Thermo Flashcards
1
Q
S.F.E.E.
A
Q̇-Ẇ = ṁ(Δh + ΔKE + ΔPE)
2
Q
Equation for rate of Heat transfer
A
Q̇ = ṁCpΔT
3
Q
Efficiency or COP
A
Desired Energy / Input Energy
η = Wout / Qin
Refrigerator COP = Qc / Win
Heat Pump COP = Qh / Win
4
Q
1st Law
A
ΔU = ΔQ - ΔW
5
Q
2nd Law
A
No engine can be built whose interactions are only positive work and heat transfer from a constant temperature body.
No heat engine can be 100% efficient.
6
Q
Reversible heat engine efficiency
A
ηR = 1 - QL/QH = 1- TL/TH
this also leads to
Q1/T1 = Q2/T2
7
Q
Carnot Cycle
A
Heat transfers are isothermal and work transfers are isentropic ∴ rectangular on T-S diagram.
8
Q
Reversible process heat transfer
A
QR = ∫TdS
9
Q
Brayton Cycle and Back Work
A
S.F.E.E. used to model energy transfers.
Back work = Wcompressor / Wturbine
