Preliminary Investigation of Direct Injection Neat n-Butanol in a Diesel Engine

2013 ◽  
Author(s):  
Tadanori Yanai ◽  
Xiaoye Han ◽  
Graham T. Reader ◽  
Ming Zheng ◽  
Jimi Tjong
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Preliminary Investigation ◽  
Pressure Rise ◽  
Injection Pressure ◽  
Injection Timing ◽  
Boost Pressure ◽  
Pressure Rise Rate ◽  
Rise Rate ◽  
Short Period

The characteristics of combustion, emissions, and thermal efficiency of a diesel engine with direct injection neat n-butanol were investigated. Tests were conducted on a single cylinder water-cooled four stroke direct injection diesel engine. The engine ran at a load of 6.5 ∼ 8.0 bar IMEP at 1500 rpm engine speed and the injection pressure was controlled to 900 bar. The intake boost pressure, injection timing and EGR rate were adjusted to investigate the engine performance. The test results showed that significantly longer ignition delays were possible when using butanol compared to diesel fuel. Butanol usage generally led to a rapid heat release in a short period, resulting in excessively high pressure rise rate. The pressure rise rate was reduced by retarding the injection timing. The butanol injection timing was limited by misfire and pressure rise rate. Thus, the ignition timing controllable window by injection timing was much narrower than that of diesel. The neat butanol combustion produced near zero soot and very low NOx emissions even at low EGR rate. The tests demonstrated that neat butanol had the potential to achieve ultra-low emissions. However, challenges related to reducing the pressure rise rate and improving the ignition controllability were identified.

Preliminary Investigation of Direct Injection Neat n-Butanol in a Diesel Engine

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Tadanori Yanai ◽  
Xiaoye Han ◽  
Graham T. Reader ◽  
Ming Zheng ◽  
Jimi Tjong
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Preliminary Investigation ◽  
Pressure Rise ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Boost Pressure ◽  
Indicated Mean Effective Pressure ◽  
Rise Rate

The characteristics of combustion, emissions, and thermal efficiency of a diesel engine with direct injection (DI) neat n-butanol were investigated. The engine ran at a load of 6.5–8.0 bar indicated mean effective pressure (IMEP) at 1500 rpm engine speed and the injection pressure was controlled to 900 bar. The intake boost pressure, injection timing, and EGR rate were adjusted to investigate the engine performance. The tests demonstrated that neat n-butanol had the potential to achieve ultralow emissions. However, challenges related to reducing the pressure rise rate and improving the ignition controllability were identified.

Investigation of Design Parameters in Partially Premixed Compression Ignition Combustion Using Adaptive Injection Strategies

2009 ◽  
Author(s):  
Sage L. Kokjohn ◽  
Rolf D. Reitz
Keyword(s):  
Peak Pressure ◽  
Pressure Rise ◽  
Injection Pressure ◽  
Air Entrainment ◽  
Premixed Combustion ◽  
Design Parameters ◽  
Injection Timing ◽  
Pressure Rise Rate ◽  
Rise Rate ◽  
Wall Impingement

Premixed combustion strategies have been shown to yield very low NOx and soot emissions, while maintaining diesel-like efficiency; however, several issues must be addressed before they can gain widespread acceptance. This paper provides guidelines for solving problems with premixed combustion strategies, viz.: lack of combustion phasing control, excessive pressure rise rate, and spray wall impingement due to early injections. Cooled EGR and a multiple injection concept is used to control combustion phasing and reduce the peak pressure rise rate. To address spray-wall impingement, an Adaptive Injection Strategy (AIS) is employed. This strategy uses two injection pulses at different injection pressures to prepare an optimal in-cylinder mixture. The first injection is early in the cycle and utilizes a low injection pressure to minimize spray-wall impingement and create a well mixed charge. The second injection is near TDC and uses a high injection pressure in order to promote air entrainment and droplet dispersion. This study uses a multi-dimensional CFD code coupled with detailed chemistry, the KIVA-CHEMKIN code, to investigate the effects of several influential design parameters and identify emissions and performance tradeoffs. The combustion process considered is at a light load operating condition (nominal IMEP of 5.5 bar and high speed, 2000 rev/min). The parameters studied were: first and second pulse injection pressure and timing, IVC timing, EGR rate, fuel split, swirl ratio, and spray targeting. The investigation showed that the use of low pressure injections early in the cycle allows improved flexibility in fuel quantity and injection timing. An improved solution was found with near zero NOx and soot, a net ISFC of only 175 g/kW-hr, and a peak pressure rise rate of ∼8 bar/deg.

Performance of Dual Fuel Engine Running on Jojoba Oil as Pilot Fuel and CNG or LPG

2007 ◽  
Author(s):  
Mohamed Y. E. Selim ◽  
M. S. Radwan ◽  
H. E. Saleh
Keyword(s):  
Methyl Ester ◽  
Natural Gas ◽  
Pressure Rise ◽  
Combustion Noise ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Injection Timing ◽  
Pressure Rise Rate ◽  
Rise Rate ◽  
Pilot Fuel

The use of Jojoba Methyl Ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or LPG at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or liquefied petroleum gas (LPG) as the main fuel and Jojoba Methyl Ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic data of 100 engine cycle in terms of maximum pressure and its pressure rise rate. The tests examined the following engine parameters: gaseous fuel type, engine speed and load, pilot fuel injection timing, pilot fuel mass and compression ratio. Results showed that using the Jojoba fuel with its improved properties has improved the dual fuel engine performance, reduced the combustion noise, extended knocking limits and reduced the cyclic variability of the combustion.

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.

Post Injection Strategy for the Reduction of the Peak Pressure Rise Rate of Neat N-Butanol Combustion

2015 ◽  
Author(s):  
Marko Jeftić ◽  
Ming Zheng
Keyword(s):  
Peak Pressure ◽  
Pressure Rise ◽  
Injection Timing ◽  
Post Injection ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Compression Ignition Engine ◽  
Pressure Rise Rate ◽  
Injection Duration ◽  
Rise Rate

Enhanced premixed combustion of neat butanol in a compression ignition engine can have challenges with regards to the peak pressure rise rate and the peak in-cylinder pressure. It was proposed to utilize a butanol post injection to reduce the peak pressure rise rate and the peak in-cylinder pressure while maintaining a constant engine load. Post injection timing and duration sweeps were carried out with neat n-butanol in a compression ignition engine. The post injection timing sweep results indicated that the use of an early butanol post injection reduced the peak pressure rise rate and the peak in-cylinder pressure and it was observed that there was an optimal post injection timing range for the maximum reduction of these parameters. The results also showed that an early post injection of butanol increased the nitrogen oxide emissions and an FTIR analysis revealed that late post injections increased the emissions of unburned butanol. The post injection duration sweep indicated that the peak pressure rise rate was significantly reduced by increasing the post injection duration at constant load conditions. There was also a reduction in the peak in-cylinder pressure. Measurements with a hydrogen mass spectrometer showed that there was an increased presence of hydrogen in the exhaust gas when the post injection duration was increased but the total yield of hydrogen was relatively low. It was observed that the coefficient of variation for the indicated mean effective pressure was significantly increased and that the indicated thermal efficiency was reduced when the post injection duration was increased. The results also showed that there were increased nitrogen oxide, carbon monoxide, and total hydrocarbon emissions for larger post injections. Although the use of a post injection resulted in emission and thermal efficiency penalties at medium load conditions, the results demonstrated that the post injection strategy successfully reduced the peak pressure rise rate and this characteristic can be potentially useful for higher load applications where the peak pressure rise rate is of greater concern.

Effect of Injection Parameters and Strategy on the Noise From a Single Cylinder Direct Injection Diesel Engine

2011 ◽  
Author(s):  
Sukhbir Singh Khaira ◽  
Amandeep Singh ◽  
Marcis Jansons
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Noise ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Frequency Spectra ◽  
Single Cylinder ◽  
Direct Injection Diesel Engine ◽  
Injection Parameters

Acoustic noise emitted by a diesel engine generally exceeds that produced by its spark-ignited equivalent and may hinder the acceptance of this more efficient engine type in the passenger car market (1). This work characterizes the combustion noise from a single-cylinder direct-injection diesel engine and examines the degree to which it may be minimized by optimal choice of injection parameters. The relative contribution of motoring, combustion and resonance components to overall engine noise are determined by decomposition of in-cylinder pressure traces over a range of load, injection pressure and start of injection. The frequency spectra of microphone signals recorded external to the engine are correlated with those of in-cylinder pressure traces. Short Time Fourier Transformation (STFT) is applied to cylinder pressure traces to reveal the occurrence of motoring, combustion noise and resonance in the frequency domain over the course of the engine cycle. Loudness is found to increase with enhanced resonance, in proportion to the rate of cylinder pressure rise and under conditions of high injection pressure, load and advanced injection timing.

An Experimental Investigation of the Effects of Common-Rail Injection System Parameters on Emissions and Performance in a High-Speed Direct-Injection Diesel Engine

1999 ◽  
Vol 123 (1) ◽  
pp. 167-174 ◽  
Author(s):  
P. J. Tennison ◽  
R. Reitz
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Injection Pressure ◽  
Injection System ◽  
Injection Timing ◽  
Pilot Injection ◽  
Common Rail Injection System ◽  
And Performance ◽  
Emissions And Performance

An investigation of the effect of injection parameters on emissions and performance in an automotive diesel engine was conducted. A high-pressure common-rail injection system was used with a dual-guided valve covered orifice nozzle tip. The engine was a four-valve single cylinder high-speed direct-injection diesel engine with a displacement of approximately 12 liter and simulated turbocharging. The engine experiments were conducted at full load and 1004 and 1757 rev/min, and the effects of injection pressure, multiple injections (single vs pilot with main), and pilot injection timing on emissions and performance were studied. Increasing the injection pressure from 600 to 800 bar reduced the smoke emissions by over 50 percent at retarded injection timings with no penalty in oxides of nitrogen NOx or brake specific fuel consumption (BSFC). Pilot injection cases exhibited slightly higher smoke levels than single injection cases but had similar NOx levels, while the single injection cases exhibited slightly better BSFC. The start-of-injection (SOI) of the pilot was varied while holding the main SOI constant and the effect on emissions was found to be small compared to changes resulting from varying the main injection timing. Interestingly, the point of autoignition of the pilot was found to occur at a nearly constant crank angle regardless of pilot injection timing (for early injection timings) indicating that the ignition delay of the pilot is a chemical delay and not a physical (mixing) one. As the pilot timing was advanced the mixture became overmixed, and an increase of over 50 percent in the unburned hydrocarbon emissions was observed at the most advanced pilot injection timing.

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