Nozzle steam distribution shafting instability fault early warning method of steam turbine

Abstract

The invention discloses a nozzle steam distribution shafting instability fault early warning method of a steam turbine. The method includes steps: adjusting the operation state of a unit, enabling theunit to operate in a single-valve mode, and acquiring data of shaft vibration and shoe temperature of #1-#3 bearings of the steam turbine with different loads and different steam pressures; calculating reference values and change values of shoe temperature and shaft vibration fluctuation of the #1-#3 bearings according to the acquired data; establishing a shafting fault diagnosis model; and customizing a shafting instability fault early warning mechanism according to the established shafting fault diagnosis model to determine whether the steam turbine has a shafting instability fault, whereinthe determination method includes that if online monitoring data of the unit exceeds a calculated early warning value, it is indicated that a shafting instability problem exists. According to the method, an ultra-limit alarm mechanism adopted during conventional shafting stability monitoring is changed, a new shafting instability fault early warning mechanism is introduced, an accurate early warning function of the steam turbine in a nozzle steam distribution mode is realized, and the performance of security operation of the unit is effectively enhanced.

Description

technical field [0001] The invention relates to the field of power grid dispatching communication, in particular to a method and device for diagnosing and on-line monitoring the stability of a shaft system of a steam turbine. Background technique [0002] At present, in the face of increasingly depleted energy sources and increasingly serious environmental pollution and other common human problems, large-scale development and utilization of new energy sources such as wind power and solar energy, and energy conservation and emission reduction measures have become important energy development strategies for all countries. Due to the dominant position of thermal power generation in my country's installed capacity, it is imperative that many high-power thermal power units participate in deep peak regulation to stabilize the random fluctuation characteristics of new energy power. Moreover, each power plant not only fully taps the energy-saving potential of the units, but also ado...

AI Technical Summary

Problems solved by technology

However, the shaft system instability fault of the steam turbine does not occur suddenly, and there is a certain development trend, and the overrun alarm mechanism does not use this trend to realize the fault early warning function

Therefore, the existing overrun alarm mechanism and online monitoring methods are not conducive to the fault diagnosis of steam turbine shafting instability problems, and it is easy to ignore the potential faults of the unit

Essentially, for a steam turbine in the nozzle adjustment mode, the shafting instability is the displacement of the turbine rotor caused by the unbalanced gas flow force, resulting in shaft vibration, which causes the unevenness of the lubricating oil and causes the bearing temperature change

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