【作者】 师卿；

【导师】 王飞；

【作者基本信息】 太原理工大学 ， 供热供燃气通风及空调工程， 2011， 硕士

【摘要】 孔网钢带耐热聚乙烯预制保温管是一种新型供热管道,由孔网钢带耐热聚乙烯复合管(含管件)、聚氨酯硬质泡沫塑料保温层和聚乙烯保护壳组成。孔网钢带耐热聚乙烯复合管是预制保温管的核心,是以冷轧冲孔钢带焊接的孔网管作为增强骨架,耐热聚乙烯(PE-RT)为主体材料复合而成。由于引入了增强骨架和耐热聚乙烯,管材的耐压强度和耐热性能都得到显著提高,可用于热水输送管道、供热二次网管道等。孔网钢带耐热聚乙烯预制保温管在直埋供热应用领域缺乏足够的理论依据和实践案例,保温层和保温外壳对管道力学性质的影响也是未知的。因此,以预制保温管整体为研究对象,对其进行力学性能分析是十分必要的。本文从有限元分析、实验研究和复合材料细观力学理论三个方面对两种规格的孔网钢带耐热聚乙烯预制保温管进行了较为系统的研究。主要研究内容和结论有：1、利用有限元软件对dn110和dn200两种规格的孔网钢带耐热聚乙烯预制保温管进行热分析和结构分析。对模型外壁施加20℃温度载荷,内壁分别施加50℃,70℃,90℃温度载荷,模拟出温度场在管道的径向分布。以温度场为边界条件,模拟出模型的轴向热位移,并根据模拟结果计算出孔网钢带耐热聚乙烯预制保温管的线膨胀系数有限元值。另对模型施加压力载荷和温度载荷,根据模拟结果计算弹性模量有限元值。2、设计了孔网钢带耐热聚乙烯预制保温管实验室实验台,通过实验得出dn110和dn200两种规格的线膨胀系数和弹性模量实验值。根据复合材料细观力学理论,计算出不同规格线膨胀系数和弹性模量的理论计算值。用Origin软件对dn110和dn200两种规格孔网钢带耐热聚乙烯预制保温管线膨胀系数和弹性模量的有限元值、实验值和理论计算值进行分析,对复合材料细观力学理论公式进行修正,推导出不同规格管道的线膨胀系数和弹性模量修正值。为孔网钢带耐热聚乙烯预制保温管应用于直埋供热工程提供设计计算参数。3、设计了孔网钢带耐热聚乙烯预制保温管地坑实验。通过模拟dn110和dn200两种规格管道在直埋供热工程中的运行状态,测得复合管的过渡段长度、热伸长和管道的轴向力。并和理论计算的复合管道最大过渡段长度、热伸长以及轴向力进行比较,验证了复合管道实验室实验结果、过渡段长度、热伸长量、弹性模量以及线膨胀系数等结论的准确性和正确性。更多还原

【Abstract】 Steel-plastic composite pre-insulated pipe is a new heating pipe. It comprises of steel-plastic composite pipe (including pipe fittings), rigid polyurethane foam plastic insulation layer and the polyethylene protection shell. The steel-plastic composite pipe is the key of steel-plastic composite pre-insulated pipe. It compose of borehole net steel pipe and PE-RT. Borehole net steel pipe is enhanced framework, it is made from cold-rolled punched hole steel sheet. And heat-resistant polyethylene (PE-RT) is main material. Owing to using of an enhanced framework and the heat-resistant polyethylene, compressive strength and heat-resistance of pipe have been significantly improved. Steel-plastic composite pre-insulated pipes can be used as hot water pipes, the secondary heating network pipes etc.Steel-plastic composite pre-insulated pipe lacks of theory evidence and practical cases in application of direct-buried heating area. Effects of pipeline mechanical properties coming from insulation layer and insulation shell are also unknown. Therefore, analyzing mechanical properties of pre-insulated pipe as a whole is extraordinary essential. This paper studies two type steel-plastic composite pre-insulated pipes from three aspects, including finite element analysis, experimental research and composite materials micromechanics theory. The main contents and conclusions are:1. Using the finite element analysis software to analyze dn110 and dn200 steel-plastic composite pre-insulated pipes for thermal analysis and structural analysis. Imposed 20 degrees temperature load on the model outer wall and 50 degrees,70 degrees,90 degrees temperature load on inner wall separately. It simulates the radial temperature distribution in the pipeline. Then it takes temperature as boundary conditions to simulate the model axial thermal displacement and calculates the finite element value of linear expansion coefficient of steel-plastic composite pre-insulated pipes according simulation results. Moreover, Imposed pressure load and temperature load on the model, to calculate the finite element value of elastic modulus according simulation results.2. Designing laboratory bench for steel-plastic composite pre-insulated pipes. It obtains the experimental value of linear expansion coefficient and elastic modulus of dn110 and dn200 two types pipes by experiment. On the basis of composite materials micromechanics theory, it calculates the theoretical value of linear expansion coefficient and elastic modulus of different types pipes.Analyzing finite element values, the experimental values and the theoretical values of linear expansion coefficient and elastic modulus of dn110 and dn200 steel-plastic composite pre-insulated pipes by the Origin, it corrects micromechanics theory formula of composite materials. It derives modifier of linear expansion coefficient and elastic modulus of different types pipes. It provides designed and calculated parameters for steel-plastic composite pre-insulated pipes applying in the direct-buried heating area.3. Paper designs pit experiment of steel-plastic composite pre-insulated pipes. It simulates running condition of dn110 and dn200 two type pipes in the direct-buried heating engineering. Through observing experimentation, it obtains transition length, thermal expansion and axial force of the composite pipes. And comparing with the theoretical values of the maximal transition length, thermal expansion and axial force of the composite pipe, the result verifies the accuracy of the laboratory experiment for composite pipes.更多还原