Disclosure of Invention
The invention aims to provide an ultrasonic atomizer which solves the problems of high energy consumption, low efficiency and the like of atomizers in the prior art.
The invention further aims to provide a self-feedback-regulated atomization cooling system, wherein the ultrasonic atomizer array is arranged, independent partition control is performed, and partition cooling is performed by matching with a temperature monitoring module, so that the problem of uneven temperature is solved, and particularly, the problem of uneven temperature is solved, and the problem of the safe operation of electronic components is greatly threatened when the thermal load of a thermal management system changes rapidly.
The technical scheme is that the invention adopts the following technical scheme:
in one aspect, the present invention provides an ultrasonic atomizer comprising
The liquid storage cavity is provided with an atomization nozzle on one side;
A piezoelectric ultrasonic transducer arranged at one side of the liquid storage cavity opposite to the atomizing nozzle for generating ultrasonic wave for atomizing, and
The array micropore silicon chip is arranged in the liquid storage cavity and covers the atomizing nozzle, and a cavity for storing liquid to be atomized is formed between the piezoelectric ultrasonic transducer and the array micropore silicon chip;
the array microporous silicon chip at least facing the atomizing nozzle area is provided with array distributed microporous nozzles, and the pore channel size of the microporous nozzles is gradually reduced from inside to outside.
Further, the liquid storage cavity is provided with at least one liquid inlet.
Further, the microporous nozzle is a micron-sized conical hole, and one end of the large hole of the conical hole is 40-100 microns in size.
Further, the taper of the conical hole is 50-70 degrees.
Further, the surface of the piezoelectric ultrasonic transducer is also provided with a metal plate for increasing ultrasonic transmission efficiency.
Another advantage of the present invention is that it provides a self-feedback regulated atomizing cooling system comprising
The array ultrasonic atomization module is formed by distributing a plurality of ultrasonic atomizers in an array mode, and each ultrasonic atomizer faces to a heat dissipation area of an object to be cooled;
A liquid distribution line providing each ultrasonic atomizer with a liquid to be atomized;
A temperature monitoring module for monitoring the temperature of each heat dissipation area of the object to be cooled, and
And the atomization control module is used for setting ultrasonic frequency and power according to the temperature of each heat dissipation area and controlling the corresponding ultrasonic atomizer to carry out ultrasonic atomization.
Further, the array ultrasonic atomization module comprises a cavity body and a plurality of grooves which are arranged on the cavity body and distributed in an array way, an ultrasonic atomizer is formed in each groove, the liquid distribution pipeline is arranged in the cavity body and comprises a liquid inlet main pipe, a liquid outlet main pipe and branch pipes, wherein the branch pipes are distributed between the liquid inlet main pipe and the liquid outlet main pipe and are used for connecting liquid inlets of each ultrasonic atomizer.
The atomization cooling system further comprises a liquid circulation module, wherein the liquid circulation module comprises a circulation pump, a cooler and a collecting pipe for collecting high-temperature working medium liquid in a heat dissipation area, the collecting pipe and a liquid outlet main pipe are connected and then are connected to the cooler through a circulation pipe, and the working medium liquid is pressurized through the circulation pump after being cooled by the cooler and then is sent to a liquid inlet main pipe for recycling.
Further, the temperature monitoring module is an infrared thermometer, and the temperature distribution of the object to be cooled is obtained through an infrared temperature measuring technology.
Further, the atomization control module comprises a computer, a signal generator and a power amplifier which are sequentially connected, wherein the power amplifier is connected to each ultrasonic atomizer through a cable, and independent control of each ultrasonic atomizer is achieved.
Compared with the prior art, the invention has the following beneficial technical effects:
(1) Compared with the common water cooling plate heat exchange, micro-channel heat exchange and the like, the invention can automatically regulate and control the cooling intensity of different areas and meet the space-time non-uniformity requirement of heat dissipation. The piezoelectric ceramic vibration is regulated and controlled by identifying local hot spots and feeding back to a power input signal so as to change the ultrasonic spray cooling intensity, thereby realizing intelligent and efficient heat dissipation.
(2) Compared with the traditional cooling mode, the invention can realize higher heat exchange efficiency and lower operation cost, and heat exchange is performed by forming liquid drop impact surface with larger surface ratio by ultrasonic waves, so that the working medium can be more fully utilized to perform two-phase heat exchange, and the invention has higher efficient heat exchange capability. Meanwhile, the liquid demand is small, so that the liquid demand on a pipeline is low, the pipeline and liquid supply burden is reduced, and the cost is reduced.
(3) The ultrasonic spray cooling technology can realize miniature integration, has practical engineering application value, and provides technical support for heat dissipation of compact integrated high-power working miniature electronic devices.
Drawings
Fig. 1 is a schematic view of an ultrasonic atomizer according to example 1 of the present invention.
FIG. 2 is a top view of an array microporous silicon wafer according to example 1 of the present invention.
Fig. 3 is a schematic diagram of the use principle of the ultrasonic atomizer in embodiment 1 of the present invention.
Fig. 4 is a schematic view of an ultrasonic atomizer according to example 2 of the present invention.
Fig. 5 is a schematic diagram of an atomization cooling system with self-feedback control in embodiment 3 of the present invention.
Fig. 6 is a schematic diagram of an array ultrasonic atomizing module in embodiment 3 of the present invention.
Fig. 7 is a cross-sectional view A-A of fig. 6.
Fig. 8 is a partially enlarged schematic view C in fig. 7.
Fig. 9 is a sectional view of B-B in fig. 6.
Fig. 10 is a partially enlarged schematic view D in fig. 9.
FIG. 11 is a schematic view of FIG. 5 with the array ultrasonic atomizing module removed.
100-Ultrasonic atomizer, 110-liquid storage cavity, 120-atomizing nozzle, 130-piezoelectric ultrasonic transducer, 131-piezoelectric ceramic plate, 132-signal input positive terminal, 133-signal input negative terminal, 140-array micropore silicon chip, 141-micropore nozzle, 150-liquid inlet, 160-jet flow, 170-metal plate;
200-array ultrasonic atomization module, 210-cavity body, 220-groove;
The device comprises a liquid distribution pipeline 300, a liquid inlet main pipe 310, a liquid outlet main pipe 320 and branch pipes 330;
400-a temperature monitoring module;
500-atomization control module, 510-computer, 520-signal generator, 530-power amplifier, 540-signal input bus;
600-liquid circulation module, 610-circulation pump, 620-cooler, 630-circulation pipe, 640-collection pipe;
700-objects to be cooled, 710-boxes.
Detailed Description
Embodiments of the present invention are described in further detail below with reference to the accompanying drawings and examples. The following examples are illustrative of the invention but are not intended to limit the scope of the invention.
In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected" and "connected" are to be construed broadly, and for example, they may be fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Embodiment 1 As shown in FIGS. 1 to 3, the present embodiment provides an ultrasonic atomizer 100 comprising
A liquid storage cavity 110, wherein one side of the liquid storage cavity 110 is provided with an atomization nozzle 120;
A piezoelectric ultrasonic transducer 130 disposed in the liquid storage chamber 110 at a side opposite to the atomizing nozzle 120 for generating ultrasonic waves for atomization, and
The array microporous silicon chip 140 is arranged in the liquid storage cavity 110 and covers the atomizing nozzle 120, and a cavity for storing liquid to be atomized is formed between the piezoelectric ultrasonic transducer 130 and the array microporous silicon chip 140;
Wherein, at least the array microporous silicon wafer 140 facing the atomizing nozzle 120 area is provided with array distribution microporous nozzles 141, and the pore channel size of the microporous nozzles 141 is gradually reduced from inside to outside.
The liquid storage cavity 110 of this embodiment is formed by milling or other processing, fig. 1 is a schematic diagram of a cross section of the cavity, fig. 2 is a schematic diagram of a top view state of the array microporous silicon wafer 140, fig. 3 is a schematic diagram of a use state of the ultrasonic atomizer 100, the piezoelectric ultrasonic transducer 130 is installed at the top in the cavity, the atomizing nozzle 120 is opened at the bottom of the cavity, and the liquid filling operation in the liquid storage cavity 110 is the most ideal state. In this embodiment, the frequency and power are set for the piezoelectric ultrasonic transducer 130, and when the piezoelectric ultrasonic transducer 130 is excited by the alternating electric field with the set frequency and power, the dielectric medium inside the piezoelectric ultrasonic transducer 130 mechanically vibrates, so as to realize electro-mechanical conversion and generate ultrasonic waves with the required frequency and power. The piezoelectric material serves as a vibration source and determines the characteristics of the output sound wave. The invention sets up the micropore nozzle 141 with gradual change of size in the main direction of ultrasonic transmission, focuses the sound pressure by gradual change of size, forms sufficient pressure gradient in the micropore nozzle 141, and forms pressure peak at the exit tip of the micropore nozzle 141, when the pressure peak acts on the liquid and overcomes the inertia force and surface tension of the liquid, the tiny liquid drop can be excited from the liquid to form jet 160 of tiny liquid drop, as shown in figure 3, has the technical advantages of adjustable and microminiaturization, etc. to the atomization of working medium liquid.
There are two technologies of piezoelectric spraying and pressure atomization using piezoelectric materials, and the piezoelectric spraying uses a piezoelectric ceramic plate 131 to drive a porous plate to vibrate so as to "screen" out droplets. The pressure atomization is to introduce liquid into a nozzle vortex chamber by means of pressure difference to generate shearing atomization and disperse the liquid into tiny liquid drop groups. Compared with the prior art, the invention adopts different atomization mechanisms and has the following technical advantages:
(1) The ultrasonic atomization can accurately control the speed and the size of liquid drops by adjusting the frequency and the power of ultrasonic waves, and the range of the working flow is wider, so that the accurate thermal control of a radiating object is realized. The generated atomized particles are more uniform in size and distribution, and are particularly suitable for objects with high requirements on temperature uniformity. Piezoelectric spraying utilizes the piezoelectric ceramic plate 131 to drive the porous plate to vibrate so as to 'screen' out liquid drops, so that the adjustable range is limited. It is difficult to meet fine control while the working flow range is limited. The main mechanism of pressure atomization is to disperse a liquid into droplets by means of a pressure difference. The uniformity of atomized particles is relatively poor, and the particle size is greatly influenced by the caliber of a spray head and the spray pressure.
(2) The ultrasonic atomization method does not generate excessive liquid drop splashing or unnecessary working medium waste in the atomization process, can accurately convey the liquid drop group to a target area, and reduces unnecessary loss. And piezoelectric atomization and pressure atomization, because the spraying impact force is larger, larger aerodynamic force can disturb sprayed liquid drops and lead to a conical spraying mode, splashing and raw material waste are easy to cause, and the dispersibility of atomized particles leads to lower utilization rate of cooling working media.
(3) Compared with the traditional atomization means, the ultrasonic atomization device has a compact structure, and the conflict between space density and power consumption is avoided. In the working process of acoustic atomization, droplets can be excited by only a small amount of electric energy, and the energy consumption is low. Meanwhile, the ultrasonic atomization has almost no mechanical noise, and is suitable for application scenes needing quiet working environments. Whereas pressure spraying typically requires compressed air or mechanical drive to generate a high pressure air stream, the energy consumption is relatively high. The piezoelectric spraying uses the piezoelectric ceramic plate 131 to drive the porous plate to vibrate, and larger mechanical noise may be generated in the working process.
As a specific embodiment, the micro-porous nozzle 141 is a micro-scale tapered hole, the size of the large hole end of the tapered hole is 40-100 micrometers, the size of the small hole end of the tapered hole is 4-20 micrometers, the taper of the tapered hole is 50-70 degrees, the thickness of the array micro-porous silicon wafer 140 is about 20-80 micrometers, the size of the small hole of the tapered hole is selected to be related to the contact angle of the micro-porous nozzle 141, the surface tension of the liquid and the pressure in the liquid storage cavity 110, and at least the requirement that the working pressure in the liquid storage cavity 110 is satisfied, if the piezoelectric ultrasonic transducer 130 is not started, the liquid (working medium liquid) cannot be ejected from the micro-porous nozzle 141.
The taper hole may be a conical hole, or may be a polygonal pyramid such as a triangular pyramid, a rectangular pyramid, or a pentagonal pyramid, and exemplary, the taper hole is a quadrangular pyramid hole, the large-caliber end side of the quadrangular pyramid hole is 50 micrometers, the taper is 56 degrees, the small-opening end side is 5 micrometers, and the thickness of the array microporous silicon wafer 140 is about 33 micrometers.
As a specific embodiment, the piezoelectric ultrasonic transducer 130 is a piezoelectric ceramic plate 131, the top of the piezoelectric ceramic plate 131 is provided with a signal input positive electrode 132, one side of the bottom of the piezoelectric ceramic plate 131 is provided with a signal input negative electrode 133, and the piezoelectric ceramic plate 131 is mounted on the inner top wall of the liquid storage cavity 110 through gluing or other estimation structures.
As a specific embodiment, the liquid storage cavity 110 is provided with at least one liquid inlet 150, and the working fluid is continuously replenished to the liquid storage cavity 110 through the liquid inlet 150, and the liquid inlet 150 is illustratively disposed on the side wall of the liquid storage cavity 110 at any time.
The reason why the array microporous silicon wafer 140 is made of a material is not limited, and the microporous nozzle 141 having a desired size and shape can be efficiently processed.
Example 2 the same as example 1, as shown in fig. 4, the difference is that the surface of the piezoelectric ultrasonic transducer 130 is further attached to the bottom of the piezoelectric ceramic plate 131 by a metal plate 170 for increasing the ultrasonic transmission efficiency, and the metal plate 170 is specifically an aluminum plate.
Embodiment 3 As shown in FIGS. 5 and 6, the present embodiment provides a self-feedback regulated atomizing cooling system comprising
The array ultrasonic atomization module 200 is formed by distributing a plurality of ultrasonic atomizers 100 in an array manner, and each ultrasonic atomizer 100 is opposite to one heat dissipation area of an object 700 to be cooled;
a liquid distribution line 300 providing each ultrasonic atomizer 100 with a liquid to be atomized;
A temperature monitoring module 400 for monitoring the temperature of each heat dissipation area of the object 700 to be cooled, and
The atomization control module 500 is configured to set an ultrasonic frequency and power according to a temperature of each heat dissipation area, and control the corresponding ultrasonic atomizer 100 to perform ultrasonic atomization.
In this embodiment, the ultrasonic atomizers 100 in embodiment 1 are arranged in an array, the liquid distribution pipeline 300 is used for providing the liquid to be atomized for each ultrasonic atomizer 100, the temperature monitoring module 400 is used for monitoring the temperature of each heat dissipation area of the object 700 to be cooled, the atomization control module 500 is used for setting ultrasonic frequency and power according to the temperature of each heat dissipation area and controlling the corresponding ultrasonic atomizers 100 to perform ultrasonic atomization, the high-efficiency and precise cooling and heat dissipation of the object 700 to be cooled are realized, the heat dissipation and cooling capacity can be automatically adjusted according to the heat distribution of the object 700 to be cooled, the local overheating is effectively prevented, and the local excessive heat dissipation of the object 700 to be cooled is also prevented, so that the energy is not wasted.
As a preferred embodiment, as shown in fig. 6 to 10, the array ultrasonic atomizing module 200 includes a cavity body 210 and a plurality of arrayed grooves 220 disposed on the cavity body 210, each groove 220 is used as a liquid storage groove to form an ultrasonic atomizer 100, as shown in fig. 8, the liquid distribution pipeline 300 is disposed in the cavity body 210 and includes a liquid inlet manifold 310, a liquid outlet manifold 320 and a branch pipe 330, and the branch pipe 330 is disposed between the liquid inlet manifold 310 and the liquid outlet manifold 320 and is used for connecting the liquid inlet 150 of each ultrasonic atomizer 100.
As a preferred embodiment, as shown in fig. 5 and 11, the atomized cooling system further includes a liquid circulation module 600, where the liquid circulation module 600 includes a circulation pump 610, a cooler 620, and a collection pipe 640 for collecting the high-temperature working fluid in the heat dissipation area, the collection pipe 640 and the liquid outlet manifold 320 are joined and then connected to the cooler 620 through the circulation pipe 630, and the working fluid is cooled by the cooler 620 and then pressurized by the circulation pump 610 and then sent to the liquid inlet manifold 310 for recycling.
As shown in fig. 11, in order to meet the requirement that the collecting pipe 640 collects the high-temperature working fluid, the object 700 to be cooled is placed in a box 710, the cooling working fluid sprayed by the ultrasonic atomizer 100 is collected by the box 710 after cooling the object 700 to be cooled, the collecting pipe 640 is connected to the low point at the bottom of the box 710, and the collected high-temperature working fluid is collected and sent to the cooler 620 through the circulating pipe 630, so that the recycling is realized.
As shown in fig. 11, the temperature monitoring module 400 is an infrared thermometer, and obtains the temperature distribution of the object 700 to be cooled by using an infrared temperature measurement technology. The object 700 to be cooled according to the present invention may be an electronic device, and it should be noted that the cooling medium should be insulated with respect to the electronic device, for example, a low boiling point liquid medium such as R134a, HFE7100, liquid ammonia, n-pentane, or deionized water may be used.
As shown in fig. 5, the atomization control module 500 includes a computer 510, a signal generator 520, and a power amplifier 530, which are sequentially connected, wherein the power amplifier 530 is connected to each ultrasonic atomizer 100 through a cable, so as to realize independent control of each ultrasonic atomizer 100.
The working process of the invention comprises the steps that after an atomization cooling system is started, a liquid circulation module 600 starts to operate, cooling working media enter a cavity body 210 through a liquid distribution pipeline 300 and flow out, in the working media circulation process, a temperature monitoring module 400 starts to operate, the temperature distribution condition of a target radiating surface is obtained through an infrared imaging technology and fed back to an atomization control module 500, an optimized cooling strategy is obtained after analysis, the frequency and the voltage of an input alternating current power supply of each ultrasonic atomizer 100 are controlled, different electric signals are input to the corresponding ultrasonic atomizers 100 according to the temperature conditions of different cooling subunit areas, and each ultrasonic atomizer 100 is driven by the corresponding electric signals to operate, so that tiny liquid drops impact the target surface at a high speed to cool. And the cooling working medium which completes the heat exchange process flows back to the circulating pipe 630 through the liquid discharge pipeline to complete the work.
In specific control, the computer 510 receives the monitoring signal of the temperature monitoring module 400, analyzes the temperature distribution of the target heat dissipation surface, determines the temperature and the set value difference of each partition unit according to the set partition units, uses the set value difference as a control signal (proportional control or PID control) signal generator 520 to generate a corresponding control signal, and adjusts the power of the corresponding ultrasonic atomizer 100 through the power amplifier 530.
On the one hand, the invention utilizes the ultrasonic spray cooling technology, has the advantages of low power consumption, less working medium consumption, high heat dissipation efficiency, small device scale and the like, can greatly improve the heat dissipation level of electronic devices, reduce the design cost and the operation burden of a cooling system, on the other hand, utilizes the adjustable characteristic of ultrasonic spray, and provides a self-feedback-control atomization cooling method.
Each ultrasonic atomizer corresponds to different areas of the cooling heat dissipation surface, the temperature monitoring module monitors the temperature distribution condition of the heat dissipation surface in real time and feeds back the temperature distribution condition to the atomization control module, the atomization control module adjusts the frequency-voltage input condition of each ultrasonic atomizer according to the temperature distribution condition of the heat dissipation surface so as to change the spray intensity (the spraying speed, the liquid drop size, the flow and the like) of the atomizer to regulate and control the cooling intensity, and finally, the self-feedback regulation and control of high-speed atomization cooling is realized, and the heat dissipation time-space non-uniformity requirement is met.
The above embodiments are only for illustrating the present invention, and are not limiting of the present invention. While the invention has been described in detail with reference to the embodiments, those skilled in the art will appreciate that various combinations, modifications, and substitutions can be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.