特征尺寸对竖管降膜太阳能海水蒸馏装置性能影响

EFFECT OF CHARACTERISTIC SIZE ON PERFORMANCE OF VERTICAL TUBULAR FALLING FILM EVAPORATION SOLAR SEAWATER DISTILLATION DEVICE

针对小型太阳能海水蒸馏装置产水速率低等问题,设计竖管降膜太阳能海水蒸馏装置,理论推导单位冷凝面积产水速率ms的计算方法,分析特征尺寸对该太阳能海水蒸馏装置单位冷凝面积产水速率、二元混合气体对流传热温度、冷凝壁面温度梯度值等热特性的影响机理。结果表明,在输入功率为168 W,特征尺寸为15 mm的装置稳态运行时,单位冷凝面积最大产水速率为240.63 g/20 min,比特征尺寸为35 mm的装置增加了24.16%,二元混合气体稳态运行温度为85.37℃,比特征尺寸为35 mm的装置提高了7.21℃。

Aiming to the low freshwater yield rate in small-scale solar seawater distiller,is designed A in this paper vertical tubular falling evaporation film solar seawater distillation device.The calculation method of ms,which is the water productivity per unit condensation area,is derived theoretically.The influence mechanism of the characteristic size of the verticaltube on water productivity of per unit condensation area,convection heat transfer temperature of binary mixture gas,temperature gradient of the condensation surface and so on is analyzed.The results indicated that when the device is in steady operation,with input power of 168 W and the characteristic size of 15 mm,the maximum water productivity per unit condensing area is 240.63 g/20 min,the operating temperature of binary mixture gas is 85.37℃.The freshwater yield per unit condensing area and the operating temperature of binary mixture gas is higher 24.16%,7.21℃higher than the device with the same input power and the characteristic size of 35 mm,respectively.