Microscale heat transfer enhancement device using the resonance effect of viscoelastic fluid pulsating flow

Abstract

The present invention relates to the field of micro-scale enhanced heat exchange technology, and proposes a technology and a corresponding experimental device for realizing enhanced heat transfer in a simple structure microchannel heat sink by utilizing the resonance effect of viscoelastic fluid pulsating flow. The technology and the experimental device have low construction costs, the heat sink structure is simple and convenient to process, and the enhanced heat transfer effect is significant. To this end, the present invention utilizes the resonance effect of viscoelastic fluid pulsating flow to enhance the heat transfer device at a microscale, including a copper-based microchannel heat sink, an overflow tank, a support plate, an electric control rail, a control motor, a cylindrical heater, an AC power supply, a clamping device, a pressure difference sensor, a breadboard, a small lifting platform, an electronic balance, a data acquisition device, a thermocouple, a first liquid storage tank, a second liquid storage tank, a third liquid storage tank, a small pump, a workbench, a small hose and a heat preservation base. The present invention is mainly used in micro-scale enhanced heat exchange occasions.

Description

Technical Field

[0001] The invention relates to the technical field of micro-scale enhanced heat exchange, and in particular to a micro-scale enhanced heat transfer device utilizing the resonance effect of viscoelastic fluid pulsating flow. Background Art

[0002] With the development of high integration and miniaturization of electronic components, the high heat flux density generated by electronic equipment will cause local hot spots and excessively high operating temperatures in some components, damaging the service life of the electronic equipment and reducing its operating reliability. The use of traditional cooling methods not only has low heat dissipation efficiency, but also cannot meet the required heat dissipation requirements. Seeking efficient microscale heat transfer technology is one of the problems that need to be urgently solved in the development of micromotor systems.

[0003] Microchannel heat sinks have become a hot topic of international research due to their compact structure and high heat transfer efficiency. However, as a commonly used microscale heat exchange method, microchannel heat sinks are limited by microscale effects. The flow of Newtonian fluids (such as water) in microchannels is in a laminar state, and the heat transfer and mass transfer processes cannot meet expectations. As an improvement, the channel structure is usually improved, structures that can produce unstable flow (such as fins and multiple composite structures) are added, or the physical properties of the working fluid (such as nanofluids) are changed to enhance heat transfer. However, complex structures will bring about instability in the channel structure, and the small size will increase the difficulty and cost of processing. Nanofluids are expensive and are not suitable for large-scale industrial applications. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to propose a technology and a corresponding experimental device for enhancing heat transfer in a simple microchannel heat sink by utilizing the resonance effect of the pulsating flow of a viscoelastic fluid. The technology and experimental device have low construction costs, the heat sink has a simple structure and is easy to process, and the enhanced heat transfer effect is significant. To this end, the technical solution adopted by the present invention is to utilize the resonance effect of the pulsating flow of a viscoelastic fluid to enhance the heat transfer of a microscale device, including a copper-based microchannel heat sink, an overflow tank, a support plate, an electric control guide rail, a control motor, a cylindrical heater, an AC power supply, a clamping device, a differential pressure sensor, a breadboard, a small lifting platform, an electronic balance, a data acquisition device, a thermocouple, a first liquid storage tank, a second liquid storage tank, a third liquid storage tank, a small pump, a workbench, a thin hose and an insulating base;

[0005] The overflow trough is fixed on the slider of the electric control rail, and the electric control rail is vertically fixed on the support plate. The overflow trough is connected to the small pump, the copper-based microchannel heat sink and the third liquid storage tank through thin hoses respectively; the small pump is also connected to the first liquid storage tank, into which viscoelastic fluids of different concentrations and types are poured according to research needs; one side of the copper-based microchannel heat sink is connected to the overflow trough, and the other side is connected to the second liquid storage tank through a thin hose, and the other two sides are connected to thermocouples and differential pressure sensors. A cylindrical heater is inserted under the copper-based microchannel heat sink, and the second liquid storage tank is set on an electronic balance. The other end of the thermocouple is connected to a data collector, and the differential pressure sensor is fixed on a breadboard fixed on a small lifting platform, and is connected to the data collector via the breadboard, and the cylindrical heater is connected to an AC power supply; the copper-based microchannel heat sink is embedded in a thermal insulation base, and the thermal insulation base is fixed by a clamping device.

[0006] The characteristic size of the copper-based microchannel heat sink described in the present invention is 1 mm, and the outer diameter of the small hose is 3 mm.

[0007] The copper-based microchannel heat sink of the present invention can be processed into different shapes according to requirements and is convenient to replace.

[0008] The characteristics and beneficial effects of the present invention are:

[0009] The system of the present invention is simple and safe, has a small volume, a simple structure and a low experimental cost.

[0010] The electric control rail of the present invention can change the movement mode by programming, so that the overflow trough device carried by it can provide different pulsating pressure inlets to the microchannel heat sink, thereby realizing the experiment of studying the pulsating flow on the heat transfer effect of viscoelastic fluid in the microchannel.

[0011] The data acquisition system in the present invention, such as thermocouples, differential pressure sensors, electronic balances, etc., can quantify the heat transfer effect under different working conditions. According to the simulation results, the heat transfer effect is nearly doubled. Figure 3 shown.

[0012] The copper-based microchannel heat sink of the invention is designed in a modular form, which is convenient for rapid replacement, thereby realizing the research of microchannel heat sinks with different structures. The microchannels used in the present invention are simple in structure and small in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the experimental device of the present invention.

[0014] Figure 2 It is a partial structural assembly diagram of the microchannel heat sink of the present invention.

[0015] Figure 3This is the effect of different pulsation frequencies and relaxation times on the average Nusselt number (Nu) in a microchannel according to a simulation embodiment of the present invention. DETAILED DESCRIPTION

[0016] The present invention belongs to the technical field of micro-scale enhanced heat exchange, and specifically relates to achieving different enhanced heat transfer degrees by using viscoelastic fluids with different proportions and applying pressure pulsations with different frequencies, and achieving quantification of the enhanced heat transfer effect by using a series of data acquisition systems.

[0017] The technical solution of the present invention is: an experimental device for enhancing heat transfer at a microscale by utilizing the resonance effect of a pulsating flow of a viscoelastic fluid, which includes a copper-based microchannel heat sink and an overflow tank. The experimental device for enhancing heat transfer at a microscale by utilizing the resonance effect of a pulsating flow of a viscoelastic fluid also includes a support plate, an electric control guide rail, a control motor, a cylindrical heater, an AC power supply, a clamping device, a pressure difference sensor, a breadboard, a small lifting platform, an electronic balance, a data acquisition device, a thermocouple, a first liquid storage tank, a second liquid storage tank, a third liquid storage tank, a small pump, a workbench, a thin hose and a thermal insulation base.

[0018] The overflow tank is fixed on the slider of the electric control rail, and the electric control rail is vertically fixed on the support plate. The overflow tank is connected to the small pump, the copper-based microchannel heat sink and the third liquid storage tank through fine hoses; the small pump is also connected to the first liquid storage tank, into which viscoelastic fluids of different concentrations and types are poured according to research needs; the first liquid storage tank contains a 500ppm CTAC / NaSal aqueous solution of viscoelastic fluid. Viscoelastic fluid is a special type of fluid with viscosity and elasticity, usually a micellar solution formed by a polymer solution or a surface additive aqueous solution, etc. Common viscoelastic fluids include polyacrylamide PAM, polyethylene oxide The invention discloses a method for preparing a heat sink comprising: preparing a heat sink comprising: a copper-based microchannel heat sink and a heat preservation device; the heat sink comprises a copper-based microchannel heat sink and a heat preservation device; the heat preservation device ...

[0019] Preferably, the characteristic size of the copper-based microchannel heat sink described in the present invention is 1 mm, and the outer diameter of the thin hose is 3 mm.

[0020] Preferably, the copper-based microchannel heat sink of the present invention can be processed into different shapes according to requirements and is easy to replace.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0022] Specific implementation method 1: Reference Figure 1 As shown, the system designed by the present invention for quantifying the heat transfer effect of a microchannel heat sink comprises a copper-based microchannel heat sink 1 and an overflow tank 2. The experimental device for realizing enhanced heat transfer at a microscale by utilizing the low-frequency pulsating laminar resonance effect of a viscoelastic fluid also comprises a support plate 3, an electric control guide rail 4, a control motor 5, a cylindrical heater 6, an AC power supply 7, a clamping device 8, a differential pressure sensor 9, a breadboard 10, a small lifting platform 11, an electronic balance 12, a data acquisition device 13, a thermocouple 14, a first liquid reservoir 15, a second liquid reservoir 16, a third liquid reservoir 17, a small pump 18, a workbench 19, a small hose 20 and a heat-insulating base 21. The assembly sequence is as follows: the overflow trough 2 is fixed on the slider of the electric control rail 4, the electric control rail 4 is vertically fixed on the support plate 3, the overflow trough 2 is respectively connected to the small pump 18, the copper-based microchannel heat sink 1 and the third liquid storage tank 17 through a small hose 20; the small pump 18 is also connected to the first liquid storage tank 15, into which viscoelastic fluids of different concentrations and types are poured according to research needs; one side of the copper-based microchannel heat sink 1 is connected to the overflow trough 2, and the other side is connected to the second liquid storage tank 16 through a small hose 20, and the other two A thermocouple 14 and a differential pressure sensor 9 are connected to the side, a cylindrical heater 6 is inserted under the copper-based microchannel heat sink, a second liquid storage tank 16 is set on the electronic balance 12, the other end of the thermocouple 14 is connected to the data collector 13, the differential pressure sensor 9 is fixed on the breadboard 10 fixed on the small lifting platform 11, and is connected to the data collector 13 via the breadboard 10, and the cylindrical heater 6 is connected to the AC power supply 7; the copper-based microchannel heat sink 1 is embedded in the insulation base 21, and the insulation base 21 is fixed by the clamping device 8.

[0023] Specific implementation method 2: Reference Figure 1 As shown, the circuit of this embodiment is an open circuit without circulation. When running, the small pump 8 is turned on to transport the viscoelastic fluid in the first liquid storage tank 15 to the overflow tank 2 and start filling the entire circuit. After the entire circuit is filled with liquid, adjust the slider carrying the overflow tank 2 on the electric control rail 4 to the top of the rail, turn on the operating program of the control motor 5 of the electric control rail 4, and make the slider slide up and down regularly to provide a pulsating pressure inlet for the circuit. The operating program can be customized to achieve the effect of controlling the pulsation type, amplitude, and frequency. Recording the temperature and pressure information in the data acquisition device 13 and recording the flow information recorded by the electronic balance can realize quantitative evaluation of the heat transfer effect of the microchannel heat sink.

[0024] Specific implementation method three: reference Figure 2 As shown, the copper-based microchannel heat sink in this embodiment is modularly designed, and a plurality of microchannel heat sinks of different shapes can be designed to facilitate rapid replacement, and the characteristic size of the channel is 1 mm.

[0025] Specific implementation method 4: Reference Figure 3As shown, the simulation results of this embodiment are as follows: Figure 3 The graph shows the relationship between the average Nusselt number of the entire microchannel and the frequency of the pulsating pressure and the elastic number of the viscoelastic fluid. The graph can be used to determine the parameters that achieve the best heat transfer effect, under which the resonance effect of the low-frequency pulsating laminar flow of the viscoelastic fluid is generated.

[0026] The above description of the present invention is not restrictive, and all changes and other implementations made within the scope of patent protection applied for by the present invention belong to the protection scope of the present invention.

Claims

1. A micro-scale heat transfer device utilizing the resonance effect of viscoelastic fluid pulsating flow, characterized in that: It includes a copper-based microchannel heat sink, an overflow tank, a support plate, an electric control rail, a control motor, a cartridge heater, an AC power supply, a clamping device, a differential pressure sensor, a breadboard, a small lifting platform, an electronic balance, a data collector, a thermocouple, a first liquid storage tank, a second liquid storage tank, a third liquid storage tank, a small pump, a workbench, a small hose and a heat-insulating base; The overflow tank is fixed on the slider of the electric control rail, and the electric control rail is vertically fixed on the support plate. The overflow tank is connected to the small pump, the copper-based microchannel heat sink and the third liquid storage tank through small hoses respectively; the small pump is also connected to the first liquid storage tank, into which viscoelastic fluids of different concentrations and types are poured according to research needs; one side of the copper-based microchannel heat sink is connected to the overflow tank, and the other side is connected to the second liquid storage tank through a small hose, and the other two sides are connected to the thermocouple and the differential pressure sensor. A cylindrical heater is inserted under the copper-based microchannel heat sink, and the second liquid storage tank is set on an electronic balance. The other end of the thermocouple is connected to the data collector, and the differential pressure sensor is fixed on a breadboard fixed on a small lifting platform, and is connected to the data collector via the breadboard, and the cylindrical heater is connected to an AC power supply; the copper-based microchannel heat sink is embedded in a thermal insulation base, and the thermal insulation base is fixed by a clamping device; During operation, a small pump is turned on to transfer the viscoelastic fluid in the first liquid storage tank to the overflow tank and start filling the entire circuit. After the entire circuit is filled with liquid, the slider carrying the overflow tank on the electric control guide rail is adjusted to the top of the slide rail, and the operating program of the control motor of the electric control guide rail is turned on to make the slider slide up and down regularly to provide a pulsating pressure inlet for the circuit.

2. The micro-scale heat transfer enhancement device using the resonance effect of viscoelastic fluid pulsating flow as claimed in claim 1 is characterized in that: The copper-based microchannel heat sink can be processed into different shapes according to needs and is easy to replace.

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