Heat exchange device

Abstract

The invention discloses a heat exchange device which is high in heat transfer coefficient, compact in structure, small in resistance and adaptive to various heat load change. The heat exchange device comprises a gas inlet, heat exchange pipes, a chamber, an outer wall and a gas outlet; and the row number n of the heat exchange pipes in the chamber is more than or equal to 2, the number m of each row of heat exchange pipe is more than or equal to 2, and (m+1) gas passages are formed between adjacent heat exchange pipes in the same row and between the heat exchange pipes and the wall surface, wherein at least one passage has the distance S1 with the value range of more than 0 and less than 0.5d, at least one passage has the distance S2 with the value range of more than S1 and less than 0.5L, and two adjacent rows of passages S2 are distributed in a staggered way and are not on the same vertical line. According to the invention, gas in the chamber of the heat exchange device forms one or multiple S-like flow fields, thus increasing flue gas flow; and meanwhile, gas flow passes between the pipes, thus increasing the flue gas flowing Reynolds number, and further increasing the heat transfer coefficient between the flue gas and the pipe wall and having good heat exchange effect.

Description

technical field [0001] The invention relates to a heat exchange device, in particular to a heat exchange device for civil and industrial boilers. Background technique [0002] At present, the water tube heat exchangers used in civil and industrial boilers in our country are in various forms and widely used, but there are problems such as low heat transfer coefficient and short heat transfer process, resulting in the boiler smoke temperature generally above 300 ° C, and the overall thermal efficiency of the boiler is less than 70 %; at the same time, when the boiler heat load decreases, the flue gas flow rate in the heat exchanger decreases, and the heat transfer coefficient drops sharply, resulting in a sharp drop in heat transfer capacity. [0003] In the prior art, the Chinese patent document ZL200920158254.0 discloses a baffle heat exchanger, the baffle heat exchanger is separated by three baffles, through the separation of the baffles, the flue gas process. In the abov...

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Problems solved by technology

[0002] At present, the water tube heat exchangers used in civil and industrial boilers in our country are in various forms and widely used, but there are problems such as low heat transfer coefficient and short heat transfer process, resulting in the boiler smoke temperature generally above 300 ° C, and the overall thermal efficiency of the boiler is less than 70 %; at the same time, when the heat load of the boiler decreases, the flue gas flow rate in the heat exchanger decreases, and the heat transfer coefficient drops sharply, resulting in a sharp drop in heat transfer capacity

In the above technology, since the baffle plate has only two heat exchange surfaces, the heat exchange area is obviously smaller than the heat exchange around the water pipe, so that the overall structure of the heat exchanger is not compact; in addition, because the baffle plate separates the inside of the heat exchanger, The flow of flue gas increases, the degree of turbulence increases, and the resistance is relatively large; when the heat load of the boiler decreases, the flow rate of the flue gas in the heat exchanger decreases, and the heat transfer coefficient drops sharply, resulting in a greatly reduced heat transfer capacity

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