A new method for evaluating heat pipe fluid compatibility. (25th May 2016)

• Record Type: Journal Article
• Authors: Stubblebine, Michael J.; Yao, Qi; Supowit, Jacob; Catton, Ivan
• Is Part Of: Applied thermal engineering. Volume 101(2016:May)
• Page Start: 796
• Page End: 803
• Publication Date: 2016-05-25
• Subjects: Heat pipe -- Thermosiphon -- Corrosion -- NCG -- Thermodynamics -- Passivation; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.04.020
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: A new method for evaluating heat pipe compatibility has been proposed. Aluminum/water based fluids are analyzed as a case study using strong oxidizing inhibitors. E –pH diagrams are generated as a function of temperature creating a "safe-zone". Comparison of "safe-zone" to published data shows agreement for two different tests. Abstract: While heat pipes are a widely used and highly efficient means of spreading heat or transferring it from one location to another, there are some fluid-casing combinations which cannot be used due to material incompatibilities. These incompatibilities generally result in the generation of non-condensable gases such as the hydrogen gas produced when water is used with aluminum devices. Some attempts at using inhibitors in aqueous solution are found in literature but a method for screening which inhibitors to use that can also predict and assess the performance of different concentrations is not available. Using a thermodynamic approach, principles of corrosion engineering have been applied to the specific application of phase change heat transfer devices. Experimental data from previous tests has been used to show the E –pH diagrams match the reported NCG generation observed experimentally. Using thermodynamic equilibrium diagrams and measurements of heat pipe fluid E and pH can be a valuable tool when investigating passivating fluids for previously incompatible fluid-casing combinations.