Improving the performance of a closed single turn pulsating heat pipe by injecting micro-coppers

In this experimental research, the performance of the close single turn pulsating heat pipe (CPHP) with distilled water as base fluid and distilled water including microparticles (micro-coppers) have been investigated. To evaluate the effect of different parameters on the CPHP performance, several characters like input powers, filling ratio and concentrations of micro-coppers were studied. Findings from experiments indicate that the multiphase flow regime inside the pipe was slug-plug in low powers but it approached to an annular flow in higher value of heat inputs. Furthermore, it is required to mention that the thermal resistance of the device with micro-coppers has decreased with enhancing in the concentration of micro-coppers and input powers and it has the minimum value (0.61degC/W) at filling ratio of 60%, at input power of 60W. Finally, according to any errors of each parameters and by using Holman methods, the maximum uncertainty of experiments was calculated about 8%.