低温烟气凝结换热及对天然气热效率的影响实验研究

为研究烟气露点附近及以下的低温烟气对流凝结换热规律与烟气换热对天然气利用热效率的影响,建立了烟气在翅片管换热器内对流凝结换热实验系统,研究了不同烟气温度、水蒸气含量对烟气凝结换热的影响,得出了烟气凝结换热实验准则关联式,分析对比了天然气利用热效率实验值与理论值.实验结果表明:当被加热水温度为23℃,烟气出口温度为73℃...

Experimental Study on the Effect of Low Temperature Flue Gas Condensation on Heat Transfer and Natural Gas Thermal Efficiency

For the study on heat transfer law of the low temperature flue gas convective condensation and the heat transfer effect on the thermal efficiency of the gas utilization near and under flue gas dew point,the convective condensation heat transfer experiment system for flue gas in the finned tube heat exchanger is established,the influences on the flue gas condensation heat transfer at the different heat exchanger inlet/outlet flue gas temperatures,and moisture contents,are studied,the experimental correlation equations of the flue gas condensation heat transfer are obtained,and the experimental values of the natural gas thermal efficiency are compared with the theoretical values.The experimental results show that the condensation begins when the heated water temperature is 23℃,the flue gas outlet temperature is 73℃which is 20℃higher than the flue gas dew point of 50℃;the flue gas temperature drops from 54.1~73.4℃to 28.7~57.8℃when the excess air coefficient is 1.3;the moisture quality content is decreased by 27%~76%and the latent heat transfer accounts for 51%~63%of the total heat transfer when the inlet temperature of the heated water is 21~25℃;the experimental value of low calorific value of natural gas utilization is 1.04%~8.74%higher than the theoretical value.It provides theoretical basis and data for the study of low temperature flue gas convective condensation heat transfer and the development and engineering application of flue gas waste heat recovery and utilization.