Publicou 8 edições por ano
ISSN Imprimir: 1065-5131
ISSN On-line: 1563-5074
Indexed in
HIGH-PERFORMANCE HEAT SINKS UTILIZING TWO-PHASE FLOW IN STACKED MINICHANNELS
RESUMO
A common approach for heat sinks designed for cooling of electronics is to use multiple parallel coolant channels etched or machined in metal, silicon, or other materials. In order to enhance the surface area in the same planform or footprint area as a heat sink with multiple parallel channels, an alternative approach investigated in this paper is to stack multiple layers of parallel channels to create multilayer heat sinks where the layers of channels are connected to common inlet and exit flow manifolds. Because heat is supplied only on one surface of the heat sink, the heat flux in each subsequent layer of channels will be different from the others due to conduction resistance. In two-phase flow, the flow resistance is dependent on the heat flux, therefore causing the mass flow rate to also differ in each layer. Thus, even with enhanced surface area, it is not known a priori whether multilayer heat sinks are advantageous when operating with two-phase flow. The thermal and hydraulic characteristics of single-layer and multilayer copper heat sinks operating in two-phase flow with water were compared in this study. A systematic approach was taken in validating and choosing the best boiling correlations for modeling the heat sinks. The experiments showed that the multilayer copper heat sinks had lower thermal resistance and much lower pressure drop than their single-layer counterparts at low to moderate heat flux. At high heat fluxes, the two-layer heat sinks exhibited instances of unstable behavior and it is hypothesized that this is due to flow bypass that deprives the hot channel of flow, thereby leading to dry-out. With more than two channels, the enhanced surface area offsets the lack of flow in the hot channel, thus reducing its heat flux and reducing the risk of a critical event.
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Valenzuela Felipe, Ortega Alfonso, A Novel Heat Exchanger Effectiveness Approach for Exploring Performance Limits of Two-Phase Mini-Channel Boilers, 2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), 2020. Crossref