Application of Film Dryout Model in Liquid Metal CHF Prediction

2014 ◽  
Author(s):  
Zaiyong Ma ◽  
Yue Nina ◽  
Suizheng Qiu ◽  
Wenxi Tian ◽  
Guanghui Su
Keyword(s):  
Heat Flux ◽  
Liquid Metal ◽  
Deposition Rate ◽  
Annular Flow ◽  
Nuclear Reactors ◽  
Liquid Metals ◽  
Large Error ◽  
Entrainment Rate ◽  
Large Heat ◽  
Sodium And Potassium

Liquid metals have been used as coolants of several kinds of nuclear reactors, and the prediction of critical heat flux (CHF) is rather important for the design, safety and economy of these reactors. A film dryout model considering the deposition and entrainment of droplets was established to obtain the CHF of liquid metal in annular flow flowing in tubes. The correlations of deposition rate, entrainment rate and so on for conventional fluids were used, and the initial entrainment fraction was determined according to experimental data. Results showed that the correlations for conventional fluids could be used for liquid metals approximately, but relatively large error might occur for large heat flux. The accuracy of this model for sodium and potassium was similar for small heat flux, but had some differences for large heat flux. Special correlations of deposition rate, entrainment rate and so on should be developed to predict the CHF of liquid metals more accurately.

Suitability of Eutectic Field’s Metal for Use in an Electromagnetohydrodynamically-Enhanced Experimental Two-Phase Flow Loop

2012 ◽  
Author(s):  
A. Lipchitz ◽  
Lilian Laurent ◽  
G. D. Harvel
Keyword(s):  
Liquid Metal ◽  
Two Phase Flow ◽  
Nuclear Reactors ◽  
Liquid Metals ◽  
Metal Flow ◽  
Phase Flow ◽  
Laboratory Setting ◽  
Flow Loop ◽  
Fast Reactors ◽  
Two Phase

Several Generation IV nuclear reactors, such as sodium fast reactors and lead-bismuth fast reactors, use liquid metal as a coolant. In order to better understand and improve the thermal hydraulics of liquid metal cooled GEN IV nuclear reactors liquid metal flow needs to be studied in experimental circulation loops. Experimental circulation loops are often located in a laboratory setting. However, studying liquid metal two phase flow in laboratory settings can be difficult due to the high temperatures and safety hazards involved with traditional liquid metals such as sodium and lead-bismuth. One solution is to use a low melt metal alloy that is as benign as reasonably achievable. Field’s metal is a eutectic alloy of 51% Indium, 32.5% Bismuth and 16.5% Tin by weight and has a melting point of 335K making it ideal for use in a laboratory setting. A study is undertaken to determine its suitability to use in a two-phase experimental flow loop enhanced by magnetohydrodynamic forces. The study investigated its reactivity with air and water, its ability to be influenced by magnetic fields, its ability to flow, and its ease of manufacture. The experiments melted reference samples of Field’s metal and observed its behaviour in a glass beaker, submerged in water and an inclined stainless steel pipe. Then Field’s metal was manufactured in the laboratory and compared to the sample using the same set of experiments and standards. To determine Field’s metal degree of magnetism permanent neodymium magnets were used. Their strength was determined using a Gaussmeter. All experiments were recorded using a COHU digital camera. Image analysis was then performed on the video to determine any movements initiated by the magnetic field forces. In conclusion, Field’s metal is more than suitable for use in experimental settings as it is non-reactive, non-toxic, simple to manufacture, easy to use, and responds to a magnetic force.

Main Results of Na-K Alloy Boiling Investigation

2002 ◽  
Author(s):  
G. A. Sorokin ◽  
G. P. Bogoslovskaya ◽  
E. F. Ivanov ◽  
A. P. Sorokin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Numerical Modeling ◽  
Liquid Metal ◽  
Critical Heat Flux ◽  
Liquid Metals ◽  
Operating Conditions ◽  
Coolant Temperature ◽  
Low Velocity ◽  
Experimental Conditions

Boiling experiments on eutectic sodium-potassium alloy in the model of fast reactor subassembly under conditions of low-velocity circulation carried out at the IPPE call for further investigations into numerical modeling of the process. The paper presents analysis of pin bundle liquid metal boiling, stages of the process, its characteristics (wall temperature, coolant temperature, flow rate. pressure void fraction and others), that allowed the pattern map to be drawn. The problem of conversion of the data gained in Na-K mock-up experiments to in-pile sodium reactor operating conditions is analyzed here, as well as thermodynamic similarity of liquid metal coolants and eutectic Na-K alloy. Data on bundle boiling in Na-K are presented in comparison with those in different liquid metals. Analysis of data on liquid metal heat transfer in cases of pool boiling, boiling in tubes, in slots, and in pin bundles, as well as data on critical heat flux in tubes was performed and discussed in the paper. The relationship for calculation of critical heat flux in liquid metal derived by the authors is presented. Results of numerical modeling of liquid metal boiling heat transfer during accident cooling of reactor core applied to experimental conditions of going from forced to natural circulation are presented, too.

scholarly journals Radionuclide Chemistry in Nuclear Facilities Based on Heavy Liquid Metal Coolants: Past, Present and Future

2020 ◽  
Vol 74 (12) ◽  
pp. 976-983
Author(s):  
Jörg Neuhausen
Keyword(s):  
Liquid Metal ◽  
Nuclear Reactions ◽  
Nuclear Reactors ◽  
Liquid Metals ◽  
Target Material ◽  
Secondary Compounds ◽  
Heavy Liquid ◽  
Nuclear Facilities ◽  
Spallation Target ◽  
Chemical Behaviour

Heavy liquid metals such as lead and lead bismuth eutectic (LBE) are considered as spallation target material for next-generation neutron sources and as coolant of fast spectrum nuclear reactors that are developed to facilitate more efficient use of nuclear fuel as well as transmutation of long-lived nuclear waste. During the operation of such facilities, the heavy liquid metal will be activated by nuclear reactions. Additionally, fission product radionuclides may be introduced into the liquid metal from leaking fuel pins or by fission of the target nuclei in spallation. The chemical behaviour of these radioactive contaminants in the liquid metal – especially their immediate volatilization or volatilization of formed secondary compounds – may affect the safety of such facilities. The present article summarizes the activities of PSI's Laboratory of Radiochemistry towards a better understanding of the chemistry of potentially hazardous radionuclides in LBE and discusses aspects that need to be addressed in future to support the licensing of heavy liquid metal-based nuclear facilities.

Liquid metal-based nanocomposite materials: Fabrication technology and applications

Nanoscale ◽  
2021 ◽  
Author(s):  
Hiroki Ota ◽  
Nyamjargal Ochirkhuyag ◽  
Ryosuke Matsuda ◽  
Zihao Song ◽  
Fumika Nakamura ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Flexible Electronics ◽  
Liquid Metals ◽  
Nanocomposite Materials ◽  
Fabrication Technology

Research on liquid metals has been steadily garnering more interest in recent times because the properties of these metals are conducive to flexible electronics applications; further, these metals are in...

scholarly journals Liquid Metals: Liquid Metal Marbles (Adv. Funct. Mater. 2/2013)

2013 ◽  
Vol 23 (2) ◽  
pp. 137-137 ◽  
Author(s):  
Vijay Sivan ◽  
Shi-Yang Tang ◽  
Anthony P. O'Mullane ◽  
Phred Petersen ◽  
Nicky Eshtiaghi ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Liquid Metals

Laminar Natural Convection About Downward Facing Heated Blunt Bodies to Liquid Metals

1976 ◽  
Vol 98 (2) ◽  
pp. 208-212 ◽  
Author(s):  
G. M. Harpole ◽  
I. Catton
Keyword(s):  
Heat Flux ◽  
Surface Temperature ◽  
Series Expansion ◽  
Surface Heat Flux ◽  
Liquid Metals ◽  
Surface Heat ◽  
Surface Shape ◽  
Boundary Layer Equations ◽  
Stagnation Points ◽  
Shape Dependence

The laminar boundary layer equations for free convection over bodies of arbitrary shape (i.e., a three-term series expansion) and with arbitrary surface heat flux or surface temperature are solved in local Cartesian coordinates. Both two-dimensional bodies (e.g., horizontal cylinders) and axisymmetric bodies (e.g., spheres) with finite radii of curvature at their stagnation points are considered. A Blasius series expansion is applied to convert from partial to ordinary differential equations. An additional transformation removes the surface shape dependence and the surface heat flux or surface temperature dependence of the equations. A second-order-correct, finite-difference method is used to solve the resulting equations. Tables of results for low Prandtl numbers are presented, from which local Nusselt numbers can be computed.

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