steam data
steam data
(OP)
I am looking at steam table data for specific volume (ft3/lb) of superheated steam in the range 500 F to 1400 F. I am ok with data at 14.7 psi but I will like to incorporate the effect of variation of pressure. The variation is not much -- May be 2"wg at the most, do you think I should at all be worrying about the effect of variation of pressure of steam in this case ? Or should I just fit a linear curve for data at 14.7 psi between the temperatures 500 F and 1400 F and use that equation?





RE: steam data
At 14.0 psia, 400°F v=34.61 h=1240.0 s = 1.8796
At 14.696 psia, 400°F v=34.68 h=1239.9 s=1.8743
At 15.0 psia, 400°F v =33.97 h=1239.9 s=1.8719
At 14.0 psia, 1400°F v=79.11 h=1745.5 s=2.2657
At 14.696 psia, 1400°F v=75.37 h=1745.5 s=2.2603
At 15.0 psia, 1400°F v=73.84 h=1745.5 s=2.2580
Where v=specific volume cu. ft. per lb
h=enthalphy Btu/lb
s=entropy Btu/(°F-lb)
RE: steam data
http://webbook.nist.gov/chemistry/name-ser.html
for water (fluid properties) and verify whatever properties you are after.
RE: steam data
I rely on tables.
You may try the following empirical formula
v(ft3/lb)=18.293+0.0410 t -1.913e-7 t^2)*14.7/p
t in °F P in psia it's OK in your range
RE: steam data
Please correct your formula. The open parenthesis is missing. It is not clear what must be multiplied by 14.7/p
RE: steam data
I wouldn't worry about 2" WG, that's less than 0.5% of the pressure assuming 14.7 psi you give is absolute. Or you could correct the specific volume just based on the inverse ratios of the absolute pressure.
The key question is here, what accuracy do you need?
RE: steam data
remove.marius@mailbox.co.za
RE: steam data
v(ft3/lb)=(18.293+0.0410 t -1.913e-7 t^2)*14.7/p
t in °F p in psia