Discrete Cooling of Supports and Multi-Layer Insulation in Helium Dewars
Methods of optimizing location of boil-off gas cooled support and insulation heat intercepts to minimize heat leak to helium dewars are discussed. Analyses include use of separate gas streams for support and insulation cooling and the much simpler case of one stream for both purposes. Calculations are made for stainless steel and epoxy-fiberglass supports with ratios α = (AILS)/(ASLI), ranging from 25 × 103 to 800 × 103. Heat intercept locations are optimized for one through six intercepts. Calculations include independent location of intercepts on the supports and insulation and the effect of positioning the intercepts with equal length/thickness fractions. Results are presented graphically for easy use by dewar designers.
KeywordsHeat Load Heat Leak Multilayer Insulation Helium Vapor Cryogenic Engineer
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