Next Article in Journal
Heat-Transfer Characteristics of Liquid Sodium in a Solar Receiver Tube with a Nonuniform Heat Flux
Previous Article in Journal
Optimization of Ventilation Spacer for Direct-Drive Permanent Magnet Wind Generator
Article Menu
Issue 8 (April-2) cover image

Export Article

Open AccessArticle

Numerical and Experimental Study of Flow Characteristics in Solar Collector Manifolds

1
University of West Attica, Campus 1, School of Engineering, Agiou Spyridonos, 12243 Aigaleo, Greece
2
Prime Laser Technology SA, Viopa Kerateas, 19001 Keratea, Greece
*
Author to whom correspondence should be addressed.
Energies 2019, 12(8), 1431; https://doi.org/10.3390/en12081431
Received: 29 November 2018 / Revised: 29 March 2019 / Accepted: 9 April 2019 / Published: 14 April 2019
  |  
PDF [3682 KB, uploaded 14 April 2019]
  |  

Abstract

The flow through a forced circulation Z-type flat plate solar collector was investigated by means of combined experimental measurements and numerical simulations. The efficient operation of such collectors depends on the uniformity of the flow rate distribution among their riser tubes, while low pumping power demand is also sought. Mass flow rate measurements in the riser tubes were performed, utilizing a specially adapted ultrasound instrument for various values of total flow rates in the collector. By means of a commercial Computational Fluid Dynamics (CFD) code, laminar and turbulent flow models in different computational grids were tested and validated against the experiments. Appropriate metrics were introduced to quantify flow rate distribution non-uniformity among the risers, and pressure drop through the manifold was calculated. Parametric studies for flow conditions outside the experimental window were performed utilizing the CFD method in order to assess the effect of the Reynolds number in the flow distribution among the riser tubes. Furthermore, aiming to enhance flow rate uniformity, a methodology based on modifying the diameter of each riser tube was applied and successfully demonstrated. The proposed method can be employed in large solar collector arrays, either as stand-alone systems or as belonging to hybrid alternative sources of energy (ASE) systems, aiming to optimize their overall efficiency. View Full-Text
Keywords: solar thermal energy models; solar collector manifold design; solar collector flow distribution; uniformity enhancement solar thermal energy models; solar collector manifold design; solar collector flow distribution; uniformity enhancement
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Karvounis, P.; Koubogiannis, D.; Hontzopoulos, E.; Hatziapostolou, A. Numerical and Experimental Study of Flow Characteristics in Solar Collector Manifolds. Energies 2019, 12, 1431.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top