直埋热水供热管道敞沟电预热安装方式  

Installation Method of Open Trench Electric Preheating for Directly Buried Hot Water Heating Pipeline

作　　者：赵欣刚 王冠英 许峰 王啸 马骏 史尚典 王翔 安振华 ZHAO Xingang;WANG Guanying;XU Feng;WANG Xiao;MA Jun;SHI Shangdian;WANG Xiang;AN Zhenhua

机构地区：[1]中国市政工程华北设计研究总院有限公司第六设计研究院,天津300381 [2]太原市热力集团有限责任公司,山西太原030001

出　　处：《煤气与热力》2020年第5期5-12,J0041,J0042,共10页Gas & Heat

摘　　要：无补偿直埋热水供热管道敞沟电预热安装常用3种连接方式:一次性补偿器连接、保持预热温度短管连接、自然冷却短管连接。提出一种新的连接方式:提高预热温度自然冷却短管连接。介绍电预热技术的原理和敞沟电预热工序,分析4种连接方式的施工方法及其优缺点。给出自然冷却短管连接方式预热管道自然冷却回缩量的计算方法。针对提高预热温度自然冷却短管连接方式,推导出提高后的预热温度的计算公式,给出了DN 1 200、1 400 mm管道的实际工程算例。分析结果表明:提高预热温度自然冷却短管连接方式通过人为提高预热温度,增加预热伸长量,这部分增加的伸长量恰好可以抵消预热管道自然冷却回缩量,从而使管道在自然冷却状态下达到的预热实际伸长量等于预热设计伸长量。优点是可以完全保留设计预热成果,结构简单,易于施工和焊缝探伤,能够保证施工质量;缺点是多消耗少量预热电能,延长施工时间。在施工工期不是很紧张的情况下,推荐采用提高预热温度自然冷却短管连接方式。There are three kinds of connection methods commonly used in the open trench electric preheating installation of directly buried hot water heating pipeline without compensation: one-time compensator connection,maintaining preheating temperature short pipe connection and natural cooling short pipe connection. A new connection mode is proposed: raising preheating temperature and natural cooling short tube connection. The principle of electric preheating technology and the open trench electric preheating process are introduced,and the construction methods of the four connection methods and their advantages and disadvantages are analyzed. The calculation method of the natural cooling shrinkage of the preheated pipeline with the short pipe connection after natural cooling is given. Aiming at the raising preheating temperature and natural cooling short pipe connection,the calculation formula of the increased preheating temperature is derived,and the actual engineering calculation examples of DN 1 200 and 1 400 mm pipelines are given. The analysis results show that the raising preheating temperature and natural cooling short pipe connection increases the preheating elongation by artificially increasing the preheating temperature,and this part of the increased elongation can just offset the natural cooling shrinkage of the preheated pipeline,so that the actual preheating elongation reached in the natural cooling state is equal to the preheating design elongation.The advantage is that the result of design preheating can be completely retained,the structure is simple,it is easy to construct and inspect welds,and the construction quality can be guaranteed. The disadvantages are that a small amount of preheating power is consumed,and the construction time is prolonged. When the construction period is not very tight,it is recommended to use the raising preheating temperature and natural cooling short pipe connection.

关 键 词：无补偿直埋热水供热管道 敞沟电预热 提高预热温度自然冷却短管连接 

分 类 号：TU995.3[建筑科学—供热、供燃气、通风及空调工程]