NOx process inhibition and energy efficiency improvement in new swirl modification device for steel slag based on coal combustion

2018 ◽  
Vol 16 (7) ◽  
Author(s):  
Junxiang Guo ◽  
Lingling Zhang ◽  
Daqiang Cang ◽  
Liying Qi ◽  
Wenbin Dai ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Flue Gas ◽  
Coal Combustion ◽  
Steel Slag ◽  
Coal Ash ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Staged Combustion ◽  
Energy Efficiency Improvement ◽  
Swirl Combustion

Abstract In this study, a novel swirl combustion modified device for steel slag was designed and enhanced with the objective of achieving highly efficient and clean coal combustion and also for achieving the whole elements utilization of coal. Coal ash and steel slag were melted in the combustion chamber and subsequently entered the slag chamber. The detrimental substances solidified and formed crystals, which allowed for the comprehensive utilization of the ash and slag. Our experiments mainly aimed to mitigate the formation of NOx, while using the heat and slag simultaneously during the coal combustion without a combustion efficiency penalty. The increase in the device’s energy efficiency and reduction in the NOx emissions are important requirements for industrialization. The experiments were carried out in an optimized swirling combustion device, which had a different structure and various coal feeding conditions in comparison to previously reported devices. The fuel-staged and non-staged combustion experiments were compared under different coal ratios (bitumite:anthracite). For the fuel-staged combustion experiments, the NOx concentration in the flue gas was observed to decrease significantly when the coal ratio of 1:1, an excess air coefficient of 1.2, and a fuel-staged ratio of 15:85 were used. Under these conditions, the flue gas temperature was as high as 1,620°C, while the NOx concentration was as low as 320 mg/m3 at 6 % O2. The air-surrounding-fuel structure that formed in the furnace was very beneficial in reducing the formation of NOx. In comparison to other types of coal burners, the experimental combustion device designed in this study achieved a significant reduction of NOx emissions (approximately 80 %).

Study on the Technology of Increasing Combustion Efficiency and Decreasing NOx Emission of Blending Coals

2012 ◽  
Vol 614-615 ◽  
pp. 41-44 ◽  
Author(s):  
Chun Zhi Wei ◽  
Yi Cong Wang
Keyword(s):  
Combustion Chamber ◽  
Flue Gas ◽  
Coal Combustion ◽  
Thermal Load ◽  
Load Distribution ◽  
Combustion Efficiency ◽  
Pollutant Emission ◽  
Gas Temperature ◽  
Emission Properties ◽  
Different Types

Study on the combustion behavior and pollutant emission properties of the different types and different ratio of blending coal have been done. The influence of the ratio of brown-blending coal on the combustion efficiency and NOx emission have been researched and concentrated ratio and method of pulverized coal have been get. The thermal-load distribution along the height of furnace and the control of the flue gas temperature at the exit of the combustion chamber have been discussed and the retrofit schema has been put forward. By reasonably blending coal, combustion efficiency increases and NOx emission goes down.

scholarly journals NOx formation of swirl burner under air-staged combustion with flue gas recycle

2020 ◽  
Vol 194 ◽  
pp. 01042
Author(s):  
Jinyan Yuan ◽  
Mingming Wang ◽  
Jihua Li ◽  
Yuyu Lin ◽  
Xiangyong Huang ◽  
...  
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Nox Emission ◽  
Temperature Decrease ◽  
Gas Temperature ◽  
Gas Velocity ◽  
Staged Combustion ◽  
Swirl Burner ◽  
Nox Formation ◽  
Furnace Outlet

Air-staged and flue gas recycle (FGC) combustion are important technologies to reduce NOx emissions. This study explores FGC ratios on the NOx formation in the primary combustion zone under air-staged combustion for a HT-NR3 swirl burner at different air excess coefficients. The coal combustion characteristics including gas velocity, temperature, gas components and NOx emission under different FGC ratios were analyzed. The results show that higher the FGC ratio will larger the gas temperature decrease and lower the NOx emission. Combined FGC technology with lower air excess coefficients technology, the NOx emission at outlet of furnace will be further reduced. When the air consumption excess coefficient is 0.8 with FGC ratio 20%, the NOx concentration at the furnace outlet will decrease from 208ppm to 138ppm, lower 33.6%.

A Theoretical Analysis of Predrying of Solid Fuels With Flue Gas

1988 ◽  
Vol 110 (2) ◽  
pp. 119-123 ◽  
Author(s):  
C. M. Kinoshita
Keyword(s):  
Moisture Content ◽  
Flue Gas ◽  
Air Entrainment ◽  
Combustion Efficiency ◽  
Solid Fuels ◽  
Fuel Moisture ◽  
Gas Temperature ◽  
Ambient Conditions ◽  
Dimensionless Parameters ◽  
Fuel Moisture Content

Combustion efficiency and flue-gas drying of solid fuels are analyzed. A simple, universal arithmetic expression for combustion efficiency is developed. This expression involves four primary dimensionless parameters which relate to (and are fixed for given) fuel and ambient conditions, and three secondary dimensionless parameters which relate to (and vary with) fuel moisture content, excess air, and flue-gas temperature. Additional expressions involving the same primary parameters are developed to calculate the decrease in fuel moisture content due to flue-gas drying with and without entrainment of air into the dryer system and the decrease in flue-gas temperature with air entrainment. Values for the four primary parameters are presented for various fuels; their values do not vary much for most biomass fuels.

scholarly journals Improvement of Energy Efficiency and Environmental Safety of Thermal Energy Through the Implementation of Contact Energy Exchange Processes

2017 ◽  
Vol 38 (4) ◽  
pp. 127-137
Author(s):  
Gennadii Borysovich Varlamov ◽  
Kateryna Alexandrovna Romanova ◽  
Iryna Nazarova ◽  
Olga Daschenko ◽  
Andry Kapustiansky
Keyword(s):  
Energy Efficiency ◽  
Flue Gas ◽  
Power Plants ◽  
Energy Exchange ◽  
Environmental Safety ◽  
Toxic Substances ◽  
Power Cycles ◽  
Energy Efficiency Improvement ◽  
Exchange Processes ◽  
Positive Effect

Abstract Energy efficiency improvement and ecological safety of heat power plants are urgent problems, which require scientifically grounded approaches and solutions. These problems can be solved partly within the presented heat-and-power cycles by including contact energy exchange equipment in the circuits of existing installations. A significant positive effect is obtained in the contact energy exchange installations, such as gas-steam installation ‘Aquarius’ and the contact hydrogen heat generator that also can use hydrogen as a fuel. In these plants, the efficiency increases approximately by 10-12% in comparison with traditional installations, and the concentration of toxic substances, such as nitrogen oxides and carbon monoxide in flue gas can be reduced to 30 mg/m3 and to 5 mg/m3, respectively. Moreover, the plants additionally ‘generate’ the clean water, which can be used for technical purposes.

Numerical Simulation and Optimization on the Variable Oxygen of a 3000 T/H Ultra-Supercritical Boiler

2013 ◽  
Vol 291-294 ◽  
pp. 1675-1678
Author(s):  
Ling Da Zeng ◽  
Zhong Guang Fu ◽  
Han Cai Zeng
Keyword(s):  
Flue Gas ◽  
Thermal Load ◽  
Rate Increase ◽  
Research Result ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Combustion Heat ◽  
Simulation And Optimization ◽  
Burnout Rate ◽  
Direction Information

The characteristics of flow,combustion,heat transfer and NOx emission were numerically investigated under the different load operation for a 3000 T/H ultra-supercritical boiler.The simulated results agree well with the measured values. The results show that there is significant influence when oxygen amount in flue gas is different. The results show that compared with the increase of oxygen,coal burnout rate increase,fly ash carbon content is reduced,combustion efficiency is raised,and NOx emissions is reduced greatly,the flue gas temperature is reduced greatly chamber exports,which helps reduce panel superheater hang the tendency of slag,wall maximum thermal load obvious move down to middle burner and the lower between the burner area,boiler oxygen best in between 3.0 and 3.5.The direction information can be provided for mastering the combustion characteristics of this type of boiler,adjusting and optimizing the operation by the research result.

scholarly journals Investigating the Effects of Parametric Variation over Performance of Boiler-Turbine Cycle

2021 ◽  
Vol 9 (8) ◽  
pp. 2620-2628
Author(s):  
Dr. S. S. L. Patel
Keyword(s):  
Adverse Effect ◽  
Energy Efficiency ◽  
Energy Loss ◽  
Ambient Temperature ◽  
Flue Gas ◽  
Environmental Temperature ◽  
Exergy Efficiency ◽  
Plant Performance ◽  
Second Law ◽  
Gas Temperature

Abstract: In this paper, the effects of variation in ambient temperature, flue gas temperature and condenser pressure over performance of boiler and turbine cycle is presented. The study is carried out with EES software. The change in ambient temperature is seriously deteriorating the boiler exergetic performance as its exergy efficiency reduces by 2.5% with increase in environmental temperature from 27C to 45C while the boiler total energy loss reduces almost 1% for same increase in ambient temperature. The turbine second law efficiency is affected slightly by ambient temperature. Increase in temperature of exhaust flue gas has adverse effect over boiler energy efficiency, which reduces by almost 1% with flue gas temperature variation from 110C to 130C. The increase in condenser pressure is reducing the turbine energy efficiency to more than 3% with variation from 0.05bar to 0.3bar. Condenser exergy efficiency is decreasing sharply with increase in its pressure. The effect of variation in condenser pressure over net output of the boiler-turbine cycle has also been studied and it is found to be decreasing with increase in condenser pressure. Keyword: Ambient temperature, Boiler-turbine cycle, Condenser pressure, Flue gas, Plant performance.

Data-driven modeling of fireside corrosion rate

2017 ◽  
Vol 64 (4) ◽  
pp. 397-404 ◽  
Author(s):  
Amrita Kumari ◽  
S.K. Das ◽  
P.K. Srivastava
Keyword(s):  
Fly Ash ◽  
Corrosion Rate ◽  
Flue Gas ◽  
Thermal Power ◽  
Coal Ash ◽  
Gas Temperature ◽  
Ann Model ◽  
Fireside Corrosion ◽  
Content Type ◽  
Network Training

Purpose This paper aims to propose an efficient artificial neural network (ANN) model using multi-layer perceptron philosophy to predict the fireside corrosion rate of superheater tubes in coal fire boiler assembly using operational data of an Indian typical thermal power plant. Design/methodology/approach An efficient gradient-based network training algorithm has been used to minimize the network training errors. The input parameters comprise of coal chemistry, namely, coal ash and sulfur contents, flue gas temperature, SOX concentrations in flue gas, fly ash chemistry (Wt.% Na2O and K2O). Findings Effects of coal ash and sulfur contents, Wt.% of Na2O and K2O in fly ash and operating variables such as flue gas temperature and percentage excess air intake for coal combustion on the fireside corrosion behavior of superheater boiler tubes have been computationally investigated and parametric sensitivity analysis has been undertaken. Originality/value Quite good agreement between ANN model predictions and the measured values of fireside corrosion rate has been observed which is corroborated by the regression fit between these values.

CFD Analysis of Coal Combustion With Oxygen/CO2/H2O Mixture

2009 ◽  
Author(s):  
Chaouki Ghenai
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Volume Ratio ◽  
Continuous Phase ◽  
Pollutant Emissions ◽  
Spherical Particles ◽  
Second Phase ◽  
Gas Temperature ◽  
Coal Particles ◽  
Discrete Phase

Coal combustion with oxygen is considered one of the most effective methods to improve thermal efficiency, reduce pollutant emissions such as NOX, and facilitate capture of CO2 pollutant from flue gas. This paper presents calculations of oxygen coal combustion with flue gas recirculation. The coal is burned in oxygen/CO2/H20 mixture. In addition to solving transport equations for the continuous phase (gas), a discrete second phase (spherical particles) is simulated in the Lagrangian frame of reference. Reaction is modeled by a mixture fractions/PDF approach. Discrete phase modeling is used for the prediction of discrete phase trajectory and heat and mass transfer to/from particles. Drayton coal with a lower heating value of 27.8 MJ/Kg is used in this study. Coal is burned in oxygen/CO2/H20 mixture with a composition of VC02+H20/VO2 = 0 to 4. The results obtained in this study show clearly the benefit of burning coal with oxygen/CO2/H20 mixture compared to coal combustion with air. The CO2 emissions increases which will help to reduce the cost of CO2 capture, NOX emissions will also decrease because of the replacement of nitrogen in air by CO2/H20 mixture, and better devolatization and burnout of coal particles for coal combustion with oxygen/CO2/H20 mixture. In addition to that, with a CO2/H20 to oxygen volume ratio of 0.67, the gas temperature is the same as the gas temperature for coal combustion with air. No modifications of the combustor materials is required during the retrofitting of power plant with oxygen coal combustion systems.

Boosting Gas Processing Energy Efficiency by Waste Heat Recovery

2021 ◽  
Author(s):  
Waneya Abdulla Al Ketbi ◽  
Saqib Sajjad ◽  
Eisa Salem Al Jenaibi
Keyword(s):  
Energy Efficiency ◽  
Feasibility Study ◽  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Dew Point ◽  
Gas Temperature ◽  
Gas Processing ◽  
Sulphur Recovery

Abstract A continual improvement in energy efficiency of existing plants is imperative to achieve ADNOC target to reduce greenhouse gas emissions (GHG) intensity of operations by 25% in year 2030. The waste heat recovery (WHR) from incinerator stacks of existing Sulphur Recovery Units (SRUs) in ADNOC Gas Processing exhibits a substantial potential & contributor of energy savings and emission abatement. A high level assessment was carried out for various heat sources, results showed substantial WHR potential can be availed from SRUs. Consequently, a feasibility study was carried out to evaluate several options to recover energy from incinerator stacks of existing Sulphur Recovery Units (SRUs). The feasibility study addressed three options of recovering energy from SRUs incinerator stack exhaust; generating saturated steam, generating power and combined solution of steam & power. Those options were assessed in terms of technical feasibility and commercial viability. The study indicated that steam generation by HRSGs is technically viable and economically feasible, and considered as the best option for WHR from the existing SRU Incinerator Stacks. The WHR benefits that can be realized from just one incinerator stack by recovering the waste heat and reducing the flue gas temperature by 400 °C only (from 700 to 300 °C) are: More than 80 TPH saturated HP steam generationFuel gas savings and corresponding monetary benefitsSignificant abatement in GHG emissions The study revealed that WHR does not pose acid condensation risk due to the safe margin between the acid dew point and the actual flue gas temperature. The study also established that other constraints like pressure drop, space, tie-in location and emissions dispersion are not the showstoppers.

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