Research On Proposal Comparison And Option For Water Supply Network Of Urban

The pipe network of water supply is an important part in the water supply system of urban,and its capital invested also have a great proportion in the whole system.It is needed to compare different alternatives and select a proper one to reduce cost and increase the benefit for the enterprise of water supply,whether for the model of regional water spply or the dispersional.The standard means to select include the technical and economic comparing visually,comparing of economic appraising and finance analyses,complex comparing with multiple objectives and so on.This article analysed and discussed the methods of program comparing and appraising and their application ,and have the conclusions below:First,with various elements involved and the uncertainty for the cost of water supply networks,and based on the theory of fuzzing mathematics and predictive subject, build the characteristic integration of works { }T = t1 , t 2tm and express the similarity of various characteristic elements t j dependent on the fuzzy set of the cost of the works T1 , T2 Tn with the membership functionμT .Analyse the cost data accumulated and the experience of the water supply networks to build the fuzzy relationship quotient table of the water supply networks and use the similar grade to measure fuzziness to build the mathematics model of estimation and get the unit cost of the different pipe diameter and the pump house.Then analyse the energy unused which can be reduced after spacing to get the operating cost saved of the water supply networks.Considering the time value,convert the construction cost generated in different time to the same time of the water supply networks to make it can be measured.Then with the analysis and measuring of annual operating cost,discuss the technic and economic elements and economic evaluation parameter in the time of counting to select a scheme with the lowest annual cost in the alternatives.Then based on the theory of multiple objective optimization and relative superiority, discuss the method of multiple objective optimization.Utilize the analytic hierarchy progress to build the hierarchical structure of the water supply networks and associate the index of quantitative and qualitative,the objective data and subjective experience to convert the problem of multi appraisal index into the form of the single properly to collate generally and select an rational one.Finally,apply the consequence into the actual,the result indicate that the ways of cost calculation and alternatives comparison presented of this article express the various factors quantitily during the desigh of water supply networks based on the fuzzing mathematics to reduce the impact of qualitative elements during the options.The method is simple, feasible and practical,and the result is reliable.