摘要
针对冷凝式燃气锅炉,利用加湿热空气模拟燃气锅炉尾部烟气,通过实验研究了不凝性气体占多数时的水蒸气冷凝换热,研究了不同水蒸气分压比(3%20%)、不同温度下(100200℃),加湿空气的冷凝换热特性。实验表明,不凝性气体(空气)占多数时,其对流冷凝复合换热系数可以达到无冷凝时干空气对流换热系数的1.53倍。复合换热系数的影响因素主要有水蒸气分压力pv、Re、Pr以及壁面温度Tw和混合气体主流温度Tg,在此基础上建立一个新的准则数Ln并拟合了冷凝换热Nu数的准则关系式。
Condensation heat transfer characterization of a single-row condensing heat exchanger was investigated experimentally by using vapor-air mixture to simulate flue gas of a natural gas boiler. The experiments were conducted at different vapor volumetric concentrations (3%~20%) and a wide range of the mixture temperature (100~200℃). The forced convection-condensation heat transfer coefficient is 0.5~2 times more than that of the forced convection without condensation. Based on the experimental data, an empirical correlation of condensation heat transfer was obtained with a new dimensionless number Ln.
出处
《工业锅炉》
2003年第1期12-15,34,共5页
Industrial Boilers
