Abstract: A method and system for performing a criticality analysis of a water distribution network is provided. The method and system provides for segmentation of the system which allows a user to determine the set of elements that comprise segments, which in turn are the smallest portion of a water distribution system that can be isolated by valving. Isolating valves are included as elements in the set of elements that are used by an associated hydraulic solver engine to segment the water distribution network. Once the network has been segmented, a criticality analysis is performed whereby a hydraulic simulation is run for an outage of one or more segments, and the shortfall in demand supplied to other segments is calculated. The system provides for a linking of the ability to automatically identify segments with a hydraulic analysis model to enable a user not only to identify segments, but to rank their importance based on a variety of user defined metrics.

Abstract: In one embodiment, a hydraulic simulation model corresponding to a real-world hydraulic network is loaded in a hydraulic modeling and simulation application executing on a computer system. The hydraulic simulation model represents leakages as pressure dependent emitter flow at selected nodes (leakage nodes). Optimization criteria include a specified maximum of possible leakage nodes. A genetic algorithm (GA) generates trial solutions for an optimization, each trial solution representing locations for leakage nodes and corresponding emitter coefficients. A hydraulic analysis is performed for the trial solutions to generated model-simulated results. The model-simulated results are compared to field-observed data for the real-world hydraulic network to generate goodness-of-fit values. The process is repeated until a particular goodness-of-fit value is achieved or a maximum number of iterations is reached.

Abstract: In one embodiment, a technique is disclosed for calculating a relative pump speed factor for attaining a prescribed hydraulic head or for pumping a prescribed amount of flow. A hydraulic model of a water distribution or collection system is defined to include link elements and node elements. At least one of the node elements represents a fixed-flow variable speed pump (VSP) that delivers a desired amount of flow, a variable speed pump battery (VSPB) that represents multiple VSPs operating in parallel with each other, a VSP with a tank located on the VSP's discharge side, or a VSP with a tank located on the VSP's suction side.

Abstract: A computer software program provides an algorithm that solves for unknown demands (and junction pressures) within a modeling system that uses a generalized, unified loop-node formulation. The program can be used to calculate the available demand (i.e., the amount of water that is to be supplied) according to the nodal pressure. Both nodal heads and flows are simultaneously solved using a gradient algorithm, which allows, in accordance with the present invention, the model to simulate situations where a change in pressure affects the quantity of water used. Criticality analyses for segments of a system in such pressure dependent scenarios can also be performed using the software program of the present invention.

Abstract: A method and system for optimal design of a water distribution network is provided. Three levels of optimization are available as options for selection by the user and these include least cost optimization, maximum benefit optimization and cost-benefit tradeoff optimization. The optimization models, in accordance with the present invention, include solutions generated by a competent genetic algorithm that can take into account multiple objective functions. Pareto-optimal solutions are produced for the whole range of a budget for the water distribution system. Tradeoff solutions allow engineers to apply engineering judgement to choose the true optimal solution under the specific application being considered.

Abstract: A water distribution model calibration technique is provided that allows a user to design a calibration model by selecting several input parameters desired to be used for the calibration of a model that allows an engineer to collect a complete set of data to represent the overall system conditions at any given time of day. For example, several parameters may be chosen including link status, the pipe roughness coefficient, junction demand, and pipe and valve operational status. Trial solutions of the model calibration are generated by a genetic algorithm program. A hydraulic network solver program then simulates each trial solution. A calibration module runs a calibration evaluation program to evaluate how closely the model simulation is to the observed data.

Abstract: A method for estimating the relative speed factor parameter for a variable speed pump in a hydraulic network sufficient to maintain a fixed pressure at a control node is provided. A desired operating characteristic is determined and this is inserted into a matrix of equations describing the hydraulic system. The largely symmetrical matrix includes certain aspects of the system representing the variable speed pumps which are non-symmetrical. Non-symmetrical portions of the matrix are separated out and solved using an LU factorization technique. Non-sparse, non symmetric matrices are generated and the difference in head correction is solved for to compute the updated nodal head vector and ultimately determine the variable pump speed parameter. The invention allows estimation of the variable speed factor for a variable speed pump drive sufficient to maintain a fixed pressure at a control node.

Abstract: A system and method of automatically calibrating a water distribution model is provided that allows a user to design a calibration model by selecting several input parameters desired to be used for the calibration. For example, several parameters may be chosen including the pipe roughness coefficient, junction demand, and pipe and valve operational status. Trial solutions of the model calibration are generated by a genetic algorithm program. A hydraulic network solver program then simulates each trial solution. A calibration module runs a calibration evaluation program to evaluate how closely the model simulation is to the observed data. In doing so, the calibration evaluation program computes a “goodness-of-fit” value, which is the discrepancy between the observed data and the model data, for each solution. This goodness of fit value is then assigned as the “fitness” for that solution in the genetic algorithm program.