JP2928584B2 - Power supply cooling device for internal pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a power supply cooling device for an internal pump for cooling a power supply for an internal pump used in a boiling water reactor (BWR). In particular, even when air conditioning is poor,
The present invention relates to a power supply cooling device for an internal pump that can control a core flow rate without causing a loss of a core cooling function.

(Prior art) In general, an internal pump used as a coolant recirculation pump for a BWR is driven at a variable speed by a static variable frequency power supply, and the cooling of this power supply adopts air cooling by an air conditioner. doing.

For this reason, when the air conditioner stops due to a failure or the like, components such as a semiconductor element of the power supply device may be heated and broken down, and the power supply device may stop. Therefore, in order to protect the power supply, it is necessary to stop the power supply by detecting a failure of the air conditioner.

Therefore, conventionally, a power supply cooling system in which a stop due to a failure of the air conditioner or the like is detected by a detector and the power supply device is stopped has been adopted.

(Problems to be Solved by the Invention) In the conventional power supply cooling method for an internal pump, since the power supply device is immediately stopped by stopping the air conditioner, the core flow rate is suddenly reduced by stopping the internal pump. In addition, the cooling function of the core is reduced, and in the worst case, the health of the core may be affected.

In addition, in order to detect a failure of the air conditioner, it is customary to adopt a method of setting a detector such as a temperature in an air supply duct of the air conditioner. In this case, in this case, not only the cooling function of the core is reduced, but also the operation rate of the plant may be significantly affected.

The present invention has been made in consideration of such points,
To prevent failure of the power supply due to heating failure of components such as semiconductor elements due to the suspension of the air conditioner, stop of the internal pump due to a single failure of the detector, etc., and to prevent deterioration of the core cooling function due to the failure. It is another object of the present invention to provide a power supply cooling device for an internal pump that can stop the internal pump without impairing the soundness of the plant when the air conditioner fails.

[Configuration of the invention]

(Means for Solving the Problems) As means for achieving the above object, the present invention detects an operating state of an air conditioner that cools a static variable frequency power supply that drives an internal pump at a variable speed based on temperature or air volume. At least three detectors, and control means for controlling the speed of the internal pump when at least two of the detectors detect an air conditioning failure. Is gradually reduced and stopped after a certain period of time.

(Operation) In the power supply cooling device for an internal pump according to the present invention, the operation state of the air conditioner is detected by at least three detectors, and when at least two of the detectors detect air conditioning failure, The speed of the internal pump is controlled by the control means. For this reason, the failure stop of the power supply device due to the heating failure of the components such as the semiconductor elements due to the stoppage of the air conditioner is prevented, and the stop of the internal pump due to the single failure of the detector is also prevented. It is possible to prevent the cooling function of the core from being reduced.

Further, the control means performs the control of gradually lowering the internal pump speed and stopping the internal pump speed after a lapse of a certain time by the operation thereof.
The internal pump can be stopped without deteriorating the soundness of the plant.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a power supply cooling device for an internal pump according to the present invention.
The air heated by the power supply 2 and heated by the power supply 2 is supplied to the fan 4 through the hot air discharge duct 3.
And is cooled by a cooler. Then, the cooled air is supplied to the power supply storage room 1 through the cool air supply duct 6 so that the power supply 2 is cooled.

In the hot air discharge duct 3, as shown in FIG.
A triplicated temperature detector 7 and air flow detector 8 are provided, respectively. Detection signals from these detectors 7 and 8 are input to an air conditioning controller 9 shown in FIG. Control is provided.

That is, FIG. 2 shows a control device of the internal pump 10, and the power supply device 2 includes a speed control circuit 11 and a power conversion device 12 as shown in FIG. It is configured as a device. And
The speed control circuit 11 of the power supply 2 controls the firing angle of the thyristor in the power converter 12 to adjust the output voltage and the output frequency of the power converter 12 so that the ratio between the output voltage and the output frequency is reduced. It is controlled to be constant.

As shown in FIG. 2, the speed control circuit 11 receives a stop signal and a run-back (gradual decrease in speed) from an air conditioning control device 9 for performing air conditioning control and a flow control device 13 for performing core flow control. The power supply device 2 controls the speed of the internal pump 10 based on the input of the speed request signal in the normal state. In addition, the run-back is performed prior to the speed request signal, and the input of the stop signal causes the internal pump 10 to stop prior to the speed request signal and the run-back signal.

The runback is performed by controlling the firing angle of the thyristor so that the ratio between the output voltage and the output frequency of the power supply device 2 is constant, and reducing the output voltage and the output frequency according to a predetermined rate. It has become.

FIG. 3 shows a control logic in the air-conditioning control device 9. In the figure, reference numerals 14a, 14b, and 14c denote low airflow signals from the triple airflow detectors 8, and reference numerals 15a, 15b, and 15c. Is a high temperature signal from each of the tripled temperature detectors 7, and these are two of the tripled detectors 7, 8 each of which detects a low air volume or high temperature. Turns on when detected 2
/ 3 AND circuits 16 and 17, respectively, and outputs of these 2/3 AND circuits 16 and 17 are input to an OR circuit 18. The output of the OR circuit 18 becomes a run-back request signal 19 and a timer 20 having a predetermined set time.
Through the power supply stop signal 21.

Therefore, when the logic of 2/3 is established by the operation of the temperature detector 7 or the air flow detector 8, the runback request signal 19 is output, the power supply 2 performs the runback, and after the start of the runback, the timer 20 When the set time elapses, the power supply stop signal 21 is output, and the power supply 2 stops.

 Next, the operation of the present embodiment will be described.

When the air conditioner stops, the temperature in the hot air discharge duct 3 increases or the air volume decreases. Then, the temperature detector 7 or the air flow detector 8 detects this, and the air-conditioning control device 9 outputs a runback signal. As a result, the power supply device 2 performs runback.

Further, when a certain time has elapsed after the start of the runback, a stop signal is output from the air conditioning control device 9, whereby the power supply device 2 stops.

At this time, even if one of the detectors 7 and 8 malfunctions,
The logic of / 3 does not hold, and even if one of the detectors 7, 8 becomes inoperable due to a failure, the logic of 2/3 holds for the other two detectors 7, 8. For this reason, there is no problem that an erroneous signal is output from the air-conditioning control device 9 to the power supply device 2 at the time of a single failure of the detectors 7 and 8, or a signal is not output to the power supply device 2 when the air-conditioning device fails. .

FIG. 4 shows a second embodiment of the present invention, in which the temperature detector 7 and the air volume detector 8 in the above embodiment are arranged in the cool air supply duct 6, respectively.

In other respects, the configuration is the same as that of the first embodiment, and the operation is the same.

Thus, even with this configuration, the same effects as in the first embodiment can be obtained.

FIG. 5 shows a third embodiment of the present invention. In place of the air volume detector 8 in the first embodiment, an overload detector 28 for the electric motor of the fan 4 is provided in triple, and FIG. As shown in FIG. 7, as the control logic of the air-conditioning control device 9, fan stop signals 34a, 34b, 34c are used instead of the low air volume signals 14a, 14b, 14c in the first embodiment.

In other respects, the configuration is the same as that of the first embodiment, and the operation is almost the same.

Thus, even with this configuration, substantially the same effects as in the first embodiment can be expected.

〔The invention's effect〕

As described above, in the present invention, the operating state of the air conditioner is detected by at least three detectors, and the speed control of the internal pump is performed when at least two of the detectors detect air conditioning failure. So that
It is possible to prevent the power supply unit from being stopped due to a heating failure of components such as semiconductor elements due to the stoppage of the air conditioner, and also possible to prevent the internal pump from being stopped due to a single failure of the detector. Can be prevented from being lowered.

In addition, the internal pump speed is gradually reduced by the operation of the control means, and the internal pump is stopped after a certain period of time. Therefore, when the air conditioner fails, the internal pump can be operated without impairing the soundness of the plant. Can be stopped.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal pump power supply cooling device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing an internal pump control device, and FIG. 3 is a control logic of an air conditioning control device. 4 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention, FIG. 5 is a diagram corresponding to FIG. 1 showing a third embodiment of the present invention, and FIG. 6 is a diagram corresponding to FIG. FIG. 2 ... power supply device, 4 ... fan, 5 ... cooler, 7 ...
Temperature detector, 8 Air flow detector, 9 Air conditioning control device,
10… Internal pump, 28… Overload detector.

Claims (1)

(57) [Claims] An internal pump power supply cooling device for cooling an internal pump used as a coolant recirculation pump for a boiling water reactor at a variable speed by an air conditioner. At least three detectors for detecting the operation state of the air conditioner based on the temperature or the air volume, and control means for controlling the speed of the internal pump when at least two of the detectors detect air conditioning failure. And a control means for controlling the internal pump power supply to gradually reduce the internal pump speed by the operation thereof and to stop the internal pump after a predetermined time has elapsed.