RISS 검색 - 국내학술지논문 상세보기

다국어 초록 (Multilingual Abstract)

Adryoutmechanism model for rectangular narrow channels at high pressure conditions is developed byassuming that the KelvineHelmholtz instability triggered the occurrence ofdryout. This model combinesthe advantages of theoretical analysis and empirical correlation. The unknown coefficients in thetheoretical derivation are supported by the experimental data. Meanwhile, the decisive restriction of theexperimental conditions on the applicability of the empirical correlation is avoided. The expression ofvapor phase velocity at the time ofdryoutis derived, and the empirical correlation of liquidfilm thicknessis introduced. Since the CHF value obtained from the liquidfilm thickness should be the same as thevalue obtained from the KelvineHelmholtz critical stability under the same condition, the convergentCHF value is obtained by iteratively calculating. Comparing with the experimental data under thepressure of 6.89e13.79 MPa, the average error of the model is 15.4% with the 95% confidence interval[-20.5%, 10.4%]. And the pressure has a decisive influence on the prediction accuracy of this model.Compared with the existingdryoutcode, the calculation speed of this model is faster, and the calculationaccuracy is improved. This model, with great portability, could be applied to different objects andworking conditions by changing the expression of the vapor phase velocity when the dryout phenom-enon is triggered and the calculation formula of the liquidfilm.©2020 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under theCC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).1. IntroductionThe plate type fuel element has the advantages of compactstructure, high power per unit volume, low central temperature,high burnup, low heat storage and good safety. It is an advanceddesign structure of the new integrated pressurized water reactorcore. The coolantflow channel of the plate type fuel element is atypical rectangular narrow channel, which has compact structure,small temperature difference of heat transfer, simple surface pro-cessing, smoothness of heat transfer surface. Besides, it is not easyto produce impurities and pollute the heat transfer surface todeteriorate heat transfer with the high-speedfluid. Due to theabove characteristics, the rectangular narrow channel is widelyused in thefields of chemical, nuclear energy, electronic devicecooling, refrigeration and others. The research on the thermal hy-draulic properties of rectangular narrow channels has become a hotresearch topic [1,2].Critical heatflux (CHF) is the most important thermal hydrauliclimit parameter to ensure reactor core safety. When the criticalboiling occurs, theflow boiling mechanism of the coolant changes,the heat transfer coefficient decreases, and the heat transfer on thesurface of the nuclear fuel element deteriorates. In severe cases, thefuel element can be burned and even cause the radioactive leakage.It is generally believed that in region of the annularflow, CHF iscaused by liquidfilm drying, and the CHF model establishedaccordingly is called dryout model. Due to the wide range of quality(about 0.1e1.0) corresponding to the annularflow pattern, dryout isof great significance for the safety analysis and transient process ofboiling water reactors and pressurized water reactors. In recentyears, the dryout model has received much attention [3,4].In rectangular narrow channels, bubble growth is limited, and*Corresponding author.**Corresponding author.E-mail addresses:dlzhang@mail.xjtu.edu.cn(D. Zhang),dengjian_npic@163.com(J. Deng).Contents lists available atScienceDirectNuclear Engineering and Technologyjournal homepage:www.elsevier.com/locate/nethttps://doi.org/10.1016/j.net.2020.03.0181738-5733/©2020 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Nuclear Engineering and Technology 52...

참고문헌 (Reference)

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