JPH07158810A - Water level control device for feedwater heater - Google Patents

Abstract

PURPOSE:To enable a superior performance of a feedwater heater to be attained by a method wherein an opening degree instruction signal is outputted to a high water level adjusting valve in response to a water level sensing signal and a valve state signal and then outputted to a normal water level adjusting valve as a full opening signal with a plant abnormal signal. CONSTITUTION:High water level control devices 38A and 38B output an opening degree instruction signal to high water level adjusting valves 18A and 18B in response to water level sensing signals of corresponding feedwater heaters 7A and 7B, a water level sensing signal of an adjoining upper stage water supplying heater, and valve state signals of normal water level adjusting valves 16A and 16B, and in turn output the opening degree instruction signal to the normal water level adjusting valves 16A and 16B as a full-open signal. Accordingly, valve state signals of the normal water level adjusting valves 16A and 16B are inputted, thereby normal water level adjusting valves and high water level adjusting valves 16A, 16B and 18A, 18B expecting a variation in an amount of drain in reference to their abnormal states are controlled, they are fully opened under an abnormal state of the plant and so the drain water within the water supplying heaters 7A and 7B can be positively discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level controller for a feed water heater which controls the drain water levels in a plurality of feed water heaters arranged in parallel and arranged in multiple stages in each series.

[0002]

2. Description of the Related Art FIG. 9 shows a plant configuration example of a nuclear power plant. In the figure, steam generated in a nuclear reactor 1 is introduced into a high-pressure steam turbine 3 via a high-pressure steam control valve 2 to rotate the high-pressure steam turbine 3. The steam that has worked in the high-pressure steam turbine 3 is reintroduced into the low-pressure steam turbine 5 from the low-pressure steam control valve 4 to rotate the low-pressure steam turbine 5, where
The steam that worked is condensed in the condenser 6.

On the other hand, a low-pressure feed water heater 7 and a high-pressure feed water heater 8 for heating the feed water supplied from the condenser 6 to the reactor 1 are provided, of which the low-pressure feed water heater 7 is connected to the low-pressure steam turbine 5. Of the extracted steam of the high-pressure steam turbine 3 is supplied to the high-pressure feed water heater 8 via the high-pressure extracted steam pipe 10. On the other hand, the condensate from the condenser 6 is sent by the condensate pump 11 to the low-pressure feed water heater 7 and the high-pressure feed water heater 8 to heat the feed water by exchanging heat with the extracted steam.

The heated feed water is fed from the feed water pipe 12 to the reactor 1 by the feed pump 13. In addition, 14
Is a generator that generates electricity by rotating the high-pressure steam turbine 3 and the low-pressure steam turbine 5.

Thus, in a nuclear power plant, the condenser 6
In order to heat the feed water supplied to the reactor 1 from the high pressure feed water heater 8 for exchanging heat between the feed water from the condenser 6 and the extraction air from the high pressure steam turbine 3, the feed water and the extraction air and heat from the low pressure steam turbine 5. There is a low-pressure feed water heater 7 to be replaced.

[0006] A plurality of feed water heaters are arranged in multiple stages in order to efficiently disperse and gradually heat, and the number thereof increases as the plant becomes larger. In addition, the thermal power station also has a feed water heater with a similar structure.

FIG. 10 shows a structural example in which a large number of feed water heaters described above are provided.

In this example, the high pressure feed water heater (HPHTR) 8A to 8D having two lines and two stages and the low pressure feed water heater (LPHTR) 7A to 7I having three stages and three lines of three lines are used to heat the high pressure feed water. The vessels 8A to 8D and the low-pressure feed water heaters 7A to 7I are externally connected by a feed water pipe 12 so that the heat exchangers incorporated therein are sequentially connected to form a feed water system.

Further, the high-pressure feed water heaters 8A to 8D are respectively connected to high-pressure extraction steam pipes 10 for supplying extraction steam from the high-pressure steam turbine 3, and the low-pressure feed water heaters 7A to 7D.
Low pressure extraction steam piping 9 for supplying extraction steam from the low pressure steam turbine 5 is connected to each I.

Further, in the high-pressure feed water heaters 8A to 8D and the low-pressure feed water heaters 7A to 7I, the water level of the condensed water (drain) of the extracted steam generated by heat exchange inside is kept constant, and excess drain is discharged. A drain pipe is provided for this purpose. This drain pipe is normally used to control the water level of the upper drain water as a heat source for keeping heat in the lower feed water heater.
The drain is connected so as to flow from the upper feed water heater to the lower feed water heater via the.

Further, the normal water level control valves 15A to 15D, 1
6A to 16I in parallel with high water level control valves 17A to 17D, 1
Piping is provided so that the drain flows directly to the condenser 6 via 8A to 18I.

Now, the operation of the above-described conventional water level controller for the feed water heater will be described with reference to FIG. 11, which shows a part of FIG.

First, referring to FIG. 11, each water level detector 19
Water level signals c1 and c2 from A and 19B are normal water level controller 2
0A, 20B and high water level controllers 21A, 21B.

For example, the high water level controller 21A shown in FIG.
As shown in FIG. 12, the high water level setting signal s1 and the water level signal c
The deviation signal from the adder / subtractor 22 and the deviation signal
The controller 23 is configured to output an opening degree instruction signal a1 obtained by performing ID calculation processing.

Further, the normal water level controller 20A shown in FIG.
As shown in FIG. 12, an adder / subtractor 24 that outputs a deviation signal between the normal water level setting signal s2 and the water level signal c1 and a controller 25 that outputs an opening degree instruction signal b1 obtained by PID calculation processing of the deviation signal Has become.

In the normal water level controller 20A, the water level signal c1
Is input to the normal water level setting signal s2 by the adder / subtractor 22.
And the deviation signal is subjected to PID calculation processing by the controller 25, and the opening degree command signal b1 is output to the normal water level control valve 16A.

On the other hand, in the high water level controller 21A, the water level signal c1 is input, a deviation signal from the high water level setting signal s1 is obtained, and this deviation signal is subjected to PID calculation processing by the controller 23 and the opening command is issued. Signal a1 indicates high water level control valve 18A
Is output to.

In this case, the high water level setting signal s1 is set higher than the normal water level setting signal s2, and the normal water level control valve 16A is normally opened so as to follow the normal water level setting signal s2 of the normal water level controller 20A. The high water level control valve 18A is fully closed by outputting a signal indicating that the opening command signal a1 from the high water level controller 21A is fully closed.

The normal water level controller 20B and the high water level controller 21B also operate similarly to the normal water level controller 20A and the high water level controller 21A.

By the way, in the water level controller for the feed water heater shown in FIG. 11, when the drain water level in the feed water heater on the upstream side fluctuates as the feed water amount and the extraction amount change when the plant output is changed, etc. The drain amount to the feed water heater also fluctuates, and the drain water level also gradually fluctuates with a time delay. For this reason, the high water level controllers 21A and 21B may not be able to control correspondingly even when the water level becomes high, and the water level high alarm point may be reached and an alarm may be issued.

Therefore, in view of the above, in order to improve the controllability of the drain water level when the plant output fluctuates, the structure shown in FIG. 13 was developed.

In this conventional example, in order to predict a change in the amount of drain flowing from the upstream side to the downstream side, the water level signal c1 of the low pressure feed water heater 7A on the upstream side is fed to the prediction controller 26B on the downstream side.
27B, for example, the predictive controller 26B, as shown in FIG. 14, the deviation signal between the water level signal c1 of the upstream low-pressure feed water heater 7A and the normal water level setting signal s3 is subjected to PID calculation processing. Then, this is added to the input as a prediction signal.

Specifically, the deviation signal between the downstream water level signal c2 and the downstream normal water level setting signal s4 is added / subtracted by the adder / subtractor 29.
And the deviation signal is output to the adder 30. Then, the deviation signal between the upstream water level signal c1 and the upstream normal water level setting signal s3 is calculated by the adder / subtractor 28, and the predicted signal obtained by performing the PID calculation process on this deviation signal is output to the adder 30. Then, the output signal of the adder 30 is subjected to PID calculation processing by the controller 32, and the opening degree command signal b2 obtained by the controller 32 is output to the normal water level control valve 16B.

With this configuration, the signal obtained by PID calculation of the deviation signal between the water level signal c1 of the upstream low pressure feed water heater 7A and the normal water level setting signal s3 is the normal water level control valve of the upstream low pressure feed water heater 7A. It becomes equivalent to the opening command b1 of 16A. Therefore, the change of this value predicts a signal corresponding to the opening command signal b1 as a predicted change amount of drain water corresponding to the change amount of drain water flowing from the upstream side, and adds this to the controller 32 in advance. The normal water level control valve 16B of the low pressure feed water heater 7B on the downstream side is opened and closed. As a result, in the predictive controller 26B on the downstream side, the predictive amount based on the amount of change in the drain water of the predictive controller 26A on the upstream side is subjected to advance control, and the responsiveness can be improved.

[0025]

However, in the above-mentioned conventional water level control device for the feed water heater, the drain water level suddenly fluctuates when the plant such as a turbine trip fluctuates or the normal water level control valve fails, and the predetermined water level is set. There is a problem that the value cannot be maintained.

First, as described with reference to FIG. 10, in the system of a plurality of feed water heaters, drain water in the drain water flows from the upper feed water heater side to the lower feed water heater in sequence. Is discharged to the condenser. Therefore, due to the occurrence of turbine trip or load interruption, etc., the high pressure steam control valve 2
When the low-pressure steam control valve 4 is fully closed to shut off the steam flowing into the turbine and the pressure difference between the upper stage and the lower stage becomes small, the extracted steam to the feed water heater is lost and the steam in each feed water heater is lost. Drain water will not be discharged.

In this state, the pressure in the feed water heater is rapidly reduced and the boiling point is lowered to bring the drain water into a boiling state, so that the boundary between the drain water and the steam, that is, the drain water level is not accurately detected, There is a problem that the drain water in the feed water heater cannot be reliably discharged to the outside of the equipment, and the drain water level in the feed water heater becomes abnormally high.

Secondly, if the upstream normal water level control valve fails, the water level of the downstream feed water heater may become abnormal and the water level control may not follow. For example, if there is a failure that the normal water level control valve of the upstream feed water heater is fully closed,
There is no drain water flowing into the feed water heater on the downstream side,
Immediately, since the opening of the normal water level control valve on the downstream side does not change following the change, there is a problem that drain water is excessively discharged from the feed water heater.

Thirdly, it is conceivable to input the signal at the time of plant fluctuation and the signal of the normal water level control valve to each controller for control, but the number of input / output points increases and the conventional general-purpose one loop controller There is a problem that the number of input / output points and the processing capacity cannot be adequately controlled for control.

In view of this, the present invention provides a water level controller for a feed water heater which is capable of promptly responding to and responding to fluctuations in a plant or an abnormality in a normal water level control valve, and which accommodates a large number of controllers compactly and is excellent in operability. The purpose is to provide.

[0031]

According to a first aspect of the present invention, heat exchangers built in adjacent feed water heaters of feed water heaters arranged in multiple stages from the upper stage to the lower stage are sequentially connected via a water feed pipe. A plurality of such water supply lines are provided, and at least the upper side and the lower side of the plurality of water supply lines are joined together, and water is supplied from the condenser to the heat exchanger of the feed water heater from the lower stage to the upper stage by the condensate pump, and the turbine is connected. A water supply system for exchanging heat with the bleed air supplied from the water supply system, while the upper side water supply heater and the lower side water supply heater arranged adjacent to each other are connected by a drain pipe through a normal water level control valve, Connect the branch drain pipe branched from the inlet side of the normal water level control valve of the drain pipe to the condenser via the high water level control valve, and connect the drain pipe connected to the feed water heater at the lowest stage of each water supply line. Merge and condense A normal water level controller and a high water level controller for controlling the water level of the drain water in each of the feed water heaters arranged in a feed water heating system including a drain discharge system for discharging drain water to the condenser. In the water level control device for a feed water heater provided with, each of the normal water level controllers, means for monitoring the valve state of the corresponding normal water level control valve and outputting a valve state signal, and the corresponding feed water heater While outputting the opening command signal to the normal water level control valve based on the water level detection signal of the water heater and the valve state signal of the normal water level control valve adjacent to the water level detection signal of
A means for outputting the opening instruction signal as a fully open signal to the normal water level control valve in response to a plant abnormality signal, each of the high water level controllers is provided with a water level detection signal of the corresponding water heater and an upper feed water heater adjacent to the water level detection signal. The opening command signal is output to the high water level control valve based on the water level detection signal of the water tank and the valve state signal of the normal water level control valve, while the normal water level control is performed by setting the opening command signal as a fully open signal by a plant abnormality signal. A means for outputting to the valve is provided.

A second aspect of the invention is to provide a plurality of water supply rows in which heat exchangers incorporated in adjacent water supply heaters of the water supply heaters arranged in multiple stages from the upper stage to the lower stage are sequentially connected through water supply pipes. At least the upper side and the lower side of each of the plurality of water supply lines are joined together, and water is supplied from the condenser by the condensate pump to the heat exchangers of the water heaters from the lower to the upper stages, and the bleed air supplied from the turbine and The water supply system for heat exchange and the feed water heater on the upper side and the feed water heater on the lower side, which are arranged adjacent to each other, are connected by a drain pipe via a normal water level control valve, while the normal water level control of the drain pipe is performed. A branch drain pipe branched from the inlet side of the valve is connected to the condenser via a high water level control valve, and a drain pipe connected to the feed water heater at the lowest stage of each water supply line is joined to condense the drain. In front of water A feed water heater including a normal water level control device and a high water level control device for controlling the water level of the drain water in each of the feed water heaters arranged in a feed water heating system including a drain discharge system for discharging to a condenser In the water level control device, the normal water level control device outputs m output signals from m normal water level control means corresponding to the n normal water level control valves arranged in the feed water heating system. Means for outputting an opening degree command signal to the corresponding normal water level control valve is provided, and the high water level control device includes m number of high water level control valves corresponding to each of the n high water level control valves. Of the normal water level is provided with means for selecting any one of the m output signals output from the high water level control means and outputting the opening degree command signal to the corresponding high water level control valve. The control means is n The normal water level controllers for outputting the output signals corresponding to the normal water level control valves are collectively housed in a predetermined number, and the high water level control means respectively outputs the output signals corresponding to the n high water level control valves. A predetermined number of high water level controllers that output signals are collectively housed.

A third aspect of the present invention is to provide a plurality of water supply rows in which heat exchangers incorporated in adjacent water supply heaters adjacent to the water supply heaters arranged in multiple stages from the upper stage to the lower stage are sequentially connected through water supply pipes. At least the upper side and the lower side of each of the plurality of water supply lines are joined together, and water is supplied from the condenser by the condensate pump to the heat exchangers of the water heaters from the lower to the upper stages, and the bleed air supplied from the turbine and The water supply system for heat exchange and the feed water heater on the upper side and the feed water heater on the lower side, which are arranged adjacent to each other, are connected by a drain pipe via a normal water level control valve, while the normal water level control of the drain pipe is performed. A branch drain pipe branched from the inlet side of the valve is connected to the condenser via a high water level control valve, and a drain pipe connected to the feed water heater at the lowest stage of each water supply line is joined to condense the drain. In front of water In the water level control device of the water heater for controlling the water level of the drain water in each of the water heaters, which is arranged in the water heating system consisting of the drain discharge system for discharging to the condenser, it is arranged in the water heating system. The opening command signal by selecting one of the m output signals output from the m water level control means for each of the n normal water level control valves and the n high water level control valves. And a means for outputting to the corresponding normal water level control valve and high water level control valve are provided, and the water level control means corresponds to the n normal water level control valves and the n high water level control valves. A predetermined number of water level controllers for outputting the output signals, respectively, and monitoring means for monitoring the m water level control means and outputting a high water level control valve fully open command when an abnormality occurs, Normal time The selected opening command signal is output to the corresponding high water level control valve, and when the high water level control valve full open command is input, the opening command signal is output to the corresponding high water level control valve as a full open signal. A switching means is provided.

[0034]

According to the first aspect of the present invention, the normal water level control valve control and the high water level control valve control predicting the fluctuation of the drain amount due to the abnormal state of each normal water level control valve by inputting the valve state signal of the normal water level control valve. It can be performed. In addition, the normal water level control valve or the high water level control valve should be fully opened in the event of an abnormal plant such as a turbine trip, and drain water in the feed water heater should be reliably discharged to the outside of the water supply heater. You can

A second aspect of the present invention has the function of the first aspect of the present invention and performs normal water level control valve control and high water level control valve control that predict fluctuations in the drain amount due to an abnormal state of each normal water level control valve. In addition, the normal water level control valve or high water level control valve should be fully opened in the event of a plant trip such as a turbine trip, and drain water in the feed water heater should be discharged to the outside of the equipment, so the soundness of the feed water heater should be ensured. You can Moreover, the normal water level control means and the high water level control means are multiplexed, and even if one of these control means fails, it is switched to the output signal of the other control means. Therefore, the control means is reliable, and it is more compact than the conventional one-loop controller arranged in large numbers, and the number of external points is small and simple.

A third aspect of the present invention performs normal water level control valve control and high water level control valve control that predict fluctuations in the drain amount due to an abnormal state of each normal water level control valve, and is normally used for abnormal plant conditions such as turbine trips. Since the water level control valve or the high water level control valve is fully opened and the drain water in the feed water heater is reliably discharged to the outside of the device, the soundness of the feed water heater can be ensured. Moreover, the water level control means are multiplexed so that even if one of these control means fails, it is switched to the output signal of the other control means. Therefore, the control means is reliable, and it is more compact than the conventional one-loop controller arranged in large numbers, and the number of external points is small and simple.

[0037]

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

FIG. 1 is a block diagram of a water level controller for a feed water heater showing a first embodiment of the present invention, and FIG. 1 shows a conventional example.
The same reference numeral as 3 indicates the same portion or a corresponding portion, and the main difference between them is that the opening degree detectors 35A and 35B and the interlock board 36 are additionally provided, and the predictive controllers 26A, 26B and 2 are provided.
Normal water level controller 37A, 37B instead of 7A, 27B
And the high water level controllers 38A and 38B.

The opening detectors 35A and 35B detect the openings of the normal water level control valves 16A and 16B and output opening detection signals d1 and d2. The interlock board 36 outputs a plant status signal f according to the status of the plant.

As shown in FIG. 2, in addition to the configuration shown in FIG. 14, the normal water level controllers 37A and 37B further input a plant state signal f to fully open (100%) or fully close (0%). A switch 40 for switching to and outputting a corresponding opening command signal, an opening command signal for the switch 40, and a controller 32.
Control signal of the opening command signal b
2 and a monitor 42 that outputs a normal water level control valve state signal e2 to the outside from the opening command signal b2 of this selector 41 and the normal water level control valve opening signal d2.
And a gain setter 4 for determining a gain from the normal water level control valve state signals e1, e2, e3 and outputting a gain setting signal.
3 and a multiplier 44 for multiplying the gain setting signal and the signal from the adder 30 are added.

The high water level controllers 38A, 38B are, as shown in FIG. 3, normal water level controllers 37A, 3B shown in FIG.
The monitoring device 42 is deleted from 7B.

With the above structure, the high water level controller 3 shown in FIG.
The switching device 40 of 8A and 38B is normally closed (0
%) Is selected and the plant state signal f is input from the interlock board 36, the full open command (100%) is selected. Therefore, since the selector 41 selects the high value signal, the fully open signal from the switch 40 is output as the opening command signal a2 when the plant is changed due to a turbine trip or the like. Therefore, when the extracted steam is lost, the drain water in the feed water heater is discharged from the high water level control valve to the outside.
As a result, an abnormal rise in the drain water level in the feed water heater is avoided.

Further, in the high water level controllers 38A and 38B,
The deviation signal between the high water level setting signal s6 and the drain water level signal c2 becomes a negative value at the normal water level, and the opening command signal a2
Is a fully closed command. For example, the normal water level control valve 16
When A becomes abnormal (for example, fully closed), first, the water level signal c
1 rises and is input to the normal water level controller 37B, the preceding signal is output from the calculator 31 to the adder 30, and the normal water level control valve 16B is controlled by the opening degree command signal b2. In this state, the normal water level control valve status signals e1, e2, e3 from the upstream and downstream feed water heaters of the same series are input to the gain setter 43, and the gain m is set to the high water level controller 38A,
38B is set so as to suppress the water level sudden rise of the corresponding feed water heater, and the normal water level controllers 37A and 37B are set as follows so as to suppress the water level sudden drop of the corresponding feed water heater.

That is, first, in the monitor 42 of the normal water level controller 37B, the opening detection signal d2 and the opening command signal b2 from the opening detector 35B are input, and a predetermined deviation amount is determined by comparing them. When the time continues, the normal water level control valve state signal e2 is created and input to the gain setter 43, and the normal water level control valve state signal e2 is output to the outside.

Here, the normal water level control valve status signal ei is e
i = {ei1, ei2}, and when the actual opening signal is small with respect to the normal water level control valve opening command signal, ei1 = 1
When the actual opening signal is large in response to the normal water level control valve opening command, it is output as ei2 = 1.

In the high water level controller 38B, the corresponding normal water level control valve state signal is ei = {1,0}, that is, the actual opening signal di is smaller than the normal water level control valve opening command signal bi. , The drain water level is the normal water level setting signal i
Since it further increases, the gain mi proportional to the increase is set.

On the other hand, when ei = {0, 1}, that is, when the abnormality occurs in which the actual opening signal di is larger than the normal water level control valve opening command signal bi, the drain water level is the normal water level setting signal i.
Since the water level drops further, it is not necessary to control the water level with the high water level control valve, so the gain mi = 1 is set.

Also, when the normal water level control valve status signal ei of the other upstream feed water heater is input, an appropriate gain setting is made in the same way, but in the case of a failure in the excessive opening direction, the drain is drained. Since the inflow amount temporarily increases and then becomes constant, the gain is temporarily increased.

Further, the further the distance from the self-contained water heater, the less the influence on the drain water level fluctuation of the self-contained water heater due to the abnormality. Therefore, the gain setting mi with respect to the normal water level control valve state signal ei is set so that m1 <m2 <m3 ... Try to delay.

Also, a plurality of normal water level control valve status signals ei
For input, set the gain more appropriately than the combination. For example, the status signal e of the normal water level control valve of the self-contained water heater described above.
In the case of i = {1,0} and the combination with the state signal ei = {1,0} of the normal water level control valve of the feed water heater at the upper stage, the normal water level of the self-supplied water heater is as described above. The gain m1 = 1 for the state of the control valve, and the direction of the inflow drain from the upper stage decreases when the normal water level control valve of the feed water heater at the upper stage malfunctions in the direction of insufficient opening. Therefore, after all, the water level control by the high water level control valve is unnecessary,
The gain m2 = 1.

As a result, the gain setting m depending on the combination
Becomes m = 1 by m1 × m2. That is, when a plurality of normal water level control valve status signals ei are input, it can be calculated by multiplying each gain set by the status of each ei. The normal water level control valve status signal e
i = {0,0}, that is, the gain setting mi in the normal state is mi = 1.

At the same time, in order to prevent the normal water level controller from being saturated in the valve fully open command output direction or the valve fully close command output direction, the normal water level control valve status signal ei1 or e
When either of i2 is 1, the gain output 1 of the gain setter 43 is set to 0.

As described above, by inputting the opening signal of the normal water level control valve and monitoring the operating state, the water level control by the high water level control valve is smoothly performed when the normal water level control valve of the self-contained water heater is abnormal. By inputting the normal water level control valve status signal of the other feed water heaters in the same series where the fluctuation of the drain quantity affects each other, the normal water level predicted the fluctuation of the drain quantity due to the abnormal state of each normal water level control valve. Control valve control and high water level control valve control can be performed.

Even in a plant fluctuation state such as a turbine trip, the normal water level control valve or the high water level control valve is fully opened to surely drain the drain water in the heater to the outside of the water heater. Can be secured. Furthermore, conventionally, even if the normal water level control valve became abnormal, it could not be detected until the water level control became abnormal, but it is possible to detect the abnormality early by monitoring the operating state, and the normal water level controller Saturation can also be prevented.

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

FIG. 4 shows the conventional example and FIG. 1 showing the first embodiment, the same reference numerals denote the same or corresponding portions, and the main difference from FIG. 4 is that the normal water level controller is used. Three
7A, 37B, etc. are multiplexed and multiplexed Normal water level controller 4
9A, 49B, 49C, and high water level controller 38
A, 38B, etc. are multiplexed to form a multiplexed high water level controller 50.
A, 50B, and 50C, and additionally a voter device 51 for switching a plurality of opening command signals from these controllers.

Here, the multiplexed normal water level controller 49A, 4
9B and 49C are normal water level controllers 37A and 3 shown in FIG.
7B, which is equivalent to 7B and is stored in one storage unit by a CPU or the like, is tripled. As for the multiplexed high water level controllers 50A, 50B, 50C, as shown in FIG. 5, those equivalent to the high water level controllers 38A, 38B, 38C shown in FIG. It is a tripled version.

The voter 51 is a multiplexed normal water level controller 4
9A, 49B and 49C respectively output an opening command signal which is in the middle of the three opening command signals and outputs it to the corresponding normal water level control valves 16A, 16B and 16C, and
The multiplex high water level controllers 50A, 50B, and 50C output an opening command signal intermediate between the three opening command signals to the corresponding high water level control valves 18A, 18B, and 18C.

With the above configuration, the output signals b11 to b11 from the multiplexed normal water level controllers 49A, 49B and 49C of the same configuration are provided.
b13, b21 to b23, b31 to b33 are selected by the respective voter units 51 by a known intermediate value selection method, and the opening command signals b1. b2 and b3 are normal water level control valves 1
It is output to 6A, 16B and 16C, respectively. In this case, even if one of the multiplex normal water level controllers 49A, 49B, 49C fails, the normal remaining two will remain due to the intermediate value selection method or the like.
An output signal of one of the units is output as the opening degree instruction signal bi. This is the same when the multiplex high water level controllers 50A, 50B, 50C corresponding to each feed water heater fail.

Further, the multiplexed normal water level controllers 49A, 49
B, 49C and multiplexed high water level controller 50A, 50B, 50
It is configured so that C and C exert an independent function. As a result, even if the multiplexed normal water level controllers 49A, 49B, 49C and related functions should lose their functions, the high water level control valves 18A, 18A, Opening / closing control of 18B and 18C is performed.

As described above, the normal water level control valve control and the high water level control valve control that predict the fluctuation of the drain amount due to the abnormal state of each normal water level control valve are performed, and the normal water level control valve is operated in the abnormal state of the plant such as the turbine trip. Alternatively, since the high water level control valve is fully opened and the drain water in the feed water heater is reliably discharged to the outside of the device, the soundness of the feed water heater can be ensured. Moreover, the normal water level control means and the high water level control means are multiplexed, and even if one of these control means fails, it is switched to the output signal of the other control means. Therefore, the control means is reliable, more compact than the conventional one-loop controller, and the number of external input / output points is reduced.

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

FIG. 6 differs from FIG. 4 showing the second embodiment in that the multiplex normal water level controllers 49A, 49B and 49C and the multiplex high water level controllers 50A, 50B and 50C are replaced by multiplex water levels. That is, the controllers 52A and 52B are provided, the voter device 53 is provided instead of the voter device 51, and the multiplexing input / output devices 54A and 54B, the monitor 55, and the switch 56 are additionally provided.

Here, the multiplexed water level controllers 52A and 52B
In the above, a plurality of normal water level controllers and a high water level controller having the same structure are housed in the respective controllers and are duplicated. The boat unit 53 is a multiplex water level controller 52A, 5 under predetermined conditions.
The two output signals from 2B are switched to one and output to corresponding normal water level control valves 16A, 16B, 16C or high water level control valves 18A, 18B, 18C.

The multiplexing input / output units 54A and 54B process the duplicated input / output signals. Monitor 55
Is for switching to the normal opening degree command signal ai from the multiplexed water level controllers 52A and 52B when an abnormality occurs in the multiplexed water level controllers 52A and 52B. Switch 56
Outputs the opening command signal ai at the normal time, and when the high water level control valve full-open command hi is input from the monitor 55, outputs the full-open signal as the high water level control valve opening command signal gi after selection. .

With the above configuration, the multiplexing input / output units 54A, 5A
The output signal from 4B is input to the voter unit 53 and appropriately selected to output the opening command signals a1, a2, a3 of the high water level control valves 18A, 18B, 18C. Boater 53
In the case of the triple configuration, the same intermediate value selection as in the case of the voter 51 shown in FIG. 4 can be used, but in the case of the double configuration, the switching method may be used as shown in FIG.

That is, the voter device 53 inputs one signal from the multiplexed input / output devices 54A and 54B, and when an abnormality is detected by the signal check circuits SC1 to SC3, the changeover switch S53 is switched to the normal input side. , Also manually selected. As a result, the high water level control valve opening command ai is input from the voter 53 to the switch 56.

In the changeover device 56, as shown in FIG. 8, the normal high water level control valve opening command ai is set by the changeover switch S56.
Is selected and output as a high water level control valve opening command signal gi after selection.

For example, the multiplexed water level controllers 52A and 52B
If all of the normal water level control valves and the high water level control valves become uncontrollable due to simultaneous failure of the
As a result, the monitor 55 detects an uncontrollable state and outputs a high water level control valve fully open command hi (fully open command hi is ON).
When the high water level control valve full open command hi is input from the monitor 55 (hi = ON), the changeover switch S56 is used to switch to the full open command side, and after selection the high water level control valve opening command signal g
It is output as i.

As described above, the normal water level control valve control and the high water level control valve control that predict the fluctuation of the drain amount due to the abnormal state of each normal water level control valve are performed, and the normal water level control valve is operated in the abnormal state of the plant such as the turbine trip. Alternatively, since the high water level control valve is fully opened and the drain water in the feed water heater is reliably discharged to the outside of the device, the soundness of the feed water heater can be ensured. Moreover, the normal water level control means and the high water level control means are multiplexed, and even if one of these control means fails, it is switched to the output signal of the other control means. Therefore, the control means is reliable, more compact than the conventional one-loop controller, and the number of external input / output points is reduced.

In the third embodiment shown in FIG. 6, the monitor 55 is arranged so as to correspond to the multiplex water level controllers 52A and 52B. The same operation and effect can be obtained even if the monitor is installed on the table.

In this case, the high water level control valve full-open command hi from the monitor also outputs multiple outputs, so that the high water level control valve opening command signal gi after selection is input to the switch by switching the voter. . With such a configuration, the number of monitors can be reduced, and at the same time, a highly reliable water level control device for the feed water heater can be obtained by multiplexing the monitors themselves.

[0073]

As described above, the first aspect of the invention can control the normal water level control valve and the high water level control valve in which the fluctuation of the drain amount is predicted based on the valve state signal of the normal water level control valve. . Further, the normal water level control valve or the high water level control valve is fully opened by the plant abnormality signal, and the drain water in the heater is reliably discharged to the outside of the heater, so that the soundness of the feed water heater can be ensured.

The second aspect of the present invention performs the normal water level control valve control and the high water level control valve control which predict the fluctuation of the drain amount due to the abnormal state of each normal water level control valve, and the normal water level control in the plant abnormal state. The valve or the high water level control valve is fully opened to drain the drain water inside the feed water heater to the outside reliably, so that the soundness of the feed water heater can be ensured and the normal water level control means and high water level The control means is multiplexed, the control means is reliable, and it is more compact than the conventional one-loop controller arranged in large numbers, and the number of external input / output points is reduced, which is simple.

A third aspect of the present invention performs normal water level control valve control and high water level control valve control that predict fluctuations in the drain amount due to an abnormal state of each normal water level control valve, and when the normal water level control valve Since the high water level control valve is fully opened and the drain water in the feed water heater is reliably discharged to the outside of the device, the soundness of the feed water heater can be ensured and the normal water level control means and the high water level control means can be secured. And are integrally multiplexed, the control means is reliable, it is more compact than the conventional one-loop controller arranged in large numbers, the number of external input / output points is reduced, and the management and operation are easy.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a water level control device for a feed water heater showing a first embodiment of the present invention.

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

FIG. 3 is a configuration diagram showing the high water level controller of FIG. 1.

FIG. 4 is a configuration diagram of a water level control device of a feed water heater showing a second embodiment of the present invention.

5 is a block diagram showing the multiplex high water level controller of FIG. 4;

FIG. 6 is a configuration diagram of a water level control device of a feed water heater showing a third embodiment of the present invention.

7 is a block diagram showing the voter of FIG.

FIG. 8 is a block diagram showing the switch of FIG.

FIG. 9 is a system diagram of a nuclear reactor.

FIG. 10 is a system diagram of a feed water heater.

FIG. 11 is a configuration diagram of a water level control device for a feed water heater showing a conventional example.

12 is a configuration diagram showing the high water level controller and the normal water level controller of FIG. 11. FIG.

FIG. 13 is a configuration diagram of a water level control device for a feed water heater showing another conventional example.

14 is a configuration diagram showing the prediction controller of FIG. 13. FIG.

[Explanation of symbols]

 7A-7I Low pressure feed heater 8A-8D High pressure feed heater 15A-15D, 16A-16I Normal water level control valve 17A-17D, 18A-18I High water level control valve 19A, 19B Water level detector 20A, 20B Normal water level controller 21A , 21B High water level controller 28, 29 Adder / subtractor 30 Adder 31 Operator 32 Controller 35A, 35B Opening detector 36 Interlock board 37A, 37B Normal water level controller 38A, 38B, 38C High water level controller 40 Changer 41 Selector 42 Monitor 43 Gain Setter 44 Multiplier 49A, 49B, 49C Multiplexing Normal Water Level Controller 50A, 50B, 50C Multiplexing High Water Level Controller 51 Boater 52A, 52B Multiplexing Water Level Controller 54A, 54B Multiplexing I / O device 55 Monitoring device 56 Switching device

Claims (6)

[Claims] 1. A plurality of water supply rows in which heat exchangers incorporated in adjacent water supply heaters of a plurality of water supply heaters arranged in multiple stages from an upper stage to a lower stage are sequentially connected through a water supply pipe, and a plurality of these water supply rows are provided. At least the upper side and the lower side of the water supply line are joined together, and water is supplied from the condenser to the heat exchanger of the feed water heater from the lower stage to the upper stage by the condensate pump, and heat exchange with the extracted air supplied from the turbine is performed. While connecting the system and the feed water heater on the upper stage side and the feed water heater on the lower stage side which are arranged adjacent to each other by a drain pipe via a normal water level control valve, the inlet side of the normal water level control valve of the drain pipe A branch drain pipe branched from the above is connected to the condenser via a high water level control valve, the drain pipes connected to the lowermost feed water heaters of the respective water supply lines are joined, and condensed drain water is returned to the condenser. Discharge to water bottle A drain water heater water level control device including a normal water level controller and a high water level controller for controlling the water level of the drain water in each of the water heaters arranged in the water heater heating system. In the above, each of the normal water level controllers, means for outputting a valve status signal by monitoring the valve status of the corresponding normal water level control valve, and the upper level adjacent to the water level detection signal of the corresponding water heater. The opening command signal is output to the normal water level control valve based on the water level detection signal of the feed water heater and the valve state signal of the normal water level control valve, while the opening command signal is normally opened as a full-open signal due to a plant abnormality signal. A means for outputting to a water level control valve, each of the high water level controllers, the water level detection signal of the corresponding feed water heater and the water level detection signal of the adjacent upper feed water heater and the normal water level An opening command signal is output to the high water level control valve based on the valve state signal of the node valve, and a means for outputting the opening command signal to the normal water level control valve as a fully open signal by a plant abnormality signal is provided. A water level control device for a water heater. 2. Each of the normal water level controllers has a deviation signal between a water level detection signal and a water level setting signal of a corresponding water heater and a deviation between a water level detection signal and a water level setting signal of an adjacent upper feed water heater. Means for outputting a signal obtained by subjecting the output signal obtained by multiplying the addition signal of the prediction signal based on the signal by the control gain to the opening instruction signal, and the actual opening signal of the normal water level control valve And a monitoring means for detecting an abnormality of the normal water level control valve from the opening command signal and outputting a valve state signal, and a normal state corresponding to the valve state signal and at least a feed water heater arranged adjacently from the upper stage to the lower stage. Gain setting means for inputting valve state signals of the water level control valve and changing the setting of the control gain so as to suppress a sharp drop in the water level detection signal of the feed water heater according to these valve state signals, And a means for outputting the opening instruction signal to the normal water level control valve as a full-open signal when a fault abnormality signal is input, each of the high water level controllers is a water level detection signal of a corresponding water heater. It is obtained by subjecting the output signal obtained by multiplying the addition signal of the deviation signal with respect to the water level setting signal and the predicted signal based on the water level detection signal of the adjacent upper feed water heater and the water level setting signal by the control gain to a predetermined arithmetic processing. A means for outputting a signal to the high water level control valve as the opening degree command signal, and a valve state signal from the normal water level control valve corresponding to the valve state signal and at least the feed water heater adjacently arranged from the upper stage to the lower stage. Input, gain setting means for changing the setting of the control gain so as to suppress a sharp rise of the water level detection signal of the feed water heater according to these valve state signals, and a plant abnormality signal 2. The water level control device for the feed water heater according to claim 1, further comprising means for outputting the opening degree instruction signal to the high water level control valve as a fully open signal when inputting. 3. A plurality of water supply rows in which heat exchangers incorporated in adjacent water supply heaters of the water supply heaters arranged in multiple stages from the upper stage to the lower stage are sequentially connected through water supply pipes, and a plurality of these water supply rows are provided. At least the upper side and the lower side of the water supply line are joined together, and water is supplied from the condenser to the heat exchanger of the feed water heater from the lower stage to the upper stage by the condensate pump, and heat exchange with the extracted air supplied from the turbine is performed. While connecting the system and the feed water heater on the upper stage side and the feed water heater on the lower stage side which are arranged adjacent to each other by a drain pipe via a normal water level control valve, the inlet side of the normal water level control valve of the drain pipe A branch drain pipe branched from the above is connected to the condenser via a high water level control valve, the drain pipes connected to the lowermost feed water heaters of the respective water supply lines are joined, and condensed drain water is returned to the condenser. Discharge to water bottle In a water level controller for a water heater provided with a normal water level controller and a high water level controller for controlling the water level of the drain water in each of the water heaters arranged in the water heater including a drain discharge system The normal water level control device is any one of m output signals output from m normal water level control means corresponding to each of the n normal water level control valves arranged in the feed water heating system. Is provided to output an opening degree instruction signal to the corresponding normal water level control valve, and the high water level control device is
One of the m output signals output from the m high water level control means corresponding to each of the high water level control valves is selected and the opening command signal is output to the corresponding high water level control valve. And a normal water level control means for accommodating a predetermined number of normal water level controllers for outputting the output signals respectively corresponding to the n normal water level control valves. The water level control device for a feed water heater, wherein the high water level control means collectively stores a predetermined number of high water level controllers each of which outputs the output signal corresponding to the n high water level control valves. 4. Each of the normal water level controllers has a deviation signal between a water level detection signal of a corresponding feed water heater and a water level setting signal, and a deviation between a water level detection signal and a water level setting signal of an adjacent upper feed water heater. Means for outputting a signal obtained by subjecting the output signal obtained by multiplying the addition signal of the prediction signal based on the signal by the control gain to the output signal as the output signal;
Monitoring means for detecting an abnormality of the normal water level control valve from the actual opening signal of the normal water level control valve and the selected opening command signal and outputting a valve status signal, the valve status signal and at least the upper stage Input the valve status signal of the normal water level control valve that corresponds to the feed water heater that is arranged adjacent to
Gain setting means for changing the setting of the control gain so as to suppress a sharp drop in the water level detection signal of the feed water heater according to these valve state signals, and when a plant abnormality signal is input, the output signal is a full open signal. While each of the high water level controller is provided with a means for outputting as a deviation signal between the water level detection signal and the water level setting signal of the corresponding feed water heater and the water level detection signal and the water level setting of the adjacent upper feed water heater. Means for outputting a signal obtained by subjecting the output signal obtained by multiplying the addition signal of the prediction signal based on the signal and the control gain by the control gain as the output signal, and the valve state signal and at least the upper stage to the lower stage. A valve state signal from a normal water level control valve corresponding to the water heater to be arranged is input, and the water level detection signal of the water heater is rapidly detected according to these valve state signals. 4. The gain setting means for changing the setting of the control gain so as to suppress the increase, and the means for outputting the output signal as a full open signal when a plant abnormality signal is input. Water level controller for water heater. 5. A plurality of water supply rows in which heat exchangers incorporated in adjacent water supply heaters of the water supply heaters arranged in multiple stages from the upper stage to the lower stage are sequentially connected through water supply pipes are provided, and a plurality of these water supply rows are provided. At least the upper side and the lower side of the water supply line are joined together, and water is supplied from the condenser to the heat exchanger of the feed water heater from the lower stage to the upper stage by the condensate pump, and heat exchange with the extracted air supplied from the turbine is performed. While connecting the system and the feed water heater on the upper stage side and the feed water heater on the lower stage side which are arranged adjacent to each other by a drain pipe via a normal water level control valve, the inlet side of the normal water level control valve of the drain pipe A branch drain pipe branched from the above is connected to the condenser via a high water level control valve, the drain pipes connected to the lowermost feed water heaters of the respective water supply lines are joined, and condensed drain water is returned to the condenser. Discharge to water bottle In the water level control device of the feed water heater for controlling the water level of the drain water in each of the feed water heaters arranged in the feed water heating system consisting of the drain discharge system to be Normally, one of the m output signals output from the m water level control means is selected for each of the normal water level control valve and the n high water level control valves to correspond to the opening command signal. A water level control valve and means for outputting to the high water level control valve are provided in a multiplexed configuration, and the water level control means corresponds to the n normal water level control valves and the n high water level control valves, respectively. A predetermined number of water level controllers for outputting is stored together, and when the m water level control means are monitored and an abnormality occurs, a monitoring means for outputting a high water level control valve fully open command and a normal time are selected. The above A switching means is provided for outputting the opening command signal to the corresponding high water level control valve, and when the high water level control valve full open command is input, outputting the opening command signal as a fully open signal to the corresponding high water level control valve. A water level control device for a water heater. 6. Among the respective water level controllers, a water level controller for controlling the normal water level control valve has an upper stage adjacent to a deviation signal between a water level detection signal and a water level setting signal of a corresponding feed water heater. Means for outputting, as the output signal, a signal obtained by subjecting an output signal obtained by multiplying an addition signal of a prediction signal based on a deviation signal between the water level detection signal of the feed water heater and the water level setting signal by a control gain to a predetermined arithmetic processing A means for detecting an abnormality of the normal water level control valve from the actual opening signal of the normal water level control valve and the opening command signal and outputting a valve status signal; and the valve status signal and at least from the upper stage to the lower stage. The valve state signals from the normal water level controller corresponding to the feed water heaters arranged adjacently are input, and the control is performed so as to suppress a sharp drop of the water level detection signal of the water heater according to these valve state signals. Gay Gain setting means for changing the setting of the water level, and means for outputting the output signal as a fully open signal when a plant abnormality signal is input, while controlling the high water level control valve in each of the water level controllers. The water level controller controls the addition signal of the deviation signal between the water level detection signal of the corresponding water heater and the water level setting signal and the prediction signal based on the water level detection signal of the adjacent upper water heater and the water level setting signal. Means for outputting a signal obtained by subjecting the output signal multiplied by the gain to a predetermined arithmetic processing, as the output signal, and the normal water level adjustment corresponding to the valve state signal and at least the feed water heater adjacently arranged from the upper stage to the lower stage And a valve state signal of a valve, and a gain for changing the setting of the control gain so as to suppress a sharp rise of the water level detection signal of the feed water heater according to these valve state signals. 6. The water level control device for a feed water heater according to claim 5, further comprising: an input setting unit; and a unit that outputs the output signal as a fully open signal when a plant abnormality signal is input.