Title: Influence of rotational oscillation on exergy efficiency of compound parabolic concentrator

Authors: Yoshiki Nishi; Yusuke Tokui

Addresses: Department of Systems Design for Ocean-Space, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa 2408501, Japan ' Division of Systems Integration, Graduate School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa 2408501, Japan

Abstract: This study examined the influence of the oscillatory time variation in the attitude angle of compound parabolic concentrator (CPC) on the thermal performance of CPC. Two experimental CPC models were constructed, one of which was fixed and the other one was provided with two rotational motions (pitch and roll) under sunlight irradiance. By comparing the temperatures of thermal collectors in the two CPCs, the influence by the oscillation was evaluated. Experimental results demonstrated that the oscillation can decrease or increase the temperatures depending on the centre and amplitude of oscillation. To see in more detail the influence of oscillation, exergy budgets were analysed. It is found that the rotational motions of CPC tend to decrease the exergy efficiency by a few percentages, whereas it can improve the efficiency by a few percentages by minimising the incident angles of solar irradiance around the noon.

Keywords: attitude angle; compound parabolic concentrator; CPC; oscillation; rotation; exergy.

DOI: 10.1504/IJEX.2018.095405

International Journal of Exergy, 2018 Vol.27 No.3, pp.311 - 333

Received: 13 Dec 2017
Accepted: 01 Jun 2018
Published online: 03 Oct 2018 *

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