Improving Brake Thermal Efficiency Using High-Efficiency Turbo and EGR Pump While Meeting 2027 Emissions

Abstract In an effort to reduce fuel consumption and lower emissions output, there is a growing need for high efficiency engines in power generation. Ultra-lean (λ > ∼1.6) combustion via air dilution is an enabling technology for achieving high efficiencies while simultaneously reducing emissions of nitrogen oxides (NOx). Jet ignition is a pre-chamber-based combustion system that enables ultra-lean operation beyond what is achievable with traditional spark ignition engines. In this paper, results and analyses related to the downspeeding of a 390cc, high efficiency low-output single cylinder jet ignition engine operating ultra-lean are presented. The engine was developed as part of the US Department of Energy’s Advanced Research Projects Agency–Energy (DOE ARPA-E) GENSETS program1. The purpose of the program is to develop technologies for use in high efficiency combined heat and power generator sets. Due to the intended application of power generation, optimization of the engine for a specific operating condition is critical. An efficiency loss breakdown based on the Thermodynamic First Law is used to analyze the interdependent trends of engine speed, brake power, and normalized air-fuel ratio, lambda, with the aim of optimizing these parameters for brake thermal efficiency. The general trends of efficiency loss pathways with enleanment are found to be relatively insensitive to speed and load although the magnitude of the loss pathways changes. As the relative importance of the efficiency loss pathways changes with operating condition, so too does the lambda at which peak brake thermal efficiency occurs. The “peak efficiency lambda” was found to be at its leanest at low speed and high power where the influence of heat transfer is greatest and mechanical losses are minimized.

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High Efficiency Natural Gas Engine Combustion Using Controlled Auto-Ignition

ASME 2019 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2019-7292 ◽

2019 ◽

Author(s):

Gregory J. Hampson

Keyword(s):

Natural Gas ◽

Thermal Efficiency ◽

High Efficiency ◽

Methane Emissions ◽

Combustion Stability ◽

Second Phase ◽

Exhaust Gas ◽

Brake Thermal Efficiency ◽

Auto Ignition ◽

Engine Knock

Abstract Increasingly restrictive limits on Oxides of Nitrogen - NOx levels and desire for low methane emissions from gas engines are driving the change from lean-burn to stoichiometric combustion strategies on heavy-duty on-highway natural gas engines in order to take advantage of inexpensive and effective three-way catalyst technology. The change to stoichiometric combustion has led to increased tendency for engine knock due to higher in-cylinder temperatures. To suppress engine knock, Exhaust Gas Recirculation (EGR) rates from 10 to 30% are used. While high EGR rates nominally improve Brake Thermal Efficiency (BTE) and reduce exhaust gas temperatures, they also slow down combustion. However, by deploying a controlled spark triggered homogeneous charge volumetric ignition, very short burn durations can be achieved without the destructive effects of engine knocking towards high efficiency gas engines. In the interest of achieving 45% BTE in spark ignited an on-highway class 8 truck engines fueled on natural gas and to meet EURO 6 and future California emissions standards of 0.02 gm/kw-hr NOx, Controlled Auto-Ignition (CAI) is herein demonstrated on a 15 liter truck engine. CAI is enabled by (a) having a combustion device capable of exceptionally good combustion stability in the presence of high EGR rates (COV of IMEP < 0.75 %), (b) cylinder pressure based combustion feedback, and (c) fast closed loop combustion control (using a Woodward RT-CDC control system). This system enables significant reduction in burn duration by controlling a two phase combustion event. The first phase is normal spark ignited propagating flame, which then triggers the second phase which is volumetric auto-ignition. The location and percentage of fuel that burns in the volumetric auto-ignition event is controlled relative to that which occurs via the conventional spark ignited flame propagation process by use of high speed combustion in the loop feedback control. Auto-ignition mass fraction burned (MFB) ratios of 25–50% have been achieved yielding higher heat release rates at the end of combustion than at the center of combustion with the result being a shortening of the combustion burn duration from a nominal 20–30 degrees to a near optimal 10–15 degrees even with EGR rates as high as 25%. A novel and patent pending burn duration control strategy is employed to stably maintain this knock-free combustion strategy even with compression ratio as high as 14:1. The benefits are significant increase in Brake Thermal Efficiency and substantial reduction in engine out methane emissions without sacrifice of transient responsiveness.

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Thermal Management for 6-Cylinder HCCI Engine: Low Cost, High Efficiency, Ultra-Low NOx Power Generation

ASME 2004 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2004-0930 ◽

2004 ◽

Cited By ~ 2

Author(s):

Joel Martinez-Frias ◽

Daniel Flowers ◽

Salvador M. Aceves ◽

Francisco Espinos-Loza ◽

Robert Dibble

Keyword(s):

Thermal Efficiency ◽

High Efficiency ◽

Thermal Control ◽

Operating Conditions ◽

Simulation Code ◽

Engine Operation ◽

Brake Thermal Efficiency ◽

Hcci Engine ◽

Cycle Simulation ◽

Wide Range

This paper investigates a purely thermal control system for a 6-cylinder HCCI engine. Thermal energy from exhaust gas and from compression is used to condition the charge for the desired engine output. HCCI engine operation is analyzed with a detailed chemical kinetics based engine cycle simulation code. This cycle simulation code is linked to an optimizer that determines the operating conditions that result in maximum brake thermal efficiency, while meeting the restrictions of low NOx, and peak cylinder pressure. The results show the values of the operating conditions that yield optimum efficiency as a function of brake power for a constant engine speed (1800 rpm). It has been determined that a thermally controlled HCCI engine can successfully operate at high efficiency and low emissions over a wide range of conditions from idle to full load. The results show that a 42% brake thermal efficiency can be reached while the NOx emissions are kept under 2 parts per million. The analytical results shown here are expected to guide the ongoing experimental effort of converting a heavy-duty stationary engine to HCCI mode. The experimental work has the goal of meeting the very aggressive efficiency and emissions targets set by the California Energy Commission (CEC) Advanced Reciprocating Internal Combustion Engine (ARICE) Program.

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Development of the Waukesha 16V150 LTD Advanced Power Generation Engine

ASME 2006 Internal Combustion Engine Division Fall Technical Conference (ICEF2006) ◽

10.1115/icef2006-1510 ◽

2006 ◽

Author(s):

Ed Reinbold ◽

Daniel Mather

Keyword(s):

Power Generation ◽

Thermal Efficiency ◽

High Efficiency ◽

Phase 1 ◽

Department Of Energy ◽

Nox Emissions ◽

Lean Burn ◽

Brake Thermal Efficiency ◽

Reciprocating Engine ◽

Engine Systems

Waukesha Engine has developed an advanced power generation engine using technologies that were developed as part of the Department of Energy-Advanced Reciprocating Engine Systems (ARES) program. The engine uses lean-burn technologies for high efficiency, and low NOx emissions. The technical goals for the ARES program were 50% Brake Thermal Efficiency (BTE) and 0.075 g/kW-hr NOx emissions (with aftertreatment). The goals for the Waukesha Engine Phase 1 Advanced Power Generation (APG) engine are 42% Brake Thermal Efficiency (BTE) and 0.75 g/kW-hr (1.0 g/Bhp-hr) NOx emissions, capable of 0.075 g/kW-hr (0.1 g/Bhp-hr) with aftertreatment. The barriers and technical paths applied to achieve this performance are discussed in this paper.

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Experimental study on the approach for improved brake thermal efficiency on a two-stage turbocharged heavy-duty diesel engine

Fuel ◽

10.1016/j.fuel.2021.121523 ◽

2021 ◽

Vol 305 ◽

pp. 121523

Author(s):

Xiaoyang Yu ◽

Binyang Wu ◽

Wanhua Su

Keyword(s):

Experimental Study ◽

Diesel Engine ◽

Thermal Efficiency ◽

Heavy Duty ◽

Two Stage ◽

Brake Thermal Efficiency ◽

Heavy Duty Diesel Engine ◽

Heavy Duty Diesel

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Decreasing hydrocarbon and carbon monoxide emissions of a natural-gas engine operating in the quasi-homogeneous charge compression ignition mode at low loads

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/095440705x34793 ◽

2005 ◽

Vol 219 (9) ◽

pp. 1125-1131 ◽

Cited By ~ 5

Author(s):

Su Ling ◽

Zhou Longbao ◽

Liu Shenghua ◽

Zhong Hui

Keyword(s):

Carbon Monoxide ◽

Natural Gas ◽

Thermal Efficiency ◽

Homogeneous Charge Compression Ignition ◽

Compression Ignition ◽

Brake Thermal Efficiency ◽

Pilot Fuel ◽

Cng Engine ◽

Standard Mode ◽

Homogeneous Charge

Experimental studies have been carried out on decreasing the hydrocarbon (HC) and carbon monoxide (CO) emissions of a compressed natural-gas (CNG) engine operating in quasi-homogeneous charge compression ignition (QHCCI) mode at low loads. The effects of three technical approaches including partial gas cut-off (PGC), intake air throttling, and increasing the pilot fuel quantity on emissions and the brake thermal efficiency of the CNG engine are studied. The results show that HC and CO emissions can be reduced with only a small penalty on the brake thermal efficiency. An increase in the brake thermal efficiency and reductions in HC and CO emissions can be simultaneously realized by increasing the pilot fuel quantity. It is also indicated from experiments that the HC and CO emissions of the engine can be effectively reduced when using intake air throttling and increasing the pilot fuel quantity are both adopted. However, nitrogen oxide (NOx) emissions increase with increase in the throttling and the pilot fuel quantity. Under PGC conditions, NOx emissions are lower than those in the standard mode; however, they increase and exceed the values in the standard mode in increases in the load and natural-gas supply.

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Development of High Efficiency Gasoline Engine with Thermal Efficiency over 42%

10.4271/2017-01-2229 ◽

2017 ◽

Cited By ~ 11

Author(s):

Byeongsoek Lee ◽

Heechang Oh ◽

SeungKook Han ◽

SooHyung Woo ◽

JinWook Son

Keyword(s):

Thermal Efficiency ◽

High Efficiency ◽

Gasoline Engine

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EXPERIMENTAL ANALYSIS OF THE COMBUSTION CHAMBER COATED WITH Mo AND Al2O3-TiO2 IN A DIESEL ENGINE

Materiali in tehnologije ◽

10.17222/mit.2020.227 ◽

2021 ◽

Vol 55 (4) ◽

Author(s):

Murugan Kuppusamy ◽

Thirumalai Ramanathan ◽

Udhayakumar Krishnavel ◽

Seenivasan Murugesan

Keyword(s):

Combustion Chamber ◽

Fuel Consumption ◽

Thermal Efficiency ◽

Performance Test ◽

Ceramic Powder ◽

Specific Fuel Consumption ◽

Emission Characteristic ◽

Powder Materials ◽

Brake Specific Fuel Consumption ◽

Brake Thermal Efficiency

The effect of thermal-barrier coatings (TBCs) reduces fuel consumption, effectively improving the engine efficiency. This research focused on a TBC with a thickness of 300 µm insulating the combustion chamber of a direct ignition (DI) engine. The piston crown, inlet and exhaust-valve head were coated using air-plasma-spray coating. Ceramic powder materials such as molybdenum (Mo) and aluminum oxide titanium dioxide (Al2O3-TiO2) were used. A performance test of the engine with the coated combustion chamber was carried out to investigate the brake power, brake thermal efficiency, volumetric efficiency, brake specific fuel consumption and air-fuel ratio. Also, an emission-characteristic test was carried out to investigate the emissions of unburned hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NO, NO2, NO3) and smoke opacity (SO). The results reveal that the brake thermal efficiency and brake specific fuel consumption show significant increases because of these coating materials. The effect of the Al2O3-TiO2 coating significantly reduces the HC and CO engine emissions.

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