Pressure control method and device for pump unit of nuclear power station

Abstract

The invention discloses a pressure control method and a device for a pump unit of a nuclear power station. The pressure control method comprises the steps that S1, a pressure switch is turned from on to off after pressure at an inlet of the pump unit detected by the pressure switch mounted at the inlet of the pump unit is smaller than a set value, an abnormal pressure signal is generated and transmitted to a delaying module; S2, the delaying module receives the abnormal pressure signal and generates a low pump unit inlet pressure signal after being delayed according to the pre-set time; and S3, the low pump unit inlet pressure signal is transmitted to a trip instruction terminal of an electric plate cabinet of the pump unit through a hard wire to cut off a power supply of the pump unit and allow the pump unit to stop operation. The pressure control device for the pump unit comprises the pressure switch (1) and the delaying module (2). The pressure control method and the device have the benefits that the immediate stop of the operation of the pump unit in an abnormal condition (for example, the low pressure at the inlet of the pump unit) can be ensured under the situation that a DCS (Distributed Control System) and LSA (Test Loops) are unavailable, the safety of equipment is ensured, and the construction time and cost are saved.

Description

technical field [0001] The invention relates to the technical field of nuclear power, and more specifically, to a method and device for controlling the pressure of a nuclear power plant pump set. Background technique [0002] When starting a large pump set in a nuclear power plant, it is necessary to strengthen the monitoring of the pump inlet pressure parameters. Usually, it is necessary to ensure that the pump inlet pressure parameters cannot be lower than a certain value, and the pump inlet pressure parameters usually cause the pump inlet pressure to decrease due to the following reasons: [0003] 1. The density of the filter screen at the pump inlet is fine, and the flow area decreases. When the pipeline flow increases, the pressure at the pump inlet decreases. [0004] 2. The inlet valve of the pump is not fully opened, resulting in an increase in the pipe resistance of the system and an increase in the local loss of the pipeline medium. [0005] 3. The suction height ...

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Problems solved by technology

[0003] 1. The density of the filter screen at the pump inlet is fine, and the flow area is reduced. When the flow rate of the pipeline increases, the pressure at the pump inlet will decrease.

[0004] 2. The inlet valve of the pump is not fully opened, resulting in an increase in the pipe resistance of the system and an increase in the local loss of the pipeline medium

[0005] 3. The suction height of the pump inlet medium is not enough

[0017] When an accident occurs on site, the equipment in operation cannot be shut down immediately

[0018] In addition, the first start-up of the pump set can also be controlled locally through the LSA (Test Loops) system, but the LSA system cannot be used on time due to various conditions

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