Substantiation of the diameters of pipelines of water supply
and wastewater disposal systems based on minimizing the costs of their life cycle

Summary

While designing urban water supply and wastewater disposal systems, substantiating the diameter of pipelines, the flow rate of water and wastewater is required. The existing approaches and regulatory requirements set forth in CP 31.13330.2012 are based, among other things, on the economic indicators calculated on the basis of the overhead costs for the construction and operation of water supply and wastewater disposal systems. At the same time, according to GOST R 587885-2019, the choice of a design option should be based on the life cycle costs of these systems. A method is proposed for calculating the optimal values of pipe diameters and the velocity of water and waste liquid in pipelines based on the costs of their life cycle. The conducted numerical experiments showed that the optimal values of the velocity depend on the flow rate of water and waste liquid, the cost of electricity and the number of years of the life cycle of water supply and wastewater disposal systems. New formulas are proposed for calculating economically justified values of the velocity of water and wastewater for steel, cast iron and polyethylene pipes.

Key words

pipeline , water and wastewater systems , minimization of life cycle costs , optimal values of water and wastewater velocity and pipe diameters