Natural circulation coupled cfb steam injection boiler at the end of the direct current vertical evaporation tube in the furnace

Abstract

The invention provides a natural circulation coupling-type CFB steam injection boiler at the tail end of a direct current vertical evaporating pipe inside a boiler, and belongs to the technical field of oil field steam injection boilers. The problem of the pipe explosion caused by the heat transferring deterioration due to the fact that salt deposits are deposited on the inner wall of a water screen wall pipe of an existing natural circulation oil field steam injection boiler in the long-term is solved. A coal economizer is communicated with a two-side wall connecting pipe and a front-and-rear wall connecting pipe through a main water discharging pipe of the coal economizer. The two-side wall connecting pipe is communicated with an upper two-side wall collecting box through a lower two-side wall water screen wall collecting box and a two-side wall membrane water screen wall. The front-and-rear wall connecting pipe is communicated with a front-and-rear wall collecting box through a lower front-and-rear wall collecting box and a front-and-rear wall membrane water screen wall. The upper two-side wall collecting box and the front-and-rear wall collecting box are communicated with a steam pocket. Water space of the steam pocket is communicated with a water inlet of an evaporator through a descending pipe. A steam-water mixture outlet of the evaporator is communicated with a second steam-water separator through a third connecting pipe. A steam space of the steam pocket is communicated with a super heater through a steam connecting pipe. The natural circulation coupling-type CFB steam injection boiler is used for oil field steam injection.

Description

technical field [0001] The invention relates to a circulating fluidized bed steam injection boiler, which belongs to the technical field of oil field steam injection boilers. Background technique [0002] Most of the existing steam injection boilers in oilfields are oil-fired and gas-fired direct-flow steam-injection boilers. In order to save operating costs, some units have developed coal-fired seam-fired direct-flow steam injection boilers. The implementation of the pollutant discharge standard GB13271-2014 has made the layer-fired steam injection boiler lose the favor of the market. This is because the NOx emission concentration of the layer-fired furnace is much higher than the existing emission standard, and the furnace cannot desulfurize, which makes the environmental protection investment even high. Investment in the boiler itself. So people turn their attention to circulating fluidized bed boilers, because the NOx emission concentration of circulating fluidized bed ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the existing natural circulation oil field steam injection boiler has the problem that the inner wall of the water wall tube is prone to salt scale, which will lead to the deterioration of heat transfer and the tube burst in the long run, and then provide natural circulation at the tail of the direct-flow vertical evaporation tube in the furnace Coupled CFB Steam Injection Boiler

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