Improvement in device performance of multi-pass flat-plate solar air heaters with external recycle

A study on improvement in device performance of multi-pass solar air heaters with external recycle has been carried out under countercurrent-flow operations. An absorbing plate and insulation sheet were inserted horizontally and vertically, respectively, into a parallel-plate channel to divide the o...

Full description

Saved in:
Bibliographic Details
Published in:Renewable energy 2005-08, Vol.30 (10), p.1601-1621
Main Authors: Ho, C.D., Yeh, C.W., Hsieh, S.M.
Format: Article
Language:English
Subjects:
Applied sciences
Channels
Energy
Energy. Thermal use of fuels
Exact sciences and technology
Flow rates
Heat transfer
Heating systems
Hydraulics
Natural energy
Q1
Renewable energy
Solar energy
Theoretical studies. Data and constants. Metering
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A study on improvement in device performance of multi-pass solar air heaters with external recycle has been carried out under countercurrent-flow operations. An absorbing plate and insulation sheet were inserted horizontally and vertically, respectively, into a parallel-plate channel to divide the open duct into four subchannels. The coupled nonlinear ordinary differential equations were derived and solved numerically. The theoretical results show that the new device of four-pass flat-plate solar air heater with external recycle can enhance the heat transfer rate compared with that in an open conduit (without the vertical insulation sheet inserted and the absorbing plate glued on the bottom insulation plate, the so-called a downward-type single-pass solar air heater) under the same flow rate and working dimensions. The effects of inserting the absorbing plate and insulation sheet on the transfer efficiency enhancement as well as on the hydraulic dissipated power increment have been also discussed.
ISSN:0960-1481
1879-0682
DOI:10.1016/j.renene.2004.11.009