【摘要】 在水平及垂直管外水蒸气凝结的条件下,对4种实验管的传热性能进行了比较实验研究。对于水平、略高于大气压的凝结条件,在实验范围内,BGT管的总传热系数约为光管的1.38~1.60倍,而BGT-1管的总传热系数约为光管的2.05~2.16倍。对于同一管型,在真空Ph=0.068 6 MPa、冷却水Re数5×103~4×104范围内,BGT-1管垂直布置时总传热系数约为水平布置时的0.78~0.87倍。实验结果表明,布置方式、蒸汽凝结负荷及压力是维持珠状凝结持久的重要影响因素。更多还原

【Abstract】 Under the condition of steam condensation outside a horizontal and vertical tube a comparative experimental investigation was conducted for the heat transfer performance of four kinds of experimental tubes.Within the range of tests for a horizontal tube with a condensation condition slightly higher than one atmospheric pressure the total heat transfer factor of tube BGT is about 1.38-1.60 times of that of a bare tube,while the total heat transfer factor of tube BGT-1 is about 2.05-2.16 times of that of a bare tube.For the same tube type within the range of vacuum P_h = 0.0686 MPa and cooling water Re number 5×10~3-4×10~4 the total heat transfer factor of a vertically installed tube BGT-1 is about 0.78 -0.87 times of that of a horizontally installed tube.The results of the tests indicate that the layout scheme,steam condensation load and pressure are major influencing factors for maintaining a sustained dropwise condensation.更多还原