CFD study of variable geometry ejector using R600a to detect optimal geometry for ejector refrigeration system

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77 mmemodaresacir Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 R6a * ghazikhani@ferdowsiumacir 9779 89 9 : 9 : : R6a + 8 9mm * + CFD study of variable geometry ejector using R6a to

Department of Mechanical Engineering, Ferdowsi University, Mashhad, Iran Department of Mechanical Engineering, Ferdowsi University, Mashhad, Iran *POB 977989 Mashhad, ghazikhani@ferdowsiumacir

1 77 mmemodaresacir Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 R6a * ghazikhani@ferdowsiumacir : 9 : : R6a + 8 9mm * + CFD study of variable geometry ejector using R6a to detect optimal geometry for ejector refrigeration system Amir Omidvar Mohsen Ghazikhani* Mohammad Reza Modarres Razavi Department of Mechanical Engineering, Ferdowsi University, Mashhad, Iran Department of Mechanical Engineering, Ferdowsi University, Mashhad, Iran Department of Mechanical Engineering, Ferdowsi University, Mashhad, Iran *POB Mashhad, ghazikhani@ferdowsiumacir ARTICLE INFORMATION ABSTRACT Original Research Paper Received January Accepted March Available Online April In this paper, numerical investigation was carried out for the sake of identifying optimum geometry for variable geometry ejector use in solar refrigeration system as the prerequisite to experimental tests Variable geometry was made by using movable primary nozzle and movable spindle in it Vacuum tube collector was postulated as heat source and R6a was used as working fluid Condenser temperature based on Middle East area temperature and evaporator based on operative condition in HVAC system were selected Generator, condenser and evaporator operating temperatures have severe effects on the optimum geometry of ejector Therefore, for maximum entrain ratio it is necessary to identify optimum geometry to cope with variations in operating condition The results showed that using variable geometry ejector is requirement for cooling during the day The following fluid structure was compared by entropy generation during mixing and shock phenomena The results showed there is optimum back pressure to minimize fluid exit entropy which coincides with critical back pressure It was found that depending on back pressure maximum entropy generation occurs for two reasons, mixing and shock phenomena Keywords: Variable Geometry Ejector AirConditioning Isobutene Numerical Simulation Entropy Generation Please cite this article using: : A Omidvar, M Ghazikhani, M R Modarres Razavi, CFD study of variable geometry ejector using R6a to detect optimal geometry for ejector refrigeration system Modares Mechanical Engineering Vol, No, pp 77, (In Persian)

2 R6a Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 [,] [] (R6a) [] [] [] Ra R6a [6] (CFD) R6a R9 Ra Ra [7] R6 Rfa Ra [] Rfa R6 R Rb R Rb [6] CFD [7] [8] CFD [8] [9] Ra [] [] R6a Ra [6] [] 8

3 R6a Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 [9] [] [] [] [] CFD (NXP ) [] + R6a Nozzle Exit Plan 9

4 R6a Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 [] [] 7W hp ( ) ( ) ( ( ) ( ) () = (Ps) ) (Pp) 7 W 6/ kpa 88 87/ 7kPa 78K 68/ 6kPa 8 K P b / mm S / mm /mm 9 mm A 9 mm B 88 mm C

5 R6a 7 Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 Pa 8 B A C 7 66 [6] 6 Pa k Densitybased SIMPLEC Realizable Pressure outlet

6 ( 9 ( 8 ) = = = 7 = = = = 8 = = = T 9 T TC 9 Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 R6a 8 6 9

7 R6a + + = = = mm kg/s = = = = = = Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 + c

8 R6a 8 6 = + = 8 + = kg/s + = = + = 8 7= = 8 + = + = + = 6 + = 6 + = = 8 = = + = 8 = + = 8 + = + = 6 + = 6 = 9= + = Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 8 9

9 R6a Downloaded from mmemodaresacir at : IRDT on Sunday August 6th = = 6 = 6 = = = kg/s 7 6 7W CFD

10 R6a j/kg K Downloaded from mmemodaresacir at : IRDT on Sunday August 6th Tc Tc Tc Tc 6 6 Tc 7 6 Tc m [] X Chen, S Omer, M Worall, S Riffat, Recent developments in ejector refrigeration technologies, Renewable and Sustainable Energy Reviews, Vol 9, No, pp 696, [] A Selvaraju, A Mani, Analysis of vapour ejector refrigeration system with environment friendly refrigerants, International Journal of Thermal Sciences, Vol, No 9, pp 99, [] A Selvaraju, A Mani, Analysis of an ejector with environment friendly refrigerants, Applied Thermal Engineering, Vol, No 6, pp 8788, [] S Varga, P M S Lebre, A C Oliveira, CFD study of variable area ratio ejector using R6a and Ra refrigerants, International Journal of Refrigeration No, [] J Chen, H Havtun, B Palm, Screening of working fluids for the ejector refrigeration system, INTERNATIONAL JOURNAL OF Refrigeration No, [6] A Dahmani, Z Aidoun, N Galanis, Optimum design of ejector refrigeration systems with environmentally benign fluids, International Journal of Thermal Sciences, Vol, No 8, pp 67, [7] F Yusefi, S Tabatabaei, E Afshari, Effect of the Working Fluid on the Ejector Refrigeration System, Energy: Engineering Managment, Vol, No, pp 6, [ [8] S Aphornratana, I W Eames, small capacity steamejector refrigerator: experimental investigation of system using ejector with movable primary nozzle, International Journal of Refrigeration, Vol, No, pp 8, 997 [9] S Balamurugan, V G Gaikar, A W Patwardhan, Effect of ejector configuration on hydrodynamic characteristics of gas liquid ejectors, Chemical Engineering Science, Vol 6, pp 77, 8 [] C Lin, Y Li, W Cai, J Yan, Y Hu, Experimental investigation of the adjustable ejector in multievaporator refrigeration system, Applied Thermal Engineering, Vol 6, No, pp, [] X Ma, W Zhang, S A Omer, S B Riffat, Experimental investigation of novel steam ejector refrigerator suitable for solar energy applications, Applied Thermal Engineering, Vol, No, pp, [] C Lin, W Cai, Y Li, J Yan, Y Hu, The characteristics of pressure recovery in an adjustable ejector multievaporator refrigeration system, Energy, Vol 6, No, pp 8, [] C Lin, W Cai, Y Li, J Yan, Y Hu, Pressure recovery ratio in variable cooling loads ejectorbased multievaporator refrigeration system, Energy No, [] W Pridasawas, P Lundqvist, yearround dynamic simulation of solardriven ejector refrigeration system with isobutane as refrigerant, International Journal of Refrigeration, Vol, No, pp 88, 7 [] A Selvaraju, A Mani, Experimental investigation on Ra vapour ejector refrigeration system, International Journal of Refrigeration, Vol 9, No 7, pp 666, 6 [6] T Sriveerakul, S Aphornratana, K Chunnanond, Performance prediction of steam ejector using computational luid dynamics: Part Validation of the CFD results, International Journal of Thermal Sciences, Vol 6, pp 9 7 6

11 Downloaded from mmemodaresacir at : IRDT on Sunday August 6th 8 R6a [] Y Zhu, W Cai, C Wen, Y Li, Numerical investigation of geometry parameters for design of high performance ejectors, Applied Thermal Engineering, Vol 9, No 6, pp 8989, 9 [] S Varga, A C Oliveira, B Diaconu, Numerical assessment of steam ejector efficiencies using CFD, International Journal of Refrigeration, Vol, pp 9, 9 [] A Omidvar, M Ghazikhani, M M Razavi, Simulation and parameter study of small scale variable geometry ejector using CFD, MME Journal, Vol, No, pp 96, fa [] A Soroureddin, A S Mehr, S M S Mahmoudi, M Yari, Thermodynamic analysis of employing ejector and organic Rankine cycles for GTMHR waste heat utilization: comparative study, Energy Conversion and Management, Vol 67, No, pp 7, [6] FLUENT 6 User's guide, FLUENT INC, Lebanon, NH, USA 7 88, 7 [7] K Pianthong, W Seehanam, M Behnia, T Sriveerakul, S Aphornratana, Investigation and improvement of ejector refrigeration system using computational fluid dynamics technique, Energy Conversion and Management, Vol 8, pp 66, 7 [8] C Lin, W Cai, Y Li, J Yan, Y Hu, K Giridharan, Numerical Investigation of Geometry Parameters for Pressure Recovery of An Adjustable Ejector in Multievaporator Refrigeration System, Applied Thermal Engineering No, [9] S B Riffat, S A Omer, CFD modelling and experimental investigation of an ejector refrigeration system using methanol as the working fluid, International Journal of Energy Research, Vol, pp 8, [] E Rusly, L Aye, W W S Charters, A Ooi, CFD analysis of ejector in combined ejector cooling system, International Journal of Refrigeration, Vol 8, pp 9, [] T Sriveerakul, S Aphornratana, K Chunnanond, Performance prediction of steam ejector using computational luid dynamics: Part Flow structure of steam ejector influenced by operating pressures and geometries, International Journal of Thermal Sciences, Vol 6, pp 88, 7

EFFECT OF THE NOZZLE EXIT POSITION ON THE EFFICIENCY OF EJECTOR COOLING SYSTEM USING R134A

EFFECT OF THE NOZZLE EXIT POSITION ON THE EFFICIENCY OF EJECTOR COOLING SYSTEM USING R134A K. Sopian 1, B. Elhub 1, Sohif Mat 1, A. N. Al-Shamani 1, AM Elbreki 1, Azher M. Abed 1, Husam Abdulrasool Hasan