Got a question or lack of answer that is now bugging me since reading this thread, i'm sure you guys can clear it up for me.
Before i do what i do now the previous 8yrs i was employed as a control & instrumentation engineer for a UK power company. The power station i worked at was CCGT : combined cycle gas turbine, i.e Gas turbines produced electricity then exhaust gases from the GT's feed heat recovery boilers generating steam in turn feeding steam turbines & walla more electricity. The steam turbine condesnate then pumps back to a de-aerator tank, this tank then feeds the 6 boiler circuits/ drums & on & on....
Can sketch the config if it makes it easier to picture
The boilers have 6 circuits, the lowest in the stack (& hottest) are HP ( high pressure circuits), the highest the LP circuits. The very top (& coolest part of stack) circuit is the pre-heater circuit. The condesnate returning from the ST condensor passes through this pre-heater section for numerous reasons & leads me onto the question:
If the actuators (valves) controlling the pre-heater inlets control to wide open (to high flow) little heat is absorbed by the pre-heater section, throttle the flow right back & significant increases in heat are observed.
We where always told & up till reading this thread i took as true that the reason was the condensate was not in the pre-heater section long enough to absorb heat.
Can anyone clear this up for me? Can expand on descriptions & include sketches if it helps
TIA
