scholarly journals MATHEMATICAL MODELLING OF INDICATIVE PROCESS PARAMETERS OF DUAL-FUEL ENGINES WITH CONVENTIONAL FUEL INJECTION SYSTEM

Transport ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Sergejus Lebedevas ◽  
Saugirdas Pukalskas ◽  
Vygintas Daukšys

Modern engine research uses multi-dimensional Mathematical Models (MMs) that are applicable to multi-fuel engines. However, their use involves the availability of detailed technical data on the design and characteristics of the engine, which is not always possible. The use of a one-dimensional MM is more expedient for the prediction of engine parameters, but their application for this purpose has not yet been sufficiently investigated. This publication presents the results of numerical studies evaluating the application of a one-dimensional MM with bi-phase Vibe combustion laws for dual-fuel (DF) Diesel (D) and Natural Gas (NG) engine power parameters. The motor test results of a high-speed 4ČN79.5/95.5 Diesel Engine (DE) with a conventional fuel injection system were used as adequacy criteria. The engines were operated with D100 and DF D20/NG80, in high- (HLM), medium- (MLM), and low- (LLM) load modes, and the angle of Diesel-fuel Injection Timing (DIT) was changed from −1 to −13 °CA in the Before Top Dead Center (BTDC) range. Modelling of the single-phase Vibe combustion law has limited applicability for efficient use only in HLM (with an error of 7%). In the MLM and LLM regimes, owing to non-compliance with real bi-phasic combustion with a strongly extended NG diffusive second phase, the modelling error is 50%. Individual MM matching in MLM and LLM in a DF D20/NG80 experiment detected a burn time increase from between 45 and 50 °CA, to 110 and 200 °CA, respectively. Limited use of the one-dimensional MM in the evaluation of DF engine performance has been identified. When comparing a one-dimensional MM with experimental data, a bi-phase law of heat release characteristic should be considered for better coincidence. In addition, individual MM matching with an experiment on each engine load mode ensured acceptable accuracy in testing and optimising the parameters of the indicator process, including DIT.

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2413 ◽  
Author(s):  
Lebedevas ◽  
Pukalskas ◽  
Daukšys ◽  
Rimkus ◽  
Melaika ◽  
...  

This paper presents a study on the energy efficiency and emissions of a converted high-revolution bore 79.5 mm/stroke 95 mm engine with a conventional fuel injection system for operation with dual fuel feed: diesel (D) and natural gas (NG). The part of NG energy increase in the dual fuel is related to a significant deterioration in energy efficiency (ηi), particularly when engine operation is in low load modes and was determined to be below 40% of maximum continuous rating. The effectiveness of the D injection timing optimisation was established in high engine load modes within the range of a co-combustion ratio of NG ≤ 0.4: with an increase in ηi, compared to D, the emissions of NOx+ HC decreased by 15% to 25%, while those of CO2 decreased by 8% to 16%; the six-fold CO emission increase, up to 6 g/kWh, was unregulated. By referencing the indicated process characteristics of the established NG phase elongation in the expansion stroke, the combustion time increase as well as the associated decrease in the cylinder excess air ratio (α) are possible reasons for the increase in the incomplete combustion product emission.


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

1932 ◽  
Vol 36 (261) ◽  
pp. 733-787 ◽  
Author(s):  
C. B. Dicksee

In this paper the author does not propose to deal with any particular form or type of engine or fuel-injection system, but to discuss some of the problems which are encountered when engaged on the development of a high-speed compression-ignition engine.The main problems to be solved consist in devising suitable means for utilising to the fullest possible extent the oxygen available within the cylinder and for avoiding the production of smoke and noise and, in so far as it is connected with combustion conditions, smell.


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%.


Author(s):  
A. K. Kathpal ◽  
Anirudh Gautam ◽  
Avinash Kumar Agarwal ◽  
R. Baskaran

The diesel fuel-injection system of ALCO DLW 251 engine consists of single cylinder injection pumps, delivery pipes, and fuel injector nozzles. Fuel injection into the combustion chamber through multi-hole nozzles delivers designed power and fuel efficiency. The two most important variables in a fuel injection system of a diesel engine are the injection pressure and injection timing. Proper timing of the injection process is essential for satisfactory diesel engine operation and performance. Injection timing needs to be optimised for an engine based on requirements of power, fuel economy, mechanical and thermal loading limitations, smoke and emissions etc. Since each of these requirements varies with the operating conditions, sometimes contrary to the requirements of the other parameters, the map of optimised injection timing can be very complex. The ALCO DLW 251 engine’s fuel injection pump is jerk type to permit accurate metering and timing of the fuel injected. The pump has a ported barrel and constant-stroke plunger incorporating a bottom helix for fuel delivery control with constant injection timing. From the point of view of good power and fuel economy, combustion should take place so that the peak firing pressure occurs at about 10–15° after TDC and is usually a few degrees after combustion starts. For this to happen, fuel should be injected at an appropriate time, depending on Injection delay and Ignition delay. Both these factors are dependent on the speed and load. Changing the operating point of the engine may change either one or both types of delay, altering the moment of start of combustion. Various researchers have shown that both the Injection and the Ignition delay are reduced as the engine speed is decreased resulting in advancement of injection timing at lower speeds (and loads). This condition will be corrected by varying the static injection timing, which can be achieved by providing a modified helix on the plunger to delay the start of fuel injection, for the lower speeds and loads. A new double helix (upper and lower helix) fuel injection pump for the ALCO DLW 251 16 V engine has been designed. The new fuel injection pump has been tested on the engine test cell at Research Designs & Standards Organisation and has shown an improvement of 1.2% in locomotive duty cycle fuel consumption. This paper describes the design & development of double helix fuel injection pump and discusses the engine tests completed to verify the projected improvements in fuel efficiency.


1991 ◽  
Author(s):  
Michael M. Schechter ◽  
Eugene H. Jary ◽  
Michael B. Levin

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