Fuel oil/gas boiler for reducing emission of nitric oxides and method

Abstract

The invention relates to a fuel oil / gas boiler for reducing emission of nitric oxides and a method, belonging to the technical fields of energy saving and emission reduction and boilers. The fuel oil / gas boiler for reducing emission of nitric oxides comprises a fuel pipeline, a combustion-supporting air pipeline, a low-nitrogen combustor, a boiler body, a smoke discharging pipeline, a chimney, a smoke circulating pipeline, a combustion-supporting fan and a water inlet pipe. Compared with the common boiler, the fuel oil / gas boiler has the advantages of reducing radiation heat exchange area by 30-50%, and increasing heat convection area by 15-25%; and 15-25% of boiler low-temperature smoke enters the combustion-supporting fan after passing through a smoke circulating cooler and the smoke circulating pipeline, and is mixed with fresh air to be used as combustion-supporting air to enter the low-nitrogen combustor. According to the invention, on the premise of no reduction of the heat efficiency of the fuel oil / gas boiler and no increase of operation cost, the emission of the nitric oxides of the fuel oil / gas boiler can be reduced by 20-50%.

Description

technical field [0001] The invention relates to boiler energy-saving and emission-reduction technology, in particular to a fuel / gas boiler with low nitrogen oxide emissions and its method, which can reduce fuel / gas boilers without affecting the thermal efficiency and operating costs of the fuel / gas boiler. Boiler nitrogen oxide emissions range from 20% to 50%. Background technique [0002] The current research on low nitrogen oxide emission boiler combustion technology is divided into three directions: pretreatment of fuel and air; optimal configuration of air and fuel and design of low nitrogen burner; post-treatment of flue gas. For fuel and air pretreatment methods and flue gas treatment methods, due to complex systems, large investment, large land occupation, and high operating costs, they are not suitable for scattered medium and small boilers. While suppressing the formation of nitrogen oxides, low-nitrogen burners often lead to problems such as reduced combustion eff...

AI Technical Summary

Problems solved by technology

For fuel and air pretreatment methods and flue gas treatment methods, due to complex systems, large investment, large land occupation, high operating costs, etc., it is not suitable for scattered medium and small boilers

While suppressing the formation of nitrogen oxides, low-nitrogen burners often lead to reduced combustion efficiency, reduced combustion temperature or increased excess air coefficient, resulting in reduced boiler efficiency and increased operating costs.

At present, low nitrogen oxide emission fuel / gas boilers have not been popularized and applied. The main problems are: 1. In the heat transfer area of ​​existing fuel / gas boilers, the radiation heat transfer surface generally accounts for 30-35%, and the convection heat transfer The surface area accounts for 65%-70%. After the combustion device is improved, the boiler structure has not been adjusted accordingly, resulting in a decrease in the rated output and thermal efficiency of the boiler; 2. While reducing the emission of nitrogen oxides, the operating cost of the boiler has increased too much

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