scholarly journals Quantitative analysis of combustion process of marine dual fuel engine under the framework of iconology

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Hongliang Yu ◽  
◽  
Weiwei Wang ◽  
Shulin Duan ◽  
Peiting Sun ◽  
...  

The methane (CH4) burning interruption factor and the characteristic values characterizing the flame combustion state in the engine cylinder were defined. The logical mapping relationship between image feature values and combustion conditions in the framework of iconology was proposed. Results show that there are two periods of combustion instability and combustion stability during the combustion of dual fuel. The high temperature region with a cylinder temperature greater than 1800K is the largest at 17°CA after top dead center (TDC), accounting for 73.25% of the combustion chamber area. During the flame propagation, the radial flame velocity and the axial flame velocity are “unimodal” and “wavy,” respectively. During the combustion process, the CH4 burning interruption factor first increased and then decreased. The combustion duration in dual fuel mode is 21.25°CA, which is 15.5°CA shorter than the combustion duration in pure diesel mode.

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1499
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik

This paper presents results of investigation of co-combustion process of biodiesel with gasoline, in form of mixture and using dual fuel technology. The main objective of this work was to show differences in both combustion systems of the engine powered by fuels of different reactivity. This paper presents parameters of the engine and the assessment of combustion stability. It turns out that combustion process of biodiesel was characterized by lower ignition delay compared to diesel fuel combustion. For 0.54 of gasoline energetic fraction, the ignition delay increased by 25% compared to the combustion of the pure biodiesel, but for dual fuel technology for 0.95 of gasoline fraction it was decreased by 85%. For dual fuel technology with the increase in gasoline fraction, the specific fuel consumption (SFC) was decreased for all analyzed fractions of gasoline. In the case of blend combustion, the SFC was increased in comparison to dual fuel technology. An analysis of spread of ignition delay and combustion duration was also presented. The study confirmed that it is possible to co-combust biodiesel with gasoline in a relatively high energetic fraction. For the blend, the ignition delay was up to 0.54 and for dual fuel it was near to 0.95.


2014 ◽  
Vol 699 ◽  
pp. 648-653 ◽  
Author(s):  
Bahaaddein K.M. Mahgoub ◽  
Suhaimi Hassan ◽  
Shaharin Anwar Sulaiman

In this review, a series of research papers on the effects of hydrogen and carbon monoxide content in syngas composition on the performance and exhaust emission of compression ignition diesel engines, were compiled. Generally, the use of syngas in compression ignition (CI) diesel engine leads to reduce power output due to lower heating value when compared to pure liquid diesel mode. Therefore, variation in syngas composition, especially hydrogen and carbon monoxide (Combustible gases), is suggested to know the appropriate syngas composition. Furthermore, the simulated model of syngas will help to further explore the detailed effects of engine parameters on the combustion process including the ignition delay, combustion duration, heat release rate and combustion phasing. This will also contribute towards the efforts of improvement in performance and reduction in pollutants’ emissions from CI diesel engines running on syngas at dual fuel mode. Generally, the database of syngas composition is not fully developed and there is still room to find the optimum H2 and CO ratio for performance, emission and diesel displacement of CI diesel engines.


Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 946 ◽  
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik

The aim of the work is a comparison of two combustion systems of fuels with different reactivity. The first is combustion of the fuel mixture and the second is combustion in a dual-fuel engine. Diesel fuel was burned with pure ethanol. Both methods of co-firing fuels have both advantages and disadvantages. Attention was paid to the combustion stability aspect determined by COVIMEP as well as the probability density function of IMEP. It was analyzed also the spread of the maximum pressure value, the angle of the position of maximum pressure. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operated with ethanol up to 50% of its energy fraction.


2019 ◽  
Vol 178 (3) ◽  
pp. 155-161
Author(s):  
Łukasz NOWAK ◽  
Wojciech TUTAK

The paper presents result of combustion stability assessment of dual fuel engine. The authors analyzed results of co-combustion of diesel fuel with alcohol in terms of combustion stability. The comparative analysis of both the operational parameters of the engine and the IMEP, as the parameters determining the stability of the combustion process, were carried out. It was analyzed, among others values of the COVIMEP coefficient, the spread of the maximum pressure value, the angle of the position of maximum pressure and the probability density distribution of the IMEP. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operat-ed with ethanol up to 50% of its energy fraction. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. It turns out that the share of ethanol does not adversely affect the stability of ignition..


2015 ◽  
Vol 19 (6) ◽  
pp. 1897-1906 ◽  
Author(s):  
Jianyong Zhang ◽  
Zhongzhao Li ◽  
Kaiqiang Zhang ◽  
Xingcai Lv ◽  
Zhen Huang

In a port fuel injection engine, Optimized kinetic process (OKP) technology is implemented to realize HCCI combustion with dual-fuel injection. The effects of intake air temperature on HCCI combustion and emissions are investigated. The results show that dual-fuel control prolongs HCCI combustion duration and improves combustion stability. Dual-fuel HCCI combustion needs lower intake air temperature than gasoline HCCI combustion, which reduces the requirements on heat management system. As intake air temperature decreases, air charge increases and maximum pressure rising rate decreases. When intake air temperature is about 55?C, HCCI combustion becomes worse and misfire happens. In fixed dual fuel content condition, HC and CO emission decreases as intake air temperature increases. The combination of dual-fuel injection and intake air temperature control can expand operation range of HCCI combustion.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2817
Author(s):  
Arkadiusz Jamrozik ◽  
Wojciech Tutak ◽  
Karol Grab-Rogaliński

The development of compression ignition engines depends mainly on using alternative fuels, such as alcohols. The paper presents the results of tests of a stationary compression ignition engine fueled with mixtures of diesel oil and n-butanol with an energy share from 0 to 60%. The combustion and emission results of a dual-fuel engine were compared to a conventional diesel-only engine. As part of the work, the combustion process, including changes in pressure and heat release rate, as well as exhaust emissions from the test engine, were investigated. The main operational parameters of the engine were determined, including mean indicated pressure, thermal efficiency and specific energy consumption. Moreover, the stability of the engine operation was analyzed. The research shows that the 60% addition of n-butanol to diesel fuel increases the ignition delay (by 39%) and shortens the combustion duration (by 57%). In addition, up to 40%, it results in increased pmax, HRRmax and PPRmax. The engine was characterized by the highest efficiency, equal to 41.35% when operating on DB40. In the whole range of alcohol content, the dual-fuel engine was stable. With the increase of n-butanol content to 40%, the emission of NOx increased. The lowest concentration of CO was obtained during the combustion of DB50. After the initial increase (for DB20), the THC emission was reduced to the lowest value for DB40. Increasing the energy share of alcohol to 60% resulted in a significant, more than 43 times, reduction in soot emissions.


2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Hailin Li ◽  
Shiyu Liu ◽  
Chetmun Liew ◽  
Timothy Gatts ◽  
Scott Wayne ◽  
...  

This paper investigates the effect of the addition of natural gas (NG) and engine load on the cylinder pressure, combustion process, brake thermal efficiency, and methane combustion efficiency of a heavy-duty NG-diesel dual fuel engine. Significantly increased peak cylinder pressure (PCP) was only observed with the addition of NG at 100% load. The addition of a relatively large amount NG at high load slightly retarded the premixed combustion, significantly increased the peak heat release rate (PHRR) of the diffusion combustion, decreased the combustion duration, and advanced combustion phasing. The accelerated combustion process and increased heat release rate (HRR) at high load were supported by the increased NOx emissions with the addition of over 3% NG (vol.). By comparison, when operated at low load, the addition of a large amount of NG decreased the PHRR of the premixed combustion and slightly increased the PHRR during the late diffusion combustion. Improved brake thermal efficiency was only observed with the addition of a relatively large amount of NG at high load. The improved thermal efficiency was due to a decrease in combustion duration and the shifting of the combustion phasing toward the optimal phasing. The overall combustion efficiency of the dual fuel operation was always lower than diesel-only operation as indicated by the excess emissions of the unburned methane and carbon monoxide from dual fuel engine. This deteriorated the potential of dual fuel engine in further improving the brake thermal efficiency although the combustion duration of dual fuel engine at high load was much shorter than diesel only operation. The addition of NG at low load should be avoided due to the low combustion efficiency of NG and the decreased thermal efficiency. Approaches capable of further improving the in-cylinder combustion efficiency of NG should enable further improvement in the brake thermal efficiency.


2021 ◽  
pp. 146808742110516
Author(s):  
Enrico Mattarelli ◽  
Carlo Alberto Rinaldini ◽  
Stefano Caprioli ◽  
Francesco Scrignoli

Dual Fuel (DF) combustion can help to reduce the environmental impact of internal combustion engines, since it may provide excellent Brake Thermal Efficiency (BTE) combined with ultra-low emissions. This technique is particularly attractive when using biofuels, or fuels with a low Carbon content, such as Natural Gas (NG). Unfortunately, as engine load decreases and the homogeneous NG-air mixture tends to become very lean, the high chemical stability of NG can be a serious obstacle to the completion of combustion. As a result, BTE drops and UHC and CO emissions become very high. A possible way to address this problem could be the addition of hydrogen (H2) to the NG-air mixture. In this paper, a numerical study has been carried out on an automotive Diesel engine, modified by the authors in order to operate in both conventional Diesel combustion and DF NG-diesel mode. A previous experimental characterization of the engine is the basis for the CFD-3D modeling and calibration of the DF combustion process, using a commercial software. The effects on combustion stability and emissions of different NG-H2 mixtures (six blends with 5%, 10%, 15%, 20%, 25%, and 30% by volume of hydrogen) are numerically investigated at a low load (BMEP = 2 bar, engine speed 3000 rpm). The results of the CFD-3D simulations demonstrate that NG-H2 blends are able to decrease strongly CO, UHC, and CO2 emissions at low loads. Advantages are also found in terms of thermal efficiency and NOx emissions.


Author(s):  
Lukáš Tunka ◽  
Adam Polcar

This article deals with the effect of the ignition timing on the output parameters of a spark-ignition engine. The main assessed parameters include the output parameters of the engine (engine power and torque), cylinder pressure variation, heat generation and burn rate. However, the article also discusses the effect of the ignition timing on the temperature of exhaust gases, the indicated mean effective pressure, the combustion duration, combustion stability, etc. All measurements were performed in an engine test room in the Department of Technology and Automobile Transport at Mendel University in Brno, on a four-cylinder AUDI engine with a maximum power of 110 kW, as indicated by the manufacturer. To control and change the ignition timing of the engine, a fully programmable Magneti Marelli control unit was used. The experimental measurements were performed on 8 different ignition timings, from 18 °CA to 32 °CA BTDC at wide throttle open and a constant engine speed (2500 rpm), with a stoichiometric mixture fraction. The measurement results showed that as the ignition timing increases, the engine power and torque also increase. The increase in these parameters is a reflection of higher pressure in the cylinder, the maximum value of which is achieved at a higher ignition timing near top dead centre in thepower stroke. In these conditions we can expect higher engine efficiency. It was also found that the combustion is more stable with a higher value of ignition timing. No significant difference was found in the combustion duration.


2020 ◽  
Vol 10 (3) ◽  
pp. 1082 ◽  
Author(s):  
Wojciech Tutak ◽  
Karol Grab-Rogaliński ◽  
Arkadiusz Jamrozik

The paper presents the results of co-combustion of biodiesel with hydrogen in a compression-ignition internal combustion engine. The tests were carried out on a stationary engine with constant settings. The paper presents the results of the assessment of the combustion process, combustion stability and exhaust emissions in a dual-fuel diesel engine fueled with biodiesel and hydrogen. It was found that it is possible to replace biodiesel with hydrogen to its energetic share of 38%. The share of hydrogen in the co-combustion process causes a change in combustion phases and reducing the duration of combustion. The increase of the engine thermal efficiency was obtained with the increase of the H2 share. A different character of heat release rate was obtained compared to a conventional engine. The reduction in the diffusion combustion phase has contributed to a significant reduction in soot emissions. The maximum 38% of hydrogen energy share acceptable by the engine, resulted in a more than 25-times reduction in soot emissions. The combustion stability assessed on the basis of the unrepeatability of the indicated mean effective pressure (COVIMEP) index and also on the basis of the indicated mean effective pressure (IMEP) normal distribution was also analyzed.


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