A real-time online cavitation monitoring and early warning system and method for thermal power station control valves

Abstract

A real-time on-line cavitation monitoring and early warning system and method for a regulating valve in a thermal power station, the system includes an external monitoring unit connected to the DCS control system of the power station, a monitoring target regulating valve, a pipeline flow sensor, a temperature sensor upstream of the regulating valve, and a pressure sensor upstream of the regulating valve And the downstream pressure sensor of the regulating valve; the external monitoring unit and the DCS control system of the power station conduct two-way communication through the standard industrial MODBUS serial port supported by the DCS of the conventional power station, and receive the pipeline flow sensor, upstream temperature sensor of the regulating valve, The measurement signals of the upstream pressure sensor of the regulating valve and the downstream pressure sensor of the regulating valve, and send the cavitation check result of the regulating valve to the DCS control system of the power station. Operators; it is of great significance to improve the equipment management level of thermal power plants, prolong the life of key equipment, and reduce maintenance and repair costs.

Description

technical field [0001] The invention relates to the technical field of automatic control of thermal power plants, in particular to a real-time on-line cavitation monitoring and early warning system and method for regulating valves in thermal power plants. Background technique [0002] Regulating valves are one of the most common industrial devices and are used in a wide range of applications. Cavitation (cavitation) is one of the main factors for the damage of the control valve, and it is also an item that must be checked in the valve selection during the system design stage. The cavitation (cavitation) of the valve is that when the liquid working medium flows through the narrowest constriction of the valve, the increase of the local velocity causes the pressure to drop rapidly. When the working medium flows further toward the outlet, the flow rate gradually decreases with the increase of the flow area, and the pressure is restored. At this time, under the action of the hig...

AI Technical Summary

Problems solved by technology

However, during the working process of the actual system, the start-stop and frequent load adjustments cause the actual working conditions of the valve to change greatly, and often deviate far from the design working conditions, which makes the cavitation check calculation in the conventional design stage unable to avoid the actual valve work. cavitation

A large number of power station system valve maintenance experience shows that although the valve selection in the power station system design process has been checked for cavitation, the actual system often causes the valve to operate under severe conditions during startup and shutdown and frequent load adjustments, which leads to Valve cavitation damage is still the main cause of valve damage in power plant systems

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