A reduced combustion mechanism of ammonia/diesel optimized with multi-objective genetic algorithm

For the deep understanding on combustion of ammonia/diesel,this study develops a reduced mechanism of ammonia/diesel with 227 species and 937 reactions.The sub-mechanism on ammonia/interactions of N-based and C-based species(N—C)/NOx is optimized using the Non-dominated Sorting Genetic Algorithm II(NSGA-II)with 200 generations.The optimized mechanism(named as 937b)is validated against combustion characteristics of ammonia/methane(which is used to examine the accuracy of N—C interactions)and ammonia/diesel blends.The ignition delay times(IDTs),the laminar flame speeds and most of key intermediate species during the combustion of ammonia/methane blends can be accurately simulated by 937b under a wide range of conditions.As for ammonia/diesel blends with various diesel energy fractions,reasonable predictions on the IDTs under pressures from 1.0 MPa to5.0 MPa as well as the laminar flame speeds are also achieved by 937b.In particular,with regard to the IDT simulations of ammonia/diesel blends,937b makes progress in both aspects of overall accuracy and computational efficiency,compared to a detailed ammonia/diesel mechanism.Further kinetic analysis reveals that the reaction pathway of ammonia during the combustion of ammonia/diesel blend mainly differs in the tendencies of oxygen additions to NH_2 and NH with different equivalence ratios.

A Study of the Effect of the Miller Cycle on the Combustion of a Supercharged Marine Diesel Engine

The Miller cycle is a program that effectively reduces NOx emissions from marine diesel engines by lowering the maximum combustion temperature in the cylinder,thereby reducing NOx emissions.To effectively investigate the impact of Miller cycle optimum combustion performance and emission capability under high load conditions,this study will perform a one-dimensional simulation of the performance of a marine diesel engine,as well as a threedimensional simulation of the combustion in the cylinder.A 6-cylinder four-stroke single-stage supercharged diesel engine is taken as the research object.The chassis dynamometer and other related equipment are used to build the test system,carry out the diesel engine bench test,and collect experimental data.The simulation results are compared with the test results,and the error is less than 5%.In this study,the authors will use simulation software to simulate several Miller cycle scenarios designed for early inlet valve closure and analyze the impact of the Miller cycle on combustion and emissions at 100%load conditions.By comparing the flow field distribution of the engine at 1500 r/min condition,it was found that proper EIVC can prolong the ignition latency period and homogeneous fuel-air mixture combustion acceleration,but it can reduce pressure and temperature within the piston chamber and NOx emission.However,the Miller cycle reduces end-of-compression temperatures,which increases combustion duration and exhaust temperatures,making it difficult to improve fuel economy at the optimum fuel consumption point,and closing the intake valves prematurely leads to excessive fuel expenditure.Furthermore,temperature and heat release rate within the piston chamber,NOx,and SOOT generation were significantly enhanced.

Optimization of Diesel and Crude Oil Degradation in a Ghanaian Soil Using Organic Wastes as Amendment

Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimulate this degradation by different means. Thus, this study aimed to improve the bio-degradation of diesel and crude oil in a Ghanaian soil by biostimulation. For this, the sampled soil was characterized by standard methods and contaminated with diesel and crude oil at a proportion of 1% (w/w). Then, contaminated soil samples were supplemented with biochar-compost, poultry manure or cow dung at the proportion of 10% (w/w). Periodically, fractions of these samples were taken to evaluate the density of hydrocarbon utilizing bacteria (HUB) and the residual quantities of diesel or crude oil. The characteristics of the soil used show the need for supplementation for better degradation of hydrocarbons. The results of the study show that supplementing the soil with organic substrates increases HUB loads in soils contaminated by diesel and crude oil. They also show that the residual quantities of diesel and crude oil are generally significantly lower in supplemented soils (p = 0.048 and p < 0.0001 respectively). In addition, the study shows that degradation was generally greater in soils contaminated by diesel compared to those contaminated by crude oil, especially at the end of the study.

Study of the Viscosity and Specific Gravity of the Ternary Used Frying Oil (UFO)-Bioethanol-Diesel System

Fossil fuels cover around 80% of global energy consumption. However, the problems linked to their use justify the choice of using biofuel. In order to reduce as much as possible, diesel rate, an increase in the number of additives may be considered. Thus, in this work, the study of the used frying oil (UFO), bioethanol and diesel ternary system was undertaken. It emerges from this study that the addition of bioethanol reduces the viscosity and the density of the ternary system and permits a 90% substitution rate for diesel between the UFO and bioethanol. Finally, the percentage of oil becomes 40% after adding alcohol compared to the binary diesel crude vegetable oil mixture where this rate is 30%.

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.

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.

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).

等温加热修正Diesel循环及其内可逆特性

提出一种新的Diesel循环,即等温加热修正的Diesel循环,并运用有限时间热力学理论建立内可逆修正Diesel循环模型,导出循环功率与效率、功率与压缩比和效率与压缩比的特性关系,研究循环温比、预胀比和传热损失对循环性能的影响,将修正后的循环性能与传统的Diesel循环性能进行比较。结果显示:循环功率与效率的关系曲线呈扭叶型,而功率与压缩比和效率与压缩比的关系曲线均呈类抛物线型;随着预胀比和循环温比的变大,循环性能明显提升;与传统的Diesel循环相比,修正后的循环性能更优。

Catalyst grading technology for promoting the diesel hydrocracking to naphtha

This paper reports the application of multi-component hydrocracking catalyst grading technology in diesel hydrocracking system to increase naphtha,and studies the influence of catalyst systems with different number of graded beds on the reaction process of diesel hydrocracking.Three hydrocracking catalysts with different physicochemical properties as gradation components,the diesel hydrocracking reaction on catalyst systems of one-component,two-component and three-component graded beds with different loading sequences are carried out and evaluated,respectively.The catalytic mechanism of the multi-component grading system is analyzed.The results show that,with the increase of the number of grading beds,the space velocity of reaction on each catalyst increases,which can effectively control the overreaction process;along the flow direction of feedstock,the loading sequences of catalysts with acidity decreasing and pore properties increasing can satisfy the demand of different catalytic activity for the conversion of reactant with changing composition to naphtha,which has a guiding role in the conversion of feedstock to target products.Therefore,the conversion of diesel,the selectivity and yield of naphtha all increase significantly on the multi-component catalyst system.The research on the grading technology of multi-component catalysts is of great significance to the promotion and application of catalyst systems in various catalytic fields.

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.

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.

Noise Control Solutions for Diesel Generator Sets

A persistent challenge for Oman's energy infrastructure was the deafening rumble of diesel generators. The Silent Generator Project addressed this challenge, developing advanced generators that deliver power quietly and efficiently. Diesel generators have historically been notorious for being noisy and vibrational, making them unsuitable for sensitive environments. To dramatically reduce noise levels, the project utilized innovative materials and design modifications to ensure reliable and quiet electricity for various applications. In all directions, the project advanced the knowledge of noise reduction through rigorous testing and meticulous integration of insulators and mufflers. As a result, quieter, more sustainable energy production is on the way, marking a major advance in silent generator technology. Furthermore, the Silent Generator Project lays the foundation for more efficient and environmentally friendly diesel generator technologies in the future. As a result of this research, a new standard for quieter, greener energy generation is established, demonstrating the critical role noise reduction plays in energy generation. Additionally, this work also suggests future diesel generator technologies that are more efficient and environmentally friendly. As a result of this research, a new standard for quieter, greener energy generation is set, demonstrating the critical role noise reduction plays in energy generation.

Development and Performance Evaluation of Catalyst for Productive Ethylene Cracking Feedstock in Selective Hydrocracking of Straight Run Diesel Oil

The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N2-low temperature adsorption-desorption, NH3-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.

Lipoid Pneumonia Caused by Diesel Aspiration: A Case Report and Literature Review

Diesel poisoning is a rare clinical condition.On September 27,2021,a 55-year-old male who mistakenly inhaled 20 mL of diesel through a siphon was admitted to our hospital.The main symptoms were cough and asthma.Chest computed tomography(CT)showed both lungs scattered with patchy consolidation,ground-glass shadow,exudation,and pleural effusion.After 61 days of lung rehabilitation training and other supportive treatment,including oxygen therapy,postural drainage,ventilator support,bronchoalveolar lavage,hemoperfusion,continuous renal replacement therapy(CRRT),hormones,and antibiotics,the patient’s condition improved,and the patient was discharged.Through literature review,we found that lung consolidation,ground-glass shadow,nodular lesions,and pleural effusion can be observed on chest images of patients with lipoid pneumonia,with severe cases showing diffuse lesions involving both lungs,possibly secondary to respiratory failure.Children with acute critical illness deteriorates rapidly and have poor prognosis,whereas adults or patients with chronic poisoning have better prognosis after active treatment.

摩擦对空气标准Diesel循环功率效率特性的影响

An irreversible simplified model for the air standard Diesel cycle is established in this paper. This model takes into account the finite-time evolution of the cycle’s compression and power strokes and it considers global losses lumped in a friction like term. The relations between the power output and the compression ratio, and between the thermal efficiency and the compression ratio are derived. Numerical example leads to loop-shaped power versus efficiency cures as is common to almost all real heat engines.

工质变比热和传热损失对Diesel循环性能的影响

用有限时间热力学的方法分析空气标准Diesel循环,由数值计算给出了存在传热损失和工质变比热时循环功与压缩比、效率与压缩比以及功和效率的特性关系,并分析了传热损失和工质变比热对循环性能的影响特点,通过分析可知传热和变比热特性对Diesel循环性能有较大影响,所以在实际循环分析中应该予以考虑.

传热对空气标准Diesel循环功和效率特性的影响

用有限时间热力学方法分析空气标准Diesel循环的性能．导出考虑传热效应下循环的功及效率与压比的关系，并得出功与效率的关系和最大功输出时的效率．给出了较为详尽的数值计算结果，它们对实际Diesel机性能的评估及改进有一定的指导意义．

Emission and performance study emulsi ed orange peel oil biodiesel in an aspirated research engine

This study paves the way on reducing smoke emission and NO_x emissions of research diesel engine by detailing the e ect of water addition in biodiesel. Fuel samples were prepared with di erent concentrations of water in orange peel oil biodiesel(94% waste orange peel oil biodiesel + 4% water + 2% Span 80(WOPOBDE1) and 90% waste orange peel oil biodiesel + 8% water + 2% Span 80(WOPOBDE2). Span 80 was employed as a nonionic surfactant, which emulsifies water in biodiesel. Experimental results revealed that the nitrogen oxides and smoke emission of orange peel oil biodiesel emulsion were reduced by 11%–19% and 3%–21%, respectively, compared to that of neat orange peel oil biodiesel(WOPOBD). In addition, the introduction of orange peel oil–water emulsions in the diesel engine considerably reduced the emissions of unburned hydrocarbons and carbon monoxide. The overall hydrocarbon emission of WOPOBDE2 was 12.2% lower than that of WOPOBD and 16.3% lower than that of diesel. The overall CO emission of WOPOBDE2 was 17% lower than that of base fuel(WOPOBD) and 21.8% lower than that of diesel. Experimental results revealed that modified fuel had higher brake thermal e ciency and lower brake specific fuel consumption than that of base fuel at all engine brake power levels.