A Diagnosis Method for Abnormal Efficiency of the Flow-through Stage of the High Pressure Cylinder of a Steam Turbine

Abstract

The invention discloses a diagnosis method for through-flow stage efficiency abnormality of a steam turbine high-pressure cylinder. The invention studies how to diagnose the cause of abnormal through-flow parameters of a high-pressure cylinder. According to the scheme, the method comprises the following steps: first, testing the influence of temperature change of inlet steam on the through-flow stage efficiency of a high-pressure cylinder, and judging whether there is a steam leakage phenomenon inside the high-pressure cylinder according to the linear trend of expansion of steam in a steam turbine; then, closing the electric doors of extraction steam in all sections of the high-pressure cylinder, measuring the pressure and temperature of inlet steam, exhaust steam and extraction steam in all sections, calculating the ratio of extraction steam pressure to after-stage flow under variable conditions, comparing the extraction steam pressure with the pressure after corresponding through-flow stage; and finally, determining the cause of through-flow stage efficiency abnormality of the high-pressure cylinder. The cause of through-flow stage efficiency abnormality of a steam turbine high-pressure cylinder is diagnosed according to boundary conditions by making use of the expansion characteristics of superheated steam in the steam turbine and the flow characteristics of superheated steam in the channel. The invention fills a technology gap in diagnosis of through-flow stage efficiency abnormality of a steam turbine high-pressure cylinder in our country.

Description

Technical field: [0001] The invention belongs to the field of thermal power generation, and in particular relates to a method for diagnosing abnormal efficiency of a flow-through stage of a high-pressure cylinder of a steam turbine. Background technique: [0002] In the field of thermal power generation, steam turbines are one of the key equipment for converting steam heat energy into electric energy. The development route of domestic steam turbines is "introduced products-introduced technology-independent production of some equipment-completely independent production-independent development of innovative products". With the improvement of the design and manufacturing level, the performance of some products produced and developed by domestic steam turbine manufacturers has approached the world-class level, but there are still many problems in some models of steam turbines, such as the abnormal efficiency of the flow stage of the high-pressure cylinder of the steam turbine (lo...

AI Technical Summary

Problems solved by technology

Generally speaking, there are two cases of abnormal efficiency of the flow stage of the high pressure cylinder of the steam turbine: (1) The efficiency of the flow stage of the high pressure cylinder is really low due to design or manufacturing defects

(2) There is high-quality steam leakage inside the high-pressure cylinder to the steam extraction pipe or the throttling phenomenon in the extraction chamber, which leads to abnormal flow parameters and abnormal efficiency of the measured flow stage.

Domestic steam turbine equipment performance acceptance test or overhaul test has relevant test standard references (such as PTC62004 and GB / T 8117), and the test standards or regulations are for the operation process of the steam turbine performance test, the type and quantity of measuring points required for the test, and the accuracy of the test instrument Detailed requirements were made, but none of them mentioned the relevant methods of steam turbine fault diagnosis and analysis such as the abnormal efficiency of the flow stage of the high-pressure cylinder

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