Study of cycle-by-cycle variations of natural gas direct injection combustion using a rapid compression machine

2003 ◽  
Vol 217 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Z Huang ◽  
S Shiga ◽  
T Ueda ◽  
H Nakamura ◽  
T Ishima ◽  
...  
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Maximum Rate ◽  
Direct Injection ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Rapid Compression Machine ◽  
Combustion Duration ◽  
Rate Of Heat Release ◽  
Rapid Compression

Cycle-by-cycle variations of natural gas direct injection (CNG DI) combustion were studied by using a rapid compression machine. Results show that CNG DI combustion can realize high combustion stability with less cycle-by-cycle variation in the maximum pressure rise, the maximum rate of pressure rise and the maximum rate of heat release at the given equivalence ratios. Mixture stratification and fast flame propagation with the aid of turbulence produced by the high speed fuel jet are considered to be responsible for these behaviours. Cycle-by-cycle variations in combustion durations and combustion products present higher magnitudes than those of maximum pressure rise and maximum rate of heat release. Cycle-by-cycle variations of CO and unburned CH4 show an interdependence with the variation of the late combustion duration, and the variation of NO x shows an interdependence with the variation of the rapid combustion duration. Cycle-by-cycle variations are found to be insensitive to the equivalence ratios in CNG DI combustion.

Combustion characteristics and heat release analysis of a direct injection compression ignition engine fuelled with diesel—dimethyl carbonate blends

2003 ◽  
Vol 217 (7) ◽  
pp. 595-605 ◽  
Author(s):  
Z H Huang ◽  
D M Jiang ◽  
K Zeng ◽  
B Liu ◽  
Z L Yang
Keyword(s):  
Heat Release ◽  
Maximum Rate ◽  
Dimethyl Carbonate ◽  
Direct Injection ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Increase With Increase ◽  
Combustion Duration

The combustion characteristics and heat release of a direct injection (DI) compression ignition engine fuelled with diesel-dimethyl carbonate blends were investigated on a compression ignition engine. The study showed that the premixed combustion is prolonged and the duration of the diffusive combustion is shortened with increase in the dimethyl carbonate (DMC) addition. For a specific brake mean effective pressure (b.m.e.p.), the maximum cylinder gas pressure, the maximum rate of pressure rise and the maximum rate of heat release increase with increase in the DMC addition at medium and high loads, while they exhibit less variation with the DMC addition at small load. Meanwhile, the maximum gas temperature decreases with increase in the DMC addition. The ignition delay increases while the rapid combustion duration and the total combustion duration show less variation with the DMC addition. The brake specific fuel consumption (b.s.f.c.) increases while the diesel equivalent b.s.f.c. decreases and the thermal efficiency increases with increase in the DMC addition. The CO and smoke decrease with increase in the DMC addition, and NOx does not increase with increase in DMC.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

scholarly journals Modelling the effect of injection pressure on heat release parameters and nitrogen oxides in direct injection diesel engines

2014 ◽  
Vol 18 (1) ◽  
pp. 155-168 ◽  
Author(s):  
Levent Yüksek ◽  
Tarkan Sandalci ◽  
Orkun Özener ◽  
Alp Ergenc
Keyword(s):  
Nitrogen Oxides ◽  
Heat Release ◽  
Direct Injection ◽  
Pressure Rise ◽  
Injection Pressure ◽  
Premixed Combustion ◽  
Crank Angle ◽  
Cylinder Model ◽  
Combustion Phase ◽  
Rate Of Heat Release

Investigation and modelling the effect of injection pressure on heat release parameters and engine-out nitrogen oxides are the main aim of this study. A zero-dimensional and multi-zone cylinder model was developed for estimation of the effect of injection pressure rise on performance parameters of diesel engine. Double-Wiebe rate of heat release global model was used to describe fuel combustion. extended Zeldovich mechanism and partial equilibrium approach were used for modelling the formation of nitrogen oxides. Single cylinder, high pressure direct injection, electronically controlled, research engine bench was used for model calibration. 1000 and 1200 bars of fuel injection pressure were investigated while injection advance, injected fuel quantity and engine speed kept constant. The ignition delay of injected fuel reduced 0.4 crank angle with 1200 bars of injection pressure and similar effect observed in premixed combustion phase duration which reduced 0.2 crank angle. Rate of heat release of premixed combustion phase increased 1.75 % with 1200 bar injection pressure. Multi-zone cylinder model showed good agreement with experimental in-cylinder pressure data. Also it was seen that the NOx formation model greatly predicted the engine-out NOx emissions for both of the operation modes.

scholarly journals Assessing the optimum combustion under constrained conditions

2018 ◽  
Vol 21 (5) ◽  
pp. 811-823 ◽  
Author(s):  
Pablo Olmeda ◽  
Jaime Martín ◽  
Ricardo Novella ◽  
Diego Blanco-Cavero
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Heat Release ◽  
Engine Speed ◽  
Direct Injection ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Low Load ◽  
Negative Effect ◽  
Constrained Conditions

This work studies the optimum heat release law of a direct injection diesel engine under constrained conditions. For this purpose, a zero-dimensional predictive model of a diesel engine is coupled to an optimization tool used to shape the heat release law in order to optimize some outputs (maximize gross indicated efficiency and minimize NO x emissions) while keeping several restrictions (mechanical limits such as maximum peak pressure and maximum pressure rise rate). In a first step, this methodology is applied under different heat transfer scenarios without restrictions to evaluate the possible gain obtained through the thermal isolation of the combustion chamber. Results derived from this study show that heat transfer has a negative effect on gross indicated efficiency ranging from −4% of the fuel energy ( ṁfHv), at high engine speed and load, up to −8% ṁfHv, at low engine speed and load. In a second step, different mechanical limits are applied resulting in a gross indicated efficiency worsening from −1.4% ṁfHv up to −2.8% ṁfHv compared to the previous step when nominal constraints are applied. In these conditions, a temperature swing coating that covers the piston top and cylinder head is considered obtaining a maximum gross indicated efficiency improvement of +0.5% ṁfHv at low load and engine speed. Finally, NO x emissions are also included in the optimization obtaining the expected tradeoff between gross indicated efficiency and NO x. Under this optimization, cutting down the experimental emissions by 50% supposes a gross indicated efficiency penalty up to −8% ṁfHv when compared to the optimum combustion under nominal limits, while maintaining the experimental gross indicated efficiency allows to reduce the experimental emissions 30% at high load and 65% at low load and engine speed.

Effects of Fuel Octane Number on Homogeneous Charge Compression Ignition (HCCI) Combustion with Rapid Compression Machine

2012 ◽  
Vol 455-456 ◽  
pp. 339-343
Author(s):  
You Kun Wang ◽  
Peng Cheng ◽  
Yun Kai Wang ◽  
Hua Li ◽  
Ying Nan Guo
Keyword(s):  
Octane Number ◽  
Homogeneous Charge Compression Ignition ◽  
Maximum Pressure ◽  
Compression Ignition ◽  
Rapid Compression Machine ◽  
Hcci Combustion ◽  
Combustion Duration ◽  
Rapid Compression ◽  
Start Of Combustion ◽  
Homogeneous Charge

The effects of fuel octane number (RON) on homogeneous charge compression ignition (HCCI) combustion were studied under different combustion boundary conditions on a rapid compression machine. The results show that the maximum pressure raise rate and maximum combustion temperature decreased as the RON increased while the start of combustion is delayed and the combustion duration is shortened at the same time.

scholarly journals Effects of Ignition Timing on Combustion Characteristics of a Gasoline Direct Injection Engine with Added Compressed Natural Gas under Partial Load Conditions

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 755
Author(s):  
Peng Zhang ◽  
Jimin Ni ◽  
Xiuyong Shi ◽  
Sheng Yin ◽  
Dezheng Zhang
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Gasoline Direct Injection ◽  
Dual Fuel ◽  
Ignition Timing ◽  
Combustion Duration ◽  
Rise Rate ◽  
Dual Fuel Combustion

The gasoline/natural gas dual-fuel combustion mode has been found to have unique advantages in combustion. The ignition timing has a significant impact on the combustion characteristics of gasoline engines. Thus, here we study the combustion characteristics of gasoline/natural gas dual-fuel combustion mode to determine the details of their respective advantages under cooperative combustion. A direct-injection turbocharged gasoline engine was modified, and an engine experimental platform was built for the coordinated control of gasoline direct-injection and natural gas port injection. A low-speed and low-load operating point was selected, and the in-cylinder pressure, heat release rate, pressure rise rate, combustion temperature, ignition delay, and combustion duration under the coordinated combustion of gasoline and natural gas dual fuel at the ignition moment were studied through bench tests among other typical combustion parameters. The results show that with the increase of the ignition advance angle, the maximum cylinder pressure, heat release rate, pressure rise rate, and maximum combustion temperature increase. The ignition advance angle is 28°CA-BTDC, and PES40 has the best fuel synergy effect and the best power performance improvement. The effect of the advance of the ignition advance angle on the ignition delay and the combustion duration reaches the peak at 20°CA-BTDC–22°CA-BTDC, and the improvement of the two periods is more significant at PES60.

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