FEM-CFD Simulation and Experimental Study of Compound Parabolic Concentrator (CPC) Solar Collectors with and without Fins for Residential Applications

Javier E Barrón-Díaz,Luis D Patiño-Lopez,J Francisco Koh-Dzul,Ali Bassam,Jose G Carrillo,Danny G Chan-Colli,Emmanuel A Flores-Johnson

doi:10.3390/app11083704

Abstract

Compound parabolic concentrator (CPC) solar collectors are widely used for solar energy systems in industry; however, CPC collectors for residential applications have not been fully investigated. In this work, the thermal performance of non-tracking, small-size and low-cost CPC collectors with an absorber with and without segmented fins was studied experimentally and by means of a proposed numerical methodology that included ray tracing simulation and a coupled heat transfer finite element method (FEM)-computational fluid dynamics (CFD) simulation, which was validated with experimental data. The experimental results showed that the CPC with a finned absorber has better thermal performance than that of the CPC with absorber without fins, which was attributed to the increase in thermal energy on the absorber surface. The numerical results showed that ray tracing simulation can be used to estimate the heat flux on the absorber surface and the FEM-CFD simulation can be used to estimate the heat transfer from the absorber to the water running through the pipe along with its temperature. The numerical results showed that mass flow rate is an important parameter for the design of the CPC collectors. The numerical methodology developed in this work was capable of describing the thermal performance of the CPC collectors and can be used for the modeling of the thermal behavior of other CPCs solar systems.

Highlights

Today, the use of renewable energy sources for the generation of hot water for industrial and residential applications is rapidly increasing to meet climate change policies worldwide [1]
A compound parabolic concentrator (CPC) is a type of non-imaging collector [7] made of two reflective parabolic surfaces, which redirect the incident solar radiation onto the surface of an absorber placed at the focal points
The first CPC collector was designed by Winston [9,10]; since several improvements to the original design have been developed including the optimization of the geometry of the reflective surface to attain a maximum concentration ratio [11], the improvement of the absorber by using evacuated tubes to surround the surface of the absorber to reduce heat loss [7] and the use of fins in the absorber to increase solar radiation absorption [12,13]

Summary

Introduction

The use of renewable energy sources for the generation of hot water for industrial and residential applications is rapidly increasing to meet climate change policies worldwide [1]. A compound parabolic concentrator (CPC) is a type of non-imaging collector [7] made of two reflective parabolic surfaces, which redirect the incident solar radiation onto the surface of an absorber placed at the focal points. The first CPC collector was designed by Winston [9,10]; since several improvements to the original design have been developed including the optimization of the geometry of the reflective surface to attain a maximum concentration ratio [11] (defined as the ratio of the aperture area to the absorber area), the improvement of the absorber by using evacuated tubes to surround the surface of the absorber to reduce heat loss [7] and the use of fins in the absorber to increase solar radiation absorption [12,13]

Methods

Findings

Discussion

Conclusion