Studies of critical heat fluxes in small diameter channels
نویسندگان
چکیده
The paper presents the results of experimental studies critical heat flows in vertical small diameter channels, when coolant moves from bottom to top, which were carried out Obninsk branch MEPhI 1970s last century but have not become widespread due lack demand for their practical use. Nowadays, interest such works is manifested, first all, development compact plants and devices, particularly nuclear power engineering. As a coolant, water, Freon-12 96% ethyl alcohol used. High velocities underheated liquid at high fluxes on channel wall lead so-called “fast crisis” transfer. In this case, magnitude flux depends mainly parameters flow zone rather than core. “slow observed vapor concentrations, relatively low mass rates an annular-dispersed flow. value case core, are probably close average parameters. conditions near-wall region also largely determined by transfer coefficients moving speed usually result much smaller slower rise temperature. Sometimes DNB can occur bypassing boiling process. core VVER-type reactor operating its nominal mode, surface present number fuel rods. Probably, will be transportable small-size plants. Therefore, important task conduct relevant research area.
منابع مشابه
ترجمه بخشی از کتاب "critical readings in translation studies"
چکیده در دنیای پیچیده ی امروز، تغییرات زیادی در زندگی بشری در حال وقوع اند و شاهد رقابت های بسیار فشرده ی جوامع در دستیابی به فناوری برتر و قدرت بیشترهستیم. به نظر می رسد که فرد وجامعه مجبورند به طریقی در وضعیت خویش دگرگونی ایجاد کنند تا از قافله ی علم، فناوری، و پیشرفت عقب نمانند. رشته مطالعات ترجمه نیز از این قاعده مستثنا نیست. علی رغم وسعت روز افزون پژوهش در این حوزه و میان رشته ای بودن مطال...
Two Phase Heat Transfer Characteristics in a Vertical Small Diameter Tube at Sub Atmospheric Pressure
Two-phase heat transfer is experimentally examined through vertical small diameter tubes, D =1.45 and 2.8 mm using water under a pressure of 50 to 81 kPa and a natural circulation condition. The pool boiling correlation by Stephan-Abdelsalam and the thermosyphon boiling correlation by Imura, et al. predict the measured experimental data in the 2.8 mm tube with an error of -30%. A large heat tra...
متن کاملThe Effect of Linear Change of Tube Diameter on Subcooled Flow Boiling and Critical Heat Flux
One of the major industry problems is the flow boiling, where reaching to the critical heat flux (CHF) condition can lead to a temperature jump and damage of the systems. In the present study, the effects of a uniform change in tube diameter on subcooled flow boiling and CHF was numerically investigated. The Euler-Euler model was used to investigate the relationship between the two liquid and v...
متن کاملExtreme heat fluxes in gyrokinetic simulations: a new critical β.
A hitherto unexplained feature of electromagnetic simulations of ion temperature gradient turbulence is the apparent failure of the transport levels to saturate for certain parameters; this effect, termed here nonzonal transition, has been referred to as the high-β runaway. The resulting large heat fluxes are shown to be a consequence of reduced zonal flow activity, brought on by magnetic field...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nuclear Energy and Technology
سال: 2021
ISSN: ['2452-3038']
DOI: https://doi.org/10.3897/nucet.7.78624