JP4431512B2 - Nuclear power plant - Google Patents

Description

  The present invention relates to a nuclear power plant, and more particularly to a nuclear power plant equipped with a feed water temperature control device suitable for controlling the feed water temperature at the time of increased output.

  As a method of increasing the output of a nuclear power plant, there is a method of expanding the increased output width without drastically replacing the equipment by lowering the feed water temperature. To use this increased output method, a feed water temperature control means is required.

JP-A-9-264983 Japanese Patent Laid-Open No. 8-233989

  In the conventional power plant increasing power method, the main steam flow rate and the feed water flow rate increase almost in proportion to the increase in electrical output. On the other hand, if the feed water temperature to the reactor is lowered, the amount of steam generated in the reactor can be reduced, so the increase in main steam flow and feed water flow at the time of increased output can be suppressed, and increased output without significant equipment replacement. The width can be enlarged. Furthermore, when this increase output method is expanded, load follow-up operation using a nuclear power plant can be performed by controlling the feed water temperature in real time. However, in this method of increasing output, it is necessary to add a control means for extending the supply water temperature control range in order to lower the supply water temperature further than the supply water temperature assumed at the time of designing the plant before the increased output.

  The objective of this invention is providing the nuclear power plant which can suppress the dispersion | variation in the electric power generation amount at the time of an increase output.

  In order to achieve the above object, the present invention is characterized in that the second reactor heat output in the second operation cycle of the reactor is the first reactor heat in the first operation cycle at least one operation cycle before the second operation cycle. The steam is extracted from the steam system in a nuclear power plant that performs an operation in which the second feed water temperature in the second operation cycle of the reactor is increased below the output and lower than the first feed water temperature in the first operation cycle of the reactor. Then, an extraction flow control valve is installed in at least one of the extraction pipes connected to the feed water heater, and at least one is provided between the plurality of feed water heaters on the feed water system or downstream from the outlet of the feed water heater. The above temperature measuring device is installed, and the extraction flow controller for controlling the opening degree of the extraction flow control valve using the measured value signal and the set value signal of the temperature measuring device is installed.

  Since the feed water temperature can be adjusted to the set temperature by controlling the opening degree of the extraction flow control valve, it is possible to suppress variations in the amount of power generation at the time of increased output of the nuclear power plant.

  Another feature of the invention for achieving the above object is that the second reactor heat output in the second operation cycle of the nuclear reactor is the first atom in the first operation cycle at least one operation cycle before the second operation cycle. In a nuclear power plant that performs an operation in which the second feed water temperature in the second operation cycle of the nuclear reactor is increased to be lower than the first feed water temperature in the first operation cycle of the nuclear reactor. A bleed flow control valve and a bleed flow meter are installed on at least one bleed pipe connected to the feed water heater, and the measured value signal and set value signal of the bleed flow meter are used. Therefore, the extraction flow controller for controlling the opening degree of the extraction flow control valve is installed.

  Another feature of the invention for achieving the above object is that the second reactor heat output in the second operation cycle of the nuclear reactor is the first atom in the first operation cycle at least one operation cycle before the second operation cycle. In a nuclear power plant that performs an operation in which the second feed water temperature in the second operation cycle of the nuclear reactor is increased to be lower than the first feed water temperature in the first operation cycle of the nuclear reactor. The extraction flow control valve is installed in at least one of the extraction pipes that extract the gas and connect to the feed water heater, and at least one steam flow measuring instrument is installed on the steam system, and the steam flow measuring instrument measures The object is to install an extraction flow controller that controls the opening degree of the extraction flow control valve using the value signal and the set value signal.

  ADVANTAGE OF THE INVENTION According to this invention, the dispersion | variation in the electric power generation amount at the time of the increased output of a nuclear power plant can be suppressed.

  A preferred embodiment in which the present invention is applied to a boiling water type light water reactor power plant that is one of direct cycle nuclear power plants will be described below with reference to FIGS.

  FIG. 1 shows a system diagram of a boiling water light water reactor power plant according to a first embodiment which is a preferred embodiment of the present invention, and FIG. 2 shows an example of a feed water temperature control logic of the extraction flow rate controller shown in FIG.

  1 shows a high pressure turbine 3 and a low pressure turbine 5 connected to a reactor pressure vessel 1, a main steam pipe 2, a main steam pipe, and a moisture separator 4 or a moisture separation superheater between the high pressure turbine and the low pressure turbine. The present invention is applied to a boiling water type light water reactor having a condenser 6 installed at a low-pressure turbine outlet and having a low-pressure feed water heater 7, a feed water pump 8 and a high-pressure feed water heater 9 on the downstream side of the condenser. The example of the plant system | strain in the case of having shown is shown typically. One operation cycle is defined as the period from the start of the reactor to the shutdown of the reactor for fuel replacement.

  When the reactor heat output is increased, it is necessary to increase the feed water flow rate in order to take the increased amount of heat, or to increase the enthalpy difference of the coolant at the inlet and outlet of the reactor pressure vessel. The conventional method of increasing power uses the former method, and increases the feed water flow rate in proportion to the reactor heat output. On the other hand, as a new power increase method, the latter method was adopted and the coolant enthalpy (temperature) at the reactor pressure vessel inlet was intentionally lowered to increase the enthalpy difference between the reactor pressure vessel inlet and outlet, and increase A method for suppressing an increase in the main steam flow rate and the feed water flow rate during output has also been proposed. The present invention is to cope with this new power increase method, and in order to lower the feed water temperature to a temperature lower than the assumed range at the time of plant construction, a device for expanding the feed water temperature control range is additionally installed. There is a need.

  Since it is necessary to expand the feed water temperature range to the low temperature side, it is necessary to reduce the amount of extracted steam for heating the feed water as compared to before the increase in output. The extraction steam for heating the feed water is extracted from the main steam system including the high-pressure turbine and the low-pressure turbine, passes through the extraction pipe 10, and is sent to the high-pressure feed water heater or the low-pressure feed water heater. In the current boiling water reactor, a plurality of main extraction points are installed downstream from the high-pressure turbine inlet and upstream from the low-pressure turbine outlet. In order to reduce the amount of extracted steam, the extraction flow control valve 11 may be installed on the extraction pipe.

  In the case of adopting the increase output method targeted by the present invention, it is important that the feed water temperature is properly lowered to the set value. Therefore, the feed water temperature measuring device 12 is installed at the feed water heater outlet on the feed water system, and the extraction flow rate controller 13 controls the extraction flow rate. The feed water temperature measuring device may be installed downstream of the feed water heater controlling the extraction amount and upstream of the reactor inlet. In other words, the feed water temperature measuring device may be installed between any feed water heaters downstream of the feed water heater that controls the extraction amount, or between the last feed water heater outlet and the reactor inlet. It may be installed in.

  FIG. 2 shows an example of the control logic of the extraction flow rate controller in the first embodiment. As an input to the extraction flow controller, a feed water temperature measurement value signal 14 measured by a feed water temperature measuring device and a feed water temperature set value signal 15 are used. The output of the extraction flow controller is an opening request signal 16 for the extraction flow control valve. If the measured value of the feed water temperature is lower than the set value of the feed water temperature, it means that the extraction amount is insufficient, and therefore an opening degree request signal in the direction to open the extraction flow control valve is output. On the other hand, when the measured value of the feed water temperature is higher than the set value, it means that the amount of extraction is too large, and therefore an opening degree request signal in the direction to close the extraction flow control valve is output.

  According to the present embodiment, since the feed water temperature can be always maintained at a set temperature, an increase in the main steam flow rate and the feed water flow rate can be suppressed by reducing the feed water temperature at the time of increased output of the nuclear reactor. Furthermore, since the feed water temperature can be adjusted in real time, the main steam flow rate and feed water flow rate can be kept constant by changing the set value of the feed water temperature accordingly even when the heat output of the nuclear power plant is changed. It can also be applied to load following operation of nuclear power plants.

  FIG. 3 shows a boiling water light water reactor power plant according to a second embodiment which is another embodiment of the present invention.

  The difference between the present embodiment and the first embodiment is a measuring instrument used as an input of the extraction flow controller. In this embodiment, the extraction flow rate measuring device 17 is installed on the extraction pipe where the extraction flow control valve is installed. Either the bleed flow control valve or the bleed flow meter may be on the upstream side. When the extraction pipe merges with another extraction pipe on the way, the extraction flow control valve or the extraction flow measuring instrument located on the downstream side may be on the pipe after the merge. When the extraction pipe branches in the middle, the extraction flow control valve or the extraction flow measuring instrument located on the downstream side may be on the branched pipe. If the reactor heat output, feedwater flow rate, and extraction flow rate are known, the feedwater temperature is uniquely determined from the plant thermal balance. Therefore, installing the extraction flow rate measuring device on the extraction pipe as in this embodiment and measuring the extraction amount is equivalent to measuring the feed water temperature.

  In this embodiment, the extraction flow rate measurement value signal 18 measured by the extraction flow rate measuring device and the extraction flow rate set value signal 19 are used as the input of the extraction flow rate controller. The output of the extraction flow controller is an opening request signal for the extraction flow control valve. When the measured value of the bleed flow rate is smaller than the set value of the bleed flow rate, it means that the bleed amount is insufficient, and therefore an opening request signal in the direction to open the bleed flow rate control valve is output. On the contrary, if the measured value of the extraction flow rate is larger than the set value, it means that the extraction amount is too large, and therefore an opening degree request signal in the direction to close the extraction flow control valve is output.

  Here, although the example in the case of using a bleed flow rate measuring device alone was shown, you may install the feed water temperature measuring device similarly to 1st Example, and may combine the control by bleed flow rate and the control by feed water temperature. FIG. 4 shows a system example of a boiling water light water reactor power plant according to a third embodiment, which is another embodiment of the present invention, in which the technical ideas of the first embodiment and the second embodiment are combined. FIG. 5 shows an example of control logic used in the third embodiment. Since there is a certain time delay between the adjustment of the extraction flow control valve and the actual change of the feed water temperature, priority is given to the control using the extraction flow when the extraction flow fluctuates in a short cycle, and a relatively long time When the water supply temperature is lowered or increased over time, the role is divided by giving priority to the control based on the water supply temperature. Specifically, as shown in FIG. 5, a setting value of the extraction flow rate is determined by control based on the feed water temperature, and an opening degree request signal for the extraction flow control valve is output from the difference between the setting value and the measurement value of the extraction flow rate. It ’s fine.

  FIG. 6 shows a system of a boiling water light water reactor power plant according to a fourth embodiment which is another embodiment of the present invention.

The difference between the present embodiment and the first embodiment is a measuring instrument used as an input of the extraction flow controller. In this embodiment, the main steam flow rate measuring device 20 is installed downstream of the reactor and upstream of the high-pressure turbine inlet. If the reactor heat output and main steam flow are known, the feedwater temperature is uniquely determined from the heat balance of the plant. Therefore, installing a main steam flow rate measuring device and measuring the main steam flow rate as in this embodiment is equivalent to measuring the feed water temperature.

  In this embodiment, the main steam flow rate measurement value signal 21 measured by the main steam flow rate measuring device and the main steam flow rate set value signal 22 are used as the input of the extraction flow rate controller. The output of the extraction flow controller is an opening request signal for the extraction flow control valve. If the measured value of the main steam flow rate is smaller than the set value of the main steam flow rate, it means that the feed water temperature is too low, that is, the extraction amount is insufficient. Outputs a request signal. On the contrary, when the measured value of the main steam flow rate is larger than the set value, the feed water temperature is too high, that is, the extraction amount is too large. Outputs a request signal.

  Here, an example in which the main steam flow rate measuring device is used alone has been shown, but a feed water temperature measuring device is installed in the same manner as in the first embodiment, and the control by the main steam flow rate and the control by the feed water temperature are combined, or Similarly to the second embodiment, an extraction flow measuring device may be installed, and the control based on the main steam flow and the control based on the extraction flow may be combined, or all of these may be combined. FIG. 7 shows a system example of the boiling water light water reactor power plant of the fifth embodiment, which is another embodiment of the present invention, combining the technical ideas of the first embodiment, the second embodiment and the fourth embodiment. Indicates. FIG. 8 shows an example of control logic used in the fifth embodiment. There is a time lag between the adjustment of the extraction flow control valve and the actual change of the main steam flow, and it is shorter than the main steam flow from the adjustment of the extraction flow control valve to the actual change of the feed water temperature. There is a certain time delay. Conversely, the time delay from the adjustment of the extraction flow control valve to the change of the extraction flow is short. Therefore, priority is given to control using the bleed flow rate when the bleed flow rate fluctuates in a short cycle, and priority is given to control by the feed water temperature if the feed water temperature has fallen or increased over a relatively long time, and a longer time. When the main steam flow rate increases or decreases over the entire range, priority is given to the control based on the main steam flow rate, and the role is divided. Specifically, as shown in FIG. 8, the set value of the feed water temperature is determined by the control based on the main steam flow rate, and the set value of the extraction flow rate is determined from the difference between the set value of the feed water temperature and the measured value of the feed water temperature. The opening request signal of the extraction flow control valve may be output from the difference between the set value and the extraction flow measurement value.

  Although the first embodiment to the fifth embodiment described above have been described by taking the boiling water light water reactor power plant as an example, the present invention can also be applied to direct cycle type plants other than the boiling water light water reactor power plant.

  In general, when the amount of extraction is reduced and the feed water temperature is lowered, the plant thermal efficiency is reduced, but in order to suppress the decrease in thermal efficiency, it is better to reduce the amount of extraction steam from the upstream extraction point as much as possible. good. Therefore, if the extraction flow control valve is installed on the extraction pipe that extracts air from the downstream side of the high-pressure turbine inlet and the upstream side of the low-pressure turbine inlet, the effect is high. Further, in the embodiment of the present invention, the extraction flow control valve is installed only in one extraction pipe, but there is a case where the feed water temperature may not be lowered sufficiently only by reducing the extraction steam amount in one extraction pipe. In this case, an extraction flow control valve is installed on a plurality of extraction pipes.

In general, in a boiling water light water reactor power plant, up to about 102% of the reactor thermal output can be implemented simply by improving the measurement accuracy of the feed water flow meter, etc., and the feed water temperature is reduced as in the present invention. Therefore, the present invention is very effective for increasing the power in the range higher than the reactor thermal output 102% and lower than 105%. Furthermore, in the case of an increase in the reactor heat output in the range of 105% to 120%, generally no significant system equipment change such as replacement of a high-pressure turbine is required. If the power increase method for lowering the feed water temperature is used as in the present invention, it is not necessary to replace the high-pressure turbine even at a power increase exceeding the reactor thermal output of 105%. A particularly large effect can be obtained when the number is increased.

  The example at the time of applying this invention to the pressurized water type light water reactor power plant which is one of the indirect cycle type nuclear power plants is shown.

  FIG. 9 shows a system of a pressurized water light water reactor power plant according to a sixth embodiment which is another embodiment of the present invention. The feed water temperature control logic used in the sixth embodiment is as shown in FIG.

  FIG. 9 shows a reactor pressure vessel 1, a steam generator 23 for transmitting heat generated in the core in the reactor pressure vessel to the secondary system, and a main steam pipe for guiding the secondary system steam emitted from the steam generator to the turbine. 2 and a high-pressure turbine 3 and a low-pressure turbine 5 connected to the main steam pipe, and a moisture separation superheater 24 between the high-pressure turbine and the low-pressure turbine, and a condenser 6 is installed at the outlet of the low-pressure turbine. In a pressurized water light water reactor having a low-pressure feed water heater 7, a feed water pump 8, and a high-pressure feed water heater 9 on the downstream side of the water vessel, an example of a plant system in the case of carrying out the present invention is schematically shown. One operation cycle is defined as the period from the start of the reactor to the shutdown of the reactor for fuel replacement.

  When the reactor heat output is increased, the amount of heat exchange in the steam generator increases almost in proportion to the increase in the reactor heat output. In order to obtain an increased amount of heat exchange in the steam generator, it is necessary to increase the feed water flow rate to the steam generator or to enlarge the difference in enthalpy of the coolant at the inlet and outlet of the steam generator. In the conventional method of increasing output, the former method is used, and the feed water flow rate is increased in proportion to the heat exchange amount of the steam generator. On the other hand, as a new power increase method, the latter method is adopted and the coolant enthalpy (temperature) at the steam generator inlet is intentionally lowered to increase the enthalpy difference between the steam generator inlet and outlet to increase the output. A method for suppressing the increase in the main steam flow rate and the feed water flow rate has also been proposed. The present invention is to cope with this new power increase method, and in order to lower the feed water temperature to a temperature lower than the assumed range at the time of plant construction, a device for expanding the feed water temperature control range is additionally installed. There is a need.

  Since it is necessary to expand the feed water temperature range to the low temperature side, it is necessary to reduce the amount of extracted steam for heating the feed water as compared to before the increase in output. The extraction steam for heating the feed water is extracted from the main steam system including the high-pressure turbine and the low-pressure turbine, passes through the extraction pipe 10, and is sent to the high-pressure feed water heater or the low-pressure feed water heater. In the current pressurized water reactor, a plurality of major extraction points are installed downstream from the high-pressure turbine inlet and upstream from the low-pressure turbine outlet. In order to reduce the amount of extracted steam, the extraction flow control valve 11 may be installed on the extraction pipe.

  In the case of adopting the increase output method targeted by the present invention, it is important that the feed water temperature is properly lowered to the set value. Therefore, the feed water temperature measuring device 12 is installed at the feed water heater outlet on the feed water system, and the extraction flow rate controller 13 controls the extraction flow rate. The feed water temperature measuring device may be installed on the downstream side of the feed water heater that controls the extraction amount and upstream of the steam generator inlet. In other words, the feed water temperature measuring device may be installed between any feed water heaters downstream of the feed water heater that controls the extraction amount, or between the feed water heater outlet and the steam generator inlet at the final stage. It may be installed in between.

  An example of the control logic of the extraction flow controller used in the sixth embodiment, which is this embodiment, will be described with reference to FIG. As an input to the extraction flow controller, a feed water temperature measurement value signal 14 measured by a feed water temperature measuring device and a feed water temperature set value signal 15 are used. The output of the extraction flow controller is an opening request signal 16 for the extraction flow control valve. If the measured value of the feed water temperature is lower than the set value of the feed water temperature, it means that the extraction amount is insufficient, and therefore an opening degree request signal in the direction to open the extraction flow control valve is output. On the other hand, when the measured value of the feed water temperature is higher than the set value, it means that the amount of extraction is too large, and therefore an opening degree request signal in the direction to close the extraction flow control valve is output.

  According to the present embodiment, since the feed water temperature can be always maintained at a set temperature, an increase in the main steam flow rate and the feed water flow rate can be suppressed by reducing the feed water temperature at the time of increased output of the nuclear reactor. Furthermore, since the feed water temperature can be adjusted in real time, the main steam flow rate and feed water flow rate can be kept constant by changing the set value of the feed water temperature accordingly even when the heat output of the nuclear power plant is changed. It can also be applied to load following operation of nuclear power plants.

  FIG. 10 shows a system of a pressurized water light water reactor power plant according to a seventh embodiment which is another embodiment of the present invention.

  The difference between the present embodiment and the sixth embodiment is a measuring instrument used as an input of the extraction flow controller. In this embodiment, the extraction flow rate measuring device 17 is installed on the extraction pipe where the extraction flow control valve is installed. Either the bleed flow control valve or the bleed flow meter may be on the upstream side. When the extraction pipe merges with another extraction pipe on the way, the extraction flow control valve or the extraction flow measuring instrument located on the downstream side may be on the pipe after the merge. When the extraction pipe branches in the middle, the extraction flow control valve or the extraction flow measuring instrument located on the downstream side may be on the branched pipe. If the reactor heat output, feedwater flow rate, and extraction flow rate are known, the feedwater temperature is uniquely determined from the plant thermal balance. Therefore, installing the extraction flow rate measuring device on the extraction pipe as in this embodiment and measuring the extraction amount is equivalent to measuring the feed water temperature.

  In this embodiment, the extraction flow rate measurement value signal 18 measured by the extraction flow rate measuring device and the extraction flow rate set value signal 19 are used as the input of the extraction flow rate controller. The output of the extraction flow controller is an opening request signal for the extraction flow control valve. When the measured value of the bleed flow rate is smaller than the set value of the bleed flow rate, it means that the bleed amount is insufficient, and therefore an opening request signal in the direction to open the bleed flow rate control valve is output. On the contrary, if the measured value of the extraction flow rate is larger than the set value, it means that the extraction amount is too large, and therefore an opening degree request signal in the direction to close the extraction flow control valve is output.

  Here, although the example in the case of using a bleed flow rate measuring device alone was shown, you may install the feed water temperature measuring device similarly to 1st Example, and may combine the control by bleed flow rate and the control by feed water temperature. FIG. 11 shows a system example of a pressurized water reactor of the eighth embodiment, which is another embodiment of the present invention, combining the technical ideas of the sixth embodiment and the seventh embodiment. Further, the control logic used in this embodiment is the control logic shown in FIG. Since there is a certain time delay between the adjustment of the extraction flow control valve and the actual change of the feed water temperature, priority is given to the control using the extraction flow when the extraction flow fluctuates in a short cycle, and a relatively long time When the water supply temperature is lowered or increased over time, the role is divided by giving priority to the control based on the water supply temperature. Specifically, as shown in FIG. 5, a setting value of the extraction flow rate is determined by control based on the feed water temperature, and an opening degree request signal for the extraction flow control valve is output from the difference between the setting value and the measurement value of the extraction flow rate. It ’s fine.

  FIG. 12 shows a system of a pressurized water LWR power plant according to the ninth embodiment which is another embodiment of the present invention. The difference between the present embodiment and the sixth embodiment is a measuring instrument used as an input of the extraction flow controller. In this embodiment, the main steam flow rate measuring device 20 is installed downstream of the reactor and upstream of the high-pressure turbine inlet. If the reactor heat output and main steam flow are known, the feedwater temperature is uniquely determined from the heat balance of the plant. Therefore, installing a main steam flow rate measuring device and measuring the main steam flow rate as in this embodiment is equivalent to measuring the feed water temperature.

  In this embodiment, the main steam flow rate measurement value signal 21 measured by the main steam flow rate measuring device and the main steam flow rate set value signal 22 are used as the input of the extraction flow rate controller. The output of the extraction flow controller is an opening request signal for the extraction flow control valve. If the measured value of the main steam flow rate is smaller than the set value of the main steam flow rate, it means that the feed water temperature is too low, that is, the extraction amount is insufficient. Outputs a request signal. Conversely, if the measured value of the main steam flow rate is larger than the set value, it means that the feed water temperature is too high, that is, the amount of bleed air is too large. Output a signal.

  Here, an example in which the main steam flow rate measuring device is used alone has been shown, but a feed water temperature measuring device is installed in the same manner as in the first embodiment, and the control by the main steam flow rate and the control by the feed water temperature are combined, or Similarly to the second embodiment, an extraction flow measuring device may be installed, and the control based on the main steam flow and the control based on the extraction flow may be combined, or all of these may be combined. FIG. 13 shows a system example of the pressurized water reactor according to the tenth embodiment, which is another embodiment of the present invention, combining the technical ideas of the sixth embodiment, the seventh embodiment and the ninth embodiment. Show. The control logic used in this embodiment is the control logic shown in FIG. There is a time lag between the adjustment of the extraction flow control valve and the actual change of the main steam flow, and it is shorter than the main steam flow from the adjustment of the extraction flow control valve to the actual change of the feed water temperature. There is a certain time delay. Conversely, the time delay from the adjustment of the extraction flow control valve to the change of the extraction flow is short. Therefore, priority is given to control using the bleed flow rate when the bleed flow rate fluctuates in a short cycle, and priority is given to control by the feed water temperature if the feed water temperature has fallen or increased over a relatively long time, and a longer time. When the main steam flow rate increases or decreases over the entire range, priority is given to the control based on the main steam flow rate, and the role is divided. Specifically, as shown in FIG. 8, the set value of the feed water temperature is determined by the control based on the main steam flow rate, and the set value of the extraction flow rate is determined from the difference between the set value of the feed water temperature and the measured value of the feed water temperature. The opening request signal of the extraction flow control valve may be output from the difference between the set value and the extraction flow measurement value.

  Although the sixth embodiment, the seventh embodiment, and the ninth embodiment of the present invention have been described by taking the pressurized water light water reactor as an example, the present invention can also be applied to an indirect cycle type plant other than the pressurized water light water reactor.

  In general, when the amount of extraction is reduced and the feed water temperature is lowered, the plant thermal efficiency is reduced, but in order to suppress the decrease in thermal efficiency, it is better to reduce the amount of extraction steam from the upstream extraction point as much as possible. good. Therefore, if the extraction flow control valve is installed on the extraction pipe that extracts air from the downstream side of the high-pressure turbine inlet and the upstream side of the low-pressure turbine inlet, the effect is high. Further, in the embodiment of the present invention, the extraction flow control valve is installed only in one extraction pipe, but there is a case where the feed water temperature may not be lowered sufficiently only by reducing the extraction steam amount in one extraction pipe. In this case, an extraction flow control valve is installed on a plurality of extraction pipes.

  In general, in a pressurized water reactor, up to about 102% of the reactor thermal output can be implemented simply by improving the measurement accuracy of the feed water flow meter, and it is necessary to reduce the feed water temperature as in the present invention. Therefore, the present invention is highly effective for increasing the power in the range higher than the reactor thermal power 102% and lower than 5%. Furthermore, in the case of an increase in the reactor heat output in the range of 105% to 120%, generally no significant system equipment change such as replacement of a high-pressure turbine is required. If the power increase method for lowering the feed water temperature is used as in the present invention, it is not necessary to replace the high-pressure turbine even at a power increase exceeding the reactor heat output of 105%. Therefore, the present invention increases the reactor heat output to 105% or more. A particularly large effect can be obtained when the number is increased.

The boiling water type light water reactor power plant system diagram of the 1st example which is a suitable example of the present invention. Explanatory drawing which shows the control logic of an extraction flow controller. The system diagram of the boiling water type light water reactor power plant of 2nd Example which is another Example of this invention. The system diagram of the boiling water type light water reactor power plant of 3rd Example which is another Example of this invention which combined each technical idea of the said 1st Example and 2nd Example. Explanatory drawing which shows the control logic of the extraction flow controller in the Example shown in FIG. The system diagram of the boiling water type light water reactor power plant of 4th Example which is another Example of this invention. The system diagram of the boiling water type light water reactor power plant of 5th Example which is another Example of this invention which combined each technical idea of said 1st Example, 2nd Example, and 4th Example. Explanatory drawing which shows the control logic of the extraction air flow controller in the Example shown in FIG. The system diagram of the pressurized water light water reactor power plant of 6th Example which is another Example of this invention. The system diagram of the pressurized water light water reactor power plant of 7th Example which is another Example of this invention. The system diagram of the pressurized water reactor power plant of the eighth embodiment which is another embodiment of the present invention, combining the technical ideas of the sixth embodiment and the seventh embodiment. The system diagram of the pressurized water light water reactor power plant of 9th Example which is another Example of this invention. The system diagram of the pressurized water reactor power plant of 10th Example which is another Example of this invention which combined each technical idea of said 6th Example, 7th Example, and 9th Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Main steam pipe, 3 ... High pressure turbine, 4 ... Moisture separator, 5 ... Low pressure turbine, 6 ... Condenser, 7 ... Low pressure feed water heater, 8 ... Feed water pump, 9 ... High pressure feed water heater, 10 ... Extraction pipe, 11 ... Extraction flow rate adjustment valve, 12 ... Feed water temperature measuring device, 13 ... Extraction flow rate controller, 14 ... Feed water temperature measurement value signal, 15 ... Feed water temperature set value signal, 16 ... Extraction Flow rate control valve opening request signal, 17 ... Extraction flow rate measuring device, 18 ... Extraction flow rate measurement value signal, 19 ... Extraction flow rate set value signal, 20 ... Main steam flow rate measurement device, 21 ... Main steam flow rate measurement value signal, 22 ... Main steam flow rate setpoint signal, 23 ... steam generator, 24 ... moisture separation superheater.

Claims (9)

A nuclear reactor,
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated in the nuclear reactor is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A plurality of feed water heaters for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides feed water to the nuclear reactor after passing through the feed water heater from the double water heater,
An extraction flow rate control valve is provided in the middle of at least one of the extraction pipes, and is provided between a plurality of feed water heaters on the feed water system or downstream from the outlet of the last feed water heater and upstream from the reactor. At least one temperature measuring means is provided on the side,
By using the measurement value of the temperature measurement means and the set value of the feed water temperature as input, and including a bleed flow controller for outputting an opening request of the bleed flow control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle before the second operation cycle. A nuclear reactor,
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated in the nuclear reactor is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A plurality of feed water heaters for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides feed water to the nuclear reactor after passing through the feed water heater from the double water heater,
In the middle of at least one of the bleed pipes, the bleed flow control valve and the bleed flow measuring means are provided on the same bleed pipe,
By using a measurement value of the extraction flow rate measuring means and a set value of the extraction flow rate as inputs, and including an extraction flow controller that outputs an opening degree request of the extraction flow control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle before the second operation cycle. A nuclear reactor,
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated in the nuclear reactor is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A plurality of feed water heaters for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides feed water to the nuclear reactor after passing through the feed water heater from the double water heater,
In the middle of at least one of the extraction pipes, an extraction flow control valve is provided, and at least one main steam flow measurement means is provided downstream from the reactor and upstream from the high-pressure turbine,
By using a measurement value of the main steam flow rate measuring means and a set value of the main steam flow rate as inputs, and including a bleed flow rate controller that outputs an opening degree request of the bleed flow rate control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle before the second operation cycle. A nuclear reactor,
A steam generator that generates steam using a coolant heated in the nuclear reactor as a heat source;
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated by the steam generator is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A feed water heater for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides the feed water toward the steam generator after passing through the feed water heater from the double water generator,
A bleed flow control valve is provided in the middle of at least one of the bleed pipes, and is provided between a plurality of feed water heaters on the feed water system or downstream of the outlet of the last feed water heater from the steam generator. At least one temperature measuring means is provided on the upstream side,
By using the measurement value of the temperature measurement means and the set value of the feed water temperature as input, and including a bleed flow controller for outputting an opening request of the bleed flow control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle prior to the second operation cycle. A nuclear reactor,
A steam generator that generates steam using a coolant heated in the nuclear reactor as a heat source;
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated by the steam generator is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A feed water heater for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides the feed water toward the steam generator after passing through the feed water heater from the double water generator,
In the middle of at least one of the bleed pipes, a bleed flow control valve and a bleed flow measuring means are provided on the same bleed pipe,
By using the measurement value of the extraction flow rate measuring means and the set value of the extraction flow rate as inputs, and including an extraction flow rate controller that outputs an opening request of the extraction flow rate control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle prior to the second operation cycle. A nuclear reactor,
A steam generator that generates steam using a coolant heated in the nuclear reactor as a heat source;
A steam system including a high-pressure turbine and a low-pressure turbine to which steam generated by the steam generator is supplied;
A condenser for condensing steam discharged from the low-pressure turbine;
A feed water heater for heating the feed water supplied from the condenser;
Including at least one extraction pipe for extracting steam from the middle of the steam system and connecting to the feed water heater;
In a nuclear power plant comprising a water supply system that guides the feed water toward the steam generator after passing through the feed water heater from the double water generator,
A bleed flow control valve is provided in the middle of at least one of the bleed pipes, and at least one main steam flow measuring means is provided downstream from the steam generator and upstream from the high-pressure turbine,
By using a measurement value of the main steam flow rate measuring means and a set value of the main steam flow rate as inputs, and including a bleed flow rate controller that outputs an opening degree request of the bleed flow rate control valve,
Increasing the second reactor heat output in the second operating cycle of the reactor above the first reactor heat output in the first operating cycle prior to the second operating cycle;
A nuclear power plant that performs an operation in which a second feed water temperature in a second operation cycle of the nuclear reactor is decreased from a first feed water temperature in a first operation cycle prior to the second operation cycle.   The nuclear power extraction unit according to any one of claims 1 to 6, wherein the extraction pipe including the extraction flow control valve is an extraction pipe for extracting steam from a downstream side of the high-pressure turbine inlet and an upstream side of the low-pressure turbine inlet. Power plant.   The second reactor heat output in the second operation cycle of the nuclear reactor is larger than the first reactor heat output in the first operation cycle before the second operation cycle in a range of 2% or more and less than 5%. A nuclear power plant according to any one of claims 1 to 7. The second reactor heat output in the second operation cycle of the reactor is larger in the range of 5% to 20% than the first reactor heat output in the first operation cycle prior to the second operation cycle. A nuclear power plant according to any one of claims 1 to 8.

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