Numerical Study of the Effect of Hydrogen or Syngas Additions to n-Decane on the Harmful Substance Emission from a Homogeneous Combustion Chamber

2020 ◽  
Vol 14 (3) ◽  
pp. 395-406
Author(s):  
V. E. Kozlov ◽  
N. S. Titova ◽  
S. A. Torokhov
Keyword(s):  
Combustion Chamber ◽  
Numerical Study ◽  
Harmful Substance ◽  
Homogeneous Combustion

The Impact of Predried Lignite Cofiring With Hard Coal in an Industrial Scale Pulverized Coal Fired Boiler

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Robert Lewtak ◽  
Zbigniew Plutecki ◽  
Marcin Baranowski ◽  
Michal Ostrycharczyk ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Bituminous Coal ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Industrial Scale ◽  
Hard Coal ◽  
Cfd Simulations ◽  
Reference Case ◽  
The Impact

The paper presents the experimental and numerical study on the behavior and performance of an industrial scale boiler during combustion of pulverized bituminous coal with various shares of predried lignite. The experimental measurements were carried out on a boiler WP120 located in CHP, Opole, Poland. Tests on the boiler were performed during low load operation and the lignite share reached over to 36% by mass. The predried lignite, kept in dedicated separate bunkers, was mixed with bituminous coal just before the coal mills. Computational fluid dynamic (CFD) simulation of a cofiring scenario of lignite with hard coal was also performed. Site measurements have proven that cofiring of a predried lignite is not detrimental to the boiler in terms of its overall efficiency, when compared with a corresponding reference case, with 100% of hard coal. Experiments demonstrated an improvement in the grindability that can be achieved during co-milling of lignite and hard coal in the same mill, for both wet and dry lignite. Moreover, performed tests delivered empirical evidence of the potential of lignite to decrease NOx emissions during cofiring, for both wet and dry lignite. Results of efficiency calculations and temperature measurements in the combustion chamber confirmed the need to predry lignite before cofiring. Performed measurements of temperature distribution in the combustion chamber confirmed trend that could be seen in the results of CFD. CFD simulations were performed for predried lignite and demonstrated flow patterns in the combustion chamber of the boiler, which could prove useful in case of any further improvements in the firing system. CFD simulations reached satisfactory agreement with the site measurements in terms of the prediction of emissions.

scholarly journals Smart ceramic materials for homogeneous combustion in internal combustion engines: A review

2009 ◽  
Vol 13 (3) ◽  
pp. 153-163 ◽  
Author(s):  
Kannan Chidambaram ◽  
Tamilporai Packirisamy
Keyword(s):  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Porous Ceramic ◽  
Ceramic Materials ◽  
Combustion Engines ◽  
Emission Level ◽  
Engine Cylinder ◽  
Homogeneous Combustion ◽  
Zero Emission ◽  
Porous Ceramic Materials

The advantages of using ceramics in advanced heat engines include increased fuel efficiency due to higher engine operating temperatures, more compact designs with lower capacity cooling system. Future internal combustion engines will be characterized by near zero emission level along with low specific fuel consumption. Homogenous combustion which realized inside the engine cylinder has the potential of providing near zero emission level with better fuel economy. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In recent days, porous ceramic materials are being introduced inside the combustion chamber to achieve the homogeneous combustion. This paper investigates the desirable structures, types, and properties of such porous ceramic materials and their positive influence on the combustion process.

scholarly journals Mathematical modeling of a swirling jet in applications to low-emission combustion of low-grade fuels

2021 ◽  
Vol 23 (3) ◽  
pp. 308-317
Author(s):  
Usama J. Mizher ◽  
Peter A. Velmisov
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Negative Impact ◽  
Numerical Study ◽  
Combustion Process ◽  
Theoretical Data ◽  
Modern Society ◽  
Low Grade ◽  
Similar Solutions

Abstract. The search for new solutions in the field of energy, preventing negative impact on the environment, is one of the priority tasks for modern society. Natural gas occupies a stable position in the demand of the UES of Russia for fossil fuel. Biogas is a possible alternative fuel from organic waste. Biogas has an increased content of carbon dioxide, which affects the speed of flame propagation, and a lower content of methane, which reduces its heat of combustion. However, the combined combustion of natural gas and biogas, provided that the mixture of fuel and oxidizer is well mixed, can, on the one hand, reduce the maximum adiabatic temperature in the combustion chamber of power boilers at TPPs, and, on the other, increase the stability of biogas combustion. For the combined combustion of natural gas and biogas in operating power boilers, it is necessary to reconstruct the existing burners. For a high-quality reconstruction of burners capable of providing stable and low-toxic combustion of fuel, it is important to have theoretical data on the combustion effect of combustion of combinations of organic fuels on the temperature distribution in the combustion zone and on its maximum value. In this paper, self-similar solutions of the energy equation for axisymmetric motion of a liquid (gas) in a model of a viscous incompressible medium are obtained. Basing on them, a stationary temperature field in swirling jets is constructed. A set of programs based on the ANSYS Fluent software solver has been developed for modeling and researching of thermal and gas-dynamic processes in the combustion chamber. On the basis of the k - ϵ (realizable) turbulence model, the combustion process of a swirling fuel-air mixture is simulated. The results of an analytical and numerical study of the temperature and carbon dioxide distribution in the jet are presented.

scholarly journals A numerical study of confined turbulent jets for homogeneous combustion with oxygen enrichment

Fuel ◽  
2020 ◽  
Vol 261 ◽  
pp. 116449 ◽  
Author(s):  
Kumar Aanjaneya ◽  
Weiyu Cao ◽  
Yawei Chen ◽  
Claus Borgnakke ◽  
Arvind Atreya
Keyword(s):  
Numerical Study ◽  
Turbulent Jets ◽  
Oxygen Enrichment ◽  
Homogeneous Combustion

Numerical Study on Flow Field in a Peripheral Ported Rotary Engine Under the Action of Apex Seal Leakage

2020 ◽  
Author(s):  
Baowei Fan ◽  
Yuanguang Wang ◽  
Jianfeng Pan ◽  
Yaoyuan Zhang ◽  
Yonghao Zeng
Keyword(s):  
Velocity Field ◽  
Flow Field ◽  
Combustion Chamber ◽  
Numerical Study ◽  
Particle Image Velocimetry Data ◽  
Calculation Model ◽  
Flow Area ◽  
Rotary Engine ◽  
Unidirectional Flow ◽  
Rotary Engines

Abstract Apex seal leakage is one of the main defects restricting the performance improvement of rotary engines. The aim of this study is to study the airflow movement in a peripheral ported rotary engine under the action of apex seal leakage. For this purpose, a 3D dynamic calculation model considering apex seal leakage was firstly established and verified by particle image velocimetry data. Furthermore, based on the established 3D model, the flow field in the combustion chamber under the four apex seal leakage gaps (0.02, 0.04, 0.06 and 0.08 mms) and the three engine revolution speeds (2000, 3500, and 5000 RPMs) was calculated. By comparing with the flow field under the condition without leakage, the influences of the existence of apex seal leakage on the velocity field, the turbulent kinetic energy and the volumetric efficiency in the combustion chamber were investigated. Thereinto, the influences of the existence of apex seal leakage on the velocity field is that at the intake stroke, a vortex formed in the middle of the combustion chamber under the condition without apex seal leakage, was intensified by the apex seal leakage action. At the compression stroke, irrespective of the condition with or without apex seal leakage, all vortexes in the combustion chamber are gradually broken into a unidirectional flow. However, there is an obvious "leakage flow area" at the end of combustion chamber due to the existence of apex seal leakage.

Significant of Isothermal Flow Studies for High Swirling Flow in Unconfined Burner

2015 ◽  
Vol 789-790 ◽  
pp. 477-483
Author(s):  
A.R. Norwazan ◽  
M.N. Mohd Jaafar
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Turbulent Flows ◽  
Recirculation Zone ◽  
Swirling Flow ◽  
Numerical Study ◽  
Tangential Velocity ◽  
Radial Distance ◽  
Navier Stokes ◽  
Reacting Flow

This paper is presents numerical simulation of isothermal swirling turbulent flows in a combustion chamber of an unconfined burner. Isothermal flows of with three different swirl numbers, SN of axial swirler are considered to demonstrate the effect of flow axial velocity and tangential velocity to define the center recirculation zone. The swirler is used in the burner that significantly influences the flow pattern inside the combustion chamber. The inlet velocity, U0 is 30 m/s entering into the burner through the axial swirler that represents a high Reynolds number, Re to evaluate the differences of SN. The significance of center recirculation zone investigation affected by differences Re also has been carried out in order to define a good mixing of air and fuel. A numerical study of non-reacting flow into the burner region is performed using ANSYS Fluent. The Reynolds–Averaged Navier–Stokes (RANS) realizable k-ε turbulence approach method was applied with the eddy dissipation model. An attention is focused in the flow field behind the axial swirler downstream that determined by transverse flow field at different radial distance. The results of axial and tangential velocity were normalized with the U0. The velocity profiles’ behaviour are obviously changes after existing the swirler up to x/D = 0.3 plane. However, their flow patterns are similar for all SN after x/D = 0.3 plane towards the outlet of a burner.

Numerical Study of Air Distribution in Combustion Chamber

2016 ◽  
Vol 832 ◽  
pp. 218-223
Author(s):  
Michal Špilaček ◽  
Martin Lisý ◽  
Zdenek Skala
Keyword(s):  
Numerical Model ◽  
Turbulent Flow ◽  
Combustion Chamber ◽  
Numerical Study ◽  
Air Distribution ◽  
Secondary Combustion ◽  
Laminar And Turbulent Flow ◽  
Secondary Air

The main goal of this article is to analyze the distribution of primary and secondary combustion air in a combustion chamber. The fuel for the combustion chamber is biomass and the main characteristics the combustion chamber must meet is to be simple, reliable, cheap and ecological. A brief summary of the importance of primary and secondary air is made and then it is compared with the results from the numerical model. The numerical model is based upon a simplified chamber geometry and the results are computed for laminar and turbulent flow. From the comparison are determined flaws of the design of the combustion chamber and outlined possible solutions for their removal and further direction of the study.

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