Abstract
In this paper, we describe on the loads of water supply in apartment houses based on the analyses of actual measurements, the Monte Carlo Simulation and theoretical considerations. Firstly, the relations between the average and maximum volume of water supply and the number of flats are clarified, and the maximum flow rates at each interval of time, more than at one-minute intervals, are suggested for design as values of common and rare occurrences based on the analyses of results of measurements in 15 apartment houses. Instantaneous maximum flow rates at one-minute or less intervals are analyzed by the simulations and actual measurements. And it is clarified that the maximum value at one-minute intervals may be considered as the instantaneous maximum flow rate in the case of apartment house consisted of more than about 50 flats. Also, the relations between instantaneous maximum flow rates and number of flats are shown on the basis of the actual measurements of 10 apartment houses. On the calculation of instantaneous maximum flow rates, we suggest the convenient method utilizing the loading units, which are calculated by the Poisson distribution approximated as the probability distribution of simultaneous uses of water and the standard flow rates of apparatuses. The calculated results of instantaneous flow rates at each failure factor, 5% or less, are very near to the values calculated by simulation. Now, on the decision of the loading unit of a flat, we show two kinds of methods. One way is to sum up the loading units of each apparatus type at peak time of water consumption in the apartment house. Another way is to calculate by the Poisson distribution with mean value of simultaneous uses of water which is determined from the total volume of water supply and the standard flow rate of a flat. We clarify that it is suitable for the standard flow rate of a flat to be determined with 15(l/min) when we use the later method above mentioned. Lastly, we show the loading units of each apparatus type and a flat, and suggest the calculating curves of three levels, which are decided with the failure factor, 0.1, 0.2 and 1.0%.
