Nomographic methodology for use in performance trade-off studies of parabolic dish solar power modules

A simple graphical method has been developed to undertake technical design trade-off studies for individual parabolic dish modules comprising a two-axis tracking parabolic dish with a cavity receiver and power conversion assembly at the focal point. The results of these technical studies can then be used in performing the techno-economic analyses required for determining appropriate subsystem sizing. Selected graphs that characterize the performance of subsystems within the module have been arranged in the form of a nomogram that would enable an investigator to carry out several design trade-off studies. Key performance parameters encompassed in the nomogram include receiver losses, intercept factor, engine rating, and engine efficiency. Design and operation parameters such as concentrator size, receiver type (open or windowed aperture), receiver aperture size, operating temperature of the receiver and engine, engine partial load characteristics, concentrator slope error, and the type of reflector surface, are also included in the graphical solution. Cost considerations are not included. The nomogram has been used to perform trade-off studies that have provided a basis for determining requirements for a single concentrator that could perform satisfactorily with either the selected Stirling or Brayton engine. This activity is summarized to illustrate the usage of the nomogram. Additionally,more » modeling relations used in developing the nomogram are presented so that the nomogram can be updated to reflect any changes in the performance characteristics of projected components.« less