A shell and tube heat exchanger

Abstract

The invention discloses a pipe casing type heat exchanger which comprises a casing, a heat exchange pipe arranged in the casing and sealing heads arranged at two ends of the heat exchanger. An inside-pipe fluid inlet and an inside-pipe fluid outlet are arranged on the sealing heads, and an outside-pipe fluid inlet and an outside-pipe fluid outlet are arranged on the casing. Two ends of the heat exchange pipe are connected with a pipe plate, the heat exchange pipe is a pipe bundle composed of at least one transformation pipe, and the transformation pipes are mutually contacted in a certain distance to form a self-support structure. The pipe casing type heat exchanger is capable of achieving the effect that fluid inside and outside the pipes flows in parallel. The heat exchanger has the advantages of being high in heat exchange efficiency, small in resistance, not apt to scaling, small in vibration and the like.

Description

technical field [0001] The invention relates to the technical field of heat exchangers, in particular to a shell-and-tube heat exchanger. Background technique [0002] In the existing ordinary shell-and-tube heat exchangers, the traditional heat exchangers generally use circular heat exchange tubes with equal diameters, and arcuate baffles are added on the shell side to support the tube bundle and enhance the fluid disturbance in the shell side. There are two major defects in this type of heat exchanger. The first is that the fluid performs a "Z" baffle movement on the shell side, and the flow resistance is large, and the rear of the baffle is easy to form a backflow dead zone, resulting in insufficient heat transfer area. use. The shell-side fluid flows in the shell outside the heat exchange tube to realize the heat exchange between the cooling medium and the cooled medium. The shell side is equipped with baffles to support the heat exchange tubes and strengthen the fluid...

AI Technical Summary

Problems solved by technology

However, this shell-and-tube heat exchanger also has some shortcomings, mainly: first, the heat exchange tube adopts a round tube, and under the condition of low flow rate in the tube, the thermal resistance of the boundary layer is large and the heat transfer coefficient is low; However, under the condition of high flow rate, the flow resistance in the pipe is relatively large.

Second, the traditional single-bow baffle heat exchanger has a flow dead zone at the junction of the baffle and the shell, which easily causes the fluid to swirl, increases the flow resistance, and easily causes fouling, reducing the heat exchange efficiency

Third, the traditional single-bow baffle is difficult to cooperate with non-circular enhanced heat transfer tubes, which greatly limits the application of enhanced heat transfer technology

These problems have seriously affected the heat transfer efficiency of traditional heat exchangers. In order to improve their efficiency, people have continuously improved their structures, but the results are not ideal.

Images