Hydraulic device of water turbine speed governing and protection system

Abstract

The invention provides a hydraulic device of a water turbine speed governing and protection system. The hydraulic device comprises a guide vane control valve group and a vane control valve group which are connected with a pressure oil source; the guide vane control valve group and the vane control valve group are respectively connected with a guide vane servomotor and a vane servomotor. The hydraulic device also comprises a pure mechanical hydraulic over-speed protection device, an accident shutdown circuit and an emergency / accident shutdown control valve group. The accident shutdown circuit is connected in series between the guide vane control valve group and the guide vane servomotor; the pure mechanical hydraulic over-speed protection device and the emergency / accident shutdown control valve group are connected in sequence; the shutdown signal output end of the emergency / accident shutdown control valve group is connected with the shutdown control signal input end of the guide vane control valve group, the accident shutdown signal input end of the accident shutdown circuit and the shutdown control signal input end of the vane control valve group. The hydraulic device provided by the invention is high in applicable pressure, reduced in size, reduced in servomotor and pipeline dimension, simple in layout and attractive in appearance. After the pressure of the system is increased, a medium-pressure air supply system is not needed, and therefore, the cost is greatly reduced and the space is saved. The hydraulic device is in favor of large-scale use and popularization.

Description

technical field [0001] The invention relates to the field of water turbines, in particular to a hydraulic device applied to the speed regulation and protection system of a water turbine with medium and high oil pressure. Background technique [0002] The mechanical hydraulic follow-up device is a part of the entire turbine control system. It is a follow-up device that connects the guide vane / vane servomotor and the electrical control system of the turbine, and is the actuator of the turbine control system. In recent years, the water turbine control system has been greatly developed, the products are more mature, and the performance has reached a higher level. The main forms of the current hydraulic turbine control system actuators are: electro-hydraulic converter (including proportional valve) + main pressure distribution valve, stepping motor + main pressure distribution valve, servo motor direct drive and other forms, among which the first two applications more extensive....

AI Technical Summary

Problems solved by technology

The main pressure distribution valves used in these two structures are divided into two types: self-developed by domestic manufacturers and imported from well-known international companies, but no matter what, they are all single-piece and small-batch production, and the size of the valve body is large, and the quality is difficult to control. As a result, units with the same main valve size are often used, and even the adjustment quality of different units in the same power station is difficult to unify, and the cost is high

[0003] At the same time, because most of the current speed control systems adopt the main pressure distribution valve structure, the applicable pressure is low, and the system requires a large amount of oil. The oil pressure device for this system mostly uses a non-isolated pressure tank, and the volume is generally 1m 3 ~40m 3 In addition, a special medium-pressure air supply system needs to be set up, so it is bulky and inconvenient to arrange, and it greatly increases the cost in terms of plant cost and equipment purchase. The system structure is shown in the attached Figure 10 shown

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