Smoke automatic internal circulation low-nitrogen combustion system

Abstract

The invention relates to a smoke automatic internal circulation low-nitrogen combustion system. The system consists of a low-nitrogen combustor and a hearth, wherein the low-nitrogen combustor comprises a cylindrical throat port, a gas spraying gun and a combustion assisting air channel; and the internal of the hearth is divided into an air and smoke mixing area leaning against a front port of thethroat port, a gun head limiting extension area positioned on the outer side of the air and smoke mixing area, and a gas combustion area in outer side surrounding space of the gun head limiting extension area. During working, high-temperature and high-pressure smoke, generated by oxygen consumption combustion in the gas combustion area and with lower oxygen content, is automatically returned to the air and smoke mixing area under the effect of pressure difference, is mixed with combustion assisting air, with higher oxygen content, in the area to generate air and smoke mixed combustion assisting gas with lower oxygen content and lower temperature, and is sent into the gas combustion area in a gas current direction to mix with gas, sprayed from the gun head limiting extension area, for low-NOx combustion; and the high-temperature and high-pressure smoke, generated by combustion and with low oxygen content, is returned to the air and smoke mixing area again along with the pressure difference to realize the smoke automatic internal circulation with the same effect with the low-nitrogen combustion under the condition of not adding external smoke circulating facilities, so that higher practicability is achieved.

Description

technical field [0001] The invention relates to the technical field of emission reduction devices for industrial boilers, in particular to an automatic flue gas internal circulation low-nitrogen combustion system. Background technique [0002] With the continuous increase of national environmental protection control in recent years, the environmental protection standards for NOx emissions of gas-fired boilers have become increasingly strict. For this reason, the industry is actively exploring new low-nitrogen combustion technologies to transform gas-fired boilers. At present, in terms of low nitrogen emissions of high calorific value natural gas boilers, it has been proposed that the NOx emission value should be reduced to less than 30mg / Nm 3 target requirements. In practice, it has been found that when upgrading a gas-fired boiler, in addition to the need to replace the low-nitrogen burner, it is also necessary to supplement the flue gas external circulation combustion tec...

AI Technical Summary

Problems solved by technology

However, when the flue gas external circulation combustion technology is configured on the gas burner, a special flue gas recirculation pipe, The necessary external smoke circulation components such as smoke mixing box and recirculation fan make the overall structure of the burner relatively complicated, the installation is troublesome and the cost is also high; in addition, due to the large temperature difference when the flue gas is mixed, it is easy to generate condensed water , affecting thermal efficiency

Therefore, from the perspective of economy and practicality, it is not ideal.

Images