A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 1983

A 'Screening model' has been formulated for the optimal distribution of pumping stations using the linear programming technique. The model provides guidelines on the selection of optimal sites for booster pumping stations from a number of candidate locations. The application of the screening model on three sample networks, each with nine candidate locations for booster pumping station which could be chosen in 511 different combi- nations, indicated that two to four program runnings are sufficient to arrive at an optimal distribution. The model has been found out to be applicable to large networks by schematizing the network extensively for the first run. The succeeding sets of runs could be made on the less exten- sively schematized subnetworks which are to be isolated by closed valves. The study has proven that in some networks the use of valves to isolate subnetworks may be necessary not only in reducing the sytem cost but also in making a design option feasible in conjunction with the use of booster pumps. A related problem of distributing the operational storage requirement has been dealt with in this study. To solve the problem, a simulation study was conducted on a simple network with one off-line booster by varying the rated capacity of the source pumps as well as the design flows of the pipes leading to the booster from the peak hour demand down to the lowest possible flow rate, i.e. to a value just enough to meet the demand pattern. The re- servoir at the off-line booster was sized correspondingly (increased as flow rate decreased) to the storage requirement of the downstream service area at each variation. The system cost for each variation was solved using a linear optimization model. The results have shown that the lower extreme of flow rate with the corresponding upper extreme of storage requirement at off-line boosters makes the optimum design. This finding was confirmed in the same study made on two large sample networks. Incidentally, it was found out that for a large. network and high service pressure requirement, the system cost could be .reduced further by using separate transmission lines to fill up the reservoirs at booster pumping stations.