Cooling Device and Method

Abstract

A cooling device for cooling a component comprising a heat sink, a housing having an inner chamber, wherein a volume-changing device is formed to withdraw a fluid into the chamber and to expel the fluid from the chamber, the withdrawal causing a first flow and the expulsion causing cortices which form a second flow. A preheating device is also provided and is configured to convey the first flow and the second flow, and to increase the temperature of the first fluid quantity entrained by the first flow during the withdrawal from an initial temperature to a first temperature, and to increase the second fluid quantity entrained by the second flow, from the first temperature to a second temperature.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a cooling device for cooling a component comprising a heat sink and a housing having an inner chamber, wherein a volume-changing device is formed to withdraw fluid into the chamber and to expel the fluid from the chamber, the withdrawal causing a first flow and the expulsion causing vortices which form a second flow.

The invention also relates to a method for operating the cooling device.

2. Description of the Related Art

U.S. Pat. No. 6,588,497, U.S. Pat. No. 5,758,823, U.S. Pat. No. 5,988,522 and U.S. Pat. No. 7,252,140 disclose known cooling devices.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a cooling device having an optimized cooling power and a method for optimizing the cooling power of the cooling device.

This and other objects and advantages are achieved in accordance with the invention by a cooling device in which a preheating device is configured to convey first and second flows, and to increase the temperature of the first quantity of fluid entrained by the first flow during withdrawal of the fluid entrained by the first flow into a chamber, from an initial temperature to a first temperature, and to increase the temperature of a second quantity of fluid entrained by the second flow from the first temperature to a second temperature. The preheating device is advantageously arranged in thermal communication with the heat sink and is heated, e.g., by the electrical component arranged on the heat sink. This heating of the preheating device is used to heat the fluid, such as air, from an initial temperature to a first temperature when the flow is being drawn in. Cooling of the preheating device already occurs with this heating of the air, and therefore also cooling of the heat sink, which directly leads to an increase in the cooling power for the electrical component.

In an advantageous embodiment, the cooling device with the chamber has a first chamber and a second chamber. These two chambers, arranged in a housing, work with a volume-changing device according to the principle of a known synthetic jet drive.

In another advantageous embodiment, the preheating device comprises a first channel and a second channel. The first channel could therefore be connected to an outlet for a first chamber and the second channel to an outlet for a second chamber. The presently contemplated two-channel embodiment is advantageous since the two flows can be conveyed separately from one another.

In a further optimized embodiment of the cooling device, a volume of the first channel corresponds to the volume of the first fluid quantity. Here, it is also advantageous for the delta of volume changes, which is caused by the volume-changing device, to be adapted to the volume of the first channel. For optimization of the cooling power, it is thus useful to adapt the spatial content of the first channel to the volume that is drawn in through the chamber. In a two-channel embodiment of the invention, i.e., a first channel and a second channel, a symmetrical layout of the volumes of the channels is useful, where the volumes of the channels should correspond to the volumes of the chambers, or the volume delta should correspond to the channel volume.

It is expedient for the heat sink to comprise the preheating device as an integral element and for a part of the heat flux flowing through the component into the heat sink to flow into the preheating device.

In another embodiment, the heat sink has a feed-through, which is arranged so that the second flow flows into the feed-through and the second fluid quantity entrained by the second flow is raised from the second temperature to a third temperature. The heat sink with its feed-through ensures further optimization of the increased cooling power. The air conveyed through the heat sink can be heated to a further higher temperature while flowing through the feed-through, and thereby preferably even achieve thermal saturation. Consequently, the amount of heat conveyed through the electrical component into the heat sink, by the flow flowing through the feed-through, can furthermore be extracted from the heat sink.

Preferably, the preheating device is arranged with a first end and a second end between an intake zone and the housing, where the first end is arranged on the housing and the second end is arranged at the intake zone between the heat sink and the second end.

The cooling power can be optimized even further if the feed-through comprises a guide device for forcing turbulent convection. Turbulent convection, which is known in physics as Rayleigh-Bénard convection, is a fluid-mechanical effect. In this process, a fluid is heated from below between two preferably horizontal plates and cooled from above. With a temperature difference beyond a certain level, turbulent convection occurs in which large-scale thermal structures are shed from the boundary layers and transport hot or cold fluid through a core region.

In a further embodiment, optimization of noise reduction of the cooling device is achieved by providing a feed-through that comprises an exit zone in the region of an outlet opening, which is configured so that interference of sub-flows occur and sound compensation can be achieved. Preferably, the feed-through is configured as an acoustic damper in the region of its exit zone. Besides phase-shifted flowing of the first flow and the second flow, guide devices for the fluid, which are arranged in the feed-through, such as baffle plates on an upper side and a lower side of the feed-through, also ensure corresponding interference of the emerging air vortices, so that sound waves are extinguished. Particularly for use in consumer electronics, such as laptops, noise-attenuating cooling of the processor contained in the laptop is advantageous.

In a further embodiment, the heat sink comprises cooling plates on an outer side.

For particular environmental conditions, it is expedient for the chamber to furthermore comprise a third chamber and a fourth chamber. Here, the housing with the four inner chambers is configured as an encapsulated synthetic jet drive with two drive systems. The particular advantage with this particular configuration of the synthetic jet drive system is that it is industrially compatible since it is configured tightly and is, thus, resistant to the entry of dust.

As for the function of the synthetic jet drive with four chambers and a configuration with dust-tightness, reference is made to the description of the figures.

The object of the invention is achieved by a method in accordance with the invention in which a first flow is conveyed through a preheating device, a temperature of a first quantity of fluid entrained by the first flow is increased from an initial temperature to a first temperature by the preheating device during withdrawal of the first fluid into a chamber, and the temperature of a second quantity of fluid entrained by the second flow is increased from the first temperature to a second temperature by the preheating device. By back and forth oscillatory movement of air-flows, for example, heat can be extracted from the preheating device with a controlled increase. A cooling power of, for example, an electrical component, is therefore optimized. It should be noted that the method not only can be used for cooling electrical components, but may be employed in any technical apparatus in which heat developed by a heat source needs to be transported away as efficiently as possible from the heat source.

For effective generation of the first and second flows, the volume-changing device is driven so that it executes an oscillatory pattern of movement. Here, it is expedient for the first movement direction to be maintained until the volume of the withdrawn first fluid quantity corresponds to the volume of the first channel of the preheating device.

It is furthermore expedient for the second movement direction to be maintained until the expelled volume of the first quantity of fluid corresponds to the volume of the first channel of the preheating device and for an alternating exchange of fluid quantities from the preheating means to be performed.

Further cooling of the preheating device and therefore also of the heat sink, and therefore in turn of the electrical component, is achieved by guiding the vortices of the second flow into a feed-through of a heat sink and by raising the second quantity of fluid entrained by the second flow from the second temperature to a third temperature. As a result, stepwise cooling occurs. In a first step, an initial temperature, for example, the temperature of the ambient air, is increased to a first temperature. This increased temperature is in turn increased from the first temperature to a second temperature when passing again through the preheating device, and finally in a third step the second temperature is further increased to the third temperature. For the example, with ambient air as the cooling fluid, this would mean that the cooling air used as ambient air reaches thermal saturation after the foregoing steps have been performed.

Cooling can furthermore be optimized if the vortices are deflected by a guide device in the feed-through and turbulent convection is generated. Turbulent convection ensures more rapid cooling of the heat fluxes occurs at the boundary layers of the feed through.

For operation of the cooling device, i.e., operation of the volume-changing device inside the chamber in the housing, it is expedient to execute the movement directions alternately to and fro, so that during a first period of time for the first movement direction, in which the first fluid quantity is drawn through an intake zone into the first channel, the second fluid quantity is expelled from a second channel and guided into the feed-through, and after reversal of the movement direction from the first movement direction to the second movement direction the first fluid quantity is sucked into the second channel and the second fluid quantity is guided from the first channel into the feed-through.

In another embodiment of the method, bidirectional heat exchange is performed by the flows, the flows are conveyed separately as far as an exit zone and sound emission reduction occurs upon exit.

Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing shows exemplary embodiments of a cooling device in accordance with the invention, in which:

FIG. 1 is a cross sectional illustration of a cooling device in accordance with an embodiment of the invention;

FIG. 2 is an illustration of a cooling device in accordance with an alternative embodiment of the invention;

FIG. 3 is a plan view illustration of the cooling device of FIG. 2;

FIG. 4 is an outline illustration of flow channels with a preheating zone in accordance with the disclosed embodiments of the invention;

FIG. 5 is an outline illustration of a device for generating first flow and second flows in accordance with the contemplated embodiments of the invention;

FIG. 6 is an illustration of a perspective view of the cooling device of FIG. 2;

FIG. 7 is an illustration of a perspective view of the cooling device in accordance with an alternative embodiment of the invention; and

FIG. 8 is an illustration of a method of in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

A schematic representation of a cooling device 1 in accordance with the invention is shown in FIG. 1. Viewed from right to left, the cooling device 1 has as its main elements a housing 4, a preheating device 8 and a heat sink 3. A thermal conduction device 61, which is placed on an electrical component 2, is arranged below the heat sink 3. The electrical component 2, such as a flip chip BGA, is arranged on a printed circuit board 60. During operation of the flip chip BGA, i.e., with a high power, the heat generated by the flip chip BGA must be dissipated by the thermal conduction device 61 through the heat sink 3. Since efficient cooling of an electrical component can only be achieved by employing active fans, such as known radial fans, in order to optimize the cooling power of the heat sink 3, the cooling device 1 has a housing 4 with an inner chamber 5, which in turn comprises a first chamber 51 and a second chamber 52.

These chambers 51 and 52, arranged inside the housing 4, are separated by a volume-changing device 6. This configuration inside the housing 4 produces a synthetic jet drive. Each of the two chambers 51, 52 has an opening. The opening of the first chamber 51 is connected to a first channel 21 of the preheating device 8. The opening of the second chamber 52 is connected to a second channel 22 of the preheating device 8. The volume-changing device 6 is configured as a piezo drive with two mobile diaphragms. The piezo drive allows a first movement direction 41 and a second movement direction 42 of the mobile diaphragms.

During operation of the volume-changing device 6, a first flow 11 is conveyed through the preheating device 8, a temperature of the first fluid quantity V1 entrained by the first flow 11 being increased from an initial temperature to a first temperature by the preheating device 8 during withdrawal by the diaphragm of the fluid entrained by the first flow, and the temperature of the second fluid quantity V2 entrained by the second flow 12 being increased from the first temperature T1 to a second temperature T2 by the preheating device 8. The first flow 11 is conveyed through the first channel 21 and the second flow 12 is conveyed separately through the second channel 22.

The first flow 11 and the second flow 12 are conveyed alternately through the first channel 21 and the second channel 22, which is represented in FIG. 1 as a further first flow 11′ and a further second flow 12′. The first flow 11 and the second flow 12 corresponding thereto are represented as solid lines, and the further first flow 11′ and the further second flow 12′ corresponding thereto are represented as dashed lines.

During an intake process by the volume-changing device 6, with the movement direction 41 being executed, a negative pressure is created in the first chamber 51 and the first flow 11 can therefore be drawn through the first channel 21 into the first chamber 51. The volume-changing device 6, the first chamber 51 and the length of the movement direction 41 are configuration so that the delta volume resulting from the movement corresponds to the volume of the first channel 21. Instead of the generally applicable fluid, air will now be referred to.

The air quantity drawn in with the first flow 11 now lies only in the first channel 21 and fills its volume entirely, and during the intake and a residence time of the air quantity in the first channel 21, the air is heated from an initial temperature T0 to a first temperature T1. Thus, in a first step the air functions as cooling air.

Simultaneously with the intake of the cooling air by the first flow 11, the second flow 12 is conveyed through the second channel 22 by the volume-changing device 6 with the aid of the second chamber 52 and its opening. When the second flow 12 emerges from the opening of the second chamber 52, vortices 7 are created by the expulsion (see FIG. 5). These vortices 7 correspond to a second air quantity V2, which can be heated from the first temperature T1 to a second temperature T2 while flowing through the second channel 22. The vortices 7, in the form of the second flow 12, flow past an intake zone 9 due to their higher speed, and are guided into the heat sink 3. To this end, the heat sink 3 has a feed-through 3a.

Guide devices for guiding the flowing air are arranged inside the feed-through 3a. Here, upper baffle plates 30b are arranged in the upper part of the feed-through 3a, and lower baffle plates 30a are arranged in the lower part of the feed-through 3a. Guiding the second flow 12 through the feed-through 3a allows the cooling air, which has already been heated to the second temperature T2, to increase again. The cooling air temperature is heated from the second temperature T2 to the third temperature T3 when flowing through the feed-through 3a.

For the cooling air, this heating means that thermal saturation is reached. The guide devices, i.e., upper baffle plates 30b and lower baffle plates 30a, ensure that the first flow 12 enters into turbulent convection 13. When there is a sufficiently large temperature difference, the turbulent convection sets in, which is reinforced by the guide devices, thermal structures being shed from the boundary layers of the feed-through 3a and hotter fluid or the air being transported into a core region of the flow, so that a cooling power of the heat sink 3 is optimized.

The cooling process has been explained above with reference to the example of the first flow 11 and the second flow 12. Since the volume-changing device 6 executes an oscillating movement pattern, the flow properties and the temperature increase may be explained similarly for the further first flow 11′ and the further second flow 12′.

In the intake zone 9, desired admixture of unheated ambient air occurs through a suction effect. The heat sink 3 has cooling plates 71, . . . ,76 on its outer side. These additional open cooling plates 71, . . . ,76 on the outer side of the heat sink 3, and therefore on the outer side of the feed-through 3a, reinforce the cooling power of the heat sink 3 by natural convection of the ambient air. Among other things, the thermal dissipation capacity of the cooling plates 71, . . . ,76 determines a working point (ambient temperature) for the use of the cooling device 1, in combination with the forced convection described above.

Desired interference of the air flowing out, and therefore sound emission reduction of the emerging air, occurs in an exit zone 10.

FIG. 2 is schematic illustration of an alternative embodiment of the cooling device 1 in a lateral sectional representation. In contrast to the exemplary embodiment of FIG. 1, the first channel 21 and the second channel 22 of the presently contemplated embodiment are now arranged next to one another so that only the first channel 21 can be seen in FIG. 2. Here, viewed from left to right, the cooling device 1 comprises the housing 4 with the inner chamber 5, the preheating device 8 with an intake zone 9 and the heat sink 3 with the feed-through 3a. An axis of symmetry is indicated symbolically through the first channel 21. The second flow 12 and the further second flow 12′ will respectively move around this axis. In order to achieve turbulent convection 13 inside the feed-through 3a, a first baffle plate 31, a second baffle plate 32, a third baffle plate 33, a fourth baffle plate 34 and a fifth baffle plate 35 are arranged as seen from left to right. The baffle plates 31, 33, 35 form the upper baffle plates and the baffle plates 32 and 34 form the lower baffle plates. When the turbulent convection 13 arrives, a suction effect through the intake zone 9 is amplified and fresh ambient air for further cooling can be delivered through the intake zone 9.

FIG. 3 is a schematic plan view illustration of the cooling device of FIG. 2. Here, the channel 22 arranged beside the first channel 21 can be seen. The channels 21, 22 are respectively configured to taper in the flow direction, so that the Bernoulli effect becomes significant. The first flow 11 can be drawn into the first channel 21 and the further first flow 11′ can be drawn into the second channel 22 through the intake zone 9. Due to the movement in opposite directions of the volume-changing device 6 according to FIG. 1, as in a two-stroke motor, intake occurs through the first channel 21 while expulsion occurs through the second channel 22, and vice versa.

Edges of the first baffle plate 31 to the fifth baffle plate 35 can be seen in the feed-through 3a. FIG. 2 shows that the feed-through 3a has a first inlet opening and a second inlet opening, the cross sections of the inlet openings increasing in the flow direction. This increase occurs approximately over half of the feed-through 3a, and beyond this half the flows previously guided forcibly are combined into a common flow. Their combination creates interferences which are promoted by the arrangement of the third, fourth and fifth baffle plates 31, 34, 35 so that sound emission is achieved for the flowing air upon exit from the exit zone 10.

The second alternative exemplary embodiment of a cooling device 1, as represented by FIG. 6, has the difference in this representation of channel bends for the first channel 21 and the second channel 22. The known devices for generating the flows, which are arranged inside the housing 4, are respectively in communication by their above-described openings with the first channel 21 and the second channel 22. The housing 4 is therefore connected through the channels 21, 22 to a first end 8a of the preheating device 8. Inside the preheating device 8, the channels 21 and 22 are guided separately from one another as far as a second end 8b of the preheating device 8. Between the second end 8b and the heat sink 3, there is a gap that is configured as the intake zone 9.

The preheating device 8 is configured as an integral element of the heat sink 3. The heat flux flowing in the heat sink 3 due to a heat source (electrical component 2) can therefore also flow into the preheating device 8, heat it and with the channels heat the ambient air flowing through the channels 21, 22. As already explained with respect to FIG. 1, the first flow 11 is sucked through the intake zone 9 into the first channel 21. Simultaneously during the intake process, through the second channel 22, the second flow 12 is expelled as a vortex flow through the second channel 22 and guided into the feed-through 3a. In this example, the feed-through 3a has longitudinally arranged guide devices, such as guide plates. The heat sink 3 has cooling plates 71, . . . , 76 on its outer side.

Another exemplary embodiment of the cooling device 1 is shown in FIG. 7 in a perspective representation. Here, the channels 21 and 22 wind through the heat sink 3 and the preheating device 8 in a meandering manner. In this alternative embodiment, the key feature is that the heat sink 3 has a first cooling plate 71 and a second cooling plate 76 for a lateral boundary. There is therefore a wide channel for natural convection of the ambient air at the two plates 71, 76. The preheating device 8 as a preheating zone is now not arranged in series with the heat sink but lies below the actual heat sink 3, although it is still thermally connected to the heat sink 3 and its cooling plates 71, 76.

FIG. 4 is a schematic illustration of a configuration of feed-through 3a in accordance with an embodiment of the invention. The second flow 12 flows out of the first channel 21 and the further second flow 12′ flows out of the second channel 22, in the direction of the feed-through 3a. Following on from an intake zone 9, the feed-through 3a has a first opening and a second opening. These two openings convey the second flow 12 and the further second flow 12′ separately as far as a first baffle plate 31. Beyond the first baffle plate 31, the second flow 12 and the second flow 12′ are combined, and these two combined flows can arrive at a second baffle plate 32, arranged further downstream as seen in the flow direction, and be prepared for preferably turbulent convection 13, or they may already have been vortexed. Arranged further along in the flow direction, there is a third baffle plate 33 and, further downstream in the flow direction, there is a fourth baffle plate 34 in the region of an exit zone 10.

FIG. 5 represents a housing 4 that is configured internally so as to fulfill the function of a synthetic jet drive. This synthetic jet drive comprises a first chamber 51, a second chamber 52, a third chamber 53 and a fourth chamber 54. The first chamber 51 and the third chamber 53 each have an opening for intake and ejection of the fluid. A first flow 11 and a further first flow 11′ are drawn in through the openings. The two chambers 51 and 53 operate reciprocally, i.e., when a first flow 11 is being drawn in through the opening of the chamber 51 the second flow 12 is expelled through the opening of the chamber 53. The second flow 12 may be formed by a series of vortices 7, which vortices 7 may flow, for example, as bubbles or rings with a faster speed through the fluid.

The first chamber 51 is separated from the second chamber 52 by the volume-changing device 6. The third chamber 53 is separated from the fourth chamber 54 by a further volume-changing device 6′. The key feature of this four-chamber alternative embodiment is that the second chamber 52 is in communication with the fourth chamber 54 through a bypass channel 55. This advantageous alternative configuration allows a dust tight synthetic jet drive to be formed inside the housing 4. That is, the volume-changing devices 6, 6′, which are configured, for example, as piezo elements, are not exposed to dusty air. Harsh and robust environmental conditions prevail especially in process automation in the industrial field, where ambient air which is used as cooling air may be strongly laden with dust and moisture.

The particular feature of this four-chamber configuration is that the ambient air is guided by the first flow 11 into first chamber 51 and is separated by a diaphragm of the volume-changing device 6 from the first chamber latter. Dirt from the ambient air can therefore be deposited in the chamber 51 without compromising the volume-changing device 6. This is because the main drive of the volume-changing device 6 is located in the second chamber 52, which only needs to be filled once with a corresponding fluid, such as air. This second chamber 52 is in hermetic communication with the fourth channel 54 through the bypass channel 55. The fourth chamber 54 in turn contains the further volume-changing device 6′, so that the volume-changing device 6′ likewise does not come in contact with an ambient fluid, such as dusty air. Again, only the chamber 53 can come in contact with dusty air, and the dust can be deposited in the chamber 53 without causing damage.

FIG. 8 is a flow chart of a method for operating a cooling device in which a volume-changing device is movably arranged in a housing having an inner chamber. The method comprises moving the volume-charging device in the housing so that a fluid is withdrawn into the chamber in a first movement direction to cause a first flow of the fluid and so that the fluid is expelled from the chamber in a second movement direction to form vortices which cause a second flow, as indicated in step 810.

The first flow is conveyed through a preheating device, as indicated in step 820. Here, the temperature of a first quantity of fluid entrained by the first flow is increased from an initial temperature to a first temperature by the preheating device during the withdrawal.

The second flow through the preheating device, as indicated in step 830. Here, the temperature of a second quantity of fluid entrained by the second flow being increased from the first temperature to a second temperature by the preheating device during the expulsion.

Constant cross section channel=h*b=r²π;

identical volumes=ΔV_SynJet=V_channel

flow resistance F_channel=flow resistance F_{plate baffle}

Q_total=Q_intake+Q_eject+Q_plates=c*m*(ΔT₁+ΔT₂+ΔT₃)

Thus, while there are shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the illustrated apparatus, and in its operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it should be recognized that structures shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.

Claims

1. A cooling device for cooling a component, comprising:

a heat sink,

a housing having an inner chamber, a volume-changing device formed to withdraw a fluid into the chamber and to expel the fluid from the chamber, the withdrawal causing a first flow and the expulsion causing vortices which form a second flow; and

a preheating device configured to convey the first and second flows, to increase a temperature of a first quantity of fluid entrained by the first flow during the withdrawal from an initial temperature to a first temperature, and to increase the temperature of a second quantity of fluid entrained by the second flow, from the first temperature to a second temperature.

2. The cooling device as claimed in claim 1, wherein the preheating device comprises a first channel and a second channel.

3. The cooling device as claimed in claim 2, wherein the inner chamber comprises a first chamber and a second chamber.

4. The cooling device as claimed in claim 2, wherein the first channel includes a volume which corresponds to the first quantity of fluid.

5. The cooling device as claimed in claim 3, wherein the first channel includes a volume which corresponds to the first quantity of fluid.

6. The cooling device as claimed in claim 1, wherein the heat sink comprises the preheating device as an integral element, and wherein a part of heat flux flowing through the component into the heat sink flows into the preheating device.

7. The cooling device as claimed in claim 1, wherein the heat sink includes a feed-through, which is arranged so that the second flow flows into the feed-through and so that the second quantity of fluid entrained by the second flow is increased from the second temperature to a third temperature by the heat sink.

8. The cooling device as claimed in claim 1, wherein the preheating device comprises a first end and a second end, and wherein an intake zone is arranged between the heat sink and the second end, the first end being arranged on the housing.

9. The cooling device as claimed in claim 7, wherein the feed-through comprises at least one guide device for forcing turbulent convection.

10. The cooling device as claimed in claim 8, wherein the feed-through comprises at least one guide device for forcing turbulent convection.

11. The cooling device as claimed in claim 7, wherein the feed-through comprises an exit zone, in a region of an outlet opening, which is configured so that interference of sub-flows occurs and sound compensation is achieved.

12. The cooling device as claimed in claim 8, wherein the feed-through comprises an exit zone, in a region of an outlet opening, which is configured so that interference of sub-flows occurs and sound compensation is achieved.

13. The cooling device as claimed in claim 9, wherein the feed-through comprises an exit zone, in a region of an outlet opening, which is configured so that interference of sub-flows occurs and sound compensation is achieved.

14. The cooling device as claimed in claim 1, wherein the heat sink comprises cooling plates on an outer side.

15. The cooling device as claimed in claim 3, wherein the inner chamber further comprises a third chamber and a fourth chamber.

16. A method for operating a cooling device in which a volume-changing device is movably arranged in a housing having an inner chamber, comprising:

moving the volume-charging device in the housing so that a fluid is withdrawn into the chamber in a first movement direction to cause a first flow of the fluid and so that the fluid is expelled from the chamber in a second movement direction to form vortices which cause a second flow;

conveying the first flow through a preheating device, a temperature of a first quantity of fluid entrained by the first flow being increased from an initial temperature to a first temperature by the preheating device during the withdrawal; and

conveying the second flow through the preheating device, a temperature of a second quantity of fluid entrained by the second flow being increased from the first temperature to a second temperature by the preheating device during the expulsion.

17. The method as claimed in claim 16, wherein the volume-changing device is driven so that the volume-changing device executes an oscillatory pattern of movement.

18. The method as claimed in claim 16, further comprising:

maintaining the first movement direction until a volume of the withdrawn first quantity of fluid corresponds to the volume of a first channel of the preheating device.

19. The method as claimed in claim 17, further comprising:

maintaining the first movement direction until a volume of the withdrawn first quantity of fluid corresponds to the volume of a first channel of the preheating device.

20. The method as claimed in claim 16, further comprising:

maintaining the second movement direction until an expelled volume of the first quantity of fluid corresponds to the volume of the first channel of the preheating device and an alternating exchange of the first and second fluid quantities flows through the preheating device.

21. The method as claimed in claim 16, wherein the vortices of the second flow are guided into a feed-through of a heat sink and the second quantity of liquid entrained by the second flow is raised from the second temperature to a third temperature by the heat sink.

22. The method as claimed in claim 20, wherein the vortices are deflected by at least one guide device in the feed-through and turbulent convection is generated.

23. The method as claimed in claim 20, wherein the movement directions are executed alternately to and fro, so that during a first period of time for the first movement direction, in which the first quantity of fluid is drawn through an intake zone into the first channel, the second quantity of fluid is expelled from a second channel and guided into the feed-through, and after reversal of the movement direction from the first movement direction to the second movement direction the first fluid quantity is drawn into the second channel and the second quantity of fluid is guided from the first channel into the feed-through.

24. The method as claimed in claim 22, wherein bidirectional heat exchange is performed by the first and second flows, the first and second flows being conveyed separately to an exit zone, and sound emission reduction occurs upon exit of the first and second flows.

25. The method as claimed in claim 23, wherein bidirectional heat exchange is performed by the first and second flows, the first and second flows being conveyed separately to an exit zone, and sound emission reduction occurs upon exit of the first and second flows.