Measurement of ion current in homogeneous charge compression ignition combustion(HCCI, Combustion Processes II)

2004 ◽  
Vol 2004.6 (0) ◽  
pp. 319-325 ◽  
Author(s):  
Tatsuya Tanaka ◽  
Kazuaki Narahara ◽  
Michihiko Tabata ◽  
Sadami Yoshiyama ◽  
Eiji Tomita
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Ion Current ◽  
Compression Ignition ◽  
Hcci Combustion ◽  
Compression Ignition Combustion ◽  
Combustion Processes ◽  
Homogeneous Charge

Ion Current Measurement of Homogeneous Charge Compression Ignition Combustion

2004 ◽  
Vol 2004.42 (0) ◽  
pp. 239-240
Author(s):  
Kazuaki NARAHARA ◽  
Tatsuya TANAKA ◽  
Michihiko TABATA ◽  
Sadami YOSHIYAMA ◽  
Eiji TOMITA
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Current Measurement ◽  
Ion Current ◽  
Compression Ignition ◽  
Compression Ignition Combustion ◽  
Homogeneous Charge

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.

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.

Characterizing the cyclic variability of ignition timing in a homogeneous charge compression ignition engine fuelled with n-heptane/iso-octane blend fuels

2008 ◽  
Vol 9 (5) ◽  
pp. 361-397 ◽  
Author(s):  
M Shahbakhti ◽  
C R Koch
Keyword(s):  
Equivalence Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Coolant Temperature ◽  
Cyclic Variation ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Compression Ignition Engine ◽  
Hcci Combustion ◽  
Cyclic Variations ◽  
Homogeneous Charge

The cyclic variations of homogeneous charge compression ignition (HCCI) ignition timing is studied for a range of charge properties by varying the equivalence ratio, intake temperature, intake pressure, exhaust gas recirculation (EGR) rate, engine speed, and coolant temperature. Characterization of cyclic variations of ignition timing in HCCI at over 430 operating points on two single-cylinder engines for five different blends of primary reference fuel (PRF), (iso-octane and n-heptane) is performed. Three distinct patterns of cyclic variation for the start of combustion (SOC), combustion peak pressure ( Pmax), and indicated mean effective pressure (i.m.e.p.) are observed. These patterns are normal cyclic variations, periodic cyclic variations, and cyclic variations with weak/misfired ignitions. Results also show that the position of SOC plays an important role in cyclic variations of HCCI combustion with less variation observed when SOC occurs immediately after top dead centre (TDC). Higher levels of cyclic variations are observed in the main (second) stage of HCCI combustion compared with that of the first stage for the PRF fuels studied. The sensitivity of SOC to different charge properties varies. Cyclic variation of SOC increases with an increase in the EGR rate, but it decreases with an increase in equivalence ratio, intake temperature, and coolant temperature.

Sign in / Sign up

Export Citation Format

Share Document