scholarly journals A3.4 - Measuring Flow Velocity and Gas Concentration in Binary Gas Mixtures Using Thermal Sensors

2011 ◽  
Author(s):  
Ch. Hepp ◽  
F. Krogmann ◽  
J. Polak ◽  
M. Lehmann ◽  
G. Urban ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Gas Mixtures ◽  
Thermal Sensors ◽  
Gas Concentration

A New Approach to Analyzing Gas Mixtures Based on Improved BP Neural Network Algorithm

2012 ◽  
Vol 260-261 ◽  
pp. 548-553
Author(s):  
Teng Li ◽  
Xiao Mei Yuan ◽  
Shi Liang Yang ◽  
Xin Hui Zhang
Keyword(s):  
Neural Network ◽  
Numerical Simulation ◽  
Bp Neural Network ◽  
Array Signal Processing ◽  
Sensor Arrays ◽  
Gas Mixtures ◽  
New Approach ◽  
Gas Concentration ◽  
Network Algorithm ◽  
Neural Network Algorithm

A new approach is presented for analyzing gas mixtures by transforming the problem into a pattern classification one to reduce the effect of the poor repeatability of sensor response on the prediction of gas concentration. The aim of numerical simulation is to determine how successfully the approach using the combination of artificial neural networks with multi-sensor arrays can analyze multi-component gas mixtures. The results indicate that the new approach is realistic for gas mixture analysis, and numerical simulation is a powerful tool to determine the architecture of a network. By constructing improved BP neural network algorithm and basic BP neural network into sensor array signal processing and extracting 6 component as the input of neural network, Our investigation results indicated that recognition results obtained from improved BP neural network algorithm more accuracy than the results obtained from basic BP neural network.

Catalytic Combustion of Ultra-Low Heating Value Fuels Over 0.5%Pd/ZrO2/γ-Al2O3 Catalyst

2017 ◽  
Author(s):  
Xiaojing Lv ◽  
Xiaoyi Ding ◽  
Yiwu Weng
Keyword(s):  
Flow Velocity ◽  
Ignition Temperature ◽  
Catalytic Combustion ◽  
Experimental Studies ◽  
Wood Chip ◽  
Inlet Temperature ◽  
Technology Application ◽  
Gas Concentration ◽  
Combustible Gas ◽  
Heat Value

Catalytic combustion of ultra-low heat value fuel over 0.5%Pd/ZrO2/γ-Al2O3 was investigated to offer an opportunity for scientifically using such fuel sources. The experimental studies were performed using single fuel, synthetic mixtures and different kinds of gasified biomasses, respectively. The effects of varied combustible gas concentration, inlet temperature and flow velocity on the conversion rate were also studied. The results showed that the ignition temperature of 1.4% CH4 over the catalyst used is lower 210 °C than that in the oxidation absence of catalyst. Conversion of CH4 increased with decreasing flow velocity and increasing combustible gas concentration. The influence of the flow velocity on the conversation is more significant when further increasing the CH4 concentration to a certain degree. The ignition temperature for CO, H2, CH4 decreased with increasing concentration, and the specific order is TCH4, TCO, TH2. The experimental data showed that the influence of H2 is very obvious for CH4 combustion-supporting character by adding different concentration of H2. Among the experiments of three kinds of gasified biomasses, the catalytic combustion characteristics of wood chip gas is best, followed by grape seed gas and cotton wood gas. These studies would provide the experimental analysis and technical support for catalytic combustion technology application in ultra-low heat value fuel.

scholarly journals Experimental Validation of a Novel Generator of Gas Mixtures Based on Axial Gas Pulses Coupled to a Micromixer

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 715
Author(s):  
Florian Noël ◽  
Claire Trocquet ◽  
Christophe A. Serra ◽  
Stéphane Le Calvé
Keyword(s):  
Experimental Validation ◽  
Gas Mixtures ◽  
Analytical Instrument ◽  
Pure Nitrogen ◽  
Gas Concentration ◽  
Multi Stage ◽  
The Times ◽  
Gas Dilution ◽  
Pollutant Mixtures ◽  
Two Parameters

In this work, a novel generator of gas mixtures previously numerically investigated and based on axial gas pulses coupled to a micromixer has been conceived, manufactured, and validated. Standard gaseous pollutant mixtures and pure nitrogen or pure air were introduced in a microdevice designed to generate alternating axial gas pulses which were downstream homogenized by means of a multi-stage modular micromixer. The dilution, and therefore the final pollutant concentration, was controlled by two parameters: the ratio between the times of each of the two gas pulses and the partial pressure of the pollutant(s) mixture added to the device. The gas mixture generator was coupled to an analyzer to monitor the concentration of aromatic pollutants. The response time was optimized to be lower than 2 min in accordance with the analytical instrument. The quantity of pollutants measured at the micromixer’s outlet increased linearly with the expected gas concentration of 3.7–100 ppb generated by this novel microfluidic generator and fitted perfectly with those obtained by a reference gas dilution bench. At 5 ppb, the precision on the concentration generated is close to that obtained with the conventional gas mixing bench, i.e., around 10%.

scholarly journals Laser gas analysis for multicomponent gas mixtures with essentially different gas concentration

2013 ◽  
Vol 13 (02) ◽  
Author(s):  
Viktor Gorodnichev ◽  
Mikhail Belov ◽  
Andrey Busargin ◽  
Larisa Eremenko
Keyword(s):  
Gas Mixtures ◽  
Gas Analysis ◽  
Gas Concentration ◽  
Multicomponent Gas

Effect of Oxygen on Diamond Deposition in CH4/O2/H2 Gas Mixtures

1993 ◽  
Vol 334 ◽  
Author(s):  
H. Matsuyama ◽  
N. Sato ◽  
H. Kawakami
Keyword(s):  
Film Growth ◽  
Microwave Plasma ◽  
Gas Mixtures ◽  
Carbon Films ◽  
Diamond Growth ◽  
Growth Region ◽  
Gas Concentration ◽  
Oxygen Gas ◽  
Effect Of Oxygen ◽  
Plasma Emission Spectroscopy

AbstractDiamond growth experiments were carried out by a microwave plasma assisted CVD technique in various gas mixtures of CH4(0–100%)/02/H2. The phase diagram obtained by this study shows that a diamond growth region exists. With addition of more than 5% O2 in reactant gases, diamond particles could be included in amorphous or graphitic carbon films even using CH4/O2 gas mixtures. Faceted diamond films were obtained if the oxygen gas concentration [O2] was approximately more than half the methane gas concentration [CH4] ([O2]>[CH4]/2). However, no films were grown when [O2] exceeded half of [CH4] plus 7% ([O2]>[CH4]/2+7%). These results corresponded to the observations by plasma emission spectroscopy. Though oxygen etches carbon films and decomposes methane by forming carbon monoxide, oxygen rarely reacts with hydrogen in a film growth region.

Effect of H2/N2 Mixtures on Reduction of Nickel Oxide

2020 ◽  
Vol 1010 ◽  
pp. 280-285
Author(s):  
Salmie Suhana Che Abdullah ◽  
Nur Nadia Mohd Nasri ◽  
Nur Hidayah Ahmad Zaidi ◽  
Siti Hawa Mohamed Salleh ◽  
Imaduddin Helmi Wan Nordin
Keyword(s):  
Nickel Oxide ◽  
Pore Size ◽  
Density Measurement ◽  
Reduction Process ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Phase Identification ◽  
Nitrogen Gas ◽  
Gas Concentration ◽  
Before And After

This paper describes the reduction of nickel oxide under different gas mixture. The influence of gas mixture on phase, density, morphology and pore size of reduced nickel oxide were studied. Nickel oxide pellets sintered at 1400 °C were reduced under various hydrogen-nitrogen gas mixtures, namely 40% H2-60% N2, 60% H2-40% N2, 80% H2-20% N2. Phase identification, density measurement and observation of morphology were conducted on samples before and after reduction process. Under all gas mixtures, nickel oxide was completely reduced to nickel. Density of the samples decreased in the range of 21% to 32% depends on H2 percentage used. Results from the density shows that the higher the H2 gas concentration, the smaller the density changes. Significant change in porosity of the sample before and after reduction was observed. Size of pore after reduction determined by H2 concentration used during reduction where the higher the H2 concentration resulted in large pore size.

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