scholarly journals Effect of Pre-Combustion Chamber Nozzle Parameters on the Performance of a Marine 2-Stroke Dual Fuel Engine

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 876 ◽  
Author(s):  
Hao Guo ◽  
Song Zhou ◽  
Majed Shreka ◽  
Yongming Feng
Keyword(s):  
Combustion Chamber ◽  
Flame Propagation ◽  
High Efficiency ◽  
Great Influence ◽  
Engine Performance ◽  
Propagation Speed ◽  
Nozzle Diameter ◽  
Dual Fuel ◽  
Shipping Industry ◽  
Reduce Emissions

In recent years and with the increasing rigor of the International Maritime Organization (IMO) emission regulations, the shipping industry has focused more on environment-friendly and efficient power. Low-pressure dual-fuel (LP-DF) engine technology with high efficiency and good emissions has become a promising solution in the development of marine engines. This engine often uses pre-combustion chamber (PCC) to ignite natural gas due to its higher ignition energy. In this paper, a parametric study of the LP-DF engine was proceeded to investigate the design scheme of the PCC. The effect of PCC parameters on engine performance and emissions were studied from two aspects: PCC nozzle diameter and PCC nozzle angle. The results showed that the PCC nozzle diameter affected the propagation of the flame in the combustion chamber. Moreover, suitable PCC nozzle diameters helped to improve flame propagation stability and engine performance and reduce emissions. Furthermore, the angle of the PCC nozzle had a great influence on flame propagation direction, which affected the flame propagation speed and thus the occurrence of knocking. Finally, optimizing the angle of the PCC nozzle was beneficial to the organization of the in-cylinder combustion.

Influence Study of Gas Pressure on the Volume Measurement of Engine Combustion Chamber by Using Helmholtz Resonance

2019 ◽  
Author(s):  
Kun Chen ◽  
Sun Jin ◽  
Shun Liu ◽  
Ang Tian ◽  
Wei Mo
Keyword(s):  
Combustion Chamber ◽  
High Efficiency ◽  
Great Influence ◽  
Engine Performance ◽  
Volume Measurement ◽  
Automobile Engine ◽  
Closed Cavity ◽  
Helmholtz Resonance ◽  
Resonance Principle ◽  
The Relationship

Abstract The combustion chamber of automobile engine is a place where gasoline is burned to provide power for automobile driving and its size has a great influence on engine performance. However, because of the irregularity of the combustion chamber, it is difficult to measure it accurately and efficiently. The principle of Helmholtz resonance reveals the functional relationship between the volume and the resonant frequency of the closed cavity. Having used the Helmholtz resonance principle, the equipment for measuring the combustion chamber of automobile engine accurately and efficiently has been built. The conditions under which the cavity is stimulated to produce resonance are explored, the relationship between volume and the pressure is deduced. Experiments are designed to verify the correctness and accuracy of the measurement. The measuring instrument is improved and the accuracy of the volume measurement is increased. The application of the high precision and high efficiency of non-contact acoustic principle in cavity volume dynamic measurement has been realized.

scholarly journals Influence of swirl and tumble motion inside the combustion chamber of a compression ignited engine on vertices formation

2018 ◽  
Vol 184 ◽  
pp. 01022 ◽  
Author(s):  
Dan Moldovanu ◽  
Florin Mariașiu ◽  
Norbert Bagameri
Keyword(s):  
Numerical Analysis ◽  
Combustion Chamber ◽  
Great Influence ◽  
Fuel Mixture ◽  
Current Paper ◽  
Air Motion ◽  
Reduce Emissions

In modern compression ignited engines, one of the key innovative directions is optimization of the burn process especially to reduce emissions. This optimization can be done by ensuring a better air-fuel mixture. To answer this problem, in the current paper, the authors analysed the vertices formation and velocity inside the combustion chamber in thirteen cases, by using numerical analysis (AVL FIRE Software), to generate pure tumble motion, pure swirl motion, no in-cylinder motion of the air, and other combinations on tumble and swirl motion. The cases that were chosen combine 0%, 50%, 70% and 100% tumble and swirl motion. The greatest velocity of the in-cylinder air motion was noted when a 100%tumble and 50% swirl motion was induced (77.2 m/s at 736 degrees CA), while the smallest velocity was noted at 100% swirl and 0% tumble (71.07 m/s at 736 degrees CA). Because of the different induced motions, the vertices that form inside the combustion chamber have a great influence on air-fuel mixture and implicitly on emissions.

scholarly journals Numerical simulation of the influence of pipe length on explosion flame propagation in open-ended and close-ended pipes

2020 ◽  
Vol 103 (4) ◽  
pp. 003685042096160
Author(s):  
Xue Li ◽  
Ning Zhou ◽  
Xuanya Liu ◽  
Weiqiu Huang ◽  
Bing Chen ◽  
...  
Keyword(s):  
Flame Front ◽  
Flame Propagation ◽  
Flame Structure ◽  
Great Influence ◽  
Propagation Speed ◽  
Rapid Expansion ◽  
Combustion Model ◽  
Pipe Length ◽  
Flame Propagation Velocity ◽  
Tulip Flame

The pipeline length exerts great influence on flame propagation characteristics, Realizable [Formula: see text] model and Premixed combustion model were used to study the influence of pipe length on propane-air explosion flame in open-ended and close-ended pipes. Using the numerical model verified by experiments, the changes of flame structure and flame propagation speed are studied. The result showed that the Realizable model was in good agreement with the experimental results. It also proved that the reflected wave produced a strong interference on the flame front, which promoted the formation of tulip flame. Besides, some obvious vortices were usually generated in the burned gas after the tulip flame formed, which will affect the flow field around the flame front and thus exert influence on the flame structure. The formation mechanism of tulip flame as well as the flame self-acceleration is different in open-ended and close-ended pipes. In close-ended pipes, the reflection wave at the pipe end and the reflection-induced countercurrent both promote the formation of tulip flame. As the flame propagates to the pipe end, the flame propagation is inhibited by the compression wave formed by the rapid expansion of combustion products under high temperature. While, in open-ended pipes, the turbulence induced by the opening at the pipe end is the main cause of tulip flame formation. The flame acceleration depends on the combustion reaction of unburned gas, so the velocity of flame propagation continues to increase. Generally, the maximum flame propagation velocity in the open-ended pipe is larger than that in the close-ended pipe.

The Design and Performance of a Sturdy Industrial Combustion Chamber for a 14 MW Gas Turbine

1981 ◽  
Author(s):  
L. Andersson
Keyword(s):  
Air Pollution ◽  
Combustion Chamber ◽  
Water Injection ◽  
Engine Performance ◽  
Dual Fuel ◽  
Combustion Chambers ◽  
Fuel Injectors ◽  
Unburned Hydrocarbons ◽  
And Performance ◽  
Engine Power

The latest stage in the evaluation of a dual fuel industrial combustion chamber is reported. The design, fitting and maintability of the cans and fuel injectors is described. The performances studied are can wall temperatures, ignition and environment air pollution. The latter cover NO, NO2, CO, unburned hydrocarbons, smoke and solids. Those have been measured over a range of engine power settings, and also over a range of water injection ratios into the combustion chambers. Full engine performance was accordingly measured.

scholarly journals Emission and Performance Optimization of Marine Four-Stroke Dual-Fuel Engine Based on Response Surface Methodology

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Huaiyu Wang ◽  
Huibing Gan ◽  
Guanjie Wang ◽  
Guoqiang Zhong
Keyword(s):  
Response Surface Methodology ◽  
Natural Gas ◽  
Response Surface ◽  
Performance Optimization ◽  
Engine Performance ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Shipping Industry ◽  
Performance And Emissions ◽  
And Performance

As the emissions regulations have become more stringent, reducing NOX emissions is of great importance to the shipping industry. Due to the price and emissions advantages of natural gas, the diesel-natural gas engines have become an attractive solution for engine manufacturers. Firstly, in this paper, the NOX emissions prediction model of a large marine four-stroke dual-fuel engine is built by using AVL-BOOST. In addition, the model is further calibrated to calculate the performance and emissions of the engine. Then, the influences of boost pressure, compression ratio, and the timing of intake valve closing on engine performance and emissions are analyzed. Finally, the response surface methodology is used to optimize the emissions and performance to obtain the optimal setting parameters of the engine. The results indicate that the response surface method is a highly desirable optimization method, which can save a lot of repeated research. Compared with the results from manufactured data, the power is increased by 0.55% and the BSFC, the NOX emissions, and the peak combustion pressure are decreased by 0.60%, 13.21%, and 1.51%, respectively, at low load.

Numerical Investigation on the Effects of Flame Propagation in Rotary Engine Performance With Leakage and Different Recess Shapes Using Three-Dimensional Computational Fluid Dynamics

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Thirumal Valavan Harikrishnan ◽  
Suryanarayana Challa ◽  
Dachapalli Radhakrishna
Keyword(s):  
Combustion Chamber ◽  
Flame Propagation ◽  
Compression Ratio ◽  
Peak Pressure ◽  
Three Dimensional ◽  
Engine Performance ◽  
Front Propagation ◽  
Fuel Mixture ◽  
Experimental Results ◽  
Rotary Engine

This study was carried out with an objective to develop a 3D simulation methodology for rotary engine combustion study and to investigate the effect of recess shapes on flame travel within the rotating combustion chamber and its effects on engine performance. The relative location of spark plugs with respect to the combustion chamber has significant effect on flame travel, affecting the overall engine performance. The computations were carried out with three different recess shapes using iso-octane (C8H18) fuel, and flame front propagation was studied at different widths from spark location. Initially, a detailed leakage study was carried out and the flow fields were compared with available experimental results. The results for first recess with compression ratio 9.1 showed that the flow and vortex formations were similar to that of actual model. The capability of the 3D model to predict the combustion reaction rate precisely as that of practical engine is presented with comparison to experimental results. This study showed that the flame propagation is dominant toward the leading apex of the rotor chamber, and the air/fuel mixture region in the engine midplane, between the two spark plugs, has very low flame propagation compared to the region in the vicinity of spark. The air/fuel mixture in midplane toward the leading apex burns partially and most of the mixture toward the trailing apex is left unburnt. Recommendations have been made for optimal positioning of the spark plugs along the lateral axis of the engine. In the comparison study with different recess shapes, lesser cavity length corresponding to a higher compression ratio (CR) of 9.6 showed faster flame propagation toward leading side. Also, mass trapped in working chamber reduced and developed higher burn rate and peak pressure resulting in better fuel conversion efficiency. Third recess with lesser CR showed reduced burn rates and lower peak pressure.

Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

2020 ◽  
pp. 095441002096645
Author(s):  
Jie Gao ◽  
Chunde Tao ◽  
Dongchen Huo ◽  
Guojie Wang
Keyword(s):  
Performance Improvement ◽  
High Efficiency ◽  
Three Dimensional ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Turbine ◽  
Flow Interactions ◽  
And Performance

Marine, industrial, turboprop and turboshaft gas turbine engines use nonaxisymmetric exhaust volutes for flow diffusion and pressure recovery. These processes result in a three-dimensional complex turbulent flow in the exhaust volute. The flows in the axial turbine and nonaxisymmetric exhaust volute are closely coupled and inherently unsteady, and they have a great influence on the turbine and exhaust aerodynamic characteristics. Therefore, it is very necessary to carry out research on coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics, so as to provide reference for the high-efficiency turbine-volute designs. This paper summarizes and analyzes the recent advances in the field of coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery. This review covers the following topics that are important for turbine and volute coupled designs: (1) flow and loss characteristics of nonaxisymmetric exhaust volutes, (2) flow interactions between axial turbine and nonaxisymmetric exhaust volute, (3) improvement of turbine and volute performance within spatial limitations and (4) research methods of coupled turbine and exhaust volute aerodynamics. The emphasis is placed on the turbine-volute interactions and performance improvement. We also present our own insights regarding the current research trends and the prospects for future developments.

scholarly journals Effect of Methanol/Water Mixed Fuel Compound Injection on Engine Combustion and Emissions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4491
Author(s):  
Changchun Xu ◽  
Haengmuk Cho
Keyword(s):  
Fuel Consumption ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Hydroxyl Group ◽  
Combustion Mechanism ◽  
Performance And Emission ◽  
Reduce Emissions ◽  
Concentration Ratios

Due to the recent global increase in fuel prices, to reduce emissions from ground transportation and improve urban air quality, it is necessary to improve fuel efficiency and reduce emissions. Water, methanol, and a mixture of the two were added at the pre-intercooler position to keep the same charge and cooling of the original rich mixture, reduce BSFC and increase ITE, and promote combustion. The methanol/water mixing volume ratios of different fuel injection strategies were compared to find the best balance between fuel consumption, performance, and emission trends. By simulating the combustion mechanism of methanol, water, and diesel mixed through the Chemkin system, the ignition delay, temperature change, and the generation rate of the hydroxyl group (−OH) in the reaction process were analyzed. Furthermore, the performance and emission of the engine were analyzed in combination with the actual experiment process. This paper studied the application of different concentration ratios of the water–methanol–diesel mixture in engines. Five concentration ratios of water–methanol blending were injected into the engine at different injection ratios at the pre-intercooler position, such as 100% methanol, 90% methanol/10% water, 60% methanol/40% water, 30% methanol/70% water, 100% water was used. With different volume ratios of premixes, the combustion rate and combustion efficiency were affected by droplet extinguishment, flashing, or explosion, resulting in changes in combustion temperature and affecting engine performance and emissions. In this article, the injection carryout at the pre-intercooler position of the intake port indicated thermal efficiency increase and a brake specific fuel consumption rate decrease with the increase of water–methanol concentration, and reduce CO, UHC, and nitrogen oxide emissions. In particular, when 60% methanol and 40% water were added, it was found that the ignition delay was the shortest and the cylinder pressure was the largest, but the heat release rate was indeed the lowest.

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