海水盐度对海水沸腾传热及淡水产率的影响

ANALYSES THE EFFECT OF SALINITY ON BRINE BOILING HEAT TRANSFER AND DISTILLATE PRODUCTION RATE

对机械蒸汽压缩式(MVC)海水淡化中的沸腾传热与海水淡化性能进行理论分析。以竖直管式蒸发冷凝器建立具有不同盐度的海水核态沸腾传热模型,对海水的传热性能、热流密度、淡水产率以及海水淡化的能耗进行系统分析。为避免单位压缩功和淡水产率不能同时达到最优,设定单位压缩功不变。计算结果表明,海水盐度的增加对海水淡化的系统性能不利:海水盐度增加,沸腾换热系数αe、总传热系数、热流密度q和淡水产率m将有不同程度减小;增加沸腾压力和单位压缩功均有利于系统的传热性能,但单位压缩功的增大,增加了海水淡化的能耗。

The investigation on the thermal and desalination performance of MVC desalination system were carried out in this paper. The nucleate boiling heat transfer model of brine was built based on a vertical evaporator condenser. And the effects of the salinity on heat transfer, heat flux and distillate production rate were analyzed systematically. The specific power consumption was kept unchanged, in order to gain the optimal design about energy consumption and distillate production rate at the same time. The theoretical results indicated that increasing salinity of the brine had an adverse influence on the performance of MVC. The boiling heat transfer coefficient, overall heat transfer coefficient, heat flux and distillate production rate decrease as the salinity increased differently. Increasing boiling pressure had a positive influence on the performance of MVC. Increasing the specific power consumption improved the thermal performance of the system MVC, and reduced the size of the equipment and the investment costs. However, the increase in the specific power consumption caused an increase in energy consumption.