【摘要】 为了研究戊烷与水直接接触汽化传热过程中其液液界面的真实传热温差,文中搭建了汽化传热的闭路循环实验装置,设计了一种戊烷-水直接接触界面面积不变的圆形接触面,运用双平行电导探针测定液液界面的波动情况,采用红外热像技术确定液液界面处水的表面温度,进而确定直接接触汽化传热的真实传热温差,同时通过实验研究了水流速和温度对热通量的影响。结果表明:戊烷汽化传热的真实传热温差Δt远远小于传统计算方法得到的温差Δt_m,这种温差的差别导致了计算得到的真实传热系数远远大于根据传热方法计算得到的传热系数。同时,热通量随着水流速和传热温差的增加而逐渐增加。该实验方法为直接接触汽化传热机理的研究提供了重要方法和新的思路。更多还原

【Abstract】 In order to study the actual driving temperature difference of pentane-water direct contact evaporation heat transfer,a novel experimental method was proposed based on an unchanged circular interface. The stability of liquid-liquid interface was determined by a double parallel conductance probe. The thermal infrared imager was used to determine the actual driving temperature difference by measuring interface water temperature. The results show that the actual driving temperature difference Δt is far lower than the temperature difference Δtmbetween bulk water temperature and pentane saturation temperature. It also causes that the actual heat transfer coefficient is far larger than the traditional algorithm. The effects of water flow velocity and temperature on heat flux were investigated experimentally. The heat flux increases as the water flow velocity and the actual temperature difference increases. The method and results provide useful data for better understanding of the mechanism of direct contact evaporation heat transfer between two immiscible liquids.更多还原