A solar ejector air-conditioning system using environment-friendly working fluids

Abstract

SUMMARYIn this paper, the performance of the solar-driven ejector air conditioning with several environment-friendly working fluids is studied. The effect of the fluid nature and operating conditions on the ejector performance is examined. This performance is calculated using an empirical correlation. Thermodynamic properties of functioning fluids are obtained with a package REFPROP7. It appears that the refrigerant R717 offers the highest coefficient of performance (COP). For generator temperature T B ¼ 908C; condenser temperature T C ¼ 358C and evaporator temperature T E ¼ 158C and with R717, the COP of ejector air-conditioning system is 0.408. Using a meteorological data for the city of Tunis, the system performance is computed for three collector types. The air-conditioning season and period were taken for six months from April to September. The daily period is between 8 and 17 h. For the solar air-conditioning application, the COP of the overall system varied from 0.21 to 0.28 and the exergy efficiency varied from 0.14 to 0.19 with the same working conditions and total solar radiation (351-875 Wm À2 ) in July.

Performance study of ejector cooling cycle at critical mode under superheated primary flow

“…Also, is found the SECS using R290, R134a and R152a suitable for higher pressures and more strong construction. In the experiment carried out by Nehdi et al [28] R717 achieved higher COP followed by R152a, R290 and R134a. Boumaraf and lallemand [29] proved that R142b can produce better performance than R600a, because R142b consider a heavier fluid than R600a.…”

Ejector refrigeration: A comprehensive review

“…However, they belong to A2L safety group; thus, they will require changes to equipment safety standards. In addition to the new halocarbon compounds, the low environment impact of HCs make them possible alternatives [98,144,146,149,156,157,171,[190][191][192][193][194][195][196][197][198][199][200]. Unfortunately, HC refrigerants are highly flammable, which may limit their usage [201].…”

“…These concerns can be relieved with additional research on new mixtures of HCs and HFCs [8]. Another working fluid that has been studied is ammonia (R717) [106,130,139,144,146,149,157,192,[202][203][204][205] for its low cost, high performance and more favorable thermodynamic properties, and it does not create environmental problems. However, it likely will remain restricted to industrial applications, as it is unsuitable for domestic use due to its toxicity [13].…”

“…For this configuration, COP ejector reached 0.42 (T g ¼100°C, Te ¼18°C, Tc ¼50°C). Another comparison of SoERS using eight working fluids, was performed by Nehdi et al [149]. The comparative study revealed that R717 provided the highest performance (COP overall ¼0.21-0.28), with an exergy efficiency between 0.14 and 0.19.…”

Performance improvement of the vapour compression refrigeration cycle by a two-phase constant area ejector

“…In heat-driven ejector refrigeration systems, the flow in the ejector is generally dealt with by considering it as a single-phase (vapour) flow [12][13][14][15][16][17]. As for the purpose of reducing throttling losses, the flow in the ejector which substitutes an expansion valve is two-phase flow and hence its analysis as compared to single-phase flow is more complex.…”