Optimisation of combustion process in furnace of coal-fired boiler PK-38 using Computational Fluid Dynamics

Fuels based on admixtures of methane/natural gas and hydrogen are a promising way to reduce CO2 emissions of spark ignition engines and increase their efficiency. A lot of work was conducted experimentally, whereas only limited numerical work is available in the context of three-dimensional modelling of the full engine cycle. This work addresses this fact by proposing a reactive computational fluid dynamics modelling framework to consider the effects of hydrogen addition on the combustion process. Part I of this two-part study focuses on the modelling and crucial considerations in order to predict the mean cycle based on the G-equation combustion model using the Reynolds-averaged Navier–Stokes equations. There, the effect of increased burning speed was globally captured by increasing the flame speed coefficient A, appearing in the considered flame speed closure. The proposed simplified modelling of the early flame stage proved to be robust for the conducted hydrogen variation from 0 to 50 vol% H2 for stoichiometric and lean operation. Scope of this work, Part II, are cyclic fluctuations and the hydrogen influence thereon using large eddy simulation and the proposed modelling framework. The model is probed towards its capabilities to predict the fluctuation of the combustion process for 0 and 50 vol% H2 and correlations influencing the observed peak pressure of the individual cycle are presented. It is shown that the considered approach is capable to reproduce the cyclic fluctuations of the combustion process under the influence of hydrogen addition as well as lean operation. The importance of the early flame phase with respect to arising fluctuations is highlighted as well as the contribution of the resolved scales in terms of the flame front wrinkling.

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Review of Computational Fluid Dynamics Studies on Chemical Looping Combustion

Journal of Energy Resources Technology ◽

10.1115/1.4048680 ◽

2020 ◽

Vol 143 (8) ◽

Author(s):

Yali Shao ◽

Ramesh K. Agarwal ◽

Xudong Wang ◽

Baosheng Jin

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Oxygen Carrier ◽

Combustion Process ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

Flow Process ◽

Gas Leakage ◽

Fuel Reactor ◽

Energy Penalty

Abstract Chemical looping combustion (CLC) is an attractive technology to achieve inherent CO2 separation with low energy penalty. In CLC, the conventional one-step combustion process is replaced by two successive reactions in two reactors, a fuel reactor (FR) and an air reactor (AR). In addition to experimental techniques, computational fluid dynamics (CFD) is a powerful tool to simulate the flow and reaction characteristics in a CLC system. This review attempts to analyze and summarize the CFD simulations of CLC process. Various numerical approaches for prediction of CLC flow process are first introduced and compared. The simulations of CLC are presented for different types of reactors and fuels, and some key characteristics including flow regimes, combustion process, and gas-solid distributions are described in detail. The full-loop CLC simulations are then presented to reveal the coupling mechanisms of reactors in the whole system such as the gas leakage, solid circulation, redox reactions of the oxygen carrier, fuel conversion, etc. Examples of partial-loop CLC simulation are finally introduced to give a summary of different ways to simplify a CLC system by using appropriate boundary conditions.

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Computational fluid dynamics simulation of the combustion process, emission formation and the flow field in an in-direct injection diesel engine

Thermal Science ◽

10.2298/tsci111218108b ◽

2013 ◽

Vol 17 (1) ◽

pp. 11-23 ◽

Cited By ~ 5

Author(s):

Ramin Barzegar ◽

Sina Shafee ◽

Shahram Khalilarya

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Diesel Engine ◽

Flow Field ◽

Direct Injection ◽

Combustion Process ◽

Dynamics Simulation ◽

Computational Fluid Dynamics Simulation ◽

Direct Injection Diesel Engine

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Optimizing combustion process by adaptive tuning technology based on Integrated Genetic Algorithm and Computational Fluid Dynamics

Energy Conversion and Management ◽

10.1016/j.enconman.2011.11.013 ◽

2012 ◽

Vol 56 ◽

pp. 53-62 ◽

Cited By ~ 2

Author(s):

X. Liu ◽

R.C. Bansal

Keyword(s):

Fluid Dynamics ◽

Genetic Algorithm ◽

Computational Fluid Dynamics ◽

Combustion Process ◽

Adaptive Tuning

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Simulation of Combustion Process in Diesel Engines Based on Eddy Dissipation Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.823.315 ◽

2016 ◽

Vol 823 ◽

pp. 315-318

Author(s):

Mahran Dawwa

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Combustion Chamber ◽

Diesel Engines ◽

Combustion Process ◽

Premixed Combustion ◽

Dissipation Model ◽

Simulation Results ◽

Dynamics Method

The aim of this study is to simulate the combustion process in the combustion chamber of diesel engines by using eddy dissipation model (EDM) and computational fluid dynamics method (CFD). Computational fluid dynamics has been used wieldy in the recent years for simulating the strokes of diesel engines including the combustion process. Eddy dissipation model can be used for simulating non-premixed combustion cases such as the combustion in diesel engines. The simulation steps and the simulation results will be discussed and illustrated. ANSYS program is the software which used for performing this simulation.

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Reduction in Pollutants Emissions From Domestic Boilers—Computational Fluid Dynamics Study

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.3159526 ◽

2009 ◽

Vol 1 (1) ◽

Cited By ~ 4

Author(s):

Gasser Hassan ◽

Mohamed Pourkashanian ◽

Derek Ingham ◽

Lin Ma ◽

Stephen Taylor

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Combustion Chamber ◽

Combustion Process ◽

Pollutant Emissions ◽

Combustion Model ◽

Cfd Model ◽

Inlet Velocity ◽

Average Temperature ◽

Partially Premixed Combustion

This study is concerned with building a computational fluid dynamics (CFD) model to simulate the combustion process occurring in the combustion chamber of some domestic boilers. The burner used in this boiler is a conventional cylindrical premix burner with small inlet holes on its surface. A two-dimensional CFD model is built to simulate the combustion chamber domain, and the partially premixed combustion model with a postprocessor for NOx calculations is used to simulate the combustion process inside the combustion chamber. A complete description of the formation characteristics of NOx produced from the boiler is discussed in detail. A comparison between the CFD numerical results and the experimental measurements at different boiler loads is performed in order to validate the numerical model and investigate the accuracy of the CFD model. The validated CFD model is used to investigate the effect of different boundaries temperatures and the mixture inlet velocity on the flue gas average temperature, residence time, and hence the CO and NOx concentrations produced from the combustion chamber. The concept of changing the mixture inlet velocity is found to be an effective method to improve the design of the burner in order to reduce the pollutant emissions produced from the boiler with no effect on the boiler efficiency.

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Computational Fluid Dynamics Modeling of Chemical Looping Combustion Process with Calcium Sulphate Oxygen Carrier

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1786 ◽

2009 ◽

Vol 7 (1) ◽

Cited By ~ 10

Author(s):

Baosheng Jin ◽

Rui Xiao ◽

Zhongyi Deng ◽

Qilei Song

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Oxygen Carrier ◽

Combustion Process ◽

Combustion Products ◽

Calcium Sulphate ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

Dynamics Modeling ◽

Fuel Reactor

To concentrate CO2 in combustion processes by efficient and energy-saving ways is a first and very important step for its sequestration. Chemical looping combustion (CLC) could easily achieve this goal. A chemical-looping combustion system consists of a fuel reactor and an air reactor. Two reactors in the form of interconnected fluidized beds are used in the process: (1) a fuel reactor where the oxygen carrier is reduced by reaction with the fuel, and (2) an air reactor where the reduced oxygen carrier from the fuel reactor is oxidized with air. The outlet gas from the fuel reactor consists of CO2 and H2O, while the outlet gas stream from the air reactor contains only N2 and some unused O2. The water in combustion products can be easily removed by condensation and pure carbon dioxide is obtained without any loss of energy for separation.Until now, there is little literature about mathematical modeling of chemical-looping combustion using the computational fluid dynamics (CFD) approach. In this work, the reaction kinetic model of the fuel reactor (CaSO4+ H2) is developed by means of the commercial code FLUENT and the effects of partial pressure of H2 (concentration of H2) on chemical looping combustion performance are also studied. The results show that the concentration of H2 could enhance the CLC performance.

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Study of dimethyl ether homogeneous charge compression ignition combustion process using a multi-dimensional computational fluid dynamics model

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2009.02.006 ◽

2009 ◽

Vol 48 (9) ◽

pp. 1814-1822 ◽

Cited By ~ 13

Author(s):

Chen Huang ◽

Mingfa Yao ◽

Xingcai Lu ◽

Zhen Huang

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Dimethyl Ether ◽

Homogeneous Charge Compression Ignition ◽

Combustion Process ◽

Compression Ignition ◽

Dynamics Model ◽

Computational Fluid Dynamics Model ◽

Compression Ignition Combustion ◽

Homogeneous Charge

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Computational fluid dynamics analysis of the combustion process and emission characteristics for a direct-injection-premixed charge compression ignition engine

International Journal of Engine Research ◽

10.1177/1468087413498868 ◽

2014 ◽

Vol 15 (5) ◽

pp. 539-548 ◽

Cited By ~ 1

Author(s):

Hiroshi Kawanabe ◽

Takuji Ishiyama

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Direct Injection ◽

Combustion Process ◽

Emission Characteristics ◽

Dynamics Analysis ◽

Compression Ignition ◽

Compression Ignition Engine ◽

Computational Fluid Dynamics Analysis

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Exergetic efficiency analysis of hydrogen–air detonation in pulse detonation combustor using computational fluid dynamics

International Journal of Spray and Combustion Dynamics ◽

10.1177/1756827716653344 ◽

2016 ◽

Vol 9 (1) ◽

pp. 44-54 ◽

Cited By ~ 3

Author(s):

Pinku Debnath ◽

KM Pandey

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Mass Fraction ◽

Transport Model ◽

Combustion Process ◽

Vital Role ◽

Exergetic Efficiency ◽

Ansys Fluent ◽

Pulse Detonation ◽

Detonation Combustion

Exergy losses during the combustion process, heat transfer, and fuel utilization play a vital role in the analysis of the exergetic efficiency of combustion process. Detonation is thermodynamically more efficient than deflagration mode of combustion. Detonation combustion technology inside the pulse detonation engine using hydrogen as a fuel is energetic propulsion system for next generation. In this study, the main objective of this work is to quantify the exergetic efficiency of hydrogen–air combustion for deflagration and detonation combustion process. Further detonation parameters are calculated using 0.25, 0.35, and 0.55 of [Formula: see text] mass concentrations in the combustion process. The simulations have been performed for converging the solution using commercial computational fluid dynamics package Ansys Fluent solver. The details of combustion physics in chemical reacting flows of hydrogen–air mixture in two control volumes were simulated using species transport model with eddy dissipation turbulence chemistry interaction. From these simulations it was observed that exergy loss in the deflagration combustion process is higher in comparison to the detonation combustion process. The major observation was that pilot fuel economy for the two combustion processes and augmentation of exergetic efficiencies are better in the detonation combustion process. The maximum exergetic efficiency of 55.12%, 53.19%, and 23.43% from deflagration combustion process and from detonation combustion process, 67.55%, 57.49%, and 24.89%, are obtained from aforesaid [Formula: see text] mass fraction. It was also found that for lesser fuel mass fraction higher exergetic efficiency was observed.

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