At present, biomass boilers on the market all have problems such as heating area ash, superheater slagging, and pollution. The accumulation of ash is mainly due to the fact that the biomass contains more alkaline substances. In the high-temperature combustion environment, alkaline substances are likely to form slag in the furnace, or adhere to the heating surface in the form of steam and fly ash particles, affecting the thermal efficiency of the boiler, and even the local heat transfer surface will be polluted and covered, losing heat transfer. thermal performance. Like coal-fired boilers, biomass boilers suffer from corrosion problems. Different from coal-fired boilers, the corrosion of biomass boilers is mainly chlorine corrosion, and the corrosion rate increases with the increase of steam temperature. The location of corrosion is usually on the heating surface of the superheater.

Another serious problem in slag-burning biomass boilers is the slag problem, once the slag will affect the adequacy of fuel combustion and reduce thermal efficiency. Especially in the combustion mode of the fluidized bed, the basic elements (mainly sodium and potassium) in the biomass react with the quartz sand in the bed to form a low-temperature eutectic mixture on the sand surface to form slag, so it needs to be in the bed Inert additives are added to reduce slag formation.

Although the emission of harmful gases is relatively clean compared with fossil fuels, SO2 gas and HCL gas can still be monitored in the exhaust gas after combustion, and the emission of HCL gas is much higher than that of coal combustion, mainly because biomass High chlorine content. These emissions easily react with potassium in biomass to form aerosols, pollute the air, increase flue gas purifiers, and reduce the pollution of exhaust ports.

Heat loss The heat loss in biomass boiler combustion is mainly flue gas heat loss. A large amount of flue gas heat is discharged through the chimney, and the loss of volumetric hot flue gas greatly reduces the efficiency of the biomass boiler. The reason for the heat loss from the flue gas is that the biomass fuel contains more water. After the biomass fuel with high water content enters the furnace, it needs to use higher drying temperature and longer drying time to reduce the water content. The higher the water content, the lower the low-calorie biomass. Therefore, when burning biomass fuel with high water content, the temperature field in the furnace is low, making it difficult to burn. More water also increases flue gas volume and increases exhaust heat loss. In order to reduce the heat loss during the combustion process of the biomass boiler, the corresponding combustion method can be reasonably selected to fully burn, and the waste heat recovery device at the exhaust gas outlet of the boiler can be added to improve the thermal efficiency of the biomass boiler.