Evaluation of the Oxidation Reactivity and Behavior of Exhaust Soot Particles from Diesel Engines with Different Emission Levels

The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel engines.PM samples from two diesel engines(1K,CY4102)with different emission levels were collected by a thermophoretic system and a quartz filter.The oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman spectroscopy.The results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic C—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel soot.Based on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation process.Surface oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal oxidation.Internal oxidation mode of soot particles from the 1K engine was significantly higher than that of CY4102.

Electronically Controlling the System of Preheating Intake Air by Flame for Diesel Engine Cold-Start

In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.

Performance, Combustion and Emission Characteristics of Oxygenated Diesel in DI Engines: A Critical Review

The transition from non-renewable to renewable energy sources is a significant challenge of our time. In the fuel industry, oxygenated additives such as butanol are transforming conventional fuels into renewable biofuels. This technology has been utilized in reciprocating engines for decades. This paper reviews the viability of using an n-butanol blend as a short-term replacement for diesel by analyzing its physical and chemical properties, combustion, performance, and emission characteristics in compression ignition (CI) engines under various conditions, including variable load, speed, acceleration, and both stationary and transient cycles. N-Butanol exhibits higher viscosity, better lubricity, higher heating value, improved blend stability, enhanced cold-flow properties, and higher density. These factors influence spray formation, injection timing, atomization, and combustion characteristics. Its higher oxygen content improves the diffusion combustion stage and efficiency. Adding 5% and 10% n-butanol to diesel increases pressure and apparent heat release rate, slightly reduces temperature, and improves thermal efficiency, with mixed effects on CO and THC emissions and a notable decrease in particulate matter emissions. Fuel consumption increases, while the impact on NOx emissions varies. A 10% butanol blend is considered optimal for enhancing performance and reducing particulate emissions without significantly affecting NOx emissions. Blending up to 40% butanol with diesel does not require engine modifications or ECU recalibrations in engines calibrated for pure diesel. Due to its advantageous properties and performance, n-butanol is recommended as a superior alcohol-diesel blend than ethanol for short-term diesel replacement.

Comparative Study of Exhaust Emissions from Diesel and Syngas Powered 3.5 kW Compression Ignition Engine with and without Load

Despite diesel engines being highly efficient, with low fuel consumption and reduced carbon dioxide emissions, they emit relatively high levels of particulate matter and oxides of nitrogen (NOx) due to high exhaust gas temperatures. Engine emissions show the quality and completeness of combustion. This paper aims to present the results of a study comparing exhaust emissions from a diesel and syngas powered engine. Syngas was produced from co-firing coal and biomass in a gasifier then cleaned, cooled and applied as an alternative fuel in an engine operated from 0 - 100% load. Exhaust-emissions were monitored at this load conditions. The exhaust-temperature was measured using thermocouples and the emission gases were analyzed using Testo 350. The emissions were lower and decreased as the engine load increased, except for sulphur dioxide and NOx. The study shows that levels of carbon monoxide, were higher in a range of 46.5 - 80.2%, while carbon dioxide was 3.3 - 18% higher compared to those from diesel. Hydrocarbon emissions were 480 and 1250 ppm for diesel and syngas respectively. The study reveals that the engine operates optimally at higher loads since hydrocarbons and oxides of carbon are low due to complete combustion at higher temperatures. Exhaust gas temperature was higher in the syngas fuel and increased as the engine load increased in the range of 455.83 - 480.03˚C which influenced the formation of NOx. NOx from diesel was found to be higher, ranging from 32.5 - 40.5%, compared to those from syngas with an engine load of 75%. The study observed that relative to diesel, the emissions of sulfur dioxide at 50% engine load were lower in a range of 23.7 - 57.1%. Emissions of hydrocarbons depended on the degree of substitution of diesel and engine load. The study therefore shows that, relative to diesel, emissions decreased when syngas was used with upgraded syngas from Prosporis juliflora presenting as the best alternative followed by Hyphanae compressa, and lastly rice husk. For optimal performance of the syngas fuelled engine, the study reports that the engine should be operated at engine loads above 50% with strategies on NOx emissions considered.

Analysis of the Emissions and Performance of a Diesel Engine Using Pumpkin Seed Oil Methyl Ester with Different Injection Pressures

Biodiesel fuel is a potential alternative energy source for diesel engines due to its physiochemical characteristics relatively similar to those of traditional diesel fuel.In this study,the performance,emission,and combustion features of a mono cylinder DI diesel engine are assessed using 20%Pumpkin seed methyl ester(PSOME20)and considering varying injection pressures(200,220,240,and 260 bar).The considered Pumpkin seed oil is converted into pumpkin biodiesel by transesterification and then used as fuel.The findings demonstrate that the Brake Thermal Efficiency(BTE)of PSOME20 can be raised by 1.68%,and the carbon monoxide(CO),hydrocarbon(HC),and smoke emanations can be lowered,while oxides of nitrogen(NOx)emissions are increased at an injection pressure(IP)of 240 bar compared to the standard IP of 200 bar.The cylinder pressure and the Heat Release Rate(HRR)become higher at 240 bar,whereas the ignition delay is shortened with respect to PSOME20 at a normal IP of 200 bar.

Influence of Urea Uneven Injection on the Performances of a Diesel Engine

The influence of heterogeneous flow injection of urea at different velocities and temperatures on NO x conversion efficiency,ammonia storage and ammonia leakage is investigated experimentally.A diesel engine employing a selective catalytic reduction(SCR)technology is considered.It is found that for a fixed injection velocity,the degree of ammonia leakage changes depending on the temperature.The higher the temperature,the faster the catalytic reduction reaction and the smaller the degree of ammonia leakage.The temperature has a great influence on the catalytic reduction reaction rate.At an injection velocity of 10000/h,the average reaction rate at 420℃ is 12 times higher than that at 180℃.The injection velocity has a weak influence on the reaction rate.When the injection velocity changes from 10000/h to 40000/h at the same temperature,the average reaction rate does not change appreciably.However,increasing the space velocity can accelerate the leakage of ammonia,thereby miti-gating the benefits associated with the NO_(x) conversion.

A Strategy to Control the Turbocharger Energy of a Diesel Engine at Different Altitudes

Power deterioration is a major problem for diesel engines operating at high altitudes.This problem stems from the limited availability of turbocharger energy,which is not enough to increase the boost pressure to the required level.In this study,a control strategy is introduced in order to achieve engine power recovery at different altitudes.It is shown that as the altitude increases from 0 to 4500 m,the required boost pressure ratio increases from 2.4 to 4.3.The needed turbocharger energy should be increased accordingly by 240%,and the TCC(turbine characterization coefficient)should be adjusted within wide ranges.A 12%decrease in the TCC can lead to a rise of the intake air pressure,which can compensate the pressure decrease due to a 1000 m altitude increase.The fluctuation range of boost pressure was within 14.5 kPa for variations in altitude from 0 to 4500 m.

Investigating the Effects of Eichhornia Crassipes Biodiesel and Liquefied Petroleum Gas on the Performance and Emissions of a Dual-Fuel Engine

This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.

Test Research on the Knock of a Common-Rail Diesel Engine Fueled with Diesel-Methanol Dual-Fuel

Experiments were conducted on a diesel-methanol dual-fuel(DMDF)engine modified by a six-cylinder,turbocharged,inter-cooled diesel engine.According to the number of diesel injection,the experiments are divided to two parts:the single injectionmode and double injectionmode.The results show that,at the double injectionmode,themaximumof pressure rise rate is small and the engine runs smoothly,however,knock still occurswhen the cocombustion ratio(CCR)is big enough.Under knock status,the power density of the block vibration concentrating at some special frequencies rises dramatically,and the special frequency of single injection mode(about 4.1 kHz)is lower than that of double injection mode(7–9 kHz).The cylinder pressure oscillations of knock status are very different fromthe non-knock status.Under knock status,cylinder pressure oscillations become more concentrated and fiercer at some special frequencies,and the same as the block vibration.The special frequency of single injection mode(3–6 kHz)is lower than that of double injection mode(above 9 kHz).

Influence of Diesel Engine Intake Throttle and Late Post Injection Process on the Rise of Temperature in the Diesel Oxidation Catalyst

In order to effectively implement DPF(Diesel Particulate Filters)regeneration control,thermal management of exhaust products before and inside Diesel Oxidation Catalyst(DOC)is necessary.In the present study,the Influence of the intake throttle valve and late post injection process on temperature rise inside DOC is analyzed through engine bench tests.The steady experiment results show that adjustment of the intake throttle valve can effectively increase exhaust temperature before DOC;in particular,with intake throttle valve opening at 20%,temperature before DOC can be increased by about 170℃ with respect to the full opening.An increase in the late post injection quantity can produce a significant rise of the temperature inside DOC,however its impact on the exhaust temperature before DOC is relatively limited.As the late post injection quantity increases,Hydrocarbon(HC)emissions also grow;in the present work it is shown that with a proper injection quantity,a considerable temperature increase inside the DOC can be obtained with relatively low HC emission.More specifically,with the intake throttle valve at 30%and DOC reaching ignition temperature as the late post injection quantity is increased,the exhaust temperature after DOC can be made larger than 550℃,adequate for DPF active regeneration.

Optimizing the Exhaust System of Marine Diesel Engines to Improve Low-speed Performances and Cylinder Working Conditions

Proper design of exhaust systems in marine high-power turbocharged diesel engines can contribute to improve the low-speed performance of these engines and make the working conditions of the cylinders more uniform.Here a high-power marine 16-cylinder V-type turbocharged diesel engine is simulated using the GT-Power software.The results reveal the differences induced by different exhaust system structures,such as an 8-cylinder-inpipe exhaust system with single/double superchargers and a 4-cylinder-in-pipe exhaust system with a single supercharger.After a comparative analysis,the 8-cylinder type with double superchargers is determined to be the optimal solution,and the structure of the exhaust system is further optimized.The simulations show that the optimized maximum exhaust temperature difference among cylinders is reduced by 66%.Finally,the simulation results and the optimized performance of the designed exhaust system are verified through experiments.

Dynamic Characteristic Investigation on the Fuel Pressure of Diesel Engines Electronic In-line Pump System

The electronic in-line pump (EIP) is a complex system consisting of mechanical, hydraulic, and electromagnetic parts. Experimental study showed that the fuel pressure of the plunger and the fuel drainage of the pressure system after fuel injection could result in fuel pressure fluctuation in the low pressure system. Such fluctuation exhibited pulsating cycle fluctuation as the amplitude rose with the increase of the injection pulse width. The time domain analysis found that the pressure time history curve and injection cylinders corresponded with a one-to-one relationship. By frequency domain analysis, the result was that with the increase of the working cylinder number, the high frequency amplitude gradually increased and the basic frequency amplitude gradually decreased. The conclusion was that through wavelet transformation, the low pressure signal simultaneously moved towards low frequency as the high frequency of the wavelet transformation signal with the working cylinder number increased. Lastly, by using the numerical model, the study investigated the simulation research concerning the relationship of the fluctuation dynamic characteristic in the low pressure system and the fuel injection characteristic of the high pressure system, completing the conclusions obtained by the experimental study.

Study of Diesel Engine Management System

Aim To study the diesel engine management spstem (DEMS). The DEMS can consider many engine parameters and so it can acquire the optimum system performance. Methods On the basis of analyzing the characteristics of diesel engine electronic system, the real-time, multi-tasks system design methods were used for the heavy duty vehicular diesel engine electronic control system . The hardware and software of DEMS were developed. Results and Conalusion By the test on dieSel engine bed, the system was verified and the foundation of the fully developed DEMS was laid.

Math Imitation of the Texture of Particle Cluster Emitted from Diesel Engine

Aim The particle texture from diesel engine was imitated by use of computer. Methods The theory of fractal geometry and the diffusion limited aggregation model were used to simulate the micron texture. Results The fractal dimensions of granule distribution and corpuscle superficial area are quite conformed with those of measurement. Conclusion The texture parameters of engine particle cluster can be obtained precisely by use of fractal theory.

Speed Disturbance in the Diesel Engine Electronic Control System

In order to sample the speed signal of electronic diesel engine in real time and make the engine work reliable, the diesel engine control system's speed acquisition was studied and the problem of speed disturbance was solved. The control system was based on the 8?bit electronic control unit(ECU) system and the assembly language was used to design the software for controlling the engine fuel quantity and the turbocharger of the variable geometry turbine for the heavy duty diesel engine. By changing the timing method for speed acquisition, the problem of speed disturbance was solved and the reliability of the ECU was improved.

Experiment Study on the Exhaust-Gas Heat Exchanger for Small and Medium-Sized Marine Diesel Engine

This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water.A new exhaust-gas heat exchanger of fins and tube,with a reinforced heat transfer tube section,unequal spacing fins,a mixing zone between the fin groups and four routes tube bundle,was designed.Numerical simulations were also used to provide reference information for structural design.Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger.The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%.After the water flow rate was adjusted,the exhaust gas waste heat recovery efficiency was higher than 70%,and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads.This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.

Effect of Palm Oil Biodiesel Blends on Engine Emission and Performance Characteristics in an Internal Combustion Engine

Increasing global environmental issues and depleting fossil fuel reserves has necessitated the need for alternative and sustainable fuel. In this paper, the effects of biodiesel and its blend on engine emission and performance characteristics in an internal combustion engine were analyzed. Biodiesel derived from the transesterification of raw palm oil was blended with diesel fuel at different proportions designated as PO5 (5% Biodiesel and 95% Diesel), PO10 (10% Biodiesel and 90% Diesel), PO15 (15% Biodiesel and 85% Diesel), PO20 (20% Biodiesel and 80% Diesel), PO50 (50% Biodiesel and 50% Diesel), PO85 (85% Biodiesel and 15% Diesel), and PO100 (100% Biodiesel). A Lombardini 2-cylinder, four-stroke direct injection diesel engine with a compression ratio of 22.8 was developed using Ricardo Wave software in which diesel, palm oil biodiesel blends and pure biodiesel are used in the model, and the obtained results were analysed and presented. The simulation was done under varying engine speeds of 1200 rpm to 3200 rpm at full load condition. Biodiesel and its blends are more environment-friendly and non-toxic when compared to diesel fuel;it also improves the mechanical efficiency of the engines, and above all can also lead to a reduction in poverty among rural dwellers. The obtained results showed that brake specific fuel consumption and brake thermal efficiency increased with palm oil biodiesel blends as compared to diesel fuel which might be a result of biodiesel’s lower heating value, and the increase in thermal energy may be a result of the oxygenation of the biodiesel blend as compared to pure diesel. In terms of brake torque, palm oil biodiesel blends were lesser than diesel fuel. The CO, HC, and NOx emissions of palm oil biodiesel blends decreased significantly compared to that of pure diesel. From this study, palm oil biodiesel emits lesser emissions than diesel fuel and its performance characteristics are similar to diesel fuel. Therefore, palm oil biodiesel can be used without any modifications directly in a diesel engine. In addition, it can also be used as blends as an alternative and sustainable fuel, decreasing air pollution, and increasing environmental sustainability.

Study on Effects of Diesel Engine Cooling System Parameters on Water Temperature

A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.

Complete Modeling for Systems of a Marine Diesel Engine

This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations The whole engine system is divided into several functional blocks： cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation （FDI） as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine＇s output of changing values for faults parameters such as： faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors （and many others）.

Development of Fuel/Engine Systems—The Way Forward to Sustainable Transport

The global demand for transport energy is large, growing, and primarily met by petroleum-derived liquid fuels powering internal combustion engines (ICEs). Moreover, the demand for jet fuel and diesel is projected to grow faster than the demand for gasoline in the future, and is likely to result in low-octane gasoline components becoming more readily available. Significant initiatives with varying motivations are taking place to develop the battery electric vehicle (BEV) and the fuel cell as alternatives to ICE vehicles, and to establish fuels such as biofuels and natural gas as alternatives to conventional liquid fuels. However, each of these alternatives starts from a very low base and faces significant barriers to fast and unrestrained growth;thus, transport—and particularly commercial transport—will continue to be largely powered by ICEs running on petroleum-based liquid fuels for decades to come. Hence, the sustainability of transport in terms of affordability, energy security, and impact on greenhouse gas (GHG) emissions and air quality can only be ensured by improving ICEs. Indeed, ICEs will continue to improve while using current market fuels, through improvements in combustion, control, and after-treatment systems, assisted by partial electrification in the form of hybridization. However, there is even more scope for improvement through the development of fuel/engine systems that can additionally leverage benefits in fuels manufacture and use components that may be readily available. Gasoline compression ignition (GCI), which uses low-octane gasoline in a compression ignition engine, is one such example. GCI would enable diesel-like efficiencies while making it easier to control nitrogen oxides (NOx) and particulates at a lower cost compared with modern diesel engines. Octane on demand (OOD) also helps to ensure optimum use of available fuel anti-knock quality, and thus improves the overall efficiency of the system.