沿程加热气泡泵流动沸腾特性及影响机理  

Flow Boiling Characteristics and Influencing Mechanisms of Bubble Pump with Full-length Heating

作　　者：杨洪海[1] 段文利 刘思琪 吴轶唯 孔则赟 陈玉萍 黄欣宇 Yang Honghai;Duan Wenli;Liu Siqi;Wu Yiwei;Kong Zeyun;Chen Yuping;Huang Xinyu(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620

出　　处：《流体机械》2020年第10期1-6,29,共7页Fluid Machinery

基　　金：国家重点研发计划项目(2016YFB0601404);上海市自然科学基金项目(13ZR1401100)。

摘　　要：气泡泵作为核心部件,为无泵吸收式制冷循环提供驱动力。搭建了沿程加热气泡泵可视化试验平台,以水为工质,着重研究受热提升管内的流动沸腾特性及其影响机理。研究表明,加热功率和沉浸高度是决定气泡泵运行的关键参数。当加热功率较小或入口过冷度较大时,系统稳定性较差,局部时刻出现间歇性断流,液体提升量及蒸汽产生量较少。随着加热功率的增加,蒸汽产生量线性增加,液体提升量先增加而后减少;存在一个最佳加热功率,使得液体提升量最大,在提升管出口观察到搅拌流状态。随着沉浸高度的增加,最佳加热功率随着增加。当沉浸高度较低时,在提升管出口段存在明显的液体回流现象,影响系统稳定性及液体提升量;增加沉浸高度,循环流速及液体提升量随之增加,但蒸汽产生量减少。降低初始压力,有利于增加液体提升量及蒸汽产量。As a critical component,bubble pump provides a driving power for the pump-free absorption refrigeration cycle.A test rig with partial visualization was set up to investigate the thermo-fluidic behavior and influencing mechanisms of bubble pump with full length heating by using water as the working fluid.The results show that the heating power and immersion height were key parameters that determine the operation of bubble pump.At lower heat input or higher inlet sub-cooling,the system stability was relatively poor,accompanied with the emergence of intermittent flow interruptions occasionally,leading to less amount of liquid flow and vapour production.With the increase in heat input,the vapour generation increased linearly,while liquid lift-up increased at the beginning and then decreased.There should exist an optimal heating power for the bubble pump to lift a maximum amount of liquid,and a churn flow regime was observed at the outlet of the lift tube.With the increase of the immersion height,the optimum heating power increased accordingly.At lower immersion height,a phenomenon of liquid reflux was observed at the outlet of the lift tube,which affected the stability of the system and amount of lifted liquid.With the increase of immersion height,the circulating flow speed and amount of lifted liquid increased,but the vapor production decreased.Reducing the initial pressure would benefit increase of lifted liquid and steam production.

关 键 词：气泡泵 沿程加热 流动沸腾 影响机理 

分 类 号：TH3[机械工程—机械制造及自动化]