Performance evaluation of a solar chimney power plant
Date
2000-12
Authors
Hedderwick, Richard Anthony
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
A solar chimney power plant consists of a central chimney that is surrounded by a
transparent canopy located a few meters above ground level. The ground beneath
this canopy or collector as it is known is heated by the solar radiation that is
effectively trapped by the collector. This in turn heats the air in the collector, which
flows radially inwards towards the chimney. This movement is driven by the
difference between the hydrostatic pressure of the air inside- and outside the solar
chimney system. The energy is extracted from the air by a turbine driven generator
situated at the base of the chimney.
The performance of such a solar chimney power plant is evaluated in this study
making use of a detailed mathematical model. In this model the relevant discretised
energy and draught equations are deduced and solved to determine the performance
of a specific plant referred to as the "reference plant". This plant is to be located at a
site near Sishen in the Northern Cape in South Africa where meteorological data is
available.
The performance characteristics of this plant are presented using values from the
21 st of December as an example. These characteristics include the instantaneous
and integrated power output, as well as the absorption of the solar radiation of each
of the parts of the collector. The air temperatures throughout the plant and the
convective heat transfer coefficients in the collector in the region of developing and
fully developed flow are presented. The pressure of the air throughout the system is
presented as well as the pressure drop over the turbine. Temperature distributions in
the ground below the collector are also presented and discussed.
Description
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2000.
Keywords
Dissertations -- Mechanical engineering, Theses -- Mechanical engineering, Solar power plants, Solar collectors