Row tube type normal-pressure coal economizer

Abstract

The invention relates to a row tube type normal-pressure coal economizer comprising a tube box, a flue gas inlet colleting box and a flue gas outlet collecting box, wherein the flue gas inlet colleting box and the flue gas outlet collecting box are connected with both ends of the tube box in screw joint, a flue gas interface is arranged on the flue gas inlet colleting box, a fan interface is arranged on the flue gas outlet collecting box, the lower part of the tube box is provided with a water outlet near the flue gas inlet colleting box, a water inlet is arranged near the flue gas outlet collecting box, a row tube is arranged in the tube box, one end of the row tube is connected with the flue gas interface, the other end of the row tube is connected with the fan interface, flue gas flowsin the row tube, and water flows in a space formed by an outer tube of the row tube and the tube box. The row tube type normal pressure coal economizer can effectively increase flue gas speed, increase a heating coefficient between the flue gas and a tube wall, obviously improve the heat exchange effect of a coal economizer, do not generate dust collecting phenomenon and become a maintenance-freecoal economizer.

Description

Technical field: [0001] The invention relates to an energy-saving equipment for recovering waste heat from boiler flue gas, in particular to an atmospheric pressure economizer capable of reducing the exhaust gas temperature of various boilers. Background technique: [0002] Economizer is an essential part of modern boilers. Its function is to use the heat of flue gas at the tail of the boiler to heat the inlet water of the boiler and reduce the heat loss of exhaust gas. At present, cast iron (tube) economizers and finned tube economizers are widely used. These two types of economizers are mainly designed for high-pressure and medium-pressure boilers. Since the exhaust gas temperature of high-pressure or medium-pressure boilers is as high as 350-450°C, and the average temperature difference with the water in the economizer is 250-300°C, the driving force of heat conduction is large, so the existing economizer can effectively recover most of the heat energy. At present, the e...

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Problems solved by technology

The flue gas velocity of the existing economizer is controlled at 7-12m / s, and increasing the gas velocity will lead to severe wear of the heat exchange tubes and fins. Therefore, the existing economizer can no longer improve the heat exchange efficiency

In addition, finned tubes are widely used in existing economizers. Although fins improve heat transfer efficiency to a certain extent, the existence of fins also leads to ash accumulation. Ash has low thermal conductivity and large thermal resistance. Therefore, the dust accumulation seriously hinders the heat transfer between the flue gas and the heat exchange tubes and fins, and the heat transfer efficiency of the economizer with dust accumulation is even lower than that without fins

Therefore, in order to maintain the heat exchange efficiency of the finned tube economizer, dust must be cleaned regularly, which undoubtedly increases maintenance costs and reduces production efficiency

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