Library Subscription: Guest
Home Archives Thermal Letter Officers Future meetings Assembly for International Heat Transfer Conferences
International Heat Transfer Conference 16

ISSN: 2377-424X (online)
ISSN: 2377-4371 (flashdrive)

FEASIBILITY STUDY OF A HYBRID SMALL-SCALE DISH-MOUNTED SOLAR THERMAL BRAYTON CYCLE WITH COGENERATION

Willem G. Le Roux
Department of Mechanical and Aeronautical Engineering, University of Pretoria, Hatfield, Pretoria, Gauteng 0028, South Africa

DOI: 10.1615/IHTC16.nee.024185
pages 7929-7936


KEY WORDS: Solar energy, Cogeneration, Cycle innovation, Gas turbine, Brayton cycle, Hybrid

Abstract

A small modular solar power plant which uses the sun, air and a turbocharger (micro-turbine) to generate electricity and hot water for a household or small community in South Africa is investigated. Solar rays are focused onto a solar receiver which heats compressed air to turn the turbine of a turbocharger, which powers a compressor and an electric generator. A recuperator is used to collect waste heat from the turbine, to pre-heat air before it enters the solar receiver and any other waste heat is used to heat water (cogeneration). It has been proposed that the setup can also be powered with gas during the night or when solar radiation levels are low, making it a hybrid, however, a cost analysis is required. The feasibility of such a small-scale dish-mounted hybrid solar thermal Brayton cycle, in terms of running costs, is therefore investigated. For a constant power load and water heating load, an expected energy utilization factor (EUF) is found by considering previous work and its effect is investigated. The annual running costs of the system are calculated and compared with similar costs when using the municipal grid. Two locations in South Africa are considered by using measured hourly solar beam irradiance data. The effects of EUF, receiver heat loss rate and solar dish area are also investigated. Results show that the hybrid solar thermal Brayton cycle with cogeneration, using an off-the-shelf turbocharger as micro-turbine, can be competitive with the national grid when the EUF is higher than 52%.

Purchase $25.00 Check subscription Publication Ethics and Malpractice Recommend to my Librarian Bookmark this Page