孔网钢带耐热聚乙烯复合管的力学分析及保温层计算.pdf

太原理工大学 硕士学位论文 孔网钢带耐热聚乙烯复合管的力学分析及保温层计算 姓名：明艳 申请学位级别：硕士 专业：@ 指导教师：王飞 20100501 太原理工大学硕士研究生学位论文 I 孔网钢带耐热聚乙烯复合管的力学分析及保温层计算 摘 要 孔网钢带耐热聚乙烯复合管是一种以孔网钢管为增强体，以耐热聚乙 烯( P E - R T ) 为基体，通过孔网钢管上的小孔和高性能的粘接树脂层将孔网 钢管与内外层耐热聚乙烯紧密地连接在一起的新型复合管道这种独特的 结构，没有了传统复合管中金属管与塑料管衬套式结构或金属管与喷塑涂 层中的连续接触界面，因而复合得十分牢固可靠的复合结构造就了孔网 钢带耐热聚乙烯复合管集钢、塑两种管材的优点于一身，又克服了金属板 骨架增强塑料复合管管材钢塑界面结合力差的缺陷， 具有十分优越的综合 性能和广阔的应用前景 孔网钢带耐热聚乙烯复合管用于直埋供热时，由于载荷的作用，可能 发生断裂或爆裂破坏的危险， 因此在强度分析的基础上开展复合管的应力 分析，对供热系统的安全运行具有十分重要的意义本文从理论分析和试 验研究两个方面对孔网钢带耐热聚乙烯复合管进行了较为系统深入的研 究。

主要研究内容和结论有： 1) 根据第三强度理论、 第四强度理论和中径公式对孔网钢带耐热聚乙 烯复合管的爆破压力进行了计算结果表明：依据第四强度理论得到的爆 破压力与实测值最接近，相对误差范围为- 9.72%~9.78%，说明用第四强度 理论对孔网钢带耐热聚乙烯复合管进行强度分析具有较高的计算精度在 这一结论的基础上，本文对该种复合管的轴向应力进行了分析，同时研究 了复合管的承载特性： 增强骨架— 孔网钢管承担的爆破压力约占总爆破压 太原理工大学硕士研究生学位论文 II 力的 70%左右；承担的轴向应力为 92%以上从这组数据我们可以看出， 孔网钢管是孔网钢带耐热聚乙烯复合管的主要承载体 2) 对一次应力和二次应力共同作用下的安定性分析 阐述了无补偿直 埋管段应力验算的弹性分析法，并计算了不同埋深，不同温差和压力下的 过渡段长度及热伸长通过应力验算，确定了满足无补偿管段强度条件的 最大允许温差，据此可以确定出经济合理、技术可靠的供水温度 3) 利用传统的和基于火用经济学原理的设计方法， 对孔网钢带耐热聚乙 烯复合管的保温层厚度进行了计算计算结果表明：基于火用经济学原理的 设计方法与传统的设计方法相比，供回水温度为85/60℃时，可节能 17~24%；60/50℃时，可节能9~22%，因此基于火用经济学原理的设计方法 更合理。

本文同时分析了经济保温层厚度的影响因素 关键词：孔网钢带耐热聚乙烯复合管，爆破压力，轴向应力，直埋，应力 分析 太原理工大学硕士研究生学位论文 III MECHANICAL ANALYSIS AND INSULATING LAYER CALCULATION OF STEEL STRIP WITH BOREHOLE NET POLYETHYLENE OF RAISED TEMPARETURE COMPOSITE PIPE ABSTRACT Steel strip with borehole net polyethylene of raised temperature composite pipe is a new kind of compound pipe, of which borehole net steel pipe is reinforcing material and PE- RT is matrix. Borehole net steel pipe connects with Internal and External Polyethylene of Raised Temperature together tightly by keyhole of borehole net steel pipe and High Performance adhesive resin layer. The unique structure is very firm without continuous contact interface of traditional composite pipe between metal tube and bush plastic pipe or metal tube and plastics sprayed coating. Steel strip with borehole net polyethylene of raised temperature composite pipe incorporate the advance of steel and plastic in a body, overcome the defect of low plastics - steel interface binding force of plastic clad pipe enhanced by metal skeleton. The reliable composite structure has superior comprehensive properties and wide application prospect. Because of the effect of load，fracture or burst may occur when steel strip with borehole net polyethylene of raised temperature composite pipe used in 太原理工大学硕士研究生学位论文 IV directly buried heating, so analyzing the stress of composite pipe on the basis of strength analysis has very important significance in safe operation of heating system. The paper carries on systematic deep research to the steel strip with borehole net polyethylene of raised temperature composite pipe from two aspects of the theoretical analysis and experimental study. The main research contents and conclusion are as follows: 1) Calculating the bursting pressure of steel strip with borehole net polyethylene of raised temperature composite pipe according to third strength theory, forth strength theory and mid- diameter formula, the results show that the bursting pressure calculated in accordance with forth strength theory is most close to the measured values. Relative error range is - 9.72%~9.78%，indicating that analyzing the strength of steel strip with borehole net polyethylene of raised temperature composite pipe on the basis of forth strength theory has high calculation precision. Based on the conclusion, the paper analyzes the axial stress of composite pipe and studies the bearing behavior of composite pipe. Enhancing Skeleton- - borehole net steel pipe undertakes about 70 percent of total bursting pressure and more than 92 percent of axis stress. - borehole net steel pipe is the main undertaker of steel strip with borehole net polyethylene of raised temperature composite pipe. 2) Shakedown analysis in the interaction between primary stress and secondary stress. The paper expounds elastic analysis on stress check of 太原理工大学硕士研究生学位论文 V no compensation direct- buried pipe and calculates transition length and its thermal expansion in different pressure and temperature difference. The maximum permissible temperature difference which satisfies the strength condition of no compensation direct- buried pipe is determined by checking stress. Economical and reasonable and technically reliable supply temperature can be defined, according to the maximum permissible temperature difference. 3) The paper calculates the insulation thickness of steel strip with borehole net polyethylene of raised temperature composite pipe based on traditional design method and design method based on the principle of economy of energy. The result shows that, comparing with the traditional design method, the design method based on the principle of economy of energy can save energy 17~24 percent when supply and return water temperature is 85/60℃ and 9~22 percent when supply and return water temperature 。