scholarly journals Research on Clean Combustion Technology of EGR-based Flameproof Diesel Engine

2021 ◽  
Author(s):  
WANG Xiao
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
Coal Mine ◽  
Combustion Process ◽  
Weighted Average ◽  
Control Program ◽  
Operating Mode ◽  
Bench Test ◽  
Nox Emissions ◽  
Clean Combustion

Abstract In view of the serious pollution of NOx emissions from flame-proof diesel engines used in coal mines and its direct and indirect hazards that cannot be ignored, the combustion process of flame-proof diesel engines is analyzed and a combustion mathematical model is established. Subsequently, the clean combustion method based on exhaust gas recirculation (EGR) is adopted, and an EGR clean combustion device is designed, which meets the requirements of the coal mine standard Safety Regulations on Coal Mine . The design content involves: (i) Composition and structure design of EGR system meeting the requirements of flame-proof standards; (ii) The closed forced cooling cycle design of the EGR system. Specifically, the clean combustion process of flame-proof diesel engine based on EGR system is simulated and analyzed by fluid simulation analysis software, and the effects of EGR system on the performance and emission of flame-proof diesel engine under 15 operating modes of three rotational speeds and five loads are obtained. Then, the control strategy and control program of the EGR system of flame-proof diesel engine are compiled based on the mathematical model and simulation results. In addition, the bench test of the flame-proof diesel engine equipped with EGR device is carried out by using this control program in the laboratory, and the control program of EGR system is modified by analyzing the experimental data. Finally, the optimized bench test is carried out by selecting the control program that optimal matches the flame-proof EGR device and the flame-proof diesel engine. The test results suggest that: (i) Under the external characteristic working mode: after installing the EGR system, the power of the flame-proof diesel engine is 58.9kW under the optimized EGR opening, and the highest output torque is 252.3 Nm, and the power performance is slightly lower than that of the original engine; (ii) Under eight operating mode: after installing the EGR system, the weighted average CO emission of the flame-proof diesel engine under the optimized EGR opening is 0.0045%, and the volume concentration is increased by 0.0045% compared with that without the EGR system; the weighted average NOx emission of the flame-proof diesel engine under the optimized EGR opening is 93.35ppm, which is 56.17% lower than that without the EGR system, indicating that the EGR system technology has significantly improved the reduction of NOx emissions of the flame-proof diesel engine; (iii)Under eight operating mode: after installing EGR system, the HC emission of flame-proof diesel engine under optimized EGR opening is basically unchanged compared with that without EGR system, and the soot emission is slightly increased; and (iv) The EGR system meets the requirements of the coal mine standard, and this method and technology can improve the basis for reducing the NOx emission from the tail gas of the underground vehicles in the coal mine.

Influence of Imperfections in the Working Media on Diesel Engine Indicator Process: Part 2 — Results

1998 ◽  
Author(s):  
Stanislav N. Danov ◽  
Ashwani K. Gupta
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
High Pressures ◽  
Combustion Process ◽  
Ideal Gas ◽  
Working Medium ◽  
High Pressures And Temperatures ◽  
Specific Heat Capacities ◽  
Working Media ◽  
The Mathematical Model

Abstract In the companion Part 1 of this two-part series paper several improvements to the mathematical model of the energy conversion processes, taking place in a diesel engine cylinder, have been proposed. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been used to provide an improved mathematical model of diesel engine indicator process. The model is based on the first law of thermodynamics, by taking into account imperfections in the working media which appear when working under high pressures and temperatures. The numerical solution of the simultaneous differential equations is obtained by Runge-Kutta type method. The results show that there are significant differences between the values calculated by equations for ideal gas and real gas under conditions of high pressures and temperatures. These equations are then used to solve the desired practical problem in two different two-stroke turbo-charged engines (8DKRN 74/160 and Sulzer-RLB66). The numerical experiments show that if the pressure is above 8 to 9 MPa, the working medium imperfections must be taken into consideration. The mathematical model presented here can also be used to model combustion process of other thermal engines, such as advanced gas turbine engines and rockets.

Experimental Study on the Combustion Process and Performance of Diesel Engines Fueled by Emulsion Diesel With Novel Organic Additives

2013 ◽  
Author(s):  
Wenming Yang ◽  
Hui An ◽  
Jing Li ◽  
Amin Maghbouli ◽  
Kian Jon Chua
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Combustion Process ◽  
Nox Emissions ◽  
Organic Additives ◽  
Oil Droplets ◽  
And Performance ◽  
One Year

Transportation is one of the major contributors to the world’s energy consumption and greenhouse gases emissions. The need for increased efficiency has placed diesel engine in the spotlight due to its superior thermal efficiency and fuel economy over gasoline engine. However, diesel engines also face the major disadvantage of increased NOx emissions. To address this issue, three types of emulsion fuels with different water concentrations (5%, 10% and 15% mass water) are produced and tested. Novel organic materials (glycerin and ployethoxy-ester) are added in the fuel to provide extra oxygen for improving combustion. NP-15 is added as surfactant which can help to reduce the oil and water surface tension, activates their surface, and maximizes their superficial contact areas, thereby forming a continuous and finely dispersed droplets phase. The stability of the emulsion fuels is tested under various environmental temperature for one year, and no significant separation is observed. It is better than normal emulsion fuel which can only maintain the state for up to three months. The combustion process and performance of the emulsion fuels are tested in a four-stroke, four cylinder diesel engine. The results indicate that the water droplets enclosed in the emulsion fuel explode at high temperature environment and help to break up the big oil droplets into smaller ones, thereby significantly increase the surface area of the oil droplets and enhance the heat transfer from hot gas to the fuel. As a result, the fuel evaporation is improved and the combustion process is accelerated, leading to an improved brake thermal efficiency (up to 14.2%). Meanwhile, the presence of the water causes the peak temperature of the flame to drop, thereby significantly bringing down the NOx emissions by more than 30%.

Economy and Emissions Characteristics of Emulsified Diesel Fuels from Diesel Engine

2011 ◽  
Vol 347-353 ◽  
pp. 3915-3919 ◽  
Author(s):  
Jun Liu ◽  
Zhen Bin Chen ◽  
Ming Wei Xiao ◽  
Sheng Jun Jiang
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Fuel Economy ◽  
Alternative Fuel ◽  
Bench Test ◽  
Nox Emissions ◽  
Diesel Fuels

To meet demands for improvements in the CO,NOx and smoke intensity and fuel economy from diesel engine,the emulsified diesel fuel are choose as alternative fuel .It is prepared through selecting appropriate compound-surfactants on the basis of the HLB (hydrophilic and lipop- hilic balance) value.Comparative experiments between the emulsified fuels and diesel are undertook based on engine bench test in the model 295A diesel engine without any modification. The results indicate that smoke intensity and NOx emissions are reduced greatly when using the emulsified fuels ,especially for those with glucose Solution.Besides,The fuel consumption of the emulsified fuels s are less than that of pure diesel and the economy characteristic from diesel engine is better.

scholarly journals Study on the Combustion Process and Emissions of a Turbocharged Diesel Engine with EGR

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Mei Deqing ◽  
Qian Junnan ◽  
Sun Ping ◽  
Miao Yan ◽  
Zhang Shuang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Combustion Process ◽  
Operating Mode ◽  
Emission Characteristics ◽  
Turbocharged Diesel Engine ◽  
Compressed Gas ◽  
Order Polynomial ◽  
Increase Rate ◽  
Smoke Opacity

A high pressure EGR system was adopted to a turbocharged inter-cooled diesel engine, to analyze its combustion and emission characteristics under the condition of different loads and constant speed. Under the same steady operating mode, with the increase of EGR rate, the temperature of compressed gas ascended, the ignition delay was shortened, the pressure and temperature of the burned gas descended, and the combustion process was prolonged. According to the experimental data, it was found that, at the same EGR rate, lower the load of engine was, lower the temperature in cylinder, and higher the increase rate of CO was. However, the increase rate of HC present a falling trend. The decrease rate of the specific emission of NOxlinearly varied with EGR rate with a slope of 1.651. The increase rate of smoke opacity behaved a second-order polynomial uprising trend, and the higher the load was, the sharpener the smoke opacity deteriorated, with the increase of EGR rate. From the point of emission view, the engine with EGR system can achieve the lesser exhaust emissions in some operations by adjusting the engine parameters.

scholarly journals Effects of Injection Rate Profile on Combustion Process and Emissions in a Diesel Engine

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Fuqiang Bai ◽  
Zuowei Zhang ◽  
Yongchen Du ◽  
Fan Zhang ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Combustion Process ◽  
Injection Rate ◽  
Injection System ◽  
Nox Emissions ◽  
Release Process ◽  
Common Rail Injection System ◽  
Soot Emissions ◽  
Rate Profile

When multi-injection is implemented in diesel engine via high pressure common rail injection system, changed interval between injection pulses can induce variation of injection rate profile for sequential injection pulse, though other control parameters are the same. Variations of injection rate shape which influence the air-fuel mixing and combustion process will be important for designing injection strategy. In this research, CFD numerical simulations using KIVA-3V were conducted for examining the effects of injection rate shape on diesel combustion and emissions. After the model was validated by experimental results, five different shapes (including rectangle, slope, triangle, trapezoid, and wedge) of injection rate profiles were investigated. Modeling results demonstrate that injection rate shape can have obvious influence on heat release process and heat release traces which cause different combustion process and emissions. It is observed that the baseline, rectangle (flat), shape of injection rate can have better balance between NOx and soot emissions than the other investigated shapes. As wedge shape brings about the lowest NOx emissions due to retarded heat release, it produces the highest soot emissions among the five shapes. Trapezoid shape has the lowest soot emissions, while its NOx is not the highest one. The highest NOx emissions were produced by triangle shape due to higher peak injection rate.

scholarly journals Two-Stroke Low Speed Diesel Engine Simulation Model for NOx Analysis

2017 ◽  
Vol 6 (1) ◽  
pp. 14-23
Author(s):  
Branko Lalić ◽  
Nikola Račić ◽  
Gojmir Radica
Keyword(s):  
Diesel Engine ◽  
Simulation Model ◽  
Flame Temperature ◽  
Combustion Process ◽  
Nox Emissions ◽  
Oxide Formation ◽  
Slow Speed ◽  
Engine Simulation ◽  
Excess Air ◽  
Marine Engines

All commercial marine engines have to comply with IMO regulations on emissions, especially of nitrogen oxides. This paper describes the gases produced in the combustion process in the diesel engine, and the manner of pollutant creation. Several models of slow-speed diesel engines have been developed and analysed. The characteristics of the simulation model are compared with the characteristics obtained on the testbed, and their differences considered. Using the term for the formation of NOx, as well as independently developed programs in MATLAB, the rate of nitrogen oxide formation was obtained as a function of excess air, pressure and temperature. The reduction of excess air increases adiabatic flame temperature and has an effect on NOx emissions. The obtained results are compared with the actual values measured on the testbed.

Combustion process and NOx emissions of a marine auxiliary diesel engine fuelled with waste cooking oil biodiesel blends

Energy ◽  
2018 ◽  
Vol 144 ◽  
pp. 73-80 ◽  
Author(s):  
Lijiang Wei ◽  
Rupeng Cheng ◽  
Hongjun Mao ◽  
Peng Geng ◽  
Yanjie Zhang ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Waste Cooking Oil ◽  
Nox Emissions ◽  
Biodiesel Blends ◽  
Cooking Oil

scholarly journals Experimental Study of Injection Parameters on the Performance of a Diesel Engine with Fischer–Tropsch Fuel Synthesized from Coal

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3280 ◽  
Author(s):  
Jinhong Shi ◽  
Tie Wang ◽  
Zhen Zhao ◽  
Tiantian Yang ◽  
Zhengwu Zhang
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Injection Pressure ◽  
Injection Timing ◽  
Nox Emissions ◽  
Cylinder Pressure ◽  
Fischer Tropsch ◽  
Ignition Point ◽  
Injection Parameters ◽  
Combustion Emissions

Experimental research was conducted on a turbo-charged, inter-cooling and common-rail diesel engine with Fischer–Tropsch fuel synthesized from Coal-to-liquid (CTL), in order to investigate the influence of different injection parameters on the combustion, emissions and efficiency characteristics of the engine. The results showed that the ignition point was advanced, the in-cylinder pressure and heat release rate increased as the injection timing advanced and the injection pressure increased. By comparing the peak in-cylinder pressure of 100 cycles for one sample, it was found that the coefficient variation (COV) remained under 2% throughout the tests and the combustion process remained stable. NOx emissions decreased with delayed injection timing and lower injection pressure. In contrast to NOXNOx emissions, soot emissions were almost zero when the injection pressure was up to 143.5 MPa. The indicated thermal efficiency (ITE) showed no obvious change with different injection parameters, and remained under 40% in all the tests.

scholarly journals Study of performance and emissions in diesel engines operating with biodiesel from soybean oil and water emulsions

2021 ◽  
pp. 19-29
Author(s):  
Sofia Orjuela-Abril ◽  
Jhan Piero Rojas-Suárez ◽  
Jorge Eliécer Duarte Forero
Keyword(s):  
Diesel Engine ◽  
Soybean Oil ◽  
Fuel Consumption ◽  
Rotation Speed ◽  
Combustion Process ◽  
Calorific Value ◽  
Nox Emissions ◽  
Performance And Emissions ◽  
Smoke Opacity ◽  
Polluting Emissions

This study evaluates the influence on the combustion process, fuel consumption, and polluting emissions in a diesel engine, which operates with biodiesel from soybean oil and water emulsions with percentages of 4% and 8%. For this study, a stationary diesel engine operating at four different torque conditions and a fixed rotation speed of 3400 rpm is used. Test fuels are diesel, soybean oil biodiesel, and SB4W and SB8W water emulsions. The results indicate that SB4W and SB8W cause a 6% reduction in calorific value and an 18% and 1% increase in viscosity and density. However, the presence of water in biodiesel can help reduce engine BSFC by 8%. The SB4W and SB8W allow a 23% reduction in NOx emissions. With the use of SB4W fuel, a reduction of 16%, 29%, and 14% in CO, HC, and smoke opacity is obtained compared to soybean oil biodiesel. The maximum inclusion of 8% water in soybean oil biodiesel is recommended since a higher percentage can cause the presence of incomplete combustions.

Mathematical Model of Diesel Engine Combustion Process: Part 1 — Theory

1997 ◽  
Author(s):  
Stanislav N. Danov ◽  
Ashwani K. Gupta
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Diesel Engine ◽  
Differential Equations ◽  
Diffusion Flame ◽  
Fuel Injection ◽  
Diffusion Flames ◽  
Direct Injection ◽  
Combustion Process ◽  
And Diffusion

Abstract A mathematical model of combustion process in a diesel engine has been developed. The combustion process is considered to have both the premixed and diffusion flame. The combustion of fuel vaporized during the self-ignition delay period is modeled according to the conditions of premixed flame. A kinetic differential equation has been formulated for modeling this kind of combustion. The combustion of fuel during the injection process is modeled according to the theory of diffusion flames. This process is strongly influenced by processes of fuel injection, vaporization and diffusion. The atomization process is taken into account by means of the Sauter mean diameter (SMD) of fuel droplets. The instantaneous vaporization rate is defined by the current values of temperature, pressure, concentration of fuel vapors and the mean fuel droplet size in terms of the SMD. The mathematical model includes differential equations describing the processes of fuel injection, vaporization, heat transfer and combustion in both the premixed and diffusion flame that takes place in the engine cylinder. The above equations are solved together with the differential equation of the first law of thermodynamics expressing the energy conversion process in the cylinder of diesel engine. The fourth-order Runge-Kutta method is applied for obtaining numerical solution of the system of differential equations. The analysis is performed on a PC using FORTRAN 90. The results have been simulated for a marine direct injection (DI) diesel engine (Model Silzer 6RLB-66) having a cylinder bore diameter of 0.66 m, and stroke of 1.4 m. The amount of fuel used in this engine during the experiments is 0.03785 kg per cycle per cylinder. The numerical experiments have been carried out for the effect of duration of fuel injection and the beginning of fuel injection (expressed in terms of degrees of crank angle before TDC) on the subsequent combustion parameters and the integral indicator parameters of the engine.

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