scholarly journals Characterization and modelling of air humidification in Fuel Cell System for transport sector

2022 ◽  
Vol 334 ◽  
pp. 06009
Author(s):  
Amedeo Grimaldi ◽  
Lorenzo Villa ◽  
Andrea Baricci ◽  
Stefano De Antonellis ◽  
Claudio Oldani ◽  
...  
Keyword(s):  
Water Transport ◽  
Transport Model ◽  
Cell System ◽  
Operating Conditions ◽  
Transport Sector ◽  
Counter Flow ◽  
Physical Description ◽  
Vapor Permeation ◽  
Individual Contributions ◽  
Transfer Properties

A model for the physical description of water transport through steady-state permeation and dynamic sorption within perfluoro-sulfonic acid (PFSA) membranes has been developed. A broad experimental campaign is conducted on several membranes, belonging to Aquivion class, varying both in thickness and equivalent weight (EW). The experimental data have been used to calibrate and validate water transport model and to find correlations for mass-transfer properties in low-EW PFSA membranes that describe consistently both water vapor permeation and sorption. It has been possible to identify individual contributions to mass transport resistance and to determine the optimal configuration and materials of a full-scale counter-flow membrane humidifier under a set of specific operating conditions.

scholarly journals Water transport through epoxy-based powder pipeline coatings

2021 ◽  
Author(s):  
Hossein Zargarnezhad ◽  
Edouard Asselin ◽  
Dennis Wong ◽  
C.N. Catherine Lam
Keyword(s):  
Water Transport ◽  
Powder Coating ◽  
Operating Conditions ◽  
Vapor Transport ◽  
Internal Stresses ◽  
Water Molecules ◽  
Epoxy Coatings ◽  
Water Permeation ◽  
Vapor Permeation ◽  
Self Association

Hydration of epoxy coatings reduces adhesion performance and causes degradation of the material, such as microstructural failures. Quantification of water vapor transport at elevated temperatures is fundamental to understanding polymer coating performance, especially when the coating is exposed to extreme operating conditions. As the water activity increases, the permeability/selectivity of polymers against other permeants changes. In this study, we examined the water permeation kinetics of two common epoxy-based powder coating systems for pipelines (fusion-bonded epoxy, FBE, and high-performance powder coating, HPPC) across a range of industrially-relevant temperatures (from room temperature to 80°C). Specifically, we utilized vapor permeation features of FBE and HPPC films with quantification of equilibrium flux as a function of temperature and pressure. In addition, we analyzed the nonlinear dependency of water transport on the vapor concentration at 65°C. The vapor transport analysis demonstrated that although data for FBE were indicative of a decrease in permeability around 65°C, perhaps due to self-association of water molecules, the coating was likely to experience a plasticization pressure around this temperature. We also examined microstructural changes of the epoxy network due to water transport. Our results revealed evidence of irreversible damage to epoxy coatings under wet-state conditions above 65°C. It appears that the combination of thermal exposure and internal stresses in the glassy epoxy lead to a phase separation of filler particles from the epoxy matrix, as well as to a distinctive cavity formation in the coating membrane. Yet, despite formation of percolating paths for water transport, our results indicate that vapor permeation is primarily restrained due to self-association of water molecules. The vapor transport flux and its permeance are lowered by one order of magnitude in the multilayered HPPC thanks to the moisture-resistant polyethylene topcoat, thus reducing the extent of damage to the underlying substrate. Since barrier protection against gas phase diffusion is controlled by the FBE primer, however, consequences of coating hydration are more pronounced in the overall selectivity toward gaseous transport. Hydrothermal exposure is likely to increase aggregate porosity of the coating and a conservative implementation of standard coating requirements is therefore reasonable to avoid early degradation issues.

scholarly journals Water transport through epoxy-based powder pipeline coatings

2021 ◽  
Author(s):  
Hossein Zargarnezhad ◽  
Edouard Asselin ◽  
Dennis Wong ◽  
C.N. Catherine Lam
Keyword(s):  
Water Transport ◽  
Powder Coating ◽  
Operating Conditions ◽  
Vapor Transport ◽  
Internal Stresses ◽  
Water Molecules ◽  
Epoxy Coatings ◽  
Water Permeation ◽  
Vapor Permeation ◽  
Self Association

Hydration of epoxy coatings reduces adhesion performance and causes degradation of the material, such as microstructural failures. Quantification of water vapor transport at elevated temperatures is fundamental to understanding polymer coating performance, especially when the coating is exposed to extreme operating conditions. As the water activity increases, the permeability/selectivity of polymers against other permeants changes. In this study, we examined the water permeation kinetics of two common epoxy-based powder coating systems for pipelines (fusion-bonded epoxy, FBE, and high-performance powder coating, HPPC) across a range of industrially-relevant temperatures (from room temperature to 80°C). Specifically, we utilized vapor permeation features of FBE and HPPC films with quantification of equilibrium flux as a function of temperature and pressure. In addition, we analyzed the nonlinear dependency of water transport on the vapor concentration at 65°C. The vapor transport analysis demonstrated that although data for FBE were indicative of a decrease in permeability around 65°C, perhaps due to self-association of water molecules, the coating was likely to experience a plasticization pressure around this temperature. We also examined microstructural changes of the epoxy network due to water transport. Our results revealed evidence of irreversible damage to epoxy coatings under wet-state conditions above 65°C. It appears that the combination of thermal exposure and internal stresses in the glassy epoxy lead to a phase separation of filler particles from the epoxy matrix, as well as to a distinctive cavity formation in the coating membrane. Yet, despite formation of percolating paths for water transport, our results indicate that vapor permeation is primarily restrained due to self-association of water molecules. The vapor transport flux and its permeance are lowered by one order of magnitude in the multilayered HPPC thanks to the moisture-resistant polyethylene topcoat, thus reducing the extent of damage to the underlying substrate. Since barrier protection against gas phase diffusion is controlled by the FBE primer, however, consequences of coating hydration are more pronounced in the overall selectivity toward gaseous transport. Hydrothermal exposure is likely to increase aggregate porosity of the coating and a conservative implementation of standard coating requirements is therefore reasonable to avoid early degradation issues.

scholarly journals Water transport through epoxy-based powder pipeline coatings

2021 ◽  
Author(s):  
Hossein Zargarnezhad ◽  
Edouard Asselin ◽  
Dennis Wong ◽  
C.N. Catherine Lam
Keyword(s):  
Water Transport ◽  
Powder Coating ◽  
Operating Conditions ◽  
Vapor Transport ◽  
Internal Stresses ◽  
Water Molecules ◽  
Epoxy Coatings ◽  
Water Permeation ◽  
Vapor Permeation ◽  
Self Association

Hydration of epoxy coatings reduces adhesion performance and causes degradation of the material, such as microstructural failures. Quantification of water vapor transport at elevated temperatures is fundamental to understanding polymer coating performance, especially when the coating is exposed to extreme operating conditions. As the water activity increases, the permeability/selectivity of polymers against other permeants changes. In this study, we examined the water permeation kinetics of two common epoxy-based powder coating systems for pipelines (fusion-bonded epoxy, FBE, and high-performance powder coating, HPPC) across a range of industrially-relevant temperatures (from room temperature to 80°C). Specifically, we utilized vapor permeation features of FBE and HPPC films with quantification of equilibrium flux as a function of temperature and pressure. In addition, we analyzed the nonlinear dependency of water transport on the vapor concentration at 65°C. The vapor transport analysis demonstrated that although data for FBE were indicative of a decrease in permeability around 65°C, perhaps due to self-association of water molecules, the coating was likely to experience a plasticization pressure around this temperature. We also examined microstructural changes of the epoxy network due to water transport. Our results revealed evidence of irreversible damage to epoxy coatings under wet-state conditions above 65°C. It appears that the combination of thermal exposure and internal stresses in the glassy epoxy lead to a phase separation of filler particles from the epoxy matrix, as well as to a distinctive cavity formation in the coating membrane. Yet, despite formation of percolating paths for water transport, our results indicate that vapor permeation is primarily restrained due to self-association of water molecules. The vapor transport flux and its permeance are lowered by one order of magnitude in the multilayered HPPC thanks to the moisture-resistant polyethylene topcoat, thus reducing the extent of damage to the underlying substrate. Since barrier protection against gas phase diffusion is controlled by the FBE primer, however, consequences of coating hydration are more pronounced in the overall selectivity toward gaseous transport. Hydrothermal exposure is likely to increase aggregate porosity of the coating and a conservative implementation of standard coating requirements is therefore reasonable to avoid early degradation issues.

The Dynamic Modeling of PEMFC System for Automotive Application

2008 ◽  
Author(s):  
Sanggyu Kang ◽  
Kyoungdoug Min
Keyword(s):  
Energy Balance ◽  
Thermal Management ◽  
Dynamic Modeling ◽  
Management System ◽  
Mass Conservation ◽  
Cell System ◽  
Operating Conditions ◽  
Automotive Application ◽  
Thermal Management System ◽  
Control Volumes

Water and thermal management are crucial factors in determining the performance of PEMFC for automotive application. In order to investigate the effect of cell humidity and temperature on the performance of PEMFC, a dynamic model of a PEMFC system for automotive application has been developed by using Matlab/Simulink®. The model is composed of a PEM unit cell, membrane humidifier, and thermal management system (TMS). At first, fuel and air are well hydrated by the shell and tube humidifier, then humidified fuel and air flow into the PEMFC for electrochemical reaction. PEMFC temperature was maintained at a constant level by the thermal management system. The active area of PEM model is 240 cm2. The cell was discretized into several control volumes in the through-plane to resolve energy balance and species diffusion. The membrane humidifier model is also discretized into three control volumes in the through-plane to resolve the mass conservation and energy balance. Fuel and air are hydrated by the diffusion of the water through the membrane. The thermal management system consists of radiator, fan and pump. De-ionized water cools down the temperature of PEMFC. In order to validate the model, the model was compared with a corresponding experiment. Comparison shows that simulation results are in good agreement with experiments. And the dynamic response of PEMFC with regard to the change of current was also investigated. The model is useful to elucidate the relationships between operating conditions such as air relative humidity, temperature, etc. It is expected that this dynamic modeling of PEMFC system can contribute to the design optimization of PEM fuel cell system for vehicle application.

Experimental and Theoretical Performance Analysis of a High Temperature PEM Fuel Cell Fed With LPG Using a Compact Steam Reformer

2011 ◽  
Author(s):  
Nicola Zuliani ◽  
Rodolfo Taccani ◽  
Robert Radu
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Cell System ◽  
Operating Conditions ◽  
Steam Reformer ◽  
Fuel Cell Performance ◽  
Fuel Processor ◽  
Balance Of Plant ◽  
Energy Balances ◽  
High Temperature Pem

High temperature PEM (HTPEM) fuel cell based on polybenzimidazole polymer (PBI) and phosphoric acid, can be operated at temperature between 120°C and 180°C. Reactants humidification is not required and CO content up to 1% in fuel can be tolerated, affecting only marginally performance. This is what makes HTPEM fuel cells very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. This paper aims to present the preliminary experimental results obtained on a HTPEM fuel cell fed with LPG using a compact steam reformer. The analysis focus on the reformer start up transient, on the influence of the steam to carbon ratio on reformate CO content and on the single fuel cell performance at different operating conditions. By analyzing the mass and energy balances of the fuel processor, fuel cell system, and balance-of-plant, a previously developed system simulation model has been used to provide critical assessment on the conversion efficiency for a 1 kWel system. The current study attempts to extend the previously published analyses of integrated HTPEM fuel cell systems.

Theoretical Analysis on the Autothermal Reforming Process of Ethanol as Fuel for a Proton Exchange Membrane Fuel Cell System

2006 ◽  
Vol 4 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Alessandra Perna
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Autothermal Reforming ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Cell System ◽  
Exchange Membrane

The purpose of this work is to investigate, by a thermodynamic analysis, the effects of the process variables on the performance of an autothermal reforming (ATR)-based fuel processor, operating on ethanol as fuel, integrated into an overall proton exchange membrane (PEM) fuel cell system. This analysis has been carried out finding the better operating conditions to maximize hydrogen yield and to minimize CO carbon monoxide production. In order to evaluate the overall efficiency of the system, PEM fuel cell operations have been analyzed by an available parametric model.

scholarly journals Fuel Cell designing with optimal high speed air compressor

2021 ◽  
pp. 29-38
Author(s):  
Nabeel Ahsan ◽  
Mahrukh Mehmood ◽  
Asad A. Zaidi
Keyword(s):  
Fuel Cell ◽  
High Speed ◽  
Proton Exchange Membrane ◽  
Cell System ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Air Compressor ◽  
Different Types ◽  
Input Parameters ◽  
Turbo Compressor

This paper discusses different air management technologies for fuel cell systems. Two different types of compressors are analyzed for Proton-exchange membrane fuel cells (PEMFC). Some important criteria are analyzed thoroughly for the selection of turbo compressor among different types of compressors illustrated with the help of matrix representations. The impacts of various input parameters for Fuel Cell (FC) are also explained thoroughly. Later the numerical modeling of an automobile fuel cell system using a high speed turbo-compressor for air supply is explained. The numerical model incorporates the important input parameters related with air and hydrogen. It also performed energy and mass balances across different components such as pump, fan, heat-exchanger, air compressor and also keeps in consideration the pressure drop across the flow pipes and various mechanical parts. The model is solved to obtain the characteristics of the FC system at different operating conditions. Therefore, it can be concluded that the high speed turbo compressor with a turbo-expander can have significant effects on the overall system power and efficiency.

scholarly journals Analysis of exhaust emission measurements in rural conditions from heavy-duty vehicle

2020 ◽  
Vol 182 (3) ◽  
pp. 54-58
Author(s):  
Andrzej Ziółkowski ◽  
Paweł Fuć ◽  
Piotr Lijewski ◽  
Łukasz Rymaniak ◽  
Paweł Daszkiewicz ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Road Transport ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Transport Sector ◽  
Exhaust Emission ◽  
Heavy Vehicles ◽  
Heavy Duty Vehicle ◽  
Emission Norm ◽  
Test Route

Road transport holds for the largest share in the freight transport sector in Europe. This work is carried out by heavy vehicles of various types. It is assumed that, in principle, transport should take place on the main road connections, such as motorways or national roads. Their share in the polish road infrastructure is not dominant. Rural and communal roads roads are the most prevalent. This fact formed the basis of the exhaust emissions and fuel consumption tests of heavy vehicles in real operating conditions. A set of vehicles (truck tractor with a semi-trailer) meeting the Euro V emission norm, transporting a load of 24,800 kg, was selected for the tests. The research was carried out on an non-urban route, the test route length was 22 km. A mobile Semtech DS instrument was used, which was used to measure the exhaust emissions. Based on the obtained results, the emission characteristics were determined in relation to the operating parameters of the vehicles drive system. Road emission, specific emission and fuel consumption values were also calculated.

scholarly journals TRANSPORT SECTOR IN MONGOLIA

2020 ◽  
pp. 61-70
Author(s):  
Vladimir Grayvoronskiy ◽  
Keyword(s):  
East Asia ◽  
Water Transport ◽  
Feasibility Study ◽  
Joint Venture ◽  
Gas Pipeline ◽  
Transport Sector ◽  
General Review ◽  
Under Construction ◽  
Main Gas Pipeline

A general review of the Mongolia’s transport sector’s development in 2000– 2019, including road, railway, civil air, water transport sub-sectors, main indicators of transport by types, new big projects are described. Mongolia’s transit transport facilities between Russia and China, as well as between East Asia and Europe are increasing. An economic corridor Russia- Mongolia- China is under construction. A Russian- Mongolian special purpose joint venture to be established for feasibility study of main gas pipeline from Russia to China across Mongolia.

Physics and Dynamics of the Atmosphere

2019 ◽  
pp. 71-90
Author(s):  
Han Dolman
Keyword(s):  
Equations Of Motion ◽  
Three Dimensional ◽  
Energy Difference ◽  
Cell System ◽  
Ideal Gas ◽  
Lapse Rate ◽  
Milankovitch Cycles ◽  
Physical Description ◽  
Geostrophic Balance ◽  
Basic Physics

This chapter describes the basic physics and thermodynamics of the atmosphere, starting from the ideal gas law and the hydrostatic equation, from which the lapse rate in the troposphere is derived. The effect of atmospheric moisture on the lapse rate is identified and the Clausius–Clapeyron equation giving the saturated humidity is derived. The effect of moisture on adiabatic vertical transport is shown. Then, the three-dimensional equations of motion are derived in vector form. From these, geostrophic balance and the thermal wind equations are derived. This, with the Coriolis force, gives the physical description of the atmospheric circulation. The driving force behind circulation is identified as the energy difference between the tropics and the extratropics. This is driven by radiation differences, including, at large geological scale, the Milankovitch cycles. Finally, circulation as a three-cell system per hemisphere, and the development of weather systems such as cyclones, are described.

Sign in / Sign up

Export Citation Format

Share Document