JP2947682B2 - Steam separator for fuel cells - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam separator for a fuel cell, and more particularly to a steam separator for a phosphoric acid type fuel cell using phosphoric acid as an electrolyte.

[0002]

2. Description of the Related Art FIG. 6 is a schematic configuration diagram of a conventional steam separation device disclosed in, for example, Japanese Patent Application Laid-Open No. 4-87158. In the figure, reference numeral 1 denotes a CO converter for converting carbon monoxide in a reformed gas obtained by a reaction between fuel and steam in a reformer (not shown), and 2 denotes a reformed gas passed through the CO converter 1. It is a fuel cell stack that obtains electric power by using it.

Reference numeral 3 denotes a CO transformer 1 and a fuel cell stack 2
The two-phase flow of pressurized water and steam obtained by the heat of reaction is separated into gas and liquid to separate steam and CO required for the reformer.
And a pressurized water necessary for cooling the fuel cell stack.

[0004] Reference numeral 4 denotes a pipe provided between the steam separator 3 and the CO converter 1 and the fuel cell stack 2, and pressurized water obtained by the steam separator 3 is supplied to the CO transformer 1 and the fuel cell stack 2 through the pipe. It is a pressurized water circulation pump for feeding.

[0005] Reference numeral 5 denotes a reforming steam flow control valve for feeding the steam obtained by the steam separator 3 at a predetermined flow rate to the reformer, and 6 denotes a steam separator 3 so that the pressurized water temperature becomes a predetermined temperature. This is a steam separator pressure control valve for discharging excess steam in the inside to a waste heat utilization system (not shown) to control the pressure in the steam separator 3.

Reference numeral 7 denotes a water level detector for detecting the level of pressurized water staying in the steam separator 3, reference numeral 8 denotes a makeup water pump for feeding pure water as makeup water into the steam separator 3, and reference numeral 9 denotes this makeup water pump. 8 is a water level control valve provided in the pipe between the outlet of the steam turbine 8 and the steam separator 3, and the makeup water pump 8 and the water level control valve 9 are turned on in response to a water level detection signal from the water level detector 7.
By turning OFF, the supply amount of makeup water to the steam separator 3 is controlled.

Reference numeral 10 denotes a load for raising the temperature of the pressurized water when the fuel cell is started and for lowering the battery voltage of the battery stack 2 so that the battery voltage of the battery stack 2 does not become too high during the low load operation when the power generation is started and stopped. It is a load heater.

Next, the operation of the above configuration will be described. When the fuel cell is started, pressurized water staying in the steam separator 3 is heated by the load heater 10, and then the pressurized water is pumped by the pressurized water circulation pump 4 into the fuel cell stack 2 and the CO.
These are sent to the transformer 1 to increase the temperature.

When the load is low at the start and stop of the power generation, the electric power generated by the fuel cell stack 2 is transferred to the inside of the steam separator 3 in order to prevent the voltage of the fuel cell stack 2 from increasing and the corrosive current from flowing, thereby promoting the corrosion of the battery. Load heater 10 inserted in
To lower the battery voltage. The load heater 1
The heating of 0 causes part of the pressurized water in the steam separator 3 to become steam, but since there is room in the gas phase volume in the steam separator, gas-liquid co-generation (steam and pressurized water mist come out in the gas phase at the same time) Phenomenon) does not occur.

During operation of the fuel cell, the reaction heat of the CO converter 1 and the fuel cell stack 2 is recovered by boiling and cooling the pressurized water supplied thereto from the steam separator 3. As a result, the two-phase flow in which a part of the pressurized water has become steam returns from the CO converter 1 and the fuel cell stack 2 to the steam separator 1, where it is separated into steam and pressurized water.

[0011] Some of the water vapor obtained by separating the Ru is supplied to the reformer at a predetermined flow rate by reforming steam flow control valve 5 as steam reforming. The excess steam is released to the exhaust heat utilization system by the steam separator pressure control valve 10, whereby the steam pressure in the steam separator 3 is controlled, and the temperature of the pressurized water is controlled to a predetermined temperature.

Since the water level of the pressurized water in the steam separator 3 decreases due to the release of steam for reforming and surplus steam, the water pump 8 and the water level control valve 7 receive the water level detection signal from the water level detector 6 by the water pump 8. Is turned ON-OFF, and low-temperature pure water as replenishing water is directly supplied to the steam separator 1. At this time, in order to prevent the ON-OFF frequency of the makeup water pump 8 from increasing and shortening the life of the makeup water pump 8,
The makeup water pump 8 is protected by providing a range between the ON level and the OFF level of the makeup water pump 8.

[0013]

SUMMARY OF THE INVENTION An object of the conventional fuel cell water vapor separation apparatus, since the low temperature of the supply water is supplied directly to the steam separator 3, reduced pressurized water temperature in the steam separator 3 is the makeup water supply As a result, the steam pressure is reduced and the pressurized water stays in the steam separator 3 so as not to lower the temperature of the pressurized water even if low-temperature make-up water is supplied so that it is not difficult to supply a predetermined flow rate of steam to the reformer. It was necessary to increase the amount of pressurized water. Therefore, since the large steam separator 3 was used, there was a problem that the apparatus was large.

When the pipe diameter is small, there is a portion that becomes a slag flow in the two-phase flow from the CO converter 1 and the fuel cell stack 2, and the slag flow flows into the pressurized water phase in the steam separator 3. Therefore, the pressurized water in the steam separator 3 resembles the boiling inside the liquid, the liquid level in the steam separator 3 fluctuates, and the steam separator 3 is heated by the load heater 10.
The liquid level in the steam separator 3 also fluctuates due to boiling of the pressurized water in the inside. Therefore, since it is necessary to increase the gas phase volume for good gas-liquid separation, a large steam separator 3 is used. Therefore, the apparatus becomes large, and the water level in the steam separator 3 is accurately detected. And cannot be controlled.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has a small size, and can accurately detect and control the water level in a steam separator and can control the water level in a fuel cell. The aim is to obtain a device.

[0016]

Means for Solving the Problems] steam separator for a fuel cell according to the inventions is a reformer by reacting fuel and steam to obtain a reformed gas, the carbon monoxide of the reformate gas The CO converter that is to be transformed, a fuel cell stack that obtains electric power using the reformed gas that has passed through the CO transformer, and the gas-liquid two-phase flow that is obtained by the reaction heat of the CO transformer and the fuel cell stack. And vapor-liquid separation of steam required for a reformer and pressurized water required for cooling the CO converter and the fuel cell stack, supplying the steam to the reformer, and supplying the pressurized water to the CO transformer and the fuel cell. In a steam separator for a fuel cell equipped with a steam separator for supplying a stack and a makeup water pump for supplying makeup water, the steam separator is provided in the inflow direction of the gas-liquid two-phase flow and in the ground surface. Against A gas-liquid separation tube in which the gas-liquid two-phase flow entering provided in a substantially perpendicular direction to the gas-liquid separation by striking the inner wall and separated provided communicating and substantially parallel to the gas-liquid separation tube A gas-liquid separation pipe for supplying steam and pressurized water, and a gas-liquid two-phase flow obtained by mixing the makeup water by the makeup water pump from the CO converter and the fuel cell stack. Is supplied into the piping flowing to the

[0017] Also, fuel and a and is reacted reformer to obtain a reformed gas steam, and the CO transformer for transforming carbon monoxide of the reforming gas, reformed passing through the CO transformer A fuel cell stack for obtaining electric power by using gas; steam required for the reformer from the gas-liquid two-phase flow obtained by the reaction heat of the CO converter and the fuel cell stack; the CO converter; and the fuel cell A pressurized water required for cooling the stack is separated into a gas and a liquid, and the steam is supplied to the reformer, and the pressurized water is supplied to the CO converter and the fuel cell stack. And a heater for consuming power when a high voltage is generated in the fuel cell, a water level detector for detecting the level of the pressurized water in the steam separator, and make-up water based on a water level detection signal of the water level detector. To In the steam separator for a fuel cell and a makeup water pump for supplying said steam separator,
A gas-liquid separation pipe, which is provided in a direction substantially perpendicular to the inflow direction and the ground surface of the gas-liquid two-phase flow and in which the gas-liquid two-phase flow that flows in collides with the inner wall of the pipe to separate gas and liquid; The separated water vapor and heating water are connected to the liquid
A gas-liquid separation pipe for supplying pressurized water, and the water level detector is provided on one of the gas-liquid separation pipes, and the heater is provided on the side of the gas-liquid separation pipe on which the water level detector is not provided. It is provided in.

Further, the fuel is reacted with steam to form a reforming gas.
And a reformer to obtain carbon dioxide and convert carbon monoxide in the reformed gas.
And the reformed gas passed through the CO converter
Fuel cell stack for obtaining electric power using the same, and the above-mentioned CO transformer
And gas-liquid obtained by the reaction heat of the fuel cell stack
Steam required for the reformer and CO conversion from the two-phase flow
And pressurized water necessary for cooling the fuel cell stack.
While separating the liquid and supplying the steam to the reformer,
The pressurized water is supplied to the CO converter and the fuel cell stack.
Steam separator for supplying to the
Pressurizes the CO transformer and the fuel cell stack
A pressurized water circulation pump installed in the pipe through which water flows, and
Heat pressurized water to raise temperature and generate high voltage for fuel cell
A heater that consumes electric power at the time of
A water level detector that detects the water level of the pressurized water, and the water level detector
Make-up water pump that supplies make-up water based on the water level detection signal
In the fuel cell steam separator comprising:
The steam separator is located in the inflow direction of the gas-liquid two-phase flow and the ground surface.
The above-mentioned gas-liquid two-phase flow which is provided in a direction substantially perpendicular to the
Gas and liquid are separated by colliding with the inner wall of the pipe, and the separated pressurized water
And a gas-liquid separation tube for feeding
Gas-liquid separation that feeds separated water vapor that is installed almost in parallel
And a pipe, and the water level detector is connected to the pressurized water.
The heater is provided on the gas-liquid separation tube to be fed, and the heater is
It is provided in a gas-liquid separation tube that supplies steam. Also,
A reformer for reacting fuel and steam to obtain a reformed gas, a CO converter for converting carbon monoxide in the reformed gas, and obtaining electric power using the reformed gas passed through the CO converter A fuel cell stack, steam required for the reformer and pressurized water required for cooling the CO converter and the fuel cell stack from a gas-liquid two-phase flow obtained by reaction heat of the CO converter and the fuel cell stack. And a steam separator for supplying the steam to the reformer and supplying the pressurized water to the CO converter and the fuel cell stack, from the steam separator to the CO converter and A pressurized water circulation pump provided in a pipe through which the pressurized water flows to the fuel cell stack; and a heater that heats the pressurized water to increase the temperature and consumes electric power when a high voltage is generated in the fuel cell. In the steam separator for charge battery, the steam separator, the gas-liquid two-phase flow entering provided in a direction substantially perpendicular to the inflow direction and the ground surface of the gas-liquid two-phase flow collides with the inner wall A gas-liquid separation tube for separating gas and liquid by means of a gas-liquid separation tube, and a gas-liquid separation tube for communicating separated steam and pressurized water provided in substantially parallel with the gas-liquid separation tube, and the heater, The gas-liquid flow from the pressurized water circulation pump to the CO converter and between the branch in the branch pipe through which pressurized water is supplied to the CO converter and the fuel cell stack and the CO converter , or from the CO converter to the steam separator. It is provided between the gas-liquid two-phase outlet of the CO converter in the merging pipe through which the phase flow flows and the merging .

[0019] Also, fuel and a reformer and a water vapor is reacted to obtain a reformed gas, a CO transformer for transforming carbon monoxide of the reforming gas, reformed passing through the CO transformer A fuel cell stack for obtaining electric power by using gas; steam required for the reformer from the gas-liquid two-phase flow obtained by the reaction heat of the CO converter and the fuel cell stack; the CO converter; and the fuel cell A pressurized water required for cooling the stack is gas-liquid separated and the steam is supplied to the reformer, and the pressurized water is supplied to the CO converter and the fuel cell stack. In a fuel cell steam separator comprising a heater that raises the temperature and consumes electric power when a high voltage is generated in the fuel cell, the steam separator is arranged such that the steam separator is in the inflow direction of the gas-liquid two-phase flow and the ground surface. Almost vertical A gas-liquid separation tube in which the gas-liquid two-phase flow entering provided countercurrent to the gas-liquid separation by impinging on the inner wall, communicating with the gas-liquid separation tube and minute provided substantially parallel
A gas-liquid separation pipe for supplying separated steam and pressurized water, a pipe through which the pressurized water flows from the steam separator to the CO converter and the fuel cell stack, the CO converter and the fuel cell A short-circuit pipe communicating with a pipe through which the mixed gas-liquid two-phase flow from the stack flows toward the steam separator is provided, and the heater is provided in the short-circuit pipe.

[0020]

[Action] In the steam separator for a fuel cell according to the inventions is, CO transformer and the gas-liquid two-phase flow from the fuel cell stack, collide with the gas-liquid flow perpendicular to the separation tube inner wall of the steam separator And gas-liquid separation. In addition, the makeup water pump supplies makeup water into a pipe between the steam separator, the CO converter, and the fuel cell stack. The low-temperature make-up water supplied into the pipe rises in temperature due to condensation of a part of the steam in the gas-liquid two-phase flow, and flows into the steam separator.

[0021] Also, the water level detector detects the water level of the gas-liquid separation tube which is not affected by the heater, controls the supply amount of the makeup water due to makeup water pump based on the water level detection signal from the water level detector I do. The gas-liquid two-phase flow from the CO converter and the fuel cell stack collides with the inner wall of the pipe in the gas-liquid separation tube that flows first, and is mostly gas-liquid separated, and the remaining gas-liquid two-phase flow is the next gas-liquid Gas-liquid separation is performed by colliding with the inner wall of the separation tube. Further, the heater heats the pressurized water to raise the temperature, consumes electric power when a high voltage is generated in the fuel cell, lowers the cell voltage at the start and stop of power generation, and suppresses battery corrosion.

Further , a low-pressure gas is supplied to a gas-liquid separation tube for supplying steam.
A water heater is installed, and the water level is detected in the gas-liquid separation tube that supplies pressurized water.
An alarm is provided to prevent fluctuations in the liquid level due to heating of the load heater.
The volume of the gas phase required for gas-liquid separation in the steam separator
The water level detector 7 can be minimized and the device can be made smaller.
With this, the pressurized water level in the steam separator is accurately detected.
Also, the pressurized water is heated by a heater provided in a pipe between the pressurized water circulation pump and the CO transformer and the fuel cell stack, or in a pipe in which only a gas-liquid two-phase flow flows from the CO transformer to the steam separator. In addition to increasing the temperature, the fuel cell consumes power when a high voltage is generated to lower the battery voltage at the start and stop of power generation, thereby suppressing battery corrosion.

[0023] Also, short communicating from the water steam separator and piping pressurized water flows into the CO shift converter and the fuel cell stack, to the pipe through the gas-liquid two-phase flow from the CO transformer and the fuel cell stack to steam separator By the heater provided in the piping,
In addition to heating the pressurized water to increase the temperature, the fuel cell consumes power when a high voltage is generated to reduce the battery voltage at the start and stop of power generation, thereby suppressing battery corrosion.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a first embodiment of the present invention. As shown in the figure, in the first embodiment, the steam separator 3A has a two-phase flow so that the two-phase flow of the steam and the pressurized water from the CO converter 1 and the fuel cell stack 2 collides with the inner wall of the pipe. having a gas-liquid separation tube 3A ₁ provided in a substantially vertical direction, and a gas-liquid separation tube 3A ₂ provided in communication with and substantially parallel with the gas-liquid separation tube 3A ₁ relative to the inflow direction and the ground surface .

The reforming steam flow control valve 5 and the steam outlet of the steam separator 3A leading to steam separator pressure control valve 6 is located directly above the gas-liquid separation tube 3A _2, the water vapor leading to the pressurized water circulation pump 4 pressurized water outlet of the separator 3A is positioned directly below the gas-liquid separation tube 3A _2.

The water level detector 7 is connected to the gas-liquid separation tube 3A ₂
To be provided. Further, the makeup water from makeup water pump 8 is supplied to C
O transformer 1 and a mixture of two-phase flow from the fuel cell stack 2 which you supplied in the piping flows into the steam separator 3A. Other configurations are the same as those in FIG.

Next, the operation of the above configuration will be described. When the fuel cell power generation equipment starts power generation, the reaction heat generated in the CO converter 1 and the battery stack 2 is converted into pressurized water controlled to a predetermined temperature in the steam separator 3A by the pressurized water circulation pump 4 and the CO converter 1 Fuel cell stack 2
And recovered by boiling cooling.

A two-phase flow in which part of the pressurized water becomes steam due to the recovery of the reaction heat flows out of the CO converter 1 and the fuel cell stack 2 and merges to form a first-stage gas-liquid separation tube 3A ₁ of the steam separator 3A. Flows into.

The two-phase flow flowing into the gas-liquid separation tube 3A ₁ impinges on the tube wall, for the most part gas-liquid separated into steam and pressurized water. In this case, two-phase flow even if the portion has a slug flow, to gas-liquid separated into more easily pressurized water and steam to the collision to the inner wall.

[0030] Most of the gas-liquid separation tube 3A ₁ of the first stage two-phase flow is a gas-liquid separation, the remaining two-phase flow is separated gas-liquid in the same manner with the gas-liquid separation tube 3A ₂ of the second stage Thus, the gas-liquid separation of the two-phase flow is almost completed. Thus, even if the two-phase flow is a slag flow, gas-liquid separation is ensured, so that the slag flow enters the pressurized water retained by the steam separator 3A, and the liquid level greatly fluctuates as in the case of internal boiling of the liquid. Therefore, the volume of the gas phase for gas-liquid separation of the steam separator 3A can be small.

Part of the steam obtained by the gas-liquid separation in the steam separator 3A is supplied from a reforming steam flow control valve 5 to a reformer (not shown). Further, excess steam is released to the exhaust heat utilization system (not shown) by the steam separator pressure control valve 6 and the pressure in the steam separator 3A is controlled, so that the temperature of the pressurized water is controlled to a predetermined temperature.

Most of the two-phase flow is generated by the first-stage gas-liquid separation tube 3A.
Since gas-liquid separation at _1, detects the water level changes in the pressurized water remaining in the water vapor separator 3A by the water level detector 7 provided in the gas-liquid separation tube 3A ₂ of the liquid level fluctuation is small second stage,
Pure water as make-up water is mixed by the make-up water pump 5 through the water level control valve 9 whose opening degree is controlled by the detection signal, and the two-phase flow from the CO converter 1 and the two-phase flow from the fuel cell stack 2 are mixed. The steam is then continuously supplied into the flowing pipe, flows into the steam separator 3A, and the level of the pressurized water in the steam separator 3A is controlled to be constant.

At this time, the makeup water supplied into the pipe is mixed into the two-phase flow, and the temperature of the water is raised to the same temperature as the steam by condensing a part of the steam in the two-phase flow.
Because there is almost no decrease in the temperature of the pressurized water that stays inside,
It is not necessary to increase the steam separator 3A to increase the amount of pressurized water staying so as to suppress the temperature change of the pressurized water staying in the steam separator 3A as in the related art. Steam separator 3
Pressurized water amount to be retained in the A may be in the amount necessary to key <br/> catcher bi tape Deployment prevention of a pressurized water circulation pump 4, it is possible to minimize, it can be made compact steam separators 3A.

In the first embodiment, as described above,
Low-temperature make-up water is continuously supplied into a pipe in which the two-phase flow from the transformer 1 and the fuel cell stack 2 flows to the steam separator 3A, and the make-up water is heated by condensing a part of the steam in the two-phase flow. since manner was, without any temperature drop of good Una pressurized water remaining in the steam separator 3A when supplying directly supply water to the steam separator 3A, required as a buffer to suppress the temperature change of the pressurized water The pressurized water retained in the steam separator 3A can be minimized. for that reason,
Since the size of the steam separator 3A is small, the size of the apparatus can be reduced.

The CO separator 1 is connected to the steam separator 3A.
And a gas-liquid separation tube 3A ₁ of the first stage which is provided in a direction substantially perpendicular to the inflow direction and the ground surface of the two-phase flow from the fuel cell stack 2, communicating with the gas-liquid separation tube 3A ₁ and substantially parallel second stage of the gas-liquid separation tube 3A ₂ and two-phase flow gas-liquid first stage of the gas-liquid separation tube 3A ₁ 2-stage gas-liquid separation tube to perform at most of the separation of comprise provided Since the fluctuation of the liquid level of the 3A ₂ is reduced, the volume of the gas phase required for the gas-liquid separation in the steam separator 3A can be minimized, and the apparatus can be made smaller. the pressurized water level in the steam separator 3A can be detected accurately by the water level detector 7 provided in the tube 3A _2.

Embodiment 2 FIG. FIG. 2 is a configuration diagram showing a second embodiment of the present invention. In Example 2, in the pressurized water is a gas-liquid liquid phase portion of the separation tube 3A ₁ steam separator 3A of FIG. 1, the start of power generation and low load operation of the power generation is stopped while heating the pressurized water when the fuel cell starts Sometimes, a load heater 10 used as a load for lowering the battery voltage is inserted so that the battery voltage of the battery stack 2 does not become too high.
Other configurations are the same as those in FIG.

Next, the operation of the above configuration will be described. When the fuel cell power generation equipment starts power generation, the reaction heat generated in the CO converter 1 and the fuel cell stack 2 is converted into pressurized water controlled to a predetermined temperature in the steam separator 3A by the pressurized water circulation pump 4 and the cell stack 2 and the CO. It is fed to the transformer 1 and recovered by boiling cooling.

The two-phase flow in which part of the pressurized water has become steam due to the recovery of the reaction heat flows from the CO converter 1 and the fuel cell stack 2 and joins, and is introduced into the first-stage gas-liquid separation pipe of the steam separator 3A. You. Here, the two-phase flow collides with the pipe wall and most of the two-phase flow separates into gas and liquid, and the gas-liquid separation of the pressurized water and the steam is almost completed in the second-stage gas-liquid separation tube.

At this time, as described in the first embodiment,
Even if the two-phase flow is a slag flow, gas-liquid separation occurs in the gas phase, and the liquid surface does not fluctuate because no state such as boiling inside the liquid occurs.
The gas phase volume for gas-liquid separation of the steam separator 3A can be small.

A part of the steam in the steam separator 3A is supplied from a reforming steam flow control valve 5 to a reformer (not shown). Further, excess steam is released to a waste heat utilization system (not shown) by the steam separator pressure control valve 10 and the pressure in the steam separator 3A is controlled, so that the steam separator 3
The temperature of the pressurized water in A is controlled to a predetermined temperature.

The change in the pressurized water level in the steam separator 3A is detected by the water level detector 7 provided in the gas-liquid separation tube 3A ₂ of the second stage, the water level control valve 9 which is opening controlled by the detection signal Pure water as make-up water by the make-up water pump 5 through the pipe, and the two-phase flow from the CO converter 1 and the two-phase flow from the fuel cell stack 2 are mixed and continuously fed into a pipe flowing to the steam separator 3A. Replenishment is mixed.

The makeup water replenished in the pipe is heated to the same temperature as the steam by condensing a part of the steam in the two-phase flow, so that the temperature of the pressurized water staying in the steam separator 3A changes. The amount of pressurized water staying in the steam separator 3A does not need to have a margin in order to suppress the temperature change of the staying water.

[0043] Therefore, the pressurized water level in the steam separator 3A may be any level required cavity tape Deployment prevention of a pressurized water circulation pump 4, water of a pressurized water staying in steam separator 3A may be minimal.

Further, in order to prevent the battery cell voltage of the fuel cell stack 2 from increasing at a low load when the power generation is started or stopped, the first-stage gas-liquid separation pipe 3 is used.
A load heater 10 is provided as a load in the liquid phase portion of A to lower the battery cell voltage and suppress battery corrosion.

[0045] At this time, although the boiling liquid surface pressurized water of the gas-liquid separation tube 3A in _one of the first stage by heating load heater 10 varies, the variation of the liquid level of the gas-liquid separation tube 3A ₂ of the second stage is rare. Therefore, the water level required pressurized water level in the steam separator 3A by the water level detector 7 provided in the gas-liquid separation tube 3A ₂ of the second stage in the cavity tape Deployment prevention of a pressurized water circulation pump 4, be precisely controlled It is possible.

As described above, in the second embodiment, the one-stage provided in the steam separator 3A in the direction substantially parallel to the inflow direction of the two-phase flow from the CO converter 1 and the fuel cell stack 2 and the ground surface. a gas-liquid separation tube 3A ₁ eye, and a second-stage gas-liquid separation tube 3A ₂ provided in communication with and substantially parallel with the gas-liquid separation tube 3A _1, the first stage of the gas-liquid separation tube 3A ₁ in, provided with a road heater 10 to heat the pressurized water to consume energy at a high voltage upon the occurrence of a raised and a fuel cell, by providing the water level detector 7 in the gas-liquid separation tube 3A ₂ of the second stage since the liquid surface by heating of the gas-liquid separation tube 3A ₁ load heater 10 in the first stage it is but the second stage of the gas-liquid separation tube 3A ₂ has no liquid level fluctuation without being affected by the load heater 10 varies,
The liquid volume of the gas phase portion required for separation of water vapor separator 3A is possible to minimize, pressurized water level in the steam separator 3A by the water level detector 7 provided in the gas-liquid separation tube 3A ₂ of the second stage Can be accurately detected.

Embodiment 3 FIG. FIG. 3 is a configuration diagram showing a third embodiment of the present invention. In the third embodiment, as shown in FIG. 3, the water level detector 7 with the provided gas-liquid separation tube 3A ₁ of the first stage, a road heater 10 second-stage gas-liquid separation tube 3A ₂
And a steam separator 3 connected to a circulating cooling water pump 4.
Providing pressurized water outlet of A immediately below the gas-liquid separation tube 3A _1.
Other configurations are the same as those in FIG.

Next, the operation of the above configuration will be described. When the fuel cell power generation equipment starts power generation, the reaction heat generated in the CO converter 1 and the fuel cell stack 2 is converted to pressurized water controlled to a predetermined temperature in the steam separator 3A by the pressurized water circulation pump 2 and to the CO converter 1 and the CO converter 1. Fuel cell stack 2
And recovered by boiling cooling.

[0049] Some of the pressurized water becomes steam by the reaction heat recovery, the inflow two-phase flow from the CO transformer 1 and the fuel cell stack 2 to the gas-liquid separation tube 3A ₁ of the first-stage steam separators 3A of pressurized water and steam I do. Two-phase flow most pressurized water collides with the tube wall to the gas-liquid separator in the pressurized water and steam in the first stage of the gas-liquid separation tube 3A _1, almost complete gas-liquid separation in the gas-liquid separation tube in the second stage I do.

At this time, as described in the first embodiment,
Even if the two-phase flow is a slag flow, it can collide with the inner wall of the gas-liquid separation tube
Since the gas-liquid separation is performed and the liquid level does not fluctuate without causing a state such as boiling inside the liquid, the gas-phase volume for gas-liquid separation of the steam separator 3A can be small. can do.

A part of the steam in the steam separator 1 is supplied from a reforming steam flow control valve 5 to a reformer (not shown). Further, excess steam is released to the exhaust heat utilization system by the steam separator pressure control valve 6 to control the pressure in the steam separator 3A, so that the temperature of the pressurized water in the steam separator 3A is controlled to a predetermined temperature.

The pressurized water level in the steam separator is detected by a water level detector 6 provided in the first-stage gas-liquid separation pipe 3A, and the replenishing water pump is supplied via a water level control valve 9 whose opening degree is controlled by this detection signal. 8, pure water is supplied as makeup water and CO
The two-phase flows from the transformer 1 and the fuel cell stack 2 are mixed and continuously replenished and mixed into a pipe flowing to the steam separator 3A.

At this time, the makeup water supplied to the pipe through which the two-phase flow flows is heated to the same temperature as the steam by condensing a part of the steam of the two-phase flow, and thus stays in the steam separator 1. The temperature of the pressurized water is small, so that it is not necessary to have a margin in the amount of the pressurized water retained in the steam separator 3A in order to suppress the temperature change of the pressurized water.

[0054] Therefore, the water level in the steam separator 3A may be any level required cavity tape Deployment prevention of a pressurized water circulation pump 4, since the amount of pressurized water to be retained in the steam separator 3A can be minimized, small 3A.

[0055] Further, at the time of low load when the power generation start or stop, in order to prevent the voltage corrosion becomes high cell voltage occurs, load heater provided in the liquid phase portion of the gas-liquid separation tube 3 A ₂ of the second stage 10, the load is taken to lower the battery cell voltage and suppress the battery corrosion.

[0056] At this time, the liquid level of the gas-liquid separation tube 3A ₂ of the second stage by boiling the pressurized water will vary, there is no effect on the liquid surface of the gas-liquid separation tube 3A ₁ of the first stage to be used for water level control So
The level required by the water level detector 7 provided in the gas-liquid separation tube 3A ₂ of the second stage in the cavity tape Deployment prevention of a pressurized water circulation pump 4, it is possible to precisely control.

[0057] Thus, in the third embodiment, provided with a road heater to the gas-liquid separation tube 3A ₂ of the second stage of the steam separator 3A, the water level detector 7 in the gas-liquid separation tube 3A ₁ of the first stage by providing, the gas-liquid separation tube 3A ₂ of the second stage b - Dohi - since there is no liquid level variations due to heating of the motor 10, the volume of the gas phase needed to gas-liquid separation in the steam separator 3A The water level detector 7 provided in the second-stage gas-liquid separation pipe 3A ₂ can minimize the size of the apparatus and reduce the size of the apparatus.
The water level of the pressurized water inside can be accurately detected.

Embodiment 4 FIG. FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention. In the fourth embodiment, the load heater 1
0 between a position where the pressurized water is diverted to the fuel cell stack 2 and a pressurized water inlet of the CO transformer 1 in a pipe through which the pressurized water is supplied from the pressurized water circulation pump 4 to the CO transformer 1 and the fuel cell stack 2. To be provided.

Then, in order to prevent the battery cell voltage from increasing and the battery from corroding when the load is low at the start or stop of power generation, the load is removed by the load heater 10 provided near the pressurized water inlet of the CO transformer 1. Reduce battery cell voltage.

Since the amount of heat recovered from the CO converter 1 is as small as about 1/10 that of the fuel cell stack 2, the proportion of water vapor in the gas-liquid two-phase flow at the outlet of the CO converter 1 is
Is smaller than the water vapor ratio at the outlet of the CO converter 1, even if the pressurized water is heated by the load heater 10 at the inlet of the CO converter 1 and the water vapor in the pressurized water slightly increases, the decrease in heat exchange performance in the CO converter 1 is small. No problem. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

[0061] In the fourth embodiment, as described above, the load heater 10, by providing near pressurized water inlet of the CO transformer 1, Mizu蒸<br/> gas separation Ri by the heating of the road heater 10 does not give the liquid level fluctuation in the vessel 3A, with only a small vapor phase volume of the steam separator 3A, it is possible to accurately detect the pressurized water level in the steam separator 3A.

The load heater 10 is connected to the CO transformer 1
The two-phase flow outlet from the CO transformer 1 and the two-phase flow from the CO transformer 1 in the pipe through which the two-phase flow flows from the fuel cell stack 2 to the steam separator 3A are combined with the two-phase flow from the fuel cell stack 2. The two-phase flow from the CO converter 1 may be provided with a small amount of water vapor.
Does not affect 0.

Embodiment 5 FIG. FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention. As shown in FIG.
A pipe is provided that communicates with a pipe through which pressurized water flows from A to the CO transformer 1 and the fuel cell stack 2 and a pipe through which a gas-liquid two-phase flow flows from the CO transformer 1 and the fuel cell stack 2 to the steam separator 3A. A load heater 10 is provided in the piping.

When the load is low at the start or stop of the power generation, the load is taken by the load heater 10 to lower the battery cell voltage, thereby suppressing battery corrosion. In this case, the cooling performance of the fuel cell stack 2 and the CO converter 1 by the pressurized water has almost no effect. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

In the fifth embodiment as well, as in the fourth embodiment, the liquid level in the steam separator 3A is not affected by the heating of the load heater, so that the gas phase volume in the steam separator 3A is small, and with a can be reduced, the pressurized water level in the steam separator 3A can be detected accurately.

Embodiment 6 FIG. In the fourth embodiment, the position where the pressurized water is diverted to the fuel cell stack 2 in the pipe through which the pressurized water flows from the steam separator 3A to the CO converter 1 and the fuel cell stack 2 and the pressurized water of the CO Although provided between the inlet and the inlet, the load heater 10 may be provided between the discharge part of the pressurized water circulation pump 4 and the fuel cell stack 2.

Normally, the ratio of water vapor in the two-phase flow flowing out of the fuel cell stack 2 is set to, for example, about 10%, so that the load heater 10 is connected to the discharge section of the pressurized water circulation pump 4 and the fuel cell stack 2. If it is set between
In order to prevent a part of the pressurized water flowing into the fuel cell stack 2 from becoming steam and the ratio of the steam in the two-phase flow from the fuel cell stack 2 exceeding, for example, 10%, the CO converter 1
Further, by changing the ratio of the pressurized water supplied to the fuel cell stack 2 to supply a large amount of pressurized water to the fuel cell stack 2 side and adjusting the boiling rate of the pressurized water, the ratio of water vapor in the two-phase flow from the fuel cell stack 2 becomes, for example, 10 Do not exceed%.

When the load heater 10 is provided at the inlet of the pressurized water circulation pump 4, the pressurized water circulation pump 4 causes cavitation, which is not appropriate. If the load heater 10 is provided between the two-phase flow outlet of the fuel cell stack 2 and the steam separator 3A, the load heater 10 is burned due to the large amount of steam in the two-phase flow. Not.

[0069]

As is evident from the foregoing description, the fuel cell water vapor separation device according to this inventions is in a direction substantially perpendicular to the inflow direction and the ground surface of the gas-liquid two-phase flow from the CO transformer and the fuel cell stack The steam separator is equipped with a gas-liquid separation pipe that separates gas and liquid by inflow of the gas-liquid two-phase flow that collides with the inner wall of the pipe. Even if a part of the flow is a slag flow, the gas-liquid separation occurs in the gas phase in the steam separator due to the temperature difference from the outside air of the gas-liquid separation tube at the time of collision with the inner wall of the gas-liquid separation tube. Since the phase flow is inserted into the pressurized water phase in the steam separator and the liquid level in the steam separator 3 does not fluctuate as in a state similar to boiling inside the liquid, the water level in the steam separator is accurately detected. And the steam separator, the CO converter, and the fuel The continuous supply of make-up water into the piping between the pond stack and the low-temperature make-up water is raised by condensation of part of the steam in the gas-liquid two-phase flow flowing through the piping. Since the steam flows into the steam separator and the temperature of the pressurized water in the steam separator does not decrease, a sufficient amount of steam can be supplied to the reformer at a predetermined flow rate. There is no need to use a large steam separator to keep a large amount of pressurized water in order to prevent the temperature of the pressurized water in the inside from dropping, and the device can be made compact.

[0070] Also, the gas-liquid two-phase flow collides with the tube wall flows provided in a direction substantially perpendicular to the inflow direction and the ground surface of the metamorphic condenser and a gas-liquid two-phase flow from the fuel cell stack A steam-liquid separator is provided with a gas-liquid separation tube for performing gas-liquid separation at and a gas-liquid separation tube connected to the gas-liquid separation tube and provided substantially in parallel, and detects the level of pressurized water in the steam separator. A water level detector is provided in any one of the gas-liquid separation pipes, and a heater that heats pressurized water to increase the temperature and consumes electric power when a high voltage is generated in the fuel cell is provided with a gas-liquid without the water level detector. Since the liquid level of the gas-liquid separation tube where the water level detector is installed is not affected by the heater and does not fluctuate due to the provision on the separation tube side, the vapor phase volume for gas-liquid separation can be small, so that the water vapor The separator is small and the An effect that can be controlled accurately detected by the water level in the steam separator.

Further , a low-pressure gas is supplied to a gas-liquid separation pipe for supplying steam.
A water heater is installed, and the water level is detected in the gas-liquid separation tube that supplies pressurized water.
By providing an alarm, the liquid level changes due to heating of the load heater
Of the gas phase required for gas-liquid separation in the steam separator.
The volume can be minimized, the equipment can be made smaller, and the water level
Accurately detects the level of pressurized water in the steam separator with the detector
This has the effect of being able to control Also, in the piping between the pressurized water circulation pump for supplying pressurized water in the steam separator to the CO transformer and the fuel cell stack and the CO transformer and the fuel cell stack, or from the CO transformer to the steam separator. In the pipe through which only the gas-liquid two-phase flow flows, the heater is inserted into the steam separator by heating the pressurized water and increasing the temperature while consuming power when a high voltage is generated in the fuel cell. Since there is no need to perform the process, the steam separator may be small, so that the apparatus can be made compact.In addition, since the liquid level in the steam separator does not fluctuate due to heating of the heater, the water level in the steam separator can be accurately determined. In this case, it is possible to perform the detection and control.

[0072] Also, short communicating from the water steam separator and piping pressurized water flows into the CO shift converter and the fuel cell stack, to the pipe through the gas-liquid two-phase flow from the CO transformer and the fuel cell stack to steam separator In addition to providing a pipe and a heater that heats pressurized water to increase the temperature and consumes power when a high voltage is generated in the fuel cell in the short-circuit pipe, it is necessary to insert the heater into the steam separator. Since the steam separator can be small because it is not necessary, the apparatus can be made compact, and since the liquid level in the steam separator does not fluctuate due to heating of the heater, the water level in the steam separator can be accurately detected. This has the effect of being able to control

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a conventional steam separation device for a fuel cell.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 CO transformer 2 Fuel cell stack 3A Steam separator 3A ₁ Gas-liquid separation pipe 3A ₂ Gas-liquid separation pipe 4 Pressurized water circulation pump 7 Water level detector 8 Make-up water pump 10 Road heater

Claims (5)

(57) [Claims] 1. A reforming apparatus for obtaining a reformed gas by reacting a fuel and steam, a CO converter for converting carbon monoxide in the reformed gas, and a reformed gas passed through the CO converter. A fuel cell stack that obtains electric power by using the CO converter and the gas-liquid two-phase flow obtained by the reaction heat of the fuel cell stack, and the steam required for the reformer and the CO converter and the fuel cell stack. A steam separator for supplying pressurized water to the CO converter and the fuel cell stack while supplying the steam to the reformer by separating the pressurized water required for cooling into gas and liquid, and a replenishment for supplying make-up water In a water vapor separation device for a fuel cell provided with a water pump,
The steam separator is provided in a direction substantially perpendicular to the inflow direction and the ground surface of the gas-liquid two-phase flow, and the gas-liquid two-phase flow that flows in collides with the inner wall of the pipe to perform gas-liquid separation. and separation tube, communicating with the gas-liquid separation tube and disposed substantially parallel
A gas-liquid separation pipe for feeding separated steam and pressurized water, and a gas-liquid two-phase flow obtained by mixing the make-up water by the make-up water pump from the CO transformer and the fuel cell stack. A steam separator for a fuel cell, wherein the steam is supplied into a pipe flowing to a separator. 2. A reformer for obtaining a reformed gas by reacting a fuel and steam, a CO converter for converting carbon monoxide in the reformed gas, and a reformed gas passed through the CO converter. A fuel cell stack that obtains electric power by using the CO converter and the gas-liquid two-phase flow obtained by the reaction heat of the fuel cell stack, and the steam required for the reformer and the CO converter and the fuel cell stack. A steam separator for supplying pressurized water necessary for cooling to the reforming device by gas-liquid separation of the pressurized water and supplying the pressurized water to the CO converter and the fuel cell stack, and heating the pressurized water. A heater that raises the temperature and consumes power when a high voltage is generated in the fuel cell, a water level detector that detects the level of the pressurized water in the steam separator, and supplies makeup water based on a water level detection signal of the water level detector. You And a makeup water pump for the fuel cell, wherein the steam separator is provided in a direction substantially perpendicular to the inflow direction of the gas-liquid two-phase flow and the ground surface. A gas-liquid separation pipe that separates gas and liquid when the phase flow collides with the inner wall of the pipe, and steam and pressurized water that are separated from each other in communication with the gas-liquid separation pipe and provided substantially in parallel.
And a gas-liquid separation tube for supplying the water level detector, the water level detector is provided on one of the gas-liquid separation tubes, and the heater is provided on the gas-liquid separation tube side where the water level detector is not provided. A water vapor separator for a fuel cell. 3. Reforming gas by reacting fuel and steam.
And a reformer for obtaining carbon monoxide in the reformed gas.
CO converter and the reformed gas passed through the CO converter
A fuel cell stack for obtaining electric power,
Gas-liquid two-phase obtained by the heat of reaction of the fuel cell stack
The steam required for the reformer from the stream and the CO
And pressurized water necessary for cooling the fuel cell stack
Separately supply the steam to the reformer and
Pressurized water is supplied to the CO converter and the fuel cell stack.
Steam separator for feeding
The pressurized water is supplied to the CO transformer and the fuel cell stack.
A pressurized water circulation pump installed in the flowing pipe
When water is heated to raise the temperature,
A heater that consumes power and pressurized water in the steam separator
Water level detector that detects the water level of the
A makeup water pump that supplies makeup water based on the detection signal
A fuel cell steam separator provided with
The separator is located in the inflow direction of the gas-liquid two-phase flow and the ground surface.
The gas-liquid two-phase flow that is provided in a substantially vertical direction
Gas-liquid separation is performed by colliding with the inner wall, and the separated pressurized water is sent.
A gas-liquid separation pipe to be supplied, and
A gas-liquid separation tube that is provided in a row and supplies separated steam
And supplies the pressurized water to the water level detector.
And the heater is connected to
Characterized by being provided in a gas-liquid separation tube for feeding
Pond steam separator. 4. A reformer for obtaining a reformed gas by reacting a fuel and steam, a CO converter for converting carbon monoxide in the reformed gas, and a reformer gas passed through the CO converter. A fuel cell stack that obtains electric power by using the CO converter and the gas-liquid two-phase flow obtained by the reaction heat of the fuel cell stack, and the steam required for the reformer and the CO converter and the fuel cell stack. A steam separator for gas-liquid separation of pressurized water required for cooling and supplying the steam to the reformer and supplying the pressurized water to the CO converter and the fuel cell stack, and A pressurized water circulating pump provided in a pipe through which the pressurized water flows to the CO transformer and the fuel cell stack; and a heat pump that heats the pressurized water to increase the temperature and consumes power when a high voltage is generated in the fuel cell. And the steam separator is provided with the gas-liquid two-phase flow provided in a direction substantially perpendicular to the inflow direction of the gas-liquid two-phase flow and the ground surface. A gas-liquid separation tube that performs gas-liquid separation by colliding with the inner wall of the tube, and a gas-liquid separation tube that communicates with the gas-liquid separation tube and is provided substantially in parallel and that supplies separated steam and pressurized water , The heater is connected to the branch in a branch pipe through which pressurized water is supplied from the pressurized water circulation pump to the CO transformer and the fuel cell stack, and to the C.
Between O transformer or be provided between the CO transformer and the CO transformer in a gas-liquid two-phase outlet and the confluence of the steam separator in collecting pipe through which gas-liquid two-phase flow to, A steam separator for a fuel cell, comprising: 5. A reformer for obtaining a reformed gas by reacting fuel and steam, a CO converter for converting carbon monoxide in the reformed gas, and a reformer gas passed through the CO converter. A fuel cell stack that obtains electric power by using the CO converter and the gas-liquid two-phase flow obtained by the reaction heat of the fuel cell stack, and the steam required for the reformer and the CO converter and the fuel cell stack. A pressurized water required for cooling is separated into gas and liquid, and the steam is supplied to the reformer, and the pressurized water is supplied to the CO converter and the fuel cell stack. And a heater for consuming power when a high voltage is generated in the fuel cell, wherein the steam separator is substantially perpendicular to the inflow direction of the gas-liquid two-phase flow and the ground surface. In the direction A gas-liquid separation tube that is provided and flows to separate gas and liquid by the gas-liquid two-phase flow colliding against the inner wall of the tube;
The gas-liquid separation pipe communicates with the
A gas-liquid separation pipe for supplying steam and pressurized water, and a pipe through which the pressurized water flows from the steam separator to the CO converter and the fuel cell stack; and the CO converter and the fuel cell stack. And a short-circuit pipe communicating with a pipe through which the mixed gas-liquid two-phase flow from the fuel cell flows toward the steam separator, and the heater is provided in the short-circuit pipe. .