Enhancing Film Stiffness of Spiral Groove Dry Gas Seal via Shape Modification at Low Speed: Numerical Results and Experiment

2019 ◽  
Vol 62 (6) ◽  
pp. 931-942 ◽  
Author(s):  
Jinbo Jiang ◽  
Xudong Peng ◽  
Cong Zong ◽  
Wenjing Zhao ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Numerical Results ◽  
Spiral Groove ◽  
Shape Modification ◽  
Low Speed ◽  
Dry Gas Seal ◽  
Film Stiffness

Performance Analyses of the Spiral Groove Dry Gas Seal with Inner Annular Groove

2013 ◽  
Vol 420 ◽  
pp. 51-55 ◽  
Author(s):  
Ying Li ◽  
Peng Yun Song ◽  
Heng Jie Xu
Keyword(s):  
Pressure Control ◽  
Operating Conditions ◽  
Performance Parameters ◽  
Spiral Groove ◽  
Dry Gas Seal ◽  
Sealing Performance ◽  
The Common ◽  
The Difference ◽  
Film Stiffness ◽  
The Given

In order to improve the performance of the spiral groove dry gas seal (S-DGS), the spiral groove dry gas seal with an inner annular groove (AS-DGS) was invented. Based on the narrow groove theory, the sealing performance parameters of the AS-DGS were gained by using approximate analytical method to solve the gas film pressure control equations, and the results were compared with those of the common S-DGS. The results show that, in the given operating conditions, the opening force of AS-DGS is smaller than that of the S-DGS with the difference less than 0.5%, and the film stiffness is larger than that of the common S-DGS with the difference less than 5% in the case of low-speed or high-pressure operation, but the leakage is a little larger.

The influence of 3-DOF film thickness disturbance on transient performance of typical spiral groove dry gas seals

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuan Chen ◽  
Hao Shang ◽  
Xiaolu Li ◽  
Yuntang Li ◽  
Bingqing Wang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Degrees Of Freedom ◽  
Thickness Distribution ◽  
Transient Performance ◽  
Spiral Groove ◽  
Double Row ◽  
Content Type ◽  
Dry Gas Seal ◽  
Sealing Performance ◽  
Gas Seals

Purpose The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS). Design/methodology/approach The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed. Findings The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance. Originality/value The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

The performance of spiral groove dry gas seal under choked flow condition considering the real gas effect

2019 ◽  
Vol 234 (4) ◽  
pp. 554-566
Author(s):  
Hengjie Xu ◽  
Pengyun Song ◽  
Wenyuan Mao ◽  
Qiangguo Deng
Keyword(s):  
Carbon Dioxide ◽  
Flow Condition ◽  
Ideal Gas ◽  
Leakage Rate ◽  
Spiral Groove ◽  
Real Gas ◽  
Dry Gas Seal ◽  
Choked Flow ◽  
Real Gas Effect ◽  
Gas Effect

By taking carbon dioxide and hydrogen as lubricating gas, respectively, this paper presents an analysis on the pressure characteristics and temperature distribution of spiral groove dry gas seal which influenced by real gas effect under choked flow condition. Numerical results show that the deviation between real gas and ideal gas, which expressed by the deviation degree between compressibility factor Z and 1, is the main reason for real gas effect affecting sealing performance. Compared with ideal gas model, real gas effect raises exit pressure, opening force, leakage rate, Mach number in dam region, and temperature for carbon dioxide ( Z < 1), while it decreases those characteristics for hydrogen ( Z > 1) under the same operating conditions. In addition, choked flow effect increases opening force and reduces leakage rate and temperature-drop between entrance and exit of sealing clearance. Meanwhile, it may cause an unstable behavior for the seal.

Dynamic coupling correlation of gas film in dry gas seal with spiral groove

2014 ◽  
Vol 27 (4) ◽  
pp. 853-859 ◽  
Author(s):  
Zhengxian Liu ◽  
Musu Wang ◽  
Yue Zhou ◽  
Ningning Wu
Keyword(s):  
Dynamic Coupling ◽  
Spiral Groove ◽  
Dry Gas Seal ◽  
Coupling Correlation

Performance of Externally Pressurized Dry Gas Seal

2011 ◽  
Vol 335-336 ◽  
pp. 610-614 ◽  
Author(s):  
Wei Bing Zhu ◽  
Sheng Ren Zhou ◽  
He Shun Wang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Reynolds Equation ◽  
Dry Gas Seal ◽  
Supply Pressure ◽  
Lubrication Equation ◽  
Air Supply ◽  
Computer Numerical Simulation ◽  
Film Stiffness

By adding the flow rate of throttle orifice to conventional stable externally pressurized gas lubrication equation, the Reynolds equation for externally pressurized dry gas seal with orifice compensation is established. The solution of the equation is studied by functional extremum algorithm and finite element method, and the computer numerical simulation is carried out in Matlab software. The effects of air supply pressure, numbers and diameter of throttle orifice, on face opening force and gas film stiffness are discussed in detail.

The Optimization of Stiffness Performance of Upstream Pumping Mechanical Seal Based on the Response Surface Method

2015 ◽  
Author(s):  
Huilong Chen ◽  
Jinfeng Liu ◽  
Tong Li ◽  
Kunteng Ren ◽  
Bin Wang
Keyword(s):  
Liquid Film ◽  
Groove Depth ◽  
Diameter Ratio ◽  
Width Ratio ◽  
Mechanical Seal ◽  
Spiral Groove ◽  
Surface Method ◽  
Film Stiffness ◽  
Face Morphology ◽  
Morphology Parameters

The face shape optimization of spiral groove upstream pumping mechanical seal is of great significance. The liquid film stiffness was calculated by considering the cavitation model and dynamic grid in this paper. The regression model was established according to the results of the end face morphology parameters and the stiffness performance. The equivalent cloud images were drawn by using Matlab software. The response surface method is used to analyze the interaction of the upstream pumping mechanical seal face morphology parameters of the groove depth, spiral angle groove diameter ratio and groove width ratio on the stiffness performance. Finally, the numerical simulation of the mechanical seal micro clearance flow is verified. The results show that spiral groove depth should be between 3 and 10 μm. The liquid film stiffness value is becoming smaller with the increase of the helical angle. The best value is around 16°; The influence of the groove diameter ratio and the groove width ratio to the liquid film stiffness is symmetrical distribution basically. And it is better to take 0.5 and 0.4 respectively.

Numerical and Experimental Investigation on the Controlling for Rotor-to-Stationary Part Rubbing in Rotating Machinery

2011 ◽  
Author(s):  
Weimin Wang ◽  
Jinji Gao ◽  
Ya Zhang ◽  
Jianfei Yao
Keyword(s):  
Field Test ◽  
High Speed ◽  
Rotating Machinery ◽  
Numerical Results ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Low Speed ◽  
Secondary Phenomenon ◽  
Main Component ◽  
External Forces

Rotor may physically contacts with stationary elements of a rotating machine, and the subsequent rubbing at the contact area is a serious malfunction in rotating machinery that may lead to the machine’s catastrophic failure. Usually, it is deemed as a secondary phenomenon resulting from a primary cause which perturbs the machine during normal operating conditions. Generally, there are two types of rubs, i.e., radial rub and axial rub. In this paper, the dynamic response of a rotor system with two types of rubs and unbalances is investigated numerically. Then, characteristics of dynamic behavior for both types of rubs could be achieved. It indicates that symptoms of axial rub are similar with that of unbalance, where 1X vibration is the main component in FFT results. While, radial rub will result 0.5X and 1X vibration in FFT result. Combing a troubleshooting process of a steam turbine in an ammonia plant and field test data, the numerical results are confirmed furthermore although there are some differences in vibration characteristics between numerical results and field test results. Under axial rub impact, the fault force emerges even at low speed. Its spectrum characteristics are more like those of radial rub impact at low speed and more like those of unbalance at high speed. On these bases, methods of preventing rub-impact faults as the machine operating are presented and investigated theoretically focusing on how to exert external forces to counteract those forces resulting from rubbing. Experimental investigations are conducted and their results indicate that the method presented in this paper is useful and feasible.

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