Title of article :
Study on constraints for heat removal duties of the main fractionator in delayed coking units
Author/Authors :
Lei، نويسنده , , Yang and Zhang، نويسنده , , Bingjian and Qi، نويسنده , , Xin and Chen، نويسنده , , Qinglin and Hui، نويسنده , , Chi-Wai، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2014
Abstract :
A novel method is presented in this paper to quantitatively define the heat removal of the main fractionator in delayed coking units on the basis of a fractionating precision diagram (Houghland diagram) and column grand composite curve (CGCC). By referring to the CGCC method, several envelopes are illustrated at draw trays including the top pumparound draw, diesel draw, intermediate pumparound draw and gas oil draw, the energy and material balances are then calculated. Assuming practical near-minimum thermodynamic condition (PNMTC), the minimum liquid reflux flow is zero in the envelope for pumparound trays without product draw and the minimum liquid reflux flow is defined by Houghland diagram for pumparound trays with product draw. The PNMTC-CGCC is constructed by calculating the enthalpy-flow deficit to quantitatively define the heat removal constraints in each envelope. Meanwhile, the corresponding practical heat removal curve is constructed. A case study shows that the high temperature heat removal ratio within the main fractionator increased by 8%. The proposed method offers heat removal inequality constraints for the model to optimize the heat integration between the main fractionator and the heat exchanger network.
Keywords :
Houghland diagram , Main fractionator , Heat removal , Delayed coking
Journal title :
Applied Thermal Engineering
Journal title :
Applied Thermal Engineering