Combustion Process Analysis and Diagnostic Using Optical Flame Scanners in Front-Fired Pulverized Coal Boiler

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Daniel Nabagło ◽  
Teresa Kurek ◽  
Konrad Wojdan
Keyword(s):  
Power Plants ◽  
Process Analysis ◽  
Flame Temperature ◽  
Combustion Process ◽  
Complete Information ◽  
Pulverized Coal ◽  
Optical Parameters ◽  
Research Activity ◽  
Burner Flame ◽  
Secondary Air

The paper presents a novel concept and method of coal combustion process analysis using flame scanners supervision system. The combustion process analysis and diagnostic has a crucial influence on boiler effectiveness, especially in high variance of load demand, which is nowadays a top challenge for coal-fired power plants. The first indicator of combustion inefficiency is flame stability, which can be observed as variation of flame intensity. Nowadays, there are no validated measuring methods dedicated for industrial usage, which are able to give complete information about flame condition. For this reason, the research activity was launched and focused on usage of commercial flame scanners for fast combustion analysis based on on-line flame parameters measuring. The analysis of combustion process was performed for 650 t/h live steam power boiler, which is supplied by five coal mill units. Each coal mill supplies four pulverized coal burners pulverized fuel ((PF) burners). The boiler start-up installation consists of 12 heavy oil burners placed in PF burners equipped with individual supervisory system based on Paragon 105f-1 flame scanners, which gave the possibility to observe and analyze the PF burner flame and oil burner flame individually. The research included numerous tests in which the combustion conditions inside the combustion chamber were changed. During stable load of selected mills, the primary air flow, secondary air dampers, air–coal mixture temperature, and balance were changed. The results of the changes were observed by flame scanners and the available optical parameters of the flame were analyzed: power spectral density, average amplitude (AA) of flame fluctuation, and flame temperature.

scholarly journals Modeling and optimization of processes for clean and efficient pulverized coal combustion in utility boilers

2016 ◽  
Vol 20 (suppl. 1) ◽  
pp. 183-196 ◽  
Author(s):  
Srdjan Belosevic ◽  
Ivan Tomanovic ◽  
Nenad Crnomarkovic ◽  
Aleksandar Milicevic ◽  
Dragan Tucakovic
Keyword(s):  
Emission Reduction ◽  
Power Plants ◽  
Position Control ◽  
Process Analysis ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Nox Emission ◽  
Boiler Furnace ◽  
Boiler Units

Pulverized coal-fired power plants should provide higher efficiency of energy conversion, flexibility in terms of boiler loads and fuel characteristics and emission reduction of pollutants like nitrogen oxides. Modification of combustion process is a cost-effective technology for NOx control. For optimization of complex processes, such as turbulent reactive flow in coal-fired furnaces, mathematical modeling is regularly used. The NOx emission reduction by combustion modifications in the 350 MWe Kostolac B boiler furnace, tangentially fired by pulverized Serbian lignite, is investigated in the paper. Numerical experiments were done by an in-house developed three-dimensional differential comprehensive combustion code, with fuel- and thermal-NO formation/destruction reactions model. The code was developed to be easily used by engineering staff for process analysis in boiler units. A broad range of operating conditions was examined, such as fuel and preheated air distribution over the burners and tiers, operation mode of the burners, grinding fineness and quality of coal, boiler loads, cold air ingress, recirculation of flue gases, water-walls ash deposition and combined effect of different parameters. The predictions show that the NOx emission reduction of up to 30% can be achieved by a proper combustion organization in the case-study furnace, with the flame position control. Impact of combustion modifications on the boiler operation was evaluated by the boiler thermal calculations suggesting that the facility was to be controlled within narrow limits of operation parameters. Such a complex approach to pollutants control enables evaluating alternative solutions to achieve efficient and low emission operation of utility boiler units.

Effect of Slot Wall Jet on Combustion Process in a 660 MW Opposed Wall Fired Pulverized Coal Boiler

2019 ◽  
Vol 17 (4) ◽  
Author(s):  
Yong Zhang ◽  
Yao Fang ◽  
Baosheng Jin ◽  
Youwei Zhang ◽  
Chunlei Zhou ◽  
...  
Keyword(s):  
Combustion Process ◽  
Side Wall ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Gas Velocity ◽  
Pulverized Coal Boiler ◽  
Inclination Angles ◽  
Secondary Air ◽  
Coal Boiler ◽  
Optimized Conditions

Abstract Numerical investigations of an anti-corrosion design and the combustion process (original conditions and optimal conditions) were conducted for a 660 MW opposed wall fired boiler. In order to solve high-temperature corrosion of the side wall, a scheme was proposed: slotting in the side wall and introducing air (closing-to-wall air) from the secondary air. The effect of anti-corrosion was disclosed in detail by varying the structures of slotting, gas velocities from nozzles and jet inclination angles. The temperature and NOx distribution in the furnace at optimized conditions were compared with those at the original operating conditions. Simulation results showed that the structures of the slot and gas velocities from the nozzles had a marked effect on anti-corrosion of the side wall. When the gas velocity was 4 m/s, an inclination angle of the gas velocity was not conducive to anti-corrosion of the side wall. When the gas velocity increased at the middle and bottom of the side wall, the anti-corrosion effect increased significantly. When the optimal scheme was adopted, the corrosion area of the side wall decreased obviously, but the furnace temperature and the NOx emission increased slightly. The detailed results of this work promote a full understanding of closing-to-wall air and could help to reduce the corrosive area in pulverized-coal furnaces or boilers.

Numerical Simulation of Turbulent Biogas Combustion

2007 ◽  
Author(s):  
Beibei Yan ◽  
Xuesong Bai ◽  
Guanyi Chen ◽  
Changye Liu
Keyword(s):  
Numerical Simulation ◽  
Mass Flow ◽  
Flame Temperature ◽  
Combustion Process ◽  
Methane Combustion ◽  
Operational Parameters ◽  
Heating Value ◽  
Air Supply ◽  
Methane Flame ◽  
Secondary Air

Operating parameters are considered important for the biogas combustion process and the resulted flame features. The paper investigated the influence of typical parameters through numerical simulation, which include the dimension of combustor, fuel and air mass flow, and secondary air supply. The results from the simulations show that the biogas combustion behaves, to some extent, similarly to the methane combustion, yet significant differences exist between their flames. The combustion process is fairly sensitive to the geometrical and operational parameters. Biogas flame temperature is even lower compared to the methane flame temperature because biogas contains CO2 resulting in low heating value, therefore it is not straightforward to obtain stable combustion. Preheated secondary air or reduced its mass flow may have to be used in this case.

scholarly journals Numerical investigation using two different CFD codes of pulverized-coal combustion process characteristic in an industrial power plant boiler

2019 ◽  
Vol 82 ◽  
pp. 01009
Author(s):  
Paweł Madejski ◽  
Norbert Modliński
Keyword(s):  
Numerical Modeling ◽  
Coal Combustion ◽  
Power Plants ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Front Wall ◽  
Coal Particles ◽  
Boiler Operation ◽  
Steam Boilers

Steam boilers using the coal as a basic fuel are still one of the most important techniques used to generate electricity in Power Plants. Many activities connected with optimization of steam boilers operation, investigation of combustion efficiency using different fuels, control and reducing pollutants emission are observed. Numerical modeling of large steam boilers using Computational Fluid Dynamic method can be a very way to develop and verify effects of all activities regarding combustion process optimization. Numerical modeling results of the coal combustion process in the front wall coal-fired boiler are presented in the paper. The behavior of the flow of pulverized coal through the burners was analyzed, and the temperature and velocity distribution in the combustion chamber were reproduced in the simulation. Despite the fact that the attention has been focused on boiler simulation at nominal load, it is possible to perform numerical studies concerning the analysis of coal combustion at different boiler loads (minimum load and flexible boiler operation). Analysis of different fuels and their impact on the combustion process, as well as analysis of coal mills operation, coal particles size distribution and they impact on boiler operation can be performed using developed models.

Effect of CO2 Capture on Combined Cycle Gas Turbine Efficiency Using Membrane Separation, EGR and OEA Effects on Combustion Characteristics

2014 ◽  
Author(s):  
G. Cabot ◽  
M. Calbry ◽  
P. Xavier ◽  
A. Vandel ◽  
S. de Persis ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Co2 Capture ◽  
Power Plants ◽  
Membrane Surface ◽  
Flame Temperature ◽  
Combustion Process ◽  
Co2 Concentration ◽  
Combined Cycle ◽  
Pollutant Emissions ◽  
Exhaust Gases

In an energetic world of fossil fuel, there is a need to reduce the CO2 emission released to the atmosphere. CO2 Capture and Sequestration (CCS) is one of the solutions. To optimize the CO2 capture cost, thermodynamic cycles of power plants have to be modified, and resulting new designs inevitably lead to new combustion modes [1][2][3]. CO2 capture of post combustion gases can be performed using membrane processes, but its efficiency is interesting only if the CO2 concentration in the combustion process exhaust gases is higher than 30% [4]. Unfortunately, in classical combustion processes (e.g. gas turbine), diluted Exhaust Gases (EG) contain no more than 5 % of CO2 because combustion products are strongly diluted in air. Our objective consists in increasing the EG CO2 concentration, by using both Oxygen-Enriched Air (OEA) combustion and exhaust gas recirculation (EGR). Our approach is based on numerical simulations and on experimental work. First, operating parameters which minimize the CO2 capture cost are calculated and compared with the reference capture cost [5] (achieved by amine absorption of CO2). In parallel, experiments and additional calculations are performed in order to check the quality and the operability of such combustion mode. This paper is organized as follows: the first part presents the optimization of a new thermodynamic GTCC cycle, using OEA and EGR to increase EG CO2 concentration and capturing it in post-combustion with membrane separator. The effects of pressure and membrane selectivity will be studied in terms of CO2 capture cost, avoided CO2, implemented membrane surface, EGR rate and OEA quality. The second part is dedicated to the experimental and calculation [6] studies of combustion met in this type of configuration. A premixed swirl flame is fed first with Air, CH4 and CO2, then with OEA, CH4 and EGR. To neglect the thermal aspect of NOx production, measurements are performed at constant adiabatic flame temperature. The flame structure, combustion instability and pollutant emissions are presented as a function of the EGR rate dilution.

Life Cycle Analysis: Sub-Critical Pulverized Coal (SubPC) Power Plants

2018 ◽  
Author(s):  
Timothy J Skone ◽  
Greg Schivley ◽  
Matthew Jamieson ◽  
Joe Marriott ◽  
Greg Cooney ◽  
...  
Keyword(s):  
Life Cycle ◽  
Life Cycle Analysis ◽  
Power Plants ◽  
Pulverized Coal

scholarly journals Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  
Keyword(s):  
Activation Energy ◽  
Waste Management ◽  
Energy Demand ◽  
Power Plants ◽  
Combustion Process ◽  
Isoconversional Methods ◽  
Low Rank ◽  
Heating Rates ◽  
Average Activation Energy ◽  
Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

scholarly journals Energy Treatment of Solid Municipal Waste in Combination with Biomass by Decentralized Method with the Respect to the Negative Effects on the Environment

2021 ◽  
Vol 13 (8) ◽  
pp. 4405
Author(s):  
Miroslav Rimar ◽  
Olha Kulikova ◽  
Andrii Kulikov ◽  
Marcel Fedak
Keyword(s):  
Heavy Metals ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Process Analysis ◽  
Combustion Process ◽  
Municipal Waste ◽  
Negative Effects ◽  
Combustion Properties ◽  
Polycyclic Aromatic ◽  
Fuel Mixtures

Waste is a product of society and one of the biggest challenges for future generations is to understand how to sustainably dispose of large amounts of waste. The main objective of this study was to determine the possibility and conditions of the decentralized combustion of non-hazardous municipal waste. The analysis of the combustion properties of a mixture of wood chips and 20–30% of municipal solid waste showed an improvement in the operating parameters of the combustion process. Analysis also confirmed that the co-combustion of dirty fuels and biomass reduced the risk of releasing minerals and heavy metals from fuel into the natural environment. Approximately 55% of the heavy metals passed into the ash. The analysis of municipal solid waste and fuel mixtures containing municipal solid waste for polycyclic aromatic hydrocarbons showed the risk of increasing polycyclic aromatic hydrocarbon concentrations in flue gases.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

Comparison of Two Linear Collectors in Solar Thermal Plants: Parabolic Trough vs Fresnel

2011 ◽  
Author(s):  
A. Giostri ◽  
M. Binotti ◽  
P. Silva ◽  
E. Macchi ◽  
G. Manzolini
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Research Activity ◽  
Optical Efficiency ◽  
Synthetic Oil ◽  
Yearly Average

Parabolic trough can be considered the state of the art for solar thermal power plants thanks to the almost 30 years experience gained in SEGS and, recently, Nevada Solar One plants in US and Andasol plants in Spain. One of the major issues that limits the wide diffusion of this technology is the high investment cost of the solar field and, particularly, of the solar collector. For this reason, since several years research activity has been trying to develop new solutions with the aim of cost reduction. This work compares commercial Fresnel technology with conventional parabolic trough plant based on synthetic oil as heat transfer fluid at nominal conditions and evaluates yearly average performances. In both technologies, no thermal storage system is considered. In addition, for Fresnel, a Direct Steam Generation (DSG) case is investigated. Performances are calculated by a commercial code, Thermoflex®, with dedicated component to evaluate solar plant. Results will show that, at nominal conditions, Fresnel technology have an optical efficiency of 67% which is lower than 75% of parabolic trough. Calculated net electric efficiency is about 19.25%, while parabolic trough technology achieves 23.6%. In off-design conditions, the gap between Fresnel and parabolic trough increases because the former is significantly affected by high radiation incident angles. The calculated sun-to-electric annual average efficiency for Fresnel plant is 10.2%, consequence of the average optical efficiency of 38.8%, while parabolic trough achieve an overall efficiency of 16%, with an optical one of 52.7%. An additional case with Fresnel collector and synthetic oil outlines differences among investigated cases. Finally, because part of performance difference between PT and Fresnel is simple due to different definitions, additional indexes are introduced in order to make a consistent comparison.

Sign in / Sign up

Export Citation Format

Share Document