Steam boilers are used to generate steam in order to meet cold process heat requirements. The most common heat exchanger network layout associated with the boiler is a completely parallel design. This observation suggests that the flowrate of steam needed for the system can be reduced, while maintaining the required duty, simply by changing the layout of the network. Phase change of saturated steam to saturated liquid plays a vital role in the targeting method as well as the design of the network layout. A hybrid graphical and mathematical technique for targeting and network synthesis is presented. The main objective of the technique is to reduce steam flowrate without compromising duty requirements of the process heat exchangers. In order to assess the advantage of a hybrid technique, a case study is used where steam savings of 29.6% is obtained. A complete mathematical technique to demonstrate the advantage of the graphical targeting concept in solution time improvement is further presented.
Dissertation (MEng)--University of Pretoria, 2008.