Heat pipe

About: Heat pipe is a research topic. Over the lifetime, 30354 publications have been published within this topic receiving 243669 citations. The topic is also known as: heatpipe & heat-pipe.

Liquid metal cooling in thermal management of computer chips

Abstract: With the rapid improvement of computer performance, tremendous heat generation in the chip becomes a major serious concern for thermal management. Meanwhile, CPU chips are becoming smaller and smaller with almost no room for the heat to escape. The total power-dissipation levels now reside on the order of 100 W with a peak power density of 400–500 W/cm2, and are still steadily climbing. As a result, it is extremely hard to attain higher performance and reliability. Because the conventional conduction and forcedair convection techniques are becoming incapable in providing adequate cooling for sophisticated electronic systems, new solutions such as liquid cooling, thermoelectric cooling, heat pipes, vapor chambers, etc. are being studied. Recently, it was realized that using a liquid metal or its alloys with a low melting point as coolant could significantly lower the chip temperature. This new generation heat transfer enhancement method raised many important fundamentals and practical issues to be solved. To accommodate to the coming endeavor in this area, this paper is dedicated to presenting an overall review on chip cooling using liquid metals or their alloys as coolant. Much more attention will be paid to the thermal properties of liquid metals with low melting points or their alloys and their potential applications in the chip cooling. Meanwhile, principles of several typical pumping methods such as mechanical, electromagnetic or peristaltic pumps will be illustrated. Some new advancement in making a liquid metal cooling device will be discussed. The liquid metal cooling is expected to open a new world for computer chip cooling because of its evident merits over traditional coolant.

Temperature regulation system for the human body using heat pipes

Abstract: A temperature regulation system for the human body is provided which uses heat pipes to distribute energy to and from portions of a body to provide heating or cooling by redistributing body heat. The heat pipes are incorporated into a garment, a blanket and a pad which may be used for medical treatment or activities or for activities in environments having extreme temperatures. Supplemental means for heating and cooling are included to improve heating or cooling to a body, and to provide heating or cooling to limited areas of a body.

The Heat Pipe

Abstract: THE HEAT PIPE IS ESSENTIALLY A CLOSED, EVACUATED CHAMBER WHOSE INSIDE WALLS ARE LINED WITH A CAPILLARY STRUCTURE, OR WICK, THAT IS SATURATED WITH A VOLATILE FLUID. THE OPERATION OF THE HEAT PIPE COMBINES VAPOR HEAT TRANSFER AND CAPILLARY ACTION. VAPOR HEAT TRANSFER IS RESPONSIBLE FOR TRANSPORTING THE HEAT ENERGY FROM THE EVAPORATOR SECTION AT ONE END OF THE PIPE TO THE CONDENSER SECTION AT THE OTHER END. CAPILLARY ACTION IS RESPONSIBLE FOR RETURNING THE CONDENSED WORKING FLUID BACK TO THE EVAPORATOR SECTION. THE VAPORIZED FLUID STORES HEAT ENERGY AT THE TEMPERATURE AT WHICH THE VAPOR WAS CREATED AND WILL RETAIN THE ENERGY AT THAT TEMPERATURE UNTIL IT MEETS A COLDER SURFACE. THIS TENDENCY TO RESIST ANY DIFFERENCE IN TEMPERATURE WITHIN THE HEAT PIPE IS RESPONSIBLE FOR THE DEVICE'S HIGH THERMAL CONDUCTANCE. THE HEAT PIPE CAN OPERATE AGAINST GRAVITY AND WITHOUT A SECOND EXTERNAL ENERGY SOURCE. DEVICES THAT OPERATE ON THE PRINCIPLE OF VAPOR HEAT TRANSFER CAN HAVE SEVERAL THOUSAND TIMES THE HEAT-TRANSFER CAPACITY OF THE BEST METALLIC CONDUCTORS. HEAT PIPES HAVE BEEN MADE TO OPERATE AT VARIOUS TEMPERATURES SPANNING THE RANGE FROM BELOW FREEZING TO OVER 3,600 F. THE POWER TRANSFERRED RANGES FROM A FEW WATTS TO MORE THAN 17,000 WATTS. THE HEAT PIPE IS A UNIQUE AND VERSATILE HEAT-TRANSFER DEVICE. ITS SPECIAL PROPERTIES ARE HIGH THERMAL CONDUCTANCE, TEMPERATURE FLATTENING, HEAT-FLUX TRANSFORMATION AND SEPARATION OF HEAT SOURCE FROM HEAT SINK.