Plate type low-temperature economizer

Abstract

The invention discloses a plate type low-temperature economizer. The economizer comprises a casing, a convergence box and a plate type heat exchange module; a smoke inlet channel and a smoke discharge channel are arranged at the upper end and the lower end of the casing; the smoke inlet channel comprises an inlet flange and a conical smoke inlet guiding barrel; the smoke discharge channel comprises an outlet flange and a conical smoke discharge guiding barrel; and the plate type heat exchange module comprises multiple heat exchange plates, flue supporting bulges and cold source channel supporting bulges are arranged on two sides of the heat exchange plates, cold source medium baffle runners are formed among the cold source channel supporting bulges of the adjacent heat exchange plates, and comprise multiple circumferential channels provided with independent medium inlets and outlets and pass partition plates arranged in the circumferential channels to enable cold source media to flow in a baffled manner, and discharged smoke once-through channels are formed among the flue supporting bulges of the adjacent heat exchange plates. Flow fields in the economizer are uniformly distributed, the medium contact area is large, the heat exchange efficiency is high, the smoke discharge resistance is small, meanwhile, spaces between the heat exchange plates are easy to clean and maintain, and the capability of the heat exchange plates for bearing pressure differences on the two sides is high.

Description

technical field [0001] The invention relates to the technical field of boiler flue gas recovery equipment, in particular to a plate-type low-temperature economizer. Background technique [0002] Excessively high exhaust gas temperature of the boiler will affect the efficiency of the boiler and the cycle efficiency of the power plant, and increase the consumption of coal. In order to solve the problem of wasting heat energy due to excessively high exhaust gas temperature, many power plants install economizers in the flue ducts to recover the temperature of the flue gas; most of the economizers used in current power plant boilers are tubular, fin The sheet tube type is the main type, the flue gas and the cooling water pipe surface contact to realize heat exchange, the contact area is small, the heat transfer stroke is too long, the exhaust pressure drop is large, and because the flue gas is in vertical contact with the heat exchange tube, the exhaust resistance is large , The...

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Problems solved by technology

[0002] Excessively high exhaust gas temperature of the boiler will affect the efficiency of the boiler and the cycle efficiency of the power plant, increasing the consumption of coal

In order to solve the problem of wasting heat energy due to excessively high exhaust gas temperature, many power plants install economizers in the flue ducts to recover the temperature of the flue gas; most of the economizers used in current power plant boilers are tubular, fin The sheet tube type is the main type, the flue gas and the cooling water pipe surface contact to realize heat exchange, the contact area is small, the heat transfer stroke is too long, the exhaust pressure drop is large, and because the flue gas is in vertical contact with the heat exchange tube, the exhaust resistance is large , The leeward side and the stagnation area of ​​the cooling water pipe are prone to dust accumulation, which is not easy to clean;

[0003] In the prior art, the patent CN104033881 discloses a plate and shell economizer, which adopts a corrugated plate structure heat exchange core for exhaust heat recovery, which can well solve the problem of large exhaust resistance, but this The patent has the following disadvantages: 1. Lack of flue gas inlet guide structure, the flow field distribution of flue gas in the heat exchange core is uneven, the effective heat exchange area in the heat exchange core is small, easy to overheat and overcool, and reduce thermal performance; 2 .There is no support between the two heat exchange plates forming the smoke exhaust channel. Since the exhaust smoke passes through at normal pressure and the cold source medium passes through under positive pressure, the heat exchange plate forming the cold source medium channel is easily torn under the action of pressure difference Detachment, and the lack of sealing structure at both ends of the heat exchange core, it is easy to cause mixed media on both sides, and the economizer will fail to work

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