According to the time-dependent heat cascade analysis technique

time places

which represent time for batch process

were imported to the self-organizing Petri Net modules of continual heat exchange network(HEN) to optimize batch HEN. Introducing time places

the representation of time in Petri Net was developed and the research of reachability became easy.Besides

based on the enabling rule of vertical heat transfer

streams split in HEN based on pinch technology were studied and the equations considering comprehensively all the principles of pinch technology were established to split steams accurately and quickly at the pinch point.An example was presented to demonstrate the validity and advantages of the proposed approach.