JPS5842794Y2 - heat transfer wall - Google Patents

Description

[Detailed description of the invention] This invention relates to a surface structure of a tube or plate used as a heat transfer member of a heat exchanger that utilizes boiling of a refrigerant liquid.

Instead of simply arranging fins adjacent to each other as a heat transfer wall surface, we have installed a number of long, narrow tunnels that are open at both ends and close to each other, and the siphon effect of each tunnel balances the release of steam and the introduction of refrigerant liquid. It has been proposed that the

This invention relates to the improvement of the heat transfer wall surface of such a configuration.
It is characterized by each tunnel being divided into a plurality of parallel narrow tunnels.

To explain this with reference to the attached drawings, 2 in the figure is a tunnel, each tunnel is provided obliquely near the surface of the virgin material 1, and both ends thereof are grooves 3 extending in a direction intersecting with the tunnels.
is open to the public.

Each tunnel 2 is divided into a plurality of narrow tunnels 21 and 22 by partition walls 11 and 12 formed by a plurality of protrusions provided on the wall along the tunnel.

The heat transfer wall surface of such a structure is made by forming grooves 3 at intervals in the virgin material 1 in advance, and then cutting thin fins with the same height as the depth of the grooves 3 in the direction intersecting the grooves 3. When forming, the partition wall 11 is formed by rolling or the like on the cut surface.
and a plurality of protrusions corresponding to 12 are formed.

The protruding fins can be laterally tilted to connect the tips of each of the partition walls 11 and 12 to adjacent fins.

The grooves 3 may be provided in advance and provided during or after deformation of the side fin.

The cross sections of the narrower tunnels 21 and 22 in the heat transfer wall shown in the figure are approximately equal along their length, but are smaller (or larger) towards one end.
Alternatively, one of the ends open to the groove 3 may be made smaller (or larger) than the other.

Such a shape can be easily obtained when forming the partition walls 11 and 12, during fin tilting processing, or by processing the relevant portions afterwards.

Although such an additional shape is extremely effective in promoting the siphon effect in each tunnel 21 and 22, the cross-sectional shape of each tunnel 21 and 22 inevitably has a certain degree of variation due to variations during processing. There is no need to force it because it can be obtained in a simple manner.

In either case, the heat transfer wall surface is used while being immersed in the refrigerant liquid.

The refrigerant liquid filling each tunnel 21 and 22 is heated by the heat transmitted through the virgin material 1 and locally induces a number of convective circulations.

This convective circulation is directional. Therefore, if the heat transmitted through the base material 1 is high, the refrigerant liquid boils in each tunnel 21 and 22, and the generated vapor bubbles grow and blow out as bubbles from one end due to convection circulation, stirring the refrigerant liquid and causing convection. and exhibits excellent heat transfer properties.

If the open ends of the tunnels 21 and 22 facing each other across the groove 3 are aligned as shown in the figure between the tunnel groups divided by the groove 3, this will not have a positive effect on local convection circulation. There is.

Of course, the cross-sections of the tunnels 21 and 22 may be changed as described above, but it is preferable to stagger the opposing open ends between the tunnel groups.

For this purpose, the intersection angle between the groove 3 and each tunnel 2 may be set to an angle other than a right angle.

The above explanation mainly applies to cases where the base material 1 is flat, but the same applies to cases where the base material 1 is a curved surface such as the wall of a pipe.

In that case, it is easy to arrange each tunnel 2 in a spiral, and it is also easy to shift the open ends of the tunnels.

As is clear from the above explanation, according to this invention, a long and narrow tunnel with both ends open is divided into a plurality of narrower tunnels, so the number of tunnels is several times larger, and the heat transfer characteristics are further improved. This makes it possible to reduce the weight and size of heat exchangers using this technology.

This also means that if the heat transfer properties are to be constant, the number of original tunnels can be reduced, and there is no need to provide dense tunnels directly under the surface, making the forming process easier and providing excellent It has the secondary effect of being able to provide heat transfer properties at low cost, and its industrial value is extremely large.

[Brief explanation of drawings]

The figure is an explanatory view showing one embodiment of the heat transfer wall surface according to this invention. 1: Base material, 2.21 and 22: Tunnel, 3: Groove, 11
and 12: septum.

Claims (1)

[Scope of utility model registration request] In a heat transfer wall surface in which a large number of elongated tunnels are arranged adjacent to each other on the surface that comes into contact with the refrigerant liquid, and both ends of each tunnel are open to grooves that intersect with each other, each tunnel is opened from the surface side to its bottom. A heat transfer wall surface located on the way to a tunnel and divided into a plurality of parts by a partition wall extending in the length direction of the tunnel.