Konvertering från luft till vätskekylning av elektronik

Sammanfattning: A Swedish electronics company wants to make the cooling of one of their electronic components more efficient. They propose that a retrofit liquid cooler is the way to achieve this goal. The current air cooling has high energy cost due to the high amount of power needed to power fans and heat exchangers. Using high volumes of air for cooling also leads to noise pollution. The conversion from air to liquid cooling would possibly make the operation of the electronics more cost efficient and less noisy. The purpose of this project is to theoretically evaluate different concepts of drawing the heat generated by the electronic component in to a fluid, using numerical calculations in Matlab and FEM simulations in ANSYS. Then using the evaluation as a base to design and construct a working prototype. This thesis will not include what happens to the liquid out side of the cooler i.e. pump performance and possible cooling of the liquid. Four concepts were generated. And to theoretically estimate the thermal flow in different concept configurations a division of the problem was made, specifically looking at the temperature drop between different parts of the construction as the heat moves from the electronics to the fluid. The maximum effect that the retrofit equipment will lead away is 200W and the air heat sink may maximally reach a temperature of 65°C. Together with the contact person at the electronics company a slot over concept was chosen for the prototype. The numerical calculations and the simulations show that in this application fourteen pipes would give the required performance and even gives the possibility of increased performance. Fourteen pipes mean a small temperature drop over the TIM even if low end thermal grease is used. Aluminum is chosen as construction material. The gable is made from rectangular tubing and the pipes are flat extruded micro tubes. To increase the rigidity of the design a solid plate that goes through the fins is placed on the top and bottom of the cooler. This plate also acts as the end plate of the gable The simulations and calculations clearly show that it is possible and more efficient to cool the heat sink that is made for air cooling with water. When comparing air and liquid cooling both with a coolant temperature of 55°C the liquid cooling system gives lower maximum heat sink temperature. A conversion would give lower running cost, a reduction of noise and would give the possibility to make use of the heat generated. This study shows that a conversion to liquid cooling is preferred therefore it is recommended that further studies and testing of conversion should be made.