JPH11326570A - Pressurizer pressure controller of nuclear fusion reactor plant cooling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressurizer pressure controller suppressing the fluctuation amplitude of pressurizer pressure against the set value of the pressurizer pressure by recovering the temperature lowering in the liquid phase due to the inflow of primary cooling water into the pressurizer after plasma activation at earliest possible time. SOLUTION: A pressure controller of nuclear fusion reactor plant cooling equipment is provided with functions detecting the outlet temperature of a diverter cassette cooling the plasma heat generated in the nuclear fusion reactor by heat exchanging with coolant 3, calculating the outlet temperature time variation rate by operating the outlet temperature with incomplete differentiation, monitoring the time variation rate with a plasma activation monitor and a plasma termination monitor and turning on 100% of a proportional heater 15/backup heater 14 heating the liquid phase part 11b of the pressurizer 11 for a specific time when plasma activation is detected and resetting the 100% making of the proportional heater 15/backup heater 14 when plasma termination is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurizer pressure control device for a cooling system of a fusion reactor plant.

[0002]

2. Description of the Related Art A typical fusion plant cooling system is shown in FIG.
Shown in The diverter cassette 1 cools the plasma heat 2 generated in the fusion reactor by heat exchange with the primary coolant 3. The primary coolant 3 is circulated by the coolant circulating pump 4, and the secondary coolant 6 is circulated by the primary heat exchanger 5.
It is cooled by heat exchange. A heat exchanger outlet valve 7 is provided between the primary heat exchanger 5 and the coolant pump 4. Further, a bypass valve 8 for bypassing the primary coolant from the primary heat exchanger 5 is also provided. The heat exchanger outlet valve 7 and the bypass valve 8 are connected to the diverter inlet temperature T of the diverter cassette 1 with respect to the fluctuation of the plasma heat input 1.
In order to keep i constant, the flow rate of the primary coolant 3 flowing into the primary heat exchanger 5 is adjusted. The inlet and outlet of the diverter cassette 1 have a diverter inlet temperature T, respectively.
Divertor inlet and outlet temperature sensors 9 and 10 are provided to measure i and outlet temperature Td.

[0003] A pressurizer 11 is provided between the diverter cassette 1 and the primary heat exchanger 5.
1, the pressure of the primary coolant 3 is controlled to a predetermined pressure. Pressurizer 11 includes a pressurizer pressure sensor 12 for detecting the internal pressure P ₁₁ in the pressurizer 11, the spray valve to spray relatively cold water at the outlet of the coolant pump 4 in the gas phase portion 11a of the pressurizer 11 13 And a backup heater 14 and a proportional heater 15 for heating the liquid phase portion 11 b in the pressurizer 11.

[0004] As a control system in the cooling plant for a fusion plant as described above, a temperature control system for controlling the diverter inlet temperature Ti by a heat exchanger outlet valve 7 and a bypass valve 8, a spray valve 13 of a pressurizer 11, The pressurizer 1 is operated by operating the heater 15 and the backup heater 14.
There are two control systems with pressure control system that controls one of the internal pressure P ₁₁ in the pressure set value, the present invention relates to the latter of the pressure control system.

FIG. 4 shows a configuration of a conventional pressurizer pressure control system based on a pressurized water reactor (PWR). As shown in FIG. 4, in the conventional control, the deviation between the preset pressurizer pressure setpoint Pref and pressurizer pressure P ₁₁ which is detected by the pressurizer pressure sensor 12 is input to the PID controller 30,
This deviation is subjected to a proportional differential integration operation by the following equation (1).

(Equation 1) Here, Kp: proportional gain, Kd: differential gain, Ti:
Integration time, Td: derivative time, s: Laplace operator.

The output after the arithmetic processing by the PID controller 30 is sent to a backup heater table 31, a proportional heater table 32 and a spray valve table 33. In the backup heater table 31, when the output from the PID control device 30 falls below a predetermined set value, a heater ON signal is output to the backup heater 14, and the backup heater 14 operates in response thereto. The proportional heater 15 operates in response to a proportional heater ON signal from the PID control device,
As the output of the ID control device 30 decreases, the output increases proportionally. Also, the spray valve is a PID control device 30.
As the output from the spray valve increases, the amount of water sprayed from the spray valve 13 is proportionally increased.

As described above, the backup heater 14, the proportional heater 15, and the spray valve 13 are provided by the PID control device 3.
It operates depending on the magnitude of the output from zero. When the two heaters 14 and 15 operate, the liquid phase 11 of the pressurizer 11
heating the b, by raising the temperature inside the pressurizer 11, increase the pressurizer pressure P _11. On the other hand, when the spray valve 13 operates, the cooling water is sprayed onto the gas phase portion 11a of the pressurizer 11, thereby lowering the internal temperature of the pressurizer ₁₁ and lowering the pressurizer pressure P11.

In the above-described conventional pressurizer pressure control system based on a pressurized water reactor, the plasma heat input 2 is shown in FIG.
FIG. 5 shows a simulation result in the case of changing as shown in FIG. As shown in FIG. 5C, the fluctuation range of the pressurizer pressure P11 with respect to the pressurizer pressure set value Pref of the pressurizer ₁₁ is, as shown in FIG. Largest, 5.7kg /
cm ² a. The reason is that when the plasma is started, 1
Since the primary coolant 3 flows into the pressurizer 11 due to expansion due to the temperature rise of the secondary coolant, the amount of water retained in the liquid phase portion 11b increases, so that the pressurizer pressure P11 inside the pressurizer ₁₁ increases. The liquid phase portion 11b in the pressurizer 11
Due to the inflow of the primary coolant 2 at a lower temperature, the liquid phase portion 11b
Temperature is lowered, the pressurizer pressure P ₁₁ with it is also to decrease. When the pressure of the pressurizer decreases in this manner, the pressure of the primary coolant 2 cannot be kept constant, and the diverter cassette 1
Since the cooling efficiency of the plasma heat input 2 becomes low, the pressurizer pressure P11 inside the pressurizer ₁₁ needs to be maintained as constant as possible.

[0009]

[SUMMARY OF THE INVENTION However, in the conventional pressurized water reactor based pressure control systems, pressurizer pressure P ₁₁ is lower than the pressurizer pressure setpoint Pref, PID controller 30
As long as the output from the heater does not change in the decreasing direction, the proportional heater 1
5 and does not increase the output of the backup heater 14, the plasma startup of pressurizer pressure P ₁₁ is temporarily raised, FIG. 5
(A), the range of decrease of the pressurizer pressure P ₁₁ in the pressurizer 11 due to a delay of both the heaters turned is disadvantageously increased.

Accordingly, the present invention has been made in order to solve such a problem, and it is intended to reduce the liquidus temperature of the liquidus part 11b due to the inflow of the primary cooling water into the pressurizer 11 after the plasma is started. Recover at the earliest possible point and pressurizer pressure P
It is an object of the present invention to provide a pressurizer pressure control device in which the fluctuation range with respect to the pressurizer pressure set value Pref of ₁₁ is reduced.

[0011]

According to a first aspect of the present invention, there is provided a pressurizer pressure control apparatus for a cooling system of a fusion reactor plant according to the present invention, which calculates a pressurizer pressure from a pressurizer. The pressurizer pressure control device controls the pressure of the pressurizer by operating the spray valve and heater according to the output, and further cools the plasma heat generated in the fusion reactor by heat exchange with coolant. The outlet temperature of the diverter cassette to be detected is detected, the detected outlet temperature is subjected to an incomplete differential operation to calculate the outlet temperature temporal change rate, and the outlet temperature temporal change rate is monitored by a plasma start monitor and a plasma stop monitor. (1) when the plasma start monitor detects the plasma start, the heater for heating the liquid phase portion of the pressurizer is fully turned on for 100% for a predetermined time;
(2) When the plasma stop monitor detects the plasma stop, a function of resetting the 100% full turn-on of the heater is added.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressurizer pressure control device according to the present invention will be described. FIG. 2 is a diagram showing a configuration of a pressure control system in one embodiment of the pressurizer pressure control device according to the present invention. In the present invention, the detection of the start and stop of the plasma is performed by the diverter exit temperature T by the diverter exit temperature sensor 10 provided at the exit of the diverter cassette 1.
This is performed based on the detected value of d. That is, in FIG.
The detected diverter outlet temperature Td is input to the PID control device 20, where it is subjected to an incomplete differential operation by the following equation (2).

(Equation 2) Here, K: differential gain, τ: differential time, s: Laplace operator.

The output from the PID controller 20 is sent to a high monitor 21 as a plasma start monitor and a low monitor 22 as a plasma stop monitor, and by monitoring the rate of temperature change over time, the plasma is started and stopped. Are respectively detected. In order to prevent malfunction, on-delay timers 23 and 24 are provided at the exits of the high monitor 21 and the low monitor 22, respectively.

When the plasma is started, the divertor outlet temperature Td rises, and the output from the high monitor 22 turns on. When the ON state continues for the timer set time, the on-delay timer 23 is turned on, and upon receiving the output, the SET of the flip-flop 25 is turned on. When the SET of the flip-flop 25 is turned on, the proportional heater 15 and the backup heater 14 are turned on with 100% output. The input time of both heaters 14 and 15 is necessary to raise the increase in water retained in the liquid phase portion 11b in the pressurizer 11 due to the flow of the primary cooling water 2 into the pressurizer 11 at the time of plasma activation to the saturation temperature. It is calculated from the heat quantity and both heater capacities. This heater turn-on time is set in the on-delay timer 26, and the output from the on-delay timer 26 is supplied to the R
Input to ESET.

On the other hand, when the plasma is stopped, the diverter output temperature Td decreases, the output from the low monitor 22 turns ON, and when the ON state continues for a set time, the ON delay timer 24 turns ON. The output from the on-delay timer 24 is supplied to the flip-flop 2 via the OR element 27.
5 is input to RESET, and all heaters are turned on (100%
Also, during plasma input, if the plasma stops, the entire heater is turned off.

FIG. 3 shows a simulation result when the pressure control system according to the present invention is added to the conventional pressure control system based on a pressurized water reactor. In FIG.
The change pattern of the plasma heat input is the same as that of the simulation in FIG. 5 of the conventional example.

As shown in FIG. 3A, when the plasma is started, the diverter outlet temperature P is controlled by the control system described above.
_The plasma activation is quickly detected from the temperature rise of ₁₁ , and the proportional heater 15 and the backup heater 14 are turned on in advance with a 100% output. Due to the prior injection of both heaters,
As shown in FIG. 3D, the liquid phase portion 11b in the pressurizer 11
The temperature, as compared with the case of FIG. 5 (d), the rapidly increased to the saturation temperature of the pressurizer, the result, as shown in FIG. 3 (c), pressurizer pressurizer pressure P ₁₁ Pressure set value Pref
Is reduced to 2.7 kg / cm ² a.

[0018]

The pressurizer pressure control device for a nuclear reactor plant cooling system according to the present invention calculates the pressurizer pressure from the pressurizer, and operates the spray valve and the heater according to the output to operate the pressurizer. The pressurizer pressure controller for controlling the pressure further detects the outlet temperature of the diverter cassette that cools the plasma heat generated in the fusion reactor by heat exchange with a coolant, and detects the detected outlet temperature as an error. The outlet temperature time change rate is calculated by performing a full differentiation operation, and the outlet temperature time change rate is monitored by a plasma start monitor and a plasma stop monitor. (1) When the plasma start monitor detects the plasma start The heater for heating the liquid phase portion of the pressurizer is fully supplied for 100% for a predetermined time. (2) When the plasma stop monitor detects the stop of the plasma, A function of resetting 100% full injection is added, so that the plasma start can be detected quickly from the rise in the outlet temperature of the diverter cassette, and the heater can be turned on in advance with a 100% output for a predetermined time. In addition, it is possible to suppress the pressure drop when the plasma is stopped in a short time after the start.

[Brief description of the drawings]

FIG. 1 is a diagram showing a typical fusion plant cooling facility.

FIG. 2 is a diagram showing a configuration of a pressure control system in an embodiment of a pressurizer pressure control device according to the present invention.

FIG. 3 is a graph showing a simulation result by a pressure control system in an embodiment of a pressure control device for a pressurizer according to the present invention.

FIG. 4 is a diagram showing a configuration of a conventional pressurizer pressure control system based on a pressurized water reactor.

FIG. 5 is a graph showing a simulation result by a conventional pressure control system based on a pressure water reactor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diver cassette, 2 ... Plasma heat input, 3 ... Primary coolant, 4 ... Coolant circulation pump, 5 ... Primary heat exchanger, 6
... secondary coolant, 7 ... heat exchanger outlet valve, 8 ... bypass valve,
9: Divertor inlet temperature sensor, 10: Divertor outlet temperature sensor, 11: Pressurizer, 11a: Gas phase, 11b ...
Liquid phase part, 12 ... Pressurizer pressure sensor, 13 ... Spray valve,
14: backup heater, 15: proportional heater, 20,
30: PID control device, 21: high monitor, 22: low monitor, 23, 24, 26: on-delay timer, 25
... Flip-flop, 27 ... OR element, 31 ... Backup heater table, 32 ... Proportional heater table, 33
... spray valve table, P ₁₁ ... pressurizer pressure, Pref ... pressurizer pressure setpoint, Ti ... diverter inlet temperature, Td ... diverter outlet temperature.

Claims (1)

[Claims] 1. A pressurizer pressure from a pressurizer is arithmetically processed,
In the pressurizer pressure control device of the fusion reactor plant cooling system that controls the pressure of the pressurizer by operating the spray valve and the heater according to the output, the plasma heat generated in the fusion reactor is further used as a coolant. The outlet temperature of the divertor cassette to be cooled by heat exchange is detected, the detected outlet temperature is incompletely differentiated, the outlet temperature time change rate is calculated, and the outlet temperature time change rate is measured by a plasma start monitor and a plasma. (1) When the plasma activation monitor detects the plasma activation, the heater for heating the liquid phase part of the pressurizer is activated for a predetermined time.
(2) a function of resetting the 100% full injection of the heater when the plasma shutdown monitor detects the plasma shutdown, Pressure control device.