Abstract
The mathematical models for calculating the energy utilization efficiency of heat exchanger networks (HENs) based on exergy analysis method and entransy analysis method are built, respectively. With the goal of maximum energy recovery, the HENs of the gasoline adsorption desulfurization (S-zorb) unit are analysed by these two models. The exergy loss is accurately calculated using subsection integral by temperature-enthalpy (T-H) diagram. The entransy dissipation is calculated by the integration of the cold and hot composite curves in the temperature-heat flow rate (T-Q) diagram. The results are obtained in three different ∆Tmin15 K, 20 K and 25 K. Then, the adaptability of the two methods to the HENs of the S-zorb unit was further compared. For the S-zorb unit, the exergy efficiency decreases, respectively 89.89 %, 88.21 %, 86.49 %, and save utility about 82.90 %, 72.13 %, 67.46 %. The entransy transfer efficiency also decreases 92.41 %, 91.07 %, 89.73 %, and save utility about 80.03 %, 72.33 %, 64.63 %. Compared with exergy analysis method, the calculation process of entransy dissipation is simpler, and the results are closer to reality. The entransy analysis method is more suitable for the analysis of energy utilization efficiency of the HENs of S-zorb unit.
