Research On Thermal Accessibility Of Heat-supply Network And Problems Related To Unidirectional Ring-shaped Heat-supply System

Thermal accessibility is a fundamental property of heat-supply network itself,whose distribution capacity can satisfies heat-users with the needed heat. Theaccessibility of thermodynamic condition of heat-supply network is an importantgurantee of good heating quality of heat-users.The research contents mainly is divided into three parts: the determination ofheating parameters of unidirectional ring-shaped heat-supply system, the analysisand design of thermal accessibility of heat-supply network, the research on strategyof improving thermal accessibility of heat-supply network.The mathematical model of hydraulic and thermodynamic condition ofunidirectional ring-shaped heat-supply network is derived. The principles ofdetermining the temperature of node on main of unidirectional ring-shapedheat-supply network is elaborated.The formula of the temperature of return water,flow and temperature of every node on main of single-loop and double-loop ofsingle heat-source, single-loop of double heat-source unidirectional ring-shapedheat-supply network is also derived.The concept of analysis of thermal accessibility is presented. The factors whichaffected thermal accessibility of heat-supply network is analysed. The analysis ofthermal accessibility of exsiting unidirectional ring-shaped heat-supply network andtraditional heat-supply network are studied and the key points of the design ofheat-supply network which meet thermal accessibility are clarified briefly. Thedifferent conditions of expanding the scale of heat-supply network is also discussed.Different methods of improving heating capacity and the influences of differentmethods on the heat-supply network are deliberated. For any expanding heat-supplynetwork, The most suitable method is determined through economical comparisonfinally.In the paper, the heat-supply network in Taonan city, Jilin province is designedto be unidirectional ring-shaped heat-supply network, the methods which meetthermal accessibility of unidirectional ring-shaped heat-supply network andproblems which need to pay attention to is illustrated.The best method to improvethe heating capacity of expanding heat-supply network in Taonan city is determinedfinally through economical comparison.The strategies of improving thermal accessibility for the traditional heatingsystem and unidirectional ring-shaped heating system are proposed respectively.Research on thermal accessibility provides an important guidance and basis for the design and expanding of heat-supply network.