Some low-temperature flue gas is directly sent into the furnace, or mixed with air

　　With the continuous promotion of coordinated development of city clusters in key national regions, urbanization strategy and rural revitalization strategy, the degree of urbanization development in China has been gradually improved. In recent years, the scale of cities has been rapidly expanded, people's consumption level has been constantly improved, and garbage production has been increasing, and many cities have been surrounded by garbage.In the section of "accelerating the reform of ecological civilization system and building a beautiful China", the 19th National Congress of the Communist Party of China (CPC) listed the issue of garbage treatment as "prominent environmental problems", and clearly required "strengthening solid waste and garbage disposal", so as to form a space pattern, industrial structure, mode of production and way of life that can save resources and protect the environment.How to deal with waste reasonably and effectively has become the focus of environmental protection for the government and the public.At present, under the principle of waste disposal reduction, recycling and harmless, waste incineration power generation gradually shows great advantages and forms a competitive emerging industry, which has become an important development direction of waste disposal.

　　In recent years, China's environmental pollution is serious, haze has caused a certain degree of impact on people's life and work.Under the strict requirements of the national environmental protection policy, power enterprises attach great importance to energy saving and emission reduction, and formulate and timely, reasonable and effective measures.For a long time in the future, China will still mainly use coal-fired power generating units to generate electricity, but many boilers of power generating enterprises cannot meet the current national environmental protection requirements.Therefore, coal power generation enterprises must carry out boiler optimization and transformation according to the emission limits of pollutants required by the state, and actively adopt a series of environmental protection measures.Adopting low nitrogen combustion technology in boiler transformation can not only greatly reduce NO emission, but also improve stability and safety of boiler operation and save cost.

　　The "medium pressure air-tumber" atomized burner developed for burning straw oil has good applicability not only to straw oil, but also to bio-oil and petroleum oil.This kind of burners can be used to realize the normal combustion of heavy asphaltene and colloid and inferior oil with high density.

　　Principle of flue gas recycling:

　　Some low-temperature flue gas is directly sent into the furnace, or mixed with air (primary or secondary air) into the furnace, because the flue gas absorbs heat and dilutes the oxygen concentration, so that the combustion speed and temperature in the furnace are reduced, because the thermal NOx is reduced.For gas boilers, NOx reduction is most significant.In general, thermal (t-no), rapid (p-no) and fuel (f-no) production pathways are available.The flue gas recycling system is connected with the gas burner. When the inert gas in the circulating flue gas enters the burner, on the one hand, the flame propagation speed will be reduced, and on the other hand, the temperature level in the furnace will be reduced due to the absorption of heat, so the absolute flame temperature will be lowered, which cannot reach the generation temperature. Therefore, the generation of t-no will be inhibited.Other components in circulating flue gas are N2,CO2and H2O in large quantities. As circulating flue gas is mixed in, oxygen concentration in the mixture of air and flue gas decreases, thus affecting the production amount.Mixing circulating flue gas in the air increases the content of N2in the reaction.Due to the high activation energy required for the reaction of oxygen and nitrogen atoms, a large amount of nitrogen failed to react with oxygen to form NO, and reacted with hydrocarbon components in the fuel.A large amount of N2increases the forward reaction of the above equation and generates a large amount of intermediate HCN.The oxygen atoms in the flue gas then react with these intermediate products. The total O2 reaction of HCN in the poor oxygen environment is as follows: HCN+ 5/4O2-+ 1/2N2+CO2+ 1/2H2O;According to the formula, under the condition of lean oxygen and dense combustion, HCN finally generates N2.Therefore, after adopting the flue gas recycling system, on the one hand, the intermediate product HCN increased, while on the other hand, the concentration of O2decreased compared with that before the flue gas recycling was not applicable, which promoted the complete reaction, and the amount of N2was greatly increased, thus reducing the generation of p-no.

　　From the perspective of heat transfer calculation, the measures to reduce the smoke exhaust temperature are analyzed from the following aspects: increasing the heat exchange surface, improving the heat exchange efficiency of the heating surface, improving the heat exchange temperature difference by using a lower temperature source, and reducing the influence of corrosion on the heat exchange efficiency.As gas boiler host first meet the low nitrogen flame furnace volume and size requirements, the second host of convection heating surface is a main export in order to reduce the smoke temperature, general control in 150 ~ 250 ° C, in order to avoid the smoke temperature increases along with the flue design difficulty of heat preservation, high smoking temperature is too low will cause corrosion in furnace convection heating surface forming wall condensation, therefore, furnace domestic demand to design proper heating surface, the physical dimension more representative chamber size.Increasing the heat exchange surface should mainly consider increasing the heat exchange area of the equipment in the rear of the boiler, which is more favorable for rapidly reducing the exhaust temperature.The second is to have a lower inlet water temperature can be used for heat exchange temperature difference characteristics;Third, corrosion resistant materials can be used to improve its service life.The new structure of efficient heat exchange mainly adopts the form of staggered tube arrangement, efficient heat exchange finned tube, plate heat exchanger, etc., to increase the flue gas disturbance and contact surface, reduce the heat resistance of flue gas stratification, and improve the heat exchange efficiency of medium and flue gas.

　　New energy enterprises are not only the direct beneficiaries of clean energy consumption, but also important participants, bearing important responsibilities.Participate in the spot power market and auxiliary service market, improve the system dispatching ability in a market-oriented way, and promote the consumption of clean energy.

——Author：ebico