LAPSE

LAPSE:2019.0386
Published Article
LAPSE:2019.0386
Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft
Yuji Ohya, Masaki Wataka, Koichi Watanabe, Takanori Uchida
February 27, 2019
A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward the center. Attached to the center of the inside of the collector is a vertical tower within which a wind turbine is mounted at the lower entry to the tower. When solar radiation heats the ground through the glass roof, ascending warm air is guided to the center and into the tower. A solar tower that can generate electricity using a simple structure that enables easy and less costly maintenance has considerable advantages. However, conversion efficiency from sunshine energy to mechanical turbine energy is very low. Aiming to improve this efficiency, the research project developed a diffuser-type tower instead of a cylindrical tower, and investigated a suitable diffuser shape for practical use. After changing the tower height and diffuser open angle, with a temperature difference between the ambient air aloft and within the collector, various diffuser tower shapes were tested by laboratory experiments and numerical analyses. As a result, it was found that a diffuser tower with a semi-open angle of 4° is an optimal shape, producing the fastest updraft at each temperature difference in both the laboratory experiments and numerical analyses. The relationships between thermal updraft speed and temperature difference and/or tower height were confirmed. It was found that the thermal updraft velocity is proportional to the square root of the tower height and/or temperature difference.
Keywords
computational fluid dynamics (CFD), diffuser, laboratory experiment, solar tower, thermal updraft
Suggested Citation
Ohya Y, Wataka M, Watanabe K, Uchida T. Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft. (2019). LAPSE:2019.0386
Author Affiliations
Ohya Y: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga 816-8580, Japan
Wataka M: Department of Aeronautics and Astronautics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
Watanabe K: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga 816-8580, Japan
Uchida T: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga 816-8580, Japan [ORCID]
[Login] to see author email addresses.
Journal Name
Energies
Volume
9
Issue
12
Article Number
E1077
Year
2016
Publication Date
2016-12-16
Published Version
ISSN
1996-1073
Version Comments
Original Submission
Other Meta
PII: en9121077, Publication Type: Journal Article
Record Map
Published Article

LAPSE:2019.0386
This Record
External Link

doi:10.3390/en9121077
Publisher Version
Download
Files
[Download 1v1.pdf] (9.2 MB)
Feb 27, 2019
Main Article
License
CC BY 4.0
Meta
Record Statistics
Record Views
61
Version History
[v1] (Original Submission)
Feb 27, 2019
 
Verified by curator on
Feb 27, 2019
This Version Number
v1
Citations
Most Recent
This Version
URL Here
http://psecommunity.org/LAPSE:2019.0386
 
Original Submitter
Calvin Tsay
Links to Related Works
Directly Related to This Work
Publisher Version