temperature drop across regulator
temperature drop across regulator
(OP)
I am struggling trying to calculate the temperature of the outlet air from a regulator which is reducing from 350 bar to 17 bar. I have read a long thread from this forum on a related subject but can't apply it to my problem. Can anyone help.
thanks
Jamie





RE: temperature drop across regulator
Steam expansion is a different story.
Regards,
RE: temperature drop across regulator
RE: temperature drop across regulator
Perry VI gives the envelope conditions for expanding air to heat or cool on a J-T expansion. It follows that at 350 bar as long as air is below 445 K (172oC) it will cool on a isenthalpic J-T expansion.
RE: temperature drop across regulator
Before asking the question I did the T1/T2 = (P2/P1)^(1-k)/k calc giving me T2=113K. When colleagues expressed disbelief that it would be so cold, I had a re-think and realised that isentropic expansion was probably not the correct process for this. I now think that it is an isenthalpic process which means the calc is much harder. Is this correct ?
As you may have guessed, this is not really my field
thanks
Jamie
RE: temperature drop across regulator
But yes, I have frozen regulators. The gas can get cold.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: temperature drop across regulator
Jamie
RE: temperature drop across regulator
RE: temperature drop across regulator
If change in KE is negligible, the isenthalpic is sat.
RE: temperature drop across regulator
Is it Thomson or Thompson?
Thomson as in Joule-Thomson, as in Lord Kelvin. My research has shown it to be Thomson, but there are as many references to Thompson.
RE: temperature drop across regulator
William Thomson (or Thomsen) later Lord Kelvin, an Irish-born scientist, was the first to study the cooling of gases on expansion into a vacuum, by the mid 19th century, realizing that heat is related with molecular motion.
Benjamin Thompson, an American-born scientist working as director of the Bavarian arsenal by the end of the 18th century, noted the large amount of heat produced in the process of boring cannons. He, then, concluded that heat is not a conserved fluid. He suggested that heating was associated with mechanical work by the boring tool.
By about half a century later the British physicist James P. Joule confirmed Thompson's observations, and quantified the relation between heat and energy (mechanical, electrical and chemical), bringing thermal phenomena under the powerful conservation-of-energy law. The SI energy unit is named after Joule in recognition of this major synthesis in physics.
RE: temperature drop across regulator