REM 350 Lecture Notes - Lecture 1: Eugenius Warming, Nuclear Reaction, Nuclear Fission
23 Apr 2016
School
Department
Course
Professor
Document Summary
Energy and materials taken from the environment are transformed. Power-measure of how fast energy can be delivered. 60 watt light bulb on for 1 hour = 60 watt hour. First law of thermodynamics-energy/matter can be neither created or destroyed. Material inputs = material outputs (mass balance principle) Gasoline -> motion (horsepower) + heat (80%) + waste (co2) Second law of thermodynamics-in an isolated system, entropy increases with every transformation. With energy, increased entropy = decreased quality of energy (i. e. exergy) With materials, increased entropy = decreased concentration of a chemical element. First law energy efficiency-the ratio of useful energy output to the total energy input of a device/process (cannot exceed 100%) E. g. car with 20% efficiency (80% lost from heat) Second law energy efficiency-the ratio of the theoretical minimum amount of energy to perform a task to the energy input of the device/process. Minimum amount of useful energy theoretically needed / energy input.
