THREE-CHANNEL PROTECTION SYSTEM OF TURBINE UNIT Russian patent published in 2011 - IPC F01D21/02 

FIELD: power industry.

SUBSTANCE: protection system of turbine unit includes gear wheel, three protection channels each of which includes rotation frequency transmitter and protection signal shaper, test signal source and switch of alternative connection of test signal to one of the protection channels, three-channel block of electromagnetic protection slide valves. Each electromagnetic slide valve includes solenoid valve and hydraulic slide valve. At that, inlet of each solenoid valve is connected to outlet of the appropriate shaper of protection signal; outlet of each solenoid valve is connected to inlet of hydraulic slide valve, and outlets of hydraulic slide valves form common outlet of block of electromagnetic protection slide valves as per logic voting scheme "2 of 3", which is connected to protection line of turbine unit and drain line of working fluid to the tank. Common outlet of block of electromagnetic slide valves is also connected to supply line of working fluid from power pump.

EFFECT: improving quality and operating reliability of protection system at failure of any one protection channel.

2 dwg