离心式高压油气透平内流数值研究  

Numerical simulation on inflow of centrifugal high-pressure oil and gas turbine

作　　者：宋刚 孙永尧 高秋英[2,3] 王胜元 李鹏 王恒[2,3] 宋鹏 SONG Gang;SUN Yongyao;GAO Qiuying;WANG Shengyuan;LI Peng;WANG Heng;SONG Peng(Sinopec Production&Management Department,Beijing 100728,China;Sinopec Northwest Oilfield Company,Urumqi,Xinjiang 830011,China;Sinopec Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-Vuggy Reservoirs,Urumqi,Xinjiang 830011,China;School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an,Shaanxi 710049,China)

机构地区：[1]中国石油化工集团有限公司生产经营管理部,北京100728 [2]中国石油化工股份有限公司西北油田分公司,新疆乌鲁木齐830011 [3]中国石油化工集团有限公司碳酸盐岩缝洞型油藏提高采收率重点实验室,新疆乌鲁木齐830011 [4]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《天然气技术与经济》2022年第4期37-43,共7页Natural Gas Technology and Economy

基　　金：国家重大专项“塔里木盆地碳酸盐岩油气田提高采收率关键技术示范工程”(编号:2016ZX05053);中国石化重点科研项目“大规模天然气液化成套技术方案”(编号:320105)。

摘　　要：为了解决井口天然气节流过程中压力能浪费严重、现有透平技术难以直接利用油气介质压力能的问题,对天然气井口压力能利用离心式高压油气透平进行整机建模及网格离散,并将包含若干凝析油及天然气组分的混合介质热物性拟合为压力及温度的函数以构建真实介质热物性模型。采用计算流体力学软件开展真实介质条件下的高压油气透平整机流场数值模拟,获得了高压油气透平在设计及非设计工况下的内流特性及整机性能。研究结果表明:①在设计工况下,整机流动状况良好,仅在叶轮流道出现部分分离,透平效率为73.33%,功率为375.93 kW;②随着压力升高,透平流量及功率逐渐增加,但是进口压力的升高将破坏喷嘴—叶轮的流动匹配,使得流道中流动分离及损失增大、整机效率降低;③随着气油比的增加,透平流量减小,功率变化不明显,但气油比的增加改善了透平内流的特性,使得整机效率显著提升。结论认为,该离心式油气透平在高压压力介于20~50 MPa及气油比介于160~400 m^(3)/t的条件下具有较高的整机效率,但是其内流匹配及整机效率受进口压力及气油比的显著影响。Pressure energy is often wasted seriously in the process of wellhead natural-gas throttle,and its oil and gas medium can be hardly utilized directly by means of existing turbine technology.So,both entire ma⁃chine modeling and grid discretization were carries out by using a centrifugal oil and gas turbine with high pres⁃sure.Then,some thermophysical properties of mixed medium containing several components of condensate oil and natural gas were fitted into two functions of pressure and temperature,so as to establish a thermophysical model on real medium.Finally,the flow domain in this oil and gas turbine under the condition of real medium was numerically simulated by using a software called computational fluid dynamics(CFD),and the inflow characteris⁃tics and overall turbine performance under design and nondesign conditions were made clear.Results show that(1)under the design condition,the flow in the entire turbine is smooth except for partial separation in the im⁃peller flow passage,with the turbine efficiency of 73.33%and the power of 375.93 kW;(2)both turbine's flow rate and power increase gradually with pressure increase,but the increase of inlet pressure may damage flow matching between nozzle and impeller,leading to the increase of flow separation and loss in the flow passage whereas the decrease of overall efficiency;and(3)with the increase of gas/oil ratio,the flow rate decreases,and the power can not change a lot.However,the ratio increase can perfect the inflow characteristics,so as to increase the overall efficiency remarkably.In conclusion,this centrifugal oil and gas turbine is characterized by higher overall efficiency at the high pressure from 20 MPa to 50 MPa and the gas/oil ratio ranging from 160 m^(3)/t to 400 m^(3)/t,but its inflow matching and overall efficiency are influenced substantially by both inlet pres⁃sure and gas/oil ratio.

关 键 词：天然气 压力能利用 离心式透平膨胀机 计算流体力学 油气混合介质 

分 类 号：TE311[石油与天然气工程—油气田开发工程]