Page 416 - Reciprocating Compressors Operation Maintenance

Reciprocating Compressor Calculations 401

Suction temperature 60°F
Suction pressure 150 psia
Discharge pressure 1000 psia
Flow rate 9MMSCFD
(Compression ratio 6.67 overall, or V6j67 = 2.58 per stage

From Figure A-1, we obtain a discharge temperature of 308°F.

Specific gravity of gas = 17.76/28.97 =0.613
Z s = 0.98
Z d = 0.97
7 = 0.975
avg.
k-1 0 26
— - 0.206
k 1.26
10 6 P std T s 1
Capacity -9MMSCFDX x x x —
1440 P s T stt, Z s
6
„ 10 14.4 520 1
vx
v/
A
A
J
— O A A vx \r
1440 150 520 0.98
= 612ACFM
Compression efficiency from Figure A-7, e ad = 80%*
Compressibility factor Z s is obtained from Figure A-8.
General HP formula:

„ 80
EITIIUTID KIClrROCATINO COW>»»SSOR
»ff«IIH«
MtCHANICM,
IHCUIDJHa
i > LOStlS
^ ° 4 f /
j
1
COMFRIItlOH RATIO
"IGURE A-7. Estimated efficiency as a function of compression ratio
jciprocating compressors.

* For comparison with centrifugal compressors, refer to Figure A-9