Pool boiling performance of lithium bromide solution on enhanced tubes

Abstract

In the present study, pool boiling heat transfer coefficients of LiBr solution were obtained for smooth, corrugated, floral and low fin tubes. Test range covered saturation pressure from 7.38 kPa to 101.3 kPa, LiBr concentration from 0% to 50%. Low fin tube yielded the highest heat transfer coefficient followed by floral, corrugated and smooth tube. The sequence was the same independent of saturation pressure or LiBr concentration. For the low fin tube, the heat transfer enhancement ratio ranged from 1.34 to 2.37. Those of floral tube are 1.16 to 1.64 and those of corrugated tube are 0.90 to 1.43. The enhancement ratio decreased as LiBr concentration increased. No general trend is observed for the effect of saturation pressure. Exceptionally high heat transfer coefficient was obtained for the low fin tube in pure water. The reason may be attributed to many small bubbles at high frequency due to the existence of low fins. Boiling heat transfer correlations were developed which are applicable for saturation pressure from 7.38 kPa to 101.3 kPa and LiBr concentration from 0% to 50%.

Numerical study on heat and mass transfer behavior of pool boiling in LiBr/H2O absorption chiller generator considering different tube surfaces

“…The dimensions of the model used in the present research are shown in Figure1. The computational dimensions are considered as follows in order to compare the results obtained from the present numerical research with the previous experimental studies by Sim et al [16,18].…”

Role of Membrane Technology in Absorption Heat Pumps: A Comprehensive Review

“…In absorption heat pumps, desorption is the separation process of the refrigerant fluid from the working mixture (integrated by a refrigerant fluid and an absorbent), and the component where the process takes place is called “desorber” (also known as generator). The most used desorber configurations are: Nucleate pool-boiling [ 19 , 20 , 21 , 22 , 23 , 24 ] and falling-film [ 25 , 26 , 27 , 28 , 29 ]. In the nucleate pool-boiling configuration, a constant heat load must be added in order to reach the working mixture saturation temperature to separate a part of the refrigerant fluid in the vapor phase.…”