Non-dimensional design parameters and performance assessment of rainwater harvesting systems
Non-dimensional design parameters and performance assessment of rainwater harvesting systems
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DOI：
10.1016/j.jhydrol.2011.02.009
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发表时间：
2011-04
影响因子：
6.4
通讯作者：
A. Palla;I. Gnecco;L. Lanza
中科院分区：
文献类型：
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作者：
A. Palla;I. Gnecco;L. Lanza
在这项研究中，提出了使用无量纲参数来研究雨水收集系统的最佳性能。一个合适的行为模式，实施评估的流入，流出和存储量的变化，雨水收集系统根据每日的质量平衡方程下的历史降水观测。该模型确定了节水效率、溢流比和滞留时间。这些被解释为长期模拟期间的系统性能的度量。在各种情况下的环境条件下，是典型的意大利领土（3降水制度和3个层次的水需求）和系统特性（10个存储容量水平）的性能进行检查。雨水收集系统的最佳尺寸作为两个无量纲参数的函数：需求分数和存储分数。结果表明，需水量对系统的节水效率和溢流比有显著影响，而储水量控制系统的滞留时间，从而影响系统内的水质恶化。敏感性分析进行调查的时间序列气候记录的长度上的可靠性的选择性能指标的影响。结果表明，30年的日降雨量记录足以让系统性能的适当评估。基于中等需求分数和低存储分数的最佳系统设计确定了系统性能，该系统性能几乎独立于所研究的三种降水制度。
The use of non-dimensional parameters is proposed in this study to investigate optimum performance of rainwater harvesting systems. A suitable behavioral model is implemented to assess the inflow, outflow and change in storage volume of a rainwater harvesting system according to a daily mass balance equation under historical precipitation observations. The model determines the water-saving efficiency, overflow ratio and detention time. These are interpreted as a measure of the system performance over the long-term simulation period. Performance is examined under various scenarios in terms of environmental conditions that are typical of the Italian territory (3 precipitation regimes and 3 levels of water demand) and system characteristics (10 storage capacity levels). Optimum sizing of the rainwater harvesting system is investigated as a function of two non-dimensional parameters: the demand fraction and the storage fraction. The demand fraction is shown to affect significantly the water-saving efficiency and overflow ratio, while the storage fraction controls the detention time thus influencing the water quality degradation within the system. Sensitivity analysis is carried out to investigate the influence of the length of the time series climate records on the reliability of the selected performance indices. Results demonstrate that 30 years of daily rainfall records are sufficient to allow suitable assessment of the system performance. Optimum system design based on the medium demand fraction and the low storage fraction determines system performance that appears almost independent on the three precipitation regimes investigated.