Turbo Expander.ppt

Gases properties

Universal Gas constant= MR

M

lb mole

379.5 cu ft

Gas Density = 379.5 * M For any perfect gas MR in lb-ft is 1545. One pound mol of any perfect gas occupies 379.5 cu ft at 60F and 1 atm.

M

kg mole

Gas Density =

22.84 * M

For any perfect gas MR in kg-m is --------. One Kg mol of any perfect gas occupies 22.84 cu mt at 0C and 1 atm.

22.84 cu mt

w

w

Turbo Expanders

CompRessor HP had(per stage) =

=

22838

lbf*ft/lb

had(per stage) = Zavg * R / MW * (ti+460) * k / (k-1) * [ (r)^((k-1)/k) -1 ] =

22836

lbf*ft/lb

144 * (Pia /

dv) * k / (k-1) * [ (r)^((k-1)/k) -1 ]

IN

MHP Zav Vs

r

9919

= Motor Horse power

0.83

=

= k-1 /Nk Nk / k-1

0.83 208300

= = Stage Pressure ratio

R k

OUT

SCFPM

1.81 1545

Cp/Cv

1.25 0.2 5

MW = Gas molecular weight P ti = to =

19.20 1050 83

1900

psia F0 F0

174

N Number of stages Adiabatic efficiency e ad

1 0.75 0.02

Gear efficiency Gas densities: dv = P*MW/10.73/(t+460)/Z

lb/ lbmole

4.17

6.46

lb/ft 3

Mass flowrate:

w1 = Vs / 379.5 * MW

10538

10538

lb/min

2528

1631

CFPM

Volumetric flowrate:

Vi = w1/dv Adiabatic head

had

22838

lbf*ft/lb

hp

30450

lbf*ft/lb

Polytropic head Gas Horse Power

Ghp =

w1* had ead /33000

9724

Turbo Expanders