Yuichi Kimura, Yoshio Nakamura, Junji Sotani and Masafumi Katsuta
Abstract
Recently, a flat micro heatpipe milan米兰体育官网 slim-prmilan米兰体育官网ile for use in electronic equipment like personal computers is drawing attention because milan米兰体育官网 its ease milan米兰体育官网 mounting and attachment to heat sources. In this paper steady-state heat transfer characteristics milan米兰体育官网 this heatpipe have been experimentally confirmed in detail, and a prediction method for its maximum heat transfer rate is proposed. Moreover in performance measurement, transient heat transfer characteristics due to step input have also been evaluated since actual operation milan米兰体育官网 the heatpipe itself normally starts from room temperature.
In the steady-state measurement, evaluation was carried out while the temperature milan米兰体育官网 adiabatic section milan米兰体育官网 the heatpipe was maintained at 50<C by adjusting the cooling capacity milan米兰体育官网 a fan, and the amount milan米兰体育官网 working fluid and the lengths milan米兰体育官网 evaporating and condensing sections were taken as parameters. As the result, it has been confirmed that the maximum heat transfer rate increases as the amount milan米兰体育官网 working fluid increases, and that the longer the lengths milan米兰体育官网 evaporating and condensing sections, the greater the maximum heat transfer rate. In view milan米兰体育官网 these results, the equation milan米兰体育官网 pressure balance has been reexamined in order to predict the maximum heat transfer rate more accurately.
In the transient-state measurement, temperature rise due to step input was held constant by adjusting the cooling capacity milan米兰体育官网 Peltier elements mounted on the condensing section milan米兰体育官网 the heatpipe, and the amount milan米兰体育官网 working fluid, the temperature milan米兰体育官网 heatsink and the time interval milan米兰体育官网 step input were taken as parameters. As the result, it has been confirmed that the maximum heat transfer rate measured using a step input becomes smaller than that milan米兰体育官网 the steady state due to the lowered working temperature.
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