AREN 2110 Second Law: Entropy, and Cycle Formula Summary Sheet
ENTROPY BALANCES
I. CLOSED SYSTEM
A. Irreversible processes:
Q
kJ
+ S gen
1 T
K
2
S = S 2 S1 =
B. Reversible processes: Sgen = 0
Q kJ
1 T K
2
S 2 S1 =
C. Adiabatic irreversible proces

FUNDAMENTAL AND MEASURABLE INTENSIVE PROPERTIES
PRESSURE, TEMPERATURE AND SPECIFIC VOLUME
PRESSURE, P
!=
!"#$%
!"#!
exerted by a fluid (liquid or gas)
Thermodynamic importance of pressure
One of two indep

RANKINE POWER GENERATION CYCLE
A HEAT ENGINE: PRODUCES WORK FROM HEAT BY WASTING A
FRACTION OF HEAT INPUT TO A LOW TEMPERATURE RESERVOIR
T oC
3
2
1
4
s (kJ/kg-K)
CHARACTERISTICS
1. Rankine cycle is a heat engine comprised of four internally reversible
pro

SECOND LAW OF THERMODYNAMICS
INTRODUCTION AND CYCLES
You could say that the 2nd Law was developed because physicists observed that
there were phenomena that were not explained by the 1st law.
There are various formulations and applications of the 2nd Law

/ ,
AREN 2110: Thermodynamics Name / 6 t 5
Spring 2011
Midterm 2
Answer all questions. Test is open book and notes. Sign honor code statement below.
I have neither given nor received unauthorized assistance during this examination.
Signed i if); :
1.

AREN 2110
Chapter 2. Sections: State of Systems, Thermodynamic Processes, Properties and
Measurements.
Learning objectives.
CONCEPTS
1. Define and give examples of the state of a system
a. Be able to define the state of a system from its thermodynamic
pro

Rubric for solving problems for properties of pure substances and boundary work in simple compressible systems
DEFINE the state of the system: require two (2)
independent intensive properties from among:
T, P, v (or = 1/v), u, h, x, where v = V/m,
Sat. mi

HEAT ENGINES
Two diagrams show the difference between a heat engine (device to produce heat
from work) that satisfies the 1st Law BUT DOES NOT satisfy the 2nd Law (a) and
one that satisfieS both the 1st and 2nd Laws (b)
(a)
Satisfies 1
HTR
st
Law:
Qin =

AREN 2110
Introduction Overview
THERMODYNAMICS IS THE SCIENCE OF ENERGY. Although everyone has some
kind of understanding of energy (what is yours?), by the end of the class, you will have
learned a precise definition of energy, including its forms and ho

CLAUSIUS INEQUALITY AND ENTROPY
with a little history thrown in.
CARNOT PROPOSED THAT HEAT MUST ALWAYS BE WASTED
IN ORDER FOR A HEAT ENGINE TO PRODUCE NET WORK, BUT
HE DID NOT QUANTIFY HOW MUCH HEAT HAD TO BE
WASTED.
IN ~ 1850 RUDOLF CLAUSIUS CONFIRMED T

CARNOT CYCLES
Sadi Carnot was a French physicist who proposed an ideal cycle for a
heat engine in 1824.
Historical note the idea of an ideal cycle came about because engineers
were trying to develop a steam engine (a type of heat engine) where they
could

Work and 1st Law notes
Work, W = all energy transferred across boundary, EXCEPT heat
BOUNDARY WORK
PdV (kJ)
Boundary Work = Wb =
Special cases:
Isobaric: w = P(v2-v1)
(kJ/kg)
Isochoric: w = 0
v
P
v
= RT ln 2 = RT ln 1 = PV1 ln 2 (kJ/kg)
Isothermal, idea

AREN 2110 CLASS NOTES
APPLICATIONS OF THERMODYNAMICS TO CURRENT ISSUES
HEATING BUILDINGS
Reference for much of this material: MacKay, David (2008) Sustainable Energy
without the hot air, UIT, Cambridge, UK.
Issues:
1. as much as 30% of the electricity ge

AREN 2110: Property Review topics
A. Basic Concepts
1. Properties
a. Intensive and extensive properties
b. Independent properties
c. Measurement of pressure and temperature, absolute and relative scales
d. State postulate for simple compressible systems:

AREN 2110: PROPERTIES OF PURE
SUBSTANCES WITH PHASE CHANGE
STATE INFORMATION FOR LIQUID,
SATURATED LIQUID-SATURATED
VAPOR PHASE MIXTURES, AND
SUPERHEATED STEAM
P-v AND T-v DIAGRAMS
SATURATED LIQUID-VAPOR AND
STEAM TABLE EXAMPLES
Phase Equilibrium Condi