EES for Thermodynamics

A hands-on short training on using Engineering Equation Solver (EES) for solving thermodynamics problems.

1. EESFOR
THERMODYNAMICS
A hands-on training.
Naveed ur Rehman
http://www.naveedurrehman.com/

2. EES–A software
•EES(pronounced ’ease’): “Engineering Equation Solver”
•Licensed and distributed by F-Chart software
(http://fchart.com)
•Demo version can be acquired free from
http://fchart.com/ees/demo.php
•Licensing and ordering information can obtained from
http://fchart.com/ees/and http://fchart.com/ees/order.php
•Single user license fee: $600-$1200
•Download software and presentation from
https://goo.gl/U9s8Ud(Disconnect internet while using EES)
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3. Environment
“Equations window”
“Menu”
“Toolbar”
Remember, EESis case-insensitive
i.e. ABC = abc= AbC= Abc…
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4. Solving linear equation
X + 3 = 5
Example:
To obtain solution:
[Menu] Calculate > Solve
or
Press “F2” key
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5. Solving linear equation
X + 3 = 5
Example:
Solution Window:
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6. Solving polynomial
3*H^2 -4*H -5 = 0
Example:
Solution Window:
6
3??????
2
−4??????−5=0
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7. Solving system of equations
Example:
X + Y = 10
X -2*Y = 5
7
X + Z = 10 -Y
X -2*Y = 5
X = 4 -Z
X + Y + Z = 10
X + Y = 0
What about this?
Remember, number of variables = number of equations!
ERROR!
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8. Solving system of equations
Example:
V = pi * (R^2) * H
R = 10
H = 12
8
Calculatevolumeofcylinderwhereradiusis10mand
height=12m(using�=????????????
2
??????)
Calculateradiusofcylinderwhereheightis10mand
volume=3000m
3
(using�=????????????
2
??????)
V = pi * (R^2) * H
H= 10
V = 3000
??????=Τ�????????????
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9. Exercise
9
Apistoncylinderdeviceinitiallycontains0.4m
3
ofairat
100kPaand80°C.Theairisnowcompressedto0.1m
3
in
suchawaythatthetemperatureinsidethecylinder
remainsconstant.Determinetheworkdoneduringthis
process.
�
??????�??????�ℎ??????��??????�=??????
1�
1ln
�
2
�
1
V1 = 0.4
P1 = 100
T1 = 80
V2 = 0.1
Wb= (P1*V1)*ln(V2/V1)
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10. Units and conversion
Try:
A = 30*Convert(ft,m)
B = 10*Convert(MJ, kJ)
C = 100*Convert(kJ/kg,BTU/lbm)
10
Solution:
Note: Unit to each variable is automatically assigned.
Convert statement is used to do unit conversion:
Convert ( from-unit , to-unit )
Right-click and
select “Units list”
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11. Exercise
a = 3*convert(bar/kW,kPa/J)
11
Convert3bar/kWtokPa/J
Convert3bar/kWtokPa.s/J
a = 3*convert(bar/kW,kPa*s/J)
ERROR!
Remember, always convert into consistent units.
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12. Units and conversion: Temperature
Try:
TheF= ConvertTEMP(C,F,30) "Convert 30 deg. C to deg. F"
TheC= ConvertTEMP(F,C,100)"Convert 100 deg. F to deg. C"
12
Solution:
ConvertTempstatement is used to do unit conversion
between degree centigrade (°C) and Fahrenheit (°F):
ConvertTEMP ( from-unit , to-unit, value)
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13. Built-in Functions
13
To access built-in functions:
[Menu] Options > Function Info
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14. Exercise
14
What is the
temperature of
water/steam at
11 MPaand
internal energy
of 2920 kJ/kg?
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15. Exercise
15
What is the enthalpy of water/steam at 100 ⁰C and 50 kPa?
Solution:
ℎ
????????????�??????�=ℎ
??????=100℃,??????=50�????????????
Tw = 100
Pw= 50
hw= enthalpy(Steam,T=Tw,P=Pw)
hw= enthalpy(Steam,T=100,P=50)
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16. Exercise
16
What is the specific volume of water/steam at 100 ⁰C and 50
kPa?
Solution:
??????
????????????�??????�=??????
??????=100℃,??????=50�????????????
v = volume(Steam,T=100,P=50)
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17. Exercise
17
A rigid tank contains 50 kg of saturated liquid water at 90
⁰C. Determine pressure in the tank and volume of tank.
Pw=Pressure(Steam,T=90,x=0)
Vw= 50*Volume(Steam, T=90,x=0)
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18. Exercise
18
A mass of 200 gmof saturated liquid water is completely
vaporized at a constant pressure of 100 kPa. Determine
the volume change and the amount of energy added to
water.
m = 200/1000
x1 = 0
x2 = 1
Pw = 100
V1 = volume(Steam, P=Pw, x=x1)
V2 = volume(Steam, P=Pw, x=x2)
V = m*(V2-V1)
h1 = enthalpy(Steam, P=Pw, x=x1)
h2 = enthalpy(Steam, P=Pw, x=x2)
H = m*(h2-h1)
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19. Exercise: RankineCycle
19
Considerasteampowerplantoperatingonasimpleideal
Rankinecycle.Steamenterstheturbineat3MPaand
350⁰Candiscondensedinacondenseratapressureof
75kPa.Determinethethermalefficiencyofthiscycle.
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20. Exercise: RankineCycle
20
P1 = 75
T1 =TEMPERATURE(Steam,P=P1,x=0)
h1 = ENTHALPY(Steam,T=T1,P=P1)
v1 = VOLUME(Steam,P=P1,x=0)
P2 = 3*convert(MPa,kPa)
Wp = v1*(P2-P1)
h2 = h1 + Wp
P3 = P2
T3 = 350
h3 = ENTHALPY(Steam,T=T3,P=P3)
s3 = ENTROPY(Steam,T=T3,P=P3)
P4 = P1
s4 = s3
h4 = ENTHALPY(Steam,s=s4,P=P4)
qin = h3 -h2
qout = h4 -h1
eta = 1-qout/qin
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21. THANK YOU!
Naveed ur Rehman
http://www.naveedurrehman.com/
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