多相流管道温降公式的推导

The Deduction of Temperature Drop Formula to Calculate Multiphase Pipeline

多相管流温降计算是压降计算的基础,其对加热器的设计和对了解气液相平衡等都具有重要的意义。多相流混输管道的温降计算和单相气体或液体有明显不同,温降计算相当复杂,气液混合物不仅要通过管壁向外界散热,而且气液之间还存在质量交换和能量交换。根据能量守恒原理,既考虑天然气的焦耳—汤姆逊效应,又考虑了液体的摩擦生热,推导出了计算多相管流温降的理论公式。在考虑管道起伏对温降的影响后,将液体持液率代替质量含气率计算混合物的比热,公式的精度更高。

Temperature drop calculation in a multiphase pipeline is based on pressure drop calculation and it isvery important to devise heater and learn about gas and liquid equilibrium. Temperature drop calculation ina multiphase pipeline is different from that of a pipe in gas or liquid alone. Mixture of gas and liquid dis-j charges heat into the atmosphere,and cause energy and mass exchange. So far,it has no good ready-made formula to calculate temperature drop. According to conservation of energy,when Joule-Thomson effect on natural gas and friction heat of liquid are considered,a temperature drop formula to calculate multiphase pipeline is deduced. After undulation of pipelines effects on temperature drop is taken into account and mass void gas is replaced by liquid holdup,the formula will be better agreement with field data.