๐ง Linde-Hampson Gas Liquefaction
Model cryogenics gas liquefaction cycles. Compute liquid fraction and compressor work requirements.
Thermodynamics
๐ Configuration
y = (hโ โ hโ) / (hโ โ h_f) โ liquid yield
W_comp = RยทTยทln(Pโ/Pโ) / ฮทc
W_liq = W_comp / y
COP = h_fg / W_liq
ฮผ_JT = (1/c_p)(2a/RT โ b)
๐ Results
Configure inputs and click Analyze to view results.
๐ Methodology
Linde-Hampson Cycle
The Linde cycle uses isothermal compression followed by JT expansion to liquefy gases. A counter-flow heat exchanger pre-cools the high-pressure stream using the cold returning gas, progressively lowering temperatures until liquefaction occurs.
Yield & Make-up
The liquid fraction y represents the fraction of compressed gas that is liquefied per pass. The unliquefied gas returns through the HX, and fresh make-up gas compensates for the liquid withdrawn. Higher pressure increases yield but also compressor work.
Limitations
- Requires Tin < Tinv for JT cooling.
- Hydrogen and helium need pre-cooling below their Tinv.
- Van der Waals model is approximate; more accurate EOS (Peng-Robinson, SRK) improve predictions.
- Real HX has finite effectiveness.
๐ Calculation Methodology: Linde-Hampson Cryogenic Liquefaction Cycle
Mathematical Model & Theory
The Linde-Hampson cycle uses regenerative recuperative heat exchange coupled with Joule-Thomson isenthalpic valve expansion to liquefy cryogens ($N_2, O_2, CH_4$):
Assumptions
- Isenthalpic Joule-Thomson expansion ($h_3 = h_4$).
- Recuperator warm-end approach $\Delta T = T_1 - T_{ret}$.
Academic References
- Barron, R. F.: Cryogenic Systems, Oxford University Press.
- Timmerhaus, K. D., & Flynn, T. M.: Cryogenic Process Engineering, Plenum.
Worked Engineering Example
A methane liquefier operates between $P_1 = 100\text{ kPa}$ ($h_1 = 800\text{ kJ/kg}$) and $P_2 = 15\text{ MPa}$ ($h_2 = 620\text{ kJ/kg}$). Saturated liquid enthalpy is $h_f = 280\text{ kJ/kg}$. Calculate liquid yield fraction $y$.
Step-by-step Solution:
1. $y = (800 - 620) / (800 - 280) = 180 / 520 \approx 0.346 = 34.6\%$.
Final Result:
Liquid production yield is $y = \mathbf{34.6\%}$ per pass.