外文翻譯---改造在寒冷氣候下單戶家庭房屋的太陽(yáng)能熱水器的生活熱水的分析(已修改)
2025-01-29 23:27 本頁(yè)面
【正文】 附 錄附錄A 外文資料Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in SingleFamily Houses in a Cold Climate:A Theoretical AnalysisAbstract: One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish singlefamily houses was theoretically investigated using the TRNSYS software. Simulation models using forced circulation flow with different system configurations and control strategies were simulated and analysed in the study. A parison with a standard solar thermal system was also presented based on the annual solar fraction. The simulation results indicate that the retrofitting configuration achieving the highest annual performance consists of a system where the existing tank is used as storage for the solar heat and a smaller tank with a heater is added in series to make sure that the required outlet temperature can be met. An external heat exchanger is used between the collector circuit and the existing tank. For this retrofitted system an annual solar fraction of % was achieved. A conventional solar thermal system using a standard solar tank achieves a parable performance for the same total storage volume, collector area andreference conditions.Keywords: solar thermal storage tank water heater retrofit domes1. IntroductionOne of the biggest obstacles to the economic profitability of domestic solar water heating (SWH) systems is the investment cost . The installation cost of forced circulation systems used in cold climates can represent up to 50% of the total investment cost depending on the size and type of system . Also, the solar storage is one of the most expensive ponents in a solar water heating system . Retrofitting existing domestic water heaters when new SWH systems are installed can reduce the total investment cost by decreasing both the installation and material costs. In Sweden there are more than half a million electrically heated single family houses that use conventional water heaters for domestic hot water production . Such retrofitting needs to be carried out with consideration of the cold Swedish climate. In such regions the solar storage is placed indoors and a freeze protection medium runs inside the collector circuit. Since existing water heaters are not provided with a heat exchanger, an external one should be used. There are two main types of systems designed with an external heat exchanger outside the storage: thermosyphon and forced flow circulation .Cruickshank and Harrison, in 2004 and 2006 , investigated this type of thermosyphon systems in the Canadian cold climate. In 2011 , the same authors studied the performance of series and parallel co
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