scholarly journals Analysis of the Effect of Anode Porosity on Temperature Distribution on Planar Radial Type SOFC

2018 ◽  
Vol 73 ◽  
pp. 01010
Author(s):  
Alif Widiyanto ◽  
Sulistyo ◽  
MSK Tony Suryo Utomo
Keyword(s):  
Temperature Distribution ◽  
Gas Flow ◽  
Hydrogen Gas ◽  
Cfd Modeling ◽  
Dynamics Modeling ◽  
Waste Products ◽  
Geometry Model ◽  
Electrolyte Surface ◽  
Fluent Software ◽  
Object Of Study

Solid Oxide Fuel Cell (SOFC) is an electrochemical equipment that converts gas into electricity directly. The waste products resulting from SOFC are water vapor and heat when using hydrogen gas. The electrode of the SOFC is the anode, electrolyte and cathode. The performance of SOFC is influenced porosity of the electrode. This study explained the relationship between porosity of the anode and temperature distribution using computational fluid dynamics modeling approach (CFD). In this study, CFD modeling was done by using Fluent software. The geometry model of computational modeling is a planar radial-type SOFC. The assumptions of some boundary conditions used from the study of literature and the object of study. The standard deviation and the different of temperature of the anode-electrolyte surface used to analyse the result. Non-homogenous temperature distribution rise if the anode porosity and gas flow rate is increasing. This indicates the gradient of temperature is bigger in the higher porosity, which may cause thermal stress and degrades the materials of electrode.

scholarly journals CFD Modeling of Particulates Erosive Effect on a Commercial Scale Pipeline Bend

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Vahid Abdolkarimi ◽  
Rasool Mohammadikhah
Keyword(s):  
Computational Model ◽  
Size Distribution ◽  
Erosion Rate ◽  
Gas Flow ◽  
Outer Wall ◽  
Solid Particles ◽  
Cfd Modeling ◽  
Dynamics Modeling ◽  
Particles Size Distribution ◽  
Erosive Effect

The computational fluid dynamics modeling of solid particles hydrodynamic based on the Lagrangian framework for diluted solid-gas flow through 90° gas pipeline bend is carried out to discover the effect of particles size distribution on particles flow pattern and their erosive effect on the bend. Particles size distribution has been obtained experimentally by measuring the sizes of solid particles that are flowing through the gas pipelines of Aghajari gas booster station. Also the erosion rate at the outer wall of the bend is predicted. The pipeline bend under study has a pipe diameter of 56 inches and ratios of the bend radius of the curvature to the pipeline diameter of 1.5. For the validation of computational model, firstly, the computational modeling is performed for a published experimental solid-gas flow data. The computational results include radial gas velocity and radial particle velocity profiles on planes which are at different angles through the bend. The comparison between the predicted numerical results and similar experimental data proves that the predictions of the computational model are acceptable. Finally, the particles' size distributions on each plane through the bend and the erosion rate on the outer wall of the bend have been obtained. The maximum rate of erosion is found to be 3.2 nm/s, occurring between 40 and 65° of the bend.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

scholarly journals Evaluation of hydrogen gas flow system in DECY - 13 cyclotron

2021 ◽  
Vol 1825 (1) ◽  
pp. 012027
Author(s):  
F I Diah ◽  
Saminto ◽  
V A F Sari ◽  
K Wibowo ◽  
F S Permana
Keyword(s):  
Gas Flow ◽  
Flow System ◽  
Hydrogen Gas

scholarly journals Hydrogen gas concentration measurement in small area using raman lidar measurement technnology

2018 ◽  
Vol 176 ◽  
pp. 01019 ◽  
Author(s):  
Sachiyo Sugimoto ◽  
Ippei Asahi ◽  
Tatuso Shiina
Keyword(s):  
Small Area ◽  
Gas Flow ◽  
Hydrogen Gas ◽  
Measurement Technology ◽  
Lidar Measurement ◽  
Measurement Point ◽  
Raman Lidar ◽  
Gas Concentration ◽  
Scattering Light ◽  
Temporal And Spatial

When change of hydrogen(H2) gas concentration in a certain point is measured, non-contact measurement technology with high temporal and spatial resolution is necessary. In this study, H2 concentration in the small area of <1cm2 under the gas flow was measured by using a Raman lidar. Raman scattering light at the measurement point of 750mm ahead was detected by the Raman lidar. As a result, it was proved that the H2 concentration of more than 100ppm could be successfully measured.

Study on Effective Radial Thermal Conductivity of Gas Flow through a Methanol Reactor

2015 ◽  
Vol 13 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Kun Lei ◽  
Hongfang Ma ◽  
Haitao Zhang ◽  
Weiyong Ying ◽  
Dingye Fang
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Temperature Distribution ◽  
Large Scale ◽  
Gas Flow ◽  
Fixed Bed ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Particle Reynolds Number

Abstract The heat conduction performance of the methanol synthesis reactor is significant for the development of large-scale methanol production. The present work has measured the temperature distribution in the fixed bed at air volumetric flow rate 2.4–7 m3 · h−1, inlet air temperature 160–200°C and heating tube temperature 210–270°C. The effective radial thermal conductivity and effective wall heat transfer coefficient were derived based on the steady-state measurements and the two-dimensional heat transfer model. A correlation was proposed based on the experimental data, which related well the Nusselt number and the effective radial thermal conductivity to the particle Reynolds number ranging from 59.2 to 175.8. The heat transfer model combined with the correlation was used to calculate the temperature profiles. A comparison with the predicated temperature and the measurements was illustrated and the results showed that the predication agreed very well with the experimental results. All the absolute values of the relative errors were less than 10%, and the model was verified by experiments. Comparing the correlations of both this work with previously published showed that there are considerable discrepancies among them due to different experimental conditions. The influence of the particle Reynolds number on the temperature distribution inside the bed was also discussed and it was shown that improving particle Reynolds number contributed to enhance heat transfer in the fixed bed.

scholarly journals Catalytic Micro Gas Sensor with Excellent Homogeneous Temperature Distribution and Low Power Consumption for Long-Term Stable Operation

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 927 ◽  
Author(s):  
Anmona Shabnam Pranti ◽  
Daniel Loof ◽  
Sebastian Kunz ◽  
Marcus Bäumer ◽  
Walter Lang
Keyword(s):  
Temperature Distribution ◽  
Low Power ◽  
Gas Sensor ◽  
Gas Flow ◽  
Pt Nanoparticles ◽  
Stable Operation ◽  
Catalytic Layer ◽  
Micro Gas Sensor ◽  
Homogeneous Temperature

This paper presents a long-term stable thermoelectric micro gas sensor with ligand linked Pt nanoparticles as catalyst. The sensor design gives an excellent homogeneous temperature distribution over the catalytic layer, an important factor for long-term stability. The sensor consumes very low power, 18 mW at 100 °C heater temperature. Another thermoresistive sensor is also fabricated with same material for comparative analysis. The thermoelectric sensor gives better temperature homogeneity and consumes 23% less power than thermoresistive sensor for same average temperature on the membrane. The sensor shows linear characteristics with temperature change and has significantly high Seebeck coefficient of 6.5 mV/K. The output of the sensor remains completely constant under 15,000 ppm continuous H2 gas flow for 24 h. No degradation of sensor signal for 24 h indicates no deactivation of catalytic layer over the time. The sensor is tested with 3 different amount of catalyst at 2 different operating temperatures under 6000 ppm and 15,000 ppm continuous H2 gas flow for 4 h. Sensor output is completely stable for 3 different amount of catalyst.

scholarly journals Transient Flow Characteristic of High-Pressure Hydrogen Gas in Check Valve during the Opening Process

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4222
Author(s):  
Jianjun Ye ◽  
Zhenhua Zhao ◽  
Jinyang Zheng ◽  
Shehab Salem ◽  
Jiangcun Yu ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Flow ◽  
Transient Flow ◽  
Check Valve ◽  
Hydrogen Gas ◽  
Strong Impact ◽  
Hydrogen Flow ◽  
Hydrogen Systems ◽  
Pressure Hydrogen ◽  
Opening Process

In high-pressure hydrogen systems, the check valve is one of the most easy-to-damage components. Generally, the high-pressure hydrogen flow can generate a strong impact on the check valve, which can cause damage and failure. Therefore, it is useful to study the transient flow characteristics of the high-pressure hydrogen flow in check valves. Using dynamic mesh generation and the National Institute of Standards and Technology (NIST) real hydrogen gas model, a transient-flow model of the high-pressure hydrogen for the check valve is established. First, the flow properties of high-pressure hydrogen during the opening process is investigated, and velocity changes and pressure distribution of hydrogen gas flow are studied. In addition, the fluid force, acceleration, and velocity of the valve spool are analyzed quantitatively. Subsequently, the effect of the hydrogen inlet-pressure on the movement characteristic of the valve spool is investigated. The results of this study can improve both the design and applications of check valves in high-pressure hydrogen systems.

scholarly journals Thermal Diffusion Performance of a Diffuser by various Guide Vanes configurations

2018 ◽  
Vol 225 ◽  
pp. 03018
Author(s):  
Aja O. Chikere ◽  
Hussain H. Al-Kayiem ◽  
Zainal Ambri A. Karim
Keyword(s):  
Gas Flow ◽  
Cfd Simulation ◽  
Bench Mark ◽  
Ansys Fluent ◽  
Guide Vanes ◽  
Pressure Losses ◽  
Fluent Software ◽  
Thermal Diffuser ◽  
Crosssectional Area ◽  
Large Diffusion

The use of vane-less diffuser with large diffusion angle has shown a setback in the diffusion process of high temperature working fluids. The hot gas flow was characterized as a jet-like flow. This paper presents problem, encountered practically, using a vane-less diffuser with large diffusion angle and how the problem is solved by CFD simulation. The investigated thermal diffuser has a length of 0.3 m, an inlet to outlet crosssectional area ratio of 1:25 and diffusion angle of 115.44o. To resolve the jet-like flow problem and poor distribution of the flow temperature at the diffuser outlet, the study suggested the use of guide-vanes into the diffuser. The study employed CFD simulation by ANSYS-FLUENT software to analyze the flow and thermal process in the diffuser. Three different shapes of guide vanes; block-shaped, oval-shaped and airfoil-shaped were considered in this study and at different vanes diffusion angles, as well as vane-less case, which was adopted as the bench mark case. The simulation results of the velocity, temperature and pressure at the diffuser outlet were compared for all cases. It was found that the guide vanes with symmetrical airfoil profile provided the best performance with most uniform distribution at the outlet of the diffuser. Also, the airfoil-shaped guide vanes resulted in lower pressure losses compared to the block-shaped and oval-shaped guide vanes. According to the analysis results, the diffuser was redesigned to improve the diffusion and temperature distribution across the diffuser outlet.

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