Nozzle governing steam turbine flow characteristic test method

Abstract

Provided is a nozzle governing steam turbine flow characteristic test method. According to the method, the steam distribution end of a steam turbine is assumed as an equivalent nozzle, the forward pressure, backward pressure and pressure ratio of the equivalent nozzle are taken as variables to perform indirect numerical mapping (direct mapping when the intermediate conversion link 'flow ratio' is removed) on 'actual flow-flow ratio-regulating valve position instruction' of the steam turbine by two different mapping methods, namely, an 'indirect method' and a 'direct method', and regulating valve overlap is finely adjusted by double means of setting 'the regulating valve opening amplitude limit under inlet air flow increase per unit' and numerically quantizing 'the degree of influence of regulating valve throttling loss to the heat consumption of the steam turbine', thereby obtaining a steam distribution function conforming to the actual flow characteristic of the steam turbine and realizing precise control on the inlet air flow of the steam turbine under different valve control modes. The nozzle governing steam turbine flow characteristic test method of the invention is suitable for nozzle governing steam turbine flow characteristic setting and steam turbine steam distribution end operation mode integrated optimizing control research.

Description

technical field [0001] The invention relates to a flow characteristic test method of a steam turbine with nozzle distribution, and belongs to the technical field of steam turbine generator unit operation. Background technique [0002] During the operation of the steam turbine using nozzle steam distribution, the inlet steam flow of the steam turbine is increased by sequentially (or synchronously) opening several regulating valves. Usually, the numerical corresponding relationship between the total valve position command of the entire control valve group and the valve position commands of each control valve and the inlet steam flow of the steam turbine is regarded as the flow characteristic of the steam turbine. The digital electro-hydraulic control system (DEH) of the steam turbine realizes the precise control of the steam inlet flow of the steam turbine through the built-in valve management function of the steam distribution function. The steam turbine flow characteristic ...

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Problems solved by technology

If the degree of overlap is too small, it is easier to observe from the flow characteristics of the steam turbine. However, there is no relevant evaluation basis for whether the setting of the degree of overlap is conservative, whether the safety and affluence are appropriate, and the numerical quantification of the impact of throttling loss on the heat consumption of the steam turbine unit. and test cases

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