Simulation of Water Distribution Network under Pressure-Deficient Condition
- 504 Downloads
Pressure deficient condition occurs in the water distribution network (WDN) when the nodal demands are in excess of the design discharge as in the case of fire demand, pump failure, pipe breaks, valve failure etc. It causes either no-flow or partial-flow depending upon the available pressure head at the nodes. To evaluate the nodal flows in such condition, node flow analysis (NFA) gives reasonable results in comparison to demand-driven analysis (DDA) and head-dependent analysis (HDA). The NFA works on the predefined pressure-discharge relationship to evaluate the nodal flows. However, this approach requires human intervention and hence cannot be applied to large WDN. Recently, modified pressure-deficient network algorithm (M-PDNA) has been developed by Babu and Mohan (2012) for pressure-deficient analysis with EPANET toolkit. However, it requires modification of the source code of EPANET. In this study a relationship with the M-PDNA and node flow analysis (Gupta and Bhave 1996) has been investigated and it is found that M-PDNA is the simplified version of NFA. Further, the working principle of M-PDNA has been investigated with suitable examples of Babu and Mohan (2012). The theoretical basis of M-PDNA has not been investigated in terms of head-discharge relationship. Herein, a head-discharge relationship based on the working principal of M-PDNA is proposed. Some of the toolkits are also readily available to modify demand driven solver of EPANET 2 to suit for the pressure-driven analysis and then it can be used for analysing pressure deficient network. Also in this study, a modification in M-PDNA approach is proposed which does not require the use of EPANET toolkit which is found to be capable of simulating both pressure-sufficient and pressure-deficient conditions in a single hydraulic simulation. Using the proposed approach, pressure-deficient condition is analysed with constant and variable demand pattern.
KeywordsWater distribution network Pressure-deficient condition Pressure-driven analysis Node-flow analysis Fire demand Variable demand pattern
The authors are very thankful to the officials of the Public Health Engineering and Water Supply Department (PHE &WSD), Itanagar, Government of Arunachal Pradesh for providing necessary data for this study. The authors are also grateful to the anonymous reviewers for their critical reviews and constructive suggestions to improve the manuscript further.
- Bhave PR (1981) Node flow analysis of water distribution systems. J Transp Eng 107(4):457–467Google Scholar
- Bhave PR, Gupta R (2006) Analysis of water distribution network. Narosa Publishing House Pvt Ltd, New DelhiGoogle Scholar
- Chanadapillai J, Narayana Iyer R (2001) Equitable distribution of water through pipe network under low supply situation. Proceedings of the 4th International Conference on Water Pipeline System, BHR Group, Mar. 28–30, York, U.KGoogle Scholar
- Guidolin M, Burovskiy, P, Kapelan, Z, Savic, DA (2010) CWSNet: An object-oriented toolkit for water distribution system simulations. Proceedings of the 12th Annual Water Distribution Systems Analysis Conference, WDSA 2010, September 12–15, Tuscon, Arizona, USA.Google Scholar
- Pathirana A (2010) EPANET 2 desktop application for pressure driven demand modelling. Proceedings of the 12th Annual Water Distribution Systems Analysis Conference, WDSA 2010, September 12–15, Tuscon, Arizona, USAGoogle Scholar
- Rossman LA (2000a) EPANET 2 users manual, Water Supply and Water Resources Division, National Risk Management Research Laboratory. U.S. Environmental Protection Agency, Cincinnati, OhioGoogle Scholar
- Rossman LA (2000b) EPANET 2 programmer’s toolkit manual, Water Supply and Water Resources Division, National Risk Management Research Laboratory. U.S. Environmental Protection Agency, Cincinnati, OhioGoogle Scholar
- Tabesh M (1998) Implications of the pressure dependency of outflows on data management, mathematical modelling and reliability assessment of water distribution systems. Ph D Thesis, Liverpool Univ, EnglandGoogle Scholar
- Todini E, Pilati S (1988) A gradient method for the solution of looped pipe networks. Proceedings of the Computer Applications in Water Supply, Vol. 1. Wiley, New York, pp 1–20Google Scholar
- Van Zyl JE, Borthwick J, Hardy A (2003) Ooten: An object-oriented programmers toolkit for epanet. Advances in Water Supply Management (CCWI 2003), supplementary paper, 2003Google Scholar