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

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 Introduction

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 semiconductor- based 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 (p- type). 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 and cooling source (Thermoelectric Handbook, 2007; Magaland Technology Inc, 2002) (Figure 1).

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 are small and relatively diffuse, thermal conduction through aluminum plates is sufficient to spread the Salali et al.

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

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Fig. 1: TEC module

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Fig. 2 : TEC module with the heat sink

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Fig. 3 : TEC direct measured temperature at cold side

2. Features of TEC Modules

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 Inc, 2006). Thermoelectric modules are noisy free because of no moving parts and are virtually 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 ability to heat and cool lends to applications where both heating and cooling is necessary or where precise International Journal of Scientific Research in Knowledge (IJSRK), 1(2), pp. 25-33, 2013 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.

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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.

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 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 making use of the TEC-Thermo Electric Coolers 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). 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 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 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.