BCP investment
worthwhile for supercritical startup
The
objective of this paper is to analyze the variation of start-up parameters such
as fuel consumption, water consumption and the start-up cost of a boiler
operating with a Boiler Circulation Pump (BCP) and without a BCP. The Boiler
Circulation Pump is equipped at the bottom of the Boiler Storage Vessel and it
circulates water back to the boiler rather than dumping it to the Boiler Flash
Tank as in once-through boilers operating without a Boiler Circulation Pump. In
boilers without BCP, enormous heat loss comes in the form of evaporation by
dumping hot water into the Boiler Flash tank. Generally, in supercritical
boilers up to 30% of the BMCR Boiler will be in wet mode of operation. Later it
will change to dry mode of operation. While the boiler is in wet mode of
operation, a small amount of feed water will become steam and the remaining will
be circulated back to the boiler, which will be separated in the Boiler
Separator. But boilers without the BCP water will circulate back to the
condenser through the boiler flash tank rather than direct circulation to the
Boiler, which leads to high heat loss, more fuel consumption and water loss in
the form of evaporation. It is more essential to make the start-up cost optimal
by minimizing the fuel consumption and water consumption. In a year on average,
a plant start-up can happen 8-10 times. Therefore, in this paper, the effect
with BCP and without BCP in the start-up of a 660 MW Super Critical thermal
Power plant is discussed. Also discussed are the other advantages of BCP for a
system’s healthy operation.