Semielliptical falling film heat exchange tube with uniform flow guiding fins

Abstract

The invention relates to a semielliptical falling film heat exchange tube with uniform flow guiding fins. The semielliptical falling film heat exchange tube comprises a first heat exchange unit, second heat exchange units and a third heat exchange unit which are vertically arranged from the top down; the first heat exchange unit comprises a first elliptical tube and a first fin; the first fin capable of uniformly guiding a flow is arranged at the exact lower part of the first elliptical tube; each second heat exchange unit comprises a second elliptical tube and a second fin; the second fins capable of uniformly guiding the flow are arranged at the exact upper parts and the exact lower parts of the second elliptical tubes correspondingly; the third heat exchange unit comprises a third elliptical tube and a third fin; the third fin capable of uniformly guiding the flow is arranged at the exact upper part of the third elliptical tube; the first fin of the first heat exchange unit is connected with the second fin at the exact upper part of the corresponding second heat exchange unit; and the third fin of the third heat exchange unit is connected with the second fin at the exact lower part of the corresponding second heat exchange unit. The flow guiding property of the semielliptical falling film heat exchange tube can be improved.

Description

technical field [0001] The invention relates to the technical field of falling film evaporation, in particular to a semi-elliptical falling film heat exchange tube with uniform guide fins. Background technique [0002] Horizontal falling film evaporator tube, liquid evaporation phase change heat occurs outside the tube, steam condensation phase change heat occurs inside the tube, phase change heat transfer occurs on both sides of the heat transfer tube, the heat transfer coefficient is very high, and it has a vacuum low phase The characteristics of variable temperature and small temperature difference heat transfer operation, the advantages of high-efficiency heat and mass transfer, and energy saving are quite prominent. In recent years, the application of MVR evaporation systems has developed rapidly. However, most of the current enhanced heat transfer technologies have a common problem. Whether it is a circular falling film evaporation tube, an elliptical falling film eva...

AI Technical Summary

Problems solved by technology

Whether it is a circular falling film evaporation tube, an elliptical falling film evaporation tube or a semi-elliptical falling film evaporation tube, the film-forming fluid on both sides will form a confluence at the bottom, and this confluence will be used as the "spray liquid" of the lower tube bundle However, there are several problems with this "spray liquid" as follows: 1. The "spray liquid" flows down under the action of gravity. The fluid outside the pipe cannot be fully utilized, thus increasing the amount of liquid distribution

2. The "spray liquid" will be disturbed by the eddy current when it converges at the tail, so that the falling trajectory may not be vertical, which will cause the uneven distribution of the fluid flow on both sides of the lower row of heat exchange tubes, and the side of the heat exchange tubes will have " "Dry spots" appear, and the thickness of the liquid film on the other side is too thick

This phenomenon leads to the underutilization of the heat exchange tube, which is not conducive to heat exchange

3. The "spray liquid" cannot produce sufficient evaporation and heat exchange during the columnar downflow process, and only provides falling film liquid for the lower heat pipes, so the space is not fully utilized, which may lead to a relatively large appearance of the entire heat exchanger

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