Condensation enhancing heat exchange device based on acoustic wave excitation liquid drop vibration falling

Abstract

The invention relates to an enhanced condensation heat exchange device based on vibration and falling of liquid drops excited by sound waves, and belongs to the technical field of radiators. The device comprises a condenser, a connecting piece and a sound wave generator, and micro-columns distributed in an array mode are arranged on the surface of the condenser; the sound wave generator comprises a sound wave generator bottom plate and sound production sources evenly arranged on the sound wave generator bottom plate, the two sides of the condenser are connected with the sound wave generator bottom plate through connecting pieces, and the top end face of the micro column directly faces the sound wave generator. The condenser adjusts the distance from the top end face of the micro-column to the sound source through the connecting piece. Liquid condensed at the top end of the micro-column rapidly falls off through sound wave excitation, thermal resistance is reduced, and heat exchange efficiency is enhanced; the purpose of strengthening condensation heat exchange is achieved by changing the surface structure of a traditional condenser and utilizing sound wave excitation to thin a liquid film, the problem that the heat transfer efficiency of the traditional condenser is limited due to the fact that the liquid film is formed on the surface in the heat exchange process can be effectively solved, and then the overall energy efficiency utilization is improved.

Description

Technical Field

[0001] The invention relates to an enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding, belonging to the technical field of radiators. Background Art

[0002] As an important component of the refrigeration system, the main function of the condenser is to cool the gas and convert it into liquid form. There are generally two forms of condensation heat transfer: film condensation and bead condensation. The heat transfer coefficient of bead condensation is much larger than that of film condensation. This is because during bead condensation, part of the solid wall surface is occupied by liquid beads and part is exposed to the steam. Therefore, the heat exchange is carried out between the steam and the liquid bead surface and between the steam and the exposed wall. Since the surface area of ​​the liquid bead is much larger than the surface area of ​​the wall it occupies, and there is no thermal resistance formed by the liquid film on the exposed wall, the heat transfer coefficient of bead condensation is large, which is more than ten times that of film condensation. In contrast, during film condensation, there is a layer of liquid film between the steam and the wall. The phase change heat (latent heat) released by condensation must pass through the liquid film to be transferred to the cooling wall surface. Since the presence of the liquid film increases the thermal resistance, the heat transfer coefficient is small. Although the heat transfer effect of bead condensation is better, it is difficult to apply in engineering due to its instability, so film condensation is mostly encountered in industrial equipment. In traditional condensers, the gradual increase in liquid film thickness will reduce the heat exchange efficiency. Therefore, after the saturated steam condenses on the condenser surface, the condensed droplets need to fall off quickly to reduce thermal resistance and improve heat exchange efficiency. Summary of the invention

[0003] In order to solve the problem that liquid film is formed on the surface of the condenser during operation, which affects the heat transfer efficiency, the present invention proposes an enhanced condensation heat exchange device based on acoustic wave-stimulated droplet vibration shedding. The present invention can make the liquid condensed on the top of the microcolumn fall off quickly through acoustic wave excitation, reduce thermal resistance, and further enhance the heat exchange efficiency. By changing the surface structure of the traditional condenser and using acoustic wave excitation to thin the liquid film, the purpose of enhancing condensation heat exchange is achieved, which can effectively solve the problem that the heat transfer efficiency of the traditional condenser is restricted by the formation of liquid film on the surface during the heat exchange process, thereby improving the overall energy efficiency.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A device for enhancing condensation heat exchange based on acoustic wave-induced droplet vibration shedding comprises a condenser 1, a connector 2 and an acoustic wave generator.

[0006] The surface of the condenser 1 is provided with micro-pillars 5 distributed in an array, and the heat exchange surface of the condenser 1 is a hydrophobic surface;

[0007] The acoustic wave generator comprises an acoustic wave generator bottom plate 3 and a sound source 4 evenly arranged on the acoustic wave generator bottom plate 3. Both sides of the condenser 1 are connected to the acoustic wave generator bottom plate 3 through a connector 2. The top end surface of the microcolumn 5 faces the acoustic wave generator. The acoustic wave generator bottom plate 3 is used to integrate the sound source 4 to ensure the effectiveness and stability of acoustic wave transmission.

[0008] The condenser 1 adjusts the distance from the top surface of the microcolumn 5 to the sound source 4 through the connecting piece 2 .

[0009] Preferably, the sound source 4 includes a shell 4-1, an iron core 4-2, a magnet 4-3, a gasket 4-4, an elastic sheet 4-5, a coil 4-6, a diaphragm 4-7, and a dust cover 4-8. The shell 4-1 includes a shell bottom plate and a shell side plate vertically fixedly arranged at the edge of the shell bottom. The shell bottom plate is fixedly arranged on the sound wave generator bottom plate 3. The iron core 4-2 includes an iron core bottom and an iron core rod vertically arranged at the center of the iron core bottom. The iron core bottom is fixedly arranged on the shell bottom plate of the shell 4-1. The magnet 4-3 is arranged at the edge of the bottom of the iron core to form a magnet cylinder, which is concentric with the iron core rod, the coil 4-6 is wound on the iron core rod, the diaphragm 4-7 is arranged just above the iron core rod, one end of the elastic sheet 4-5 connects the coil 4-6 and the diaphragm 4-7, the other end of the elastic sheet 4-5 is fixed to the inner wall of the shell 4-1 through two upper and lower gaskets 4-4, and the dust cover 4-8 is fixed just above the diaphragm 4-7 and the dust cover 4-8 is connected to the top of the inner wall of the shell 4-1. The iron core rod at the center of the iron core 4-2 is the carrier of the coil 4-6, the magnet 4-3 cooperates with the electromagnetic coil 4-6, the elastic sheet 4-5 vibrates under the action of magnetic force, the coil 4-6 generates a magnetic field when it is energized, and the magnetic field generated by the coil 4-6 interacts with the magnet 4-3 to generate a vibration force, so that the diaphragm 4-7 vibrates and emits sound waves of a preset frequency; the dust cover 4-8 can protect the internal parts of the shell 4-1 of the sound source 4 from external pollution.

[0010] The magnet 4-3 is preferably a high-strength neodymium iron boron magnet to ensure the generation of a strong magnetic field and optimize the generation and propagation of sound waves; ensuring excellent magnetic properties can enhance the intensity of sound waves, which can more effectively stimulate droplet shedding.

[0011] The elastic sheet 4-5 can generate high-frequency vibration under the action of magnetic force, and cooperates with the diaphragm 4-7 to form the main sound-generating component.

[0012] The coils 4-6 are highly conductive coils, preferably copper coils, which are wound around an iron core rod to form a spiral state.

[0013] The dust cover 4-8 is used to protect the internal components of the sound source from external pollution, extend the service life of the equipment, and reduce the performance degradation caused by external interference.

[0014] Preferably, a slideway is provided on the connecting member 2, and sliders are fixedly provided on both sides of the condenser 1, and the sliders are slidably arranged on the slideway to adjust the distance between the condenser 1 and the sound wave generator.

[0015] More preferably, a scale is provided on the slider along the sliding direction, and the scale can facilitate accurate adjustment of the distance between the condenser 1 and the sound wave generator.

[0016] Preferably, the sound wave generator base plate 3 is built with a control circuit of the sound source 4 of the sound wave generator (see Figure 6 ), the control circuit includes a power supply, a sound source 4 of a sound wave generator, a time relay and a switch which are electrically connected in sequence; after the switch is turned on, the time relay opens and closes according to the set time interval to realize the periodic emission of sound waves.

[0017] More preferably, the height of the microcolumn 5 is 30-40 μm, the surface at the top 1 / 4-1 / 3 of the height of the microcolumn 5 is a hydrophilic surface, and the surface at the bottom 2 / 3-3 / 4 of the height of the microcolumn 5 is a hydrophobic surface.

[0018] More preferably, the sound wave frequency is 20kHz to 20MHz, and the intensity is 0.5 to 5W / cm 2 The frequency and intensity of the sound waves can be adjusted according to the specific situation to meet the control needs of liquid films of different thicknesses.

[0019] More preferably, the surface of the shell 4-1 of the sound source 4 is provided with an anti-corrosion coating to extend the service life of the sound source 4. The shell 4-1 is preferably made of aluminum alloy material, which has good thermal conductivity and corrosion resistance.

[0020] Preferably, the distance between adjacent sound sources 4 (such as Figure 5 )for:

[0021]

[0022] Wherein, D is the distance between adjacent sound sources 4, d is the distance from the sound source to the top surface of the microcolumn 5 of the condenser 1, r is the radius of the sound source 4, and θ is the sound wave diffusion angle.

[0023] Beneficial effects of the present invention:

[0024] The present invention has the characteristics of simple structure, low cost, strong adaptability, environmental protection and energy saving. It can address the problem of excessively thick surface liquid film deteriorating heat transfer during the operation of the condenser, and use ultrasonic waves to stimulate the liquid adsorbed on the top of the microcolumn to make it vibrate and fall off, thereby reducing thermal resistance and improving the heat transfer rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding;

[0026] Figure 2 Schematic diagram of the sound source structure;

[0027] Figure 3 Schematic diagram of the microcolumn structure;

[0028] Figure 4 Schematic diagram of acoustic wave-induced droplet shedding;

[0029] Figure 5 Schematic diagram of sound wave diffusion;

[0030] Figure 6 A control circuit for the sound wave generator;

[0031] In the figure, 1-condenser, 2-connector, 3-sound wave generator base plate, 4-sound source, 5-microcolumn, 4-1-housing, 4-2-iron core, 4-3-magnet, 4-4-gasket, 4-5-elastic sheet, 4-6-coil, 4-7-diaphragm, 4-8-dust cover. DETAILED DESCRIPTION

[0032] Below, the technical solutions in the present invention will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments of the present invention. It should be understood that the present invention is not limited to the example embodiments described herein. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0033] Example 1: A device for enhancing condensation heat exchange based on acoustic wave-induced droplet vibration shedding (see Figure 1 ), comprising a condenser 1, a connecting piece 2 and a sound wave generator,

[0034] The surface of the condenser 1 is provided with micro-pillars 5 distributed in an array, and the heat exchange surface of the condenser 1 is a hydrophobic surface;

[0035] The acoustic wave generator comprises an acoustic wave generator bottom plate 3 and a sound source 4 evenly arranged on the acoustic wave generator bottom plate 3. Both sides of the condenser 1 are connected to the acoustic wave generator bottom plate 3 through a connector 2. The top end surface of the microcolumn 5 faces the acoustic wave generator. The acoustic wave generator bottom plate 3 is used to integrate the sound source 4 to ensure the effectiveness and stability of acoustic wave transmission.

[0036] The condenser 1 adjusts the distance between the top surface of the microcolumn 5 and the sound source 4 through the connecting piece 2;

[0037] The height of the micro-pillar 5 is preferably 30 to 40 μm, the surface of the top 1 / 4 to 1 / 3 of the height of the micro-pillar 5 is a hydrophilic surface, and the surface of the bottom 2 / 3 to 3 / 4 of the height of the micro-pillar 5 is a hydrophobic surface (see Figure 3 );

[0038] The frequency of the sound wave is preferably 20kHz to 20MHz, and the intensity is preferably 0.5 to 5W / cm 2 , in order to achieve effective excitation of the liquid film on the surface of the condenser; the frequency and intensity of the sound wave can be adjusted according to the specific situation to meet the control requirements of liquid films of different thicknesses;

[0039] The distance between adjacent sound sources 4 (such as Figure 5 )for:

[0040]

[0041] Wherein, D is the distance between adjacent sound sources 4, d is the distance from the sound source to the top surface of the microcolumn 5 of the condenser 1, r is the radius of the sound source 4, and θ is the sound wave diffusion angle;

[0042] During condensation heat exchange, the working fluid condenses on the surface of the condenser 1 and the micro-column 5 to form droplets. The heat exchange surface of the condenser 1 and the surface at 2 / 3 to 3 / 4 of the height of the bottom of the micro-column 5 are both hydrophobic surfaces. The droplets gather on the hydrophilic surface at the top of the micro-column 5. The sound source 4 of the sound wave generator synchronously emits sound waves of a preset frequency to stimulate and thin the liquid film on the hydrophilic surface at the top of the micro-column 5, causing the droplets to vibrate and fall off, thereby reducing thermal resistance and increasing the heat transfer rate (see Figure 4 ).

[0043] Example 2: The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in this example is basically the same as the enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in Example 1, except that:

[0044] like Figure 2As shown, the sound source 4 includes a shell 4-1, an iron core 4-2, a magnet 4-3, a gasket 4-4, an elastic sheet 4-5, a coil 4-6, a diaphragm 4-7, and a dust cover 4-8. The shell 4-1 includes a shell bottom plate and a shell side plate vertically fixedly arranged at the edge of the shell bottom. The shell bottom plate is fixedly arranged on the sound wave generator bottom plate 3. The iron core 4-2 includes an iron core bottom and an iron core rod vertically arranged at the center of the iron core bottom. The iron core bottom is fixedly arranged on the shell bottom plate of the shell 4-1. The magnet 4-3 is arranged at the edge of the bottom of the iron core to form a magnet cylinder, which is concentric with the iron core rod. The coil 4-6 is wound on the iron core rod, and the diaphragm 4-7 is arranged just above the iron core rod. One end of the elastic sheet 4-5 connects the coil 4-6 and the diaphragm 4-7, and the other end of the elastic sheet 4-5 is fixed to the inner wall of the shell 4-1 through two upper and lower gaskets 4-4. The dust cover 4-8 is fixed just above the diaphragm 4-7 and the dust cover 4-8 is connected to the top of the inner wall of the shell 4-1. The iron core rod at the center of the iron core 4-2 is the carrier of the coil 4-6, the magnet 4-3 cooperates with the electromagnetic coil 4-6, the elastic sheet 4-5 vibrates under the action of magnetic force, and the coil 4-6 generates a magnetic field when it is energized. The magnetic field generated by the coil 4-6 interacts with the magnet 4-3 to generate a vibration force, so that the diaphragm 4-7 vibrates and emits sound waves of a preset frequency; the dust cover 4-8 can protect the internal components of the shell 4-1 of the sound source 4 from external pollution;

[0045] The magnet 4-3 is preferably a high-strength neodymium iron boron magnet to ensure the generation of a strong magnetic field and optimize the generation and propagation of sound waves; ensuring that the excellent magnetic properties can enhance the intensity of the sound waves, so as to more effectively stimulate the droplet to fall off;

[0046] The elastic sheet 4-5 can generate high-frequency vibration under the action of magnetic force, and cooperates with the diaphragm 4-7 to form the main sound-generating component;

[0047] The coils 4-6 are highly conductive coils, preferably copper coils, which are wound around the iron core rod to form a spiral state;

[0048] The dust cover 4-8 is used to protect the internal components of the sound source from external pollution, extend the service life of the equipment, and reduce the performance degradation caused by external interference;

[0049] The surface of the shell 4-1 of the sound source 4 may be provided with an anti-corrosion coating to extend the service life of the sound source 4; the shell 4-1 is preferably made of aluminum alloy material, which has good thermal conductivity and corrosion resistance, enhances the structural strength and durability of the equipment, and also ensures the effective conduction of heat to avoid temperature rise caused by the operation of the sound source.

[0050] Example 3: The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in this example is basically the same as the enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in Example 2, except that:

[0051] The connector 2 is provided with a slideway, and sliders are fixedly provided on both sides of the condenser 1. The sliders are slidably arranged on the slideway to adjust the distance between the condenser 1 and the sound wave generator, thereby ensuring that the control effect of the sound wave on the liquid film is optimized.

[0052] More preferably, a scale is provided on the slider along the sliding direction, and the scale can facilitate accurate adjustment of the distance between the condenser 1 and the sound wave generator.

[0053] Example 4: The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in this example is basically the same as the enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding in Example 3, except that:

[0054] The control circuit of the sound source 4 of the sound wave generator is built in the sound wave generator bottom plate 3 (see Figure 6 ), the control circuit includes a power supply, a sound source 4 of a sound wave generator, a time relay and a switch which are electrically connected in sequence; after the switch is turned on, the time relay opens and closes according to a set time interval to achieve periodic emission of sound waves;

[0055] The control circuit can control the period of the sound waves emitted by the sound source as required, so as to achieve periodic vibration shedding of the droplets on the top of the micro-columns on the surface of the condenser.

[0056] The specific embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. An enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding, characterized in that: It comprises a condenser (1), a connecting piece (2) and a sound wave generator, The surface of the condenser (1) is provided with micro-columns (5) distributed in an array, and the heat exchange surface of the condenser (1) is a hydrophobic surface; The sound wave generator comprises a sound wave generator bottom plate (3) and a sound source (4) evenly arranged on the sound wave generator bottom plate (3); both sides of the condenser (1) are connected to the sound wave generator bottom plate (3) via a connecting piece (2); and the top end surface of the microcolumn (5) faces the sound wave generator; The condenser (1) adjusts the distance from the top end surface of the microcolumn (5) to the sound source (4) through the connecting piece (2).

2. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: The sound source (4) comprises a shell (4-1), an iron core (4-2), a magnet (4-3), a gasket (4-4), an elastic sheet (4-5), a coil (4-6), a diaphragm (4-7), and a dust cover (4-8); the shell (4-1) comprises a shell bottom plate and a shell side plate vertically fixedly arranged at the edge of the shell bottom; the shell bottom plate is fixedly arranged on the sound wave generator bottom plate (3); the iron core (4-2) comprises an iron core bottom and an iron core rod vertically arranged at the center of the iron core bottom; the iron core bottom is fixedly arranged on the shell bottom plate of the shell (4-1); the magnet (4-3) is arranged at the edge of the bottom of the iron core to form a magnet cylinder, the magnet cylinder is cocentric with the iron core rod, the coil (4-6) is wound on the iron core rod, the diaphragm (4-7) is arranged just above the iron core rod, one end of the elastic sheet (4-5) connects the coil (4-6) and the diaphragm (4-7), the other end of the elastic sheet (4-5) is fixed to the inner wall of the shell (4-1) through two upper and lower gaskets (4-4), and the dust cover (4-8) is fixedly arranged just above the diaphragm (4-7) and the dust cover (4-8) is connected to the top of the inner wall of the shell (4-1).

3. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: A slideway is provided on the connecting member (2), and sliding blocks are fixedly provided on both sides of the condenser (1), and the sliding blocks are slidably arranged on the slideway to adjust the distance between the condenser (1) and the sound wave generator.

4. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: The sound wave generator bottom plate (3) has a built-in control circuit for the sound source (4) of the sound wave generator, and the control circuit comprises a power supply, the sound source (4) of the sound wave generator, a time relay and a switch which are electrically connected in sequence.

5. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: The height of the microcolumn (5) is 30 to 40 μm, the surface of the top 1 / 4 to 1 / 3 of the height of the microcolumn (5) is a hydrophilic surface, and the surface of the bottom 2 / 3 to 3 / 4 of the height of the microcolumn (5) is a hydrophobic surface.

6. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: The sound wave frequency is 20kHz~20MHz.

7. The enhanced condensation heat exchange device based on acoustic wave-induced droplet vibration shedding according to claim 1 is characterized in that: The distance between adjacent sound sources (4) is: Wherein, D is the distance between adjacent sound sources (4), d is the distance from the sound source to the top surface of the microcolumn (5) of the condenser (1), r is the radius of the sound source (4), and θ is the sound wave diffusion angle.

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