Experimental study on variation of natural gas utilization low calorific value thermal efficiency with exhausted gas temperature

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.