Highly integrated continuous droplet micro heat exchanger

Abstract

The application discloses a high-integration continuous liquid drop type micro heat exchanger, which comprises a water storage tank assembly and a cooling chamber assembly installed at one end of the water storage tank assembly; the water storage tank assembly is connected with an external injection pump to introduce fluid into the water storage tank; the outlet pipeline end of the water storage tank of the water storage tank assembly is provided with a jet orifice plate, and the surface of the jet orifice plate is uniformly provided with jet orifices; a piezoelectric element is installed on the side surface of the outlet pipeline of the water storage tank, and a piezoelectric ceramic is installed on the side surface outside the water storage tank; a chip support is installed at the end of the cooling chamber assembly away from the water storage tank, and a heating chip is embedded in the chip support. The micro heat exchanger realizes a micro high-liquid-drop-flux piezoelectric liquid drop generator, combines the liquid drop generator with a micro chip to form an applicable micro heat exchanger, and realizes efficient cooling in a narrow environment.

Description

Technical Field

[0001] This invention relates to the field of liquid microfluidics, and in particular to a highly integrated continuous droplet micro heat exchanger. Background Technology

[0002] Microfluidics refers to the precise control and manipulation of microscale fluids. Because its applications involve micro- and nano-scale structures, fluids exhibit unique properties within these structures that differ from their macroscopic counterparts, necessitating the analysis of their distinctive physicochemical properties. For the preparation of uniform microdroplets, high-precision, highly regular monodisperse droplet strings hold great promise in chemical, food, inkjet printing, and medical fields. However, precisely controlling the flow rate and regularity of these droplets remains a challenge in these applications. Furthermore, as applications become more sophisticated, efficiently and rapidly preparing microdroplets to meet diverse needs is also a current focus.

[0003] Currently, some devices, both domestically and internationally, can generate uniform droplet sequences, but most droplet generators suffer from poor accuracy and limited quantity. Furthermore, typical piezoelectric droplet generators employ a method of separating the fluid chamber, nozzle, piezoelectric module, and BNC connector, combined with mechanical means, to produce continuous monodisperse droplets. Because the main components are not integrated, the devices are complex, require significant space, are cumbersome to use, and have poor commercial viability. Moreover, there are no continuous droplet micro heat exchangers available.

[0004] Therefore, based on the above-mentioned technical problems, those skilled in the art urgently need to develop a highly integrated continuous droplet micro heat exchanger. Summary of the Invention

[0005] The purpose of this invention is to provide a highly integrated continuous droplet micro heat exchanger. This structure combines the advantages of traditional jet and spray cooling, solves the problem of large space occupation of traditional structures, and meets the high precision requirements of microdroplets.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The present invention discloses a highly integrated continuous droplet micro heat exchanger, the micro heat exchanger comprising:

[0008] Water storage tank assembly; and

[0009] A cooling chamber assembly installed at one end of the water storage tank assembly;

[0010] The water storage tank assembly is connected to an external injection pump to introduce fluid into the water storage tank. The outlet pipe end of the water storage tank assembly is equipped with a jet orifice plate, and jet orifice plates are uniformly formed on the surface of the jet orifice plate.

[0011] A piezoelectric element is installed on the side of the outlet pipe of the water storage tank, and a piezoelectric ceramic is installed on the outer side of the water storage tank.

[0012] A chip bracket is installed at the end of the cooling chamber assembly away from the water storage tank, and a heating chip is embedded in the chip bracket.

[0013] Furthermore, the water storage tank assembly includes:

[0014] A water storage tank, which is fitted with the cooling chamber assembly, has an outlet pipe protruding from one end;

[0015] A water tank cover is installed at the other end of the water tank. The water tank cover is sealed to the water tank by a square sealing gasket, and a water inlet is provided at the center of the water tank cover.

[0016] The water inlet of the water tank cover is threaded with an M10 pagoda connector, and the water inlet is connected to the connection port of the external injection pump via the M10 pagoda connector using a hose.

[0017] Furthermore, the outer wall of the water storage tank has a groove, which is configured as a piezoelectric ceramic groove. The piezoelectric ceramic is embedded in the groove and fixed to the outer wall of the water storage tank by cable ties.

[0018] Furthermore, an orifice plate fixing component is installed at the end of the outlet pipe of the water storage tank. The orifice plate fixing component is provided with a groove that matches the jet orifice plate. The jet orifice plate is embedded in the groove of the orifice plate fixing component and fastened with screws.

[0019] A circular washer is provided at the connection between the jet orifice plate and the outlet pipe.

[0020] Furthermore, the cooling chamber assembly includes:

[0021] The cooling chamber is made of a transparent material;

[0022] A cooling chamber cover fitted to the end of the cooling chamber;

[0023] A gasket is provided between the cooling chamber cover and the cooling chamber, and the chip holder is installed inside the cooling chamber cover and fastened with screws.

[0024] Furthermore, the cooling chamber has a water outlet at the center of its bottom, and the bottom of the cooling chamber is provided with a slope of 5° to 30°, which is inclined toward the water outlet to guide the cooling water to be discharged through the water outlet.

[0025] Furthermore, the thickness of the jet orifice plate is 0.2mm to 0.4mm. The orifice plate is processed by first drilling holes with a micro drill, followed by polishing and plasma cleaning steps, so as to ensure the opening accuracy and roundness of the microholes.

[0026] Furthermore, the piezoelectric ceramic has a reserved electrical signal input terminal, through which a square wave or sine wave control signal amplified by a power amplifier is transmitted to the piezoelectric ceramic to drive the piezoelectric ceramic to generate micron-level vibration.

[0027] The selection of the control circuit and piezoelectric elements for the entire device is a core aspect of this invention. The resonant frequency of the piezoelectric elements must exceed 100kHz, and the output force must exceed 2000N. The driving voltage of such piezoelectric elements is often higher than 100V.

[0028] The highly integrated continuous droplet micro heat exchanger provided by the present invention, as described above, has the following beneficial effects:

[0029] The micro heat exchanger of the present invention realizes a micro high droplet flux piezoelectric droplet generator, which combines the droplet generator with a microchip to form an applicable micro heat exchanger, achieving efficient cooling in confined environments. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0031] Figure 1 This is an exploded view of the highly integrated continuous droplet micro heat exchanger disclosed in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the highly integrated continuous droplet micro heat exchanger disclosed in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of droplet generation in a highly integrated continuous droplet micro heat exchanger disclosed in an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Water tank assembly; 2. Cooling chamber assembly; 3. Piezoelectric element; 4. Washer;

[0036] 101. Water storage tank; 102. Water storage tank cover; 103. Water inlet; 104. Orifice plate fixing component; 105. Jet orifice plate; 106. Circular washer; 107. Square sealing washer; 108. Groove; 109. Outlet pipe;

[0037] 201. Cooling chamber; 202. Cooling chamber cover; 203. Chip holder; 204. Water outlet; 205. Pressure relief valve; 206. Slope. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] See Figures 1 to 3 As shown;

[0040] This embodiment provides a highly integrated continuous droplet micro heat exchanger, which includes:

[0041] Water storage tank assembly 1; and

[0042] Cooling chamber assembly 2 is installed at one end of water storage tank assembly 1;

[0043] The water storage tank assembly 1 is connected to an external injection pump to introduce fluid into the water storage tank 101. The outlet pipe 109 of the water storage tank 101 of the water storage tank assembly 1 is equipped with a jet orifice plate 105, and jet orifice plates 105 are uniformly provided on the surface of the jet orifice plate 105.

[0044] A piezoelectric element 3 is installed on the side of the outlet pipe 109 of the water storage tank 101, and a piezoelectric ceramic is installed on the outside side of the water storage tank 101.

[0045] A chip holder 203 is installed at the end of the cooling chamber assembly 2 away from the water storage tank 101, and a heating chip is embedded in the chip holder 203.

[0046] Specifically, this embodiment discloses a novel cooling method that integrates the advantages of traditional jet and spray cooling. At present, the heat transfer mechanism and effect of continuous droplet impact on the wall have been proven. Its heat transfer capacity is higher than that of traditional jet cooling. At the same time, its controllability is far superior to that of spray cooling. All droplet sizes and droplet numbers can be obtained by adjusting the signal generator, providing a new solution for high-precision thermal fluid control of high heat flux electronic devices.

[0047] The micro heat exchanger in this embodiment consists of two main components: a water tank assembly 1 and a cooling chamber assembly 2. The water tank assembly 1 is connected to an external injection pump to introduce fluid into the water tank 101, which then drips through a jet orifice plate 105. Meanwhile, a chip holder 203 is mounted on one side of the cooling chamber assembly 2, and a heating chip is installed within the chip holder 203. Additionally, a piezoelectric element 3 is mounted on the side of the outlet pipe 109 of the water tank assembly 1, and piezoelectric ceramics are mounted on the outside of the water tank 101.

[0048] The device in this embodiment integrates a water storage device, a piezoelectric device, a cooling chamber, and a high-power microchip into one unit, solving the problem of large space occupation while meeting the high precision requirements of microdroplets.

[0049] Preferably, the water storage tank assembly 1 in this embodiment includes:

[0050] The water storage tank 101 and the cooling chamber assembly 2 have an outlet pipe 109 protruding from one end;

[0051] The water tank cover 102 is installed at the other end of the water tank 101. The water tank cover 102 is sealed to the water tank 101 by a square sealing gasket 107, and a water inlet 103 is provided at the center of the water tank cover 102.

[0052] The water inlet 103 of the water tank cover 102 is threaded with an M10 pagoda connector, and the water inlet 103 is connected to the external injection pump via a hose through the M10 pagoda connector.

[0053] Secondly, the outer wall of the water storage tank 101 in this embodiment has a groove 108, which is configured as a piezoelectric ceramic groove. The piezoelectric ceramic is embedded in the groove 108 and is tied and fixed to the outer wall of the water storage tank 101 by cable ties.

[0054] This embodiment further defines the structure of the water storage tank assembly 1, which includes a water storage tank 101 and a water storage tank cover 102. The water storage tank 101 has a protruding outlet pipe 109. In this embodiment, an orifice plate fixing member 104 is installed at the end of the outlet pipe 109 of the water storage tank 101. The orifice plate fixing member 104 has a groove that matches the jet orifice plate 105. The jet orifice plate 105 is embedded in the groove of the orifice plate fixing member 104 and fastened with screws. A circular washer 106 is provided at the connection between the jet orifice plate 105 and the outlet pipe 109. In this embodiment, the jet orifice plate 105 has multiple rows of jet holes with the same spacing between adjacent jet holes. The thickness of the jet orifice plate 105 in this embodiment is 0.2mm to 0.4mm. The orifice plate processing method requires first drilling with a micro-drill, followed by polishing and plasma cleaning steps to ensure the opening accuracy and roundness of the micro-holes. In this embodiment, a square sealing gasket 107 is installed at the other end of the water storage tank 101. The outer wall of the water storage tank 101 has two grooves 108. The piezoelectric ceramic is installed in the grooves 108 and secured with cable ties to provide a large pre-tightening force. An electrical signal input terminal is also provided. In this way, the square wave or sine wave control signal amplified by the power amplifier is transmitted to the piezoelectric ceramic to generate micron-level vibration. The control circuit and the selection of piezoelectric elements are a core aspect of this invention. The resonant frequency of the piezoelectric element must exceed 100 kHz, and the output force must exceed 2000 N. The driving voltage of such piezoelectric elements is often higher than 100 V.

[0055] Preferably, the cooling chamber assembly 2 in this embodiment includes:

[0056] Cooling chamber 201 is made of transparent material;

[0057] Cooling chamber cover 202 is assembled at the end of cooling chamber 201;

[0058] A gasket 4 is provided between the cooling chamber cover 202 and the cooling chamber 201. The chip holder 203 is installed inside the cooling chamber cover 202 and is fastened with screws.

[0059] In this embodiment, the cooling chamber 201 has a water outlet 204 at the center of its bottom, and the bottom of the cooling chamber 201 is provided with a slope 206 with a slope of 5° to 30°. The slope 206 is inclined toward the water outlet 204 to guide the cooling water to be discharged through the water outlet 204.

[0060] This embodiment further defines the structure of the cooling chamber assembly 2. In this embodiment, the chip holder 203 is fixed by bolts passing through the corresponding threaded holes of the cooling chamber cover 202. The overall size of the device in this embodiment is approximately 70mm*70mm*110mm, with a compact structure. The original connecting plate, fluid chamber, injection pump connection port, piezoelectric ceramic tank, and screw cap are integrated in the right-side water storage tank 101, and a wiring hole for the piezoelectric ceramic wire is reserved. The cooling chamber 201 in this embodiment is made of plexiglass, which facilitates the observation of the generated droplets. A slope of 5° to 30° is set at the bottom of the chamber to facilitate the smooth drainage of cooling water. The chip holder 203 is used on the left-side cooling chamber cover 202 to place the heating chip, adjust the chip position, and the distance of the drip nozzle can be adjusted by using holders of different thicknesses.

[0061] Except for the cooling chamber 201, all other parts of the device in this embodiment are made of high-temperature resistant resin material.

[0062] The working principle of droplet production in this embodiment is as follows:

[0063] The 5V square wave or sine wave signal from the signal generator is amplified by a power amplifier (the power amplifier's multiplier is set to 50). This electrical signal is then applied to a piezoelectric ceramic, which exhibits capacitive impedance. This allows the electrical energy to be converted into regular mechanical vibrations, which then regularly disturb the continuous fluid, causing it to break into uniform, spherical droplets. The specific process is as follows:

[0064] 1. Adjust the pump parameters and set the required liquid flow rate and velocity. The pump flow rate and velocity can be adjusted by adjusting the pump parameters. The stable flow rate is approximately above 4 m / s, and the experimental range is approximately 4-20 m / s. Due to the better stability of the structure design compared to existing devices, this flow rate range is larger than that of existing technology devices.

[0065] 2. The piezoelectric element 3 is attached to the wall of the outlet pipe of the liquid storage chamber. The wall thickness is less than 1 mm. The displacement of the piezoelectric element 3 along the vibration direction must not be less than 2 μm. The signal generator for driving the piezoelectric ceramic in the pipe can be set to either a sine wave or a square wave, with a peak voltage of 5V. A square wave may provide better performance. The output impedance is set to 5Ω (to match the impedance of the power amplifier). Due to the extremely fast continuous droplet generation rate, the sensitivity to phase is not high. The initial phase can be selected from position 0. The frequency can be determined using empirical formulas.

[0066]

[0067] In the formula: u is the fluid velocity, d is the nozzle diameter, and the flow velocity and orifice diameter are the diameter of the droplet after it flows out. The minimum wavelength under these operating conditions is calculated to satisfy the minimum wavelength formula: λ > πd.

[0068] 3. After adjusting the signal generator, continue to adjust the power amplifier. After turning on the power amplifier, the impedance of the power amplifier should be 10Ω. Start the voltage amplification factor from the lower factor of 10 to avoid damage to the power amplifier if there is a short circuit due to wiring errors.

[0069] 4. Place the piezoelectric ceramic into the groove 108 and secure it with plastic insulating cable ties to increase the preload (if no preload is applied to the ceramic sheet, the stress will break the stacked ceramic). Connect the piezoelectric ceramic to the adapter cable, and then connect it to the power amplifier, ensuring that the entire wiring circuit is insulated.

[0070] 5. Press the pump start button, click the signal generator output button, and after pressing the power amplifier output button and hearing the piezoelectric ceramic beep, gradually adjust the multiplier from 10 to 50. Finally, observe and check the droplet quality of the droplet generator using a high-speed camera, and then further confirm the frequency using the signal generator. Initially, adjust in 1kHz increments, and after finding the optimal frequency, adjust in 100Hz increments. Finally, make final fine adjustments in 10Hz and 1Hz increments to find the optimal breakage phenomenon and achieve the best results.

[0071] See Figure 3 As shown, Figure 3 This diagram illustrates the droplet generation process of the device described in this application, which achieves a droplet count exceeding 2,000,000 per square centimeter per second. This world-leading droplet flux is the foundation for the high efficiency of this micro heat exchanger. The jet orifice plate requires extremely stringent processing, necessitating the use of micro-drills and polishing techniques, followed by plasma cleaning to obtain a burr-free jet orifice plate with exceptionally high roundness.

[0072] The highly integrated continuous droplet micro heat exchanger provided by the present invention, as described above, has the following beneficial effects:

[0073] The micro heat exchanger of the present invention realizes a micro high droplet flux piezoelectric droplet generator, which combines the droplet generator with a microchip to form an applicable micro heat exchanger, achieving efficient cooling in confined environments.

[0074] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A highly integrated continuous droplet micro heat exchanger, characterized in that, This miniature heat exchanger includes: Water storage tank assembly (1); and Cooling chamber assembly (2) installed at one end of the water storage tank assembly (1); The water storage tank assembly (1) is connected to an external injection pump to introduce fluid into the water storage tank (101). The outlet pipe (109) of the water storage tank (101) of the water storage tank assembly (1) is equipped with a jet orifice plate (105), and jet orifice plates (105) are uniformly provided on the surface of the jet orifice plate (105). A piezoelectric element (3) is installed on the side of the outlet pipe (109) of the water storage tank (101), and a piezoelectric ceramic is installed on the outside side of the water storage tank (101). A chip holder (203) is installed at the end of the cooling chamber assembly (2) away from the water storage tank (101), and a heating chip is embedded in the chip holder (203); The water storage tank assembly (1) includes: A water storage tank (101) is provided, and the outlet pipe (109) is formed by protruding from one end of the water storage tank (101) in conjunction with the cooling chamber assembly (2). A water tank cover (102) is installed at the other end of the water tank (101). The water tank cover (102) is sealed to the water tank (101) by a square sealing gasket (107), and a water inlet (103) is provided at the center of the water tank cover (102). The inlet (103) of the water tank cover (102) is threaded with an M10 pagoda connector, and the inlet (103) is connected to the external injection pump via a hose through the M10 pagoda connector. The outer wall of the water storage tank (101) has a groove (108), the groove (108) is configured as a piezoelectric ceramic groove, the piezoelectric ceramic is embedded in the groove (108) and is tied and fixed to the outer wall of the water storage tank (101) by cable ties; The outlet pipe (109) of the water storage tank (101) is equipped with an orifice plate fixing member (104). The orifice plate fixing member (104) is provided with a groove that matches the jet orifice plate (105). The jet orifice plate (105) is embedded in the groove of the orifice plate fixing member (104) and fastened with screws. A circular washer (106) is provided at the connection between the jet orifice plate (105) and the outlet pipe (109). The cooling chamber assembly (2) includes: Cooling chamber (201), wherein the cooling chamber (201) is made of transparent material; Cooling chamber cover (202) is assembled at the end of the cooling chamber (201); A gasket (4) is provided between the cooling chamber cover (202) and the cooling chamber (201), and the chip holder (203) is installed inside the cooling chamber cover (202) and fastened with screws.

2. The highly integrated continuous droplet micro heat exchanger according to claim 1, characterized in that, The cooling chamber (201) has a water outlet (204) at the center of its bottom, and the bottom of the cooling chamber (201) is provided with a slope (206) with a slope of 5°~30°. The slope (206) is inclined toward the water outlet (204) to guide the cooling water to be discharged through the water outlet (204).

3. The highly integrated continuous droplet micro heat exchanger according to claim 1, characterized in that, The thickness of the jet orifice plate (105) is 0.2mm~0.4mm. The orifice plate processing method requires first drilling holes with a micro drill, followed by polishing and plasma cleaning steps, so as to ensure the opening accuracy and roundness of the microholes.

4. The highly integrated continuous droplet micro heat exchanger according to claim 1, characterized in that, The piezoelectric ceramic has a reserved electrical signal input terminal. A square wave or sine wave control signal, amplified by a power amplifier, is transmitted to the piezoelectric ceramic to drive it to generate micron-level vibration.

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