include an electric deionization device, an activated carbon filter, and an ion exchange resin. These may be used alone or in combination. Especially, it is preferable to use an electric deionization apparatus from the reason that a running cost and a maintenance cost can be reduced, and it is more preferable to arrange and use water treatment resin in the downstream of an electric deionization apparatus. In this embodiment, an electric deionizer is used as the water treatment device 10.

  Here, the electrical deionization apparatus has 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 water filled with an ion exchange resin. In the treatment apparatus, ions flowing into the desalting chamber react with the ion exchange resin based on the 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. As a result, the recovered water can be separated into deionized water and concentrated water, and deionized water with a reduced ion concentration can be recovered from the demineralization chamber of the electric deionization device. Can supply. On the other hand, the concentrated water discharged from the concentration chamber of the electric deionizer contains a large amount of ions in the recovered water, and is concentrated in the concentrated water discharge line L22 extending from the demineralization chamber of the electric deionizer. Is configured to be connected to the decarboxylation device 5 so as to return the concentrated water to the upstream side of the water tank.

  Next, a method for starting the fuel cell power generation device including the operation of the fuel cell power generation device of the present invention will be described.

  The raw fuel supplied from the raw fuel supply line L9 is mixed with the reformed water supplied from the reforming water supply line L10, supplied to the reforming catalyst layer 3a, and reformed in hydrogen by a steam reforming reaction. Generate gas. Since the steam reforming reaction is an endothermic reaction, the anode offgas from the anode offgas discharge line L3 and the combustion air from the combustion air supply line L11 are supplied to the combustion unit 3b of the reformer 3 and burned. Then, the reforming catalyst unit 3a is heated.

  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 passes through the reformed gas condensed water supply line L2 to the decarbonation device 5. Supplied.

  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 supply 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 after removal of metal ions by the metal ion removal device 9, It is sent to the treatment device 10 to be deionized, and the treated water is sent to the battery cooling water tank 12.

However, when stopping the fuel cell power plant in a state in which the condensed water staying in the metal ion removing device 9, and the like chelate resin in the metal ion removing device 9, once occurs elimination of metal ions adsorbed. Therefore, as described above, the water discharged from the metal ion removing device 9 immediately after the start of the fuel cell power generation device contains a large amount of metal ions, and the subsequent water treatment device 10 has a large amount of water. There was a risk that water containing metal ions would flow in.

  In the present invention, when the fuel cell power generator is started, the on-off valve V1 is closed, the drain valve V2 is opened, and water containing a large amount of metal ions staying in the metal ion removing device 9 is discharged from the drain line L21. A drainage process to drain outside the water treatment system is performed.

  The draining step is preferably performed until the electrical conductivity of the water discharged from the metal ion removing device 9 is lower than the set value, and more preferably 20 μS / cm or less. In addition, when measuring electrical conductivity, it can measure by arrange | positioning an electrical conductivity meter between the metal ion removal apparatus 9 and the drain valve V2.

  Moreover, as another aspect, it is preferable to perform a drainage process from the metal ion removal apparatus 9 until the water of the volume more than twice the volume of the metal ion removal apparatus 9 is drained from the drainage line L21. It is more preferable to carry out until 2 to 3 times the volume of the device 9 is drained from the drain line L21.

  And after implementing the said drainage process, the on-off valve V1 is opened, the drainage valve V2 is closed, and the water which passed the metal ion removal apparatus 9 is introduce | transduced into the water treatment apparatus 10. FIG.

Thus, according to the present invention, when the fuel cell power generation device is started, the metal ion removal device 9 is caused to pass condensed water and stays in the metal ion removal device 9 while the fuel cell power generation device is stopped. After the drainage process of draining the accumulated water to the outside of the system, the condensed water treated by the metal ion removing device 9 is introduced into the water treatment device 10, so that metal ions are reduced in the water treatment device 10. Water can be introduced, the load on the water treatment apparatus 10 can be reduced, and the flow obstruction caused by the deposit can be prevented. As a result, the water treatment device 10 replacement cycle can be extended, and maintenance costs can be reduced.

  A second embodiment of the fuel cell power generator of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same location as 1st embodiment, and the description is abbreviate | omitted.

  In this embodiment, the difference from the first embodiment is that the downstream side of the drainage line L21 is connected to the upstream side of the recovered water pump P1 of the recovered water supply line L20.

  According to this embodiment, when the fuel cell power generator is started, the water drained from the drain line L21 is recirculated and supplied again to the metal ion removing means, so that the amount of drainage can be greatly reduced, and the fuel It becomes easy to maintain water independence in the battery power generation system.

  After holding for 48 hours in a metal ion removal device filled with a chelate resin (trade name: “Amberlite IRC748” manufactured by Rohm and Haas), water is allowed to pass through the metal ion removal device. The electrical conductivity of the water discharged from the metal ion removing device was measured. The results are shown in Table 1.

The electric conductivity could be reduced to 20 μS / cm by passing water more than twice the volume of the metal ion removing device.
And at the time of starting of a fuel cell power generation device, water more than twice the volume of the metal ion removing device was allowed to flow, and then water was introduced by introducing the water that passed through the metal ion removing device into the water treatment device. However, the load on the water treatment apparatus could be reduced.

1 is a schematic configuration diagram of a first embodiment of a fuel cell power generator of the present invention. It is a schematic block diagram of 2nd embodiment of the fuel cell electric power generating apparatus of this 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 removing device 10: Water treatment device 12: Battery cooling water tank L1: Reformed gas supply line L2: Reformed gas condensed water supply line L3: Anode offgas discharge line L4: Anode offgas condensation 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 Exhaust gas line L17: Exhaust line L18: Battery cooling water overflow line L19: Tank water overflow line L20: Recovered water Supply line L21: Drain line L22: Concentrated water discharge line P1: Recovered water pump Q1: Reformed gas drain trap Q2: Anode offgas drain trap Q3: Cathode offgas heat exchanger Q4: Combustion exhaust gas heat exchanger V1: On-off valve V2: Drain valve

Claims (6)

Reaction of a reforming catalyst layer for steam reforming hydrocarbons to produce a hydrogen-containing gas, a reformer having a combustion section for supplying reaction heat to the reforming catalyst layer, and the hydrogen-containing gas and oxidant gas A fuel cell body that generates electric power, a water tank that collects condensed water from the exhaust gas of the combustion section and the fuel cell body and stores the condensed water, and metal ions contained in the condensed water stored in the water tank. A water treatment system having a metal ion removing means for removing and a water treatment device for deionizing the condensed water from which the metal ions have been removed.
When the fuel cell power generator is started, water is passed through the metal ion removing means, and the accumulated water staying in the metal ion removing means while the fuel cell power generator is stopped is discharged from the metal ion removing means. A drainage step of draining outside the water treatment system until the electrical conductivity of the water is 20 μS / cm or less, and then introducing the water that has passed through the metal ion removing means into the water treatment device. The starting method of the fuel cell power generator. 2. The method for starting a fuel cell power generator according to claim 1 , wherein the draining step is performed until water having a volume that is twice or more the volume of the metal removing unit is drained out of the water treatment system. The method for starting a fuel cell power generator according to claim 1 or 2 , wherein the water drained from the metal removal means to the outside of the water treatment system is returned to the upstream side of the metal ion removal means. A reforming catalyst layer that steam-reforms hydrocarbons to generate a hydrogen-containing gas, and a reforming device having a combustion section that supplies reaction heat to the reforming catalyst layer;
A fuel cell body that generates power by reaction with the hydrogen-containing gas and the oxidant gas;
A water tank for collecting and storing condensed water from the exhaust gas of the combustion section and the fuel cell body;
Metal ion removing means for removing metal ions contained in the condensed water;
A condensed water feed line connecting the water tank and the metal removing means;
A water treatment device for deionizing the condensed water from which metal ions have been removed;
A demetalized ion water feed line connecting the metal ion removing means and the water treatment device;
A drainage line for draining water that has passed through the metal ion removing means;
A switching valve composed of one or more of the water that has passed through the metal ion removing means and switched to the water treatment device or the drainage line;
The switching valve is configured to open on the drain line side until the electrical conductivity of water discharged from the metal ion removing means is 20 μS / cm or less .
A fuel cell power generator characterized by that. 5. The fuel cell power generation according to claim 4 , wherein the switching valve is configured to open to the drain line side until water having a volume more than twice the volume of the metal removing unit drains from the drain line. apparatus. The fuel cell power generator according to claim 4 or 5 , wherein a downstream side of the drainage line is connected to the condensed water feed line.