Start-up visualization and performance of flat-plate CLPHP based on PEMFC cooling

Abstract

Aiming at the structural characteristics and heat dissipation requirements of proton exchange membrane fuel cell (PEMFC), the passive flat-plate CLPHP cooling is proposed, and its start-up heat transfer performance is studied. A visual start-up experiment is carried out by bonding high-borosilicate glass with a 2 mm thick aluminum alloy plate which has a 2.3 mm × 1.4 mm rectangular flow channel. The vapor-liquid flow variation rules in the evaporation section when the temperature is stable and the filling ratio (FR) is 40% and 50% under different heating powers are photographed. Meanwhile, the temperature of each section and internal pressure changes of the flat-plate CLPHP are also collected. It is found that under lower heating power, the evaporation section pushes the liquid slug to move slowly under the action of the vapor pressure generated by the evaporation of the liquid film, and the edge flow channel starts to flow first. The temperature of the evaporation section rises as the heating power increases, with the bottom of the elbow first nucleating and boiling to produce bubbles and gradually transforming from slug flow to semi-annular/annular flow, and the heat transfer power is enhanced. The FR40% has better start-up performance, and the heat transfer power is higher than FR50%.