三相点压力0.00611213bar是否要改为0.00611657bar

uesoft

杨工：你的delphi代码if97.pas中有个常数0.00611213，是不是应该改成0.00611657？

请看IF97.pdf Page 7

Since the 5th International Conference on the Properties of Steam in London in 1956, the
specific internal energy and the specific entropy of the saturated liquid at the triple point have
been set equal to zero:
u¢t=0 ; s¢t=0. (8)
In order to meet this condition at the temperature and pressure of the triple point
Tt = 273.16 K [8] pt = 611.657 Pa [9] , (9)
the coefficients n3 and n4 in Eq. (7) have been adjusted accordingly. As a consequence, Eq. (7)
yields for the specific enthalpy of the saturated liquid at the triple point
t ‡
h = 0.611 783 J kg-1 .

但是我这样改了之后，计算三相点饱和液体焓居然ht\'= 0.000611783049 kJ/kg，

怎么比IF97正式文档多了3个0！

可是计算出来其他数据第9页Table 5数据一样

Table 5. Thermodynamic property values calculated from Eq. (7) for selected values of T and pa
T = 300 K,p = 3 MPa T = 300 K,p = 80 MPa T = 500 K,p = 3 MPa
v / (m3 kg–1) 0.100 215 168 × 10–2 0.971 180 894 × 10–3 0.120 241 800 × 10–2
h / (kJ kg–1) 0.115 331 273 × 103 0.184 142 828 × 103 0.975 542 239 × 103
u / (kJ kg–1) 0.112 324 818 × 103 0.106 448 356 × 103 0.971 934 985 × 103
s / (kJ kg–1 K–1) 0.392 294 792 0.368 563 852 0.258 041 912 × 101
cp / (kJ kg–1 K–1) 0.417 301 218 × 101 0.401 008 987 × 101 0.465 580 682 × 101
w / (m s–1) 0.150 773 921 × 104 0.163 469 054 × 104 0.124 071 337 × 104
It is recommended to verify programmed functions using 8 byte real values for all three combinations of T and
p given in this table.

[此贴子已经被作者于2007-8-17 18:55:05编辑过]

uesoft

很多公式使用的都是三相点压力吧，新的冰点应该是0.01C，0.00C下饱和压力是否已经失去意义了？