Investigation of Cold Starting and Combustion Mode Switching as Methods to Improve Low Load RCCI Operation

Volume 1: Large Bore Engines; Fuels; Advanced Combustion ◽

10.1115/icef2015-1093 ◽

2015 ◽

Cited By ~ 1

Author(s):

Reed Hanson ◽

Rolf Reitz

Keyword(s):

Steady State ◽

High Speed ◽

Closed Loop ◽

Cold Start ◽

Mode Switching ◽

Combustion Mode ◽

Low Load ◽

Performance And Emissions ◽

And Performance ◽

Emissions And Performance

Reactivity Controlled Compression Ignition (RCCI) is an engine combustion strategy that utilizes in-cylinder fuel blending to produce low NOx and PM emissions while maintaining high thermal efficiency. The current study investigates RCCI and conventional diesel combustion (CDC) operation in a light-duty multi-cylinder engine using a transient capable engine test cell. The main focus of the work uses engine experiments to investigate methods which can improve low-load RCCI operation. The first set of experiments investigated RCCI operation during cold start conditions. The next set of tests investigated combustion mode switching between RCCI and CDC. During the cold start tests, RCCI performance and emissions were measured over a range of engine coolant temperatures from 48 to 85°C. A combination of open and closed loop controls enabled RCCI to operate at a 1,500 rpm, 1 bar BMEP operating point over this range of coolant temperatures. At a similar operating condition, i.e. 1,500 rpm, 2 bar BMEP, the engine was instantaneously switched between CDC and RCCI combustion using the same open and closed loop controls as the cold start testing. During the mode switch tests, emissions and performance were measured with high speed sampling equipment. The tests revealed that it was possible to operate RCCI down to 48°C with simple open and closed loop controls with emissions and efficiency similar to the warm steady-state values. Next, the mode switching tests were successful in switching combustion modes with minimal deviations in emissions and performance in either mode at steady-state.

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Investigation of Cold Starting and Combustion Mode Switching as Methods to Improve Low Load RCCI Operation

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4032711 ◽

2016 ◽

Vol 138 (9) ◽

Cited By ~ 5

Author(s):

Reed Hanson ◽

Rolf Reitz

Keyword(s):

Steady State ◽

High Speed ◽

Closed Loop ◽

Cold Start ◽

Mode Switching ◽

Combustion Mode ◽

Low Load ◽

Performance And Emissions ◽

And Performance ◽

Emissions And Performance

Reactivity controlled compression ignition (RCCI) is an engine combustion strategy that utilizes in-cylinder fuel blending to produce low NOx and particulate matter (PM) emissions while maintaining high thermal efficiency. The current study investigates RCCI and conventional diesel combustion (CDC) operation in a light-duty multicylinder engine (MCE) using a transient capable engine test cell. The main focus of the work uses engine experiments to investigate methods which can improve low load RCCI operation. The first set of experiments investigated RCCI operation during cold start conditions. The next set of tests investigated combustion mode switching between RCCI and CDC. During the cold start tests, RCCI performance and emissions were measured over a range of engine coolant temperatures (ECTs) from 48 °C to 85 °C. A combination of open- and closed-loop controls enabled RCCI to operate at a 1500 rpm, 1 bar BMEP operating point over this range of coolant temperatures. At a similar operating condition, i.e., 1500 rpm, 2 bar BMEP, the engine was instantaneously switched between CDC and RCCI combustion using the same open- and closed-loop controls as the cold start testing. During the mode switch tests, emissions and performance were measured with high-speed sampling equipment. The tests revealed that it was possible to operate RCCI down to 48 °C with simple open- and closed-loop controls with emissions and efficiency similar to the warm steady-state values. Next, the mode switching tests were successful in switching combustion modes with minimal deviations in emissions and performance in either mode at steady state.

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The Effects of Intake Valve Closing Timing on Engine Performance and Emissions in a DME Compression Ignition Engine at Low Load Cold Start Condition

Lecture Notes in Electrical Engineering - Proceedings of the FISITA 2012 World Automotive Congress ◽

10.1007/978-3-642-33777-2_16 ◽

2012 ◽

pp. 211-226

Author(s):

Jaeheun Kim ◽

Choongsik Bae

Keyword(s):

Engine Performance ◽

Cold Start ◽

Compression Ignition ◽

Intake Valve ◽

Compression Ignition Engine ◽

Low Load ◽

Performance And Emissions ◽

Engine Performance And Emissions

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Assessing the Effect of E22 Fuel on Two-Stroke and Four-Stroke Snowmobile Performance and Emissions

ASME 2012 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2012-92185 ◽

2012 ◽

Author(s):

Michael D. Rittenour ◽

James C. Weber ◽

Scott A. Miers

Keyword(s):

Fuel Consumption ◽

Exhaust System ◽

Feedback Controls ◽

Ethanol Content ◽

Performance And Emissions ◽

Hc Emissions ◽

And Performance ◽

Emissions And Performance ◽

The Impact ◽

Recreational Vehicle

A limited amount of information exists on the effect of higher ethanol content fuel (greater than 10 vol%) for recreational vehicle engines. The possibility exists for misfueling of these vehicles, as ethanol content may increase at gas stations in the near future. Engine management systems in the recreational vehicle market are typically not equipped with feedback controls to adapt to the increased ethanol content. To address this concern and generate preliminary data related directly to the recreational industry, a study was conducted to evaluate the impact of E22 fuel on steady-state emissions and performance of two production snowmobiles. To fully analyze the impact of higher ethanol blends, cold-start, durability, and material compatibility tests should be performed, in conjunction with emissions and performance tests. While these additional tests were not performed as part of this study, there is a test program that is assessing all these factors on E15 fuel, which will be released in fall 2012. E0 fuel was used to establish baseline performance and emissions data. A 2009 four-stroke snowmobile with a 998cc, liquid-cooled, four-cylinder, intake port-fuel injected engine and a 2009 two-stroke snowmobile with a 599cc, liquid-cooled, two-cylinder, electronically controlled, crankcase-fuel injected engine were used for this study. Neither vehicle had any feedback air-fuel controls or after-treatment devices in the exhaust system. Power, fuel consumption, relevant engine temperatures, as well as, regulated exhaust emissions were recorded using the EPA 5-mode certification test cycle. The data showed no major impact on power output for either the four-stroke or two-stroke snowmobile. Brake specific fuel consumption varied with E22 as compared to E0. A reduction in CO emissions for both vehicles was observed for the E22 fuel. Both vehicles were factory calibrated rich of stoichiometric and hence, the addition of ethanol to the fuel effectively leaned out the air/fuel ratio and thus reduced the CO emissions. HC emissions were reduced for both the four-stroke and two-stroke engines, though certain test points of the two-stroke engine produced HC emissions that exceeded the analyzer measurement range (idle). Leaner operation reduced HC formation. Exhaust gas temperatures were observed to increase from 20°C – 50°C with E22 fuel, due to enleanment.

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An Experimental Investigation of the Effects of Common-Rail Injection System Parameters on Emissions and Performance in a High-Speed Direct-Injection Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1340638 ◽

1999 ◽

Vol 123 (1) ◽

pp. 167-174 ◽

Cited By ~ 45

Author(s):

P. J. Tennison ◽

R. Reitz

Keyword(s):

Diesel Engine ◽

High Speed ◽

Direct Injection ◽

Injection Pressure ◽

Injection System ◽

Injection Timing ◽

Pilot Injection ◽

Common Rail Injection System ◽

And Performance ◽

Emissions And Performance

An investigation of the effect of injection parameters on emissions and performance in an automotive diesel engine was conducted. A high-pressure common-rail injection system was used with a dual-guided valve covered orifice nozzle tip. The engine was a four-valve single cylinder high-speed direct-injection diesel engine with a displacement of approximately 12 liter and simulated turbocharging. The engine experiments were conducted at full load and 1004 and 1757 rev/min, and the effects of injection pressure, multiple injections (single vs pilot with main), and pilot injection timing on emissions and performance were studied. Increasing the injection pressure from 600 to 800 bar reduced the smoke emissions by over 50 percent at retarded injection timings with no penalty in oxides of nitrogen NOx or brake specific fuel consumption (BSFC). Pilot injection cases exhibited slightly higher smoke levels than single injection cases but had similar NOx levels, while the single injection cases exhibited slightly better BSFC. The start-of-injection (SOI) of the pilot was varied while holding the main SOI constant and the effect on emissions was found to be small compared to changes resulting from varying the main injection timing. Interestingly, the point of autoignition of the pilot was found to occur at a nearly constant crank angle regardless of pilot injection timing (for early injection timings) indicating that the ignition delay of the pilot is a chemical delay and not a physical (mixing) one. As the pilot timing was advanced the mixture became overmixed, and an increase of over 50 percent in the unburned hydrocarbon emissions was observed at the most advanced pilot injection timing.

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SI/HCCI Mode Switching Optimization in a Gasoline Direct Injection Engine Employing Dual Univalve System

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4041516 ◽

2018 ◽

Vol 141 (3) ◽

Cited By ~ 1

Author(s):

Yintong Liu ◽

Liguang Li ◽

Haifeng Lu ◽

Stephan Schmitt ◽

Jun Deng ◽

...

Keyword(s):

High Efficiency ◽

Direct Injection ◽

Load Condition ◽

Gasoline Direct Injection ◽

Mode Switching ◽

Nox Emissions ◽

Combustion Mode ◽

Timing Control ◽

Main Challenge ◽

Low Load

Homogeneous charge compression ignition (HCCI) is a feasible combustion mode meeting future stringent emissions regulations, and has high efficiency and low NOX and particle emissions. As the narrow working condition range is the main challenge limiting the industrialization of HCCI, combustion mode switching between SI and HCCI is necessary when employing HCCI in mass production engines. Based on a modified production gasoline direct injection (GDI) engine equipped with dual UniValve system (a fully continuously variable valvetrain system), SI/HCCI mode switching under low load condition is investigated. According to the results, combustion mode switching from SI to HCCI is more complicated than from HCCI to SI. As HCCI requires strict boundary conditions for reliable and repeatable fuel auto-ignition, abnormal combustion easily appears in transition cycle, especially when combustion switches from SI to HCCI. Timing control strategies can optimize the combustion of transition cycles. With the optimization of timing control, the mode switching from SI to HCCI can be completed with only two transition cycles of late combustion, and abnormal combustion can be avoided during the mode switching from HCCI to SI. Under the low load condition, the indicated efficiency reaches 39% and specific NOX emissions drop down to around 1 mg/L/s when the combustion mode is switched to HCCI mode. Compared to SI mode, the indicated efficiency is increased by 10% and the specific NOX emissions are reduced by around 85%.

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Managing the Transition Between Low Temperature Combustion and Conventional Diesel Combustion During a Load Change

ASME 2012 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2012-92049 ◽

2012 ◽

Author(s):

Asish K. Sarangi ◽

Colin P. Garner ◽

Gordon P. McTaggart-Cowan ◽

Martin H. Davy ◽

Emad A. Wahab ◽

...

Keyword(s):

Steady State ◽

Diesel Engine ◽

Low Temperature ◽

Low Temperature Combustion ◽

Drive Cycle ◽

Test Conditions ◽

Temperature Combustion ◽

And Performance ◽

Emissions And Performance ◽

Diesel Operation

High-EGR diesel low temperature combustion breaks the traditional diesel NOx-PM trade-off, thereby facilitating ultra-low NOx emissions with simultaneously low smoke emissions. High-EGR LTC is currently limited to low and medium load and speed conditions. Therefore, in order to implement a high-EGR diesel LTC strategy in a passenger vehicle, a transition to conventional diesel operation is required when either a high load or high speed is demanded. This transition must be carefully managed to ensure smooth operation and to avoid excessive pollutant emissions—a task that is complicated by the markedly different response time-scales of the engine’s turbocharger, EGR, and fuelling systems. This paper presents the results of a combination of numerical simulation and steady-state engine experiments that describe the performance and emissions of an automotive-sized 2 litre turbocharged diesel engine during a rapid transition from high-EGR LTC to conventional diesel operation. The effects of load change at constant engine speed during the Extra-Urban Drive Cycle (EUDC) part of the New European Drive Cycle (NEDC) are first evaluated using a one-dimensional engine simulation (Ricardo WAVE). The inputs to the model are; the initial and final fuelling quantities, the duration of the transient events, and the response of the engine’s control systems. The WAVE model outputs the intake manifold pressure and EGR level for each cycle during the transition. The predicted intake pressure, EGR rate and the corresponding known injected fuel mass for each individual cycle are used to define a set of ‘pseudo-transient’ test conditions—matching the conditions encountered at discrete points within the modelled transient—for subsequent steady-state engine testing on a 0.51 litre AVL single cylinder diesel engine. These test conditions are established on the engine using independently controllable EGR and boost systems and the corresponding emissions (NOx, smoke, CO, and THC) and performance data (GISFC) were recorded. The experimental emissions and performance data are subsequently presented on a cycle-by-cycle basis. The results of this study provide significant insight into the combustion conditions that might be encountered during mode switching and their deleterious effect on emissions and performance. Strategies to mitigate these effects are examined.

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