Pure countercurrent inner and outer finned tubes and heat exchanger composed of pure countercurrent inner and outer finned tubes

Abstract

The invention belongs to the technical field of heat exchangers, and particularly relates to pure countercurrent inner and outer finned tubes and a heat exchanger composed of the same. The invention provides a pure countercurrent internal and external finned tube which comprises a heat exchange tube, and the heat exchange tube is of a hollow tubular structure with the wall thickness and the axial length. The inner fins are arranged in the cavity of the heat exchange tube, and the inner fins have the extension length parallel to the axial direction of the heat exchange tube; the outer fins are arranged on the outer side of the outer wall of the heat exchange tube, and the outer fins have the extension length parallel to the axial direction of the heat exchange tube. The heat exchanger is widely applied to heat transfer of two-strand fluid or heat transfer of multiple-strand fluid, and the fluid can be gas or liquid or gas-liquid mixture. The heat exchanger manufactured by adopting the inner and outer finned tubes provided by the invention does not need to be provided with baffle plates; the temperature difference formed by the pure countercurrent inner and outer finned tubes and the heat exchanger composed of the pure countercurrent inner and outer finned tubes is large, the heat exchange efficiency is high, and the structure is compact and reasonable.

Description

technical field [0001] The invention belongs to the technical field of heat exchangers, and particularly relates to a pure countercurrent inner and outer finned tube and a heat exchanger composed thereof. Background technique [0002] In order to improve the heat transfer efficiency, the heat exchanger is required to continuously improve its structure. For the shell and tube heat exchanger, the number of baffles should be increased. [0003] The heat exchangers currently in use are mostly bare tubes and finned tubes. The bare tube heat exchangers are further divided into straight tube, U-shaped tube, coiled tube, coiled tube and other types of heat exchangers. The finned tube is further divided into inner For finned tube and external finned tube heat exchangers, no matter which heat exchanger is used, everyone is trying to increase the heat transfer area as much as possible, change the fluid state of the fluid to improve the heat transfer efficiency and reduce the volume of ...

AI Technical Summary

Problems solved by technology

[0003] Most of the heat exchangers currently in use are bare tubes and finned tubes. The bare tube heat exchangers are divided into straight tubes, U-shaped tubes, coiled tubes, and coiled tubes. The finned tubes are divided into inner tubes. For finned tube and outer finned tube heat exchangers, no matter which kind of heat exchanger is used, everyone is trying to increase the heat transfer area as much as possible, change the fluid state of the fluid to improve heat transfer efficiency, and reduce the volume of the heat exchanger , to maximize the heat transfer performance, but no matter how it is improved, there are several problems that are difficult to get a perfect answer

The first is that the flow state of the fluid cannot completely achieve pure counterflow, and there will always be cross-flow and cross-flow phenomena in the flow directions of the two fluids; second, the maximum temperature difference of fluid heat transfer cannot be guaranteed, and the temperature difference is the driving force for heat transfer. The larger the heat transfer is, the more intense the heat transfer will be. Both cross flow and cross flow will reduce the heat transfer temperature difference, thereby affecting the heat transfer effect; third, prevent fluid short circuit, heat exchange tube and heat exchange tube, heat exchange tube and shell deflection The gap between the plates will cause the fluid to bypass and cannot fully transfer heat; fourth, the local dead zone, where the fluid will inevitably have a dead angle during the flow and heat transfer process, where the fluid will stagnate or stay and affect the heat transfer; Fifth, in the pipe layout area, the heat exchange area between the heat exchange tubes and the inner space of the heat exchange tubes has not been maximized

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