Impact of the solution channel thickness while investigating the effect of membrane characteristics and operating conditions on the performance of water-LiBr membrane-based absorbers

In this study, a numerical analysis is performed to investigate the effect of membrane contactor characteristics and operating conditions on the absorption performance in plate-and-frame membrane-based absorbers used in water-LiBr absorption cooling systems. This paper critically evaluates the impact of the solution channel thickness while investigating the effect of membrane characteristics. Results show that the effect of membrane characteristics is different in the case of different solution channel thicknesses. For instance, increasing the membrane mean pore size from 0.25 μm to 1 μm enhances the absorption rate by 75% in the case of a 0.1 mm solution channel, whereas in a 0.5 mm solution channel the absorption rate increases by 40%. In addition, a parametric study is performed to study the effect of solution mass flow rate, vapour pressure, solution inlet concentration and cooling water temperature on the absorption performance, taking into consideration different solution channel thicknesses. Results show that a high absorption rate can be achieved in the case of thinner solution channels. Moreover, the percentage change in the absorption rate remains almost the same when the vapour pressure, solution inlet concentration and coolant inlet temperature are varied in the case of different solution channel thicknesses.