Utilizing mixed refrigerant cycle to develop small scale nitrogen liquefier

Liquefied gases which are cooled below -150 oC temperature are called Cryogens. Liquefaction of gases has been a major application of the Cryogenics field. The gas liquefaction industry is growing nowadays with a faster pace, to facilitate increasing applications of cryogens in areas like heat treatment of metals, industrial and biomedical research, production of jet propellants and so on. This increasing demand of liquefied gases is driving intensive research for improvement and optimization of the gas liquefaction systems. Various innovative approaches of gas liquefaction are being developed and tested. The comprehensive objective of this research work is to find a suitable mixed-refrigerant cycle for the liquefaction of Nitrogen gas in small scale. To accomplish this objective a detailed study of the effects of variation of operating parameters such as, gas compression ratio, number of heat exchangers and expansion methods for mixed-refrigerant, on the system performance is studied. A comparative study of currently used liquefaction systems is also presented. This study will be followed by simulation of the developed mixed-refrigerant system for its analyses and optimization