Seasonal-Storage Solar-Energy Heating System for the Charlestown, Boston Navy Yard National Historic Park. Phase II. Analysis with Heat Pump

摘要

This Phase II study provides further analysis for a seasonal-storage solar-heating system utilizing two existing underground, concrete tanks in the National Historic Park of the Charlestown Navy Yard in Boston. The initial Phase I study was reported in ANL-82-90. The new results focus on the effect of including a heat pump in the system to extend the useful heat-storage capacity of the tanks. The analysis was performed with MINSUN Version III, a computer simulation model written particularly for seasonal storage systems. Input parameters were derived in Phase I and reviewed and updated for this study. Three collector types were studied with and without a heat pump. Results indicate a definite performance and economic improvement for all collector types by including the heat pump. Flat plate collectors showed substantially greater improvement due to their more pronounced increase in efficiency at the lower inlet temperatures. With the heat pump, all three collectors provide comparable performance, and the flat plates were chosen as the design system due to their lower cost. A design system of 2300 m exp 2 flat plate collectors with heat pump was selected. The system provides a solar fraction of 50% for the 2167 MWH annual heat load. The annualized cost of the solar energy supplied is $66.60/MWH which is competitive with the conventional heating alternative for a conventional heating cost of $0.05/kWh. Considerations regarding the implementation and financing of this project are also discussed. (ERA citation 08:050943)