Abstract: Through the statistics analysis，the technical difficulties in recovery of low temperature heat in domestic aromatic complexes were summarized. Using C6 or C7 hydrocarbons as a internal heat transfer medium，the In/Out double heat exchange system was designed for an aromatics unit through detailed analysis of its current situation of low temperature heat. The low temperature heat of the unit could be fully recovered by the new system which could achieve the amount of 41MW/h，this will further reduce the energy consumption by 10%～15%．This technique has made a breakthrough in technical difficulties for recovery of low temperature heat in aromatic unit and provided a new way to recover the low temperature heat of the column top stream of raffinate oil column，extraction column and p-xylene column in the aromatics unit.

Key words: aromatics unit, low temperature heat, heat transfer medium, hot water