Performance characteristics of R1234yf ejector-expansion refrigeration cycle

Effect of Suction Nozzle Pressure Drop on the Performance of an Ejector-Expansion Transcritical CO2 Refrigeration Cycle

“…(2) The pressure difference among the motive nozzle outlet, the suction nozzle outlet and the mixing chamber is negligible [9,10,16,18]. …”

Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

“…(ii) no heat transfer with the environment for the system except in the condenser, (iii) refrigerant conditions at the evaporator and condenser exits are saturated, (iv) both liquid and vapor streams separated from the separator are saturated, It may be noted that the assumptions for both nozzles and a diffuser are similar to the previous studies [12][13][14]. Hence, the outlet enthalpies and velocities of the motive stream and suction stream are given by [12] …”

“…Although, the ejector expansion refrigeration system with R134a has been studied extensively (both theoretical and experimental), similar studies for its alternatives are very limited. Within selected alternatives, only R290, R600a, R32, R152a, and R1234yf have been studied in ejector expansion refrigeration system by various authors [9,12,14] and most of these works have considered constant mixing pressure in ejector, which is not so realistic. With best of author's knowledge, no previous study has considered all these issues.…”

“…The research and development activities on ejector expansion vapor compression refrigeration system have achieved a milestone recently. Worldwide research activities on this area can be broadly classified in the following groups: (i) ejector-expansion transcritical refrigeration systems, (ii) energetic and exergetic performance improvements by using various refrigerants, (iii) CFD simulation and design optimization, (iv) experimental studies and ejector flow control, and (v) various ejector based cycle modifications [9][10][11][12][13][14][15][16][17]. Although, the ejector expansion refrigeration system with R134a has been studied extensively (both theoretical and experimental), similar studies for its alternatives are very limited.…”

Theoretical energy performance evaluation of different single stage vapour compression refrigeration configurations using R1234yf and R1234ze(E) as working fluids

“…Harrell et al [15] performed an experiment of an ejector as an expansion device in a system using R134a as refrigerant, reporting improvements on the COP over standard cycles between 3.9% and 7.6%. Li et al [16] analyse an ejectorexpansion refrigeration cycle using R1234yf as refrigerant, highlighting that the cycle outperforms the standard one, especially under extreme working conditions. Lawrence et al [17][18][19][20] conducted an experimental and analytical investigation of two-phase ejector cycles using low pressure refrigerants R134a and R1234yf, concluding that when compared to a single evaporation temperature expansion valve cycle the ejector cycle showed maximum COP improvements of 6% with R1234yf and 5% with R134a.…”