流速对非等温凝结表面Marangoni凝结换热特性的影响

在具有温度梯度的凝结表面上进行了水-酒精混合蒸气的Marangoni凝结的实验。研究了3种流速(V=2、4和6 m/s)对凝结表面上不同位置热流密度的影响。研究发现:流速对纯水蒸气和混合蒸气凝结时的表面温差和热流密度的影响是不同的。对纯水蒸气而言,流速增大后,表面温差和热流密度是增加的,并加剧了热流密度的分布不均(热流密度的相对差值在压力为31.2 kPa,流速2 m/s时为0.538,流速4 m/s时为0.6,流速6 m/s时为0.625)。对于混合蒸气,表面温差随流速的增加而减小,而热流密度增大很少(压力31.2 kPa,流速2 m/s时为0.186,4 m/s时为0.182,6m/s时为0.098)。

Influence of the Flow Velocity on the Marangoni Condensation Heat Exchange Characeristics of Nonisothermal Condensation Surfaces

A Marangoni condensation test was performed of a steam-alcohol mixture on a condensation surface with a temperature gradient.The influence of three flow speeds(V=2,4 and 6 m/s)on the heat flux density at various locations on the condensation surface was studied.It has been found that the influence of the flow speed on the surface temperature difference and heat flux density when the steam and its mixture are being condensed is different.In terms of the pure steam,after the flow speed has increased,the surface temperature difference and heat flux density will also increase,thus exacerbating the non-uniform distribution of the heat flux density(the relative difference of the heat flux density is 0.538 at a pressure of 31.2 MPa and a flow speed of 2 m/s,0.6 at 4 m/s and 0.625 at 6 m/s).In terms of the steam mixture,the surface temperature will decrease with an increase of the flow speed while the heat flux density will increase little(the relative difference of the heat flux density is 0.186 at a pressure of 31.2 MPa and a flow speed of 2 m/s,0.182 at 4 m/s and 0.098 at 6 m/s).