Numerical Simulation of Heavy Fuel Oil Combustion Characteristics and NOx Emissions in Calciner in Cement Industry

2015 ◽  
Author(s):  
Hisham Abou ElSoad ◽  
Essam E. Khalil
Keyword(s):  
Mixture Fraction ◽  
Radiation Heat Transfer ◽  
Combustion Characteristics ◽  
Cement Industry ◽  
Fuel Oil ◽  
Combustion Model ◽  
Injection Velocity ◽  
Nox Emissions ◽  
Heavy Fuel Oil ◽  
Probability Density Function Pdf

The aim of the present study is to numerically investigate the combustion characteristics of Heavy Fuel Oil (HFO) and NOx emissions inside a Calciner used in cement industry. The combustion model was based on the conserved scalar (mixture fraction) and prescribed Probability Density Function (PDF) approach. The (RNG) k-ε turbulence model has been used. The HFO droplet trajectories were predicted by solving the momentum equations for the droplets using Lagrangian treatment. The radiation heat transfer equation was solved using P1 method. A swirl number greater than 0.6 was found to be optimal for good combustion characteristics and NOx emissions concentration. Meanwhile, it was found that the HFO viscosity value assumption has a significant effect on the injection velocity and must be considered as a function of temperature during the analysis as this will significantly affect the combustion characteristics.

Numerical Simulation of Heavy Fuel Oil Combustion Characteristics and NOx Emissions in Calciner in Cement Industry

2015 ◽  
Author(s):  
Hisham Aboelsaod ◽  
Essam E. Khalil
Keyword(s):  
Molecular Nitrogen ◽  
Combustion Characteristics ◽  
Cement Industry ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Combustion Model ◽  
Injection Velocity ◽  
Nox Emissions ◽  
Heavy Fuel Oil ◽  
Swirl Number

The aim of the present study is to numerically investigate the combustion characteristics of Heavy Fuel Oil (HFO) and NOx emissions inside a calciner used in cement industry. The calciner is a furnace placed before the rotary Kiln its main objectives are the reduction of CO2 emissions and air pollutions while enhancing the cement quality through separating the calcination and clinkering processes. In order to conduct the present investigations the calciner at CEMEX Egypt Cement Company was considered and real dimensions and operating conditions were applied. The combustion model was based on the conserved scalar (mixture fraction) and prescribed Probability Density Function (PDF) approach. The (RNG) k-ε turbulence model has been used. The HFO droplet trajectories were predicted by solving the momentum equations for the droplets using Lagrangian treatment. The radiation heat transfer equation was solved using P1 method. The formation of thermal NOx from molecular nitrogen was modeled according to the extended Zeldovich mechanism. The effects of varying the burner’s swirl number and viscosity grade on the combustion performance of HFO and the resulting NOx emissions were considered. The burner’s swirl number influences the mixing rate of air and fuel. A small swirl number ≤ 0.6 is not desired as it elongates the flame; increases flue gases temperatures and increases the NOx emissions inside the calciner. A swirl number ≥ 0.6 is found optimal for good combustion characteristics and NOx emissions concentration. Meanwhile, it was found that the HFO viscosity has a significant effect on the injection velocity and must be considered as a function of temperature during the analysis as this will significantly affects the combustion characteristics.

A Study of the NOx Emission in a Regenerative Industrial Furnace

2001 ◽  
Author(s):  
Qing Jiang ◽  
Chao Zhang
Keyword(s):  
Mixture Fraction ◽  
Combustion Process ◽  
Nox Emission ◽  
Moment Closure ◽  
Combustion Model ◽  
Industrial Furnace ◽  
Low Emission ◽  
Reduction Of Nox ◽  
Closure Method ◽  
Probability Density Function Pdf

Abstract A study of the nitrogen oxides (NOx) emission and combustion process in a gas-fired regenerative, high temperature, low emission industrial furnace has been carried out numerically. The effect of two additives, methanol (CH3OH) and hydrogen peroxide (H2O2), to fuel on the NOx emission has been studied. A moment closure method with the assumed β probability density function (PDF) for mixture fraction is used in the present work to model the turbulent non-premixed combustion process in the furnace. The combustion model is based on the assumption of instantaneous full chemical equilibrium. The results showed that CH3OH is effective in the reduction of NOx in a regenerative industrial furnace. However, H2O2 has no significant effect on the NOx emission.

Careful Parameter Study to Enhance the Effect of Injecting Heavy Fuel Oil Into a Crossflow Using Numerical Approaches

2018 ◽  
Author(s):  
Masoud Darbandi ◽  
Ali Fatin ◽  
Gerry E. Schneider
Keyword(s):  
Flow Velocity ◽  
Cross Flow ◽  
Droplet Breakup ◽  
Computational Method ◽  
Fuel Oil ◽  
Injection Velocity ◽  
Parameter Study ◽  
Spray Parameters ◽  
Heavy Fuel Oil ◽  
Spray Characteristics

The flow and spray parameters can have noticeable roles in heavy fuel oil (HFO) spray finesse. As known, the interaction between droplets and cross flow should be considered carefully in many different industrial applications such as the process burners and gas turbine combustors. So, it would be so important to investigate the effect of injecting HFO into a crossflow more subtly. In this work, the effects of various flow and spray parameters on the droplet breakup and dispersion parameters are investigated numerically using the finite-volume-element method. The numerical method consists of a number of different models to predict the droplets breakup and their dispersion into a cross flow including the spray-turbulence interaction one. An Eulerian–Lagrangian approach, which suitably models the interaction between the droplets and turbulence, and also models the droplets secondary breakup is used to investigate the interactions between the flow and the droplet behaviors. After validating the computational method via comparing them with the data provided by the past researches, four test cases with varying swirl number, air axial velocity, droplet size, and fuel injection velocity are examined to find out the effects of preceding parameters on some spray characteristics including the droplets path, sauter mean diameter (SMD), and dispersed phase mass concentration. The results show that the droplets inertia and the flow velocity magnitude have significant effects on spray characteristics. As the droplets become more massive, the deflection of spray in flow direction becomes less. Also, increasing of flow velocity causes more deflection for sprays with the same droplet sizes.

Effect of Chemical Fuel Additives on Liquid Fuel Saving, and Emissions for Heavy Fuel Oil

2016 ◽  
Author(s):  
Ahmed Emara
Keyword(s):  
Mass Flow ◽  
Acoustic Noise ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Fuel Oil ◽  
Mass Spectrometry Analysis ◽  
Fuel Additive ◽  
Fuel Saving ◽  
Fuel Additives ◽  
Heavy Fuel Oil

As fossil fuel resources are considered non-renewable sources of fuel, they will be totally consumed in the near or far future. Due to the intensive and extensive consumption of these fossil fuels in all life sectors such as transportation, power generation, industrial processes, and residential consumption, it is important to find other new methods to cover this fuel demand. Fuel additives are chemicals used to enhance fuel combustion performance, save fuel amounts required for combustion, and correct deficiencies in power and efficiency during consumption. The fuel additives are blended with the traditional fuel even by parts per million range for controlling chemical contaminants and emission reduction. In the present work, the experimental measurements were done, to evaluate the effect of fuel additive blending with the raw heavy fuel oil (Mazut) on fuel saving which is of a great significance, emissions control, and combustion characteristics as well as the combustion efficiency. These measurements are as follows: initial temperature of Mazut, exhaust gas temperature at the end of combustor, air and fuel mass flow rates to determine the heat load, inlet and outlet temperatures of cooling water, mass flow rate of water, concentration of different exhaust gases, acoustic (noise level) measurements, smoke number, and flame length. These measurements are performed using swirled vanes, co-axial, and double heavy fuel nozzle (1.5 gal/hr for each one) burner with maximum heating load of 550 kW. GC-MS (Gas chromatography-mass spectrometry) analysis was performed by using Hewlett Packard model 5890 equipped with a flame ionization detector (FID) to identify the fuel additives substances within the tested samples. The results reveal that the use of fuel additives improves the combustion characteristics and play an important role in fuel saving as well as emission and combustion process.

Study on the Relationship Between Combustion Characteristics and Properties of Marine Heavy Fuel Oil

2003 ◽  
Author(s):  
Takaaki Hashimoto ◽  
Senichi Sasaki
Keyword(s):  
Ignition Delay ◽  
Average Molecular Weight ◽  
Poor Quality ◽  
Combustion Characteristics ◽  
Carbon Residue ◽  
Fuel Oil ◽  
Heavy Fuel Oil ◽  
Marine Fuel ◽  
Fuel Oils ◽  
Flame Retardation

The combustion characteristics (ignition delay and combustion period in this paper) of marine heavy fuel oil are affected by many factors such as density, carbon residue, asphaltene, aromaticity and carbon/hydrogen (C/H) ratio. When investigating the causes of operational problems in diesel engines, what properties should we check to find whether the main causes of the problems are related to fuel oil or not? What is the threshold of ignition delay and combustion period of fuel oil? The authors studied these topics using a combustion test apparatus called FIA 100, and arrived at the following conclusions: 1. The aromaticity index (CCAI) and the C/H ratio have good correlation with the combustion characteristics of marine fuel oil. These factors cannot be ignored during troubleshooting. 2. The carbon residue and asphaltene in fuel oil have no correlation with ignition delay, but have some correlation with the combustion period. 3. There is practically no correlation between the average molecular weight of fuel oil, and both ignition delay and combustion period. 4. Tentative threshold values of ignition delay and combustion period can be set for fuel oils of poor quality (flame retardation).

scholarly journals Evaluation of Combustion Characteristics of Heavy Fuel Oil by Single Droplet Combustion

1998 ◽  
Vol 33 (6) ◽  
pp. 441-447
Author(s):  
Kazuyuki Maeda ◽  
Shin-ichi Morishita ◽  
Koji Takasaki ◽  
Tomoaki Kirihata
Keyword(s):  
Combustion Characteristics ◽  
Fuel Oil ◽  
Droplet Combustion ◽  
Single Droplet ◽  
Heavy Fuel Oil

Study of the combustion characteristics of sewage sludge pyrolysis oil, heavy fuel oil, and their blends

Energy ◽  
2020 ◽  
Vol 201 ◽  
pp. 117559 ◽  
Author(s):  
Yong-Hao Kuan ◽  
Fang-Hsien Wu ◽  
Guan-Bang Chen ◽  
Hsien-Tsung Lin ◽  
Ta-Hui Lin
Keyword(s):  
Sewage Sludge ◽  
Combustion Characteristics ◽  
Fuel Oil ◽  
Pyrolysis Oil ◽  
Heavy Fuel Oil

Reduction of NOx in a Regenerative Industrial Furnace With the Addition of Methanol in the Fuel

2004 ◽  
Vol 126 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Q. Jiang ◽  
C. Zhang ◽  
J. Jiang
Keyword(s):  
Mixture Fraction ◽  
Nox Reduction ◽  
Combustion Process ◽  
Nox Emission ◽  
Moment Closure ◽  
Combustion Model ◽  
Industrial Furnace ◽  
Reduction Of Nox ◽  
Closure Method ◽  
Probability Density Function Pdf

The analysis of the combustion process and NOx emission in a gas-fired regenerative industrial furnace has been carried out numerically. The effect of the additive, methanol CH3OH, to the fuel on the NOx emission is studied. A moment closure method with the assumed β Probability Density Function (PDF) for the mixture fraction is used to model the turbulent non-premixed combustion process in the furnace. The combustion model is based on the assumption of instantaneous full chemical equilibrium. The P-1 model is chosen as the radiation model, and the Weighted-Sum-of-Gray-Gases Model is used to calculate the absorption coefficient. The numerical results showed that the use of CH3OH is effective in the reduction of NOx in a regenerative industrial furnace. The mechanism of NOx reduction by the use of CH3OH is also discussed.

Burning Methanol and its Blends Attractive Alternative for Emission Reduction

2016 ◽  
Author(s):  
B. Chudnovsky ◽  
D. Livshits ◽  
S. Baitel
Keyword(s):  
Emission Reduction ◽  
Liquid Fuel ◽  
Turbulent Energy ◽  
Diesel Oil ◽  
Fuel Oil ◽  
Nox Emissions ◽  
So2 Emissions ◽  
Heavy Fuel Oil ◽  
Reduction Of Nox ◽  
Reduction Of Emissions

Traditional methods for reducing emissions, by modification of the firing system to control the mixing of fuel and air, the reduction of flame temperatures (for NOx emission reduction), and/or the post combustion treatment of the flue gas to remove NOx, SO2 particulates are very expensive. Hence, before implementation of expensive measures for the reduction of emissions, it is necessary to evaluate all low cost alternatives, such as burning alternative fuels and mixing it with other liquid fuels. Methanol offers these advantages, being a derivative of natural gas which is partly de-linked from oil, and is a clean burning fuel. Existing experience [1, 2] has shown that with inexpensive and minimal system modifications, methanol is easily fired and is fully feasible as an alternative fuel. Relative to heavy fuel and light fuel, methanol can achieve improved efficiency and lower NOx emissions due to the lower flame temperature and nitrogen content. Since methanol contains no sulfur, there are no SO2 emissions. The clean burning characteristics of methanol are expected to lead to clean pressure parts and lower maintenance costs. In this paper we present results for the specific 10 ton/hr industrial boiler (results of the burning of methanol in large utility boilers we presented in our earlier publications) located at DOR Chemicals. In this study we experimented with methanol fractions (from 0 to 100 % by heat) at different boiler loads and found that the methanol and heavy fuel oil mixtures enabled us to meet the commonly accepted emissions limit for NOx with zero CO emissions. SO2 emissions were also reduced according to methanol heat fraction. Methanol burning leads to a more than 10 % reduction of CO2. It should be noted that in our tests we used a special patented mixing device (the “Fuel Activation Device – FAD) developed by Turbulent Energy Inc. for preparing premixed or in-line blends. The results show that more than 50% of NOx reduction is achieved when light fuel oil is replaced by methanol and more than an 80% reduction when heavy fuel oil is replaced by methanol. For all boiler operation modes 100% of combustion efficiency is achieved. Methanol and liquid fuel blends lead to significant reduction of emissions depending on the methanol heat fraction. Burning of a blend of liquid fuel with water leads to a significant reduction of NOx. In addition, the usage of the FAD in our tests had positive effects on boiler efficiency improvement both for LFO and methanol firing. In this paper we also present the study of methanol and diesel fuel burning in diesel engine. It should be noted that blends were prepared by a using special mixing device developed by Turbulent Energy Inc. The performance of the engine using blended fuel compared to the performance of the engine with diesel fuel. It was also found that with using the blend one may achieve a more than 75 % reduction of NOx emissions when diesel oil is replaced by 20% methanol. Methanol and diesel oil co-firing leads to a reduction of SO2 emissions depending on the heat fraction of methanol. We believe that the conclusions of the work presented are general and can be applied to any other industrial, utility boiler, or diesel engine as well.

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