Modeling Dry Wear of Piston Rod Sealing Elements of Reciprocating Compressors Considering Gas Pressure Drop Across the Dynamic Sealing Surface

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
A. Kaufmann ◽  
T. Lindner-Silwester ◽  
T. Antretter
Keyword(s):  
Numerical Model ◽  
Pressure Drop ◽  
Analytical Solution ◽  
Gas Pressure ◽  
Differential Pressure ◽  
Compressed Gas ◽  
Packing Rings ◽  
Packing Ring ◽  
Sealing Elements ◽  
Counter Surface

The wear of dynamic sealing elements, i.e., elements that seal against a moving counter-surface, is highly complex. In dry-running reciprocating compressors, these sealing elements, commonly referred to as packing rings, have to seal the compressed gas against the environment along the reciprocating rod. Since the packing rings' seal effect arises from the differential pressure to be sealed, it is of paramount importance to take into account the gas pressure drop across the dynamic sealing surface. This paper presents a numerical model that allows us to calculate how the wear of such a packing ring evolves with time. An analytical solution is used to verify the numerical model.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

Experimental measurements of gas pressure drop of packed pebble beds

2020 ◽  
Vol 160 ◽  
pp. 111836
Author(s):  
Maulik Panchal ◽  
Abhishek Saraswat ◽  
Paritosh Chaudhuri
Keyword(s):  
Pressure Drop ◽  
Gas Pressure ◽  
Experimental Measurements

Understanding Carbon Dioxide Transfer in Direct Methanol Fuel Cells Using a Pore-Scale Model

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nathaniel Metzger ◽  
Archana Sekar ◽  
Jun Li ◽  
Xianglin Li
Keyword(s):  
Carbon Dioxide ◽  
Pressure Drop ◽  
Gas Flow ◽  
Direct Methanol Fuel Cells ◽  
Gas Pressure ◽  
Mass Transfer Resistance ◽  
Transfer Resistance ◽  
Cell Components ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Abstract The gas flow of carbon dioxide from the catalyst layer (CL) through the microporous layer (MPL) and gas diffusion layer (GDL) has great impacts on the water and fuel management in direct methanol fuel cells (DMFCs). This work has developed a liquid–vapor two-phase model considering the counter flow of carbon dioxide gas, methanol, and water liquid solution in porous electrodes of DMFC. The model simulation includes the capillary pressure as well as the pressure drop due to flow resistance through the fuel cell components. The pressure drop of carbon dioxide flow is found to be about two to three orders of magnitude higher than the pressure drop of the liquid flow. The big difference between liquid and gas pressure drops can be explained by two reasons: volume flowrate of gas is three orders of magnitude higher than that of liquid; only a small fraction of pores (<5%) in hydrophilic fuel cell components are available for gas flow. Model results indicate that the gas pressure and the mass transfer resistance of liquid and gas are more sensitive to the pore size distribution than the thickness of porous components. To buildup high gas pressure and high mass transfer resistance of liquid, the MPL and CL should avoid micro-cracks during manufacture. Distributions of pore size and wettability of the GDL and MPL have been designed to reduce the methanol crossover and improve fuel efficiency. The model results provide design guidance to obtain superior DMFC performance using highly concentrated methanol solutions or even pure methanol.

scholarly journals SHORELINE AT JETTY DUE TO CYCLIC AND RANDOM WAVES

1988 ◽  
Vol 1 (21) ◽  
pp. 141
Author(s):  
Todd L. Walton ◽  
Philip L.F. Liu ◽  
Edward B. Hands
Keyword(s):  
Time Series ◽  
Sediment Transport ◽  
Numerical Model ◽  
Analytical Solution ◽  
Numerical Models ◽  
Random Waves ◽  
Dimensionless Form ◽  
Wave Direction ◽  
Continuous Cycling ◽  
Small Wave

This paper examines the effects of random and deterministic cycling of wave direction on the updrift beach planform adjacent to a jetty. Results provided using a simplified numerical model cast in dimensionless form indicate the importance of the time series of wave direction in determining design jetty length for a given net sediment transport. Continuous cycling of • wave direction leads to the expected analytical solution. Simplications in the numerical model used restrict the applications to small wave angles, no diffraction, no reflection of waves off structure, no refraction, and no sand bypassing at jetty. The concept can be extended to more sophisticated numerical models.

The mechanism of gas pressure and temperature dependent surface flashover in compressed gas involving gas adsorption

2021 ◽  
Vol 539 ◽  
pp. 148107
Author(s):  
Zhen Li ◽  
Shengtao Li ◽  
Haoming Xu ◽  
Guanghao Qu ◽  
Huan Niu ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Gas Pressure ◽  
Temperature Dependent ◽  
Surface Flashover ◽  
Compressed Gas

Simulation of the Performance of the Venturi Scrubber for an Advanced Reactor Containment Venting Conditions

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Goel Paridhi ◽  
K. Nayak Arun
Keyword(s):  
Numerical Model ◽  
Pressure Drop ◽  
Gas Flow ◽  
Pressure Profile ◽  
Absorption Efficiency ◽  
Severe Accident ◽  
Mitigation Measures ◽  
Liquid Loading ◽  
Venturi Scrubber ◽  
Iodine Absorption

Abstract Post Fukushima, nuclear plants are being retrofitted with severe accident mitigation measures. For attaining depressurization of the containment and mitigate the consequences of the release of the radioactivity to the environment during a severe accident condition, filtered containment venting systems (FCVS) are proposed to be installed in existing reactors and being designed for advanced reactors. The design of FCVS is particular to the reactor type. The FVCS configuration considered in this paper comprises of a manifold of venturi scrubber enclosed in a scrubber tank along with metal fiber filter and demister for an advanced Indian reactor. This study focuses on the assessment of the design of the venturi scrubber for the reactor conditions at which venting is carried out through a numerical model. The numerical model is first validated with experiments performed for prototypic conditions. The predicted pressure drop and the iodine absorption efficiency were found to be in good match with the experimental measurements. Subsequently, the model is implemented for predicting the hydrodynamics, i.e., pressure drop, droplet sizes and distribution, and iodine absorption for prototypic conditions. The hydrodynamics, i.e., pressure profile in the venturi scrubber showed a decrease in the converging section and in the throat section. The diverging section showed decrease in recovery of pressure with the decrease in gas flow because of the increased liquid loading to the scrubber. The iodine absorption efficiency showed a value of 92% for high gas velocity which decreased to 68% for the lowest gas flow rate.

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