Pool boiling heat transfer from an inclined tube bundle

The combined effects of an inclination angle and the heat flux of a lower tube on pool boiling heat transfer of a tube bundle were investigated experimentally. For the test, two heated stainless steel tubes of 19 mm diameter and the water at atmospheric pressure were used. The increase of the heat flux of the lower tube and the decrease of the inclination angle increases the heat transfer coefficient of the upper tube. The increase of the heat transfer coefficient is clearly observed when the inclination angle is less than 30° and the heat flux of the lower tube is greater than that of the upper tube. The major reason of the heat transfer enhancement on the upper tube is due to the convective flow and liquid agitation caused by the bubbles departed from the lower tube.