Heat Pipe Collectors for Cost Reduction of Solar Installations

摘要

Heat pipes in solar thermal collectors offer the advantage of a simpler hydraulic interconnection of the solar circuit while reducing the system load during stagnation compared to direct flow collectors. Within a research project, we basically analyzed heat pipe solutions for collectors, developed design methods and optimization potential and investigated the integration of heat pipes in flat plate collectors. Novel flat plate collector prototypes with an inherent overheating protection have been built and tested successfully. The maximum fluid temperature was limited to 140 °C, thus compared to a direct flow collector, a temperature decrease of more than 40 K is achieved. This paper presents the developed technology and explains, that the transfer of complexity from the system to the collector by the use of heat pipes can lead to a reduction of system costs of more than 25 %.