JP3246819B2 - Fuel cell steam separation system - 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 separation system for a fuel cell, and more particularly to a steam separation system for a phosphoric acid type fuel cell using phosphoric acid as an electrolyte.

[0002]

BACKGROUND ART FIG. 6, for example JP-A-1-217864
FIG. 1 is a schematic flow chart of a conventional steam separation system shown in Japanese Unexamined Patent Publication (Kokai) No. H06-27139, wherein 1 is a steam separator, 2 is a cooling water circulation pump, 3 is a reactor such as a battery stack or a carbon monoxide converter, and 16 is a reactor. A water level detector for detecting the level of the cooling water staying in the steam separator 1, a makeup water pump 5 for supplying makeup water to the steam separator, and a makeup water 6 receiving a signal from the water level detector 16. A water level controller that operates the pump 5 to control the level of the pressurized cooling water in the steam separator 1. A control unit 7 receives a signal from the reforming steam flow rate detector 8 and controls the reforming steam flow rate control valve 9. Reforming steam flow rate controller, 1
Reference numeral 0 denotes a surplus steam pressure controller, which receives a signal from the steam pressure detector 11 to operate a steam pressure control valve 12 to control a flow rate of surplus steam discharged to the waste heat utilization facility, and 13 denotes a waste heat utilization. Equipment.

Next, the operation will be described. During operation of the fuel cell, the cooling water in the steam separator 1 is supplied at a constant flow rate by the cooling water circulation pump 2 to the reactor 3 such as a cell stack or a carbon monoxide converter, and the reaction heat is cooled by the cooling water. Collect and control the reaction temperature. The cooling water is injected into the steam separator 1 as a multiphase flow of vapor, which is a gas, and liquid, and is separated into gas and liquid. A part of the separated steam is controlled by the reforming steam flow control valve 9 so that the required steam flow rate is obtained while measuring the steam flow rate by the reforming steam flow rate detector 8 by the reforming steam flow rate controller 7. It is supplied to a reformer. The remaining steam is controlled by operating the steam pressure control valve 12 by the steam pressure controller 10 while measuring the steam pressure with the steam pressure detector 11 so that the steam pressure of the steam separator 1 becomes constant. The heat is discharged to the waste heat utilization facility 13.

[0004] Since the water level of the cooling water in the steam separator 1 is reduced by the release of water vapor and surplus steam reforming, water level controller while measuring the water level of the cooling water in the water level detector 16 6
Thus, the make-up water pump 5 is operated to directly supply low-temperature make-up water (pure water is used) to the steam separator 1.
At this time, the startup level and stop level of the make-up water pump 5 are given a range in order to avoid the frequency of starting and stopping of the make-up water pump 5 and shortening of the life of the pump. When the power generation load is large, the amount of heat recovered from the reactor 3 to the steam separator 1 increases, the amount of steam released from the steam separator 1 increases, and the amount of cooling water retained in the circulating water line decreases. Despite this, the apparent volume of the cooling water increases due to bubbles in the liquid phase, and the water level rises, so that the supply amount of makeup water decreases. On the other hand, when the power generation load is small, the amount of released steam is reduced, but the amount of recovered heat is also reduced, so that the bubbles in the liquid phase are reduced, the apparent volume of the cooling water is reduced, and the water level is lowered. Therefore, it stays in the circulating water line
Although the amount of cooling water does not decrease, the amount of makeup water increases. By increasing the volume of the steam separator for allowing the reverse control phenomenon of the amount of make-up water generated when the power generation load fluctuates, fluctuations in the amount of cooling water remaining in the circulating water line are absorbed. .

[0005]

The conventional steam separation system for a fuel cell is configured as described above. (1) The low-temperature make-up water is supplied with steam from the start to the stop of the make-up water pump. When the amount of cooling water staying in the circulating water line is small because it is supplied directly into the separator, the temperature of the cooling water in the steam separator goes up and down, and the cooling condition of the reactor changes, depending on the operating conditions. However, there is a problem that supply of reforming steam becomes difficult. For this reason, it is necessary to suppress the temperature change by increasing the amount of cooling water staying in the steam separator, and it is necessary to use a large-volume horizontal drum-type steam separator as the steam separator.

(2) Further, since the mixed-phase flow of steam and liquid returning to the steam separator after recovering heat from a reactor such as a fuel cell stack or a carbon monoxide converter becomes a slag flow, the cooling water of the steam separator is cooled. A state occurs in which the steam is injected and the vapor is separated in a state similar to the internal boiling of the liquid. Therefore, when the power generation load is reduced, the bubble volume in the liquid phase is reduced, so that the water level of the cooling water is reduced despite the decrease in the amount of steam released, and when the power generation load is increased, the bubbles in the liquid phase are increased. As the apparent liquid phase capacity increases, the water level of the cooling water rises despite the increase in the amount of steam released from the steam separator. There was a problem that high-quality steam could not be obtained, such as accompanied by mist in the steam.

(3) Since the cooling water circulation pump is operated without control, the cooling water flow rate does not change and the heat exchange amount does not change even when the power generation load at which the calorific value of the reactor decreases is small. There is a problem that the temperature of the fuel cell 3 is lowered, for example, the efficiency of the fuel cell stack is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a cylinder having a relatively small internal volume and a predetermined diameter whose main body stands substantially vertically, and has a predetermined volume inside. Of the cooling water from the reactor in the middle part and a steam separator (hereinafter referred to as a pipe-type steam separator) whose lower part is connected to a cooling water circulation pump. Maintains the mass balance of the cooling water in the separator, suppresses fluctuations in the water level and rapid temperature changes in the steam separator, ensures reliable gas-liquid separation, and maintains the water level to prevent cavitation of the cooling water circulation pump It is an object of the present invention to provide a small-sized steam separation system that can be used.

[0009]

A steam separation system according to a first aspect of the present invention corresponds to a flow rate of reformed steam.
Pump filled continuously cooling water circulation supply apparatus the amount of makeup water
It is intended to be supplied to the mouth .

[0010] In the steam separation system according to a second aspect of the present invention, the total amount of make-up water and condensed water is equal to the reformed steam flow rate and the remaining amount.
Replenish so that the amount corresponds to the total surplus steam flow rate
Water and condensed water are continuously pumped into the cooling water circulation supply device
It is intended to be supplied to the mouth .

The steam separation system according to a third aspect of the present invention continuously cools condensed water in an amount corresponding to the flow rate of surplus steam and make-up water in an amount corresponding to the flow rate of reformed steam. > It is designed to supply to the pump inlet of the water circulation supply device .

According to a fourth aspect of the present invention, there is provided a steam separation system for controlling a water level based on a water level of a pipe-type steam separator by using make-up water supplied from a make-up water supply device and supplying steam to a surplus steam supply device. Control of the gas phase of the pipe-type steam separator based on the above control, and the upper and lower limits of the gas-phase pressure control of the pipe-type steam separator are set. Alternatively, when the lower limit is reached, the steam flow valve to the surplus steam supply device for a predetermined period is controlled so as to be maintained at a constant opening corresponding to each of the upper limit and the lower limit.

According to a fifth aspect of the present invention, the flow rate of the reformed steam is increased when the load of the fuel cell fluctuates.
Corresponding to the amount of replenishing water continuously cooling water circulation supply device
The water is supplied to the inlet of the pump , and the flow rate of the make-up water is continuously controlled so that the water level of the pipe-type steam separator becomes constant during a steady load state.

[0014]

In the steam separation system according to the first aspect of the present invention, make-up water is not directly supplied to the steam separator of the piping type, and the amount of make- up water corresponding to the flow rate of the reformed steam is circulated through the cooling water.
As it was made to supply continuously to the pump inlet of the supply device, while maintaining the material balance of the cooling water circulation line,
Fluctuations in the water level and rapid temperature changes of the water retained in the steam separator can be suppressed, and a compact steam separation system can be realized.

[0015] In the steam separation system according to a second aspect of the present invention, the total amount of the makeup water and the condensed water is supplied from the steam separator.
Reforming steam flow supplied to reformer and steam separator?
Flow rate of surplus steam supplied to waste heat utilization equipment
Cooling water circulation of make-up water and condensed water so that the amount corresponds to
Cooling because water is continuously supplied to the pump inlet of the supply device
Maintain the material balance of the water circulation line, and suppress the fluctuation of the water level and the rapid temperature change of the stagnant water in the steam separator,
It is possible to realize a small-sized steam separation system capable of reliably performing gas-liquid separation.

In the steam separation system according to a third aspect of the present invention, the amount of condensed water corresponding to the flow rate of surplus steam released from the steam separator to the waste heat utilization equipment, and the reforming supplied to the reformer. The amount of water corresponding to the steam flow rate is continuously supplied to the pump inlet of the cooling water circulating supply device, so that the material balance of the cooling water circulating line is maintained and the level of the water retained in the steam separator is maintained. It is possible to realize a small-sized steam separation system capable of suppressing fluctuations and rapid temperature changes and reliably separating gas and liquid.

In the steam separation system according to a fourth aspect of the present invention, the makeup water and the condensed water from the exhaust heat utilization facility are cooled by the cooling water.
Water is supplied to the pump inlet of the circulating supply device to control the water level and to control the pressure in the gas phase of the pipe-type steam separator based on the control of the flow rate of the steam supplied to the surplus steam supply device. Set upper and lower limits of phase pressure control, and when the pressure in the gas phase of the pipe-type steam separator reaches the upper or lower limit, set the steam flow valve to the excess steam supply device for a predetermined period according to the upper and lower limits, respectively. Since the opening degree is controlled to be kept at a constant level, it is possible to realize a small-sized steam separation system capable of suppressing water level fluctuation and rapid temperature change in the steam separator and reliably performing gas-liquid separation.

In the steam separation system according to a fifth aspect of the present invention, when the load of the fuel cell fluctuates , the amount of make-up water corresponding to the flow rate of the reformed steam supplied to the reformer is supplied. When the system is in a steady state, make-up water is continuously circulated through the cooling water so that the water level in the steam separator is constant.
Since water is supplied to the inlet of the pump of the supply device, fluctuations in the water level and rapid temperature changes in the steam separator can be suppressed, and a small-sized steam separation system capable of reliably performing gas-liquid separation can be realized.

[0019]

[Embodiment 1] Hereinafter, a first embodiment of the first invention will be described with reference to the drawings. In FIG. 1, 100 is a pipe type steam separator,
2 is a cooling water circulation pump for supplying pressurized cooling water to a reactor 3 such as a fuel cell stack or a carbon monoxide converter, 4 is a make-up water flow detector, 5 is a make-up water pump, and 6 is a make-up water flow controller. , 7 is a reformed steam flow controller that operates the reformed steam flow control valve 9 based on the signal of the reformed steam flow detector 8 to control the amount of steam supplied to the reformer, and 10 is an excess steam pressure controller. In response to the signal from the steam pressure detector 11, the steam pressure control valve 12 is controlled so that the steam pressure in the steam separator becomes constant. 13 is a waste heat utilization facility, 14 is a condensed water tank for receiving the condensed water of the surplus steam used by the waste heat utilization facility, and 15 is a condensed water pump for returning the condensed water to the cooling water circulation line.

Next, the operation will be described. When the fuel cell power generation equipment starts power generation, reaction heat is generated in the reactor 3 such as the battery stack and the carbon monoxide converter.
Cooling water controlled to a predetermined pressure and temperature in the pipe-type steam separator 100, mixed water and condensed water are sent to the reactor as circulating cooling water by the cooling water circulating pump 2 to cool the reactor. to recover. The cooling water returns to the pipe-type steam separator 100 as a two-phase flow of steam and liquid to be separated into gas and liquid. A part of the separated steam is reformed as steam necessary for the reforming reaction by controlling the reforming steam flow control valve 9 by the reforming steam flow controller 7 which receives the flow rate signal of the reforming steam flow detector 8. Supplied to the device.

The temperature of the cooling water in the pipe-type steam separator is controlled by operating a steam pressure control valve 12 by a steam pressure controller 10 which receives a pressure signal from a steam pressure detector 11 so that the steam release amount is controlled to a constant pressure. Controlled and maintained at a predetermined temperature. Excess steam released from the steam pressure control valve is used as heat in the waste heat utilization equipment 13, for example, the absorption chiller, to become condensed water, and the condensed water entering the condensed water tank 14 is not shown in the figure. The condensed water is returned to the inlet of the cooling water circulation pump 2 by the condensed water pump 15 while controlling the water level in the condensed water tank to be constant.

Since the cooling water level in the pipe-type steam separator 100 decreases due to the release of reforming steam, the flow rate signal of the reforming steam flow rate detector 8 and the flow rate of the make-up water flow rate detector 4 The make-up water pump 5 is continuously operated by the make-up water flow controller 6 that has taken in the signal to supply the make-up water in an amount corresponding to the reforming steam flow rate to the cooling water circulation pump inlet to maintain the material balance of the cooling water circulation line. I do. Therefore, the supply amount of make-up water to the pipe-type steam separator is supplied without excess or shortage, and low-temperature condensed water or make-up water is supplied to the inlet of the cooling water circulation pump without being supplied directly to the pipe-type steam separator. Since the water is circulated, a small-sized pipe-type steam separator can be adopted, and the temperature fluctuation in the pipe-type steam separator can be suppressed, so that the fluctuation of the excess steam flow rate is small, and the water level of the cooling water in the pipe-type steam separator is reduced. The steam separation system can maintain fluctuations within a range in which the cooling water circulation pump does not cause cavitation.

Embodiment 2 FIG. Hereinafter, a second embodiment according to the second invention will be described with reference to the drawings. In FIG. 2, reference numerals 100, 2, 3, 5, 7 to 1
5 is the same as or equivalent to the first invention. Reference numeral 4 denotes a total flow rate detector of make-up water and condensed water, 6 denotes a make-up water pump 5 which receives the total flow rate signal of the reformed steam flow rate detector 8 and the surplus steam flow rate detector 17 and the total flow rate signal of make-up water and condensed water. Is a make-up water flow rate controller that operates.

Next, the operation will be described. When the fuel cell power generation equipment starts power generation, heat of reaction is generated in the reactor 3 such as the cell stack and the carbon monoxide converter, so that the cooling water controlled to a predetermined pressure, that is, a predetermined temperature in the pipe-type steam separator 100, and The mixed water of the makeup water and the condensed water is sent to the reactor as circulating cooling water by the cooling water circulating pump 2 to cool and recover heat. The cooling water returns to the pipe-type steam separator 100 as a two-phase flow of steam and liquid to be separated into gas and liquid.

A part of the separated steam is controlled by a reforming steam flow control valve 9 by a reforming steam flow rate controller 7 which receives a flow rate signal of a reforming steam flow rate detector 8 to control a steam necessary for a reforming reaction. And supplied to the reformer. The temperature of the cooling water in the pipe-type steam separator is controlled by operating the steam pressure control valve 12 by the steam pressure controller 10 which has taken in the pressure signal of the steam pressure detector 11 and controlling the amount of steam release to a constant pressure. It is maintained at a predetermined temperature. Excess steam released from the steam pressure control valve is used as heat in the waste heat utilization equipment 13, for example, the absorption chiller, to become condensed water, and the condensed water entering the condensed water tank 14 is not shown in the figure. The condensed water is returned to the makeup water pump outlet by the condensed water pump 15 while controlling the water level in the condensed water tank to be constant.

Since the cooling water level in the pipe-type steam separator 100 decreases due to the release of the reforming steam and the surplus steam, the make-up water flow controller controls the reforming steam flow rate detector 8 and the surplus steam. The total flow signal of the flow signal of the flow detector 17 is fetched, and the make-up water pump 5 is continuously operated so that this amount is equal to the amount of the flow signal of the total flow detector 4 of the condensed water flow and the make-up water flow. Then, an amount of water equal to the amount of steam discharged from the pipe-type steam separator is supplied to the inlet of the cooling water circulation pump 2 to maintain the material balance of the cooling water circulation line. Therefore, the supply amount of makeup water to the cooling water circulation line is supplied without excess or shortage, and the low-temperature condensed water and makeup water are supplied to the inlet of the cooling water circulation pump without being directly supplied to the pipe-type steam separator. Circulation allows the use of a small-sized pipe-type steam separator, which suppresses temperature fluctuations in the pipe-type steam separator, resulting in small fluctuations in excess steam flow rate and fluctuations in the cooling water level in the pipe-type steam separator. Can be maintained in a range where the cooling water circulation pump does not cause cavitation.

Embodiment 3 FIG. Hereinafter, a third embodiment according to the third invention will be described with reference to the drawings. In FIG. 3, reference numerals 100 and 2 to 15 indicate the first
The invention is the same as or equivalent to the invention of the above. Reference numeral 17 denotes a surplus steam flow rate detector, 18 denotes a condensed water flow rate detector, and 19 denotes a surplus steam flow rate detector 17 of the steam flow rate and the condensed water flow rate detector 1.
8 is a condensed water flow rate controller that operates the condensed water pump 15 so as to take in the condensed water flow rate signal of No. 8 and obtain a condensed water flow rate corresponding to the surplus steam flow rate.

Next, the operation will be described. When the fuel cell power generation equipment starts power generation, heat of reaction is generated in the reactor 3 such as the battery stack and the carbon monoxide converter, so that the cooling water controlled to a predetermined pressure and temperature in the pipe-type steam separator 100 is The mixed water of the makeup water and the condensed water is sent to the reactor as circulating cooling water by the cooling water circulating pump 2 to cool and recover heat. The cooling water returns to the pipe-type steam separator 100 as a two-phase flow of steam and liquid to be separated into gas and liquid.
A part of the separated steam is reformed as steam necessary for the reforming reaction by controlling the reforming steam flow control valve 9 by the reforming steam flow controller 7 which receives the flow rate signal of the reforming steam flow detector 8. Supplied to the device.

The temperature of the cooling water in the pipe-type steam separator is controlled by operating a steam pressure control valve 12 by a steam pressure controller 10 which receives a pressure signal from a steam pressure detector 11 so that the steam release amount is controlled to a constant pressure. Controlled and maintained at a predetermined temperature. Excess steam released from the steam pressure control valve is condensed by heat utilization in the waste heat utilization equipment 13, for example, the absorption refrigerator, and is introduced into the condensed water tank. Since the amount of condensed water varies depending on the operation state of the absorption refrigerator, the amount of condensed water may not be the amount corresponding to the surplus steam flow rate. In the present invention, the condensed water corresponding to the surplus steam amount is condensed by the condensing pump 15 by the condensed water flow rate controller 19 which takes in the surplus steam flow rate signal of the surplus steam flow rate detector 17 and the condensed water flow rate signal of the condensed water flow rate detector 18. It is returned to the cooling water circulation pump 2 inlet.

Since the cooling water level in the pipe-type steam separator 100 decreases due to the release of the reforming steam, the flow rate signal of the reforming steam flow rate detector 8 and the flow rate of the make-up water flow rate detector 4 are determined. The make-up water pump 5 is continuously operated by the make-up water flow controller 6 that has taken in the signal to supply the make-up water in an amount corresponding to the reforming steam flow rate to the cooling water circulation pump inlet to maintain the material balance of the cooling water circulation line. I do. Accordingly, since the amount of water corresponding to the amount of water vapor discharged from the pipe type steam separator of the cooling water circulation line is supplied to the cooling water circulation line as makeup water and condensed water, replenishing supply to pipe-type steam separator The amount of water is supplied without excess or shortage, and the low-temperature condensed water and makeup water are not supplied directly to the pipe-type steam separator, but are supplied to the inlet of the cooling water circulation pump and circulated. The temperature fluctuation in the pipe-type steam separator can be suppressed, so that the excess steam flow rate fluctuation is small and the cooling in the pipe-type steam separator
The steam separation system can maintain the fluctuation of the reject water level within a range in which the cooling water circulation pump does not cause cavitation.

Embodiment 4 FIG. Hereinafter, a fourth embodiment according to the fourth invention will be described with reference to the drawings. 4, 16 from the code 2,3,5 is the same as or equivalent to the conventional steam separation system shown in FIG.

Next, the operation will be described. When the fuel cell power generation equipment starts power generation, reaction heat is generated in the reactor 3 such as a battery stack and a carbon monoxide converter,
A mixture of cooling water , make-up water and condensed water controlled at a predetermined pressure, that is, a predetermined temperature, in the pipe-type steam separator 100 is supplied to the reactor as circulating cooling water by the cooling water circulation pump 2 to cool and recover heat. . The cooling water returns to the pipe-type steam separator 100 as a two-phase flow of steam and liquid to be separated into gas and liquid. Part of the separated steam is the reformed steam flow rate controller 7 which has taken in the flow rate signal of the reformed steam flow rate detector 8.
By controlling the reforming steam flow control valve 9, the steam is supplied to the reformer as steam necessary for the reforming reaction.

The temperature of the cooling water in the pipe-type steam separator is controlled by operating the steam pressure control valve 12 by the steam pressure controller 10 which receives the pressure signal from the steam pressure detector 11, and the steam release amount is controlled to a constant pressure. Controlled and maintained at a predetermined temperature. Excess steam released from the steam pressure control valve is used as heat in the waste heat utilization equipment 13, for example, the absorption chiller, to become condensed water, and the condensed water entering the condensed water tank 14 is not shown in the figure. The condensed water is returned to the inlet of the cooling water circulation pump 2 by the condensed water pump 15 while controlling the water level in the condensed water tank to be constant.

Since the cooling water level in the pipe-type steam separator 100 decreases due to the release of reforming steam or surplus steam, the water level controller 6 detects the cooling water level from the water level detector 16 of the pipe-type steam separator. The supply water pump 5 is continuously operated by the water level signal to supply pure water to the inlet of the cooling water circulation pump 2 at the outlet of the pipe-type steam separator 100, and the water level in the pipe-type steam separator 1 is maintained.

The water level of the pipe-type steam separator is controlled as described above during a steady operation, but if the same control is performed during a load fluctuation, the water level fluctuation becomes large. That is, when the power generation load is increased, the reactor 3 is disconnected from the pipe-type steam separator 100.
The amount of heat recovered in the pipe-type steam separator 10
Despite an increase in the amount of steam released from zero and a decrease in the amount of water retained in the circulating water line, the apparent level of cooling water increases due to an increase in the bubble volume in the liquid, and the water level rises. Water supply is reduced. On the other hand, when the power generation load decreases, the amount of steam released decreases, but the amount of recovered heat decreases, so the apparent volume of the cooling water decreases due to the decrease in the bubble volume in the liquid, and the water level decreases. For this reason, the amount of makeup water increases even though the amount of water remaining in the circulating water line does not decrease.

As shown in FIG. 7 , the upper limit of the steam pressure control is set as shown in FIG. 7 in order to suppress the reverse control decrease of the make-up water amount which occurs when the power generation load fluctuates and to enable normal water level control immediately after the load fluctuation. Value (for example, 7.5 kg / cm
² G) and the lower limit value (e.g. 6.5Kg / cm ² G) provided, at the time of change of the power generation load, and stops the steam pressure control,
When the upper limit or the lower limit of the steam pressure control is reached, a short-time pressure control is performed to reduce the steam pressure to the pressure control value (7 kg / c).
An open control for leading to the m ² G) side is performed. When the power generation load rises, the amount of water vapor that becomes bubbles in the liquid increases, but the pressure control is stopped and the opening of the water vapor pressure control valve is kept constant. Increases, the increase in the bubble volume in the liquid is suppressed, and the apparent rise in the water level is suppressed.

When the power generation load is reduced, the amount of water vapor that becomes bubbles in the liquid is reduced. However, since the opening of the water vapor pressure control valve remains the same as before the load was reduced, the amount of surplus water vapor released is reduced. Since the water vapor pressure decreases to a small extent, the decrease in bubble volume in the liquid is suppressed, and the decrease in water level is suppressed. Therefore, the reverse control decrease in the supply of make-up water to the pipe-type steam separator is suppressed, and low-temperature condensed water and make-up water are supplied to the inlet of the cooling water circulation pump without being supplied directly to the pipe-type steam separator. Because of the circulation, a small-sized pipe-type steam separator can be adopted, and the temperature fluctuation in the pipe-type steam separator can be suppressed. The steam separation system can maintain fluctuations within a range in which the cooling water circulation pump does not cause cavitation.

Embodiment 5 FIG. DETAILED DESCRIPTION OF THE PREFERRED EXAMPLE 5 according to the fifth aspect in FIG. In FIG. 5 , reference numerals 100, 2, 3 , 5 to 16 are the same as or equivalent to those of the fourth invention. Reference numeral 4 denotes a makeup water flow rate detector.

Next, the operation of the fifth invention will be described.
Reference numerals 100, 2, 3, and 7 to 16 perform the same operations as those of the fourth invention, and thus will be omitted. When the power generation load of the fuel cell fluctuates, the flow rate signal of the reforming steam flow rate detector 8 and the flow rate signal of the make-up water flow rate detector 4 are taken into the water level controller 6 so that the quantity of the reforming steam and the quantity of the make-up water become equal. The pump 5 is operated. Therefore, even if there is an apparent fluctuation in the water level, the mass balance of the cooling water circulation line can be maintained. Also,
At the time of steady load operation, since the amount of heat recovered from the reactor 3 is almost constant, there is no change in the water vapor bubble volume in the liquid phase. Therefore, the water level controller 6 which has taken in the water level signal of the water level detector 16 of the pipe type steam separator has By operating the make-up water pump 5 to control the make-up water flow rate, a small pipe-type steam separator can be adopted, and the temperature fluctuation in the pipe-type steam separator can be suppressed, so that the fluctuation of the excess steam flow rate is small. In addition, a water vapor separation system capable of maintaining the water level fluctuation of the cooling water in the pipe-type water vapor separator within a range in which the cooling water circulation pump does not cause cavitation can be provided.

[0040]

As described above, in the steam separation system according to the first aspect of the present invention, since the amount of make-up water corresponding to the flow rate of the reformed steam discharged from the steam separator is continuously supplied, cooling is performed. can maintain the material balance of water circulation line, also not directly replenished cold makeup water to the pipe type steam separator, a cooling water circulation supplying instrumentation combined with condensed water of the exhaust heat recovery equipment
The temperature fluctuation in the pipe-type steam separator can be suppressed by replenishing it at the inlet of the pump, so that a small-sized pipe-type steam separator can be adopted. The fluctuation of the cooling water level in the inside can be maintained within a range in which the cooling water circulation pump does not cause cavitation.

In the steam separation system according to a second aspect of the present invention, the total amount of make-up water and condensed water is supplied from the steam separator.
Reforming steam flow supplied to reformer and steam separator?
Flow rate of surplus steam supplied to waste heat utilization equipment
Since the makeup water and the condensed water so that an amount corresponding continuously supplying water to the cooling water circulation line, to maintain the mass balance of the cooling water circulation line, also, the low temperature of the supply water to the pipe type steam separator A small-sized pipe-type steam separator is adopted because temperature fluctuations in the pipe-type steam separator can be suppressed by directly supplying water and condensed water from the exhaust heat recovery facility and supplying it to the pump inlet of the cooling water circulating supply unit. Therefore, the fluctuation of the flow rate of the surplus steam is small, and the fluctuation of the cooling water level in the pipe-type steam separator can be maintained within a range where the cooling water circulation pump does not cause cavitation.

In the steam separation system according to a third aspect of the present invention, the amount of condensed water corresponding to the flow rate of surplus steam discharged from the steam separator to the waste heat utilization facility, and the reforming supplied to the reformer Water is supplied continuously to the pump inlet of the cooling water circulating supply unit with the amount of makeup water equivalent to the flow rate of steam, so that temperature fluctuations in the pipe-type steam separator can be suppressed. A change in the flow rate of the surplus steam is small, and the fluctuation of the cooling water level in the pipe-type steam separator can be maintained within a range where the cooling water circulation pump does not cause cavitation.

In the steam separation system according to a fourth aspect of the present invention, the makeup water and the condensed water from the exhaust heat utilization facility are cooled by the cooling water.
Water is supplied to the pump inlet of the circulating supply device to control the water level and to control the pressure in the gas phase of the pipe-type steam separator based on the control of the flow rate of the steam supplied to the surplus steam supply device. An upper limit and a lower limit of the phase pressure control are provided, and when the pressure of the gas phase portion of the pipe type steam separator reaches the upper limit and the lower limit, the steam flow valve to the surplus steam supply device for a predetermined period is set according to the upper limit and the lower limit, respectively. Since the opening is controlled to be maintained at a constant opening, temperature fluctuations in the pipe-type steam separator can be suppressed, and fluctuations in the cooling water level can be maintained within a range in which the cooling water circulation pump does not cause cavitation.

In the steam separation system according to the fifth aspect of the present invention, when the load of the fuel cell fluctuates , the amount of make-up water corresponding to the flow rate of the reformed steam supplied to the reformer is supplied. When the system is in a steady state, make-up water is continuously circulated through the cooling water so that the water level in the steam separator is constant.
Since water is supplied to the pump inlet of the supply device , a small-sized pipe-type steam separator can be adopted, the fluctuation of the flow rate of excess steam is small, and the fluctuation of the cooling water level in the pipe-type steam separator is calibrated by the cooling water circulation pump. Can be maintained within the range that does not occur.

[Brief description of the drawings]

FIG. 1 is a flow chart in a steam separation system of Embodiment 1 according to the first invention.

FIG. 2 is a flow chart in a steam separation system of Embodiment 2 according to the second invention.

FIG. 3 is a flow chart in a steam separation system of Embodiment 3 according to the third invention.

FIG. 4 is a flow chart in a steam separation system of Embodiment 4 according to the fourth invention.

FIG. 5 is a flowchart in a steam separation system according to Embodiment 5 of the fifth invention.

FIG. 6 is a flow diagram of the water vapor separation system of the traditional.

FIG. 7 is an explanatory diagram of a steam pressure control operation in the fourth invention.

[Explanation of symbols]

 2 cooling water circulation pump 3 reactor 4 makeup water flow detector 5 makeup water pump 6 makeup water flow controller 7 reformed steam flow controller 8 reformed steam flow detector 9 reformed steam flow control valve 10 surplus steam pressure controller DESCRIPTION OF SYMBOLS 11 Steam pressure detector 12 Steam pressure control valve 13 Waste heat utilization equipment 14 Condensed water tank 15 Condensed water pump 100 Pipe type steam separator

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-41231 (JP, A) JP-A 1-217863 (JP, A) JP-A-60-241668 (JP, A) JP-A 63-241 241874 (JP, A) JP-A-5-225994 (JP, A) JP-A-3-228801 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/00-8 /twenty four

Claims (5)

(57) [Claims] 1. A cooling water circulating / supplying device having a pump for circulating and supplying cooling water at a predetermined temperature to a fuel cell or a reactor such as a fuel cell and a carbon monoxide converter; and steam generated by cooling the reactor. A pipe-type steam separator for receiving a multi-phase flow of liquid and separating water vapor, and a make-up water supply for supplying make-up water to a pump inlet of the cooling water circulating supply device and maintaining a cooling water amount of the pipe-type steam separator. A device for detecting the flow rate of make-up water; a reforming steam supply device for supplying a steam having a flow rate necessary for generating fuel gas of the fuel cell from a gas phase portion of the pipe-type steam separator to a reforming device; A flow rate detection device for high quality steam, and a pressure control of a gas phase portion of the pipe-type steam separator to obtain cooling water at the predetermined temperature, and a surplus steam supply for supplying surplus steam to a waste heat utilization facility. Device and the result of the condensed water excess steam that is thermally utilized in waste heat utilization facility and a condensed water collecting device for collecting the pump inlet of the cooling water circulation supply device, replenishment in an amount corresponding to the flow rate of the reforming water vapor Water continuously
A steam separation system for a fuel cell, wherein the steam is supplied to a pump inlet of the cooling water circulation supply device . 2. A cooling water circulating supply device having a pump for circulating and supplying cooling water at a predetermined temperature to a reactor such as a fuel cell or a fuel cell and a carbon monoxide converter; and steam generated by cooling the reactor. A pipe-type steam separator for receiving a multi-phase flow of liquid and separating water vapor, and a make-up water supply for supplying make-up water to a pump inlet of the cooling water circulating supply device and maintaining a cooling water amount of the pipe-type steam separator. An apparatus, a reformed steam supply device for supplying steam at a flow rate required for fuel gas generation of the fuel cell from a gas phase portion of the pipe-type steam separator to a reforming device, a reformed steam flow rate detecting device, A surplus steam supply device for supplying cooling water at the predetermined temperature by pressure control of a gas phase portion of the pipe-type steam separator and supplying surplus steam to a waste heat utilization facility; Detection device and a condensed water collecting device for collecting the condensed water excess steam that is thermally utilized in the waste heat utilization equipment pump inlet of the cooling water circulation supply device, the total flow rate detecting apparatus of the condensed water and the makeup water The total amount of the make-up water and the condensed water is the reforming steam flow rate
And an amount corresponding to the total flow rate of the excess steam flow rate.
As described above, the makeup water and the condensed water are continuously circulated through the cooling water.
A steam separation system for a fuel cell, wherein the steam is supplied to a pump inlet of a supply device . 3. A cooling water circulating supply device having a pump for circulating and supplying cooling water at a predetermined temperature to a fuel cell or a reactor such as a fuel cell and a carbon monoxide converter, and steam generated by cooling the reactor. A pipe-type steam separator for receiving a multi-phase flow of liquid and separating water vapor, and a make-up water supply for supplying make-up water to a pump inlet of the cooling water circulating supply device and maintaining a cooling water amount of the pipe-type steam separator. A device, a reformed steam supply device that supplies a steam having a flow rate necessary for generating fuel gas of the fuel cell to a reforming device from a gas phase portion of the pipe-type steam separator, and a reformed steam flow rate detecting device; An excess steam supply device that obtains the cooling water at the predetermined temperature by controlling the pressure of a gas phase portion of the pipe-type steam separator, and supplies excess steam to a waste heat utilization facility; Of the flow rate detecting device, the exhaust heat utilization and condensed water collecting device for collecting the condensed water heat the utilized excess steam to the pump inlet of the cooling water circulation supply device in equipment, the flow rate detector and the condensed water of the makeup water The condensed water in an amount corresponding to the flow rate of the excess water vapor,
A steam separation system for a fuel cell, characterized by continuously supplying an amount of the make-up water corresponding to the flow rate of the reforming steam to a pump inlet of the cooling water circulation supply device . 4. A cooling water circulating supply device having a pump for circulating and supplying cooling water at a predetermined temperature to a fuel cell or a reactor such as a fuel cell and a carbon monoxide converter, and steam generated by cooling the reactor. A pipe-type steam separator that receives a multi-phase flow of liquid and separates steam, and a makeup water for supplying makeup water to a pump inlet of the cooling water circulation supply device and maintaining a cooling water level of the pipe-type steam separator. A supply device, a reformed steam supply device for supplying a flow rate of steam required for fuel gas generation of the fuel cell to a reformer from a gas phase portion of the pipe-type steam separator, and a gas of the pipe-type steam separator. A surplus steam supply device for supplying the surplus steam to the waste heat utilization facility, while obtaining the cooling water at the predetermined temperature by the pressure control of the phase unit, and a surplus heat utilized in the waste heat utilization facility. It becomes condensed water vapor from the condensed water collecting device for collecting the pump inlet of the cooling water circulation supply device, based on the water level of the pipe type steam separator, and the water level control by replenishing water supplied from the makeup water supply device Performing pressure control of the gas phase portion of the pipe-type steam separator based on control of the flow rate of steam supplied to the surplus steam supply device, and setting upper and lower limits of gas-phase pressure control of the pipe-type steam separator, When the pressure of the gas phase portion of the pipe-type steam separator reaches the upper limit or the lower limit, the steam flow valve to the surplus steam supply device for a predetermined period is set to a fixed opening corresponding to the upper limit and the lower limit, respectively. A steam separation system for a fuel cell, wherein the system is controlled to maintain the same. 5. A cooling water circulating supply device having a pump for circulating and supplying cooling water at a predetermined temperature to a fuel cell or a reactor such as a fuel cell and a carbon monoxide converter, and steam generated by cooling the reactor. A pipe-type steam separator that receives a multi-phase flow of liquid and separates steam, a cooling water level detecting device of the pipe-type steam separator, and a supply of makeup water to a pump inlet of the cooling water circulating supply device. A makeup water supply device for maintaining a cooling water level of the steam separator; a flow rate detection device for the makeup water; and a flow rate required for fuel gas generation of the fuel cell from the gas phase portion of the pipe-type steam separator. A reforming steam supply device for supplying steam to the reforming device; and a cooling water at the predetermined temperature obtained by controlling pressure in a gas phase portion of the pipe-type steam separator, and using excess steam for exhaust heat. And surplus steam supply device for supplying Bei, this excess steam that is thermally utilized in the waste heat utilization facility
Collect compressed water at the pump inlet of the cooling water circulating supply device
That consists of a condensed water collecting device, when the load variation of the fuel cell, the flow rate of the reforming water vapor
Continuously the cooling water circulation supplying instrumentation make-up water in an amount corresponding to
A steam separation system for a fuel cell, characterized in that a supply flow rate is supplied to a pump inlet of the apparatus, and a flow rate of the makeup water is continuously controlled such that a water level of the pipe-type steam separator becomes constant during a steady load state.