摘要
为了研究减压膜蒸馏过程中膜管内的温度、压力分布及传质通量特性,分别建立膜蒸馏过程的传热、传质数学模型,对其中的温度、压力分布和蒸馏通量进行了理论分析和数值模拟,推导了计算膜蒸馏通量的新方法——对数平均压差法,并分别比较了对数平均压差法和算术平均压差法计算通量的特点．结果表明,采用对数平均压差法计算总蒸馏通量,其误差在１．２%以内;当膜管进、出口内外压差之比△ｐ’/△ｐ”≤１．６时,采用算术平均压差法来计算通量可将误差控制在＋２%内,而当△ｐ’/△ｐ”较大时,不能采用算术平均压差法计算膜管内外平均压差及蒸馏通量．
The mathematical models of mass and heat transfer of vacuum membrane distillation have been established to research the temperature and pressure distribution and mass flux. Theoretical analyses and numerical simulation were explored and a new method to calculating mass flux was developed - logarithmic mean pressure difference. The characteristics of calculating mass flux with logarithmic mean pressure difference were compared with those of arithmetic mean pressure difference. The results show that the error percentage of logarithmic mean pressure difference is less than 1.2%; the arithmetic mean pressure difference can not be true unless the pressure difference ratio of inlet to outlet △p'/△p'≤1.6,its error percentage is less than 2%.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2002年第1期12-16,38,共6页
Membrane Science and Technology
