CN215572348U

CN215572348U - Heat transfer device for enhancing boiling micro-channel by applying ultrasonic field and linear electrode

Info

Publication number: CN215572348U
Application number: CN202121115087.9U
Authority: CN
Inventors: 罗小平; 许静姝; 李景生; 杨书斌; 张超勇
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2022-01-18
Anticipated expiration: 2031-05-21

Abstract

The application discloses a heat transfer device for strengthening a boiling micro-channel by an external ultrasonic field and a linear electrode, wherein a cover plate is covered and connected on a base to seal the base; a micro-channel plate mounting position is arranged in the base, and flow stabilizing cavities are arranged in the base and positioned at two sides of the micro-channel plate mounting position; the micro-channel plate is arranged on the micro-channel plate mounting position, and a plurality of micro-channels are formed in the micro-channel plate; the linear electrode strengthening device comprises a plurality of electrode wires correspondingly arranged in the plurality of micro channels, and two ends of each electrode wire are respectively used for being connected with the positive electrode and the negative electrode of the power supply; the two ends of the base, which are positioned in the micro-channel, are equally provided with the ultrasonic field transduction devices, the ultrasonic field transduction devices comprise ultrasonic transducers and vibrating plates, the ultrasonic transducers are used for being connected with an ultrasonic generator, and the ultrasonic transducers are fixed on the vibrating plates. The electric field and the sound field are introduced into the micro channel, and the composite enhanced heat transfer effect of the micro channel is enhanced through the coupling effect of the electric field and the sound field.

Description

Heat transfer device for enhancing boiling micro-channel by applying ultrasonic field and linear electrode

Technical Field

The utility model relates to the field of heat exchangers, in particular to a boiling micro-channel heat transfer device enhanced by an external ultrasonic field and a linear electrode.

Background

With the rapid development of modern science and technology, various electronic component devices develop towards miniaturization, under the condition that the original power consumption is not changed, the reduction of the volume size means that the heat quantity on a unit area can be increased rapidly, the heat dissipation of partial national-level supercomputer CPUs reaches 4.5MW/m2, the local heat flux density is even higher, the requirements cannot be met by common air cooling and water cooling alone, if measures are not taken, the too high heat can cause the rapid rise of the surface temperature of the components, so that the devices cannot operate normally, and relevant documents show that when the temperature of the electronic components rises to 70-80 ℃, the temperature rises by 1 ℃ every time, and the reliability of the components can be reduced by 5%. Compared with single-phase flow heat transfer, phase-change heat transfer can take away heat more quickly through vaporization of working media, and has stronger heat dissipation capacity, so that the research on phase-change heat transfer of micro-channels is necessary.

Chubb in the patent "Improvements relating to methods and apparatus for improving liquids" studies the enhancement effect by introducing an electric field, finds that the electric field has a better heat transfer effect than that without the electric field, and currently, mainly studies the enhancement heat transfer mechanism of the electric field by injecting a single bubble, and studies the influence of factors such as electric field distribution, electrode arrangement, electrode distance, voltage magnitude and the like on the electric field enhancement heat transfer by introducing the electric field through pool boiling under a conventional size. The sound field enhanced heat transfer research is later than the electric field enhanced heat transfer research, and in the 60 s, Fand et al, he in the flame of acoustic aspects on heat transfer by natural convection from a horizontal cylinder to water (Journal of heat transfer,1965,87(2):309-310) found that ultrasonic waves have enhanced heat transfer effects, and found that the enhanced heat transfer of the sound field is mainly caused by the cavitation effect of the sound field. Subsequent researchers find that the ultrasonic waves can reduce thermal resistance, accelerate bubble separation and the like to enhance heat transfer by researching a series of mechanisms such as the thermal effect, the cavitation effect, the mechanical effect and the like of the ultrasonic waves.

Therefore, both the electric field and the acoustic field have non-trivial potential for enhancing heat transfer, and for such dimensions of the microchannel, the electric field and the acoustic field are rarely studied, mainly because the microchannel has small dimensions, the arrangement of the electrode and the acoustic field transducer is difficult to realize, and the study of the boiling heat transfer of the flow of the microchannel under the coupling action of the electric field and the acoustic field is rare. Aiming at the problems, the utility model designs a novel device for introducing an electric field and a sound field into a micro channel and researching the composite enhanced heat transfer effect of the micro channel under the coupling action of the electric field and the sound field.

Disclosure of Invention

The utility model provides a device for strengthening a boiling micro-channel heat transfer by an external ultrasonic field and a linear electrode, which is used for achieving a better heat exchange strengthening effect by the cooperation of an ultrasonic field transduction technology and an electric field strengthening heat transfer technology.

In order to achieve the above object, the present invention provides a device for enhancing boiling micro-channel heat transfer by applying an ultrasonic field and a linear electrode, comprising a cover plate, a base, a micro-channel plate, a linear electrode enhancing device and an ultrasonic field transducer,

the cover plate is covered and connected on the base to seal the base;

a micro-channel plate mounting position is arranged in the base, and flow stabilizing cavities are arranged in the base and positioned at two sides of the micro-channel plate mounting position;

the micro-channel plate is arranged on the micro-channel plate mounting position, and a plurality of micro-channels are formed in the micro-channel plate;

the linear electrode strengthening device comprises a plurality of electrode wires correspondingly arranged in the plurality of micro channels, and two ends of each electrode wire are respectively used for being connected with the positive electrode and the negative electrode of the power supply;

the two ends of the base, which are positioned in the micro-channel, are equally provided with the ultrasonic field transduction devices, the ultrasonic field transduction devices comprise ultrasonic transducers and vibrating plates, the ultrasonic transducers are used for being connected with an ultrasonic generator, and the ultrasonic transducers are fixed on the vibrating plates.

Furthermore, a window is formed in the cover plate, and a glass plate is arranged on the visual window. The glass plate is arranged, so that the flowing state of the refrigerant in the micro channel can be observed conveniently.

Further, the glass sealing gasket is arranged between the window and the glass plate. The sealing effect is ensured by arranging a glass sealing gasket.

Further, the sealing device also comprises a cover sealing gasket, and the cover sealing gasket is used for being arranged at the covering position of the base and the cover. The sealing effect is ensured by arranging the cover plate sealing washer.

Further, the angle of the ultrasonic transducer in each ultrasonic field transducing device relative to the base is adjustable. Different ultrasonic field environments are realized by adjusting the angle of the ultrasonic transducer.

Furthermore, each ultrasonic field energy conversion device also comprises a fixing plate, the two sides of the vibrating plate are fixed on the base through the fixing plates, and the fixing plates are provided with angle adjusting holes. After the angle of the fixing plate is adjusted, the fixing plate is fixed on the base through the angle adjusting hole, so that the adjusted angle is kept.

Furthermore, an inlet and an outlet temperature measuring holes for installing a temperature sensor are formed in the base and correspond to two ends of the micro channel. Temperature measuring points are arranged at the inlet end and the outlet end of the micro-channel to measure the inlet temperature and the outlet temperature of the refrigeration working medium.

Further, the micro-channel plate material is aluminum alloy.

Further, the micro-channel is rectangular.

Furthermore, a plurality of first temperature measuring holes are formed in the side wall of the micro-channel plate along the length direction, and a plurality of second temperature measuring holes are correspondingly formed in the base at positions corresponding to the first temperature measuring holes. The temperature of the refrigerating working medium along the micro-channel is measured by arranging a temperature measuring point on the micro-channel plate.

Further, the cover plate is made of polytetrafluoroethylene materials.

Further, the heating plate is arranged below the base and corresponds to the position of the micro-channel plate.

By adopting the scheme, the heating power of the device needing heat dissipation is simulated by arranging the heating plate, and the heat flux density of the micro channel is adjusted by arranging different heating powers.

Further, the heating plate is a mica heating plate.

Further, the heating plate is coated with heat conductive silicone grease on the side opposite to the micro-channels to increase the stability of the heat transfer of the channel.

Further, the maximum heating power of the heating plate is 1200W.

Compared with the prior art, the utility model can realize the following beneficial effects:

1. the utility model introduces two active enhanced heat transfer modes of an electric field and a sound field into the micro-channel, the linear electrodes are distributed in the micro-channel, and the frequency and the power can be adjusted by changing the voltage and the sound field generator.

2. The electrode adopts the linear electrode, the distance between the electrode and the micro-channel is small, the relative coverage area is large, and a high-strength electric field can be formed in the local area of the micro-channel under the condition of low voltage.

3. The materials used in the utility model are all common industrial materials, and the price is low; simple structure, processing is convenient, and structural stability is strong.

Drawings

Fig. 1 is a schematic diagram of an exploded view structure of an embodiment of the present invention.

Fig. 2 is a schematic diagram of an installation manner of the ultrasonic transducer according to the embodiment of the utility model.

FIG. 3 is a schematic view of a wire electrode mounting method according to an embodiment of the present invention.

Fig. 4 is a schematic perspective view of a microchannel heat exchange group according to an embodiment of the present invention.

Fig. 5 is a partially enlarged schematic view at a in fig. 4.

Fig. 6 is a schematic perspective view of a base according to an embodiment of the utility model.

FIG. 7 is a front view of a pedestal along a temperature measurement point of an embodiment of the present invention.

Fig. 8 is an assembly schematic of a heat transfer device in an embodiment of the utility model.

Shown in the figure are: 1. a cover plate; 2. fixing screws; 3. a cover plate mounting hole; 4. a glass sealing gasket; 5. a glass plate; 6. a linear electrode reinforcing means; 7. an electrode wire; 8. fastening screws; 9. a fixed block; 10. an ultrasonic field transducing device; 11. an ultrasonic transducer; 12. a positive and negative electrode connecting sheet; 13. mounting screws for the transducer; 14. a transducer fixing device; 15. a microchannel plate; 16. a cover plate sealing gasket; 17. a base; 18. heating plates; 19. a micro channel; 20. a second temperature measuring hole; 21. a vibrating plate; 22. a fixing plate; 23. an angle adjusting hole; 24. a fixing hole; 25. a base mounting hole; 26. a refrigerating working medium inlet and outlet.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the device for enhancing boiling micro-channel heat transfer by applying an ultrasonic field and a linear electrode provided by the utility model is a device for enhancing boiling micro-channel heat transfer by applying an ultrasonic field and a linear electrode to a micro-channel heat exchanger, thereby achieving the effect of composite enhanced heat transfer, and comprises a cover plate 1, a base 17, a micro-channel plate 15, a linear electrode enhancing device 6 and an ultrasonic field transducer 10.

The cover plate 1 is coupled to the base 17 to close the base 17. Referring to fig. 6 and 7, a plurality of base mounting holes 25 are recessed from top to bottom on the contact surface of the base 17 and the cover plate 1, and the cover plate 1 is also correspondingly provided with cover plate mounting holes 3, when mounting, the cover plate mounting holes 3 on the cover plate 1 and the base mounting holes 25 on the base 17 are in one-to-one correspondence, and the cover plate 1 can be fixed on the base 17 by screwing the fixing screws 2.

In one embodiment of the present invention, the base 17 is provided with a refrigerant inlet/outlet 26 at both ends. The refrigerant enters from the refrigerant inlet/outlet 26 at one end and flows out from the refrigerant inlet/outlet 26 at the other end.

In one embodiment of the present invention, the base 17 is provided with a sealing gasket installation groove, and when the base is closed, the sealing gasket 16 is installed in the sealing gasket installation groove to enhance the sealing effect.

In one embodiment of the utility model, the cover plate 1 is made of a polytetrafluoroethylene material.

In the utility model, a window is arranged on the cover plate 1, and a glass plate 5 is arranged on the visual window.

By passing

The glass plate 5 is provided to visualize the apparatus, so that the flow state of the refrigerant in the minute passage can be observed,

in one embodiment of the utility model, a glass sealing gasket 4 is arranged between the window and the glass plate to ensure the sealing effect.

In the utility model, a micro-channel plate mounting position is arranged in a base 17, and flow stabilizing cavities are arranged in the base 17 and positioned at two sides of the micro-channel plate mounting position; the microchannel plate 15 is provided at a microchannel plate mounting position, and a plurality of microchannels 19 are opened in the microchannel plate 15.

Referring to fig. 4 and 5, in one embodiment of the present invention, the microchannel plate 15 has a length of 220mm, a width of 100mm, and a height of 50mm, and is composed of 11 microchannels 19 to form a microchannel group,the micro-channel 19 is rectangular and has a width W_chIs 2mm, height H_chIs 2mm, rib width W_wI.e. the spacing between adjacent microchannels is 4 mm.

In one embodiment of the present invention, the material of the microchannel plate 15 is 6061 aluminum alloy.

In the present invention, the linear electrode strengthening device 6 includes a plurality of electrode wires correspondingly disposed in the plurality of micro channels 19, and two ends of the electrode wires are respectively used for connecting with the positive electrode and the negative electrode of the power supply. Furthermore, each electrode wire 7 is respectively fixed in two steady flow cavities through a fixing block 9, and then a certain length of thin wires are left at the tail parts of the two ends of the electrode wires to penetrate out of the upper hole of the cover plate 1 and are externally connected with the positive electrode and the negative electrode of the high-voltage power supply.

In one embodiment of the present invention, two rows of 3mm electrode wire mounting holes are formed at equal intervals on the upper portion of the fixing block 9, wherein 5 electrode wires are arranged in one row, 6 electrode wires are arranged in the other row, four through holes and an arc hole are respectively formed in the middle portion and the lower portion of the side surface, two ends of each electrode wire 7 are fixed in the corresponding electrode wire mounting holes through fastening screws 8, and each electrode wire 7 with the diameter of 0.2mm is embedded in the middle of the corresponding micro channel 19. The arc hole is used for leading out a positive and negative connecting wire of the ultrasonic transducer from the arc hole and connecting the positive and negative connecting wires with the positive and negative electrodes of an external ultrasonic generator.

In the utility model, the ultrasonic field transducing devices 10 are respectively arranged at two ends of the micro channel in the base 17 to apply inlet and outlet ultrasonic field environments to the micro channel, wherein each ultrasonic field transducing device 10 comprises an ultrasonic transducer 11 and a vibrating plate 21, the ultrasonic transducer 11 is used for being connected with an ultrasonic generator, and the ultrasonic transducer 11 is fixed on the vibrating plate 21.

In one embodiment of the present invention, the ultrasonic transducer 11 has positive and negative connecting pieces 12, which are connected to the positive and negative electrodes by wrapping wires and then led out to be connected to an external ultrasonic generator. In operation, the transducer 11 vibrates, thereby vibrating the vibrating plate 21 to generate ultrasonic waves.

In one embodiment of the present invention, a transducer mounting hole is formed in the middle of the vibration plate 21, and the ultrasonic transducer 11 is fixed to the vibration plate 21 by a transducer mounting screw 13 and the transducer mounting hole.

In one embodiment of the present invention, referring to fig. 2, the angle of the ultrasonic transducer 11 in each ultrasonic field transducing device 10 relative to the base 17 is adjustable, and by adjusting the angle of the ultrasonic transducer, different ultrasonic field environments can be realized. Preferably, each ultrasonic field transducer 10 further includes a fixing plate 22, the fixing plate 22 and the vibrating plate 21 constitute the transducer fixing device 14, in each ultrasonic field transducer 10, there are two fixing plates 22, which are respectively fixed to two sides of the vibrating plate 21, and the fixing plate 22 is provided with a fixing hole 24 and an angle adjusting hole 24. When the fixing device 14 is installed, the transducer fixing device 14 is preliminarily fixed on the base 17 through the fixing hole 24, and then the fixing hole 24 is rotated to adjust to a desired angle, and then the transducer fixing device 14 is fixed on the base 17 through the angle adjusting hole 24.

In one embodiment of the present invention, an inlet and outlet temperature measuring hole for installing a temperature sensor is opened on the base 17 and corresponding to both ends of the micro channel 19. The inlet temperature and the outlet temperature of the refrigerant are measured by setting temperature measuring points at the inlet and outlet ends of the minute passage 19.

In one embodiment of the utility model, the aperture of the inlet and outlet temperature measuring holes is 15 mm.

In one embodiment of the present invention, a plurality of first temperature measuring holes are formed in the side wall of the microchannel plate 15 along the length direction, and a plurality of second temperature measuring holes 20 are correspondingly formed in the base 17 at positions corresponding to the first temperature measuring holes. The temperature measuring points are arranged at the positions corresponding to the micro-channel plates to measure the temperature of the refrigerant along the micro-channel, and the temperature measuring points are arranged along the length direction to calculate the heat transfer coefficient along the micro-channel according to the measured temperature value.

In one embodiment of the utility model, the first and second temperature measuring holes 20 have a hole diameter of 15 mm.

In one embodiment of the utility model, the temperature sensor used for temperature measurement is a WRNK-191K armored thermocouple.

In one embodiment of the present invention, please refer to fig. 8, which further includes a heating plate 18, wherein the heating plate 18 is disposed below the base 17 and directly below the microchannel plate 15. The heating power of the components is simulated by arranging the heating plate.

In one embodiment of the utility model, the heating plate is coated with a layer of heat conductive silicone grease on the side opposite to the micro-channels to increase the stability of heat transfer.

In one embodiment of the present invention, the maximum heating power of the heating plate 18 is 1200W.

When the heat transfer device provided by the utility model is used, a refrigerant enters the heat transfer device through a refrigerating working medium inlet/outlet 26 at one end of the device, flows through a steady flow cavity and then enters a micro channel 19, the refrigerant continuously absorbs heat from a heating plate 18 in the flowing process of the refrigerant in the micro channel 19 (when the heat is radiated for an actual device needing to be radiated, the heating plate is not arranged in the heat transfer device, but the device needing to be radiated is arranged below a micro channel plate, the refrigerant continuously absorbs the heat from the device needing to be radiated), the temperature gradually rises, when the saturated temperature under a certain pressure condition is reached (the pressure condition is not fixed, and the pressure of the refrigerant at different positions in the micro channel under different working conditions is different), the refrigerant gradually boils to generate bubbles (which are gas-liquid mixed working media), the more the absorbed heat is, and the more bubbles are generated, when the gas-liquid mixed working media flow, under the effect of the high pressure that the electrode line 7 that switches on the power supply produced and the sound field that the ultrasonic wave produced, the bubble receives extremely strong electric field force effect and Bjerknes power for the miniature bubble is oppressed after growing gradually for the small bubble and is shaken on the heat transfer wall, the quantity of bubble has been increased, the reunion degree of bubble is further aggravated, thereby the interact between the bubble is bigger, make the heat transfer capacity of microchannel further strengthen, heat transfer performance is very good.

The above examples of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A kind of external ultrasonic field and linear electrode strengthen the tiny channel heat transfer device of boiling, characterized by that: comprises a cover plate (1), a base (17), a micro-channel plate (15), a linear electrode strengthening device (6) and an ultrasonic field transduction device (10),

the cover plate (1) is covered and connected on the base (17) to seal the base (17);

a micro-channel plate mounting position is arranged in the base (17), and flow stabilizing cavities are arranged in the base (17) and positioned at two sides of the micro-channel plate mounting position;

the micro-channel plate (15) is arranged on the micro-channel plate mounting position, and a plurality of micro-channels (19) are formed in the micro-channel plate (15);

the linear electrode strengthening device (6) comprises a plurality of electrode wires (7) which are correspondingly arranged in a plurality of micro channels (19), and two ends of each electrode wire are respectively used for being connected with the positive electrode and the negative electrode of a power supply;

the two ends of the base (17) and the two ends of the micro channel are respectively provided with the ultrasonic field transduction device (10), the ultrasonic field transduction device (10) comprises an ultrasonic transducer (11) and a vibrating plate (21), the ultrasonic transducer (11) is connected with an ultrasonic generator, and the ultrasonic transducer (11) is fixed on the vibrating plate (21).

2. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: a window is arranged on the cover plate (1), and a glass plate (5) is arranged on the visual window.

3. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode as claimed in claim 2, wherein: the glass sealing gasket (4) is further included, and the glass sealing gasket (4) is arranged between the window and the glass plate (5).

4. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: the sealing device further comprises a cover sealing gasket (16), and the cover sealing gasket (16) is arranged at the covering position of the base (17) and the cover plate (1).

5. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: the angle of the ultrasonic transducer (11) in each ultrasonic field transducing device (10) relative to the base (17) is adjustable.

6. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode as claimed in claim 5, wherein: each ultrasonic field transducer (10) further comprises a fixing plate (22), the two sides of the vibrating plate (21) are fixed on the base (17) through the fixing plates (22), and the fixing plates (22) are provided with angle adjusting holes (23).

7. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: an inlet and outlet temperature measuring hole for installing a temperature sensor is formed in the base (17) and corresponds to two ends of the micro channel (19).

8. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: a plurality of first temperature measuring holes are formed in the side wall of the micro-channel plate (15) along the length direction, and a plurality of second temperature measuring holes (20) are correspondingly formed in the positions, corresponding to the first temperature measuring holes, on the base (17).

9. The device for enhancing the boiling micro-channel heat transfer by the external ultrasonic field and the linear electrode according to claim 1, is characterized in that: the cover plate (1) is made of polytetrafluoroethylene materials.

10. The device for enhancing the boiling microchannel heat transfer by applying the ultrasonic field and the linear electrode according to any one of claims 1 to 9, wherein: the device also comprises a heating plate (18), wherein the heating plate (18) is positioned below the base (17) and corresponds to the position of the micro-channel plate (15).