BrodyA.A said:
Hey guys, I've been given this mini project for my thermodynamics2 class. It's supposed to be a really good example of how the upcoming exam will be. The downside is i don't really know what values I should pick. I really need help with strictly the analysis part of this project. If anyone could help me and explain the analysis step by step i would greatly appreciate at. The powerplant design that I've decided to use will also be posted. Also, sorry in advance, i know it's a long problem. But i really want a good understanding of this so i can do well on my exam
I'm not a power plant engineer, but I have some experience with marine steam plants.
I looked at your preliminary plant layout, and I have one suggestion. The Open Feed Heater is located in the wrong sequence after the condensate leaves the condenser.
The last heater in your chain, just before the feed water is sent into the boiler, should be an open deaerating feed heater. You are going to need a pretty hefty feed pump between the de-aerator and the steam drum, in order to raise the pressure of the feed sufficiently for it to be forced into the drum. Making the first two feed heaters after the feed leaves the condenser of the closed type would be normal practice.
Apparently, large power plants use two groups of feed heaters: a series of low pressure FHs after the condenser, a de-aerator, then the HP feed pump, followed by a series of high pressure FHs before the feed enters the steam drum.
A case study of a large power plant (2600 MW) can be found here:
https://www.ohio.edu/mechanical/thermo/Applied/Chapt.7_11/SteamPlant/GavinCaseStudy.html
As to selecting the operating pressure and temperature for your modest 115 MW output, I suggest you research similar plants to see what conditions and performance they have, to see if one of these can meet the Project Requirements.
This looks like an interesting project. Good Luck!
