This paper aims at presenting analysis of the thermodynamic of the performance of an absorption refrigeration system of the single-effect ammonia/sodium thiocyanate couple. Since the generator is the starting point for the operation of system, one of the most important point to be addressed in this work is to determine the generator’s temperatures at which the system can accept the best quantities and qualities of energy. A mathematical model has been developed to study the performance of the system. Equations obtained from the thermodynamic properties of the ammonia/sodium thiocyanate couple were implemented in Matlab. The analysis consists of determining the effects of the generator’s temperature on the energy performance of the system. The computerized performance parameters are the coefficient of performance and the energy efficiency. Results indicate that the coefficient of performance increases with the temperature of the generator. Moreover, these remarks are not observed on the exergetic efficiency, because the latter increases until its maximum value 0.43, in order to decrease until its final value 0.35. In addition, the maximum value of the coefficient of performance tends towards 0.7 with increasing generator temperature. The system admits better operation when the generator temperatures are between 80°C and 90°C. The determination of this temperature interval by simulation can be use as a variable setting point in controlling the real system.
References
[1]
Cengel, Y.A. and Boles, M.A. (2008) Thermodynamique: Une approche pragmatique. Traduction et adaptation de Marcel Lacroix. Cheneliere McGraw-Hill, Montreal.
[2]
Sun, D.W. (1998) Comparaison of Performances of NH3-H2O, NH3-LiNO3, NH3-NaSCN Absorption Refrigeration Systems. Energy Conversion and Management, 39, 357-368. https://doi.org/10.1016/S0196-8904(97)00027-7
[3]
Talbi, M.M. and Agnew, B. (2000) Exergy Analysis: An Absorption Refrigerator Using Lithium Bromide and Water as the Working Fluids. Applied Thermal Engineering, 20, 619-630. https://doi.org/10.1016/S1359-4311(99)00052-6
[4]
Zhu, L.H. and Gu, J.J. (2010) Second Law-Based Thermodynamic Analysis of Ammonia/Sodium Thiocyanate Absorption System. Renewable Energy, 35, 1940-1946. https://doi.org/10.1016/j.renene.2010.01.022
[5]
Ceroso, J., Best, R. and Romero, R.J. (2011) A Study of a Bubble Absorber Using a Plate Exchanger with NH3-H2O, NH3-LiNO3 and NH3-NaSCN. Applied Thermal Engineering, 31, 1869-1876. https://doi.org/10.1016/j.applthermaleng.2011.02.032
[6]
Acuna, A., Velaquez, N. and Cereso, J. (2013) Energy Analysis of a Diffusion Absorption Cooling System Using Lithium Ammonia, Sodium Thiocyanate and Water as Absorbent Substances and Ammonia as the Refrigerant. Applied Thermal Engineering, 51, 1273-1281. https://doi.org/10.1016/j.applthermaleng.2012.10.046
[7]
Gong, S.Y. and Boulama, K.G. (2014) Parametric Study of an Absorption Refrigeration Machine Using Advanced Exergy Analysis. Energy, 76, 453-467. https://doi.org/10.1016/j.energy.2014.08.038
[8]
Xu, Y.J., Jiang, N., Wang, Q. and Chen, G.M. (2016) Comparative Study on the Energy Performance of Two Different Absorption-Compression Refrigeration Cycles Driven by Low-Grade Heat. Applied Thermal Engineering, 106, 33-41. https://doi.org/10.1016/j.applthermaleng.2016.05.169
[9]
Cai, D.H., Jiang, J.K., He, G.G., Li, K.Q., Niu, L.J. and Xiao, R.X. (2016) Expérimental Evaluation on Thermal Performance of an Air-Cooled Absorption Refrigeration Cycle with NH3-LiNO3 and NH3-NaSCN Refrigerant Solutions. Energy Conversion and Management, 120, 32-43. https://doi.org/10.1016/j.enconman.2016.04.089
