JPH06341607A - Water supply control device - Google Patents

Abstract

PURPOSE:To embody a water supply control device which suppresses malfunction and trips a water feed pump by detecting accurately its abnormel condition to avoid the stoppage of the operation of a power plant. CONSTITUTION:In a treating part 25 for treating an abnormal feed water flow amount, when the opening degree of a governor valve 7 becomes small due to the trouble of a water supply control device, etc., a valve opening degree signal 202 decreases and a valve opening degree signal 203 increases. A deviation occurs between the signals 202 and 203 and a computing element 112 outputs a minus opening degree deviation signal 206 to a comparator 109. When the signal 206 goes over a predetermined value, a large deviation signal 207 is output from the comparator 109. The signal 207 is output through OR circuit 104 to AND circuit 101. A judging computing element 231 outputs a low nuclear reactor water level signal 201. A pump starting signal 210 is output by the AND conditions of the large deviation signal 207 and the low signal 201 to start a water feed pump. The signal 207 output from the comparator 109 is delayed by TPU 115 and output to an AND circuit 102 and, by the AND conditions of the signals 201 and 207, a trip signal 212 is output to trip an abnormal water feed pump 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply controller for a boiling water reactor, a pressurized water reactor or a thermal power plant.

[0002]

2. Description of the Related Art A conventional water supply control apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-116804, in which a turbine-driven water supply pump driven by a steam turbine and an electric motor-driven water supply pump which is a standby machine are used. And are provided. A control mechanism is provided for detecting the cause of the decrease in the flow rate of water supplied by the turbine-driven water supply pump and tripping the steam turbine. FIG. 9 is a system diagram of an example of a conventional water supply control device. In FIG. 9, two turbine-driven feed water pumps 11 and 12 are driven by the reactor, and are automatically operated by the reactor feed water control device 16. During this automatic operation, the speeds of the steam turbines 9 and 10 are detected by the speed detectors 18 and 19, and turbine speed signals 214 and 215 are output. Then, the turbine speed signal 214 of the steam turbine and the reactor water supply control device 1
The difference from the feed water flow rate signal 216a output from the control unit 6 is added / subtracted by the addition / subtraction calculator 112a, and the absolute value signal 217a of the difference is supplied to the comparator 108a. In the comparator 108a, the signal 217a is compared with the set value,
When the set value is exceeded, the abnormal signal 218a is output.

Further, the turbine speed signals 214 and 215 of both steam turbines 9 and 10 are added / subtracted by an adder / subtractor calculator 112b, and an absolute value signal 217b of the difference is supplied to a comparator 108b. Then, the signal 217b is compared with the set value in the comparator 108b, and when the set value is exceeded, the abnormal signal 218b is output. When both abnormal signals 218a and 218b are output at the same time, AN
The trip signal 219 is supplied from the D circuit 101 to the trip dump valve 28. The dump valve 28 controls the supply of hydraulic oil to the steam control valve of the steam turbine 9 that drives the turbine drive water supply pump 11, and causes the steam turbine to trip by the trip signal 219. The above-described example is an example of performing water supply control by using the speed signal of the steam turbine, and similar control can be performed by using the suction flow rate and the discharge flow rate instead of the speed signal.

[0004]

In the above-mentioned prior art, the presence or absence of an abnormality is confirmed by adjusting the deviation of any of the suction flow rate, the discharge flow rate, and the rotational speed of the A-system and B-system turbine drive feed water pumps. In addition, an abnormal pump is presented by the reference signal which is the output of the water supply control device or the main steam flow rate. If the water supply control device or a similar control device fails and an abnormal water supply flow rate signal is output,
An abnormal turbine-driven feed pump cannot be presented because the feed water flow rate signal, which is the reference signal, is abnormal. as a result,
If this state continues, the reactor water level may drop and the power plant may stop because the supply flow rate of water supplied to the reactor is insufficient.

Similarly, the main steam flow rate is used as a reference signal for abnormality determination of the turbine driven feed water pump, and when the main steam flow rate itself is fluctuating during load following operation such as daily load following or AFC, the abnormality can be judged. However, the trip of the turbine-driven feed water pump may be delayed, and the reactor water level may drop and the power plant may stop. That is, in the prior art, the reference signal for determining the abnormal turbine driven feed pump,
For example, there is a problem in using the feedwater flow rate signal and the main steam flowrate signal, and if the reference signal fluctuates, an abnormal turbine-driven feedwater pump cannot be presented together, causing a drop in the reactor water level. The nuclear power plant may shut down.

FIG. 10 shows the behavior of the turbine driven feed water pump when the reactor water level rises in the prior art, and the behavior of the turbine driven feed water pump when the reactor water level rises is shown using the system diagram of the prior art in FIG. This will be described below. Water supply control device 1
6 or a control device failure corresponding thereto causes the feed water flow rate signal 216 to become abnormal, and as shown in FIG. 10 (A), the feed water flow rate signal 21 on the turbine drive water feed pump 11 side.
When 6a rises, the speed S11 of the steam turbine 9
Also rises following the water supply flow rate signal 216a. Further, since the feed water flow rate signal 216b of the turbine driven feed water pump 12 holds a predetermined feed water flow rate, the speed of the steam turbine 10 is reduced to try to maintain a constant feed water flow rate. But,
Speed signals 214 of A and B steam turbines 9 and 10,
Since the speed deviation is generated in 215, when the absolute value 217b of the speed deviation exceeds the set value of the comparator 108b at a certain time, the abnormal signals 218b of the two turbine driven water feed pumps are output.

However, the system A feed water flow rate signal 216
Since there is no deviation between the speed signal 214 and the speed signal 214 of the steam turbine, the AND condition is not satisfied, and the turbine drive feed water pump 11 cannot be tripped. Therefore, as shown in FIG. 10B, the reactor water level rises. However, there is a risk that the turbine trips and the nuclear power plant shuts down.

FIG. 11 shows the behavior of the turbine-driven feed water pump when the reactor water level drops, and the behavior of the turbine-driven feed water pump when the reactor water level rises will be described below with reference to the conventional system diagram of FIG. When the feedwater flow rate signal becomes abnormal due to a failure of the feedwater control device 16 or a control device equivalent thereto, and as shown in FIG. 11 (A), the feedwater flow rate signal 216a of the turbine-driven feed water pump 11 decreases.
The speed S11 of the steam turbine 9 also decreases following the feedwater flow rate signal 216a. In addition, the turbine driven water supply pump 12
The feed water flow rate signal 216b of (1) increases the speed S12 of the steam turbine 10 in order to maintain a predetermined feed water flow rate, and tries to maintain a constant feed water flow rate. However, since speed deviations occur in the speed signals 214 and 215 of the A and B steam turbines 9 and 10, when the absolute value 217b of the speed deviation exceeds the set value of the comparator 108b at a certain time. ,
The abnormal signals 218b of the two turbine-driven feed water pumps are output.

However, the system A feed water flow rate signal 216
Since there is no deviation between a and the speed signal 214 of the steam turbine, the AND condition is not satisfied, and the turbine drive feed water pump trip is impossible. Further, from the viewpoint of pump protection, the upper limit of the feed water flow rate that can be supplied by one turbine drive water feed pump is limited in terms of control, so that the turbine drive water feed pump 11 is eventually limited to a certain flow rate. Therefore, the reactor water level may drop and the nuclear power plant may stop.

FIG. 12 shows the behavior of the turbine-driven feed water pump of the prior art during load following, and FIG. 13 shows a system diagram of another example of the prior art. In this conventional technique, the main steam flow rate and the absolute value of the difference between the discharge flow rates of the two turbine-driven feed water pumps are controlled, but the main steam flow rate during load following operation such as AFC (automatic frequency control) operation Is always ±
It has changed by about 5%. During this load following operation, as shown in FIG.
(A), if the discharge flow rate of the turbine drive water feed pump 12 decreases due to some abnormality, the discharge flow rate of the turbine drive water feed pump 11 increases in an attempt to maintain a predetermined water supply flow rate. However, as shown in FIG. 12B, since the main steam flow rate is constantly changing, there is no deviation between the main steam flow rate signal 221 and the discharge flow rate signal 220 of the turbine drive feed water pump 12. Therefore, the abnormality detection of the turbine drive water feed pump 12 is delayed, and during that time, as shown in FIG. 12C, the reactor water level may be lowered, and the nuclear power plant may be stopped. Further, when the turbine drive feed water pump 11 increases the discharge flow rate and tries to keep the feed water flow rate constant, a deviation occurs between the turbine drive feed water pump 11 and the main steam flow rate signal 221. Further, two turbine driven water supply pumps 11 and 12
Since the absolute value 217b of the discharge flow rate deviation is large, the normal turbine drive water supply pump 11 may accidentally trip.

An object of the present invention is to realize a water supply control device in which malfunctions are suppressed, an abnormality of a water supply pump is reliably detected and tripped, and an operation stop of a power generation plant can be avoided.

[0012]

In order to achieve the above object, the present invention is configured as follows. Controls water supply of a plant having a steam generator, a plurality of steam turbines, a plurality of turbine-driven water supply pumps, and a motor-driven water supply pump that is a standby machine, and drives a motor when a turbine-driven water supply pump is tripped. In the water supply control device for starting the water supply pump, the water level detector in the steam generator, the change amount detecting means for detecting the change amount corresponding to the rotation speed of each steam turbine, and the detection signal of the change amount detecting means. ,
An arithmetic unit that calculates the deviation of the variation between each steam turbine,
Based on the water level signal from the steam water level detector and the deviation signal from the calculator, the turbine drive feed water pump that has an abnormality is identified, and a determination means that supplies a trip signal to the abnormal turbine drive water feed pump and the water level detection A standby machine starting means for supplying a starting signal to the electric motor drive water feed pump based on the water level signal from the vessel and the deviation signal from the calculator.

Preferably, in the water supply control device,
When the water level detector outputs a signal indicating a drop in the water level, the determining means delays the standby machine from the standby machine start-up means by a predetermined time, and outputs a trip signal to the abnormal turbine drive water supply pump. Supply. Also, preferably,
In the water supply control device, when the signal indicating the water level rise is output from the water level detector, the standby machine starting means, from the determining means, after the trip signal is supplied to the turbine drive water supply pump in which the abnormality has occurred, A water supply control device which starts a standby machine after a predetermined time delay.

Further, preferably, in the above water supply control device, when the water level detector outputs a signal indicating a drop in water level, the determining means delays the standby machine from the startup of the standby machine by a predetermined time. If a trip signal is supplied to the turbine drive water pump that has become abnormal and the water level detector outputs a signal indicating that the water level has risen, the standby unit start-up means determines from the determination means that the turbine drive After the trip signal is supplied to the water supply pump, the standby machine is started with a predetermined delay. Further, preferably, in the water supply control device, the predetermined time delay is a delay time of 1 second or more.

Preferably, in the water supply control device, the amount of change corresponding to the rotation speed of the steam turbine is the suction flow rate of the turbine driven water supply pump. Further, preferably, in the water supply control device, the amount of change corresponding to the rotation speed of the steam turbine is the discharge flow rate of the turbine-driven water supply pump. Further, preferably, in the water supply control device, the amount of change corresponding to the rotation speed of the steam turbine is the opening degree of the steam control valve of the steam turbine.

[0016]

When the water level signal from the water level detector indicates a drop or rise in the water level, the discriminating means accurately discriminates the abnormal turbine drive water supply pump based on the deviation signal from the calculator. Then, a trip signal is supplied to the abnormal turbine drive water supply pump to stop the abnormal pump. In addition, when the water level signal from the water level detector indicates a decrease in water level, if an abnormal water supply pump is determined, the motor-driven water supply pump that is a standby machine is activated, and after a predetermined time delay, an abnormal water supply pump is activated. A trip signal is supplied to the feed pump. Therefore, the recovery of the water level of the steam generator is preceded by the standby machine, and then the abnormal water supply pump is stopped. Also, if the water level signal from the water level detector indicates a rise in water level, if an abnormal water supply pump is determined, a trip signal is supplied to the abnormal water supply pump, and after a predetermined time delay, the standby machine An electric motor driven water feed pump is started. Therefore, the rise of the water level of the steam generator is first suppressed, and then the standby machine is operated. Therefore,
The water level in the steam generator is maintained at a stable level, the power plant is prevented from being stopped, and stable plant operation can be continued.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings, taking a nuclear power plant as an example.

FIG. 1 is an overall schematic configuration diagram of a nuclear power plant which is an embodiment of the present invention. In FIG. 1, steam generated from a nuclear reactor 1 (steam generator) passes through a main steam pipe 2 to drive a steam turbine 3 for power generation, and a generator (not shown) is driven to generate power. The steam that has passed through the steam turbine 3 for power generation is returned to water in the condenser 4, passes through the water supply pipe 5, and passes through the turbine-driven water supply pump 1
It is returned to the nuclear reactor 1 again from the water supply pipe 15 via 1 and 12. The water supplied to the nuclear reactor 1 is supplied from the power generation steam turbine 3 through the steam turbine driving pipe 6 and the steam having passed through the water supply pump driving steam control valves 7 and 8 to supply water pump driving steam turbine 9. 10 is driven, and turbine driven water supply pumps 11 and 12 are rotated.

Further, the turbine rotation speed request signals 211A and 211B from the water supply control device 16 are transmitted to the turbine control device 1.
It is output to 7A and 17B. Then, in the turbine control devices 17A and 17B, the turbine rotation speed request signal 2
The control valve opening request signals 205A and 205B are generated from the deviation of the actual rotational speed from 11A and 211B, and the steam control valves 7 and 8
Is output to. The control valve opening / closing request signals 205A, 20
The steam control valves 7 and 8 are controlled by 5B, and the flow rate of steam to the feed water pump driving steam turbines 9 and 10 is adjusted.

In the embodiment of the present invention, the abnormal water supply flow rate processing unit 25 is provided with the turbine driven water supply pumps 11 and 12 described above.
The abnormality of the turbine driven feed water pumps 11 and 12 is detected by the deviation of any of the suction flow rate, the discharge flow rate, the turbine rotation speed or the steam control valve opening degree and the reactor water level. Then, by promptly tripping the pump on the abnormal side and automatically starting the electric motor drive water supply pump, it is possible to stabilize the flow rate of the water supply and to continue the operation of the power generation plant.

FIG. 2 shows a processing section 25 for abnormal supply water flow rate shown in FIG.
This is an example of the configuration, in which the control valve openings and the reactor water level signals of the two feed water pump driving steam control valves 7 and 8 are input. In FIG. 2, the abnormal supply water flow rate processing unit 25 includes a control valve opening / closing signal 20 for each of the drive steam control valves 7, 8 detected by the opening detectors 20, 21 (change amount detection means).
2, 203 and the reactor water level signal 230 detected by the reactor water level gauge 24 are input. Then, the control valve opening / closing signals 202 and 203 are compared by the control calculator 112, and the reactor water level signal 230 is judged and calculated by the judgment calculator 231.

Therefore, in the unlikely event that the feed water control device 16 on the upstream side of the turbine-driven feed water pump 11 or a control device 17A corresponding thereto malfunctions, the control valve opening / closing request signal 205A becomes abnormal, and the control signal is lowered to lower the feed water pump. It is assumed that the opening degree of the drive steam control valve 7 has become smaller. In this case, the control valve opening / closing signal 202 on the abnormal side decreases,
The normal side control valve opening / closing signal 203 increases to compensate for the abnormal side control valve opening / closing signal 202. As a result, a deviation occurs between the adjustment valve opening signals 202 and 203, and the adjustment calculator 1
12 outputs an adjustment valve opening deviation signal 206. In this case, since the control valve opening degree of the turbine drive water supply pump 11 is reduced, the control valve opening deviation signal 206 is output as a negative value and compared by the comparator 109 having a negative set value. The adjustment valve opening deviation signal 206 indicates the comparator 10
If the value exceeds the set value of 9, the comparator 109 outputs the large increase / decrease valve opening deviation signal 207. The large increase / decrease valve opening deviation signal 207 is sent to the AND circuit 10 via the OR circuit 104.
It is output to 1.

On the other hand, the turbine-driven feed water pump 12 cannot fully compensate for the decrease in the flow rate of the turbine-driven feed water pump 11, so that the total feed water flow rate drops and the reactor water level signal 230 drops. As a result, the determination calculator 231 determines that the reactor water level has dropped, and outputs the reactor water level low signal 201. The control valve opening deviation large signal 207 and the reactor water level low signal 20
When 1 is satisfied at the same time, the AND condition is satisfied in the AND circuit 101, the electric motor drive water supply pump start signal 210 is output, and the electric motor drive water supply pumps 13 and 14 which are the standby machines are activated.

The adjusting valve opening / closing deviation signal 207 output from the comparator 109 is output to the AND circuit 102 after being held by the time delay pickup (TPU) 115 for a certain period of time, for example, 5 seconds. Then, the AND condition is satisfied together with the reactor water level low signal 201, the turbine drive feed water pump trip signal 212 is output, and the abnormal turbine drive feed water pump 11 is tripped to continue the operation of the nuclear power plant. Can be done.

The time delay pickup 11
From the viewpoints of preventing the reactor water level from decreasing and preventing malfunction, the motors 5 and 114 start the motor-driven water supply pumps 13 and 14 of the standby machine, wait for the reactor water level to recover, and then turn off the abnormal water supply pump. It is added for tripping. The set values of the comparators 108 and 109 are, for example, + 10% and -10% of the standard valve opening, respectively, which are sufficient values for detecting the deviation between the two turbine-driven feed water pumps. Also, when the turbine drive water supply pump 12 becomes abnormal,
The adjustment valve opening deviation signal 206 is output as a positive signal, the adjustment valve opening deviation large signal 207 is output from the comparator 108, and the turbine drive water supply pump trip signal 213 is output, which can be similarly dealt with. The comparators 108 and 109, the time delay pickups 114 and 115, and the AND circuit 10
A discriminating unit is constituted by the reference numerals 2 and 103. Further, the OR circuit 104 and the AND circuit 101 constitute a standby machine starting means.

FIG. 3 is an operation timing chart in the example of FIG. 2, and FIG. 4 is an operation timing chart in the prior art. It is assumed that, out of the two turbine-driven water feed pumps A and B, a water feed control device or a control device corresponding to the water feed pump B side has a failure or abnormality, and the pump B flow rate is reduced ((in FIGS. 3 and 4). (A) shows a water supply pump A, and (B) shows a water supply pump B). In this case, in the conventional technique shown in FIG. 4, in order to compensate for the decrease in the flow rate of the water supply pump B, the flow rate of the water supply pump A is increased and a large flow rate deviation signal between the water supply pumps A and B is output. However, since the large deviation signal between the control signal for the water supply pump B and the rotation speed of the water supply pump B is not output, the water supply pump trip signal and the standby unit start signal are not output, and the reactor water level is the reactor scrum set value. It drops to level 3 ((D) of FIG. 4). However, as shown in FIG. 3, in the present invention, since the deviation between the reactor water level and the turbine driven feedwater pumps A and B is monitored, even if a similar event occurs, the feedwater pumps A and B are The deviation increases.
Furthermore, when the reactor water level drops to a certain value, the abnormal side water supply pump can be judged and tripped ((B) of FIG. 3), and the standby machine can be started early (see FIG. 3). (C)), the reactor scrum can be avoided (D in FIG. 3).

FIG. 5 shows a processing section 25 for abnormal supply flow rate of FIG.
It is another structural example of. The example of FIG. 5 is an example effective when the reactor water level rises due to an abnormality in the turbine-driven feed water pump 11 or 12. In the example of FIG. 5, turbine speed signals 232 and 233 and a reactor water level signal 230 are input. When the turbine drive water supply pump 11 becomes abnormal due to the same factor as in the example of FIG. 2, a deviation occurs in the turbine rotational speeds of the two water supply pumps. Addition / subtraction calculator 1
12 computes turbine speed signals 232, 233,
The rotation speed deviation signal 203 is output. The comparator 110 having a positive set value outputs the large rotational speed deviation signal 204 when the rotational speed deviation signal 203 reaches the set value. The rotation speed deviation signal 204 is output to the AND circuit 105 after being held by the time delay pickup (TPU) 116 for a fixed time, for example, 5 seconds.

On the other hand, the increase in the reactor water level due to the increase in the flow rate of the turbine driven feed water pump 11 is judged by the judgment calculator 231 and the reactor water level high signal 202 is sent to the AND circuit 10.
It is output to 5.

The AND circuit 105 which receives the large rotational speed deviation signal 204 and the reactor water level high signal 202 generates the turbine drive feed water pump trip signal 212 to trip the abnormal side turbine drive feed water pump 11. Further, the turbine drive feed water pump trip signal 212 is supplied to the OR circuit 1
Output to 07, time delay pickup (TPU)
After being held for a certain period by 118, an electric motor drive water supply pump start signal 214 is output to start the electric motor drive water supply pumps 13 and 14 which are standby machines.

As described above, the fluctuation of the reactor water level can be suppressed and the stoppage of the nuclear power plant can be avoided. Further, even when the turbine drive water supply pump 12 becomes abnormal, the turbine drive water supply pump trip signal 213 can be output to deal with it in the same manner. The time delay pickups 116 and 117 are added to prevent malfunction.
The time delay pickup 118 is added to lower the reactor water level and then start the electric motor driven water supply pump that is a standby machine. The set values of the comparators 110 and 111 are, for example, +1 of the standard valve opening degree as a sufficient value for detecting the deviation between the two turbine-driven feed water pumps.
It is set to 0% and -10%.

Further, the comparators 110 and 111, the time delay pickups 116 and 117, the AND circuit 105,
A determination unit is configured by 106. Further, the OR circuit 107 and the time delay pickup 118 constitute a standby device starting means.

FIG. 6 is an operation timing chart in the example of FIG. 5, and FIG. 7 is an operation timing chart in the prior art. It is assumed that, out of the two turbine-driven water feed pumps A and B, a water feed control device or a control device corresponding to the water feed pump B side has a failure or abnormality, and the pump B flow rate has increased ((in FIG. 6 and FIG. 7). (A) shows a water supply pump A, and (B) shows a water supply pump B). In this case, in the conventional technique shown in FIG. 7, in order to compensate for the increase in the flow rate of the water supply pump B, the flow rate of the water supply pump A decreases and the large flow rate deviation signal between the water supply pumps A and B is output. However, since the large deviation signal between the control signal for the water supply pump B and the rotation speed of the water supply pump B is not output, the water supply pump trip signal and the standby unit start signal are not output, and the reactor water level is the reactor upper limit setting value. It rises to level 8 ((D) of FIG. 7). However, as shown in FIG. 6, in the present invention, the deviation between the reactor water level and the turbine-driven feedwater pumps A and B is monitored. The deviation increases. Furthermore, when the reactor water level rises to a certain value, the abnormal side water supply pump can be determined and tripped ((B) in FIG. 6), and the standby machine can be started early (in FIG. 6). (C)), the reactor scrum can be avoided (D in FIG. 6).

FIG. 8 shows an example in which the example of FIG. 2 and the example of FIG. 5 are combined. In this case, when the water level of the reactor 1 is lowered, the determination calculator 231 determines that the reactor water level low signal 201
Is output. Further, the determination calculator 231 outputs the reactor water level high signal 202 when the water level of the reactor 1 rises. Then, in the example of FIG. 8, in the example of FIG.
AND circuits 105 and 106, an OR circuit 107, and a time delay pickup 118 are added. At the input end of the AND circuit 105, the signal 2 from the determination calculator 231 is input.
02 and the signal from the time delay pickup 114 are supplied. Further, at the input end of the AND circuit 106,
The signal 202 from the determination calculator 231 and the signal from the time delay pickup 115 are supplied.

The output signal from the AND circuit 105 is output as the signal 212 and the OR circuit 1
07 is one of the input signals. Also, the AND circuit 10
The output signal from 6 is output as the signal 213 and is also the other input signal of the OR circuit 107. Further, the output signal of the OR circuit 107 is supplied to the time delay pickup 118, and the output signal from the time delay pickup 118 is output as the electric motor drive water feed pump activation signal 210.

According to the example of FIG. 8, when the pump flow rate becomes abnormal when the reactor water level drops and rises, the pump on the abnormal side is accurately judged and tripped, and the standby machine is set to the atomic level. Adapting to the decrease and rise of reactor water level,
It is activated prior to or after the trip.
This makes it possible to avoid shutting down the reactor power plant.

As described above, according to the present invention, the control signal becomes abnormal due to the failure of the water supply control device on the upstream side of the turbine driven water supply pump 11, 12 or a control device corresponding thereto, and the flow rate of the pump 11, 12 is increased. When deviation is detected, the pump on the abnormal side is accurately judged and tripped. Furthermore, the standby machine is started at an appropriate timing. Therefore, it is possible to suppress fluctuations in the reactor water level, avoid operation stoppage of the reactor power plant, and continue operation. Further, in the present invention, since the reactor steam flow rate is not used as an input signal, it is possible to accurately detect the flow rate abnormality of the turbine driven feed water pumps 11 and 12 even during a large load following operation such as daily load following.

The same device can be realized by using either the suction flow rate or the discharge flow rate in place of the steam control valve opening degree and the turbine rotation speed used in the above embodiment. Further, in the above embodiment, the delay time of the time delay pickup is set to, for example, 5 seconds, but the delay time is not limited to 5 seconds and may be a delay time of 1 second or more. Furthermore, although the above-described embodiment is an example in which the present invention is applied to a nuclear power plant, the present invention is not limited to a nuclear power plant, and the present invention can also be applied to, for example, a thermal power plant.

[0038]

Since the present invention is constructed as described above, it has the following effects. In the water supply control device, a water level detector in the steam generator, and a change amount detecting means for detecting a change amount corresponding to the rotation speed of each steam turbine,
Based on the detection signal of the change amount detection means, a calculator for calculating the deviation of the change amount between each steam turbine, based on the water level signal from the steam water level detector and the deviation signal from the calculator,
The motor drive water supply is determined based on the determination means that determines the turbine drive water supply pump that has an abnormality and supplies a trip signal to the abnormal turbine drive water supply pump, and the water level signal from the water level detector and the deviation signal from the calculator. Standby machine starting means for supplying a starting signal to the pump. Therefore,
It is possible to realize a water supply control device in which malfunctions are suppressed, an abnormality in the water supply pump is reliably detected and tripped, and an operation stop of the power generation plant can be avoided.

Further, in the above water supply control device, when the water level detector outputs a signal indicating a drop in the water level, the determination means delays from the activation of the standby equipment by the standby equipment activation means for a predetermined time, and the abnormality occurs. Is configured to provide a trip signal to the turbine driven feedwater pump. With this configuration, when the water level of the steam generator drops, the abnormal water supply pump is stopped after the water level of the steam generator is restored by the standby machine, so it is possible to more reliably prevent the power plant from shutting down. can do.

Further, in the above water supply control device, when the water level detector outputs a signal indicating a rise in the water level, the standby unit starting means sends a trip signal from the discriminating means to the turbine-driven water supply pump in which the abnormality has occurred. It is configured to start the standby machine after a predetermined time delay after being supplied. According to this structure, when the water level of the steam generator rises, first, after the abnormal water supply pump is stopped, the standby machine is started, so it is possible to more reliably avoid the shutdown of the power plant. .

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram of a nuclear power plant that is an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an example of a water supply flow rate abnormality processing unit in the example of FIG.

FIG. 3 is an operation timing chart of the example of FIG.

FIG. 4 is an operation timing chart of a conventional example.

5 is a schematic configuration diagram of another example of the water supply flow rate abnormality processing unit in the example of FIG. 1. FIG.

FIG. 6 is an operation timing chart of the example of FIG.

FIG. 7 is an operation timing chart of a conventional example.

FIG. 8 is a schematic configuration diagram of still another example of the feed water flow rate abnormality processing unit in the example of FIG. 1.

FIG. 9 is a schematic configuration diagram of an example of a water supply control device according to a conventional technique.

FIG. 10 is a graph showing the behavior of the turbine-driven feed water pump when the reactor water level rises in the prior art.

FIG. 11 is a graph showing the behavior of the turbine-driven feed water pump when the reactor water level drops in the prior art.

FIG. 12 is a graph showing the behavior of the turbine-driven feed water pump during load following in the conventional technique.

FIG. 13 is a schematic configuration diagram of another example of the water supply control device in the related art.

[Explanation of symbols]

1 Reactor 2 Main Steam Piping 3 Steam Turbine for Power Generation 4 Condenser 5 Water Supply Piping 6 Steam Turbine Driving Piping 7, 8 Steam Control Valve 9, 10 Steam Pump Driving Water Turbine 11, 12 Turbine Driving Water Pump 13, 14 Electric motor driven water supply pump 15 Water supply pipe 16 Water supply control device 17A, 17B Turbine control device 18, 19 Speed detector 20, 21 Suction flowmeter 22, 23 Discharge flowmeter 24 Water level detector 25 Water supply flow rate abnormal time processing part 101, 102 AND Circuit 103 AND circuit 104, 107 OR circuit 105, 106 AND circuit 108, 109 Comparator 110, 111 Comparator 112 Addition / subtraction calculator 114, 115 Time delay pickup 116, 117 Time delay pickup 118 Time delay pickup 201 Low reactor water level low signal 202 Reactor water level high signal 203 Rotation speed deviation 204 Rotation speed deviation signal 206 Suction flow rate deviation 207 Suction flow rate deviation signal 208 Discharge flow rate deviation 209 Discharge flow rate deviation signal 210 Electric motor drive feed pump start signal 211 Steam control valve opening request signal 212 Turbine Drive water pump trip 1
1 signal 213 Turbine drive water pump trip 1
2 signals

Claims (8)

[Claims] 1. A steam generator, a plurality of steam turbines to which steam from the steam generator is supplied, a plurality of turbine-driven water feed pumps driven by each of the plurality of steam turbines, and an electric motor that is a standby machine. Drive water pump,
In a water supply control device that controls the water supply of a plant having a water supply and starts the electric motor driven water supply pump when the turbine driven water supply pump is tripped, a water level detector for detecting the water level in the steam generator, and each steam turbine Change amount detecting means for detecting the change amount corresponding to the number of revolutions of the engine, a calculator for calculating the deviation of the change amount between the steam turbines based on the detection signal of the change amount detecting means, and a steam water level detector. Of the turbine drive feed water pump in which an abnormality has occurred based on the water level signal of the above and the deviation signal from the arithmetic unit, and a determination means for supplying a trip signal to the turbine drive feed water pump in which the abnormality has occurred; A standby machine starting means for supplying a starting signal to the electric motor drive water supply pump based on the water level signal from the detector and the deviation signal from the arithmetic unit. Water supply control apparatus, characterized in that. 2. The water supply control device according to claim 1,
When the water level detector outputs a signal indicating a decrease in water level, the determination means delays the standby machine from the standby machine start-up means by a predetermined time, and determines that the turbine drive water supply pump has become abnormal. A water supply control device characterized by supplying a trip signal. 3. The water supply control device according to claim 1,
When the signal indicating the water level rise is output from the water level detector, the standby machine starting means delays a predetermined time after the trip signal is supplied from the determining means to the turbine drive water feed pump in which the abnormality has occurred. Then, the water supply control device is characterized in that the standby machine is activated. 4. The water supply control device according to claim 1,
When the water level detector outputs a signal indicating a decrease in water level, the determination means delays the standby machine from the standby machine start-up means by a predetermined time, and determines that the turbine drive water supply pump has become abnormal. If a trip signal is supplied and a signal indicating the rising water level is output from the water level detector,
The water supply control device, wherein the standby machine starting means starts the standby machine with a predetermined delay after a trip signal is supplied from the determining means to the turbine-driven water supply pump in which an abnormality has occurred. 5. The water supply control device according to claim 2, 3 or 4, wherein the predetermined time delay is a delay time of 1 second or more. 6. The water supply control device according to claim 1,
The water supply control device, wherein the amount of change corresponding to the rotational speed of the steam turbine is the suction flow rate of the turbine-driven water supply pump. 7. The water supply control device according to claim 1,
The water supply control device, wherein the amount of change corresponding to the rotation speed of the steam turbine is a discharge flow rate of a turbine-driven water supply pump. 8. The water supply control device according to claim 1,
The water supply control device, wherein the amount of change corresponding to the number of rotations of the steam turbine is an opening degree of a steam control valve of the steam turbine.