Isolation performance of a small modular reactor using 1D periodic foundation

2021 ◽  
Vol 244 ◽  
pp. 112825
Author(s):  
Chunfeng Zhao ◽  
Chao Zeng ◽  
Witarto Witarto ◽  
Hsuan wen Huang ◽  
Junwu Dai ◽  
...  
Keyword(s):  
Small Modular Reactor ◽  
Isolation Performance

An hourglass-type electromagnetic isolator with negative resistance electromagnetic shunt circuit

2020 ◽  
Vol 64 (1-4) ◽  
pp. 549-556
Author(s):  
Yajun Luo ◽  
Linwei Ji ◽  
Yahong Zhang ◽  
Minglong Xu ◽  
Xinong Zhang
Keyword(s):  
Vibration Isolation ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Negative Resistance ◽  
Isolation System ◽  
Amplitude Vibration ◽  
Vibration Responses ◽  
The Stability ◽  
Isolation Performance ◽  
Shunt Circuit

The present work proposed an hourglass-type electromagnetic isolator with negative resistance (NR) shunt circuit to achieve the effective suppression of the micro-amplitude vibration response in various advanced instruments and equipment. By innovatively design of combining the displacement amplifier and the NR electromagnetic shunt circuit, the current new type of vibration isolator not only can effectively solve the problem of micro-amplitude vibration control, but also has significant electromechanical coupling effect, to obtain excellent vibration isolation performance. The design of the isolator and motion relationship is presented firstly. The electromechanical coupling dynamic model of the isolator is also given. Moreover, the optimal design of the NR electromagnetic shunt circuit and the stability analysis of the vibration isolation system are carried out. Finally, the simulation results about the transfer function and vibration responses demonstrated that the isolator has a significant isolation performance.

Beneficial performance of a quasi-zero stiffness vibration isolator with generalized geometric nonlinear damping

2020 ◽  
pp. 095745652097238
Author(s):  
Chun Cheng ◽  
Ran Ma ◽  
Yan Hu
Keyword(s):  
Damping Ratio ◽  
Nonlinear Damping ◽  
Vibration Isolator ◽  
Equivalent Damping ◽  
Frequency Responses ◽  
Geometric Nonlinear ◽  
Resonant Region ◽  
Force Transmissibility ◽  
Isolation Performance ◽  
Force And Displacement Transmissibility

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

Isolation Performance of Intelligent Seismic Isolation System Using Air Bearing

2009 ◽  
Author(s):  
Satoshi Fujita ◽  
Keisuke Minagawa ◽  
Mitsuru Miyazaki ◽  
Go Tanaka ◽  
Toshio Omi ◽  
...  
Keyword(s):  
Seismic Isolation ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Vertical Motion ◽  
Air Bearings ◽  
Natural Period ◽  
Isolation System ◽  
Vertical Excitation ◽  
Long Period ◽  
Isolation Performance

This paper describes three-dimensional isolation performance of seismic isolation system using air bearings. Long period seismic waves having predominant period of from a few seconds to a few ten seconds have recently been observed in various earthquakes. Also resonances of high-rise buildings and sloshing of petroleum tanks in consequence of long period seismic waves have been reported. Therefore the isolation systems having very long natural period or no natural period are required. In a previous paper [1], we proposed an isolation system having no natural period by using air bearings. Additionally we have already reported an introduction of the system, and have investigated horizontal motion during earthquake in the previous paper. It was confirmed by horizontal vibration experiment and simulation in the previous paper that the proposed system had good performance of isolation. However vertical motion should be investigated, because vertical motion varies horizontal frictional force. Therefore this paper describes investigation regarding vertical motion of the proposed system by experiment. At first, a vertical excitation test of the system is carried out so as to investigate vertical dynamic property. Then a three-dimensional vibration test using seismic waves is carried out so as to investigate performance of isolation against three-dimensional seismic waves.

Feasibility of full-core pin resolved CFD simulations of small modular reactor with momentum sources

2021 ◽  
Vol 378 ◽  
pp. 111143
Author(s):  
Jun Fang ◽  
Dillon R. Shaver ◽  
Ananias Tomboulides ◽  
Misun Min ◽  
Paul Fischer ◽  
...  
Keyword(s):  
Cfd Simulations ◽  
Small Modular Reactor ◽  
Full Core

Research on debris in-vessel cooling and retention behavior for the small modular reactor ACP100

2021 ◽  
Vol 134 ◽  
pp. 103641
Author(s):  
Qingan Xiang ◽  
Jian Deng ◽  
Juan Du ◽  
Jinsheng Bi ◽  
Baowen Chen ◽  
...  
Keyword(s):  
Retention Behavior ◽  
Small Modular Reactor

Analysis of the natural circulation flow map uncertainties in an integral small modular reactor

2021 ◽  
Vol 378 ◽  
pp. 111156
Author(s):  
Seyed Ali Hosseini ◽  
Reza Akbari ◽  
Amir Saeed Shirani ◽  
Francesco D'Auria
Keyword(s):  
Natural Circulation ◽  
Circulation Flow ◽  
Small Modular Reactor ◽  
Flow Map

Study on Typical Initial Event of ATWS for Small Modular Reactor

2016 ◽  
Author(s):  
Zhang Dan ◽  
Ran Xu ◽  
Qiu Zhifang ◽  
Zhou Ke ◽  
Feng Li
Keyword(s):  
Optimum Design ◽  
Safety Analysis ◽  
Accident Analysis ◽  
Pressurized Water ◽  
Control Rod ◽  
Reactor Coolant ◽  
Initial Event ◽  
Small Modular Reactor ◽  
Activation System

The method for ATWS (anticipated transient without scram) analysis was completely developed for commercial pressurized water (PWR) reactor plants, especially for selecting of typical initial events. For accident analysis of ATWS, it is different between PWR and small modular reactor (SMR), as different structures and characters, and it is necessary to study the typical initial events for these reactors. Based on the standard of PWR, the demanding for ATWS analysis was studied and the consequences for typical anticipated transient was calculated using RELAP5/MOD3.2 code, “maintain reactor coolant pressure boundary integrity” was selected as limiting criterion. The results shows for SMR, anticipated transient with the most serious consequence for ATWS are loss of offsite power and inadvertent control rod withdraw event, this conclusion will support to prepare the safety analysis report and optimum design of diversity activation system (DAS) for SMR.

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