Supercritical carbon dioxide boiler cooling wall matched with non-uniform thermal load

Abstract

The invention discloses a supercritical carbon dioxide boiler cooling wall matched with non-uniform thermal load, which comprises a plurality of cooling pipes uniformly arranged on the inner wall surface of a supercritical carbon dioxide boiler, the cooling pipes are eccentric pipes, and the eccentricity ratio of the eccentric pipes is in positive correlation with the thermal load of the eccentric pipes. The working conditions of non-uniform thermal load in the circumferential direction of the cooling wall and non-uniform thermal load distribution in the width direction of the hearth are considered, the eccentric cooling wall pipes are adopted to strengthen heat exchange towards the fire side, and the eccentricity rates of the eccentric cooling wall pipes in different thermal load areas are reasonably arranged to be matched with thermal load distribution of the heating surfaces of the hearths, so that the heat exchange efficiency is improved, and the energy consumption is reduced. And meanwhile, the reduction of the highest wall temperature is also beneficial to guaranteeing the safe and efficient operation of the boiler, the convection heat exchange effect of the fire-facing side is enhanced, and the circumferential temperature difference of the wall of the cooling pipe is effectively reduced. The eccentric pipes with different eccentricity rates are adopted, so that the circumferential stress and the over-temperature pipe explosion phenomenon are reduced, and the effective service life of the pipeline is prolonged.

Description

technical field [0001] The present application relates to the technical field of coal-fired power generation in supercritical carbon dioxide boilers, and in particular, to a supercritical carbon dioxide boiler cooling stave matched with non-uniform heat loads. Background technique [0002] Carbon dioxide, as a natural fluid for boiler cooling stave matching non-uniform heat load, is non-toxic, non-flammable, colorless and odorless. CO 2 It has better stability, less corrosiveness to metals, and CO 2 The critical parameter is lower, and it is easier to reach the supercritical parameter. These inherent advantages make it possible to replace steam as a new heat transfer medium for coal-fired power plants. Today, coal-fired power generation in China still occupies a dominant position, and the basic fact that coal-fired power is the main power source for power generation in my country remains unchanged. Therefore, S-CO used in coal-fired power generation 2 The power cycle ha...

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Problems solved by technology

[0008] lead to S-CO 2 One of the main reasons for boiler cooling wall overheating tube burst is that the circumferential stress caused by the uneven heating of the cooling wall tube bundle and the maximum tube wall temperature is higher than the allowable temperature of the material, so control or solve the cooling wall overtemperature For the problem of pipe burst, it is necessary to grasp the distribution law of non-uniform heat load on the pipe wall, strengthen the heat transfer capacity of the cooling pipe under the circumferential non-uniform heat flow, reduce the circumferential temperature difference of the cooling pipe wall, and reduce the maximum temperature of the pipe wall

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