Natural Convection Heat Transfer of Liquid Metal Gallium Nanofluids in a Rectangular Enclosure

2015 ◽  
Vol 46 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Cong Qi ◽  
Xin Cui ◽  
Yibo Liu ◽  
Zhongbo Yang ◽  
Chao Huang
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Liquid Metal ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Rectangular Enclosure

Natural Convection Heat Transfer in a Rectangular Liquid Metal Pool With Bottom Heating and Top Cooling

2006 ◽  
Author(s):  
Il S. Lee ◽  
Yong H. Yu ◽  
Hyoung M. Son ◽  
Jin S. Hwang ◽  
Kune Y. Suh
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Liquid Metal ◽  
Convection Heat Transfer ◽  
Bottom Surface ◽  
Natural Convection Heat Transfer ◽  
Metal Pool ◽  
Convection Heat ◽  
Integral System ◽  
Bottom Heating

An experimental study is performed to investigate the natural convection heat transfer characteristics with subcooled coolant to create engineering database for basic applications in a lead alloy cooled reactor. Tests are performed in the ALTOS (Applied Liquid-metal Thermal Operation Study) apparatus as part of MITHOS (Metal Integrated Thermo Hydrodynamic Operation System). A relationship is determined between the Nusselt number Nu and the Rayleigh number Ra in the liquid metal rectangular pool. Results are compared with correlations and experimental data in the literature. Given the similar Ra condition, the present test results for Nu of the liquid metal pool with top subcooling are found to be similar to those predicted by the existing correlations or experiments. The current test results are utilized to develop natural convection heat transfer correlations applicable to low Prandtl number Pr fluids that are heated from below and cooled by the external coolant above. Results from this study are slated to be used in designing BORIS (Battery Optimized Reactor Integral System), a small lead cooled modular fast reactor for deployment at remote sites cycled with MOBIS (Modular Optimized Brayton Integral System) for electricity generation, tied with NAVIS (Naval Application Vessel Integral System) for ship propulsion, joined with THAIS (Thermochemical Hydrogen Acquisition Integral System) for hydrogen production, and coupled with DORIS (Desalination Optimized Reactor Integral System) for seawater desalination. Tests are performed with Wood’s metal (Pb-Bi-Sn-Cd) filling a rectangular pool whose lower surface is heated and upper surface cooled by forced convection of water. The test section is 20 cm long, 11.3 cm high and 15 cm wide. The simulant has a melting temperature of 78°C. The constant temperature and heat flux condition was realized for the bottom heating once the steady state had been met. The test parameters include the heated bottom surface temperature of the liquid metal pool, the input power to the bottom surface of the section, and the coolant temperature.

Natural Convection Heat Transfer of the PCM Microcapsule Slurry for a Solid Phase State in a Horizontal Rectangular Enclosure

2011 ◽  
Vol 295-297 ◽  
pp. 1393-1396
Author(s):  
Yan Lai Zhang ◽  
Zhong Hao Rao ◽  
Shuang Feng Wang ◽  
Hong Zhang ◽  
Li Jun Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Phase State ◽  
Solid Phase ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Cooling Plate ◽  
Rectangular Enclosure ◽  
Heating Plate

This experiment on natural convection heat transfer with the PCM microcapsule slurry for a solid phase state of the PCM were performed at a horizontal rectangular enclosure heating from below and cooling from top. In the present study, important parameters affecting the natural convection heat transfer of the slurry with the PCM were taken into account such as the mass concentration of the PCM microencapsulated into the slurry, the temperature difference between heating plate and cooling plate, the Rayleigh number Ra and the aspect ratio (width/height) of the horizontal rectangular enclosure. The heat transfer characteristics of the PCM microcapsule slurry on natural convection were concluded from predicted conditions simplified by classifying the temperature ranges into three sub-regions, in which the PCM in the slurry was in only solid phase state, phase change state or solid-liquid coexistence state and only liquid phase state of the PCM in the microcapsule, respectively. The upper cooling plate was fixed at a constant temperature in each region, and the lower heating plate temperature was varied by carefully adjusting the electric power input of an electric plate heater. And experiment was done under the thermal steady condition in the PCM microcapsule slurry. Emphasis was given on phase changing temperature range, and experiments had been performed for four kinds of enclosures with various heights.

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