Potential improvement and comparative assessment of supercritical Brayton cycles for arid climate

Abstract

In this study, the globally known supercritical Brayton cycles have been evaluated for their ability to accommodate dry cooling. Dry cooling is the most favourable choice for concentrated solar power plants, since these plants are more productive in drought areas. The performance of six Brayton cycle layouts (regenerative, recompression, intercooling, partial cooling, pre-compression, and split expansion) has been determined by developing complete mathematical models. Key parameters, such as, cycle efficiency, specific work requirement and incorporation ability of the cycle with solar receiver have been investigated for arid climate conditions. In addition, an effort has been made to enhance the cycle performance by increasing the critical temperature of the working fluid by using a mixture of carbon dioxide and benzene. The computed results revealed that cycles using binary mixture offer high efficiency in drought areas in combination with air cooling. Moreover, binary mixture showed higher integration ability with solar power plant because of expanded temperature difference across the solar receiver.