JPH06159606A - Drain pump-up equipment for feed water heater - Google Patents

Abstract

PURPOSE:To prevent a desalting function from lowering when an inlet temp. signal of a desalting device exceeds a temp. setting signal by opening or closing a flow control valve to lower the inlet temp. of the device below a given value. CONSTITUTION:When the flow rate of feed water from a condenser decreases, an inlet temp. signal of a desalting device 6 rises and exceeds a setting temp. signal of a temp. controller 16, a normal water level control valve opening signal 13a is less than 100%, and is less than a normal water level control valve opening signal 13b of a normal water level controller 12. Therefore, a low value prefering device 17 selects the opening signal 13a of the temp. controller 16, so that a normal water level control valve 1 1 is in a closed position according to the inlet temp. signal of the desalting device 6, the rate of drain feeding into the condenser system decreases and the inlet temp. is lowered. Thus, the inlet temp. of the desalting device can be lowered below the setting temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling water nuclear power plant having a feed water heater drain pump up facility, and more particularly to a feed water heater drain pump up facility in a condensate system.

[0002]

2. Description of the Related Art A feed water heater drain pump up facility in a boiling water nuclear power plant is a facility that has not yet been operated in Japan. In this equipment, the extracted water from the steam turbine and the feed water from the condenser undergo heat exchange in the feed water heater, and the heated feed water is sent to the reactor, while
The drain cooled and condensed by the feed water heater is collected and accumulated in the drain tank, pressurized by the drain pump, and injected into the condensate system.

The outline of the above equipment will be described with reference to FIG. 7. In the condensate system, the water supplied from the condenser 1 is boosted by the low pressure condensate pump 2, the air extractor 3 and the grant steam condenser. 4. Flows from the condensate filtration device 5 using a hollow fiber membrane into the desalination device 6. Next, the feed water from the desalination device 6 flows into the low pressure feed water heater 8 from the high pressure condensate pump 7, and then the feed water merges with the drain from the high pressure drain tank, although not shown in the drawing. It flows into the reactor via the feed water heater.

In the low-pressure feed water heater 8, the bleed air from the low-pressure turbine flows in and exchanges heat with the feed water, and the drain that has cooled the bleed air and condensed is recovered in the low-pressure feed water heater drain tank 9. The drain collected in the low-pressure feed water drain tank 9 is increased in pressure by the low-pressure drain pump 10 and is usually fed through the water level control valve 11 to the condensate filtration device 5 and the desalination device 6.
Is injected into the condensate system between. As a result, in the feedwater heater drain pump up facility, it is possible to improve the thermal efficiency by heat recovery.

FIG. 8 shows an outline of a control unit for injecting the drainage drain from the drain tank of the low-pressure feed water heater described above into the condensate system.

In the figure, the drain discharged from the low-pressure feed water heater 8 is accumulated in the low-pressure feed water heater drain tank 9, and is sent to the condensate system by two pumps of the low-pressure drain pump 10 and the desalination device 6 Flow to. Note that one of the three low pressure drain pumps 10 is stopped during normal operation.

At normal times, the normal water level control valve opening signal 13 sent from the normal water level controller 12 operates the normal water level control valve 11 provided at the discharge port of the low pressure drain pump to discharge from the low pressure feed water heater drain tank 9. The water level in the low pressure feed water heater drain tank 9 is controlled by controlling the amount of drain that is generated.

If the water level in the low-pressure feed water heater drain tank 9 increases for some reason, and the water level in the low-pressure feed water heater drain tank 9 continues to rise even if the normal water level control valve 11 is fully opened, a high The side water level controller 14 operates the high side water level control valve 15 by the high side water level control valve opening signal 14e to return the drainage drain to the condenser 1.

As described above, the amount of drainage flowing into the condensate system is determined by the water level control in the low pressure feedwater heater drain tank 9 regardless of the feedwater flow rate of the condensate system.

[0010]

However, the structure described with reference to FIG. 8 has a problem that hot water may flow into the desalination device 6 and impair the desalination function.

That is, since the low-temperature feed water and the high-temperature drain flow into the desalination unit 6, the inlet temperature of the desalination unit 6 is determined by the ratio of the low-temperature feed water flow rate and the high-temperature drain amount, and the high-temperature drain amount. If the ratio is high, hot water flows to the desalination device 6. When this high-temperature water flows into the desalination device 6, there is a problem that salt content may be released from the desalination element, impairing the desalination function.

[0012] Therefore, an object of the present invention is to provide a feed water heater drain pump-up facility in which the inlet temperature of the desalination device is set to a predetermined value or less and the desalination function is not impaired.

[0013]

According to a first aspect of the present invention, steam generated by a nuclear reactor is used to drive a turbine to perform work, and then the steam is introduced into a condenser, and water supplied from the condenser is supplied. The low-pressure feed water heater provided in the condensate system heats the turbine by exchanging heat with the extraction air of the turbine, and the drainage drained by the extraction air is collected and accumulated in the drain tank of the low-pressure feed water heater drainage drain. In the feed water heater drain pump up equipment configured to inject water into the inlet side of the desalination device provided in the condensate system via the flow control valve by the drain pump, the water level measurement signal and water level setting signal of the low pressure water heater heater drain tank And a water level controller that outputs a first water level control valve opening signal and a deviation signal between the inlet temperature signal and the temperature setting signal of the desalination device, and the second water. A temperature controller that outputs a control valve opening signal, a low value signal of the first water level control valve opening signal and the second water level control valve opening signal is selected, and the flow control valve is selected by this signal. A low-value priority device for controlling opening and closing is provided.

According to a second aspect of the present invention, the steam generated by the nuclear reactor is used to drive the turbine to perform the work, and then the steam is introduced into the condenser, and the water supplied from the condenser is provided in the condenser system. The low-pressure feed water heater heats the turbine by exchanging heat with the bleed air, and the drainage drain from the bleed air is collected and stored in the low-pressure feed water heater drain tank. In the feed water heater drain pump up equipment configured to inject into the inlet side of the desalination device provided in the condensate system via the control valve, the deviation signal between the water level measurement signal and the water level setting signal of the low pressure feed water heater drain tank is sent. Injection into the condensate system based on the water level controller that performs control calculation and outputs the first water level control valve opening signal, and the inlet flow rate measurement signal of the desalination device and the pressure measurement signal of the low pressure feed water heater The upper limit value of the drainage drain is calculated and the upper limit flow rate setter that outputs the upper limit flow rate setting signal and the deviation signal between the upper limit flow rate setting signal and the discharge drain signal are control-calculated to obtain the second water level control valve opening signal. A low-value signal of the output flow controller, the first water level control valve opening signal and the second water level control valve opening signal is selected, and the flow control valve is opened / closed by this signal. A low value priority device is provided.

[0015]

According to the present invention, the deviation signal between the water level measuring signal and the water level setting signal of the drain tank of the low-pressure feed water heater is control-calculated and output as the first water level control valve opening signal. On the other hand, the deviation signal between the inlet temperature signal of the desalination device and the temperature setting signal is control-calculated and output as the second water level control valve opening signal. The first water level control valve opening signal and the second water level control valve opening signal are input to a low value priority device, and the low value priority device selects either of the low value signals, and this signal causes the flow rate to change. The control valve is controlled to open and close. As a result, normally, the flow control valve is opened and closed by the first water level control valve opening signal to keep the water level of the drain tank of the low-pressure feed water heater constant, but the inlet temperature signal of the desalination device exceeds the temperature setting signal. In this case, the flow control valve is opened / closed by the second water level control valve opening signal based on the inlet temperature signal of the desalination device, and the rise of the inlet temperature signal of the desalination device is prevented. Therefore, hot water does not flow into the desalination apparatus, and the desalination function is not impaired.

According to the second aspect of the present invention, the deviation signal between the water level measurement signal of the low pressure feed water heater drain tank and the water level setting signal is control-calculated and output as the first water level control valve opening signal. On the other hand, the upper limit value of the drainage to be injected into the condensate system is calculated based on the inlet flow rate measurement signal of the desalination device and the pressure measurement signal of the low pressure feed water heater, and is output as the upper limit flow rate setting signal. A deviation signal between the upper limit flow rate setting signal and the discharge drain flow rate signal is control-calculated and output as a second water level control valve opening signal. The first water level control valve opening signal and the second water level control valve opening signal are input to the low value priority device, and one of the low value signals is selected, and the flow control valve is opened and closed by this signal. Controlled. As a result, normally, the flow control valve is opened and closed by the first water level control valve opening signal to keep the water level of the drain tank of the low-pressure feed water heater constant, but the drain flow rate signal becomes larger than the upper limit flow rate setting signal. In this case, the flow control valve is prevented from opening and closing by the second water level control valve opening signal, and the discharge drain flow rate signal becomes equal to or higher than the upper limit flow rate setting signal. Therefore, the rise of the inlet temperature signal of the desalination device is prevented, high temperature water does not flow into the desalination device, and the desalination function is not impaired.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a feed water heater drain pump up system equipped with a desalination device inlet temperature control device showing a first embodiment of the present invention. The same reference numerals as those in FIG. 8 showing the prior art indicate the same or corresponding portions. FIG. 1 is FIG.
2 is that the temperature controller 16 and the low value priority device 17 are additionally provided.

Here, the temperature controller 16 outputs the first normal water level control valve opening signal 13a to the low value priority device 17 so that the inlet temperature signal of the desalination device 6 does not exceed the set temperature signal. The low value priority device 17 inputs the normal water level control valve opening signal 13b of the normal water level controller 12 and the normal water level control valve opening signal 13a of the temperature controller 16 and outputs a low value signal to the normal water level control valve opening. It is output to the normal water level control valve 11 as a degree signal 13c.

Next, the operation of the present invention will be described with reference to FIGS.

The normal water level controller 12 is constituted by the control block diagram shown in FIG. 2. First, the water level measurement signal from the water level detector 12a is input to the deviation calculator 12b and compared with the normal water level setting signal 12c. , The deviation signals of both are input to the proportional-plus-integral-derivative calculator 12d, the control calculation is performed, and the normal water level control valve opening signal 13b is output.

On the other hand, in the temperature controller 16, as shown in the control block diagram of FIG. 3, the temperature measurement signal from the temperature detector 16a is input to the deviation calculator 16b and compared with the temperature setting signal 16c, and the deviation between the two is detected. Signal is proportional to integral differential calculator 16d
To the control signal, and the normal water level control valve opening signal 1
3a is output.

In the low value priority device 17, the normal water level controller 12
The normal water level control valve opening signal 13b and the normal water level control valve opening signal 13a of the temperature controller 16 are input, and a low value is selected from these signals to select the normal water level control valve opening signal 13
c is output to the normal water level control valve 11.

That is, the normal water level control valve opening signal 13a
Is A, the normal water level control valve opening signal 13b is B, and the selected normal water level control valve opening signal 13c is C, the following (1)
Is processed.

[0025]

[Equation 1] C = min (A, B) …………… (1)

In the above case, the normal water level control valve 11 is controlled to be opened / closed by the signal C selected by the low value priority device 17.

On the other hand, the water level in the drain tank 9 of the low-pressure feed water heater is not limited to the normal water level controller 12, but the high-side water level controller 1
Controlled by 4.

The high-side water level controller 14 is constructed by the control block diagram shown in FIG. 4. The water level measurement signal from the water level detector 14a is input to the deviation calculator 14b and compared with the high side water level setting signal 14c. The deviation signals of the both are input to the proportional-plus-integral-derivative calculator 14d, control calculation is performed, and the high-side water level control valve opening signal 14e is output to the high-side water level control valve 15.

As a result, the high-side water level control valve 15 is operated so that the actual water level does not exceed the set high-side water level, and the drain flowing therethrough is directly returned to the condenser 1.

During normal operation of the plant, the inlet temperature signal of the desalination device 6 is lower than the set temperature signal of the desalination device 6, and the normal water level control valve opening signal 13a is larger than 100%. Therefore, the normal water level control valve opening signal 13b of the normal water level controller 12 is selected by the low value priority device 17, and the normal water level control valve 11 is selected as the normal water level control valve opening signal 13c.
Is operated.

As a result, the normal water level control valve opening signal 13 for maintaining the normal water level setting signal 12c of the normal water level controller 12 is obtained.
c is output to the normal water level control valve 11, and the normal water level control valve 1
1 is controlled to open and close to maintain the water level in the low-pressure feed water heater drain tank 9 at a predetermined value. On the other hand, the feed water flow rate from the condenser 1 is decreased, the inlet temperature signal of the desalination device 6 is increased, and the temperature controller 16
When the set temperature signal of is exceeded, the normal water level control valve opening signal 1
3a is smaller than 100%. Further, if the rise in the temperature signal at the inlet of the desalination device 6 is large, the normal water level controller 1
The normal water level control valve opening signal 13a is smaller than the normal water level control valve opening signal 13b of 2. Therefore, in the low value priority device 17, the normal water level control valve opening signal 13a of the temperature controller 16 is selected.

As a result, the normal water level control valve 11 is closed in accordance with the inlet temperature signal of the desalination device 6, the amount of drain injected into the condensate system is reduced, and the inlet temperature is lowered.

In this case, the low-pressure feed water heater drain tank 9
Since the internal water level increases, the drain is discharged under the control of the high-side water level controller 14 to prevent the water level in the low-pressure feed water heater drain tank 9 from rising.

As described above, when the inlet temperature of the desalination device 6 is detected, and when the temperature exceeds the set temperature, the normal water level control valve 11 is controlled to open and close, and the drain amount injected into the condensate system. The inlet temperature of the desalination device 6 can be made equal to or lower than the set temperature by adjusting the.

Next, a second embodiment of the present invention will be described with reference to FIG.

The difference from the first embodiment shown in FIG. 1 is that the temperature controller 16 is omitted and the flow rate measuring device 28 and the pressure measuring device 29 are used.
And upper limit flow rate setting device 30, flow rate measuring device 31, and flow rate controller 3
This is the point where 2 was added.

Here, the flow rate measuring device 28 is provided in the desalination apparatus 6, measures the flow rate flowing into the desalination apparatus 6, and outputs a flow rate measurement signal F1. The pressure measuring device 29 measures the pressure in the low-pressure feed water heater drain tank 9 and outputs a pressure measurement signal P. The upper limit flow rate setter 30 uses the flow rate measurement signal F3, the pressure measurement signal P, and a preset temperature set value T3 based on a predetermined calculation formula to form the low-pressure feed water heater drain tank 9
Then, the upper limit value of the drain flow rate injected into the condensate system is obtained, and the upper limit flow rate setting signal F2 is output. The flow rate measuring device 31 measures the flow rate from the outlet side of the low-pressure drain pump 10 to the condensate system, and outputs a flow rate measurement signal F1. The flow rate controller 32 is
The deviation signal between the upper limit flow rate setting signal F2 and the flow rate measurement signal F1 is subjected to proportional-plus-integral-derivative calculation processing and a normal water level control valve opening signal 13a is output.

The specific operation of the second embodiment will be described with reference to FIG. 6. First, in the upper limit flow rate setting unit 30, the calculator 30a calculates the upper limit flow rate setting signal F2 according to the following equation (2). .

[0039]

[Formula 2] F2 = (T3 · F3-T1 · F3) / (T2-T1) ……………… (2)

Here, T1: feed water temperature (constant) that enters the desalination apparatus 6 from the condenser T2: drain temperature injected from the low pressure feed water heater drain tank 9 into the condensate system (low pressure feed water heater drain tank 9 It can be calculated as the saturation temperature from the internal saturation pressure) F3: Desalination device 6 inlet flow rate T3: Desalination device 6 inlet temperature set value (constant)

On the other hand, in the flow rate controller 32, the flow rate measuring device 3
The drain flow rate measurement signal F1 from 1 and the upper limit flow rate setting signal F2 are input to the deviation calculator 32a, and the deviation signals of both are input to the proportional-integral-derivative calculator 32b for control calculation, and the normal water level control valve opening The signal 13a is output.

Next, in the low value priority device 17, the normal water level control valve opening signal 13b of the normal water level controller 12 and the flow rate controller 3 are supplied.
The second normal water level control valve opening signal 13a is input, and a low value signal is output to the normal water level control valve 11 as a normal water level control valve opening signal 13c. That is, when the normal water level control valve opening signal 13a is A, the normal water level control valve opening signal 13b is B, and the selected normal water level control valve opening signal 13c is C,
The following process (3) is performed.

[0043]

[Equation 3] C = min (A, B) ………… (3)

As a result, the normal water level control valve 11 is opened / closed by the normal water level control valve opening signal 13c selected by the low value priority device 17 in the above process.

Explaining the above operation in detail, during normal operation of the plant, the flow rate measurement signal F1 of the drain discharged from the low pressure feed water heater drain tank 9 is the upper limit flow rate setting signal F2 calculated by the upper limit flow rate setting unit 30. Lower than
In order to fully close the normal water level control valve 11, the normal water level control valve opening signal 13a becomes larger than 100%.
Therefore, the normal water level control valve opening signal 13b of the normal water level controller 12 is selected by the low value priority device 17, and the normal water level control valve 1 is selected.
1 is operated.

On the other hand, when the flow rate of water supplied from the condenser 1 decreases, the ratio of the drain flow rate to the inlet flow rate of the desalination device 6 increases and the upper limit flow rate setting signal F2 decreases. Therefore, when the actual drain flow rate measurement signal F1 exceeds the value of the upper limit flow rate setting signal F2, the normal water level control valve opening signal 13a is smaller than 100% in order to close the normal water level control valve 11. Become. As a result, when the water supply flow rate from the condenser 1 is greatly reduced and the normal water level control valve opening signal 13a is smaller than the normal water level control valve opening signal 13b, the low value priority device 17 causes the flow rate controller to operate. 32 normal water level control valve opening signal 1
3a is selected. Then, the amount of drain injected into the condensate system is reduced to reduce the ratio of the amount of drain of the supply water.

In this case, the low-pressure feed water heater drain tank 9
Since the internal water level increases, the drain is discharged under the control of the high-side water level controller 14 to prevent the water level in the low-pressure feed water heater drain tank 9 from rising.

In this manner, the inlet flow rate of the desalination device 6 is measured, and the upper limit value of the drain amount to be injected into the condensate system is obtained from the flow rate and the internal pressure of the drain tank 9 of the low-pressure feed water heater. When it exceeds, the amount of drain to be injected into the condensate system can be adjusted by operating the normal water level control valve 11 so that the inlet temperature of the desalination apparatus 6 can be set to the set temperature or lower. In this way, the response of the change in the inlet flow rate of the desalination device 6 due to the decrease in the flow rate of the water supplied from the condenser 1 is very good, so the control effect by this means is great. Therefore, by protecting the inlet temperature of the desalination device 6, the feed water heater drain pump up facility can be operated without impairing the desalination function.

[0049]

As described above, according to the invention of claim 1, when the inlet temperature signal of the desalination device exceeds the temperature setting signal, the second water level control valve based on the inlet temperature signal of the desalination device. The flow rate control valve is opened / closed by the opening signal to prevent the inlet temperature signal of the desalination apparatus from rising. Therefore, hot water does not flow into the desalination apparatus, and the desalination function is not impaired.

According to the second aspect of the present invention, when the discharge drain flow rate signal becomes larger than the upper limit flow rate setting signal as the process amount corresponding to the inlet temperature signal of the demineralizer,
The flow control valve is prevented from opening and closing by the second water level control valve opening signal and the discharge drain flow rate signal becomes equal to or higher than the upper limit flow rate setting signal. Therefore, the rise of the inlet temperature signal of the desalination device is prevented, and the desalination function is not impaired by the inflow of high-temperature water.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a feed water heater drain pump up facility showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a normal water level controller applied to FIG.

FIG. 3 is a configuration diagram of a temperature controller applied to FIG.

FIG. 4 is a configuration diagram of a high-side water level controller applied to FIG.

FIG. 5 is a configuration diagram of a feed water heater drain pump-up facility showing a second embodiment of the present invention.

6 is a configuration diagram of a control block applied to FIG.

FIG. 7 is a schematic system diagram of a feed water heater drain pump up facility.

FIG. 8 is a configuration diagram of a conventional feed water heater drain pump up facility.

[Explanation of symbols]

 8 Low Pressure Feed Water Heater 9 Low Pressure Feed Water Heater Drain Tank 10 Low Pressure Drain Pump 11 Normal Water Level Control Valve 12 Normal Water Level Controller 12a Water Level Detector 12b Deviation Calculator 12c Normal Water Level Setting Signal 12d Proportional Integral Derivative Calculator 13a, 13b, 13c Normal water level control valve opening signal 14 High side water level controller 14a Water level detector 14b Deviation calculator 14c High side water level setting signal 14d Proportional integral derivative calculator 15 High side water level control valve 16 Temperature controller 16a Temperature detector 16b Deviation calculator 16c Temperature setting signal 16d Proportional integral differential calculator 17 Low value priority device 28 Flow rate measuring instrument 29 Pressure measuring instrument 30 Upper limit flow rate setting device 30a Calculator 31 Flow rate measuring instrument 32 Flow rate controller 32a Deviation calculator 32b Proportional integral differential calculator

Claims (2)

[Claims] 1. A low-pressure feed water heater provided with a condensate system by introducing steam into the condenser after driving the turbine by steam generated from the nuclear reactor to perform work. In addition to heating by exchanging heat with the extraction air of the turbine,
The drainage drainage by the extraction is collected and accumulated in the low-pressure feedwater heater drain tank, and the drainage drain from the low-pressure feedwater heater drain tank is connected to the condensate system through a flow rate control valve by a drain pump. In a feed water heater drain pump up facility configured to inject into the side, a deviation signal between the water level measurement signal and the water level measurement signal of the low pressure water feed heater drain tank is controlled and calculated to output a first water level control valve opening signal. A water level controller for controlling the deviation signal between the inlet temperature signal and the temperature setting signal of the desalination device and outputting a second water level control valve opening signal, and a first water level control valve A water supply unit characterized by comprising a low value priority device for selecting a low value signal from the opening signal and the second water level control valve opening signal and controlling the opening and closing of the flow rate control valve by this signal. Vessel drain pump up equipment. 2. A low-pressure feed water heater provided with a condenser system in which steam after driving a turbine by steam generated from a nuclear reactor to perform work is introduced into the condenser, and water supplied from the condenser is provided in a condensate system. In addition to heating by exchanging heat with the extraction air of the turbine,
The drainage drainage by the extraction is collected and accumulated in the low-pressure feedwater heater drain tank, and the drainage drain from the low-pressure feedwater heater drain tank is connected to the condensate system through a flow rate control valve by a drain pump. In the feed water heater drain pump up facility configured to inject into the side, a deviation signal between the water level measurement signal and the water level setting signal of the low pressure water heater heater drain tank is control-calculated and a first water level control valve opening signal is output. A water level controller, and calculates the upper limit flow rate set value of the drainage to be injected into the condensate system based on the inlet flow rate measurement signal of the desalination device and the pressure measurement signal of the low pressure feed water heater, and the upper limit flow rate is calculated. An upper limit flow rate setting device that outputs a setting signal, and a control signal for the deviation signal between the upper limit flow rate setting signal and the discharge drain flow rate signal to output a second water level control valve opening signal A low-value signal of the flow controller, the first water level control valve opening signal or the second water level control valve opening signal is selected, and the flow control valve is opened / closed by this signal. A water heater drain pump up facility that is equipped with a low-priority device that is controlled.