EFFECTIVENESS ANALYSIS OF THERMAL MANAGEMENT SYSTEMS OF LAPTOPS
The advancements in the field of technology in the last few decades have led to a significant improvement in the speed of computers along with reduction in their sizes. However, this has also increased the heat generation rate in the modern computer systems. This heat if not rejected by a proper channel, may cause formation of hot spots in the circuitry and may even damage the hardware. Many techniques have been proposed and being used so far in order to eradicate their heat. Hybrid thermal management is one such way to overcome the heating problem and is used extensively in modern laptops. In this technique, the part of the computer that is the source of heat generation is glued to a conductive surface. Further, the conductive surface is attached to a surface with extrusions and/or projections via heat pipe so as to increase the surface area and thus to facilitate better heat transfer from the heating element. The heat is then removed out from the system through forced convection by using a fan or blower.
The current work focuses on presenting a numerical analysis of the effectiveness of thermal management system in laptop circuit board. Three cases are analyzed so as to showcase a comparative picture of how heat transfer could be enhanced using thermal management systems of different types. In the first case, the analysis is made for passive cooling provided by conducting plates mounted on the components and serving as heat sinks. In the second case, the model is improved by enhancing heat transfer through incorporation of finned heat sink and heat pipe combination which serves as a heat exchanger. In the final case a hybrid thermal cooling system is studied which comprises of fans along with conducting plates and heat exchanger. The three cases are compared in terms of heat rejection and temperature distribution and thus the need of hybrid system is justified.
The analysis is done using Finite Element based software COMSOL 4.2. All the three modes of heat transfer are taken into account. Special emphasis has been laid on simplifying the complex geometry wherever possible with equivalent two dimensional computational domains but keeping the physics intact. This significantly reduced the computational cost. The results were validated for the selected cases. The current work could enable us to gain a clear and better understanding of the cooling mechanism in laptops and thus serve as an initial step toward the modifications and improvisation in existing laptop thermal management systems.