JPH113722A - Steam separator for fuel cells - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the space occupied in a packaged fuel cell power generator and dead space in layout,
An object of the present invention is to provide a small-sized steam separator for a fuel cell. A steam separator for separating a gas-liquid two-phase stream into a gaseous phase and a liquid phase, wherein the steam separator separates at least the gas-liquid two-phase stream into the steam separator. An outlet, a gas-phase discharge opening, and a cooling water outlet are provided in a container of a steam separator, and a part of the inner wall surface of the container of the steam separator is used as a gas-liquid separation surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package type on-site phosphoric acid fuel cell power generator, and more particularly to a two-phase fluid of cooling water supplied to remove heat generated in a fuel cell body. TECHNICAL FIELD The present invention relates to a fuel cell steam separator for separating fuel and steam.

[0002]

2. Description of the Related Art In a phosphoric acid type fuel cell power generator, heat generated during power generation is removed by circulating cooling water so that the operating temperature of the fuel cell main body is maintained at a constant level and generated by the fuel cell main body. The heat is recovered for effective use.

FIG. 4 shows an outline of a system for circulating cooling water of a conventional fuel cell power generator. In FIG. 4, the fuel cell main body 1 is schematically shown, and has a configuration in which a cooling plate 2 provided with a cooling pipe is provided every time a plurality of cells (not shown) are stacked. The cooling water discharged from the steam separator 3 is sent to the cooling pipe by a cooling water circulation pump 4. The cooling water absorbs the heat generated by the power generation and lowers the temperature of the fuel cell body, and at the same time, partly turns into steam,
It becomes a two-phase flow of steam. The two-phase flow of water / steam discharged from the outlet of the cooling pipe provided on the cooling plate of the fuel cell circulates to the steam separator 3. The steam separator 3 supplies steam for fuel reforming, mixes with the raw fuel and sends it to the reformer 5, while sending steam to the external waste heat treatment equipment 6 to release heat and condense. Receive the water. Thus, the steam separator 3 receives the heat generated in the fuel cell body,
The heat is sent to the reformer, which is used for fuel reforming while maintaining a thermal balance. The steam separator 3 incorporates a heater 7 for heating and controls the internal pressure by heating water as needed and adjusting the amount of steam in the steam separator.

FIG. 5 schematically shows a schematic configuration of a conventional steam separator 3. Since the steam separator 3 is used in a pressurized state, it is necessary to make the structure strong against the internal pressure. Therefore, the cylindrical body 3 in which the cylindrical containers are arranged horizontally.
A container is formed by disposing spherical end plates 3b and 3c on both left and right sides of a. At the upper part of the steam separator in contact with the vapor phase, a cooling water inlet 9 for receiving cooling water discharged as a two-phase flow of water / steam from the fuel cell body, and steam for fuel reforming to the reformer 5 (FIG. 4) And a heat recovery steam outlet 11 for discharging steam to the waste heat treatment equipment 6 (shown in FIG. 4). The lower part of the steam separator in contact with the liquid phase is provided. A cooling water outlet 8 for sending cooling water to the fuel cell body and a condensed water inlet 12 for taking in water that has lost heat in the waste heat treatment equipment 6 and condensed.

[0005] The gas-liquid separation performance in the steam separator becomes better as the gas-liquid contact surface is wider, and depends on the size of the area. Accordingly, in the steam separator 3 used in the phosphoric acid type fuel cell power generator having an output of 100 kW, the diameter of the body 3a (D in the figure) is about 10 mm in order to secure the area of the gas-liquid contact surface. 600 mm, length (L in the figure) is 600-
700 mm is required, and when such a steam separator 3 is incorporated into a package type on-site fuel cell power generator, a considerably large space in the power generator is occupied.
In addition, there is a problem that a dead space is formed around the stored steam separator and an efficient layout cannot be performed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to reduce the space occupied in a packaged fuel cell power generator and the dead space in layout. Another object of the present invention is to provide a small-sized steam separator for a fuel cell.

[0007]

The invention of claim 1 is a steam separator for separating a gas-liquid two-phase flow into a gas phase and a liquid phase, wherein the steam separator separates at least the gas-liquid two-phase flow. A vapor-liquid two-phase flow outlet for taking in the steam separator, a gas-phase discharge opening, and a cooling water outlet are provided in the vessel of the steam separator, and a part of the inner wall surface of the vessel of the steam separator is subjected to gas-liquid separation. It is characterized in that it is used as a surface.

Here, the horizontal cross-sectional shape of the container is circular, and the gas-liquid two-phase flow is applied along the circumferential direction of the inner wall surface of the container by utilizing the inertial force of the gas-liquid two-phase flow in the flow direction. The gas phase and the liquid phase may be separated by flowing.

Further, the container may have an upright cylindrical shape, and the gas-liquid two-phase flow outlet may be disposed at a position eccentric with respect to the center line of the upright cylindrical shape.

[0010] The gas-liquid two-phase flow outlet may be provided on a side surface of the container.

Further, the gas-phase discharge opening may be arranged at a position above the container and including the center line of the container.

Here, one end of the gas-phase discharge opening is
The tube can be opened in the gas phase inside the container by a tube inserted inside the container.

A barrier may be provided between the gas-liquid two-phase flow outlet and the gas-phase discharge opening to guide the two-phase flow taken in from the gas-liquid two-phase flow outlet to the inner wall surface of the container.

Here, the barrier may be arranged in a circular shape around the gas-phase discharge opening.

According to a ninth aspect of the present invention, there is provided the fuel cell steam separator according to the first aspect, wherein the gas-liquid two-phase flow is blown from the gas-liquid two-phase flow outlet to the inner wall surface of the container, and the liquid phase is discharged from the container. The gas phase and the liquid phase are separated by free fall along the inner wall surface.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The steam separator of the present invention utilizes a part of the inner wall surface of a container as a gas-liquid separation surface. for that purpose,
Forming a gas-liquid separation surface using the inertial force of the gas-liquid two-phase flow in the flow direction, or free-falling the gas-liquid two-phase flow using gravity to form a gas-liquid separation surface Is preferred. A steam separator of any configuration may be used as long as a part of the container can be used as a gas-liquid separation surface,
For example, by using a vertical cylindrical steam separator, the outlet of the gas-liquid two-phase flow is disposed at a position eccentric from the center line of the vertical cylinder. Alternatively, this is achieved by providing a gas-liquid two-phase flow outlet having small holes in the center of a vertical cylindrical steam separator. The shape of the steam separator is not limited to a vertical cylindrical shape, and may be, for example, a spherical shape.

Embodiment 1 FIG. 1 schematically shows a first embodiment of a steam separator for a fuel cell according to the present invention. FIG. 1A is a vertical sectional view showing the basic configuration of the steam separator, and FIG. 1B is a plan sectional view of the state cut along the XX plane in FIG. 1A as viewed from above. FIG. 2 shows a cooling water system diagram of a fuel cell power generator using the steam separator of the present invention. However, components having the same functions as those in FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, a steam separator 31 (shown in FIG. 1) converts a gas-liquid two-phase flow into a gas phase and a liquid phase by using a part of the inner wall surface 21 of the vessel as a gas-liquid separation surface. To separate. The cross-sectional shape of the container inner wall surface 21 serving as a gas-liquid separation surface is circular, and a structure in which the gas-liquid two-phase flow is guided to the inner wall surface of the container by using the inertial force in the flow direction held by the gas-liquid two-phase flow. It has become. Specifically, an opening 22 for receiving a gas-liquid two-phase flow is disposed on a side surface of the vertical cylinder and eccentric from a center line of the vertical cylinder, with the container shape being a vertical cylinder. It is preferable that the openings 22 are arranged in a positional relationship such that the center line thereof is normal to the radius of the vertical cylinder. When the opening 22 is disposed at the eccentric position, the two-phase flow flows in a circular shape along the inner wall in the cylinder. The height of the opening in the container is not particularly limited as long as the inertia force in the flow direction held by the two-phase flow can be used. In the embodiment of FIG.
Although the center of 2 is arranged at a position slightly above the lower end position of the tube 24, it may be a position far above the lower end position or a position below the lower end position. In the present invention,
The head plate is preferably curved so that the separated liquid phase easily falls and is easily collected below.

Opening 2 for discharging the separated gas phase
Numeral 3 is preferably provided at the upper part of the container and at a position including the center line of the vertical cylinder. The distal end of the opening 23 for discharging the gaseous phase is disposed at a position away from the upper wall portion of the container via a pipe 24 arranged to be inserted into the container along the center line of the vertical cylinder. Is preferred. However, the lower end position of the opening, that is, the length of the tube 24 is not particularly limited as long as the lower end is in the gas phase, and can be appropriately designed. In the present invention, it is preferable to provide a barrier 25 between the two-phase flow outlet 22 and the opening 23 for discharging the separated gas phase. Here, between the gas-liquid two-phase flow outlet and the gas-phase discharge opening is the closest part of the inner wall of the container of the gas-liquid two-phase flow outlet (the pipe part of the gas-liquid two-phase flow outlet, (Part farthest from the center of the shape or the center of the spherical shape) and outside the wall of the gas-phase discharge opening. The provision of the barrier facilitates separation of the condensed water formed on the gas-liquid separation surface from the gas phase. This barrier is designed to help direct the flow direction of the two-phase flow to the inner wall of the cylinder and may be arranged, for example, in a circular shape around the opening 23. The size and position of the barrier are appropriately determined in consideration of the flow rate and the like.

The gas-liquid two-phase flow flowing from the opening 22 flows in the vertical cylindrical container in the circumferential direction by utilizing the inertial force of the gas-liquid two-phase flow in the flow direction. While the gas-liquid two-phase flow is flowing along the circumferential direction, condensation occurs near the inner wall surface of the cylinder. The peripheral portion of this trajectory becomes the gas-liquid separation surface.

The condensed water thus obtained is accumulated below the inner wall of the cylinder. On the other hand, the non-condensed gas phase is discharged to the outside through the opening 23 for discharging the gas phase, a part is sent to the reformer 5 (shown in FIG. 2) together with the raw fuel, and a part is It is sent to the waste heat treatment equipment 6 (shown in FIG. 2).

In FIG. 2, the steam separator 31 of the present invention is used.
Has the same piping as the conventional steam separator,
The heating electric heater 7 is not installed in the steam separator 31 but is installed on the outlet side of the fuel cell main body 1 in the cooling water circulation line. Further, here, the steam and condensed water lines connected to the waste heat treatment equipment 6 are branched from the fuel reforming steam line and the cooling water outlet line, respectively, but similar to the case of FIG. 5 shown in the conventional example. A nozzle may be provided in the steam separator to output the line independently.

According to the above construction of the present invention, the inner wall surface 2 of the container
Since 1 can be a gas-liquid separation surface, the volume of the steam separator can be extremely reduced while maintaining the conventional gas-liquid separation performance. Therefore, compared with a conventional steam separator having a water surface as a gas-liquid separation surface, the size of the vessel of the steam separator could be reduced. In addition, the area occupied when assembled into the fuel cell power generator can be reduced, and
Since the dead space is reduced, an efficient layout is possible. For example, in a phosphoric acid fuel cell power generator with an output of 100 kW, the internal volume of a conventional steam separator is 24
While the volume is 0 liter, the internal volume of the steam separator of the present invention may be 39 liters.

Embodiment 2 FIG. 3 shows a basic structure of a second embodiment of the steam separator for a fuel cell according to the present invention. This fuel cell steam separator is
An outlet 22 for receiving a two-phase flow is constituted by a number of small-diameter holes 41. The two-phase flow blown out from the small hole falls freely along the inner wall surface using gravity.
In this case, the outlet of the opening 22 is not particularly limited as long as the size, shape, number, and the like of the two-phase flow can reach the inner wall surface of the cylinder and the liquid phase can freely fall. It is preferable that the temperature is appropriately determined so as to provide a wide gas-liquid separation surface. The inner wall surface of the cylinder where condensation occurs due to the free fall becomes a gas-liquid separation surface. In addition, the outlet into the container may be a slit instead of a large number of small-diameter holes. However, an embodiment in this case is not shown.

The outlet is preferably arranged near the center including the center line so that the entire inner wall surface of the cylindrical container in the circumferential direction becomes a wide gas-liquid separation surface. The basic system diagram of the cooling water system of the fuel cell power generator is the same as that of FIG.

[0026]

As described in detail above, according to the present invention, by utilizing the inner wall surface of the container as a gas-liquid separation surface, a small dead space in the layout in the package and a small water vapor separation for a fuel cell can be obtained. Vessel could be provided.

In consideration of the area of the gas-liquid contact surface, it is considered that the horizontal cylindrical container is easier to have a larger area than the vertical cylindrical container. Therefore, the shape of the conventional steam separator has been mainly a horizontal cylinder. However, there is an advantage in that the vertical cylindrical container is easier to lay out and the dead space can be reduced. According to the present invention, the gas-liquid separation ability can be improved even in the shape of a vertical cylinder, so that such an advantage is also obtained.

[Brief description of the drawings]

FIG. 1 (a) is a vertical sectional view showing a basic configuration of a fuel cell steam separator of the present invention, and FIG. 1 (b) is a plan sectional view taken along the line XX in FIG. 1 (a). is there.

FIG. 2 is a cooling water system diagram of a fuel cell power generator using the steam separator of the present invention.

FIG. 3 is an elevational sectional view showing a basic configuration of another fuel cell steam separator of the present invention.

FIG. 4 is a basic system diagram for circulating cooling water of a conventional fuel electric power generator.

FIG. 5 is a schematic diagram showing a schematic shape of a conventional steam separator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell main body 2 Cooling plate 3 Steam separator 3a Cylindrical body 3b, 3c End plate 4 Cooling water circulation pump 5 Reformer 6 Waste heat treatment equipment 7 Electric heater for heating 8 Cooling water outlet 9 Cooling water inlet 10 Reforming steam outlet 11 Heat Recovery steam outlet 12 Condensed water inlet 21 Container inner wall surface 22 Two-phase flow outlet 23 Gas phase outlet opening 24 Tube 25 Barrier 26 Cooling water outlet 31 Steam separator 41 Small hole

Claims (9)

[Claims] 1. A steam separator for separating a gas-liquid two-phase stream into a gaseous phase and a liquid phase, wherein the steam separator has at least a gas-liquid two-phase stream for taking at least the gas-liquid two-phase stream into the steam separator. A fuel cell comprising a steam outlet, a gas-phase discharge opening, and a cooling water outlet provided in a vessel of a steam separator, and using a part of the inner wall surface of the vessel of the steam separator as a gas-liquid separation surface. For steam separator. 2. The container has a circular horizontal cross-sectional shape,
The gas-liquid two-phase flow is separated by separating the gaseous phase and the liquid phase by flowing the gas-liquid two-phase flow along the circumferential direction of the inner wall surface of the container using the inertial force in the flow direction held by the gas-liquid two-phase flow. The steam separator for a fuel cell according to claim 1, wherein 3. The container according to claim 1, wherein the container has a vertical cylindrical shape, and the gas-liquid two-phase flow outlet is disposed at a position eccentric with respect to a center line of the vertical cylindrical shape. Item 3. A steam separator for a fuel cell according to item 2. 4. The steam separator for a fuel cell according to claim 2, wherein the gas-liquid two-phase flow outlet is provided on a side surface of the container. 5. The container according to claim 1, wherein the gas-phase discharge opening is located above the container and includes a center line of the container. Steam separator for fuel cells. 6. The container according to claim 5, wherein one end of the gas-phase discharge opening is opened in a gas phase in the container by a tube inserted into the container. Steam separator for fuel cells. 7. A barrier for guiding a two-phase flow taken from the gas-liquid two-phase flow outlet to the inner wall surface of the container, between the gas-liquid two-phase flow outlet and the gas-phase discharge opening. The steam separator for a fuel cell according to any one of claims 1 to 6, wherein: 8. The steam separator for a fuel cell according to claim 7, wherein the barrier is disposed in a circular shape around the gas-phase discharge opening. 9. A gas-liquid two-phase flow is blown from the gas-liquid two-phase flow outlet to the inner wall surface of the container, and the liquid phase is allowed to freely fall along the inner wall surface of the container, thereby separating the gas phase and the liquid phase. The steam separator for a fuel cell according to claim 1, wherein: