AU2021101193A4

AU2021101193A4 - A novel sound assisted cooling system

Info

Publication number: AU2021101193A4
Application number: AU2021101193A
Authority: AU
Inventors: Nilesh P. Awate; Vinod D. Bhaiswar; Dheeraj S. Deshmukh; Vivek W. Khond; Amol D. Pitale; Ashish S. Raut; Rupesh S. Shelke; Pramod V. Walke
Original assignee: Awate Nilesh P Dr; Deshmukh Dheeraj S Dr; Khond Vivek W Dr; Raut Ashish S Dr; Shelke Rupesh S Dr; Walke Pramod V Dr
Current assignee: Awate Nilesh P Dr; Deshmukh Dheeraj S Dr; Khond Vivek W Dr; Raut Ashish S Dr; Shelke Rupesh S Dr; Walke Pramod V Dr
Priority date: 2021-03-06
Filing date: 2021-03-06
Publication date: 2021-05-06
Anticipated expiration: 2029-03-06

Abstract

A NOVEL SOUND ASSISTED COOLING SYSTEM A refrigeration system can cause global warming and deplete ozone layer through the release of refrigerants directly into the atmosphere. There are large numbers of air conditioners and refrigerators still in use worldwide on refrigerant R134a which has substantial ozone depleting potential along with high global warming potential. As per the Montreal & Kyoto protocol, the conventional refrigerants are to be phased out ( Now all the CFCs and compounds such as Halons have been completely phased-out, while by 2030 almost all other ODSs will be phased out) and instead of that eco-friendly refrigeration / cooling systems are used in refrigeration and air conditioning appliances. The current invention relates generally to sound assisted cooling system and, more specifically, to optimization of sound assisted cooling system having a relatively small size which utilizes inert gas and different geometries of stack. Use one acoustic driver to generate high frequency sound within a resonator. The interaction of the high frequency sound with stack creates a temperature difference across the stack which is thermally anchored at each end to a pair of heat exchangers located on opposite sides of the stack. /1 5gr1 Figure1I

Description

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Figure1I

A NOVEL SOUND ASSISTED COOLING SYSTEM

Technical field of invention:

The present invention relates generally to Sound Assisted Cooling System and, more specifically, to optimization of sound assisted cooling system having a relatively small size which utilizes inert gas and stack. Use one sound driver to generate high frequency sound within a resonator. The interaction of the high frequency sound with stack creates a temperature difference across the stack which is thermally anchored at each end to a pair of heat exchangers located on opposite sides of the stack.

Background of the invention:

The sound assisted cooling has a long history and it is only recently that new applications have stimulated its development. In the 1 8 th century it was discovered that a glass tube open at one end, would produce sound when the closed end was heated. This device is known as the Soundhaus Tube. Subsequently it was discovered that a tube open at both ends will also produce sound when a metallic mesh located in the lower half of the tube is heated and the tube is held up vertically. In such a device, convection plays an important role. This is known as the Rijke Tube. It was not until the end of the 91th century when Lord Rayleigh explained how it works. The device is essentially an example of a relaxation oscillator where '0 oscillations are sustained when energy is injected at the right phase of the oscillation cycles.

In 1975, Merkli and Thomann observed the converse of the above effect, that sound field can produce cooling in a resonant tube. In 1983, Wheatley et. al. built the first sound assisted cooling device; it operated at 500 Hz and produced temperature differences of approximately 1000 C. Since the discovery by Merkli and Thomann that cooling can be produced by the sound assisted cooling effect in a resonance tube, research has concentrated on developing the effect for practical applications. One approach in the art has been to increase the audio pumping rate. While the experiments of Merkli and Thomann used frequencies of around 100 Hz, Wheatley et al. successfully raised the operating frequency to around 500 Hz and achieved impressive cooling rates in their refrigerator.

However, merely four decades before important efforts into this field were started at the Los Alamos National Laboratory (Los Alamos National Laboratory is the only laboratory in New Mexico, United States where Classified work towards the design of nuclear weapons has been undertaken besides the Lawrence Livermore National Laboratory), where various sort of sound assisted heat engine, refrigerator were developed. In this field a small amount of other research group are also carrying out there research work such as Acoustic Society of America, Acoustical Society of Australia, ASME, ASHERE, and other National Laboratories etc. On the other hand, the growth of sound assisted refrigeration devices is still at beginning phase. This has encouraged others to build various configurations of it.

The essential ingredients of a sound assisted refrigerator or heat pump are: i. A source of sound to pump heat into the device; ii. A Working gas, typically air at 1 atmosphere or inert gas; iii. An resonator for amplifying the level of sound and for providing phasing for the operation of the refrigerator; iv. A secondary medium comprising a stack along Which sound pumps heat, i;e a thermal rectifier; and v. Two heat exchangers, one at each end of stack providing a hot heat exchanger and a cold heat exchanger.

Each of the prior art sound assisted cooling system are relatively complicated to manufacture and thus expensive. In addition, sound assisted cooling system known in the art tend to be massive and typically not well suited for use on a very small level such as for use in cooling semiconductors and other small electronic devices or biological samples. Thus, it would be advantageous to provide a sound assisted cooling system that can be made relatively small with a fast response time while retaining good cooling abilities. In addition, it would be advantageous to provide sound assisted cooling system that operates relatively efficiently and that is relatively simple and economical to manufacture.

Objective of the invention

An objective of the present invention is to attempt to overcome the problems of the prior art and provide a novel sound assisted cooling system.

The present invention relates to optimization of sound assisted cooling system which provides batter cooling effect than existing system; this is the main reason.

Also the present system having advantages over existing technology such as; the present invention has small size device; improve cooling effect; can be utilized for cooling in automobile application; semiconductors and other small electronics devices etc.

Summary of the invention:

Accordingly following invention provides a novel sound assisted cooling system. Herein use one acoustic driver to generate high frequency sound within a resonator. The interaction of the high frequency sound with stack creates a temperature difference across the stack which is thermally anchored at each end to a pair of heat exchangers located on opposite sides of the stack.

Brief description of drawing:

Figure 1 denotes "Experimental Set-up" where 1 shows sound driver housing, 2 shows sound driver or speaker, 3 shows hot heat exchanger, 4 shows stack, 5 shows cold heat exchanger, 6 shows resonator, 7-8 shows flange, 9 shows buffer volume, 10 shows gas charging valve, 11 shows pump, 12-13 shows pressure gauge, 14 shows temperature indicator, 15 shows energy meter, 16-21 shows temperature sensors.

The sound driver housing, speaker, hot & cold heat exchanger, stack, resonator, buffer volume are connected together. Temperature sensors were connected with temperature indicator.

Detailed description of the invention:

A sound assisted cooling system utilizes the thermal interactions of the sound waves with the medium while they travel to produce cooling effect. Sound energy propagates in longitudinal fashion through the medium, thus resulting in compressions and rarefactions in the medium and hence heating and cooling the medium subsequently. The stack acts as a medium to transfer the heat from one point in the system to another. The stack is thus the heart of any sound assisted cooling system. The present invention provides a brief overview of the construction and working of sound assisted cooling system and focuses on the combination of stack geometry, gas mixture and optimization of a sound assisted cooling system. The proposed system can further be used in various cooling applications such as cooling devices for electronic components, laptops, computers or mobile phones, I. C. Engine components etc.

Basically most of the researchers work on spiral stack manufactured with Mylar sheet because of Mylar easily available in sheets and easy manufacturing. In this invention the stack is in manufactured with ABS (Acrylonitrile Butadiene Styrene) which is low thermal conductivity and high heat capacity material. Also the various geometries of stack such as circular, mesh, honeycomb, parallel, spiral etc. are used. Also the combination of such geometries also tested.

The experimentations firstly carried out with the helium gas and spiral stack manufactured with Mylar sheet and the COP of thermoacoustic refrigerator was recorded. Then the different stack manufactured with 3D printing technology and with different geometry such as circular, mesh, honeycomb, parallel, spiral are used with helium gas and the performance of the of the system for each stack is evaluated, the COP is estimated and then each stack '0 compared. All of the experiments are carried out at the same conditions. The ABS stack with different geometry with manufactured 3D printing technology are designed and installed accordingly to improve the performance of the system.

The sound assisted cooling system, which designed to work with helium, pressure were recorded with two pressure gauges at the gas charging and sound driver housing, and another one at before hot heat exchanger for variable pressure. The pressure gauges with resolution of 0.01 bar were used to indicate the pressure at charging and before cold heat exchanger in the sound assisted cooling system. A digital watt-hour meter which has 0.01 W resolutions were used to record the instantaneous power input to the cooling system and the integrated energy consumption.

The speaker is installed in housing before hot heat exchanger for generating sound wave with the help of sound generator. Two heat exchanger are installed in sound assisted cooling system one before stack is hot heat exchanger and another one after stack is cold heat exchanger, tubing is provided in heat exchanger for water flow to take out heat and coldness from heat exchanger

A sound assisted cooling system was instrumented with six temperature sensors (PT 100), the temperatures of the cooling system at six different points, as indicated in Figure 1, were recorded with PT 100 temperature sensors. Service ports were installed at the inlet of sound driver housing for charging and recovering the working gas. The system was charged with the help of a charging system and evacuated with the help of a vacuum pump. The sound assisted cooling system was charged with helium and spiral stack with Mylar sheet is used for the base line performance study. After completing the baseline test with Mylar sheet spiral stack, the gas and stack was recovered from the system and the experimental procedures were repeated with circular, mesh, honeycomb, parallel, spiral stack manufactured on 3D printer with ABS material.

The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated '0 and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A novel sound assisted cooling system, comprises of speaker, hot heat exchanger, cold heat exchanger, stack, resonator, buffer volume, water pump, pressure gauge, gas charging valve and temperature sensors.

2. The novel sound assisted cooling system as claimed in claim 1 wherein said stack is manufactured with 3D printing technology.

3. The novel sound assisted cooling system as claimed in claim 1 wherein said stack which is manufactured by material ABS (Acrylonitrile Butadiene Styrene).

4. The novel sound assisted cooling system as claimed in claim 1 wherein said stack may have different geometry such as circular, mesh, honeycomb, parallel, and spiral.

5. The novel sound assisted cooling system as claimed in claim 1 wherein said COP with Mesh, honeycomb and circular geometry of stack with ABS material is better than the spiral stack manufacture with Mylar sheet.