SET Proceedings 2978-4387 Caravel Press 10.65582/set.2008.244 2008.244 Thermodynamic and Heat Transfer Characteristics in Single Stage NH3-H2O Absorption Heat Pump IbrahimTalaat A. HassanMohamed A. M. Vice Presidency of Projects, King Saud University, P.O. 70908, Riyadh 11577, Saudi Arabia Mech. Power Eng. Dept., Faculty of Engineering, Helwan Uni., Mattaria, Cairo 11718, Egypt 24082008 7 1 978-1-995850-08-5 1756 1764 24 August 2008 © 2008 Copyright WSSET 2008

In this paper, the thermodynamic behavior of the ammonia-water mixture at different pressures and range of ammonia concentration, ξ, after rectifier of 0.9000 to 0.9999 has been theoretically studied. At ξ = 0.9000 and saturation pressures of 75 and 0.5 bar, the temperature glides are 64.4 and 81.21°C respectively, while this glides are 0 and 16.1°C at ξ = 0.9999 and the same pressures. This mixture properties affects considerably the absorption system performance and the design of the rectifier as well as other absorption components. The effects of ξ, mass fraction spread, Δξ, specific solution circulation ratio, f, and pressure ratio, Rp, on the heat transfer coefficients during the condensation and the evaporation are investigated. ξ has insignificant effect on the evaporation heat transfer coefficient, but has a little effect on the condensation and the absorber heat transfer coefficients. Δξ and f have considerable effects on the heat transfer coefficient for different absorption heat pump components. Rp has pronounced effect on the evaporation heat transfer coefficient; while has a slight effect on the condensation and the absorber heat transfer coefficients. For Δξ > 0.18, the effect of Rp may be eliminated on the heat transfer coefficient in the absorber.

 thermodynamic heat transfer absorption ammonia-water 24 to 27 August 2008 7th International Conference on Sustainable Energy Technologies SET2008 7 Seoul, Korea De Francisco, A., Illanes, R., Torres, J.L., Castillo, M., De Blas, M., Prieto, E., Garcıa, A., 2002, "Development and Testing of a Prototype of Low Power Water–Ammonia Absorption Equipment for Solar Energy Applications", Renewable Energy, Vol. 25, PP. 537-544 Mejbri, K., Bellagi, A., 2006, "Modeling of the Thermodynamic Properties of the Water–Ammonia Mixture by Three Different Approaches", Int. J. of Refrigeration, Vol. 29, PP. 211-218 Fernández-Seara, J., Sieres, J., Rodríguez, C., Vázquez, M., 2005, "Ammonia–Water Absorption in Vertical Tubular Absorbers", Int. J. of Thermal Sciences, Vol. 44, PP. 277-288 Ferna´ndez-Seara, J., Uhı´a, F.J., Sieres, J., 2008, "Research on the Condensation of the Ammonia–Water Mixture on a Horizontal Smooth Tube", Int. J. of Refrigeration, Vol. 31, PP. 304-314 Sencan A. 2006, "Artificial intelligent methods for thermodynamic evaluation of ammonia–water refrigeration systems", Energy Conversion and Management, Vol. 47, PP. 3319-3332 Kaynakli, O., Yamankaradeniz, R., 2007, "Thermodynamic Analysis of Absorption Refrigeration System Based on Entropy Generation", Current Science, Vol. 92 (4), PP. 472-479 Shelton, S.V., Jacob, D., Schaefer L.A., 2000, “Modeling and Analysis of the Air Cooled Ammonia-Water Triple Effect Cycle”, Proceedings of the ASME Advanced Energy Systems Division, AES Klein, S.A., Alvarado, F.L., 2001, “Engineering Equation Solver; EES”, Version 6.205, Wisconsin Madison. Ibrahim, T.A., 2002, "Thermally Activated Air Conditioning Systems", Dissertation, Institute of Thermal Engineering, Graz, Austria Ibrahim, T.A., Gadalla, M., Krotil, R., Halozan, H., 2005, "Steady State Simulation of a Single Stage Ammonia-Water Absorption Heat Pump", Int. Exergy, Energy, and Environment Symposium (IEEES2), 3-7 July, Kos-Greece Palmer, S.C., Payne, W.V., Domanski P.A., 2000, “Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate Heat Exchanger”, National Institute of Standards and Technology, NISTIR 6541 Yan, Y., Lio, H. Lin, T., 1999, ”Condensation Heat Transfer and Pressure Drop of Refrigerant R-134a in a Plate Heat Exchanger”, Int. J.l of Heat and mass Transfer 42 PP. 993-1006 Kim, H.B., Tadini, C.C., Singh, R.K., 1999, “Heat Transfer in a Plate Heat Exchanger during Pasteurization of Orange Juice”, J. of Food Engineering 42 PP. 79-84 Schnell, H., Their, B., 1991, "Waermetauscher, Energieeinsparung durch Optimierung von Waermeprozessen“, Handbuch 1. Ausgabe, Vulkan Verlag, Essen. Ohadi, M.M., Li, S.S., Radermacher, R., Dessiatioun, S., 1996, "Critical Review of Available Correlations for Two-Phase Flow Heat Transfer of Ammonia“, Int. J. of Refrigeration Vol. 19/4 PP. 272-284. Kang, Y.T., Akisawa, A., Kashiwagi, T., 2000, “Analytical Investigation of Two Different Absorption Modes: Falling Film and Bubble Types”, Int. J. of Refrigeration Vol. 23 Niebergall, W., 1959, “Sorptionskältemaschinen“ , ISBN 3-540-02404-2 Springer Verlag Berlin.