Oxygen-enriched burner

Abstract

The invention discloses an oxygen-enriched burner which comprises a burner communicated with a hearth and an oxygen-enriched gas generator that includes an air separator, an air inlet pipe, a nitrogen outlet pipe and an oxygen-enriched gas outlet pipe; wherein, the air inlet pipe, the nitrogen outlet pipe and the oxygen-enriched gas outlet pipe are respectively connected with three ports of the air separator; the burner comprises an inner bushing, a middle bushing, an outer bushing and a connecting pipe between the inner and the outer bushings, wherein, the inner bushing is arranged inside the middle bushing which is positioned inside the outer bushing, one end of the inner bushing is connected with one end of the outer bushing by the connecting pipe between the inner and the outer bushings, the other end of the inner bushing is communicated with an inlet of the hearth, and the other end of the outer bushing is an inlet of regenerative cycle flue gas; one end of the middle bushing is communicated with an inlet of the hearth, and the other end thereof is an inlet of coal dust and oxygen-enriched gas. The oxygen-enriched burner leads the oxygen-enriched gas and the coal dust to be fully and evenly mixed together, and improves the heat exchange efficiency of preheating the coal dust by back-flow gas, so as to overcome the defects of the existing oxygen-enriched combustion technology.

Description

technical field [0001] The invention relates to an oxygen-enriched burner, in particular to an oxygen-enriched burner used for a coal-fired boiler in a power station. Background technique [0002] Due to the long ignition time of pulverized coal, high consumption and unstable combustion at low load, its ignition conditions are much higher than those of fuel oil and gas. Therefore, oil gun ignition was generally used for ignition of traditional power plant boilers in the past. The ignition process is as follows: when the boiler is started, light the fuel gun first, and after the oil burns in the furnace for a certain period of time, the furnace is heated to the ignition temperature of the pulverized coal. At this time, the pulverized coal is sprayed into the furnace for mixed combustion of kerosene and oil; And when the pulverized coal can burn stably, the oil is gradually cut off to complete the ignition start process. This ignition method has the following two disadvantage...

AI Technical Summary

Problems solved by technology

This ignition method has the following two disadvantages: 1. It consumes a lot of fuel. According to the sampling survey on the ignition oil consumption of coal-fired units, it shows that the average oil consumption of 100MW, 125MW, 200MW, 300MW and 600MW units in cold start-up units per year Respectively 216.4 tons / set, 309.6 tons / set, 291.66 tons / set, 908.24 tons / set and 451.62 tons / set

2. It will cause environmental and social problems. The mixed combustion of heavy oil and pulverized coal will lead to the deterioration of the technical and economic indicators of the thermal power plant. When the oil is injected into the combustion, the electrostatic precipitator supporting the boiler cannot be used, resulting in a series of social problems such as environmental protection and ecology.

However, the standards for comprehensive evaluation of pulverized coal direct ignition burners, such as calculation standards (ignition technology, stable combustion technology, pollutant discharge level) and economic standards (initial investment, operation, maintenance and other comprehensive costs), existing pulverized coal ignition burners Always stick to the form of a pure pre-combustion chamber, that is, to create a high-temperature heat source, while ignoring another problem of stable combustion: how to reduce the ignition temperature of the primary air powder, so this ignition method needs to be further improved

This kind of combustion device cannot fully and uniformly mix the oxygen-enriched gas and pulverized coal, and the heat exchange efficiency of preheating by recirculation gas is also relatively low. There are still deficiencies in thermal

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