JP2000348752A - Generated water recovery device for fuel cell power generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to water produced by an electrochemical reaction in a fuel cell body of a fuel cell power generator and water produced by a reformer for reforming a fuel gas supplied to a fuel cell. The present invention relates to a generated water recovery device for recovery.

[0002]

2. Description of the Related Art A fuel cell power generator is a reformer for reforming a raw fuel gas such as city gas, LP gas, methanol, etc. into a hydrogen-rich gas, and using the reformed gas obtained by the reformer as a fuel. The main components are a fuel cell body that generates power, a quadrature conversion device that converts a DC output of the fuel cell body into an AC, and the like. As is well known, the hydrogen-rich reformed gas generated in the reformer is consumed inside the fuel cell main body in accordance with the load of the fuel cell and the hydrogen utilization rate, and the surplus gas is used as a fuel electrode off-gas in the reformer. It is introduced into a burner, burned and consumed as energy for the reformer.

FIG. 4 is a system flow diagram showing a configuration example of a main part of a gas system and a water system of a conventional fuel cell power generator of this type. Raw fuel gas such as city gas and LP gas
After being sucked by the steam ejector 9 and mixed with the steam supplied from the steam separator 4 of the battery cooling water circulation system, it is sent to the catalyst layer 2b of the reformer 2 and steam reformed to produce a hydrogen-rich reformed gas. Becomes The obtained reformed gas is supplied to the fuel electrode 1a of the fuel cell body 1 schematically shown through the reformed gas supply system 10. Off-gas containing unused hydrogen that did not contribute to the cell reaction at the fuel electrode 1a is supplied to the burner 2a via an off-gas supply system 11 that connects the outlet of the fuel electrode 1a and the burner 2a of the reformer 2. You.
The off-gas reacts with the separately supplied air in the burner 2a and burns, thereby heating the catalyst layer 2b of the reformer 2. The flue gas generated by the combustion is sent to the generated water recovery device 3 through the reformer combustion off-gas system 13, and the water contained in the flue gas, that is, the water generated by the combustion is recovered and effectively used.

On the other hand, the air electrode 1b of the fuel cell body 1 has
Air is supplied by an air blower not shown. The off-gas discharged from the air electrode 1b contains water produced by the reaction of the battery,
The reaction water is sent to the generated water recovery device 3 through the second device 2, and the reaction water is recovered and used effectively.

When the fuel cell body 1 is operated,
It is necessary to maintain the temperature of the fuel cell main body 1 at a predetermined operating temperature by removing the heat generated by the cell reaction. For this reason, a cooling plate 1c for allowing cooling water to flow is incorporated in the fuel cell main body 1. The cooling plate 1c includes a steam separator 4, a battery cooling water cooler 5, and a battery cooling water circulation pump 6. A method of circulating and supplying the battery cooling water stored in the steam separator 4 by a battery cooling water circulating system incorporating the above is adopted.

The product water recovery device 3 comprises a condenser 3a using a shell-and-tube or plate type heat exchanger and a water tank 3b for storing condensed water, and contains combustion product water as steam. The combustion exhaust gas and the reaction air off-gas containing the reaction product water as steam are supplied to the condenser 3
a, is cooled by the heat exchanger, and the contained steam is condensed and collected in the water tank 3b.

However, in this configuration, since a large-sized heat exchanger needs to be used, there has been a problem that the generated water recovery device 3 becomes large and the cost increases. FIG.
FIG. 10 is a basic configuration diagram of another conventional example of a generated water recovery device of a fuel cell power generation device configured as a device that solves this difficulty.

The product water recovery apparatus 3A of this configuration comprises a cooling water direct contact condenser 14, a recovered water cooler 15, a recovered water circulating pump 16, and an inlet strainer 17. At the upper part of 14 is a packed layer 14b made of Raschig ring or the like, and at the lower part is a water tank 14c.
However, a spray nozzle 14a for spraying a part of the recovered water cooled by the recovered water cooler 15 onto the packed layer 14b is disposed further above the packed layer 14b.

In the cooling water direct contact condenser 14 of this configuration, the combustion exhaust gas containing steam and the reaction air off-gas are introduced and flow upward from the lower part of the packed bed 14b, and at the same time, from the watering nozzle 14a. The collected water cooled by the collected water cooler 15 is sprinkled. As a result, the gas and the cooling water come into direct contact with each other in the packed bed 14b, and the vapor in the gas is condensed and collected as water.

In this configuration, the cooling water direct contact condenser 14
Since the filling layer 14b and the water tank 14c are housed in the same container, the system is simplified as compared with the configuration shown in FIG. In addition, a recovered water cooler 15 is additionally provided. Since the recovered water cooler 15 is a water-water heat exchanger, it can be configured to be small. Therefore, with the configuration shown in FIG. 5, the generated water recovery apparatus 3A is small in size and can be manufactured at low cost.

[0011]

As described above, in a fuel cell power generator, a reaction water and a combustion water are collected and efficiently utilized by incorporating a simplified product water recovery device. There is a problem.

That is, in the cooling water direct contact type condenser 14 as described above, an exhaust port is provided above the upper watering nozzle 14a, and the reaction air off-gas and the combustion exhaust gas after water recovery are exhausted to the atmosphere. Since it has a so-called open-air circulating cooling water system, it is in an environment where various microorganisms can easily propagate. For this reason, microorganisms inhabit the packed bed 14b in the condenser, and particulate matter such as rust may be entangled with the adhesive substance secreted by the microorganisms during a long operation, and a large amount of ooze-like slime may adhere to the packing material. .

Further, when a large amount of slime adheres to the surface of the packing material in the packing layer 14b, the slime flows out along with the recovered water sprinkled from the upper part, and the water tank 14c in the lower part
Will flow into As a result, the recovered water circulation pump 1
The inlet strainer 17 of 6 and the recovered water cooler 15 are closed, and continuous operation becomes impossible. For this reason, in the product water recovery device 3A incorporating the cooling water direct contact condenser 14 as described above, in order to remove the attached slime, the packing of the packed bed 14b is periodically replaced or filled. Things need to be cleaned.

[0014] In the method of replacing the packing material, the operation of the apparatus is stopped, the packing material is taken out from the container of the condenser, and
It is necessary to perform a complicated filling exchange operation of uniformly filling the filling again.

As a method for cleaning the filling material, a method of performing water jet cleaning and a method of performing chemical cleaning using about 10% hydrogen peroxide water are generally used. In the case of a fuel cell power generator, austenitic stainless steel is used in a pure water system, and thus cleaning with a chlorine-based chemical is not preferable.

Since the operation of the apparatus is stopped and the water jet cleaning is performed from the upper and lower openings of the packed bed 14b, there is a risk that the cleaning effect is limited to the vicinity of the openings. However, there is a problem in that it may be re-bred and must be washed again within a short period of time.

Further, in the case of chemical cleaning using hydrogen peroxide solution, there is a drawback in that hydrogen peroxide solution is a powerful chemical, and thus requires the work of a special cleaning treatment company. After the washing, it is necessary to sufficiently wash the fresh water, and thus there is a problem that the operation must be stopped for a long time.

The present invention has been made in consideration of the problems of the prior art as described above, and an object of the present invention is to remove slime-based foreign matter adhering to a cooling water direct contact condenser of a product water recovery device. In a short time and easily washed and removed,
The shutdown time of the fuel cell power generator is reduced to a short time,
It is an object of the present invention to provide a product water recovery device that enables efficient operation.

[0019]

In order to solve the above problems, the present invention provides a cooling water direct contact condenser having a water spray nozzle above a packed bed, a generated water tank, and a recovered water cooling system. The air electrode off-gas discharged from the fuel cell and the combustion exhaust gas after burning off the fuel electrode off-gas with the burner of the reformer are introduced into a cooling water direct contact condenser to be cooled, and the steam contained In the generated water recovery device of the fuel cell power generation device, which collects as a generated water in a generated water tank and cools a part of the collected water by flowing through a collected water cooler and sprays water from a spray nozzle onto a packed bed,
(1) The cooling water direct contact condenser is provided with a washing means for washing the packed bed. (2) For example, as the washing means, a sprinkling pipe is provided inside the packed bed of the cooling water direct contact condenser. It will be installed.

(3) Alternatively, at least one of the side walls of the packing layer storage portion of the above-mentioned cooling water direct contact condenser is detachably incorporated, and a net for holding the packing layer is provided inside the side wall surface. A water washer is provided as a washing means for disposing and injecting water into the packed bed through this net.
(4) Alternatively, the above-mentioned packed bed is housed in at least one detachable basket, and is incorporated in the cooling water direct contact condenser.

The cooling water direct contact condenser is provided with a washing means for washing the packed bed as described in (1) above. For example, in the case of (2), water is supplied to the watering pipe. Accordingly, the cleaning operation can be performed when the apparatus is stopped, so that the packed bed can be easily and quickly cleaned. In addition, even during operation of the apparatus, it is possible to spray a jet jet on the surface of the packing material in the packed bed, so that it is possible to prevent microorganisms from growing on the surface of the packed material as a culture medium. The progress of adhesion is suppressed. Further, according to the above (3), by removing one surface of the side wall surface, cleaning can be performed relatively easily, and cleaning can be performed in a wide range, so that effective slime removal can be performed. The slime can be more effectively removed if the plurality of side wall surfaces are configured to be detachable and washed from the corner surface.

According to the above (4), when replacing the packed bed, the packed bed may be replaced in a form in which the packed bed is stored in a basket. Since an operation or the like for filling is not required, the replacement operation can be performed in a short time.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a generated water recovery apparatus for a fuel cell power generator according to the present invention will be described with reference to the drawings. In the configuration of the drawings of the following embodiments, components having the same functions as those of the components used in the configuration of the conventional example shown in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted. <Embodiment 1> FIG. 1 is a basic configuration diagram of Embodiment 1 of a generated water recovery device of a fuel cell power generation device. The difference between the product water recovery device 3B of this configuration and the product water recovery device 3A of the conventional example shown in FIG.
b, a sprinkling pipe 18 as a washing means is arranged, and a collected water circulation pump 16
It is connected to the exit side of.

Therefore, when the power generation operation of the fuel cell power generation device is stopped and the manual valve 19 is opened, a jet water stream is jetted from the water sprinkling pipe 18 to the packed bed 14b, and the surface of the packed bed 14b is filled. The slime adhered to the surface can be effectively washed away by a simple operation. It is also possible to jet the jet water flow from the water sprinkling pipe 18 during the power generation operation of the fuel cell power generation device. The manual valve 19 is opened during the power generation operation to continuously or intermittently jet the jet water flow. Then, the propagation of microorganisms using the surface of the packing as a culture medium can be prevented or suppressed, so that the required frequency of the washing operation after stopping the power generation operation is reduced. <Embodiment 2> FIG. 2 is a basic configuration diagram of Embodiment 2 of a generated water recovery device of a fuel cell power generation device. The feature of the generated water recovery apparatus 3C of this configuration is that one side wall surface 20a of the side wall surface of the storage portion of the packed bed 14b of the cooling water direct contact condenser 14 is detachably incorporated, and the side wall surface 20a A net 20b for preventing the falling of the packed layer 14b is disposed inside, and the net 20b is
b to fill the packed bed 14b.

Therefore, the generated water recovery apparatus 3C of this configuration
In this case, the water jet cleaning of the filling material of the filling layer 14b can be performed not only from the upper and lower openings of the filling layer 14b but also from the side wall surface 20a side, so that more effective cleaning can be performed.

In this embodiment, only one of the side walls of the storage portion of the filling layer 14b is detachable.
It is needless to say that the cleaning can be more effectively performed if three or four sides are similarly configured to be detachable and configured to be able to inject water into the filling layer 14b by the water jet cleaning device 21. <Embodiment 3> FIG. 3 is a basic configuration diagram of Embodiment 3 of a generated water recovery device of a fuel cell power generator. The difference between the generated water recovery apparatus 3D of this configuration and the generated water recovery apparatus 3A of the conventional example shown in FIG. 5 is that a service hatch 23 is provided above the cooling water direct contact condenser 14 and the packed bed 14b is 2 packing
This is in that it is housed and incorporated in individual wire mesh baskets 22.

Therefore, in the generated water recovery apparatus 3D, the service hatch 23 is opened, the packing material is taken out of the basket 22, and the packing material newly placed in the basket 22 is attached, whereby the packing material of the packing layer 14b is removed. Can be exchanged. Therefore, it is not necessary to perform a complicated and uniform operation of uniformly arranging the packing material in the packing layer 14b as in the related art, and the packing material can be replaced in a short time.

Therefore, it is also possible to periodically replace a filler having slime adhered to the surface with a new filler.
Since the replacement operation is completed in a short time, the operation stop time of the fuel cell power generator is limited to a short time, and efficient operation can be performed.

[0029]

As described above, according to the present invention, (1) the produced water recovery device of the fuel cell power generator is configured as in claim 1, 2, or 3;
Cleaning and removal of slime-based foreign matter adhering to the packing of the packed bed incorporated in the cooling water direct contact condenser constituting the product water recovery unit can be performed very easily and in a short time. The operation water stoppage time is reduced to a short time, and a product water recovery device capable of efficient operation is obtained.

(2) Further, if the generated water recovery device of the fuel cell power generation device is configured as in claim 4, the above-mentioned replacement of the filler can be performed in a short time. It is suitable as a product water recovery device that enables efficient operation.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of Embodiment 1 of a generated water recovery device of a fuel cell power generator of the present invention.

FIG. 2 is a basic configuration diagram of Embodiment 2 of a generated water recovery device of the fuel cell power generator of the present invention.

FIG. 3 is a basic configuration diagram of Embodiment 3 of a generated water recovery device of the fuel cell power generation device of the present invention.

FIG. 4 shows a gas system of this type of conventional fuel cell power generator,
System flow diagram showing a configuration example of the main part of the water system

FIG. 5 is a basic configuration diagram of another conventional example of the generated water recovery device of the fuel cell power generation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell main body 2 Reformer 3, 3A Produced water recovery device 3B, 3C, 3D Produced water recovery device 4 Steam separator 5 Battery cooling water cooler 6 Battery cooling water circulation pump 7 Water treatment device 8 Feed water pump 9 Steam ejector 12 Reaction air off-gas system 13 Reformer combustion off-gas system 14 Cooling water direct contact condenser 14a Sprinkling nozzle 14b Packing bed (Raschig ring) 14c Water tank 15 Collected water cooler 16 Collected water circulation pump 17 Inlet strainer 18 Sprinkling pipe 19 Manual valve 20a Side wall surface (detachable) 20b Net 21 Water jet washer 22 Basket 23 Service hatch

Claims (4)

[Claims] 1. An air electrode off-gas discharged from a fuel cell, comprising: a cooling water direct contact condenser having a water spray nozzle above a packed bed; a water tank for produced water; and a reformer. The combustion exhaust gas after burning the fuel electrode off-gas with the burner is introduced into the cooling water direct contact condenser to be cooled, and the contained steam is collected as product water in the product water tank, and a part thereof is collected. In the generated water recovery device of the fuel cell power generation device, in which the cooling water is cooled by flowing through the recovered water cooler and the water is sprayed onto the packed bed from the water spray nozzle, the packed bed is washed by the cooling water direct contact condenser. A water recovery device for a fuel cell power generation device, comprising: 2. The generated water recovery apparatus for a fuel cell power generator according to claim 1, wherein said washing means is a water spray pipe disposed inside a packed bed of a cooling water direct contact condenser. . 3. A cooling water direct contact type condenser wherein at least one of a side wall surface of a packed layer storage portion is detachably incorporated and a net for holding a packed layer is arranged inside the side wall surface. 2. The apparatus according to claim 1, wherein the washing means is a water washer for detaching the detachable side surface and injecting water into the packed bed through the net. 4. An air electrode off-gas comprising a cooling water direct contact condenser having a water spray nozzle above a packed bed, a water tank for product water, a recovered water cooler and discharged from a fuel cell; The flue gas after burning the pole off-gas with the burner of the reformer is introduced into the cooling water direct contact condenser to be cooled, and the contained steam is recovered as product water in the product water tank, and A cooling water flowing through the recovered water cooler, and spraying water from the water spray nozzle onto the packed bed, wherein at least one basket in which the packed bed is detachable. A water recovery device for a fuel cell power generator, wherein the water recovery device is housed in a cooling water direct contact condenser.