摘要
建立了直接接触式膜蒸馏(DCMD)的传递模型,对膜蒸馏过程中膜通量和热效率等影响因素进行了详细研究.实验探索了膜蒸馏热侧进口温度、冷侧和热侧流量对过程的影响,为膜通量和热效率优化提供依据.结果表明,热侧进口温度升高、热侧和冷侧流量增加均有助于膜通量增加;热侧进口温度升高、热侧流量增加和冷侧流量减小均有利于提高热效率.膜通量取决于传质推动力,即蒸汽压差;热效率取决于平均膜面温度,凡是有利于膜面温度提高的操作条件都会增大热效率.
The effects of operating conditions (feeding temperature, hot and cold side flow) on flux and thermal efficiency were investigated. Some heat and mass transfer models of direct-contact membrane distillation (DCMD) based on hollow fiber membrane were used to analyze the mechanism of flux and thermal efficiency changing with operating conditions. The results showed that the flux increased with the increases of feed temperature, hot and cold side flow, because they greatly increased the mass transfer driving force across membrane, but had limit effect on mass transfer coefficient. The mass transfer driving force, or the vapor pressure difference across membrane decided the membrane flux, and the mean temperature of the membrane surface decided the thermal efficiency. Both increasing the feed temperature and flow, and decreasing the cold side flow benefited increasing the thermal efficiency for higher average membrane temperature.
出处
《膜科学与技术》
CAS
CSCD
北大核心
2016年第4期67-74,共8页
Membrane Science and Technology
基金
国家自然科学基金的支持(21576004)
关键词
直接接触式膜蒸馏
传递模型
膜通量
热效率
direct-contact membrane distillation (DCMD)
transfer model
flux
thermal efficiency