Design guidelines for solar assisted district heating systems with a solar fraction of approximately 35

摘要

Solar assisted district heating systems with a solar fraction of approximately 35% based on the total heat demand enable to save a significant amount of fossil fuels. Compared to systems with solar fractions of 50% the investment costs are moderate because seasonal heat storage is not required. Literature search showed that no design guidelines for solar assisted district heating systems with ground-buried or above-ground hot water heat stores and a solar fraction of 35% are available up to now. In this paper such guidelines are presented for systems with ground-buried heat stores based on the results of extensive dynamic simulations. Similar guidelines for systems with above-ground heat stores will be published shortly.