JPH0212098A - Method for controlling fast breeder reactor plant - Google Patents

Abstract

PURPOSE:To safely operate the title plant at an output corresponding to a load without causing an unexpected rise in reactor output due to a Doppler effect by making the feeding water quantity controlling mode and feeding water temperature controlling mode changeable to each other. CONSTITUTION:A controller is constituted of a feeding water quantity controlling mode producing section 21 which generates a feeding water quantity controlling mode signal 20 which for setting the feeding water quantity to an aimed value by adjusting the opening of a feeding water controlling valve, feeding water temperature controlling mode signal producing section 23 which generates a feeding water temperature controlling mode signal 22 for setting the feeding water temperature to an aimed value by adjusting the opening of a controlling valve, and signal switching section 25 which generates a feeding water controlling valve opening requesting signal 24 for adjusting the opening of the controlling valve based on the signal 20 or 22. When the power load unbalance relay of a turbine speed controlling system is actuated, the feeding water quantity controlling mode is switched to the feeding water temperature controlling mode so that the reactor can be operated safely at an output corresponding to a load without causing a remarkable decline in the feeding water temperature.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a method for controlling a fast breeder reactor plant.

(Prior technology) Generally, in a fast breeder reactor plant, main steam generated by heat exchange with a secondary sodium system passes through a main steam control valve, is used for power generation in a turbine, and is then returned to water in a condenser. The water is then sent to the feedwater heater, where it is heated, and then sent again to the evaporator (or steam generator, hereinafter the same).

By the way, in such a fast breeder reactor plant, the valve openings of the turbine bypass valve and main steam control valve in the turbine bypass system are controlled by the turbine speed control system (hereinafter referred to as E! (C: Elcc).
ttro Hydraulic Controller
), load loss occurs,
the difference between the generator load and the turbine output by more than a predetermined value,
For example, if a difference of 40% or more occurs for 0 milliseconds or more, the power/load unbalance relay (hereinafter referred to as PLUR) is activated by the activation of this EHC, and the main steam control valve is instantly fully opened in a few milliseconds. Rapidly shuts off steam flowing into the turbine.

Thereafter, by canceling PLUR, the power plant is operated to maintain the output equivalent to the load within the power plant.

By the way, since feedwater heaters generally use turbine extracted steam as a heating source, when the output state is equivalent to the load in the power plant due to the above-mentioned P L U R operation, the internal pressure will decrease due to the decrease in turbine exhaust pressure. This causes the evaporator feed water temperature to drop.

Such a decrease in the feed water temperature not only gives a cold shock to the evaporator feed water nozzle, but also risks causing an unexpected increase in reactor output due to the Doppler effect. For this reason, fast breeder reactor plants are provided with an interlock mechanism that detects this temperature drop and trips the entire system when the feed water temperature drops below a predetermined temperature.

(Problem to be solved by the invention) However, when the entire system is tripped due to the operation of the interlock as described above, it takes a long time to start generating power again, resulting in a significant decrease in the operating rate. This leads to an increase in power generation costs.

The present invention was made in response to such conventional circumstances, and it is possible to avoid applying cold shock to the evaporator water supply nozzle,
It is possible to safely perform load-equivalent output operation without causing an unexpected increase in reactor output due to the Doppler effect, and the possibility of tripping the entire system due to interlock activation is significantly reduced compared to conventional methods, resulting in improved availability. The purpose is to provide a control method for a fast breeder reactor plant that can improve the performance of the fast breeder reactor plant.

[Structure of the Invention] (Means for Solving the Problems) That is, the fast breeder reactor plant control method of the present invention adjusts the opening degree of the feed water control valve to adjust the feed water flow rate to a predetermined feed water temperature target value. It is possible to switch between the feed water flow rate control mode and the feed water temperature control mode, which adjusts the opening degree of the feed water control valve to set the feed water temperature to a predetermined feed water temperature target value, and activates the power/load imbalance relay of the turbine speed control system. When this occurs, the feed water flow rate control mode is switched to the feed water temperature control mode, and a load-equivalent output operation is performed in the feed water temperature control mode.

(Function) In the fast breeder reactor plant control method of the present invention having the above configuration, when the power/load imbalance relay of the turbine speed control system is activated due to load loss, the opening degree of the water supply control valve is adjusted to supply water. Switch from the feed water flow rate control mode in which the flow rate is set to a predetermined feed water flow rate target value to the feed water temperature control mode in which the feed water temperature is set to a predetermined feed water temperature target value by adjusting the opening degree of the water supply 21-node valve to perform load-equivalent output operation. .

Therefore, it is possible to safely perform load-equivalent output operation without causing a significant drop in the water supply temperature, and compared to the past, the i+J ability of the entire system trip due to interlock activation is significantly reduced, improving operating efficiency. can be achieved.

(Example) Hereinafter, details of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 2 shows a schematic configuration of a fast breeder reactor power plant. Main steam generated by exchanging heat with a secondary sodium system in an evaporator 1 passes through a steam separator 2, and then After passing through a superheater 3, the steam is introduced into a turbine 6 through a main steam pipe 5 in which a main steam control valve 4 is inserted, and is used for power generation.

After rotating the turbine 6, the steam is returned to water in a condenser 7, and the steam is removed in a deaerator 8. The steam is then sent to a feed water heater by a feed water pump 10 driven by a pump driving turbine 9. After being heated there, it is sent to the evaporator 1 again via the water supply control valve 12.

Further, the steam/water separator 2 is connected to a flash tank 14 via a drain valve 13.
The steam introduced into 4 is sent to a condenser 7, a deaerator 8, and a feed water heater 11, respectively. The drain valve 13 is normally closed as a steam/water separator type internal pressure control valve, but when the turbine 6
If air cannot be expected to bleed from the tank, it is forced to open. For example, it opens when the turbine output signal is 25% or less.

On the other hand, the main steam pipe 5 is branched from the upstream side of the main steam control valve 4 and connected to the condenser 7, and is connected to the turbine bypass valve 15.
A turbine bypass pipe 16 is provided in which a turbine bypass pipe 16 is inserted, and its turbine bypass capacity is, for example, 50%.

FIG. 1 schematically shows the configuration of a control device for realizing the fast breeder reactor plant control method of this embodiment.
This control device includes a water supply flow rate control mode signal generation unit 21 that generates a water supply flow rate control mode signal 20 for adjusting the opening degree of the water supply control valve 12 and adjusting the water supply flow rate to a predetermined water supply flow rate target value; A feed water temperature control mode signal generation unit 2 that generates a feed water temperature control mode signal 22 for adjusting the opening degree of the valve 12 to set the feed water temperature to a predetermined feed water temperature.
3, and a signal switching unit 25 that generates a water supply regulating valve opening request signal 24 for adjusting the opening of the water supply regulating valve 12 based on the water supply flow rate control mode signal 20 or the water supply temperature control mode signal 22. ing.

That is, the feed water flow rate control mode signal generating section 21 converts the feed water flow rate target signal 28 created by the function generator 26 based on the plant output command into a predetermined proportional value to the deviation between the evaporator outlet steam temperature and the target value. The water supply flow control mode signal 20 is generated by applying a predetermined proportional/integral element 31 to the deviation between the corrected signal and the water supply flow rate.

On the other hand, the feed water temperature control mode signal generating section 23 generates the feed water temperature control mode signal 22 by applying a predetermined proportional/integral element 32 to the deviation between the preset feed water temperature target value and the feed water temperature.

Then, the signal switching unit 25 selects the water supply flow rate control mode signal 2o from the water supply flow rate control mode signal generation unit 21 during normal times through the relay circuit 33, and opens the water supply regulating valve based on this water supply flow rate control mode signal 20. It generates a degree request signal 24, adjusts the opening degree of the water supply control valve 12, and controls the water supply flow rate to a predetermined flow rate. Furthermore, when the power/load imbalance relay of the turbine speed control system is activated during load loss, this activation signal is input, and the relay circuit 33 selects the feed water temperature control mode signal 22 from the feed water temperature control mode signal generation section 23. This feed water temperature control mode signal 2
2, a water supply regulating valve opening request signal 24 is generated, and the opening of the water supply regulating valve 12 is adjusted to control the water supply flow rate so that the temperature of the water supply becomes a predetermined temperature.

In other words, in the fast breeder reactor plant control method of this embodiment, the power/loss of the turbine speed control system is reduced due to load loss.
If the load unbalance relay is activated, adjust the opening degree of the water supply control valve 12 to set the water supply flow rate to a predetermined water supply flow rate target value. Switch to the feed water temperature control mode in which the temperature is set to a predetermined target value of the feed water temperature, and perform load-equivalent output operation.

Therefore, it is possible to safely perform load-equivalent output operation without causing a significant drop in the water supply temperature, and compared to conventional methods, the possibility of tripping the entire system due to interlock activation is greatly reduced, improving operating efficiency. can be achieved.

[Effects of the Invention] As explained above, according to the fast breeder reactor plant control method of the present invention, cold shock is not given to the evaporator water supply nozzle, and the reactor output does not increase unexpectedly due to the Doppler effect. , it is possible to perform load-equivalent output operation safely, and the possibility of tripping the entire system due to interlock activation is significantly reduced compared to the conventional method, thereby improving the operating rate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control device for explaining one embodiment of the method of the present invention, and FIG. 2 is a block diagram of a fast breeder reactor plant for explaining one embodiment of the method of the present invention. 20...Water supply flow rate control mode signal 21.
...Water supply flow rate control mode signal generation section 22.
......Feed water temperature control mode signal 23...
...Feed water temperature control mode signal generation section 24...
...Water supply control valve opening request signal 25...
...Signal Switching Department Applicant: Tsujido, Japan Atomic Energy Corporation
Toshiba Corporation Representative Patent Attorney Sasa Suyama −

Claims (1)

[Claims] (1) A water supply flow rate control mode that adjusts the opening degree of the water supply control valve to bring the water supply flow rate to a predetermined water supply flow rate target value, and a water supply flow rate control mode that adjusts the opening degree of the water supply control valve to bring the water supply temperature to a predetermined water supply temperature target value. When the power/load imbalance relay of the turbine speed control system is activated, the feed water flow rate control mode is switched to the feed water temperature control mode, and the load equivalent to the feed water temperature control mode is switched from the feed water flow rate control mode to the feed water temperature control mode. A method for controlling a fast breeder reactor plant characterized by performing power operation.