Low Temperature Combustion (LTC) Optimization and Cycle-by-Cycle Variability Through Injection Optimization and Gas-to-Liquid (GTL) Fuel-Blend Ratio

2012 ◽  
Author(s):  
A. D. Michailidis ◽  
R. K. Stobart ◽  
G. P. McTaggart-Cowan
Keyword(s):  
Low Temperature ◽  
Research Work ◽  
Combustion Process ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Fuel Blend ◽  
Blend Ratio ◽  
Temperature Combustion ◽  
Gas To Liquid ◽  
Combustion Cycle

The advent of common rail technology alongside powerful control systems capable of delivering multiple accurate fuel charges during a single engine cycle has revolutionized the level of control possible in diesel combustion. This technology has opened a new path enabling low-temperature combustion (LTC) to become a viable combustion strategy. The aim of the research work presented within this paper is the understanding of how various engine parameters of LTC optimize the combustion both in terms of emissions and in terms of fuel efficiency. The work continues with an investigation of in-cylinder pressure and IMEP cycle-by-cycle variation. Attention will be given to how repeatability changes throughout the combustion cycle, identifying which parts within the cycle are least likely to follow the mean trend and why. Experiments were formulated to include rail pressure, injection settings of single injection and split-injection of varying dwell times. All injection conditions were phased across several crank-angles to demonstrate the interaction between emissions and efficiency. These tests are then repeated with blends of 30% and 50% gas-to-liquid (GTL)-Diesel blends in order to determine whether there is any change in the trends of repeatability and variance with increasing GTL blend ratio. Compression-ignition has been traditionally regarded as sufficiently stable that such investigation is irrelevant. Major improvements have been made, however, both to the understanding of compression-ignition and its control. Re-assessing and investigating how pressure repeatability fluctuates over the combustion cycle, especially in atypical engine conditions will help our understanding of combustion and facilitate a more accurate optimization of the combustion process.

Experimental Study on Low Temperature Combustion Dual Fuel Biodiesel/Natural Gas Engine

2015 ◽  
Author(s):  
A. Gharehghani ◽  
M. Mirsalim ◽  
A. Jazayeri ◽  
R. Hosseini
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Natural Gas ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Dual Fuel ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Temperature Combustion

Low Temperature combustion (LTC) strategies are capable of simultaneous reduction in NOx and particulate matter (PM) emissions. However, this combustion process generally leads to higher HC and CO emissions together with more cyclic variation (unstable combustion) especially at light engine loads. These emissions could drastically be reduced using certain alternative fuels like natural gas and biodiesel in LTC or PCI combustion engines. In the present research, a single cylinder compression ignition engine has been modified to operate in dual fuel mode with natural gas injection into the intake manifold as the main fuel and biodiesel as the pilot fuel to ignite the gas/air mixture. The combustion characteristics, engine performance and exhaust emissions of the reactivity controlled compression ignition (RCCI) dual fueled CNG/biodiesel engine are investigated and compared with the conventional diesel engine mode at various load conditions. The analysis of the results revealed that biodiesel as the high reactivity fuel in RCCI mode leads to higher in-cylinder pressure together with shorter heat release rate duration, compared to the common diesel engine. Experimental results indicated that combining the low temperature combustion concept and alternative fuels (e.g. biodiesel and naturals gas) causes lower levels of unburned hydrocarbon (UHC) and carbon monoxide (CO) as well as nitrogen oxide (NOx) emissions.

Performance of multi-dimensional models for simulating diesel premixed charge compression ignition engine combustion using low- and high-pressure injectors

2005 ◽  
Vol 6 (5) ◽  
pp. 475-486 ◽  
Author(s):  
S-C Kong ◽  
Y Ra ◽  
R D Reitz
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Spray Angle ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Detailed Chemistry ◽  
Engine Combustion ◽  
Temperature Combustion ◽  
Hsdi Diesel Engine

An engine CFD model has been developed to simulate premixed charge compression ignition (PCCI) combustion using detailed chemistry. The numerical model is based on the KIVA code that is modified to use CHEMKIN as the chemistry solver. The model was applied to simulate ignition, combustion, and emissions processes in diesel engines operated to achieve PCCI conditions. Diesel PCCI experiments using both low- and high-pressure injectors were simulated. For the low-pressure injector with early injection (close to intake valve closure), the model shows that wall wetting can be minimized by using a pressure-swirl atomizer with a variable spray angle. In the case of using a high-pressure injector, it is found that late injection (SOI = 5 ° ATDC) benefits soot emissions as a result of low-temperature combustion at highly premixed conditions. The model was also used to validate the emission reduction potential of an HSDI diesel engine using a double injection strategy that favours PCCI conditions. It is concluded that the present model is useful to assess future engine combustion concepts, such as PCCI and low-temperature combustion (LTC).

A Comprehensive Review on Low-Temperature Combustion Technologies for Emission Reduction in Diesel Engines

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Amit Jhalani ◽  
Dilip Sharma ◽  
Pushpendra Kumar Sharma ◽  
Digambar Singh ◽  
Sumit Jhalani ◽  
...  
Keyword(s):  
Low Temperature ◽  
Diesel Engines ◽  
Alternative Fuels ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Lean Burn ◽  
Performance And Emissions ◽  
Temperature Combustion ◽  
Hc Emissions ◽  
Ci Engines

Diesel engines are lean burn engines; hence CO and HC emissions in the exhaust are less likely to occur in substantial amounts. The emissions of serious concern in compression ignition engines are particulate matter and nitrogen oxides because of elevated temperature conditions of combustion. Hence the researchers have strived continuously to lower down the temperature of combustion in order to bring down the emissions from CI engines. This has been tried through premixed charge compression ignition, homogeneous charge compression ignition (HCCI), gasoline compression ignition and reactivity controlled compression ignition (RCCI). In this study, an attempt has been made to critically review the literature on low-temperature combustion conditions using various conventional and alternative fuels. The problems and challenges augmented with the strategies have also been described. Water-in-diesel emulsion technology has been discussed in detail. Most of the authors agree over the positive outcomes of water-diesel emulsion for both performance and emissions simultaneously.

scholarly journals A Review on Homogeneous Charge Compression Ignition and Low Temperature Combustion by Optical Diagnostics

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
Chao Jin ◽  
Zunqing Zheng
Keyword(s):  
Low Temperature ◽  
Chemical Reaction ◽  
Homogeneous Charge Compression Ignition ◽  
Optical Diagnostics ◽  
Diagnostic Methods ◽  
Pollutant Emissions ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Temperature Combustion ◽  
Homogeneous Charge

Optical diagnostics is an effective method to understand the physical and chemical reaction processes in homogeneous charge compression ignition (HCCI) and low temperature combustion (LTC) modes. Based on optical diagnostics, the true process on mixing, combustion, and emissions can be seen directly. In this paper, the mixing process by port-injection and direct-injection are reviewed firstly. Then, the combustion chemical reaction mechanism is reviewed based on chemiluminescence, natural-luminosity, and laser diagnostics. After, the evolution of pollutant emissions measured by different laser diagnostic methods is reviewed and the measured species including NO, soot, UHC, and CO. Finally, a summary and the future directions on HCCI and LTC used optical diagnostics are presented.

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