K-2238 A Cold Start Procedure of Premixed-Compression-Ignition Natural-Gas Engines using a Hot Glow Plug

2001 ◽  
Vol V.01.1 (0) ◽  
pp. 311-312
Author(s):  
Yukihisa YAMAYA ◽  
Takaaki TAKEMOTO ◽  
Masahiro FURUTANI ◽  
Yasuhiko OHTA
Keyword(s):  
Natural Gas ◽  
Cold Start ◽  
Compression Ignition ◽  
Glow Plug ◽  
Natural Gas Engines

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.

Transient Behaviour of Glow Plugs in Direct Injection Natural Gas Engines

2011 ◽  
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 KIVA-3V 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.

Modeling of Ignition and Combustion for Glow Plug Assisted Direct Injection Natural Gas Engines

2012 ◽  
Author(s):  
Stewart Xu Cheng ◽  
James S. Wallace
Keyword(s):  
Natural Gas ◽  
Heated Surface ◽  
Direct Injection ◽  
Cfd Modeling ◽  
Spontaneous Ignition ◽  
Layer Model ◽  
Glow Plug ◽  
Natural Gas Engines ◽  
Gas Ignition ◽  
Ignition And Combustion

Direct injection natural gas (DING) engines offer the advantages of high thermal efficiency and high power output compared to spark ignition natural gas engines. Injected natural gas requires some form of ignition assist in order to ignite in the time available in a diesel engine combustion chamber. A glow plug — a heated surface — is one form of ignition assist. Simple experiments show that the thickness of the heat penetration layer of a glow plug is very small (≈10−5 m) within the time scale of the ignition preparation period (1–2 ms). Meanwhile, the theoretical analyses reveal that only a very thin layer of the surrounding gases (in micrometer scale) can be heated to high temperature to achieve spontaneous ignition. A discretized glow plug model and virtual gas sub-layer model have been developed for CFD modeling of glow plug ignition and combustion for DING diesel engines. In this paper, CFD modeling results are presented. The results were obtained using a KIVA3 code modified to include the above mentioned new developed models. Natural gas ignition over a bare glow plug was simulated. The results were validated against experiments. Simulation of natural gas ignition over a shielded glow plug was also carried out and the results illustrate the necessity of using a shield. This paper shows the success of the discretized glow plug model working together with the virtual gas sub-layer model for modeling glow plug assisted natural gas direct injection engines. The modeling can aid in the design of injection and ignition systems for glow plug assisted DING engines.

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.

Numerical studies of the ignition characteristics of a high-pressure gas jet in compression ignition engines with glow plug ignition assist: Part 2-Effects of multi-opening glow plug shields

2017 ◽  
Vol 19 (9) ◽  
pp. 977-1001 ◽  
Author(s):  
Kang Pan ◽  
James S Wallace
Keyword(s):  
Natural Gas ◽  
Flame Propagation ◽  
Ignition Time ◽  
Propagation Path ◽  
Compression Ignition ◽  
Glow Plug ◽  
Compression Ignition Engines ◽  
Gas Ignition ◽  
Single Opening ◽  
Ignition Characteristics

The results of a previous study, part 1, showed that use of a shield can improve the thermal performance of a glow plug, and thereby reduce ignition time. However, the part 1 study also found that use of a simple shield with only one circular opening can delay flame propagation out of the shield. The conclusions of that study suggested that there is scope for further improvements of the shield design, especially the shield opening geometry. Accordingly, this article presents the results of computational studies investigating the influence of multi-opening shield designs on natural gas ignition characteristics in glow plug–assisted compression–ignition engines. Two types of multi-opening glow plug shield, consisting of four small circular openings distributed in either diamond-pattern or square-pattern arrangements, were employed. The simulated results demonstrated that both multi-opening shields can not only increase glow plug surface temperature, but also increase the residence time of fuel mixture adjacent to the glow plug surface in the early injection stage, resulting in a faster ignition than the single-opening shield. Furthermore, the diamond-pattern multi-opening glow plug shield provides a faster or comparable flame propagation path back to combustion chamber, compared to single-opening glow plug shield, while the square-pattern multi-opening glow plug shield delays the flame propagation under several specific engine conditions. Compared to the single-opening glow plug shield, the overall natural gas ignition delays are further reduced by 6%–44% when using the diamond-pattern multi-opening glow plug shield, while the square-pattern multi-opening glow plug shield is only able to reduce the natural gas ignition delay under a few specific conditions.

Study of Assisted Compression Ignition in a Direct Injected Natural Gas Engine

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Ivan M. Gogolev ◽  
James S. Wallace
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Direct Injection ◽  
Air Entrainment ◽  
Source Analysis ◽  
Compression Ignition ◽  
Glow Plug ◽  
Injection Duration ◽  
Intake Pressure

Natural gas direct injection (DI) and glow plug ignition assist technologies were implemented in a single-cylinder, compression-ignition optical research engine. Initial experiments studied the effects of injector and glow plug shield geometry on ignition quality. Injector and shield geometric effects were found to be significant, with only two of 20 tested geometric combinations resulting in reproducible ignition. Of the two successful combinations, the combination with 0 deg injector angle and 60 deg shield angle was found to result in shorter ignition delay and was selected for further testing. Further experiments explored the effects of the overall equivalence ratio (controlled by injection duration) and intake pressure on ignition delay and combustion performance. Ignition delay was measured to be in the range of 1.6–2.0 ms. Equivalence ratio was found to have little to no effect on the ignition delay. Higher intake pressure was shown to increase ignition delay due to the effect of swirl momentum on fuel jet development, air entrainment, and jet deflection away from optimal contact with the glow plug ignition source. Analysis of combustion was carried out by examination of the rate of heat release (ROHR) profiles. ROHR profiles were consistent with two distinct modes of combustion: premixed mode at all test conditions, and a mixing-controlled mode that only appeared at higher equivalence ratios following premixed combustion.

Numerical Evaluation of Spray-Guided Glow Plug Assistance on Gasoline Compression Ignition During Cold Idle Operation in a Heavy-Duty Diesel Engine

2020 ◽  
Author(s):  
Le Zhao ◽  
Yuanjiang Pei ◽  
Yu Zhang ◽  
Praveen Kumar ◽  
Tom Tzanetakis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Cold Start ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Glow Plug ◽  
Fuel Vaporization ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Ignition And Combustion

Abstract Starting compression ignition engines under cold conditions is extremely challenging, due to insufficient fuel vaporization, heavy wall impingement, and low ignitability of the fuel. For gasoline compression ignition (GCI) combustion strategies, which offer the potential for an enhanced NOx-PM tradeoff with diesel-like fuel efficiency, robust ignition and combustion in very cold conditions pose a significant challenge due to the low reactivity of gasoline fuels. Based on the previous understanding of the spray, ignition and combustion processes for a GCI engine under cold conditions, this study focuses on investigating the cold combustion performance of a heavy-duty GCI engine with glow plug ignition assist. Glow plugs, commonly used for low temperature cold starts in diesel engines, are used to pre-heat a segment of the mixture to improve its ignitability. Here, CFD studies are carried out to explore the influence of a spray-guided glow plug on the spray and combustion behavior of a GCI engine under cold operating conditions. In a prior study, the underlying CFD model has been validated using experimental data from a six-cylinder, 15 L heavy-duty diesel engine operating with a compression ratio (CR) of 17.3 at a 600 rpm cold idle condition with RON92 E0 gasoline. The energy intensity required by the glow plug to deliver stable combustion isparametrically studied. The size and location of the glow plug are also parametrically varied to evaluate their effects on the combustion process. The influence of the glow plug on the in-cylinder mixture distribution and the ensuing combustion process is also investigated. In particular, the localized fuel spray distribution and mixture formation near the glow plug are examined. The results reveal that the glow plug enhances GCI combustion under cold idle conditions and that the spray-guided glow plug improves fuel vaporization, leading to a rich mixture near the glow plug and an enhancement of the combustion efficiency. In addition, the effectiveness of the glow plug at a low ambient temperature of 0°C and a 200 rpm cold start condition is evaluated. These simulations suggest that the glow plug can improve the cold start performance of a GCI engine.

scholarly journals Sub-23 nm Solid Particle Number Emission Characteristics for a Heavy-duty Engine Fuelled with Compression Natural Gas

2021 ◽  
Vol 329 ◽  
pp. 01012
Author(s):  
Xiaowei Wang ◽  
Lin Zhang ◽  
Mingda Wang ◽  
Xiaojun Jing ◽  
Xuejing Gu
Keyword(s):  
Natural Gas ◽  
Great Influence ◽  
Calorific Value ◽  
Cold Start ◽  
Particulate Emissions ◽  
Heavy Duty ◽  
Test Bed ◽  
Fuel Gas ◽  
Natural Gas Engines ◽  
Number Of Particles

Cold and hot WHTC (World harmonized Transient-State Cycle) were separately run on the engine test bed for a heavy-duty natural gas engine fuelled with high calorific value natural gas and low calorific value natural gas. The particle emissions including PN10 (number of particles above 10nm) and PN23 (number of particles above 23nm) were measured. The results show that the transient emission of PN10 and PN23 have basically the same trends. The weighted specific emission of PN10 is 21.6 times of PN23. Cold start PN emissions account for a relatively large proportion. Fuel property has a great influence on the PN emissions of natural gas engines. The increase of carbon-containing fuels such as methane and ethane in the fuel gas will lead to a rapid increase in PN emissions especially in the cold start process. It is extremely important to strengthen the control of sub-23nm particulate emissions for heavy-duty natural gas engines.

Numerical studies of the ignition characteristics of a high-pressure gas jet in compression-ignition engines with glow plug ignition assist: Part 1—Operating condition study

2017 ◽  
Vol 18 (10) ◽  
pp. 1035-1054 ◽  
Author(s):  
Kang Pan ◽  
James S Wallace
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Operating Conditions ◽  
Gas Jet ◽  
Compression Ignition ◽  
Fuel Injector ◽  
Compression Ignition Engine ◽  
Glow Plug

This article presents the results of computational studies investigating the ignition of high-pressure natural gas jets in a compression-ignition engine with glow plug ignition assist. The simulation was conducted using a KIVA-3V-based three-dimensional engine model, along with an improved fuel injector model, a detailed cut-off glow plug shield model and a modified two-step methane reaction mechanism, to simulate the natural gas injection and ignition. The simulated results demonstrate the significance of using a shield for the glow plug. Compared to an unshielded (bare) glow plug, the shield not only reduces the heat loss from the hot glow plug surface to the cold intake air charge and the cold injected gas jet but also traps the fuel mixture to increase its residence time adjacent to the hot surface. Over a representative range of heavy-duty diesel engine operating conditions, a shielded glow plug greatly improves the natural gas engine performance and provides reliable ignition, while an unshielded glow plug can only be optimized for specific conditions. The understanding of glow plug shield behavior gained from the simulations suggests avenues for improved shield designs that would yield further reduced ignition delays.

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