Exergy Analysis and Optimization of Steam-driven Jet Ejector System for Papermaking

Exergy analysis method was applied to develop exergy analysis mathematical model of steam-driven jet ejector(SDJE) system and its main devices used in paper industry.A typical domestic SDJE system was chosen to be the object of this study,in which exergy efficiency,exergy loss coefficients and exergy loss rate as a function of dryer cylinder differential pressure was analyzed and the differences of the parameters of each devices and systems were compared to each other.The results showed that the exergy loss of the steam separator is the minimum,and its exergy efficiency is the highest.Dryer cylinder is the device with the highest exergy loss in the whole system,whose exergy loss rate is over 0.86,exergy loss coefficient is maximum;SDJE can reduce steam consumption,but can't reduce exergy consumption,and exergy efficiency is about 40%.The optimal working condition of SDJE system comes out that the system exergy efficiency is 52% when the dryer differential pressure is 0.02 MPa.Finally energy-saving technology improvement direction of SDJE is proposed based on the exergy analysis of the devices in SDJE and the whole SDJE system.