Numerical investigation on screw rotor deformation and influence on volumetric efficiency of the twin-screw multiphase pump

During on-site operation under wet gas compression, the volumetric efficiency of a twin-screw pump decreases sharply, the temperature in the pump rises significantly, severe vibration and even jamming can occur. To solve the problems caused by wet gas compression structurally, a method for optimizing the design of a decompression screw is proposed in this paper based on the characteristics of a twin-screw pump and screw compressor. A fluid–solid multi-field thermal-coupling scheme is used to calculate the pressure, temperature, deformation, outflow, and volumetric efficiency of a screw pump before and after optimization. The average deviation between the calculated outflow and the experimental results was no more than 5%, demonstrating the accuracy of the calculation. After optimization, the return flow between the pump stages was significantly reduced and the outflow had increased. When the pressure difference between the inlet and outlet was 1 MPa, the maximum increase was about 18%. With an increase of the gas volume fraction from 95% to 99%, the average increase of the volumetric efficiency was about 14%. The temperature rise in the chambers at all levels and the temperature difference between the inlet and outlet of the decompression screw pump were lower than those of a traditional screw pump. The deformations at the three clearances were also less than those of a traditional screw pump, which helps to avoid jamming caused by thermal expansion.

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“…Radial leakage can be regarded as a throttling process through an orifice. It is calculated as follows 11 :…”

Section: Leakage Mathematical Modelmentioning

confidence: 99%

Optimal design and numerical analysis of multi-field coupling in a screw pump under wet gas compression

et al. 2022

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“…Yin investigated into the thermal deformation of screw pumps and its influence on volumetric efficiency adopting ANSYS. The results were used to investigate the clearance variation, which had much influence on the leakage of the multiphase pump 8 . Buckney researched on the local clearance deformation of screw machine at elevated discharge temperatures, creating the concept of “Rotor Boundary Map” with the help of non‐dimensional chamber model 9 .…”

Section: Introductionmentioning

confidence: 99%

A novel method for rotor profile optimization of high temperature screw expanders employed in waste heat recovery systems

et al. 2021

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High temperature expanders have always been employed in industrial waste heat recovery systems, where twin-screw expanders were frequently adopted.However, the significant thermal deformation of rotors contributes to much technical difficulty on the designation and manufacturing of high temperature twin-screw expanders. The profile should be optimized with consideration of its thermal deformation in high temperature working conditions. In this article, a novel method for twin-screw expander profile optimization is developed.The thermal deformation of rotors is considered with meshing pair rules and interlobe clearance presetting. Theoretical analysis on interlobe clearance is made any steam inlet temperature from 20 C to 400 C, while experimental facility was built to figure out its reliability at high temperature. The optimized profile proved the effectiveness of this method. The clearance decreases significantly, decreasing from 1.28 mm at the working temperature of 20 C to 0.16 mm at 400 C. The testing results illustrated that the significant thermal deformation of rotors causes much interlobe abrasion once the operating temperature reached 400 C. With clearance of 0.1 mm and the radius correction angle of 0.0758 , the screw expander was proved to be reliably working at 400 C.

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“…Moreover, the flow characteristics of the fluid in the pump and the process of cavitation formation were investigated under different speeds and discharge pressures [3,4]. The temperature and pressure distribution at multiple points of the progressive cavity pump was obtained experimentally and the effect of screw deformation on the leakage and volumetric efficiency of the progressive cavity pump was analyzed [5,6]. At the same time, the gas-liquid mixed transportation process of the twin-screw pump was simulated by the thermo-fluid-solid coupling method [7].…”

Section: Introductionmentioning

confidence: 99%

Characteristics of embedded triple screw pump based on thermal-fluid-structure coupling

Zhu¹,

Zhao²,

Hou³

et al. 2021

J. vibroeng.

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To accommodate special applications where installation space is limited and noise and vibration requirements are high, a new triple screw pump structure was proposed, which was integrated into a servo motor. The design optimizes the profile of the master and slave screws of the embedded triple screw pump. The temperature and pressure fields of the embedded triple screw pump, as well as the heat transfer and pressure distribution between the fluid in the pump and the screw, were investigated through a thermal-fluid-structure approach. The deformation and stresses of the screw were compared for three operating conditions: temperature loading, pressure loading, and thermal-fluid-structure coupling. The results show that the deformation and stresses in the screw tended to increase with increasing pressure and temperature and the pressure load caused more significant deformation and stresses in the screw than the temperature load. The screw deformation caused by pressure loading was found to be the main factor affecting the thermal-fluid-structure coupling. The screw deformation after coupling was smaller than the sum of the screw deformation caused by individual temperature and pressure loads, and the stress values were the same. The results indicate that the coupling action weakens the deformation and stresses in the master and slave screws.

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Numerical investigation on screw rotor deformation and influence on volumetric efficiency of the twin-screw multiphase pump

Cited by 20 publications

References 14 publications

Optimal design and numerical analysis of multi-field coupling in a screw pump under wet gas compression

Optimal design and numerical analysis of multi-field coupling in a screw pump under wet gas compression

A novel method for rotor profile optimization of high temperature screw expanders employed in waste heat recovery systems

Characteristics of embedded triple screw pump based on thermal-fluid-structure coupling

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