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Exploring heat and work in engines, OTEC energy, conservation of energy, and second law of thermodynamics. Discussing energy efficiency and innovative solutions like smart buildings, superconductive cables, distributed generation, and more to tackle energy problems effectively. Delve into practical aspects of OTEC, maximum efficiency, entropy, and heat pumps. Discover the reasons behind hypothermia, heat loss equilibrium, and the science behind cold windows and warm fires.
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Heat and Work: Part 2 • Conservation of Energy • Heat Engines • Second Law of Thermodynamics • Energy Efficiency • OTEC
Energy in the News • Possible solutions to Energy Problems • 1) Smart Buildings and Machines • 2) Superconductive Cables • 3) Fewer Phantom Loads • 4) Distributed Generation • A) Solar Cells • B) Wind • C) Diesel Generators • D) Microturbines • E) Fuel Cells
Heat Loss • Hypothermia-what causes it? Basic physics • Lakes-ice and summer warmth. Why retained? • Space blankets-very thin-what do they do? • Why cold when standing near a window in winter? • Why warm near a fire?
Two basic types of heat engines • What are they?
Vapor or Rankine Cycle • Steam engines • Heat pumps
Gas Cycle • Automobiles (Internal Combustion) • Jet Engines (External Combustion) • Where is the fuel burned? • What does the force from burning move?
Practicalities of OTEC • Maximum Efficiency (Carnot efficiency) • =100% * ( Thigh-Tlow)/Thigh • T in degrees Kelvin • What is more efficient? • Thermal engines with large or small temperature differences? • When will it be 100% efficient?
Second Law of Thermodynamics • Entropy (Disorder) always increases Unless energy is added • Examples: • Kids room • Spontaneous heat flow (Hot to Cold yes, never cold to hot) • Waste Heat is always present
Ideal Case • A completely reversible process • Do common heat engines use reversible processes, why or why not?