Thermodynamic considerations for optimal thermal compressor design

A unified framework for the modeling of the thermal compressor of a single-effect ammonia-water absorption system is developed. An optimal thermal compressor configuration is found through a comparative assessment of various desorption and rectification configurations, and pertinent figures of merit are defined. The diabatic distillation column configuration is shown to achieve the highest thermal compressor performance. Parameters relevant to quantitative thermal compressor characterization are identified. Two optimal operating temperatures are identified, for the optimization of energetic and exergetic objectives, respectively. Statistical regression and artificial neural network analyses from thermodynamic simulations over a wide range of ambient and evaporator temperatures provide accurate prediction of thermal compressor performance and are compared. These results facilitate the assessment of absorption technology through simple predictive tools at the cycle design stage. This framework could also yield a design tool and could guide system design, optimal control, and flexible operation.