Cooling channel heat dissipation method and device based on controllable deformation piezoelectric spoiler array

Abstract

The present invention proposes a cooling channel heat dissipation method and device based on a controllable deformable piezoelectric spoiler array. By installing a controllable deformable piezoelectric spoiler inside the cooling channel, the inverse piezoelectric effect is used to cause the spoiler to produce mechanical deformation, thereby disturbing the internal flow field of the cooling channel and improving its thermal performance. By applying an AC signal with controllable voltage and frequency to the controllable deformable piezoelectric spoiler, active control of its working state is achieved, thereby adjusting the thermal performance of the cooling channel. By controlling the spoiler array in different regions, the flow field distribution and heat transfer structure in the cooling channel are changed, the local or global heat transfer performance of the radiator is improved, the temperature uniformity of the components is improved, and temperature fluctuations are reduced. Different from the traditional cooling channel radiator based on a fixed spoiler device, the present invention can actively change the working state according to the temperature characteristics of the components and the radiator base and the power loss of the components, thereby achieving controllable adjustment of the temperature distribution and heat dissipation performance of the cooling channel radiator base.

Description

Technical Field

[0001] The present invention belongs to the technical field of cooling channel heat dissipation, and in particular relates to a cooling channel heat dissipation method and device based on a controllable deformable piezoelectric spoiler array. Background Art

[0002] High-power, high-heat-flux electronic components (hereinafter referred to as components) are crucial components for various aircraft systems. To meet the demands for compactness and lightweighting, component integration is increasing, leading to a corresponding increase in their heat flux. However, the performance of existing miniaturized heat sinks is insufficient to match the heat flux of these components during high-power operation, causing a sharp rise in component operating temperature, severely impacting operational stability and reliability. This has become a major technical bottleneck that needs to be addressed urgently.

[0003] Currently, cooling channel radiators with turbulent structures have been used in the field of component heat dissipation. They have a compact structure and excellent heat transfer performance. The use of turbulent fins can expand the heat transfer area of ​​the radiator, change the turbulent structure, reduce thermal resistance, and thus enhance the overall heat dissipation performance. For example, in the article "Study on hydraulic and thermal performance of printed circuit heat transfer surface with distributed airfoilfins" (Applied Thermal Engineering, 2017, 114: 1309-1318) published by Chu et al., a cooling channel radiator with an array of airfoil fins inside the channel was designed. The heat transfer performance of this radiator is significantly improved compared to traditional straight channel radiators. However, for the heat dissipation problem of components in aircraft applications, this method has the following shortcomings:

[0004] (1) Since the shape and position of the spoilers in the radiator are fixed, its heat dissipation capacity is relatively constant. However, during flight, the components' working conditions change dynamically, causing their heat generation power to vary greatly. Therefore, the radiator cannot meet the wide-area heat dissipation requirements of the components under flight conditions.

[0005] (2) The heat transfer capacity of the cooling channel continues to decrease, resulting in a significant increase in the temperature of the component base along the way;

[0006] (3) When a component experiences a local high heat flux (local hot spot) due to positional changes, the radiator cannot achieve the heat transfer performance improvement and matching in the corresponding area, making it difficult to suppress and eliminate the local high temperature and meeting the temperature uniformity requirements;

[0007] (4) It is difficult for the radiator to achieve dynamic matching between the heat dissipation capacity and the heat generation of the components. When the heat generation power of the components changes, its operating temperature will fluctuate.

[0008] The above problems will cause components to exceed the temperature limit, deteriorate temperature uniformity, and experience operating temperature fluctuations, thereby generating thermal stress and even causing components to overheat and burn, affecting their working reliability and stability and shortening their working life. Therefore, it is necessary to design a new type of heat dissipation device to solve the above problems. Summary of the Invention

[0009] Traditional cooling channel heat sinks typically use a fixed configuration, making their heat dissipation capacity difficult to adjust. However, for high-power aircraft electronic components, the heat flux is unevenly distributed in space and time under actual operating conditions. Limited by the heat sink's capacity, this can lead to excessive component temperature rise, uneven temperature distribution, and large temperature fluctuations with operating conditions, reducing component stability and reliability.

[0010] In response to the above problems, the present invention proposes a cooling channel heat dissipation method and device based on a controllable deformable piezoelectric spoiler array. The inventive concept of the present invention is: the controllable deformable piezoelectric spoiler installed inside the cooling channel uses the inverse piezoelectric effect to cause the spoiler to produce mechanical deformation, thereby disturbing the internal flow field of the cooling channel and improving its thermal performance. By applying an AC signal with controllable voltage and frequency to the controllable deformable piezoelectric spoiler, active control of its working state is achieved, thereby adjusting the thermal performance of the cooling channel. By controlling the spoiler array in different regions, the flow field distribution and heat transfer structure in the cooling channel are changed, the local or global heat transfer performance of the radiator is improved, the temperature uniformity of the components is improved, and temperature fluctuations are reduced. Different from the traditional cooling channel radiator based on a fixed spoiler device, the present invention can actively change the working state according to the temperature characteristics of the components and the radiator base and the power loss of the components, thereby achieving controllable adjustment of the temperature distribution and heat dissipation performance of the cooling channel radiator base.

[0011] The technical solution of the present invention is:

[0012] A cooling channel heat dissipation device based on an array of controllable deformable piezoelectric spoilers comprises a cooling channel, controllable deformable piezoelectric spoilers, and a drive system; the cooling channel comprises a base and a cover plate, and a plurality of the controllable deformable piezoelectric spoilers are arranged in a set configuration in the cooling channel;

[0013] The driving system can generate an AC driving signal to control the controllable deformable piezoelectric spoiler; the driving signal parameters include voltage and frequency; after the AC driving signal is applied to the controllable deformable piezoelectric spoiler, the tail end of the controllable deformable piezoelectric spoiler can produce controlled deformation under the piezoelectric effect; the deformation amplitude is proportional to the voltage of the AC driving signal, a positive voltage signal produces positive deformation, and a negative voltage signal produces reverse deformation, and the tail end of the controllable deformable piezoelectric spoiler is swung by the AC driving signal, thereby disturbing the flow field of the cooling medium in the cooling channel; the oscillation frequency is the same as the frequency of the AC driving signal.

[0014] Furthermore, the controllable deformable piezoelectric spoiler is composed of a base, electrode contacts fixed on the base, and a parallel bimorph piezoelectric sheet;

[0015] The AC driving electrical signal input from the electrode contact can cause the two layers of piezoelectric medium in the parallel bimorph piezoelectric piece to alternately generate stretching deformation and contraction deformation, thereby achieving the tail end swing of the parallel bimorph piezoelectric piece.

[0016] Furthermore, the base and the cover plate are provided with corresponding mounting grooves that match the size of the base, and the controllable deformable piezoelectric spoiler is fixed in the mounting grooves of the base and the cover plate through the base, and the controllable deformable piezoelectric spoiler is fixed in the cooling channel, and the base of the controllable deformable piezoelectric spoiler is limited by the keyway of the base and the mounting groove.

[0017] Furthermore, an electrode is installed in the mounting groove of the cover plate; the electrode matches the electrode contacts on the base; a driving circuit with an outer insulating layer is embedded inside the cover plate, and the driving circuit is connected to the electrode in the mounting groove; the driving circuit is an electrical signal transmission bridge connecting the external controller and the controllable deformable piezoelectric spoiler, and is responsible for transmitting the AC driving electrical signal emitted by the external controller to the controllable deformable piezoelectric spoiler.

[0018] Furthermore, a single controllably deformable piezoelectric spoiler is independently powered by a driving circuit in the cover plate, so that the controlled deformation of each controllably deformable piezoelectric spoiler can be independently controlled.

[0019] The above-mentioned device is used to implement a method for cooling channel heat dissipation. The device base is fixed to the cooling surface of the component. In the initial state, the drive system does not output an AC drive signal, and the controllable deformable piezoelectric spoiler remains in its initial fixed state, performing conventional cooling channel heat dissipation. When the component generates higher heat dissipation requirements, the drive system generates a corresponding AC drive signal based on the heat dissipation requirements, controlling all or some of the controllable deformable piezoelectric spoilers to oscillate at their corresponding amplitudes and frequencies, thereby improving the heat dissipation effect.

[0020] Furthermore, when the heat flux of the component exceeds the upper limit of the heat transfer performance when the controllable deformable piezoelectric spoiler remains in the initial fixed state, the drive system generates a corresponding AC drive electrical signal to control all the controllable deformable piezoelectric spoilers to operate at the rated state, generate swings of maximum amplitude and frequency, improve the global heat transfer coefficient, reduce the component temperature to an acceptable range, and enable it to continue to work normally.

[0021] Furthermore, all the controllable deformable piezoelectric spoilers are arranged in the cooling channel in the same direction, and the cooling medium flows in from the base of the controllable deformable piezoelectric spoiler. The driving system generates a corresponding AC driving electrical signal, and controls the swing amplitude and swing frequency of the controllable deformable piezoelectric spoiler to gradually increase along the flow direction of the cooling medium, so that the heat transfer capacity of the cooling channel gradually increases along the flow direction of the cooling medium, thereby achieving spatial matching between the heat transfer capacity of the radiator and the temperature field, and improving the temperature uniformity along the base of the cooling channel.

[0022] Furthermore, when a local high-temperature hot spot is generated at the substrate, the drive system generates a corresponding AC drive electrical signal to control the controllable deformable piezoelectric spoiler at the upstream position near the hot spot to swing, thereby disturbing the thermal boundary layer of the fluid during heat transfer near the local hot spot, enhancing the hot and cold mixing of the cooling medium, increasing the local heat transfer coefficient of the cooling channel radiator at the hot spot position, and enhancing the local heat transfer capacity of the radiator, thereby achieving better temperature uniformity of the components.

[0023] Furthermore, the drive system controls all controllable deformable piezoelectric spoilers to swing in advance before the temperature of the components rises based on the real-time values ​​of the collected component power losses, so that the overall heat transfer performance of the cooling channel radiator gradually changes to adapt to subsequent changes in heat flow.

[0024] Beneficial effects

[0025] The present invention has the following effects:

[0026] (1) By arranging a controllable deformation piezoelectric spoiler array in the cooling channel radiator, the spoiler produces controlled deformation based on the inverse piezoelectric effect to disturb the flow field and change the heat transfer structure, which can enhance the heat transfer performance of the cooling channel radiator, improve the operating temperature rise and temperature uniformity of the components, and reduce temperature fluctuations.

[0027] (2) By changing the working state of the controllable deformable piezoelectric spoiler, the heat transfer performance of the radiator can be changed, the heat dissipation capacity of the radiator can be actively adjusted, and the upper limit of the heat transfer performance of the radiator can be improved.

[0028] (3) In order to solve the problem of temperature rise along the radiator caused by the gradual decrease of heat transfer performance along the radiator, the swing frequency and amplitude of each spoiler in the controllable deformable piezoelectric spoiler array are gradually increased along the flow direction of the working fluid, thereby improving the heat transfer performance along the radiator and improving the temperature uniformity.

[0029] (4) To address the problem of local high-temperature hot spots in components, by driving the local spoilers located near the hot spots in the controllable deformable piezoelectric spoiler array to swing, the local heat transfer performance can be enhanced, the regional high temperature rise caused by the local hot spots can be suppressed, and the temperature uniformity can be improved.

[0030] (5) The device of the present invention is used as the actuator of the thermal control system. By monitoring the power loss of components and estimating their heating status, the working status of the controllable deformable piezoelectric spoiler is controlled, thereby achieving dynamic matching between the heat dissipation capacity of the radiator and the heat flow of the components, thereby reducing the temperature fluctuation of the components.

[0031] (6) The heat dissipation device based on the controllable deformable piezoelectric spoiler has the advantages of low power consumption and long life. It can work for a long time at low power consumption, ensuring the working stability and reliability of the cooling channel radiator.

[0032] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0034] Figure 1 1 is a schematic diagram of the structure of a controllable deformable piezoelectric spoiler;

[0035] Figure 2 Schematic diagram of the disturbance of the flow field by the controllable deformable piezoelectric spoiler;

[0036] Figure 3 This is a schematic diagram of the installation of a controllable deformable piezoelectric spoiler array in a cooling channel radiator;

[0037] Figure 4 is a schematic diagram of the connection between the driving circuit and a single controllable deformable piezoelectric spoiler;

[0038] Figure 5 This is the wiring diagram of the drive circuit;

[0039] Figure 6 This is a diagram of the control scheme of the controllable deformable piezoelectric spoiler;

[0040] Figure 7 This is a schematic diagram of the temperature rise suppression working mode along the process;

[0041] Figure 8 This is a schematic diagram of the local temperature rise suppression working mode;

[0042] Figure 9 It is a flow chart of performance matching working mode;

[0043] Figure 10 This is the control principle diagram of the performance matching working mode;

[0044] The numbers in the figure are: 1 is the cover, 2 is the driving circuit, 3 is the electrode, 4 is the electrode contact, 5 is the base, 6 is the controllable deformation piezoelectric spoiler, 7 is the mounting groove, 8 is the substrate, and 9 is the parallel bimorph piezoelectric piece. DETAILED DESCRIPTION

[0045] To meet the variable-condition heat dissipation requirements of components in aircraft applications, the present invention proposes a cooling channel heat dissipation method and device based on an array of controllable deformable piezoelectric spoilers. Compared to traditional cooling channel heat dissipation devices with fixed spoilers, by changing the working position and working state (swing amplitude and swing frequency) of the controllable deformable piezoelectric spoilers, the local heat transfer performance of the heat dissipation device can be enhanced, and the coordinated operation of the array composed of multiple spoilers can improve the overall heat transfer performance of the radiator. The details are as follows:

[0046] (1) Without changing the layout configuration of the radiator spoiler array, the heat dissipation requirements of components with various heating characteristics can be met; the flow field distribution and heat transfer structure in the cooling channel are changed by swinging the spoiler, thereby actively adjusting the heat transfer performance of the radiator and improving the upper limit of the heat transfer performance of the radiator.

[0047] (2) By swinging the spoilers at different positions in the array in a variable state, the heat dissipation performance along the cooling channel can be improved, solving the problem of the base temperature gradually increasing along the direction of the working fluid flow due to the fixed heat transfer coefficient of the cooling channel.

[0048] (3) By controlling the swing of the local spoiler to disturb the local flow field, the local heat transfer performance of the cooling channel radiator is effectively improved, and the local high temperature caused by the hot spots of the components is solved.

[0049] (4) By utilizing the hysteresis of the thermal effect of components causing heat generation due to power loss and thus temperature rise, the controllable deformable piezoelectric spoiler array is controlled in advance to achieve dynamic matching of the cooling channel radiator's heat dissipation capacity with the component's heat flow, thereby reducing the component's temperature fluctuation.

[0050] The present invention is described below from the aspects of working principle, control mechanism, structural scheme and working mode:

[0051] (1) Working principle of controllable deformation piezoelectric spoiler

[0052] The electro-induced oscillation of the controllable deformable piezoelectric spoiler is realized based on the inverse piezoelectric effect. When an electric field is applied in the polarization direction of the piezoelectric medium, the piezoelectric medium will produce mechanical deformation or mechanical pressure in a certain direction. By bonding two layers of piezoelectric medium together to form a piezoelectric bimorph structure, this mechanical deformation can be amplified. The present invention adopts a parallel bimorph piezoelectric sheet with a large electro-induced deformation deflection as a deformation driving device for the controllable deformable piezoelectric spoiler. One end of the parallel bimorph piezoelectric sheet is fixed to the fixed end, and the other end (tail end) produces a controlled deformation swing under the piezoelectric effect, thereby forming a controllable deformable piezoelectric spoiler, which is essentially a flexible cantilever beam structure.

[0053] The rated swing amplitude of the controllable deformable piezoelectric spoiler after power is applied is:

[0054]

[0055] Where, δ r Indicates the rated swing amplitude, d 31 represents the piezoelectric strain constant, V r Indicates the rated operating voltage, L indicates the length of the bimorph piezoelectric sheet, and H indicates the thickness of the bimorph piezoelectric sheet.

[0056] The relationship between the deflection curve and the electrical signal of the controllable deformable piezoelectric spoiler is:

[0057]

[0058] Where x represents the distance from any point on the center line of the controllable deformable piezoelectric spoiler to the fixed end, y represents the deflection of the point, t is the time, V represents the actual input voltage, and f represents the frequency of the input electrical signal.

[0059] As can be seen from the above equation, the swing amplitude of the controllable deformable piezoelectric spoiler is proportional to the voltage of the input electrical signal. A positive voltage signal produces a positive swing, while a negative voltage signal produces a negative swing. The swing frequency is the same as the frequency of the input electrical signal. By regulating the voltage and frequency of the input electrical signal, the operating state of the controllable deformable piezoelectric spoiler can be controlled, resulting in the desired swing of the spoiler.

[0060] (2) Thermal performance control mechanism of controllable deformation piezoelectric spoiler

[0061] The heat dissipation method of installing controllable deformable piezoelectric spoilers in the cooling channel is an active heat dissipation method. The swinging motion generated by a single controllable deformable piezoelectric spoiler can disturb the flow field of the cooling medium in the channel, forming a vortex at the tail of the spoiler with a flow velocity higher than that in the mainstream area. As the cooling medium flows, the turbulence intensity of this vortex continues to develop, which can weaken the thickness of the thermal boundary layer and enhance the mixing between the low-temperature medium in the mainstream area and the high-temperature medium near the base, thereby improving the heat transfer coefficient of the cooling channel radiator. The swing amplitude and swing frequency of the controllable deformable piezoelectric spoiler are positively correlated with the influence range and turbulence intensity of the vortex generated at its tail. Therefore, by regulating the working state of the piezoelectric spoiler, the radiator can have a variable heat transfer coefficient and excellent heat transfer performance.

[0062] (3) Structural scheme of controllable deformation piezoelectric spoiler array

[0063] A single, controllably deformable piezoelectric spoiler is positioned vertically within the heat sink channel, aligning the plane of the parallel bimorph piezoelectric disc perpendicular to the heat sink base and parallel to the direction of the fluid flow. The base acts as a fixed end, confined within a mounting slot between the cover and base. The parallel bimorph piezoelectric disc is fixed to the base at one end and movable at the other end. The cooling fluid flows through the base and then through the piezoelectric spoiler, where the oscillation of the piezoelectric spoiler's tail causes the flow to change state.

[0064] Multiple controllable deformable piezoelectric spoilers are arranged in a certain pattern in the cooling channel of the radiator to form an array of controllable deformable piezoelectric spoilers. In the array, the direction along the working medium flow is defined as the horizontal direction, and the direction perpendicular to the flow along the channel width is defined as the vertical direction. A horizontal row of controllable deformable piezoelectric spoilers is defined as a row, and a vertical row of controllable deformable piezoelectric spoilers is defined as a column. A drive circuit is embedded in the cover of the cooling channel, and electrodes connected to the drive circuit are provided in the cover mounting groove. The piezoelectric spoiler electrode contacts on the base are in contact with the cover drive electrodes, transmitting the drive electrical signal to the parallel bimorph piezoelectric pieces to cause them to swing. Each piezoelectric spoiler in the array is individually powered by the drive circuit in the cover, so the controlled deformation of each piezoelectric spoiler is independent. Therefore, by utilizing the different working states of each spoiler in the controllable deformable piezoelectric spoiler array, the radiator has adjustable heat transfer performance, and the heat transfer performance can be controlled and changed at different positions and at different times, solving the problem that the heat transfer performance of traditional radiators is difficult to adjust due to the fixed configuration.

[0065] (IV) Working mode of controllable deformation piezoelectric spoiler array

[0066] Under a given configuration of a controllable deformable piezoelectric spoiler array heat sink, different operating modes should be adopted to address different heat dissipation issues. When the component is operating at low power (generating low heat), the controllable deformable piezoelectric spoiler array is set to non-operating mode. At this time, the heat sink can be regarded as a traditional heat sink based on a fixed spoiler array. When the component is operating at high power, the drive electrical signal of the controllable deformable piezoelectric spoiler is controlled to operate in different states according to different heating characteristics and heat dissipation requirements, thereby achieving different flow field structures inside the channel and adjusting its overall or local heat dissipation capacity.

[0067] For components, there are generally three different types of heat dissipation and temperature control requirements:

[0068] Heat dissipation requirement 1: Excessive component temperature rise. Excessive component temperature rise is a common heat dissipation problem. This problem arises when the heat sink fails to meet the component's heat dissipation requirements. This causes the component's temperature to rise, exceeding the maximum operating temperature limit, affecting its operating lifespan and, in severe cases, causing component burnout. To address this issue, the present invention has designed a high-temperature rise suppression operating mode.

[0069] Heat dissipation requirement 2: Temperature uniformity exceeds the limit. In addition to temperature rise exceeding the limit, poor temperature uniformity will also affect the service life of components. Due to the different heat fluxes at different positions of the components, there are differences in the spatial distribution of temperature in the components. At this time, although the components can work normally, the uneven temperature will cause thermal stress inside them. In severe cases, the components will be desoldered and broken, affecting their working stability. Generally, there are two common situations where temperature uniformity exceeds the limit: temperature rise exceeds the limit along the process and local temperature rise exceeds the limit. In order to solve these two types of problems, the present invention designs two working modes: temperature rise suppression working mode along the process and local temperature rise suppression working mode.

[0070] Heat dissipation requirement 3: Excessive temperature fluctuations. Component power loss fluctuates significantly with operating conditions, leading to significant temperature fluctuations within the component and the generation of alternating thermal stresses. When the number of stress cycles reaches its fatigue life, fatigue fractures in the solder joints will occur, resulting in device failure. Therefore, suppressing component temperature fluctuations is essential, and this is addressed by the design of a performance matching operating mode.

[0071] For the three heat dissipation requirements mentioned above, the working modes of the four piezoelectric spoiler arrays are detailed as follows:

[0072] a. High temperature rise suppression working mode

[0073] Working mode of spoiler: All controllable deformable piezoelectric spoilers in the array oscillate at rated frequency and amplitude.

[0074] When components experience excessive heat flux through the heat sink base due to continuous high-power operation, exceeding the upper limit of the heat transfer performance of a fixed spoiler array heat sink, the component temperature will continue to rise. To prevent component burnout, the heat sink's overall heat transfer performance needs to be improved. Therefore, the controllable deformable piezoelectric spoilers in the entire array should operate at their rated operating conditions, with each piezoelectric spoiler generating controlled oscillations of the same frequency and amplitude. This improves the heat sink's overall heat transfer performance, thereby reducing the component's operating temperature and enabling normal operation.

[0075] b. Along-process temperature rise suppression working mode

[0076] Working mode of the spoiler: along the flow direction of the working medium, the oscillation frequency and amplitude of each column of controllable deformable piezoelectric spoilers in the array are gradually increased according to a rule.

[0077] Due to heat transfer between the radiator and the cooling medium, the temperature of the cooling medium in the cooling channel gradually increases, and the temperature difference between the cooling channel wall and the cooling medium decreases, causing the heat transfer capacity of the radiator along the flow direction of the working medium to gradually weaken. The temperature of the radiator base increases along the flow direction, which can easily cause the temperature uniformity along the radiator base to exceed the acceptable threshold. To address this phenomenon, the oscillation frequency and amplitude of the controllable deformable piezoelectric spoiler are gradually increased according to a certain pattern along the flow direction of the working medium. This changes the turbulence state at different locations along the flow direction, gradually improving the heat transfer coefficient of the cooling channel as the working medium flows, suppressing the temperature increase along the flow direction of the radiator base, and achieving better temperature uniformity along the components.

[0078] c. Local temperature rise suppression working mode

[0079] Working mode of the spoiler: The controllable deformable piezoelectric spoiler near the hot spot area in the control array is swung at the rated frequency and amplitude.

[0080] The present invention is applicable to situations where there are local hot spots in components. Near the hot spots, especially in the incoming flow direction, a single or multiple adjacent controllable deformable piezoelectric spoilers are controlled to produce swinging deformation, thereby changing the local flow field of the cooling medium in the cooling channel radiator near the hot spots, disturbing its thermal boundary layer to enhance heat exchange, thereby improving the local heat transfer performance of the cooling channel radiator and improving the temperature uniformity of the substrate.

[0081] d. Performance matching working mode

[0082] Working mode of spoiler: The oscillation frequency and amplitude of all controllable deformable piezoelectric spoilers in the array are adjusted as the power loss of the components changes.

[0083] In view of the situation where the temperature fluctuations of components are caused by the fluctuations in their heating power, the hysteresis from the change in power loss caused by the change in the working signal to the fluctuation in the heating temperature rise is considered. By monitoring the power loss of the components, their heating characteristics can be predicted in advance. Based on this, the controllable deformable piezoelectric spoiler array in the radiator can be controlled in advance to intervene in the subsequent heat flow changes and temperature fluctuations in time, so as to achieve dynamic matching of the heat transfer performance of the radiator and the heat flow of the components, thereby improving the temperature fluctuations of the components caused by power loss fluctuations.

[0084] The following describes in detail embodiments of the present invention. The embodiments are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0085] In this embodiment, the arrangement of the array of controllable deformable piezoelectric spoilers 6 is first selected based on the heating characteristics of the heat-generating components, and the internal mechanical structure of the cooling channel radiator is determined to ensure that its heat dissipation performance can meet the heat dissipation requirements of the radiator base 8 under various component heating modes. Simulations are then used to determine the specific operating state of the array of controllable deformable piezoelectric spoilers 6 under specific operating conditions. Based on this, the controllable deformable piezoelectric spoilers 6 are controlled to ensure that the cooling channel radiator achieves the desired heat dissipation performance.

[0086] (1) Mechanical structure of cooling channel radiator

[0087] like Figure 1 As shown, a single controllable deformable piezoelectric spoiler 6 is composed of a base 5, an electrode contact 4 fixed to the base 5, and a parallel bimorph piezoelectric sheet 9. After an AC signal is supplied through the drive circuit 2, one layer of the parallel bimorph piezoelectric sheet 9 produces an extension deformation and the other layer produces a contraction deformation as the AC signal changes positively or negatively, thereby causing the controllable deformable piezoelectric spoiler 6 to alternately produce flexible bending and swinging in both directions, thereby disturbing the flow field of the cooling medium in the cooling channel. Figure 2 As shown, this disturbance will form a gradually developing vortex at the rear end of the controllable deformable piezoelectric spoiler 6, thereby enhancing the mixing of cold and hot fluids and improving the heat transfer performance of the cooling channel radiator.

[0088] like Figure 3 As shown, a spoiler array consisting of multiple rows and columns of controllable piezoelectric spoilers 6 is mounted on the cooling channel heat sink base 8, based on a single vertically positioned controllable piezoelectric spoiler 6. The row spacing, column spacing, row stagger, and column stagger of the array can be pre-designed based on actual heat transfer requirements. In this embodiment, the controllable piezoelectric spoilers 6 in each row and column are not staggered, and the row and column spacings are fixed. The specific values ​​do not affect the subsequent description of the control scheme and operating mode.

[0089] like Figure 4As shown, an array of mounting grooves 7 that match the size of the base 5 is provided on the cooling channel radiator base 8 and the cover plate 1. The controllable deformable piezoelectric spoiler 6 is fixed in the mounting groove 7 between the base 8 and the cover plate 1 through the base 5. The controllable deformable piezoelectric spoiler 6 is fixed inside the cooling channel radiator, and the fixed end of the spoiler is limited by the keyway of the base 5 and the mounting groove 7. An electrode 3 is installed in the mounting groove 7 of the cover plate 1. An electrode contact 4 is installed on the base 5. The electrode contact 4 matches the electrode 3 and is connected and fixed with a conductive adhesive. A driving circuit 2 with an outer insulating layer is embedded inside the cover plate 1, and the driving circuit 2 is connected and conductive to the electrode 3 in the mounting groove 7. The driving circuit 2 is an electrical signal transmission bridge connecting the external controller and the controllable deformable piezoelectric spoiler 6, and is responsible for transmitting the driving signal sent by the controller to a single controllable deformable piezoelectric spoiler 6.

[0090] (2) Connection method of spoiler array control circuit

[0091] The controllable deformable piezoelectric spoiler 6 uses external power supply, and the driving circuit 2 in the cover is as follows: Figure 5 As shown, only the circuit connection mode of some controllable deformable piezoelectric spoilers 6 is used to illustrate their connection rules, and the remaining controllable deformable piezoelectric spoilers 6 follow this connection rule. In this embodiment, each controllable deformable piezoelectric spoiler 6 is powered separately by the drive circuit 2 in the cover plate 1, so the controlled deformation of each controllable deformable piezoelectric spoiler 6 can be independently controlled. According to formula (2), the swing amplitude of the controllable deformable piezoelectric spoiler 6 is proportional to the voltage of the electrical signal, and the swing frequency is the same as the frequency of the electrical signal. Therefore, it is only necessary to input a sinusoidal alternating current signal of a certain amplitude and frequency into the drive circuit 2 to enable the controllable deformable piezoelectric spoiler 6 to produce a regular swing with positive and negative deflection changes. By performing voltage and frequency conversion on the sinusoidal alternating current signal and then inputting it into the drive circuit 2, the working state of the controllable deformable piezoelectric spoiler 6 can be actively controlled, and the flow field and heat transfer state in the cooling channel are also changed, thereby achieving the regulation of the heat transfer performance of the radiator.

[0092] (3) Control scheme and working mode

[0093] like Figure 6 As shown, in response to the various heat dissipation requirements caused by the different heating characteristics of components, it is necessary to design a control scheme and working mode corresponding to the array of controllable deformable piezoelectric spoilers 6 to achieve targeted heat dissipation control effects. The mechanical structure designed in this embodiment supports four different working modes:

[0094] a. High temperature rise suppression working mode

[0095] When the heat flux of components exceeds the upper limit of the heat transfer performance of the fixed spoiler array heat sink due to high power operation, the component temperature will increase cumulatively and eventually exceed the normal operating temperature range. To avoid component burnout, the priority is to improve the overall heat dissipation performance of this heat sink. Figure 6 The high temperature rise suppression working mode of the first scheme controls all the controllable deformable piezoelectric spoilers 6 in the array to operate at the rated state, generating swings of maximum amplitude and frequency, so that the overall heat transfer performance of the radiator breaks through the limitations of the fixed structure, improves the global heat transfer coefficient, and reduces the temperature of the components to an acceptable range, so that it can continue to work normally.

[0096] b. Along-process temperature rise suppression working mode

[0097] like Figure 7 As shown in the figure, assuming that the cooling medium flows in from the left, when the base 8 of the cooling channel radiator is a uniform heat flow, the temperature of the cooling medium in the channel gradually increases as it flows and transfers heat along the channel, causing the heat transfer performance of the radiator along the flow direction of the cooling medium to gradually decrease, and the temperature of the radiator base 8 gradually increases along the channel (indicated by the shade of the shade in the figure), resulting in poor temperature uniformity along the channel. At this time, take Figure 6 The temperature rise suppression working mode along the middle scheme 2 controls the swing amplitude and swing frequency of each row of controllable deformable piezoelectric spoilers 6 in the spoiler array to gradually increase along the flow direction, so that the heat transfer capacity of the cooling channel radiator gradually increases along the flow direction of the cooling medium, realizes the spatial matching of the heat transfer capacity of the radiator and the temperature field, and improves the temperature uniformity of the base along the cooling channel radiator.

[0098] Among them, the growth law of the swing frequency and amplitude of the controllable deformable piezoelectric spoiler 6 can be selected according to the temperature distribution of the radiator base, such as linear growth, exponential growth, and custom law growth. Take the linear growth law as an example. Figure 7 As shown, the swing control rule of each column of spoilers is explained by taking the swing of three consecutive controllable deformable piezoelectric spoilers 6 along the way as an example. The controllable deformable piezoelectric spoilers 6 at the rear of each row can be controlled according to this rule.

[0099] The swing amplitude control rule is:

[0100]

[0101] Where, δ i represents the swing amplitude of the i-th column of controllable deformable piezoelectric spoilers 6, and n represents the number of columns of the array of controllable deformable piezoelectric spoilers 6.

[0102] The swing frequency control rule is:

[0103]

[0104] Where, f i represents the oscillation frequency of the controllable deformable piezoelectric spoiler 6 in the i-th column, f r It represents the rated oscillation frequency of the controllably deformable piezoelectric spoiler 6.

[0105] Since it is known that the last row of controllable deformable piezoelectric spoilers 6 adopts the rated working state (maximum swing frequency+maximum swing amplitude), the working state of each row of controllable deformable piezoelectric spoilers 6 can be obtained by reverse deduction using Formula 3 and Formula 4.

[0106] c. Local temperature rise suppression working mode

[0107] When components are operating, they can easily cause localized high-temperature hotspots on the heat sink base 8. To address this, the controllably deformable piezoelectric spoiler 6 upstream of the hotspot is controlled to oscillate, disrupting the thermal boundary layer of the fluid conducting heat near the hotspot. This enhances the mixing of hot and cold coolant, increases the local heat transfer coefficient of the cooling channel heat sink at the hotspot, and strengthens the heat transfer capacity of the heat sink, thereby achieving better temperature uniformity for the components.

[0108] like Figure 8 As shown, there is a local hot spot area on the cooling channel radiator base 8 (such as the dark circular shadow area in the figure). Figure 6 The local temperature rise suppression operating mode of Scheme 3 is described. Based on the hotspot location and heating radius, the controllable deformable piezoelectric spoilers 6 in the spoiler array that need to be oscillated are determined. The operating area is defined as a circular region within the hotspot heating radius, and all controllable deformable piezoelectric spoilers 6 within this region oscillate. The controllable deformable piezoelectric spoilers 6 within the operating area oscillate at the rated amplitude and frequency, while the remaining controllable deformable piezoelectric spoilers 6 outside the operating area do not oscillate.

[0109] d. Performance matching working mode

[0110] In the actual heat dissipation process, since the working characteristics of the components change dynamically over time, when the heating power changes significantly, the temperature of the heat sink base 8 fluctuates greatly. In order to avoid excessive temperature fluctuations causing thermal fatigue failure of components, Figure 6 The performance matching working mode of Option 4 controls the temperature fluctuation amplitude of components within a certain range.

[0111] Considering that changes in component power loss always precede changes in its temperature, all the controllable deformable piezoelectric spoilers 6 in the spoiler array can be controlled to swing in advance before the component temperature rises based on the real-time changes in component power loss. This gradually changes the overall heat transfer performance of the cooling channel radiator to adapt to subsequent changes in heat flow. This achieves a dynamic match between the overall heat transfer performance of the cooling channel radiator and the heat flow, reducing component temperature fluctuations. Therefore, the key to the effective implementation of this solution lies in matching the power loss of the component with the operating state of the controllable deformable piezoelectric spoilers 6 in the spoiler array, so that the controllable deformable piezoelectric spoilers 6 in the spoiler array adopt appropriate swing states under different component power losses.

[0112] The specific process of matching the power loss and the swing state of the controllable deformable piezoelectric spoiler 6 is as follows: Figure 9 As shown. In the power loss range that the components can achieve, select the most representative j instantaneous power loss points P1, P2, ..., P j . Then determine the working state of the controllable deformable piezoelectric spoiler 6 in the spoiler array at each power loss point when the radiator performance meets the standard. The specific method is: first, estimate the initial working state value of the controllable deformable piezoelectric spoiler 6 in the spoiler array according to the power loss. If the initial working state value does not meet the heat dissipation requirement, increase the swing frequency and re-perform CFD simulation while keeping the swing amplitude unchanged. When the swing frequency reaches the maximum limit, keep the swing frequency unchanged and increase the swing amplitude until the working state of the controllable deformable piezoelectric spoiler 6 in the spoiler array meets the heat dissipation requirement at this power loss point.

[0113] At a fixed swing amplitude, f k represents the oscillation frequency of the controllably deformable piezoelectric spoiler 6 after the kth frequency increase, and its expression is:

[0114] f k =f k-1 +Δf# (5)

[0115] Where Δf represents the frequency correction rate.

[0116] δ m represents the swing amplitude of the controllably deformable piezoelectric spoiler 6 after the mth increase in amplitude, and its expression is:

[0117] δ m =δ m-1 +Δδ# (6)

[0118] Where Δδ represents the amplitude correction rate.

[0119] Generally speaking, we can set f0 = f r / 10 and δ0=δ r / 10.

[0120] When the radiator performance meets the requirements, the power loss point is paired with the operating state of the controllable deformable piezoelectric spoiler 6. After completing the pairing of j power loss points, a matching function for the operating state of the controllable deformable piezoelectric spoiler 6 is fitted using the j power loss points as independent variables. This facilitates real-time determination of the operating state of the controllable deformable piezoelectric spoiler 6 by monitoring the power loss of the components in practical applications.

[0121] The state matching function is expressed by the following system of equations:

[0122] State matching function: Where P(t) represents the real-time power of the component, and G and H represent the functional relationship.

[0123] At this point, the matching of different power losses with the working state of the controllable deformable piezoelectric spoiler 6 can be completed. Using formula 7, the working state of the controllable deformable piezoelectric spoiler 6 in the spoiler array is controlled in real time. The principle of the control scheme is as follows Figure 10 As shown, after obtaining the power loss value of the heat-generating component, the state matching function is used to obtain the expected working state of the controllable deformable piezoelectric spoiler 6 at this time, and the controllable deformable piezoelectric spoiler 6 is controlled by the controller. The flow field is appropriately disturbed by its swing, which changes the heat exchange effect between the radiator and the component, thereby suppressing the temperature fluctuation of the component and achieving dynamic matching of the heat dissipation performance of the cooling channel radiator and the heat flow.

[0124] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for heat dissipation using a cooling channel heat dissipation device based on a controllable deformable piezoelectric spoiler array, characterized in that: The heat dissipation device includes a cooling channel, a controllable deformable piezoelectric spoiler and a driving system; the cooling channel includes a base and a cover plate, and the controllable deformable piezoelectric spoiler is arranged in the cooling channel; The driving system is capable of generating an AC driving electrical signal for controlling the controllably deformable piezoelectric spoiler; The driving electrical signal parameters include voltage and frequency; after the AC driving electrical signal is applied to the controllably deformable piezoelectric spoiler, the tail end of the controllably deformable piezoelectric spoiler can produce controlled deformation under the piezoelectric effect; The deformation amplitude is proportional to the voltage of the AC drive signal. A positive voltage signal produces positive deformation, and a negative voltage signal produces reverse deformation. The AC drive signal is used to achieve the tail end swing of the controllable deformable piezoelectric spoiler, thereby disturbing the flow field of the cooling medium in the cooling channel. The swing frequency is the same as the frequency of the AC drive signal. The device base is fixed on the cooling surface of the component. In the initial state, the drive system does not output an AC drive signal, and the controllable deformable piezoelectric spoiler remains in the initial fixed state. When the component generates a heat dissipation demand, the drive system generates a corresponding AC drive signal according to the heat dissipation demand, and controls all or part of the controllable deformable piezoelectric spoiler to swing according to their corresponding amplitudes and frequencies, thereby improving the heat dissipation effect. All of the controllably deformable piezoelectric spoilers are arranged in the same direction in the cooling channel, and the cooling medium flows in from the base of the controllably deformable piezoelectric spoilers. The drive system generates a corresponding AC drive signal to gradually increase the swing amplitude and frequency of the controllably deformable piezoelectric spoilers along the flow direction of the cooling medium, thereby gradually increasing the heat transfer capacity of the cooling channel along the flow direction of the cooling medium, achieving spatial matching between the heat transfer capacity of the radiator and the temperature field, and improving the temperature uniformity of the base along the cooling channel. The drive system controls all controllable deformable piezoelectric spoilers to swing in advance before the component temperature rises based on the real-time value of the component power loss collected, so that the overall heat transfer performance of the cooling channel radiator gradually changes to adapt to subsequent changes in heat flow.

2. The method according to claim 1, wherein: The controllable deformable piezoelectric spoiler is composed of a base, electrode contacts fixed on the base, and a parallel bimorph piezoelectric sheet; The AC driving electrical signal input from the electrode contact can cause the two layers of piezoelectric medium in the parallel bimorph piezoelectric piece to alternately generate stretching deformation and contraction deformation, thereby achieving the tail end swing of the parallel bimorph piezoelectric piece.

3. The method according to claim 2, wherein: The base and the cover plate are correspondingly provided with mounting grooves that match the size of the base. The controllably deformable piezoelectric spoiler is fixed in the mounting grooves of the base and the cover plate through the base, and the controllably deformable piezoelectric spoiler is fixed in the cooling channel. The base of the controllably deformable piezoelectric spoiler is limited by the keyway of the base and the mounting groove.

4. The method according to claim 3, wherein: An electrode is installed in the mounting groove of the cover plate; the electrode matches the electrode contacts on the base; a drive circuit wrapped in an insulating layer is embedded inside the cover plate, and the drive circuit is connected to the electrode in the mounting groove; the drive circuit is an electrical signal transmission bridge connecting the external controller and the controllable deformable piezoelectric spoiler, and is responsible for transmitting the AC drive electrical signal emitted by the external controller to the controllable deformable piezoelectric spoiler.

5. The method according to claim 4, characterized in that: A single controllably deformable piezoelectric spoiler is powered independently by a driving circuit in the cover plate, so that the controlled deformation of each controllably deformable piezoelectric spoiler can be independently controlled.

6. The method according to claim 1, wherein: When the heat flux of the component exceeds the upper limit of the heat transfer performance when the controllable deformable piezoelectric spoiler remains in the initial fixed state, the drive system generates a corresponding AC drive electrical signal to control all the controllable deformable piezoelectric spoilers to operate at the rated state, generate swings with maximum amplitude and frequency, improve the global heat transfer coefficient, reduce the component temperature to an acceptable range, and enable it to continue normal operation.

7. The method according to claim 1, wherein: When a local high-temperature hot spot is generated at the substrate, the drive system generates a corresponding AC drive electrical signal to control the controllable deformable piezoelectric spoiler at an upstream position near the hot spot to swing, thereby disturbing the thermal boundary layer of the fluid during heat transfer near the local hot spot, enhancing the hot and cold mixing of the cooling medium, increasing the local heat transfer coefficient of the cooling channel radiator at the hot spot position, and enhancing the local heat transfer capacity of the radiator, thereby achieving better temperature uniformity of the components.

Images