含油制冷剂在泡沫金属圆管内流动沸腾的换热特性  

Heat Transfer Characteristics of Refrigerant-oil Mixture Flow Boiling inside Circular Tubes Filled with Metal Foam

作　　者：胡海涛[1] 朱禹[1] 丁国良[1] 孙硕[1] 

机构地区：[1]上海交通大学制冷与低温工程研究所,上海200240

出　　处：《制冷学报》2013年第1期24-29,共6页Journal of Refrigeration

基　　金：国家自然科学基金(50906048)资助项目~~

摘　　要：实验研究了填充泡沫金属的蚓管内制冷剂与润滑油混合物流动沸腾换热特性。实验对象为两根分别填充5PPI、90％孔隙率与IOPPI、90％孔隙率泡沫铜的圆管，以及相同管径的光管。实验工况为蒸发压力995kPa，质流密度为10～30kg／（m2．s），热流密度为3．1-9．3kW／m2，入口十度0．175--0．775，油浓度为0～5％。实验结果表明：纯制冷剂工况下，泡沫金属的存在强化流动沸腾换热，换热系数最多提高185％；含油工况下，泡沫金属强化换热的效果弱化；相同工况下，更小的孔径可以提高流动沸腾换热系数，相比5PPI泡沫金属的实验数据，10PPI的泡沫金属叮以使换热系数最多提高0．6倍。基于流型建直了填充泡沫金属的圆管内制冷剂与润滑油流动沸腾换热系数的预测模型，预测模型与98％的实验数据误差存±30％以内。The heat transfer characteristics of refrigerant-oil mixture flow boiling inside circular tubes filled with metal foam were experimentally investigated. The metal foams are 5 ppi / 95% porosity and 10 ppi / 95% porosity copper foams. The experimental conditions include saturation pressure of 995 kPa, mass flux from 10 to 30 kg/（m2.s）, heat flux from 3.1 to 9.3 kW/m2, inlet vapor quality from 0.175 to 0.775, and oil concentration from 0% to 5%. The experimental results show that： metal foam enhances the flow boiling heat transfer coefficient of refrigerant by a maximum of 185% at oil free conditions, while the enhancement effect of metal foam is weaken at oil presence conditions; the flow boiling heat transfer coefficient for the circular tube filled with high ppi metal foam is higher than that for the tube filled with low ppi ones. A new correlation of heat transfer coefficient for refrigerant-oil mixture flow boiling inside circular tubes filled with metal foam is developed based on the flow pattern, and it can agree with 98% of the experimental data within a deviation of ±30%.

关 键 词：流动沸腾 换热特性 泡沫金属 制冷剂 润滑油 

分 类 号：TK124[动力工程及工程热物理—工程热物理] TB64[动力工程及工程热物理—热能工程]