Heat Transfer Analysis and Modeling for a Coaxial Solar Collector in a Domestic Cogeneration System
Abstract
The need for efficient energy generation in domestic houses push the research toward innovative system, that can efficiently cogenerate electrical and thermal power for heating and cooling. A good electrical conversion rate can be achieved when an energy source (hot sink) can reach temperatures of at least 250 °C. Both conventional and renewable sources can be used to run a domestic cogeneration system; they can be in the form of fossil fuels, biomass and solar energy. This paper presents the analysis for a domestic solar concentration system, that is intended to be coupled with a Stirling cogeneration unit. The proposed solar collector consists of an array of linear reflecting parabolas housed on a small tracking system (Fig. 1), which focuses solar radiation on a series of vacuum tubes. The heat is transferred to thermal oil suitable for operating at medium-high temperatures and finally to the heat exchanger of a Stirling engine (Fig. 2). An example for such solar configuration has been developed by the Digespo project (Digespo, 2010).