System and method for preventing spontaneous combustion by oxidization of raw coal in spherical bunker by drawing low-temperature flue gas into bunker for inerting

Abstract

The invention discloses a system and a method for preventing spontaneous combustion by oxidization of raw coal in a spherical bunker by drawing low-temperature flue gas into the bunker for inerting. The system comprises a tail flue heat exchanger, a dust remover, an induced draft fan, a desulfurizing tower, a chimney, a low-temperature flue gas fan, a flue gas preprocessor, flue gas nozzles, an automatic steam trap, a condensate pool, a condensate pump and pipeline valves, wherein flue gas of a boiler passes through the tail flue heat exchanger and then enters the dust remover for dedusting, the dedusted flue gas enters the desulfurizing tower after passing through the induced draft fan, low-temperature flue gas at an outlet of the desulfurizing tower is divided into two paths, and one path of flue gas is discharged into the atmosphere through the chimney while the other path of flue gas is pressurized by the low-temperature flue gas fan, then cooled and dehumidified by the flue gas preprocessor and finally fed into the flue gas nozzles through a pipeline to be sprayed into the spherical bunker. Inert components of flue gas enable a pile of raw coal in the spherical bunker to be separated from oxygen in air, thereby preventing spontaneous combustion caused by oxidization of the raw coal.

Description

【Technical field】 [0001] The invention belongs to the technical field of coal-fired power generation, and in particular relates to a system and method for preventing raw coal from oxidation and spontaneous combustion by extracting low-temperature furnace smoke and inerting a spherical coal bunker. 【Background technique】 [0002] Spherical coal bunker is a kind of storage equipment for storing raw coal. It has the advantages of less coal lifting, beautiful appearance, large coal storage capacity, and less land occupation. Therefore, it has an important application prospect in coal storage in power plants. Due to the relatively closed space of the spherical coal bunker, the heat dissipation conditions in the coal bunker are poor. When coal with high volatile content such as bituminous coal is stored in the coal bunker, the coal stored in the coal bunker is prone to oxidative spontaneous combustion, which seriously damages the coal. The safety of storage and withdrawal equipmen...

AI Technical Summary

Problems solved by technology

Due to the relatively closed space of the spherical coal bunker, the heat dissipation conditions in the coal bunker are poor. When coal with high volatile content such as bituminous coal is stored in the coal bunker, the coal stored in the coal bunker is prone to oxidative spontaneous combustion, which seriously damages the coal. The safety of storage and withdrawal equipment such as warehouses also causes the heat loss of raw coal, which affects the economics of coal storage.

Although there are fire-fighting systems such as N2 fire-extinguishing systems in the existing spherical coal bunkers, due to the large space of the coal bunkers and the use of bottled steam sources such as liquid nitrogen, the existing fire-fighting systems cannot meet the conditions of continuous operation of the coal bunker. In order to meet the needs of chemical prevention of spontaneous combustion, it is urgent to develop a system based on the characteristics of the existing resources of the power plant, which uses the inert furnace smoke easily obtained by the power plant as the inert protection gas of raw coal to prevent the oxidation and spontaneous combustion of raw coal, so as to protect the safe operation of the coal bunker and prevent the heat loss of raw coal.

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