variavel0=<b>Eduardo Mach Queiroz</b> - mach@eq.ufrj.br DEQ/EQ/UFRJ
<b>Fernando Luiz Pellegrini Pessoa</b> - pessoa@eq.ufrj.br DEQ/EQ/UFRJ
<b>Fábio dos Santos Liporace</b> - liporace@petrobras.com.br EBS/PDEAB/CENPES/PETROBRAS
<b>Abstract.</b> The Pinch Design Method was developed considering one-phase streams, with constant specific heats (Cp) throughout streams` temperature ranges. Its first step has as objective utility targets determination and pinch point (PP) identification. For changing phase streams, the usual description of the enthalpy behavior, by constant Cp`s, can lead to errors in this step and hence in the next one, the synthesis of the network. This work uses a simple procedure, proposed in the literature, but not tested and not discussed in details, to deal with these streams. Its results are discussed through an example involving multicomponent streams. Changing phase streams are split into two or three sub-streams, taken as independent streams with constant Cp, using bubble and dew points as limit temperatures. With the new streams set, the traditional procedure is applied. Results show significant changes on the value of the PP and utility targets. Moreover, as the network synthesis uses the PP as a reference, it is also shown that the obtained final network structure is also a function of the way that the enthalpy behavior is represented.
<b>Keywords.</b> Pinch Design Method,, changing phase streams, heat exchanger networks, network synthesis, multicomponent streams.