Parabolic Trough Solar System Piping Model. Final Report for May 13, 2002 to December 31, 2004

摘要

One requirement in a conceptual design of a solar power plant is to estimate the cost of the solar steam system. The main elements of that cost estimate are the solar collectors, control system, heat transfer fluid (HTF) piping system, HTF pump system, and solar heat exchangers. The piping system consists of header piping, valves, and fittings. Since the piping system cost can constitute up to 10% of the total solar system cost, it is important to obtain a reasonably accurate estimate. The piping system design also affects performance. The pumping power required to circulate the HTF through the system is a significant contributor to the plant parasitic power requirement. Further, the piping heat loss reduces the useful heat delivered by the solar field to the power plant. As part of their performance and cost modeling development for parabolic trough power plant development, Flabeg Solar International (Cologne, Germany) developed an internal solar field piping model termed SolPipe -- for use in their solar system design work on parabolic trough configurations. The purpose of the model was to estimate, for a solar field size and layout configuration, the piping system parts list, costs, and pumping power for the HTF flow at design capacity. These results can then be utilized to provide input into subsequent performance and investment cost models, with the final criterion being the impact of the solar field piping design on the overall levelized electricity cost. NREL requires a similar piping model to provide similar input to the Trough Excelergy parabolic trough plant performance and cost model. The purpose of the present work is to develop a spreadsheet model to satisfy this need. Flabeg has provided access to SolPipe for purposes of comparison of the methodology and results.