CAJ | 학술논문

以中国石油大学(北京)自主研发的新一代螺旋轴流式多相泵为研究对象,在不同工况下对其进行外特性试验研究.实验表明新一代螺旋轴流式多相泵能够输送很大范围的单相或多相流体.并且测定了转速、进口含气率、吸入压力等主要操作参数对多相泵性能的影响.通过实验发现多相泵的性能随着转数和进口吸入压力的提高得到明显改善,增压有所提高,高效区变宽,最优工况对应的流量增大.当含气率升高时,多相泵内两相流体产生速度滑移,泵内流型发生转变,导致多相泵振动、性能不稳定,多相泵的增压能力降低.另外多相泵入口处的均混器能够改善多相泵入口来流的条件,扩大多相泵的操作范围,对多相泵的性能影响很大.为了更好地了解多相泵内流场情况,建立了多相泵CFD数学模型.运用Fluent 6.2进行数值模拟.通过求解雷诺时均N-S方程,并应用标准k-ε湍流模型来模拟泵内流动特性.首先用收敛的模拟结果与实验结果进行对比,将模型进一步修正,然后进行其他工况下的模拟.修正后的模型以及本文模拟的结果很好的反映了多相泵内流体流动的特点,同时利用该模型还可以进行各种工况下的性能预测以及多相泵的叶片翼型的优化.为今后新泵的设计提供了一种经济实用的方法.
이중국석유대학(북경)자주연발적신일대라선축류식다상빙위연구대상,재불동공황하대기진행외특성시험연구.실험표명신일대라선축류식다상빙능구수송흔대범위적단상혹다상류체.병차측정료전속、진구함기솔、흡입압력등주요조작삼수대다상빙성능적영향.통과실험발현다상빙적성능수착전수화진구흡입압력적제고득도명현개선,증압유소제고,고효구변관,최우공황대응적류량증대.당함기솔승고시,다상빙내량상류체산생속도활이,빙내류형발생전변,도치다상빙진동、성능불은정,다상빙적증압능력강저.령외다상빙입구처적균혼기능구개선다상빙입구래류적조건,확대다상빙적조작범위,대다상빙적성능영향흔대.위료경호지료해다상빙내류장정황,건립료다상빙CFD수학모형.운용Fluent 6.2진행수치모의.통과구해뢰낙시균N-S방정,병응용표준k-ε단류모형래모의빙내류동특성.수선용수렴적모의결과여실험결과진행대비,장모형진일보수정,연후진행기타공황하적모의.수정후적모형이급본문모의적결과흔호적반영료다상빙내류체류동적특점,동시이용해모형환가이진행각충공황하적성능예측이급다상빙적협편익형적우화.위금후신빙적설계제공료일충경제실용적방법.
This paper aims at presenting some research underway at China University of Petroleum(Beijing)both in experimental study and numerical simulations. After an extensive check on the multiphase loop to investigate its hydraulic and mechanical behavior under different working conditions, a new generation helico-axial MPP was tested. Performance test results showed that the MPP had the flexibility to handle wide range of flow rates, both steady-state and slug flows. Some factors, such as rotation speed, inlet suction pressure and gas void fraction(GVF)etc, had great influence on its performance. Test results showed that rising the rotation speed and suction pressure could better its performance, pressure boost improved, high efficiency zone expanding and the flow rate corresponding to the optimum working condition largened. The pump worked unstable as GVF increased to a certain extent and slip occurred between two phases in the pump, creating surging and gas lock at a high GVF. Also the mixer installed upstream played a vital role on its performance, improving the inlet flow condition, expanding the flexibility of the MPP. In order to improve the understanding of the flow field inside the pump, a Computational Fluid Dynamics(CFD)model has been developed. The commercial CFD code Fluent 6. 2 is used to carry out the flow simulations. The mean flow and turbulence were characteristics computed by solving the Reynolds averaged Navier-Stokes equations combined with the standard k-ε turbulence model. After the transient computational results had been obtained for a sufficiently long time period, the model was verified by comparing the transient computational results with experimental results. Good agreement between experiment and computations was obtained. Flow analysis reveals the distribution of velocities, pressures and volume fractions for all phases inside the MPP, which improves our understanding of the process. The computational model and results discussed in this paper would be useful for understanding the flow process and characteristics inside the pump, and also can provide a prediction method of MPP performance under any working condition and a cost effective method of shape optimization for future MPP designing.