The Research Of Economy Of District Heating Pipe Network

Since1978, China’s urbanization rate in2008reached50.11%. With the risingrate of urbanization, as an important part of urban infrastructure, district heating arelivelihood, energy and environmental program. It is a pivotal importance forsustainable economic development and achieving energy reduction. The daily lives ofordinary people are also closely related with it.In heating system, heating pipe network is considered as a bridge between heatingsources and users, and its importance is self-evident. While designing a pipe network,it is critical to choose a proper friction, which affects investment and operation qualityof pipe network. The friction in common pipe network is less than30Pa/m, far belowthe regulatory requirements of30Pa/m~70Pa/m. And the data from Jinzhong City,Shanxi Yuci district heating system showed that the entire heating system can saveenergy30%to40%, is more energy-efficient than other cities which are same scale,but still the friction of entire network is just20Pa/m. For this problem, according tothe pipe network’s lifetime cost of investment and operating, analyze whether the smallfriction is rational.The study bases on Yuci district heating network data. Analytic method is used tobuild a mathematical model, which is the most convenient method by compared withnonlinear method, multi objective function method and scenario comparison method.Through the mathematical model, the best economic friction is35Pa/m at the designheat load condition. According this friction, a new heating pipe network is designed.The data shows that maximum heat load is less than the design heat load, so it isnecessary to calculate the economic friction and heating pipe network is designedagain. Then, the flow of the two design heating pipe network is simulated by Fluent, asoftware of CFD, for validating the rationality. In the final, the pipe network’s lifetime cost of local network and the two designnetwork are calculated. The result shows that only considering the cost of operating,local network is1.63times more than the first design network,1.51times more thanthe second design network. However, the highest pipe network’s lifetime cost ofinvestment and operating is local network,7.6%more expensive than the first designnetwork,29%more expensive than the second design network. So it is proved that thelocal network still have some space for a further optimization.The result may have some help for improving other cities’ heating network.