FEA Based Methodology to Optimize Sealing Performance in Fuel Vapor Emission Valves

2021 ◽  
Author(s):  
Mayur Pote ◽  
Anushri Pethe ◽  
James Ostrosky ◽  
Sanjay Mohite
Author(s):  
Dibo Pan ◽  
Haijun Xu ◽  
Bolong Liu ◽  
Congnan Yang

The sealing characteristics of an annular power cylinder based on the Twin-rotor piston engine are studied, which provides a theoretical foundation for the sealing design of a new high-power density piston engine. In this paper, the basis thermodynamic realization process of an annular power cylinder is presented. The Runge Kutta equation is used to establish the coupled leakage model of adjacent working chambers under annular piston seal. And the sealing performance of the annular power cylinder is analyzed in detail. Moreover, the influence of rotor speed and compression ratio on the sealing characteristics and leakage is studied. Finally, some tests are carried out to verify the sealing principle and simulation results, which verifies the theoretical basis of simulation analysis. Results show that there are double pressure peaks in the leakage chamber between two working chambers, which is beneficial to reduce the leakage rate. Besides, increasing the speed and decreasing the compression ratio can help to reduce gas leakage. Furthermore, the effects of speed variation on the leakage are only significant when rotating at low speed. Changing the compression ratio has a greater effect on the slope of the leakage curve at a low compression ratio, and the lower the compression ratio, the better the sealing effect.


Author(s):  
Minghao Yi ◽  
Liang Wang ◽  
Congmeng Hao ◽  
Qingquan Liu ◽  
Zhenyang Wang

AbstractThe purpose of underground methane drainage technology is to prevent methane disasters and enable the efficient use of coal mine methane (CMM), and the sealing depth is a key factor that affects the performance of underground methane drainage. In this work, the layouts of in-seam and crossing boreholes are considered to analyze the stress distribution and failure characteristics of roadway surrounding rock through a numerical simulation and field stress investigation to determine a reasonable sealing depth. The results show that the depths of the plastic and elastic zones in two experimental coal mines are 16 and 20 m respectively. Borehole sealing minimizes the air leakage through the fractures around the roadway when the sealing material covers the failure and plastic zones, and the field test results for CMM drainage at different sealing depths indicate that the CMM drainage efficiency increases with increasing sealing depth but does not change once the sealing depth exceeds the plastic zone. Moreover, sealing in the high-permeability roadway surrounding rock does not have a strong influence on the borehole sealing performance. Considering these findings, a new CMM drainage system for key sealing in the low-permeability zone was developed that is effective for improving the CMM drainage efficiency and prolonging the high-concentration CMM drainage period. The proposed approach offers a valuable quantitative analysis method for selecting the optimum sealing parameters for underground methane drainage, thereby improving considerably the drainage and utilization rates of CMM.


2021 ◽  
Vol 714 (3) ◽  
pp. 032080
Author(s):  
Wei Tan ◽  
Jinya Xu ◽  
Xin Zhou ◽  
Wenfei Deng ◽  
Xiaoming Yu ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2153
Author(s):  
Tengfei Zhang ◽  
Jie Su ◽  
Yuanjie Shu ◽  
Fei Shen ◽  
Liaoliang Ke

Rubbers are widely used in various fields as the important sealing materials, such as window seal, door seal, valve, pump seal, etc. The fretting wear behavior of rubbers has an important effect on their sealing performance. This paper presents an experimental study on the fretting wear behavior of rubbers against the steel ball under air conditions (room temperature at 20 ± 2 °C and humidity at 40%). Three kinds of rubbers, including EPDM (ethylene propylene diene monomer), FPM (fluororubber), and NBR (nitrile–butadiene rubber), are considered in experiments. The sphere-on-flat contact pattern is used as the contact model. The influences of the displacement amplitude, normal force, frequency, and rubber hardness on the fretting wear behavior are discussed in detail. White light profiler and scanning electron microscope (SEM) are used to analyze the wear mechanism of the rubber surface. The fretting wear performances of three rubbers are compared by considering the effect of the displacement amplitude, normal force, frequency, and rubber hardness. The results show that NBR has the most stable friction coefficient and the best wear resistance among the three rubbers.


Author(s):  
Hao Qian ◽  
Li Yiguo ◽  
Peng Dan ◽  
Wu Xiaobo ◽  
Lu Jin ◽  
...  

In order to solve the problem that the current unloading operation will destroy the sealing performance of Miniature Neutron Source Reactor (MNSR) reactor vessel and the tightness can’t be restored, and to meet the application requirements that the original reactor vessel will be reloaded and operated after MNSR LEU conversion, the new unloading device is designed, which can be used without separation of reactor vessel. There has only one fuel assembly in MNSR. When the fuel assembly are unload for MNSR LEU conversion, the cover plate of the pool is removed, the cadmium string is put in, and the neutron detector is placed at first. After removing the drive mechanism and the control rod, and opening the small cover plate at the top of reactor vessel, the fuel assembly can be grabbed and unloaded by unloading tool only through the opening of the small top cover plate. The MNSR spent fuel has very high radioactivity. The auxiliary mechanical device can be used with unloading tools to realize operation in a long distance by lifting and level motion, which is convenient to shield and can reduce the works’ irradiation dose level effectively. Through calculation and analysis, the results show that the structure strength of unloading device is much larger than the actual load to ensure operation safety and reliability. The unloading device is easy to process and operate, and can be used in the practical operation of MNSR LEU conversion or decommissioning at home and abroad to simplify the operation steps and improve the working efficiency.


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