Using a state of the art one dimensional, two-phase, dynamic system model, the size effects of a portable two-phase microchannel electronic cooling system are investigated using different refrigerants (R134a, R236fa, R245fa). Special attention is given to the accumulator size and its limitations for portable applications. An analytical model is developed to investigate the accumulator size effect on the loop and compared to the numerical results obtained from the system model. The
influence of various loop parameters and possible improvements are investigated. Finally usable
design equations are developed to calculate the needed accumulator size. These equations are further used to compare the performance of the different refrigerants and control techniques with regard to the size effects.