The Analysis Of Computing Method Of Water Design Flow For Plumbing System In Buildings

The determination of water design second flow is one of the most important subject in building water supply and drainage system, and it is the most frequent question in designing them. How to make the design flow accord with actual situation needs inquiring into.The design water flow formulas for drainage system, water supply system, and piped drinking water system in the Code for design of building water supply and drainage were studied in the paper. It studied the design water flow formulas in developed countries in Europe and the USA, and compared it with that of Chinese, which shows that the Cholesky formula can not properly illustrate all factors affect the calculation of the flux, such as use probability. It is known to all that when and how many which water appliances were in use is a random event, they work independently and there's no relationship between them. So the calculation of Design second Flow belongs to probability theory, and the formulas of Design second Flow with probability theory were more scientific and advanced, and they were accord with actual situation.Design water flow formula for water supply system in the Code was studied and use probability of the plumbing fixture was redefined in the thesis. At the mean time, with Normal Distribution approximately cover of Binomial Distribution and by the use of law of large numbers and a function of random variables, design flow formulas were set up. The thesis compared the law of various design flow formulas, with the example of various kinds of housing residences.According to the change rule of the design flow in drainage system must consistent with that of water supply system, the use probability of the plumbing fixture was redefined, and new design flow formulas were set up. The thesis compared the law of various design flow formulas, various kind of housing residences as example.Based on derivation and interpretation of the design water flow formula for potable water system in the Code, a simplified design water flow formula was set up by the use of Normal Distribution and Poisson distribution approximately cover of Binomial Distribution. Design water flow formula for comprehensive portable water units was given in the thesis. And examples were given to support the theory.