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针对不同压力和不同流速下的饱和水蒸气在竖直微细圆管(内外径分别为0.571 mm和0.793 mm)外的凝结传热特性分别进行了实验研究,分析了蒸气压力和蒸气流速对凝结传热特性的影响。实验结果表明,凝结传热表面传热系数随着蒸气流速的增加而增加,在较高的蒸气压力下增加的更明显,且大于相同实验条件下的Nusselt理论分析解。在蒸气流速为2 m·s~(-1)时,凝结传热系数随压力的变化不大;在4 m·s~(-1)和6 m·s~(-1)时,随着蒸气压力的升高,凝结表面传热系数明显增大。
Experimental investigations were carried out on the condensation heat transfer characteristics of saturated water vapor at different pressures and different velocities except vertical and horizontal circular tubes (inner and outer diameters of 0.571 mm and 0.793 mm respectively). The effects of vapor pressure and vapor velocity on the condensation heat transfer Effect of thermal characteristics. The experimental results show that the heat transfer coefficient of the condensation heat transfer surface increases with the increase of the vapor velocity and increases more obviously under the higher vapor pressure than the theoretical analysis of the Nusselt under the same experimental conditions. When the steam velocity is 2 m · s -1, the condensation heat transfer coefficient does not vary with the pressure. At 4 m · s -1 and 6 m · s -1, Vapor pressure increases, the condensation surface heat transfer coefficient increased significantly.