Claude çevriminin termodinamik analizi ve optimizasyonu

In this thesis, common gas liquefaction cycles are introduced and thermodynamic analysis and optimization of Claude liquefaction cycle is performed using common gases including air, oxygen, nitrogen, argon, methane, and fluorine. The cycle is simulated using EES software and operating data of the cycle is obtained under certain assumptions. In thermodynamic analysis of Claude cycle, liquid yield, net work input, COP, and second law efficiency are used as performance parameters. Parametric studies are done to investigate effects of gas inlet temperature, liquefaction temperature, compressor outlet pressure, effectiveness of heat exchangers, and expander flow ratio on the performance of Claude cycle. Optimum operating conditions that maximize system performance by minimizing the work consumption are determined. Thermodynamic analysis of this cycle indicates that the COP value is the highest for methane (0.386), second-law efficiency is the highest for nitrogen (57.5%), and work consumption is the lowest for argon (968 kJ/kg liq). Parametric studies show that a decrease in the inlet gas temperature, an increase in liquefaction temperature, and an increase in heat exchanger effectiveness provide higher values of liquid yield, COP, and second-law efficiency and lower values of work consumption. An optimum value is determined for the fraction of gas diverted to the expander, which turns out to be around 0.7. Also, the pressure for which the COP is maximum is determined to be a little over 5 MPa.