BT-39 Enhanced Flow Boiling Inside a Porous Coated Vertical Tube

LiDong Huang

Using pure p-xylene and mixtures of n-pentane/p-xylene as test fluids, HTRI conducted flow boiling tests in a vertical double-pipe heat exchanger with an internally porous coated tube provided by Beijing Guangsha Huanneng Technology Co., Ltd. Flow boiling in the tube was significantly enhanced at low heat flux, primarily via creation of nucleation sites; less pronounced benefit was observed for mixtures. In this report, data trends are analyzed and compared with predictions of our flow boiling methods for vertical plain tubes. A flow boiling model for predicting heat transfer coefficients and pressure drop in porous coated tubes is also presented.