Numerical assessment of the dynamic behavior of a solar-driven jet-ejector refrigeration system equipped with an adjustable jet-ejector. (January 2021)

• Record Type: Journal Article
• Authors: Galindo, José; Dolz, Vicente; Tiseira, Andrés; Ponce-Mora, Alberto
• Is Part Of: International journal of refrigeration. Volume 121(2021)
• Page Start: 168
• Page End: 182
• Publication Date: 2021-01
• Subjects: Solar refrigeration -- Jet-ejector refrigeration -- Environmentally friendly refrigerants -- Energy efficiency -- Adjustable jet-ejector -- Dynamic behavior; Froid solaire -- Froid à éjecteur à jet -- Frigorigènes respectueux de l'environnement -- Efficacité énergétique -- Éjecteur à jet réglable -- Comportement dynamique; Refrigeration and refrigerating machinery -- Periodicals; 621.56
• DOI: 10.1016/j.ijrefrig.2020.10.019
• Languages: English
• ISSNs: 0140-7007

Abstract

Highlights: The dynamic behavior of an adjustable jet-ejector refrigeration system is assessed. A thermal storage system is considered to cope with variable solar irradiation. The influence of two different jet-ejector architectures is evaluated using R1234yf. The transient response is computed under real climatic conditions. Abstract: In the present paper, the mid-term performance of two different architectures of a solar-driven jet-ejector refrigeration system is numerically compared: the first one is fitted with a fixed-geometry jet-ejector while the second one is equipped with an adjustable spindle that modifies the jet-ejector area ratio. The jet-ejector behavior has been predicted with a validated computational fluid dynamics approach and the dynamic response of the overall system accounts for transient effects in a small parabolic trough collector and a hot thermal storage tank. The investigation shows that the adjustable jet-ejector allows for continuous and smooth operation in a much wider range of outdoor conditions. Additionally, it enables more efficient management of the thermal level in the hot storage system. As a result, the adjustable refrigeration system improves the performance indicators in all the warm months of the typical meteorological year under evaluation. The maximum improvement potential is found in May; the fixed-geometry system provides an average C O P th of 0.34 while the adjustable system reaches an average C O P th of 0.48 considering the same boundary conditions in both cases.