Electronics cooling

About: Electronics cooling is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 17608 citations.

Miniature Vapor Compressor Refrigeration System for Electronic Cooling

Abstract: This paper experimentally investigated the thermal performance of a miniature vapor compressor refrigeration system using a thermal resistance model for electronic cooling. The evaporator, compressor, expansion valve, and condenser are the four main devices forming the refrigeration system with R-134a as a working fluid. The experimental parameters considered were the openings of the expansion valve and input heating power. The results indicated that the system in this paper had the largest cooling capacity of 150 W and coefficient of performance of 4.25 at the 8th and 9th openings of the expansion valve, respectively. The results also showed that correlations of the thermal resistance of the evaporator and the condenser are developed with experimental data and their precision, compared with the experimental data, was about 4.42% and 12%, respectively. Besides the adjustment of the compressor speed could decrease the possibility of the occurrence of condensation phenomena near the inlet and outlet of the evaporator. Also, the smallest dimension of the combination of the evaporator and condenser is presented at the input heating power of 150 W and the 8th opening of the expansion valve.

Multiscale modelling of nucleate boiling on nanocoatings for electronics cooling—From nanoscale to macroscale

Abstract: This paper presents a review of the latest experimental and theoretical studies on enhancing boiling/evaporative heat transfer using nanofabricated porous coatings, with potential applications in the fields of electronics thermal management. It is proposed that the key to enhanced heat transfer lies in optimal design of nanostructures that can activate a reduced/negative pressure through nanoscale evaporation, allow continuous liquid microflow through the porous nanostructures, and facilitate bubble release from the coating. In this point of view, a multiscale predictive approach that covers a wide size range from nanoscale to the system size is critical. We propose this can be achieved by combing Molecular Dynamics (MD) simulations, the Lattice Boltzmann Method (LBM), and Two-Fluid Model (TFM) in a coupled way, with the MD addressing the generation of negative pressure, LBM modelling the liquid microflow, and TFM simulating the two-phase coolant flows. The comprehensive modelling strategy will provide a mechanistic all-in-one simulation of the complex multiscale process, and greatly boost the design of optimal nanostructures.

On the use of second law based cost functions in plate fin heat sink design

Abstract: This paper discusses the use of the second law in heat sink design. A new entropy-based cost function is proposed and compared with existing heat sink cost functions. A case study of a plate fin heat sink points out that this newly developed cost function offers a heat sink which is more than twice as efficient as a heat sink designed with the traditional thermal resistance minimization objective. The effects of this new heat sink design on data center cooling systems are considered and found to be significantly improving the system efficiency and waste heat recovery.

Rapid design of heat sinks for electronic cooling using computational and experimental tools

Abstract: Design of electronic cooling systems for high volume manufacturing within the time frame of months for increasingly aggressive performance and cost requirements is difficult without the use of sophisticated computational and experimental tools. Described here are the tools and methods for evaluating designs of electronic cooling heat sinks. Examples using thermal finite element analysis (FEA) and computational fluid dynamics (CFD) are presented. Quantitative data from wind tunnel testing compare well with model results. Qualitative data from infrared (IR) spectroscopy provides insight on the interfacial effect. Issues associated with the interface resistance are discussed.

Heat Pipes for High Temperature Thermal Management

Abstract: Copper water heat pipes are a well-established solution for many conventional electronics cooling applications; however they have several problems when applied to high temperature electronics. The high vapor pressure of the working fluid combined with the decreasing strength of an already soft material leads to excessive wall thickness, high mass, and an inability to make thermally useful structures such as planar heat pipes (vapor chambers) or heat pipes with flat input surfaces. Titanium/water and Monel/water heat pipes can overcome the disadvantages of copper/water heat pipes and produce a viable thermal management solution for high temperature electronics. Water remains the fluid of choice at temperature up to about 280°C due to its favorable transport properties. Life tests have shown compatibility at high temperature. At temperatures above roughly 300°C, water is no longer a suitable fluid, due to high vapor pressure and low surface tension as the critical point is approached. At higher temperatures, another working fluid/envelope combination is required, either an organic or halide working fluid. Preliminary halide life test results are presented, giving fluids that can operate at temperatures as high as 425°C. At higher temperatures, alkali metal heat pipes are suitable. Water and the higher temperature working fluids can offer solutions for cooling high-temperature electronics, or those working at or above 150°C.Copyright © 2007 by ASME