RU76432U1 - HEAT TRANSFER DEVICE FOR COOLING ELECTRONIC INSTRUMENTS - Google Patents

Abstract

The utility model is intended for use in cooling heat-loaded elements of electronic devices, including computers, and also relates to the field of heat engineering, in particular, to heat pipes. The heat transfer device for cooling electronic devices is made in the form of a closed sealed circuit, partially filled with a coolant, including an evaporator with a capillary-porous structure inside, coupled to a steam collector and a reservoir, and a hollow condenser connected by a hollow separate steam and condensate conduit with freely and continuously placed in them along their entire length with an elastic insert, and the sections of the elastic insert placed in the steam manifold and reservoir are made in ide loop, while the elastic insert is made in the form of a cylinder, the volume of which is at least 10% relative to the volume in which this insert is placed, and made of a material that can repeatedly absorb mechanical forces and restore its original shape after they are removed. The utility model allows to increase the reliability of the device by ensuring its operability after repeated cycles of freezing and thawing of the coolant in it. 4 cp, 5 ill.

Description

The utility model is intended for use in cooling heat-loaded elements of electronic devices, including computers, and also relates to the field of heat engineering, in particular, to heat pipes.

A conventional heat pipe (CT) is known [US Pat. No. 4,248,295], partially filled with liquid, containing an independent, simple porous structure freely installed in the evaporator in the form of a cylinder, the outer diameter of which is not in contact with the inner diameter of the CT, and the length of the structure is such that part of it located above the liquid level filling the evaporator.

Such a device allows to avoid damage to the body of the TT during freezing liquid in it, because the porous structure partially perceives the forces arising from this. However, this applies only to a certain position of the device - when the condenser is located above the evaporator.

The disadvantage of this device is that it can only work in thermosiphon mode, i.e. only at a certain position in space: inclined and vertical, when the condenser is located above the evaporator. In this case, the return of condensate from the condenser to the evaporator is carried out under the influence of gravitational forces. And since the porous structure is placed in such a device only in the evaporator, at negative ambient temperatures in a horizontal position, it is possible to freeze the coolant, for example, water, in the volumes of TT in which there is no porous structure and liquid accumulates, with subsequent destruction of the device’s body, because it is known that at the time of turning water into ice, the volume of the latter almost instantly increases by about 10% relative to the volume of water, from

which he formed. (A.A. Ottavnov, V.A. Ustyugov, V.A. Kharkin, BCIonov. Features of the behavior of pressure pipelines when water freezes in them. Magazine "Plumbing, heating, air conditioning", No. 12, 2007, p. one)

Closest to the claimed technical solution is a heat transfer device for cooling electronic devices [RF Patent No. 2296929], made in the form of a closed sealed circuit, partially filled with a coolant, including an evaporator with a capillary-porous structure inside, coupled to a steam collector and reservoir, and a hollow condenser connected by hollow separate steam line and condensate line.

This device provides efficient operation for any orientation in space due to the action of capillary forces arising in a special capillary-porous structure located in the evaporator and acting as a “capillary pump”.

The disadvantage of this device is that when the coolant, for example, water freezes in it, deformation and subsequent destruction of the device elements (steam collector, steam pipe, condenser, condensate pipe and tank) will occur. In the case when, before freezing, the evaporator was at the top and the condenser at the bottom, the forces arising from the freezing of the coolant accumulated in the hollow steam pipe, condenser and condensate pipe will lead to their destruction (rupture). In the event that the freezing was preceded by a different vertical position: the evaporator is at the bottom and the condenser is at the top, there is a danger of rupture of the steam collector and tank bodies when the coolant accumulated in them turns into ice. In this case, the device (especially after repeated cycles of freezing-thawing) loses its performance.

The utility model is based on the task of increasing the reliability of the device by ensuring its operability after

repeated cycles of freezing and thawing the coolant in it.

The problem is solved in that in a heat transfer device for cooling electronic devices, made in the form of a closed sealed circuit, partially filled with a coolant, including an evaporator with a capillary-porous structure inside, coupled to a steam collector and a reservoir, and a hollow condenser connected by a hollow separate steam line and the condensate line, according to the utility model, in the steam manifold, steam line, condenser, condensate line and tank freely and continuously along an elastic insert is placed over their entire length.

Wherein

- sections of the elastic insert located in the steam manifold and the tank are made in the form of a loop;

- the elastic insert is made in the form of a cylinder, the volume of which must be at least 10% with respect to the volume in which this insert is placed;

- the elastic insert is made of a material capable of repeatedly absorbing mechanical forces and restoring its original shape after they are removed, for example, from kapron.

Placing the elastic insert in the steam manifold, steam line, condenser, condensate line and reservoir freely and continuously along their entire length will increase the reliability of the device by ensuring its operability after repeated freezing and thawing of the coolant in it by preventing the destruction of the elements of the device, because . an elastic insert, which occupies a certain volume, is first compressed under the influence of forces arising from the freezing of the coolant and its transformation into ice, and during the subsequent reverse transformation, this insert restores its original shape.

The execution of the parts of the elastic insert placed in the steam manifold and the tank in the form of a loop allows you to prevent the insert from moving in the axial direction when the device is in operation, when steam and condensate are moving along the steam pipe, condensate pipe and can “grab” the insert with them. And the presence of loops in the steam manifold and tank will not allow the insert to move axially along with steam and condensate flows, which will ensure the reliability of the device.

The implementation of the elastic insert with a volume of not less than 10% of the volume in which this insert is placed will provide the most complete perception of the forces arising in the device when the coolant is converted into ice, the volume of which almost instantly increases by 10% with respect to to the volume of coolant from which this ice was formed ..

The implementation of the elastic insert from a material capable of repeatedly absorbing mechanical forces and restoring its original volume after they are removed, will prevent the destruction of the device during repeated freezing-thawing of the coolant in it.

Figure 1 presents a diagram of a heat transfer device for cooling electronic devices in the absence of heat load with the location of the evaporator at the top and the condenser at the bottom;

figure 2 shows a diagram of a heat transfer device for cooling electronic devices in the absence of heat load with the location of the evaporator at the bottom, and the condenser at the top;

figure 3 presents a diagram of a working heat transfer device for cooling electronic devices;

figure 4 shows a view A of the cross section of the steam pipe and the condensate pipe with an elastic insert placed inside them;

figure 5 shows a view B of a heat transfer device for cooling electronic devices with a heat supply zone;

Heat transfer device for cooling electronic devices

made in the form of a closed sealed circuit (figure 1), including an evaporator 1 and a condenser 2 connected by a separate hollow steam line 3 and a condensate line 4. The evaporator 1 contains a capillary-porous (wick) structure 5, a steam manifold 6, to which a steam line 3 is connected, and a heat supply zone 7 to accommodate a heat load source or a cooled object (not shown). The evaporator 1 is connected to the tank 8, to which the condensate pipe 4 is connected. The condenser 2, made in the form of a section of the hollow pipe, is located between the steam pipe 3 and the condensate pipe 4. In the steam manifold 6, steam pipe 3, condenser 2, condensate pipe 4 and tank 8 continuously throughout their length is freely placed elastic insert 9, made, for example, of kapron. Sections 10 and 11 of the elastic insert 9, located, respectively, in the steam manifold 6 and the tank 8, are made in the form of a loop. Air has been removed from the heat transfer device, and it is partially filled with coolant 12, for example, water. The heat transfer device operates as follows.

First, consider the position of the device when the evaporator 1 is located at the top and the condenser 2 is at the bottom (Fig. 1). When the device is frozen, the coolant accumulated in the steam line 3, the condenser 2 and the condensate line 4 begins to turn into ice. The volume of ice almost instantly increases by about 10% relative to the volume of the coolant from which it was formed. The forces arising from this are perceived by the elastic insert 9, made in the form of a cylinder, the volume of which is at least 10% with respect to the volume into which this insert is placed, namely: in the steam line 3, the condenser 2 and the condensate line 4. During subsequent defrosting, when the ice is again converted into a liquid coolant, the elastic insert 9 restores its original shape, allowing you to repeatedly repeat the freeze-thaw cycles. No destruction occurs

steam pipe 3, condenser 2 and condensate pipe 4, which allows to maintain the operability of the device.

Next, we consider the position of the device when the evaporator 1 is located at the bottom, and the condenser 2 is at the top (figure 2). In this case, when the device is frozen, the coolant accumulated in the steam line 3, the condensate line 4, the steam manifold 6 and the tank 8 also begins to turn into ice. The forces arising in this case are perceived by the elastic insert 9 located in the steam line 3, the condensate line 4, the steam manifold 6 and the tank 8. During subsequent thawing, when the ice is again converted into a heat transfer fluid, the elastic insert 9 restores its original shape, allowing it to repeat the freezing cycle many times. defrosting. At the same time, there is also no destruction of the steam pipe 3, the condensate pipe 4, the steam manifold 6 and the tank 8, which allows to maintain the operability of the device.

The operation of the device after defrosting is as follows. The most difficult situation is considered when the device is located vertically, and the evaporator 1 is located above the condenser 2 (figure 3). When the heat load is applied to zone 7, the coolant 12 begins to evaporate from the wick structure 5, while taking away the latent heat of vaporization and cooling the source of heat load. The vapor pressure in the steam manifold 6 is higher than the vapor pressure in the tank 8, since the heat supply zone 7 is shifted towards the steam manifold 6, and the evaporation of the coolant 12 into the steam manifold 6 is much more intense than in the reservoir 8. Due to this the pressure difference, the coolant 12 is displaced from the steam pipe 3 and the condenser 2, completely filling the condensate pipe 4 and the tank 8. The steam through the steam pipe 3 enters the condenser 2, condenses here and gives off heat to its environment, as which I can t be air or liquid. Condensate formed through condensate line 4 moves in

the reservoir 8 is absorbed into the wick structure 5 and enters the heat supply zone 7, thereby closing the device operation cycle. The movement of the coolant 12 through the condensate line 4 is carried out against the action of gravity due to the fact that the wick structure 5 performs not only the role of a “capillary pump”, but also a “thermal shutter”, which allows creating a temperature and vapor pressure difference between its evaporating and absorbing surfaces. In this case, the sections 10 and 11 of the elastic insert 9, made in the form of a loop, and placed, respectively, in the steam manifold 6 and the tank 8, do not allow the axial movement of the insert when the heat carrier 12 moves, which ensures stability of the device characteristics.

Thus, the repeated repetition of freeze-thaw cycles, regardless of the orientation of the device in space, does not lead to the destruction of the steam manifold 6, steam pipe 3, condenser 2, condensate pipe 4 and tank 8, which allows to maintain the operability of the device.

The design of the heat transfer device for cooling electronic devices, corresponding to paragraphs 1-5 of the claims, was implemented in the experimental practice of LLC Terkon-KTT. In particular, a heat transfer device with a steam collector, a reservoir, a steam pipe and a condensate pipe was made, in which an elastic capron insert was placed in accordance with claims 1 to 5 of the claims. Distilled water was used as a heat carrier. To date, 65 cycles of freezing and thawing the device. Freezing was carried out at a temperature of minus 18 ° C, and thawing at a temperature of 20 ± 2 ° C. Exposure at the indicated temperatures in each cycle ranged from 2 to 16 hours. The device was frozen in 3 positions: vertical, when the evaporator was at the top and the condenser at the bottom; horizontal vertical, when the capacitor was located at the top, and

evaporator downstairs. After a series of freeze-thaw cycles, thermal tests were periodically carried out - the dynamics of changes in the most important parameter, the evaporator temperature, was determined. The heat load supplied to the evaporator was 100 watts. The test results showed that the device with an elastic insert, corresponding to claims 1-5 of the claims, withstood the test without damage. At the same time, the device maintained its operability, while the value of the most important parameter, the evaporator temperature, remained stable at the level of 75 ± 1.5 ° С.

Claims (5)

1. A heat transfer device for cooling electronic devices, made in the form of a closed sealed circuit, partially filled with a coolant, including an evaporator with a capillary-porous structure inside, coupled to a steam collector and reservoir, and a hollow condenser connected by a hollow separate steam and condensate pipes, characterized in that in the steam manifold, steam line, condenser, condensate line and tank, an elastic insert is freely and continuously along their entire length but. 2. The heat transfer device according to claim 1, characterized in that the sections of the elastic insert located in the steam line and the tank are made in the form of a loop. 3. The heat transfer device according to claim 1, characterized in that the elastic insert is made in the form of a cylinder, the volume of which must be at least 10% with respect to the volume in which this insert is placed. 4. The heat transfer device according to claim 1, characterized in that the elastic insert is made of a material capable of repeatedly absorbing mechanical forces and restoring its original shape after they are removed, for example, from nylon. 5. The heat transfer device according to claim 1, characterized in that water is used as a heat carrier.