I. Overview
In order to improve the economy of power plants, steam turbines are equipped with regenerative heating system, which is equipped with high and low pressure heaters, high and low pressure heater when full of water failure occurs, the normal water level of the heater to maintain the hydrophobic regulating valve can not meet the fault state Under drainage capacity, required by the quick opening of the larger flow of critical hydrophobic regulating valve to drain the water. This series of critical hydrophobic regulating valve for 125,200,300,600,1000MW supporting the use of high and low pressure heaters. Also suitable for regulating the flow of all kinds of small units under 100MW hydrophobic.
Hydrophobic regulating valve poor working conditions, cavitation is very serious, critical hydrophobic regulating valve to ensure reliable operation, the company improved the original hydrophobic regulating valve structure, and learn from foreign experience in the construction and the materials have been improved so that the valve has a good anti-cavitation performance. As the seat and the valve body contact surface using a reasonable point of view, it is in the closed state is no leakage; all flow hood and spool using a high-quality stainless steel, running even in the two-phase flow and throttle status, cavitation speed is quite slow, thus extending the life of the valve, the noise is small. Because of the critical requirements of the trap door opened and can not quickly produce jamming phenomenon, it all flows between the cover and plug gaps than normal hydrophobic regulating valve to be bigger, flow holes are generally designed to reverse convex. Valves are designed using simple assembly and disassembly of the structure, when damage to internal parts, just remove the bonnet nut, remove the valve cover, you can remove each part in turn, free to replace any parts, maintenance is very convenient.
Second, the principle
Emergent Drain valve is by electric actuators and critical hydrophobic regulating valve composed of two parts. Electric control valve actuator input is sent direct current signal, the servo amplifier and later drive actuators, produce axial thrust, driving the regulator valve action, causing medium flow changes in the system to adjust various parameters. Also issued a valve actuator position signal for servo amplifier comparison, the regulator valve is always maintained at a position corresponding to the input signal, the complete servo adjustment task.
|
