Experimental Study on Pool Boiling Heat Transfer Characteristics of Porous Surface Tube

Abstract

The pooling boiling plays an important role in the operation of the passive residual heat removal heat exchanger (PRHR HX). At present, smooth tubes are still widely used as boiling element in the PRHR HX; there is great extension to improve the security and miniaturize the size of PRHR HX if the smooth tubes were replaced by porous surface tubes. In this paper, the pool boiling heat transfer characteristics of porous surface tube was researched experimentally. The result shows that the porous surface tube can enhance the pooling boiling significantly: Compared with the smooth tube, the porous surface tube can greatly reduced the time before the water reached saturation; the wall superheat decreases about 1.5°C and the boiling heat transfer coefficient increases 68% to 75%. Besides, the enhanced mechanism of the porous surface tubes is also discussed in this paper.