Study On Condensate Recovery Of Continuous Regenerative Biomass Gasification Combustion Boiler

Continuous haze weather has a serious impact on people’s lives and health.In order to improve environmental problems,China vigorously promotes natural gas energy,but the energy situation is becoming increasingly tense.In order to make up for the shortage of clean natural gas energy,and in response to the national trend of energy saving and emission reduction,it is particularly important to design a system that can maximize the recovery of waste heat.A complete set of high-efficiency and low-emission biomass heat utilization system is formed by organic combination of upper-suction biomass gasifier and high temperature air combustion technology.It is expected to maximize the thermal efficiency of biomass utilization process,reduce pollutant emissions and make up for the serious shortage of natural gas supply in China.In addition,biomass fuels have high carbon-hydrogen ratio and oxygen content.High H/C makes biomass produce more water vapor after combustion,while high oxygen content greatly reduces the amount of air required for combustion,thus greatly reducing the total amount of combustion flue gas,coupled with the high moisture content of biomass fuel itself,so the 1 water vapor in the flue gas after biomass combustion is very high.If the latent heat can be recovered,the thermal efficiency of biomass boilers can be further improved.In order to study the feasibility of recovering condensate water and latent heat from biomass boilers,theoretical calculations were made for the condensation recovery of flue gas burned by three different biomass under different conditions.The results show that the volume fraction of water vapor in the flue gas after combustion is about 13%～22%for pine,13%～23%for rice straw and 17%-27%for enteromorpha clathrata.Ideally,waste heat recovery can improve the total thermal efficiency of pine and rice straw by 6%-20%and enteromorpha clathrate by 15%～40%.A self-designed condensation heat exchanger was tested on a biomass gasification combustion test bench.The results show that under the experimental conditions,the thermal efficiency increases by about 6%～9%,but the potential for further improvement is very high.It shows that the method of recovering condensation water and latent heat from biomass boilers to improve thermal efficiency has great potential and practical application value.