Multi-criteria evaluation of parabolic trough collector with internally finned absorbers. (1st November 2017)

• Record Type: Journal Article
• Authors: Bellos, Evangelos; Tzivanidis, Christos; Tsimpoukis, Dimitrios
• Is Part Of: Applied energy. Volume 205(2017)
• Page Start: 540
• Page End: 561
• Publication Date: 2017-11-01
• Subjects: PTC -- Finned absorber -- Multi-criteria evaluation -- Thermal enhancement -- Thermal efficiency; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2017.07.141
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: Twelve different internally finned absorbers are examined in the LS-2 PTC. The thermal enhancement and the pressure drop are the main calculated parameters. Four evaluation criteria are used for determining the optimum fin geometry. The fin with 10 mm length and 2 mm thickness is found to be the optimum case. The optimum fin presents 0.82% thermal efficiency enhancement compared to smooth case. Abstract: Among the solar concentrating technologies, parabolic trough collector (PTC) is the most mature and cost-effective technology for medium and high-temperature levels (150–400 °C). This paper investigates the utilization of internally finned absorbers in LS-2 PTC module for various operating conditions. Twelve different longitudinal fins are tested and compared with the smooth case. The analysis is performed with SolidWorks Flow Simulation, using a validated model by literature results. Generally, it is proved that both greater length and thickness lead to higher thermal enhancement and to higher pressure losses. Various methods are presented for evaluating together the thermal efficiency or Nusselt number enhancement versus the increase in pressure drop or in the friction factor. Taking into consideration four different criteria, the absorber with 10 mm fin length and 2 mm fin thickness is found to be the overall optimum case. For this case, the thermal efficiency is enhanced about 0.82%, the Nusselt number increase 65.8%, while the friction factor and the pressure losses are about the double compared to the smooth case.