Experimental Study on the Effects of Injector Nozzle and Piston Bowl Geometry on Combustion and Performance in Medium-Speed Diesel Engines

2007 ◽  
Author(s):  
Byong-Seok Kim ◽  
Ki-Doo Kim ◽  
Wook-Hyeon Yoon ◽  
Seung-Hyup Ryu
Keyword(s):  
Engine Performance ◽  
Nox Emission ◽  
Fuel Oil ◽  
Nozzle Geometry ◽  
Fuel Injector ◽  
Oil Consumption ◽  
Piston Bowl ◽  
Injector Nozzle ◽  
Current Limit ◽  
Medium Speed

In recent years, many regulations of exhaust gas emissions have been enhanced in not only automotive engines but also marine and power generation engines. So we have done the various studies to reduce NOx in a medium speed diesel engine, HYUNDAI HiMSEN, for satisfying the next IMO(International Maritime Organization) regulation (Tier2, 20∼30% reduction for current limit). The selected parameters for in this study are fuel injector nozzle and piston bowl geometry. These have significant effect on engine performance and combustion. In this study, engine performance experiments have been carried out to investigate the effects of fuel injector nozzle geometry including the nozzle hole diameter, hole number, hole length, and injection angle on the fuel oil consumption and NOx emission of HYUNDAI HiMSEN engine. Also experiments have been carried out to evaluate engine performance and combustion with changing piston bowl geometry including the diameter and depth of piston bowl. The measured parameters of engine performance include cylinder pressure, fuel pump pressure, injection pressure, and heat release rate and NOx, etc. We could find out the optimum point of the nozzle geometry and the piston bowl shape regarding to the trade-off curve on fuel oil consumption versus NOx emission to minimize fuel oil consumption and to satisfy NOx regulation of HYUNDAI HiMSEN engines.

A Study on the Applicability of Straight Vegetable Oils to Medium Speed Diesel Engines

2009 ◽  
Author(s):  
Hyoung-Keun Park ◽  
Sang-Hak Ghal ◽  
Tae-Hyung Park ◽  
Yong-Hee Ahn ◽  
Sung-Hyeok Kim
Keyword(s):  
Vegetable Oil ◽  
Diesel Engines ◽  
Short Interval ◽  
Injection Pressure ◽  
Acid Number ◽  
Fuel Oil ◽  
Oil Consumption ◽  
Total Acid ◽  
Medium Speed ◽  
Marine Diesel

Straight vegetable oil (SVO) fuels such as palm oil, animal fat oil and waste vegetable oil were tested as fuels in a single-cylinder diesel engine to evaluate applicability to medium-speed diesel engines. Fuel-related properties of the SVO were assessed and compared with conventional marine diesel fuel oil (MDO). The total acid number (TAN) of the SVO fuels changed during a short interval in a drying oven which heated the SVO fuels to 170 degrees Celsius for several weeks. The SVO have not gone rancid any further after reaching limit. And the TAN of the SVO fuels was not related to corrosion of the parts. The SVO fuels needed to be heated to an appropriate temperature to use as fuel of the engine since the SVO fuels are more viscous than conventional diesel fuels. Both the injection period and the injection pressure increased due to low heating values of the SVO fuels. By the same token, fuel oil consumption increased over 10%. The overall exhaust emissions were lower with the SVO fuels, but NOx emission was as much as MDO at the higher loads.

scholarly journals Numerical Analysis of Fuel Injector Nozzle Geometry - Influence on Liquid Fuel Contraction Coefficient and Reynolds Number

2019 ◽  
Vol 57 (1) ◽  
pp. 23-45
Author(s):  
Lino Kocijel ◽  
Vedran Mrzljak ◽  
Maida Čohodar Husić ◽  
Ahmet Čekić
Keyword(s):  
Reynolds Number ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Injection Rate ◽  
Nozzle Diameter ◽  
Nozzle Geometry ◽  
Fuel Injector ◽  
Contraction Coefficient ◽  
Nozzle Length ◽  
Injector Nozzle

This paper investigates the influence of the fuel injector nozzle geometry on the liquid fuel contraction coefficient and Reynolds number. The main three fuel injector nozzle geometry parameters: nozzle diameter (d), nozzle length (l) and nozzle inlet radius (r) have a strong influence on the liquid fuel contraction coefficient and Reynolds number. The variation of the nozzle geometry variables at different liquid fuel pressures, temperatures and injection rates was analyzed. The liquid fuel contraction coefficient and Reynolds number increase with an increase in the nozzle diameter, regardless of the fuel injection rate. An increase in the r/d ratio causes an increase in the fuel contraction coefficient, but the increase is not significant after r/d = 0.1. A nozzle length increase causes a decrease in the fuel contraction coefficient. Increase in the nozzle length of 0.5 mm causes an approximately similar decrease in the contraction coefficient at any fuel pressure and any nozzle length. Fuel injectors should operate with minimal possible nozzle lengths in order to obtain higher fuel contraction coefficients.

scholarly journals Optimization of Marine Medium Speed Diesel Engine Performance based on Multi-Injector System

2021 ◽  
Vol 236 ◽  
pp. 01026
Author(s):  
Dai Liu ◽  
Yingzhu Guo ◽  
Long Liu ◽  
Qian Xia ◽  
Yong Gui
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Fuel Injection ◽  
Engine Performance ◽  
Injection Rate ◽  
Nox Emission ◽  
Spray Angle ◽  
Medium Speed ◽  
Injector System ◽  
Marine Medium

Multi-injector system is potential to improve thermal efficiency and NOx emission of diesel engine at the same time. In order to optimize the combustion and emission of Marine medium speed diesel engine, the engine combustion with a multi-injector system is simulated and analyzed by CFD software Converge. In this research, two injectors are installed at the side of the cylinder head while the central injector is maintained. Various injection directions of side injectors and injection strategies of multi-injector system are simulated to optimize the fuel spray and combustion. The analysis results show that the spray angle of the side injector plays a key role for effective thermal efficiency improvement, since complex spray jet-jet interaction and spray impingement may deteriorate the combustion if the arrangement of spray angle was not set properly. Once the fuel injection direction has been optimized, the fuel ratio of the three injectors is optimized and improved the effective thermal efficiency with lower NOx emission. The results show that the two side injectors could increase the fuel injection rate into the cylinder, leading to high brake power and consequently increased the thermal efficiency by 1.26% and decreased the NOx emission by 16% for the best optimization.

Numerical simulation of cavitating flow in maritime high-pressure direct fuel injection nozzles and assessment of cavitation-erosion damage

2021 ◽  
pp. 146808742110521
Author(s):  
Sherwin Falsafi ◽  
Martin Blume ◽  
Thomas Klaua ◽  
Maximilian Indrich ◽  
Johann Wloka ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Internal Flow ◽  
Fuel Oil ◽  
Nozzle Geometry ◽  
Fuel Injector ◽  
Heavy Fuel Oil ◽  
Flow Solver ◽  
Lower Viscosity ◽  
Nozzle Geometries ◽  
Direct Fuel Injection

The internal flow of Heavy Fuel Oil (HFO) in two maritime direct fuel injector nozzles is studied by 3D flow simulations for the assessment of erosion-sensitive wall regions. The nozzle geometries differ in number, diameter and inclination angle of holes as well as sac wall curvature. Long-term endurance experiments reveal characteristic damage locations for both nozzles. Simulations are performed by a compressible density-based flow solver with a barotropic cavitation model to capture shock wave dynamics. Real geometries and the entire injection cycle with time-dependent rail pressure and transient needle movement are considered. A statistical evaluation of individual collapsing voids in terms of their condensation rate yield an erosion probability that is compared against experimental damage locations. Due to the scatter in the values of viscosity of real fuels a viscosity variation is carried out, which shows that while a lower viscosity leads to a rise of erosion probability, the location of erosion-sensitive wall zones is not significantly changed. The analysis of 3D velocity and void field evolutions motivates the introduction of distinct injection sub-phases of the entire cycle. Erosion probability is separately evaluated within each sub-phase. By this simulation procedure, experimentally found erosion spots are associated with particular sub-phases and can be traced back to characteristic flow and void structures that are linked to particular nozzle geometry features.

Optimization of a Marine Medium-Speed Engine With Multi-Injector System by 1D Predictive Simulation

2021 ◽  
Author(s):  
Dai Liu ◽  
Peng Zhang ◽  
Long Liu ◽  
Qian Xia ◽  
Xiuzhen Ma
Keyword(s):  
Diesel Engine ◽  
Thermal Efficiency ◽  
Engine Performance ◽  
Nox Emission ◽  
Combustion Model ◽  
Injection Timing ◽  
Engine Model ◽  
Medium Speed ◽  
Injector System ◽  
Marine Medium

Abstract The thermal efficiency and emission of large bore marine medium-speed diesel engine are required to be improved under the stringent legislations. A multi-injector system has been proposed in order to improve the thermal efficiency and NOx emission instantaneously. However, application of the multi-injector system increased the complexity of parameter optimization and control. To develop proper control strategy of the novel multi-injector system, a 1D engine model of the original engine configurations was developed initially, including a predictive combustion model in commercial 1D simulation program (GT-Power). After calibrated by test results and literature data under various engine loads, the engine model was modified from a central single injector engine to a multi-injector engine. On the basis of a conventional direct-injection diesel engine, another two injectors were added to the cylinder as side injectors in the model. And the fundamental combustion characteristics and engine performance of the marine medium-speed diesel engine with multi-injector are investigated under various injection quantity ratio between the central injector and side injectors. The effects of injection timing and split injection are also studied by simulation. The result indicated that the effective thermal efficiency and NOx emission of the medium speed marine diesel engine are optimized instantaneously by changing the injection strategies of the central and side injectors. Finally, the preferred injection strategy is proposed by the 1D model.

SFC Benefit With Split Injection in Two-Stroke Diesel Engine

2009 ◽  
Author(s):  
Manoj Gokhale ◽  
Bhaskar Tamma ◽  
Roy J. Primus ◽  
Benzi John
Keyword(s):  
Diesel Engine ◽  
Engine Performance ◽  
System Level ◽  
Injection Timing ◽  
Fuel Injector ◽  
Cfd Model ◽  
Split Injection ◽  
Fuel Savings ◽  
Medium Speed ◽  
Data Calibration

The influence of split-injection on engine performance is studied using system and in-cylinder simulation of a two-stroke medium speed diesel engine. System level models for the engine and fuel system and a multi-dimension CFD model for the combustion chamber were developed and calibrated with experimental data. Calibration of these models from the available test data is discussed and calibration results are presented. The SFC and NOx predictions show good sensitivity to injection timing variation. These calibrated models were then used to simulate split injection through the modification of the fuel injector. Split injection achieved through this modification results in fuel savings while maintaining same NOx levels.

scholarly journals Influence of Combustion Chamber Shapes and Nozzle Geometry on Performance, Emission, and Combustion Characteristics of CRDI Engine Powered with Biodiesel Blends

2021 ◽  
Vol 13 (17) ◽  
pp. 9613 ◽  
Author(s):  
K. M. V. Ravi Teja ◽  
P. Issac Prasad ◽  
K. Vijaya Kumar Reddy ◽  
N. R. Banapurmath ◽  
Manzoore Elahi M. Soudagar ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Fossil Fuels ◽  
Methyl Esters ◽  
Direct Injection ◽  
Engine Performance ◽  
Nozzle Geometry ◽  
Fuel Blends ◽  
Injector Nozzle ◽  
Combustion Duration ◽  
Green Fuels

Environmentally friendly, renewable, and green fuels have many benefits over fossil fuels, particularly regarding energy efficiency, in addition to addressing environmental and socioeconomic problems. As a result, green fuels can be used in transportation and power generating applications. Furthermore, being green can ably address the emission-related issues of global warming. In view of the advantages of renewable fuels, two B20 fuel blends obtained from methyl esters of cashew nutshell (CHNOB), jackfruit seed (JACKFSNOB), and jamun seed oils (JAMSOB) were selected to evaluate the performance of a common rail direct injection (CRDI) engine. Compatibility of the nozzle geometry (NG) and combustion chamber shape (CCS) were optimized for increased engine performance. The optimized CCS matched with an increased number of injector nozzle holes in NG showed reasonably improved brake thermal efficiency (BTE), reduced emissions of smoke, HC, and CO, respectively, while NOx increased. Further combustion parameters, such as ignition delay (ID) and combustion duration (CD) reduced, while peak pressure (PP) and heat release rates (HRR) increased at the optimized injection parameters. The CRDI engine powered with JAMSOB B20 showed an increase in BTE of 4–5%, while a significant reduction in HC and CO emissions was obtained compared to JACKFSNOB B20 and CHNOB B20, with increased NOx.

A Study on NOx Reduction in a Medium Speed Diesel Engine Using a Charge Air Moisturizing Method

2005 ◽  
Author(s):  
Hyoung-Keun Park ◽  
Byong-Seok Kim ◽  
Jin-Won Kim ◽  
Sang-Hak Ghal ◽  
Jong-Kuk Park
Keyword(s):  
Diesel Engine ◽  
Nox Reduction ◽  
Flame Temperature ◽  
Combustion Process ◽  
Reduction Rate ◽  
Fuel Oil ◽  
Gas Temperature ◽  
Oil Consumption ◽  
Medium Speed ◽  
A Charge

NOx forms during a combustion process and contributes to ozone, smog, acid rain, eutrophic soil, etc. The use of water to prevent NOx formation during the combustion process is well known. Adding water to the combustion process reduces the flame temperature by increasing the specific heat capacity of charge air. Moisturizing a charge air is one of the most effective methods to add water to the combustion process. In this study, the characteristics of charge air moisturizing method were evaluated on cylinder pressure, heat release rate, exhaust gas temperature, specific fuel oil consumption, NOx reduction rate, etc., using the medium speed diesel engine with a single cylinder.

Advanced Fuel Injection System Using a Supercavitating Fuel Injector

2015 ◽  
Author(s):  
John M. Gattoni ◽  
David M. Sykes ◽  
Paul E. Yelvington
Keyword(s):  
Droplet Size ◽  
High Speed ◽  
Fuel Injection ◽  
Injection System ◽  
Nozzle Geometry ◽  
Fuel Injection System ◽  
Fuel Injector ◽  
Penetration Length ◽  
Injector Nozzle ◽  
Fuel Delivery

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.

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