Method for detecting shaft breakage of circulating water pump of thermal power plant

Abstract

The embodiment of the invention discloses a method for detecting shaft breakage of a circulating water pump of a thermal power plant. The method comprises the following steps of 1, recording and analyzing the current of the circulating water pump, screening out no-load current and running current, selecting a proper parameter between the no-load current and the running current as a characteristic parameter, measuring circulating water pump outlet pressure parameter signals and recording a pressure parameter signal curve to obtain circulating water pump outlet butterfly valve switch feedback and a circulating water pump motor state; and 2, picking up the signals measured in the step 1 by an N-second interval data continuous comparator, carrying out threshold judgment by the N-second interval data continuous comparator, and inputting a judgment result signal into a data logic judgment arithmetic unit. According to the method for detecting shaft breakage of the circulating water pump of the thermal power plant, efficient, stable and reliable detection alarm is achieved, and after the shaft breakage of the circulating water pump occurs, the signals can be sent out in time, the running of the circulating water pump with the shaft breakage is stopped immediately, and a circulating pump outlet butterfly valve is closed.

Description

technical field [0001] The present application relates to the field of detection of circulating water pumps, and more specifically, to a method for detecting broken shafts of circulating water pumps in thermal power plants. Background technique [0002] The function of the circulating water pump is to supply cooling water to the steam turbine condenser to condense the exhaust steam of the steam turbine. In the power plant, the circulating water pump also provides cooling water to the oil cooler, water cooler, generator air cooler, etc. Thermal power plants are generally equipped with two circulating water pumps, which can be operated as a single pump or two pumps at the same time according to the needs. Unlike other water pumps in thermal power plants, because the outlet pipe diameter of the circulating water pump is very large, almost all the circulating water pump outlets of power plants are not equipped with backstops. In the actual operation process, due to the manufactu...

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Problems solved by technology

[0002] The function of the circulating water pump is to supply cooling water to the steam turbine condenser to condense the exhaust steam of the steam turbine. In the power plant, the circulating water pump also provides cooling water to the oil cooler, water cooler, generator air cooler, etc. Thermal power plants are generally equipped with two circulating water pumps, which can be operated as a single pump or two pumps at the same time according to the needs. Unlike other water pumps in thermal power plants, because the outlet pipe diameter of the circulating water pump is very large, almost all the circulating water pump outlets of power plants are not equipped with backstops. In the actual operation process, due to the manufacturing and installation process and other reasons, once the shaft of the circulating water pump breaks, even if the backup pump is started, the circulating water will not be able to maintain the normal pressure and flow due to the pressure relief channel formed by the circulating water pump with the broken shaft. In the worst case, the unit trips, and in the worst case, it will cause damage to the main equipment such as the condenser and steam turbine, resulting in major economic losses. Therefore, the broken shaft of the circulating pump can be effectively detected, and the broken shaft of the circulating pump can be quickly shut down and shut down through the broken shaft protection interlock function. Exit gates will be extremely important

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