Heat and Mass Transfer Properties of Water-LiBr Solution in a Plate Type Falling Film Absorber

Absorber is an important component in absorption refrigerating system. Its performance plays a significant role on the overall efficiency of absorption refrigerating system. The nanofluids which can enhance the heat and mass transfer will be utilized to absorber for enhancing the water vapor absorption process and improving the absorber efficiency. The software CFD-FLUENT is used to analyze the falling film absorption process of the nanofluids, which consists of H2O/LiBr solution with Fe3O4 nanoparticles in this paper. The results indicate that the enhancing heat and mass transfer of nanofluids is related to the nanoparticle concentration and size. The stronger the nanoparticle concentration, the greater enhancement of heat and mass transfer of falling film; while the smaller the nanoparticle size, the greater enhancement of heat and mass transfer of falling film. It is also found that the enhancement ratio of heat and mass transfer flux reach 1.48 and 1.37, respectively, as the Fe3O4 nanoparticles mass concentration of 0.01wt% and the size of 50nm.

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An Experimental Study on Heat and Mass Transfer in a Helical Absorber Using LiBr+LiI+LiNO3+LiCl Solution

10.1115/imece2000-1310 ◽

2000 ◽

Author(s):

Jung-In Yoon ◽

Choon-Geun Moon ◽

Oh-Kyung Kwon ◽

Eunpil Kim

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Experimental Study ◽

Heat And Mass Transfer ◽

Working Fluid ◽

Transfer Performance ◽

Falling Film ◽

Absorption Chiller ◽

Libr Solution ◽

Cylindrical Form

Abstract An experimental study has been performed to investigate the heat and mass transfer performance in a falling film absorber of a domestic small-sized absorption chiller/heater. The components of the chiller/heater were concentrically arranged in a cylindrical form with low temperature generator, an absorber and an evaporator from the center. The arrangement of such a helical-type heat exchanger allows to make the system more compact as compared to a conventional one. As a working fluid, the LiBr+LiI+LiNO3+LiCl solution is used to get improved heat transfer. The heat and mass flux performance of the LiBr+LiI+LiNO3+LiCl solution shows 2 ∼ 5% increase than that of the LiBr solution. When a surfactant in the LiBr+LiI+LiNO3+LiCl solution is used, the performance of heat and mass transfer improves 15 ∼ 20%. This result shows the LiBr+LiI+LiNO3+LiCl solution with a surfactant can be applied to a small-sized absorption chiller/heater.

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COMPARISON OF HEAT AND MASS TRANSFER IN FALLING FILM AND BUBBLE ABSORBERS OF AMMONIA-WATER

Experimental Heat Transfer ◽

10.1080/08916150290082621 ◽

2002 ◽

Vol 15 (3) ◽

pp. 191-205 ◽

Cited By ~ 15

Author(s):

Ki Bong Lee ◽

Byung Hee Chun ◽

Jae Cheol Lee ◽

Jae Chun Hyun ◽

Sung Hyun Kim

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Falling Film ◽

Ammonia Water

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Modeling of conjugated heat and mass transfer in the entrance region of falling liquid film at various values of the Froude number

MATEC Web of Conferences ◽

10.1051/matecconf/201819401007 ◽

2018 ◽

Vol 194 ◽

pp. 01007

Author(s):

Maria V. Bartashevich

Keyword(s):

Heat Transfer ◽

Mass Transfer ◽

Liquid Film ◽

Froude Number ◽

Heat And Mass Transfer ◽

Water Solution ◽

Lithium Bromide ◽

Entrance Region ◽

Falling Film ◽

Falling Liquid Film

Mathematical model of conjugated heat and mass transfer in absorption on the entrance region of the semi-infinite liquid film of lithium bromide water solution is investigated for different values of Froude number. The calculations shown that larger values of Froude number corresponds to a smaller thickness of the falling film. It was demonstrated that for large values of the Froude number the heat transfer from the surface is greater than for smaller values.

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