Diesel Engine Exhaust Gas Research Articles

Селективне каталітичне очищення вихлопних газів дизельних двигунів локомотивів від оксидів азоту на блочному волокнистому ванадієвому каталізаторі

Селективне каталітичне очищення вихлопних газів дизельних двигунів локомотивів від оксидів азоту на блочному волокнистому ванадієвому каталізаторі

БЕЗПЕКА ПРОДУКЦІЇ. ПОКАЗНИКИ ЕКОЛОГІЧНОСТІ ВІДПРАЦЬОВАНИХ ГАЗІВ ТЕПЛОВОЗІВ, ЯКИМ ПОДОВЖЕНО СТРОК СЛУЖБИ ПІСЛЯ КАПІТАЛЬНО-ВІДНОВЛЮВАЛЬНОГО РЕМОНТУ АБО ПІСЛЯ МОДЕРНІЗАЦІЇ

This article is the first in a series of related publications urgent in the field of railway transport, namely absence of new traction rolling stock and the presence of existing in operation, the condition of which remains uncommented. The article is concerned with the requirements specified in normative documents for the environmental security indices of diesel locomotives operated on the railways of Ukraine, the volume and qualitative characteristics of environmental indices, which must be checked before the operation of the repaired or upgraded locomotive is given; the impact of overhaul reconditioning or modernization measures of locomotives on the environmental indices of exhaust gases was determined. In the context of the article, it is reasonable to consider the safety requirements of the main, even the only source of exhaust gases - internal combustion engines used on locomotives (general view of locomotives is shown in Fig. 1). Safety requirements for engines and methods of their control are usually set in the technical specifications, design and operating documentation for engines of certain types. Engines must also meet the requirements of national technical regulations and national standards for them, taking into account their operational functions for which they are intended. In this case, any danger to personnel, which may occur during the operation of the engine, as a necessary element of the overall system to create a moving force (e.g. locomotive engine), its moving parts, hot surfaces, should be minimal. During the design of engines their purpose, operating conditions, environmental conditions, as well as characteristics of used materials, in particular the brand of diesel fuel should be taken into account. Special attention should be paid to the structure safety of: fuel supply systems; lubrication and cooling systems; engine control systems. The physical factors of dangerous and harmful effect include: moving elements; hot surfaces; exhaust gases; increased noise level; increased vibration level; flame emissions; - excess pressure in the crankcase; electric current. The chemical factors of dangerous and harmful effect include: harmful components of exhaust gases; fuel and fuel vapor; lubrication and its vapour; coolant; non-metallic materials. According to the lists of physical and chemical factors of dangerous and harmful effects of engines, one of the most important is indices of exhaust gases of diesel engines.

Characterization of a Thermoelectric Energy Recovery System Applied To Low Displacement Diesel Engines

In the present study, the performance of an applied TEG for the recovery of residual heat from the low displacement engine diesel engine exhaust gases was evaluated. A total of 20 thermoelectric modules located on the upper and lower surface of a rectangular duct heat exchanger were used in a 2 x 5 arrangement. By means of a cooling system formed by two rectangular coolers, the temperature of the cold surface of the TEMs. The diesel engine worked a total of nine operating conditions, in which the rotation speed was varied in 3000, 3400, and 3800 rpm, while the torque was modified in 3, 4.5, and 6 Nm. The experimental results indicated that the electrical performance of the thermoelectric modules decreases for an electrical current greater than 1.6 A. In general, the maximum electrical power of the TEG was reached when the external load resistance approached the total internal resistance of the TEMs . The maximum value of electric power generated by the TEG was 72 W, achieved with a rotation speed of 3800 rpm and a torque of 6 Nm. These same conditions allowed to reach an energy conversion efficiency of 2.61%.

Enhancing of low-temperature OHC-SCR activity of Ag/TiO2 with addition of MnO2 nanoparticles, and performance evaluation using diesel engine exhaust gases

The purpose of this study is to investigate the NO x removal activity of Ag/TiO 2 catalyst with addition of MnO 2 to improve the low temperature activity in the SCR system. The catalysts were prepared using washcoating method and were characterized with SEM, BET, XRD and FT-IR analyzes. According to results of SEM analysis, the catalysts exhibited a regular structure and fine particles dispersed over the surface and pores. BET analysis showed that the surface area and pore volume of catalysts decreased significantly with increasing of Mn amount. A strong interaction between catalytic materials and TiO 2 was determined by XRD analysis. FT-IR results indicated the presence of loading catalytic species on the catalyst surface. The effects of MnO 2 amount, reaction temperature, space velocity and engine load on catalytic performance were investigated by using ethanol as the reductant. The results indicated that Ag–Mn (3%)/TiO 2 catalyst was very effective in the temperature range of 170–290 °C. NO x conversion on the Ag–Mn (3%)/TiO 2 catalyst reached 92.9% at 290 °C and 30000 h −1 space velocity. The NO x removal performance of Ag/TiO 2 catalyst with high amount of MnO 2 decreased at low temperatures. In general, NO x conversion ratios of the catalysts reduced at 50000 h − 1 . • NO x removal performance of Ag based catalysts are insufficient at low temperatures. • Ag–Mn (3%)/TiO 2 catalyst shows highest NO x conversion ratios at low temperatures. • High MnO 2 loading reduces catalytic activity at low temperatures. • Increasing of GHSV decreases activity of catalysts.

Mathematical Modelling and Heat Transfer Performance of a TEG for Engine Exhaust Heat Recovery

In recent years, thermoelectric power generation has been investigated widely for waste heat recovery of internal combustion engines. In this paper, the exhaust gas of a heavy-duty diesel engine is used as the heat source. A mathematical model and the simulation program of a large thermoelectric generator(TEG) are established. Using the MATLAB software, the trends of the TEG working parameters in the flow direction are analysed. The flow rate and the temperature of the cold sources, the engine speed and load, and the fin structure parameters of the tube-fin heat exchanger are studied. The results show that the error between the simulated output power and the experimental one is within 11%. A higher engine load rate and a lower coolant temperature are conducive to improving the output power and the conversion efficiency of the TEG. Optimizing the fin spacing and fin height is helpful to improve the heat transfer performance of the heat exchanger and increase the thermoelectric conversion efficiency.

IMPLEMENTATION ON THE BASIS OF A MICROTUNNEL OF THE DYNAMIC CONTROL METHOD OF PARTICULATE MATTER CONCENTRATION IN THE EXHAUST GASES OF DIESEL ENGINES

Modern methods of dynamic control of particulate matter emissions from diesel engine exhaust gases are analyzed. The principles of operation and technical characteristics of the methods are considered: Method for Real-Time Mass Microbalances, Tapered element oscillating microbalance - TEOM, Quartz Crystal Microbalance - QCM and Laser Induced Incandescence - LII. It was found that the accuracy of these methods provides the ability to measure ultra-low concentrations of solid particles with a sensitivity of up to ± 2 μg/m3 in the ranges: 1.25 ... 0.25 ... 0.063 mg/m3 in accordance with the requirements of Euro-3, Euro -4.5 and Euro-6, and the speed of these methods provides the ability to control instantaneous values of particulate matter emissions during the execution of transient diesel test cycles: European Transient Cycle (ETC), Worldwide Transient Vehicle Cycle (WTVC), Worldwide heavy-duty transient cycle (WHTC) and others. Based on the analysis of these methods, world and domestic experience in the creation and operation of systems for environmental diagnostics of diesel engines, a method for dynamic control of the concentration of solid particles with an optical sensitive element is proposed for practical application. The essence of this method lies in the indirect determination of the instantaneous concentrations of solid particles by the optical opacity index - the smoke of diesel exhaust gases using the empirical relationship between these values, which is established during the calibration of the optical particle detector with the gravimetric system - the MKT-2 microtunnel. The following are considered: a schematic diagram of this method, technical means for its implementation, which include: a partial-flow system for diluting exhaust gases with air with MKT-2 and a dynamic particle detector. The maximum permissible values of the dilution coefficients of exhaust gases with air in MKT-2 have been established, at which the required accuracy of measurements of particulate concentrations by an optical detector with a sensitivity of ± 0.1% on the Hartridge scale is provided, while the levels of diesel particulate emissions comply with the requirements of Euro 3-6.

Flow Field Simulation and Experimental Analysis of Flue Guide Plate of Marine Desulfurization Tower

Du, J.; Zhao, H., and Xue, Y.F., 2020. Flow field simulation and experimental analysis of flue guide plate of marine desulfurization tower. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 396-400. (Coconut Creek, Florida), ISSN 0749-0208.In this paper, the exhaust gas of marine diesel engine under rated condition is taken as the research object, the newer version of fluent18.0 software is used as the platform, the self-defined function and SO2 absorption model are compiled by using C++software and double membrane theory, and the compiled self-defined function is imported through UDF interface. The uneven distribution of flue gas and the phenomenon of sticking to the wall in the side feed desulfurization tower lead to the reduction of desulfurization efficiency. The number and position of the guide plates in the flue of the marine desulfurization tower need not be simulated and optimized. Through the analysis and comparison of the velocity flow field and SO2 mass fraction cloud chart, the desulfurization efficiency of zero to three guide plates is 94.31%, 95%, 96.84% and 97.63% respectively. Then, compared with the experimental data, and the difference of simulation results is small, which has great practical value and theoretical significance for optimizing desulfurization tower and improving sodium alkali desulfurization system.

Influence of crankshaft speed on biofuel combustion in a diesel engine

At present, the use of renewable alternative fuels of non-petroleum origin has become a challenge. Primarily, this is due to the fact that oil resources are gradually being depleted, and their cost is growing proportionally every year. Switching to renewable fuels will reduce air pollution and ensure independence from crude oil. The article presented describes the results of bench tests of an air-cooled diesel engine 2F 10.5/12.0 running on methyl alcohol and methyl ether of rapeseed oil. Herewith, a dual fuel supply system was used. That allowed ensuring synchronous fuel feeding into the engine cylinder. The article also presents diagrams of indicator pressure, heat release and roughness of the combustion process of a diesel engine running on alternative fuels, depending on the change in the crankshaft speed. Along with this, positive environmental effects were also revealed in terms of the amount of toxic agents in the exhaust gases of a tractor diesel engine. Thus, there is a significant reduction in nitrogen oxides (by 47.4%) as compared to the diesel process, and the soot content in the exhaust gases has decreased by 10.42 times.

Development and Validation of 4 Stroke Marine Diesel Engine Numerical Model

Increasing demands on energy efficiency and environmental acceptance are being imposed on marine propulsion plants. The fulfilment of the conditions set by the MARPOL Convention, Annex VI, regarding the emissions from exhaust gases of marine diesel engines is of particular interest. This paper presents the development and validation of a zero-dimensional, single-zone diesel engine numerical model. Presented numerical model is based on the law of conservation of energy and mass and solving the resulting differential equations. The single-zone model will serve as the basis for a model where the cylinder space is divided into two or three zones during combustion. In this way, the multi-zone model will allow the modelling of nitrogen oxide emissions with satisfactory accuracy. Validation of the diesel engine model was carried out for the Wärtsilä 12V50DF 11700 kW motor designed to drive a synchronous alternator. Obtained results and deviations of certain parameters in the operation of the engine with respect to the data obtained from the measurements on the test bed, are more than satisfactory regarding complexity of the numerical model. This confirmed the usability of the model for research purposes to optimize the marine diesel engine.

Waste heat recovery through cascaded thermal energy storage system from a diesel engine exhaust gas

One-third of heat generated is dissipated through the engine exhaust gas. Latent heat storage is one of the most efficient ways of storing thermal energy. Thermal storage units that utilise latent heat storage materials/phase change materials have received greater attention in the recent years because of their higher storage density with a smaller temperature difference between storing and releasing heat. In the present work, a heat recovery heat exchanger integrated with an IC engine and a cascade thermal energy storage systems with phase change materials, as the latent heat material is designed, fabricated and investigated. The performance characteristics of the system are also studied in detail. It is found that about 15% of fuel power is stored in the cascaded thermal energy storage system, which is available at higher and lower temperatures and it can be used for suitable applications.

Измерительные приборы для определения состава отработавших газов судовых двигателей внутреннего сгорания

The article describes the problem of air pollution by engines of sea and river vessels. Compliance with environmental requirements established by state and international regulatory documents is a prerequisite for the safe operation of sea and river vessels. The composition of the exhaust gases of marine diesel engines should be considered the main and most objective criterion for the environmental safety of marine power plants. The requirements for the exhaust gases composition and the procedure for determining regulated indicators are established by various regulatory documents which indicate only the principle the device operation. Most regulatory documents do not take into account the capabilities of modern devices and design features of ship power plants. In the process of analyzing exhaust gases, the composition of toxic substances and solid particles is determined by gas analyzers and smoke meters. The principles of operation of modern instruments are described, their capabilities and metrological characteristics are presented, and the prospects for using such instruments on sea and river vessels are evaluated. The problems that arise during the analysis of exhaust gases on small displacement vessels with wet exhaust gases are considered. There have been proposed the measures which will improve the quality of marine diesel emissions control and contribute to improving the technical operation of the fleet. The necessity of updating the instrumental base for monitoring toxicity and smoking of exhaust gases of marine diesel engines is indicated. The solution to the problem requires an integrated approach, taking into account the operating conditions of ships, capabilities of measuring equipment, design features of ship engines, requirements of regulatory documents and rules of classification societies.

The Role of Sodium-alkali Waste Gas Washing and Desulfurization Technology in the Exhaust Gas Treatment of Marine Diesel Engines

to reduce the concentration of sulfur oxide in the exhaust gas of marine diesel engines, the application of sodium-alkali waste gas washing and desulfurization technology in the exhaust gas treatment of marine diesel engines is explored. First, the reaction mechanism of sodium-alkali wet washing desulfurization technology is introduced, including the absorption process model of sulfur oxide, the absorption rate equation, the equation for absorbing sulfur oxide in aqueous solution, and the process of dissolving and absorbing sulfur oxide in sodium hydroxide solution. Then, a method to improve the absorption rate of sulfur oxides is proposed. Finally, the influence of load and pH of washing solution on desulfurization efficiency is discussed. The results show that the sodium-alkali waste gas washing and desulfurization technology has a good desulfurization efficiency. The desulfurization efficiency under different loads is more than 99%, and the maximum is 99.7%, which meets the desulfurization requirements of the national heavy oil exhaust gas treatment system. The higher the pH of washing solution, the more obvious the desulfurization efficiency. The results of this research provide a theoretical basis for the development of Chinese ships.

Pollution Control of Exhaust Emissions of Marine Diesel Engines

This paper describes the impact of marine diesel engine exhaust gas on the atmospheric environment and the international control requirements for marine diesel engine emissions internationally; introduces the current technical measures to reduce emissions of diesel engine exhaust pollution. On this basis, the advantages and disadvantages of each measure and the application scopes are explored.

Passive Nitrogen Oxides Removal from a Diesel-engine Exhaust Gas using a Biomass-Carbon Catalyst

Nitrogen oxides (NOx) removal from a diesel-engine exhaust gas is limited to the utilization of ammonia/urea as a reducing agent (SCR) which arose environmental concerns over the use of this chemical. Therefore, this study explored the potential of a sustainable NOx removal system by replacing ammonia with intrinsic reductants present in the exhaust gas such as hydrocarbons and carbon monoxide, and by application of cost-effective carbon-supported transitional metals catalyst. Copper-cerium catalyst supported over palm kernel shell activated carbon (Cu-Ce/PKS) was synthesized via deposition-precipitation method. The characterization shows that the catalyst has a considerably high surface area (though lower than the support). The high NOx removal by Cu-Ce/PKS in a passive catalytic reaction is attributed to the surface area provided by the carbon support, the low copper reducibility giving the low optimum operating temperature, and the synergistic effect between Cu and Ce resulting in the wide temperature window at low-temperature range. It is concluded that Cu-Ce supported over palm kernel shell activated carbon can be further developed to reduce NOx in a passive catalytic removal for a sustainable and cost-effective SCR system.

Simulation and experiment of NOX concentration detection in diesel engine exhaust gas

As people pay more attention to environmental problem, the issue of how to measure and reduce pollutant of the exhaust of ships were put on the agenda. To realize the detection of NOX(nitrogen oxides) content in the marine diesel exhaust emissions, the SIMULINK of MATLAB software with superior data processing capabilities was selected in this paper to enable the detection of NOX content by direct absorption measurement based on laser absorption spectroscopy (TDLAS).). The absolute error of the simulation model was less than 0.15%, and the maximum relative error didn’t exceed 1.25%. At the same time, the simulation error of the model was less than 5.0% compared with the test results of the AVL emission meter. The results had shown that the model can accurately simulate the detection process of nitrogen oxides of diesel exhaust emissions. It not only provides reference data onto people to detect harmful gases in ships but also provides valuable experience in optimizing diesel engines control strategies.

Multi-mode analysis of a CO2-based combined refrigeration and power cycle for engine waste heat recovery

To realize the adjustable allocation of refrigeration and power in a combined refrigeration and power cycle, this study proposes a multi-mode cycle using CO2 as the working fluid. A refrigerated truck is selected as the research objective, the refrigeration demand and power demands of which vary frequently with different transportation conditions. The proposed system is driven by the exhaust gas of the main diesel engine and can replace the original refrigerator and related small-scale diesel engine. Three operating modes can be realized for different energy demands: full refrigeration output, combined refrigeration and power output, and full power output. The results indicate that the proposed system exhibits considerable potential for energy saving and diversified energy supply capacity. Following optimization of the configuration and parameters, the proposed energy solution (engine + proposed system) under the mode of combined refrigeration and power output can achieve a 2.9% fuel saving and 4.8% power increase simultaneously versus the original energy solution (engine + refrigerator) under refrigeration condition, 3.4% fuel saving and 1.6% power increase simultaneously under freezing conditions. The fuel economy is correspondingly improved 7.4% and 4.9%. Moreover, the proposed method can provide greater refrigeration and power capacities under the full refrigeration output and full power output modes.

The Application of Neural Networks for Prediction of Concentration of Harmful Components in the Exhaust Gases of Diesel Engines

The Application of Neural Networks for Prediction of Concentration of Harmful Components in the Exhaust Gases of Diesel Engines

Effect of Wet Scrubbing Oxidation Denitration Technology Combined with Ultraviolet Online Irradiation on the Efficiency of Desulfurization and Denitrification of Ship Exhaust Gas

In order to alleviate the air pollution caused by nitrogen and sulfur oxides discharged from ships, the efficient method of deoxidization and desulfurization of marine diesel engine exhaust gas has been explored. In this study, at present, the mainstream technology of ship exhaust gas removal at home and abroad, wet scrubbing oxidation denitration technology is taken as the research object. Ultraviolet (UV) online irradiation is introduced into the process of wet scrubbing oxidation denitration of NaClO2 solution. The effects of different parameters, such as the concentration of NaClO2, the temperature of washing solution, the concentration of O2 and SO2, on the removal of No are studied. The reaction mechanism is further analyzed. The results show that photochemical reaction will take place between UV online irradiation and NaClO2 solution, resulting in a large number of active radicals with strong oxidation, which can obviously enhance the effect of No removal by wet scrubbing of NaClO2 solution. It can be seen that the wet scrubbing oxidation denitration technology combined with UV online irradiation can greatly improve the efficiency of desulfurization and denitrification of ship's exhaust gas. It is an efficient method of deoxidization and desulfurization of ship's diesel engine exhaust gas, which is of great help to alleviate exhaust gas pollution.

“NaClO2-Sea Water” Wet Denitrification Technology Using NOx Treatment Technology in the Desulfurization and Denitrification of Ship Exhaust Gas

To minimize the emission pollution of nitrogen oxides (NOx) in marine diesel engine exhaust, based on the existing NOx treatment technology, the "NaClO2-sea water" wet denitrification technology was further proposed. The denitrification performance of NaClO2 solution in seawater and NaClO2 solution in fresh water was analyzed by self-designed and built experimental platform. Moreover, the effects of the temperature of the absorption solution, the initial concentration of NaClO2 and the concentration of NO in diesel exhaust gas on the denitrification performance of NaClO2 sea water solution were studied. The experimental results showed that the denitrification rate of NaClO2 solution with seawater as solvent was slightly lower than that of NaClO2 solution with fresh water, but the denitrification duration of seawater solution had obvious advantages over that of fresh water solution. In addition, by increasing the temperature of the absorption solution and the initial concentration of NaClO2 and decreasing the concentration of NO, the denitrification rate of NaClO2 sea water solution was increased. Whereas, if the temperature exceeded a certain limit, the continuous denitrification time of the solution would be decreased. Therefore, “NaClO2-sea water” wet denitrification technology has the advantages of cheap raw materials and long continuous denitrification time. High denitrification efficiency can be achieved by optimizing reaction conditions, so it can be used for denitrification of marine diesel engine exhaust gas.

Thermodynamic analysis and performance optimization of the supercritical carbon dioxide Brayton cycle combined with the Kalina cycle for waste heat recovery from a marine low-speed diesel engine

With the continuous rise in world oil prices and increasing environmental awareness, how to improve ship energy efficiency and reduce ship pollution emissions has become a common concern of the shipping industry. Waste heat recovery technology is an effective method to improve the fuel economy of ships and help the future ships to meet the increasingly stringent Energy Efficiency Design Index of the International Maritime Organization. Under the thermodynamic analysis results of the 8S90ME-C10.2 low-speed marine diesel engine, this paper proposed a waste heat recovery scheme that combined the supercritical carbon dioxide Brayton cycle power generation system with the Kalina cycle power generation system. According to the energy and exergy balances of the combined cycle system, a MATLAB program based on the REFPROP database was established. With the application of control variate method, the influence of the key operating parameters including the main compressor inlet temperature, the turbine inlet temperature, the main compressor outlet pressure, the expander inlet pressure, and the ammonia solution mass concentration on the system performance was thoroughly analyzed. Moreover, the multi-objective optimization matching between the diesel engine and the combined power generation system was carried out from the viewpoints of the thermodynamic performance and economic performance and the impact of the system on the fuel economy and the Energy Efficiency Design Index of the ship was calculated. The results showed that the combined power generation system was used to recycle the waste heat of diesel engine exhaust gas and bypass exhaust gas to generate electricity, which reduced the annual fuel consumption and the Energy Efficiency Design Index to 16.62% and 15.01%, respectively. Finally, this study provides a reference for researchers to study the combined use of supercritical carbon dioxide Brayton cycle and Kalina cycle to recycle the waste heat of the marine diesel engine.