Thermodynamic modeling of an ammonia-water absorption chiller

Abstract This article develops a general thermodynamic framework for the modeling of an irreversible absorption chiller at the design point, with application to a single-stage ammonia–water absorption chiller. Component models of the chiller have been assembled so as to quantify the internal entropy production and thermal conductance (UA) in a thermodynamically rigorous formalism, which is in agreement with the simultaneous heat-and-mass transfer processes occurring within the exchangers. Local thermodynamic balance (viz. energy, entropy, and mass balance) and consistency within the components is respected, in addition to the overall thermodynamic balance as determined by the inlet and outlet states of the components. For the absorbers, Colburn-and-Drew mass transfer equations are incorporated to describe the absorption process. Furthermore, the impact of various irreversibilities on the performance of chiller is also evaluated through the use of a general macroscopic equation.

[1]  K. Ng,et al.  Thermodynamic analysis of absorption chillers: internal dissipation and process average temperature , 1998 .

[2]  D. C. Erickson,et al.  Use of the colburn-drew equations to model mass transfer , 1998 .

[3]  T. B. Drew,et al.  The condensation of mixed vapors , 1965 .

[4]  K. Ng,et al.  On the modeling of absorption chillers with external and internal irreversibilities , 1997 .

[5]  A. Conlisk,et al.  Nonisothermal absorption on a horizontal cylindrical tube—1. The film flow , 1996 .

[6]  Yong Tae Kang,et al.  Development of design model for a rectifier in GAX absorption heat pump systems , 1996 .

[7]  R. N. Christensen,et al.  GAX absorption cycle design process , 1999 .

[8]  R. Christensen,et al.  Ammonia-water bubble absorber with a plate heat exchanger , 1998 .

[9]  H. Perez-blanco.  A model of an ammonia-water falling film absorber , 1988 .

[10]  Kim Choon Ng,et al.  A general thermodynamic framework for understanding the behaviour of absorption chillers , 2000 .

[11]  Y. Kang,et al.  Development of a counter-current model for a vertical fluted tube GAX absorber , 1994 .

[12]  C. A. Infante Ferreira,et al.  Heat and mass transfer in vertical tubular bubble absorbers for ammonia-water absorption refrigeration systems , 1984 .

[13]  A. Colburn,et al.  Mass Transfer (Absorption) Coefficients Prediction from Data on Heat Transfer and Fluid Friction , 1934 .

[14]  S. Klein,et al.  A model of the steady-state performance of an absorption heat pump , 1982 .

[15]  J.A.M. Kuipers,et al.  Diffusion Coefficients and Viscosities of CO2 + H2O, CO2 + CH3OH, NH3 + H2O, and NH3 + CH3OH Liquid Mixtures , 1996 .

[16]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[17]  W. K. Lewis,et al.  Principles of Gas Absorption. , 1924 .

[18]  Daniel G. Friend,et al.  A Helmholtz Free Energy Formulation of the Thermodynamic Properties of the Mixture {Water + Ammonia} , 1998 .

[19]  G. S. Herbine.  Model of an ammonia-water bubble adsorber , 1995 .