16 آذر 1402
مرضيه بابايي ربيعي

مرضیه بابایی ربیعی

مرتبه علمی: استادیار
نشانی: دانشکده مهندسی - گروه مهندسی مکانیک
تحصیلات: دکترای تخصصی / مهندسی مکانیک
تلفن: 07733448200
دانشکده: دانشکده مهندسی

مشخصات پژوهش

عنوان An experimental investigation of natural convection heat transfer from a helically coiled heat exchanger
نوع پژوهش مقالات در نشریات
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مجله INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID
شناسه DOI
پژوهشگران احسان ایزدپناه (نفر اول) ، احمد زارعی (نفر دوم) ، سعید اخوان (نفر سوم) ، مرضیه بابایی ربیعی (نفر چهارم)

چکیده

The natural convection heat transfer over the outer surface of a helically coiled tube heat exchanger located inside a water storage tank is investigated experimentally in the present study. The fluid inside the coil is R-134a with phase changing. Seventeen helical coils are applied to study the effect of coil diameter, pitch, turns, and mass flow rate on the outside Nusselt number (?Nu?_of), overall coefficient of performance of the refrigeration cycle (?COP?_ov), and destroyed exergy (?EX?_des). A new empirical correlation is presented for ?Nu?_of with respect to the Rayleigh number (Ra) and coil parameters as the characteristic length. Several characteristic lengths are used to numerically predict the temperature of water based on the presented correlation. The best result, in comparison with the experimental data, was obtained for coil length as the characteristic length. The Rayleigh number based on coil length is in the range of . The best coil based on minimum ?EX?_des and maximum ?COP?_ov is introduced. Results indicate that ?Nu?_of, ?COP?_ov and ?EX?_des increase with enhancing coil diameter while the other parameters are constant.