集中供热蒸汽热网设计现状分析及发展趋势综述

Situation analysis and development trends overview of central heating steam heating network design

集中供热技术是供热行业发展的重要方向,而蒸汽热网设计工作是集中供热系统研究的重点和热点。随着蒸汽热网输配技术指标的提高和节能政策的日趋严格,对热网的设计及其新材料新工艺研发、运行稳定性和长输热网经济性均提出更高的要求。对热网设计技术相关成果进行梳理并阐明当前的设计现状:在降低输送温降方面,系统介绍了保温材料的关键性能指标、保温结构和材料、隔热管托特点和应用效果;在降低输送压降方面,较为全面地分析管材和蒸汽流速选取要点,介绍旋转补偿器的特点和重要设计参数;最后分析集中供热热网设计存在的问题,对其未来的发展进行展望。结果表明:保温材料经历由膨胀珍珠岩到岩棉、再到离心玻璃棉、纳米气凝胶的发展过程,保温结构实现了由圆形结构转变为椭圆形复合结构变革。新材料、新工艺、新管道附件的开发和应用,显著提高了蒸汽热网的节能效果,压降由传统设计的0.1 MPa/km降低至0.02 MPa/km~0.03 MPa/km,温降由15℃/km~20℃/km降低至5℃/km~7℃/km。随着技术进步和设计的精细化,压降和温降指标还会进一步降低。

The central heating energy saving and environmental protection technology has important application and market prospect,and it is also the important direction for heating industry development.Central heating steam heating network design is the focus and hot spots in central heating system research.As the improvement of technological parameters and the increasingly strict energy saving policy,the higher requirements for design of steam heating network,development of new materials and new process,stability of network operation and economy of long-distance steam heating network were proposed.This paper combed the related achievements for heat network design technology and demonstrated the designing status.For reducing temperature drop,aspects such as the key performance indicators of insulation materials,new composite insulation structure and insulation material,characteristics and application effects of heat insulation pipe support,were introduced systematically.For reducing pressure drop,the pipe and main points of steam velocity selection were analyzed comprehensively,features and important design parameters of rotary joint compensator were introduced as well.Finally,the existing problems of central heating steam heating network design were analyzed,and the prospects for future development were demonstrated.The results show that the insulation materials experiences several stages of development(from expanded perlite to rock wool,then centrifugal glass wool and presently the nano aerogel),the insulation structure has realized the change of turning circular structure to oval composite structure which has aluminum foil fiberglass cloth in insulation layers,and has insulation shawl on the top part.In order to reduce the temperature drop and pressure drop in the conveying process of steam heating network furtherly,the insulated pipe support and rotary joint compensator which has been improved and optimized continuously has been used widely.Development and application of new materials,new processes and new pipe accessory can significantly increase the energy saving effect of steam heating network,the pressure drop can be reduced from 0.1 MPa/km to 0.02 MPa/km~0.03 MPa/km,the temperature drop can be reduced from 15℃/km~20℃/km to 5℃/km~7℃/km.With the refinement of technical progress and design,the pressure drop and temperature drop can be reduced furtherly.