Comparative Optical and Thermal Analysis of Compound Parabolic Solar Collector with Fixed and Variable Concentration Ratio

Hamza Riaz,Javed Akhtar,Muhammad Kaleem,Muzaffar Ali,Rashid Muhammad

doi:10.3390/engproc2021012085

Abstract

Solar thermal collectors, such as flat plate and evacuated tube collectors, are used for maximum of 60–80 °C temperature and parabolic trough collectors are used for 700–900 °C temperature ranges. It is needed to develop and analyze solar collectors, such as compound parabolic collectors (CPC) which can operate in an intermediate temperature range from 50–300 °C for industrial and domestic applications. However, optical and thermal performance of CPC is strongly influenced by concentration ratio. The current study presents a comparative optical and thermal analysis of CPC with fixed (4) and variable (4.5 to 5.7) concentration ratio by using model-based transient simulation approach. Two profiles of compound parabolic collector are analyzed with fixed and variable concentration ratio for the subtropical climate of Taxila, Pakistan. 2D profiles of both collectors are modeled and designed in MATLAB and are then analyzed optically by using Monte Carlo ray tracing technique through TracePro. In addition, thermal analysis of both profiles is also performed through ANSYS. The resulting optical efficiencies with fixed and variable concentration are 72% and 79%, respectively. Whereas maximum temperature achieved with both profiles is 352 K and 367 K, respectively. Thus, it is concluded that performance of CPC with variable concentration ratio is much better compared to fixed value.

Highlights

Energy Engineering Department, University of Engineering and Technology, Taxila 47080, Pakistan; Mechanical Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan; Mechanical Engineering Department, University of Chakwal, Chakwal 48800, Pakistan; Presented at the 1st International Conference on Energy, Power, and Environment, Gujrat, Pakistan, 11–12 November 2021
Collector with fixed concentration ratio (FCR) is installed in E–W orientation while collector with variable concentration ratio (VCR) is designed with respect to working hours and is placed in a N–S orientation
Both profiles of collector having fixed, and variable concentration ratio are analyzed optically in TracePro to determine the optical efficiency of collector

Summary

Introduction

Energy Engineering Department, University of Engineering and Technology, Taxila 47080, Pakistan; Mechanical Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan; Mechanical Engineering Department, University of Chakwal, Chakwal 48800, Pakistan; Presented at the 1st International Conference on Energy, Power, and Environment, Gujrat, Pakistan, 11–12 November 2021 Solar thermal collectors, such as flat plate and evacuated tube collectors, are used for maximum of 60–80 ◦ C temperature and parabolic trough collectors are used for 700–900 ◦ C temperature ranges. The current study presents a comparative optical and thermal analysis of CPC with fixed (4) and variable (4.5 to 5.7) concentration ratio by using model-based transient simulation approach. Compound parabolic collector was invented by Winston in 1960 and was presented later in 1974 which was used for the supply of hot water as end application [1] These collectors are developed because efficiency of non-imaging collectors was low because of high convection losses. In 1976, Rabl made its optical analysis by deriving a mathematical model of the average number of rays reflected towards the absorber from the reflector [2]

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