%0 Journal Article
%T Prediction the Vapor-Liquid Equilibria of CO2-Containing Binary Refrigerant Mixtures Using Artificial Neural Networks
%A Ahmad Azari
%A Saeid Atashrouz
%A Hamed Mirshekar
%J ISRN Chemical Engineering
%D 2013
%R 10.1155/2013/930484
%X Artificial neural network (ANN) technique has been applied for estimation of vapor-liquid equilibria (VLE) for eight binary refrigerant systems. The refrigerants include difluoromethane (R32), propane (R290), 1,1-difluoroethane (R152a), hexafluoroethane (R116), decafluorobutane (R610), 2,2-dichloro-1,1,1-trifluoroethane (R123), 1-chloro-1,2,2,2-tetrafluoroethane (R124), and 1,1,1,2-tetrafluoroethane (R134a). The related experimental data of open literature have been used to construct the model. Furthermore, some new experimental data (not applied in ANN training) have been used to examine the reliability of the model. The results confirm that there is a reasonable conformity between the predicted values and the experimental data. Additionally, the ability of the ANN model is examined by comparison with the conventional thermodynamic models. Moreover, the presented model is capable of predicting the azeotropic condition. 1. Introduction For nearly 60 years, chlorofluorocarbons (CFCs) have been widely used as solvents, foam blowing agents, aerosols, and especially refrigerants due to their stability, nontoxicity, nonflammability, good thermodynamic properties, and so on. However, they also have a harmful effect on the earth¡¯s protective ozone layer. So, they have been regulated internationally by Montreal Protocol since 1987. Much effort has been made to find the suitable replacement for CFCs. Initial CFC alternatives included some hydrochlorofluorocarbons (HCFCs), but they will be also phased out internationally because their ozone depletion potentials (ODPs) and global warming potentials (GWPs) are significant though less than those of CFCs. Hydrofluorocarbons (HFCs) synthetic refrigerants which have zero ODPs were proposed as promising replacements for CFCs and HCFCs [1]. The deadline for HCFCs which have low ozone depletion potential is 2030. Also there is no report for another type of refrigerants such as light hydrocarbons or perfluorocarbons as harmful refrigerants. In order to develop new refrigerants for replacement with harmful refrigerants, the mixtures of carbon dioxide and clean refrigerants have been studied in the number of researches [2¨C8] that was reviewed in the present study. R134a is an environmentally acceptable refrigerant, which has replaced the ozone-depleting CFC-12 (dichlorodifluoromethane) in a wide range of applications especially in automotive air conditioning and domestic refrigeration. Another natural refrigerant, carbon dioxide (R744), has received new worldwide interest as a working fluid in automotive air conditioning. To
%U http://www.hindawi.com/journals/isrn.chemical.engineering/2013/930484/