蒸汽长距离供热管道传输特性分析

Analysis of Transmission Characteristics of Steam Long-distance Heating Pipeline

为研究蒸汽长距离供热过程中蒸汽状态参数的变化以及水力计算与热力计算间的相互影响,通过可压缩流体管网分析软件AFT Arrow结合控制变量法模拟了多种工况。结果表明:传统计算方法得到的蒸汽出口压力要低于考虑蒸汽状态参数变化时的出口压力。蒸汽的密度变化与蒸汽的流速及管径有关。当长输直管中蒸汽最大流速为20 m/s时,蒸汽每千米的温降逐渐降低。当蒸汽最大流速为40 m/s、60 m/s时,蒸汽每千米的温降先降低后增加。可见,传统计算蒸汽压降的方法与实际还是存在一定的误差,尤其是对于管径较小,蒸汽的流速在供热过程中发生较大变化的供热管道。

In order to study the changes of steam state parameters and the interaction between hydraulic calculation and thermal calculation during the long-distance heating of steam, a variety of working conditions were simulated by the compressible fluid pipe network analysis software AFT Arrow combined with the control variable method. The results show that the steam outlet pressure obtained by traditional calculation methods is lower than the outlet pressure when considering the change of steam state parameters. The density change of steam is related to the flow velocity and pipe diameter of steam. When the maximum flow rate of steam in a long straight pipe is 20 m/s, the temperature drop of steam per kilometer gradually decreases. When the maximum steam flow rate is 40 m/s, 60 m/s, the temperature drop of steam per kilometer decreases first and then increases. This shows there is still a certain error between the traditional method of calculating steam pressure drop and the actual, especially for small pipe diameters,heating pipes where the flow rate of steam changes greatly during the heating process, heating pipes where the flow rate of steam changes greatly during the heating process.