Ethylene cracking furnace of double-section heat supply structure

Abstract

The invention provides an ethylene cracking furnace of a double-section heat supply structure. The ethylene cracking furnace comprises a radiation section (1), a convection section (5), a radiation coiled tube (4), a quenching boiler (6), a high-pressure steam pocket (7) and a draft fan (8), wherein the quenching boiler (6) is connected with the radiation coiled tube (4); the draft fan (8) is connected with the top of the convection section (5); and the high-pressure steam pocket (7) is connected with the quenching boiler (6). The ethylene cracking furnace is of the double-section combined heat supply structure that the radiation section (1) is internally provided with an upper heat supply section and a lower heat supply section. By adopting the ethylene cracking furnace of the double-section heat supply structure, the arrangement of a combustor and the design of a combustion tube line arrangement are simplified, the flame inside a hearth is prevented from coiling to touch furnace tubes, interference of flame is also prevented, uniform distribution of heat in the height direction inside the hearth in the radiation section is maintained, and meanwhile the emission of NOx is reduced.

Description

technical field [0001] The invention relates to a cracking furnace suitable for producing ethylene by steam cracking of petroleum hydrocarbons. Specifically, the invention relates to an ethylene cracking furnace with a double-stage heating structure. Background technique [0002] For the cracking furnace for ethylene production by steam cracking of petroleum hydrocarbons, the cracking reaction in the furnace tube of the radiant section is a strong endothermic cracking reaction, and the heat required for the reaction is supplied by the fuel consumed by the heating equipment (burner) in the furnace. According to the position installed in the furnace of the cracking furnace, the burner is divided into two types: bottom burner and side wall burner, so the heating mode of the cracking furnace is divided into three types: full bottom burner heating, full side wall burner Combined heat supply and bottom sidewall heating. [0003] The heat supply method of all side wall burners was...

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Problems solved by technology

[0006] In addition to the above-mentioned problems, the traditional heating method also faces other new challenges with the development of large-scale cracking furnaces and the increase in the demand for operation automation: to further increase the height of the furnace while maintaining uniform heat distribution in the direction of the furnace height. The upward flame of the burner must be extended to meet the requirements of heat supply; therefore, affected by the jet entrainment effect of the bottom burner, the probability of the flame turning over and licking the furnace tube is greatly increased, and the problems of local overheating of the furnace tube and shortened operating cycle appear, and the device is long. The stable and safe operation is seriously affected; in addition, the increase in the height of the furnace increases the number of side wall burners, increases the risk of overheating of the outer wall of the furnace, and aggravates the intensity of daily inspection and maintenance work of field operators, which is not conducive to meeting the increasing Strict requirements for energy saving, emission reduction and operation automation

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