Table 1 shows the total heat load, the temperature ranges and the fluids of every each heat exchanger. The design process consists of dividing each heat exchanger into smaller elements, i.e., sub-heat exchangers. Thus, the behavior of each fluid along the channels can be obtained. The method starts introducing the inlet temperature and pressure of the fluids in each sub-heat exchanger and follows an iterative process until the heat balance for every sub heat exchanger is accurate. Also the pressure drop defined in the development of the power cycle has to be satisfied, as is presented by Dostal [9]. Three different empirical correlations to obtain the Nusselt number and the pressure drop in each element are introduced. These were extracted from the studies performed by Moisseytsev [11], Gnielinsky [9,12] and Dittus–Boelter [12]. The design process is programed and solved with Engineering Equation Solver (EES) [13]. For the evaluation of the Nusselt number(Nu), Dostal [9] recommended the use of the Gnielinski empirical correlation for Printed Circuit Heat Exchangers, based on [12]. Thus,