Thermo Scientific Sarasota SG901, Руководство пользователя

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Configuration Considerations when Using Sarasota CM515
Critical Temperature and Critical Pressure
Thermo Fisher Scientific Sarasota SG901 User Guide
F-3
Table F–1.
Ct K CP Bar A Acentric Factor
H2 33.2 12.9696 -0.22
CH4 190.6 45.94076 0.008
C2H6 305.4 48.83865 0.098
C3H8 396.8 42.45518 0.152
C4H10 452.2 37.99688 0.193
C5H12 496.6 33.74123 0.251
Table F–2.
Data assuming curve fit gives ax^2 + bx +c
CT is in K and CP is in bar A.
Standard Form Coefficients a b c
Sarasota CM515 Coefficients B A Base
CT calc -61.092 344.82 12.901
CP calc -17.72 50.606 12.9
Acentric factor 0.0775 Isentropic exp 1.3
Unlike the Thermo Scientific Sarasota HC900 and Sarasota HME900, the
Sarasota CM515 calculates compressibility using Critical Pressure and
Critical Temperature rather than Az and Bz, which are derived (partially
calculated) constants for the RK equation of state.
Where gas mixtures are used, pseudo Critical Pressure and Temperatures
can be calculated. However, in SG applications there is the option of
including a quadratic fit where Critical Pressure and Critical Temperature
are inferred from SG.
The entry of Critical Pressure and Critical Temperature is arranged such
that:
If the entry of CT or CP is made as a Base figure with the values of
Constants A and B set to zero, then the entered base figures are used as
CT and CP.
If the constants A and B are entered as non-zero values, then CT and
CP are calculated as:
( )
2 SG B SG A 1 Base CP ) or ( CT
× + × + × =
.
Critical
Temperature and
Critical Pressure