A pool boiling experimental system

Abstract

The utility model relates to the technical field of pool boiling experiment device, disclose a kind of pool boiling experiment system, comprising: boiling pool device and acoustic wave generating device, boiling pool device includes pool body, and pool body is filled with working medium, and working medium is placed with test piece, and the chip of fixed connection direct current is on test piece;Sound generating device includes power supply and piezoelectric ceramic piece connected with it, piezoelectric ceramic piece is fixedly connected to the top of test piece, and chip is exposed in working medium, and the density of piezoelectric ceramic piece and test piece is greater than the density of working medium;Limiting structure is also connected in pool body, and limiting structure is connected with test piece, to limit the displacement amount of test piece in horizontal direction in pool body.The utility model uses small power, and the piezoelectric ceramic piece of smaller volume realizes heat exchange strengthening, does not need special structure, and small power can realize greater chip temperature reduction and critical heat flux density higher, i.

Description

Technical Field

[0001] This utility model relates to the technical field of pool boiling experimental devices, and in particular to a pool boiling experimental system. Background Technology

[0002] With the rapid development of semiconductor technology, the integration level and performance of integrated circuit (IC) chips continue to improve, while chip size continues to shrink to meet the demands of thinner, lighter, higher-performance, and lower-power electronic devices. In highly integrated chips, the power density per unit area increases dramatically, and excessively high temperatures can degrade chip performance and reliability. Pool boiling tests are widely used to measure the two-phase heat transfer characteristics of chips.

[0003] Pool boiling experiments involve immersing a chip in a highly insulating, low-boiling-point working fluid, causing a phase transition at the heat source surface. A significant amount of heat is dissipated through the latent heat of this phase transition, thus achieving a cooling effect. To enhance and control boiling heat transfer, many researchers use active methods such as electric fields, magnetic fields, and acoustic fields to modulate the pool boiling effect.

[0004] A typical boiling experimental system that can realize surface acoustic wave effects usually includes a boiling pool device, an acoustic wave generator, a cooling circulation device, and a data acquisition device. The acoustic wave generator relies heavily on a high-power ultrasonic transducer, which is bulky and generates significant heat. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a pool boiling experimental system that can reduce the overall size and power of the device.

[0006] This utility model provides a boiling test system, including: a boiling pool device and a sound wave generating device. The boiling pool device includes a pool body containing a working medium, and a test piece placed inside the working medium. A chip connected to a direct current is fixed on the test piece. The sound wave generating device includes a power supply and a piezoelectric ceramic sheet connected to it. The piezoelectric ceramic sheet is fixed to the top of the test piece, and the chip is exposed in the working medium. The density of the piezoelectric ceramic sheet and the test piece is greater than the density of the working medium. A limiting structure is also connected inside the pool body. The limiting structure is connected to the test piece to limit the horizontal displacement of the test piece inside the pool body.

[0007] Optionally, the limiting structure includes multiple limiting bolts fixed in the pool body. Both sides of the test piece extend out of the piezoelectric ceramic sheet. Multiple limiting holes are opened on one side of the test piece extending out of the piezoelectric ceramic sheet. The diameter of the limiting hole is larger than the diameter of the limiting bolt. The limiting bolts are inserted into the limiting holes one by one. The chip is fixed on the other side of the test piece extending out of the piezoelectric ceramic sheet.

[0008] Optionally, the limiting structure includes multiple traction wires, one end of which is fixed to the perimeter of the test piece, and the other end extends out of the pool body.

[0009] Optionally, the limiting structure includes a limiting groove formed in the pool body, the inner dimension of the limiting groove being larger than the outer dimension of the test piece, and the test piece being located inside the limiting groove.

[0010] Optionally, the test chip has a placement slot and a through hole. The through hole passes through the test chip and communicates with the placement slot. The chip is fixed in the placement slot, and the wires connected to the chip extend out of the test chip through the through hole.

[0011] Optionally, the chip is fixed to the placement slot with heat-insulating adhesive.

[0012] Optionally, the piezoelectric ceramic sheet and the test piece are fixed together with adhesive.

[0013] Optionally, the piezoelectric ceramic sheet can be rectangular, circular, annular, semi-annular, or elongated.

[0014] Optionally, a viewing window is provided on the side of the pool.

[0015] Optionally, balloons are attached to the pool.

[0016] The technical solution provided by this utility model has the following advantages compared with the prior art: This utility model provides a pool boiling experimental system that reduces the overall system size by replacing the ultrasonic transducer with a piezoelectric ceramic plate. The piezoelectric ceramic plate is fixed to the top of the test piece, and the chip is fixed on the test piece. By connecting the piezoelectric ceramic plate to a power source, it generates strong acoustic radiation during the boiling process in the pool, allowing the test piece to move with the piezoelectric ceramic plate. The limiting structure prevents the test piece from undergoing large horizontal displacement or direct flipping due to vibration in the pool, without affecting the vibration effect. This promotes the rapid detachment and migration of bubbles on the chip surface, reduces the bubble size, and decreases the possibility of bubble aggregation, thereby changing the mode of acoustic wave action. Furthermore, at the same power, the chip surface temperature is lower, enhancing the cooling effect at lower power. Therefore, the improved bubble behavior enhances heat transfer performance, manifested as an increase in maximum power and a higher heat transfer coefficient. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a pool boiling experimental system provided in this embodiment of the present invention; Figure 2 A schematic diagram of the structure of the pool boiling device provided in this embodiment of the utility model; Figure 3 for Figure 2 A cross-sectional view along the GG direction; Figure 4 A top view of the pool boiling device provided in an embodiment of this utility model.

[0018] Explanation of reference numerals in the attached figures: 1. Low-temperature constant temperature cold water bath; 2. First thermocouple; 3. High-speed camera; 4. First signal generator; 5. Second signal generator; 6. Viewing window; 7. DC power supply; 8. Heating rod; 9. Data acquisition unit; 10. Light source; 11. Computer; 12. Balloon; 13. Second thermocouple; 14. Condenser; 15. Liquid inlet; 16. Liquid outlet; 17. Limit bolt; 18. Copper double-ended bolt; 19. Chip; 20. Test piece; 21. Piezoelectric ceramic sheet. Detailed Implementation

[0019] The following describes a specific embodiment of the present invention in detail with reference to the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0020] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and components may be omitted. When any component of an embodiment of the present invention appears in more than one drawing, the component may be represented by the same reference numerals in each drawing.

[0022] Traditional passive enhanced boiling heat transfer methods typically employ alterations to the heating surface structure (adding micron-sized pillars or depositing nanoscale structures) and the working fluid properties (such as using nanofluids). These methods suffer from drawbacks such as difficulty in fabrication (micro / nano structures are difficult to fabricate), high cost (the difficulty in fabrication determines the high price), unstable performance (different tolerances and deposition methods lead to performance variations), and increased flow resistance (surface structure can cause fluidization of the working fluid). However, they are effective in increasing the critical heat flux density and reducing surface temperature. Acoustic waves, with their low cost, ease of use, flexible control, strong penetration, and pollution-free characteristics, play an important role in materials science, defense and transportation, as well as medical diagnostics and environmental fields. As an active enhanced heat transfer technology, acoustic waves allow for precise control of the heat transfer process. For example, by changing the operating position and direction of the acoustic transducer, the heat transfer performance of a specific area can be adjusted; by applying different operating voltages and frequencies, the heat exchange rate can be controlled; and by adjusting the number and type of acoustic transducers, different heat sinks can be thermally managed. Therefore, they are gradually attracting the attention and importance of researchers. Currently, the combination of acoustic waves and heat dissipation technology can effectively enhance single-phase convection and boiling heat transfer processes, becoming an important approach to solving the heat dissipation and cooling problems of microelectronic devices. Current acoustic wave-enhanced heat transfer mainly uses high-power acoustic transducers. The transducers themselves also generate heat, and compared to the heat source's own heating power, the transducer's heating power is not negligible.

[0023] Based on the above issues, refer to Figure 1 , Figure 2 and Figure 3 As shown, where, Figure 1 This is a schematic diagram of the structure of a pool boiling experimental system provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of the pool boiling device provided in an embodiment of the present invention. Figure 3 for Figure 2 A cross-sectional view along the GG direction, such as Figure 1 , Figure 2 and Figure 3 As shown, this utility model embodiment provides a boiling test system, including: a boiling pool device and a sound wave generating device. The boiling pool device includes a pool body made of PMMA (plexiglass), which contains a working medium. A test piece 20 is placed inside the working medium, and a chip 19 connected to a direct current is fixed on the test piece 20. The sound wave generating device includes a power supply and a piezoelectric ceramic sheet 21 connected to it. The piezoelectric ceramic sheet 21 is fixed to the top of the test piece 20, and the chip 19 is exposed in the working medium. The density of the piezoelectric ceramic sheet 21 and the test piece 20 is greater than the density of the working medium. A limiting structure is also connected inside the pool. The limiting structure is connected to the test piece 20 to limit the horizontal displacement of the test piece 20 inside the pool. The limiting structure is characterized by not completely fixing the chip 19, so that it can vibrate fully under the action of the sound wave, thereby accelerating the release of bubbles.

[0024] This utility model provides a pool boiling experimental system that reduces the overall system size by replacing the ultrasonic transducer with a piezoelectric ceramic plate. The piezoelectric ceramic plate is fixed to the top of the test piece, and the chip is fixed on the test piece. By connecting the piezoelectric ceramic plate to a power source, it generates strong acoustic radiation during the boiling process in the pool, allowing the test piece to move with the piezoelectric ceramic plate. The limiting structure prevents the test piece from undergoing large horizontal displacement or direct flipping due to vibration in the pool, without affecting the vibration effect. This promotes the rapid detachment and migration of bubbles on the chip surface, reduces the bubble size, and decreases the possibility of bubble aggregation, thereby changing the mode of acoustic wave action. Furthermore, at the same power, the chip surface temperature is lower, enhancing the cooling effect at lower power. Therefore, the improved bubble behavior enhances heat transfer performance, manifested as an increase in maximum power and a higher heat transfer coefficient.

[0025] Specifically, the entire experimental system is as follows: Figure 1 As shown, it includes a pool boiling device, a sound wave generator, a cooling device, and a testing device, such as... Figure 2 and Figure 3 As shown, the boiling device also includes a DC power supply 7, a heating rod 8, a liquid inlet 15, a liquid outlet 16, and a copper double-ended bolt 18. The heating rod 8 is used to heat the working medium when the temperature in the pool is too low. The liquid inlet 15 is used to add the working medium used in the boiling pool. The liquid outlet 16 is used to remove the working medium from the pool after the experiment. Copper wires are soldered on the chip 19. The chip 19 is connected to the test chip 20. The DC power supply 7 supplies power to the chip 19 through the copper double-ended bolt 18.

[0026] The sound wave generating device also includes a first signal generator 4 and a second signal amplifier 5. The electrodes of the piezoelectric ceramic sheet 21 are connected to the first signal generator 4 and the second signal amplifier 5 through copper wires and copper double-headed bolts 18. Both the first signal generator 4 and the second signal amplifier 5 are connected to an external power supply, so that the piezoelectric ceramic sheet 21 generates sound waves.

[0027] The cooling device includes a condenser tube 14 and a low-temperature constant-temperature cold water bath 1, which are connected by a rubber tube. The condenser tube 14 is connected to the pool body. When the chip 19 is heated, the cooling medium in the condenser tube 14 (copper tube) is cooled in the low-temperature constant-temperature cold water bath 1. The condenser tube 14 is used to maintain a constant temperature in the pool body and keep the working medium temperature constant.

[0028] The testing device includes a first thermocouple 2, a second thermocouple 13, a data acquisition unit 9, and a computer 11. Both the first thermocouple 2 and the second thermocouple 13 are K-type thermocouples. The second thermocouple 13 is used to measure the temperature of the working fluid in the cell. The data acquisition unit 9 collects the temperature of the working fluid body, the temperature of the bottom surface of the chip 19, the current, and the voltage, and inputs the data into the computer 11 for recording.

[0029] This utility model provides a pool boiling experimental system that reduces the overall system size by replacing the ultrasonic transducer with a piezoelectric ceramic plate. The piezoelectric ceramic plate is fixed to the top of the test piece, and the chip is fixed on the test piece. By connecting the piezoelectric ceramic plate to a power source, it generates strong acoustic radiation during the boiling process in the pool, allowing the test piece to move with the piezoelectric ceramic plate. The limiting structure prevents the test piece from undergoing large horizontal displacement or direct flipping due to vibration in the pool, without affecting the vibration effect. This promotes the rapid detachment and migration of bubbles on the chip surface, reduces the size of the bubbles, and also reduces the possibility of bubble aggregation, thereby changing the mode of acoustic wave action. Furthermore, at the same power, the chip surface temperature is lower, enhancing the cooling effect at lower power. Therefore, the improved bubble behavior enhances the heat transfer performance, manifested as an increase in CHF (chip maximum heat flux density) and a decrease in chip surface temperature.

[0030] refer to Figure 4 , Figure 4 A top view of the pool boiling device provided in an embodiment of this utility model, as shown below. Figure 4 As shown, the limiting structure includes multiple limiting bolts 17 fixed in the pool body. Both sides of the test piece 20 extend out from the piezoelectric ceramic sheet 21. Multiple limiting holes are opened on one side of the test piece 20 extending out from the piezoelectric ceramic sheet 21. The diameter of the limiting hole is larger than the diameter of the limiting bolt 17. The limiting bolt 17 is inserted into the limiting hole one by one. The chip 19 is fixed on the other side of the test piece 20 extending out from the piezoelectric ceramic sheet 21. The hole of the limiting bolt 17 that mates with the test piece 20 is larger than the diameter of the limiting bolt 17, so that the test piece 20 can move with the piezoelectric ceramic sheet 21. The function of the limiting bolt 17 is to prevent the test piece 20 from undergoing large horizontal displacement or direct flipping in the pool body due to vibration.

[0031] As an alternative, the limiting structure includes multiple traction wires, which can be made of natural fibers, synthetic fibers, or metal wires. One end of each traction wire is fixed around the test piece 20, and the other end extends out of the pool body.

[0032] As an alternative, the limiting structure includes a limiting groove formed in the pool body, the inner dimension of the limiting groove being larger than the outer dimension of the test piece 20, and the test piece 20 being located within the limiting groove.

[0033] Optionally, the test piece 20 has a placement slot and a through hole. The through hole passes through the test piece 20 and communicates with the placement slot. The chip 19 is fixed in the placement slot, and the wires connected to the chip 19 extend out of the test piece 20 through the through hole.

[0034] Optionally, the chip 19 is fixed to the placement slot with thermally insulating adhesive to reduce heat loss and obtain the chip's heat transfer characteristics more accurately.

[0035] Optionally, the piezoelectric ceramic sheet 21 and the test piece 20 are fixed together with adhesive.

[0036] Optionally, the piezoelectric ceramic sheet 21 can be rectangular, circular, annular, semi-annular, or elongated, and different shapes can exert different forces on the bubbles.

[0037] Optionally, a viewing window 6 is provided on the side of the pool body for observing the boiling situation on the boiling surface. In addition, the pool boiling device is also equipped with a high-speed camera 3 and a light source 10. The viewing window 6 can also be used by the high-speed camera 3 to observe the bubble phenomenon, and the light source 10 is used for supplementary lighting for shooting.

[0038] Optionally, a balloon 12 is connected to the pool body. The balloon 12 is used to maintain a constant internal pressure in the pool body, close to atmospheric pressure.

[0039] This invention uses a low-power, small-volume piezoelectric ceramic sheet to achieve enhanced heat transfer. It does not require a special structure and can achieve a large reduction in chip temperature and a higher critical heat flux density with low power (i.e., electronic devices can operate at higher power and lower surface temperature).

[0040] The above-described embodiments are merely a few specific examples of this utility model. However, the embodiments of this utility model are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of this utility model.

Claims

1. A pool boiling experimental system, characterized in that, include: A boiling pool device and a sound wave generating device, wherein the boiling pool device includes a pool body, the pool body contains a working medium, a test piece (20) is placed in the working medium, and a chip (19) connected to direct current is fixed on the test piece (20). The acoustic wave generating device includes a power supply and a piezoelectric ceramic sheet (21) connected thereto. The piezoelectric ceramic sheet (21) is fixed to the top of the test piece (20), and the chip (19) is exposed in the working medium. The density of the piezoelectric ceramic sheet (21) and the test piece (20) is greater than the density of the working medium. The pool body is also connected to a limiting structure, which is connected to the test piece (20) to limit the horizontal displacement of the test piece (20) in the pool body.

2. The pool boiling experimental system as described in claim 1, characterized in that, The limiting structure includes multiple limiting bolts (17) fixed in the pool body. Both sides of the test piece (20) extend out of the piezoelectric ceramic sheet (21). Multiple limiting holes are opened on one side of the test piece (20) extending out of the piezoelectric ceramic sheet (21). The diameter of the limiting hole is larger than the diameter of the limiting bolt (17). The limiting bolt (17) is inserted into the limiting hole one by one. A chip (19) is fixed on the other side of the test piece (20) extending out of the piezoelectric ceramic sheet (21).

3. The pool boiling experimental system as described in claim 1, characterized in that, The limiting structure includes multiple traction wires, one end of which is fixed around the test piece (20), and the other end extends out of the pool body.

4. The pool boiling experimental system as described in claim 1, characterized in that, The limiting structure includes a limiting groove formed in the pool body, the inner dimension of the limiting groove being larger than the outer dimension of the test piece (20), and the test piece (20) being located in the limiting groove.

5. The pool boiling experimental system as described in claim 1, characterized in that, The test piece (20) has a placement slot and a through hole. The through hole passes through the test piece (20) and communicates with the placement slot. The chip (19) is fixed in the placement slot. The wires connected to the chip (19) extend out of the test piece (20) through the through hole.

6. The pool boiling experimental system as described in claim 5, characterized in that, The chip (19) is fixed to the placement slot by heat-insulating adhesive.

7. The pool boiling experimental system as described in claim 1, characterized in that, The piezoelectric ceramic sheet (21) and the test piece (20) are fixed together with glue.

8. The pool boiling experimental system as described in claim 1, characterized in that, The piezoelectric ceramic sheet (21) is in the shape of one of the following: rectangular, circular, annular, semi-annular, or elongated.

9. The pool boiling experimental system as described in claim 1, characterized in that, A viewing window (6) is provided on the side of the pool.

10. The pool boiling experimental system as described in claim 1, characterized in that, A balloon (12) is attached to the pool.

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