The Theory Research Of Economic Friction Of Heating Pipe Network

The heating is an essential part to people in daily life, it is not only the foundationindustry of the national economic development, also affects the overall situation ofnational economic by all walks of life in our country. Through the founding the heatingenterprise develops quickly, the problems that exist in the heating system are also can’tbe ignored by people. With the continuous development of social economic, thebuilding energy consumption in China is still1to2times higher than that in the abroad,and the heating energy consumption is much more higher than abroad. As is known tous all, China is a country whose energy is relatively scarce, especially the per capitaresources, so the energy conservation is imperative.Heating pipe network takes the role of a bridge, between heat users and heatingsource, it is not only related to the quality of heating system, also guarantee thereliability of the heating system.In life cycle of the heating network, the design phase of the investment shareoccupies about85%of the total investment. Selection of parameters of the heatingsystem, especially the selection of friction plays an irreplaceable role in the life cyclecost. The selection of friction also associated with the network in safety and reliabilityby a large extent.At present stage of our country, many designers in the chosen of specific frictionalresistance, are generally based on the former Soviet union and recommends theexperience of30-70Pa/m or40-80Pa/m. But the social economy and naturalenvironment had big changed and developmentd today, whether the original experiencevalue is still meet the needs of society and still economy to environmental protection.The problem remains to be further researched. So the heating pipe network design optimization, make limited resources can maximize improve the standard of people’sliving, make the heating costs, to energy frugal, and at the same time play a good effect.Economic specific frictional resistance of primary network in heating system weremainly analyzed and calculated in this paper. Using the concept of minimum life cyclecost, analysis and calculate the life cycle cost particularly, and on the basis of theminimum life cycle cost set up a mathematical model, objective optimization the singleparameter of the friction. The influence of supply and return water temperature ofheating system to economic specific friction, and other related components influence tothe economic specific friction, and compared with traditional computing economystudies contrast of the friction method. Analyzed the elements’ influence of economicspecific friction. Determined the factors both the insensitivity and the sensitivity,obtained the original recommendation that range although in certain cases friction iseconomic, but to the actual adjustment, to contrast the influence of friction on thebackwater temperature difference is very big, the economic than friction decreases withthe growth of the local industrial electricity price, and compared the influence of frictionon the electricity; The friction between the tube outer surface and the environment alongwith the network of exothermic coefficient increases, increases heat loss coefficient isnot insulation parts will lead to increased than friction; The friction increases with thetemperature of water growing exponentially, so in the case of heating scale, using higherwater temperature difference, can be appropriate to reduce the costs of networkinfrastructure investment. The impact of price comparison of friction is larger; increasethe heat transfer coefficient friction resistance with thermal management outer surfacebetween environment and increases without thermal insulation parts, heat dissipationwill also lead to increased friction resistance; friction resistance with increasing supplyand return water temperature difference of exponential growth, so the heating a certainscale, the supply and return water temperature higher, can be appropriate to reduce thenetwork infrastructure investment costs.By the relation curve of life cycle cost economic specific frictional resistance andthe friction factor directly affects the size of the initial investment and operation ofnetwork system cost, select the strict control of the economic specific frictionalresistance, balance pipe network construction investment and operating costs, to achieve the best value can be of great contribution to energy saving.