Research On The Simulation And Optimization Of Cryogenic Unit

Natural gas is a valuable resource, plays a significant role in the economicdevelopment under the present energy scarce environment. Recovering lighthydrocarbons from natural gas not only use light hydrocarbons, but can also improvethe quality of natural gas, including lowering its dew point, decreaing the spoil ofpetroleum and natural gas, increasing economic and social benefit of natural gas.Flow simulation and optimization of the Nanya cryogenic unit designed byDaqing Oilfield Design Institute were studied in this thesis. The operationconditions of the equipment like the demethanizer tower, mobile equipment or heatexchanger were calculated, and existed major problems were analyzed. Results showthat,(1) the refrigeration temperature was far failed to achieve the design value.(2)the separating efficiencythe demethanizer was weak.(3) the refrigeratingtemperatures of propane for Refrigerating was too high. The results of optimization ofthe equipment show that,(1) the optimization scheme of the demethanizer: thescheme that the materiel temperature for D0301should be further reduced, and thefeed location be exchanged between D0301and X0301was proposed, which couldfurther improve the separation performance of demethanizer, imoprove the yield oflight hydrocarbons by175kg/h, that is,1470tones more than normal output of lighthydrocarbons p under the condition that a daily processing capacity of60×104m3.(2)the scheme of low temperature absorption method was transferred to improve theseparating effect demethanizer, the yield of light hydrocarbons was imoproved by4099t every year and and the yield of ethane was increase by17.1%.