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Open Access
Investigation of failure load and fracture pattern of single and double U-notched beam under three point bending
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2013-07) Bisht, Deepak Singh; Singh, V.K.
Open Access
Thermodynamic analysis of collins Helium liquefaction system based on I & II law
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2013-08) Pal, Amit Kumar; Pratihar, A.K.
Collins cycle or the modified Claude cycle is the one which is normally used for the liquefaction of helium gas. The liquefaction of helium is obtained by compressing the helium to a higher pressure and then cooling by heat exchangers and finally by the expansion through Joule Thomson valve.In present study, Collins helium liquefaction system with six heat exchangers, two expanders and a J-T valve is taken for the thermodynamic analysis based on I and II law. Parameters that mainly affect the performance ofCollins system are compression efficiency, efficiencies of expanders, effectiveness of heat exchangers and mass fractions diverted to expanders. The results shows that to obtain higher yield of liquid helium, expander’s efficiency and heat exchanger’s effectiveness of the system should be greater than 0.75 and 0.95 respectively. The diverted mass fraction in certain ratio only leads to higher yield and higher exergetic efficiency. This mass fraction found in this study is 0.85.