Optimization of the Design of Water Distribution Systems for Variable Pumping Flow Rates

Abstract

Water supply systems need to be designed in an efficient way, accounting for both construction costs and operational energy expenditures when pumping is required. Since water demand varies depending on the moment’s necessities, especially when it comes to agricultural purposes, water supply systems should also be designed to adequately handle this. This paper presents a straightforward design methodology that using a constant flow rate, the total cost is equivalent to that of the variable demand flow. The methodology is based on the Granados System, which is a very intuitive and practical gradient based procedure. To adapt it to seasonal demand, the concepts of Equivalent Flow Rate and Equivalent Volume are presented and applied in a simple case study. These concepts are computationally straightforward and facilitate the design process of hydraulic drives under demand variability and can be used in multiple methodologies, aside from the Granados System. The Equivalent Flow Rate and Equivalent Volume offer a solution to design procedures that require a constant flow regime, adapting them to more realistic design situations and therefore widening their practical scope.

Use of Fixed and Variable Speed Pumps in Water Distribution Networks with Different Control Strategies

“…However, using more FSPs than the minimum required in the system generates significant benefits in energy costs because pumps improve their efficiency, as was demonstrated by Walsky and Creaco [33]. Later, Candilejo et al [4,34] improved a methodology to estimate pump's performance for a proper design of a pumping station in order to reduce operational costs and then create a methodology for the optimal design of a water pumping system with variable flow rates.…”

Economic design of alternative system to reduce the water distribution losses for sustainability

“…Such that approximately 60% of total water losses are comprised of physical losses and the remaining 40% are accounted for apparent losses in Turkey. Araceli et al (2020) represents a straight forward methodology using the flow rate as constant. Here total cost is equivalent to variable demand flow.…”

Pumping Station Design in Water Distribution Networks Considering the Optimal Flow Distribution between Sources and Capital and Operating Costs

“…Consequently, the obtainable energy savings are restricted by the previous PS design, and insufficient or idle capacity may be generated. Therefore, the investment and operating costs of PSs should be minimized together to achieve a complete solution to the optimization problem [11].…”