scholarly journals Effect of the In-Cylinder Back Pressure on the Injection Process and Fuel Flow Characteristics in a Common-Rail Diesel Injector Using GTL Fuel

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 452
Author(s):  
Luka Lešnik ◽  
Breda Kegl ◽  
Eloísa Torres-Jiménez ◽  
Fernando Cruz-Peragón ◽  
Carmen Mata ◽  
...  

The presented paper aims to study the influence of mineral diesel fuel and synthetic Gas-To-Liquid fuel (GTL) on the injection process, fuel flow conditions, and cavitation formation in a modern common-rail injector. First, the influence on injection characteristics was studied experimentally using an injection system test bench, and numerically using the one-dimensional computational program. Afterward, the influence of fuel properties on internal fuel flow was studied numerically using a computational program. The flow inside the injector was considered as multiphase flow and was calculated through unsteady Computational Fluid Dynamics simulations using a Eulerian–Eulerian two-fluid approach. Finally, the influence of in-cylinder back pressure on the internal nozzle flow was studied at three distinctive back pressures. The obtained numerical results for injection characteristics show good agreement with the experimental ones. The results of 3D simulations indicate that differences in fuel properties influence internal fuel flow and cavitation inception. The location of cavitation formation is the same for both fuels. The cavitation formation is triggered regardless of fuel properties. The size of the cavitation area is influenced by fuel properties and also from in-cylinder back pressure. Higher values of back pressure induce smaller areas of cavitation and vice versa. Comparing the conditions at injection hole exit, diesel fuel proved slightly higher average mass flow rate and velocities, which can be attributed to differences in fluid densities and viscosities. Overall, the obtained results indicate that when considering the injection process and internal nozzle flow, GTL fuel can be used in common-rail injection systems with solenoid injectors.

Author(s):  
Michela Costa ◽  
Bianca M. Vaglieco ◽  
Felice E. Corcione ◽  
Hiroshi Omote

Present paper couples the use of a modified version of the KIVA-3V code including a model for detailed chemistry to an experimental investigation performed on an optically accessible diesel engine. The engine is equipped with a commercial four valves cylinder head and a Common Rail injection system. Digital images and UV-visible flame emission measurements are compared with the visualization of the numerical results. The diesel fuel surrogate is considered within the numerical code, namely a blend consisting of n-heptane and toluene, approximating the physical and ignition properties of the diesel oil. Products, soot and NOx formation is described by a chain of 283 reactions involving 69 species. The Partially Stirred Reactor (PaSR) assumption is adopted to maintain the computational cost within acceptable limits. The collections of digital images of the spray evolution, the mixture formation and the combustion processes are undertaken by running the engine at 1000 rpm. Commercial diesel fuel is injected by using a single injection.


Author(s):  
Ibrahim Najar ◽  
Bert Buchholz ◽  
Benjamin Stengel ◽  
Christian Fink ◽  
Egon Hassel

The present paper deals with the influence of fuel properties on the spray behaviour. This influence was studiedexperimentally using a common rail injection system from a medium speed diesel engine. The experiments have been performed with diesel fuel (EN-590) and heavy fuel oil (RMG 180) on a constant volume chamber at room temperature. Comparison of the spray characteristics shows that the heavy fuel oil penetrates deeper in the chamber. However, the diesel spray has a bigger cone angle. These results formed the basis for a further development of the 1D-model [1] to predict the spray penetration by considering the fuel properties and temperature.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4787


2012 ◽  
Vol 151 (4) ◽  
pp. 72-76
Author(s):  
Leszek PIASECZNY ◽  
Mirosław WALKOWSKI

Injection Systems of Common Rail type are becoming widely used in marine engines. The aim of the research and development of these systems is to optimize the multi-injection process. The authors of the paper present the results of research on the fuel supply system of research common-rail marine medium-speed engine. The study was conducted for the nominal circulation engine speed. For the analysis were established three variants of fuel supply – a single dose, two-piece and three-piece The interdependence of measured injection parameters and their effect on engine operation have been presented in graphical form.


Author(s):  
O. Chiavola ◽  
F. Palmieri ◽  
G. Chiatti

A model for the analysis of diesel engine common rail injection system has been developed and the influence that different fuels have on the injection performances has been investigated. Diesel fuel, biodiesel and kerosene have been used and the differences of injection flow rate, injection pressure time trace, nozzle flow features and break up mechanism have been highlighted. The coupling of two different codes has been used in the simulations: the former one, AMESim code, has been adopted to model the common rail system and to investigate the fuel flow rate and the injection pressure dependence on the fuel type. The latter computational tool, FIRE code, has been initialized by means of the results obtained from the injection system simulation and has been used to perform the 3D investigation of the internal nozzle flow and of the spray formation phenomena, aimed at evaluating the effect of physical fuel features on local flow characteristics and their influence on the system performances. Details of the adopted modeling strategy are described and results of each simulation step are presented.


2020 ◽  
Vol 10 (2) ◽  
pp. 549
Author(s):  
Sang-Wook Han ◽  
Yun-Sub Shin ◽  
Hyun-Chul Kim ◽  
Gee-Soo Lee

In this paper, a nozzle flow model was used to design an injector nozzle and obtain initial spray conditions for the dimethyl ether (DME) common rail-injection system. In order to deliver the same amount of energy as that provided by diesel at a low injection pressure of 50 MPa, the injector for DME needs nozzle holes with larger diameters and a higher SAC volume for the same injection duration. In addition, the needle lift and needle seat diameter should be increased to maintain a minimum flow area ratio. Although the vapour pressure and maximum injection pressure of DME are lower than those of diesel, the nozzle in a DME system showed higher discharge coefficients and effective nozzle exit diameters for the same injection duration owing to low kinematic viscosity. However, because the maximum injection pressure in DME is lower than that with diesel, and the length of the cavitation region is narrower.


2014 ◽  
Vol 681 ◽  
pp. 19-22
Author(s):  
Hayat Qaisar ◽  
Li Yun Fan ◽  
En Zhe Song ◽  
Xiu Zhen Ma ◽  
Bing Qi Tian ◽  
...  

High pressure (HP) fuel pipeline is one of the vital components of Combination Electronic Unit Pump (CEUP) fuel injection system besides pump and injector. Effect of four key fuel properties including density, viscosity, acoustic wave speed and bulk modulus on pressure wave profile has been investigated using a 1D viscous damped mathematical model. Wave equation (WE) based mathematical model has been developed in MATLAB using finite difference method. Dynamic variations of these fuel properties during fuel injection cycles have also been incorporated in mathematical model by utilizing empirical formulas. The results show that these four key fuel properties not only vary with the pressure during fuel injection process but also define the trend of pressure wave propagation inside HP fuel pipeline.


Transport ◽  
2015 ◽  
Vol 31 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Raimondas Kreivaitis

This paper presents a comparative experimental study for determining the effect of ethanol on functionality of a high pressure pump of the common rail fuel injection system. For experimental durability tests were prepared two identical fuel injection systems, which were mounted on a test bed for a fuel injection pump. One of the fuel injection systems was feed with diesel fuel; other fuel injection system was fuelled with ethanol–diesel fuel blend. A blend with 12% v/v ethanol and 88% v/v diesel fuel and low sulphur diesel fuel as a reference fuel were used in this study. To determine the effect of ethanol on the durability of the high pressure pump total fuel delivery performance and surface roughness of pump element were measured prior and after the test. Results show that the use of the ethanol–diesel blend tested produced a negative effect on the durability of the high pressure fuel pump. The wear of plungers and barrels when using ethanol–diesel fuel blend caused a decrease in fuel delivery up to 30% after 100 h of operation.


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