scholarly journals Optimization of Ventilation Spacer for Direct-Drive Permanent Magnet Wind Generator

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1430 ◽  
Author(s):  
Xiang Zhao ◽  
Yu Fan ◽  
Weili Li ◽  
Dong Li ◽  
Junci Cao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Permanent Magnet ◽  
Heat Transfer Process ◽  
Calculation Model ◽  
Direct Drive ◽  
Thermal Fields ◽  
Wind Generator ◽  
Flow And Heat Transfer ◽  
Thermal Calculations ◽  
Heat Transfer Capacity

As the rated capacity of the Direct-Drive Permanent Magnet Wind Generator (DDPMWG) increases, the heat produced from the generator’s inner components also increases and it becomes difficult to transfer the inner heat to the ambient. The ventilation spacer has a significant influence on the heat transfer process of DDPMWG. Thus, this paper focuses on the optimization of the ventilation spacer on the thermal field of DDPMWG. Firstly, the fluid flow and heat transfer coupled numerical calculation model is established. The physical model, composed of two half-slots and one tooth of DDPMWG, is established due to the structural symmetries to save the calculations. The sources and boundary conditions for the thermal calculations are also given. Five new ventilation spacers, compared with the original one, are proposed to investigate the thermal fields. The pressure drop and temperature field are compared to find the optimized ventilation spacer for the DDPMWG. The criteria are also presented for judging the heat transfer capacity. To validate the optimized ventilation spacer, the temperature rises of the armature winding with original and optimized ventilation spacers are measured. It proves that the armature winding’s temperature rise of the optimized ventilation spacer is about 4.7 K lower than that with the original ventilation spacer.

Develop artificial neural network numerical modeling to study fluid flow and heat transfer of dispersed nanoparticles through base liquid

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tawfeeq Abdullah Alkanhal
Keyword(s):  
Heat Transfer ◽  
Hybrid Nanofluid ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Flow And Heat Transfer ◽  
Heat Transfer Capacity ◽  
The Cost ◽  
Heat Transfers ◽  
Base Liquid

Purpose This paper aims to disperse the silicon dioxide in water (as the mono nanofluid [MN]) and then, carbon nanotube (CNT)-silica composite in water (as the hybrid nanofluid [HN]). Design/methodology/approach Nanofluids have gained lots of attention through the recent years. Due to their usage in the industries and also medical applications, they have high protentional to be studied in different aspects. The most common study for the nanofluids is to understand the heat transfer capacity for each material in each fluid. These material(s) or fluid(s) can be one (mono nanofluid) or more than one (hybrid nanofluid). Findings The mixture of two solids is to assess the unique properties of each material and also to decrease the cost of experiments. The heat transfers for both MN and HN were measured at volume fractions up to 1.0%, and temperatures up to 50°C. Also, the heat transfers were compared. By more CNT, thermal conductivity was enhanced about 17.39% (from 12.42% of MN to 29.81% of HN). Originality/value X-Ray diffraction and field emission scanning electron microscope (FESEM) were examined for mono solids and the composite. After the experimental study, for MN and HN, four novel correlations calculated.

The Research on Direct Drive Permanent Magnet Synchronous Wind Generator Vector Control

2012 ◽  
Vol 512-515 ◽  
pp. 798-802
Author(s):  
Jia Ying Zhang ◽  
Li Ping Zhang
Keyword(s):  
Wind Turbine ◽  
Vector Control ◽  
Permanent Magnet ◽  
Control Strategy ◽  
High Efficiency ◽  
Synchronous Generator ◽  
Direct Drive ◽  
Operating Characteristics ◽  
Permanent Magnet Synchronous Generator ◽  
Wind Generator

Direct drive permanent magnet synchronous generator have the advantages of direct drive, simple structure, high efficiency and so on, in which make it become one of mainstream models within MW wind turbine presently. Making the direct drive permanent magnet wind power generation system as the main research object, based on the principle of the operating characteristics of direct drive permanent magnet synchronous wind generator ( DDPMG ), establish mathematical model of the whole system including wind turbine, direct drive permanent magnet synchronous generator and machine side converter, applying the method of stator flux orientation to make the study of vector control strategy, to build the simulation model of direct drive permanent magnet synchronous generator system with Matlab to simulate the operation of generator when wind speed changes by step, the results validate the reasonableness of the model and the correctness and feasibility of the control strategy.

Direct Drive Permanent Magnet Synchronous Wind Generator Maximum Power Tracking Control

2013 ◽  
Vol 724-725 ◽  
pp. 459-462
Author(s):  
Jia Ying Zhang ◽  
Li Ping Zhang ◽  
Gui Ling Xiao
Keyword(s):  
Wind Turbine ◽  
Permanent Magnet ◽  
Control Strategy ◽  
High Efficiency ◽  
Synchronous Generator ◽  
Direct Drive ◽  
Operating Characteristics ◽  
Permanent Magnet Synchronous Generator ◽  
Generator System ◽  
Wind Generator

Direct drive permanent magnet synchronous generator have the advantages of direct drive, simple structure, high efficiency and so on, in which make it become one of mainstream models within MW wind turbine presently. Making the direct drive permanent magnet wind power generation system as the main research object, based on the principle of the operating characteristics of direct drive permanent magnet synchronous wind generator ( DDPMG ), establish mathematical model of the whole system including wind velocity, wind turbine, direct drive permanent magnet synchronous generator and machine side converter, Appling the method of stator flux orientation to make the study of vector control strategy, to build the simulation model of direct drive permanent magnet synchronous generator system with Matlab and simulate when wind speed changes by step, the results validate the reasonableness of the model and the correctness and feasibility of the control strategy.

Transient Leading to Periodic Fluid Flow and Heat Transfer in a Differentially-Heated Cavity Due to an Insulated Rotating Object

2007 ◽  
Author(s):  
Y.-C. Shih ◽  
J. M. Khodadadi ◽  
K.-H. Weng ◽  
H. F. Oztop
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Convection Heat Transfer ◽  
Reynolds Numbers ◽  
High Heat ◽  
Thermal Fields ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
Transient Variations ◽  
Rotating Objects

Computational analysis of transient phenomenon followed by the periodic state of laminar flow and heat transfer due to an insulated rotating object in a square cavity is investigated. A finite-volume-based computational methodology utilizing primitive variables is used. Various rotating objects (circle, square and equilateral triangle) with different sizes are placed in the middle of the cavity. A combination of a fixed computational grid with a sliding mesh was utilized for the square and triangle shapes. The cavity is maintained as a differentially-heated enclosure and the motionless insulated object is set in rotation at time t = 0. Natural convection heat transfer is neglected. For a given shape of the object and a constant angular velocity, a range of rotating Reynolds numbers are covered for a Pr = 5 fluid. The Reynolds numbers were selected so that the flow fields are not generally affected by the Taylor instabilities (Ta < 1750). The evolving flow field and the interaction of the rotating objects with the recirculating vortices at the four corners are elucidated. The corresponding thermal fields in relation to the evolving flow patterns and the skewness of the temperature contours in comparison to conduction-only case were discussed. The skewness is observed to become more marked as the Reynolds number is lowered. At the same time, similarity of the thermal fields for various shapes for the same Reynolds number varifies the appropriate selection of the hydraulic diameter. Transient variations of the average Nusselt numbers on the two walls show that for high Re numbers, a quasi-periodic behavior due to the onset of the Taylor instabilities is dominant, whereas for low Re numbers, periodicity of the system is clearly observed. Time-integrated average Nusselt number of the cavity is correlated to the rotational Reynolds number and shape of the object. The triangle object clearly gives rise to high heat transfer followed by the square and circle objects.

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