千瓦级质子交换膜燃料电池电堆的实验研究

空泡率是汽液两相流动的基本参数之一，而已有过冷沸腾空泡率计算方法研究以高质量流速为主。且大量文献报道现有空泡率模型难以适用于低流速过冷沸腾工况。该文基于低流速过冷沸腾净蒸汽产生点(NVG)理论模型，进一步建立了计算过冷沸腾空泡率的分布拟合模型。在较宽广的压力、质量流速、热流密度和流道尺寸范围内将模型计算结果与现有空泡率实验数据进行了比较，低流速工况下该模型与实验数据符合良好，表明该模型可适用于低流速过冷沸腾工况。

Experimental Study of a PEM (Proton Exchange Membrane) Fuel Cell Stack of l kW Class

A large capacity PEM (proton exchange membrane) fuel cell stack of 1 kW class has been developed by the authors. During experiments hydrophilic membrane electrode assemblies were prepared. By making use of membranes of Nafion 115 and Nafion 1135 and with the Pt content of cathode and anode both being assessed at 0.5mg/cm2 the maximum power density of a single cell can respectively attain 0.19 w/cm2 and 0.24 w/cm2. Through an enlargement test and a stability test of a single cell verified were the feasibility of a bipolar plate flow field of the cell stack and the stable performance of the cell proper. By way of assembling a cell stack of 100watt class the feasibility of sealing technology in a cell stack of 1 kW class and the ability of a gas manifold to achieve gas uniform distribution on a bipolar plate have been verified. Finally, it is shown that the maximum output power of the PEM cell stack composed of 30 single cells each with a reaction area of 235 cm2 may attain 1160w.