Document Type : Original Article
Authors
Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
Abstract
A number of isentropic coefficients are used in the one-dimensional models which predict ejector performance at critical mode. Some of these coefficients have considerable effects on accuracy of the model. These coefficients depend on geometry, working fluid and operating conditions; but, they are usually taken constants or are presented as functions of geometry and working condition based on a specific experiment. In this work, the idea of using the flow parameters to determine these coefficients is introduced and has been analyzed. For this purpose, four models with different formulations are employed. The fluid has been considered as a real gas; hence, the models which are based on the ideal gas assumption are modified. The experimental data related to some ejectors with different geometries, working fluids and working conditions have been used. Using the empirical data, correlations between some of the isentropic coefficients and the flow parameters are developed for some models. Using these correlations, entrainment ratios are calculated with the maximum relative error of 35%, while in most cases the maximum relative error is about 10%. However, errors are acceptable since the empirical data are extracted from a vast range of different geometrical and operational conditions.
Keywords
Main Subjects
- Shestopalov, K. O., Huang, B. J., Petrenko, V. O. and Volovyk, O. S., 2015. “Investigation of an Experimental Ejector Refrigeration Machine Operating with Refrigerant R245fa at Design and Off-Design Working Conditions. Part 1. Theoretical Analysis”. International Journal of Refrigeration, 55, pp.201-211.
Doi: 10.1016/j.ijrefrig.2015.01.016 - Ahmadi Boyaghchi, F. and Taheri, R., 2014. “3e Analysis and Ga-Based Multi Objective Optimization of an Ejector-Flash Tank-Absorption Refrigeration System Fuelled by Solar Energy”. Iranian (Iranica) Journal of Energy & Environment, 5(4), pp.419-435. Doi: 10.5829/idosi.ijee.2014.05.04.10
- Chen, W., Liu, M., Chong, D., Yan, J., Little, A. B. and Bartosiewicz, Y., 2013. “A 1d Model to Predict Ejector Performance at Critical and Sub-Critical Operational Regimes”. International Journal of Refrigeration, 36(6), pp.1750-1761.
Doi: 10.1016/j.ijrefrig.2013.04.009 - Aidoun, Z., Ameur, K., Falsafioon, M. and Badache, M., 2019. “Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors”. Inventions, 4(15),
Doi: 10.3390/inventions4010015 - Liu, Y., Yu, M. and Yu, J., 2022. “An Improved 1-D Thermodynamic Modeling of Small Two-Phase Ejector for Performance Prediction and Design”. Applied Thermal Engineering, 204, pp.118006.
Doi: 10.1016/j.applthermaleng.2021.118006 - Haghparast, P., Sorin, M. V. and Nesreddine, H., 2018. “Effects of Component Polytropic Efficiencies on the Dimensions of Monophasic Ejectors”. Energy Conversion and Management, 162, pp.251-263. Doi: 10.1016/j.enconman.2018.02.047
- Liu, F. and Groll, E. A., 2013. “Study of Ejector Efficiencies in Refrigeration Cycles”. Applied Thermal Engineering, 52(2), pp.360-370. Doi: 10.1016/j.applthermaleng.2012.12.001
- Kumar, N. S. and Ooi, K. T., 2014. “One Dimensional Model of an Ejector with Special Attention to Fanno Flow within the Mixing Chamber”. Applied Thermal Engineering, 65(1), pp.226-235.
Doi: 10.1016/j.applthermaleng.2013.12.055 - Chen, J., Havtun, H. and Palm, B., 2014. “Parametric Analysis of Ejector Working Characteristics in the Refrigeration System”. Applied Thermal Engineering, 69(1), pp.130-142.
Doi: 10.1016/j.applthermaleng.2014.04.047 - Huang, B. J., Chang, J. M., Wang, C. P. and Petrenko, V. A., 1999. “A 1-D Analysis of Ejector Performance”. International Journal of Refrigeration, 22(5), pp.354-364.
Doi: 10.1016/S0140-7007(99)00004-3 - Besagni, G., Mereu, R., Chiesa, P. and Inzoli, F., 2015. “An Integrated Lumped Parameter-Cfd Approach for Off-Design Ejector Performance Evaluation”. Energy Conversion and Management, 105, pp.697-715.
Doi: 10.1016/j.enconman.2015.08.029 - Aly, N. H., Karameldin, A. and Shamloul, M. M., 1999. “Modelling and Simulation of Steam Jet Ejectors”. Desalination, 123(1), pp.1-8. Doi: 10.1016/S0011-9164(99)00053-3
- Zhu, Y., Cai, W., Wen, C. and Li, Y., 2007. “Shock Circle Model for Ejector Performance Evaluation”. Energy Conversion and Management, 48(9), pp.2533-2541.
Doi: 10.1016/j.enconman.2007.03.024 - Zhu, Y. and Li, Y., 2009. “Novel Ejector Model for Performance Evaluation on Both Dry and Wet Vapors Ejectors”. International Journal of Refrigeration, 32(1), pp.21-31.
Doi: 10.1016/j.ijrefrig.2008.08.003 - Cardemil, J. M. and Colle, S., 2012. “A General Model for Evaluation of Vapor Ejectors Performance for Application in Refrigeration”. Energy Conversion and Management, 64, pp.79-86. Doi: 10.1016/j.enconman.2012.05.009
- Chen, J., Havtun, H. and Palm, B., 2014. “Investigation of Ejectors in Refrigeration System: Optimum Performance Evaluation and Ejector Area Ratios Perspectives”. Applied Thermal Engineering, 64(1), pp.182-191. Doi: 10.1016/j.applthermaleng.2013.12.034
- Chen, W., Shi, C., Zhang, S., Chen, H., Chong, D. and Yan, J., 2017. “Theoretical Analysis of Ejector Refrigeration System Performance under Overall Modes”. Applied Energy, 185, pp.2074-2084. Doi: 10.1016/j.apenergy.2016.01.103
- Li, F., Tian, Q., Wu, C., Wang, X. and Lee, J.-M., 2017. “Ejector Performance Prediction at Critical and Subcritical Operational Modes”. Applied Thermal Engineering, 115, pp.444-454.
Doi: 10.1016/j.applthermaleng.2016.12.116 - Chen, H., Zhu, J., Ge, J., Lu, W. and Zheng, L., 2020. “A Cylindrical Mixing Chamber Ejector Analysis Model to Predict the Optimal Nozzle Exit Position”. Energy, 2239(C).
Doi: 10.1016/j.energy.2020.118302 - Zheng, L. and Deng, J., 2017. “Research on CO2 Ejector Component Efficiencies by Experiment Measurement and Distributed-Parameter Modeling”. Energy Conversion and Management, 142, pp.244-256.
Doi: 10.1016/j.enconman.2017.03.017 - Besagni, G., Mereu, R., Di Leo, G. and Inzoli, F., 2015. “A Study of Working Fluids for Heat Driven Ejector Refrigeration Using Lumped Parameter Models”. International Journal of Refrigeration, 58, pp.154-171.
Doi: 10.1016/j.ijrefrig.2015.06.015 - Bell IH, Wronski J, Quoilin S and V., L., 2014. “Pure and Pseudo-Pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library Coolprop”. Industrial & Engineering Chemistry Research,, 53(6), pp.2498-2508.
Doi: 10.1021/ie4033999 - Ablwaifa, A. E., A Theoretical and Experimental Investigation of Jet-Pump Refrigeration System. 2006, University of Nottingham.
- Yapıcı, R., Ersoy, H. K., Aktoprakoğlu, A., Halkacı, H. S. and Yiğit, O., 2008. “Experimental Determination of the Optimum Performance of Ejector Refrigeration System Depending on Ejector Area Ratio”. International Journal of Refrigeration, 31(7), pp.1183-1189. Doi: 10.1016/j.ijrefrig.2008.02.010
- Hakkaki-Fard, A., Aidoun, Z. and Ouzzane, M., 2015. “A Computational Methodology for Ejector Design and Performance Maximisation”. Energy Conversion and Management, 105, pp.1291-1302. Doi: 10.1016/j.enconman.2015.08.070
)