JPH1116582A - Method of detecting abnormality of battery cooling water supplying water system in fuel cell generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repair or replace an abnormal position while continuing the operation before a generating device is stopped for protection by monitoring the opening time of a feed water switching three-way valve to compare the actual feed time with an estimated feed time, and giving an alarm from a control device when the compared value exceeds a set value. SOLUTION: The quantity of water released by a steam separator 1 is calculated by a control device 20 while a feed switching three-way valve 9 is operated on feed side. The water quantity calculated on the basis of the feed time is added to the water capacity within a control range in stopping, and the sum is divided by the feed flow rate of a supplying water system 10 to calculate an estimated feed time. The estimated feed time is compared with the actual feed time, and the control device 20 gives an alarm when a slippage is caused between them. When the filters 13, 15 of a water processing device 14 are clogged in the supplying water system 10, the water quantity supplied to the steam separator 1 is reduced, and the difference between the estimated feed time and the actual feed time is gradually increased. This difference is arithmetically compared by the control device 20, and when it exceeds an alarm value, the alarm is given.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a makeup water system for a steam separator provided in a fuel cell power generator, that is, a method for detecting an abnormality in a battery cooling water makeup water system.

[0002]

2. Description of the Related Art FIG. 1 shows a configuration of a cooling water system of a fuel power generator. In a normal operation state, the steam-water separator 1 of the fuel cell power generator supplies cooling water 4 to the fuel cell 3 by the circulating pump 2 and collects water that has absorbed the heat generated by the fuel cell 3, thereby providing fuel. This is a container for recovering the heat generated by the battery 3, and the inside of the container is kept in a high temperature and high pressure state. Further, in the fuel cell power generator, natural gas, propane gas, or the like is used as a raw fuel, and in order to use these as a fuel, it is reacted with steam in a reformer (not shown) to reform the gas into a hydrogen-rich gas. Steam for reforming 5 to be sent to the reformer is supplied from the steam separator 1. Further, in the fuel cell power generation device, surplus steam (excess steam) 6 generated by the steam separator 1 is discharged to the outside for use of waste heat, and the water quality in the steam separator 1 is maintained. For this reason, the water in the steam separator 1 is discharged as blowdown water 7, and the state in which the water in the steam separator 1 is constantly consumed during operation of the apparatus.

The water in the steam separator 1 is replenished from a make-up water system 10. In the makeup water system 10, water is pumped out of the water in the condenser 11 by a condensation pump 12, and the water is circulated through a circulation water purification circuit having a filter 13, a water treatment device 14, a filter 15 and a makeup water pump 16. The required amount of water is supplied to the makeup water pump 16 and the water supply switching three-way valve 9.
Thus, the steam-water separator 1 is supplied. Normally, the water level in the steam-water separator 1 is controlled by monitoring a water level gauge 8 provided in the steam-water separator 1 and controlling the water supply switching three-way valve 9. And within
The water level control is performed by the control device 20. FIG. 2 shows a flow chart of this conventional supply water supply control.

If the water level in the steam-water separator 1 rises due to some abnormality in the conventional makeup water replenishment, the above-mentioned reforming steam 5 cannot be taken out as a gas. When the water level drops, steam cannot be supplied, and the cooling of the fuel cell 3 becomes insufficient. In such a case, the control device 20 issues an alarm, and when the water level in the steam separator 1 drops or rises, the control device 20 makes an emergency stop of the power generation device. In the event of an emergency stop, many man-hours are required before the operation of the power generator is restarted.

[0005]

As shown in FIG. 2, a conventional method for detecting an abnormality in a cooling water replenishing water system is a steam-water separator 1 shown in FIG.
Is controlled by switching the water supply switching three-way valve 9 so that the water amount is within the range between the water level at which replenishment starts and the water level at which replenishment is stopped, but the water level is not maintained in that range. Only when was the abnormality recognized.
However, if the state becomes gradually abnormal due to a change over time such as clogging of the filters 13 and 15 and the strainer of the makeup water system, or if the air of the makeup water pump 16 is clogged, the failure has not occurred. Regardless, the original performance of the device cannot be exhibited, which has been a factor that causes the device to stop. In addition, even if the water supply amount is reduced due to such a state, if the water level of the steam separator is maintained within the range of the control water level, it is not regarded as abnormal.

An object of the present invention is to provide a method for detecting an abnormality in a battery cooling water replenishing water system which solves the above-mentioned conventional problems.

[0007]

In order to solve the above-mentioned problems, the opening time of the water supply switching three-way valve to the water supply side is monitored and detected as the actual water supply time. The expected water supply time is obtained by dividing the total water amount obtained by adding the control range water amount of the steam-water separator to the amount of water consumed as down water, and comparing the actual water supply time with the expected water supply time. When the comparison value exceeds a preset value, an operation sequence for issuing an alarm is installed in the control device, and a reduction or excessive state of the supply water amount, that is, an initial state in the supply system of the steam separator is set. Recognize that an abnormality has occurred. In this way, it is possible to repair an abnormal part while continuing the operation of the power generation device before the power generation device stops protection. FIG. 3 shows a flowchart of such a method for detecting an abnormality in the makeup water system of the present invention.

[0008] The method of measuring the amount of water supply without a flow meter, which is not necessary in a device having a flow meter for water supply, is as follows. First, when the device is stopped, water is supplied to the steam separator to the replenishment stop water level, and then replenished. Drain water up to the starting water level and measure the volume of water drained at this time. This water amount is the control range water amount of the steam separator. In the operation state of the apparatus, while water is supplied from the replenishment start water level to the replenishment stop water level, the amount of water consumed by the steam separator due to reforming steam, blowdown, etc. The total water amount obtained by adding the amount of water discharged from the water separator) and the control range water amount of the steam-water separator (that is, the water amount obtained by subtracting the lower limit water amount from the control range upper limit water amount) is referred to as water supply. By dividing by time, the water supply flow rate can be calculated. In the steam-water separator during operation, the volume of water is different from the volume measured during stoppage due to a high-temperature and high-pressure state, so it is necessary to correct the volume with the temperature during operation.

[0009]

[Equation 1] ｛(Amount of water consumed when supplying water)
+ (Control range water amount)｝ / water supply time = water supply flow rate The above-mentioned estimated water supply time is the sum of the amount of water consumed when the makeup water system is in the water supply state and the amount of water within the control range, and is calculated by adding the water supply flow rate Calculated by dividing by

[0010]

[Equation 2] ｛(Amount of water consumed when supplying water) +
(Volume within control range) / water supply flow rate = expected water supply time Here, this expected water supply time is compared with the time (actual water supply time) when the water supply switching three-way valve is operating on the water supply side. When the difference exceeds a preset value, an alarm is set. Thus, the abnormality is detected before the water level control of the steam separator becomes impossible.

According to the abnormality detection method having the above-described structure, the expected water supply time is compared with the time during which the water supply switching three-way valve is actually operated in the water supply state (actual water supply time). By providing an arbitrary alarm point and detecting a failure, it is possible to grasp a failure due to a temporal change of the makeup water system.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described, but the following description is a preferred example for describing the present invention, and does not limit the present invention.

FIG. 3 is a schematic view of the fuel cell power generator shown in FIG.
This will be described with reference to the flowchart of FIG.

The water level control of the steam-water separator 1 is the same as the conventional method shown in FIG. 2, and the water level gauge 8 of the steam-water separator 1 is monitored by the control device 20, and the three-way water supply switching is performed within the control water level range. The water level of the steam separator 1 is controlled by switching the valve 9.
Then, when falling into an uncontrollable state and exceeding the control water level range and reaching the warning water level, the control device 20 issues an alarm. If the state is not improved, the control device 20 reaches the protection stop water level. Stop the protection of the fuel cell power generator. Here, as shown in FIG. 1, the present invention is in a state before reaching an uncontrollable state, that is, in a control water level range,
For the purpose of detecting abnormalities and failures, abnormalities are detected by the following method.

(1) In the operation state of the power generator, the water supply time is set as the water supply time from the time when the water level of the steam-water separator 1 drops to the water supply start water level and the water supply switching three-way valve 9 switches from the circulation side to the water supply side. At 20, the timer starts counting.

(2) Water supply stop When the water level rises to the water level, the control device 20 stops counting and stores this as the actual water supply time.

(3) At this time, the count of the water supply time is:
Since it is assumed that the output of the device is constant, the timer is reset when there is a load change.

(4) Here, based on the measured actual water supply time, the amount of water discharged from the steam separator 1 while the water supply switching three-way valve 9 is operating on the water supply side, ie, ,
The control device 20 calculates the amount of water consumed in the steam separator 1 by the power generation device as reforming steam, surplus steam or blowdown water from the respective consumption flow rates.

(5) The replenishment water system 10 is calculated by adding the water supply time calculated based on the water supply time (the amount of water consumed during water supply) and the volume of water within the control range (control range water amount) measured at the time of stoppage.
The expected water supply time can be calculated by dividing by the water supply flow rate.

(6) The predicted water supply time is compared with the actual water supply time, and when a deviation occurs, the control unit 20 calculates and issues a warning so as to issue a comparison. Note that this shift is a protection value.

Next, the state of the apparatus when an abnormality occurs in the makeup water system 10 will be described with reference to FIG. When the filters 13 and 15 of the water treatment device 14 are gradually clogged, the amount of makeup water supplied to the steam separator 1 by the makeup water pump 16 gradually decreases. Due to this phenomenon, the actual water supply time gradually increases, so that the difference between the expected water supply time and the actual water supply time gradually increases. This difference is calculated and compared by the control device 20, and an alarm is issued when the alarm value is exceeded.

With the conventional method, as shown in FIG.
Since the alarm is not detected until reaching the warning water level, if the control is maintained within the control water level range, even if the water supply amount decreases due to clogging of the filters 13 and 15, the water supply amount is not detected as an abnormality. Furthermore, this phenomenon is caused by the water treatment device 14
The same phenomenon occurs not only when the filters 13 and 15 are used but also when the water supply pump 16 bites air. In addition, even when the water supply is excessively or insufficiently supplied due to a malfunction of the three-way valve 9 for switching water supply, it can be detected as an abnormality. As a result, if measures can be taken at the stage when the alarm is issued, parts can be repaired or replaced while the operation of the power generator is continued before protection stops.

[0023]

According to the present invention, it is possible to detect the initial abnormality of the makeup water system of the steam separator in the fuel cell power generator, so that the operation of the power generator is not stopped before the protection is stopped.
An abnormal part can be repaired.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram mainly showing a cooling water system of a fuel cell power generator.

FIG. 2 is a flowchart showing a conventional method for detecting an abnormality in a battery cooling water makeup water system in a fuel cell power generation device.

FIG. 3 is a flowchart showing a method for detecting an abnormality in a battery cooling water makeup water system of the fuel cell power generation device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas-water separator 2 Battery cooling water circulation pump 3 Fuel cell 4 Battery cooling water 5 Reforming steam 6 Excess steam 7 Blowdown water 8 Water level gauge 9 Water supply switching three-way valve 10 Supply water system 11 Condenser 12 Condenser pump 13, 15 Filter 14 Water treatment device 16 Make-up water pump 20 Control device

Claims (3)

[Claims] An abnormality is detected in a battery cooling water replenishing water system of a fuel cell power generator which supplies water to a steam-water separator for supplying cooling water to a fuel cell from a replenishing water system via a water supply switching three-way valve. A method of monitoring the opening time of the water supply switching three-way valve to the water supply side and detecting as an actual water supply time, and controlling the water / water separator to the amount of water consumed by the water / water separator at the time of water supply. The expected water supply time is obtained by dividing the total water amount to which the range water amount is added by the water supply flow rate, and the actual water supply time is compared with the expected water supply time.If the comparison value exceeds a preset value, an alarm is issued. And, by recognizing that an initial abnormality has occurred in the make-up water system of the steam separator, before the fuel cell power generator reaches the protection stop, while continuing the operation of the power generator,
A method for detecting an abnormality in a battery cooling water replenishing water system of a fuel cell power generation device, wherein an abnormal portion can be repaired. 2. The control range water amount of the steam separator is determined by filling the steam separator with water to a replenishment stop water level when the power generator is stopped, and then draining the water to a replenishment start water level. The method of claim 1, wherein the volume is the volume of water drained. 3. The flow rate of the water consumed by the steam / water separator while the steam / water separator is being supplied with water from the replenishment start water level to the replenishment stop water level in the operating state of the power generator. The method according to claim 1 or 2, wherein the total water amount obtained by adding the water amount and the control range water amount of the steam / water separator is divided by an actual water supply time.