Development of a tube receiver for a solar-hybrid microturbine system

Kurzfassung

Solar-hybrid microturbine systems with cogeneration offer new possibilities for the generation of electricity and heat or air conditioning. The solar receiver is an important component of such a system. For a prototype system demo project a tube receiver for a 100kWe microturbine system is currently under development. The receiver is designed for air preheating up to 800°C at a pressure of 4.5 barabs. The challenge of the design is to find the right compromise between high efficiency, low pressure drop, high durability and low cost. The receiver consists of multiple metallic tubes, arranged in a cavity and connected in parallel. For the design the knowledge of local flux density, fluid and material temperature is required. A finite-element program coupled with a ray tracer was used for the layout. The final receiver design is described, which was optimized with respect to efficiency, material temperatures and pressure drop. Expected performance data for nominal load and off-design conditions will be presented, including the expected annual receiver and system performance. In addition, several possibilities for future improvements will be outlined.