An experimental study is performed to investigate nucleate pool boiling heat transfer of a tube array having an inclined upper tube and a horizontal lower one. For the analysis, two stainless steel tubes submerged in the saturated water are tested at atmospheric pressure. The heat transfer coefficient of the upper tube decreases as the inclination angle increases because of the reduction in the affected region by the upward flow. The enhancement in heat transfer is related to half of the tube where the local pitch is lower than the average one.

pool boiling, inclination angle, tube array, passive heat exchanger.