Performances of grooved plates falling film absorber

This study presents a new plate-type falling film absorber design, consisting in a vertical grooved falling film absorber. The grooves are designed to obtain good absorber plate wettability, even at a low solution flow rate, resulting in a laminar solution flow regime. Using experimental and numerical tools, the vapor absorption on a LiBr falling film solution is characterized for different operating conditions. The impact of absorber length, cooling water inlet temperature, absorber water vapor pressure, solution inlet temperature, LiBr mass fraction and flow rate is investigated. Experimentally, a high absorption rate is achieved: as high as 7·10−3 kg s−1 m−2. Moreover, a 1D stationary model of water vapor absorption in a laminar vertical falling film is introduced and validated. Numerical investigations allow defining the absorber effectiveness for a wide range of operating conditions.