System and method for monitoring water level of nuclear power plant evaporator

Abstract

The invention discloses a system and method for monitoring the water level of a nuclear power plant evaporator. The system comprises a deviation signal generation mechanism, a first master controller, a second master controller, a first slave controller, a mismatching signal generation mechanism, a negative deviation signal generation mechanism, a first manual controller, a second slave controller, a feedforward signal generation mechanism and a second manual controller. The first master controller and the second master controller are connected with the deviation signal generation mechanism. The first slave controller is connected with the first master controller and a large valve. The mismatching signal generation mechanism is connected with the first master controller and the first slave controller. The negative deviation signal generation mechanism and the first manual controller are connected with the first slave controller. The second slave controller is connected with the second master controller and a pet valve. The feedforward signal generation mechanism and the second manual controller are connected with the second master controller and the second slave controller respectively. According to the system and method for monitoring the water level of the nuclear power plant evaporator, manual control can be optimized to achieve undisturbed switching on the premise that automatic control is not influenced, so that manual control and automatic control over the large valve and the pet valve do not influence each other under any condition, and control over the water level of the evaporator is easier and more stable.

Description

technical field [0001] The invention relates to the field of nuclear power plant equipment, in particular to a nuclear power plant evaporator water level monitoring system and a monitoring method thereof. Background technique [0002] The evaporator is an important piece of equipment in a nuclear power plant, and the control of the water level of the evaporator is very important for the equipment protection and heat transfer of the nuclear power plant. The water level of the evaporator is a key parameter that can directly lead to pile jumping. If the water level is too high, it will flood the dryer, increase the humidity of the outlet steam, aggravate the erosion of the turbine blades, affect the life of the unit and even damage the unit; if the water level is too low, it will cause primary circuit damage. The coolant temperature increased, resulting in insufficient core cooling and damage to the steam generator heat transfer tubes. [0003] Due to the complexity of the par...

AI Technical Summary

Problems solved by technology

But there are the following disadvantages: when the load is greater than 20%, the large valve can realize the non-disturbance switch between automatic control and manual control, while the small valve cannot realize the non-disturbance switch between automatic control and manual control, which will easily lead to water level fluctuations and affect the normal operation of the nuclear power plant run

However, when the water level deviation of the evaporator is large, the automatic control cannot well achieve the purpose of keeping the water level on the secondary side of the evaporator at the required setting value, so manual control is required

(2) When the load is greater than 20%, and the large valve is automatically controlled, if the opening of the small valve is controlled by the second manual controller, since the main controller only receives the manual signal from the first manual controller, it does not Receive the manual signal from the second manual controller. At this time, there is an inconsistency between the output signals of the second secondary controller and the second manual controller. When switching from manual control to automatic control, due to sudden changes in the signal, the Achieve bumpless switching of small valves

(3) When the load is greater than 20%, the opening of the large valve can be manually controlled through the cooperation of the main controller and the first manual controller, and the opening of the small valve can be automatically controlled through the main controller and the second sub-controller. When the large valve is manually controlled, the water level fluctuates greatly, generating a steam-water mismatch signal, which affects the balance control of the water level, resulting in overshoot and out-of-control water level control of the small valve

(4) When the load is greater than 20%, the first manual controller and the second manual controller send manual signals to control the opening of the large valve and the small valve respectively. At this time, the main controller only receives the manual signal from the first manual controller. signal, not directly the manual signal of the second manual controller, and the signal transmitted by the second sub-controller received by the main controller is inconsistent with the manual signal of the second manual controller, which will easily lead to switching from manual control to automatic control When, due to the sudden change of the signal, the undisturbed switching of the small valve cannot be realized

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