International Journal of Heat and Mass Transfer, Vol.127, 799-812, 2018
Experimental investigation of flow boiling heat transfer characteristics in smooth horizontal tubes using NH3/NaSCN solution as working fluid
Ammonia-sodium thiocyanate (NH3-NaSCN) solution is an efficient absorption refrigeration working pair. This paper presents the experimental results of the flow boiling heat transfer coefficients (HTCs) of ammonia-sodium thiocyanate solution in horizontal tubes with three different inner diameters (4, 6 and 8 mm). The experimental measurements were conducted with different heat fluxes, mass fluxes, boiling temperatures and vapor qualities to determine their impact on the flow boiling heat transfer coefficients of the tested working pair. Comparison of NH3-NaSCN and NH3-LiNO3 solution has been performed and higher flow boiling HTCs of NH3-NaSCN solution than that of NH3-LiNO3 solution are obtained under similar working conditions. The results also indicate that the heat flux has the most significant influence on the flow boiling HTCs. The updated flow boiling HTCs prediction correlation for ammonia-salt working pair proposed by the authors' previous work has been validated by the present experimental results. The present study help to extend the basic researching results of NH3-NaSCN working pair, which is of great significance to the design and optimization of generators in the absorption refrigeration units, and will ultimately be beneficial to energy saving for refrigeration area. (C) 2018 Elsevier Ltd. All rights reserved.