Experimental Study On Absorber Of Flue Gas Heat Recovery And Soot Removal

Industrial waste heat recovery and utilization technology of wet flue gas has developed rapidly in recent years, such as the flue gas of gas fired boiler and wet flue gas desulfurization (WFGD). The waste heat of low temperature wet flue gas is mainly latent heat. The latent heat of the flue gas of gas fired boiler accounts for a large proportion, which is equivalent to about 10% of net calorific value of natural gas. The dew point is around 50-60℃. The flue gas of WFGD is close to saturation state, and the dew point of it is about 50℃. It contains considerable latent heat, if recycled, the efficiency of energy systems can be improved greatly. Besides, it also contains lots of soot, such as WFGD of power plant, in which the mass concentration of fine particulate matter (PM2.5) is about 76% and the number concentration can be as high as 99%. But the traditional soot removal technology is difficult to remove fine particulate matter. The team that author works in has carried out a systematic study on the technology of open cycle absorption heat pump, unit parts, working substance and so on. Open cycle absorption heat pump technology can recover the latent heat of the flue gas without dropping the temperature to the dew point. Furthermore, it has high latent recovery rate and grade. The high gravity rotating packed bed has an excellent soot removal performance and high removal rate of particulate matter whose size bigger than 3 μm. In this thesis, the open cycle absorption heat pump technology is combined with the high gravity rotating packed bed technology to deal with the high humidity flue gas. The experimental results show that solution absorption process has contributions to the removal of fine particles. An absorber experimental table of the waste heat recovery and soot removal is designed and built, in order to recover latent heat and reduce soot emission. The performance of waste heat recovery and soot removal under different operating parameters is studied. Conclusions are as follows:(1) When used with concurrent operation, the absorber can have the self boosting effect, which is suitable for flue gas system without induced fan.(2) The law of the waste heat recovery performance is obtained along with the change of the operating parameters. In a certain range, increasing the liquid to gas ratio, the high gravity factor, the solution inlet concentration and reducing the solution inlet temperature can improve the water recovery rate(3) Solution absorption process has a significant promoting effect on soot removal, especially on the removal of fine particles. Increasing the liquid to gas ratio and the high gravity factor can improve the soot removal rate.