ТЕПЛООБМІН ПООДИНОКОЇ ПЛОСКООВАЛЬНОЇ ТРУБИ З НЕПОВНИМ ОРЕБ-РЕННЯМ В УМОВАХ ВІЛЬНОЇ КОНВЕКЦІЇ

• Datum: 2020
• Hauptverfasser: Vozniuk, M.M., Kondratiuk, V.A., Pismennyy, E. N., Terekh, A.M.
• Format: Artikel
• Sprache: Ukrainian
• Veröffentlicht: Institute of Engineering Thermophysics of NAS of Ukraine 2020
• Online Zugang: https://ihe.nas.gov.ua/index.php/journal/article/view/403
• Назва журналу: Thermophysics and Thermal Power Engineering

The article discusses the relevance of using of recuperative air-coolers for removing heat from the working fluid. It is shown that in order to save electricity on drive of the fans of air-cooled devices, it is advisable to transfer them to a fanless mode for a certain time of the year, while energy savings can be up to 37% per year. To increase the efficiency of air coolers, it is proposed to use flat-oval tubes with incomplete finning as their heat exchange surface. A technique for computer modeling of heat transfer of a single flat-oval tube with incomplete finning under free convection conditions is presented. Varying geometric parameters of a finned tube are substantiated when simulating its heat transfer under free convection conditions. The paper presents the results of computer simulation of the intensity of heat transfer of a single flat-oval tube with incomplete finning. It is shown that the results of CFD modeling of heat transfer of a single flat oval tube with incomplete finning are satisfactorily consistent with experimental data. The analysis of the change in the exponent with the Rayleigh number depending on the geometric characteristics of the finned tube is presented. The studies carried out made it possible to obtain calculated dependences, which, with sufficient accuracy for engineering calculations, describe the intensity of heat transfer of a single flat-oval tube with incomplete finning in a wide range of changes in its basic geometric characteristics. The developed model for calculating the heat transfer of a wide range of flat-oval pipes with incomplete finning makes it possible to select the optimal geometric characteristics of these tubes without expenses for changing and adapting the technology of their production.