JPS6380101A - Evaporator-outlet sodium temperature controller - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an evaporator outlet sodium temperature control device, and in particular controls the opening degree of a water supply control valve to control the evaporator outlet sodium temperature to a predetermined value. This invention relates to an evaporator outlet sodium temperature control device that controls the temperature at the outlet of the evaporator.

(Prior Art) In general, a liquid metal cooled fast breeder reactor plant consists of a primary cooling system that transfers the nuclear energy generated in the liquid metal fast breeder reactor to an intermediate heat exchanger, and a primary cooling system that transfers the nuclear energy generated in the liquid metal cooled fast breeder reactor to an intermediate heat exchanger. The main part consists of a secondary cooling system that transfers water to the evaporator, and a water/steam system that uses the energy obtained from the evaporator to drive a steam turbine.

Figure 4 shows an example of a liquid metal sodium cooled fast breeder reactor plant, which is one of such liquid metal cooled fast breeder reactor plants. The main part is composed of the system 2 and the water/steam system 3.

The primary sodium system 1 is provided to transfer the nuclear energy generated in the reactor 4 to the intermediate heat exchanger 5 via liquid metal sodium, and is a primary system that circulates the liquid metal sodium in the reactor 4. The pipe 6 is provided with an intermediate heat exchanger 5 and a primary pump 7 in this order from the upstream side.

The secondary sodium system 2 is provided to transfer the energy obtained by the intermediate heat exchanger 5 to the superheater 8 via liquid metal sodium, and the secondary sodium system 2 is provided to transfer the energy obtained by the intermediate heat exchanger 5 to the superheater 8 through the liquid metal sodium. A superheater 8 is installed in the secondary system piping 9 that circulates liquid metal sodium. An evaporator 10 and a secondary pump 11 are provided in this order.

The water/steam system 3 is provided to drive the steam turbine 12 with the energy obtained from the evaporator 10 and the superheater 8, and is connected to the water/steam system piping 13 that circulates the steam heat exchanged with the superheater 8. are a steam turbine 12, a water supply pump 14,
An evaporator 10 and a steam/water separator 15 are provided.

In other words, the steam heated to high temperature through heat exchange in the superheater 8 is
The water is led to the steam turbine 12 through a pipe in which an isolation valve 16, a main steam stop valve 17, and a steam control valve 18 are installed, and after driving the steam turbine 12, it is converted into condensate by a condenser 19, and then the condensate pump 20. The water is led to the water supply pump 14 through the low-pressure feed water superheater 21 in order.

In addition, a turbine bypass pipe 23 is arranged in the inlet side pipe of the steam turbine 12, which branches from the upstream side of the main steam stop valve 17, has one end connected to the condenser 19, and has a turbine bypass valve 22 inserted therein. ing.

The water led to the water supply pump 14 passes through the high-pressure water supply superheater 24 and the water supply control valve 25 and flows into the evaporator 10.
After being turned into steam here, it flows into the steam/water separator 15 and is led to the superheater 8 via the isolation valve 26.

Note that the superheater 8 is connected to the steam/water separator 15 via the isolation valve 26.
A superheater bypass pipe 28 is branched from the upstream side of the isolation valve 26 to the pipe leading to the pipe, one end is connected to the upstream side of the isolation valve 16 of the low temperature outlet side pipe of the superheater 8, and a superheater bypass valve 27 is inserted. It is arranged.

In the liquid metal sodium cooled fast breeder reactor plant configured as described above, the nuclear energy generated in the reactor 4 is transferred to the steam turbine via the primary sodium system 1, the secondary sodium system 2, and the water/steam system 3. It is used as energy to drive 12.

(Problem to be Solved by the Invention) However, in a liquid metal sodium cooled fast breeder reactor plant configured in this way, it is difficult to stabilize the sodium temperature at the evaporator outlet to a predetermined value when starting up the fast breeder reactor plant. The problem is that it is very difficult to control.

The present invention has been made in response to such conventional circumstances,
An object of the present invention is to provide an evaporator outlet sodium temperature control device that can stably control the evaporator outlet sodium temperature to a predetermined value.

[Structure of the invention]

(Means for Solving the Problems) That is, the present invention operates the opening degree of the water supply control valve inserted upstream of the evaporator disposed in the steam system piping of a fast breeder reactor, and controls the sodium temperature at the evaporator outlet. This is an evaporator outlet sodium temperature control device that controls the sodium temperature at the evaporator outlet to a predetermined value. A water supply flow rate target value is set, and the opening degree of the water supply control valve is operated based on the deviation between the water supply flow rate target value and the water supply flow rate.

(Function) It becomes possible to stably control the sodium temperature at the evaporator outlet to a predetermined temperature at the time of startup of a fast breeder reactor plant, etc.

(Example) The details of the present invention will be described below with reference to an example shown in the drawings.

FIG. 1 shows the input/output relationship of the evaporator outlet sodium temperature control device of the present invention, and in the figure, reference numeral 10 indicates the evaporator disposed in the steam system piping 13. A water supply control valve 25 and a water supply flow meter 29 for measuring the flow rate of water supply are arranged on the upstream side of the evaporator 10 in the steam system piping 13.

Further, on the outlet side of the evaporator 10 of the secondary system piping 9, a temperature detector 30 is arranged to measure the sodium temperature at the evaporator outlet.

In the figure, reference numeral 31 indicates an evaporator outlet sodium temperature control device, and this evaporator outlet sodium temperature control device receives input of the feed water flow rate from the feed water flow meter 29 and the evaporator outlet sodium temperature from the temperature sensor 30. , to operate the opening degree of the water supply control valve 25.

FIG. 2 shows a block diagram of the evaporator outlet sodium temperature control device shown in FIG.
D 1g1tal Control) method. In this evaporator outlet sodium temperature control device, the evaporator outlet sodium temperature is input, and the deviation between the evaporator outlet sodium temperature value and the evaporator outlet sodium temperature setting value is calculated by PI, and the feed water flow rate target value is determined by this. Further, the deviation between this water supply flow rate target value and the water supply flow rate is calculated by PI, and the opening degree of the water supply control valve 28 is directly operated based on this value.

Figure 3 shows the sodium temperature at the evaporator outlet when the opening degree of the water supply control valve 28 is controlled by the evaporator outlet sodium temperature control device configured as described above. Indicates outlet sodium temperature.

In addition, the curved line indicated by the broken line in the figure represents the steam separator 1.
5 is the drain valve flow rate, and curve C is the water supply flow rate.

Curve d represents the sodium temperature at the outlet of superheater 8, and curve e
indicate the inlet sodium temperature of the superheater 8, respectively.

That is, according to the evaporator outlet sodium temperature control device configured as described above, when starting up a fast breeder reactor plant, the evaporator outlet sodium temperature is set to a predetermined value in superheater outlet steam temperature control, etc., which is performed simultaneously with main control. This makes it possible to stably control the operation of the fast breeder reactor plant, thereby improving reliability during start-up operation of the fast breeder reactor plant.

In addition, direct computer control facilitates automatic control, making it possible to improve economic efficiency by reducing the number of operators and improving controllability.

In addition, when nonlinearity exists between the opening degree of the water supply control valve 25 and the water supply flow rate, more stable control can be achieved by arranging a valve nonlinear compensation circuit on the input side of the M/A shown in FIG. becomes possible.

〔Effect of the invention〕

As described above, according to the evaporator outlet sodium temperature control device of the present invention, it is possible to stably control the evaporator outlet sodium temperature to a predetermined value during startup of a fast breeder reactor plant, etc. Reliability can be improved.

[Brief explanation of the drawing]

Fig. 1 is a piping system diagram showing the input/output relationship of the evaporator outlet sodium temperature control device of the present invention, Fig. 2 is a block diagram showing an embodiment of the evaporator outlet sodium temperature control device of the present invention, and Fig. 3 is a graph showing the change in the sodium temperature at the evaporator outlet when the opening degree of the water supply control valve is controlled by the evaporator outlet sodium temperature control device shown in FIG. 2, No. 4'vA
is a piping system diagram showing a fast breeder reactor power plant. 9... Secondary system piping 10... Evaporator 15...
Steam water separator 25...Water supply control valve agent Patent attorney Norihiro Ken Yudo Mitsumata Hirofumi Figure 1 Figure 2

Claims (1)

[Claims] (1) Evaporator outlet sodium temperature that controls the evaporator outlet sodium temperature to a predetermined value by manipulating the opening degree of the water supply control valve inserted upstream of the evaporator located in the steam system piping of the fast breeder reactor. In the control device, the feed water flow rate and evaporator outlet sodium temperature on the upstream side of the evaporator of the steam system piping are input, a feed water flow rate target value is set based on the evaporator outlet sodium temperature, and this feed water flow rate target value and the An evaporator outlet sodium temperature control device, characterized in that the opening degree of the water supply control valve is controlled based on a deviation from the flow rate of the water supply.