Evaluation method of steam turbine high-pressure regulating valve frequency modulation capacity for improving peak shaving of unit

Abstract

The invention discloses an evaluation method of the steam turbine high-pressure regulating valve frequency modulation capacity for improving peak shaving of a unit. The method includes the steps thatDCS data of downstream pressure of high-pressure regulating valves of the unit from the moment when the opening degree is 0 to the moment that the valves are completely switched on is collected; the steam flow of each high-pressure regulating valve is calculated at different opening degrees of the valve; according to the opening degrees of the high-pressure regulating valves and the calculated steam flows of the high-pressure regulating valves at different opening degrees, a valve opening degree and steam flow relationship curve is drawn, the drawn relationship curve is matched with a factorydesign relationship curve, a difference absolute value is obtained according to the difference of the data, at any two adjacent moments, in the collected DCS data of the downstream pressure, and whether the absolute value of deltaP is in the interval from 0 to deltaPmax is judged; if it is judged that the absolute value of deltaP exceeds the interval from 0 to deltaPmax, it is judged that the high-pressure regulating valves have hardware faults. According to the method, fault pre-warning is carried out on sudden load changes of the unit on the basis of monitoring the downstream pressure of thehigh-pressure regulating valves, the steam turbine high-pressure regulating valve frequency modulation capacity is evaluated in real time, and the peak shaving performance of the unit is improved.

Description

technical field [0001] The invention relates to the field of power grid dispatching communication, in particular to an evaluation method for improving the frequency regulation capability of a high-frequency door of a steam turbine for peak regulation of a unit. Background technique [0002] At present, the state strongly supports the development of new energy. In order to ensure a stable and reliable supply of the new energy power system, more and more large-power thermal power units (even heating units) participate in deep and rapid peak regulation to stabilize the impact of new energy such as wind power on the grid. instability. Many large-scale thermal power generating unit steam turbines often have sudden load failures when they are put into AGC operation mode to participate in peak regulation, which seriously affects the safe and efficient operation of the unit. Generally speaking, there are many factors that lead to sudden load failures of steam turbines in practice. ...

AI Technical Summary

Problems solved by technology

When a hardware failure occurs in the high-profile door, such as the valve stem nut of the high-profile door is worn and the connecting parts of the valve head are tripped and loosened (or even fall off), the valve stem is lifted and lowered according to the given command, but the valve head is under steam pressure. Under the action of the generated airflow force and the gravity of the valve head itself, there will be a sudden change in the opening of the high-profile door (such as figure 2 Shown), and then lead to a sudden change in unit load, the pressure difference after the high-profile gate valve between adjacent moments of the valve stem will be greater than the maximum value during normal operation

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