化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
12期
4692-4698
,共7页
于培宁%徐英%张涛%魏靖%巴玺立%李静%秦自耕
于培寧%徐英%張濤%魏靖%巴璽立%李靜%秦自耕
우배저%서영%장도%위정%파새립%리정%진자경
气液两相流%文丘里%气含率%压降%动力学模型
氣液兩相流%文丘裏%氣含率%壓降%動力學模型
기액량상류%문구리%기함솔%압강%동역학모형
gas-liquid flow%Venturi meter%gas holdup%pressure drop%kinetic modeling
运用两相流理论对湿气中的气相与液相流动进行分析,在分层流与环雾状流的条件下推导了两相流通过水平标准文丘里流量计的理论模型。通过分别考虑截面气含率、相间摩擦以及液滴夹带等因素,在文丘里轴向对湿气流动中的气相动量方程进行求解。通过对水平直管中的截面气含率公式进行修正,建立了适用于收缩管道的截面气含率模型,并在此基础上模拟了湿气流经标准文丘里时其两个取压孔之间的轴向静压分布。实验证实,使用修正后的截面气含率公式将使模型对文丘里压降的预测准确度明显提升,其相对误差在15%以内。该模型以湿气两相流在水平文丘里中的流动形态为依据,具有较充分的物理背景,而且在推导过程中较少依赖特定实验装置与数据,为建立具有一定普适性的文丘里湿气计量模型奠定了基础。
運用兩相流理論對濕氣中的氣相與液相流動進行分析,在分層流與環霧狀流的條件下推導瞭兩相流通過水平標準文丘裏流量計的理論模型。通過分彆攷慮截麵氣含率、相間摩抆以及液滴夾帶等因素,在文丘裏軸嚮對濕氣流動中的氣相動量方程進行求解。通過對水平直管中的截麵氣含率公式進行脩正,建立瞭適用于收縮管道的截麵氣含率模型,併在此基礎上模擬瞭濕氣流經標準文丘裏時其兩箇取壓孔之間的軸嚮靜壓分佈。實驗證實,使用脩正後的截麵氣含率公式將使模型對文丘裏壓降的預測準確度明顯提升,其相對誤差在15%以內。該模型以濕氣兩相流在水平文丘裏中的流動形態為依據,具有較充分的物理揹景,而且在推導過程中較少依賴特定實驗裝置與數據,為建立具有一定普適性的文丘裏濕氣計量模型奠定瞭基礎。
운용량상류이론대습기중적기상여액상류동진행분석,재분층류여배무상류적조건하추도료량상류통과수평표준문구리류량계적이론모형。통과분별고필절면기함솔、상간마찰이급액적협대등인소,재문구리축향대습기류동중적기상동량방정진행구해。통과대수평직관중적절면기함솔공식진행수정,건립료괄용우수축관도적절면기함솔모형,병재차기출상모의료습기류경표준문구리시기량개취압공지간적축향정압분포。실험증실,사용수정후적절면기함솔공식장사모형대문구리압강적예측준학도명현제승,기상대오차재15%이내。해모형이습기량상류재수평문구리중적류동형태위의거,구유교충분적물리배경,이차재추도과정중교소의뢰특정실험장치여수거,위건립구유일정보괄성적문구리습기계량모형전정료기출。
In this study, by using the two-phase hydrokinetic theory, a theoretical model for gas-liquid annular and stratified flows through a horizontal Venturi meter was developed. The momentum equation for the gas phase was solved in the axial direction, by considering the factors including void fraction, friction between two phases and entrainment of droplets in the gas core. By modifying the void fraction model proposed by Lockhart and Martinelli, a void fraction model for the convergent tube was developed. Using the modified void fraction model, the distribution of wet gas static pressure between two pressure tappings of the venture meter was simulated. For the sake of checking the validity of this model, wet gas flow experiments were performed by using the standard venture meters with diameter ratio of 0.55 and 0.4 in the flow laboratory of Tianjin University. The predicted points of the modified model were within error band of ±15%. As the model was developed more based on dynamics characteristics of wet gas flow, it could form the basis for further establishing a general flow measurement model of wet gas.