Economic design of water distribution systems in buildings

Abstract

This paper discusses an engineering optimization problem which arises in hydraulics and is related to the use of a new criterion for sizing water distribution piping in large buildings. The optimization model aims to find the most suitable interior pipe diameters for the various pipes in the system, using commercial sizes and minimizing the overall installation cost according to some boundary conditions. The problem is formulated as a nonconvex nonlinear program and a branch-and-bound algorithm is introduced for its solution. A procedure is proposed to obtain a feasible solution with standard values from the optimal solution of the nonconvex program. The performance of the algorithm is analysed for a real-life problem and the cost of the computed solution is assessed, showing the appropriateness of the model and the optimization techniques.

Hybridizing the electromagnetism-like algorithm with descent search for solving engineering design problems

“…These values, for both EM and hybrid EM algorithms, are Table 12 under the columns headed by "real". These results are equal to those reported in [16] where a branch-and-bound type algorithm is used. The solution obtained by the hybrid EM algorithm required 184577 function evaluations and the EM algorithm needed 174331 function evaluations (for a population of 210 points).…”

“…The last problem is related with the design of a water distribution system in a building. The case herein solved is fully described in [16] and has 21 pipes. The decision variables x i , i = 1, .…”

“…, 21, are the interior pipe diameters. Bounds for the variables and data concerning the length and the design flow for each pipe are reported in [16]. We solved the problem 50 times and recorded the optimal design variables that gave the least function value.…”

“…{0.0138, 0.0166, 0.0206, 0.0264, 0.0330, 0.0396, 0.0516, 0.0603, 0.0721, 0.0849, 0.104}, as shown in[16].…”

Designing of water distribution system

“…Ostfeld et al developed and demonstrated an ant colony methodology for the least-cost design of gravitational water distribution systems with a single loading case [5], to the conjunctive least-cost design and operation of multiple loading pumping water distribution systems. Judice et al discussed an engineering optimization problem that arises in hydraulics and was related to the use of a new criterion for sizing water distribution piping in large buildings [6]. The optimization model aimed to find the most suitable interior pipe diameters for the various pipes in the system, using commercial sizes and minimizing the overall installation cost according to some boundary conditions.…”