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

Abstract 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.

[1]  Hitoshi Matsushima,et al.  Dynamic simulation program with object-oriented formulation for absorption chillers (modelling, verification, and application to triple-effect absorption chiller) , 2010 .

[2]  Paul Kohlenbach,et al.  A dynamic simulation model for transient absorption chiller performance. Part I The model , 2008 .

[3]  J. R. García Cascales,et al.  MODELLING AN ABSORPTION SYSTEM ASSISTED BY SOLAR ENERGY , 2011 .

[4]  J. S. Spevack,et al.  Heat Conversion Systems , 1993 .

[5]  Jaroslav Pátek,et al.  A simple formulation for thermodynamic properties of steam from 273 to 523 K, explicit in temperature and pressure , 2009 .

[6]  Vojislav Novakovic,et al.  Optimization of energy consumption in buildings with hydronic heating systems considering thermal comfort by use of computer-based tools , 2007 .

[7]  Franck Lucas,et al.  Decision making tool to design solar cooling system coupled with building under tropical climate , 2012 .

[8]  Paul Kohlenbach,et al.  A dynamic simulation model for transient absorption chiller performance. Part II: Numerical results and experimental verification , 2008 .

[9]  François Boudéhenn,et al.  Proposal and validation of a model for the dynamic simulation of a solar-assisted single-stage LiBr/water absorption chiller , 2013 .

[10]  Jean Castaing-Lasvignottes,et al.  Assessing performance and controlling operating conditions of a solar driven absorption chiller using simplified numerical models , 2012 .

[11]  Alain Bastide,et al.  Modeling and experimental validation of the solar loop for absorption solar cooling system using double-glazed collectors , 2011 .

[12]  Paul Bourdoukan,et al.  Potential of solar heat pipe vacuum collectors in the desiccant cooling process: Modelling and experimental results , 2008 .

[13]  Ibrahim Dincer,et al.  Performance evaluation of an SOFC based trigeneration system using various gaseous fuels from biomass gasification , 2015 .

[14]  Franck Lucas,et al.  Experimental investigation of a solar cooling absorption system operating without any backup system under tropical climate , 2010 .

[15]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[16]  Jean-Philippe Praene,et al.  Simulation and experimental investigation of solar absorption cooling system in Reunion Island , 2011 .

[17]  Younggy Shin,et al.  Simulation of dynamics and control of a double-effect LiBr-H2O absorption chiller. , 2009 .

[18]  Inmaculada Zamora,et al.  Performance analysis of a trigeneration system based on a micro gas turbine and an air-cooled, indirect fired, ammonia–water absorption chiller , 2011 .

[19]  Georgios A. Florides,et al.  Design and construction of a LiBr–water absorption machine , 2003 .

[20]  Timothy A. Davis,et al.  Algorithm 832: UMFPACK V4.3---an unsymmetric-pattern multifrontal method , 2004, TOMS.

[21]  J. Pátek,et al.  A computationally effective formulation of the thermodynamic properties of LiBr-H2O solutions from 273 to 500 K over full composition range , 2006 .

[22]  Michael Wetter,et al.  Building design optimization using a convergent pattern search algorithm with adaptive precision simulations , 2005 .

[23]  Ala Hasan,et al.  Minimisation of life cycle cost of a detached house using combined simulation and optimisation , 2008 .

[24]  C. A. Infante Ferreira,et al.  Analytic modelling of steady state single-effect absorption cycles , 2008 .

[25]  Marc A. Rosen,et al.  Greenhouse gas emission and exergy analyses of an integrated trigeneration system driven by a solid oxide fuel cell , 2015 .