天然气利用低热值热效率随排烟温度变化规律实验研究
Experimental study on variation of natural gas utilization low calorific value thermal efficiency with exhausted gas temperature
摘要：
基于天然气燃烧烟气对流冷凝换热实验，以北京市天然气为例，实验研究了天然气利用低热值热效率随排烟温度的变化规律，并与理论计算值进行了比较。结果表明：即使烟气流动断面平均温度未达到理论烟气露点温度，但烟气中水蒸气已凝结放出汽化潜热，表明换热面温度低于露点温度；天然气利用低热值热效率实验值比理论值大，当过剩空气系数为2.0时，实验值比理论值大1.01%～7.80%。
Abstract：
Based on the convective condensation heat transfer experiment of flue gas from natural gas combustion, taking natural gas in Beijing as an example, experimentally studies the variation of natural gas utilization low calorific value thermal efficiency with exhausted gas temperature, and compares the results with the theoretical values. The results show that even if the average temperature of the flue gas flow section does not reach the theoretical flue gas dew-point temperature, but the water vapor in the flue gas condenses and releases latent heat of vaporization, indicating that the heat transfer surface temperature is lower than the dew-point temperature. The experimental value of low calorific value thermal efficiency of natural gas utilization is higher than the theoretical value. When the excess air ratio is 2.0, the experimental value is 1.01% to 7.80% higher than the theoretical value.
Keywords:natural gas, flue gas, low calorific value, thermal efficiency, exhausted gas temperature, dew-point temperature