Influence of Injection Angle and Valve Opening Manner on Mixing Performance in a Large-Bore Port Fuel Injection Compressed Natural Gas-Fueled Engine

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Tianbo Wang ◽  
Siqin Chang ◽  
Liang Liu
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Ignition Time ◽  
Intake Port ◽  
Compressed Natural Gas ◽  
Injection Angle ◽  
Mixing Performance ◽  
Port Fuel Injection ◽  
Poppet Valve ◽  
Valve Opening

One new kind of gas injection devices (GIDs), with moving-coil electromagnetic linear actuator (MCELA) and mushroom-type poppet valve, was projected to inject sufficient compressed natural gas (CNG) to a large-bore port fuel injection (PFI) engine. It had larger mass flow rate and better controllability than conventional GID. And the transient computational fluid dynamics (CFD) engine model incorporating the GID's motion was established to analyze the effects of the GID injection angle and poppet valve opening manner on the mixing homogeneity in the intake port, and finally, the in-cylinder mixing performance and gas movement intensity were compared. The results indicate that with the increasing of injection angle, the mixing homogeneity in the near-field injection location of intake port will be better, and the time when fuel starts to get into cylinder will be later. At ignition time, the injection angles 60 deg, 90 deg, and 120 deg show better in-cylinder mixing performance, while 150 deg has the worst. The pull-open GID injects more momentum to the intake port than the push-open one, and the mixing degree both in the intake port and cylinder is higher.

Comparison between gasoline direct injection and compressed natural gas port fuel injection under maximum load condition

Energy ◽  
2020 ◽  
Vol 197 ◽  
pp. 117173 ◽  
Author(s):  
Jeongwoo Lee ◽  
Cheolwoong Park ◽  
Jongwon Bae ◽  
Yongrae Kim ◽  
Sunyoup Lee ◽  
...  
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Direct Injection ◽  
Load Condition ◽  
Maximum Load ◽  
Gasoline Direct Injection ◽  
Compressed Natural Gas ◽  
Port Fuel Injection

scholarly journals Performance, Efficiency and Emissions Evaluation of Gasoline Port-Fuel Injection, Natural Gas Direct Injection and Blended Operation

2016 ◽  
Author(s):  
Michael Pamminger ◽  
Thomas Wallner ◽  
James Sevik ◽  
Riccardo Scarcelli ◽  
Carrie Hall ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Internal Combustion ◽  
Intake Port ◽  
Combustion Engines ◽  
Part Load ◽  
Port Fuel Injection

The need to further reduce fuel consumption and decrease the output of emissions — in order to be within future emissions legislation — is still an ongoing effort for the development of internal combustion engines. Natural gas is a fossil fuel which is comprised mostly of methane and makes it very attractive for use in internal combustion engines because of its higher knock resistance and higher molar hydrogen-to-carbon ratio compared to gasoline. The current paper compares the combustion and emissions behavior of the test engine being operated on either a representative U.S. market gasoline or natural gas. Moreover, specific in-cylinder blend ratios with gasoline and natural gas were also investigated at part-load and wide open throttle conditions. The dilution tolerance for part-load operation was investigated by adding cooled exhaust gas recirculation. The engine used for these investigations was a single cylinder research engine for light duty application which is equipped with two separate fuel systems. Gasoline was injected into the intake port; natural gas was injected directly into the cylinder to overcome the power density loss usually connected with port fuel injection of natural gas. Injecting natural gas directly into the cylinder reduced both ignition delay and combustion duration of the combustion process compared to the injection of gasoline into the intake port. Injecting natural gas and gasoline simultaneously resulted in a higher dilution tolerance compared to operation on one of the fuels alone. Significantly higher net indicated mean effective pressure and indicated thermal efficiency were achieved when natural gas was directly injected after intake valve closing at wide open throttle, compared to an injection while the intake valves were still open. In general it was shown that the blend ratio and the start of injection need to be varied depending on load and dilution level in order to operate the engine with the highest efficiency or highest load.

Modelling characteristics of gasoline wall films in the intake port of port fuel injection engines

2001 ◽  
Vol 2 (4) ◽  
pp. 231-248 ◽  
Author(s):  
G-S Zhu ◽  
R D Reitz ◽  
J Xin ◽  
T Takabayashi
Keyword(s):  
Film Thickness ◽  
Fuel Injection ◽  
Pipe Wall ◽  
Film Structure ◽  
Intake Port ◽  
Fuel Film ◽  
Injection Angle ◽  
Port Fuel Injection ◽  
Wall Film ◽  
Wall Interaction

Models were developed to describe the vaporization of well-mixed wall films of multi-component engine fuels based on continuous thermodynamics and applied to describing multi-component fuel spray-wall interactions. All the models were implemented into the KIVA3V Release 2.0 code. Validation calculations were conducted for pulsed injection cases and compared with experimental wall film thickness data under different air-fuel ratios and inflow conditions in an inclined pipe, which simulates an intake port of port fuel injection engines. Calculations with single-component iso-octane fuel were also conducted for comparison. The influence of wall temperature, inflow-air velocity and injection angle on the gasoline wall film characteristics was studied. The results indicate that the multi-component fuel film is composed of increasingly heavy species as the vaporization proceeds. The fuel-film structure which results from spray-pipe-wall interaction is greatly different from that resulting from spray-plane-wall interaction. An increase in the wall temperature significantly decreases both the film thickness and the film area. The injection angle significantly changes the wall film structure. Although the inflow velocity enhances the fuel vaporization rate, it has a relatively small effect on the fuel film movement along the pipe wall.

Numerical Studies of Glow Plug Shield on Natural Gas Ignition Characteristics in a CI Engine

2016 ◽  
Author(s):  
Kang Pan ◽  
James S. Wallace
Keyword(s):  
Natural Gas ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Numerical Study ◽  
Direct Injection ◽  
Fuel Mixture ◽  
Injection Angle ◽  
Glow Plug ◽  
Gas Ignition ◽  
Ignition And Combustion

This paper presents a numerical study on fuel injection, ignition and combustion in a direct-injection natural gas (DING) engine with ignition assisted by a shielded glow plug (GP). The shield geometry is investigated by employing different sizes of elliptical shield opening and changing the position of the shield opening. The results simulated by KIVA-3V indicated that fuel ignition and combustion is very sensitive to the relative angle between the fuel injection and the shield opening, and the use of an elliptical opening for the glow plug shield can reduce ignition delay by 0.1∼0.2ms for several specific combinations of the injection angle and shield opening size, compared to a circular shield opening. In addition, the numerical results also revealed that the natural gas ignition and flame propagation will be delayed by lowering a circular shield opening from the fuel jet center plane, due to the blocking effect of the shield to the fuel mixture, and hence it will reduce the DING performance by causing a longer ignition delay.

Performance, Efficiency and Emissions Assessment of Natural Gas Direct Injection compared to Gasoline and Natural Gas Port-Fuel Injection in an Automotive Engine

2016 ◽  
Vol 9 (2) ◽  
pp. 1130-1142 ◽  
Author(s):  
James Sevik ◽  
Michael Pamminger ◽  
Thomas Wallner ◽  
Riccardo Scarcelli ◽  
Ronald Reese ◽  
...  
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Direct Injection ◽  
Automotive Engine ◽  
Port Fuel Injection

A study on premixed charge compression ignition combustion of natural gas with direct injection

2005 ◽  
Vol 6 (5) ◽  
pp. 443-451 ◽  
Author(s):  
T Ishiyama ◽  
H Kawanabe ◽  
K Ohashi ◽  
M Shioji ◽  
S Nakai
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Direct Injection ◽  
Pressure Rise ◽  
Combustion Efficiency ◽  
Compression Ignition ◽  
Load Range ◽  
Injection Angle ◽  
Nozzle Orifice ◽  
Rich Mixture

In order to extend the available load range and obtain higher thermal efficiency in natural gas premixed charge compression ignition (PCCI) engines, a strategy for controlling direct injection combustion is discussed. Experimental results from single-cylinder engine tests demonstrate the possibility to extend load range by direct fuel injection. Reduced nozzle orifice size and reduced injection angle provide higher combustion efficiency; however, this promotes the tendency to knock because of the formation of a locally rich mixture. Arising from discussions based on prediction by computational fluid dynamics (CFD) code, considering mixture heterogeneity, it is suggested that controlling probability density functions (PDFs) of fuel concentration could be a means to control the rate of pressure rise. Restricted air utilization is useful to activate combustion at low overall equivalence ratios; on the other hand, full utilization of in-cylinder air and formation of a quantity of lean mixture can provide mild combustion.

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