Abstract: The departure-site spacing between liquid columns was measured for water, ethylene glycol, water and ethylene glycol binary mixture with volume fraction 0.5/0.5 on eight different orifice configurations with a visualization method. The influences of flow rate, tube spacing, surface structure and orifice configuration on departure-site spacing were investigated for the subcooled liquid columns flowing between horizontal tubes at the ambient temperature and normal pressure. Under the conditions of this study, the departure-site spacing increases with the decrease of Re for high-Ga flow. For a fixed Re,the departure-site spacing increases with the increase of tube spacing. The surface structure and thermo-physical properties of fluid influence the departure-site spacing. Bigger hole diameter brings smaller departure-site spacing at a fixed distance between adjacent holes, while larger distance between adjacent holes leads to larger departure-site spacing at a fixed hole diameter.The departure-site spacing between liquid columns was measured for water, ethylene glycol, water and ethylene glycol binary mixture with volume fraction 0.5/0.5 on eight different orifice configurations with a visualization method. The influences of flow rate, tube spacing, surface structure and orifice configuration on departure-site spacing were investigated for the subcooled liquid columns flowing between horizontal tubes at the ambient temperature and normal pressure. Under the conditions of this study, the departure-site spacing increases with the decrease of Re for high-Ga flow. For a fixed Re,the departure-site spacing increases with the increase of tube spacing. The surface structure and thermo-physical properties of fluid influence the departure-site spacing. Bigger hole diameter brings smaller departure-site spacing at a fixed distance between adjacent holes, while larger distance between adjacent holes leads to larger departure-site spacing at a fixed hole diameter.

Key words: horizontal falling-film evaporation tube, departure-site spacing, surface structure, tube spacing

摘要： 采用可视化方法对水、乙二醇、水/乙二醇混合物在8种液体分布装置开孔规格下的管间相邻液柱分离间距进行了实验测量，得到了分离间距随流量、管间距、管外表面结构和开孔规格的变化规律。随着Reynolds数增加，分离间距呈减小趋势；随着管间距增大，分离间距先增大后趋于稳定值。管外表面结构和工质热物性共同影响分离间距。在开孔孔径一定的条件下，开孔间距逐步增大，分离间距随之增大；在孔间距一定的条件下，开孔孔径逐步增大，分离间距随之减小。

关键词: 水平降膜蒸发管, 分离间距, 表面结构, 管间距