Nội dung Text: Summary of doctor thesis of engineerin: Identification of components of exhaust from automobile engines using diesel – LPG dual fuel MINISTRY OF EDUCATION AND TRAINING UNIVERSITY OF TRANSPORT AND COMMUNICATIONS VUONG VAN SON IDENTIFICATION OF COMPONENTS OF EXHAUST FROM AUTOMOBILE ENGINES USING DIESEL – LPG DUAL FUEL Major: Automobiles and Tractors Engineering Code: 62.52.35.01 SUMMARY OF THESIS FOR DOCTOR OF ENGINEERING HA NOI 2014This thesis is completed at UNIVERSITY OF TRANSPORT AND COMMUNICATIONS Scientific Advisers: 1. Ass.Prof.Dr. Cao Trong Hien 2. Ass.Prof.Dr. Dao Manh Hung Opponent 1: Prof.Dr Pham Van Lang Opponent 2: Ass.Prof.Dr Lai Van Dinh Opponent 3: Ass.Prof.Dr Tran Van Nam This thesis will be defended at Universitarian dissertation Committee at University of Transport and Communications. At …hour….date…month…year. The thesis can be found at: National Library Library of University of Transport and Communications
Trang 1UNIVERSITY OF TRANSPORT AND COMMUNICATIONS
VUONG VAN SON
IDENTIFICATION OF COMPONENTS OF EXHAUST
FROM AUTOMOBILE ENGINES USING
DIESEL – LPG DUAL FUEL
Major: Automobiles and Tractors Engineering Code: 62.52.35.01
SUMMARY OF THESIS FOR DOCTOR OF ENGINEERING
HA NOI - 2014
Trang 2This thesis is completed at UNIVERSITY OF TRANSPORT AND COMMUNICATIONS
Scientific Advisers:
1 Ass.Prof.Dr Cao Trong Hien
2 Ass.Prof.Dr Dao Manh Hung
Ass.Prof.Dr Tran Van Nam
This thesis will be defended at Universitarian dissertation Committee
at University of Transport and Communications
Trang 3INTRODUCTION
1 Background of the study
Exhaust emission from automobiles using diesel fuel is one of the factors causing air pollution, particularly in urban areas Among the research plans to reduce the emission of toxic substances from the diesel engine, many scientists are interested in the use of diesel - LPG dual fuel engine A lot of developed countries in the world have put finance and efforts into this research
When this method is applied, it will help to solve the two following problems: protecting air environment and taking advantage of available fuel resources in many parts of the world while fossil fuels are gradually running out
In Vietnam, LPG application for internal combustion engines has been interested in many studies, but not really in-depth The research results only stopped at using LPG fuel for the engine but not interested in optimizing fuel supplying system, combustion and pollutant formation yet
With that situation, calculating and identifying components of exhaust from automobile engines using diesel - LPG dual fuel becomes imperative and incredibly practical
2 Purposes of the study
- To identify the content of emission components when the LPG supply system is fitted into diesel engine
- To assess the effect of reducing emissions of diesel - LPG dual fuel engine
3 Subjects and scope of the study
* The subject of the study: This thesis focuses on engines using diesel
- LPG dual fuel mounted on small and medium -sized automobiles
* The scope of the study: This thesis studies the exhaust emission of
the selected object on the basis of remaining all the specifications (torque capacity) of the original diesel engine
4 Methods of the study
This study combines theoretical research with empirical research
* In theory: Using theory of heat exchange and mass exchange of
internal combustion engines, using AVL - BOOST software to simulate the engine working process and calculate the content of emissions
* In empiric: The experiment was carried on the modern test tape
according to ECE cycle of Vietnam Register Department to determine the amount of harmful exhaust, and base on the result to adjust the theoretical
Trang 4calculation results
5 The scientific and practical meanings
* Scientific meaning: The thesis developed simulation models to
evaluate the emissions of diesel – LPG dual fuel engine The calculation results were compared and verified by experiment on the system of modern testing equipment with international standards
* Practical meaning: The results of the thesis are the basis for
evaluating environmental performance and engine power when using diesel – LPG dual fuel
Chapter I OVERVIEW OF RESEARCH PROBLEMS
1.1 Overview of environmental pollution caused by automobiles’ emissions
1.1.1 The development of transportation in Vietnam
In recent years, along with economic growth, the demand for transportation of people and goods in Vietnam has increased rapidly This has led to the increase of number of transport vehicles, especially ones using diesel fuel The increasing number of vehicles while the transportation infrastructure has not developed causes pressure on the environment, especially in urban areas
1.1.2 Environmental pollution caused by automobiles’ emissions in Vietnam
The increasing numbers of Transportation vehicles in undeveloped infrastructure causes traffic jams in big cities Meanwhile we do not have any effective controlling measures to reduce emissions leading to the alarming rate of air pollution in big cities, especially in Hanoi and Ho Chi Minh City
1.2 Production and utilization of LPG
1.2.1 Production of LPG
1.2.1.1 Production of LPG in the world
The total supply of LPG in the world reached 198 million tons in
2000 and 239 million tons in 2008 The growth rate of the LPG supply in the world increased 2.4 % / year in 2000-2008 In 2013, the world supply could reach 260 million tons and is expected to reach 291.7 million tons in
2015
1.2.1.1 Production of LPG in Vietnam
Vietnam has about 3,000 billion m3 of gas concentrated mainly in our continental shelf In 2009, Dinh Co gas processing factory began producing
Trang 5LPG (about 29,000 tons / month) serving for industrial and consumer products From the second quarter of 2009, the Dung Quat oil filtration factory has officially gone into operation and produced LPG to meet the needs of LPG in the whole country
1.2.2 The utilization of LPG
In the world: The use of LPG in the world focuses on four fields: domestic consumption accounts for nearly 50 % , followed by the chemicals field with 24 % , the use of LPG in industry is at the third rank with total consumption accounting for about 13 % , while transport only ranks the fourth with a total annual consumption of 8.8 %
In Vietnam: Demand for LPG in Vietnam in recent years has increased very quickly In 2015, the demand for LPG is expected to be about 1.5 million tons and 2 million tons by 2020 However, in our country, LPG is mainly used as fuel; the use of LPG for transportation means is not popular
1.3 Domestic and foreign studies on emissions of diesel engines and diesel – LPG engines
1.3.1 The research results in the world
In the world, there have been many studies in this field , as typical : Works of BEROUN and MARTINS , Z.H Zhang , C.S Cheung , T.L Chan and C.D Yao , Bogdan Cornel BENEA and Adrian Ovidiu SOICA , Dong Jian , Gao Xiaohong , Li Gesheng and Zhang Xintang , Thomas Renald C.Ja and Somasundaram P , MP Poonia However, those studies focused mainly on engines mounted on passenger cars, large trucks and specialized vehicles The number of researches using diesel - LPG engines fitted on small cars is very limited
1.3.2 The research results in the country
In Vietnam, there have been some studies on the engines using diesel
- LPG dual fuel such as the studies of Bui Van Ga , Pham Minh Tuan , Le Anh Tuan , Pham Huu Tuyen , Mai Son Hai , Tran Thanh Hai Tung , Le Minh Xuan and Vu An The initial results showed that automobiles using diesel – LPG dual fuel helpes to reduce the harmful emissions, especially its ability to reduce PM emissions on some engines However, there have not been any completed studies of diesel - LPG engine fitted on small cars
1.4 Conclusion of Chapter I
Among many research plans to reduce the emission of toxic substances from the diesel engine, the scientiests are very interested in the use of diesel - LPG dual fuel engine Many developed countries in the world have put their finance and efforts into this research
Trang 6In Vietnam LPG applications for internal combustion engines has been interested in many studies, but not really in-depth The research results only stopped at using LPG fuel for the engine but not interested in optimizing fuel supplying system, combustion and pollutant formation yet
Chapter II THEORETICAL BASIS OF CALCUALTING COMPONENTS OF EXHAUST EMISSION FROM DIESEL AND DIESEL – LPG ENGINES
2.1 Mixture of diesel – LPG dual fuel
Based on the advantages and disadvantages of these methods and to meet the research objectives, the study chose to inject the LPG into charging pipe to survey and empiric The diagram of LPG supply system into diesel engine is presented in Figure 2.4
Figure 2.4 Diagram of LPG supply system and turbochargers diesel fuel system
1 Air filters; 2 Charging air coolers; 3 Exhaust pipe 4 High pressure pump 5 Coarse filters; 6 Turbochargers; 7 Nozzle; 8 The pipeline takes the pressure loading; 9 Vaporized LPG Pipeline; 10 Fuel pump; 11 LPG flow control valve; 12 Crystal filters; 13 LPG cylinders; 14 LPG Pipeline; 15 Engine cooler; 16 Diesel fuel tank; 17 Vaporized depression
Trang 7-25 25 75 125 175 225 275
-25 25 75 125 175 225 275
340 1 2 4
2.2 Theoretical basic of diesel engine and diesel – LPG engine
2.2.1 Combustion process in diesel engines
Combustion process in diesel engines can be divided into 4 phases: Late Fire, rapid fire, main fire ( slow fire ) and dropped fire
2.2.2 Combustion process in diesel – LPG dual fuel engines
Combustion process in diesel – LPG dual fuel engines is rather
complicated because of the combination of combustion in gasoline engines and diesel engines Besides late fire and dropped fire as the diesel fuel engine, the combustion process can be divided into 3 main phases
- Phase 1: The rapid fire with diesel fuel and a small portion of fuel gas
- Phase 2: The rapid fire with most of LPG fuel and a portion of diesel fuel
- Phase 3: The diffusion fire of diesel and remaining gas
100 % diesel
75, 9 diesel + 24, 1 %
Crank’s angle of rotation(Degree)
Figure 2.8 Calorific process in diesel – LPG engine
2.2.3 Modeling basic of producing the mix and combustion in Diesel - LPG dual fuel engine
Modeling basic of producing the mix and combustion are based on the
Trang 8- The first thermodynamics equation
- Solvent mixture model is described by the components forming the mixture including diesel fuel, LPG (C3H8, C4H10), O2, N2, CO2, H2O, CO, and H2
- Heat transfer model is calculated according to the Woschni formula
2.3 The exhaust components
Toxic products of combustion in diesel engines and diesel - LPG engines included the following materials: HC, NOx, SO2, and dust particles (PM)
2.4 Calculation base of emission component in diesel engines and diesel – LPG engines
2.4.1 Calculating the NOx emission
The formation of NOx is calculated based on parameters such as engine speed, fuel components, pressure, temperature, air intake coefficient
λ, volume and mass, burning time as well as areas of burning
2.4.2 Calculating the CO emission
CO is combustion product lack of O2, mainly produced from the incompleted combustion Therefore, CO can be calculated based on the responses according to A Onorati:
CO + OH ↔ CO2 + H;
CO2 + O ↔ CO + O2
2.4.3 Calculating the HC emission
For diesel engines, HC component generated in the process of working is negligible, so most of the research on exhaust of diesel engine has not mentioned the calculation of this component
2.4.4 Calculating the soot emission (Soot)
Soot emission is calculated according Hiroyasu model In this model , the change of the soot volume is calculatedvia the formula:
Trang 9inject LPG into charging pipe of the original diesel engine was selected as the research plan This plan has several advantages such as compact structure, simple installation, no improvement to the original diesel engine
The study used Vibe 2 zone fire model, the reactions of Zeldovich chain with speed coefficient to calculate the amount of NOx, the reactions according to A Onorati to calculate CO, Hiroyasu model to calculate emissions of soot in the exhaust of diesel engines and diesel- LPG engines
Chapter III DEVELOPING MODEL TO IDENTIFYING COMPONENTS OF EXHAUST FROM DIESEL ENGINE AND DIESEL – LPG ENGINE
3.1 AVL BOOST software
Based on the objectives and content of the study, the researcher chose
to calculate the emission of diesel engine by the simulation software With the available features and tools, AVL - BOOST can develop the model and calculate the exhaust components of the engine
3.2 Application of AVL - BOOST software in calculating exhaust components of the FAWDE - 4DX23 engine
3.2.1 The basic parameters of FAWDE - 4DX23 engine
FAWDE - 4DX23 - 110 engine is the turbocharged diesel engine made in China This engine is used on passenger cars and small and medium trucks Rated power at 2800 rev / min is 81 KW, max torque at
3.2.2.2 Liquefied petroleum gas (LPG)
The chemical composition of LPG is mainly paraffinic hydrocarbon types, general formula is: CnH2n+2 such as : Propane (C3H8), Butane (C4H10), Pentane (C5H12)… In addition, in LPG there are Ethane (C2H6), Ethylen (C2H4), Butadiene (C4H4) but they account for a very small percentage
3.2.3 Developing the diesel model on AVL - BOOST
Based on the structure of motor in fact, the elements defined in AVL - BOOST and the specifications of the engine, FAWDE 4DX23 - 110 - engine model can be built as in Figure 3.2 The function name of the elements on the simulation model are presented in Table 3.4
Trang 10After developing the model, the input data was entered basing on the specifications of the engine, then run the program and export the results
3.2.4 Verifying the accuracy of the model
The accuracy of the model was assessed by comparing the results such as power, torque between the experimental results (the manufacturer has tested and recorded in catalog before taking out the factory) with simulation results The simulation results showed that the highest deviation range of the engine capacity was 6.48 % at the speed 1400 vg/ph and the lowest is 1.13 %, this deviation range is acceptable
3.2.5 Developing diesel - LPG engine model on AVL - BOOST
The basic difference between combustion model in diesel – LPG engine and diesel engine is the fuel component for the cycle However, various factors such as late combustion characteristics, heat exchange coefficient , combustion speed when replacing LPG into diesel fuel has been defined by the definition the nature of the fuel using (although the general formula for the calculation is the same) Besides the basic parameters such as low calorific value, A / F ratio, fuel is defined through the thermodynamic parameters (heat capacity, enthalpy, entropy ) for the process of calculating and conversion chemical energy into calorific energy The developed model will be verified experimentally (it will be conducted
in the next part of this study) If simulation results are much different from empirical results, it can be adjusted the parameter a, m of Vibe 2 zone fire model when building the model
To build the diesel – LPG engine model on AVL - BOOST, it must be
Figure 3.2 The simulation model of FAWDE- 4DX23-110 engine on AVL-BOOST
Trang 11based on the layout of LPG supply system into diesel engine and the way to mix them According to the selected plan, LPG will be injected into the engine's charging pipe Thus on the model of diesel – LPG engine , apart from the basic elements such as original diesel engine model will have more injector ( I1 ) to simulate the process of providing LPG
In the declaration on the input parameters for the model, in Classic Specles Setup Section, after selecting fuel for diesel engine, it is necessary
to declare the chemical compositions of LPG, rate of Propane and Butane
3.2.6 Computational simulation results
The simulation results of exhaust components of diesel engine and diesel - LPG engine when running under ECE R49 cycle are showed in the figure (3.7), (3.8), (3.9) and Table 3.8
The simulation results in Figure 3.7 above shows that , when running according to ECE R49 test cycle ,there is an increase of CO , the average increase in LPG mode replaced 10 % of diesel by 77.42 % and in LPG mode replace 20 % diesel by 151.8 % compared with using 100 % diesel
Figure 3.5 Simulation model of diesel - LPG engine on AVL-BOOST
I1
Trang 12The simulation results in Figure 3.8 above shows that the concentration of NOx in diesel- LPG engine decreased, In the LPG mode replacing 10 % diesel, the average reduction is 3,427 % and the LPG mode replacing 20 % diesel, the average reduction is 6,178 % comparing with 100
% diesel
For soot emission, the result shows that when using dual fuel, soot level fell average 16.76 % in the LPG mode replacing 10 % diesel and the average reduction is 25.4 % in the LPG mode replacing 20 % diesel
Figure 3.7 CO emission in the simulation modes according to ECE R49 cycle
Figure 3.8 NOx emission in the simulation modes according to ECE R49 cycle
Diesel LPG_10 LPG_20
Diesel LPG_10 LPG_20