蒸发式冷凝器单位传热面积最佳风量水量配比研究

Research on Optimal Ratio of Air Volume to Water Mass Flowrate for Evaporative Condenser

利用自主设计的顺流式椭圆管型蒸发式冷凝器性能实验台,研究风量和水量对其传热传质性能的影响。通过改变迎面风速和喷淋密度的大小,得出单位传热面积最佳风量水量配比值为299.9 m3/(h·m2)、0.63 kg/(h·m2);相对应的最佳迎面风速和喷淋密度分别是3.28 m/s和0.057 kg/(m·s);测得干工况运行传热系数为正常工况的1/10,充分证明蒸发式冷凝器主要利用潜热带走热量;并指出在设计过程中,要综合考虑整个系统的性能,保证EER达到最佳值。

The influence of air volume to water mass flowrate ratio on heat and mass transfer was investigated in the test bench designed by the authors with oval tube evaporative condenser of parallel flow. Through research on the change of wind speed and spray density, it is found that the optimum air volume and water mass flowrate per unit heat transfer area to are 299. 9 m3/（h·m2） and 0. 63 kg/（h·m2） respectively, and the best face velocity of air and spraying density are 3. 28 m/s and 0. 057 kg/（ m·s） respectively. The heat transfer coefficient measured at dry condition is only 1/10 of the normal working condition, which fully proves that the heat is mainly taken away by the latent in evaporative condenser. It is also pointed out that the performance of the whole system should be comprehensively consid-ered in the process of design to ensure the best EER of the system.