Electronics cooling

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

Comparative analysis of heat sink pressure drop using different methodologies

Abstract: Pressure drop across heat sink is one of the key variables that govern the thermal performance of the heat sink in forced convection environment. There are several analytical methods to estimate the heat sink pressure drop, however correctly selecting one that can represent the reality over a range of airflow found in typical electronics cooling application is difficult. In this paper, we propose a modified analytical method to estimate the channel velocity and used it to calculate the total heat sink pressure drop through different theoretical pressure drop equations. The theoretical results produced from the theoretical equations were compared against results gathered from experimental study and numerical method.

Transport Phenomena and Chemical Reactions in Modular Microstructured Devices

Abstract: Fluid flow and heat transfer in microchannels is since decades a wide area of vivid research in electronics cooling, compact heat exchangers, or chemical analytics. Fluid dynamics, mixing, and heat transfer are very important for performing exothermic chemical reactions in microchannels under stable and robust conditions. This contribution describes the complex interplay of single and multi-phase flow, residence time, mixing, and heat transfer with chemical kinetics. Dimensionless numbers and typical time scales guide the appropriate design and operation of microstructured equipment and chemical processes. Well-characterized, modular equipment enable short cut methods in the conceptual design phase and allow for consistent scale-up to production scale. The complex correlations are displayed here in a simple fashion with arrows, which can be replaced by relevant equations. The equipment is categorized with a toolbox concept of plate, tube, and vessel on certain platform levels for similar volumetri...

An overview and comparison of various refrigeration methods for microelectronics cooling

Abstract: Small-scale refrigerators, termed mesoscale refrigerators, are possible cooling solutions for high-power microelectronics. The performance of mesoscale refrigerators has not yet been experimentally demonstrated, although a recent theoretical model indicated that at temperatures near room temperature and above, a vapor compression refrigerator may compete successfully with a thermoelectric cooler having extremely high efficiency [1]. The present study proposes an overview and comparison between several alternative refrigeration methods used to actively cool the electronic components in a power microelectronics system. Three systems are evaluated, namely a miniaturized classical mechanical vapor compression system using an off-the-shelf compressor, a miniaturized system with ejector used for vapor compression, and finally a miniaturized refrigeration system with absorption, designed for similar cooling powers. The efficiency and COP of each system will be evaluated, together with associated reliability and cost related issues. The specifics of all proposed systems are based on the optimized performance of the miniaturized components of the various refrigeration systems, designed to fit the smaller scale power electronics populating a printed circuit board (PCB) in a high-power microelectronics system. For all designs, an array of micro-channels is used for vaporizer/condenser units. Several components of the refrigeration system are thermally evaluated for cooling powers ranging from 20- 100 W, with direct application to high power telecom units. Several advantages and/or disadvantages of these refrigeration-based cooling methods are highlighted. The study is concluded by identifying the pros and cons of implementing such systems to real-life microelectronics applications.

Modeling and control of single and multiple evaporator vapor compression cycles for electronics cooling

Abstract: This paper presents a dynamic model and feedback control strategies for vapor compression cycles (VCC) in electronics cooling applications. A notable difference between traditional VCC and VCC for electronics cooling is that two-phase flow is required at the evaporator outlet in order to avoid burnout. Therefore, the control objective is to avoid critical heat flux during transient heating conditions. An emphasis is placed on the heated accumulator, which is a necessary component to guarantee superheated flow in the compressor suction-line. Addition of heat in the accumulator provides control actuation that may be used to avoid the critical heat flux via the effect on system pressure. In contrast to previous work, we present more detailed evaporator and accumulator models, implement the heated accumulator as a control actuator, and consider both single and multiple evaporator systems. For single evaporator VCC, we use frequency-domain techniques to design a dual-input, proportional-integral controller using accumulator heat and compressor speed. Both simulation and experiment show this design to be superior to strategies that do not actuate accumulator heat. We then use similar design strategies to develop a controller for the much more challenging two-evaporator VCC.

Numerical simulation of phase change heat transfer in PCM-encapsulated heat sinks

Abstract: The enthalpy-based computational model is developed for analysing PCM-encapsulated heat sinks for electronics chips. Solution is obtained by developing a control volume-based finite difference code and results are validated by comparing results with that given by analytical solution available for a limiting case problem. Preliminary results based on a parametric study indicate the two-dimensional code developed for this study can be used in evaluating PCM, and selecting geometrical dimensions of the PCM encapsulated heat sink.