Combined circulating fluid bed boiler

Abstract

A combined circulating fluidized bed boiler belongs to the field of mechanical engineering. The invention includes: a furnace, a cyclone separator, a throat, a return valve, and an air distribution plate, and the specific improvements are as follows: a plurality of transverse partition wall structures protruding into the furnace are arranged along the wall surface of the circulating fluidized bed to form a throat , the furnace is divided into several combustion chambers along the height, and after the throat is increased, multiple internal circulations appear in the furnace, and the external circulation is added to form a combined circulation structure. The invention can effectively improve the rising ability of the particle group in the furnace, reduce the density difference of the particles distributed along the bed height; increase the circulation amount of the particles near the wall of the furnace combustion chamber, and enhance the convective heat transfer between the particles and the wall; The residence time in the furnace strengthens combustion and promotes smoother feeding.

Description

technical field [0001] The invention relates to a fluidized bed boiler structure, in particular to a combined circulating fluidized bed boiler structure, which belongs to the field of mechanical engineering. Background technique [0002] Existing typical circulating fluidized bed boilers, through literature search, found that the patent applied by the Institute of Engineering Thermophysics, Chinese Academy of Sciences, the patent application number is: 94115512, the patent name is: circulating fluidized bed combustion device, the patent includes primary air Inlet, fuel inlet, secondary tuyere, furnace, high temperature gas-solid separator, split regulator, heat exchanger, tail convection flue, medium and low temperature gas-solid separator. Among them, the main section of the furnace is usually arranged in a vertical wall manner. This circulating fluidized bed structure has the following defects: the concentration of particles along the height of the bed drops sharply, and ...

AI Technical Summary

Problems solved by technology

This circulating fluidized bed structure has the following defects: the particle concentration drops sharply along the height of the bed, and there is an obvious situation where the particle concentration in the lower part is too dense and the particles in the upper part are too thin, resulting in serious uneven heat transfer along the furnace height, and the upper part is heated The heat transfer utilization rate of the surface is low; most of the particles enter the cyclone separator through the furnace at one time, and the amount of reflux particles near the inner side wall of the furnace is small, and the heat transfer is weak; the falling distance of the side wall reflux particles is long, resulting in side wall particles The lower temperature also affects heat transfer, and even affects the normal combustion of particles in severe cases

In addition, the particles in the furnace are easy to agglomerate at the axis, affecting burnout and reducing combustion efficiency

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