Double-circulation water-flow window is a novel-designed solar-building-integrated energy saving system. The window part is composed of four layers of glass panes and 2 layers of flowing water, which contributes to building energy conservation by utilizing solar energy for domestic hot water preheating and regulating indoor heat gain through window. In heating season, warm water is supplied to the water-flow window cavity and it releases heat to the room through the innermost glass pane. Thermal, energy and economic performance of the compact double-circulation water-flow window was numerically analyzed in the present study. Results showed that direct solar transmission could be largely reduced with water-flow window, compared with common curtain wall. The year-round solar collection efficiency was 16.2% for the external water circulation and 4.3% for the internal water circulation. The predicted static payback period was around 7 years, with the extra investment of water-flow window over common curtain wall and the saving in electricity charge taken into consideration. For higher inlet water temperature at the internal window cavity during heating season, the predicted payback period was slightly longer, since part of the heat was lost to the outdoor environment. The results showed preferable potential of double-circulation water-flow window system in buildings with stable hot water demand and high-density energy demand.

中文翻译：

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双循环水流窗系统作为太阳能集热器和室内供暖终端的性能

双循环水流窗是一种新颖设计的集成了太阳能建筑的节能系统。窗户部分由四层玻璃板和两层流动水组成，通过利用太阳能对生活热水进行预热并通过窗户调节室内热量获取，从而为建筑节能做出了贡献。在供暖季节，将热水供应到流水窗腔，然后通过最里面的玻璃板将热量释放到房间。本研究对紧凑型双循环水流窗的热，能量和经济性能进行了数值分析。结果表明，与普通幕墙相比，水流窗可以大大减少太阳的直接透射。全年外部水循环的太阳能收集效率为16.2％，为4。3％用于内部水循环。预计静态投资回收期为7年左右，其中考虑了在普通幕墙上增加水流窗的投资以及节省电费的问题。在供暖季节，由于内部窗户空腔的进水温度较高，预计的投资回收期会略长，因为部分热量会散失到室外环境中。结果表明，在热水需求稳定且能量需求高的建筑物中，双循环水流窗系统具有更好的潜力。在供暖季节，由于内部窗户空腔的进水温度较高，预计的投资回收期会略长，因为部分热量会散失到室外环境中。结果表明，在热水需求稳定且能量需求高的建筑物中，双循环水流窗系统具有更好的潜力。在供暖季节，由于内部窗户空腔的进水温度较高，预计的投资回收期会略长，因为部分热量会散失到室外环境中。结果表明，在热水需求稳定且能量需求高的建筑物中，双循环水流窗系统具有更好的潜力。