The Survey And Study Of Urban Water Supply And Drainage System Energy Consumption

The urban water supply and drainage system is not only the basis of the normal operation of modern society and the lifeline of cities,but also the main component of energy consumption.This paper does a systematically and in-depth research of the water-energy nexus of urban water supply and drainage system by the means of investigating the status of energy consumption,assessmenting the energy level,analysising the energy influencing factors,simulating the energy scenarios and discussing the energy saving potential.The main work and results are as follows:Through collecting and analyzing large amounts of literatures at home and abroad,the urban water and drainage system is divided into 8 parts which is raw water supply,water treatment,water distribution,wastewater collection,wastewater treatment,domestic hot water,stormwater management,space heating and cooling.Respresentative values of the energy consumed per unit water of each part are as follows:0.1～2Kwh/m3,0.1～0.5 Kwh/m3,0.05～1.0 Kwh/m3,0.05～0.2 Kwh/m3,0.25～1.5 Kwh/m3,0.25～3.4 Kwh/m3,46～52 Kwh/m3 and 2～20 Kwh/m2.This paper identifies the influencing factors of energy consumption of every part through literatures review and expert consultation and further uses statistical methods such as correlation analysis by SPSS to determine the main factors,which are the kind of water source and the way of water extraction for raw water supply,the water treatment plant scale and effluent quality and kind of inflow for water treatment,water volume and average pressure and leakage of pipe network for water distribution,the network management level and pump stations layout for wastewater collection,the wastewater treatment plant scale and the inflow-outflow quality for wastewater treatment,the engineering type and rainwater end use for stormwater management,the energy source and heating mode for domestic hot water,the energy source and system mode for space heating and cooling.On this basis,this paper uses the energy intensity "E" to established calculation models for each part which is Q =∑inEi*Vi.Taking a typical residential area and its related urban water supply and drainage system as appraisal object,this paper designs typical scenarios of each part and the whole system according to the main influencing factors and the energy consumption of different scenarios were evaluated by the calculation model.Each part has significant difference of energy consumption in different scenarios and under the systematic scenarios each part influence each other of the energy consumption.The results show that the scenario simulation method can be applied to guide the energy consumption evaluation and energy saving design of urban water supply and drainage system.The energy saving potential of the main parts of the system has carried on the preliminary discussion.Aiming at the space heating and cooling part which is high energy consumption and has high potential to save energy,this paper puts forward a new heat pump which is named"decentralized supply water source heat pump" using the municipal water as energy source.And the feasibility of this technology applied in the water supply and drainage system is also preliminary discussed.Water-energy integration is a necessary condition for the sustainable development of future cities.The survey and assessment of energy consumption and energy saving potential for the urban water supply and drainage system carried out by this study provide basic data and guiding methods for the further relaxed researches.