code:Property Metric Unit Standard Unit
Temperature (T) 232.2 C 450.0 F
Pressure (P) 29.103 bar 422.10 psi
Density Saturated Liquid (rhof) 824.29 kg/m3 51.459 lb/ft3
Saturated Vapor (rhog) 14.548 0.90818
Specific Volume Saturated Liquid (vf) 0.0012132 m3/kg 0.019433 ft3/lb
Saturated Vapor (vg) 0.068739 1.1011
Internal Energy Saturated Liquid (uf) 996.92 kJ/kg 428.60 Btu/lb
Evaporated (ufg) 1607.0 690.90
Saturated Vapor (ug) 2604.0 1119.5
Enthalpy Saturated Liquid (hf) 1000.6 kJ/kg 430.20 Btu/lb
Evaporated (hfg) 1803.6 775.4
Saturated Vapor (hg) 2804.2 1205.6
Entropy Saturated Liquid (sf) 2.6301 kJ/kg-K (mayer) 0.62820 Btu/lb-R
Evaporated (sfg) 3.5684 0.8523
Saturated Vapor (sg) 6.1990 1.4806
code:Property Metric Unit Standard Unit
Temperature (T) 260.0 C 500.0 F
Pressure (P) 46.884 bar 680.00 psi
Density Saturated Liquid (rhof) 784.07 kg/m3 48.948 lb/ft3
Saturated Vapor (rhog) 23.692 1.4791
Specific Volume Saturated Liquid (vf) 0.0012754 m3/kg 0.020430 ft3/lb
Saturated Vapor (vg) 0.042208 0.67610
Internal Energy Saturated Liquid (uf) 1128.3 kJ/kg 485.10 Btu/lb
Evaporated (ufg) 1470.7 632.30
Saturated Vapor (ug) 2599.1 1117.4
Enthalpy Saturated Liquid (hf) 1134.4 kJ/kg 487.70 Btu/lb
Evaporated (hfg) 1662.6 714.8
Saturated Vapor (hg) 2797.0 1202.5
Entropy Saturated Liquid (sf) 2.8839 kJ/kg-K (mayer) 0.68880 Btu/lb-R
Evaporated (sfg) 3.1183 0.7448
Saturated Vapor (sg) 6.0018 1.4335
quote:A bunch. Here is a big list.
Originally posted by Tatiana:
I wonder how many other very odd properties water has?
quote:This isn't quite accurate because about the critical pressure, there is not phase transition therefore the liquid and gas phases don't really exist -- there is only one phase. Also, this isn't a property that is unique to water. Most if not all liquids have a critical point.
The boilers at the power plant I work at are classed as “supercritical.” That means that the water doesn’t actually boil. The boilers do not have drums just tubes. We run the water pressure in the boiler tubes up to over 3500 psi and at some point (nobody knows just where or when) the water changes from a liquid state to steam. And the steam is at the same density as water.
quote:This may not be true. You have to consider both the second law and the first law to determine if work can be done by a system.
So what that means is that if you had a pound of sat. steam at 450 F, you should be able to let it do work, like move a piston to run an engine or something, and then it would be in the lower energy state of 500 F (at a much higher pressure too). .
quote:I considered this possibility but what we are dealing with here is sort of a negative specific heat. I way sort of becaue specific heats are general defined at either constant pressure or constant volume and never at constant %saturation which makes analyzing the system all in all a bit wierd. I can't see any way that you could get a negative specific heat by adding a vibrational mode, I think you have to add in a chemical potential well to get this result.
Originally posted by King of Men:
I couldn't find anything in a quick Google, but it's possible that there is a temperature somewhere in that range where a new vibration mode becomes available. That would absorb some energy by the virial theorem, and account for some of your U.
quote:Once again, not necessarily. We have only considered the first law. To know whether or not a process will occur spontaneously we need to look at the second law. The Gibbs free energy will tell you whether or not a constant pressure process will occur spontaneously. Helmholtz free energy will tell you whether or not a constant volum process will occur spontaneously, but there isn't a standard free energy equation for constant %saturation processes.
when the system got to 450 F, would it quickly slide down the curve past the inflection point, and back up to whatever temperature has the same enthalpy as it does at 450 F? In a sense, it would be sort of an explosion (implosion?) that would rapidly take the temperature of the system to a much higher level.