The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Xuexing Ding - One of the best experts on this subject based on the ideXlab platform.
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experiment of frictional vibration performance of the micro texture of dlc thin film with Dry Gas Seal rings
Tribology International, 2020Co-Authors: Xuexing Ding, Deli Che, Weizheng ZhangAbstract:Abstract The frictional vibration performances of textured surface coated with DLC(Diamond-like Carbon)film of Dry Gas Seals ring were investigated. In the meantime, the mechanism of textured surface on interfacial tribological behavior was revealed under Dry frictional condition. The acceleration and frictional force were measured by using universal friction and wear tester which type is MMW-1, and the surface topographies were measured by using SEM and ST400 three-dimensional non-contact surface topography instrument. Results show that the textured surface coated with DLC film can significantly improve the tribological behavior of Dry Gas Seal. Textured surface with reasonable size parameters can capture debris and avoid strong impact between the friction pairs, which improves effectively the tribological behavior of interfaces.
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theoretical analysis and experiment on Gas film temperature in a spiral groove Dry Gas Seal under high speed and pressure
International Journal of Heat and Mass Transfer, 2016Co-Authors: Xuexing DingAbstract:Abstract Experimental tests are conducted in this study to determine the temperature distribution in a Dry Gas Seal by establishing a temperature field test system and choosing sensors that are stable for extreme operating conditions. The temperatures of a narrow gap-occurring Gas film with Seal rings under different rotating speeds and pressures are measured, and a theoretical method is developed to compare the temperature data. A theoretical procedure based on the compressible Reynolds equation and energy equation considering thermal dissipation is used to explore the temperature distribution in the Gas film. The results obtained from the experimental data and thorough theoretical calculations are consistent. The temperature distribution in the Gas film face shows the following order: root radius temperature > inner radius > outer radius. Increases in temperature are attributed to thermal dissipation caused by a significant pressure drop in the root radius region. A Seal isothermal model is compared with the thermal model and values of the Sealing opening force and leakage flow in the thermal model are greater than the values in the isothermal model. Thus, the results of this research reveal that the proposed theoretical calculation method can be applied to analyze Dry Gas Seal temperatures and that thermal dissipation is a significant factor that may be used to optimize groove designs in the future.
Osama Badr - One of the best experts on this subject based on the ideXlab platform.
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three dimensional computational study for spiral Dry Gas Seal with constant groove depth and different tapered grooves
Procedia Engineering, 2013Co-Authors: Ibrahim Shahin, Mohamed S Gadala, Mohamed Alqaradawi, Osama BadrAbstract:Abstract The three dimensional simulation for Dry Gas Seal with constant depth spiral grooves and with different taper grooves is done using ANSYS FLUENT CFD code. Grid independence study and code validation are done with experimental work. The fluid state effect on the Gas Seal internal flow and performance is studied. The laminar and turbulent flow with RNG K-ɛ turbulence model and LES is examined for the same geometrical and operating conditions. The influence of film thickness for constant depth groove Gas Seal is simulated for 2, 3 and 4 μm film. The effect of different rotational speeds on Gas Seal performance is examined for 0, 2500, 5000, 7500 and 10380 rpm. Three taper spiral grooves are studied each with three different angles, including taper grooves in the radial, circumferential and combined radial-circumferential directions. The laminar flow simulation for the Dry Gas Seal agree well with the experimental results more than the turbulent flow simulation which overestimate the pressure distribution inside the Seal. The results indicate that as the rotational speed increases the Seal open force and leakage increase. The use of tapered type spiral groove causes a reduction in the Seal open force and the leakage rate. Increasing the angle of radial taper groove reduces the temperature distribution inside the Gas film. The reduction in Seal open force and leakage rate is higher when the combined radial-circumferential taper is more than radial and circumferential taper used.
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three dimensional computational study for spiral Dry Gas Seal with constant groove depth and different tapered grooves
Procedia Engineering, 2013Co-Authors: Ibrahim Shahin, Mohamed S Gadala, Mohamed Alqaradawi, Osama BadrAbstract:Abstract The three dimensional simulation for Dry Gas Seal with constant depth spiral grooves and with different taper grooves is done using ANSYS FLUENT CFD code. Grid independence study and code validation are done with experimental work. The fluid state effect on the Gas Seal internal flow and performance is studied. The laminar and turbulent flow with RNG K-ɛ turbulence model and LES is examined for the same geometrical and operating conditions. The influence of film thickness for constant depth groove Gas Seal is simulated for 2, 3 and 4 μm film. The effect of different rotational speeds on Gas Seal performance is examined for 0, 2500, 5000, 7500 and 10380 rpm. Three taper spiral grooves are studied each with three different angles, including taper grooves in the radial, circumferential and combined radial-circumferential directions. The laminar flow simulation for the Dry Gas Seal agree well with the experimental results more than the turbulent flow simulation which overestimate the pressure distribution inside the Seal. The results indicate that as the rotational speed increases the Seal open force and leakage increase. The use of tapered type spiral groove causes a reduction in the Seal open force and the leakage rate. Increasing the angle of radial taper groove reduces the temperature distribution inside the Gas film. The reduction in Seal open force and leakage rate is higher when the combined radial-circumferential taper is more than radial and circumferential taper used.
Yua Che - One of the best experts on this subject based on the ideXlab platform.
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enhancing film stiffness of spiral groove Dry Gas Seal via shape modification at low speed numerical results and experiment
Tribology Transactions, 2019Co-Authors: Jinbo Jiang, Xudong Peng, Cong Zong, Wenjing Zhao, Yua CheAbstract:The film stiffness of Dry Gas Seal must be sufficient to keep Gas film stable at high and low speed. A generalized geometric model based on triangles is proposed to characterize spiral grooves. A m...
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experimental and theoretical studies of the dynamic behavior of a spiral groove Dry Gas Seal at high speeds
Tribology International, 2018Co-Authors: Yua Che, Jinbo Jiang, Xudong Peng, Xiangkai MengAbstract:Abstract Because of great axial vibration of the rotor system, Dry Gas Seal has a big film thickness disturbance, which may cause contact rubbing of Seal faces or excessive leakage. Focusing on this problem, experimental studies on transient-state film thickness and leakage rate of a spiral groove Dry Gas Seal at high-speeds are carried out under different spring pressures and different spiral groove depths. And the experimental results of film thickness disturbance and average leakage rate are predicted by perturbation method and Gas lubrication theory. Results show that the theoretical results of variation trends of film thickness disturbance amplitudes coincide well with the experimental data, and it also represents that the perturbation method is an effective forecasting method in dynamic analysis.
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Leakage and Stiffness Characteristics of Bionic Cluster Spiral Groove Dry Gas Seal
Chinese Journal of Mechanical Engineering, 2018Co-Authors: Jinbo Jiang, Xudong Peng, Yua CheAbstract:Spiral groove Dry Gas Seal (S-DGS), the most widely used DGS in the world, encounters the problem of high leakage rate and inferior film stability when used in high-speed machinery equipment, which could not be well solved by optimization of geometrical parameters and molded line of spiral groove. A new type of bionic cluster spiral groove DGS (CS-DGS) is proved to have superior film stability than S-DGS at the condition of high-speed and low-pressure numerically. A bionic CS-DGS is experimentally investigated and compared with common S-DGS in order to provide evidence for theoretical study. The film thickness and leakage rate of both bionic spiral groove and common spiral groove DGS are measured and compared with each other and with theoretical values under different closing force at the condition of static pressure, high-speed and low-pressure, and the film stiffness and stiffness-leakage ratio of these two face Seals are derived by the relationship between closing force and film thickness at the steady state. Experimental results agree well with the theory that the leakage and stiffness of bionic CS-DGS are superior to that of common S-DGS under the condition of high-speed and low-pressure, with the decreasing amplitude of 20% to 40% and the growth amplitude of 20%, respectively. The opening performance and stiffness characteristics of bionic CS-DGS are inferior to that of common S-DGS when rotation speed equals to 0 r/min. The proposed research provides a new method to measure the axis film stiffness of DGS, and validates the superior performance of bionic CS-DGS at the condition of high-speed and low-pressure experimentally.
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Gas film disturbance characteristics analysis of high speed and high pressure Dry Gas Seal
Chinese Journal of Mechanical Engineering, 2016Co-Authors: Yua Che, Jinbo Jiang, Xudong PengAbstract:The Dry Gas Seal(DGS) has been widely used in high parameters centrifugal compressor, but the intense vibrations of shafting, especially in high-speed condition, usually result in DGS’s failure. So the DGS’s ability of resisting outside interference has become a determining factor of the further development of centrifugal compressor. However, the systematic researches of which about Gas film disturbance characteristics of high parameters DGS are very little. In order to study Gas film disturbance characteristics of high-speed and high-pressure spiral groove Dry Gas Seal(S-DGS) with a flexibly mounted stator, rotor axial runout and misalignment are taken into consideration, and the finite difference method and analytical method are used to analyze the influence of Gas film thickness disturbance on Sealing performance parameters, what’s more, the effects of many key factors on Gas film thickness disturbance are systematically investigated. The results show that, when Sealed pressure is 10.1MPa and Seal face average linear velocity is 107.3 m/s, Gas film thickness disturbance has a significant effect on leakage rate, but has relatively litter effect on open force; Excessively large excitation amplitude or excessively high excitation frequency can lead to severe Gas film thickness disturbance; And it is beneficial to assure a smaller Gas film thickness disturbance when the stator material density is between 3.1 g/cm3 to 8.4 g/cm3; Ensuring Sealing performance while minimizing support axial stiffness and support axial damping can help to improve dynamic tracking property of Dry Gas Seal. The proposed research provides the instruction to optimize dynamic tracking property of the DGS.
Razi Abdulrahma - One of the best experts on this subject based on the ideXlab platform.
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the effect of convection area on the deformation of Dry Gas Seal operating with supercritical co2
Tribology International, 2019Co-Authors: Z M Fairuz, Ingo Jah, Razi AbdulrahmaAbstract:Air riding Seals require flat and near parallel surfaces to operate correctly and deformations can deteriorate their performance or cause catastrophic failure. Deformations arise due to non-uniform thermal and pressure loads or due to the effect of centrifugal forces on the Sealing rings. Coupled simulations are conducted to explore trends and methods to reduce the distortion of a Dry Gas Seal operating with supercritical CO . The Seal experiences significant deformations, especially those induced by non-uniform temperatures leading to thermal deformations. The results demonstrate that reducing the surface area exposed to convective heat transfer is an effective approach to reduce thermal deformation.
Z M Fairuz - One of the best experts on this subject based on the ideXlab platform.
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the effect of convection area on the deformation of Dry Gas Seal operating with supercritical co2
Tribology International, 2019Co-Authors: Z M Fairuz, Ingo Jah, Razi AbdulrahmaAbstract:Air riding Seals require flat and near parallel surfaces to operate correctly and deformations can deteriorate their performance or cause catastrophic failure. Deformations arise due to non-uniform thermal and pressure loads or due to the effect of centrifugal forces on the Sealing rings. Coupled simulations are conducted to explore trends and methods to reduce the distortion of a Dry Gas Seal operating with supercritical CO . The Seal experiences significant deformations, especially those induced by non-uniform temperatures leading to thermal deformations. The results demonstrate that reducing the surface area exposed to convective heat transfer is an effective approach to reduce thermal deformation.
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Performance of supercritical CO2 Dry Gas Seals near the critical point
'ASME International', 2016Co-Authors: Z M Fairuz, Jahn, Ingo H. J.Abstract:The Queensland Geothermal Energy Centre of Excellence is investigating the use of supercritical CO closed loop Brayton cycles in the Concentrated Solar Thermal power cycle plant. One of the important components in the turbomachinery within the plant are Seals. As the cycle is closed loop and operating at high pressures, Dry Gas Seals have been recommended for future use in these systems. One of the main challenges of using supercritical CO Dry Gas Seals is that operating conditions are near the critical point. In the supercritical region in the vicinity of the critical point (304 K, 7.4 MPa), CO behaves as a realGas, exhibiting large and abrupt non-linear changes in fluid and transport properties and high densities. To correctly predict the Seal operation and performance, the interaction between this real Gas and the Seal rotor (primary ring) and the Seal stator (mating ring) need to analysed and investigated in detail, as they can lead to significant changes in flow and Seal performance. Results from this paper show that increased centrifugal effects caused by higher Gas densities can reduce the pressure in the Sealing dam region. This adversely affects the loading capacity of the Dry Gas Seal. However, it also benefits Seal performances by reducing the leakage rate. The current work presents an investigation of the supercritical CO Dry Gas Seals operating close to the critical point with an inlet pressure and temperature of 8.5Mpa and 370K respectively and a speed of 30000 RPM. Results highlighting the effects of the groove length or dam to groove ratio on the performance of the Dry Gas Seal are presented. The Seal is simulated using Computational Fluid Dynamics to study the flow behaviour of the supercitical CO in the Dry Gas Seal. Supercritical CO fluid properties are based on the fluid database REFPROP. The numerical model was validated with previous work and good agreement was demonstrated
