Monitoring device and online monitoring method of quick closing process of steam turbine inlet valve

Abstract

The invention discloses a monitoring device and an online monitoring method of a quick closing process of a steam turbine inlet valve. The monitoring device comprises first to n-th main valve displacement transducers for measuring the opening of a main valve of the steam turbine, first to m-th control valve displacement transducers for measuring the opening of a control valve of the steam turbine, a first pressure sensor for measuring the oil pressure of a servomotor, a second pressure sensor for measuring the oil pressure of AST, a trip circuit for measuring trip signals, a high-speed data acquisition device and a computer. The on-line monitoring method comprises the following steps of initialization, parameter setting, acquisition, alarming, displaying and querying. The monitoring device and the online monitoring method provided by the invention have the beneficial effects of realizing real-time online continuous monitoring of a steam turbine valve closing process, evaluating and early warning the valve state, realizing fast fault positioning, and having an important significance for realizing the predictive maintenance of equipment, reducing the operational security risk, and ensuring the reliable operation of the steam turbine.

Description

technical field [0001] The invention belongs to the technical field of steam turbine measurement and diagnosis, and relates to a monitoring device and an online monitoring method for the fast closing process of a steam inlet valve of a steam turbine. Background technique [0002] The overspeed of the steam turbine generator set is a vicious accident in a thermal power plant, which will cause great harm to the safety of production, and have a great impact on the production of enterprises and even people's lives. Astringency is the main cause of overspeed, and the relevant technical standards clearly stipulate that the valve closing time test must be carried out. However, the closing time of the valve is at the millisecond level. The control system currently configured on site cannot meet the requirements of the valve closing time test due to the long sampling period. At the same time, there are also shortcomings in the measurement of the valve opening. The stroke of the o...

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Problems solved by technology

However, the closing time of the valve is at the millisecond level. The control system currently configured on site cannot meet the requirements of the valve closing time test due to the long sampling period. At the same time, there are also shortcomings in the measurement of the valve opening. The stroke of the oil motor of the valve is used to represent the valve opening, but the stroke of the oil motor cannot truly reflect the valve opening when a failure such as valve stem falling off occurs; in addition, some steam inlet valves of the steam turbine use stroke switches to measure the opening and closing status of the valve. method, when the limit switch has problems such as poor contact contact, the valve state will lose monitoring, and the closing time cannot reflect the trend of the whole process of valve closing, which is not convenient for fault analysis

[0003] At present, the valve closing time test method is to connect the valve oil motor stroke, stroke switch and other signals to the high-speed recording instrument for testing and offline manual analysis when the unit is out of operation. The test cannot be performed when the steam turbine is running, but the steam turbine is running due Due to heat deformation, gap change and other reasons, the valve is more likely to be closed slowly or even jammed, resulting in the loss of monitoring means for the valve status of the unit during normal operation, and the failure of the valve cannot be found in time, posing a great safety hazard, so online monitoring is required , real-time monitoring of the closing process of the steam turbine valve when the unit trips

At the same time, due to the complex causes of valve failure, it is difficult to locate the fault location after the valve fails, and it is often necessary to re-simulate the fault state to check one by one, so it is necessary to carry out online fault diagnosis

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