Preliminary communication
Published in: Holistic Approach Environ. 5(2015) 4, pp. 171 – 177
Paper reference number: HAE-95
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Martin Smitka*, Patrik Nemec*, Zuzana Kolkova*, Milan Malcho*

* Faculty of Mechanical Engineering, University of Žilina, Slovakia



Given the rapid progress in the electronics industry, the thermal management of electronics components becomes an important and serious issue. Natural and forced cooling are often deficient. One possibility for heat dissipation for high heat flux is using loop heat pipe. A loop heat pipe (LHP) is a two-phase device with extremely high effective thermal conductivity that utilizes pressure difference in wick to circulate working fluid. It was invented in Russia in the early 1980’s. LHP is composed by an evaporator, a condenser, a compensation chamber (reservoir) and a vapour and liquid lines. Only the evaporator and part of the compensation chamber are equipped with a wick structure. The use of the wick structure in the evaporator provides a stable physical interface between the liquid and the vapor phases in the LHP. This work deals with the design of LHP for cooling of Insulated gate bipolar transistor and impact of tilt angle of LHP on temperature of transistor. The LHP position is changed from the vertical position (90°) to the horizontal position (0°) during the measurement. The LHP evaporator is made up with copper pipe and alumina saddle. Inside of the evaporator is wick structure and it is made from copper powder. The condenser is made as a tube heat exchanger. The water temperature for cooling is set at 20 °C and it is regulated by a thermostat. The temperatures are measured with the thermocouples. As the working fluid was used distilled water. The maximum permissible temperature of transistor is 100 °C.

Keywords: loop heat pipe, cooling, wick, position