Full Article - PDF - International Journals of Scientific Research

advertisement

International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013

Available online at http://www.ijsrpub.com/ijsrk

ISSN: 2322-4541; ©2013 IJSRPUB http://dx.doi.org/10.12983/ijsrk-2013-p025-033

Full Length Research Paper

Solar Powered Air Conditioning by Aid of TEC for Mina Tents Application

Wael A. Salah

1

, Soib Taib

2

, Anwar Al-Mofleh

3

, Hamza A. Ghulman

4

1

Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor, Malaysia

2

School of Electrical and Electronics Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal,

Penang, Malaysia

3

Faculty of Engineering Technology, Al-Balqa’ Applied University, Marka Ashamalia, Amman, Jordan

4

College of Engineering and Islamic Architecture, Umm Al-Qura University, Saudia Arabia

*

Corresponding author: Email: wael_sal@yahoo.com

, waelsalah.dr@gmail.com

; Tel: +603--8312 5508 ext. 5508, Fax:

+603-8318 3029

Received 4 January 2013; Accepted 15 February 2013

Abstract. This paper provides a review of some thermoelectric cooling (TE) applications in terms of the aspect of cooling at electronic equipments and some proposed cooling application for the future. A background discussion of thermoelectric cooling is provided in brief citing early history and current developments. In this paper, a review of the traditional cooling techniques, a highlight on the problems faced by each of the techniques is made and it is compared to the thermoelectric cooling. The aim of this paper is to discuss the possibility of making use of the Thermo Electric Coolers (TEC) for outdoor cooling applications. The utilization of water for cooling aid is discussed. The factors affecting the TE performance is discussed as well. The assembling consideration for best performance of TEC and the supply requirements for TEC will be discussed. Effects of water cooling and the other methods of cooling procedures also is discussed with practical comparisons.

Key words: TEC Cooling, TEG, Solar energy, Underwater, Outdoor.

1.

I NTRODUCTION

The advancements in computer technology have been made possible by the ongoing developments in the packaging density of electronics. In order to ensure satisfactory electrical circuit operation, limitation on the chip temperature is imposed to prevent it to rise above the ambient coolant temperature (Simons and

Chu, 2010). In many cases, special allocations with specific temperature for some electrical equipments has been implemented for safe and efficient operation.

The traditional cooling techniques have several problems such as noises and vibrations, and the usage of cooling gas has disastrous effect on the environment, not to mention the regular services for compressors.

A thermoelectric cooler (TEC) is a semiconductorbased electronic component that functions as a small heat pump. A thermoelectric device is a completely solid-state heat pump that is operated based on Peltier effect in which electrons carry energy to transfer heat from hot to cold junction, the heat will be moved through the module from one side to the other as a low voltage DC power source applied to a TE module

(Lau et al., 1994; The Technology Inc, 2006).

The energy required for the electrons movement through the system is provided by the power supply, this energy is expelled to a heat sink at the hot junction as electrons move from a high energy level element (n-type) to a lower energy level element (ptype). The n-p elements array is assembled so that it is electrically connected in series and thermally connected in parallel, then it affixed to two ceramic substrates, one on each side of the elements as shown in Fig.1.

One face will be cooled while the opposite module face is heated simultaneously. At the cold junction heat is absorbed by electrons as they pass from a low energy level in the p-type semiconductor element to a higher energy level in the n-type semiconductor element. Heat is absorbed at the cold side of the n- and p- type elements. The absorbed heat at the cold junction is pumped to the hot junction at a rate proportional to current passing through the circuit and the number of p-n junctions. With a suitable system design, the TEC device will operate as an effective heating

(Figure 1). and cooling source (Thermoelectric

Handbook, 2007; Magaland Technology Inc, 2002)

Commercially, the thermoelectric cooling (TEC) modules are widely available thus making them a potential candidate to be used in the thermal management of electronics applications (Moores et al., 1999). The typical cooling technique for

Electronics systems is by the forced air flow using axial fans or centrifugal blowers. When the heat loads

25

Salah et al.

Solar Powered Air Conditioning by Aid of TEC for Mina Tents Application are small and relatively diffuse, thermal conduction through aluminum plates is sufficient to spread the heat into finned heat sinks for convection from the fins into the air flow stream (Dubourdieu and Tribou,

1997). Liquid cooling system that can cool single or multiple heat sources is an adoptive solution in some current applications. A highly reliable compact pump is used to circulate the fluid in a closed loop. The overall system is integrated using assembly methods and materials that enable very low fluid permeation for long life (Kang et al., 2007).

Fig. 1: TEC module

Fig. 2: TEC module with the heat sink

Temp

Amps

Fig. 3: TEC direct measured temperature at cold side

2.

F EATURES OF TEC M ODULES Inc, 2006). Thermoelectric modules are noisy free because of no moving parts and are virtually

Thermoelectric systems are highly reliable provided they are installed and used in an appropriate manner.

Thermoelectric modules are at steady state and have a high mean time between failures (The Technology maintenance free due to the useless of chlorofluorocarbon gas. They can be operated in any orientation; also they are ideal for cooling applications that may be sensitive to mechanical vibration. The

26

International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013 ability to heat and cool lends to applications where both heating and cooling is necessary or where precise temperature control is critical (Optimizing TEC Drive

Current, 2006). Although the environmental legislation is getting tougher, the usage of thermoelectric as cooling system needs not to worry due to its non-negative impact on the environment.

The thermoelectric cooling system is triggered by electricity, thus eliminating the emissions of CFCs.

Another benefit is that, it needs no refill compared to conventional systems (Supercool, 2012; Salah et al.,

2010).

Fig. 4: Mini Cooler/ heater

In addition, the installation of TEC is quite simple and easy, with the caring of the conduction of TEC with the cooling object and the conduction of the hot side with the heat sink in order to insure the right operation of TEC modules. making use of the TEC-Thermo Electric Coolers cooling applications. Such application with small area is away-connected with the use solar energy as power source. The use of TEC in refrigeration application will be highlighted. The practical application of TEC

Air-conditioning is an important issue for providence of the necessity of human comfort. It is of great importance and would provide for environmental comfort to pilgrims during the Hajj performance, especially in times of summer.

Therefore, there is an essential requirement in the direction of creating the design that helps increase cooling service to be longer in life and reduce the use is presented for potential commercialization.

Mina is the largest membrane project in the world every year; more than three millions pilgrims perform the Hajj, the pilgrimage to the Holy Mosque in

Makkah. The Mina Valley is one of the Hajj stations and hosts the pilgrims for three days and nights.

During the 1997 Hajj season, a disastrous fire destroyed tens of thousands of cotton tents. The Saudi of energy consumed. For this purpose, the design is developed for this effect by using air conditioner accompanied by bands capture solar energy and use in to supply the process of Thermo- Electric Cooler

(TEC) plate, which provides additional cooling to occupied zone (tent).The essential search will be taken more focus in the design of cooling plate that attached with TE.

In the last few years, many researchers made effort to find out solution for hot and humid climate. This research is emphasizing to find out the appropriate air cooling develop solution that can work under any climate. Thermoelectric cooling (TEC) is a viable alternative for today’s traditional cooling techniques which have problems such as noise and vibration, more over the use of cooling gas and effect on the environment, and regular services for compressor. The aim of this paper is to discuss the possibility of

Authorities decided to re-build this vast city of tents by installing 40,000 durable fireproof tents. The only fabric that met these requirements was PTFE coated fiberglass.

It is obvious that any climate has corresponding air-conditioning, in order to deal with the environmental conditions to provide the necessary human comfort. A high-quality design should be required to accomplish this function. The issue of providing occupied zone (tent) in the Mina, and walls between Safa and Marwa air conditioning system of pressing issues is of great importance and would provide for environmental comfort to pilgrims during the Hajj performance, especially in times of summer.

Therefore, there is an essential requirement in the direction of creating the design which helps increase cooling service to be longer in life and reduce the use of energy consumed.

27

3.

TEC C OOLING D

Salah et al.

Solar Powered Air Conditioning by Aid of TEC for Mina Tents Application

ESIGN

The heat pumping capacity of a module is proportional to the current and is dependent on the element geometry, number of couples, and material properties (Thermoelectric Handbook, 2007).

Fig. 5: TEC attached to heatsink drown in water

Fig. 6: TEC performance

Fig. 7: Concept of TEC application for air cooling system

3.1. TEC Proper Fit Consideration although good thermal isolation between heat and cold side will give better performance. Figure 3 shows

The proper fit between the heat side of TEC and the heat sink affect the performance of TEC. Good thermal conduction will lead to better performance, the temperature measured directly from TEC cold side, this shows two states of measurements, one shows the data measured good thermal conduction of

28

International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013 heat sink and hot side of TEC and the other one with bad thermal conduction.

Figure 2 shows a single TEC module with the heat side attached to a heat sink and the cool side is free to air. The proper fit of TEC will improve its performance, especially when heat sink compound is added.

3.2. Thermal Isolation

To ensure the best performance to be achieved from

TEC module the importance of good thermal isolation between hot and cold sides are huge due to its sensitivity and the distance between the two sides is so small. To overcome such problem the attached heat sink is extended which it increases the distance from the heat sink plate to the cold sink plate. This allows for thicker insulation and longer assembly bolts. As a result, heat conducting from the heat sink plate back to the cold sink plate is reduced (Figures 2 and 3).

Appropriate air cooling solution that can work under any climate is a solution for hot and humid climate. For this purpose, by using air conditioner accompanied by bands capture solar energy and use in to supply the process of Thermo- Electric Cooler

(TEC) plate, this provides additional cooling to the tent. The aim is to determine the optimum operating parameters by the meaning if the comfort parameters in the occupied zone were within the range of acceptable comfort standards, and also to investigate the range of temperatures under varying space load conditions which was ranged between (23- 25°C) for the purpose of predicting and studying its effects in the functioning as well as its performance.

4.

A PPLICATIONS

TEC size and simplicity make it easy to be applied for cooling application where size and simplicity are required. One main application that can be under consideration is the cooling of away connected electronics, such as in the telecommunication cabinets. This cooling arrangement can be easily supplied from a PV panel with a DC converter.

Thermoelectric refrigeration is thought to be one of the alternative technologies that would help to reduce the rate of chlorofluorocarbon (CFC) refrigerants emission to the atmosphere, as this do not employ working fluids that are harmful to the environment.

(Lertsatitthanakorn, 2003).

4.1. Solar Fridge

A sample of fridge prototype unit is developed using 4

TEC as shown in Fig.4. The prototype with a 12 in x 8 in x 6 dimension using solar module of 70 W is

29 capable of functioning in both cooling and heating operation. The unit takes about 30 min to reach the minimum temperature of 18

0

C within the compartment (Figure 4).

4.2. Water and Thermoelectric Cooling

The efficient cooling system uses service water to cool the modules, a feature contributing to the converter’s compact design. An air-to-water heat exchanger is included, which cools the internal enclosure and is connected to the same cooling circuit as the power parts (ABB Schweiz AG, 2006; Melcor,

2000).

Fig.5 shows the TEC module attached to heat-sink, instead of attaching a fan, the heat-sink is been drown in the water. From this technique it has been observed that the performance of TEC cooling system improved by an average of 3 o

C, this effect is shown in Fig.6. If the supply is connected to solar module then the cooling system produces zero CO

2

emission.

As the trend towards higher power dissipation and more concentrated heat sources continues, a more attractive solution is to use closed liquid cooling loops to efficiently spread heat to finned surfaces that can be situated almost anywhere within the electronics system. These closed loops may be two-phase capillary pumped systems such as loop heat pipes or single or two-phase mechanically pumped systems.

The closed loop cooling systems function only as efficient heat spreaders internally within the electronics system enclosure by the closed loop liquid cooling systems, the need for high speed fans is mitigated and the noise levels can be significantly lowered (ABB Schweiz AG, 2006; Tellurex

Corporation, 2001) (Figures 5 and 6).

For under water application, the water cooling arrangements will be much easier as it will be open loop cooling, so there will be elimination of the heat exchanger and also the need for high speed fan is mitigated.

4.3. Underwater Thermoelectric Generator

Thermoelectric Generation could be done when thermoelectric modules are placed between hot and cold plates, then voltage and power could be obtained

(Optimizing TEC Drive Current, 2006). Proposed application could utilize the underwater environment that is, the use of Thermoelectric Generator where the water will present the cold side, and the heat generated by power components will present the hot side. This prospective application is expected to utilize the cold temperature of water and the heat generated by power components.

Salah et al.

Solar Powered Air Conditioning by Aid of TEC for Mina Tents Application

4.4. Air Cooling Medium for Various Applications

The nature of TEC is exploited by sticking the cold side to material which the air is to be flowed against.

Insulation between hot and cold side is very important than ever, in order for both; a) heat transfer mechanism to work well, and (b) TEC cooling mechanism working to maximum effect. It has been known that dissipation of heat will ensure the cold side to produce lower temperature. Thus, for this reason, a 12-Volt fan is attached at the heat sink end to provide greater heat dissipation.

Heat transfer mechanisms of conduction and radiation are practiced for this type of application.

Figure 7 is a related diagram that further explains the concept of air cooling system and cooler performance for high power electronic packages.

Fig. 8: Mina Tent Campus

Fig. 9: Proposed design of TEC tent

The thermoelectric cooler (TEC) performance could be conducted for high power electronic packages such as processors. In (Zhang et al., 2012;

Bierschen and Gilley, 2006; Hasan and Kok Chuan,

2007), two cooling scenarios, the processor test and the processor cooling under end-user conditions, are analyzed based on the present analysis models for two commercial TECs with high cooling power capacities nominal. The analytical results show that significant thermal enhancements are achievable based on optimized currents and cooling configurations (Figure

7).

The material to be used for heat transfer needs a very thorough examination. While the best heat conductor is gold, the material is very expensive in cost and also unpractical in mass productions. Copper represent a much logical and practical option and is rated second behind gold. In short, for such application to reach maximum potential, a good heat transferable material is essential so that the heat transfer mechanism occur effortlessly.

4.5. Air Conditioning by Aid of TEC for Tents

Cooling Application

It is obvious that climate has corresponding airconditioning, in order to deal with the environmental conditions to provide the necessary human comfort.

30

International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013

Air-conditioning is an important issue to provide comfortable condition for human. TEC application will enable adequate solutions for temporary usage of mobile tents where for example during the summer in the most Middle East countries, the heat is almost unbearable. An obvious applicable example is The

Mina Valley which is one of the Hajj stations and hosts the pilgrims for three days and nights as shown in Fig.8. Implementation of TEC on traditional cooling system is absolutely important in order to conserve energy and the fact that TEC utilizes natural source of solar, any system with the aid of TEC will be working fine at anywhere as the sunlight permits

(Figure 8).

The essential required in the direction of creating the design helps increase cooling service to be longer in life and reduce the use of energy consumed. An appropriate air cooling solution that can work under any climate is a solution for hot and humid climate.

For this purpose, by using air conditioner accompanied by bands capture solar energy and use in to supply the process of Thermo- Electric Cooler

(TEC) plate, this provides additional cooling to the tent. A future application of the system can be applied to tents as shown in (Figure 9).

5.

C ONCLUSION

The TEC cooling technique is found to be free of some problems attached to traditional cooling techniques such as noise, size and vibration. In addition, it has no side effect on the environment where there is zero emission of CO

2

gas. With their small size, efficiency, reliability, and environmental friendliness, TECs are becoming widely accepted as the most effective cooling source for many applications. The paper had discussed the use of the

TEC-Thermo Electric Coolers in cooling away connected applications with the use of solar energy as power source. The prototype TEC fridge has the potential for commercialization. Cooling system uses service water to cool the converter modules contributing to compact an efficient design. The TEC system had improved the temperature by an average of 3 o

C when water is used for direct cooling, therefore this technique become an alternative solution for underwater cooling. TEC could be an effective heating and cooling source with a proper design of TE system. An additional cooling to the tent could be supplied by the Thermo- Electric Cooler (TEC) plate, this will leads to more comfortable condition.

R EFERENCES

ABB Schweiz AG (2006). Avilable at: www.abb.com/powerelectronics .

31

Bierschenk J, Gilley M (2006). Assessment of TEC

Thermal and Reliability Requirements for

Thermoelectrically Enhanced Heat Sinks for

CPU Cooling Applications. in Thermoelectrics,

ICT '06. 25th International Conference.

Dubourdieu P, Tribou G (1997). Thermoelectric generator for underwater wellhead. The 16th

International Conference on Thermoelectrics.

Hasan MH, Kok Chuan T (2007). Optimization of a

Thermoelectric Cooler-Heat Sink Combination for Active Processor Cooling. in Electronics

Packaging Technology Conference, EPTC. 9th.

Jin W, Ke Z, Friend J (2009). Minimum power loss control thermoelectric technology in power electronics cooling. in Energy Conversion

Congress and Exposition, ECCE 2009. IEEE.

Kang S, Miller D, Cennamo J (2007). Closed Loop

Liquid Cooling For High Performance

Computer Systems Proceedings of IPACK2007,

ASME Inter PACK, Vancouver, CANADA.

Lau PG, Ritzer TM, Buist RJ (1994). Thermodynamic

Optimization of Heat/Cold Sink Extenders in

Thermoelectric Cooling Assemblies. TE

Technology Inc., Michigan, USA.

Lertsatitthanakorn C (2003). Cooling Performance of

Thermoelectric Water Cooler. Naresuan

University Journal, 11(2): 1-9.

Magaland Technology Inc (2012). Thermoelectric

Cooling Modules Application Note. Available at: www.magaland.com

.

Melcor (2000). Avilable at: www.melcor.com

.

Moores KA, Joshi YK, Miller G (1999). Performance assessment of thermoelectric coolers for use in high temperature electronics applications. 18th

International Conference on Thermoelectrics,

31- 34.

Optimizing TEC Drive Current (2006). Application

Note. Available at: www.ilxlightwave.com

.

Salah W, Taib S, Al-Mofleh A (2010). Development of Multistage Converter for Outdoor Thermal

Electric Cooling (TEC) Applications. Jordan

Journal of Mechanical and Industrial

Engineering (JJMIE), 4(1): 15 – 20.

Simons RE, Chu RC (2000). Application of

Thermoelectric Cooling to Electronic

Equipment: A Review and Analysis. Sixteenth

IEEE SEMI-THERM

Poughkcepsie, NY, USA.

Symposium,

Supercool AB (2012) www.supercool.com

.

Available at:

Tellurex Corporation (2001). Introduction to

Thermoelectrics, International Drive, Michigan.

Avilable at: http://www.tellurex.com

.

TE Technology Inc (2006). Available at: www.tetech.com/techinfo/ .

Salah et al.

Solar Powered Air Conditioning by Aid of TEC for Mina Tents Application

Thermoelectric Handbook (2007). Available at: www.melcor.com

.

Zhang HY, Mui YC, Tarin M (2012). Analysis of thermoelectric cooler performance for high power electronic packages. Applied Thermal

Engineering. In Press, Corrected Proof.

32

International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013

Wael A Y Salah was born in Hebron, Palestine in 1978. He received his B.Eng in Industrial Automation

Engineering (IAE) from Palestine Polytechnic University (PPU) in 2001. Awarded with M.Sc and Ph.D degrees from University Science Malaysia (USM) in 2007 and 2012 respectively. Attached to the

Faculty of Engineering, Multimedia University - Malaysia since 2012.

Research interest in Power Electronic and Drives, Energy Management Power Control and

Management, Renewable Energy System, Energy Efficiency.

Soib Bin Taib recieved his B.Sc from University Sains Malaysia in 1984. Works as system Engineer at

PERNAS NEC in 1985. Awarded with M.Sc and Ph.D degrees from Bradford University UK in 1986 and 1990 respectively. Attached to the department of Electrical and Electronic Engineering USM since

1990. Appointed as the Head of Power Program from 1997 until 2005. From 2004 appointed as the

R&D Task Manager for Centre for Education of Energy Efficiency and Renewable Energy (CETREE)

USM.

Research interest in Power Electronic and Drives, Experts Systems and currently involved in the development of Renewable Energy System Published more than 150 papers in Local and International journal and Proceeding.

Anwar al-Mofleh was born in Mahes, Jordan in 1969.recived his B.Sc and MSc from Byelorussian

Polytechnic academy in 1993. He is currently working as lecturer in Al-Balqa Applied University in

Jordan.

Research interest in Power and Energy Systems, Renewable Energy and Energy Efficiency.

Hamza A. Ghulman received his BSc from University King Abdulaziz in 1988 in Saudia Arabia and

MSc in 1993. Awarded with another MSc and PhD degrees from Ohio University in USA in 1996 and

2001 respectively. He is currently Professor at University Umm Al-Qura and involve in researches

(during Hajj seasons) with the Pilgrimage Researches Center in Makkah. Published more than 25 publications worldwide and two books. Member in ASME, SME, IIE, ASNT, and others.

33

Download