Experimental Study of Enhanced Boiling Heat Transfer with Suction

In this paper, the tested chip was directly immersed in subcooled ( ΔT sub = 3 K) FC-72 for boiling heat transfer, and an experimental apparatus with suction tube was designed. A smooth silicon chip with the dimension of 10 × 10 × 0.5 mm 3 (length × width × thickness) was used as a heater. The effects of inner diameter of suction tube ( D = 2.2, 5.5 and 9.6 mm) and the distance from the suction tube inlet to the tested chip surface ( H = 1, 3 and 5 mm) on boiling heat transfer performance were explored. For comparison, experiment without suction on a smooth surface was also conducted. The experimental results showed that the suction boiling has a significant heat transfer enhancement compared with the traditional pool boiling without suction. The suction tube with the diameter of 5.5 mm has the best boiling heat transfer performance, and then 9.6 mm followed by 2.2 mm under the same variables, and the suction distance of 1 mm shows the largest heat transfer enhancement. The heat transfer coefficient (HTC) increases with the decrease of the distance from the suction tube inlet to the tested heating surface. At D = 5.5 mm and H = 1 mm, the maximum critical heat flux (CHF) increased by 39.22% compared with pool boiling without suction, while the maximum CHF increased to 33.4 W·cm −2 , and the maximum HTC increased by 79.77% compared with pool boiling without suction, while the maximum HTC increased to 1.093W·cm −2 ·K −1 . The mechanism of the enhancement of the boiling heat transfer performance is attributed to that the liquid supplement is enhanced and the bubbles departure velocity is accelerated due to the local low pressure and shear lift force generated by the suction.