๐ Throttling Valve & Joule-Thomson Effect
Analyze isenthalpic throttling processes. Compute the Joule-Thomson coefficient, outlet temperature, inversion temperature, and liquefaction feasibility using the van der Waals equation of state.
๐ Configuration
Isenthalpic: hin = hout
ฮผJT = (1/cp)(2a/RT โ b) [Van der Waals]
Tout = Tin + ฮผJTยทฮP
Tinv = 2a/(Rb) [max inversion temp]
Ideal gas: ฮผJT = 0
๐ Results
Configure inputs and click Analyze to view results.
๐ Methodology
Isenthalpic Process
Throttling through a valve is isenthalpic (hin = hout) at steady state with negligible kinetic and potential energy changes. For a real gas, this causes a temperature change due to intermolecular forces.
Joule-Thomson Effect
The JT coefficient ฮผJT = (โT/โP)h determines whether throttling causes cooling (ฮผ>0) or heating (ฮผ<0). Most gases cool at room temperature; hydrogen and helium heat up because their inversion temperatures are very low.
Inversion Curve
The inversion temperature is where ฮผJT = 0. Below Tinv, the gas cools upon expansion. For the Van der Waals model: Tinv,max = 2a/(Rb). Gas liquefaction (Linde process) requires operating below Tinv.