scholarly journals FUEL INJECTION PROCESS AT SPEED CHARACTERISTICS OF MEDIUM-SPEED DIESEL ENGINE AT VARIABLE MODES

2020 ◽  
Vol 0 (2) ◽  
pp. 28-37
Author(s):  
Н. В. Слободянюк
2002 ◽  
Vol 8 (5) ◽  
pp. 659-671 ◽  
Author(s):  
Mosaad Mosleh ◽  
Amier Al-Ali

A linear time invariant (LTI) model of a marine diesel engine is presented. The effect of the discontinuity of the fuel injection into the cylinders and the injection period is considered. The proposed discrete model consists of a sampler and zero-order-hold mechanism, representing the fuel injection process. The design of the discrete controller is based on the pole assignment of the characteristic polynomial of the closed-loop transfer function with the goal of achieving zero steady-state error, and satisfying other design specifications. A numerical example illustrating the characteristic performance of a two stroke marine diesel engine is presented.


1992 ◽  
Vol 114 (3) ◽  
pp. 515-521 ◽  
Author(s):  
B. D. Hsu ◽  
G. L. Confer ◽  
Z. J. Shen

In the GE 7FDL single-cylinder research diesel engine, coal-water slurry (CWS) fuel combustion optimization studies were conducted using electronically controlled CWS and pilot accumulator injectors. The most important performance parameters of peak firing pressure, combustion efficiency (coal burnout), and specific fuel comsumption were evaluated in relationship to CWS and pilot injection timing, CWS injector hole size, shape, and number, CWS fuel injection spray angles and injection pressure. Heat release diagrams, as well as exhaust samples (gaseous and particulate), were analyzed for each case. Interesting effects of fuel spray impingement and CWS fuel “Delayed Ignition” were observed. With the engine operating at 2.0 MPa IMEP and 1050 rpm, it was able to obtain over 99.5 percent combustion efficiency while holding the cylinder firing pressure below 17 MPa and thermal efficiency equivalent to diesel fuel operation.


Author(s):  
J A Stephenson ◽  
B A Hood

The paper describes the development of a high-speed direct injection (HSDI) diesel engine suitable for passenger car applications. The evolution from a low emissions medium-speed engine, through a four-cylinder 2.3 litre research engine, into a four-cylinder 2.0 litre production engine is presented. The challenge to the engineer has been to develop the HSDI engine to operate with acceptable noise, emissions, smoke and driveability over the wide speed range (up to 5000 r/min) required for passenger cars. The key element in this task was the optimization of the combustion system and fuel injection equipment. The HSDI is shown to have a significant fuel economy advantage over the prechamber indirect injection (IDI) engine. Future developments of the fuel injection system are described which will further enhance the HSDI engine and provide additional noise and emissions control.


Author(s):  
Girish Parvate-Patil ◽  
Manuel Vasquez ◽  
Malcolm Payne

This paper emphasizes on the effects of different biodiesels and diesel on; heat release, ignition delay, endothermic and exothermic reactions, NOx, fuel injection pressure due to the fuel’s modulus of elasticity and cylinder pressure. Two 100% biodiesel and its blends of 20% with of low sulfur #2 diesel, and #2 diesel are tested on a single cylinder diesel engine under full load condition. Engine performance and emissions data is obtained for 100% and 20% biodiesels blends and #2 diesel. Testes were conducted at Engine Systems Development Centre, Inc. (ESDC) to evaluate the effects of biodiesel and its blends on the performance and emissions of a single-cylinder medium-speed diesel engine. The main objective of this work was to gain initial information and experience about biodiesel for railway application based on which biodiesel and its blends could be recommended for further investigation on actual locomotives.


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


Author(s):  
Gong Chen

The influence of inlet liquid fuel temperature on direct-injection diesel engines can be noticeable and significant. The work in this paper investigates the effects of inlet fuel temperature on fuel-injection in-cylinder combustion, and output performance and emissions of medium-speed diesel engines. An enhanced understanding and simplified modeling of the variations in the main fuel-injection parameters affected by inlet fuel temperature are developed. The study indicates that the main injection parameters affected include the injection timing at the injector end relative to the injection-pump actuation timing, the fuel-injection rate, the fuel-injection duration, and the injection spray atomization. The primary fuel temperature effects on the injection parameters are from the fuel bulk modulus of elasticity and the density with the fuel viscosity less significant as the injector-nozzle flow is usually in a turbulent region. The developed models are able to predict the changes in the injection parameters versus the inlet fuel temperature. As the inlet fuel temperature increases, the nozzle fuel-injection-start timing is predicted to be relatively retarded, the injection rate is reduced, and the needle-lift duration is prolonged from the baseline. The variation trends of the engine outputs and emissions versus fuel temperature are analyzed by considering its consequent effect on in-cylinder combustion processes. It is predicted that raising fuel temperature would result in an increase in each of CO, HC, PM, and smoke emissions, and in a decrease in NOx, and may adversely affect the fuel efficiency for a general type of diesel engine at a full-load condition. The experimental results of the outputs and emissions from testing a medium-speed four-stroke diesel engine agreed with the trends analytically predicted. The understanding and models can be applied to compression-ignition direct-injection liquid fuel engines in general.


2021 ◽  
Vol 236 ◽  
pp. 01026
Author(s):  
Dai Liu ◽  
Yingzhu Guo ◽  
Long Liu ◽  
Qian Xia ◽  
Yong Gui

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.


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