21-07-2012, 04:58 PM
DEH GOVERNING
DEH GOVERNING.ppt (Size: 104 KB / Downloads: 70)
TURBINE RESET
Turbine RESET command (DEH HMI Screen) reset electromagnetic valve 1VY , import lube oil to emergency breaker device plunger side chamber , plunger runs up to top dead center , make the stay hook of emergency breaker device reset (ZS1- Open & ZS2- Close) , reset mechanical intercept valve , seal the oil drain port.. when the two out of three pressure switch in pressure switch unit check that high pressure safety oil found , sent out signal to DEH , discharge resetting electromagnetic valve 1VY plunger return bottom dead center, DEH check NO contact of ZS1 , ZS2 interrupted , DEH finishes the procedure of latch.
Mechanical Overspeed Protection
When the speed of turbine is up to 110% ~ 120% (3300 ~ 3360 RPM) of rated speed , the fly ring of emergency breaker will knock out and hit the stay hook , then stay hook trips to make the mechanical interrupting valve act to discharge high pressure safety oil.
Hand Trip Gear
Rotate the handgrip of the hand trip gear 30 degree to the left side to make it leave the self lock position , then draw the hand trip gear to make the mechanical interrupting valve act to discharge high pressure safety oil.
TURBINE TRIP BOILER
When there is no tightness test of valve and if atleast one of HP throttle valves,and one of the IP valve close at the same time DEH sent out instruction to shutdown turbine and trigger MFT of the boiler.
TURBINE TRIP GENERATOR
When there is no tightness test of valve and if atleast one of HP throttle valves,and one of the IP valve close at the same time DEH sent out instruction to shutdown turbine and make generator trip.
OPC Protection
Condition(1)
When the rotation speed reaches the 104% of rated speed.
OPC valve ( 27VY , 28VY ) and the interrupting electromagnetic valve of the servomotor valve act at the same time to discharge the oil , valve closes quickly by the force of the spring , when the rotation speed falls to 3090 RPM every electromagnetic valves resets and open the CV again and keep the speed of turbine at 3000 RPM..