scholarly journals The Flow-Heat Coupling Study of Cooling Circulating Channel of Magnetic Drive Pump

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 285-294
Author(s):  
Zhenjun GAO ◽  
Jianbo ZHANG ◽  
Wenyang LI ◽  
Jintao LIU ◽  
Changqing SI ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Centrifugal Pump ◽  
Permanent Magnets ◽  
Convection Heat Transfer ◽  
Stable Operation ◽  
Coefficient Distribution ◽  
Flow Heat ◽  
Magnetic Drive ◽  
Drive Pump ◽  
Bearing Friction

The medium in the cooling circulation channel of the magnetic drive centrifugal pump will take away the heat generated by the magnetic eddy current and bearing friction in time to avoid the high temperature demagnetization phenomenon of the permanent magnets. Therefore, the reasonable design of the cooling circulation channel directly affects the stable operation of the magnetic drive centrifugal pump. In this paper, the heat exchange and temperature distribution in the cooling circulating channel of magnetic drive pump are studied by means of numerical calculation of fluid-heat coupling and external characteristic test. The temperature distribution and development law of the isolation sleeve clearance, the bottom of the isolation sleeve and the reflow hole are analysed emphatically, and the convection heat transfer coefficient distribution in the isolation sleeve clearance is studied.

Electromagnetic performance and thermal analysis of a novel permanent magnet fluxed-switching coupler

2021 ◽  
pp. 1-18
Author(s):  
Lezhi Ye ◽  
Yulong Zhang ◽  
Mingguang Cao
Keyword(s):  
Temperature Distribution ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Load Condition ◽  
Maximum Load ◽  
Maximum Temperature ◽  
The Novel ◽  
Transient Field ◽  
Three Dimensional Finite Element

To solve the problem of complex operating device and permanent magnets (PMs) demagnetization at high temperature, a new type of permanent magnet fluxed-switching coupler (PMC) with synchronous rotating adjuster is proposed. Its torque can be adjusted by rotating a switched flux angle between the adjuster and PMs along the circumferential direction. The structural feature and working principle of the PMC are introduced. The analytical model of the novel PMC was established. The torque curves are calculated in transient field by using the three-dimensional finite element method (3-D FEM). The temperature distribution of the novel PMC under rated condition is calculated by 3-D FEM, and the temperature distribution of the PM is compared with that of the conventional PMC. The simulation and test results show that the maximum temperature of copper disc and PM of the novel PMC are 100 °C and 48 °C respectively. The novel PMC can work stably for a long time under the maximum load condition.

scholarly journals Catalytic Micro Gas Sensor with Excellent Homogeneous Temperature Distribution and Low Power Consumption for Long-Term Stable Operation

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 927 ◽  
Author(s):  
Anmona Shabnam Pranti ◽  
Daniel Loof ◽  
Sebastian Kunz ◽  
Marcus Bäumer ◽  
Walter Lang
Keyword(s):  
Temperature Distribution ◽  
Low Power ◽  
Gas Sensor ◽  
Gas Flow ◽  
Pt Nanoparticles ◽  
Stable Operation ◽  
Catalytic Layer ◽  
Micro Gas Sensor ◽  
Homogeneous Temperature

This paper presents a long-term stable thermoelectric micro gas sensor with ligand linked Pt nanoparticles as catalyst. The sensor design gives an excellent homogeneous temperature distribution over the catalytic layer, an important factor for long-term stability. The sensor consumes very low power, 18 mW at 100 °C heater temperature. Another thermoresistive sensor is also fabricated with same material for comparative analysis. The thermoelectric sensor gives better temperature homogeneity and consumes 23% less power than thermoresistive sensor for same average temperature on the membrane. The sensor shows linear characteristics with temperature change and has significantly high Seebeck coefficient of 6.5 mV/K. The output of the sensor remains completely constant under 15,000 ppm continuous H2 gas flow for 24 h. No degradation of sensor signal for 24 h indicates no deactivation of catalytic layer over the time. The sensor is tested with 3 different amount of catalyst at 2 different operating temperatures under 6000 ppm and 15,000 ppm continuous H2 gas flow for 4 h. Sensor output is completely stable for 3 different amount of catalyst.

Heat transfer from a rotating disk

1956 ◽  
Vol 236 (1206) ◽  
pp. 343-351 ◽  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Outer Part ◽  
Rotating Disk ◽  
Friction Torque ◽  
Practical Applications ◽  
A Value ◽  
Flow Heat

The flow due to a disk rotating in its own plane has been investigated theoretically by von Kármán, Goldstein, and others, but little has been published on the heat transfer. For laminar conditions theoretical solutions have been given by Millsaps & Pohlhausen and by Wagner, but for conditions when the flow is turbulent over the outer part of the disk there is no previous information. The present paper describes an experimental investigation of the heat transfer for a range of conditions from entirely laminar flow to conditions when the outer 80% of the disk area is under turbulence. For laminar flow the heat transfer agrees with Wagner’s results, but Millsap’s theory is found to give too low values and an explanation is given. For the turbulent case, which occurs in most practical applications, values are given for the heat transfer which is found to approach the expression N = 0∙015 R 0∙8 for all-turbulent flow. An attempt is made to deduce the turbulent flow heat transfer theoretically by assuming a 1/7 power law of temperature distribution, but this gives too low a value. Some measurements of the velocity and temperature profiles both for laminar and for turbulent conditions are given. For laminar flow these show fair agreement with the theoretical values. For turbulent flow the temperature ratios are higher than those of velocity, which explains the low heat transfer values calculated assuming a 1/7 power temperature distribution. The relation between heat transfer and friction torque is also discussed.

Transient Response of Cross Flow Heat Exchangers Subjected to Simultaneous Temperature and Flow Perturbations

2015 ◽  
Vol 799-800 ◽  
pp. 665-670
Author(s):  
Karthik Silaipillayarputhur
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Convection Heat Transfer ◽  
Cross Flow ◽  
Balance Equations ◽  
Transfer Resistance ◽  
Mass Flow Rates ◽  
Flow Heat ◽  
Transient Thermal ◽  
Central Finite Difference

This paper compares the transient thermal performance between counter and parallel cross flow heat exchangers subjected to time varying inlet mass flow rates and inlet temperatures that hasn’t been previously discussed in the available literature. Specifically the transient performance of 2 pass and 3 pass cross flow heat exchangers is discussed in this paper. In the present study the energy balance equations for the hot and cold fluids and the heat exchanger wall were solved using an implicit central finite difference method. Representative values of NTU were considered, and the NTU’s of the heat exchanger were assumed to be uniformly distributed among the heat exchanger passes. Other physically significant parameters such as the capacity rate ratio and the convection heat transfer resistance ratio were systematically varied. A detailed summary based on the observations has been presented.

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Centrifugal Pump Leak-Free Technology Introduction and Its Applications in EPR Nuclear Power Plant

2010 ◽  
Author(s):  
Guohui Cong ◽  
Ling Zhang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Centrifugal Pump ◽  
Nuclear Power ◽  
Operating Conditions ◽  
Critical Conditions ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Canned Motor ◽  
Magnetic Drive

Environmental protection requirement is more and more critical now, and it increases the request to prevent dangerous liquid to leak outside in nuclear power plant too. Centrifugal pumps are the most important active equipments in nuclear power plant, but there is a shaft clearance between rotor and stator of centrifugal pump. The shaft clearance can lead pumped fluid to the outside, so the environment may be polluted by the leakage. In some critical conditions such as transferring high radioactive fluid in the pump, the leakage shall be totally forbidden. So solutions have to be found to make centrifugal pumps totally leak-free for applications in nuclear power plant. Normally there are three leak-free technologies for centrifugal pumps: mechanical seal with auxiliary system, canned motor and magnetic drive. In this paper, all the three leak-free technologies and some of their applications in EPR 3rd generation PWR nuclear power plants are presented and discussed. The results show that in EPR nuclear power plant, canned motor pumps can be preferably used for strict environmental requirement of leak-free if the pump power and operating conditions are applicable. For other conditions, pumps with double mechanical seal can also be used with additional sealing water system support. For centrifugal pumps with magnetic drive are not so applicable in high pressure condition, and the safety aspect is weaker than canned motor pumps, generally they are not used in EPR nuclear power plant at present.

scholarly journals The Study on Internal Flow Characteristics of Magnetic Drive Pump

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 100003-100013 ◽  
Author(s):  
Gao Zhenjun ◽  
Hu Chaoqun ◽  
Liu Jianrui ◽  
Su Huashan
Keyword(s):  
Flow Characteristics ◽  
Internal Flow ◽  
Magnetic Drive ◽  
Drive Pump

scholarly journals Two-Dimensional Analytical Solution of the Laminar Forced Convection in a Circular Duct with Periodic Boundary Condition

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. R. Astaraki ◽  
N. Ghiasi Tabari
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Periodic Function ◽  
Forced Convection ◽  
Solid Wall ◽  
Convection Heat Transfer ◽  
Axial Direction ◽  
Energy Balance Equation ◽  
Circular Duct

In the present study analytical solution for forced convection heat transfer in a circular duct with a special boundary condition has been presented, because the external wall temperature is a periodic function of axial direction. Local energy balance equation is written with reference to the fully developed regime. Also governing equations are two-dimensionally solved, and the effect of duct wall thickness has been considered. The temperature distribution of fluid and solid phases is assumed as a periodic function of axial direction and finally temperature distribution in the flow field, solid wall, and local Nusselt number, is obtained analytically.

Transient Thermal Response of a Rotating Cylindrical Silicon Nitride Workpiece Subjected to a Translating Laser Heat Source, Part II: Parametric Effects and Assessment of a Simplified Model

1998 ◽  
Vol 120 (4) ◽  
pp. 907-915 ◽  
Author(s):  
J. C. Rozzi ◽  
F. P. Incropera ◽  
Y. C. Shin
Keyword(s):  
Temperature Distribution ◽  
Convection Heat Transfer ◽  
Surface Region ◽  
Ambient Air ◽  
Laser Source ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Beam Diameter ◽  
Radial Temperature ◽  
Near Surface

In a companion paper (Rozzi et al., 1998), experimental validation was provided for a transient three-dimensional numerical model of the process by which a rotating workpiece is heated with a translating laser beam. In this paper, the model is used to elucidate the effect of operating parameters on thermal conditions within the workpiece and to assess the applicability of an approximate analysis which is better suited for on-line process control. From detailed numerical simulations, it was determined that the thickness of a surface thermal layer decreases with increasing workpiece rotational speed and that the influence of axial conduction on the workpiece temperature distribution increases with decreasing laser translational velocity. Temperatures increase throughout the workpiece with increasing laser power, while the influence of increasing beam diameter is confined to decreasing near-surface temperatures. Temperature-dependent thermophysical properties and forced convection heat transfer to the laser gas assist jet were found to significantly influence the maximum temperature beneath the laser spot, while radiation exchange with the surroundings and mixed convection to the ambient air were negligible. The approximate model yielded relations for calculating the radial temperature distribution within an r-φ plane corresponding to the center of the laser source, and predictions were in reasonable agreement with results of the numerical simulation, particularly in a near-surface region corresponding to the depth of cut expected for laser-assisted machining.

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