Internal film receiver possibilities for the third generation of central receiver technology

Abstract
During the last few years, a 0.5 MW_t internal film receiver type was developed, mounted and tested at the Plataforma Solar de Almería, Spain. The chief goal was to test the feasibility of this concept operability and acceptable performance. In order to find out what the real performance is, several objectives were planned like measuring the heat transfer coefficient between salt film and panel surface, studying the behavior of the panel coating, checking the maximum allowable incident flux as well as the salt flow rate and the way to measure it. The maximum power on the panel expected was reached with flat distribution without any damage, in spite of later calculations which advised prudence. Thus the this type of receiver's potential can be considered very high. Other objectives, such as reducing the original power consumption and minimizing the heat losses were also reached. The obtained efficiency was very close of the expectations. We are optimistic taking into account the different parts which could be improved. Most of the problems appeared were solved during the test campaign while the roots of the unsolved problems were known and the acquired knowledge allows us to avoid them in a future receiver.