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Modeling and Optimization of Shell and Tube Heat Exchanger in Treatment Unit of South Pars Fifth Refinery by Fluent Software
Kazem Moaveni,
Mehran Zarkesh
Issue:
Volume 2, Issue 4, July 2017
Pages:
150-161
Received:
11 April 2017
Accepted:
21 April 2017
Published:
4 July 2017
Abstract: In this thesis, the numerical solution of navier stockes equations and turbulent equations have also been investigated in fluent software, to investigate baffle type change from cut off to helical in shell and tube heat exchanger. RNG K-ε turbulence model was used to perturbations modelling. The main objective of baffle changing in thesis is increasing propane temperature in pipes outlet. 4 heat exchanger type with different helical angles (35, 40, 45 and 50) compared with simple baffle type. Studies indicate that heat exchanger with helical angle of 50°, maximum outlet temperature of propane will result and have the maximum heat transfer rate in shell. Exchangers with helical angle of 40 degrees have the highest ratio h / Δp, which reflects the heat transfer rate to pressure drop ratio.
Abstract: In this thesis, the numerical solution of navier stockes equations and turbulent equations have also been investigated in fluent software, to investigate baffle type change from cut off to helical in shell and tube heat exchanger. RNG K-ε turbulence model was used to perturbations modelling. The main objective of baffle changing in thesis is increa...
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Optimization of Heat Recovery for Shell & Tube Exchangers in Sulphur Granulation Unit of South Pars Fifth Refinery by Software, ASPEN B-JAC
Kazem Moaveni,
Mehran Zarkesh
Issue:
Volume 2, Issue 4, July 2017
Pages:
162-173
Received:
28 April 2017
Accepted:
6 May 2017
Published:
5 July 2017
Abstract: Shell and tube heat exchangers are the most important tools in heat transfer process. Optimization efficiency of these tools is always the goal of designers. Now a day there are a lot of efficient methods for selecting the best heat exchanger, such as analytic and numerical methods that everyone has advantages and defects. For example, confront of jamming in calculations by receiving to the local minimums and errors during interruption quantities. Today by entering of simulation and design softwares in industries, the simulation of process tools is so simple. the procedure of studies in this thesis is in these steps: first simulation of sulfur solidification heat exchangers in ASPEN B-JAC software same as operation conditions and then evaluation the effects of changing the design parameters in tube bundle section such as number of passes, arrangement of tubes, number of baffles,…. the sulfur solidification package’ heat exchanger that it’s active fluid is demine water for cooling of package will be optimized till the rate of exchanged heat increases to 15 percent and pressure drop will not affect the operation conditions. The most important note in the correction of tube bundle is that the heat exchanger should be out of service and stopping of production, on the other hand changing in shell of heat exchanger needs to change the piping system and redesign of supports that will spend a lot of time for shut down of plant, so it is out of order for this thesis and optimization of tube bundle will be done.
Abstract: Shell and tube heat exchangers are the most important tools in heat transfer process. Optimization efficiency of these tools is always the goal of designers. Now a day there are a lot of efficient methods for selecting the best heat exchanger, such as analytic and numerical methods that everyone has advantages and defects. For example, confront of ...
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Dynamic Analysis of Flexible-Link Planar Parallel Manipulator with Platform Rigidity Considerations
K. V. Varalakshmi,
J. Srinivas
Issue:
Volume 2, Issue 4, July 2017
Pages:
174-188
Received:
31 October 2016
Accepted:
13 May 2017
Published:
6 July 2017
Abstract: This paper presents dynamic analysis studies of planar parallel flexible 3-RRR manipulator with and without considering the flexibility of mobile platform. Initially, by treating all the members of the manipulator as flexible, the joint displacements, reaction forces and stresses are obtained during a specified trajectory tracking in Cartesian space. A comparative study is conducted with manipulator configuration having rigid mobile platform using coupled dynamics of limbs and kinematic constraints of mobile platform. Dynamic response of flexible manipulator is validated using ANSYS simulations for two different cases of trajectories. The results show a remarkable effect of flexibility of mobile platform on the overall dynamic response. After validation of the model, the inverse dynamic analysis data is used to create the system dynamics by employing generalized regression neural network (GRNN) model and the forward dynamic solutions of the flexible manipulator are predicted instantaneously. This study is useful for the real time implementation of motion control of flexible manipulators with complex dynamic model of manipulators.
Abstract: This paper presents dynamic analysis studies of planar parallel flexible 3-RRR manipulator with and without considering the flexibility of mobile platform. Initially, by treating all the members of the manipulator as flexible, the joint displacements, reaction forces and stresses are obtained during a specified trajectory tracking in Cartesian spac...
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Nd-rich Effects on Structural and MagneticProperties of Nd2Fe14B Magnets
Syahrul Humaidi,
Achiruddin,
Kurnia Sembiring,
Hanifah,
Nenen Rusnaeni,
Muljadi
Issue:
Volume 2, Issue 4, July 2017
Pages:
189-193
Received:
9 April 2017
Accepted:
12 June 2017
Published:
17 July 2017
Abstract: Hard magnetic material Nd2Fe14B was synthesized via powder metallurgy technique. The magnetic powder Nd2Fe14B was produced by mixing Neodymium powder (Nd), Iron powder (Fe), and Boron powder (B) in a vacuum and then followed by firing process at 720ºC. The Nd2Fe14B powder produced was grained with addition of 0.3g and 0.7g Neodymium respectively. The powder was sintered at 720ºC. The characterization of magnetic properties by using VSM and phase analyse using XRD. SC-70 was used as detector with 40 kV and 30 mA (CuKα/1.5418Ao). The scan range was 10o-90o with a speed of 2 deg/min. The crystal structure of the samples were determined based on data obtained from XRD pattern. The tetragonal crystal structure of Nd2Fe14B was confirmed with lattice parameters ‘a’ = ‘b’ = 8.707Å and ‘c’ = 12.203Å. The result showed that remanence magnetization (Mr). The maximum energy product (BH) max of Nd2Fe14B was increased from 8,56 KGOe to 16,59 KGOe with adddition of 0,3g Nd. The BHmax reached 17,83KGOe when 0,7g Nd-rich was introduced.
Abstract: Hard magnetic material Nd2Fe14B was synthesized via powder metallurgy technique. The magnetic powder Nd2Fe14B was produced by mixing Neodymium powder (Nd), Iron powder (Fe), and Boron powder (B) in a vacuum and then followed by firing process at 720ºC. The Nd2Fe14B powder produced was grained with addition of 0.3g and 0.7g Neodymium respectively. T...
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