2nd Law of Thermo and Heat Engines

1
2nd Law of Thermo and Heat Engines
2
Carnot Cycle is highest efficiency possible
3
Carnot Engine
T
hi
Q
in
Q
out
T
lo
4
Carnot Refrigerator
T
hi
Q
Hi
Coef of Performance
Q
Lo
T
lo
5
Space Heating - Furnace
Qlo 90QHi
6
Electric Heat
Electric
Work
Resistance heater (100) 30 of fuel
Power Plant 30 effecient
Heat Destination
7
Electric heat pump
Heat Destination
QHi
Electric 30 Efossil
Heat Source (Earth)
8
Summary for heating

• Electric Heat 30 of fossil energy
• Furnace 90 of fossil energy
• Recycling power plant heat output (70 fossil
  energy 30 fossil energy for work and light)
• Heat pump 300 fossil energy