Effect of the inlet gas volume fraction on the turbulent dissipation characteristics in the multiphase pump

2022 ◽  
pp. 095440622110230
Author(s):  
Guangtai Shi ◽  
Yue Dan ◽  
Yexiang Xiao ◽  
Zekui Shu ◽  
Xiaobing Liu
Keyword(s):  
Volume Fraction ◽  
Pure Water ◽  
Internal Flow ◽  
Outlet Section ◽  
Inlet Section ◽  
Turbulent Dissipation ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Two Phases ◽  
Gas Volume

The internal flow of the multiphase pump is complicated owing to its specific structure. To reveal the effect of the inlet gas volume fraction (IGVF) on the turbulent dissipation characteristics, the method of combining numerical simulation based on k-ε turbulence model with experiment was adopted, and the turbulent dissipation of the multiphase pump was quantitatively and qualitatively analyzed in both the pure water and gas-liquid two phases condition. Results showed the vortexes were primarily distributed in the diffusers at different inlet gas volume fractions (IGVFs), near the middle of the first diffuser and the outlet of the next diffuser. At the same time, the larger value of the turbulent dissipation than that in the impellers was concentrated in the inlet and outlet of the impellers and diffusers. In addition, the effect of IGVFs on the turbulent dissipation increased gradually from the hub to the shroud at the inlet section of the first impeller. Moreover, the turbulent dissipation became increasingly unsymmetrical from the hub to the shroud at the outlet section of the first impeller.

scholarly journals Effect of the Gas Volume Fraction on the Pressure Load of the Multiphase Pump Blade

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 650
Author(s):  
Guangtai Shi ◽  
Dandan Yan ◽  
Xiaobing Liu ◽  
Yexiang Xiao ◽  
Zekui Shu
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Volume Fraction ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Multiphase Pump ◽  
Pressure Load ◽  
Gas Volume Fraction ◽  
Power Capability ◽  
Gas Volume

The gas volume fraction (GVF) often changes from time to time in a multiphase pump, causing the power capability of the pump to be increasingly affected. In the purpose of revealing the pressure load characteristics of the multiphase pump impeller blade with the gas-liquid two-phase case, firstly, a numerical simulation which uses the SST k-ω turbulence model is verified with an experiment. Then, the computational fluid dynamics (CFD) software is employed to investigate the variation characteristics of static pressure and pressure load of the multiphase pump impeller blade under the diverse inlet gas volume fractions (IGVFs) and flow rates. The results show that the effect of IGVF on the head and hydraulic efficiency at a small flow rate is obviously less than that at design and large flow rates. The static pressure on the blade pressure side (PS) is scarcely affected by the IGVF. However, the IGVF has an evident effect on the static pressure on the impeller blade suction side (SS). Moreover, the pump power capability is descended by degrees as the IGVF increases, and it is also descended with the increase of the flow rate at the impeller inlet. Simultaneously, under the same IGVF, with the increase of the flow rate, the peak value of the pressure load begins to gradually move toward the outlet and its value from hub to shroud is increased. The research results have important theoretical significance for improving the power capability of the multiphase pump impeller.

scholarly journals Effect of Gas Volume Fraction on the Gas-Phase Distribution in the Passage and Blade Surface of the Axial Flow Screw-Type Oil-Gas Multiphase Pump

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 760
Author(s):  
Guangtai Shi ◽  
Sijia Tao ◽  
Xiaobing Liu ◽  
Haigang Wen ◽  
Zekui Shu
Keyword(s):  
Gas Phase ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Axial Flow ◽  
Distribution Area ◽  
Phase Volume ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Volume ◽  
Oil Gas

The axial flow screw-type oil-gas multiphase pump is mainly applied to oil and gas transport in the deep sea. In the process of transporting the multiphase medium, the gas volume fraction (GVF) on the gas phase changes from time-to-time, resulting in the performance of the oil-gas multiphase pump being greatly influenced by the gas phase. This paper presents a detailed analysis of the gas-phase distribution law and the vortex distribution in the flow passages within the oil-gas multiphase pump by means of numerical calculations, supplemented by experimental verification. The results show that the gas phase is mainly concentrated in the diffuser at different GVFs, and the gas phase gathering in the diffuser becomes more significant with the increase in the GVF. The gas-phase volume fraction increases gradually from rim to hub, that is, the gas-phase gathering degree increases. The maximum gas-phase volume distribution area is mainly concentrated in the area near the hub of the diffuser inlet and the middle blade height area at the outlet of the diffuser. The flow in the impeller is relatively stable under the different GVFs, while there is a large vortex near the inlet of the diffuser near the hub, and there is a backflow phenomenon between the outlet of the diffuser and the tip clearance of the impeller. The volume fraction of the gas phase near the rim fluctuates more than that near the hub because the gas phase is squeezed by the liquid phase more violently. The research results can provide theoretical guidance for the optimal design of oil-gas multiphase pump blades.

scholarly journals Transport Performance Improvement of a Multiphase Pump for Gas–Liquid Mixture Based on the Orthogonal Test Method

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1402
Author(s):  
Guangtai Shi ◽  
Helin Li ◽  
Xiaobing Liu ◽  
Zongku Liu ◽  
Binxin Wang
Keyword(s):  
Flow Rate ◽  
Volume Fraction ◽  
Liquid Mixture ◽  
Suction Side ◽  
Orthogonal Test ◽  
Test Method ◽  
Trailing Edge ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Volume

To improve the transport performance of a rotodynamic multiphase pump for a gas–liquid mixture, we took the head and efficiency index at rated flow rate with 15% inlet gas volume fraction as the indices, and used the orthogonal test design method and CFD technology to optimize. We selected the blade shroud angles at the leading edge and trailing edge, and axial length of the impeller, as well as the inlet incidence angle and blade number of the diffuser, and a total of five factors were used for the orthogonal test. The weight function was used to determine the final trial protocol. The results showed that the blade shroud angle at the trailing edge had the greatest influence on the head and efficiency indices. Under the rated flow rate with a 15% inlet gas volume fraction, the head and efficiency of the optimized pump were increased by 2.81 m and 5.6%, respectively, in comparison to the base pump. After the optimization, the partial fast-speed regions at the inlet of the impeller passage and the partial low-pressure regions on the blade suction side of the impeller disappeared, the accumulation of the gas phase on the blade suction side at the impeller outlet was suppressed, and the pumping performance of the impeller using the gas–liquid mixture was improved greatly. This study provides an important theoretical basis for the optimization and design of a multiphase pump.

scholarly journals Effect of Gas Volume Fraction on the Energy Loss Characteristics of Multiphase Pumps at Each Cavitation Stage

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2293
Author(s):  
Jianwei Shi ◽  
Sijia Tao ◽  
Guangtai Shi ◽  
Wenwu Song
Keyword(s):  
Energy Loss ◽  
Volume Fraction ◽  
Axial Flow ◽  
Two Phase ◽  
Multiphase Pump ◽  
Cavitation Phenomenon ◽  
Flow Loss ◽  
Gas Volume Fraction ◽  
Critical Cavitation ◽  
Gas Volume

In the process of conveying a medium, when the inlet pressure is low, the cavitation phenomenon easily occurs in the pump, especially in the gas–liquid two-phase working condition. The occurrence of the cavitation phenomenon has a great impact on the performance of the multiphase pump. In this paper, the SST (sheard stress transport) k-ω turbulence model and ZGB (Zwart–Gerber–Belamri) cavitation model were used to simulate the helical axial flow multiphase pump (hereinafter referred to as the multiphase pump), and the experimental verification was carried out. The effect of gas volume fraction (GVF) on the energy loss characteristics in each cavitation stage of the multiphase pump is analyzed in detail. The study shows that the critical cavitation coefficient of the multiphase pump gradually decreases with the increase in GVF, which depresses the evolution of cavitation, and the cavitation performance of the multiphase hump is improved. The ratio of total loss and friction loss to total flow loss in the impeller fluid domain gradually increases with the development of cavitation, and the pressurization performance of the multiphase pump gradually decreases with the development of cavitation. The results of the study can provide theoretical guidance for the improvement of the performance of the multiphase pump.

Performance Test of a 5-Stage Helico-Axial Multiphase Pump

2011 ◽  
Vol 52-54 ◽  
pp. 399-404 ◽  
Author(s):  
Jin Ya Zhang ◽  
Hong Wu Zhu ◽  
Huan Wei ◽  
Jing Ying Peng
Keyword(s):  
Performance Test ◽  
Volume Fraction ◽  
Differential Pressure ◽  
Future Application ◽  
Multiphase Pump ◽  
The Future ◽  
Gas Volume Fraction ◽  
Gas Volume ◽  
Test Result

A 5-stage helico-axial multiphase pump was tested for studying its performance. The multiphase pump was tested on the conditions of different speed and different gas volume fraction (GVF). According to the test result, performances of the pump were analyzed. And the effects of speed and GVF to differential pressure and efficiency as well as to power of the pump were analyzed at the same time, so some conclusions were made basing of the above research and some of them are very helpful for the future application on the oilfield.

Qualification of a New Multiphase Pump. the Setting of a New Standard

2021 ◽  
Author(s):  
Åge Hofstad ◽  
Tarje Olderheim ◽  
Magnus Almgren ◽  
Marianna Rondon ◽  
Edouard Thibaut ◽  
...  
Keyword(s):  
High Speed ◽  
Oil And Gas ◽  
Volume Fraction ◽  
Two Phase ◽  
Specific Product ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Market ◽  
Gas Volume ◽  
Winding Insulation

Abstract The recent trend in the oil industry is to save CAPEX and exploit every offshore field to increase production and maximize reserves. Also, deeper water and longer step-out is a challenge for new fields. The most adapted technology to unlock these reserves is the use of subsea boosting like a multiphase pump on the seafloor. Subsea boosting has been used for decades with well proven results, but up to now, some limitations in power and lift pressure exist. This new multiphase pump development has increased the potential pressure generation manyfold from the typical ΔP of 50 bar (725 psi) at the beginning of the project. Developing such a powerful two-phase pump driven by a liquid-filled motor requires a unique combination of expertise in machinery engineering, electrical engineering, fluid mechanics and rotor dynamics. The objective of the co-authors is to share this experience by bringing some insights on what it takes to develop, test, and qualify such specific product. Outlines of the methodology will be described, key results will be detailed, and lessons learnt will be presented. The new design was fully tested first component-wise and then for a full-size prototype. A wide process envelope was mapped during the final qualification program with 3,000 points tested in the range 2,000-6,000 RPM and 0 - 100% GVF (Gas Volume Fraction). Qualification tests concluded with more than 2,000 cumulative hours. The main challenges in this program were the development of an innovative multiphase impeller and the qualification of the first MPP (MultiPhase Pump) with a back-to-back configuration. Concerning the motor, the development includes a high speed 6,000 RPM, 6 MW liquid-filled induction motor and a new stator winding insulation cable. With this new product, the pump market is ready to overcome challenges to produce deeper and further reservoirs in a constant evolutive oil and gas market.

scholarly journals 3D Blade Hydraulic Design Method of the Rotodynamic Multiphase Pump Impeller and Performance Research

2014 ◽  
Vol 6 ◽  
pp. 803972 ◽  
Author(s):  
Yongxue Zhang ◽  
Jinya Zhang ◽  
Hongwu Zhu ◽  
Shujie Cai
Keyword(s):  
Volume Fraction ◽  
Design Method ◽  
Three Dimensional ◽  
Bench Test ◽  
Pump Impeller ◽  
Multiphase Pump ◽  
Hydraulic Design ◽  
Gas Volume Fraction ◽  
And Performance ◽  
Gas Volume

A hydraulic design method of three-dimensional blade was presented to design the blades of the rotodynamic multiphase pump. Numerical simulations and bench test were conducted to investigate the performance of the example impeller designed by the presented method. The results obtained from the bench test were in good agreement with the simulation results, which indicated the reasonability of the simulation. The distributions of pressure and gas volume fraction were analyzed and the results showed that the designed impeller was good for the transportation of mixture composed of gas and liquid. In addition, the advantage of the impeller designed by the presented method was suitable for using in large volume rate conditions, which were reflected by the comparison of the head performance between this three-dimensional design method and another one.

scholarly journals Research on the pressurization performance of an impeller in a multi-phase pump under different working conditions

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982714
Author(s):  
Guangtai Shi ◽  
Zhiwen Wang ◽  
Zhengwei Wang ◽  
Zhenggui Li ◽  
Xiaobing Liu
Keyword(s):  
Working Conditions ◽  
Flow Rate ◽  
High Efficiency ◽  
Volume Fraction ◽  
Outlet Section ◽  
Inlet Section ◽  
Volume Fractions ◽  
Performance Area ◽  
Multi Phase ◽  
Gas Volume

In order to improve the working performance of the impeller in a multi-phase pump under different working conditions and expand the range of the high-efficiency areas of the multi-phase pump, each section of the impeller was divided into an inlet section, middle section and outlet section. The pressurization performance of different areas within the impeller was obtained by numerical calculation under different flow rates and different gas volume fractions, respectively. The results show that the pressurization performance of the different areas within the impeller can be predicted well. In the first half of the impeller, when the blades were closer to the rim, the pressurization performance was stronger, and in the second half of the impeller, when the blades were closer to the hub, the pressurization performance was stronger. With an increase in the flow rate, from the inlet section to the outlet section, the pressurization performance of each stage of the impeller gradually decreased, and the strongest pressurization performance area was always in the inlet section with no obvious movement. With the increase in the gas volume fractions, the pressurization value of each stage of the impeller dropped faster, except for the outlet section. When there was an increase in the flow rate or the gas volume fraction, the inlet section was influenced the most and the outlet section was influenced the least. The research results provide an important theoretical basis for further optimization of the impeller design for a multi-phase pump.

scholarly journals Energy performance and flow characteristics of a multiphase pump with different tip clearance sizes

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882335 ◽  
Author(s):  
Jinsong Zhang ◽  
Honggang Fan ◽  
Wei Zhang ◽  
Zhifeng Xie
Keyword(s):  
Volume Fraction ◽  
Flow Characteristics ◽  
Energy Performance ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Great Success ◽  
Tip Leakage Flow ◽  
Multiphase Pump ◽  
Gas Volume Fraction ◽  
Gas Volume

Deep sea oil resources worldwide possess great potential for exploration; however, multiphase medium technology requires urgent development. The multiphase pump has achieved great success as one of the most advanced machinery in underwater oil and gas exploration. Tip clearance is inevitable between the rotating and stationary components of the multiphase pump. In this study, tip clearance sizes of 0.0, 0.2, 0.5, and 0.8 mm are selected to investigate the effect of tip clearance on energy performance and flow characteristics of a multiphase pump. Results show that pressure rises decrease by 10.72%, 24.96%, and 41.39% with gas volume fraction = 0% under different tip clearance sizes, while the pressure rises decrease by 17.10%, 25.35%, and 38.11% with gas volume fraction = 10%. The dominant frequencies and maximum amplitudes of pressure fluctuation rise with the increase in tip clearance. The entrainment effect between the tip leakage flow and main flow in the impeller strengthens with the increase in tip clearance size; the induced vortex area and leakage flow rate also increase.

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