Análise comparativa de dispositivos de proteção contra transitórios hidráulicos para diferentes materiais de tubulação e configurações geométricas do sistema

Abstract

The study of watterhammer in water supply systems is essential to ensure operational safety and the integrity of water supply infrastructure, since sudden pressure variations can generate overpressures and depressions capable of causing structural failures in pipelines, damaging equipment, and compromising service continuity. In this context, the implementation of protection devices capable of mitigating these effects is imperative to ensure the proper performance of the system. Considering this need, the main objective of this research is to analyze how the physical characteristics of pipelines and the hydraulic system influence the behavior of protection devices against watterhammer. Thus, the study seeks to understand the influence of wave speed in different pipe materials and to investigate how flow rate, pipeline length, and head affect the severity of transient events. To achieve these objectives, the study presents simulations carried out using the free software Allievi ®, developed by the Polytechnic University of Valencia, which employs the Method of Characteristics. These simulations were carried out to observe behavior variations in system, changing length and head parameters and subsequently compare the performance of different protection devices in systems subjected to watterhammer resulting from pump shutdown. The results show that pipelines with lower wave celerity tend, in general, though not absolutely, to exhibit smaller amplitudes of overpressures and depressions, with this behavior becoming more pronounced in larger systems. Among the devices analyzed, the two way surge tank demonstrated the greatest reduction in pressure envelope; however, its application is limited by the dimensions required for its operation, especially in larger systems. Both the two way surge tank and the one way surge tank show greater potential for application at intermediate points of the pipeline. Meanwhile, the hydropneumatic tank demonstrated high efficiency in attenuating pressure waves and protecting the pump discharge manifold when installed at the beginning of the system, while maintaining feasible dimensions even in larger systems. It is concluded that the feasibility and efficiency of the protection devices analyzed depend directly on the characteristics of the hydraulic system, with particular emphasis on the elevation profile of the transmission main.