We made a test at our power station ( 2*350 MW - Gas/Oil Fired ) , this test is LOAD SWING TEST.
This test is implies the load of the unit at 350MW , for a while . and collect our data from the unit especially the boiler and Turbine system. , Then Decrease the sharply to the lowest load at 250 MW .
Hold time at this minimum load and collect data , and identify the performance of BOILER MASTER and GOVERNOR behaviors, and judge on the performance for these equipment.
Repeat this swing two and three times about this range , and collect the data for the system.
What Happened with our unit ??
It is noted that when decreasing the load , the water heaters ( Medium Pressure Heaters ) are going out of service because of hi level , this is very dangerous for the behavior of steam unit.
because when water heaters , the cascaded drains causes to trip all the heaters from service , and suddenly the load may increase sharply , especially the high pressure heaters.