Nuclear power plant evaporator liquid level control method and system

Abstract

The invention provides a nuclear power plant evaporator liquid level control method which comprises the following steps: when a liquid level control system of the nuclear power plant evaporator is switched from a manual mode to an automatic mode, obtaining a liquid level deviation signal; acquiring a steam-water mismatch signal; calculating a current steam-water mismatch state according to the liquid level deviation signal and the steam-water mismatch signal; identifying the current steam-water mismatch state as a positive effect or a negative effect; and when the steam-water mismatch state isthe negative effect, performing feed-forward compensation on the liquid level of the nuclear power plant evaporator. The invention further provides a nuclear power plant evaporator liquid level control system. According to the nuclear power plant evaporator liquid level control method and system, the liquid level adjusting speed of the evaporator can be increased, overshoot is reduced, the automation level of the system is improved, the human error risk is reduced, and safe operation of a unit is guaranteed.

Description

【Technical field】 [0001] The invention relates to the technical field of automatic control, in particular to a liquid level control method and system for an evaporator in a nuclear power plant. 【Background technique】 [0002] In nuclear power plants, the steam generator (evaporator) is an important heat exchange device connecting the primary and secondary circuits of the pressurized water reactor. The water in the circuit makes it generate steam, which drives the steam turbine to do work. The water level of the evaporator directly affects the quality of the outlet steam and the safety of the evaporator. Therefore, relevant monitoring and protection measures such as liquid level threshold alarm, tripping machine and stacking are designed. . [0003] The water level adjustment of the evaporator is accomplished by controlling the feedwater flow into the evaporator. The normal feedwater circuit of each evaporator is provided with two parallel pipelines. The main feedwater regul...

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Problems solved by technology

[0006] Therefore, in the design of the replica loop of the existing nuclear power plant evaporator liquid level control system, the feedforward signal is canceled when the manual mode is switched to the automatic mode, and then loses the feedforward effect on the quick adjustment of the steam-water mismatch, resulting in a liquid level The problem of sluggish adjustment has also occurred in various nuclear power bases. After operators manually intervene in the evaporator liquid level adjustment and turn it on automatically, the liquid level adjustment is sluggish and the overshoot is too large. Consequences, bring great risk to unit operation

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