Boiling heat transfer and pressure drop of NH3/LiNO3 and NH3/(LiNO3 þ H2O) in a plate heat exchanger

Identificador:  imarina:5129619

Handle: https://hdl.handle.net/20.500.11797/imarina5129619

Autors:  Táboas, F; Bourouis, M; Vallès, M

Resum:
This paper presents the experiments carried out to determine the flow boiling heat transfer coefficient and associated frictional pressure drop in a plate heat exchanger which uses the binary fluid mixture ammonia/lithium nitrate and the ternary fluid mixture ammonia/(lithium nitrate þ water) with a water content in the absorbent of 20% by weight. The effects on the flow boiling heat transfer coefficient and two phase frictional pressure drop are analysed with a heat flux range of 5e20 kW m2, a mass flux of 50 e100 kg m2 s1 and a mean vapour quality of 0e0.2. The mass flux greatly influenced the flow boiling heat transfer coefficient, whereas the addition of water only produced a slight increase. The measurements taken experimentally indicated that the parameters with a pronounced effect on the frictional pressure drop were vapour quality followed by mass flux. Finally, the correlations proposed in Taboas et al. [1] used to predict the flow boiling heat transfer coefficient and frictional pressure drop were well in agreement with the experimental results.