Normal Heptane-Diesel Combustion and Odorous Emissions in Direct Injection Diesel Engines

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Murari Mohon Roy
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Boiling Point ◽  
Direct Injection ◽  
Volatile Components ◽  
Diesel Combustion ◽  
Gas Temperature ◽  
Eye Irritation ◽  
Heat Of Evaporation ◽  
High Latent Heat

This study investigated normal heptane (N-heptane)-diesel combustion and odorous emissions in a direct injection diesel engine during and after engine warmup at idling. The odor is a little worse with N-heptane and blends than that of diesel fuel due to overleaning of the mixture. In addition, formaldehyde (HCHO) and total hydrocarbon (THC) in the exhaust increase with increasing N-heptane content. However, 50% and 100% N-heptane showed lower eye irritation than neat diesel fuel. Due to low boiling point of N-heptane, adhering fuel on the combustion chamber wall is small and as a single-component C7 fuel, relatively high volatile components present in the exhaust are low. This may cause lower eye irritation. On the contrary, bulk in-cylinder gas temperature is lower and ignition delay significantly increases for 50% and 100% N-heptane due to the low boiling point, high latent heat of evaporation, and low bulk modulus of compressibility of N-heptane than standard diesel fuel. This longer ignition delay and lower bulk in-cylinder gas temperature of N-heptane blends deteriorate exhaust odor and emissions of HCHO and THC.

Effect of n-heptane and n-decane on exhaust odour in direct injection diesel engines

2005 ◽  
Vol 219 (4) ◽  
pp. 565-571 ◽  
Author(s):  
M M Roy
Keyword(s):  
Direct Effect ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Boiling Point ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Cetane Number ◽  
Mixture Formation ◽  
Incomplete Combustion

This study investigated the effect of n-heptane and n-decane on exhaust odour in direct injection (DI) diesel engines. The prospect of these alternative fuels to reduce wall adherence and overleaning, major sources of incomplete combustion, as well as odorous emissions has been investigated. The n-heptane was tested as a low boiling point fuel that can improve evaporation as well as wall adherence. However, the odour is a little worse with n-heptane and blends than that of diesel fuel due to overleaning of the mixture. Also, formaldehyde (HCHO) and total hydrocarbon (THC) in the exhaust increase with increasing n-heptane content. The n-decane was tested as a fuel with a high cetane number that can improve ignition delay, which has a direct effect on wall adherence and overleaning. However, with n-decane and blends, the odour rating is about 0.5-1 point lower than for diesel fuel. Moreover, the aldehydes and THC are significantly reduced. This is due to less wall adherence and proper mixture formation.

Improvements in premixed charge compression ignition combustion and emissions with lower distillation temperature fuels

2005 ◽  
Vol 6 (5) ◽  
pp. 433-442 ◽  
Author(s):  
A Sakai ◽  
H Takeyama ◽  
H Ogawa ◽  
N Miyamoto
Keyword(s):  
Diesel Fuel ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Lubricating Oil ◽  
Compression Ignition ◽  
Gas Temperature ◽  
Compression Stroke ◽  
Charge Mixture ◽  
Rate Of Heat Release ◽  
Wall Wetting

The charge mixture in a premixed charge compression ignition (PCCI) engine with direct in-cylinder injection early in the compression stroke is still heterogeneous even at the compression end. Direct injection of a low-volatility fuel, such as diesel fuel, early in the compression stroke results in adhesion of unevaporated fuel on the cylinder liner wall. It may be possible to improve both mixture formation and homogeneity, and decrease wall wetting by using higher-volatility fuels with distillation temperatures lower than the in-cylinder gas temperature early in the compression stroke. This research addressed the potential for improvements in early direct injection type PCCI combustion with a higher-volatility fuel, experimentally and computationally. A normal heptane + isooctane blended fuel with ignitability similar to diesel fuel in PCCI operation was used as the higher-volatility fuel. The experimental results showed that the deterioration in thermal efficiency that occurs with advanced injection timings with ordinary diesel fuel could be eliminated with the higher-volatility fuel without significantly altering the total hydrocarbons (THC) and CO emissions. With early injection timings, the rate of heat release with diesel fuel is smaller than with higher-volatility fuels. This result suggests that with diesel fuel there is significant fuel adhesion to the cylinder liner wall and also absorption into the lubricating oil.

Experimental investigations on combustion of jatropha methyl ester in a turbocharged direct-injection diesel engine

2008 ◽  
Vol 222 (10) ◽  
pp. 1865-1877 ◽  
Author(s):  
K Anand ◽  
R P Sharma ◽  
P S Mehta
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Peak Pressure ◽  
Direct Injection ◽  
Pressure Rise ◽  
Experimental Investigations ◽  
Injection Timing ◽  
Gas Temperature

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.

Combustion Phenomena of Alcohols in C. I. Engines

1989 ◽  
Vol 111 (3) ◽  
pp. 439-444 ◽  
Author(s):  
M. N. Saeed ◽  
N. A. Henein
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Direct Injection ◽  
High Activation ◽  
Alcohol Content ◽  
Compression Ignition Engines ◽  
Test Parameters ◽  
Alternate Fuels ◽  
Research Type ◽  
Ignition Delay Period

A study was conducted on a direct-injection, single-cylinder, research-type diesel engine to determine the effect of adding ethanol or isopropanol to diesel fuel on the ignition delay period. The test parameters were alcohol content, intake-air properties, and fuel-air ratio. It was found that the ignition delay of alcohol-diesel blends is prolonged as the alcohol content is increased. Ethanol-diesel blends developed longer ignition delays than those developed by isopropanol-diesel blends. The results showed that ignition delay of alcohol-diesel blends can be effectively shortened using intake-air preheating and/or supercharging. The high activation energy of alcohols with respect to diesel fuel is believed to be responsible for the long ignition delays associated with the use of alcohols as alternate fuels in compression ignition engines.

scholarly journals The effect of Diesel-Methanol Blends with Volumetric Proportions on The Performance and Emissions of A Diesel Engine

Mechanika ◽  
2019 ◽  
Vol 25 (5) ◽  
pp. 363-369 ◽  
Author(s):  
ADNAN BERBER
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Direct Injection ◽  
Engine Performance ◽  
Exhaust Emission ◽  
Gas Temperature ◽  
Engine Torque ◽  
Performance And Emissions ◽  
Maximum Decrease

In this work, the methanol is added to the diesel fuel in the volumetric proportions of 5%-%10-%15 to diminish negative environmental impacts of diesel engines. The diesel-methanol blends in the various proportions are tested in a single-cylinder direct-injection diesel engine. According to the test results, the addition of methanol to the diesel fuel causes a maximum decrease of 13.07 % in the engine torque, and a maximum decrease of 12.54 % in the specific fuel consumption. On the other hand, the exhaust emission results show that the values of CO and CO2 decrease 38.4 % and 5.04%. However, the increase of 3.66% in the exhaust gas temperature causes the increase of 17.1% in the NOx emission. Also, a significant decrease of 39.37% in the smoke opacity is observed compared to that of the diesel fuel. Although the addition of methanol to diesel fuel causes a slightly decrease in the engine performance, the diesel-methanol blends have a reasonable and considerable positive effect on environmental concerns of diesel engines.

Ignition delays in diesel combustion and intake gas conditions

2017 ◽  
Vol 19 (8) ◽  
pp. 805-812 ◽  
Author(s):  
Hideyuki Ogawa ◽  
Akihiro Morita ◽  
Katsushi Futagami ◽  
Gen Shibata
Keyword(s):  
Oxygen Concentration ◽  
Compression Ratio ◽  
Ignition Delay ◽  
Cetane Number ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Diesel Combustion ◽  
Gas Temperature ◽  
Gas Recirculation ◽  
Oxygen Concentrations

Ignition delays in diesel combustion under several intake gas conditions, including different oxygen concentrations changed with exhaust gas recirculation quantities and different intake gas temperatures, were measured for four cetane numbers and three compression ratios in a single-cylinder, naturally aspirated, direct injection diesel engine (bore: 110 mm, stroke: 106 mm, and stroke volume: 1007 cm3). The engine has a common rail fuel injection system which can be set to optional injection timings and has an injector with a needle lift sensor to accurately estimate the injection timing. The intake oxygen concentrations were set by the quantity of exhaust gas recirculation gas, and the intake gas temperatures were changed with a water-cooled exhaust gas recirculation cooler and an electric heater in the intake pipe. Three compression ratios, 16.7, 18.0, and 21.3, were established with three pistons of different cavity volumes. Four fuels with different cetane numbers, 32 (CN32), 45 (CN45), 57 (CN57), and 78 (CN78), consisting of normal and isoparaffins, were examined for the three compression ratios, and the influence of exhaust gas recirculation and intake gas temperature is discussed for 12 combinations of compression ratios and cetane numbers. The results showed that the ignition delay increases linearly with the 1.67 power of the decrease in the intake oxygen concentration changed with cooled exhaust gas recirculation at the same cetane number and the same compression ratio. The ignition delay increases linearly with lowering intake gas temperatures, and the degree of increase in the ignition delay is more significant with lower cetane number fuels and lower compression ratios. Under practical conditions with the intake oxygen concentration between 21% and 11% and the intake gas temperature between 40°C and 100°C, the changes in ignition delays with the intake oxygen concentration are more significant than the changes with intake gas temperature. The ignition delay increases linearly with lowering compression ratios, and the degree of increase in the ignition delay with reductions in the compression ratio is larger in the cases with lower intake oxygen concentrations and lower cetane number fuels. The ignition delays at the higher compression ratios are significantly shorter than with the lower compression ratios in the case of the same in-cylinder gas temperature at top dead center due to higher in-cylinder gas pressures. The degree of increase in the ignition delay with lower cetane numbers is more significant at lower intake oxygen concentrations and lower compression ratios, and the ignition delay decreases linearly with the 0.25 power of the increase in cetane numbers.

Experimental Investigation on the Effects of Diethyl Ether Additive on Cashew Nut Shell Liquid Biodiesel

2014 ◽  
Vol 984-985 ◽  
pp. 924-931 ◽  
Author(s):  
T. Pushparaj ◽  
M.Anto Alosius ◽  
S. Ramabalan
Keyword(s):  
Diesel Engine ◽  
Diethyl Ether ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Biodiesel Production ◽  
Gas Temperature ◽  
Cashew Nut Shell Liquid ◽  
Engine Torque ◽  
Cashew Nut ◽  
Cashew Nut Shell

Vegetable oils are a potential alternative to partial or total substitution of diesel fuels. In this study, we used diethyl ether as an additive to investigate the possible use of increased percentages of biodiesel in diesel engine without any retrofitting. Biodiesel was made by pyrolysis process. Cashew nut shell liquid (CNSL) was selected for biodiesel production. Number 2 diesel fuel containing 20% biodiesel and 80% diesel fuel, is called here as B20. The effects of diethyl ether, blended with B20 in 5, 10, 15 % by volume were used in a single cylinder, four strokes direct injection diesel engine. The effect of test fuels on engine torque, power, brake specific fuel consumption, brake thermal efficiency, exhaust gas temperature, were ascertained by performance tests. The influence of blends on CO, CO2, HC, NO and smoke opacity were evaluated by emission tests. The experimental results showed that the exhaust emissions were fairly reduced for 10% diethyl ether with B20; especially the NO is reduced remarkably by 69.4% while comparing B20.

Spray and Flame Structure in Diesel Combustion

1989 ◽  
Vol 111 (3) ◽  
pp. 451-457 ◽  
Author(s):  
E. N. Balles ◽  
J. B. Heywood
Keyword(s):  
Ignition Delay ◽  
Direct Injection ◽  
Flame Structure ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Fuel Spray ◽  
Fuel Vapor ◽  
Diesel Combustion ◽  
Combustion Phase ◽  
Luminous Region

The diesel combustion process in direct-injection diesel engines consists of four distinct stages: an ignition delay, a premixed phase, a mixing-controlled phase, and a late combustion phase. This paper uses geometric information from high-speed direct and shadowgraph movies and corresponding combustion chamber pressure histories, taken in a rapid compression machine study of direct-injection diesel combustion, for a coupled analysis of the diesel flame geometry and energy or heat release to develop our understanding of the diesel spray and flame structure during the ignition delay period and premixed combustion phase. It is shown that each fuel spray from a multihole fuel-injector nozzle consists of a narrow liquid-containing core centered within a much larger fuel-vapor air region, which has a distinct boundary. The liquid core does not penetrate to the chamber periphery, while the vapor containing spray interacts strongly with the boundary. Ignition occurs part way along each growing spray. Once combustion starts, the outer boundary of the fuel-vapor-containing region expands more rapidly due to the combustion energy release. Very high initial spreading rates of the luminous region boundary are observed. A comparison of enflamed areas and volumes, and burned gas volumes, indicates that the luminous region during the early stages of combustion (assumed stoichiometric) is around 1 cm thick and does not fill the full height of the chamber. During the premixed combustion phase, the burned gas volume is one-half the enflamed volume, indicating the presence of a substantial unburned (rich) fuel-vapor/air core within the luminous region of each fuel spray. A close correspondence of flame geometry to spray geometry is evident throughout the combustion process.

Engine Performance with Diesel-Biodiesel Blends Fuel and Emission Characteristics

2020 ◽  
Vol 38 (5A) ◽  
pp. 779-788
Author(s):  
Marwa N. Kareem ◽  
Adel M. Salih
Keyword(s):  
Sulfur Content ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Esterification Reaction ◽  
Biodiesel Fuel ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Biodiesel Blends ◽  
Fuel Blends ◽  
Hc Emissions

In this study, the sunflowers oil was utilized as for producing biodiesel via a chemical operation, which is called trans-esterification reaction. Iraqi diesel fuel suffers from high sulfur content, which makes it one of the worst fuels in the world. This study is an attempt to improve the fuel specifications by reducing the sulfur content of the addition of biodiesel fuel to diesel where this fuel is free of sulfur and has a thermal energy that approaches to diesel.20%, 30% and 50% of Biodiesel fuel were added to the conventional diesel. Performance tests and pollutants of a four-stroke single-cylinder diesel engine were performed. The results indicated that the brake thermal efficiency a decreased by (4%, 16%, and 22%) for the B20, B30 and B50, respectively. The increase in specific fuel consumption was (60%, 33%, and 11%) for the B50, B30, and B20 fuels, respectively for the used fuel blends compared to neat diesel fuel. The engine exhaust gas emissions measures manifested a decreased of CO and HC were CO decreased by (13%), (39%) and (52%), and the HC emissions were lower by (6.3%), (32%), and (46%) for B20, B30 and B50 respectively, compared to diesel fuel. The reduction of exhaust gas temperature was (7%), (14%), and (32%) for B20, B30 and B50 respectively. The NOx emission increased with the increase in biodiesel blends ratio. For B50, the raise was (29.5%) in comparison with diesel fuel while for B30 and B20, the raise in the emissions of NOx was (18%) and...

scholarly journals Thermal Performance of Compression Ignition Engine Using High Content Biodiesels: A Comparative Study with Diesel Fuel

2021 ◽  
Vol 13 (14) ◽  
pp. 7688
Author(s):  
Asif Afzal ◽  
Manzoore Elahi M. Soudagar ◽  
Ali Belhocine ◽  
Mohammed Kareemullah ◽  
Nazia Hossain ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Fatty Acid Content ◽  
Engine Performance ◽  
Waste Cooking Oil ◽  
Gas Temperature ◽  
Compression Ignition Engine ◽  
Brake Thermal Efficiency ◽  
Acid Oil ◽  
Exhaust Gas Temperature

In this study, engine performance on thermal factors for different biodiesels has been studied and compared with diesel fuel. Biodiesels were produced from Pongamia pinnata (PP), Calophyllum inophyllum (CI), waste cooking oil (WCO), and acid oil. Depending on their free fatty acid content, they were subjected to the transesterification process to produce biodiesel. The main characterizations of density, calorific range, cloud, pour, flash and fire point followed by the viscosity of obtained biodiesels were conducted and compared with mineral diesel. The characterization results presented benefits near to standard diesel fuel. Then the proposed diesel engine was analyzed using four blends of higher concentrations of B50, B65, B80, and B100 to better substitute fuel for mineral diesel. For each blend, different biodiesels were compared, and the relative best performance of the biodiesel is concluded. This diesel engine was tested in terms of BSFC (brake-specific fuel consumption), BTE (brake thermal efficiency), and EGT (exhaust gas temperature) calculated with the obtained results. The B50 blend of acid oil provided the highest BTE compared to other biodiesels at all loads while B50 blend of WCO provided the lowest BSFC compared to other biodiesels, and B50 blends of all biodiesels provided a minimum % of the increase in EGT compared to diesel.

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