JPH09330730A - Steam separator for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a package type phosphoric acid type fuel cell power generator with its low equipment height and less dead space on layout, capable of being compactly formed. SOLUTION: A circular first and second containers 32 and 33 of their same shape circularly formed horizontally using circles whose diameter are same are arranged vertically by coupling them by means of a coupling tube 34, a cooling water inlet 9 for introducing two-phase flow from a fuel cell unit, a reformed vapor outlet 10 for fuel reforming, and a steam outlet 11 for heat recollection for exhaust heat treatment facility are provided on the top face of the first container 32, and a cooling water outlet 8 for the fuel cell unit and a condensed water inlet 12 are provided on a lower face of the circular second container 33. In addition, a heater 7 for heating to be used for internal pressure adjustment from the side face of the circular second container 33 is incorporated.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package type phosphoric acid fuel cell power generator for on-site use, which separates a two-phase fluid of water and steam discharged from the fuel cell body into water and steam. Concerning the composition of the vessel.

2. Description of the Related Art In a phosphoric acid fuel cell power generator, the heat generated during power generation is removed by supplying cooling water to keep the operating temperature of the fuel cell main body constant and recover the generated heat effectively. We are using. FIG. 3 is a basic system diagram of a cooling water system of this type of fuel cell power generator. In the figure, a fuel cell main body 1 is schematically shown, and a cooling plate 2 provided with a cooling pipe is arranged every time a plurality of unit cells (not shown) are stacked. The cooling pipe provided in the cooling plate 2 includes
The cooling water circulation pump 4 sends the cooling water from the steam separator 3 through the cooling water circulation pipe. The cooling water cools the heat generated by power generation, and by obtaining the heat, a part thereof becomes steam and becomes a two-phase flow of water / steam. The two-phase flow of water / steam discharged from the outlet of the cooling pipe of the fuel cell is returned to the steam separator 3. The steam separator 3 supplies steam for fuel reforming, mixes it with raw fuel and sends it to the reformer 5, and at the same time discharges steam to an external exhaust heat treatment facility 6 to receive condensed water to generate heat. Balance is maintained. A heater 7 for heating is incorporated in the steam separator 3,
It controls the internal pressure by heating and controls the amount of steam. FIG. 4 is an outline view showing a schematic shape of the steam separator 3 which has been conventionally used. Since the water vapor separator 3 is used under pressure, in order to have a strong structure against internal pressure, spherical containers 3b and 3c are arranged on both sides of the cylindrical body 3a to form a container. There is. On the upper surface facing the steam layer, a cooling water inlet 9 for receiving cooling water discharged as a two-phase flow of water / steam from the fuel cell main body, a reforming steam outlet 10 for supplying steam for fuel reforming, and an exhaust gas A heat recovery steam outlet 11 for discharging steam to the heat treatment equipment 6 is installed, and a cooling water outlet 8 for sending cooling water to the fuel cell body and condensed water from the waste heat treatment equipment 6 are provided on the lower surface facing the liquid layer. Is provided with a condensed water inlet 12. In the steam separator 3 used in the phosphoric acid fuel cell power generator having an output of 100 kW, the diameter of the body 3a (D in the figure) is set to about 600 mm. In a package type on-site fuel cell power generation device, a considerably large space is occupied.

Therefore, when the water vapor separator constituted by the container having the large diameter as described above is housed in the package, it not only occupies a considerably large space but also the periphery of the housed water vapor separator. However, there is a dead space and it is difficult to layout efficiently. Also, if a packaged fuel cell power generator is constructed using a water vapor separator consisting of a container with a diameter of about 600 mm as described above, the height of the device will be high, and it will be difficult to carry it underground into the building where it is installed. There is a problem that
That is, the cooling water circulation pump 4 always sucks the saturated water from the steam separator 3, so that the effective NPS
H (Net Positive Suction Head) is a water vapor separator 3
The water level height of the cooling water circulation pump 4 (that is, the height of the pump shaft center) and the water head corresponding to the flow path resistance between the water vapor separator 3 and the cooling water circulation pump 4 are subtracted from the water level height of.
This effective NPSH is the NPSH required in the system.
If it is less than the specified value, the cooling water circulation pump 4 causes cavitation and is damaged, or the flow rate of the cooling water is insufficient to cause overheating of the fuel cell body. Must be configured to have. For example, in a system of a phosphoric acid fuel cell power generator with an output of 100 kW, even if the pump is installed as low as possible, the height of the pump shaft center is about 0.3 m, so the water level of the cooling water circulation pump is at least high. 0.3
m. Even if the flow path between the steam separator and the cooling water circulation pump is made as thick and short as possible, the water head corresponding to the flow path resistance between them is about 0.15 m. On the other hand, the NPSH required for the cooling water circulation pump is at least about 1 m, so the effective NPSH of the cooling water circulation pump is the required NP.
In order to exceed SH, the water level of the steam separator must be 1.45m.
It must be above. Therefore, as described above, the water level of the water vapor separator consisting of a vessel with a diameter of about 600 mm should be kept above 1.45 m, and a sufficient vapor phase space should be provided above the inside of the vessel so that vapor can be smoothly discharged from the water vapor separator. If the space is secured and a space for valves and pipes is provided above the container, the height of the packaged fuel cell power generator configured to house it will be 2.0 m or more. The carry-in property of the product will be poor. An object of the present invention is to provide a water vapor separator for a fuel cell, which has a low apparatus height, has a small layout dead space in the package, and can be formed into a compact package.

In order to achieve the above object, in the present invention, a two-phase fluid of water and steam discharged from the fuel cell main body is introduced and separated into water and steam, In a steam separator for supplying cooling water to the fuel cell main body and at the same time supplying steam to be mixed with the raw fuel, (1) the container main body of the steam separator is provided with a circular pipe having the same diameter over the entire length. It is formed by arranging in a ring shape in the horizontal direction. (2) Alternatively, the container body of the water vapor separator is formed by arranging circular pipes having the same diameter over the entire length in an annular shape in the horizontal direction, and the same shape and the same shape as the first container. The second container formed to have dimensions is arranged vertically on the same axis, and the first container and the second container are connected by a circular pipe to form the second container. With the above-mentioned configuration (1), since the water vapor separator is formed in a flat shape in the vertical direction, the device height can be kept low and the upper and lower dead spaces are small. The package incorporating the water vapor separator can be made compact. Further, with the above-mentioned configuration (2), even a steam separator that stores a large amount of water and steam can be formed by using a circular tube having a small diameter, and the apparatus height is lower than that of the conventional apparatus. It is suppressed and the upper and lower dead spaces are reduced. Furthermore, if a circular tube with a small diameter is used, the required wall thickness to withstand the internal pressure will be thin and the weight will be reduced.
The package can be formed compactly.

FIG. 1 is a basic configuration diagram of a first embodiment of a steam separator for a fuel cell according to the present invention. (A) is a side view and (b) is (X)-(X) of (a). It is the top view seen more. A feature of the steam separator for a fuel cell of the present embodiment is that the container is constituted by an annular container 31 which is formed in an annular shape in the horizontal direction by using a circular tube having the same diameter. A cooling water inlet 9 for receiving cooling water discharged as a two-phase flow of water / steam from the fuel cell main body, a reforming steam outlet for supplying steam for fuel reforming, on the upper surface of the annular container 31 facing the steam layer. 10 and a heat recovery steam outlet 11 for discharging steam to the exhaust heat treatment equipment are installed. On the lower surface facing the liquid layer, a cooling water outlet 8 for sending cooling water to the fuel cell body and a waste heat treatment equipment A condensed water inlet 12 for receiving condensed water is installed. Further, a heater 7 for adjusting the internal pressure and the amount of steam is incorporated on the lower surface. In addition,
In the present embodiment, the heater 7 is arranged at the center of the annular container 31, but it may be arranged at the end, for example, in consideration of the storage space of the package. Therefore, in this configuration, the container is configured to be flat in the vertical direction, the height of the device is reduced, and the dead space in the periphery is also reduced. Therefore, by incorporating the fuel cell water vapor separator of this configuration, a compact package type phosphoric acid fuel cell power generator can be obtained. 2A and 2B are a basic configuration diagram of a second embodiment of a steam separator for a fuel cell according to the present invention, FIG. 2A is a side view, and FIG. 2B is a plan view seen from YY of FIG. . The feature of the steam separator for a fuel cell of the present embodiment is that the container is an annular first container 32 formed in a horizontal annular shape using a circular tube having the same diameter, and an annular second container 33 having the same shape.
Are connected by a connecting pipe 34. On the upper surface of the upper annular first container 32 facing the vapor layer, a cooling water inlet 9 from the fuel cell body, a reforming vapor outlet 10 for fuel reforming, and a heat recovery vapor outlet 11 to the exhaust heat treatment facility are provided. Is installed. Further, a cooling water outlet 8 to the fuel cell body and a condensed water inlet 12 from the exhaust heat treatment facility are installed on the lower surface of the lower annular second container 33 facing the liquid layer. Further, in the liquid layer of the second annular container 33, a heater 7 for adjusting the internal pressure and the amount of vapor is inserted and incorporated from the side surface. Also in this configuration, since the container is configured to be flat in the vertical direction, the height of the device becomes low and the dead space around the device becomes small. Therefore, by incorporating the fuel cell water vapor separator of this configuration, a compact package type phosphoric acid fuel cell power generator can be obtained. In addition, the annular container 31 of the steam separator for a fuel cell of the first embodiment, or the annular first container 32 and the annular second container 33 of the steam separator for a fuel cell of the second embodiment have a diameter of If a circular tube of 150 mm or less is used, the weight can be reduced, and the easily manufactured circular tube can be easily manufactured, so that it can be manufactured at low cost. Therefore, it is more effective in making the package type phosphoric acid fuel cell power generator compact.

As described above, according to the present invention, the two-phase fluid of water and steam discharged from the fuel cell main body is introduced,
In a water vapor separator that separates water and water vapor, supplies cooling water to the fuel cell main body, and at the same time supplies water vapor to be mixed with the raw fuel, (1) make the vessel main body of the water vapor separator the entire length Since the circular tubes having the same diameter are arranged horizontally in an annular shape, the device height is low and the dead space in the layout in the package is small, so that the package can be formed compactly. A separator is to be obtained. (2) Further, the container body of the water vapor separator is formed by arranging circular pipes having the same diameter over the entire length in an annular shape in the horizontal direction, and the same shape and the same shape as the first container. If the second container formed in the size is arranged vertically on the same axis, and the first container and the second container are connected by a circular pipe, the device height can be increased. Since it is low and the dead space in the layout in the package is small, it is suitable as a steam separator for a fuel cell for forming a compact package.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a first embodiment of a steam separator for a fuel cell according to the present invention, where (a) is a side view and (b) is a plan view seen from XX of (a).

FIG. 2 is a basic configuration diagram of a second embodiment of a fuel cell water vapor separator according to the present invention, in which (a) is a side view and (b) is a plan view seen from YY of (a).

[Fig. 3] Basic system diagram of the cooling water system of the phosphoric acid fuel cell power generator

FIG. 4 is an outline view showing a schematic shape of a conventionally used steam separator 3.

[Explanation of symbols]

 1 Fuel Cell Main Body 2 Cooling Plate 3 Steam Separator 5 Reformer 6 Exhaust Heat Treatment Facility 7 Heater 8 Cooling Water Outlet 9 Cooling Water Inlet 10 Reforming Steam Outlet 11 Heat Recovery Steam Outlet 12 Condensate Inlet 31 Annular Container 32 Annular No. 1 container 33 annular second container 34 connecting pipe

Claims (2)

[Claims] 1. Water and steam discharged from the fuel cell body
Introducing a phase fluid, separating it into water and water vapor, supplying cooling water to the fuel cell body, and at the same time supplying water vapor to be mixed with the raw fuel, the water vapor separator container body of the water vapor separator Is formed by arranging circular pipes having the same diameter over the entire length in an annular shape in the horizontal direction, and a steam separator for a fuel cell. 2. Water and steam discharged from the fuel cell body
Introducing a phase fluid, separating it into water and water vapor, supplying cooling water to the fuel cell body, and at the same time supplying water vapor to be mixed with the raw fuel, the water vapor separator container body of the water vapor separator A first container formed by arranging circular pipes having the same diameter over the entire length in an annular shape in the horizontal direction,
A second container having the same shape and size as the first container
The fuel cell water vapor separator for fuel cells, wherein the first container and the second container are formed by connecting the first container and the second container vertically on the same axis.