Air distribution structure for improving combustion efficiency of fuel oil steam injection boiler and air distribution method

Abstract

The invention discloses an air distribution structure for improving the combustion efficiency of a fuel oil steam injection boiler and an air distribution method. The structure comprises an upper steam-air heat exchanger arranged on a radiant section, wherein an outer pipe of the upper steam-air heat exchanger is connected with an air guiding pipeline and an inlet pipeline of a hot air distributor, and an inner pipe of the upper steam-air heat exchanger is connected with a steam guiding pipeline and a water returning pipeline; the steam guiding pipeline is connected with a steam sample separator, the water returning pipeline is connected with a plunger pump, and the air guiding pipeline is connected with the outlet of the fan; and the inlet pipeline of the hot air distributor is connected with the inlet of the hot air distributor, and the outlet of the air distributor is connected with the tail of the radiant section through a second stage air distribution pipeline. The method comprises the following steps of: heating second stage air distribution after pressurization by the fan in the steam-air heat exchanger so as to be divided into three ways through the hot air distributor, and spraying three ways of hot air with same flow in the tail of the radiant section in a tangential circle dry blast manner; improving the oxygen content at the tail of the radiant section through the second stage air distribution, promoting the further combustion of fuel oil, simultaneously forming whirlwind, and isolating silt in fume; and reducing fly ash concentration in the fume of a down stream convection section, and reducing dust stratification of a convection pipe bundle.

Description

technical field [0001] The invention relates to the technical field of fuel-fired steam injection boilers, in particular to an air distribution structure and an air distribution method for improving the combustion efficiency of a fuel-fired steam injection boiler. Background technique [0002] The steam injection boiler is an important equipment for the exploitation of heavy oil. The boiler injects the high-temperature and high-pressure saturated steam generated into the oil well, so that the temperature of the heavy oil increases, the viscosity decreases, and it is easy to extract. The steam injection boiler consists of a radiation section, a transition section, a convection section, a water-water heat exchanger and connecting pipes. Steam injection boilers use oil as fuel, but from an economical point of view, heavy oil is usually used as the main fuel. Heavy oil is the last remaining low-volatility product in the petroleum refining process. High-boiling-point high-molecu...

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Problems solved by technology

Heavy oil contains a lot of colloidal asphaltenes, which increases the difficulty of atomizing heavy oil. Using traditional oil burners, all the air is mixed with heavy oil, which will lead to a serious lack of oxygen in the air at the tail of the flame in the radiation section, and it is difficult to burn heavy oil. Sufficiently, a large amount of flocculent coke shell dust will be produced. Due to the lack of oxygen, the pyrolysis of hydrocarbons in heavy oil vapor will produce carbon black particles, resulting in carbon black dust

Heavy oil is difficult to burn completely, and the combustion efficiency is low, which leads to limited energy utilization of heavy oil and low energy utilization rate, which does not meet the national energy saving and emission reduction requirements, and the flue gas after heavy oil combustion contains a large amount of coke dust, carbon black, Marl, after long-term operation, serious cohesive dust will appear in the convection tube bundle, which will seriously affect the heat transfer effect of the convection section and reduce the thermal efficiency of the steam injection boiler

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