scholarly journals Research on Rotational Resistance Moment of Rotary Energy Recovery Device

2018 ◽  
Vol 53 ◽  
pp. 02001
Author(s):  
Ang GUO ◽  
Zuo-dong HUANG ◽  
Zai-ran DING ◽  
Yi SHI ◽  
Lei JIAO ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Rotation Speed ◽  
Structural Characteristics ◽  
Internal Flow ◽  
Operational Conditions ◽  
Clearance Flow ◽  
Resistance Moment ◽  
Changing Trend ◽  
Rotational Resistance ◽  
Rotation Resistance

The effects of operational conditions on the resistance moment of a rotary energy recovery device have been systematically investigated through the computational fluid dynamics in this paper. Based on the structural characteristics of the rotary energy recovery device, the hydro-static bearing was established on both sides of the rotor. Simulation results indicate that for the rotation resistance moment generated by the rotor internal flow path, the rotation speed is linearly positive with the rotational resistance moment. For the rotation resistance moment generated by the clearance flow, the rotation speed is also positively correlated with the rotational resistance moment. The circular clearance size is negatively correlated with the rotation resistance moment, and the endcover fluid film size is negatively correlated with the rotation resistance moment. The boundary speed between laminar flow and turbulent flow was found by comparing the changing trend of rotational resistance moment. The obtained relation between clearance, the speed of the rotor and resistance moment provides a simple way to predict the resistance moment of the device, which will be beneficial to design the energy-efficient rotary energy recovery device

Study on Expander-Auxiliary Compressor Unit Used in Refrigeration System

2011 ◽  
Vol 354-355 ◽  
pp. 811-818
Author(s):  
Tao He ◽  
Zhi Yuan Wang ◽  
Yu Qing Xue
Keyword(s):  
Energy Recovery ◽  
Rotation Speed ◽  
Cooling Capacity ◽  
Compressor Unit ◽  
Performance Parameters ◽  
Refrigeration System ◽  
Two Phase ◽  
Speed Up ◽  
Testing Condition ◽  
Auxiliary Unit

The throttling valve used in the refrigeration system always causes energy loss. In this paper, an energy recovery device in the refrigeration system which was composed of an expander-auxiliary compressor unit to replace the throttling valve was investigated. On the basis of thermodynamic analysis, two typical arrangements which the auxiliary compressor was connected to the main compressor of the refrigeration system were compared and the system performance parameters were discussed. A prototype of an expander-auxiliary unit was manufactured to observe the expander performance using R410A as refrigerant. The results showed the reliability of the unit working in the two-phase flow condition with the rotation speed up to 21020 rpm. And the maximum increases in the cooling capacity by 3.9% and COP by 3.2% could be obtained under the testing condition.

Study on Characteristics and Operating Parameters of Axial Rotating Hydrocyclone

2009 ◽  
Author(s):  
Yan Xu ◽  
Zunce Wang ◽  
Fengxia Lv ◽  
Sen Li
Keyword(s):  
Pressure Drop ◽  
Laboratory Experiments ◽  
Separation Efficiency ◽  
Rotation Speed ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Axial Rotation ◽  
Rotating Wall ◽  
Simulation Results

The axial rotation of the hydrocyclone affects its internal flow characteristics and separating effect directly, as some local applications require the static hydrocyclone rotates about its own axis. Based on CFD, velocity distribution in the axial rotating hydrocyclone is studied. It is shown that as the rotation speed increasing, the tangential velocity improves and its gradient reduces in free vortex region observably, while the radial velocity has an incremental trend in the section of the small cone. The laboratory experiments are carried out for the static hydrocyclone of disposal capacity of 4 m3/h at 100r/min ∼ 300r/min. The relationships among rotation speed, flowrate, pressure drop and separated efficiency are achieved, which agree well with the numerical simulation results. The results indicate that the disposal capacity of hydrocyclone subjected to the rotation wall can be more flexible than that with no-rotating wall, the scope of best disposal capacity gradually enlarges with the increase of rotation speed of wall. Appropriate rise of the rotation speed is favor of the separation efficiency at the steady flowrate, however the increase of the flowrate and rotation speed induces the growth of the hydrocyclone’s pressure drop correspondingly to some extent.

scholarly journals Resistance force pulsations of annular flow in the Couette-Taylor system with counter-rotating cylinders

2019 ◽  
Vol 196 ◽  
pp. 00045
Author(s):  
Nikolay Miskiv ◽  
Anatoly Serov ◽  
Aleksandr Nazarov ◽  
Valery Mamonov
Keyword(s):  
Reynolds Numbers ◽  
Mean Value ◽  
Working Fluid ◽  
Resistance Force ◽  
Taylor Vortices ◽  
Slit Flow ◽  
Ring Channel ◽  
Resistance Moment ◽  
Tension Sensor ◽  
Rotation Resistance

The paper presents the results of an experimental study of the Couette-Taylor flow fluctuations in a ring channel with oppositely rotating multicylinder rotors. Experiments were carried out using water-glycerine solutions as a working fluid. The rotation resistance moment and its pulsations were investigated, using the system for measuring the torque resistance of rotation of rotors, made in the form of a digital dynamometer based on a tension sensor. The investigations made it possible to establish that the classic dependence of the appearance of Taylor vortices is observed in the slit flow of a multicylinder system rotating oppositely. It was shown that in the range of Reynolds numbers Re = (100 – 500), pulsations of dissipative processes with variable frequency and amplitude up to 10% of the mean value of rotation resistance are observed.

Research on Floating Moment Balancing Mechanism of a Gear Pump's Asymmetric Floating Plate with a V-Shaped Groove

2013 ◽  
Vol 415 ◽  
pp. 555-558
Author(s):  
An Lin Wang ◽  
Xiao Lu Zhang ◽  
Xue Wen Shan ◽  
Wei Liu
Keyword(s):  
Flow Field ◽  
Structural Characteristics ◽  
Evaluation Criteria ◽  
Internal Flow ◽  
Experimental Tests ◽  
Gear Pump ◽  
Balance Performance ◽  
Floating Plate ◽  
Gear Pumps ◽  
Groove Structure

Symmetrical floating plate of the high pressure and large displacement gear pump in rated conditions is inability to achieve the floating moment balance. To solve this problem, a new balancing mechanism is presented in this paper, which is asymmetric with a V-shaped groove structure on its driven side, called asymmetric balancing mechanism. Compared with traditional symmetric balancing mechanism, the floating plate with asymmetric balancing mechanism the can the coupling problem between the gear shaft and gear inner flow field through its own asymmetrical structure, so that the gear pumps internal flow field was the symmetrical distribution. According to the structural characteristics of the floating plates, Parameterized moment model based on discrete feature points was established. Theoretical analysis and experimental tests show the result , when suffered floating moment as evaluation criteria, in rated conditions, compared with the traditional symmetrical balancing mechanism one, that the balance performance of the floating plate with V-shaped groove asymmetric balancing mechanism improve by 41.42%.

scholarly journals Effect of Rotational Speed on Performance of Mixed Flow Pump as Turbine

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jun Chen ◽  
Tao Dai ◽  
Qing Yang
Keyword(s):  
Energy Recovery ◽  
Theoretical Calculations ◽  
Flow Characteristics ◽  
Internal Flow ◽  
High Water ◽  
Mixed Flow ◽  
High Water Period ◽  
Shaft Power ◽  
Pumped Storage ◽  
Flow Pump

In order to research the flow characteristics of mixed flow pump as turbine (MF-PAT) with different rotation speeds, a hydraulic model of mixed flow pump was established based on a pumped storage power station. The k-ε turbulent model was used to simulate internal flow fields with three rotation speeds by SMPLEC algorithms. Subsequently, theoretical calculations and experiments were carried out to verify the precision of numerical simulation. The results showed that the rotation speed of MF-PAT has a significant impact on its performance. Both numerical calculations and experimental test presented that all efficiency curves consist of ascending and descending stages, while the shaft power and head increase nonlinearly from 1000 to 2000 r/min. When the MF-PAT  deviates from the rated environment, increase in speed is positive to the energy recovery efficiency in the high water period and negative in the dry season. This work could provide a reference for further study of MF-PAT.

scholarly journals Characteristics of Combined Motor of Separator Drive

2021 ◽  
Vol 2096 (1) ◽  
pp. 012094
Author(s):  
V A Kim ◽  
Ya M Kashin ◽  
L E Kopelevich
Keyword(s):  
Simulation Experiment ◽  
Rotation Speed ◽  
Supply Voltage ◽  
Electromagnetic Torque ◽  
Voltage Amplitude ◽  
Line Voltage ◽  
Resistance Moment ◽  
The Impact

Abstract The paper describes the characteristics of a combined motor of a separator drive. Simulation experiment provided the characteristics of a combined motor of a separator drive, which allow considering the impact of the line voltage parameters (the supply voltage amplitude and frequency) and the resistance moment created by the separated product on the electromagnetic torque of a combined motor of the separator drive and the rotation speed of the working body of the separator with a combined motor.

scholarly journals Numerical Simulation on the Influence of Rotating Speed on the Hydraulic Loss Characteristics of Desalination Energy Recovery Turbine

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Bing Qi ◽  
Desheng Zhang ◽  
Qi Zhang ◽  
Mengcheng Wang ◽  
Ibra Fall
Keyword(s):  
Flow Separation ◽  
Energy Recovery ◽  
Internal Flow ◽  
Leading Edge ◽  
Suction Side ◽  
Radial Pressure ◽  
Hydraulic Loss ◽  
Rotating Speed ◽  
The Impact ◽  
Loss Mechanisms

The performance of energy recovery turbine (ERT) directly determines the cost and energy consumption of reverse osmosis desalination. In order to study the performance and loss mechanisms of ERT under different conditions, the external characteristics and the losses of different components were quantitatively analyzed. The loss mechanisms of each component in the turbine were revealed through the comparative analysis of the internal flow field. The results show that the efficiency is 2.2% higher than that at the design speed when turbine runs at n = 22000 r/min. The impeller losses account for more than 67% of the total losses. The impeller loss is mainly observed at the leading edge. The vortex on the pressure side of the leading edge is caused by the impact effect, while the vortex on the suction side of the leading edge is caused by the flow separation. With the increase in the rotating speed, the loss caused by flow separation in impeller decreases obviously. The volute loss is mainly observed near the tongue, which is caused by the flow separation at the tongue. The design of the tongue is very important to the performance of the volute. The turbulent kinetic energy (TKE) and loss decrease with the increase in the rotating speed. The loss in the draft tube is mainly observed at the inlet core. With the increase in the rotating speed, the turbulence pulsation and the radial pressure fluctuation amplitude reduce. Therefore, the turbine can be operated at the design or slightly higher than the design rotating speed under the condition that both the hydraulic condition and the intensity are satisfied, which are conducive to the efficient utilization of energy.

A Detailed Loss Analysis Methodology for Centrifugal Compressors

2021 ◽  
Author(s):  
Luying Zhang ◽  
Loukia Kritioti ◽  
Peng Wang ◽  
Jiangnan Zhang ◽  
Mehrdad Zangeneh
Keyword(s):  
Flow Field ◽  
Evaluation Method ◽  
Deep Understanding ◽  
Internal Flow ◽  
Tip Clearance ◽  
Optimized Design ◽  
Centrifugal Compressors ◽  
Design Modification ◽  
Operational Conditions ◽  
The Impact

Abstract A deep understanding of loss mechanisms inside a turbomachine is crucial for the design and analysis work. By quantifying the various losses generated from different flow mechanisms, a targeted optimization can be carried out on the blading design. In this paper an evaluation method for computational fluid dynamics simulations has been developed to quantify the loss generation based on entropy production in the flow field. A breakdown of losses caused by different mechanisms (such as skin friction, secondary flow, tip clearance vortex and shock waves) is achieved by separating the flow field into different zones. Each zone is defined by the flow physics rather than by geometrical locations or empirical correlations, which makes the method a more general approach and applicable to different machine types. The method has been applied to both subsonic and transonic centrifugal compressors, where internal flow is complex due to the Coriolis acceleration and the curvature effect. An evaluation of loss decomposition is obtained at various operational conditions. The impact of design modification is also assessed by applying the same analysis to an optimized design.

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