Research On Cascade Mixing Hot Water Heating System

With the raise the level of urbanization in China and the continuousimprovement of living conditions, Cities and towns throughout the heating area,especially the central heating area will be further expanded. In order to meet thedemand for heating that building heat load is gradually increased, construction ofheating network or transformation of the existing pipe network is necessary.Therefore, this paper proposes a new type of heating system-hot water heatingcascade mixing with water system. For the new heating network, this system canminimize the cost of the heating system. It also ensures the safety and reliability ofthe heating system what is running. In the process of renovation and expansion ofthe heating network, Improve the heating capacity is the most significant features ofthis system while the diameter does not change.This article first analyzes the characteristics of the cascade mixing watersystem. And design the system to connect the form of a variety of applicable underdifferent circumstances. It made a presentation and analysis of part of the core of thesystem-mixing water installations. The article selects a typical cascade mixingwater systems form for the theoretical analysis. It discusses the system flows,mixing pump settings and the option of requesting through the system hydrauliccalculation. Combined with the heat balance equation, it calculated and analyzed thesupply and return water temperature when the system is running. And it introducesthe heat regulation and the corresponding control strategy.Finally, as an example of the Fujin heating pipe network lines, the article givesthree heating rehabilitation programs when the heat load increases. One is thetransformation program of conventional transform the diameter. The other two arerehabilitation programs of hot water heating cascade mixing with water system inthis paper. By the theoretical analysis and specific economic analysis, hot waterheating cascade mixing with water system adapts to new load capability more in thethermal network transformation project. And it has higher economic efficiency.This topic is from the “12th Five-Year” National Science and TechnologySupport Program of China “cold district heating system energy saving keytechnology and engineering demonstration”(2011BAJ05B04) and “the urban districtheating energy efficient planning and key technology research anddemonstration”(2012BAJ04B01)...