Compact cooler for electronics on the basis of a pulsating heat pipe

The paper presents the results of developing and investigating a compact cooler for electronics made on the basis of a closed loop pulsating heat pipe (CLPHP). The cooler is made of a copper tube 5.6 m long with OD of 2 mm and ID of 1.2 mm in the form a 3D spiral containing 17 turns. The device is equipped with a light copper radiator with a finning area of 1670 cm2, which was blown by an axial fan located inside the spiral. The thermal interface of the cooler situated in the heating zone is made of a copper plate with a thermocontact surface measuring 40 x 35 mm, which was in thermal contact with all the turns of the device. The cooler overall dimensions are 105 x 100 x 60 mm, its mass is 350 g. The operation of the cooler has been investigated with water, methanol and R141b as working fluids at a uniform and concentrated supply of a heat load in different heating modes. A reliable operation of the device has been demonstrated in the range of heat loads from 5 to 250 W. A minimum thermal resistance 'heat source-ambient air' equal to 0.32 deg. C/W was attained with water and methanol as working fluids at a uniform heat load of 250 W. With a heat load concentrated on a section of the thermal interface limited by an area of 1 cm2, a minimum value of thermal resistance equal to 0.62 deg. C/W was attained at a heat load of 125 W when methanol was used as a working fluid.