Regulated, greenhouse gas, and particulate emissions from lean-burn and stoichiometric natural gas heavy-duty vehicles on different fuel compositions

Emissions from heavy-duty vehicles need to be reduced to decrease their impact on the climate and to meet future regulatory requirements. The use of a cost-optimized thermoelectric generator based on total cost of ownership is proposed for this vehicle class with natural gas engines. A holistic model environment is presented that includes all vehicle interactions. Simultaneous optimization of the heat exchanger and thermoelectric modules is required to enable high system efficiency. A generator design combining high electrical power (peak power of about 3000 W) with low negative effects was selected as a result. Numerical CFD and segmented high-temperature thermoelectric modules are used. For the first time, the possibility of an economical use of the system in the amortization period of significantly less than 2 years is available, with a fuel reduction in a conventional vehicle topology of already up to 2.8%. A significant improvement in technology maturity was achieved, and the power density of the system was significantly improved to 298 W/kg and 568 W/dm3 compared to the state of the art. A functional model successfully validated the simulation results with an average deviation of less than 6%. An electrical output power of up to 2700 W was measured.

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A high efficiency lean-burn mono‑fuel heavy‑duty natural‑gas engine for achieving Euro VI emissions legislation and beyond – part 2

Proceedings - Heavy-Duty-, On- und Off-Highway-Motoren 2018 ◽

10.1007/978-3-658-25889-4_9 ◽

2019 ◽

pp. 135-158

Author(s):

André Barroso ◽

Andrew Auld ◽

James Manuelyan ◽

Matthew Keenan ◽

Paolo Ferrero Giacominetto ◽

...

Keyword(s):

Natural Gas ◽

High Efficiency ◽

Heavy Duty ◽

Lean Burn ◽

Gas Engine ◽

Natural Gas Engine

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Onboard Natural Gas Reforming for Heavy Duty Vehicles

SAE International Journal of Commercial Vehicles ◽

10.4271/02-12-01-0004 ◽

2019 ◽

Vol 12 (1) ◽

pp. 45-56 ◽

Cited By ~ 2

Author(s):

Brian Weiss ◽

Tilman W. Beutel ◽

Bryan R. Chapman ◽

Jonathan D. Saathoff ◽

Shamel Merchant ◽

...

Keyword(s):

Natural Gas ◽

Heavy Duty ◽

Natural Gas Reforming ◽

Heavy Duty Vehicles

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Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural Gas Spark Ignition

Volume 6A: Energy ◽

10.1115/imece2018-87761 ◽

2018 ◽

Cited By ~ 8

Author(s):

Jinlong Liu ◽

Cosmin E. Dumitrescu

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Spark Ignition ◽

Operating Conditions ◽

Combustion Stability ◽

Fuel Injector ◽

Heavy Duty ◽

Lean Burn ◽

Spark Timing ◽

Heavy Duty Diesel

Increased utilization of natural-gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduce greenhouse-gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOx, CO, and HC emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing, engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late burn (including double-peak heat release rate) was observed for advanced spark timing. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3 %), moderate rate of pressure rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

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Effects of natural gas composition and compression ratio on the thermodynamic and combustion characteristics of a heavy-duty lean-burn SI engine fueled with liquefied natural gas

Fuel ◽

10.1016/j.fuel.2019.115733 ◽

2019 ◽

Vol 254 ◽

pp. 115733 ◽

Cited By ~ 17

Author(s):

Xiongbo Duan ◽

Yiqun Liu ◽

Ming-Chia Lai ◽

Genmiao Guo ◽

Jingping Liu ◽

...

Keyword(s):

Natural Gas ◽

Compression Ratio ◽

Liquefied Natural Gas ◽

Combustion Characteristics ◽

Gas Composition ◽

Heavy Duty ◽

Si Engine ◽

Lean Burn

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Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark Ignition

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4042501 ◽

2019 ◽

Vol 141 (7) ◽

Cited By ~ 11

Author(s):

Jinlong Liu ◽

Cosmin Emil Dumitrescu

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Spark Ignition ◽

Operating Conditions ◽

Combustion Stability ◽

Fuel Injector ◽

Heavy Duty ◽

Lean Burn ◽

Heavy Duty Diesel ◽

Ci Engines

Increased utilization of natural gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduced greenhouse gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOX, CO, and hydrocarbon (HC) emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing (ST), engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late-burn (including double-peak heat release rate) was observed for advanced ST. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3%), moderate rate of pressure-rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

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