Plasma oil-free ignition system in oxygen-enriched environments

Abstract

The invention relates to a plasma oil-free ignition system in oxygen-enriched environments. The system comprises a plasma generator, a combustor, and a sleeve set, wherein the sleeve set and the combustor are coaxially arranged; the sleeve set comprises a plurality of coaxially-arranged sleeves, an annular space is respectively formed between two adjacent sleeves and between the sleeves and the combustor, an oxygen guide tube is arranged on each sleeve, and the combustor is provided with an oxygen guide tube; plasmas spouted out from the plasma generator are formed into a localized high-temperature area, and the localized high-temperature area is filled with high-temperature plasmas and pulverized coal airflows. Through supplementing a certain amount of oxygen to the inside of the combustor by the oxygen guide tube in the combustor, and a localized oxygen-enriched area is respectively formed in the annular space and a subsequent adjacent space through which an airflow flows, thereby realizing the oxygen-enriched combustion of volatile matters or cokes or a mixture of the volatile matters and the cokes, so that the pulverized coal airflows is combusted more severely and releases more heats, and finally, a primary air pulverized coal airflow is rapidly ignited and combusted stably. The plasma oil-free ignition system in oxygen-enriched environments provided by the invention is simple in structure, wide in coal applicability, and especially suitable for low-volatile coals.

Description

technical field [0001] The invention belongs to the field of thermal boilers, and relates to boiler accessories, in particular to a plasma oil-free ignition system in an oxygen-enriched environment. Background technique [0002] The traditional way of igniting boilers in power plants is oil gun ignition. When the boiler is ignited, the fuel gun is first lit. 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 flow. At this time, the pulverized coal is blown into the furnace for mixed combustion of oil and coal. When the load of the boiler reaches more than 50% and the pulverized coal flow can burn stably, the fuel oil is gradually cut off to complete the ignition and start-up process of the boiler. In order to save costs and reduce fuel oil consumption of power plant boilers, many companies at home and abroad have developed plasma oil-free ignition technology, which has been widely used in...

AI Technical Summary

Problems solved by technology

At present, there are a large number of successful plasma ignition application examples in domestic power plant boilers that use bituminous coal as power coal. Airflow is easily ignited

However, the plasma ignition technology has poor adaptability to coal types with low volatile content such as anthracite, lean coal and low-quality bituminous coal. There are few examples of successful application of plasma ignition technology to lean coal boilers in China. At present, no anthracite boiler has successfully applied plasma ignition technology. instance of

[0005] Second, when the boiler is ignited, since the energy of the plasma generator is usually around 100-200KW, it is not enough to ignite all the pulverized coal

The actual operation shows that the boiler adopts plasma ignition technology. At the initial stage of boiler start-up, the fly ash has high carbon content, and a large amount of pulverized coal is not burned out. Especially for difficult-to-burn coal types, the burn-out performance is even worse.

Unburned pulverized coal is easy to accumulate on the corrugated plate of the air preheater or the catalyst injection part of the SCR reactor, which may easily cause secondary combustion of unburned pulverized coal, causing major accidents and economic losses

[0006] Third, when the boiler is ignited, in order to ensure the stable ignition of pulverized coal, a relatively high concentration of pulverized coal is usually used in actual operation, so the load is high when the boiler is started, and the heating rate of the boiler is fast, which may easily cause the temperature of the steam side to overheat, which may easily lead to Accidents such as superheater pipe overheating and bursting

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