Control method and system for feed water pump steam turbine

Abstract

The invention discloses a control method for a feed water pump steam turbine. The control method comprises the steps of S1, sending a command of expanding a servo valve and controlling a low pressureside regulating valve to open wide according to the deviation between the target speed and actual speed of a steam turbine through a controller; S2, detecting the low pressure side inlet steam pressure parameter of the feed water pump steam turbine through a pressure transmitter, and transmitting the determined low pressure side inlet steam pressure parameter of the steam turbine to the controller; S3, judging whether the low pressure side inlet steam pressure is matched with the target speed of the steam turbine or not through the controller according to the low pressure side inlet steam pressure of steam turbine from the pressure transmitter, and if not, controlling a high pressure side regulating valve to open and enable the low pressure side inlet steam pressure to adapt to the targetspeed of the steam turbine, and enable the speed of the feed water pump steam turbine to stabilize at the target speed. Correspondingly, the invention further discloses a control system for the feed water pump steam turbine. By using the control method and system, the control is more practical; when the working conditions are changed, the high and low pressure side regulating valves of the feed water pump steam turbine respond quickly, and the speed response capability is improved.

Description

technical field [0001] The invention relates to the technical field of a feedwater pump steam turbine, in particular to a control method and a control system for a feedwater pump steam turbine. Background technique [0002] In recent years, with the rapid development of the global economy, the total energy consumption has been rising year after year, and energy saving and consumption reduction are imminent. Industrial steam turbines ("small steam turbines" for short) are used in thermal power plants to drive feedwater pumps to reduce energy conversion links. Steam as a steam source realizes the low-level utilization of energy and improves energy utilization. Moreover, industrial steam turbines operate at variable speeds according to load requirements, and no longer rely on throttling to adjust water supply, avoiding a large amount of throttling losses. Power plants are used more and more widely. [0003] The small steam turbines commonly used to drive the feedwater pump in ...

AI Technical Summary

Problems solved by technology

Such a control method will cause the pressure on the high pressure side to be higher than the pressure on the low pressure side. When the valve on the high pressure side is greatly adjusted, the pressure before the low pressure valve will rise suddenly and is higher than the steam supply pressure on the low pressure side. The phenomenon of "steam grabbing" on the high and low pressure side may cause large fluctuations in the water supply when the speed of the steam turbine of the feed water pump deviates greatly from the set value, or cause the vibration of the feed water pump to aggravate and cause the trip of the feed water pump when the degree of overlap is improperly set. As a result, there is a period of "empty travel" before the opening of the high-pressure side regulating valve, resulting in an abnormal drop in the speed of the feedwater pump turbine, which will seriously threaten the safe operation of the unit

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