Optimization of High Pressure Direct Injection Micro-Pilot As a Retrofit Technology for Conventional Dual Fuel Engines

Author(s):  
Greg Beshouri ◽  
Gerry Fischer

Abstract In the late 1980’s Enterprise Engine Company performed a single cylinder test of micro-pilot high pressure direct injection as a retrofit technology for conventional dual fuel engines. While that testing demonstrated a number of benefits for this technology, non-technical considerations led to the use of low pressure Pre-Combustion Chamber (PCC) micro-pilot technology as the retrofit technology instead. Thirty years later, when the automotive components of the PCC micro-pilot system were no longer available, the opportunity again arose to test the capabilities of an off the shelf high pressure direct injection micro-pilot system as a retrofit technology for a conventional dual fuel engine. Single cylinder and full engine testing of the high pressure direct injection micro-pilot injection confirmed the results of the 1980’s testing. The test results also corroborated modern analytical and experimental testing of high pressure pilot technology. In particular, the interaction between the diesel pilot and primary fuel gas charge is very complex and sometimes counterintuitive. Likewise performance optimization requires careful balance of injection timing, injection quantity and fuel gas air/fuel ratio. Even then, exhaust gas methane emissions remain counterintuitive. This paper reviews modern single cylinder and full engine test results focusing on optimization parameters for high pressure direct injection micro-pilot for retrofit and new engine applications.

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Hal Gurgenci ◽  
Saiied M. Aminossadati

A scope study is conducted to investigate the technical and commercial feasibility of converting existing mine haul truck engines to a fuel regime of methane and diesel. A dual fuel engine with two technology options of homogeneous gas charge and high pressure direct injection are considered. The results of this study show that cost reduction is only possible when methane is available at a cost saving that compensates for the expense of building a new fuel infrastructure, and a clean combustion is expected. In contrast to diesel-only engines, particulate emissions in dual fuel engines are less. However, unburned methane in the exhaust gases or significant methane leakage must be seriously taken into consideration for replacing diesel with methane. This scope study argues that the dual fuel operation with HGC/CNG technology is expected to be feasible even at a relatively small truck fleet size.


2019 ◽  
Vol 895 ◽  
pp. 109-114 ◽  
Author(s):  
C. Jagadish ◽  
Gumtapure Veershetty

The aim of this work is to examine the performance, combustion as well as emission characteristics of diesel engine performed for various mixtures of methane-enriched biogas (95% CH4). Experiments were performed on a single cylinder, four-stroke constant speed, direct injection, water-cooled diesel engine. The engine is operated by means of dual fuel mode using diesel and different mixtures of methane-enriched biogas (BG) like BG10, BG20, BG30, and BG40 mixed with the air (i.e. BG40-40% of CH4 by volume respectively) for different loads and at injection timing of 27.5° before top dead centre (bTDC). The performance, combustion and emission characteristics of the engine operated by dual fuel mode were experimentally analyzed, and compared with respect to diesel mode. The experimental result reveals that better performance and lower emissions were observed for BG40 compared to other mixtures. The brake thermal efficiency of BG40 is lower by 2.43% compared to diesel at full load. The cylinder peak pressure for dual fuel mode is higher by 6.55% when compared with diesel mode. NOx emission reduced by 2.6 % and CO emission increased by 3.3% compared to diesel at full load respectively. Keywords: Biogas, Energy, Combustion, Emission, Injection timing, dual fuel mode


Author(s):  
Won Geun Lee ◽  
David Montgomery

High Pressure Direct-Injection (HPDI) is a technology option for engines used in mobile equipment applications where use of LNG as a fuel is desired. Using the combination of a diesel pilot injection and direct gas injection, HPDI has the potential to deliver low emissions, excellent transient performance, high efficiency, and high gas substitution. When the HPDI program was initially undertaken, in order to aid in initial hardware design, 3-dimensional computational fluid dynamic modeling was conducted to understand the mixing and reaction processes in the combustion chamber of an HPDI engine. Gaining insight into qualitative trends of operation parameters and hardware configurations was a first critical step toward delivering a hardware set to demonstrate HPDI natural gas combustion system capabilities. To model the combustion of multi-component fuel at arbitrary constituent ratios, a combustion model based on a detailed chemical kinetics approach was employed. Several published mechanisms and combinations of established mechanisms were tested by comparing results with existing fumigated dual fuel engine results. The result shows that some of combined mechanisms for n-heptane combustion and methane combustion are capable of adequately predicting combustion behavior in diesel-natural gas dual fuel combustion systems. One of the reduced n-heptane mechanisms (by Patel et al.) also matched dual fuel combustion results reasonably well. This preliminary simulation study was conducted with typical trapped air conditions and fuel quantities matching the energy delivery for a 100 % load condition in existing DI diesel engines. A full 360-degree mesh at intake valve closing was constructed and a detailed geometry of the gas injector nozzle and sac area was modeled in locally refined grids using a Caterpillar proprietary CFD code that accepts industry standard mechanisms. The diesel pilot injection followed by gas injection and resulting combustion inside an HPDI engine was simulated from IVC through the compression and combustion strokes. The operating parameters — such as diesel pilot injection timing, pilot injection amount, and start of gas injection — were varied, and the effect on IMEP, NOx, CO and cylinder pressure were investigated. It was shown that the start of gas injection is the strongest parameter for control of combustion. Subsequent to the work discussed in this paper, the hardware configuration established as optimal during the modeling work was carried forward to the physical engine testing and was successful in delivering the performance and emissions goals without modification, demonstrating the accuracy and value of modern combustion modeling.


2008 ◽  
Vol 12 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Kapilan Nadar ◽  
Pratap Reddy ◽  
Rao Anjuri

In this work, an experimental work was carried out to compare the performance of biodiesels made from non edible mahua oil and edible gingili oil in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas was used as primary fuel. Biodiesel was prepared by transesterification process and mahua oil methyl ester (MOME) and gingili oil methyl ester (GOME) were used as pilot fuels. The viscosity of MOME is slightly higher than GOME. The dual fuel engine runs smoothly with MOME and GOME. The test results show that the performance of the MOME is close to GOME, at the pilot fuel quantity of 0.45 kg/h and at the advanced injection timing of 30 deg bTDC. Also it is observed that the smoke, carbon monoxide and unburnt hydro carbon emissions of GOME lower than the MOME. But the GOME results in slightly higher NOx emissions. From the experimental results it is concluded that the biodiesel made from mahua oil can be used as a substitute for diesel in dual fuel engine.


Fuel ◽  
2020 ◽  
Vol 277 ◽  
pp. 117932 ◽  
Author(s):  
Yabin Dong ◽  
Ossi Kaario ◽  
Ghulam Hassan ◽  
Olli Ranta ◽  
Martti Larmi ◽  
...  

1991 ◽  
Vol 113 (3) ◽  
pp. 390-398 ◽  
Author(s):  
G. M. Beshouri

The world-wide consolidation of many engine manufacturers, along with the relatively low production rate of new engines, has resulted in a significant reduction in the facilities, engines, and personnel available for conducting full-engine laboratory quality tests against calibrated dynamometers. Concurrently, the continued pressure for further reduction in exhaust emissions, along with improvements in fuel consumption, has created a growing aftermarket for the retrofit/upgrade of new technologies requiring further engine development. Regrettably, the prohibitive cost and capital investment associated with full engine tests, along with the lack of facilities, makes such tests prohibitive. Therefore, a number of new experimental techniques and associated analysis methods have been developed for conducting laboratory quality single-cylinder tests on commercial engines without interfering with their profitable operation. Such tests have been successfully conducted on both spark-ignited and dual fuel engines. Many details of the methods utilized, along with estimations of their accuracy and reliability, are described.


2013 ◽  
Vol 388 ◽  
pp. 217-222
Author(s):  
Mohamed Mustafa Ali ◽  
Sabir Mohamed Salih

Compression Ignition Diesel Engine use Diesel as conventional fuel. This has proven to be the most economical source of prime mover in medium and heavy duty loads for both stationary and mobile applications. Performance enhancements have been implemented to optimize fuel consumption and increase thermal efficiency as well as lowering exhaust emissions on these engines. Recently dual fueling of Diesel engines has been found one of the means to achieve these goals. Different types of fuels are tried to displace some of the diesel fuel consumption. This study is made to identify the most favorable conditions for dual fuel mode of operation using Diesel as main fuel and Gasoline as a combustion improver. A single cylinder naturally aspirated air cooled 0.4 liter direct injection diesel engine is used. Diesel is injected by the normal fuel injection system, while Gasoline is carbureted with air using a simple single jet carburetor mounted at the air intake. The engine has been operated at constant speed of 3000 rpm and the load was varied. Different Gasoline to air mixture strengths investigated, and diesel injection timing is also varied. The optimum setting of the engine has been defined which increased the thermal efficiency, reduced the NOx % and HC%.


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