Thermal management

Eig. 11. Liquid-cooled cold plates or heat sinks have been developed as thermal management solutions to cool components for Hquid-cooled computer systems and other electronic systems where heat removal becomes one of the important design criteria. 

Applied Sciences, Inc. has, in the past few years, used the fixed catalyst fiber to fabricate and analyze VGCF-reinforced composites which could be candidate materials for thermal management substrates in high density, high power electronic devices and space power system radiator fins and high performance applications such as plasma facing components in experimental nuclear fusion reactors. These composites include carbon/carbon (CC) composites, polymer matrix composites, and metal matrix composites (MMC). Measurements have been made of thermal conductivity, coefficient of thermal expansion (CTE), tensile strength, and tensile modulus. Representative results are described below. 

Ting, J.-M., and Lake,. M.L., Carbon/carbon for thermal management, Proc. 16th Ann. Conf. Comp., Mat. Structures, Cocoa Beach, FL, January, 1992. 

Alternatively, the fuel cell stack can he operated at ambient pressure. Although this simplifies the system considerably and raises overall efficiency, it docs reduce stack power and increase thermal management challenges. 

Heat rejection is only one aspect of thermal management. Thermal integration is vital for optimizing fuel cell system efficiency, cost, volume and weight. Other critical tasks, depending on the fuel cell, are water recovery (from fuel cell stack to fuel processor) and freeze-thaw management. 

The thermal management of the battery necessitates heaters and cooling devices together with temperature sensors. Both oil... 

Piezoelectric fans are small, low-power, relatively low-noise, solid-state devices that provide viable thermal management solutions for a variety of portable electronic appliances, including laptop computers and cellular phones. In these fans piezoceramic patches are bonded onto thin, low-frequency flexible blades driven at resonance frequency, thereby creating an air stream directed at the electronics components. Thereby, up to 100% improvement over natural convective heat transfer can be achieved (Acikalin et al. 2004). 

In a phase-change controlled thermal management system, the energy associated with phase change will account for most of the heat removal... 

Calame JP, Myers RE, Binari SC, Wood FN, Garven M (2007) Experimental investigation of micro-channel coolers for the high heat flux thermal management of GaN-on-SiC semiconductor devices. Int J Heat Mass Transfer 50 4767-4779 Celata GP, Cumo M, Zummo G (2004) Thermal-hydraulic characteristics of single- phase flow in capillary pipes. Exp Thermal Fluid Sci 28 87-95 Celata GP (2004). Heat transfer and fluid flow in micro-channels. Begell House, N.Y. 

Morini Gl, Lorenzini M, Salvigini S (2006) Friction characteristics of compressible gas flows in micro-tubes. Exp. Thermal and Fluid Science 30 733-744 Mudawar 1 (2001) Assessment of high-heat-flux thermal management schemes. IEEE CPT Trans 24 122-141... 

Thermal management Heat-sink diodes Heat-sink PC boards Thermal printers Target heat-sinks... 

To remove this unwanted heat (also known as thermal management), it is often necessary to use hybrid circuits and bulky heat-dissipation devices or complicated and expensive refrigeration. Metals with good thermal conductivity, such as copper or aluminum, are presently used as heat sink materials but, since being metals they also have high electrical conductivity, they require an electrical-insulation barrier. 

Eden, R. C., Application of Synthetic Diamond Substrate for Thermal Management of High Performance Electronic Multi-Chip Modules, in Applications of Diamond Films and Related Materials, (Y. Tzeng, etal., eds.), Elsevier Science Publishers, pp. 259-266(1991)... 

By an industrial investigation of a gas-phase reaction, the chlorination of alkanes, thermal management (faster temperature ramping, avoidance of overshoots) was improved and, hence, control over radical formation was exerted. As a result, a significant increase in space-time yield to about 430 g h 1 was achieved using a hybrid micro-reactor plant compared with the conventional performance of 240 g h [127, 161]. 

When considering the thermal management of very exothermic reactions and the avoidance of corresponding explosions, it is the minute volume of micro readors that is addressed [4]. 

Figure 7-5 Thermal Management Constraints Can Force Nonoptimum Secondary-side Routing and Cause Excessive Ringing and Even Diode Failures—Possible Solution May Be to Put a Small Bead in Series with the Diode, to Damp out the Ringing... 

Of course there is no copyright or patent issue involved in showing you the fairly clever routing cum thermal management scheme of Figure 7-5. At least not today. But try to understand how delicate that situation was at that time (over a dozen years ago). My... 

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