Thermodynamics
ENERGY, WORK, AND HEAT
Summary
The important information from this chapter is summarized below.
Energy, Work, and Heat Summary
•
Heat is described as energy in transit. This transfer occurs
on a molecular level as a result of temperature differences.
The unit of heat is the British thermal unit (Btu).
Latent heat
=
the amount of heat added or
removed to produce only a
phase change.
Sensible heat =
the heat added or removed
that causes a temperature
change.
•
The following properties were defined:
Specific enthalpy (h) is defined as h = u +
Pn, where u is the specific internal energy
(Btu/lbm) of the system being studied, P is
the pressure of the system (lbf/ft2), and n is
the specific volume (ft3/lbm) of the system.
Entropy is sometimes referred to as a
measure of the inability to do work for a
given heat transferred.
Rev. 0
Page 25
HT-01
