scholarly journals Equivalence Ratio-EGR Control of HCCI Engine Operation and the Potential for Transition to Spark-Ignited Operation

Author(s):  
Joel Martinez-Frias ◽  
Salvador M. Aceves ◽  
Daniel Flowers ◽  
J. Ray Smith ◽  
Robert Dibble
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.


2014 ◽  
Vol 694 ◽  
pp. 54-58
Author(s):  
Ling Zhe Zhang ◽  
Ya Kun Sun ◽  
Su Li ◽  
Qing Ping Zheng

A reduced chemical kinetic model (103species and 468 reactions) for new low-RON(research octane number) gasoline surrogate fuels has been proposed. Simulations explored for ignition delay time have been compared with experimental data in shock tubes at pressure of 10atm-55 atm and temperatue of 600-1400 K (fuel/air equivalence ratio=0.5,1.0,2.0 and EGR rate=0, 20%). The simulation data presented 15% enlargement compared with experiments showed applicability of the new kinetic mode in this work. A combustion simulation model has been build for HCCI(homogeneous charge compression ignition) engine with Chemkin-pro. The effects of different air inlet temperature, inlet pressure, engine speed and the fuel air equivalence ratio on the combustion characteristics of the fuel were researched. The results indicated the combustion in an HCCI engine worked sufficiently with lean mixtures and low speed. Meanwhile the material strength could be influenced when the inlet conditions changed. This helps to promote the low-RON gasoline surrogate fuel application in the HCCI engine.


2008 ◽  
Author(s):  
S. Swami Nathan ◽  
J. M. Mallikarjuna ◽  
A. Ramesh
Keyword(s):  

2015 ◽  
Vol 812 ◽  
pp. 70-78
Author(s):  
S. Natarajan ◽  
A.U. Meeanakshi Sundareswaran ◽  
S. Arun Kumar ◽  
N.V. Mahalakshmi

In this paper the work deals with the computational analysis of early direct injected HCCI engine with turbocharger using the CHEMKIN-PRO software. The computational analysis was carried out in the base of auto ignition chemistry by means of reduced chemical kinetics. For this study the neat diesel and Bio ethanol diesel blend (E20) were used as fuel. The inlet pressure was increased to 1.2 bar to simulate the turbocharged engine operation. The injection time was advanced to 18° before top dead centre (BTDC) i.e., 5° BTDC than normal injection time of 23° BTDC. The equivalence ratio was kept at 0.6 (ɸ=0.6) and the combustion, emission characteristics and chemical kinetics of the combustion reaction were studied. Since pressure and temperature profiles plays a very important role in reaction path at certain operating conditions, an attempt had been made here to present a complete reaction path investigation on the formation/destruction of chemical species at peak temperature and pressure conditions. The result showed that main draw backs of HCCI combustion like higher levels of unburned hydrocarbon emissions and carbon monoxide emissions are reduced in the turbocharged operation of the HCCI engine when compared to normal HCCI engine operation without turbocharger.


1993 ◽  
Vol 115 (4) ◽  
pp. 769-776 ◽  
Author(s):  
T. W. Ryan ◽  
T. J. Callahan ◽  
S. R. King

A procedure has been developed and documented for determining the methane number of gaseous fuels. The methane number provides an indication of the knock tendency of the fuel. An experimental test matrix was designed for quantifying the effects of ethane, propane, butane, and CO2. A unique gas mixing and control system was developed to supply test gases to the engine and to control the equivalence ratio and engine operation. The results of the experiments agreed well with the limited data published in the literature. Predictive equations were developed for the methane number (MN) of gaseous fuels using the gas composition. The forms of these equations are suitable for incorporation in a computer program or a spreadsheet.


2016 ◽  
Vol 95 (1) ◽  
pp. 139-143
Author(s):  
Munehiro MATSUISHI ◽  
Yasuhide ABE ◽  
Akira IIJIMA ◽  
Hideo SHOJI ◽  
Kazuhito MISAWA ◽  
...  

Author(s):  
C. Liu ◽  
G. A. Karim ◽  
A. Sohrabi ◽  
F. Xiao

The effects of the introduction of the gaseous fuels, methane, hydrogen and carbon monoxide into the intake of a variable compression ratio n-heptane fuelled HCCI, CFR engine were investigated. The variations in some of the key combustion and operational parameters were determined experimentally. These included cylinder pressure and its rise rate temporal developments, autoignition timing, combustion durations for both the low and high temperature reaction regions, COV values for IMEP and maximum cylinder pressure, and the incidence of knock and its intensity. In parallel with the experimental investigation, results of a numerical simulation of the processes involved obtained by employing a KIVA based approach while incorporating sufficiently detailed chemical kinetics are presented. It was found that supplementing n-heptane HCCI with gaseous fuels could inhibit the low temperature combustion region and delay to varying extents the high temperature combustion region. Methane admission produced lengthening of the delay to autoignition and extended the combustion durations. It is suggested that supplementing the liquid fuel with methane may be a means for controlling the combustion process of a liquid fuelled HCCI engine while obtaining higher power and acceptable levels of emissions without producing unacceptably heavy knock. However, the addition of hydrogen or carbon monoxide could not reduce the intensity of knock while improving power output.


2013 ◽  
Vol 2013 (0) ◽  
pp. _S084012-1-_S084012-4
Author(s):  
Fumiya SHIMIZU ◽  
Yudai YAMASAKI ◽  
Shigehiko KANEKO

Sign in / Sign up

Export Citation Format

Share Document