Crude and fine coal powder separation and burn method and device

Abstract

A coal powder thickness separation burning method and a device thereof belong to coal powder burning technology field and are adapted to coal powder burning boiler. The method includes: (1) separating step, separating the conventional coal powder to fine coal powder and thick coal powder; (2) flow lead burning step, setting the thick coal powder to the middle part of the burning jet flow, leading the fine coal powder to the external of the thick coal powder air flow to burn, forming a stable fire source around the thick coal powder air flow to strength the fire and stable burning for the thick coal powder air flow. The device of the invention is mounted with a cyclone separation apparatus on the front part of the main burner, the outlet of the cyclone separation apparatus is disposed with a double layer circular bushing, the inner pipe of the double layer circular bushing is connected to a hypo-wind circular tube outside of the main burner by a connection device, the outer pipe of the double layer circular bushing is connected to a hypo-wind circular tube in the main burner by a connection device. The invention has good fire characteristic, strong stable fire ability, high coal burnt rate, low NOx exhaust amount, strong adaptability for load and coal kinds and realizes high efficiency low-pollution combustion for coal powder.

Description

technical field [0001] The invention belongs to the technical field of pulverized coal combustion, in particular to a pulverized coal coarse and fine separation combustion method and a device thereof, which are suitable for pulverized coal combustion boilers. Background technique [0002] China is a big country with coal as the main energy source. Coal accounts for more than 70% of the primary energy, and this coal-based energy structure will not change for a long period of time in the future. dominant configuration. With the development of large-capacity generating units, the power industry has put forward higher and higher requirements for pulverized coal combustion, which can be summarized as: high combustion efficiency, stable combustion, anti-slagging, low pollution, and good adaptability to coal types. Rapid load change adaptability. The combustion of pulverized coal is mainly based on heterogeneous reaction, and its reaction rate is mainly determined by the temperat...

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Problems solved by technology

[0006] (2) Contradictions between the concentration of pulverized coal and its later mixing

Therefore, the primary air powder is divided into thick and thin streams after entering the furnace. If the post-mixing measures are not strengthened in the furnace, it will inevitably increase the carbon content of fly ash and reduce the efficiency of the boiler, especially for low-volatile coal.

Indeed, because the concentrated pulverized coal ignites earlier, it is beneficial to the burnout of the pulverized coal, which can partially compensate for the decline in boiler efficiency caused by poor mixing in the later stage after the separation of thick and thin. Low-volatility bituminous coal, low-quality bituminous coal and lignite may not be a big problem, and may even reduce the carbon content of fly ash, but for low-volatility coal, the contradiction will become prominent

[0008] (3) High-temperature corrosion of water-cooled wall tubes on the concentrated side of large boilers

Therefore, many power plant boilers have to use non-design coal types, and they are non-design coal types with large differences in combustion characteristics in different regions, and the quality of coal combustion is getting worse and worse.

This has brought a series of problems to the operation of the boiler: unstable combustion or even fire extinguishing, increased carbon content in fly ash, reduced combustion efficiency, increased coal consumption for power generation, difficulty in controlling steam temperature characteristics, frequent boiler tube bursts, serious slagging of boilers, etc. Safe and Economical Operation of Boilers

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