Soğutucu Akışkan Distribütöründe İki Fazlı Akışın Bilgisayarlı Simülasyonu

Abstract

Soğutucu akışkan basınç düşümünün düşük seviyede tutulması ve evaporatör girişinde homojen bir dağılımın sağlanması amacıyla distribütördeki akış karakteristiklerinin anlaşılması gerekmektedir. Bu çalışmanın amacı geleneksel olarak kullanılan ve yeni dizayn edilmiş bir soğutucu akışkan distribütöründe iki fazlı akış karakteristiklerinin elde edilmesi ve doğrulanmasıdır. Bu amaçla deneysel veriler kullanılarak bir simülasyon modeli hazırlanmıştır. Distribütördeki iki fazlı akış dağılımının evaporatör performansı üzerindeki etkisi göz önünde bulundurulmuştur. Distribütör kanallarındaki kütlesel debilerin dağılımı ve basınç düşümleri numerik olarak hesaplanmış ve deney düzeneğinden alınan sonuçlar ile karşılaştırılmıştır. Sonuç olarak, deney düzeneğinden alınan basınç düşümü sonuçlarının numerik olarak elde edilen sonuçlarla % 2’den daha az bir farkla örtüştüğü görülmüştür. 

Keywords

• Soğutucu akışkan distribütörü,bilgisayarlı simülasyon

Computational Simulation of Two Phase Flow in a Refrigerant Distributor

Abstract

In order to keep pressure drops at lower levels and to maintain uniform refrigerant distribution, flow behavior of refrigerants in the distributors at the entrance of evaporators should be elucidated. The aim of this study is to obtain a validated computational simulation of two-phase flow distribution in conventional and new designs refrigerant distributor. The results of the computational simulations of the distributor are validated against the experimental results. The influence of the flow distribution on the evaporator performance has been considered. Distribution of mass flow rate in the distributor channels and pressure drop are numerically calculated and then compared to the data obtained from the experimental facility. As a result, the difference between numerical and experimental study of the pressure drop is less than % 2.  

Keywords

• Refrigerant distributor,computational simulation

References

1. [1] Lee, J., Kwon, Y.-C., Kim, M.H., (2003) An improved method for analyzing a fin and tube evaporator containing a zeotropic mixture refrigerant with air maldistribution. Int. J. Refrigeration 26, 707-720.
2. [2] Kim, J. H., Braun, J., Groll, E. (2009), A hybrid method for refrigerant flow balancing in multi-circuit evaporators: upstream versus downstream flow control. Int. J. Refrigeration 32, 1271-1282, USA
3. [3] Nakayama, M., Y. Sumida, S. (2000), Development of a refrigerant two-phase flow distributor for a room air conditioner, International Refrigeration Conference at Purdue, pp. 313-319, USA
4. [4] Wen, M.-Y., Lee, C.-H., Tasi, J.-C., (2008) Improving two-phase refrigerant distribution in the manifold of the refrigeration system, App. Thermal Eng., 28:2126-2135.
5. [5] Gang Li , Steven Frankel , James E. Braun (2002), Application of CFD Models To Two Phase Flow In Refrigerant Distributors, International Refrigeration and Air Conditioning Conference, Paper 592, USA
6. [6] Gang Li , Steven Frankel , James E. Braun and Groll, E. A. (2002), Evaluating The Performance Of Refrigerant Flow Distributors, International Refrigeration And Air Conditioning Conference, Paper 593, USA
7. [7] Dong, Z. G. and Bean, J., 2006, Experimental research and CFD simulation on microchannel evaporator header to improve heat exchanger efficiency, International Refrigeration and Air Conditioning Conference. Paper 753.
8. [8] Gang Li , Steven Frankel , James E. Braun and Groll, E. A. (2005), Application of CFD Models To Two Phase Flow In Refrigerant Distributors, HVAC&R Research, VOLUME 11, NUMBER 1

9. [9] Fei, P., Hrnjak, P.S. (2004) Adiabatic Developing Two-phase Refrigerant Flow in Manifolds of Heat Exchangers in Manifolds of Heat Exchangers, ACRC, University of Illinois, 2004. Tech. Rep. TR-225.
10. [10] Abishek, S., King, A.J.C., Ramesh N., (2017), Computational analysis of two-phase flow and heat transfer in parallel and counter flow double-pipe evaporators, International Journal of Heat and Mass Transfer, Volume 104, January Pages 615-626.
11. [11] Yuan P., Jiang G.B., He Y.L., Tao W.Q., Performance simulation of a two-phase flow distributor for plate-fin heat exchanger (2016) *Applied Thermal Engineering 99 1236–1245
12. [12] ANSYS Meshing User's Guide, (2013), ANSYS, Inc. Release 15.0, USA.
13. [13] Bell S., (1999), A Beginner's Guide to Uncertainty of Measurement, Measurement Good Practice Guide”, No:11(2), Thermal and Length Metrology National Physical Laboratory, Middlesex, United Kingdom.