Sierra INNOVA-MASS 241-VTP - Manual (Page 74)

Series 24-HP Instruction Manual Appendix C Fluid Calculations
IM-24-HP C-1
Appendix C Fluid Calculations
Calculations for Steam T & P
When “Steam T & P” is selected in the “Real Gas” selection of the Fluid
Menu, the calculations are based on the equations below.
Density
The density of steam is calculated from the formula given by Keenan and
Keys. The given equation is for the volume of the steam.
B
p
T
v
+
•
=
04 . 555 . 4
12 12
3
13
0
3 3
2
4
0 1
2
0 0
) ( ) ( ) ( p g B p g B p g B B B
⋅ − ⋅ + ⋅ + = τ τ τ τ τ τ
2 80870
0
10 62 . 2641 89 . 1
τ τ ⋅ ⋅ − =
B
2 5
1
10 6246 . 1 546 . 82 ) (
τ τ τ ⋅ ⋅ − ⋅ =
g
2 5
2
10 2697 . 1 21828 . 0 ) (
τ τ ⋅ ⋅ − =
g
24 64 4
3
10 768 . 6 10 635 . 3 ) (
τ τ ⋅ ⋅ − ⋅ = −
g
Where tau is 1/ temperature in Kelvin.
The density can be found from 1/(v/ standard density of water).
Viscosity
The viscosity is based on an equation given by Keenan and Keys.
T
T
poise
/ 8 . 446 1
10 501 . 1
) (
5
+
⋅
=
−
η
Where T is the temperature in Kelvin