JPH062807A - Water supply control device - Google Patents

Abstract

(57) [Summary] [Structure] The water supply control device inputs the water supply pump flow rate signal S4 to the opening / closing controller 11, and operates the water supply pump flow rate controller 4 by the switch operation signals S8 and S9 from the opening / closing controller 11. Then, the two-loop control in the water supply pump flow controller is turned on and off to control the water supply pump flow rate. [Effect] The flow rate of the water supply pump can be stably controlled even when the water supply pump is started or stopped, or when an abnormality occurs in the flow rate detector of the water supply pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply control system for adjusting a water supply flow rate to a steam generator, and more particularly to controlling a water supply pump by supplying a flow rate request signal to a water supply pump and a deviation signal of each water supply pump flow rate. The present invention relates to a water supply control device used as a signal correction signal.

[0002]

2. Description of the Related Art Generally, when the water level of a steam generator is controlled to be constant, the flow rate of feed water supplied from a feed water pump to the steam generator is controlled.

The control device for controlling the water supply flow rate is a water supply control device, which compares and calculates the water level setting signal and the actual water level signal to control the water supply flow rate request signal.

Further, in general, in order to control the water level of the steam generator more stably, in addition to the actual water level signal, three-element control using the deviation between the total feed water flow rate signal and the main steam flow rate signal is performed.

Further, when there are a plurality of water supply pumps,
In order to equalize the flow rates of the individual water supply pumps, two-loop control is performed to feed back the flow rates of the individual water supply pumps.

FIG. 3 shows the configuration of a conventional water supply control device.

The water supply control device 1 uses the water level signal S1 from the steam generator 18, the total water supply flow rate signal S2 from the water supply line 6 and the main steam flow rate signal S3 from the main steam line 7, and each water supply from each pump water supply line 8. The water level controller 2 which inputs the pump flow rate signal S4 and outputs the feed water flow rate correction signal S5 from the water level signal S1, the feed water flow rate correction signal S5, the total feed water flow rate signal S2 and the water feed pump flow rate request signal S6 from the steam flow rate signal S3. The valve opening request signal S7 of the control valve 10 for adjusting the flow rate of each water supply pump 9 from the output flow rate controller 3, the water supply pump flow rate request signal S6, and each water supply pump flow rate signal S4.
It is composed of a feed water pump flow rate controller 4 for outputting.

In FIG. 3, the water supply pump is an electrically driven type, and the flow rate of the water supply pump is changed by changing the opening of the control valve. In addition to this, there is also a turbine driven water supply pump. In this case, By changing the turbine speed, the feed water pump flow rate will be changed.

[0009]

In the conventional feed water control apparatus, the feed water flow rate request signal is corrected by the deviation signal from each feed water pump flow rate to adjust the feed water flow rate.

However, when the water supply pump is started and stopped, the flow rate of the water supply pump is small, and the error of the flow rate detector and the fluctuation of the flow rate may become large, so that the water supply pump flow rate may not be controlled appropriately.

The same applies when an abnormality occurs in the flow rate signal of each pump detected by the flow rate detector.

The object of the present invention is defined in order to prevent the feed water pump flow rate controller, which controls the feed water flow rate of each pump, depending on the operating state of the water feed pump from being affected by the error of the flow rate detector. A water supply control device having a function of automatically turning off the correction by the water supply pump flow rate deviation signal below the water supply flow rate and a bumpless function of preventing the water supply pump flow rate from changing when the water supply flow rate deviation signal is turned on and off. To provide.

[0013]

The water supply control apparatus of the present invention automatically turns on / off the correction control by the water supply pump flow rate request signal and the deviation signal of the total water supply pump flow rate according to the operating state of the water supply pump. The feature is that the function to perform is provided.

[0014]

In the present invention, the water supply pump flow controller performs the conventional two-loop control when the water supply system is in a normal state and the water supply pump secures a flow rate equal to or higher than the predetermined value.

Here, when the error of the flow rate detector is large at a low flow rate at the time of starting and stopping the water supply pump, or when the two-loop control becomes impossible due to a defect in the water supply pump flow rate signal, the water supply pump is switched by the switching signal. Turn off the flow deviation signal to control the water supply flow rate.

[0016]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a diagram when the feed water control apparatus according to the present invention is applied to a boiling water nuclear reactor feed water system. In the present drawing, the opening / closing controller 11 switches the switch operation signals S11 and S1 for switching the control system of the water supply pump flow rate controller 4 from the water supply pump flow rate signal S4 and the water supply pump flow rate request signal S6.
2 is output. As a result, when the water supply pump 9 is started or stopped, the water supply pump flow rate controller 4 does not perform the two-loop control and outputs the pump valve opening request signal S7. When the water supply pump flow rate signal S4 exceeds a predetermined flow rate, the opening / closing controller 1
1 outputs switch operation signals S11 and S12 to the water supply pump flow rate controller 4 so as to perform two-loop control.

In the case of a water supply system for a thermal power plant, the reactor is replaced with a boiler in FIG.

FIG. 2 is a block diagram of the water supply pump flow controller of the water supply control device according to the present invention. In the figure, the proportional signal generator 12 outputs a pump valve opening signal S8 from the feed water pump flow rate request signal S6. The correction signal generator 13 outputs a pump valve opening correction signal S9 from the water supply pump flow rate request signal S6 and the water supply pump flow rate signal S4. The bumpless signal generator 14 generates a bumpless signal S10 from the feed water pump flow rate signal S4 and the pump valve opening signal S8 to the correction signal generator 13. The signal corrector 15 converts the pump valve opening signal S8 and the pump valve opening correction signal S9 into the pump valve opening request signal S7.
Is output. The bumpless signal S10 and the pump valve opening correction signal S9 are turned on / off by the switches 16 and 17 operated by the opening / closing operation signals S11 and S12, respectively. When the trim control is not performed, the pump valve opening correction signal S9 is turned off by the switch 17, and the pump valve opening signal S8 becomes the pump valve opening request signal S7 directly by the signal corrector 15. When switching to trim control, the bumpless signal S10 is output from the correction signal generator 13 as the pump valve opening correction signal S9. The pump valve opening degree signal S8 is corrected by the signal corrector 15 by the pump valve opening degree correction signal S9 and output as the pump valve opening degree request signal S7.

FIG. 4 shows the structure of the pressurized water reactor water supply system of the present invention. In this case, steam is generated in the steam generator 18 by the heat output obtained from the pressurized water reactor 19.

Further, although the present embodiment exemplifies the system for controlling the control valve of the motor-driven water feed pump, the same effect can be obtained by controlling the turbine speed even in the case of the turbine-driven water feed pump. .

[0022]

According to the present invention, the pump valve opening request signal is corrected by the feedwater pump flow rate deviation signal when the feedwater pump is started or stopped, or when an abnormality occurs in the flow rate detector of each feed pump. By not providing it, it becomes possible to control the feed water pump flow rate more stably.

[Brief description of drawings]

FIG. 1 is a system diagram when a feedwater control device according to the present invention is applied to a boiling water reactor.

FIG. 2 is a block diagram of a pump flow rate controller in the water supply control device of the present invention.

FIG. 3 is a system diagram of a conventional water supply control device.

FIG. 4 is a system diagram when the water supply control device of the present invention is applied to a pressurized water reactor.

[Explanation of symbols]

1 ... Water supply controller, 2 ... Water level controller, 3 ... Flow controller,
4 ... Water supply pump flow controller, 5 ... Reactor, 6 ... Water supply line, 7 ... Main steam line, 8 ... Pump water supply line, 9 ... Water supply pump, 10 ... Control valve, 11 ... Open / close controller.

Claims (1)

[Claims] 1. A first control means for outputting a flow rate control signal of a water feed pump using a water level, a feed water flow rate and a steam flow rate; and a first control means which is provided for each water feed pump and receives a flow rate control signal of the water feed pump. And a second control means for outputting a feed water pump control signal, wherein the second control means is arranged in parallel with the proportional signal generating means for inputting a flow rate control signal of the water feed pump, and the proportional signal generating means. Correction signal generating means for outputting a correction signal using the input flow rate control signal of the water supply pump and the detected pump flow rate signal;
Means for correcting the output signal from the proportional signal generating means by using the correction signal and making it a control signal to the water supply pump; and switching means for switching between input and non-input of the correction signal to the correction means. And a third controller which outputs a signal for turning on the switching means when the input water flow rate signal exceeds a set value.