## St 0 X ni Ii S1 1 Ji TJ

 i d0 ' /A ~d20 " /A ' d0 ' /A d20 " /A ' d20 " S [ dT2 J S dSdT

Equation (28) covers region 3 of IAPWS-IF97 defined by the following range of temperature and pressure, see Fig. 1:

623.15 K < T < T(p)^) p( T)Eq.(5) < p < 100 MPa . In addition to the properties in the stable single-phase region defined above, Eq. (28) also yields reasonable values in the metastable regions (superheated liquid and subcooled steam) close to the saturated liquid and saturated vapor line.

Computer-program verification

To assist the user in computer-program verification of Eq. (28), Table 33 contains test values of the most relevant properties.

Table 33. Thermodynamic property values calculated from Eq. (28), for selected values of Tand pa

T = 650 K, T = 650 K, T = 750 K, p = 500 kg m-3 p = 200 kg m-3 p = 500 kg m-3

T = 650 K, T = 650 K, T = 750 K, p = 500 kg m-3 p = 200 kg m-3 p = 500 kg m-3

Table 33. Thermodynamic property values calculated from Eq. (28), for selected values of Tand pa

 p/ MPa 0.255 837 018 X 102 0.222 930 643 X 102 0.783 095 639 X 102 h/ (kJ kg-1) 0.186 343 019 X 104 0.237 512 401 X 104 0.225 868 845 X 104 u/ (kJ kg-1) 0.181 226 279 X 104 0.226 365 868 X 104 0.210 206 932 X 104 s/(kJ kg-1 K-1) 0.405 427 273 X 101 0.485 438 792 X 101 0.446 971 906 X 101 cp/(kJ kg-1 K-1) 0.138 935 717 X 102 0.446 579 342 X 102 0.634 165 359 X 101 w/ (m s-1) 0.502 005 554 X 3 103 0.383 444 594 X 3 103 0.760 696 041 X 3 103

a It is recommended to verify programmed functions using 8 byte real values for all three combinations of T and p given in this table.

a It is recommended to verify programmed functions using 8 byte real values for all three combinations of T and p given in this table.

0 0