安装温井对燃气管道压力监测的影响

Influence of Thermowell Installing on Gas Pipeline Pressure Monitoring

对国内某海洋平台项目燃气系统中一段安装有温井的管线进行了数值模拟,分析了不同工况下温井对压力表监测值的影响。分析结果表明,在工业常规管道设计流速下,温井前后的压力波动小于30 kPa,波动影响的管长范围不足100 mm,波动段后管线压力表监测值稳定。考察了同一管线无温井时的压力分布,模拟结果表明压力监测值稍有增大,但在工程设计允许的范围内。提出几点设计建议,在无外界条件限制时,压力取源点设置在温度取源点上游,且距离大于50 mm;若受空间或操作限制,压力取源点位于温度取源点下游时,压力取源点距温度取源点应大于100 mm,温井与压力取源点成45°错位安装。

A section of thermowell installed pipeline in some offshore gas system was simulated. The pressure monitoring values were obtained at different conditions. The analysis results show that under the industrial conventional pipeline design flow rate, the pressure fluctuation before and after the thermowell is less than 30 kPa, the length of the tube affected by the fluctuation is less than 100 mm, and the monitoring value of the pipeline pressure gauge after the fluctuation section is stable. The pressure distribution of the same pipeline without thermowell was investigated. The simulation results show that the pressure monitoring value is increased however within the allowable range of engineering design. Two design suggestions were proposed: when there is no external condition limitation, the pressure source point should be set upstream of the temperature source point and the distance should be greater than 50 mm;if it is limited by space or operation, the pressure source point could be located downstream of the temperature source point and the source of the pressure should be greater than 100 mm from the source of the temperature to avoid the influence of turbulence, and the thermowell and the pressure source point should be installed at 45 degrees dislocation.