Estimated water inlet pipe's flow rate is commonly adopted to calculate supplementary water capacity of fire cisterns of architectures, the calculating method of which lacks theoretical basis. It is inevitable that the result of the calculation would influence the safety and investment of fire water supply systems.
The problem of reasonable calculation of supplementary water capacity is approached in theory, and a calculating formula for supplementary water capacity is deduced. Such calculation method can simplify hydraulic calculation, and help decrease the volume of fire cisterns while maintaining sufficient water capacity for fire fighting.
Based on the scientific method of tests combined with technical analysis, the surplus water from weak acid ion exchangers is used as the additional water of circulation water, which has increased thickening efficiency of the circulation water and has reduced the additional water amount.