Term
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Definition
make energy more convenient & easy to use
make energy easier to transport
to make it cleaner |
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Term
| how do you measure energy conversion? |
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Definition
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Term
| is it possible to completely convert energy from one form to another? |
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Definition
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Term
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Definition
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Term
| what is the 0th law of thermo? |
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Definition
| if A is in thermal equilibrium with B, and B with C, then A is in thermal equilibrium with C |
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Term
| what does the 0th law do/tell us? |
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Definition
-permits conduction of heat
-basis of measuring temp with thermometers
-heat goes from hot->cold until equilibrium |
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Term
| classical vs. statistical thermo |
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Definition
| classical considers properties of bulk matter while statistical takes into account atoms & molecules |
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Term
| what is the 1st law of thermo? |
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Definition
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Term
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Definition
| motion against an opposing force |
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Term
| what is the 2nd law of thermo? |
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Definition
| can't complete convert heat into work |
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Term
| equation for internal energy |
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Definition
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Term
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Definition
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Term
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Definition
| (DELTA)Stot = (DELTA)S - (DELTA(U)/T |
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Term
| equation for Helmholtz energy |
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Definition
| (DELTA)A = (DELTA)U - T(DELTA)S |
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Term
| if a process is spontaneous, Helmholtz energy is __ and Gibbs free energy is __ |
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Definition
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Term
| equations for Gibbs free energy |
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Definition
G = A + PV
(DELTA)G = -T(DELTA)S |
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Term
| what is the 3nd law of thermo? |
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Definition
| no cyclic process can cool a body to absolute zero |
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Term
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Definition
| eta = W/Q_R = (T_H - T_L)/T_H |
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Term
| in the Carnot cycle, the work is... |
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Definition
| the area inside the rectangle on the P-V diagram |
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Term
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Definition
the heat from the source
the area under the upper curve on the P-V diagram |
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Term
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Definition
the heat to the sink
the area under the lower curve on the P-V diagram |
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Term
| for Carnot, you get more work as... |
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Definition
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Term
| Carnot limit represents... |
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Definition
| the maximum work that can be obtained from a quantity of heat |
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Term
| thermal efficiency increases as as irreversibility __ |
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Definition
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Term
Carnot cycle run forward is a __.
reverse is __ |
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Definition
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Term
| draw the Carnot cycle on a P-V diagram |
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Definition
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Term
| draw the Carnot cycle on a T-S diagram |
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Definition
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Term
| does Carnot efficiency depend on the working substance? |
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Definition
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Term
| the more reversible a process, the ___ thermal efficiency |
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Definition
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Term
| give 3 examples of irreversible processes |
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Definition
non-isothermal heat transfer
turbulent flow
friction |
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Term
| efficiency of any actual device is __ than Carnot efficiency |
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Definition
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Term
| why is actual efficiency never equal to ideal efficiency? |
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Definition
| because actual devices have irreversibility (the ideal device is completely reversible) |
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Term
| define economic efficiency of energy |
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Definition
| (eta)_(econ)=(money in)/(energy out) |
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Term
| describe a low economic eff.-low thermal eff. case, and give an example |
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Definition
fuel is both expensive and inefficient in making energy out per energy in
ex, use Fischer-Tropsch to make liquid fuel from coal |
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Term
| describe a low economic eff.-high thermal eff. case, and give an example |
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Definition
fuel is expensive but high efficiency in making energy out per energy in
ex, usually only happens in special cases, like rocket fuel |
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Term
| describe a high economic eff.-low thermal eff. case, and give an example |
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Definition
cheap but low efficiency in making energy out per energy in; people don't care about the efficiency because it's cheap
ex, gasoline now |
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Term
| describe a high economic eff.-high thermal eff. case, and give an example |
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Definition
| fuel is both cheap and really efficient (ideal case) |
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Term
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Definition
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Term
| name several ways to reduce CO2 emissions |
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Definition
-improve thermal efficiency so that less CO2-producing fuel use is necessary
-use CCS
-switch to fuel that emits less CO2 (biomass)
-switch to carbon-free energy sources (most renewables) |
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Term
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Definition
| carbon capture and sequestration |
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Term
| name the 3 efficiencies we are concerned about in this course |
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Definition
economic efficiency
thermal efficiency
carbon efficiency |
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Term
| explain how implementing CCS on a powerplat would impact the three efficiencies |
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Definition
carbon efficiency would go up
CCS reduces thermal efficiency of the plant
economic efficiency goes down because the CCS equipment costs extra |
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Term
| define energy concentration, and when it is relevant |
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Definition
(energy)/(area)
relevant when large amounts of land are necessary to effect the energy (biomass, solar) |
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Term
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Definition
(energy)/(mass)
materials cost of energy |
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Term
| define energy conversion efficiency |
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Definition
(energy out, form B)/(energy in, form A)
ex, how much energy goes into making ethanol from corn compared to the energy we get from burning the ethanol? |
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Term
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Definition
Qualitative concept indicating
how easy or difficult it is to get public to accept new technology |
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