The Study Of Energy Consumption And Several Mechanical Properties Of Steel-Plastic Composite Heating Buried Pipe

Steel-plastic composite pipe is a new type of heating pipes. It consists of two kinds of different quality, different characteristic and different shape materials which are called hole net pipes and PE-RT . Hole net pipe is enhanced framework. And PE-RT is basal body. In steel-plastic composite pipes, work load in operation is mainly supported by hole net pipes. The PE-RT symmetrically distributes on both sides of the hole net steels and plays the function of bolstering and protecting hole net steels. It also distributes and transfers loads. The composite pipes'ability of pressure and heat resistance is more significantly increased than plastic pipes by introducing the enhanced framework to PE-RT. Thus composite pipes are useful for transporting sanitary hot water (the temperature is not above 90℃and the pressure is not above 1.0MPa), transportation medium of high temperature in secondary heating network and some fields of industry just as pharmaceutical chemical. Consequently, it makes into preformed insulation pipes and installs in direct-buried.This paper analyses energy consumption of the steel-plastic composite pipes and the steel pipes in the production phase and in-service phase by the method of Life Cycle Assessment. Compared with the steel pipes, the results indicate that the same specification composite pipes save 184,000 tons of standard coal and reduce the discharge of carbon dioxide by 500,500 tons nationwide in the heating period. It is equivalent to reducing consumption about 17.9%. If the steel-plastic composite pipes replace steel pipes, there is a large energy-saving emission reduction benefits.As the state investment standard, this paper analyses the techno-economic indicator of two different pipes by the static analysis. The results indicate that the steel-plastic composite preformed insulation pipes'cost-sharing a year is much lower than the steel preformed insulation pipes'in the service life.Modulus is an important parameter of heat calculation in the thermal calculation of direct-buried pipe. This paper concludes a limit value of the modulus and the relationship between the stress and the strain by analyzing the macro-mechanics and micro-mechanics of the steel-plastic composite pipes. This paper concludes the modulus of dn160 steel-plastic composite pipe by pit experimentation. On the analogy of this, it finds other specification modulus. It provides data base for prefabricated heating buried of new composite pipes. By the pit experimentation, this paper also draws a linear expansion coefficient of dn160 steel-plastic composite pipes, which coincides the theoretic calculated value. We can get other specification linear expansion coefficient of steel-plastic composite pipes by the theoretic calculation.This paper analyzes the stability of the steel-plastic composite pipe. The analysis shows that new heating directly buried pipe will not happen overall instability. If it's directly buried under theⅠandⅡroad, it will not happens buckling instability. It is proper for heat supplying secondary network and district cooling pipes.