JPS5842779Y2 - Control device for condensate system in nuclear power generation equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a condensate system in a nuclear power generation facility.

In general, a condensation system condenses exhaust steam from the main turbine in a condenser and sends water as condensate to the nuclear reactor via the water supply system. This system is characterized in that the condensate purification system of the water system always operates at a constant flow rate regardless of the plant output and operating conditions.

As shown in Fig. 1, this purification system consists of a condenser 1 that condenses and cools exhaust steam to form condensate, a condensate filtration pump 2 that increases the pressure of condensate, and a condensate filtration device 3. and a condensate desalination device 4 are arranged in series and connected to the condensate desalination device 4,
The air extractor intercooler 5 and the gland steam condenser 6 are arranged in parallel, and the air extractor intercooler 5 and the gland steam condenser 6 join together again at the outlet and form a condensate pipe 7. is connected to the condensate pipe 7 to form a recirculation pipe 8 leading to the condenser 1.

Further, a condensate pump 9 is disposed downstream of the condensate pipe 7, and is connected to a nuclear reactor 11 via a water supply pipe 10 on its discharge side.

Therefore, the steam condensed in the condenser 1 and the feed water heater drain etc. are collected together, and after the necessary radioactivity decay time in the condenser 1, the pressure is increased by the condensate filtration pump 2. The water is sent to the condensate purification system, and becomes clean condensate through the condensate filtration device 3 and the condensate desalination device 4, and then undergoes heat exchange through the air extractor intercooler 5 and the grand steam condenser 6. After that, the water is sent to the suction of the condensate pump 9, but as mentioned above, this system always operates at a constant flow rate regardless of the plant output and operating conditions, so the recirculation pipe 8 to the condenser 1 is is installed.

However, in order to make the main system independent, simply providing the recirculation line 8 to the condenser 1 causes various problems.

That is, when the recirculation pipe 8 of this system is used to flow the water to the condenser 1, paper is generated.

Changes in differential pressure within this system cannot be absorbed.

It is not possible to instantaneously respond to the reactor's maximum water supply demand.

Alternatively, if one of the condensate filtration pumps 2 trips, it is not possible to take immediate action on the reactor water supply system.

Furthermore, the condensate filtration pump 2 that is being started runs out.

FIG. 2 shows an outline of a solution to the above problem, and the same parts as those in FIG. 1 are given the same reference numerals and the explanation thereof will be omitted.

An intermediate storage tank 12 connected to the recirculation pipe 8 is installed, and as a control system for the intermediate storage tank 12, a water level detector 13, a water level controller 14, and a water level control valve 15 are installed on the recirculation pipe.

The intermediate storage tank 12 is generally controlled by a water level detector 13, a water level regulator 14, and a water level control valve 15.

However, as mentioned above, when a flow rate change occurs due to a water supply request from the reactor side or a trip of one of the condensate filtration pumps 2, the water level control method does not reflect the flow rate change in the water level change in the intermediate storage tank 12. Then, in order to control the system, fluctuations in the flow rate to the reactor water supply system occur.

In addition, if the flow rate changes in the water supply system, for example, if one of the two condensate pumps in operation trips and the standby pump does not start automatically, the main water supply system is independent of plant operation, so the flow rate will be exceeded. The missing bone appears as a change in the water level in the intermediate storage tank 12.

This water level change is detected by the water level detector 13 and a water level change signal is sent to the water level control valve 1 via the water level controller 14.
5 is operated to discharge the excess or deficiency of the flow rate to the condenser 1 and ensure the flow rate of the intermediate storage tank 12. However, the change in flow rate appears as a change in the water level of the intermediate storage tank 12, and the water level control valve 15
It takes more than 10 seconds for the opening/closing operation to occur, and the condensate is allowed to overflow for this amount of time.
As a result, the water level in the intermediate storage tank 12 will be raised or lowered.

For example, when the water level rises, the intermediate storage tank 12 becomes full of water, and when the water level falls, paper is generated within the system.

The present invention was developed in view of the above points, and is a control device for a condensate system in a nuclear power generation facility, which prevents fluctuations in flow rate to the water supply system when flow fluctuations occur on the condensate system side, and Eliminates condensate overflow from the time the water level changes in the intermediate storage tank until the control operation is completed when the flow rate changes on the side, and also prevents the intermediate storage tank from becoming full due to the rise and fall of the water level in the intermediate storage tank, or the generation of paper in the condensate system. The purpose of the present invention is to provide an excellent control device for condensate systems.

An embodiment of the present invention will be described below with reference to the attached FIG. 3.

Note that the same parts as in FIGS. 1 and 2 are designated by the same reference numerals, and the explanation thereof will be omitted.

A condensate flow rate detector 16 and a feed water flow rate detector 17 are disposed on the condensate pipe line 7 and the water supply line 10 to detect the respective flow rates, and the flow rate signals detected by both flow rate detectors are used to detect both flow rates. A deviation calculator 18 is installed to detect the balanced state of the pipe flow rate, and a deviation signal transmitted from the deviation calculator 18 and an output signal from the water level controller 14 are used to detect the balance state of the flow rate in the recirculation pipe 8. An addition calculator 19 is installed to transmit an operation instruction signal to a flow rate adjustment mechanism consisting of a water level adjustment valve 15.

Therefore, the flow rate of the condensate pipe 7 is detected by the condensate flow rate detector 16, and the flow rate of the reactor feed water pipe 10 is detected by the feed water flow rate detector 1.
The balance state of both pipes is detected by the deviation calculator 18 based on the side flow rate signal detected and transmitted by 7, and if there is a deviation between the condensate flow rate and the feed water flow rate, the deviation is added to the calculation unit 18. 19.

The addition calculator 19 adds the output signal of the water level regulator 14 to the transmitted deviation signal and transmits an operation instruction signal to the water level regulating valve 15.

This controls the flow rate in the recirculation line 8 to the condenser 1.

That is, the balance state between the water supply flow rate and the condensate flow rate is constantly monitored, and as soon as the balance is lost, the flow rate adjustment mechanism consisting of the water level control valve 15 is operated so that the deviation between the water supply flow rate and the condensate flow rate becomes zero, After that, the control device performs a corrective operation for the deviation of the water level using a water level detector 13 and a water level controller 14.

Therefore, even if an imbalance occurs between the water supply flow rate and the condensate flow rate, the operation of the control valve 15, which is the operating end, follows the flow rate deviation, so there is no time delay.

Since this time delay is smaller than that of a simple water level control method, this control device can perform stable control without causing any disturbance to the condensate system or water supply system.

As a modification, the same effect can be obtained by monitoring the balance state between the plant load and the condensate flow rate.

As explained above, according to the present invention, the balance between the water supply flow rate and the condensate flow rate is constantly monitored, and if the balance is lost, the flow rate adjustment mechanism is immediately activated to reduce the flow rate of the recirculation pipe to the condenser. By installing a control device that eliminates the deviation between the water supply flow rate and the condensate flow rate, even if an imbalance occurs between the water supply flow rate and the condensate flow rate, the flow rate adjustment mechanism can be operated to follow the flow rate deviation. However, it is possible to provide a control device for a condensate system in a nuclear power generation facility that can perform stable control without causing a time delay, without causing any disturbance to the condensate system or the water supply system.

[Brief explanation of the drawing]

Figure 1 is a system diagram showing the configuration of a general condensate system and water supply system in nuclear power generation equipment, Figure 2 is an explanatory diagram of the configuration of the conventional condensate system control device in the same figure, and Figure 3 is an implementation according to the present invention. FIG. 2 is an explanatory diagram showing the configuration of an example condensate control device. 1... Condenser, 3... Condensate filtration device,
4... Condensate desalination device, 7... Condensate pipe line, 8... Recirculation pipe line, 12... Intermediate storage tank, 13... ...Water level detector, 14...Water level controller, 15...Water level control valve, 16...
...Condensate flow rate detector, 17... Water supply flow rate detector, 18... Deviation calculator, 19... Addition calculator.

Claims (1)

[Scope of utility model registration request] A condensate purification system is formed by a condenser/condensate filtration device, a condensate desalination device, an air extractor intercooler, a grand steam condenser, etc., and is connected to a condensate pipe leading to the condenser. In a condensate system that has an intermediate storage tank and its control system, a water level detector, a water level controller, and a water level control valve on the recirculation pipe,
A condensate flow rate detector and a feed water flow rate detector are installed on the condensate pipe and water supply pipe to detect the respective flow rates, and a deviation calculator is installed to detect the balanced state of the flow rate of both pipes based on the detected flow rate signal. A nuclear power generation facility, characterized in that an addition calculator is installed and provides an operation instruction signal to a flow rate adjustment mechanism based on a deviation signal transmitted from the deviation calculator and an output signal from a water level controller. Condensate system control device.