JP2924671B2 - Water treatment system for fuel cell power plant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment system for a fuel cell power generation facility for suppressing the electric conductivity of cooling water for a fuel cell.

[0002]

2. Description of the Related Art FIG. 7 is a system diagram showing a conventional water treatment system for a fuel cell power generation facility disclosed in Japanese Patent Application Laid-Open No. Hei 5-315002. In FIG.
Reference numeral 2 denotes a steam separator for separating water and water of the cooling water of the fuel cell 1, reference numeral 3 denotes a battery cooling water circulating pump for sending battery cooling water from the steam separator 2 to the fuel cell 1, and reference numeral 100 denotes a water passage through the fuel cell 1 The battery cooling water system, which handles the battery cooling water to be cooled and has a steam separator 2 and a battery cooling water circulation pump 3, is blowdown water from the steam separator 2 (cooling water taken out from the battery cooling water system to the water treatment system). Is referred to as blowdown water. The same shall apply hereinafter.) A blowdown water pipe line for extracting the blowdown water, a water receiving tank for storing the blowdown water and city water used as replenishing water, and 6 is an electric conductivity of the water stored in the water receiving tank. A conductivity improving device having a reverse osmosis membrane 7 for improving the conductivity and an ion exchange resin 8 for further improving the conductivity of the reclaimed water passing through the membrane, and water is supplied from the water receiving tank 5 to the conductivity improving device 6. A feed water pump 10 for feeding regenerated water that has passed through the conductivity improving device 6 to the steam separator 2; a control valve 11 for controlling the amount of makeup water according to the water level of the steam separator 2; A heat exchanger 13 for cooling water passed through the conductivity improving device 6 is a safety valve for releasing pressure when the outlet pressure of the makeup water supply pump 10 increases.

Next, the operation will be described. Since the cell cooling water passes through the fuel cell 1 and plays a role of cooling, it receives heat from the fuel cell 1 and enters a gas-liquid mixed state to form a water vapor separated gas 2.
Come back to. In the steam separator 2, the battery cooling water in a gas-liquid mixed state is separated into steam and water, and only the liquid phase portion is sent to the fuel cell 1 by the battery cooling water circulation pump 3. The battery cooling water needs to maintain a low conductivity in order to prevent battery ground faults and cooling pipe corrosion. For this reason, it is necessary to blow down a part of the water in the steam separator 2 and replace it with water having low conductivity. Usually, a method of recycling blowdown water through a water treatment system is used in order to save water volume.

The blowdown water is supplied to a blowdown water piping 4
And is collected in the water receiving tank 5. City water and blowdown water used as replenishing water in the water receiving tank 5 are mixed and stored, and the water stored in the water receiving tank 5 is sent to the conductivity improving device 6 by the raw water pump 9, and the reverse osmosis membrane is formed. The electric conductivity is improved through the ion exchange resin 7 and the ion exchange resin 8. Since the reverse osmosis membrane 7 has a low heat-resistant temperature of about 40 ° C. and a high blow-down water temperature of about 170 ° C., the temperature is lowered by mixing city water replenished in the water receiving tank 5, and the mixed water is further cooled. It is necessary to lower the temperature to a predetermined temperature or lower by the heat exchanger 12. City water or industrial water is used as cooling water for the heat exchanger 12. The regenerated water thus obtained is supplied to the makeup water supply pump 10
And the pressure is returned to the steam separator 2. Usually, the steam in the steam separator 2 is also used as a raw material steam for reforming, so that the water in the steam separator 2 is constantly consumed, and the consumed amount is supplied to the water receiving tank 5 as supplementary water. It is covered by mixed city water and replenished by a water treatment system. The amount of the makeup water is controlled by the control valve 11 so that the water level in the steam separator 2 is always constant. The discharge pressure of the make-up water supply pump 10 increases due to the make-up water that has become excessive due to the control, and when the supply pressure exceeds a predetermined value, the water is discharged as excess water by the safety valve 13.

[0005]

The conventional water treatment system for a fuel cell power plant has the following problems because it has been constructed as described above. The use of reverse osmosis membranes is not stable because the water flow temperature at the entrance of the reverse osmosis membrane is affected by the temperature of city water mixed as replenishment water, city water for cooling the heat exchange air heater, or industrial water. When the temperature exceeds the upper limit of 40 ° C, the reverse osmosis membrane cannot provide a proper desalination effect, and the reverse osmosis membrane has an extremely short life, or the temperature is too low, and the water resistance of the reverse osmosis membrane increases, which is necessary. However, there was a problem that the water flow rate of the fuel cell could not be secured, the amount of makeup water was insufficient, the water level of the steam separator dropped, and the entire fuel cell power generation facility stopped.

[0006] Further, since the make-up water returning to the steam separator has a low temperature and is directly supplied to the steam separator, it acts in the direction of lowering the temperature of the steam separator to reduce the amount of retained heat. Therefore, there is a disadvantage that the steam separator heat becomes overall thermal efficiency decreases less extractable as excess heat
Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and efficiently utilizes the heat generated by a fuel cell to prevent the performance of a conductivity improving device from deteriorating. The purpose is to obtain a water treatment system for battery power generation equipment.

[0008]

According to a first aspect of the present invention, there is provided a water treatment system for a fuel cell power plant, wherein a pipe for extracting blowdown water is provided in the pipe, and the blowdown water taken out is cooled. heat exchanger, a temperature detector for detecting the temperature of the water flowing through the conductivity improving apparatus, provided in the piping path <br/>, the temperature of detection of the temperature detector, blowdown water flowing in the piping line valve to adjust the flow rate, your
And the cooling water sent to the fuel cell
It is equipped with a heat exchanger for cooling .

According to a second aspect of the present invention, there is provided a water treatment system for a fuel cell power generation facility, comprising: a pipe for extracting blowdown water; a heat exchanger provided in the pipe for cooling the blowdown water extracted; A temperature detector for detecting the temperature of the water flowing through the rate improving device; a temperature detector provided in a cooling water pipe for cooling the heat exchanger; and the heat flowing through the cooling water pipe based on the temperature detected by the temperature detector. A valve for adjusting the cooling water flow rate of the exchanger, and cooling water sent to the fuel cell
Is provided with a heat exchanger for cooling directly with make-up water .

According to a third aspect of the present invention, there is provided a water treatment system for a fuel cell power generation facility, wherein at least one of the two or more pipelines for extracting blowdown water and the pipeline for extracting blowdown water is provided. A heat exchanger that cools down water, a temperature detector that detects the temperature of the water flowing through the conductivity improvement device, a pipe line having the heat exchanger, and a pipe line without the heat exchanger are provided respectively. A valve for adjusting the flow rate of blowdown water flowing through the piping according to the temperature detected by the temperature detector , and cooling sent to the fuel cell
It is equipped with a heat exchanger for cooling water directly with make-up water .

According to a fourth aspect of the present invention, there is provided a water treatment system for a fuel cell power generation facility, wherein cooling of a heat exchanger provided in a pipe line for extracting blowdown water from a battery cooling water system is performed through a conductivity improving device. The replenishing water is returned to the battery cooling water system .

[0012]

According to a first aspect of the present invention, in the water treatment system for a fuel cell power plant, a heat exchanger provided in a pipe line for extracting blowdown water cools the extracted blowdown water. A valve provided at the air conditioner adjusts the flow rate of blowdown water flowing through the pipe line in accordance with the output of a temperature detector that detects the temperature of the water flowing through the conductivity improving device, so that the flow through the conductivity improving device is controlled. Control the water temperature. In addition, the heat exchanger provides cooling water to the fuel cell.
Exchange heat with the make-up water returned to the battery cooling water system,
The cooling water is further cooled and supplied to the fuel cell.
It is heated and returned to the battery cooling water system.

According to a second aspect of the present invention, there is provided a water treatment system for a fuel cell power plant, wherein a heat exchanger provided in a pipe line for extracting blowdown water cools the extracted blowdown water, A valve provided in the cooling water pipe of the heat exchanger controls the amount of cooling water of the heat exchanger flowing through the cooling water pipe in accordance with the output of the temperature detector which detects the temperature of the water flowing through the conductivity improving device. The adjustment controls the temperature at which water is passed through the conductivity improving device. In addition, heat exchangers
Between the cooling water sent to the fuel cell and the battery cooling water system
Heat exchange between the returning make-up water and the cooling water is further cooled
Is supplied to the fuel cell, and the make-up water is heated and
It is returned to the system.

According to a third aspect of the present invention, there is provided a water treatment system for a fuel cell power plant, wherein the heat exchanger provided in at least one of the two or more pipe lines for extracting blow-down water includes the heat exchanger. Cooling the blowdown water flowing through the pipes, the pipes having the heat exchanger, and the valves provided in each of the pipes without the heat exchanger, the temperature at which the temperature of the water flowing to the conductivity improvement device is detected According to the output of the detector, the flow rate of the blowdown water flowing through the pipe line is adjusted to change the respective amounts of the cooled blowdown water and the uncooled blowdown water, thereby improving the conductivity. Controls the temperature of the water passing through the device. In addition, heat exchange
The cooling water supplied to the fuel cell and the battery cooling water system
Heat exchange between the makeup water and the cooling water
Is supplied to the fuel cell, and the makeup water is heated to cool the cell.
Returned to water system.

According to a fourth aspect of the present invention, there is provided a water treatment system for a fuel cell power generation facility, wherein cooling of a heat exchanger provided in a pipe line for extracting blowdown water from a battery cooling water system is performed by passing through a conductivity improving device. The heat exchanger cools the blowdown water and heats the make- up water by using the make-up water returned to the battery cooling water system .

[0016]

【Example】

Embodiment 1 FIG. Hereinafter, a part of the first embodiment of the present invention will be described with reference to FIG. In FIG. 1, 21 to 23, 25 to 31,
Reference numerals 33 and 200 denote conventional examples, respectively.
Numerals 21, 13 and 100 correspond to a fuel cell 21, a steam separator 22 for separating water and water of the cooling water of the fuel cell 21, and 23 a cell cooling water from the steam separator 22 to the fuel cell 21. Battery cooling water circulation pump for water supply, 2
00 is a battery cooling water system having a steam separator 22 and a battery cooling water circulating pump 23, which handles steam generated by the fuel cell 21, and 25 is a blowdown water taken out from the steam separator 22 and a city used as supplement water. A water receiving tank for mixing and storing water, 26 is a reverse osmosis membrane 27 for improving the conductivity of the water stored in the water receiving tank, and an ion exchange resin 2 for further improving the conductivity of the regenerated water passing through the membrane.
8, a raw water pump for sending water from the water receiving tank 25 to the conductivity improving device 26; and 30, a regenerated water that has passed through the conductivity improving device 26, to a steam separator 22.
A supply valve for controlling the amount of supply water according to the water level of the steam separator 22, and a safety valve 33 for releasing the pressure when the outlet pressure of the supply water supply pump 30 increases. is there.

Further, in FIG.
34a and 34b are blowdown water pipes for extracting blowdown water from the steam separator 22, and 35 is provided in a blowdown water pipe 34a. Heat exchangers 36a, 36b for cooling the blowdown water passing therethrough
Is a motor-operated valve provided in each of the blowdown water pipe lines 34a and 34b, and 37 is a temperature detector for detecting the water temperature at the entrance of the conductivity improving device 26.

Next, the operation will be described. As in the conventional example, the water treatment system for the fuel cell equipment according to the first embodiment is
The battery cooling water that passes through the fuel cell 21 and plays a role of cooling is separated into steam and water and stored in a steam separator 22 in the battery cooling water system 200. This battery cooling water is taken out of a part of the liquid layer portion of the steam separator 22 as blow-down water in order to prevent a ground fault of the battery and corrosion of the cooling pipe, and the low conductivity of the water is supplied through the conductivity improving device 26. Regenerated and replaced with water.

Since the steam in the steam separator 22 is sent to the reformer utilizing the excess heat, the steam is maintained at a high temperature of about 170 ° C., and the blowdown water as the liquid layer portion has the same temperature. Is kept. However, the reverse osmosis membrane 27 in the conductivity improving device 26 for reducing the conductivity is used.
When water having a high temperature of 40 ° C. or higher is passed, its performance deteriorates. Also, depending on the season, this cooling may be excessive, and the water flow resistance of the reverse osmosis membrane 27 may increase, so that a required flow rate of the water cannot be secured. Therefore, the blowdown water taken out from the steam separator 22 is branched into two piping lines 34a and 34b, and one of the blowdown water piping lines 34a is provided with a heat exchanger 35 for cooling and the other blowdown water is cooled. Water is directly supplied without providing a heat exchanger in the water piping 34b, and the flow rate of blowdown water in these pipings is adjusted by electric valves 36a and 36b provided in the respective pipings 34a and 34b, and the mixed water is supplied. Receiving tank 2
Store it in 5. The blowdown water is further mixed with city water as replenishing water in the water receiving tank 25 to replenish the amount of water consumed for steam from the steam separator 22 to the reformer and the like.
Is supplied to the conductivity improving device 26, and the conductivity is improved through the reverse osmosis membrane 27 and the ion exchange resin 28.

The temperature detector 37 is connected to the conductivity improving device 2.
The temperature of the water passing through 6 is detected at its entrance. Based on the detected temperature, the blowdown water piping 34a,
When the temperature becomes lower than the required temperature, the electric valves 36a and 36b provided in the
a, the valve opening of the motor-operated valve 36b is changed to the opening direction, and when this temperature becomes higher than a required temperature, the valve opening of the motor-operated valve 36a is changed. Is changed in the opening direction so that the valve opening of the motor-operated valve 36b is in the closing direction, and the flow rate of blowdown water passing through the respective pipe lines 34a and 34b is adjusted and stored in the water receiving tank 25. In the receiving tank 25, city water is further mixed as supplementary water,
This replenishment is a constant amount in accordance with the consumption of steam sent from the steam separator 22 to the reformer or the like, and the water temperature of the city water is constant during a period of about the valve control cycle. In addition, the mixing of the replenishing water works to lower the temperature of the water in the water receiving tank 25 by a certain temperature. Since the mixed water in the water receiving tank 25 is sent to the conductivity improving device 26 by the raw water pump 29, the water temperature at the entrance of the conductivity improving device 26 is controlled to fall within a predetermined range.

As described above, according to the first embodiment, the temperature of the water passing through the reverse osmosis membrane 27 of the conductivity improving device 26 can be maintained at an appropriate temperature for maintaining the performance of the reverse osmosis membrane. It is possible to avoid an increase in the flow resistance of the reverse osmosis membrane 27 due to a low water temperature, and without causing a shortage of regenerated water, that is, a shortage of makeup water.
Inadvertent plant trips can be avoided, and conversely, there is an effect that deterioration of the reverse osmosis membrane 27 due to high water temperature can be prevented and the life of the reverse osmosis membrane 27 can be extended.
Further, the electric valves 36a and 36b are controlled so as to control the temperature to a predetermined temperature by changing the mixing ratio of the cooled blowdown water and the high-temperature blowdown water as it is. There is an effect that the water flow temperature of the conductivity improving device 26 can be controlled while keeping the constant.

In the first embodiment, the flow rate of the blowdown water is adjusted by adjusting the valve opening of the motor-operated valves 36a and 36b provided in the respective pipe lines 34a and 34b. May be an electromagnetic valve. In this case, when the temperature detected by the temperature detector 37 becomes lower than a required temperature, the electromagnetic valve 36a
Is closed, the solenoid valve 36b is opened, and when this temperature becomes higher than the required temperature, the solenoid valve 36a is opened,
By switching the electric valve 36b to the closed state, the same effect as in the first embodiment can be obtained.

In the first embodiment, the flow temperature of the conductivity improving device 26 is controlled by adjusting the flow rate of the blowdown water, but the flow rate of city water or industrial water for cooling the heat exchanger 35 is controlled. May be adjusted to change the heat exchange rate of the heat exchanger 35 to control the water temperature. That is, the conductivity improving device 26 which detects the opening degree of the motor-operated valve provided in the pipe line on the cooling water side of the heat exchanger 35 by the temperature detector 37.
The same effects as in the first embodiment can be obtained by adjusting the temperature according to the water temperature at the entrance.

Embodiment 2 FIG. 2 is a system diagram showing a water treatment system of a fuel cell power generation facility as a part of the second embodiment of the present invention, and is different from the system diagram of FIG. 1 showing a part of the first embodiment. In place of the heat exchanger 35 using city water for cooling down blowdown water, a heat exchanger 38 using makeup water returned to the steam separator 22 is provided. The blow-down water that has just been taken out maintains the internal temperature of the steam separator 22 at about 170 ° C., while the conductivity of the reverse osmosis membrane 27 at the entrance of the conductivity improving device 26 as described in Example 1 above. To maintain 40 ℃
Since the following control is performed, the temperature of the makeup water is kept lower than that of the blowdown water. Heat exchanger 3
8 exchange heat between these waters.

Therefore, in the second embodiment, in addition to the effects described in the first embodiment, the temperature of the makeup water
Since the difference between the temperature of Step 2 and the temperature of the makeup water is reduced before returning to the steam separator 22, the amount of heat held by the steam separator 22 can be used more effectively as compared with the prior art. There is an effect that high overall thermal efficiency can be obtained as a whole of the power generation equipment.

Embodiment 3 FIG. 3 is a system diagram showing a water treatment system for a fuel cell power generation facility as a part of the third embodiment of the present invention. In addition to the system diagram of FIG. 2 showing a part of the second embodiment, FIG. At the outlet of the conductivity improving device 26, an intermediate tank 39 for temporarily storing the regenerated water subjected to water treatment by the device 26 is provided. The reclaimed water treated through the conductivity improving device 26 is temporarily stored in the intermediate tank 3.
9 is stored. The water surface of the intermediate tank 39 is open to the atmospheric pressure, and the makeup water supply pump 30 takes in the regenerated water stored in the intermediate tank 39 and uses the heat exchanger 38 as makeup water.
The water is sent to the steam separator 22 through. The make-up water supply pump 30 is operated when the water level in the intermediate tank 39 is equal to or higher than a predetermined level, and is stopped when the water level is equal to or lower than the predetermined level. The reclaimed water overflowing from the intermediate tank 39 is drained.

As described above, according to the third embodiment, in addition to the effects described in the first and second embodiments, the inlet pressure of the makeup water supply pump 30 is always maintained at the atmospheric pressure and the inlet flow rate is reduced. As a result, the reverse osmosis membrane 27 and the ion exchange resin 28 of the conductivity improving device 26 are clogged, the water pressure at the outlet of the conductivity improving device 26 decreases, the flow rate of the makeup water supply pump 30 is insufficient, and the inlet pressure is negative. Cavitation due to the pump can be prevented, and there is an effect that inadvertent failure of the pump is eliminated. Fluctuations in the required amount of makeup water
Since the water can be absorbed by the intermediate tank 39, the amount of the reclaimed water passing through the conductivity improving device 26 can be always constant, and the conductivity improving device 26 can reduce the amount of water required instantaneously to the maximum required water amount. There is no need to have combined playback capabilities,
There is an effect that the capacity can be reduced.

Embodiment 4 FIG. 4 is a system diagram showing a water treatment system for a fuel cell power generation facility as a part of the fourth embodiment of the present invention. In addition to the system diagram of FIG. 3 showing a part of the third embodiment, FIG. And an excess water channel 40 for returning excess water drained from the safety valve 33 to the intermediate tank 39. The amount of water consumed by the steam separator 22 varies depending on the power generation output of the fuel cell, and is constantly fluctuating because the control timing of the amount of water consumed and the amount of supplied water is shifted even at a constant output. For this reason, the flow rate of the makeup water is controlled by the control valve 31 that adjusts the flow rate of the makeup water so that the water level of the steam separator 22 becomes constant. When the required amount of makeup water in the steam separator 22 is small, the makeup water becomes excessive and the discharge pressure of the makeup water supply pump 30 becomes abnormally high. Therefore, a safety valve 33 is provided to release the pressure. Excess water has escaped from the circuit.
However, in the conventional water treatment system, since the surplus water was discharged outside the system, high-purity regenerated water was wasted.

In the fourth embodiment, a surplus water channel 40 for returning surplus water drained from the safety valve 33 to the intermediate tank 39 is provided.
By returning the surplus water to the intermediate tank 39 and storing the surplus water, the surplus water is reused. With this configuration, according to the fourth embodiment, the first to the first embodiments are used.
In addition to the effects described in the third embodiment, since the surplus water discharged from the safety valve 33 is returned to the intermediate tank 39, the fluctuation in demand for make-up water results in wasteful surplus of high-purity regenerated water with improved conductivity. There is an effect that it is not thrown away as water.

Embodiment 5 FIG. Figure 5 is a system diagram showing a water treatment system for a fuel cell power plant in some embodiments 5 of the present invention, in addition to the system diagram of Figure 4 showing the <br/> portion of Example 4 An overflow water channel 41 is provided for returning the regenerated water overflowing from the intermediate tank 39 to the water receiving tank 25. The surplus regenerated water stored in the intermediate tank 39 fluctuates due to excess and deficiency in the supply and consumption, but if it overflows, it is wasted when discarded.
Return to 5. Thus, according to Example 5, Examples 1 to
In addition to the effects described in the fourth embodiment, the amount of city water to be supplied to the water receiving tank 25 can be reduced, and the life of the reverse osmosis membrane 27 and the ion exchange resin 28 is prolonged because the water is higher in purity than city water. There is.

Embodiment 6 Figure 6 is a system diagram showing a water treatment system for a fuel cell power plant which is Embodiment 6 of the present invention, in addition to the system diagram of Figure 5 showing part of Example 5, from the steam separator 22 A heat exchanger 42 for cooling the battery cooling water with make-up water is provided in the middle of the circuit for supplying the battery cooling water to the fuel cell 21. In order to maintain the operating temperature of the fuel cell 21, it is necessary to set the battery cooling water temperature to a required temperature (about 150 ° C.).
There was no other way but to control the cooling water temperature. However, the excess heat of the steam separator 22 is used for waste heat utilization, such as for use in a double effect absorption refrigerator.
Keep the temperature of the water inside as high as possible,
It is necessary to set the battery cooling water temperature to a required temperature.

For this reason, in the sixth embodiment, the heat exchanger 42 provided in the battery cooling water circuit cools only the battery cooling water using the makeup water branched from the makeup water channel. Thus, according to the sixth embodiment, in addition to the effects described in the first to fifth embodiments, in the heat exchanger 42, the temperature of the makeup water returned to the steam separator 22 is increased, and the battery cooling water is Since the cooling is performed, the battery cooling water can be suppressed to a low temperature while keeping the calorific value of the steam separator 22 high, and a higher overall thermal efficiency can be obtained as a whole fuel cell power generation facility than in the other embodiments. effective.

[0033]

Since the present invention is configured as described above, it has the following effects.

According to the water treatment system of the fuel cell power generation equipment according to the first aspect of the present invention, the heat exchanger provided in the piping for taking out the blowdown water cools the blowdown water taken out. The valve provided in the pipeline adjusts the flow rate of the blowdown water flowing through the pipeline according to the output of the temperature detector that detects the temperature of the water flowing through the conductivity improvement device. The temperature of the passing water,
There is an effect that an appropriate temperature for maintaining the performance of the conductivity improving device can be maintained. In addition, heat exchangers
Returns to the cooling water supplied to the fuel cell and the cell cooling water system.
Heat exchange with the makeup water, and the cooling water is further cooled
Supply water is supplied to the fuel cell and the makeup water is heated and
To maintain the heat capacity of the battery cooling water system high.
The battery cooling water can be kept at a low temperature while
Obtaining high overall thermal efficiency for the entire fuel cell power generation facility
There is an effect that can be.

According to the water treatment system for the fuel cell power generation equipment according to claim 2 of the present invention, the heat exchanger provided in the piping for taking out the blowdown water cools the blowdown water taken out. A valve provided in a cooling water pipe of the heat exchanger cools the heat exchanger flowing through the cooling water pipe in accordance with an output of a temperature detector for detecting a temperature of water flowing to the conductivity improving device. Since the flow rate of the water is adjusted, there is an effect that the temperature of the water flowing through the conductivity improving device can be maintained at an appropriate temperature for maintaining the performance of the conductivity improving device. In addition, the heat exchanger is used to supply cooling to the fuel cell.
Heat exchange between reject water and make-up water returned to the battery cooling water system
The cooling water is further cooled and supplied to the fuel cell,
The feedwater is heated and returned to the battery cooling water system,
Keep the battery cooling water while keeping the heat capacity of the cooling water system high.
The temperature can be kept low and the entire fuel cell power generation facility
High overall thermal efficiency.
You.

[0036] According to the water treatment system for a fuel cell power generation facility according to claim 3 of the present invention, the heat exchanger provided in at least one of the two or more pipe lines for extracting blowdown water includes the heat exchanger. The blow-down water flowing through the piping is cooled, and valves provided in each of the piping having the heat exchanger and the piping having no heat exchanger detect the temperature of the water flowing to the conductivity improving device. The flow rate of the blowdown water flowing through the pipe line is adjusted in accordance with the output of the temperature detector to change the amount of each of the cooled blowdown water and the uncooled blowdown water. The temperature of the water passing through the improvement device can be maintained at an appropriate temperature for maintaining the performance of the conductivity improvement device, and furthermore, the mixture of the cooled blowdown water and the high-temperature blowdown water as it is can be mixed. Rate By controlling the valve so that the temperature is controlled to a predetermined temperature, it is also possible to control the water flow temperature of the conductivity improving device while keeping the whole amount taken out as blowdown water constant. This has the effect. In addition, heat exchangers
Between the supplied cooling water and make-up water returned to the battery cooling water system
Heat exchange, and the cooling water is further cooled and supplied to the fuel cell
And the makeup water is heated and returned to the battery cooling water system.
The battery cooling water system keeps the heat
Cooling water can be kept at a low temperature, and fuel cell power generation
It is said that high overall thermal efficiency can be obtained as a whole
effective.

According to the water treatment system of the fuel cell power generation equipment according to claim 4 of the present invention, the cooling of the heat exchanger provided in the piping for taking out blowdown water is performed by passing the cooling battery through the conductivity improving device. It is performed by make-up water returned to the cooling water system, and the heat exchanger cools the blowdown water and heats the make-up water, so that the temperature of the make-up water is raised to make the temperature of the battery cooling water system, the make-up water temperature and Therefore, there is an effect that the disparity of the battery cooling water system can be reduced and the calorific value of the battery cooling water system can be effectively used .

[Brief description of the drawings]

FIG. 1 is a system diagram of a water treatment system for a fuel cell power plant showing a part of Embodiment 1 of the present invention.

FIG. 2 is a system diagram of a water treatment system for a fuel cell power plant showing a part of Embodiment 2 of the present invention.

FIG. 3 is a system diagram of a water treatment system for a fuel cell power plant showing a part of Embodiment 3 of the present invention.

FIG. 4 is a system diagram of a water treatment system for a fuel cell power plant showing a part of Embodiment 4 of the present invention.

FIG. 5 is a system diagram of a water treatment system for a fuel cell power plant showing a part of a fifth embodiment of the present invention.

FIG. 6 is a system diagram of a water treatment system for a fuel cell power plant showing a sixth embodiment of the present invention.

FIG. 7 is a system diagram showing a conventional water treatment system for a fuel cell power generation facility.

[Explanation of symbols]

Reference Signs List 21 fuel cell 25 water receiving tank 26 conductivity improving device 30 makeup water supply pump 34a, 34b blowdown water piping 35
Heat exchanger 36a, 36b Electric valve 37
Temperature detector 38 Heat exchanger 39 Intermediate tank 40 Surplus water channel 41 Overflow water channel 42 Heat exchanger 200 Battery cooling water system

Claims (4)

(57) [Claims] 1. A part of cooling water is taken out from a cell cooling water system of a fuel cell as blowdown water, and the blowdown water and fresh replenishment water are passed through a conductivity improving device to reduce the conductivity. In a water treatment system of a fuel cell power generation facility that returns as make-up water to the battery cooling water system, a pipe line for taking out the blowdown water, a heat exchanger provided in the pipe line and cooling the blowdown water taken out,
A temperature detector that detects the temperature of water flowing through the conductivity improving device, a valve that is provided in the pipe line , and adjusts a flow rate of blowdown water flowing through the pipe line by a temperature detected by the temperature detector ; and Cooling water sent to the fuel cell
A water treatment system for a fuel cell power generation facility, comprising a heat exchanger for directly cooling water with the make-up water. 2. A part of cooling water is taken out from a cell cooling water system of a fuel cell as blowdown water, and the blowdown water and fresh replenishment water are passed through a conductivity improvement device to reduce the conductivity. In a water treatment system of a fuel cell power generation facility that returns as make-up water to the battery cooling water system, a pipe line for taking out the blowdown water, a heat exchanger provided in the pipe line and cooling the blowdown water taken out,
A temperature detector for detecting the temperature of water flowing through the conductivity improving device, provided in a pipe line of cooling water for cooling the heat exchanger, the pipe line of the cooling water is provided by a temperature detected by the temperature detector. A valve for adjusting the flow rate of the cooling water of the heat exchanger ,
And the cooling water sent to the fuel cell directly
A water treatment system for a fuel cell power plant, comprising a heat exchanger for cooling by water supply . 3. A part of the cooling water is taken out from the cell cooling water system of the fuel cell as blowdown water, and the blowdown water and fresh replenishment water are passed through a conductivity improving device to reduce the conductivity. In a water treatment system of a fuel cell power generation facility that returns as make-up water to the battery cooling water system, the blowdown water is provided in at least one of two or more pipe paths and the pipe path, and is taken out. A heat exchanger that cools blowdown water, a temperature detector that detects the temperature of water flowing through the conductivity improving device, a pipe line having the heat exchanger, and a pipe line without the heat exchanger are provided. The temperature detected by the temperature detector,
A valve for adjusting the flow rate of blowdown water flowing through the piping ,
And the cooling water sent to the fuel cell directly
A water treatment system for a fuel cell power plant, comprising a heat exchanger for cooling by water supply . 4. The cooling system according to claim 1, wherein cooling of the heat exchanger provided in the piping for extracting blow-down water from the battery cooling water system is performed by make-up water which passes through the conductivity improving device and returns to the battery cooling water system. The water treatment system for a fuel cell power generation facility according to claim 1 or 3.