Hydraulic transient in residential buildings with a direct pump connection

Abstract

This paper consists of an experimental and numerical study into transient behaviour in a residential building. The analysed effects occur by centrifugal pumps when they start with a direct supply (fixed-speed pumps are connected to the service pipe without an atmospheric tank). Direct supply increases the transient effect and places higher demands on the water main. The properties of such an installation were analysed using a hydraulic model in order to detect the most unfavourable scenario. The results were compared to experimental data. Basic hydraulics demonstrates that a pressure drop occurs during the start-up. The magnitude mainly depends on the pump capacity. But, numerical and field results show that other variables related to service pipe design could also negatively affect the pressure surge. The study provides water utilities with information about the influence of the different variables on pressure surge magnitude and basic design criteria to minimize these effects.

Keywords:

• hydraulic transient
• water hammer
• direct supply
• water plumbing system
• pump station

Acknowledgement and disclaimer

We would like to acknowledge the Empresa Metropolitana de Abastecimiento y Saneamiento de Aguas de Sevilla (EMASESA) for giving us the opportunity to modify and test the behaviour of one of their buildings, and we would like to give especial thanks to Mr. Camilo Veiga, the head of the water meter unit, for his technical support and endeavour.

Additional information

Funding

This work was supported by the Ministerio de Educación y Ciencia of the Spanish Government under Grant N° CGL2005-03666.