Oxidation of Ferrous Alloys and Coatings Under Isothermal, Impulse Heating, and Diesel Engine Operation: Part II—MCrAlY Coatings for Protection of 4140 Steel

Oxidation of Ferrous Alloys and Coatings Under Isothermal, Impulse Heating, and Diesel Engine Operation: Part I—4140 Steel

The object of research is the process of operation of marine diesel engines using biodiesel fuel. The subject of research is the process of experimental determination of the optimal concentration of biodiesel fuel in a mixture with fuel of petroleum origin. At the same time, a simultaneous maximum increase in environmental and minimum decrease in the economic parameters of the operation of a marine diesel engine should be ensured. The studies were carried out on Hyundai Heavy Industries 5H17/28 marine diesel engines. Three such diesel engines were part of the power plant of a specialized marine ship with deadweight of 9600 tons. The study was aimed at determining the concentration of biofuel in a mixture with diesel fuel, which provides the best environmental performance of a diesel engine. The fuel supply circuit to the first diesel did not change and the diesel was operated on RMB30 fuel. Two other diesel engines were operated on a fuel mixture – RMB30 fuel and B99.9 FAME biofuel. The content of biofuel in the mixture varied in the range of 5–20 %. The main quantities measured during the experiment were the concentration of nitrogen oxides and the volumetric content of carbon monoxide in the exhaust gases, as well as the specific effective fuel consumption. By switching groups of consumers, the operation of diesel engines was carried out at the same load, the support of which was required during the experiment. The load on diesel engines during the experiments varied in the range of 55–85 % of the nominal value. The operation of diesel engines in each of the studied modes was carried out for at least 1.5–2 hours, during which the main parameters were measured and the obtained values were averaged. It has been established that the use of biofuel increases the environmental friendliness of the marine diesel engine: – by 7.6–26.61 % (depending on the diesel loading and the content of biofuel in the fuel mixture), the emission of nitrogen oxides with exhaust gases is reduced; – by 3.8–23.6 % (depending on diesel loading and biofuel content in the fuel mixture) reduces the emission of carbon oxides with exhaust gases. It has been also determined that when using biofuel, there is an increase in the specific effective fuel consumption by 0.5–8.65 %, which reduces the efficiency of a diesel engine. The optimal composition of the fuel mixture containing biofuel is proposed to be determined experimentally for each diesel load, taking into account its environmental and economic indicators.

The diesel engine combustion process is mainly controlled by the fuel injection characteristics, which will have a direct impact on the performance of the diesel engine, more flexible injection strategy is the development direction of high pressure common-rail system. In order to obtain the change law of the performance of extra-high pressure common-rail diesel engine under variable injection strategy, and improve the overall performance of diesel engine, the effect of different post-injection parameters on the performance of diesel engine was studied on a self-designed extra-high pressure common-rail diesel engine experiment bench, and the relevant results were discussed and analyzed. The results show that: with the rise of post-injection fuel quantity, NOx concentration and soot concentration decrease gradually, and with the rise of post-injection interval angle, NOx concentration decreases gradually, while soot concentration first decreases and then increases. Therefore, choosing post-injection fuel quantity and post-injection interval angle rationally can achieve lower NOx and soot emission at the same time. Meanwhile, with the rise of post-injection fuel quantity or post-injection interval angle, the fuel consumption rate presents an increasing trend.

Advances in diesel–alcohol blends and their effects on the performance and emissions of diesel engines

In order to improve the performance of a mini-type air-cooled diesel engine in terms of the overall efficiency and engine emissions, a swirl chamber of a variable cross-section dual-channel model was developed. This study proposed nine turbulent swirl chambers with a variable cross-section for a dual-channel combustion solution, which applied a dual-channel cross-section to the insert between the original swirl chamber and the main chamber. Model-based design, simulation and experiments were applied as a feasible approach to address this issue to find out the influence of the dual-channel inclination angle and divergence angle on the swirl rate in the swirl chamber, the power and the emissions performance, including the fuel efficiency. By comparing the tests, the performance of the diesel engine with a variable cross-section dual-channel swirl chamber was superior to the original one with a single channel in terms of the swirl rate, fuel consumption rate and emissions.

Local types of fuels occupy 33.6% in the fuel balance of the Kirov region. The share of consumption of local fuels in the region is one of the highest in Russia.
 The Vyatka State University (VyatSU) in cooperation with the Belarusian State Agricultural Academy (BSAA) carry out the tests of the operation of automotive diesel engines on fuels with rapeseed oil (RO) and ethanol (E) additives, and spark internal combustion engines with generator gas (GG) additives. A new area of work of the scientific school is the study of the use of multicomponent compositions of biofuel compositions (MKBTK-15 and MKBTK-25). The use of such compositions as a fuel compensates some of their distinctive properties for further use in internal combustion engines without changing the design and adjustments.
 The use of alternative fuels (AF) in internal combustion engines is a main topic for research. However, the use of any AF requires that the environmental indicators of the engine remain within acceptable limits. An important task is to determine the dependences of the emissions of toxic components on the load.
 The use of MKBTK-15 and MKBTK-25 as AF for engines will improve the environmental situation in the region and reduce the need for commercial fuel. The operation of a diesel engine on multicomponent biofuel compositions makes it possible to reduce the smoke content of exhaust gases by 65% and 85%, the content of total nitrogen oxides remains at the same level or slightly decreases.
 There is a slight increase in the content of carbon dioxide СО2 up to 22.3%, but the solutions to this problem are already known. One of the ways is to preserve and increase boreal forests, which have great potential for absorbing greenhouse gases.

Shape of combustion chamber plays a major role in controlling combustion process and emission characteristics occurring inside internal combustion engines in general and diesel engines in particular. To optimize a combustion chamber for diesel engine applications, suitable design modifications are required that meet both emission norms as well as acceptable engine performance. In this context, experimental investigations were carried out on a single cylinder four stroke direct injection diesel engine operated in single fuel mode using Mahua oil methyl ester (MhOME) and neem oil methyl ester (NOME). Different combustion chamber shapes were designed and fabricated keeping the compression ratio same for the existing diesel engine. The existing engine was provided with hemispherical combustion chamber (HCC) shape. In order to study the effect of other combustion chamber shapes on the performance of diesel engine, cylindrical (CCC), trapezoidal (TrCC), and toroidal combustion chamber (TCC) shapes were designed and developed. Various engine parameters such as power, torque, fuel consumption, and exhaust temperature, combustion parameters such as heat release rate, ignition delay, combustion duration, and exhaust emissions such as smoke opacity, hydrocarbon, CO, and NOx, were measured. Results revealed that the TCC shape resulted in overall improved performance with reduced emission levels compared to other shapes tested. Total hydrocarbon emission (THC) and carbon monoxide (CO) were also decreased significantly compared to other combustion chambers.

Structure parameters of diesel engine spray system have decisive effects on its performance. The paper studies the effects of 8 sets of nozzles with different structure parameters on performance of diesel engine with the purpose to realize high-efficiency, low-emission and low-noise combustion process in diesel engine, based on requirements and characteristics of performance optimization of DI diesel engine, thus realizing optimum design of nozzle structure parameters for high pressure common rail diesel engine.

Turbocharger matching is a rather difficult task during design of highly rated diesel engines, especially for marine application. The sequential turbocharging (STC) technique is used to improve the performance of highly rated diesel engines in particular at part loads, the paper introduces the working principle of the sequential turbocharging system. To improve the performance of the TBD234V12 diesel engine, a STC system of four turbochargers and two unequal turbochargers for the diesel engine was designed. Experimental research was done on this improved marine diesel engine. Then, a 3-phase STC system is presented by analyzing and comparing the test result and the switching boundary of this system is confirmed. The test results show that the part-load performance is improved obviously by using of four turbochargers and two unequal turbochargers STC system.

Methanol fumigation in compression-ignition engines: A critical review of recent academic and technological developments

Effect of alumina nanoparticles as additive with diesel–biodiesel blends on performance and emission characteristic of a six-cylinder diesel engine using response surface methodology (RSM)

Improving the parameters of diesel engines is an urgent task. Work has been carried out to significantly reduce the consumption of their fuel with the introduction of water dispersions into the fuel. Currently, water-fuel emulsions with exotic emulsifiers are mainly tested. (Research purpose) The research purpose is in creation of a water-fuel emulsion without an emulsifier with a simple installation and identifying the influence of the composition and quality of this WFE on the performance of the YaMZ-236 diesel engine. (Materials and methods) The article presents a plant for the preparation of a "rough" water- fuel mixture from diesel fuel according to GOST 32511-2013 and distilled water according to GOST 6709. Authors conducted standard bench tests at the KI-5540- GOSNITI stand with a YaMZ-236 diesel engine with an upgraded fuel system and performed the control of the smoke content of the exhaust gases with the gas analyzer "AUTOTEST". The dependence of diesel performance indicators on the composition and dispersion of water-fuel emulsions without an emulsifier was studied experimentally with a minimum number of tests, but with the maximum possible combination of the values of three variable factors. (Results and discussion) The influence of various water-fuel emulsions on the performance of the diesel engine was evaluated according to the plan of a full factor experiment, including 20 tests. The second-order regression equations were obtained by mathematical processing of the test results. The feasibility of using water-fuel emulsions for diesel engines was confirmed. By modeling a water-fuel mixture without emulsifiers, there was created an aqueous dispersion with drops up to two micrometers. In the load tests of the diesel engine with it, there was noticed an improvement in its performance. (Conclusions) The introduction of 17-20 percent water dispersion with drops of up to two micrometers into diesel fuel reduced the specific fuel consumption by 18 percent, the smokiness in the K indicator by 20- 22, and in the N indicator by 30-35 percent.

Present work is focused on experimental investigation of performance, combustion and emission of DI diesel engine using Simarouba Oil Methyl Ester (SuOME). Control of combustion process in order to achieve better performance with reduced emission has been achieved by varying the shape of combustion chamber. In order to study the effect of shapes of different combustion chambers on performance of diesel engine, Toroidal Re-entrant Combustion Chamber (TRCC), Lateral Swirl Combustion Chamber (LSCC), Dual Swirl Combustion Chamber (DSCC) and Lateral Dual Swirl Combustion Chamber (LDSCC) were developed without changing compression ratio of standard diesel engine. Experiments were carried out using optimum injection timing of 27°bTDC, injector opening pressure of 240 bar and nozzle geometry of 6 holes with 0.2 mm diameter. Results of DI diesel engine operated with SuOME revealed that the LSDCC shape resulted in improved engine brake thermal efficiency with minimum HC and CO emission levels compared to other selected combustion chamber shapes.

<div class="section abstract"><div class="htmlview paragraph">This study’s objective is to examine the combustion and performance of mosambi waste peel biodiesel (MWPB) combined with butylated hydroxytoluene (BHT) nanoparticles as a substitute fuel for diesel engines. It also aims to assess the impact of this blend on engine combustion, such as in-cylinder pressure, heat release rate (HRR), ignition delay (ID), combustion duration (CD) and mass fraction burnt (MFB) and performance indicators, including brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), engine torque, exhaust gas temperature (EGT), indicated mean effective pressure (IMEP), air-fuel ratio (A/F ratio) and volumetric efficiency, while also considering the feasibility of employing waste materials in fuel generation. The experimental configuration utilized a research diesel engine functioning under standard conditions, emphasizing the maintenance of uniform injection pressure to ensure optimal fuel atomization and combustion. The test fuels are diesel, MWPB, MWPB+10 μm BHT 10 ppm and MWPB+20 μm BHT 10 ppm mixtures were utilized, and essential performance metrics were assessed. The results showed that incorporating BHT nanoparticles enhances the combustion properties of the MWPB mixes. The in-cylinder pressure increased in MWPB, and HRR increased in MWPB+20 μm BHT 10 ppm blend compared to diesel, but the diesel fuel has a higher ID, CD and MFB than other test fuels. Also, findings indicate an increase in BTE and a reduction in BSEC relative to pure diesel fuel. Furthermore, diesel fuel has higher engine torque, IMEP, A/F ratio and volumetric efficiency than other test fuels, but MWPB has higher EGT than diesel. The research suggests that biodiesel derived from mosambi peel, combined with BHT nanoparticles, is a feasible alternative to traditional diesel fuel, providing improved combustion efficiency and decreased energy usage. This study underscores the potential of agricultural waste for biodiesel generation. It enlightens the significant role of additives such as BHT in enhancing fuel performance and sustainability in diesel engines.</div></div>

Effects of altitude and fuel oxygen content on the performance of a high pressure common rail diesel engine