scholarly journals Effects of ethanol port injection timing and delivery rate on combustion characteristic of a heavy-duty V12 diesel engine

2021 ◽  
pp. 137-137
Author(s):  
Kien Nguyen Trung ◽  
Hai Hoang Tuan

Using bio-based fuels in diesel engines is an effective solution to reduce the generation of toxic components in the exhaust gas. One of them, alcohol, is the potential fuel to reduce emissions and dependence on fossil fuels. So, this study is aimed to investigate the effects of ethanol port injection timing and delivery rate on the combustion characteristic of a heavy-duty V-12 diesel engine when ethanol substitution percentage is 30% to reach the original diesel quantity at full load. The combustion characteristic analysis indicates that the variation in cylinder gas pressure and temperature decreases when retarded ethanol injection timing and decreased ethanol delivery rate, the engine works more smoothly due to the maximum rate of pressure rise decreases. However, the changes are greater when changing the ethanol injection timing as compared to ethanol delivery rate case.

Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lyes Tarabet ◽  
Khaled Loubar ◽  
Mohand Said Lounici ◽  
Samir Hanchi ◽  
Mohand Tazerout

Nowadays, the increasing oil consumption throughout the world induces crucial economical, security, and environmental problems. As a result, intensive researches are undertaken to find appropriate substitution to fossil fuels. In view of the large amount of eucalyptus trees present in arid areas, we focus in this study on the investigation of using eucalyptus biodiesel as fuel in diesel engine. Eucalyptus oil is converted by transesterification into biodiesel. Eucalyptus biodiesel characterization shows that the physicochemical properties are comparable to those of diesel fuel. In the second phase, a single cylinder air-cooled, DI diesel engine was used to test neat eucalyptus biodiesel and its blends with diesel fuel in various ratios (75, 50, and 25 by v%) at several engine loads. The engine combustion parameters such as peak pressure, rate of pressure rise, and heat release rate are determined. Performances and exhaust emissions are also evaluated at all operating conditions. Results show that neat eucalyptus biodiesel and its blends present significant improvements of carbon monoxide, unburned hydrocarbon, and particulates emissions especially at high loads with equivalent performances to those of diesel fuel. However, the NOx emissions are slightly increased when the biodiesel content is increased in the blend.


Author(s):  
Praveen Kandulapati ◽  
Chuen-Sen Lin ◽  
Dennis Witmer ◽  
Thomas Johnson ◽  
Jack Schmid ◽  
...  

Synthetic fuels produced from non-petroleum based feedstocks can effectively replace the depleting petroleum based conventional fuels while significantly reducing the emissions. The zero sulfur content and the near zero percentage of aromatics in the synthetic fuels make them promising clean fuels to meet the upcoming emissions regulations. However due to their significantly different properties when compared to the conventional fuels; the existing engines must be tested extensively to study their performance with the new fuels. This paper reports a detailed in-cylinder pressure measurement based study made on adaptability of the engine control module (ECM) of a modern heavy duty diesel engine to optimize the engine performance with the F-T diesel fuel. During this study, the F-T and Conventional diesel fuels were tested at different loads and various injection timing changes made with respect to the manufacturer setting. Results from these tests showed that the ECM used significantly different injection timings for the two fuels in the process of optimizing the engine performance. For the same power output the ECM used a 2° advance in the injection timing with respect to the manufacturer setting at the full load and 1° retard at the no load condition. While the injection timings used by the ECM were same for both the fuels at the 50% load condition. However, a necessity for further changes in the control strategies used by the ECM were observed to get the expected advantages with the F-T fuels.


Author(s):  
K Anand ◽  
R P Sharma ◽  
P S Mehta

Suitability of vegetable oil as an alternative to diesel fuel in compression ignition engines has become attractive, and research in this area has gained momentum because of concerns on energy security, high oil prices, and increased emphasis on clean environment. The experimental work reported here has been carried out on a turbocharged direct-injection multicylinder truck diesel engine using diesel fuel and jatropha methyl ester (JME)-diesel blends. The results of the experimental investigation indicate that an increase in JME quantity in the blend slightly advances the dynamic fuel injection timing and lowers the ignition delay compared with the diesel fuel. A maximum rise in peak pressure limited to 6.5 per cent is observed for fuel blends up to 40 per cent JME for part-load (up to about 50 per cent load) operations. However, for a higher-JME blend, the peak pressures decrease at higher loads remained within 4.5 per cent. With increasing proportion of JME in the blend, the peak pressure occurrence slightly advances and the maximum rate of pressure rise, combustion duration, and exhaust gas temperature decrease by 9 per cent, 15 per cent and 17 per cent respectively. Although the changes in brake thermal efficiencies for 20 per cent and 40 per cent JME blends compared with diesel fuel remain insignificant, the 60 per cent JME blend showed about 2.7 per cent improvement in the brake thermal efficiency. In general, it is observed that the overall performance and combustion characteristics of the engine do not alter significantly for 20 per cent and 40 per cent JME blends but show an improvement over diesel performance when fuelled with 60 per cent JME blend.


2020 ◽  
pp. 346-346
Author(s):  
Ivan Grujic ◽  
Jovan Doric ◽  
Oday Abdullah ◽  
Nadica Stojanovic ◽  
Aleksandar Davinic

From an ecological aspect, the hydrogen has all properties to be a very good fuel for IC engines. However the high combustion speed, as well as the possibility of backfire, is inconvenient properties of port injection. In this paper, the influence of the injection timing on the IC engine working cycle parameters (pressure and temperature) was investigated deeply. The investigation, of the injection timing influence on the IC engine working cycle parameters, was performed numerically by application of ANSYS software. It was observed the geometry of the real engine with added pre chamber, in order of layer mixture formation and pressure damping, because of high combustion speed. The results are presented for four cases with different injection timing and the same spark timing. By earlier injection, the time for mixing rise as well as the possibility of homogenization and uniform mixture creation, in pre chamber and cylinder. This claim it is confirmed on the basis of obtaining pressure and pressure rise gradient, which are growing with earlier injection, because of hydrogen combustion characteristics in stoichiometric mixture. The higher pressures as well as the surface under the diagram are positive from the aspect of the engine efficiency. However, with the earlier injection, the values of the pressure rise gradient are higher than for the classic diesel engine. This means that this phenomena can cause brutal engine work from the aspect of mechanical stresses. However the value of the maximum pressure is smaller than this in a diesel engine, this is due to added pre chamber, which has decreased the compression ratio.


This paper represents the relative performance of a small single-cylinder diesel engine having capacity 3.5 kW. This paper covers experimental investigations of most influencing combustion parameters such as compression ratio, injection pressure and start of injection timing and their values on performance, emission and combustion characteristic of the small single-cylinder CRDI diesel engine for which the mechanical fuel injection system retrofitted with a simple version of the CRDI system. CRDI has yielded good results for large diesel and petrol engines but still not incorporate for cheaper small single-cylinder engines, typically used in the agricultural sector and decentralized power sector for a country like India. It is observed that starts of injection timing and injection pressure are the key parameters for improving the combustion characteristics and therefore engine performance while compression ratio mainly affects the emission characteristics of the engine. Retrofitted CRDI system yielded improved exhaust emission and performance of the engine.


Author(s):  
Yongcheng Huang ◽  
Yaoting Li ◽  
Kun Luo ◽  
Jiyuan Wang

Although both biodiesel and n-butanol are excellent renewable biofuels, most of the existing research works merely use them as the additives for petroleum diesel. As the main fuel properties of biodiesel and n-butanol are complementary, the biodiesel/ n-butanol blends are promising to be a pure biomass-based substitute for diesel fuel. In this paper, the application of the biodiesel/ n-butanol blends on an agricultural diesel engine was comprehensively investigated, in terms of the combustion, performance, and emission characteristics. First, the biodiesel/ n-butanol blends with 10%, 20%, and 30% n-butanol by weight were prepared and noted as BBu10 (10 wt% n-butanol + 90 wt% biodiesel), BBu20 (20 wt% n-butanol + 80 wt% biodiesel), and BBu30 (30 wt% n-butanol + 70 wt% biodiesel). It was found that adding 30 wt% n-butanol to biodiesel can reduce the viscosity by 39.3% and increase the latent heat of vaporization by 57.3%. Then the engine test results showed that with the addition of n-butanol to biodiesel, the peak values of the cylinder pressure and temperature of the biodiesel/ n-butanol blends were slightly decreased, the peak values of the pressure rise rate and heat release rate of the blends were increased, the fuel ignition was delayed, and the combustion duration was shortened. BBu20 has the approximate ignition characteristics with diesel fuel. Both the brake thermal efficiency and the brake-specific fuel consumption of BBu30 were increased by the average percentages of 2.7% and 14.9%, while NO x, soot, and CO emissions of BBu30 were reduced by the average percentages of 17.6%, 34.1%, and 15.4%, compared to biodiesel. The above variations became more evident as the n-butanol proportion increased.


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