满液型海水淡化蒸发器的换热特性研究

海水淡化装置，太阳能或余热吸收式制冷机中的蒸发换热器目前使用管排外降膜式蒸发方式。如将传热管束紧凑排列置于饱和状态液体中则变为满液式蒸发换热器，利用传热管束间受限空间内早期沸腾强化换热机理，将中小热负荷条件下的自然对流换热转化为核沸腾换热，在间隙尺寸适宜时，其换热性能可能优于降膜式蒸发换热器。该研究以盐水为实验工质，对紧凑传热管束受限空间的沸腾换热进行了实验研究，确认了满液式蒸发换热器也具有很好的换热性能，在中小热负荷条件下甚至超过降膜式蒸发换热器。

EXPERIMENTAL STUDY ON ENHANCED HEAT TRANSFER OF FULL LIQUID TYPE DESALINIZATION EVAPORATOR

Enhanced Heat Transfer characteristics of Full Liquid Type Desalinization Evaporator, which consists of a heated tubes bundle submerging in the saturated water/salt mixture, were investigated experimentally for understanding effects of the tube gaps, locations of the tubes and salt water concentration on water/salt mixture boiling in the restricted spaces. The experimental results show that, when the tube gaps are quite small, boiling in the restricted spaces can easily occur and it can make greater heat transfer than general pool boiling. The locations of the tubes and salt water concentration have no significant effects on the boiling heat transfer. Full Liquid Type Evaporator with small tube gaps can obtain a great heat transfer coefficient than that of fall film type Evaporator.