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AN ANALYSIS AND STUDY ON COOLING JACKET
UDDAISHYA PRAJAPATI, SHREYA PANDEY, VEDANT VERMA,PRAKHAR KUSHWAHA1 , SHIRISH JAIN2
1Project Scholar,Department of Electrical Engineering, GGITS Jabalpur
2 Asst. Prof. Department of Electrical Engineering, GGITS Jabalpur
ABSTRACT:Due to metabolic heat generation from our body, we are very uncomfortable both incold and hot weather, especially when we work hard.
In cold weather we wear jacket to havemore comfort. We can’t have much comfort when we use jacket. Unlike cold weather, in hotweather we don’t have such an alternative solution for comfort. If there is a jacket cooler, then it will be comfort both in cold and hot weather. A thermoelectric cooling prototype jacket hasbeen fabricated. An innovative evaporative type heat sink has been designed and fabricated. Acontrol switch to regulate the flow of current through the circuit thus to control the heatcapacity of the module has been prepared. The performance of the prototype jacket wasevaluated by analytical and numerical methods. Ansys 9.0 was used for numerical analysis.
Keywords: Thermoelectric cooler, Cooling jacket, Control switch, Heat sink 1. INTRODUCTION
The Peltier effect is a temperature difference created by applying a voltage between two electrodes connected to a sample of semiconductor material. This phenomenon can be useful when it is necessary to transfer heat from one medium to another on a small scale. The Peltier effect is one of three types of thermoelectric effect;
the other two are the Seebeck effect and the Thomson effect. The virtualized network poses challenges to network management systems and as more hardware components become virtualized, that challenge becomes even greater. This handbook discusses the steps IT must take to both build and corral their virtualized infrastructure. Thermoelectric cooler or Pettier cooler is a solid- state heat pump that uses the Peltier effect tomove heat.
Thermoelectric elements are so small and light that they have been used in manyfields [1]. A cooling device for personal use outdoors is
a necessity under very hot atmosphere.The purpose of this project was to make a prototype of cooling jacket that is refrigerated by moelectric element driven by battery and to investigate the possibility of a personal coolingunit for outdoor use. A literature survey is conducted to review the proceedings along this way.The personal care apparels are given due care in the review. Here, mainly two type reviews areconducted. One review is strictly restricted on the papers published on the journals. There aremany papers on thermoelectric elements. But there are only a few papers on applications ofthermoelectric modules. There are headgears refrigerated by thermoelectric modules [2].
Butunfortunately there is no cooling jacket refrigerated by thermoelectric modules. But there aremany cooling jackets with different methods for cool them.
One is phase change material
2 basedand another is a fan cooled one. The design of a heat sink suitable for the efficient operation ofthe thermoelectric module is necessary. During the operation heat will be continuously rejectedat the hot end. Thus there will be a chance for accumulation of heat at the hot end. Thus, due tothe accumulation of heat at the hot end the temperature difference between the cold end and thehot end will be more. This will enhance the heat transfer rate from the hot end to the cold end,i.e., reverse flow of heat from hot end to cold end. So to operate the thermoelectric modulemore efficiently there must be a heat sink at the hot end. The thermoelectric module with heatsink must be kept inside the Jacket to cool the inside of the jacket. So it is not possible to use an ordinary air cooled type heat sink or complicated water cooled type heat sink. An innovativetype heat sink must be designed for this purpose. A simple Evaporative cooling type heat sinkhas been designed for this purpose. The electrons are the heat carries in the thermoelectricmodule. To control the heat carrying capacity or the temperature of the cold end of thethermoelectric module the number of electrons passing through the module must be regulated.A control switch (CS) can be used to regulate the current through the circuit. The design andthe fabrication of the control switch have been discussed here.
ANSYS PROVIDES A COST EFFECTIVE
way to explore the performance of products or processes in a virtual environment. This type ofproduct
development is termed virtual prototyping. The finite element method (FEM) hasbecome an essential solution technique in many areas of engineering and physics. The methodcan easily be adapted to different sets of constitutive equations, which makes it particularlyattractive for coupled-physics simulation. The numerical analysis of the thermoelectric modulehas been done in the ANSYS software package.
2. PROPOSED MODEL
The suitable thermoelectric modules are selected according to the selection procedure described[3]. The model presented here has two thermoelectric modules. Each thermoelectric modulecan absorb approximately 6 watts. For a typical person, for 70 W heat load of moderate work,there must at least 12 modules (70/6 = 12) [4]. More number of modules can be used dependsupon the severe of activity.
But unfortunately due to some constraints only two modules areused in the model. The modules are connected electrically in series to pass equal amount ofcurrent through all the modules. The components included in the prototype are as follows,
(i)Two thermoelectric modules (ii) Two heat sinks with water reservoir
(iii) A control switch (iv)A DC power source.
The modules are connected to a DC power source via a control switch.The control switch regulates the flow of current through the modules in the circuit. To
3 measurethe temperature at the surface of the cold end a temperature sensor is attached into the surface.The temperature can be read from the display provided on the control switch.
Eachthermoelectric module has its own heat sink. The heat sinks are evaporative cooling type. Thereis a common water reservoir to supply water in to the heat sink from where the water getsevaporated by receiving heat from the module.
Figure 1.Proposed model of the Cooling Jacket
The jacket is a specifically designed one with pocket to house the modules with heat sinks.
Themodules with heat sinks are inserted into the pocket provided in the back side of the jacket.
Aninsulation layer is provided to separate the cold side from the hot side. There is a separatepocket for keeping battery. The interconnections are made internally. A temperature sensor canbe incorporated in the model to control the temperature.
3. OPERATION OF THE COOLING JACKET
The operation of the model presented here is described below.
All the components areconnected in the manner mentioned above.
The components are mainly two coolers with heatsinks, a battery and a control switch. When the switch in the control switch is put on, thecurrent from the battery flows through the cooler via control switch. The control switch gives a Pulsating current from the control switch [5]. The control switch is used to control thetemperature of the faces. By adjusting the potentiometer in the control switch, the temperatureof the faces can be altered.When the current passes through the cooler the electrons carries heat from the cold face to thehot face. The heat is rejected at the hot face of the cooler. Due to this the heat will be accumulated at the hot face. An innovative type of heat sink is attached at the hot face of thecooler. The heat sink has a sponge in it. The sponge can hold water. When it receives heat fromthe hot face of the cooler, the water in the sponge of the heat sink gets evaporated and escapes,thus heat is dissipated away. There is a water reservoir to store the required amount of water forthe continuous operation of four hours. The water from a reservoir is fed continuously in to theheat sink. When all the water is exhausted from the reservoir, then the water must be filledbefore the next use. The battery must be recharged when it is exhausted before the next use.
4 Figure 2. The operation of the
cooler
4. DESIGN OF HEAT SINK
The main parts of this evaporative cooling type heat sink are as follows:
(i) Heat sink with a piece of sponge attached into it
(ii) A container to store enough water
(iii)A regulator to control the flow of water
Figure. 3 Total thermal resistance of the heat sink and the ambient
air
Figure 4. Proposed model of heat sink
The total thermal resistance of the heat sink and the ambient air is taken as 2.42 oC / W. Thethermal interface material used here is heat sink compounds. There is a carrier liquid such assilicone (or other synthetic fluid) that is filled with micro fine particles of thermally conductivematerials such as zinc oxide, aluminum oxide, boron nitride, or silver.
Thermal conductivityranges from 0.8 W/m-K to 7.5 W/m-K. The amount heat rejected at the hot end of the moduleis around 14 W, 50.4 kJ / hr. Therefore, the amount of water required to operate onethermoelectric module for four hours is 79.01 ml.
5. CONCLUSIONS
A jacket for safe guarding a person from hot atmosphere is the objective of this project.
Thethermoelectric refrigeration is the method adopted here. A prototype of the proposed coolingjacket is designed and fabricated. The following are main components to fabricate the proposedcooling jacket. The thermoelectric modules which work on the principle of Peltier effect areselected for the cooling jacket for refrigerating effect. To order to operate the thermoelectricmodule efficiently, the heat accumulates at the hot end must be dissipated. A heat sink with awater reservoir is designed and fabricated for this purpose. The thermoelectric module must notbe overloaded.
The temperature at the cold end can be varied by adjusting the flow of currentthrough the circuit. A control switch is designed and assembled to do this. The componentsmust be suitably
5 concealed in a jacket. A suitable fabric jacket is designed and prepared for this.The works done are properly ordered and documented in the thesis.
APPLICATIONS
Cooling vests are also used by personswithmultiple sclerosis. In multiple sclerosis, nerve fibers become demyelinated which leads to pain and discomfort when temperature is elevated. Nerve fibers may also be remyelinating or in the process of repairing themselves and still be sensitive to elevated temperatures. The cooling vest keeps the patient's temperature down, reducing the pain symptoms The effects of cooling vests on athletes to improve their performance has been evaluated on several occasions; These jackets are used in summer for maintaining the body temperature.It helps in proper cooling.
REFERENCES
[1] TE Technology, Inc. (2012).
Thermoelectric Modules. Retrieved April2012.http://www.tetech.com/
modules/
[2] T. Hara, H. Azuma, H. Shimizu, H. Obora, Cooling performance of solar cell driven, thermoelectric coolingprototype headgear, Applied thermal engineering, Vol. 18 (1998), pp. 1159-1169.
[3] Mollar (2003). Thermoelectric
Cooler Selection
Procedure.Retrieved June 2011.http://www.marlow.com/Tec hnicalInfo/themoelectric_cooler_sel ection_p.htm
[4] Yunus A Cengel, and Michel A Boles, Thermodynamics: An Engineering Approach, 5th Edition, McGrawHill, 1998.
[5] D. Roy Choudhury, Linear Integrated Circuits, New Age International (P) Limited, New Delhi, ThirteenthReprint, Jan 1999.
[6] Landau L D, and Lifshitz, E. M., Electrodynamics of Continuous Media, 2nd Edition, Butterworth- Heinemann, Oxford, 1984.
[7] Silvester P P and Ferrari, R. L., Finite Elements for Electrical Engineers, 3rd Edition, University Press,Cambridge, 1996.
[8] Monohar Prasad, Refrigeration and Air conditioning, 2nd Edition, 2003.
[9] Angrist, S. W., Direct Energy Conversion, 4rd Edition, Ally and Bacon, Baston, 1986, pp. 146-166.
[10] Ansys Coupled–Field analysis guide, Ansys Release 10.0, Ansys, Inc. and Ansys Europe, Ltd, 002184,August 2005.
6 About Authors
UDDAISHYA PRAJAPATI, Pursuing bachelor degree in Electrical Engineering from Gyan Ganga Institute of Technology and Sciences, Currently I’m in 6th Semester (Session 2014-2018)
SHREYA PANDEY,
Pursuing bachelor degree in Electrical Engineering from Gyan Ganga Institute of Technology and Sciences, Currently I’m in 6th Semester (Session 2014-2018)
PRAKHAR KUSHWAHA, Pursuing bachelor degree in Electrical Engineering from Gyan Ganga Institute of Technology and Sciences, Currently I’m in 6th Semester (Session 2014-2018)
VEDANT VERMA,
Pursuing bachelor degree in Electrical Engineering from Gyan Ganga Institute of Technology and Sciences Currently I’m in 6th Semester (Session 2014-2018)
