JP3836537B2 - Turbine accessory control device for nuclear power plant - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a turbine accessory control device for a nuclear power plant.
[0002]
[Prior art]
The main steam and auxiliary steam system of the nuclear power plant will be described with reference to FIG. Steam generated in the nuclear reactor 1 is guided to the high-pressure steam turbine 5 through the main steam isolation valve 2, the main steam stop valve 3, and the steam control valve 4, and further to the low-pressure steam turbine 7 through the moisture separation heater 6. This steam expands in the high-pressure steam turbine 5 and the low-pressure steam turbine 7, and at this time, the generator 8 is driven to obtain an electrical output.
[0003]
In the high-pressure steam turbine 5 and the low-pressure steam turbine 7, the steam speed and the turbine inlet pressure are controlled by adjusting the openings of the steam control valve 4 and the turbine bypass valve 9 by a steam turbine control device (not shown). For this reason, a speed detector 10 for detecting the turbine speed and a pressure detector 11 for detecting the turbine inlet pressure are provided. By the way, in the new type reactor, instead of the turbine inlet pressure, the pressure detector 12 detects the reactor dome pressure and adjusts the opening of the steam control valve 4 and the turbine bypass valve 9 to control the turbine speed and the turbine inlet pressure. Is called.
[0004]
In addition, a heating steam system for supplying heating steam to the moisture separation heater 6 from the main steam system, a heating steam system for supplying heating steam to the turbine ground steam evaporator 13, and a steam turbine 14 for driving a reactor water pump are provided. A steam system for supplying driving steam and a steam system for supplying driving steam to the air extractor 15 are branched.
[0005]
The moisture separation heater 6 provided between the high-pressure steam turbine 5 and the low-pressure steam turbine 7 includes a first stage heater 16 that uses the extraction of the high-pressure steam turbine 5 as a heat source, and the main steam of the main steam system as a heat source. The second stage heater 17 to be used is provided, and the exhaust of the high pressure steam turbine 5 is heated and led to the low pressure steam turbine 7. Among them, the heating steam system of the second stage heater 17 is heated because the main steam having a constant pressure is used for the heating steam of the first stage heater 16 using the extraction gas that changes in accordance with the plant output. A steam source valve 18, a pressure control valve 19, and a pressure control valve bypass valve 20 that is used in a fully open state to reduce the pressure loss of the pressure control valve 19 in a high load region of the plant are provided. The extraction system of the first stage heater 16 is provided with a heating steam source valve 21. In the figure, reference numeral 22 denotes a reactor containment vessel, and reference numeral 23 denotes a condenser.
[0006]
[Problems to be solved by the invention]
By the way, when some accident occurs inside or outside the reactor containment vessel 22 and the main steam isolation valve 2 is closed, the main steam is left in the main steam system. A part of the residual steam flows to the second stage heater 17 and the rest flows to the turbine ground steam evaporator 13 and the like. At this time, the rotation speed of the high-pressure steam turbine 5 and the low-pressure steam turbine 7 decreases due to the loss of the main steam, but continues to rotate, and the steam that seals the turbine ground portion is supplied from the turbine ground steam evaporator 13. I have to.
[0007]
However, there is not much main steam left in the main steam path, and if a large amount of steam flows as the heating steam of the second stage heater 17, only a small amount of heating steam is present in the turbine ground steam evaporator 13. Not flowing. If the supplied heating steam decreases, the turbine ground steam evaporator 13 cannot generate a necessary amount of steam, and a sufficient amount of steam does not flow in the turbine ground portion. At this time, a large amount of external air flows into the low-pressure steam turbine 7 communicating with the condenser 23 through the turbine gland portion, and this flows into the condenser 23 and the vacuum degree of the condenser 23 is suddenly increased. It will drop to. Further, the inflow of external air causes adverse effects such as the blades coming into contact with the air in the low-pressure steam turbine 7 and the temperature of the blades becoming extremely high due to friction.
[0008]
Therefore, an object of the present invention is to provide a turbine auxiliary equipment control device for a nuclear power plant that can secure heating steam required by a turbine ground steam evaporator by residual steam in a main steam system when an isolation valve is closed. There is to do.
[0009]
[Means for Solving the Problems]
The invention according to claim 1,
The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the nuclear reactor is led to the steam turbine through the main steam system , and the turbine ground steam evaporator and the heater of at least the moisture separation heater are passed through the steam system branched downstream of the main steam isolation valve . In a nuclear power plant configured to lead to
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When the isolation valve closure signal is given from the operation detecting means, and a circuit for outputting a valve closing signal to the heating steam source valve of the heater,
It is characterized in that the Ru further comprising a.
[0010]
Further, the invention according to claim 2,
The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the reactor is guided to the steam turbine through the main steam system , and the turbine ground steam evaporator and the steam turbine for driving at least the reactor feed water pump through the steam system branched downstream of the main steam isolation valve. In a nuclear power plant configured to lead to
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
A circuit for outputting from the operation detecting means when the isolation valve closure signal is supplied, the steam turbine trip signal for the reactor feedwater pump driven trip solenoid of the reactor feedwater pump driving steam turbine,
It is characterized in that the Ru further comprising a.
[0011]
The invention according to claim 3,
The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the reactor is guided to the steam turbine through the main steam system, and is guided to a turbine ground steam evaporator and at least an air extractor through a steam system branched downstream of the main steam isolation valve. In the nuclear power plant
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When said isolation valve closing signal from the operation detecting means is provided, and a circuit for outputting the air extractor stop signal to the air ejector stop circuit of the air ejector,
It is characterized in that the Ru further comprising a.
[0012]
Further, the invention according to claim 4,
The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the nuclear reactor is led to the steam turbine through the main steam system , and the turbine ground steam evaporator and the heater of at least the moisture separation heater are passed through the steam system branched downstream of the main steam isolation valve . In a nuclear power plant configured to lead to
Than said heating steam source valve of the heater provided upstream of the steam system, a heating steam shut-off valve having a pneumatic drive unit,
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When said isolation valve closing signal from the operation detecting means is provided, and a circuit for outputting a valve closing signal to the air drive part of the heating steam shut-off valve,
It is characterized in that the Ru further comprising a.
[0013]
The invention according to claim 5,
A water level control unit for outputting a signal for determining the opening of the water level control valve of the drain tank based on the actual water level signal and installation value of the drain tank of the heater,
An opening setting device for outputting a signal for holding the opening of the water level control valve fully open;
When the heater heating steam source valve is closed, and the second movement detecting means for outputting a heating steam source valve closed signal,
Means for switching the opening signal to the water level control valve from the water level regulator to the opening degree setter when a heating steam source valve closing signal is given from the operation detecting means ;
Is further provided.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a start signal and an operation permission signal by the motor switch 31 are added to the input terminal of the AND circuit 32, and when the condition is satisfied according to the logical product, the valve opening signal V1 is output. The valve opening signal V1 is input to the motor control unit 33, and the electric drive unit 34 is operated by the output to open the heating steam source valve 18.
[0015]
Further, the stop signal from the switch 31, the valve closing signal output when the turbine load is 10% or less, and the isolation valve closing signal supplied from the main steam isolation valve closing operation detector 35 provided in the main steam isolation valve 2 are isolated. A valve closing signal V2 is output when the condition is satisfied in accordance with a logical sum applied to the input terminal of the valve OR circuit 36. This valve closing signal V2 is input to the motor control unit 33, and the electric drive unit 34 is operated by the output to close the heating steam source valve 18.
[0016]
Next, the operation according to the above configuration will be described. When some accident occurs inside or outside the reactor containment vessel 22 and the main steam isolation valve 2 is closed, the main steam is left in the main steam system. A main steam isolation valve closing operation detector 35 provided in the main steam isolation valve 2 detects that the main steam isolation valve 2 is closed, and outputs an isolation valve closing signal to the OR circuit 36. When the isolation valve closing signal is input to the OR circuit 36, the valve closing signal V2 is output, and the electric drive unit 34 opens the heating steam source valve 18 via the motor control unit 33.
[0017]
Thus, since the steam source valve 18 is closed, the main steam remaining in the main steam system does not go to the second stage heater 17, and the entire amount flows to the turbine ground steam evaporator 13 and the like. The turbine ground steam evaporator 13 has a smaller capacity than the second stage heater 17 that heats the cycle steam, and a sufficient amount of heated steam can be secured by the amount of steam flowing to the second stage heater 17. .
[0018]
In particular, in a reactor having a reactor dome pressure control function, when the main steam isolation valve 2 is closed, the steam control valve 4 operates in the opening direction, and a part of the residual steam is directed to the high-pressure steam turbine 5. Although there is a concern that the shortage becomes large, in the present embodiment, turbine ground steam can be obtained by the heated steam that flows continuously even after the main steam isolation valve 2 is closed, which is extremely useful.
[0019]
Furthermore, another embodiment of the present invention will be described with reference to FIG. A steam turbine trip signal for driving the reactor water pump by the switch 37, a turbine trip signal from the OR circuit 38, and an isolation valve closing signal provided from the main steam isolation valve closing operation detector 35 are applied to the input terminal of the OR circuit 39, When the condition is satisfied according to the logical sum, the steam turbine trip signal v3 for driving the reactor water pump is output. The reactor water pump driving steam turbine trip signal v3 is output to the trip solenoid 40, and the reactor water pump driving steam turbine 14 is stopped.
[0020]
In the above configuration, when the main steam isolation valve 2 is closed, the main steam isolation valve closing operation detector 35 detects this and outputs an isolation valve closing signal to the OR circuit 39. When the isolation valve closing signal is input to the OR circuit 39, the reactor feedwater pump drive steam turbine trip signal v3 is output to the trip solenoid 40, and the reactor feedwater pump drive steam turbine 14 is stopped by excitation of the solenoid 40. To do.
[0021]
As a result, the flow of the driving steam toward the reactor feed water pump driving steam turbine 14 stops, and the main steam remaining in the main steam system flows to the turbine ground steam evaporator 13 and the like. That is, heating steam can be increased in the turbine ground steam evaporator 13 as much as the driving steam flowing to the reactor feedwater pump driving steam turbine 14 disappears. As described above, also in the present embodiment, it is possible to obtain a necessary amount of turbine ground steam using the heating steam that flows continuously even after the main steam isolation valve 2 is closed.
[0022]
Another embodiment will be described with reference to FIG. The isolation valve closing signal provided from the main steam isolation valve closing operation detector 35 is added to the input terminal of the OR circuit 41 together with other stop signals, and when the condition is satisfied according to the logical sum, the air extractor stop signal v4 is output. Is done. The air extractor stop signal v4 is output to the air extractor stop circuit 42, and the air extractor 15 is stopped.
[0023]
In the above configuration, when the main steam isolation valve 2 is closed, the main steam isolation valve closing operation detector 35 detects this and outputs an isolation valve closing signal to the OR circuit 41. When the isolation valve closing signal is input to the OR circuit 41, the air extractor stop signal v4 is output to the air extractor stop circuit 42, and the air extractor stop circuit 42 is activated to stop the air extractor 15. Thereby, the flow of the driving steam toward the air extractor 15 is stopped, and the main steam remaining in the main steam system flows to the turbine ground steam evaporator 13 and the like.
[0024]
That is, the heating steam can be increased in the turbine ground steam evaporator 13 as much as the driving steam flowing to the air extractor 15 disappears. As described above, in the present embodiment as well, the required amount of turbine ground steam can be obtained using the heated steam that flows continuously even after the main steam isolation valve 2 is closed, as in the other embodiments described above. Is possible.
[0025]
Furthermore, another embodiment will be described with reference to FIGS. In FIG. 4, a heating steam cutoff valve 43 is provided on the upstream side of the heating steam source valve 18 of the heating steam system of the second stage heater 17. Moreover, in this Embodiment, the following circuit which controls the heating steam cutoff valve 43 is provided. In FIG. 5, the start signal and the operation permission signal by the switch 44 are added to the input terminal of the AND circuit 45, and when the condition is satisfied according to the logical product, the valve opening signal v5 is output. This valve opening signal v5 is input to the pneumatic drive unit 46, and the operation of the pneumatic drive unit 46 opens the heating steam cutoff valve 43.
[0026]
Further, the stop signal from the switch 44 and the isolation valve closing signal provided from the main steam isolation valve closing operation detector 35 provided in the main steam isolation valve 2 are applied to the input terminal of the OR circuit 47, and the condition is satisfied according to the logical sum. When this is done, the valve closing signal v6 is output. This valve closing signal v <b> 6 is input to the pneumatic drive unit 46, and the heating steam cutoff valve 43 is closed by the operation of the pneumatic drive unit 46.
[0027]
In the above configuration, when the main steam isolation valve 2 is closed, the main steam isolation valve closing operation detector 35 detects this and outputs an isolation valve closing signal to the OR circuit 47. When the isolation valve closing signal is input to the OR circuit 47, the valve closing signal v 6 is output, and the pneumatic drive unit 46 opens the heating steam cutoff valve 43.
[0028]
Thus, since the heating steam shutoff valve 43 is also closed in the present embodiment, the entire main steam remaining in the main steam system flows to the turbine ground steam evaporator 13 and the like, and the turbine ground steam evaporator 13 Can secure the necessary amount of heating steam by the amount of steam flowing to the second stage heater 17. In the present embodiment, by configuring the pneumatic drive unit 46, the operation time can be shortened, and more heating steam can be secured as compared with that of the above-described embodiment (FIG. 1). become.
[0029]
As described above, also in the present embodiment, it is possible to obtain a necessary amount of turbine ground steam using the heating steam that flows continuously even after the main steam isolation valve 2 is closed.
[0030]
Another embodiment will be described with reference to FIGS. In FIG. 6, the second stage heater 17 is connected to a drain tank 48 that collects the drain generated in the container. The drain tank 48 is provided with a water level adjustment valve 49. The water level control valve 49 is connected to a water level detector 50 that detects the drain water level and a water level controller 51 that adjusts the drain water level.
[0031]
In the present embodiment, the following circuit for controlling the water level adjustment valve 49 is provided. In FIG. 7, the heating steam source valve closing signal provided from the heating steam source valve closing operation detector 52 provided in the heating steam source valve 18 is input to the signal switch 53. When the heating steam source valve closing signal is input, the signal switching unit 53 outputs a switching signal to the contact 54, and the contact 54 is switched. In addition, the fully open signal from the opening setting device 55 is output to the water level control valve 49 through the contact 54 together with the signal output from the water level controller 51.
[0032]
The operation of the above configuration will be described. Normally, the water level control valve 49 is forcibly fully opened by a low load signal in order to prevent water hammer in the piping at the time of starting and stopping of the plant, but the water level is adjusted before the heating steam source valve 18 is fully opened. When the control valve 49 is fully opened, the drain flows out from the drain tank 48, and at this time, the heating steam may flow from the main steam system to the second stage heater 17. Therefore, in the present embodiment, the amount of heating steam flowing through the second stage heater 17 is limited by delaying the full opening of the water level adjustment valve 49.
[0033]
During the operation of the plant, the contact 54 is closed so as to control the water level control valve 49 with a signal from the water level controller 51. At this time, the drain flowing out from the drain tank 48 is properly maintained by the opening signal from the water level adjuster 51. On the other hand, when the main steam isolation valve 2 is closed, the heating steam source valve 18 is fully closed. For example, this is performed by the control of the above embodiment (FIG. 1). When the heating steam source valve 18 is fully closed, a heating steam source valve closing signal is input to the signal switching unit 53 from the superheated steam source valve closing operation detector 52, and the signal switching unit 53 outputs a switching signal to the contact 54. To do. At this time, the contact 54 is switched, and a fully open signal from the opening setting device 55 is input to the water level adjustment valve 49.
[0034]
The water level control valve 49 is fully opened, and a larger amount of drain flows out than the drain flow rate that has been properly maintained by the signal from the water level controller 51 until then. That is, the full opening of the water level adjustment valve 49 can be temporarily delayed, and the amount of heated steam flowing through the second stage heater 17 can be reduced.
[0035]
【The invention's effect】
As described above, the invention according to claim 1 is configured to close the heating steam source valve of the second stage heater by the isolation valve closing signal given from the operation detecting means of the main steam isolation valve. The remaining steam can secure the heating steam required in the turbine ground steam evaporator.
[0036]
Furthermore, the invention according to claim 2 excites the trip water solenoid of the reactor water pump driving steam turbine by the isolation valve closing signal given from the operation detecting means of the main steam isolation valve to Since the operation is stopped, the heating steam required in the turbine ground steam evaporator can be secured by the residual steam in the main steam system.
[0037]
Further, in the invention according to claim 3, the air extractor is stopped by operating the air extractor stop circuit of the air extractor by the isolation valve closing signal given from the operation detecting means of the main steam isolation valve. The residual steam in the steam system can secure the heating steam required by the turbine ground steam evaporator.
[0038]
Furthermore, the invention according to claim 4 is provided with a heating steam cutoff valve in the steam system upstream of the heating steam source valve, and the heating steam cutoff valve is closed by an isolation valve closing signal given from the operation detection means of the main steam isolation valve. Since it did in this way, the heating steam required by a turbine ground steam evaporator can be ensured with the residual steam in the main steam system.
[0039]
In the invention according to claim 5, the opening signal to the water level control valve of the drain tank of the second stage heater is fully opened from the water level controller by the heating steam source valve closing signal given from the operation detecting means of the heating steam source valve. Therefore, the steam required for the turbine ground steam evaporator can be secured by the residual steam in the main steam system.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of a turbine accessory control apparatus according to the present invention.
FIG. 2 is a configuration diagram showing another embodiment of the present invention.
FIG. 3 is a configuration diagram showing another embodiment of the present invention.
FIG. 4 is a system diagram showing another embodiment of the present invention.
FIG. 5 is a configuration diagram showing another embodiment of the present invention.
FIG. 6 is a system diagram showing another embodiment of the present invention.
FIG. 7 is a configuration diagram showing another embodiment of the present invention.
FIG. 8 is a system diagram showing a conventional nuclear power plant.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reactor 2 Main steam isolation valve 6 Moisture separation heater 14 Steam turbine 15 for driving a reactor feed water pump Air extractor 17 Second stage heater 18 Steam source valve 35 Main steam isolation closing operation detectors 36, 38, 41 OR circuit 43 Heating steam shutoff valve 48 Drain tank 49 Water level control valve 52 Heating steam source valve closing operation detector

Claims (5)

The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the nuclear reactor is led to the steam turbine through the main steam system , and the turbine ground steam evaporator and the heater of at least the moisture separation heater are passed through the steam system branched downstream of the main steam isolation valve . In a nuclear power plant configured to lead to
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When the isolation valve closure signal is given from the operation detecting means, and a circuit for outputting a valve closing signal to the heating steam source valve of the heater,
The Ru further comprising a turbine auxiliary control device of a nuclear power plant, characterized in. The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the reactor is guided to the steam turbine through the main steam system , and the turbine ground steam evaporator and the steam turbine for driving at least the reactor feed water pump through the steam system branched downstream of the main steam isolation valve. In a nuclear power plant configured to lead to
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
A circuit for outputting from the operation detecting means when the isolation valve closure signal is supplied, the steam turbine trip signal for the reactor feedwater pump driven trip solenoid of the reactor feedwater pump driving steam turbine,
The Ru further comprising a turbine auxiliary control device of a nuclear power plant, characterized in. The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the reactor is guided to the steam turbine through the main steam system, and is guided to a turbine ground steam evaporator and at least an air extractor through a steam system branched downstream of the main steam isolation valve. In the nuclear power plant
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When said isolation valve closing signal from the operation detecting means is provided, and a circuit for outputting the air extractor stop signal to the air ejector stop circuit of the air ejector,
The Ru further comprising a turbine auxiliary control device of a nuclear power plant, characterized in. The main steam system connected from the reactor to the steam turbine has a main steam isolation valve,
The main steam flowing from the nuclear reactor is led to the steam turbine through the main steam system , and the turbine ground steam evaporator and the heater of at least the moisture separation heater are passed through the steam system branched downstream of the main steam isolation valve . In a nuclear power plant configured to lead to
Than said heating steam source valve of the heater provided upstream of the steam system, a heating steam shut-off valve having a pneumatic drive unit,
Operation detecting means for outputting an isolation valve closing signal when the main steam isolation valve is closed;
When said isolation valve closing signal from the operation detecting means is provided, and a circuit for outputting a valve closing signal to the air drive part of the heating steam shut-off valve,
The Ru further comprising a turbine auxiliary control device of a nuclear power plant, characterized in. A water level control unit for outputting a signal for determining the opening of the water level control valve of the drain tank based on the actual water level signal and installation value of the drain tank of the heater,
An opening setting device for outputting a signal for holding the opening of the water level control valve fully open;
When the heater heating steam source valve is closed, and the second movement detecting means for outputting a heating steam source valve closed signal,
Means for switching an opening signal to the water level control valve from the water level regulator to the opening degree setter when a heating steam source valve closing signal is given from the second operation detecting means ;
The turbine auxiliary equipment control device for a nuclear power plant according to claim 1, further comprising:

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