Cylinder Selective Combustion, the New Diesel Dual Fuel Combustion Control Concept for Low Load Operating Condition

2018 ◽  
Author(s):  
Krisada Wannatong ◽  
Thananchai Tepimonrat ◽  
Sompach Kongviwattanakul
Keyword(s):  
Fuel Combustion ◽  
Dual Fuel ◽  
Combustion Control ◽  
Operating Condition ◽  
Low Load ◽  
Control Concept ◽  
Dual Fuel Combustion

Remote Combustion Sensing Methodology for PCCI and Dual-Fuel Combustion Control

2015 ◽  
Author(s):  
Fabrizio Ponti ◽  
Vittorio Ravaglioli ◽  
Matteo De Cesare ◽  
Federico Stola ◽  
Davide Moro
Keyword(s):  
Fuel Combustion ◽  
Dual Fuel ◽  
Combustion Control ◽  
Dual Fuel Combustion

Impact of low reactivity fuel type on low load combustion, emissions, and cyclic variations of diesel-ignited dual fuel combustion

2021 ◽  
pp. 146808742110419
Author(s):  
Prabhat R Jha ◽  
Kendyl R Partridge ◽  
Sundar R Krishnan ◽  
Kalyan K Srinivasan
Keyword(s):  
Fuel Combustion ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Boost Pressure ◽  
Brake Mean Effective Pressure ◽  
Start Of Injection ◽  
Crank Angle ◽  
Low Load ◽  
Cyclic Variations ◽  
Dual Fuel Combustion

In this study, cyclic variations in dual fuel combustion with diesel ignition of three different low reactivity fuels (methane, propane, and gasoline) are examined under identical operating conditions. Experiments were performed on a single cylinder research engine (SCRE) at a low load of 3.3 bar brake mean effective pressure (BMEP). The start of injection (SOI) of diesel was varied from 280 to 330 absolute crank angle degrees (CAD). Engine speed, rail pressure, and boost pressure were held constant at 1500 rpm, 500 bar, and 1.5 bar, respectively. The energy substituted by the low reactivity fuel was fixed at 80% of the total energy input. It was found that diesel-methane (DM) and diesel-propane (DP) combustion were affected by diesel mixing to a greater extent than diesel-gasoline (DG) combustion due to the higher reactivity of gasoline. The magnitude of low temperature heat release was greatest for DG combustion followed by DM and DP combustion for all SOIs. The ignition delay for DG combustion was the shortest, followed by DM and DP combustion. DM and DP combustion exhibited more cyclic variations than DG combustion. Cyclic variations decreased for DM and DP combustion when SOI was advanced; however, DG combustion cyclic variations remained essentially constant for all SOIs. Earlier SOIs (280, 290, 300, and 310 CAD) for DM and (280, 290, and 300 CAD) for DP combustion indicated some prior-cycle effects on the combustion and IMEP (i.e. some level of determinism).

Combustion and Emission Characteristics of a CI Engine Operating in Diesel-1-Butanol/CNG Dual Fuel Mode With Low and High CNG Substitution Rates in Light Load Operation

2016 ◽  
Author(s):  
Xiangyu Meng ◽  
Yuanxu Li ◽  
Karthik Nithyanandan ◽  
Wuqiang Long ◽  
Chia-Fon F. Lee
Keyword(s):  
Thermal Efficiency ◽  
Substitution Rate ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Combustion Mode ◽  
Substitution Rates ◽  
Low Load ◽  
Pilot Fuel ◽  
Dual Fuel Combustion

Dual-fuel combustion mode with direct injection of diesel as the pilot fuel and port injection of compressed natural gas (CNG) in compression ignition (CI) engines has been widely investigated to comply with the latest emission regulations. The diesel-CNG dual-fuel combustion mode shows some potential to decrease NOx and soot emissions simultaneously, while it reveals a lower thermal efficiency compared to the pure diesel combustion mode under low load condition. The purpose of the current study is to investigate the possibility of using diesel blended with 1-butanol as the pilot fuel to enhance the engine performance and reduce emissions. Three pilot fuels — B0 (pure diesel), B10 (90% diesel and 10% 1-butanol by volume) and B20 (80% diesel and 20% 1-butanol) with the CNG substitution rates of 50% and 80% were compared at an engine speed of 1200 rpm. The experiments were conducted by sweeping the pilot fuel injection timing from −3 to −18 ° CA ATDC with an equivalent total energy (∼5 bar IMEP). The results illustrated that, for the 50% CNG substitution rate, the dual-fuel operation mode revealed a higher indicated thermal efficiency (ITE) under low load conditions, and B10 can significantly improve the ITE due to the shorter combustion duration. The emission results of B10 showed that it obtained lower THC and CO emissions, but a slightly higher NOx emission. For the 80% CNG substitution rate, the results presented lower ITE, higher THC and lower NOx emissions, comparatively.

Numerical investigations of low load diesel-methane dual fuel combustion at early diesel injection timings

Fuel ◽  
2022 ◽  
Vol 315 ◽  
pp. 123077
Author(s):  
P.R. Jha ◽  
S. Wijeyakulasuriya ◽  
S.R. Krishnan ◽  
K.K. Srinivasan
Keyword(s):  
Fuel Combustion ◽  
Dual Fuel ◽  
Numerical Investigations ◽  
Diesel Injection ◽  
Low Load ◽  
Dual Fuel Combustion

Influence of Swirl Ratio on Diesel-Methane Dual Fuel Combustion: A CFD Investigation

2017 ◽  
Author(s):  
P. R. Jha ◽  
K. K. Srinivasan ◽  
S. R. Krishnan
Keyword(s):  
Carbon Monoxide ◽  
Heat Release ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Swirl Ratio ◽  
Cycle Simulation ◽  
Low Load ◽  
Dual Fuel Combustion

Dual fuel combustion has garnered attention in recent years because of its potential for reducing emissions of oxides of nitrogen (NOx) and particulate matter (PM) while sustaining diesel-like fuel conversion efficiencies. However, most dual fuel combustion strategies suffer from higher engine-out hydrocarbon (HC) and carbon monoxide (CO) emissions, leading to poor combustion efficiencies, especially at low loads. The present work examined computationally the effect of in-cylinder swirl on diesel-ignited methane dual fuel combustion with a focus on devising strategies for improving part-load combustion efficiencies. For this purpose, diesel-methane dual fuel combustion was studied on a heavy-duty single cylinder research engine (SCRE) platform using CONVERGE computational fluid dynamics (CFD) software. A typical low load condition (IMEP = 5.1 bar) was selected at an engine speed of 1500 rpm and a relatively high methane percentage energy substitution (PES) of 80 percent (because experiments show poorer combustion efficiencies at high methane PES) at a nominal diesel injection timing of 2 degrees BTDC (358 CAD). The closed cycle simulation was first validated with experimental results (cylinder pressure and heat release histories as well as engine-out exhaust emissions) for neat diesel and diesel-methane dual fuel combustion, respectively. Subsequently, the influence of increasing swirl ratio from 0 to 1.5 on diesel-methane dual fuel combustion was characterized. Analysis of the computational results showed that peak cylinder pressure and heat release rate increased with increasing swirl ratio while the combustion duration (as determined by CA10-80) decreases from 25 CAD at a swirl ratio of 0.05 to nearly 15 CAD at a swirl ratio of 1.5. Indicated-specific hydrocarbon (ISHC) and indicated-specific carbon monoxide (ISCO) emissions decreased by about 60 percent and 50 percent, respectively, when swirl ratio was increased from 0.05 to 1.2; however, these reductions were accompanied by a 26 percent increase in indicated-specific NOx (ISNOx) emissions under these conditions. Therefore, the present study indicates that swirl optimization is a potentially viable strategy for reducing engine-out HC and CO emissions and for improving low-load combustion efficiencies in dual fuel engines, assuming additional NOx mitigation strategies are also employed simultaneously.

Impact of methane energy fraction on emissions, performance and cyclic variability in low-load dual fuel combustion at early injection timings

2019 ◽  
pp. 146808741989238
Author(s):  
Prabhat R Jha ◽  
Sundar R Krishnan ◽  
Kalyan K Srinivasan
Keyword(s):  
Pressure Rise ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Energy Fraction ◽  
Pressure Rise Rate ◽  
Rise Rate ◽  
Low Load ◽  
Dual Fuel Combustion ◽  
Early Injection

This work experimentally examines the effect of methane (a natural gas surrogate) substitution on early injection dual fuel combustion at representative low loads of 3.3 and 5.0 bar BMEPs in a single-cylinder compression ignition engine. Gaseous methane fumigated into the intake manifold at various methane energy fractions was ignited using a high-pressure diesel pilot injection at 310 °CA. For the 3.3 bar BMEP, methane energy fraction sweeps from 50% to 90% were performed; while at 5.0 bar BMEP, methane energy fraction sweeps from 70% to 90% were performed. It is observed that minimum methane energy fraction is limited by maximum pressure rise rate leading to knock and maximum methane energy fraction is limited by a high coefficient of variation in netIMEP, which leads to high cyclic variations. For 3.3 bar BMEP, maximum pressure rise rate is 8 bar/°CA at 50% methane energy fraction while at 5 bar BMEP, it is 12 bar/°CA at 70% methane energy fraction. For 3.3 bar BMEP, engine-out NOx emissions decrease by 43 times when methane energy fraction increases from 50% to 90%, and it decreases by nearly 46 times when methane energy fraction increases from 70% to 90% at 5 bar BMEP. Engine-out unburned hydrocarbon emissions increase by nearly 9 times when methane energy fraction increases from 50% to 90% at 3.3 bar BMEP, and it increases by nearly 5 times when methane energy fraction increases from 70% to 90% at 5.0 bar BMEP. Engine-out carbon monoxide emissions increase by nearly 7 times when methane energy fraction increases from 50% to 90% at 3.3 bar BMEP and by nearly 5 times when methane energy fraction increases from 70% to 90% at 5.0 bar BMEP. In addition, cyclic combustion variations at both loads were analyzed to obtain further insights into the combustion process and identify opportunities to further improve fuel conversion efficiencies at low load operation.

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