Butane model operating at 320 F and
58.35 PSI pressures
Superheated/expanded to 100 psi
|
Temp (F) |
Pressure (psia) |
Density
(lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy (BTU/ lbm) |
Entropy (BTU/ lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
320.00 |
100.00 |
0.73909 |
1.3530 |
357.35 |
382.42 |
0.72037 |
0.51736 |
0.56287 |
Minus 125.49
Total Heat energy invested 256.93
Saturated Vapor at 100 F
|
Temp(F) |
Pressure (psia) |
Density
(lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy
(BTU/lbm) |
Entropy (BTU /lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
100.00 |
51.675 |
0.55503 |
1.8017 |
257.91 |
275.16 |
0.58078 |
0.39689 |
0.45206 |
Press Diff =58.325
psi
Minus 125.49
Latent heat of fusion 149.67
Liquid – condenser side – 100 F
|
Temp(F) |
Pressure (psia) |
Density (lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy (BTU/lbm) |
Entropy (BTU/ lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
100.00 |
51.675 |
34.799 |
0.028736 |
125.22 |
125.49 |
0.31355 |
0.42655 |
0.60381 |
Total Heat Energy invested = 256.93
Minus Latent Heat of fusion losses =
149.67
Recoverable mechanical Energy = 107.26
Maximum theoretical thermal efficiency =
41.7%
(149.67/256.93)
Steam Modeling at 320 F and pressure
drop of 59.05 psi
between inlet and
condenser
Superheated/expanded to 60 psi
|
Temp (F) |
Pressure (psia) |
Density
(lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy (BTU/ lbm) |
Entropy (BTU/ lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
320.00 |
60 |
|
7.5 |
|
1181.6 |
|
|
|
Minus 67.97
Total energy invested 1113.63
Saturated Vapor at 100 F Atmospheric at sea level = 14.696 PSI
|
Temp(F) |
Pressure (psia) |
Density
(lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy
(BTU/lbm) |
Entropy (BTU /lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
100.00 |
0.9492 |
|
350.4 |
|
1105.2 |
|
|
|
Press Diff = -59.05
psi Minus 67.97
Latent heat of fusion 1037.23
Liquid – condenser side – 100 F
|
Temp(F) |
Pressure (psia) |
Density (lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy (BTU/lbm) |
Entropy (BTU/ lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
100.00 |
0.9492 |
62 |
0.01613 |
|
67.97 |
|
|
|
Total Heat Energy invested = 1113.63
Minus Latent Heat of fusion losses =
1037.23
Recoverable mechanical Energy =
76.4
Maximum theoretical thermal efficiency =
6.86%
(76.4/1113.63)
Why Steam only works (efficiently) with 800 F and plus
superheat!!
Then:
Superheated/expanded to 60 psi
|
Temp (F) |
Pressure (psia) |
Density
(lbm/ft3) |
Volume (ft3/lbm) |
Internal Energy (BTU/lbm) |
Enthalpy (BTU/ lbm) |
Entropy (BTU/ lbm*R) |
Cv (BTU/ lbm*R) |
Cp (BTU/ lbm*R) |
|
320.00 |
60 |
|
12.5 |
|
1430.5 |
|
|
|
Minus 67.97
Total energy invested 1362.30
Total Heat Energy invested = 1430.50
Minus Latent Heat of fusion losses =
1037.23
Recoverable mechanical Energy =
393.27
Maximum theoretical thermal efficiency =
35.3%
(393.27/1113.63)