Optimal Design of Seasonal Storage for 100% Solar Space Heating in Buildings

摘要

An analysis is presented of seasonal solar systems that contain water as the sensible heat storage medium. A concise model is developed under the assumption of a fully mixed, uniform temperature, storage tank that permits efficient simulation of long-term (multi-day) system performance over the course of the year. The approach explicitly neglects the effects of short-term (sub-daily) fluctuations in insolation and load, effects that will be extremely small for seasonal solar systems. This approach is useful for examining the major design tradeoffs of concern here. The application considered is winter space heating. The thermal performance of seasonal solar systems that are designed to supply 100% of load without any backup is solved for, under ''reference year'' monthly normal ground temperature and insolation conditions. Unit break-even costs of seasonal storage are estimated by comparing the capital and fuel costs of conventional heating technologies against those of a seasonal solar system. A rough comparison between the alternatives for more severe winters was made by examining statistical variations in winter season conditions over the past several decades. (ERA citation 04:013043)