Centre for Water Systems, School of Engineering, Computing and Mathematics, University of Exeter, Exeter EX4 4QF, UK.
Water Sci Technol. 2010;61(1):85-96. doi: 10.2166/wst.2010.783.
The rate of uptake of rainwater harvesting (RWH) in the UK has been slow to date, but is expected to gain momentum in the near future. The designs of two different new-build rainwater harvesting systems, based on simple methods, are evaluated using three different design methods, including a continuous simulation modelling approach. The RWH systems are shown to fulfill 36% and 46% of WC demand. Financial analyses reveal that RWH systems within large commercial buildings maybe more financially viable than smaller domestic systems. It is identified that design methods based on simple approaches generate tank sizes substantially larger than the continuous simulation. Comparison of the actual tank sizes and those calculated using continuous simulation established that the tanks installed are oversized for their associated demand level and catchment size. Oversizing tanks can lead to excessive system capital costs, which currently hinders the uptake of systems. Furthermore, it is demonstrated that the catchment area size is often overlooked when designing UK-based RWH systems. With respect to these findings, a recommendation for a transition from the use of simple tools to continuous simulation models is made.
到目前为止，英国雨水收集（RWH）的普及率一直很慢，但预计在不久的将来会有所加快。使用三种不同的设计方法，包括连续模拟建模方法，对两种基于简单方法的新型雨水收集系统的设计进行了评估。结果表明，RWH 系统可以满足 36%和 46%的 WC 需求。财务分析表明，大型商业建筑中的 RWH 系统可能比小型住宅系统更具财务可行性。研究结果表明，基于简单方法的设计方法生成的水箱尺寸比连续模拟大得多。实际水箱尺寸与使用连续模拟计算的尺寸的比较表明，为相关需求水平和集水区尺寸安装的水箱过大。水箱过大可能导致系统资本成本过高，这目前阻碍了系统的采用。此外，研究结果还表明，在设计英国 RWH 系统时，往往会忽略集水区面积大小。鉴于这些发现，建议从使用简单工具转向连续模拟模型。
