Gas film vibration inside dry gas seal gap

2018 ◽  
Author(s):  
Renat Badykov ◽  
Sergei Falaleev ◽  
Houston Wood ◽  
Alexander Vinogradov
Keyword(s):  
Dry Gas Seal

Enhancement of Dry Gas Seal Reliability

2018 ◽  
Author(s):  
Roy Sahadevan ◽  
Basma Al Menhali
Keyword(s):  
Dry Gas Seal

Study on the Thermo-Hydrodynamic of a Dry Gas Seal in Helium Circulator for High Temperature Gas-Cooled Reactor

2011 ◽  
Author(s):  
Jianshu Lin ◽  
Hong Wang
Keyword(s):  
High Temperature ◽  
Film Flow ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Analysis Method ◽  
Dry Gas Seal ◽  
Safety Requirements ◽  
Simulation Results ◽  
Gas Seals ◽  
High Temperature Gas

A comprehensive analysis method is proposed to resolve the problem of simulating a complex thermo-flow with two kinds of distinct characteristic length in the dry gas seal, and a conjugated simulation of the complicated heat transfer and the gas film flow is carried out by using the commercial CFD software CFX. By using the proposed method, a three dimensional of velocity and pressure field in the gas film flow and the temperature distribution within the sealing rings are investigated for three kinds of film thickness, respectively. A comparison of thermo-hydrodynamics of the dry gas seals is conducted between the sealed gas of air and helium. The latter one is used in a helium circulator for High Temperature Gas-cooled Reactor (HTGR). From comparisons and discussions of a series of simulation results, it will be found that the comprehensive proposal is effective and simulation results are reasonable, and the maximum temperature rise in the dry gas seal is within the acceptable range of HTGR safety requirements.

scholarly journals Centrifugal Compressor Spiral Dry Gas Seal Simulation Working at Reverse Rotation

2013 ◽  
Vol 68 ◽  
pp. 285-292 ◽  
Author(s):  
Ibrahim Shahin ◽  
Mohamed Gadala ◽  
Mohamed Alqaradawi ◽  
Osama Badr
Keyword(s):  
Centrifugal Compressor ◽  
Dry Gas Seal

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.

Study of Fault Self-Recovery and Seal Improvement for Centrifugal Compressor

2010 ◽  
Author(s):  
Weimin Wang ◽  
Jinji Gao ◽  
Yan Li ◽  
Shuangxi Li
Keyword(s):  
Experimental Study ◽  
Centrifugal Compressor ◽  
Thrust Bearing ◽  
Mechanical Performance ◽  
High Reliability ◽  
Relevant Information ◽  
Axial Displacement ◽  
Oil Film ◽  
Dry Gas Seal ◽  
Low Leakage

For centrifugal compressor, discharge or suction pressure variations due to process fluctuations or balance drum seal degradation can result in rotor thrust increasing which may jeopardize thrust bearing and compressor’s reliability. Also, the leakage flow through balance drum seal can seriously affect the efficiency of compressor. Summarizing the characteristic of axial displacement fault about centrifugal compressor and analyzing the mechanical performance of tilt pads thrust bearing, theory of axial displacement fault self-recovery is presented and realized through experimental study. The method presented in this paper monitors the stiffness of oil film and identifies the reason of axial displacement increasing. Also the low leakage feature of Dry-Gas-Seal (DGS), high reliability of labyrinth, and the feasibility of upgrading existing structure are taken into account at the same time to design a combined labyrinth-dry gas seal system on the balancing drum. Based on the combined seal system, a Fault Self-Recovering (FSR) mechanism for the fault of rotor axial displacement is introduced to assure the minimum oil film thickness was ensured in real time. The modern Computational Fluid Dynamics (CFD) and experimental study were used to validate this concept. The result and relevant information indicate that the method can realize axial displacement fault self-recovering effectively and the combined sealing system could improve the efficiency of the centrifugal compressor about four percent.

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.

Research on the temperature field of a dry gas seal

2010 ◽  
Author(s):  
Heshun Wang ◽  
Qing Wang ◽  
Weibing Zhu ◽  
Zepei Huang ◽  
Chening Zhang
Keyword(s):  
Temperature Field ◽  
Dry Gas Seal

Development of a Supersonic Ejector for Capturing Very Low-Pressure Vent Gases and Re-Injection Into a High-Pressure Gas Stream

2006 ◽  
Author(s):  
K. K. Botros ◽  
J. Geerligs ◽  
H. Imran ◽  
W. Thompson
Keyword(s):  
Mach Number ◽  
Optimum Design ◽  
Nozzle Exit ◽  
Pressure Ratio ◽  
Supersonic Nozzle ◽  
Low Pressure ◽  
Fuel Gas ◽  
Dry Gas Seal ◽  
Supersonic Ejector ◽  
Exit Mach Number

The purpose of the ejector device is to capture the gas leakage from a dry-gas seal at low pressure, and re-inject it into the fuel gas line to the gas generator (without the use of compressors or rotating elements), hence providing a means to utilize the gas that would otherwise be vented to atmosphere. Implementation of this device will also have the benefit of reducing greenhouse gas emissions to the atmosphere. The primary challenge to achieve the above goal lies in the fact that the leakage gas pressure is in the range of 70–340 kPag, while the minimum pressure required upstream of the fuel gas regulator is in the range of 2400–3300 kPag. The device consists of a two-stage supersonic ejector. The first stage is highly supersonic (nozzle exit Mach number ≃ 2.54), while the second stage is moderately supersonic (nozzle exit Mach number ≃ 1.72). Several tests where conducted on various configurations of the two stages on natural gas in order to arrive at the optimum design and operating parameters. The optimum design gave an expansion pressure ratio (motive/suction) of the order of 14.0 and compression pressure ratio (discharge/suction) of around 8.1. These ratios would meet the requirement of the minimum suction and discharge pressure mentioned above. This paper presents the optimum configuration arrived at after several iterations of different geometries of the supersonic nozzles, particularly for the first stage ejector, and presents the performance test results of the integrated system. The results indicate that the device would meet the requirements of capturing the low pressure, low flow dry gas seal leakage and re-inject it into the fuel gas stream with an overall ejector efficiency (based on thermodynamic availability) of 80%.

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