Supersonic Injection of Gaseous Fuel Described as Possible Solution for NOx Emissions From Large-Bore Gas Engines

Author(s):  
Anatoli Borissov ◽  
James J. McCoy

Both physical and mathematical models were built to describe the main processes in large-bore gas engines. Based on the detail modeling and analysis of cylinder airflow, fuel injection, mixing, combustion and NOx generation, it was possible to pinpoint the problem of abnormal NOx production, even for lean mixtures, that occurs in these engines. In addition, analysis of the experimental data of jet mixing using high-speed photographic evidence, as well as engine performance data, has helped in the understanding of the mixing process. This has resulted in the development of a new way of the mixing of fuel and air utilizing multiple-nozzle supersonic injection. The fuel injection system is designed to optimize the mixing of the methane fuel with the air in the cylinder of a large bore natural gas engine. The design goals of low-pressure (<130 psi), all-electronic valve actuation, and optimal mixing were all achieved with a unique valve/nozzle arrangement. Later, a laser induced fluorescence method was used to take high-speed photographs of the development of the fuel jet exiting the newly developed supersonic electronic fuel injector (SSEFI). This result, together with the results of numerous experimental testing of SSEFI on different engines (GMVH-6, GMW-10, V-250, UTC-165) are presented as evidence of the success of the SSEFI application for the improvement of engine performance, engine control and NOx reduction.

Author(s):  
Koji Takasaki ◽  
Tatsuo Takaishi ◽  
Hiroyuki Ishida ◽  
Keijirou Tayama

Now, it is essential to apply some measures for NOx reduction to low-speed diesel engines emitting much more NOx than high-speed engines. At the same time PM emission must be reduced especially when bunker fuel or heavy fuel is burned. This paper describes the applications of SFWI (Stratified Fuel Water Injection) system and DWI (Direct Water Injection) system to large sized diesel engines to reduce NOx and PM emission. SFWI system makes it possible to inject water during fuel injection from the same nozzle hole without mixing the liquids. DWI system injects water with high injection pressure from the other injection hole than the fuel injection hole into the combustion chamber directly. For testing both the systems, a 2-stroke-cycle low-speed test engine was used.


2012 ◽  
Vol 482-484 ◽  
pp. 1943-1946
Author(s):  
Li Dan Chen ◽  
Huang Xiang Shan

Through the discussion of main shortages of the high-speed electromagnetic valve used in electronic fuel injection system, the author introduced a new design thought of fuel injector based on 2D technology. Axial displacement of controlling valve was used to control the volume of gushing oil, while radial revolution of spool valve was used to change the time of injection. Additionally, mathematic modeling and MATLAB simulating indicated that, the injector designed based on 2D technology acquired the advantages of quick response and also realized the ideal shape of fuel injection rate.


Author(s):  
Nallannan Balasubramanian ◽  
Titus Iwaszkiewicz ◽  
Jayabalan Sethuraman

Two-wheeler engines still use carburetor as a fuelling system in many Asian countries, owing to its low cost andless maintenance. The usage of carburetor to handle the upcoming stringent emission norms gets difficult, due to the absence of a closed-loop fuel correction. An electronic fuel injector (EFI), on the other hand, with the help of an electronic control unit (ECU), can correct the fuel quantity and set the air-fuel mixture close to stoichiometric, based on the feedback obtained from the oxygen sensor placed in the exhaust pipe. In this context, an innovative injection system has been developed, that can be applied for such electronic fuel injection in two-wheelers. In this design, the pump and injector are integrated into a single unit, making the system, simple, compact and less expensive. The integrated injector uses a solenoid and spring arrangement, for pressurizing the fuel in a small chamber, and the pressurized fuel is then injected through orifices to produce spray in the intake port. Two-wheeler engines can operate in the order of 10,000 rpm and it poses a big challenge in such injector designs, and therefore the time response of the mechanical and magnetic components of the injector become critical. High-speed back-lit imaging helps in understanding the time response of such injector, by visualizing the spray, while injecting continuously over a period of time. This paper presents the results of high-speed images, obtained from the spray of this new-concept gasoline pump injector (GPI). This exercise, demonstrated that this injector can work at a frequency as high as 83 Hz and also consistently. The spray pattern was found to be very unique and different from the conventional PFIinjection sprays.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4796


Author(s):  
John M. Gattoni ◽  
David M. Sykes ◽  
Paul E. Yelvington

Using the latest manufacturing technology and patented nozzle geometry, an innovative high-speed (two or more injections at an engine operating speed of 6,000 RPM), lightweight fuel injection system was developed that controls supercavitation within the fuel injector nozzle. The patented supercavitating fuel injector nozzle reduces the penetration length of the fuel spray by 25–30%, average droplet size by 15.5% when operating at the same fuel pressure, and improves droplet size uniformity over conventional nozzles. The combination of these properties represents a tremendous opportunity to improve fuel delivery in engines. In addition to the performance benefits, this technology could be easily implemented into any direct-injected engine system, both compression ignition and spark ignition engines, reciprocating and rotary, because only the nozzle assembly needs to be developed for that particular fuel injector platform.


Author(s):  

The necessity of adapting diesel engines to work on vegetable oils is justified. The possibility of using rapeseed oil and its mixtures with petroleum diesel fuel as motor fuels is considered. Experimental studies of fuel injection of small high-speed diesel engine type MD-6 (1 Ch 8,0/7,5)when using diesel oil and rapeseed oil and computational studies of auto-tractor diesel engine type D-245.12 (1 ChN 11/12,5), working on blends of petroleum diesel fuel and rapeseed oil. When switching autotractor diesel engine from diesel fuel to rapeseed oil in the full-fuel mode, the mass cycle fuel supply increased by 12 %, and in the small-size high-speed diesel engine – by about 27 %. From the point of view of the flow of the working process of these diesel engines, changes in other parameters of the fuel injection process are less significant. Keywords diesel engine; petroleum diesel fuel; vegetable oil; rapeseed oil; high pressure fuel pump; fuel injector; sprayer


2001 ◽  
Author(s):  
Göran Almkvist ◽  
Tomas Karlsson ◽  
Styrbjörn Gren ◽  
Jörgen Bengtsson ◽  
Conny Andersson ◽  
...  

2018 ◽  
Vol 173 (2) ◽  
pp. 3-8
Author(s):  
Mirosław KARCZEWSKI ◽  
Krzysztof KOLIŃSKI

Majority of modern diesel engines is fitted with common-rail (CR) fuel systems. In these systems, the injectors are supplied with fuel under high pressure from the fuel rail (accumulator). Dynamic changes of pressure in the fuel rail are caused by the phenomena occurring during the fuel injection into the cylinders and the fuel supply to the fuel rail through the high-pressure fuel pump. Any change in this process results in a change in the course of pressure in the fuel rail, which, upon mathematical processing of the fuel pressure signal, allows identification of the malfunction of the pump and the injectors. The paper presents a methodology of diagnosing of CR fuel injection system components based on the analysis of dynamic pressure changes in the fuel rail. In the performed investigations, the authors utilized LabView software and a µDAC data acquisition module recording the fuel pressure in the rail, the fuel injector control current and the signal from the camshaft position sensor. For the analysis of the obtained results, ‘FFT’ and ‘STFT’ were developed in order to detect inoperative injectors based on the curves of pressure in the fuel rail. The performed validation tests have confirmed the possibility of identification of malfunctions in the CR system based on the pressure curves in the fuel rail. The ‘FFT’ method provides more information related to the system itself and accurately shows the structure of the signal, while the ’STFT’ method presents the signal in such a way as to clearly identify the occurrence of the fuel injection. The advantage of the above methods is the accessibility to diagnostic parameters and their non-invasive nature.


Author(s):  
Ripudaman Singh ◽  
Andrew Mansfield ◽  
Margaret Wooldridge

Emissions compliance during engine start-up conditions is a major obstacle for current automotive manufacturers across global markets. The challenges to meeting emissions targets are both due to increasingly stringent regulations and the difficulty in developing control strategies for a high degree-of-freedom and highly non-linear system. Online extremum-seeking (ES) methods offer a promising alternative to traditional optimization based on design-of-experiment based automotive calibration. With extremum-seeking methods, results from all prior experiments are used to intelligently and efficiently generate the next iteration of the control parameter(s). In this work, the applicability of the online extremum-seeking method is explored to optimize five performance variables (injection timing for two injection events, the injection fuel mass divided between the first and second injection events, air-fuel equivalence ratio and exhaust cam timing) to minimize brake specific fuel consumption while imposing different constraints on NOx emissions. The experiments were conducted using a production turbocharged four-cylinder gasoline engine with an advanced fuel injection system. The results show the utility of the ES strategy to quickly identify optimal control parameter combinations and the emissions and engine performance improvements during the calibration process. The results also demonstrate the dramatic benefit of the ES calibration strategy in terms of test time required.


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