Properties of Homogeneous Charge Compression Ignition (HCCI) Engine With N-Butane Fuel

2001 ◽  
Author(s):  
Minoru Iida ◽  
Motoaki Hayashi ◽  
David E. Foster ◽  
Jay K. Martin
Keyword(s):  
Fourier Transform ◽  
Homogeneous Charge Compression Ignition ◽  
Maximum Load ◽  
Compression Ignition ◽  
Effective Pressure ◽  
Cylinder Pressure ◽  
Indicated Mean Effective Pressure ◽  
Hydrocarbon Emission ◽  
Infrared Spectrometer ◽  
Homogeneous Charge

Abstract In this paper, some basic properties of homogeneous charge compression ignition operation are investigated. The HCCI operating range for a CFR engine was determined with n-butane as fuel. The minimum and maximum load was determined using criteria of covariance of indicated mean effective pressure and the derivative of in-cylinder pressure respectively. Exhaust emissions, particularly hydrocarbons, were measured using a Fourier transform infrared spectrometer. The concentration of intermediate hydrocarbon species rapidly decreased as the magnitude of the heat release increased. Hydrocarbon emission at the maximum HCCI load mainly consists of the fuel itself, which is probably emitted from colder areas in the combustion chamber. The relation between IMEPCOV and ISFC is discussed.

Characteristics of Homogeneous Charge Compression Ignition (HCCI) Engine Operation for Variations in Compression Ratio, Speed, and Intake Temperature While Using n-Butane as a Fuel

2003 ◽  
Vol 125 (2) ◽  
pp. 472-478 ◽  
Author(s):  
M. Iida ◽  
M. Hayashi ◽  
D. E. Foster ◽  
J. K. Martin
Keyword(s):  
Compression Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Inlet Temperature ◽  
Compression Ignition ◽  
Engine Operation ◽  
Indicated Mean Effective Pressure ◽  
Ratio Speed ◽  
Hydrocarbon Emission ◽  
Infrared Spectrometer ◽  
Homogeneous Charge

In this paper, some basic properties of homogeneous charge compression ignition operation are reported. The effect of inlet temperature, compression ratio and engine speed on the homogeneous charge compression ignition (HCCI) operating ranges were evaluated in a CFR engine using n-butane as a fuel. The minimum and maximum loads for HCCI operation were determined using criteria of coefficient of variation of the indicated mean effective pressure and the derivative of in-cylinder pressure, respectively. Exhaust emissions, particularly hydrocarbons, were measured using a Fourier transform infrared spectrometer. The concentration of intermediate hydrocarbon species rapidly decreased as the magnitude of the energy release increased. Hydrocarbon emission at the maximum HCCI load mainly consists of the fuel itself, which is probably emitted from colder areas in the combustion chamber. Finally, the relationship between IMEPCOV and ISFC is discussed.

Ion current–based homogeneous charge compression ignition combustion control using direct water injection

2020 ◽  
pp. 146808742092783 ◽  
Author(s):  
Denghao Zhu ◽  
Jun Deng ◽  
Raphael Dewor ◽  
Maximilian Wick ◽  
Jakob Andert ◽  
...  
Keyword(s):  
Heat Release ◽  
Homogeneous Charge Compression Ignition ◽  
Water Injection ◽  
Ion Current ◽  
Compression Ignition ◽  
Effective Pressure ◽  
Indicated Mean Effective Pressure ◽  
Direct Water Injection ◽  
Compression Ignition Combustion ◽  
Homogeneous Charge

Homogeneous charge compression ignition has proven to be both highly efficient and to operate with ultra-low NOx raw emissions. However, homogeneous charge compression ignition combustion is a dynamic process due to strong cycle-to-cycle coupling effects caused mainly by the residual gas. Compared to conventional spark-ignited and diesel engines, the lack of direct mixture composition and ignition control increases the challenge of combustion instabilities, especially at boundary conditions. To stabilize the combustion process, real-time in-cylinder combustion diagnostics and control are often used. In this study, for the first time, ion current detection technology and direct water injection are combined for homogeneous charge compression ignition combustion control. By analyzing the return map of the crank angle at 50% cumulative heat release under unstable conditions, it was identified that a misfire or incomplete combustion is usually followed by knocking-like early combustion with high cylinder pressure gradients. Through the correlation analysis between ion current and combustion, a cycle-to-cycle closed-loop control strategy was developed and implemented on a rapid control prototyping engine control unit. Real-time calculated ion current parameters were used to predict the 50% cumulative heat release position of the next cycle and prevent early combustion by direct water injection. The calculation results and controller performance were validated on a single-cylinder research engine. With the controller activated, the standard deviation of 50% cumulative heat release and dynamic programming to the max could be reduced by 19% and 11%, respectively. The coefficient of variation of indicated mean effective pressure was reduced by 12%. A slight increase in indicated mean effective pressure after activating the controller also shows the potential for efficiency improvement. Moreover, not only early combustion is controlled, but also late combustion is significantly reduced.

An Experimental Investigation of the Exhaust Emissions From Spark-Assisted Homogeneous Charge Compression Ignition in a Single-Cylinder Research Engine

2009 ◽  
Author(s):  
P. E. Keros ◽  
B. T. Zigler ◽  
J. T. Wiswall ◽  
S. M. Walton ◽  
M. S. Wooldridge
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Exhaust Emissions ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Single Cylinder ◽  
Spark Timing ◽  
Homogeneous Charge

The present study investigates the potential impact of spark-assisted (SA) homogeneous charge compression ignition (HCCI) on pollutant exhaust gas emissions from an internal combustion engine. A single-cylinder research engine was used to compare the exhaust emissions of the engine when operated in HCCI, SA-HCCI and conventional spark ignited modes of operation. The study builds on previous results demonstrating the effects of the spark plasma kernel on the ignition process [1, 2]. Specifically, this study investigates the NOx, CO, and HC emissions from an optical engine fueled with indolene in HCCI and SA-HCCI modes at fuel lean conditions. Fuel/air equivalence ratios ranged from φ = 0.3–0.6. Time-averaged emissions were measured using an exhaust gas analyzer. In-cylinder pressure data were also acquired. The results show NOx emissions follow the trends of peak in-cylinder pressure implying that thermal NOx mechanisms dominate both the HCCI and SA-HCCI modes of engine operation. For SA-HCCI, spark timing could be used to change ignition phasing, and consequently change the in-cylinder peak pressure and resulting NOx emissions. Comparing HCCI and SA-HCCI emissions at nominally similar conditions (specifically, comparable indicated mean effective pressures and equivalence ratios) yielded similar NOx emissions. These data show that SA-HCCI may not have a NOx penalty when the spark timing is carefully applied.

scholarly journals Cycle-by-cycle variations in autonomous and spark assisted homogeneous charge compression ignition combustion of stoichiometric air–fuel mixture

2018 ◽  
Vol 10 (3) ◽  
pp. 231-243 ◽  
Author(s):  
Jacek Hunicz
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Fuel Injection ◽  
Fuel Mixture ◽  
Compression Ignition ◽  
Indicated Mean Effective Pressure ◽  
Start Of Injection ◽  
Negative Valve Overlap ◽  
Compression Ignition Combustion ◽  
Valve Overlap ◽  
Homogeneous Charge

This study investigates cycle-by-cycle variations in a gasoline fuelled, homogeneous charge compression ignition (HCCI) engine with internal exhaust gas recirculation. In order to study the effects of exhaust-fuel reactions occurring prior to the main combustion event fuel was injected directly into the cylinder at two selected timings during the negative valve overlap period. The engine was operated as both autonomous HCCI and spark assisted HCCI (SA-HCCI). The primary interest in this work was the operating region where the engine is switched between HCCI and spark ignition modes, thus operation with stoichiometric air–fuel mixture, which is typical for this region, was considered. Cycle-by-cycle variations in both combustion timing and indicated mean effective pressure (IMEP) were investigated. It was found that long-period oscillations of the IMEP occur when fuel injection is started at early stages of the negative valve overlap period, and that these can be suppressed by delaying the start of injection. This behaviour remained even when fuel injection was split into early and late-negative valve overlap injections. Spark assisted operation allowed eliminating late combustion cycles, thus improving thermal efficiency. However, characteristic patterns of IMEP variations were found to be the same for both HCCI and SA-HCCI operations, irrespective of the adopted negative valve overlap fuel injection strategy, as evidenced by using symbol-sequence statistics.

Residual-effected homogeneous charge compression ignition at a low compression ratio using exhaust reinduction

2003 ◽  
Vol 4 (3) ◽  
pp. 163-177 ◽  
Author(s):  
P. A. Caton ◽  
A. J. Simon ◽  
J. C. Gerdes ◽  
C. F. Edwards
Keyword(s):  
Compression Ratio ◽  
Equivalence Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Compression Ignition ◽  
Single Digit ◽  
Hcci Combustion ◽  
Actuation System ◽  
Order Of Magnitude ◽  
No Emissions ◽  
Homogeneous Charge

Studies have been conducted to assess the performance of homogeneous charge compression ignition (HCCI) combustion initiated by exhaust reinduction from the previous engine cycle. Reinduction is achieved using a fully flexible electrohydraulic variable-valve actuation system. In this way, HCCI is implemented at low compression ratio without throttling the intake or exhaust, and without preheating the intake charge. By using late exhaust valve closing and late intake valve opening strategies, steady HCCI combustion was achieved over a range of engine conditions. By varying the timing of both valve events, control can be exerted over both work output (load) and combustion phasing. In comparison with throttled spark ignition (SI) operation on the same engine, HCCI achieved 25–55 per cent of the peak SI indicated work, and did so at uniformly higher thermal efficiency. This was accompanied by a two order of magnitude reduction in NO emissions. In fact, single-digit (ppm) NO emissions were realized under many load conditions. In contrast, hydrocarbon emissions proved to be significantly higher in HCCI combustion under almost all conditions. Varying the equivalence ratio showed a wider equivalence ratio tolerance at low loads for HCCI.

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