Electronics cooling

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

Identification of the Dominant Heat Transfer Mechanisms during Confined Two-phase Jet Impingement

Abstract: Two-phase jet impingement is a compact cooling technology capable of dissipating the large heat fluxes required for thermal management of high-power electronics devices. It is important to understand the primary heat transfer mechanisms that occur during regimes of jet impingement for which boiling occurs, specifically in the confined impingement geometries common to electronics cooling applications. In this study, heat transfer from a surface is experimentally characterized in both confined jet impingement and pool boiling configurations. The dielectric liquid HFE-7100 is used as the working fluid. For the impingement configuration, the jet issues through a single orifice with a diameter of 2 mm, at exit velocities of 1 m/s and 3.33 m/s, into a confinement gap with an orifice-to-target spacing ratio of 3. Additional orifice-to-target spacings of 0.5 and 5 times the jet diameter are tested at the lower jet velocity. The heat flux applied at the surface was increased in steps to characterize the single-phase and two-phase heat transfer performance; all experiments were carried through to critical heat flux conditions. Over the range of velocities and orifice-to-target spacings tested, the jet impingement data in the fully boiling regime coincide with the pool boiling data. This result indicates, for the range of parameters considered in this study, that nucleate boiling is the dominant heat transfer mechanism in the fully boiling regime in confined jet impingement. The impinging jet velocity and orifice-to-target spacing only influence the single-phase heat transfer and critical heat flux.

Microchannel Radiator: an Investigation of Microchannel Technology with Applications in Automotive Radiator Heat Exchangers

Abstract: Microchannels have been used in electronics cooling and in air conditioning applications as condensers. Little study has been made in the application of microchannels in automotive heat exchangers, particularly the radiator. The presented research captures the need for the design improvement of radiator heat exchangers in heavy-duty vehicles in order to reduce aerodynamic drag and improve fuel economy. A method for analyzing an existing radiator is set forth including the needed parameters for effective comparisons of alternative designs. An investigation of microchannels was presented and it was determined that microchannels can improve the overall heat transfer of a radiator but this alone will not decrease the dimensions of the radiator. Investigations into improving the air-side heat transfer were considered and an improved fin design was found which allows a reduction in frontal area while maintaining heat transfer. The overall heat transfer of the design was improved from the original design by 7% well as 52% decrease in frontal area but at the cost of 300% increase in auxiliary power. The energy saved by a reduction in frontal area is not substantial enough to justify the increase of auxiliary power. The findings were verified through a computational fluid dynamic model to demonstrate the heat transfer and pressure drop of microchannel tubes. The results confirmed that heat transfer of microchannels does improve the thermal performance of the radiator but the pressure drop is such that the net benefit does not outweigh the operating cost. An additional CFD study of the new fin geometry and air-side heat transfer predictions was conducted. The results of the study confirmed the theoretical calculations for the fin geometry.

Electronics cooling device

Abstract: PROBLEM TO BE SOLVED: To cool electronics even while a power supply is stopped. SOLUTION: An electronics cooling device includes: a first air-conditioner for air-conditioning a computer room and a second air-conditioner for air-conditioning a cabinet, where one is constituted of an electric air-conditioner for driving a compressor by an electric motor and the other is constituted of a gas engine air-conditioner for driving the compressor and the electric motor by gas engine and driving the auxiliary machine of the air-conditioner by generated power; and a detection means (a central controller 200) for detecting the occurrence of the power supply stop state from a commercial power supply 300 to the electric air-conditioner. In a normal operation, the electronics stored in the cabinet are cooled by the total ability of the electric air-conditioner and the gas engine air-conditioner. In the power supply stop state, the ability of the gas engine air-conditioner is increased, so as to cool the electronics in the cabinet by the increased ability of the gas engine air-conditioner. COPYRIGHT: (C)2010,JPO&INPIT

Thermal Management of Electronics to Avoid Fire Using Different Air Flow Strategies

Abstract: Due to high heat generation within closely packed smart electronic devices, some efficient thermal management systems are required for their reliable performance, avoid overheating, long lifecycle and safety. In this study, a novel thermal management system based on forced air cooling having three airflow configurations is developed to explore the thermal characteristics of each configuration. A customized cavity is designed to have provision for three airflow configurations (axial, cross, and reverse flow) and temperature profiles are investigated within the cavity for each configuration. The experiments are performed at three heat generation rates, i.e., 10 W, 20 W, and 30 W to analyze the cooling effectiveness at a variable heat generation rate. It was observed that the maximum temperature within the setup increases with the increase in heat generation rate. In axial flow air configuration, cavity temperature has been reduced remarkably by 69 and 82.4% at 10 W and 30 W, respectively. Second to axial flow, cross flow configuration performs better than reverse flow and an overall 65.7~78.6% temperature drop is obtained compared with enclosed cavity from 10 W to 30 W, respectively. Furthermore, a similar cooling rate trend in the cavity is obtained for an increased heat generation rate in the cavity.

Thermal analysis of proposed heat sink design under natural convection for the thermal management of electronics

Abstract: The rapid development in the field of electronics has led to high power densities and miniaturization of electronic packages. Because of the compact size of electronic devices, the rate of heat dissipation has increased drastically. Due to this reason, the air-cooling system with a conventional heat sink is insufficient to remove large quantity of heat. A novel macro-channel ?L-shaped heat sink? is pro-posed and analyzed to overcome this problem. The thermal resistance and fluid-flow behavior under natural convection, of the novel and conventional air-cooled heat sink designs, are analyzed. Governing equations are discretized and solved across the computational domain of the heat sink, with 3-D conjugate heat transfer model. Numerical results are validated through experimentation. The effect of parameters i.e., fin height, number of fins and heat sink size, on the thermal resistance and fluid-flow are reported. Examination of these parameters provide a better physical understanding from energy conservation and management view point. Substantial increase in the thermal performance is noted for the novel ?L-shaped heat sink? compared to the conventional design.