Experimental assessment of ammonia adiabatic absorption into ammonia–lithium nitrate solution using a flat fan nozzle

This paper presents the experimental evaluation of the adiabatic absorption of ammonia vapour into ammonia–lithium nitrate solution using a flat fan nozzle and an upstream single-pass subcooler. Data are representative of the working conditions of adiabatic absorbers in absorption chillers. The nozzle was located at the top of the absorption chamber, separated 205 mm from the bottom surface. The diluted solution mass flow rate was modified between 0.04 and 0.08 kg/s and the solution inlet temperature between 24.5 and 29.7 °C. The influence of these variables on the absorption ratio, mass transfer coefficient, outlet subcooling and approach to equilibrium factor is analysed in the present paper. A linear relation between the inlet subcooling and the absorption ratio is observed. The approach to equilibrium factor for the conditions essayed is always between 0.81 and 0.89. Mass transfer coefficients and correlations for the approach to equilibrium factor and the Sherwood number are obtained. Results are compared with other ones reported in the literature.

► Adiabatic absorption of NH3 vapour into NH3–LiNO3 using flat fan nozzle created spray. ► A linear relation exists between solution inlet subcooling and absorption ratio. ► The approach to equilibrium factor is always between 0.81 and 0.89 at 205 mm height. ► Experimental values of mass transfer coefficient and outlet subcooling are presented. ► Correlations for the approach to equilibrium factor and the Sherwood number are given.