Parabolic trough plant performance in China with focus on comparison of heat transfer fluids HELISOL®5A and Therminol® VP-1

The heat transfer fluid HELISOL® 5A is particular interesting for the Chinese CSP market due to its low freezing point. In this paper the plant performance of a system operated with HELISOL® 5A was compared to a system operated with Therminol® VP-1 with the help of system simulation. Firstly, the simulation model was validated with measured data from the HELISOL® 5A test loop of Royal Tech in Inner Mongolia. Secondly the plant performance was assessed for a reference plant in China and South Africa. The simulation results showed a higher annual yield for the HELISOL® 5A system, mainly due to the increase in power block efficiency because of the higher temperature level. Furthermore a sensitivity analysis on the effect of hydrogen formation was carried out for both heat transfer fluids. It showed that the yield curve of HELISOL® 5A lied above the curve of Therminol® VP-1 for all hydrogen percentages. As hydrogen formation is expected to be much lower for HELISOL® 5A the benefit will especially show in long-term operation.