JPS58165096A - Fbr power plant control device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a control device for an FBR power plant, particularly a control device for an FBR power plant.
In order to prevent frequent occurrences such as tripping of the plant due to a system failure or damage to the fuel, the control system should be replaced.

In Figure 1), which shows an example of the plant output control equipment of a BR (fast breeder reactor) power plant, the heat transport system is
It is composed of several loops, but only one of them is homologous.

FBR, the main system of the power plant is the reactor 5, primary system circulation cylinder 7'11, medium heat exchanger x2, :ja system circulation pump 17, evaporator 18, superheater set 4, Rice feed pump 2'6
31, 32, a power generation 133, a condenser 34, and a condensate pump 35. Various control systems are provided externally to this main system.

The external control system includes an output command device 1, a reactor power control device 2, a control rod drive control device 3, and a primary cooling system flow rate control device 7.
．． Primary circulation pump speed control device 8. Secondary cooling system flow rate control device 13. Secondary circulation pump speed control device 14, evaporator outlet temperature setting device 21. It consists of an evaporator outlet temperature control device 22, a feedwater lid control device 23, a main steam pressure setting device 28, a main steam pressure control device 29, a turbine control device 30, and a feedwater differential pressure control device 25.

The control device 2 takes in a detected neutron flux 4 (n) and a detected reactor output temperature 6 (T). The control device 7 takes in the detected primary cooling system flow rate sH't). Control device □II (8 examines the detection @1o (S). The control device 22 takes in the detected evaporator outlet temperature is ('r), and the control device 23 takes in the detected feed water flow rate 20 (F). The control device 29 takes in the detected main steam pressure 27 (P), the control device 13 takes in the detected secondary cooling system flow rate 15 (F), and the control device 14 takes in the detected value 16 (8).

The power plant is controlled by keeping the main steam pressure 27 and the main steam temperature 36 constant, and adjusting the reactor output (neutron flux), 4. the primary cooling system flow rate, so that the generator output meets the demand command from the power grid. 9. Control the secondary cooling system flow rate 15, water supply flow rate 20, etc.

Figure 2 shows the load characteristics of the plant. In the FBR plant, the main steam temperature T1 is controlled to be kept constant according to the requirements of the turbine. Therefore, depending on the characteristics of the intermediate heat exchanger 12, evaporator 18, and superheater 24 that constitute the heat transport system,
It is necessary to increase the reactor outlet temperature To as the load increases, and in order to make the reactor outlet temperature To' have the load characteristics shown in the figure, the reactor output Qφ and the cooling system flow rate W6 are changed as shown in the figure. 1. Control.

゛・l・;1・ In FIG. 1, the reactor power is controlled by the reactor power control, control device 2, and control rod drive control device 3 by adjusting the position of the control rods. First, the cooling system flow rate is controlled by the primary cooling system flow rate controller 7 and the primary circulation pump speed controller 8.
The rotation speed of the primary cooling pump 11 is adjusted and controlled.

The reactor power control device 2 of the power control system shown in FIG.
FIG. 2 shows a conventional example of the internal configuration of the primary cooling system flow rate control device 7 of the coolant flow rate control system.

The reactor power control device 2 creates a required reactor outlet temperature value using a reactor outlet temperature setter (program) 38 and performs Ichinoseki compensation via a time link circuit 40.

Next, the output of the time delay circuit 40 is compared with the detected reactor outlet temperature 6, and the deviation is manually inputted to the PI calculator 41 and the adder 42. The control rod 43 is driven to maintain the reactor output temperature at a predetermined value. In addition, a reactor output request command is sent through a reactor output request command setting device (program) 37 that generates a signal for the output request command of the detection power command device 1 that suppresses temperature fluctuations due to the time delay to the reactor outlet temperature detector. is created, and the deviation signal between the request command and neutral −F$4 is added to adder 4? - Manually control the reactor output. On the other hand, 1
The next cooling effect rate control device 7 outputs the output command f? of the output command device l? The even number is the primary cooling system flow rate setting device (program), 3
9 to create an arbitrary flow rate request signal. This primary system flow rate request signal is compared with the detected primary system flow rate 9, and the deviation is supplied to the control device 8 via the PI calculator 44.
The rotation speed of the secondary circulation pump 11 is adjusted to control the primary system flow rate.

In such a power generation plant system^, if the reactor output temperature device rIt2 causes some abnormality and fails on the side that increases the output, the fuel temperature will decrease due to the imbalance of the reactor output and primary system flow rate. There is a risk that the temperature will rise above the reactor exit temperature and damage the fuel cladding, and the safety system will activate and the reactor will scram. Additionally, if the secondary flow control system fails and the flow rate decreases, the reactor is similarly scrammed.

As described above, when the reactor output side system and the secondary cooling flow control system are controlled independently, a failure in one control system can cause
When a reactor reaches a scram, it not only reduces plant operability, but also causes thermal stress during the scram, shortens the life of the plant, and in the worst case, destroys the fuel cladding. It is possible that this could lead to damage to the plant, which had a negative impact on safety, operation, and life of the plant.

An object of the present invention is to coordinate the reactor power control system and the cooling system flow rate control system so that they can compensate for each other's failures.
The present invention provides a control device for a BR power generation plant.

The gist of the present invention is to focus on load characteristics that have a correlation between the neutron flux signal in the reactor control system and the flow rate in the primary cooling flow system, and to perform coordinated *lJ# If an abnormality occurs in one of the two control systems, backup can be provided by the other control system to prevent the plant from tripping, and each control system can normally control the plant.

FIG. 4 shows an embodiment of the control device of the present invention. The nuclear reactor power control device 2 includes the setting device 37 shown in FIG.
38, time delay circuit 40, PI calculator 41゜・In addition to adder 42, new gain setting device 46, low 7;・
” Has a value selection circuit (LVG) 47t'. Primary cooling system current,
1] Engineering, 7□, 3゜J murmur, Engineering, 39, PI calculator 4-
4, a gain setter 45, a high value' selection circuit (HVG
) has 48.

With this configuration, the gain setter 45 multiplies the primary cooling system flow 17 by a predetermined gain and provides an input to the low value selection circuit 47. The gain setter 461 multiplies the reactor output (neutron flux) 4 by a predetermined gain and provides an input to the high value selection circuit 48 . The details will be explained below.

Normally, the reactor power control system is controlled as described above, but in addition thereto is a signal W based on the secondary cooling system flow rate.

The calculated value is added to the reactor power control system as a control variable. The reactor output side # signal added here is obtained by multiplying the primary system flow rate by the following coefficient and number.

K1-1+α(α〉0) ・・・・・・・・・
(1) W = K I W O, ” ”° = (2) However, W: Signal W based on flow rate: L V G, input signal falcon, signal entering low value selection path 47 is based on reactor output Qφ and paralysis amount signal W according to
Since the relationship holds true, the low value selection circuit 47 selects Qφ
A signal is passed through. Therefore, the atomic power control device is
It is controlled by the Qφ signal.

Similarly, in addition to the flow rate signal, the secondary cooling system flow control device also adds a control variable obtained by computationally processing a neutron flux signal indicating the output of the reactor. m is given by the following formula.

K Mayuzumi = 1-α (α>O) ・・・・・・・・・＋4+
Q′φ= K s Qφ ・・・・・・・・・
(5) However, Q-; neutron flux signal Q'φ, HVG input signal block, normally input signal to the high value selection circuit 48 as described above, reactor output signal Q'φ and flow rate signal W.

Since there is the relationship shown in (6), the output from the high value selection circuit 48 is a signal based on the flow rate, and the output from the primary cooling system is determined by W. The flow rate is controlled.

Next, a control example when a gain setting device 45 etc. is added is shown in the fifth section.
This will be explained with reference to FIGS. There is a certain relationship between the neutron flux signal, which is the output signal in the reactor control system, and the primary cooling system flow rate. and the amount of cicada in the secondary cooling system W. is constant. When the circuit according to the present invention is added, two upper and lower bands are provided as shown by the dotted line. Even if the control function of one side is lost and the line of Qφ/W changes, the other side's normal flllJ control will work so that it stays within the band. The case of failure is illustrated in Figure 6a.The plant is operating normally, but at a certain time t1, the reactor power control device fails to the increasing side, and the output continues to increase as shown by the dotted line. , the reactor safety system works and the reactor scrams.In the case of the present invention, the reactor output, Qφ increases,
- Signal (j +, a) due to the stealth cooling flow rate W.
When Wa and K become larger, the current signal of the primary cooling system flow rate is used as □1 and adopted 1 for the LVG, and the reactor output Q-
Fortunately, the reactor can continue normal operation after 8 degrees of recovery. 5
.

Further, a case in which the secondary cooling system flow rate control device fails will be explained with reference to FIG. During steady operation, if the secondary cooling system flow control device fails in the direction of the flow rate paper, the signal due to the flow rate will be canceled, and the signal (1+a) Qφ value due to the reactor output Qφ will pass through the HVG. - Control of the secondary cooling system flow is performed by this signal.

As described above, according to this embodiment, in the event of a failure of the reactor power control device, the reactor power is controlled by the -secondary cooling system flow rate, and the -secondary cooling system flow rate control device In the event of a failure, by controlling the amount of the primary cooling system based on the reactor output, plant abnormalities and trips can be prevented, and plant safety and operation rates can be improved. ...: In the above embodiment, the output side system and the flowing view control (2) system are just an example, and for example, the setting -::38 eliminates the delay circuit 40 and directly gives the output command value. You can do it like this. Further, advance control may be made more complex or simpler. The same applies to the flow control system. Also, low value,
Prioritizing high prices is just one example, but cooperation based on more complex functional relationships is also possible.

As detailed above, according to the present invention, the following effects can be achieved.

(1) By adding some additional functions to the conventional control functions, even if one control system fails, the other control system will provide backup, preventing disturbances to the plant and preventing plant trips. This can improve operation and reliability.

(2) Some functions are added to the existing system, so the control function does not become complicated and is economical.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the control equipment of the FBR plant, Figure 11 and Figure 2 are diagrams showing the load characteristics, Figure 3 is a diagram without the conventional 'i control block diagram, and Figure 4 is the diagram shown in this book. fruits of invention)...
. Embodiment diagrams @ Figures 5 to 7 show explanatory diagrams when the control function according to the present invention is activated. 1... Output command device, 2... Nuclear reactor power control device,
3... Control rod drive control device, 4... Neutron flux, 5...
...Reactor, 6.Reactor outlet temperature, 7..Primary cooling system flow rate control device, ..Primary system circulation pump speed control device, 9..Primary cooling system flow rate, ll. ...Primary system** pump, 12...Intermediate heat exchanger, 13...Secondary cooling system flow rate control device, 14...Secondary circulation pump speed control device, 15...2' secondary cooling System flow rate, 17... Secondary circulation pump, 18...! Evaporator, 19...Evaporator outlet flow rate, 20...Water supply flow rate, 21...Evaporator outlet warm film capacity, 22...Evaporator outlet temperature control device, 23...Water supply flow rate Control device, 24... Superheater, 25... Feed water differential pressure control device, 26... Feed water pump, 27... Main steam pressure, 28... Main steam pressure setting device, 29... Main Steam pressure setting device, 30...Turbine control device, 31.3
2... Steam turbine, 33... Generator, 34...
Condensate 6.35...Condensate pump, 37...Reactor power setting device, 38...Reactor outlet temperature setting device, 39...
Primary cooling system flow rate setting device, 40... time delay circuit, 41
．． 44... Proportional/integral (PI) controller, 42... Adder, 43... Control rod, 45... Gain setting device, 4
6... Gain adjuster, 47... Low value selection circuit (LV
G), 48-... High value selection circuit (HVG), To...
Reactor outlet temperature, T1...main furnace temperature, W...1
Secondary cooling system flow rate, Qφ...Reactor output. Agent Patent Attorney Masami Akimoto

Claims (1)

[Scope of Claims] 1. Consisting of an output control system for controlling the reactor output of the FBR based on the output request, and a flow rate control system for controlling the reactor coolant flow rate of the FBR based on a flow rate command. 1 The power control system takes in the coolant flow rate taken into the flow control system, and the flow rate control system takes in the reactor output taken into the power control system, and controls the output control system and the flow rate. In order to complement each other, the FBR reactor output control is performed by matching the coolant flow rate from the other system with the reactor output.
F configured to control the reactor coolant flow rate of FBH
BR power plant control device. 2. An output control system that controls the FBH reactor output according to the output request, and a flow control system that controls the reactor coolant flow rate based on the flow rate command (FBRC). , takes the actual coolant flow rate that has not been taken into the flow control system, multiplies it by a predetermined gain, compares the multiplication result with the reactor output command value, and outputs the larger value (reactor output The flow rate control system takes the actual reactor power input into the output control system, multiplies it by a predetermined gain, and uses the multiplication result and the coolant flow rate command value. A pB Kyusaku power plant control device configured to compare and output a smaller value and apply it to a reactor coolant flow rate control means.