Study On The Strength Of Directly Buried Hot Water Heating Pipeline

Heating technology in China, from learning abroad after the founding of PRC toestablishing our own heating technology standard in1980s, and the implementing of"design code of district heating network", is promoting the enterprise of district centralheating step by step. Industry workers had successful experiences of The Nordic countriesand did lots of study, have summarized the national technology of directly buried hot waterheating pipeline. An analysis and count in strength of the pipeline is the base of its designtechnology; strength analysis theories come through Elastic analysis, Limit analysis, andStability analysis. At present, directly buried pipeline adopts the Stability analysis theory inthe range of small pipe diameter, and in the condition of big pipe diameter the theory isconservatively using. In a general way, Sand box experiment or Coefficient of friction sitetest provides the coefficient for the analysis in the pipeline’s strength. Under the support of’Study on the key of directly buried hot water heating pipeline technology’, this paperpresents a data base of the stress from site test for the pipeline’s strength analysis, and givesa study on the strength of directly buried hot water heating pipeline.In structural engineering, using the strain measured from Resistance type sensor toreflect the stress of the measure point, it does is the idea of the test. A difference is,temperature effect in resistance of the strain gauge at a big temperature difference heatingpipeline can’t be simply ignored. Combining the demand and condition of the test, thewritings give an analytic technique of stain measured by Resistance type sensor in bigtemperature difference condition. After the compute of limited monitoring points’ parameterfrom the test, we find out the size of stress at the monitoring point on the test tubulation.The pipeline directly has been buried under green belt, uses hot water as heat medium, isordinary prefabricated insulation tube. Through the analysis of computing result, summarizethe conclusion as follow: steel-pipe’s axial stress has the linear relation with the temperatureof tube wall in arbitrary cross of partly restrained section.