Method for testing flow characteristics of control valve of turboset in constant power mode

Abstract

The invention provides a method for testing flow characteristics of a control valve of a turboset in a constant power mode. The method comprises the following steps of: putting a coordination mode into a unit CCS coordination control system, and exiting an AGC automatic power generation control function and a CSS / DEH bilateral primary frequency modulation function; maintaining the unit load unchanged, continuously increasing the set bias of the main steam pressure according to a certain rate, and enabling the opening degree of the control valve to be continuously decreased along with continuous increase of the main steam pressure; and synchronously recording and acquiring related thermal parameters under multiple different load test conditions, performing normalization correction and related calculation on the original data, obtaining the flow characteristics of the control valve of the turboset, and further carrying out setting or verification operation of a steam distribution function of a DEH system of the turboset. According to the method disclosed by the invention, due to transverse comparison between different loads or repeated testing of the same load, the system error and random error in the testing process are effectively reduced, and the test efficiency and test quality are obviously improved. The method disclosed by the invention can be applied to offline setting orverification of the steam distribution function of the DEH system and can also be applied to online verification of the steam distribution function of the DEH system.

Description

technical field [0001] The invention relates to a test method for the flow characteristics of a steam turbine unit in a constant power mode, and belongs to the technical field of steam turbine unit operation. Background technique [0002] Modern steam turbine units have widely used DEH (Digital Electro-Hydraulic Control System) digital electro-hydraulic control system to implement valve sequence management. The flow characteristic of the regulating valve refers to the numerical correspondence between the inlet steam flow and the opening of the regulating valve under the established steam distribution structure and valve sequence mode when the steam turbine unit operates with variable load and constant parameters. During operation, the flow characteristic of the regulating gate is the external performance of the steam distribution method of the steam turbine unit; the steam distribution function of the DEH system must follow the inherent flow characteristics of the unit in or...

AI Technical Summary

Problems solved by technology

Practice shows that the conventional test has the following deficiencies: First, the setting of the test valve position is discretely distributed, and there are large human factors, so it is difficult to accurately grasp the nonlinear characteristic information of the flow characteristics of the control valve

Third, some units are limited by the functions of the DEH system, and the total valve position command needs to be manually assigned, which may cause a safety risk of non-stop of the unit due to misoperation; at the same time, in order to increase the number of test samples, the number of on-site manual assignments often reaches 300-400 times ( If the total valve position instruction interval is 0.1%)

Not only is the work intensity high, but also, due to the weak flow adjustment ability of the valve during the pre-opening stage and the idle stroke stage, the valve position changes rapidly; manual assignment often cannot keep up with the changes in the system state, and cannot guarantee the stable control and stability of soda parameters. Continuous sampling of door opening

Fourth, due to the large drop in unit load during the test (for example, a 600MW unit, the difference between the highest load and the lowest load is about 250MW), the test period is long and the test process is complicated, it is not suitable for multiple tests on site; the systematic error of the test and random errors often cannot be effectively eliminated by repeated testing

Therefore, it is difficult for conventional test methods to effectively capture and collect a sufficient number of representative test samples, which brings many uncertainties to the later adjustment of flow characteristics and overlap settings, resulting in low test efficiency and poor quality.

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