翅片管换热器孔板型竖直集管的流量分配特性  

Flow distribution characteristics of vertical header with orifice plate in finned-tube heat exchangers

作　　者：孙瑜 胡凯恒 黄东[1] 赵日晶 SUN Yu;HU Kaiheng;HUANG Dong;ZHAO Rijing(School of Energy and Power Engineering,Xi′an Jiaotong University,Xi′an 710049,Shaanxi Province,China)

机构地区：[1]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《化学工程》2025年第3期57-64,共8页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(51876154)。

摘　　要：为解决翅片管换热器中目前常用的喷嘴式分配器成本高,安装要求高的问题,提出了孔板型竖直集管式分配器,并在不同入口质量流量、入口干度、集管结构的条件下对两相制冷剂的分液特性进行实验和数值计算。结果表明:工质在孔板型竖直集管流动时存在“二次分配”的特征,即向上流动时会进行一次分配,之后其余工质会冲顶到达竖直集管顶部后回流,回流过程中会与向上流动的工质碰撞进行二次分配。随着质量流量和入口干度增加,两相工质进入竖直集管内速度增大,一次分配时液相工质进入下部出口管的流量减少,顶部回流后碰撞流入上部出口管较多。竖直集管管径的大小和进出口管位置与角度分别通过改变工质流动速度和流动方向从而改变流量分布。集管管径增加可以提升下部出口管出口流量,出口管管径的增加,距离孔板最近的出口管流量减少。Finned tube heat exchangers are widely used in air conditioning industry due to the less charge amount and lower copper consumption.Nozzle distributors are commonly used to improve the uniformity of liquid distribution in compact finned tube heat exchangers to solve the problem of low efficiency of heat exchangers caused by uneven refrigerant distribution.However,the nozzle distributor has high cost and high installation requirements.In this paper,a vertical header distributor with orifice plate was proposed,and the flow and distribution characteristics of two-phase refrigerant were experimentally and numerically studied under different inlet mass flowrate,inlet vapor quality and header structure parameters.The results show that the working fluid is firstly distributed when it flows upward,and then the rest of the working fluid can rush to the top of the vertical header and then flow back.During the flow back process,the working fluid collides with the upward flowing working fluid for the second distribution.With the increase of mass flowrate and vapor quality,the flowrate of two-phase working fluid into the vertical tube increases,the flow rate of liquid phase working fluid into the lower outlet tube decreases during the first distribution,and more flows into the upper outlet tubes.The diameter of vertical header and the position and angle of inlet pipe change the flow distribution by influencing the velocity and direction of the two-phase flow,respectively.Increasing the header diameter can increase the outlet mass flowrate of the lower tubes.As the outlet pipe diameter increases,the mass flowrate of the outlet pipes nearest to the orifice plate decreases.

关 键 词：两相流动 孔板 竖直集管 流量分配 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]