Experimental Investigation on the Thermal Performances of a New Design of Pulsating Heat Pipe with Two Condensers

In this paper a novel design of pulsating heat pipe (PHP) with one evaporator and two condensers located on both sides of the evaporator at an angle to the horizon was proposed, manufactured and experimentally investigated for the purpose of use in cooling systems for electronic devices operating in a tilted position. The PHP body is made of a copper capillary tube with an inner diameter of 1.5 mm. The working fluid is methanol. The number of turns is 4. The heating zone dimensions are 60 mm × 36 mm, the cooling zone is 200 mm × 35 mm. The dependences of the temperature in the heating and cooling zones and the PHP thermal resistance both on the power input (from 30 W to 200 W), and on the orientation in space (at tilt angles of 0°, 15°, 30°, 60°, 90°) were obtained. In the power range from 120 W to 200 W the tilt angle practically does not affect the thermal resistance. A comparison of the thermal resistance of the developed PHP with known PHPs filled with methanol, showed the high efficiency of the developed PHP: at power input from 120 W to 200 W, the thermal resistance was from 0.2 °C W−1 to 0.18°C W−1. The developed PHP design is promising for use in air cooling systems, for instance, of radar transmit/receive modules and high-power LED lighting systems.