Development and Performances Overview of Ammonia-water Absorption Chillers with Cooling Capacities from 5 to 100 kW

International audienceFrom 2010 to 2015, three similarly design based absorption chillers have been developed, manufactured and characterized on testbenches. The chillers are all ammonia-water thermally driven single effect chiller. They are intended to operate using directlysolar thermal energy or using waste heat from Concentrated Solar Plant (CSP). The first one is a laboratory prototype, fullyinstrumented with a cooling capacity of 5 kW. The second one is a pre-industrial version of the first prototype with the samecooling capacity but less instrumented and with a compact design. The last development is a 100 kW cooling capacity chiller,with technical choices between the two first prototypes, but design to provide cooling effect at temperatures suitable from air-conditioning to ice making. In this paper, the design principles and the technological choices made for each chiller are describedand a comparison of the experimental results is done

Modeling and Experimental Study of an Ammonia-water Falling Film Absorber

International audienc

Experimental and numerical study of a falling film absorber in an ammonia-water absorption chiller

International audienceIn this paper,experimental and numerical studies of heat and mass transfer in a falling film absorber are presented. The investigated absorber is a plate heat exchanger used ina falling film configuration. The ammonia-water solution flows in a falling film mode along the plates. The vapour flows co-current with the falling film and the coolant fluid is in a counter-current flow with the falling film. A prototype of ammonia-water absorption chiller isused to experimentally study the absorber behaviour in real operating conditions. Amacro study of the absorber and a local analysis deduced from local temperatures measurements along the falling film are presented. A numerical model and a simulation tool aredeveloped in order to complete the experimental investigations.The associatednumerical parametric studyaims to separatethe coolant mass flow rate impact.The model is validated with experimental dataand a maximal relative error of 15 % is observedbetween experimental and numerical results. The results of this study suggest that during the absorption process,mass transfers are controlled by the falling film mass transfer resistance and that the liquid-side heat transfer resistance is negligible