The effects of partially premixed combustion mode on the performance and emissions of a direct injection natural gas engine

Li, Menghan; Zheng, Xuelong; Zhang, Qiang; Li, Zhenguo; Shen, Boxiong; Liu, Xiaori

doi:10.1016/j.fuel.2019.04.009

Cited by 45 publications

(11 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Faghani et al, 13 McTaggart-Cowan et al 14,15 ), and (ii) stratified-premixed PIDING modes where one or more NG injections are performed during the compression stroke to generate highly premixed conditions (e.g. Florea et al, 16,17 Li et al 18 ). For both these strategies, late-cycle SO I pilot is used for fast-response combustion phasing control.…”

Section: Introductionmentioning

confidence: 99%

“…Splitting the main NG injection into early- and late-cycle injections has also been considered as a strategy to control NG stratification. Li et al 18 report an increase in efficiency and reduction of PM and CO when a greater fraction of the NG (50%–90%) is injected in the first of two injections. Munshi et al 22 investigated a similar split NG injection strategy with the NG pre-injection occurring during the intake stroke and an early pilot injection similar to reactivity controlled compression ignition (RCCI) combustion.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heat release rate and emissions regimes of stratified pilot-ignited direct-injection natural gas combustion

Rochussen

McTaggart-Cowan

Kirchen

2021

International Journal of Engine Research

View full text Add to dashboard Cite

Natural gas (NG) is an attractive fuel for heavy-duty internal combustion engines because of its potential for reduced CO2, particulate, and NOX emissions and lower cost of ownership. Pilot-ignited direct-injected NG (PIDING) combustion uses a small pilot injection of diesel to ignite a main direct injection of NG. Recent studies have demonstrated that increased NG premixing is a viable strategy to increase PIDING indicated efficiency and further reduce particulate and CO emissions while maintaining low CH4 emissions. However, it is unclear how the combustion strategies relate to one another, or where they fit within the continuum of NG stratification. The objective of this work is to present a systematic evaluation of pilot combustion, NG combustion, and emissions behavior of stratified-premixed PIDING combustion modes that span from fully-premixed to non-premixed conditions. A sweep of the relative injection timing, [Formula: see text], of NG and pilot diesel was performed in a heavy-duty PIDING engine with [Formula: see text] = 140–220 bar, [Formula: see text] = 0.47–0.71, and a constant NG energy fraction of 94%. Apparent heat release rate and emissions analyses identified interactions between the pilot fuel and NG, and qualitatively characterized the impact of NG stratification on combustion and emissions. Changes in the [Formula: see text] resulted in six distinct PIDING combustion regimes, for all considered injection pressures and equivalence ratios: (i) RIT-insensitive premixed, (ii) stratified-premixed (early-cycle injection), (iii) NG jet impingement transition, (iv) stratified-premixed (late-cycle injection), (v) variable premixed fraction, and (vi) minimally-premixed. Parametric definitions for the bounds of each regime of combustion were valid for the wide range of [Formula: see text] and [Formula: see text] investigated, and are expected to be relevant for other PIDING engines, as previously identified regimes agree with those identified here. This conceptual framework encompasses and validates the findings of previous stratified PIDING investigations, including optimal ranges of operation that provide significantly increased efficiency and lower emissions of incomplete combustion products.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Heat release rate and emissions regimes of stratified pilot-ignited direct-injection natural gas combustion

Rochussen

McTaggart-Cowan

Kirchen

2021

International Journal of Engine Research

View full text Add to dashboard Cite

show abstract

“…However, increasing the amount of pilot fuel increases the particulate matter emissions [11]. A simulation calculation showed that the partial premixing of NG can effectively reduce CO and soot emissions, but causes the increase of NO x emissions, which can be solved by adding EGR [12,13].…”

Section: Introductionmentioning

confidence: 99%

Effect of the HPDI and PPCI Combustion Modes of Direct-Injection Natural Gas Engine on Combustion and Emissions

Jin

2021

Energies

View full text Add to dashboard Cite

Natural gas (NG) engines have very broad application prospects. The pilot-ignited NG diesel engine can be organized into two combustion modes according to the sequence of oil and gas injection: (1) High-pressure direct injection, where NG is mainly diffused combustion; and (2) partially premixed compression ignition, where NG is mainly premixed combustion. In this study, we used CONVERGE to explore the influence of the NG injection timing on the distribution of the mixture equivalence ratio, ignition characteristics, thermal efficiency, emission, and combustion reaction rate under the two combustion modes. We also used a multi-step soot model to analyze the particle mass and quantity. We showed herein that the NG injection timing significantly affects the mixture distribution in the cylinder, thereby consequently affecting the combustion process. Both very early and very late injection times were not conducive to NG combustion. In addition, the mass, quantity, and diameter of the soot produced by diffusion combustion were larger than those produced with premixed combustion.

show abstract

“…As a result, the natural gas must mix well with the background air inside the cylinder in a limited time just before combustion. Li natural gas engine emission performance, and they reported that soot and CO emissions could be substantially reduced without penalties in NOx and thermal efficiency by the optimization of natural gas injection timing and proportion [7]. Therefore, the natural gas injection characteristics are important for the engine, and it is crucial to control the pulsed natural gas injection so that the combustible air-fuel mixture is ready for good combustion quality.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research of High-Pressure Methane Pulse Jet and Premixed Ignition Combustion Performance of a Direct Injection Injector

et al. 2021

View full text Add to dashboard Cite

Natural gas (NG) direct injection (DI) technology benefits the engine with high efficiency and clean emissions, and the high-pressure gas fuel injection process causes crucial effects on the combustion. This study presents an optical experimental investigation on the high-pressure methane single-hole direct injection and premixed ignition combustion based on a visualization cuboid constant volume bomb (CVB) test rig. The experimental results show that the methane jet process is divided into two stages. The methane gas jet travels at a faster speed during the unstable stage I than that during the stable stage II. The injection pressure causes more influence on both the jet penetration distance and the jet cone area during stage II. The methane jet premixed flame is a stable flame with a nearly spherical shape, and its equivalent radius linearly increases. The methane jet premixed flame area also increases while the flame stretch rate declines. The methane jet premixed flame velocity rises as both the standing time and equivalent ratio increase. The methane jet premixed flame is a partial premixed flame, and the peak of the methane jet premixed flame occurs at greater equivalence ratio ϕ, i.e., ϕ > 2. As the injection pressure rises, the jet premixed flame equivalent radius increases, and the flame velocity linearly increases. The higher the methane injection pressure, the faster the jet premixed flame velocity.

show abstract

The effects of partially premixed combustion mode on the performance and emissions of a direct injection natural gas engine

Cited by 45 publications

References 19 publications

Heat release rate and emissions regimes of stratified pilot-ignited direct-injection natural gas combustion

Heat release rate and emissions regimes of stratified pilot-ignited direct-injection natural gas combustion

Effect of the HPDI and PPCI Combustion Modes of Direct-Injection Natural Gas Engine on Combustion and Emissions

Experimental Research of High-Pressure Methane Pulse Jet and Premixed Ignition Combustion Performance of a Direct Injection Injector

Contact Info

Product

Resources

About