Dynamic modeling and experimental validation elements of a 30 kW LiBr/H2O single effect absorption chiller for solar application

• Published in: Applied thermal engineering 2015-11, Vol.90 (C), p.980-993
• Main Authors: Marc, Olivier, Sinama, Frantz, Praene, Jean-Philippe, Lucas, Franck, Castaing-Lasvignottes, Jean
• Format: Article
• Language: English
• Subjects: Absorption chiller; Dynamic model; Experimental validation; Mechanics; Optimization; Physics; Simulation; Thermics
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2015.07.067

This paper presents a dynamic modeling of a single-effect absorption chiller working with LiBr–H2O solution used in a solar cooling installation operating without any backup systems (hot or cold). In this case, the absorption machine is powered only by a solar collector field. Given the highly variable nature of solar radiation and the building loads, the range of the three source temperatures of the chiller can vary widely since there is no backup system. These fluctuating source temperatures mean that the chiller does not operate in steady state phase during the day. The dynamic modeling of the absorption chiller is therefore very important to predict its performance, taking into account both the transient and steady state phases. The numerical model presented in this paper is based on the mass and energy balances of each component, equations of state and equations of heat transfers. In the first part, this article presents the dynamic modeling of a LiBr/H2O absorption chiller. Then, experimental validation elements are proposed to validate pressures and temperatures of the chiller. Finally, a method is presented to optimize the thermal COP according to different levels of refrigerating capacities. •A dynamic absorption chiller model has been developed in this paper.•The model is described and an experimental validation is carried out.•The good agreement between the prediction and the experimental data is presented.•Then the model is used to optimize heat source temperatures to produce different levels of refrigerating capacities.