Heat transfer mechanism in flow boiling through vertical narrow channels differs from that in larger circular tubes with diameters more than 10mm due to the increased surface forces. Basing on the experimental data, the main factors which have influence on heat flux of the onset of nucleate boiling (ONB), such as mass flux, system pressure and dimension of the narrow channel, are analyzed in this paper. The empirical correlation which used to calculate heat flux of the onset of nucleate boiling in vertical narrow annular channels in similar conditions is given here. The calculation results of this correlation are compared with the experimental data and agree well with it while the deviation is less than ±15%. And it’s concluded that narrow channels could enhance flow boiling heat transfer.
The advantage and shortcoming of anisotropic material of thermal conductivity using as building envelope
were analyzed in this paper. The thermal performance of anisotropic material of thermal conductivity was presented by rotating
the original rectangular axes so as to determine the principal axes and make the cross-derivative terms disappear.
The results indicated that the heat flux vector is commonly not perpendicular to the isothermal surface in anisotropic material.
Double skin facade has been successfully applied in many building designs. The application of laminated composite
with anisotropic thermal conductivity in double skin envelope was proposed to avoid its disadvantage. The interior envelope
in double skin system may be made of laminated glaze or other laminated materials. Basing on the combination of
anisotropic material and double skin envelope, the indoor cooling and heating load decrease in summer and winter respectively
while the anisotropic material was used as interior building envelope. Especially in summer, the effect of energy
saving is obvious since the partial magnitude of conductive heat in the interior envelope could be brought out from the
cavity by natural ventilation through it.
:By importing the meteorological data of water temperatures to TRNSYS software, temperature differential control method was applied to simulate hybrid ground source heat pump system for three months in Wuhan. In order to obtain running effect of this system, the inlet and outlet water temperatures of heat pump and buried pipe, as well as the soil temperature change trend and the COP of this system were investigated respectively. The results show that this system is running well under given conditions and it provides reference for the operation of hybrid ground source heat pump system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.