Proceedings of the
International Conference on Mechanical Engineering 2009
(ICME2009) 26- 28 December 2009, Dhaka, Bangladesh

ICME09-TH-14

OPERATIONAL AND PRESSURE CHARACTERISTICS OF A
THERMOLOOP DEVICE

ABSTRACT

Thermoloop, a particular kind of two phase pulsated thermosyphon (PTPT) is passive cooling device which can meet high heat flux dissipation requirements. This paper gives emphasis on the analysis of working phenomena and operational characteristics of this device. The PTPT comprises of three components; evaporator, condenser and reservoir connected by flexible tubing. Experiments were carried out for different working fluids and thermal loads for a specific geometry of the device. During each experiment the temperature of the components at different points and pressure at evaporator were measured at steady state condition. Neither mechanical pump nor gravity force is used to assist the flow. Only natural convection was allowed for condensation. It is realized that, the variation of pressure drives the working fluid through the system components. Development of vacuum pressure due to condensation plays key role to refill the evaporator with fresh liquid at the end of each cycle. For a particular working fluid the cycle duration decreases with thermal load but, the ΔTsat, maximum evaporator wall temperature, and maximum cycle pressure increases. The condensate return temperature and maximum vacuum pressure increases slightly with thermal load. The operating cycle can be described by three regions viz. constant volume heat addition, vapor transfer and condensate return region.

Keywords: Thermoloop, Evaporator Pressure Drop, Cycle Time.

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