초록 |
An energy-efficient crude distillation unit (CDU) was proposed, and its performance was examined with that of the conventional CDU. The problem of large energy demand associated with the single column operation of the conventional CDU was solved with the two-column operation in the proposed CDU. The two-column operation eliminates feed tray mixing to raise the thermodynamic efficiency of the CDU. The results of the performance evaluation of the proposed system indicate that the proposed unit saves 35% of heating duty over the conventional unit, and reduces the cooling duty by 23%. The economic analysis shows that a 22% decrease of investment cost and a 51% reduction of utility cost are yielded from the proposed unit. The thermodynamic efficiency increases by 0.7% point over the conventional unit. Though the two-column CDU is not built as a single column DWC for easy construction, vapor flows between two columns are readily available by adjusting the difference of column operating pressure and the two-column operation leaves no difficulty in field application.
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