Device for eliminating flue gas temperature deviation

Abstract

A device for eliminating flue gas temperature deviation is arranged between an air preheater and a dust collector and comprises a circulation flue. A heat transfer fin tube bundle is arranged in the circulation flue along the width direction of the flue, the fin pitch of the heat transfer fin tube bundle is gradually changed from small to large from a high-temperature smoke zone to a low-temperature smoke zone, or the low-temperature smoke zone and the high-temperature smoke zone are of a large variable-pitch structure and a small variable-pitch structure respectively, and the heat transfer fin tube bundle comprises H-shaped fin tubes, spiral fin tubes or needle-shaped fin tubes. By the aid of the device, exhausted flue gas of a boiler is cooled, waste heat of the exhausted flue gas of the boiler is effectively recycled to heat condensed water, the flue gas temperature of an inlet of the dust collector is decreased, the internal gas temperature deviation between the flue and the dust collector is eliminated, the abnormal working condition of uneven airflow distribution caused by uneven distribution of the internal temperature of the dust collector is improved, dust collection efficiency and boiler or unit efficiency are improved, and the comprehensive targets of safe and efficient operation of the dust collector and energy conservation and emission reduction of the boiler or a unit are achieved.

Description

technical field [0001] The invention belongs to the technical field of flue at the tail of an air preheater, and in particular relates to a device for eliminating flue gas temperature deviation. Background technique [0002] The air preheater is an important equipment in a thermal power plant, which serves the purpose of reducing the exhaust gas temperature and improving the combustion efficiency of the boiler. With the development of large-capacity units, the current domestic large and medium-sized power plant boilers (200MW and above units) usually use a rotary air preheater with high heat transfer surface density, compact structure, steel saving, and easy layout as the tail heat exchange equipment. Especially for units above 300MW, rotary air preheaters are used. However, the structure of the rotary air preheater is complex, and there are common problems such as internal ash accumulation, low temperature corrosion, large air leakage rate, and deviation from the design va...

AI Technical Summary

Problems solved by technology

However, the flue gas dust content before the dust removal system is large, the dust accumulation and wear on the heating surface are serious, and the heat transfer effect is poor.

The usual waste heat recovery device can reduce the temperature of the exhaust gas, but it cannot eliminate the deviation of the gas temperature

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