Patent ID: 8397679
Filing Date: 2013-03-19
Classification: F22B,F22D

Abstract:
1. A liquid level control system comprising: a boiler which boils liquid; a steam-liquid separator which separates the liquid from two-phase fluid containing steam and liquid flowing out of the boiler and allows the separated liquid to fall; a steam drum which contains the steam-liquid separator, supplies the liquid-free steam to a turbine, and supplies the internally retained liquid to the boiler; feed liquid flow rate adjustment means which is capable of adjusting the flow rate of feed liquid supplied from a steam condenser to the steam drum; a level meter for detecting a liquid level of the liquid retained in the steam drum; a flowmeter for detecting a feed liquid flow rate of the feed liquid supplied from the steam condenser to the steam drum; a flowmeter for detecting a steam flow rate of the steam supplied from the steam drum to the turbine; and liquid level control means which uses the feed liquid flow rate adjustment means to control the feed liquid flow rate in accordance with the detected liquid level, feed liquid flow rate, and steam flow rate; wherein the liquid level control means determines a change rate of the volume of liquid retained in the steam-liquid separator, and allows the feed liquid flow rate adjustment means to compensate the feed liquid flow rate in accordance with the determined change rate of the volume of liquid.