采用焓法方程计算埋地管道含蜡原油停输温降  

Temperature drop calculation of waxy crude in a buried pipeline after shutdown using enthalpy formulation

作　　者：许康[1] 张劲军[1] 

机构地区：[1]石油大学石油天然气工程学院,北京102249

出　　处：《石油大学学报（自然科学版）》2005年第1期84-88,共5页Journal of the University of Petroleum,China(Edition of Natural Science)

基　　金：中国石油天然气股份公司科技攻关项目(020201 01 02)

摘　　要：埋地热含蜡原油管道停输后,当管内原油温度降到析蜡点以下时,原油中的蜡晶将逐渐析出。根据含蜡原油降温过程中蜡结晶放热的特点,使用焓法方程对析蜡点以下伴随有析蜡胶凝现象的原油降温过程进行了数学描述,并详细给出了使用有限元法对焓法方程进行求解的方法。将焓法方程的计算结果与Φ426mm×6mm管道实测数据进行了对比。结果表明,土壤的计算温度和实测温度最大偏差在1.4℃以内,管内平均温度的计算值与实测值的偏差为0.3℃。由此证明了使用焓法方程计算埋地热油管道停输温降具有较高的准确性。After the shutdown of a buried waxy crude pipeline, wax crystals will start to precipitate when the crude cools to the temperature below the wax appearance temperature (WAT). With the quantity of wax crystal increasing, an interlocking gel-like structure forms at the wall of pipeline and gradually causes the entire mass of waxy crude to gel. According to the characteristics of wax precipitation and latent heat release during cooling down, a new approach was presented to illustrate the temperature drop along with gelling of hot waxy crude at the temperature below WAT using enthalpy formulation. The approach to calculate the enthalpy formulation by finite element method was given in detail. Compared with the measured values using a pipeline of 426 mm in diameter and 6 mm in wall thickness, the calculated result shows that the maximum deviation between the calculated soil temperature and the measured is less than 1.4 ℃, and the error between the calculated average temperature inside pipe and the measured is 0.3 ℃. The accurate temperature drop can be obtained using enthalpy formulation.

关 键 词：含蜡原油管道 温降 析蜡点 埋地管道 埋地热油管道 油温 求解 方程 证明 过程 

分 类 号：TE832[石油与天然气工程—油气储运工程] G633[文化科学—教育学]