scholarly journals Electricity Evaluation and Emission Characteristics of Poultry Litter Co-Combustion Process

2019 ◽  
Vol 9 (19) ◽  
pp. 4116 ◽  
Author(s):  
Qian ◽  
Lee ◽  
Chandrasekaran ◽  
Yang ◽  
Caballes ◽  
...  
Keyword(s):  
Fly Ash ◽  
Natural Gas ◽  
Water Flow Rate ◽  
Poultry Litter ◽  
Combustion Process ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Combustion System ◽  
Fluidized Bed Combustion ◽  
Secondary Air

Electricity generation and emission characteristics during the poultry litter and natural gas co-combustion process has rarely been studied. In this study, a Stirling engine was successfully integrated into the existing lab-scale swirling fluidized bed combustion system in order to further investigate the poultry litter and natural gas co-combustion process. Electricity, gaseous emissions, particulate matter (PM), and fly ash composition were analyzed under various operating conditions. Results indicated that the electricity reached 905 W under a water flow rate of 13.1 L/min and an engine head temperature of 584 °C. It was found that excess air (EA) ratios between 0.79 and 1.08 can relatively produce more electricity with lower emissions. At a secondary air (SA) height of 850 mm, secondary air/total air (SA/TA) ratios between 0.22 and 0.44 may significantly reduce NOx and CO emissions. By increasing the mixing ratio (MR), SO2 was reduced while NOx increased at the beginning of co-combustion process but then decreased again. Additionally, PM results were lower than Maryland emissions standards. The fly ash results showed a higher nutrient content (close to 16%). This study shows the possibility of using poultry litter as a sustainable energy source for energy production while emitting lower emissions in the small decentralized combustion system

scholarly journals A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Simulation Software ◽  
Dual Fuel ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Cylinder Pressure ◽  
Marine Engine ◽  
Full Load ◽  
Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

Extension of Fuel Flexibility in the Siemens Dry Low Emissions SGT-300-1S to Cover a Wobbe Index Range of 15 to 49 MJ/m3

2012 ◽  
Author(s):  
Kexin Liu ◽  
Varkey Alexander ◽  
Victoria Sanderson ◽  
Ghenadie Bulat
Keyword(s):  
Natural Gas ◽  
Nox Reduction ◽  
Operating Conditions ◽  
Combustion System ◽  
Combustion Dynamics ◽  
Fuel Supply ◽  
Supply Pressure ◽  
Fuel Flexibility ◽  
Wobbe Index ◽  
Standard Production

The extension of gas fuel flexibility in the Siemens SGT-300 single shaft (SGT-300-1S) is reported in this paper. A successful development programme has increased the capability of the Siemens Industrial Turbomachinery, Lincoln (SITL) dry low emissions (DLE) burner configuration to a fuel range covering a Wobbe Index (WI) from 15 to 49 MJ/m3. The standard SGT-300-1S SITL DLE combustion hardware allowed for gas and liquid fuels within a specified range typically associated with natural gas and diesel, respectively. Field operation of the standard production SGT-300-1S has confirmed the reliable operation with an extension to the fuels range to include processed land fill gas (PLG) from 32 to 49 MJ/m3. The further extension of the fuel range for the SGT-300-1S SITL DLE combustion system was achieved through high pressure testing of a single combustion system at engine operating conditions. The rig facility allowed for the actual fuel type to be tested using a mixing plant. The variations in fuel heating value were achieved by blending natural gas with diluent CO2 and/or N2. Various diagnostics were used to assess the performance of the combustion system including measurement of combustion dynamics, temperature, fuel supply pressure and emissions of NOx, CO and unburned hydrocarbon (UHC). The results of the testing showed that the standard production burner can operate for a fuel with WI as low as 23 MJ/m3 which corresponds to 35% CO2 (in volume) in the fuel. This range can be extended to 15 MJ/m3 (54.5% CO2 in the fuel) with only minor modification, to control losses through the burner and to maintain similar fuel injection characteristics. The SITL DLE combustion system is able to cover a WI range of 15 to 49 MJ/m3 in two configurations. The results of testing showed a lowering in WI, from diluting with CO2 and/or N2, a benefit in NOx reduction is observed. This decrease in WI may lead to an increased requirement in fuel supply pressure.

CFD Analysis of Turbec T100 Combustor at Part Load by Varying Fuels

2015 ◽  
Author(s):  
Raffaela Calabria ◽  
Fabio Chiariello ◽  
Patrizio Massoli ◽  
Fabrizio Reale
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Combustion Process ◽  
Calorific Value ◽  
Operating Conditions ◽  
Liquid Fuels ◽  
Cfd Analysis ◽  
Part Load ◽  
Gaseous Fuels ◽  
Wide Range

In recent years an increasing interest is focused on the study of micro gas turbines (MGT) behavior at part load by varying fuel, in order to determine their versatility. The interest in using MGT is related to the possibility of feeding with a wide range of fuels and to realize efficient cogenerative cycles by recovering heat from exhaust gases at higher temperatures. In this context, the studies on micro gas turbines are focused on the analysis of the machine versatility and flexibility, when operating conditions and fuels are significantly varied. In line of principle, in case of gaseous fuels with similar Wobbe Index no modifications to the combustion chamber should be required. The adoption of fuels whose properties differ greatly from those of design can require relevant modifications of the combustor, besides the proper adaptation of the feeding system. Thus, at low loads or low calorific value fuels, the combustor becomes a critical component of the entire MGT, as regards stability and emissions of the combustion process. Focus of the paper is a 3D CFD analysis of the combustor behavior of a Turbec T100P fueled at different loads and fuels. Differences between combustors designed for natural gas and liquid fuels are also highlighted. In case of natural gas, inlet combustor temperature and pressure were taken from experimental data; in case of different fuels, such data were inferred by using a thermodynamic model which takes into account rotating components behavior through operating maps of compressor and turbine. Specific aim of the work is to underline potentialities and critical issues of the combustor under study in case of adoption of fuels far from the design one and to suggest possible solutions.

Design and CFD Simulation of a Micro Gas Turbine Combustor Fuelled With Low LHV Producer Gas

2020 ◽  
Author(s):  
Francesco F. Nicolosi ◽  
Massimiliano Renzi
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Operating Conditions ◽  
Inert Gases ◽  
Injection System ◽  
Small Scale ◽  
Producer Gas ◽  
Part Load ◽  
Average Temperature ◽  
Gasification Process

Abstract In this paper, the authors analyze the feasibility of fuelling a small-scale 3.2 kWe MGT, manufactured by the Dutch company MTT, with a low LHV fuel produced via a gasification process. In particular, a CFD analysis on the combustor of the MGT is carried out in order to assess the behaviour of the component when it is fuelled with a traditional fuel (natural gas) and with a producer gas coming from a gasification process. The operating conditions of the combustor, used as boundary conditions for the simulations, are obtained by analyzing the characteristic performance curves of the turbo-machines used in the MGT. The simulation of the combustion process with methane has been validated using the temperature output from experimental tests and the NOX emissions. A RANS simulation using the Non-Adiabatic Non-Premixed Combustion Model Approach has been adopted. NOX formation has been simulated by the adoption of the extended Zel’dovich mechanism. Both nominal and part load simulations have been performed. This simplified modelling strategy allows to assess the main issues and figures of the combustion process with a reasonable computational effort. The CFD simulations showed that the combustion with a low LHV fuel are feasible but some modifications of the present configuration of the combustor are required, with specific attention to the fuel injection system. Results showed that, with Natural Gas, the average temperature of the exhaust mass flow is 1297 K, the level of CO and NOX referred to the 15% of O2 are respectively less than 1 ppm and 30.365 ppm, respectively. With S the original design of the injector proved to be non-adequate for a proper air and fuel mixing; therefore, a modified design has been proposed with an increased injection section. In the novel design for syngas, a better temperature distribution and lower emissions have been found: an average temperature of the flue gas at the combustor discharge of 1249 K is obtained, and the level of CO and NOX are both less than 1 ppm. The lower operating temperature is determined by the higher fuel flow rate and, in particular, by the high share of inert gases in the fuel. Additional simulations have been run at part load operation to assess the viability of the proposed design also in off-design conditions.

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.

Experimental Study on the Effects of Declivitous Angle of Secondary Air on the Flow Characteristics and Coal Combustion of a Down-Fired

2011 ◽  
Author(s):  
Jian Shi ◽  
Yuzhong Chen ◽  
Yubo Hou ◽  
Bin Yao
Keyword(s):  
Fly Ash ◽  
Flow Field ◽  
Carbon Content ◽  
Coal Combustion ◽  
Field Experiments ◽  
Combustion Process ◽  
Flow Characteristics ◽  
Cold Flow ◽  
Horizontal Momentum ◽  
Secondary Air

Aiming at Foster Wheeler (FW) technology down-fired boiler with horizontal F layer secondary air, in which the strong horizontal momentum of the secondary air seriously pounds the down flowing coal gas flame, making the problems of short trip of coal flame and low flame fullness of the furnace, and this leads to higher carbon content of fly ash and so on. A designed adjusting device making the declivitous angle of secondary air is erected in the F layer wind box of a FW down-fired furnace, so the declivitous angle of secondary air can be regulated freely. By this means, the declivitous angle of the F layer secondary air is able to be refined depending on the real combustion situation to achieve the best configuration of the momentum radio by downward momentum from the arch and horizontal momentum from the front/rear wall. As a result, it is able to adapt the change of the furnace combustion situation, extending the flame travel, and improving the combustion process and efficiency. This method was applied to a 300MW grade FW down-fired boiler, and the cold flow field results by fireworks showed the down flow depth of the primary air increasing with the declivitous angle. The best flow field was achieved as the declivitous angle was set to 45°. Based on the cold flow field experiments, combustion experiment was accomplished to compare with the coal combustion performance before the declivitous refinement of the F layer secondary air. It was shown that the carbon content of the fly ash was greatly decreased after the refinement, and the combustion efficiency was increased by 3.3%.

Influence of Micro-Emulsified Biodiesel on Combustion and Emission Characteristics of a Turbocharged Diesel Engine

2012 ◽  
Vol 608-609 ◽  
pp. 269-274
Author(s):  
Qi Min Wu ◽  
Ping Sun ◽  
De Qing Mei ◽  
Zhen Chen
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Emission Characteristics ◽  
Combustion Duration ◽  
Rise Rate ◽  
Di Diesel Engine ◽  
Emulsified Biodiesel

In this paper, two kinds of micro-emulsified biodiesel containing 5.6% and10% water are prepared. The effects of micro-emulsified biodiesel on engine’s power, combustion and emission characteristics are investigated in a DI diesel engine. The results show that under the rated speed and full load operating conditions, the maximum pressure rise rate and peak heat release rate for micro-emulsified biodiesel increase dramatically, while the ignition delay is prolonged and the combustion duration becomes shorter. Compared to base diesel, the HC, CO and smoke emissions from the engine fueled with biodiesel decrease sharply, except for a 9% increased NOx at large loads. However, micro-biodiesel could significantly reduce the NOx and smoke emissions, except for the higher HC and CO emissions at low and medium loads. When fuelled with 10%MB, the NOx and smoke emissions are 9% and 90% lower than that of diesel, respectively. Results reported here suggest that the application of micro-emulsified biodiesel in diesel engines has a potential to improve combustion process and reduce NOx, PM emissions simultaneously.

scholarly journals Influence of H2O on Oxygen Enriched Diffusion Combustion of Natural Gas

2021 ◽  
Vol 39 (3) ◽  
pp. 925-932
Author(s):  
Xiang He ◽  
Xin Ren ◽  
Fanjin Zeng ◽  
Yindi Zhang ◽  
Yue Xin ◽  
...  
Keyword(s):  
Natural Gas ◽  
Carbon Black ◽  
Volume Fraction ◽  
Combustion Process ◽  
Clean Energy ◽  
Operating Conditions ◽  
Chemical Effect ◽  
Chemical Action ◽  
Chemical Effects ◽  
Combustion Technology

O2/H2O combustion technology, as the next generation of oxy-fuel combustion technology with great potential, can greatly increase the utilization rate of clean energy CH4. In this paper, the natural gas combustion process under 6 operating conditions of O2/H2O atmosphere and O2/FH2O atmosphere is numerically simulated. The horizontal analysis is carried out on the characteristics of H2O fraction, CO2 volume fraction and the amount of pollutants (NOx, carbon black), and in-depth exploration of the content of additive H2O and the influence of chemical action on the above characteristics. The research results show that the chemical effects of H2O have a negative effect on combustion temperature, and the physical effects are dominant. The chemical effects of H2O have a great impact on CO production and little effect on the production of CO when the proportion of H2O is 65-79%. The chemical effects of H2O inhibit the formation of NOx and carbon black when the proportion of H2O is within the range of 55-70%. The chemical effect has the greatest impact on the formation of dyes (NOx, carbon black) when the proportion of H2O is within the range of 65-70%.

Impact of Secondary Air Flow on Combustor Emissions

2020 ◽  
Author(s):  
Bassam S. Mohammad ◽  
Brian Volk ◽  
Keith McManus
Keyword(s):  
Flame Temperature ◽  
Operating Conditions ◽  
Published Data ◽  
Inlet Temperature ◽  
Combustion System ◽  
Combustion Emissions ◽  
Exit Temperature ◽  
Combustion Systems ◽  
Secondary Air ◽  
The Impact

Abstract It is a common practice to relate emissions performance of Dry Low Emissions (DLE) combustion systems to the flame temperature that is estimated from the mass flows of air and fuel flowing through the premixer. In many combustion systems, the exit temperature (or turbine nozzle inlet temperature) is quite low and is not a good parameter for estimating combustion emissions. The difference between the combustion flame temperature and exit temperature is mainly due to secondary air dilution. To our knowledge there are no detailed published data that quantify the impact of this temperature difference on combustion emissions. The target of this study is to quantify the impact of secondary air variation on emissions, both globally and locally. High pressure experiments are conducted at H class gas turbine operating conditions using a DLE combustion system. In the context of this DLE system, secondary air refers to cooling and leakage flows because direct air dilution of the combustion gasses is not necessary. This is because the flame stabilized downstream of the premixer is well mixed and fuel-lean. With NOx requirements moving toward single digit (ppm) levels, it becomes essential to accurately quantify the impact of reducing the secondary air percentage on emissions performance. In addition to the need to carefully study the impact of local interaction of the secondary air with the flame. The combustion system is configured with two independently controlled mixers along with a variable secondary air circuit that can change the secondary air fraction from 14 to 8%. Multiple emissions rakes are used at the combustor exit to delineate the interaction and relate it to the flame structure. The system is configured to enable sampling from individual rakes to study local emissions and the rakes can be ganged together to measure the bulk-averaged combustion emissions. This research provides a quantification of the improvement of the NOx margin with a decrease in the secondary air percentage. The study shows that the increase in margin is not a simple re-estimate of the combustor emissions using the NOx design curve due to flame quenching effects. The results also show that the secondary air can be used to improve the NOx emissions via controlling the interaction with the primary flame. The impact is quantified in terms of emissions, acoustics and metal temperatures.

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