Effect of high Condenser Vacuum

Candenser vacuum pressure has limitation for not too high and low. If Condenser vacuum too low already describe on http://anto-hendarto.blogspot.com/2012/02/exhaust-hood-pressure-and-temperature.html.

But if we got condenser vacuum to high, the output of LP Turbine well be reduce too from 2x162MW to 2x160MW for example. So the total output on the Generator also reduce from 710MW to 704MW.

To compesate that we need more coal to produce more steam flow to increase the Generator output back to 710MW. But too much steam flow through the turbine could be created high vibration so that we have limitation condenser vacuum not more that 0.1Bara.

Please see pictures below for detail.

































































Effect condenser vacuum high could be happen from condenser dirty. Those two curves below tell about Foster Wheeler predicted condenser performance curves if 100% clean and 90% clean.

If condenser 100% clean with circulating water temperature 29.2C, condenser pressure predicted will be 0,082Bara.






















If condenser 90% clean with circulating water temperature 29.2C, condenser pressure predicted will be 0,085Bara.