Real-time computation and control of solar flux density ona central receiver (solar two) (protection against excess flux density)

摘要

The molten salt external central receiver at Solar Two (Daggett, CA) is designed to operate at a very high flux density, near the material limits of the multi-pass receiver. As a result, the system design must address conflicting requirements of high uniform flux density, a limiting flux density which should never be exceeded,low spillage, a rapid reduction in flux density near the high temperature outlet and cost effective use of the heliostat field. This aggressive design also needs to be dealt with during the operation of the receiver, as the solar insolation or the operating conditions may well diverge significantly from the design conditions, resulting in areas on the receiver where the flux density is higher than the allowable flux density, i.e., in local hot spots. Such local"hot spots" have been addressed by adding two significant improvements to the original system: interactive helistat-aiming computation; and real-time control of the solar flux densities on the receiver. In this article, we will describe in detail the processors which operate to prevent flux desnity from exceeding the defined allowable value.