Effect of the ramp injection rate shape on the performance and emissions of a natural gas/diesel dual fuel engine

2021 ◽  
pp. 146808742110591
Author(s):  
Tara Yazdani Motlagh ◽  
Leila N Azadani

Injection rate shape has a great influence on the spray evolution, and consequently on the performance and emission characteristics of compression ignition engines. In this study, effect of different ramp injection rate shapes on the performance and exhaust emissions of a natural gas/diesel reactivity controlled compression ignition (RCCI) engine was investigated. 64 numerical experiments were performed to study effect of two characteristic parameters of the ramp injection rate shape, including ramp duration and ramp injection rate on the engine gross indicated efficiency (GIE) and emissions formation. It was realized that for a constant value of the ramp duration, the engine gross indicated efficiency and [Formula: see text] emissions are lower, and CO and unburned hydrocarbons (UHC) emissions are higher for medium values of the ramp injection rate. Moreover, for a constant value of the ramp injection rate, the engine gross indicated efficiency and [Formula: see text] emissions are higher, and CO and unburned hydrocarbons emissions are lower for medium values of the ramp duration. The optimum values of the ramp duration and ramp injection rate were determined and it was revealed that the optimum ramp injection rate shape can improve the engine gross indicated efficiency by 54.78%.

Fuel ◽  
2021 ◽  
Vol 292 ◽  
pp. 120330
Author(s):  
Sohayb Bahrami ◽  
Kamran Poorghasemi ◽  
Hamit Solmaz ◽  
Alper Calam ◽  
Duygu İpci

Author(s):  
Y Ren ◽  
Z H Huang ◽  
D M Jiang ◽  
L X Liu ◽  
K Zeng ◽  
...  

The performance and emissions of a compression ignition engine fuelled with diesel/dimethoxymethane (DMM) blends were studied. The results showed that the engine's thermal efficiency increased and the diesel equivalent brake specific fuel consumption (b.s.f.c.) decreased as the oxygen mass fraction (or DMM mass fraction) of the diesel/DMM blends increased. This change in the diesel/DMM blends was caused by an increased fraction of the premixed combustion phase, an oxygen enrichment, and an improvement in the diffusive combustion phase. A remarkable reduction in the exhaust CO and smoke can be achieved when operating on the diesel/DMM blend. Flat NO x/smoke and thermal efficiency/smoke curves are presented when operating on the diesel/DMM fuel blends, and a simultaneous reduction in both NO x and smoke can be realized at large DMM addition. Thermal efficiency and NO x give the highest value at 2 per cent oxygen mass fraction (or 5 per cent DMM volume fraction) for the combustion of diesel/DMM blends.


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Nikhil Sharma ◽  
Akhilendra Pratap Singh ◽  
Vikram Kumar ◽  
Dev Prakash Satsangi ◽  
...  

Miscibility of methanol in mineral diesel and stability of methanol–diesel blends are the main obstacles faced in the utilization of methanol in compression ignition engines. In this experimental study, combustion, performance, emissions, and particulate characteristics of a single-cylinder engine fueled with MD10 (10% v/v methanol blended with 90% v/v mineral diesel) and MD15 (15% v/v methanol blended with 85% v/v mineral diesel) are compared with baseline mineral diesel using a fuel additive (1-dodecanol). The results indicated that methanol blending with mineral diesel resulted in superior combustion, performance, and emission characteristics compared with baseline mineral diesel. MD15 emitted lesser number of particulates and NOx emissions compared with MD10 and mineral diesel. This investigation demonstrated that methanol–diesel blends stabilized using suitable additives can resolve several issues of diesel engines, improve their thermal efficiency, and reduce NOx and particulate emissions simultaneously.


Author(s):  
N. T. Shoemaker ◽  
C. M. Gibson ◽  
A. C. Polk ◽  
S. R. Krishnan ◽  
K. K. Srinivasan

Different combustion strategies and fuel sources are needed to deal with increasing fuel efficiency demands and emission restrictions. One possible strategy is dual fueling using readily available resources. Propane and natural gas are readily available with the current infrastructure and biodiesel is growing in popularity as a renewable fuel. This paper presents experimental results from dual fuel combustion of methane (as a surrogate for natural gas) and propane as primary fuels with biodiesel pilots in a 1.9 liter, turbocharged, 4-cylinder compression ignition engine at 1800 rev/min. Experiments were performed with different percentage energy substitutions (PES) of propane and methane and at different brake mean effective pressures (BMEP/bmep). Brake thermal efficiency (BTE) and emissions (NOx, HC, CO, CO2, O2 and smoke) were also measured. Maximum PES levels for B100-methane dual fueling were limited to 70% at 2.5 bars bmep and 48% at 10 bars bmep, and corresponding values for B100-propane dual fueling were 64% and 43%, respectively. Maximum PES was limited by misfire at 2.5 bars bmep and the onset of engine knock at 10 bars bmep. Dual fuel BTEs approached straight B100 values at 10 bars bmep while they were significantly lower than B100 values at 2.5 bars bmep. In general, dual fueling was beneficial in reducing NOx and smoke emissions by 33% and 50%, respectively, from baseline B100 levels; however, both CO and THC emissions were significantly higher than baseline B100 levels at all PES and loads.


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