scholarly journals Application of Ultrasonic Atomization on a Micro Jet Engine Using Biofuel for Improving Performance

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1963
Author(s):  
Amer Alajmi ◽  
Fnyees Alajmi ◽  
Ahmed Alrashidi ◽  
Naser Alrashidi ◽  
Nor Mariah Adam
Keyword(s):  
Carbon Dioxide ◽  
Combustion Process ◽  
Nitrogen Monoxide ◽  
Load Level ◽  
Exhaust Gas ◽  
Jet Engines ◽  
Turbine Wheel ◽  
Ultrasonic Atomization ◽  
Engine Efficiency ◽  
Set Up

Jet engines are commonly used in aeronautical applications, and are one of the types of gas turbine engines. The circulation of air releases heat energy to expand the volume of hot fluids and impact the turbine wheel to generate power of hot gases. The present study investigates the potential of using ultrasonic atomization technology to assist in the combustion process. An experimental rig was set up to determine the performance of jet engines using ultrasonic droplets. A gas analyzer was used to measure various greenhouse emissions of exhaust gas. The performance of the engine was tested under three load levels (high, medium, low), starting from 10 psi at a steady state, to the minimum value. A significant result was tested for a low value of nitrogen monoxide at the three levels of load, and a specific result was tested for an efficiency value of 2% at the three levels of load. Carbon dioxide was found to decrease at the low load level. The use of an ultrasonic atomization device to assist in the combustion process was useful in achieving engine efficiency of 1% and a reduction of 25% in carbon dioxide exhaust gas.

The effects of exhaust gas recirculation on diesel combustion and emissions

2000 ◽  
Vol 1 (1) ◽  
pp. 107-126 ◽  
Author(s):  
N Ladommatos ◽  
S Abdelhalim ◽  
H Zhao
Keyword(s):  
Carbon Dioxide ◽  
Heat Capacity ◽  
Diesel Engine ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Particulate Emission ◽  
Gas Recirculation ◽  
Charge Temperature

An investigation was conducted with the aim of identifying and quantifying the effects of exhaust gas recirculation (EGR) on diesel engine combustion and exhaust emissions. Five effects of EGR were identified and investigated experimentally: the reduction in oxygen supply to the engine, participation in the combustion process of carbon dioxide and water vapour present in the EGR, increase in the specific heat capacity of the engine inlet charge, increased inlet charge temperature and reduction in the inlet charge mass flowrate arising from the use of hot EGR. The experimental methodology developed allowed each one of these effects to be investigated and quantified separately. The investigation was carried out on a high-speed, direct injection diesel engine, running at an intermediate speed and load. A limited number of tests were also conducted in an optically accessible diesel engine, which established the effects of EGR on local flame temperature. Finally, tests were conducted with simulated EGR being used additionally to the engine air supply. This contrasts with the conventional use of EGR, whereby EGR replaces some of the air supplied to the engine. It was found that the first effect of EGR (reduction in the oxygen flowrate to the engine) was substantial and resulted in very large reductions in exhaust NOx at the expense of higher particulate emissions. The second and third effects (participation of carbon dioxide and water vapour in the combustion process and increase in the charge specific heat capacity) were almost insignificant. The fourth effect (higher inlet charge temperature) increased both exhaust NOx and particulate emissions. The fifth effect (reduction in the inlet charge due to thermal throttling) reduced NOx but raised particulate emission. Finally, when EGR was used additionally to the inlet air charge (rather than displacing air), substantial reductions in NOx were recorded with little increase in particulate emission.

The effects of carbon dioxide in exhaust gas recirculation on diesel engine emissions

1998 ◽  
Vol 212 (1) ◽  
pp. 25-42 ◽  
Author(s):  
N Ladommatos ◽  
S M Adelhalim ◽  
H Zhao ◽  
Z Hu
Keyword(s):  
Carbon Dioxide ◽  
Diesel Engine ◽  
High Speed ◽  
Combustion Process ◽  
Dilution Effect ◽  
Exhaust Gas Recirculation ◽  
Chemical Effect ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Gas Recirculation

The investigation was conducted on a high-speed direct injection diesel engine and was concerned with the effects of exhaust gas recirculation (EGR) on diesel engine combustion and emissions. In particular, the effects of carbon dioxide (CO2), a principal constituent of EGR, on combustion and emissions were analysed and quantified experimentally. The use of CO2 to displace oxygen (O2) in the inlet air resulted in: reduction in the O2 supplied to the engine (dilution effect), increased inlet charge thermal capacity (thermal effect), and, potentially, participation of the CO2 in the combustion process (chemical effect). In a separate series of tests the temperature of the engine inlet charge was raised gradually in order to simulate the effect of mixing hot EGR with engine inlet air. Finally, tests were carried out during which the CO2 added to the engine air flow increased the charge mass flowrate to the engine, rather than displacing some of the O2 in the inlet air. It was found that when CO2 displaced O2 in the inlet charge, both the chemical and thermal effects on exhaust emissions were small. However, the dilution effect was substantial, and resulted in very large reductions in exhaust oxides of nitrogen (NO x) at the expense of higher particulate and unburned hydrocarbon (uHC) emissions. Higher inlet charge temperature increased exhaust NO x and particulate emissions, but reduced uHC emissions. Finally, when CO2 was additional to the inlet air charge (rather than displacing O2), large reductions in NOx were recorded with little increase in particulate emissions.

Waste Heat Recovery in Heavy-Duty Diesel Engines: A Thermodynamic Analysis of Waste Heat Availability for Implementation of Energy Recovery Systems Based Upon the Organic Rankine Cycle

2012 ◽  
Author(s):  
A. Cozzolini ◽  
M. C. Besch ◽  
D. Littera ◽  
H. Kappanna ◽  
P. Bonsack ◽  
...  
Keyword(s):  
Waste Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Combustion Process ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exhaust Gas ◽  
Engine Efficiency ◽  
Waste Energy ◽  
Heavy Duty Diesel

In the past decade automotive industries have focused on the development of new technologies to improve the overall engine efficiency and lower emissions in order to satisfy the always more stringent emission standards introduced all around the world. Technical progress has primarily focused on two aspects; the optimization of the air-fuel mixture in the combustion chamber as well as the combustion process itself, leading to simultaneous improvements in both, efficiency (lowering fuel consumption for same power output) and emissions levels which ultimately result from the optimized combustion process. Although engine technology has made significant progress, even modern Diesel combustion engines do not exceed a maximum efficiency of approximately 40%. Hence, around 60% of the available energy carried by the fuel and entering the combustion chamber is dissipated as heat to the environment. The next steps in engine optimization will see the integration of waste heat recovery systems (WHRS) to increase the overall energy efficiency of the propulsion system by means of recovering parts of the waste heat generated during normal engine operation. The presented was aimed at analyzing the availability as well as the quality of heat to be used in WHRS for the case of heavy-duty Diesel (HDD) engines employed in Class-8 tractors, which are suitable candidates for optimization via WHRS implementation as their engines spend most of their time operating at quasi steady state conditions, such as highway cruise. Three different primary energy sources have been considered: exhaust gas recirculation (EGR) cooling system, engine cooling system and exhaust gas stream. Experimental data has been gathered at West Virginia University’s Engine and Emissions Research Laboratory (EERL) facility in order to quantify individual heat flows in a model year (MY) 2004 Mack® MP7-355E HDD engine operated over the 13 modes of the European Stationary Cycle (ESC). Analysis based on second law efficiency underlined that not the whole amount of waste heat can be successfully used for recovery purposes and that heat sources which offer a large amount of waste energy reveal to be inappropriate for recovery purposes in case of low operating temperature. Time integral analysis revealed that engine modes which appear to offer high recovery potential in terms of waste power may not be suitable engine operating conditions when the analysis is performed in terms of waste energy, depending on the particular engine cycle. Finally a simple thermodynamic model of a micro power unit running on an Organic Rankine Cycle (ORC) has been used to assess the theoretical improvement in engine efficiency during steady state operations based on a second law efficiency analysis approach.

scholarly journals The Synergy of Two Biofuel Additives on Combustion Process to Simultaneously Reduce NOx and PM Emissions

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2784
Author(s):  
Jerzy Cisek ◽  
Szymon Lesniak ◽  
Winicjusz Stanik ◽  
Włodzimierz Przybylski
Keyword(s):  
Heat Release ◽  
Combustion Rate ◽  
Combustion Process ◽  
The Other ◽  
Fuel Additive ◽  
Exhaust Gas ◽  
Synergy Effect ◽  
Engine Exhaust ◽  
Other Hand ◽  
Heat Released

The article presents the results of research on the influence of two fuel additives that selectively affect the combustion process in a diesel engine cylinder. The addition of NitrON® reduces the concentration of nitrogen oxides (NOx), due to a reduction in the kinetic combustion rate, at the cost of a slight increase in the concentration of particulate matter (PM) in the engine exhaust gas. The Reduxco® additive reduces PM emissions by increasing the diffusion combustion rate, while slightly increasing the NOx concentration in the engine exhaust gas. Research conducted by the authors confirmed that the simultaneous use of both of these additives in the fuel not only reduced both NOx and PM emissions in the exhaust gas but additionally the reduction of NOx and PM emissions was greater than the sum of the effects of these additives—the synergy effect. Findings indicated that the waveforms of the heat release rate (dQ/dα) responsible for the emission of NOx and PM in the exhaust gas differed for the four tested fuels in relation to the maximum value (selectively and independently in the kinetic and diffusion stage), and they were also phase shifted. Due to this, the heat release process Q(α) was characterized by a lower amount of heat released in the kinetic phase compared to fuel with NitrON® only and a greater amount of heat released in the diffusion phase compared to fuel with Reduxco® alone, which explained the lowest NOx and PM emissions in the exhaust gas at that time. For example for the NOx concentration in the engine exhaust: the Nitrocet® fuel additive (in the used amount of 1500 ppm) reduces the NOx concentration in the exhaust gas by 18% compared to the base fuel. The addition of a Reduxco® catalyst to the fuel (1500 ppm) unfortunately increases the NOx concentration by up to 20%. On the other hand, the combustion of the complete tested fuel, containing both additives simultaneously, is characterized, thanks to the synergy effect, by the lowest NOx concentration (reduction by 22% in relation to the base). For example for PM emissions: the Nitrocet® fuel additive does not significantly affect the PM emissions in the engine exhaust (up to a few per cent compared to the base fuel). The addition of a Reduxco® catalyst to the fuel greatly reduces PM emissions in the engine exhaust, up to 35% compared to the base fuel. On the other hand, the combustion of the complete tested fuel containing both additives simultaneously is characterized by the synergy effect with the lowest PM emission (reduction of 39% compared to the base fuel).

scholarly journals The flame spectrum of carbon monoxide

1940 ◽  
Vol 176 (967) ◽  
pp. 505-521 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Electronic State ◽  
Excited Electronic State ◽  
Combustion Process ◽  
Wave Number ◽  
Band Spectrum ◽  
Liquid Form ◽  
Triangular Form ◽  
Reduced Pressure

The spectrum of the flame of carbon monoxide burning in air and in oxygen at reduced pressure has been photographed on plates of high contrast which display the band spectrum clearly above the continuous background. Greater detail has been obtained than has been recorded previously and new measurements are given. The structure of the spectrum has been studied systematically. It is shown that the bands occur in pairs with a separation of about 60 cm. -1 , this separation being due probably to the rotational structure. Various wave-number differences are found to occur frequently, and many of the strong bands are arranged in arrays using intervals of 565 and 2065 cm. -1 . The possible origin of the spectrum is discussed. The choice of emitter is limited to a polyatomic oxide of carbon, of which carbon dioxide is the most likely. The spectrum of the suboxide C 3 O 2 shows some resemblance to the flame bands, but this molecule is improbable as the emitter on other grounds. A peroxide C0 3 is also a possibility, but no evidence for the presence of this has been obtained from experiments on the slow combustion of carbon monoxide. Carbon dioxide in gaseous or liquid form is transparent through the visible and quartz ultra-violet, and the flame bands are not obtained from CO 2 in discharge tubes. Comparison with the Schumann-Runge bands of oxygen shows that it is possible that the flame bands may form part of the absorption band system of CO 2 which is known to exist below 1700 A if there is a big change in shape or size of the molecule in the two electronic states. The electronic energy levels of CO 2 are discussed. Since normal CO 2 is not built up from normal CO and oxygen, an electronic rearrangement of the CO 2 must occur after the combustion process. Mulliken has suggested that the molecule in the first excited electronic state, corresponding to absorption below 1700 A, may have a triangular form. The frequencies obtained from the flame bands are compared with the infra-red frequencies of CO 2 . The 565 interval may be identified with the transverse vibration v 2 , indicating that the excited electronic state is probably triangular in shape. The 2065 interval cannot, however, be identified with the asymmetric vibration v 3 with any certainty. If the excited electronic state of CO 2 is triangular, then molecules formed during the combustion by transitions from this level to the ground state may be “vibrationally activated”. This is probably the reason for many of the peculiarities of the combustion of carbon monoxide.

scholarly journals Assessment of the Deterioration State of Post-Installed Bonded Anchors Using Ultrasonic

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2077
Author(s):  
Oliver Zeman ◽  
Michael Schwenn ◽  
Martin Granig ◽  
Konrad Bergmeister
Keyword(s):  
Maximum Load ◽  
Assessment Method ◽  
Load Level ◽  
Experimental Investigations ◽  
Load History ◽  
Anchor System ◽  
Ultrasonic Methods ◽  
Building Maintenance ◽  
History Of ◽  
Set Up

The assessment of already installed anchorages for a possible exceeding of the service load level is a question that is gaining more and more importance, especially in building maintenance. Bonded anchors are of particular interest here, as the detection of a capacity reduction or load exceedance can cause damage to the concrete-bonded mortar behavior. This article investigates the extent to which ultrasonic methods can be used to make a prediction about the condition of anchorages in concrete and about their load history. A promising innovative assessment method has been developed. The challenges in carrying out the experimental investigations are the arrangement of the transducers, the design of the test set-up and the applicability of direct, indirect or semidirect ultrasonic transmission. The experimental investigations carried out on a test concrete mix and a bonded anchor system show that damage to the concrete structure can be detected by means of ultrasound. The results indicate the formation of cracks and therefore a weakening of the response determined by means of direct, indirect and semidirect ultrasonic transmission. However, for application under non-laboratory conditions and on anchors with unknown load history, the calibration with a reference anchor and the identification of the maximum load is required. This enables a referencing of the other loaded anchors to the unloaded conditions and allows an estimation of the load history of individual anchors.

Synthesis of Macro-Porous De-NOx Catalysts for Poly-Tetra-Fluoro-Ethylene Membrane Bag Filter

2021 ◽  
Vol 21 (8) ◽  
pp. 4537-4543
Author(s):  
Byung Chan Kwon ◽  
Dohyung Kang ◽  
Seung Woo Lee ◽  
No-Kuk Park ◽  
Jang Hun Lee ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nitrogen Oxides ◽  
Porous Alumina ◽  
Combustion Process ◽  
Textural Properties ◽  
Filter Material ◽  
Facilitated Diffusion ◽  
Exhaust Gas ◽  
Bag Filter ◽  
Combustion Exhaust

This study examined the effects of the porosity of catalytic bag-filter materials for applications to the SNCR (selective noncatalytic reduction)-SCR (selective catalytic reduction) hybrid process for highly treating nitrogen Oxides (NOx) in the exhaust gas of a combustion process. A V2O5/TiO2 catalyst was dispersed in a PTFE (poly-tetra-fluoro-ethylene) used as the catalytic bag-filter material to remove particulate matter and nitrogen oxides contained in the combustion exhaust gas. Macroporous alumina was added into a V2O5/TiO2-dispersed PTFE to improve the catalytic activity of V2O5/TiO2 dispersed in the PTFE material. In this study, the textural properties and denitrification performances of the V2O5/TiO2-dispersed PTFE materials were examined according to the addition of macro-porous alumina. When the denitrification catalyst was solely dispersed in the PTFE material, the catalyst inside the PTFE backbone had low gas-solid contact efficiency owing to the low porosity of the PTFE materials, resulting in low denitrification efficiency. On the other hand, the catalytic activity of V2O5/TiO2 dispersed inside the macro-porous PTFE material was significantly enhanced by adding macro-porous alumina into the PTFE matrix. The enhanced textural properties of the macro-porous PTFE material where V2O5/TiO2 was uniformly dispersed proved the facilitated diffusion of combustion exhaust gas into the PTFE material.

Innovative Passive Flame Ameliorator for a Diffusion Flame Burner Using Chevrons

2015 ◽  
Vol 787 ◽  
pp. 732-735
Author(s):  
A. Alaguraja ◽  
S. Balaji ◽  
Inti Sandeep ◽  
M. Karthikeyan ◽  
S. Soma Sundaram
Keyword(s):  
Diffusion Flame ◽  
Acoustic Noise ◽  
Combustion Process ◽  
Ambient Air ◽  
Premixed Flame ◽  
Experimental Investigations ◽  
Exhaust Gas ◽  
Novel Approach ◽  
Flame Burner ◽  
Safety Considerations

Diffusion flame burners are mainly used in industries over premixed flame burners for safety considerations. But the combustion process in a diffusion flame is not complete and the flame is usually in bright yellow in colour in contrast to the premixed flame which gives a bluish flame. To improve the combustion process in a diffusion flame burner a novel approach, using chevrons has been carried out. The chevrons are found to reduce the aero-acoustic noise in the exhaust jets of aircraft engines by allowing better mixing of the exhaust gas with the ambient air. The similar concept is used here where the tips of the burners are cut in the form of chevrons. Experimental investigations are carried out on burners with three and four chevrons in addition to a standard burner using LPG as the fuel. The results indicate that with the introduction of chevrons the diffusion flame becomes more compact. The premixed region, in the diffusion flame, where the air and fuel is mixed well is found to increase by nearly 100 % with the usage of chevrons, indicating better mixing of fuel and air. The results also indicate that increasing the number of chevrons from three to four does not show much variation. Further experiments are to be carried out to determine the improved fuel consumption with the usage of chevrons.

Modeling and prediction for the oxidation efficiency of magnesium sulfite in aeration tank of magnesium-based seawater exhaust gas clean system

2017 ◽  
Vol 233 (1) ◽  
pp. 164-173
Author(s):  
Quan Liu ◽  
Yimin Zhu ◽  
Tie Li ◽  
Xiaojia Tang ◽  
Weifeng Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Initial Conditions ◽  
Negative Impact ◽  
Fluid Model ◽  
Aeration Tank ◽  
Exhaust Gas ◽  
Clean System ◽  
Physics Modeling ◽  
Set Up ◽  
Oxidation Efficiency

In magnesium-based seawater exhaust gas clean system, the desulfurization by-product, magnesium sulfite (MgSO3), has a negative impact on the ecological environment, which needs to be treated to make harmless. Due to the limited space on board, the aeration oxidation method is used to convert it to magnesium sulfate. Because of the variable size, shape and flow field of aeration tank, it is difficult and expensive to design and verify the oxidation efficiency of the aeration tank by experimental method. In this work, in order to predict the oxidation efficiency accurately, RFlow, a computational fluid dynamics software, was used to analyze the flow field and MgSO3 oxidation reaction in aeration tank. The subdomain technology was adopted for physics modeling and mesh generation of the aeration tank, and the total number of meshes was 285,000. The multi-phase flow field model was set up using the multi-fluid model and dispersive k-ε turbulence model. Under the given initial conditions, the predicted oxidation efficiency was 94.2%. Compared with the results of the actual ship test, the prediction model for MgSO3 oxidation efficiency of the aeration tank is reliable.

scholarly journals Improvement of the method of purification of exhaust gases in the production of asphalt concrete

2020 ◽  
Vol 77 (3) ◽  
pp. 218-225
Keyword(s):  
Carbon Dioxide ◽  
Hazardous Waste ◽  
Asphalt Concrete ◽  
Working Life ◽  
Waste Recycling ◽  
Exhaust Gas ◽  
Protection Measures ◽  
Purification System ◽  
Gaseous Waste ◽  
Harmful Substances

The article analyzes the air protection measures of LLP «Asphaltbeton» demonstrated the disadvantages of the efficacy of the purification system for calculating waste emissions and scattering of atmospheric contaminants, as the concentration of sludge substances (dust) is 2.5 times more than 1.206 mg/m3, and nitrogen, the concentration of carbon dioxide and the amount of hydrocarbons in the sanitary dimensions and according to it. The effectiveness of purification of exhaust gas from the asphalt mixer D-645 with the CF-10 chain filter allowed the choice of more systems. The calculations in the FTS-10 showed that it is possible to efficiently clean gas emissions from 95% to 95% by removing the waste from gaseous waste. When preparing asphalt concrete, harmful substances such as dust, oxides, nitrogen and carbon, hydrocarbon are distributed. Therefore, the permissible threshold for all hazardous waste recycling sites has been identified (DHM, mg/m3), which prevents the dust, steam, gas workers from exposing the flu or fluid to the workplace while maintaining a working life of less than 8 hours per day.

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