Study on Energy Saving of Epichlorohydrin Unit Based on Entransy Theory

Abstract

The mathematical models for calculating the energy utilization efficiency of heat exchanger networks (HENs) based on entransy analysis method was built. The energy utilization efficiency of HENs for epichlorohydrin unit were calculated by exergy analysis and entransy analysis. Aiming at the maximum energy recovery, the entransy analysis of epichlorohydrin unit’s HENs was done. By taking three different ?Tmin, 10 K, 15 K and 20 K, the results show that the exergy efficiencies are 61.01 %, 59.28 % and 57.27 %. The entransy transfer efficiency is 42.81 %, 42.13 % and 41.00 %. Using the entransy analysis method, utilities were saved by 19.41 %, 18.01 % and 15.70 %. Using the exergy analysis method, utilities were saved by 16.59 %, 14.86 % and 12.02 %.The results of different methods were analysed and compared. Exergy is more complicated than entransy in the calculation process. The exergy analysis method can not complete HENs Synthesis. But the entransy analysis method not only can complete HENs synthesis, but also can calculate the energy utilization efficiency of HENs. The entransy analysis method is more suitable for analyzing the energy utilization of epichlorohydrin unit.