scholarly journals Dependence of the Flue Gas Flow on the Setting of the Separation Baffle in the Flue Gas Tract

2021 ◽  
Vol 11 (7) ◽  
pp. 2961
Author(s):  
Nikola Čajová Kantová ◽  
Alexander Čaja ◽  
Marek Patsch ◽  
Michal Holubčík ◽  
Peter Ďurčanský
Keyword(s):  
Particulate Matter ◽  
Flue Gas ◽  
Gas Flow ◽  
Negative Impact ◽  
Combustion Process ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Computational Fluid Dynamics Cfd ◽  
Particle Imaging ◽  
Combustion Of Solid Fuels

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. This article aims to optimize the flue gas tract using separation baffles. This design can make it possible to capture particulate matter by using three baffles and prevent it from escaping into the air in the flue gas. The geometric parameters of the first baffle were changed twice more. The dependence of the flue gas flow on the baffles was first observed by computational fluid dynamics (CFD) simulations and subsequently verified by the particle imaging velocimetry (PIV) method. Based on the CFD results, the most effective is setting 1 with the same boundary conditions as those during experimental PIV measurements. Setting 2 can capture 1.8% less particles and setting 3 can capture 0.6% less particles than setting 1. Based on the stoichiometric calculations, it would be possible to capture up to 62.3% of the particles in setting 1. The velocities comparison obtained from CFD and PIV confirmed the supposed character of the turbulent flow with vortexes appearing in the flue gas tract, despite some inaccuracies.

Experimental and Numerical Flow Visualization in Patient Specific Pre Operative Human Airway Geometry

2011 ◽  
Author(s):  
Mathias Vermeulen ◽  
Cedric Van Holsbeke ◽  
Tom Claessens ◽  
Jan De Backer ◽  
Peter Van Ransbeeck ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Particle Image ◽  
Patient Specific ◽  
Lung Volume Reduction ◽  
Cfd Simulations ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Specific Geometry ◽  
Computational Fluid Dynamics Cfd ◽  
Human Airways

An experimental and numerical platform was developed to investigate the fluidodynamics in human airways. A pre operative patient specific geometry was used to create an identical experimental and numerical model. The experimental results obtained from Particle Image Velocimetry (PIV) measurements were compared to Computational Fluid Dynamics (CFD) simulations under stationary and pulsatile flow regimes. Together these results constitute the first step in predicting the clinical outcome of patients after lung surgeries such as Lung Volume Reduction.

Integrated modeling of coking flue gas indices based on mechanism model and improved neural network

2018 ◽  
Vol 41 (1) ◽  
pp. 85-96
Author(s):  
Yaning Li ◽  
Xuelei Wang ◽  
Jie Tan
Keyword(s):  
Neural Network ◽  
Adaptive Learning ◽  
Flue Gas ◽  
Gas Flow ◽  
Rbf Neural Network ◽  
Combustion Process ◽  
Material Balance ◽  
Integrated Modeling ◽  
Flow Diagram ◽  
Mechanism Model

Focusing on the first domestic coking flue gas desulfurization and denitration integrated unit in China, the current condition of inlet flue gas indices cannot be determined timely owing to the large detection lag and complex upstream coking process, which is extremely unfavorable for the optimal control of desulfurization and denitration process. In order to solve this problem, an intelligent integrated modeling method of flue gas SO2 concentration, O2 content and NOx concentration is proposed. Firstly, the gas flow diagram in combustion process is built, the mechanism models of SO2, NOx concentration and O2 content are established according to the principle of material balance and reaction kinetics, respectively. Then the RBF neural network is adopted to compensate the prediction error, an improved training algorithm combining optimal stopping principle and dual momentum adaptive learning rate is proposed to improve the training speed and generalization ability of neural network. Based on the practical data of two 55-hole and 6-meter top charging coke ovens in the coking group, the effectiveness and superiority of proposed model and method are verified by simulation via comparison of various methods.

CFD Simulations and PIV Measurements for Optimization of Flow Pattern in a Sieve Plate Extraction Column

2011 ◽  
Vol 391-392 ◽  
pp. 1464-1468
Author(s):  
Chang Chun Duan ◽  
Chun Jiang Liu ◽  
Xi Gang Yuan
Keyword(s):  
Flow Pattern ◽  
Reverse Flow ◽  
Continuous Phase ◽  
Extraction Column ◽  
Sieve Plate ◽  
Cfd Simulations ◽  
Flow Area ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Cfd

Present work deals with the optimization for flow pattern of continuous phase in a sieve plate extraction column using both computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. Firstly single-phase simulation was conducted for the traditional column and it was found that there was a very large reverse flow area between every two plates. Then step by step, by changing the downcomer structure, consisting of inclining downcomers, adding baffles, slotting downcomers and baffles and adjusting the number and size of slots, the reverse flow area was decreased and thereby the flow pattern of continuous phase was optimized. Finally, an optimal flow pattern was obtained with reverse flow area greatly reduced. In order to prove the validity of the simulation results, PIV experiments of two columns were carried out and it was found that the results of simulations and experiments are in good agreement.

scholarly journals Influence of ammonia on wet-limestone flue gas desulfurization process from coal-based power plant

2019 ◽  
Vol 116 ◽  
pp. 00101
Author(s):  
Tomasz Wypiór ◽  
Renata Krzyżyńska
Keyword(s):  
Particulate Matter ◽  
Flue Gas ◽  
Gas Flow ◽  
Catalytic Reduction ◽  
Flue Gases ◽  
Flue Gas Desulfurization ◽  
Flow Capacity ◽  
Desulfurization Process ◽  
Denitrification Process ◽  
Raw Wastewater

The paper presents data concerning the influence of ammonia on wet flue gas desulfurization (WFGD) absorber. Paper presents preliminary results of an industrial scale study on WFGD absorber, that collects flue gases from four boilers with total flue gas flow capacity of the WFGD equal to 1 500 000 Nm3/h. Each boiler is equipped with selective non-catalytic reduction (SNCR) with urea injection. It was shown, that ammonia present in the flue gas upstream the WFGD increases the pH of absorption slurry, impacting the desulphurization process. In addition, analysis of particulate matter upstream and downstream the absorber shows an increase of the concentration of ammonium species in the particulate matter about 14 times, as average. Moreover, a non-optimized denitrification process can cause a high NH4+ concentration in the absorption slurry (up to 768 mg/L) and raw wastewater (up to 891 mg/L).

High Performance of the CFBC Pilot Plant with CO2 Chemical Absorption by Optimizing the Absorber Parameters

2013 ◽  
Vol 746 ◽  
pp. 3-8
Author(s):  
Cristian Dinca ◽  
Adrian Badea ◽  
Horia Necula
Keyword(s):  
Flue Gas ◽  
High Performance ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Energy Requirement ◽  
Combustion Process ◽  
Process Efficiency ◽  
Solution Temperature ◽  
Fluidized Bed Combustion ◽  
Capture Process

The objective of this paper consists to identify the influence of absorption process temperature and pressure on the energy requirement of the CO2 chemical capture process. The study aimed to reducing CO2 emissions from coal combustion process in the circulating fluidized bed combustion (CFBC). The post-combustion CO2 capture process was analyzed using primary amine MEA in the following conditions: the ratio L/G was varied between 0.45..1.6 kgliquid/kggas keeping constant the flue gas flow and varying the solvent flow between 500 .. 1 600 kg/h. The CO2 capture process efficiency was maintained constant around 90%. For a concentration of 30% MEA in solution, it was observed that when the absorber solution temperature increasing from 32 to 49 °C, the amount of heat required for the solvent regeneration increased from 2.1 to 3.3 GJ/tCO2 according to the solvent pressure and flue gas pressure respectively. On the other hand, for varying the absorber solvent pressure in the range 1.1 .. 2.1 atm, the heat required by the process was not significantly influenced. Considering the same variation of the absorber solvent temperature, the rich loading solvent was increased from 0.43 to 0.57 mol CO2/mol MEA and consequently the MEA capacity of CO2 absorption from 0.3 to 0.422 molCO2/mol MEA.

scholarly journals The Subcooling Effect of the Flue Gas Flow Mixture Internal Dynamic and Heating Capacity

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 295-300
Author(s):  
Žilvinas ULDINSKAS ◽  
Vytautas DAGILIS
Keyword(s):  
Flue Gas ◽  
Energy Recovery ◽  
Energy Production ◽  
Gas Flow ◽  
Waste Heat ◽  
Combustion Process ◽  
Heat Energy ◽  
Internal Dynamic ◽  
System Combination ◽  
Heat Energy Recovery

Growing environmental restrictions in energy production industry calls for greater efficiency and cleaner fuel burning processes. Biomass (wood chips) as a fuel is in great demand for boiler and power plants as it is considered widely available and relatively clean. While combining woodfuel flue gas and condensing economizers significantly raises the efficiency and makes it even more viable solution for energy production although the biomass fuel usage still has reservations in waste heat, which could be utilized. The calculation algorithm is presented for evaluation of subcooled biomass flue gas components concentration values which determine the leftover heat energy value carried by flue gas flow. Several cases of biomass quality (regarding moisture w=45%, 50%, 55% and 60%) and combustion process quality (regarding air excess value λ=1,2; 1,5; 1,8) in the flue gas temperature range of 50 to 20°C and effects for flue gas internal dynamic were examined. It was determined that water vapour amount depends only on temperature, while every other component concentration change with different air excess and temperature values. It was observed that further usage of biomass flue gas could result in up to 13% additional heat energy recovery for 1MW of fuel input, system combination together with condensing economizers could result in up to 31% of heat energy recovery.

scholarly journals The Prototype of Non-thermal Plasma After treatment System for Simultaneous Reduction of Nitrogen Oxide Emission in Flue Gas

2021 ◽  
Vol 302 ◽  
pp. 01010
Author(s):  
Dararat Laohalertdecha ◽  
Kampanart Theinnoi ◽  
Sak Sittichompoo
Keyword(s):  
Nitrogen Oxides ◽  
Nitrogen Oxide ◽  
Flue Gas ◽  
Thermal Plasma ◽  
Power Plants ◽  
Gas Flow ◽  
Nox Reduction ◽  
Combustion Process ◽  
Operating Conditions ◽  
Non Thermal Plasma

Nowadays, global warming is the main environmental problems all over the world. The air pollutants mainly from the burning of fossil fuels and coal in power plants, transportation, and automobiles. There are release major point emission of the atmosphere. The nitrogen oxides are the most relevant for air pollution that contribute to the formation of photochemical smog and acid rain. Numerous methods have been studied to eliminate the nitrogen oxides such as the use low-nitrogen fuels technology, the selective catalytic reduction (SCR), wet scrubbing. The aim of this research is investigated non-thermal plasma (NTP) techniques offer an innovation to eliminate both nitrogen oxide (NOx) and soot emissions from combustion. This study is used to selectively transfer input electrical energy to electrons without expending this in heating the entire gas flow which creates free radicals in the flue gases. The simulated flue gas from combustion process is applied to the system. The results showed that the prototype of nonthermal plasma system is shown the highly efficient of NOx removal was achieved. However, the optimised of NTP operating conditions are required to enhance the NOx reduction activities.

Numerical Study on Flow Field Distribution Regularities in Wet Gas Desulfurization Tower Changing Inlet Gas/Liquid Feature Parameters

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Qingbo Deng ◽  
Jingyu Ran ◽  
Juntian Niu ◽  
Zhongqing Yang ◽  
Ge Pu ◽  
...  
Keyword(s):  
Flow Field ◽  
Field Distribution ◽  
Flue Gas ◽  
High Speed ◽  
Gas Flow ◽  
Negative Impact ◽  
Numerical Study ◽  
Negative Influence ◽  
Wet Gas ◽  
Integration Effect

Abstract In the wet gas desulphurization tower, the uneven distribution of flue gas will have a negative impact on the desulphurization process. The effect should be counterbalanced by increasing the amount of slurry spray, which will increase the operating costs. Adding deflectors will also bring negative effects and increase the expenses. In order to avoid the negative influence, this paper studied the flow field distribution regularities of flue gas in desulfurization tower at different inlet velocities and liquid–gas ratios. Velocity field distribution character was evaluated by uniformity index. The results showed that the flue gas forms a vortex in the tower and a local high-speed gas-flow appears in the empty tower, which led to a poor flow field uniformity. After adding the spray, the flow field is integrated into uniformity. The slurry has obvious integration effect on flue gas. The lower the inlet flue gas velocity is, the higher the velocity uniform index in the desulfurization tower will be, and the heat exchange between the two phases more sufficient. To achieve the same uniformity, the less amount of slurry is required while the inlet velocity is slower. The energy consumption and material consumption of the desulfurization system can be effectively reduced by reducing the import speed reasonably.

Retrofit of WtE Boiler: Case Study on Bonn Plant

2002 ◽  
Author(s):  
Mark Pe´rilleux ◽  
Dirk Eeraerts
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Natural Circulation ◽  
Combustion Process ◽  
Circulation System ◽  
Gas Temperature ◽  
Complete Combustion ◽  
Parallel Flows ◽  
Secondary Air Injection ◽  
Secondary Air

The implementation of the European-directive requiring a residence time of at least two seconds at a temperature above 850°C (1562°F), the change in waste characteristics, and the pursuit of higher thermal efficiencies has pushed many of the existing WtE plants in Europe to their operational limits. Most existing WtE plants were not designed to operate under these conditions and may require modifications to the combustion system. Within the SEGHERS better technology (SEGHERS) company, the SEGHERS-IBB-Prism was developed to deal with the cause of these problems, which are essentially related to insufficient mixing and burnout of the flue gases in the combustion area. In the Boiler Prism the flue gas flow is divided into two parallel flows prior to entering the first radiant pass of the boiler. This division is achieved by means of a prism shaped construction, which is water-cooled and integrated with the natural circulation system of the boiler. Additional secondary air injection nozzles are fitted in the prism. This technology results in a more uniform flue gas temperature and a complete combustion of the flue gas immediately above the prism. In the Bonn Plant, these improvements in the combustion process resulted in a decrease of the fireside cleaning requirements of more than 50%.

scholarly journals Analysis of Swirling Flow on Cyclone Separator Using CFD to Reduce Particulate Matter of Diesel Engine

2019 ◽  
Vol 2 (1) ◽  
pp. 71-76
Author(s):  
S. Nurcholik ◽  
L. Adnyani ◽  
D. Sa’adiyah ◽  
L. Rahmah ◽  
R. Revari
Keyword(s):  
Fluid Dynamics ◽  
Air Pollution ◽  
Computational Fluid Dynamics ◽  
Particulate Matter ◽  
Diesel Engine ◽  
Flue Gas ◽  
Swirling Flow ◽  
Cyclone Separator ◽  
Particle Movement ◽  
Computational Fluid Dynamics Cfd

Particulate matter (PM) is one of the component in flue gas of diesel engine. As one of air pollution, PM needs more attention, because its existence irritates respiratory. The using of cyclone as additional part of diesel engine, can reduce PM concentration before released to surrounding. However, the shape of cyclone affects the percentage of PM due to turbulence and length of track. In this paper, the prediction of swirling flow in different type of cyclone separator will be conducted by using Computational Fluid Dynamics (CFD). The analysis will focus on particle movement inside the cyclone separator and its turbulence phenomenon. There are four types of cyclone separator which will be observed: Perry’s method, Stairmand’s method, and the modification of each methods. All of these cyclone separator will have the same velocity inlet, and will be simulated using RNG k- model as the turbulence modelling. The simulation shows that the Stairmand’s method has the best turbulence and can collect most of PM.

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