Soot and combustion models for direct-injection natural gas engines

2020 ◽  
pp. 146808742097801
Author(s):  
Kang Pan ◽  
James Wallace
Keyword(s):  
Kinetic Model ◽  
Natural Gas ◽  
Soot Formation ◽  
Direct Injection ◽  
Emission Characteristics ◽  
Gas Engine ◽  
Glow Plug ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Soot Model

This paper summarizes the validation of a modified multi-step phenomenological soot model and an enhanced combustion model used for direct-injection natural gas engines. In this study, a modified phenomenological soot model including the key steps for soot formation, such as particle inception and surface growth, was developed in KIVA-3V to replace the empirical model for use in a glow plug assisted natural gas direct-injection engine. The soot model was integrated with a CANTERA based kinetic model, which employs a recently developed low temperature natural gas mechanism to predict the reactions of some important gaseous species involved in the soot formation, such as acetylene and hydroxyl. The simulated in-cylinder flame propagation process induced by a glow plug was compared to the experimental optical images obtained in an engine-like environment. In addition, both the kinetic model and modified soot model were compared with the experimental emission data to validate their reliability for predicting natural gas engine emission characteristics. The engine combustion efficiencies obtained in simulations and experiments were compared as well. The matched results suggest that the computational models can well predict the natural gas combustion and emission characteristics, and will be suitable for investigating the direct-injection natural gas engine technologies.

scholarly journals Knocking characteristics of a high pressure direct injection natural gas engine operating in stratified combustion mode

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 534-538
Author(s):  
Qiang Zhang ◽  
Yubo Yang ◽  
Demin Jia ◽  
Menghan Li
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Cylinder Pressure ◽  
Combustion Mode ◽  
Pressure Oscillations ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Combustion Modes ◽  
Stratified Combustion

Abstract Knocking becomes an increasingly important issue in direct injection natural gas engines with the application of new combustion modes. In this article, the knocking characteristics of natural gas engine operating in stratified combustion mode were studied with the aid of cylinder pressure oscillations and combustion parameters. The results indicated that knocking tendency will be stronger when operating in stratified combustion mode. The first to the fourth circumferential modes and the first radial mode are the featured modes for knocking behavior, while knocking is more serious when the duration of 10–50% of total energy released is shorter.

Numerical Simulation of Marine Diesel Ignited Natural Gas Engine Based on the Finite Volume Method

2014 ◽  
Vol 926-930 ◽  
pp. 3124-3127
Author(s):  
Hong Liang Yu ◽  
Feng Shuo Xing ◽  
Shu Lin Duan
Keyword(s):  
Numerical Simulation ◽  
Natural Gas ◽  
Finite Volume ◽  
Combustion Process ◽  
Combustion Model ◽  
Emission Characteristics ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Marine Diesel

Currently, the research of marine natural gas engine is rare, while the combustion and emission characteristics of natural gas engine are affected greatly by the diesel ignition. This paper built a finite volume combustion model of diesel ignited natural gas engine by AVL FIRE software, and compared experimental data to prove the accuracy of the model, and numerical simulation of the combustion process that the diesel ignited natural gas was carried, analyzed the combustion and emission characteristics of natural gas engines, provided a theoretical basis for the further optimize and design of marine natural gas engine.

Transient Behavior of Glow Plugs in Direct-Injection Natural Gas Engines

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Stewart Xu Cheng ◽  
James S. Wallace
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Direct Injection ◽  
High Surface ◽  
Cold Start ◽  
Transfer Model ◽  
Ignition Process ◽  
Computational Domain ◽  
Glow Plug ◽  
Natural Gas Engines

Glow plugs are a possible ignition source for direct injected natural gas engines. This ignition assistance application is much different than the cold start assist function for which most glow plugs have been designed. In the cold start application, the glow plug is simply heating the air in the cylinder. In the cycle-by-cycle ignition assist application, the glow plug needs to achieve high surface temperatures at specific times in the engine cycle to provide a localized source of ignition. Whereas a simple lumped heat capacitance model is a satisfactory representation of the glow plug for the air heating situation, a much more complex situation exists for hot surface ignition. Simple measurements and theoretical analysis show that the thickness of the heat penetration layer is small within the time scale of the ignition preparation period (1–2 ms). The experiments and analysis were used to develop a discretized representation of the glow plug domain. A simplified heat transfer model, incorporating both convection and radiation losses, was developed for the discretized representation to compute heat transfer to and from the surrounding gas. A scheme for coupling the glow plug model to the surrounding gas computational domain in the KIVA-3V engine simulation code was also developed. The glow plug model successfully simulates the natural gas ignition process for a direct-injection natural gas engine. As well, it can provide detailed information on the local glow plug surface temperature distribution, which can aid in the design of more reliable glow plugs.

Soot emission prediction in pilot ignited direct injection natural gas engine based on n-heptane/toluene/methane/PAH mechanism

Energy ◽  
2018 ◽  
Vol 163 ◽  
pp. 660-681 ◽  
Author(s):  
Menghan Li ◽  
Qiang Zhang ◽  
Xiaori Liu ◽  
Yuxian Ma ◽  
Qingping Zheng
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Soot Emission ◽  
Gas Engine ◽  
Natural Gas Engine

Railplug Design Optimization to Improve Large-Bore Natural Gas Engine Performance

2005 ◽  
Author(s):  
Hongxun Gao ◽  
Matt J. Hall ◽  
Ofodike A. Ezekoye ◽  
Ron D. Matthews
Keyword(s):  
Natural Gas ◽  
High Energy ◽  
Parameter Study ◽  
Transfer Model ◽  
High Speed Photography ◽  
Discharge Process ◽  
Ignition System ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine

It is a very challenging problem to reliably ignite extremely lean mixtures, especially for the low speed, high load conditions of stationary large-bore natural gas engines. If these engines are to be used for the distributed power generation market, it will require operation with higher boost pressures and even leaner mixtures. Both place greater demands on the ignition system. The railplug is a very promising ignition system for lean burn natural gas engines with its high-energy deposition and high velocity plasma jet. High-speed photography was used to study the discharge process. A heat transfer model is proposed to aid the railplug design. A parameter study was performed both in a constant volume bomb and in an operating natural gas engine to improve and optimize the railplug designs. The engine test results show that the newly designed railplugs can ensure the ignition of very lean natural gas mixtures and extend the lean stability limit significantly. The new railplug designs also improve durability.

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