Optimization of the Mass Flow Rate Distribution of an Open Volumetric Air Receiver

The thermodynamical efficiency of a solar power tower power plant with an open volumetric air receiver depends among others on the operational strategy of the receiver. This strategy includes, on the one hand, controlling the distribution of irradiated power on the receiver surface via aim point optimization, and on the other hand, controlling the air mass flow rate and its distribution by choosing suitable dimensions of fixed orifices and controlling air flaps. The maximum mass flow rate of the receiver as an indication of the thermal power is commonly used as a quality function when assessing new component designs, comparing different operational strategies, or evaluating the role of aim point optimization for the open volumetric air receiver technology. In this paper, a method is presented to maximize the mass flow rate of the receiver using given technical capabilities of the receiver technology like orifices and air flaps for a desired air outlet temperature of the receiver. The method is based on dynamic programming, a general technique for solving decision making problems where a complex problem can be split up into a sequence of simpler ones. The potential of the method is demonstrated for a prototype solar thermal power tower with open volumetric air receiver technology.