Screen type heating surface and circulating fluidized bed boiler with same

Abstract

The invention provides a screen type heating surface and a circulating fluidized bed boiler with the same. The screen type heating surface comprises: a horizontal upper header unit comprising a horizontal first upper header; a vertical lower header unit comprising a vertical first lower header and a vertical second lower header; and a tube bundle unit comprising a first tube bundle and a second tube bundle, wherein the first end of the first tube bundle is communicated with the first lower header, the second end of the first tube bundle is communicated with the upper header, the first end of the second tube bundle is communicated with the second lower header, the second end of the second tube bundle is communicated with the upper header, and the first tube bundle and the second tube bundle each comprise at least two L-shaped tubes located in the same plane.

Description

technical field [0001] The invention relates to the technical field of circulating fluidized bed boilers, in particular to a panel-type heating surface and a circulating fluidized bed boiler with the same. Background technique [0002] my country is currently the country with the largest number of circulating fluidized bed boilers in operation and the highest operating steam parameters in the world. In order to control the furnace temperature and ensure boiler steam parameters, a large number of furnace heating surfaces are usually arranged in the circulating fluidized bed boiler furnace, including panel superheaters and panel reheaters (hereinafter referred to as panel heating surfaces). [0003] The typical arrangement of the panel heating surface of the existing circulating fluidized bed boiler mainly includes the following two types: the first arrangement of the heating surface is an L-shaped panel (such as figure 1 As shown), its structural feature is formed by a plura...

AI Technical Summary

Problems solved by technology

The L-shaped panel heating surface has the following two problems: first, usually the L-shaped panel heating surface is only arranged on the front wall of the furnace, and no heating surface is arranged on the rear wall of the furnace, because there are high-temperature materials and smoke on the front wall of the furnace. There is a heat exchange process between the gas and the working medium in the tube on the heating surface, so that the bed temperature near the front wall is lower than the bed temperature near the rear wall, resulting in uneven bed temperature distribution in the furnace section

Second, the steam enters from the lower inlet of the lower header, and after being heated by a single group of tube bundles, it is drawn out from the two outlet pipes in the middle of the top of the upper header. Asymmetry, so the resistance of the steam working medium passing through each tube in a single group of tube bundles is inconsistent, so the steam flow through each tube is also different, so there is a large steam temperature deviation between the outlets of each tube , which brings certain hidden dangers to the safe operation of the boiler

[0007] (1) The existing L-shaped panel heating surface is usually arranged on the front wall of the furnace, and no heating surface is arranged on the rear wall of the furnace, because there are high-temperature materials and flue gas on the front wall of the furnace. The thermal process makes the bed temperature near the front wall lower than the bed temperature near the back wall, which brings about a large deviation of the bed temperature of the furnace section and brings hidden dangers to the safe operation of the boiler

[0008] (2) Due to the structural asymmetry of the single group of tube bundles on the L-shaped panel heating surface with respect to the two outlet pipes in the middle of the outlet header, the resistance difference along the way of each tube of the steam working medium flowing through the L-shaped panel heating surface is different. Larger, and there is a large deviation of steam temperature between different tubes at the outlet of the heating surface, which brings hidden dangers to boiler hydrodynamic safety

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