Impact of the mixing theories on the performance of ejector expansion refrigeration cycles for environmentally-friendly refrigerants
Küçük Resim Yok
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Ejector expansion refrigeration cycle was investigated theoretically to compare the constant pressure mixing and constant area mixing ejector theories making use of thermodynamic models. Performance improvement was presented according to optimum and constant value pressure drop assumptions in order to simulate the design and off-design conditions, respectively. The agreement between the results with respect to both pressure drop assumptions is better at higher condenser and lower evaporator temperatures for each ejector mixing theory. Optimum area ratio (phi(opt)) is less for constant area mixing approach since the ratio of the secondary flow velocity to the primary flow is higher for this ejector theory at each operation point. Although a group of low-global-warming-potential refrigerants were compared in terms of the performance and expansion losses, deep investigations were presented for R1234yf in main and sometimes R1234ze(E). Finally, when compared to other ejector sections, the mixing section efficiency has the most critical effect on the optimum performance improvement ratio of R1234yf with reference to constant pressure mixing assumption. (C) 2018 Elsevier Ltd and IIR. All rights reserved.
Açıklama
Anahtar Kelimeler
Ejector expansion refrigeration cycles, Constant area mixing, Constant pressure mixing, Low-GWP refrigerants, Zero-dimensional (OD) modelling, Ejector section efficiency
Kaynak
International Journal of Refrigeration-Revue Internationale Du Froid
WoS Q Değeri
Q1
Scopus Q Değeri
Cilt
97
