Diesel Engine Exhaust Gas Research Articles

A New Electronic Ethanol Injection Management System for Diesel Engines

This work shows an electronic management system equipped with two microcontrollers for ethanol injection in the air intake pipe of a diesel engine. The aim was to reduce the NOx emissions, while increasing the amount of renewable fuel in the mixture. The system was specially developed to detect the high-pressure pulse in the diesel injection line and to trigger the ethanol injection. An intrusive pressure sensor was installed in the diesel injection pipe to allow the measurement. Through a security protocol, the timing and duration of injection can be adjusted. The system evaluates the temperature reduction caused by the ethanol injection using two NTC thermal sensors. The exhaust gas temperature was determined by a type K thermocouple. The system was tested in a single cylinder diesel generator with mechanical injection at 1,750, 1,800, and 1,850 rpm in order to verify the injection frequency, the injection delays, the NOx emissions and the intake air, and exhaust gas temperature variation. It was found that the injection delays were less than 850 $$\mu $$ s. A reduction in the intake air and exhaust gas temperatures was observed as the ethanol content increased. Injections of 15 v/v% ethanol into the intake air pipe have shown a considerable reduction (60 %) in NOx emissions when compared to diesel-biodiesel blend composed of 70 v/v% mineral diesel and 30 v/v% soybean biodiesel. It was demonstrated that the addition of ethanol can be an important method to reduce the amount of NOx in the exhaust gas of Diesel engines.

Оценка экологической безопасности силовых установок с дизельными двигателями

Toxicological properties of diesel engines’ exhaust gases, in particular polycyclic aromatic hydrocarbons, as well as diesel
 engines’ exhaust gases composition, toxicity assessment technique for exhaust gases of diesel engines working at different
 types of fuel have been presented. Advantages related to use in diesels a biological fuel made on basis of vegetable oils
 have been shown.

Numerical analysis of internal flow characteristics of urea injectors for SCR dosing system

The urea SCR (selective catalytic reduction) system is an exhaust gas after-treatment system that reduces NOx from diesel engine exhaust gas. In this study, the internal flow characteristics of two types of commercial urea SCR injectors were analyzed, especially according to the injector needle lift. The two types of injectors considered in this study are the H type, which has three nozzles, and the D type, which has one nozzle. Various analysis methods were applied for evaluating and estimating the performance characteristics of the injectors. The reverse engineering method was applied for modeling commercial injectors, and a computational model was developed for simulating the mutual counteraction of the injector needle and the urea solution. The H-type injector shows relatively better urea solution supply characteristics and attains the steady flow condition faster than the D-type injector. Furthermore, the average discharge coefficient of the D-type injector is 0.53, whereas that of the H type is 0.59. The injector flow characteristics data obtained in this study could be used as basic design information for further development of urea SCR injectors.

Analyzing Of Exhaust Gas of Single Cylinder Diesel Engine by Injection of Sunflower 0il (Bio-Fuel)

Many attempts to use vegetable oils as fuel have been performed since the early days of the Diesel engine. When a Diesel engine is used with vegetable oil fuel for a short period of time, the performance and global efficiency are usually very close to Diesel fuel. However, during long-term engine tests with vegetable oils as fuel, heavy deposits build-up can be observed in the combustion chamber. These deposits can lead to engine breaks. A fuel droplet vaporization experiment proved that the deposits build-up is mainly controlled by the combustion chamber temperature. A new thermally insulated combustion chamber made it possible to raise the combustion chamber wall temperature. With this combustion chamber, the deposits were greatly reduced. To use vegetable oils as fuel, DI Diesel engines need to be redesigned to accommodate the specificity of the vegetable oils combustion, one possibility is to use a thermally insulated combustion chamber. This paper is related with performance analysis of Compression Ignition Engine using sunflower oil for different engine load from 1 kg to 10 kg and different portmanteau ratios like Portmanteau:1000, Portmanteau:7525, Portmanteau:5050, Portmanteau: 2575, and Portmanteau:0010. With the injection of above Portmanteau in different portmanteau ratio and at different load we found the exhaust emission in terms of CO emission, HC emission, Exhaust gas temperature and smoke density and performance analysis of the bio-fuel.

Additional Power Generation From Waste Energy of Diesel Engine Using Parallel Flow Shell and Tube Heat Exchanger

High temperature diesel engine exhaust gas can be an important source of heat to operate a bottoming Rankine cycle to produce additional power. In this research, an experiment was performed to calculate the available energy in the exhaust gas of an automotive diesel engine. A shell and tube heat exchanger was used to extract heat from the exhaust gas, and the performance of two shell and tube heat exchangers was investigated with parallel flow arrangement using water as the working fluid. The heat exchangers were purchased from the market. As the design of these heat exchangers was not optimal, the effectiveness was found to be 0.52, which is much lower than the ideal one for this type of application. Therefore, with the available experimental data, the important geometric aspects of the heat exchanger, such as the number and diameter of the tubes and the length and diameter of the shell, were optimized using computational fluid dynamics (CFD) simulation. The optimized heat exchanger effectiveness was found to be 0.74. Using the optimized heat exchangers, simulation was conducted to estimate the possible additional power generation considering 70% isentropic turbine efficiency. The proposed optimized heat exchanger was able to generate 20.6% additional power, which resulted in improvement of overall efficiency from 30% to 39%. Upon investigation of the effect of the working pressure on additional power generation, it was found that higher additional power can be achieved at higher working pressure. For this particular application, 30 bar was found to be the optimum working pressure at rated load. The working pressure was also optimized at part load and found that 2 and 20 were the optimized working pressures for 25% and 83% load. As a result 1.8% and 13.3% additional power were developed, respectively. Thus, waste heat recovery technology has a great potential for saving energy, improving overall engine efficiency, and reducing toxic emission per kilowatt of power generation.

Pilot-Scale Aftertreatment Using Nonthermal Plasma Reduction of Adsorbed NOx in Marine Diesel-Engine Exhaust Gas

Regulations governing marine diesel engine NOx emissions have recently become more stringent. As it is difficult to fulfill these requirements by combustion improvements alone, effective aftertreatment technologies are needed to achieve efficient NOx reductions. In this study, we develop an effective NOx-reduction aftertreatment system for a marine diesel engine that employs combined nonthermal plasma (NTP) and adsorption. Compared with selective catalytic reduction, the proposed technology offers the advantages of not requiring a urea solution or harmful heavy-metal catalysts and low operating temperatures of less than 150 °C. The NOx reduction comprises repeated adsorption and desorption flow processes using NTP combined with NOx adsorbents made of MnOx–CuO. High concentrations of NOx are treated by NTP after NOx adsorption and desorption, and this aftertreatment system demonstrates excellent energy efficiencies of 161 g(NO2)/kWh, which fulfills the most recent International Maritime Organization emission NOx standards in the Tier II–III regulations for 2016 and requires only 4.3 % of the engine output power.

Performance and emissions analysis of additional ethanol injection on a diesel engine powered with A blend of diesel-biodiesel

This work shows the performance and emissions profile of a diesel engine operating with ethanol injected into the air of the inlet manifold in time with the high-pressure injection of a mixture of diesel and biodiesel. The ethanol injection uses an electronic management system that detects the high-pressure pulse in the diesel injection line as the injection trigger. The air intake temperature reduction caused by the ethanol injection could be evaluated. The tests were made in an engine at 1800rpm, connected to an electric generator. The high-pressure injection fuel was always a binary blend of diesel and biodiesel, which was supplemented by injected ethanol, producing 5 different fuel compositions. The first of the tested compositions was the binary blend without ethanol, while the others had increasing alcohol content. The fifth composition used 15% of ethanol but had a 0.4% of the additive di-tert-butyl peroxide mixed in the main fuel. The addition of ethanol led to a reduction in diesel fuel consumption, although the overall energy expenditure was increased. The emissions profile showed a consistent reduction in NOx emissions and opacity with the addition of ethanol, breaking up the traditional inverse relationship between NOx and PM emissions, but shown an increase in CO and THC emissions. The energy analysis showed a decrease in engine efficiency with the addition of ethanol. The use of the additive showed a slight increase of engine efficiency and the reduction of the CO and THC emissions. There was a significant reduction in the air intake temperature with the use of ethanol, suggesting that part of the reduction of NOx may be attributed to this temperature reduction. It was proven that the ethanol addition can be an important method to reduce the amount of NOx in the exhaust gases of diesel engines.

A New Drying Room Heated by Marine Diesel Engine Exhaust Gas

To recycle the waste heat in the exhaust gas of marine diesel engine, a new drying room heated by marine diesel engine exhaust gas is introduced. The drying room`s structure, working principle and the main design parameters calculating methods is designed. Comparing to the traditional heating methods, this kind of drying room make full use of the heat energy and will acquire huge economic benefits.

Analysis of impact of EGR valve construction on the exhaust gas flow parameters in the engine

In this paper an analysis of the EGR valve design impact, in particular the outlet diameter, on the gasflow parameters in diesel engine (Z1505) exhaust gas recirculation system ofZetor tractor was made. For this purpose the experimental and simulation studies of gasflow through the valve were carried out. The simulations using Fluent were made. Also distribution of the pressure and velocity vectors in the area of the valve outflow was presented. Analysis of the phenomena occurring in the exhaust area of the EGR valve was made. Also influence of the outlet diameter on the flow characteristics of the EGR valve was determined.

Development of a Predictive CFD Fouling Model for Diesel Engine Exhaust Gas Systems

This article presents a numerical simulation procedure for studying soot particle deposition in diesel exhaust systems, with a particular focus on fouling layer thickness evolution. In the proposed algorithm, particle transport toward the wall, adhesion, and reentrainment of particles from the surface have been modeled, including Brownian motion and turbulent diffusion, thermophoresis, adhesion, and removal. This model has been implemented in ANSYS Fluent, which makes the inclusion of local effects possible. A cross-flow device, with a tube positioned transverse to the flow, has been simulated and tested. A comparison of the predicted fouling layer at several angular positions with the experimental observation shows acceptable agreement. This model makes it possible to predict the real depth of the fouling layer and its effects on the hydrodynamics of the flow. This model represents a valuable tool for the prediction of the main aspects of the performance of heat exchangers exposed to fouling.

Ammonia as hydrogen carrier for transportation; investigation of the ammonia exhaust gas fuel reforming

In this paper we show, for the first time, the feasibility of ammonia exhaust gas reforming as a strategy for hydrogen production used in transportation. The application of the reforming process and the impact of the product on diesel combustion and emissions were evaluated. The research was started with an initial study of ammonia autothermal reforming (NH3 – ATR) that combined selective oxidation of ammonia (into nitrogen and water) and ammonia thermal decomposition over a ruthenium catalyst using air as the oxygen source. The air was later replaced by real diesel engine exhaust gas to provide the oxygen needed for the exothermic reactions to raise the temperature and promote the NH3 decomposition. The main parameters varied in the reforming experiments are O2/NH3 ratios, NH3 concentration in feed gas and gas – hourly – space – velocity (GHSV). The O2/NH3 ratio and NH3 concentration were the key factors that dominated both the hydrogen production and the reforming process efficiencies: by applying an O2/NH3 ratio ranged from 0.04 to 0.175, 2.5–3.2 l/min of gaseous H2 production was achieved using a fixed NH3 feed flow of 3 l/min. The reforming reactor products at different concentrations (H2 and unconverted NH3) were then added into a diesel engine intake. The addition of considerably small amount of carbon – free reformate, i.e. represented by 5% of primary diesel replacement, reduced quite effectively the engine carbon emissions including CO2, CO and total hydrocarbons.

New Technologies for Marine Diesel Engine Emission Control

Atmospheric emissions of pollutants from marine diesel engines fuelled with heavy fuel oils contribute significantly to environmental pollution. To limit the presence of such pollutants in the environment, the International Maritime Organization recently introduced specific regulations to control SO2, NOx and particulate concentrations in exhaust gases. This paper is a short communication on two innovative techniques for marine diesel engine exhaust gas cleaning: the Electrostatic Seawater Scrubbing and the Electron Beam/Microwave Non-Thermal Plasma. These technologies are developed within the EFP7 DEECON (Innovative After-Treatment System for Marine Diesel Engines Emission Control) project and are able to provide State-of-the-Art removal of SO2 and NOx, together with a significant removal of Volatile Organic Compounds and Diesel Particulate Matter, which are among the most toxic pollutants emitted by ships and are currently excluded in the regulations due to the absence of reliable technologies for their removal. Preliminary experimental and modelling results on the treatment of model diesel exhaust gas are reported.

Experimental Results of a Combined DBD Reactor-Catalyst Assembly for a Direct Marine Diesel-Engine Exhaust Treatment

This paper gives an overview of a robust dielectric barrier discharge reactor-catalyst construction used in a bypass of a marine diesel-engine exhaust gas system. Electrode arrangement, housing, and electrode positioning systems are discussed allowing for high temperature and reasonable vibration operation. Preliminary test results are given considering the chemical reactions, particulate matter, and CO and HC reductions. An operative removal efficiency up to 99 percent is obtained (relative percentage units with respect to initial maximal concentrations). The basics of power supply construction and output waveforms are given.

169 水-軽油エマルション燃料およびバイオ燃料使用によるディーゼル機関性能への影響(マイクロ・ナノ工学II/エンジンシステム,一般講演)

169 水-軽油エマルション燃料およびバイオ燃料使用によるディーゼル機関性能への影響(マイクロ・ナノ工学II/エンジンシステム,一般講演)

High Harmonic Surface Acoustic Wave Devices for Harsh Environment Sensor Applications

ABSTRACTSurface acoustic wave (SAW) devices are ideal candidates for gas sensors due to their small size, low cost of production and high sensitivity. Increasing restrictions on pollution and emissions create the necessity for sensors that can operate in the harsh environments found in vehicle exhaust systems and industrial production. Gallium nitride (GaN) is a robust, chemically inert, piezoelectric semiconductor, making it an attractive material for SAW devices designed to detect and monitor gases in harsh environments. In this work, SAW devices designed to operate at the 5th and 7th harmonics are fabricated on GaN thin films and their performance is measured through insertion loss, signal to noise ratio, operating frequency and quality factor. Devices are directly exposed to the exhaust gas of a common diesel engine. Device performance is then re-measured and compared. SAW devices fabricated in this work have measured operating frequencies above 1 GHz, and quality factors up to and higher than 2000, depending on the harmonic mode. SAW devices on GaN showed good chemical stability and measured changes in device performance after exhaust exposure was negligible.

Decreasing of carbon dust emissions with the exhaust gases of diesel engines by the application of alternative fuels

Methods of carbon dust content decreasing in the exhaust gases of diesel engines by means of application of alternative fuels, namely of compressed natural gas and methanol, are considered. Results of experimental and theoretical researches allowing to draw a conclusion on the effectiveness and expediency of specified fuels application are presented.

Cu-zeolite NH3-SCR catalysts for NOx removal in the combined NSR–SCR technology

The challenge of efficient NOx removal from diesel and lean-burn engine exhaust gas by combining NSR and SCR catalyst is studied. Several Cu exchanged zeolites have been prepared, varying the preparation method (ion exchange and impregnation), the copper content (1–6%) and the zeolite (BETA and ZSM5). The prepared catalysts have been characterized, and acidity, surface area, crystallinity and metal reducibility have been compared. SCR experiments under 750ppm NO, 750ppm NH3 and 9.5% O2 (Ar to balance) discriminated low copper loading, prepared by ion exchange catalyst (Z-IE-1.4 and B-IE-2.1) as the most active for NOx conversion (>95%) in ample temperature range (280–450°C). These active SCR catalysts were placed downstream a monolith NSR Pt–BaO/Al2O3 catalyst, running under cycled lean–rich conditions, and the improvement on NOx removal and selectivity to only N2 were determined. In an ample range of temperature, from 200 to 400°C, NOx conversion was increased in more than 30%, also notably increasing the production of nitrogen, and reducing production of ammonia and N2O below 3% and 2%, respectively, when comparing the combined NSR–SCR configuration versus the single NSR catalyst.

Deposition–precipitation versus anionic-exchange Au/Al2O3 catalysts: A comparative investigation towards the selective reduction of NOx

Catalytic properties of supported gold catalysts on γ -Al 2 O 3 prepared by a conventional deposition–precipitation method were compared with those obtained by anionic‐exchange for the reduction of NO x by hydrocarbon under lean conditions that simulate Diesel engine exhaust gas. Interestingly, a catalytic activity enhancement is observed after thermal ageing under reactive conditions at 500 °C on anionic-exchanged samples which make them suitable for practical developments. On the other hand, the reverse trend is observed on the solids prepared by deposition–precipitation which deactivate at low temperature. Such changes in catalytic properties have been tentatively explained on the basis of textural and structural modifications taking place during thermal ageing under wet atmosphere. ► Redispersion of gold species under operating conditions in wet atmosphere at 500 °C. ► Surface reconstructions inducing selectivity enhancement toward N 2 production. ► Detrimental effect of pre-reductive treatment on the selective NO conversion to N 2 . ► Anionic exchange Au/Al 2 O 3 as promising issue in DeNO x catalysis.

Reduction of nitric oxides' content in the exhaust gases of diesel engine by means of methanol application with usage of double fuel supply system

Д-21А1 (2Ч 10.5/12.0) tractor diesel engine was researched for the improvement of ecological performance by methanol application with the use of double fuel supply system in Vyatka State Agricultural Academy. Possibility of improvement of ecological performance of a diesel engine, in particular the reduction of nitric oxides in exhaust gases, economy of diesel fuel and increase of effective results, is established.

Valve steel oxidation rate in the exhaust gases of diesel engines fueled with 5% biocomponent diesel oil

Out of the many components of four-stroke diesel engines the exhaust valves are under significant constant thermal and mechanical loads. They operate in a highly corrosive environment of hot exhaust gases. The durability of these elements is determined by the creep resistance of steel i.e. simultaneous resistance to mechanical deformations under high temperatures and the resistance of the surface to corrosive hot exhaust gases. Long term cyclic heating and burning of the exhaust valves in the exhaust gases whose main components are oxygen, carbon dioxide and superheated steam results in a simultaneous rrosion of the steel surface and core diffusion of carbon and alloy elements in the thin layer of the steel surface. In extreme operating conditions this may lead to a deformation of the exhaust valves, a reduction of the air tightness of the combustion chamber or damage or destruction of the engine. The paper discuses the results of investigations of the influence of Cr, Ni, Mn and Si on the oxidation rate of high alloy austenitic valve steel in the diesel oil exhaust gases containing 5% of biocomponents. The corrosion tests were conducted in the temperate of 973 K and 1173 K under the conditions simulating the operation of the exhaust valves in diesel engines under heavy thermal loads. Based on the conducted research significant influence of the said alloy elements on the oxidation rate of the valve steel in the exhaust gases has been observed. The tests were conducted on the engine durability test stand in Automotive Research and Development Institute BOSMAL in Bielsko-Biała.