Thermodynamics I

bronzekerplunkMechanics

Oct 27, 2013 (3 years and 9 months ago)

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Thermodynamics II


Contact information


Educate.spsu.edu


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-
mail


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Syllabus


Power Point


Class Schedule


Thermodynamics II


Outcomes


Credits


Text: M&S 6
th

or 7
th

Edition



Thermodynamics II


Learn A


A basis for learning B


Read text


Examples


Homework


Questions


Practice

Thermodynamics II


Principles → working equations → applications


Thermo I: lots of principles & some working
equations


Thermo II: some working equations & lots of
applications

Thermodynamics II


No cookbook


Orderly/logical approach


Read carefully


Describe system


Sketch


Assumptions


Principles & working equations


Solve


Reasonable


Thermodynamics II


Read


Type of system


Type of working fluid


Type of process

Thermodynamics II


Assumptions


reasonable


Steady state


Ideal gas


Incompressible liquid




KE & PE often negligible

Solve Equation


Include units


Consistent unit system


Significant digits

Thermodynamics II


Reasonable


Make sense?


Sign


Units


Magnitude

Thermodynamics II


“Heat strength”


Energy transformations


Transportation


Comfort


Manufacturing



Energy usage


Effective


thermodynamics
understanding


Costs


Pollution


Resource conservation

Thermodynamics II


Energy usage ~10
+
% income


24 %

Nuclear Power


SPSU: Nuclear Power Generation &
Training sessions.

Thermodynamics Basics


Systems


Closed


Open


Processes


Isothermal


Isobaric


Isometric


Adiabatic


Isentropic


Polytropic


Thermodynamics Basics


Working fluid: changes phase
processes


Steam


R134a


R22


NH
3


Propane

Working Fluid


phase change


Property tables


State diagram: pressure & volume


Compressed liquid


Saturated liquid


Vapor dome


quality


Saturated vapor


Superheated vapor

Working Fluid


phase change


Properties: P, T, v, u, h, s

Working fluid


No phase change: ideal gas


Ideal gas law


Caloric equations for u & h: constant
specific heats


Variable specific heats: table for air
as ideal gas

Thermodynamic basics


State


defined by properties


Process


described by change of
state


First Law of Thermodynamics


Conservation of mass & energy


Closed system:


Heat: direction & magnitude


Work: direction & magnitude


Kinetic energy: property


Potential energy: property


Internal energy: property

First Law of Thermodynamics


Open system: control volume


Additional: flow energy

* Internal energy
u

for

CLOSED SYSTEM

* enthalpy:
h

= u+pv for
OPEN SYSTEM

Cycles


Two or more processes in series
which return working fluid to its initial
state


Heat engine


Reversed cycle


Heat engine


Thermal efficiency

Reversed cycle


Coefficient of performance


Reversed cycle


COP cooling (
β
): refrigeration & air
conditioning


COP heating(

): heat pump

Ideal cycle


Carnot: ideal cycles with no wasted
energy.


Ideal COP


Cooling


Heating

Assignment


3.129 & 3.130


4.43 & 4.45

QUESTIONS







Chapter 8: Vapor Power Systems / F8
-
1

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Examples


8.2


8.17


8.29