SU1725423A1 - Radiator for cooling radio components - Google Patents

Abstract

The invention relates to electronics, in particular to devices for cooling electronic equipment. The purpose of the invention is to increase the cooling efficiency. The radiator contains a base 1, on which ribs 3 are parallel to one another, forming closed channels; and a casing with a lid 4, the fins being made of a porous permeable heat-conducting material, and the intercostal adjacent channels are blocked on opposite sides by plugs 7. forming collectors 8 and 9, intended for supplying and discharging cooling air. 1 il.

Description

The invention relates to electronics, in particular to devices for cooling electronic equipment.

A device for cooling is known, in which a structural element of porous permeable material, which is the base, plays the role of a transport channel for supplying cooling fluid to the cooled elements. When purging the base with air in order to intensify the heat exchange, it loses the role of the transport channel due to the displacement of coolant from the air flow.

A radio-electronic unit is known, in which a structural element of porous permeable material is a septum, which serves to keep the coolant splashed out during boiling time. By holding this liquid in and passing steam, the partition actually plays the role of a filter for separating the vapor-liquid mixture.

The closest is the design of the radiator, the channels of which are closed, but their side walls (ribs) are made of porous air-tight material with a heat-conducting frame.

In closed channels, the perimeter of the cross section of the flow is equal to the length of the boundary of this section, and with walls impermeable to air, such channels obviously should have an inlet and an outlet. In the channels of this radiator, the cooling air moves in transit and their muffling, i.e. the installation of impenetrable partitions on the side of the inlet or outlet openings would make the radiator into an inoperable design.

The aim of the invention is to increase the cooling efficiency of radio elements.

This goal is achieved by the fact that in a radiator for cooling radioelements containing a base on which edges are parallel to one another to form closed channels and a casing, the edges are made of porous permeable heat-conducting material, and intercostal adjacent channels are blocked on opposite sides.

The drawing shows the device of the proposed design of the radiator, a General view in axonometry.

The proposed radiator design is a flat heat-conducting plate (base) 1, to which, on the one hand, the heat-generating elements of the 2 electronic systems are attached, and on the other hand

the sides are installed with a perfect thermal contact parallelly arranged fins 3, forming a system of intercostal channels. The ribs are made of an air-permeable porous material with a heat-conducting frame; for example, porous permeable materials on a metal base, obtained by pressing followed by sintering of metal powders, fibers and meshes, can be used. At the top, the ribs are covered with a box-shaped lid 4, having holes 5 and 6, and the ends of adjacent intercostal channels are closed on opposite sides by plugs 7, forming collectors 8 and 9, intended for supplying and discharging cooling air, channel group 10 communicating with the collector 8, and channel group 11 communicating with collector 9.

The radiator works as follows.

Cooling air is supplied to one of the collectors, for example, through the opening 5 to the collector 8. From the collector 8, the air is distributed through the intercostal channels 10 and, following them, is filtered through porous fins into adjacent intercostal channels 11, from which it enters the collector 9, with which it is removed through the opening 6. Air, flowing through the pores of the fins, takes heat from their metal frame, heated by heat from plate 1, thereby cooling it and the heat-generating elements of electronic circuits attached to it. The total internal surface of the pair of fins, which is a heat exchange surface, is large, which ensures a high intensity of heat exchange in the proposed radiator design. During the filtration movement of air through the porous rib, flow turbulization takes place, which also contributes to the intensification of heat exchange. It should be noted that in addition to the internal surface of the pores of the ribs, their side surface is not involved in heat exchange, is not occupied by pores, and the surface of the plate located between the ribs. All this in sum and provides a high intensity of heat transfer and, consequently, increases the efficiency of cooling products in the proposed design of the radiator. The maximum height of the ribs of porous material, which ensures its efficient operation can be defined as

ü „v1,„ W V ZET7

max o l Y - -Y t-

3-4 (1)

where a is the heat transfer coefficient from the surface of the interstitial space to the air flow in the pores of the permeable material;

a- specific surface of the porous matrix;

Yak - thermal conductivity of the material of the rib cage;

B - rib porosity.

The value of the specific surface area of heat transfer for the proposed design of a finned radiator can be calculated as

with () n RUD.R-- Vo,

where Vp is the edge volume;

Rb is the side surface area of the rib;

n is the number of edges;

V0 is the total volume.

The effectiveness of the proposed design of the radiator in comparison with the designs of radiators with fins of solid material can be estimated by the ratio

and Fyfl.p cgb. . and p - lt I,

good

where B is the thickness of the rib.

This ratio shows how many times, all other things being equal, the heat exchange surface of the proposed construction is greater than that of the known designs of ribbed radiators.

The technical and economic effect of the proposed radiator is that by blowing cooling air through the porous permeable heat-conducting structure, the ribs can be made thin enough in the direction of cooling air through them, and the required cooling surface can be obtained by varying the height of the porous ribs and their installation frequency, which is significantly reduces the aerodynamic resistance of the porous structure; moreover, the cooling air is blown uniformly through the porous structure uktsiyu without formation of stagnant zones.

In all channels of the proposed radiator design, one of the extreme cross sections is plugged, which prevents transit air flow in them, and the location of the plugs in adjacent channels from opposite sides allows the filtration flow of cooling air through heated porous

permeable ribs from the channels opened from the side of the air supply to the radiator, to the channels open from the side of the air outlet from the radiator. Thus, the presence

the plugs in the channels of the proposed radiator design with porous permeable fins, when the plugs in adjacent channels are located on opposite sides, is a necessary condition for

ensuring the performance of the proposed design.

In contrast to the known designs of ribbed radiators, due to the porous permeable structure of the ribs, their

blowing air in the transverse direction. The heat exchange surface in such a radiator is entirely determined by the inner surface of the pores of all the ribs. When air moves inside the winding pores, it is turbulized, as a result of which the values of the local heat transfer coefficients increase during the interstitial heat exchange. The heat exchange surface and the increase of heat transfer coefficients with

side of the air provides intensive heat exchange between the surface to be cooled and the air, and blowing air through the fins in the transverse direction reduces the hydraulic resistance

filtration flow of air, since the ribs can be made sufficiently small thickness. The fabrication of radiator fins from porous permeable heat-conducting material allows to obtain

A new technical solution, which manifests itself in an increase in thermal power removed from the cooled surface during air cooling, the use of which in many cases is more preferable than evaporative cooling or water cooling.

Claims (1)

BRIEF DESCRIPTION OF THE INVENTION A radiator for cooling radio elements comprising a base on which the ribs are parallel to each other with the formation of closed intercostal channels, and a casing, characterized in that, in order to increase the cooling efficiency, the ribs are made of porous permeable heat-conducting material, and intercostal adjacent channels are closed on opposite sides.