- Email: [email protected]
Combustion Characteristics of Biodiesel blended Gasoline Fuel in Engine like Condition using Constant Volume Combustion(CVCC)
Energy Procedia 00 (2018) 000–000 Available online at www.sciencedirect.com
ScienceDirect
www.elsevier.com/locate/procedia
Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2018) 000–000
www.elsevier.com/locate/procedia ScienceDirect ScienceDirect Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids,
REM 2017, 18–20 October 2017, Tianjin, China Energy (2018) 000–000 187–192 EnergyProcedia Procedia145 00 (2017)
www.elsevier.com/locate/procedia
Combustion Characteristics of Biodiesel blended Gasoline Fuel in Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Engine like Condition using Constant Volume Combustion(CVCC) REM 2017, 18–20 October 2017, Tianjin, China a
a
a
b
3
Shubhra Kanti Das , Hyun Jo , Kyung Hoon Jwa Ocktaeck Lim , Youngmin Woo TheCharacteristics 15th International Symposium on District Heating and Cooling Fuel in Combustion of Biodiesel blended Gasoline * Engine like Condition using Constant Volume Combustion(CVCC) Assessing of using demand-outdoor Graduatethe Schoolfeasibility of Mechanical Engineering, University ofthe Ulsan,heat Ulsan, 680-749, South Korea a Mechanical Engineering, a a Ulsan, 680-749, South b Korea 3 School of University of Ulsan, Shubhra Kanti Das , Hyunfor Jo , a Kyung Hoon Jwadistrict Ocktaeck Lim ,Daejeon Youngmin Woo temperature long-term heat demand forecast Energy Efficiency Researchfunction Division, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, 34129, Republic of Korea a)
b)
c)
*
a,b,c I. Andrić *, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc a) Graduate School of Mechanical Engineering, University of Ulsan, Ulsan, 680-749, South Korea b) Abstract a School of Mechanical Engineering, Ulsan, Técnico, Ulsan, 680-749, SouthPais Korea IN+ Center for Innovation, Technology and Policy ResearchUniversity - Instituto of Superior Av. Rovisco 1, 1049-001 Lisbon, Portugal c) Energy Efficiency ResearchbDivision, Korea Institute of Energy 152 Gajeong-ro, Yuseong-gu, Veolia Recherche & Innovation, 291Research, Avenue Dreyfous Daniel, 78520 Limay,Daejeon France 34129, Republic of Korea
This paper cDépartement is an investigation and study etofEnvironnement how combustion characteristics appear in 44300 constant volume Systèmes Énergétiques - IMT Atlantique, 4 rue Alfred Kastler, Nantes, Francecombustion chamber(CVCC) when biodiesel is mixed with pure gasoline. Experimental data for this study included four gasoline biodiesel fuel mixtures with concentrations of biodiesel of 5 and 20 designated GB05 and GB20 respectively. The study involves studying Abstract the positive aspects of combustion efficiency because biodiesel contains an oxygenated fraction. Through this study, we can find Abstract the most effective and efficient substitute fuel by comparing the total fuel mixture. Through these paper, you can improve your This paperofis gasoline an investigation studyfuels of how appear in constant volume combustion knowledge biodiesel and blended and combustion then utilize characteristics alternative fuels in high combustion efficiency and chamber(CVCC) when biodiesel is mixedcompression with pure gasoline. Experimental for this included four gasoline biodiesel District heatingfriendly networks are commonly addressed inignition the literature of the moststudy effective solutions for decreasing the environmentally modern gasoline engines.as onedata fuel mixtures gas withemissions concentrations of biodiesel of 5 andThese 20 designated GB05 and respectively. study involves greenhouse from the building sector. systems require highGB20 investments which The are returned throughstudying the heat the positive of combustion because an oxygenated fraction. Through study, we can find sales. Due to theElsevier changed climate conditions and biodiesel building contains renovation policies, heat demand in the this future could decrease, Copyright ©aspects 2018 Ltd. Allefficiency rights reserved. the most effective and efficient substitute fuel byof comparing the total fuel mixture. paper, you can improve your prolonging investment return period. Selection andthepeer-review under responsibility the scientific committee of theThrough Appliedthese Energy Symposium and Forum, knowledge of gasoline biodiesel blended fuels and intemperature high combustion and The main scope ofIntegration this paper is to assess the feasibility ofthen using the heatalternative demand – fuels outdoor function efficiency for heat demand Renewable Energy with Mini/Microgrids, REM 2017.utilize environmentally friendly modern gasoline compression ignition engines. forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665
buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district Copyright © © 2018 2018 Elsevier The Authors. Published by Elsevier Ltd. Copyright All rights reserved. renovation scenarios wereLtd. developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Selection and peer-review under responsibility of of the the scientific committee of theofApplied Energy Symposium and Forum, Selection and peer-review under responsibility scientific committee the Symposium and Forum, compared with results from a dynamic heat demand previously developed and Applied validatedEnergy by the authors. Renewable Energy Integration with Mini/Microgrids, model, REM 2017 Renewable Energy Integration with Mini/Microgrids, REM 2017. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Keywords: characteristic, CVCC, Biodiesel,Compression ignition engine (the errorSpray in annual demandCombustion was lowercharacteristic, than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the Keywords: Spray characteristic, Combustion characteristic, Biodiesel,Compression ignition engine for the scenarios considered, and coupled scenarios). The values suggested could be CVCC, used to modify the function parameters * Corresponding author. Tel.: +82) 052-259-1633; fax: +82) 052-259-1633. improve the accuracy of heat demand estimations. E-mail address: [email protected]
© 2017 The Authors. Published by Elsevier Ltd.
1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Cooling. Integration with Mini/Microgrids, REM 2017. * Corresponding author. Tel.: +82) 052-259-1633; fax: +82) 052-259-1633. E-mail address: [email protected] Keywords: Heat demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017 10.1016/j.egypro.2018.04.033
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
188 2
1. Introduction The study of combustion processes and fuel injection is the most important part of combustion research. To find a next-generation engine that targets high efficiency and low emissions, researchers need to find important parameters. Scientific understanding and experimentation on fuel injection and combustion have a direct impact on efficient combustion and reducing emissions. The study of combustion and injection takes place in a very short time domain and depends on the thermodynamic state of the surrounding environment. In addition, ambient pressure, density, temperature, air-fuel mixture, geometry of the combustion chamber also influence. Several types of combustion test methods are used to simulate and visualize cylinder-like conditions without any compression and expansion strokes within the engine. Among them, rapid compression machine, constant pressure flow rig, constant volume hot cell, constant volume pressure cell and optical research engines have been used in numerous research institutes with different research strategies. [1,2]. Figure 1 compares the operating conditions and operating conditions of various test rigs to simulate the incylinder conditions of the CI engine before fuel injection. Among different optical test rigs e.g. ORE1 [3], ORE2 [4], RCM [5], CPFR [6], CVHC [7] and CVPC [8] covers the full range in Figure 1. In this respect, CVPC, CPFR, and CVHC are found the best suited optical test rigs for the core research on free spray development and spray combustion.
Fig. 1 Operating range of different optical test rigs [3] The Constant Volume Combustion chamber (CVCC) of Ulsan University's Smart Powertrain Lab is a CVCC (Constant Volume Pressure Cell) as shown in Table 1. This CVCC was previously used to conduct an experimental survey of unreacted and unvented fuel sprays of different types of alternative fuels using multi-hole or single-hole fuel injectors with a pressurized common rail system. Test Rig
Acronym
Simulates
Optical Research Engine
ORE
These engines have optical access into the combustion chamber
Constant Volume Hot Cell
CVHC
Chamber Increases the temperature with external heat elements
Constant Volume Pressure Cell
CVPC
Chamber using pre-combustion technique to pressurize the rig to simulate the TDC conditions right before fuel injection
Rapid Compression Machine
RCM
One compression stroke during an engine cycle
Constant Pressure Flow rig
CPFR
Chamber using additional flow into the rig to pressurize the rig
Table 1 Experimental approaches to obtain in-cylinder condition of different test rig [3]
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
189 3
2. The Experimental Setup and Test Equipments 2.1 Constant Volume Combustion Chamber CVCC is a useful tool for studying the combustion characteristics of various fuels and can be used to test various types of fuel injectors and spark plug technology. CVCC can be used in combustion studies to isolate the injection and combustion processes from all affected sub-processes occurring in the engine. A schematic drawing of the experimental test facility are shown in figures 2.
Fig. 2 A picture and a schematic drawing of the experimental test facility 2.2 Composition of the Pre-combustion Reactants CVCC provides various test conditions for pressure, temperature and ambient configuration separately from the fuel injection system. The remaining oxygen content after pre-burn combustion is including both reactants (C2H2, Ar, O2, N2) and products (O2, CO2, N2, H2O). The elevated pressure and temperature for target density conditions within the CVCC are generated by spark ignition by carefully selecting the proper mixture of reactants. The composition, pressure and temperature after a socalled pre-burn event in which a combustion spray is injected are directly related to the composition of the mixture filled before ignition. Four gases are used to fill the vessel and prepare the initial reaction mixture to define the four gas characteristics at the start of the injection. C2H2 is more volatile, but C2H4 has been chosen because fewer hydrogen molecules require less heat in the chamber window to minimize moisture production and prevent condensation. Figure 3.shows diagram of controller system. Fig.3 Diagram of gas control system
2.3 Working principle of the experimental event Since CVCC has a constant volume and no moving parts to compress the charge air, the chamber is prepared by igniting the gas mixture inside the chamber. This process of preparing the test environment and obtaining test conditions that allow auto-ignition of gasoline biodiesel blended fuel after so-called pre-combustion. The temperature immediately after the pre-combustion must wait for the heat loss to reduce the chamber condition because the ambient temperature is too high to simulate the actual engine. When conditions are met, fuel is injected
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
190 4
and main combustion occurs. The gas composition inside the chamber after pre-combustion can be controlled to simulate different operating conditions. E.g. Use of EGR (Exhaust Gas Recirculation). Fuel Type
GB05, GB20
Orifice Diameter (mm)
0.33 mm
Density Range Tested, ρamb
10kg/㎥
Injection Pressure Range Tested, Pinj
400-800-1200 bar
Ambient temperature range tested
700-800-900 K
Injection duration
1200 μs
Fuel temperature
Ambient
Table 2. Non-vaporizing spray experimental condition 3. Experimental Test and Analysis Procedure 3.1 Spray combustion experiment Two different sets of experimental conditions have been implemented to visualize the fuel injection and evaporation process. Using a premixed combustion method in a constant volume combustion chamber (CVCC), simulated experimental in-cylinder engine conditions similar to compression ignition engines during fuel injection. Condition of experiment is shown in Table 2. Although it is assumed that complete combustion occurs during premix combustion, the residual gas after pre-combustion combustion is not similar to a diesel engine, but the oxygen concentration that helps to ignite the fuel spray is accurate. Composition of the pre-combustion reactants is controlled by program, which already calculated. In this study, target is 15% of oxygen in 10 kg/㎥. Figure 4. shows target of composition. Table 3. Target of composition
3.2 Fuel characteristics Fuel characteristics are the most important parameters affecting most processes during the spraying and combustion of compression ignition engines. The standard fuel specification is developed to ensure that fuel has a certain quality and ensures safe use and to distribute specific fuel from all suppliers. Biodiesel and petroleum diesel have very similar chemical and thermodynamic characteristics, but with slight differences, affecting spray and combustion characteristics and emission characteristics. Therefore, the experiment was carried out by referring to the characteristics of gasoline and biodiesel in K-petro. 3.3 Combustion characteristics Combustion characteristics are associated with the combustion process, and different fuels will exhibit different properties based on their characteristics and chemical composition. 3.3.1 Heat release rate
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
191 5
The Heat Release Rate (HRR) is calculated from the first law of thermodynamics for an open system at the rate at which the chemical energy of the fuel is converted to thermal energy when the fuel is burned [John b. Heywood]. 3.3.2 Ignition delay Ignition delay is an important characteristic for injection system design and injection timing adjustment. Delay period in the diesel engine exerts a very great influence on both engine design and performance. The delay period has been found to be different when diesel and biodiesel are used individually. The ignition delay is defined as the time between the start of injection and the start of combustion. In this study, the ignition delay will be calculated by the MFB method [8]. Figure 4 shows ignition delay tends to decrease with increasing oxygen concentration in all fuels.
Figure4. Ignition delay as a function of ambient oxygen concentration for the diesel and emulsified fuels. 3.4 Experiment This experiment measured the ignition delay when the temperature was in the range of 700 to 900K with a density of 10kg/m3 and an oxygen concentration of 15% with gasoline biodiesel blended condition GB05 and GB20. The measured values were as follows Figure 5.
Figure 5. Plots of measured ignition delays of GB05 and GB20 at different ambient gas temperature ranging from 700-900K at 10 kg/m3 and 15% O2 concentration 4. Conclusion This paper investigates the combustion characteristics of gasoline biodiesel blended fuels and studies whether they can serve as alternative fuels. Experimental results show that biodiesel is not significantly different from existing combustion characteristics even when it is mixed with gasoline. The higher the content of biodiesel, the shorter the ignition delay, which is the result of increased oxygen content in the biodiesel.
192 6
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
Acknowledgements This research was supported by The Leading Human Resource Training Program of Regional Neo industry through the National Research Foundation of Korea (NRF) funded by The Ministry of Science, ICT and Future Planning (2016H1D5A1908826). This research was financially supported by the CEFV(Center for Environmentally Friendly Vehicle) as Global-Top Project of KMOE(Ministry of Environment, Korea). References [1] Bardi M, Bazyn T, Bruneaux G, Johnson J, Lee S-Y, Malbec LM, et al. Engine Combustion Network (Ecn): Characterization and Comparison of Boundary Conditions for Different Combustion Vessels. At Sprays 2012;22:777–806. doi:10.1615/AtomizSpr.2012006083. [2] Bardi M, Payri R, Malbec LM, Bruneaux G, Pickett LM, Manin J, et al. Engine Combustion Network: Comparison of Spray Development, Vaporization, and Combustion in Different Combustion Vessels. At Sprays 2012;22:807–42. doi:10.1615/AtomizSpr.2013005837. [3] Upatnieks A, Mueller CJ, Martin GC. The influence of charge-gas dilution and temperature on DI diesel combustion processes using a short-ignition-delay, oxygenated fuel. SAE Trans 2005;114:773–85. doi:10.4271/2005-01-2088. [4] Espey C, E. DJ. Diesel engine combustion studies in a newly designes optical-access engin using high-speed visualization and 2-d laser imaging. Sae 1993;SAE-930971. doi:10.4271/930971. [6] Sung C-J, Curran HJ. Using rapid compression machines for chemical kinetics studies. Prog Energy Combust Sci 2014;44:1–18. doi:10.1016/j.pecs.2014.04.001. [5] Pastor JV, Payri R, Garcia-Oliver JM, Nerva J. Schlieren Measurements of the ECN-Spray A Penetration under Inert and Reacting Conditions. SAE Tech Pap 2012-01-0456 2012. doi:10.4271/2012-01-0456. [6] Phan A. Development of a Rate of Injection Bench and Constant Volume Combustion Chamber for Diesel Spray Diagnostics. 2009. [7] Pickett LM, Genzale CL, Bruneaux G, Malbec L-M, Hermant L, Christiansen C, et al. Comparison of Diesel Spray Combustion in Different High-Temperature, High-Pressure Facilities. SAE Int J Engines 2010;3:156–81. doi:10.4271/2010-01-2106. [8] Park SH, Lee D, Lee CS. Influence of gas-to-liquid fuel on the combustion and pollutant emission characteristics. Proc Inst Mech Eng Part D J Automob Eng 2013;228:85–93. doi:10.1177/0954407013504743. [9] Tie Li, Xiao-Qing Zhang, Bin Wang, Tao Guo, Qi Shi, Ming Zheng. Characteristics of non-evaporating, evaporating and burning sprays of hydrous ethanol diesel emulsified fuels. Fuel 191 (2017) 251–265 Biography Ocktaeck Lim received his B.S. and M.S degrees in Mechanical Engineering from Chonnam National University, Korea, in 1998 and 2002, respectively. He received his Ph.D. degree from Keio University in 2006. Dr. Lim is currently a Professor at the School of Automotive and Mechanical Engineering at Ulsan University in Ulsan, Korea. Dr. Lim’s research interests include Internal Combustion Engines, Alternative Fuel and Thermodynamics. email: [email protected]
ScienceDirect
www.elsevier.com/locate/procedia
Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2018) 000–000
www.elsevier.com/locate/procedia ScienceDirect ScienceDirect Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids,
REM 2017, 18–20 October 2017, Tianjin, China Energy (2018) 000–000 187–192 EnergyProcedia Procedia145 00 (2017)
www.elsevier.com/locate/procedia
Combustion Characteristics of Biodiesel blended Gasoline Fuel in Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, Engine like Condition using Constant Volume Combustion(CVCC) REM 2017, 18–20 October 2017, Tianjin, China a
a
a
b
3
Shubhra Kanti Das , Hyun Jo , Kyung Hoon Jwa Ocktaeck Lim , Youngmin Woo TheCharacteristics 15th International Symposium on District Heating and Cooling Fuel in Combustion of Biodiesel blended Gasoline * Engine like Condition using Constant Volume Combustion(CVCC) Assessing of using demand-outdoor Graduatethe Schoolfeasibility of Mechanical Engineering, University ofthe Ulsan,heat Ulsan, 680-749, South Korea a Mechanical Engineering, a a Ulsan, 680-749, South b Korea 3 School of University of Ulsan, Shubhra Kanti Das , Hyunfor Jo , a Kyung Hoon Jwadistrict Ocktaeck Lim ,Daejeon Youngmin Woo temperature long-term heat demand forecast Energy Efficiency Researchfunction Division, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, 34129, Republic of Korea a)
b)
c)
*
a,b,c I. Andrić *, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc a) Graduate School of Mechanical Engineering, University of Ulsan, Ulsan, 680-749, South Korea b) Abstract a School of Mechanical Engineering, Ulsan, Técnico, Ulsan, 680-749, SouthPais Korea IN+ Center for Innovation, Technology and Policy ResearchUniversity - Instituto of Superior Av. Rovisco 1, 1049-001 Lisbon, Portugal c) Energy Efficiency ResearchbDivision, Korea Institute of Energy 152 Gajeong-ro, Yuseong-gu, Veolia Recherche & Innovation, 291Research, Avenue Dreyfous Daniel, 78520 Limay,Daejeon France 34129, Republic of Korea
This paper cDépartement is an investigation and study etofEnvironnement how combustion characteristics appear in 44300 constant volume Systèmes Énergétiques - IMT Atlantique, 4 rue Alfred Kastler, Nantes, Francecombustion chamber(CVCC) when biodiesel is mixed with pure gasoline. Experimental data for this study included four gasoline biodiesel fuel mixtures with concentrations of biodiesel of 5 and 20 designated GB05 and GB20 respectively. The study involves studying Abstract the positive aspects of combustion efficiency because biodiesel contains an oxygenated fraction. Through this study, we can find Abstract the most effective and efficient substitute fuel by comparing the total fuel mixture. Through these paper, you can improve your This paperofis gasoline an investigation studyfuels of how appear in constant volume combustion knowledge biodiesel and blended and combustion then utilize characteristics alternative fuels in high combustion efficiency and chamber(CVCC) when biodiesel is mixedcompression with pure gasoline. Experimental for this included four gasoline biodiesel District heatingfriendly networks are commonly addressed inignition the literature of the moststudy effective solutions for decreasing the environmentally modern gasoline engines.as onedata fuel mixtures gas withemissions concentrations of biodiesel of 5 andThese 20 designated GB05 and respectively. study involves greenhouse from the building sector. systems require highGB20 investments which The are returned throughstudying the heat the positive of combustion because an oxygenated fraction. Through study, we can find sales. Due to theElsevier changed climate conditions and biodiesel building contains renovation policies, heat demand in the this future could decrease, Copyright ©aspects 2018 Ltd. Allefficiency rights reserved. the most effective and efficient substitute fuel byof comparing the total fuel mixture. paper, you can improve your prolonging investment return period. Selection andthepeer-review under responsibility the scientific committee of theThrough Appliedthese Energy Symposium and Forum, knowledge of gasoline biodiesel blended fuels and intemperature high combustion and The main scope ofIntegration this paper is to assess the feasibility ofthen using the heatalternative demand – fuels outdoor function efficiency for heat demand Renewable Energy with Mini/Microgrids, REM 2017.utilize environmentally friendly modern gasoline compression ignition engines. forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665
buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district Copyright © © 2018 2018 Elsevier The Authors. Published by Elsevier Ltd. Copyright All rights reserved. renovation scenarios wereLtd. developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Selection and peer-review under responsibility of of the the scientific committee of theofApplied Energy Symposium and Forum, Selection and peer-review under responsibility scientific committee the Symposium and Forum, compared with results from a dynamic heat demand previously developed and Applied validatedEnergy by the authors. Renewable Energy Integration with Mini/Microgrids, model, REM 2017 Renewable Energy Integration with Mini/Microgrids, REM 2017. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Keywords: characteristic, CVCC, Biodiesel,Compression ignition engine (the errorSpray in annual demandCombustion was lowercharacteristic, than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the Keywords: Spray characteristic, Combustion characteristic, Biodiesel,Compression ignition engine for the scenarios considered, and coupled scenarios). The values suggested could be CVCC, used to modify the function parameters * Corresponding author. Tel.: +82) 052-259-1633; fax: +82) 052-259-1633. improve the accuracy of heat demand estimations. E-mail address: [email protected]
© 2017 The Authors. Published by Elsevier Ltd.
1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Cooling. Integration with Mini/Microgrids, REM 2017. * Corresponding author. Tel.: +82) 052-259-1633; fax: +82) 052-259-1633. E-mail address: [email protected] Keywords: Heat demand; Forecast; Climate change 1876-6102 Copyright © 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. 1876-6102 Copyright © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, Renewable Energy Integration with Mini/Microgrids, REM 2017 10.1016/j.egypro.2018.04.033
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
188 2
1. Introduction The study of combustion processes and fuel injection is the most important part of combustion research. To find a next-generation engine that targets high efficiency and low emissions, researchers need to find important parameters. Scientific understanding and experimentation on fuel injection and combustion have a direct impact on efficient combustion and reducing emissions. The study of combustion and injection takes place in a very short time domain and depends on the thermodynamic state of the surrounding environment. In addition, ambient pressure, density, temperature, air-fuel mixture, geometry of the combustion chamber also influence. Several types of combustion test methods are used to simulate and visualize cylinder-like conditions without any compression and expansion strokes within the engine. Among them, rapid compression machine, constant pressure flow rig, constant volume hot cell, constant volume pressure cell and optical research engines have been used in numerous research institutes with different research strategies. [1,2]. Figure 1 compares the operating conditions and operating conditions of various test rigs to simulate the incylinder conditions of the CI engine before fuel injection. Among different optical test rigs e.g. ORE1 [3], ORE2 [4], RCM [5], CPFR [6], CVHC [7] and CVPC [8] covers the full range in Figure 1. In this respect, CVPC, CPFR, and CVHC are found the best suited optical test rigs for the core research on free spray development and spray combustion.
Fig. 1 Operating range of different optical test rigs [3] The Constant Volume Combustion chamber (CVCC) of Ulsan University's Smart Powertrain Lab is a CVCC (Constant Volume Pressure Cell) as shown in Table 1. This CVCC was previously used to conduct an experimental survey of unreacted and unvented fuel sprays of different types of alternative fuels using multi-hole or single-hole fuel injectors with a pressurized common rail system. Test Rig
Acronym
Simulates
Optical Research Engine
ORE
These engines have optical access into the combustion chamber
Constant Volume Hot Cell
CVHC
Chamber Increases the temperature with external heat elements
Constant Volume Pressure Cell
CVPC
Chamber using pre-combustion technique to pressurize the rig to simulate the TDC conditions right before fuel injection
Rapid Compression Machine
RCM
One compression stroke during an engine cycle
Constant Pressure Flow rig
CPFR
Chamber using additional flow into the rig to pressurize the rig
Table 1 Experimental approaches to obtain in-cylinder condition of different test rig [3]
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
189 3
2. The Experimental Setup and Test Equipments 2.1 Constant Volume Combustion Chamber CVCC is a useful tool for studying the combustion characteristics of various fuels and can be used to test various types of fuel injectors and spark plug technology. CVCC can be used in combustion studies to isolate the injection and combustion processes from all affected sub-processes occurring in the engine. A schematic drawing of the experimental test facility are shown in figures 2.
Fig. 2 A picture and a schematic drawing of the experimental test facility 2.2 Composition of the Pre-combustion Reactants CVCC provides various test conditions for pressure, temperature and ambient configuration separately from the fuel injection system. The remaining oxygen content after pre-burn combustion is including both reactants (C2H2, Ar, O2, N2) and products (O2, CO2, N2, H2O). The elevated pressure and temperature for target density conditions within the CVCC are generated by spark ignition by carefully selecting the proper mixture of reactants. The composition, pressure and temperature after a socalled pre-burn event in which a combustion spray is injected are directly related to the composition of the mixture filled before ignition. Four gases are used to fill the vessel and prepare the initial reaction mixture to define the four gas characteristics at the start of the injection. C2H2 is more volatile, but C2H4 has been chosen because fewer hydrogen molecules require less heat in the chamber window to minimize moisture production and prevent condensation. Figure 3.shows diagram of controller system. Fig.3 Diagram of gas control system
2.3 Working principle of the experimental event Since CVCC has a constant volume and no moving parts to compress the charge air, the chamber is prepared by igniting the gas mixture inside the chamber. This process of preparing the test environment and obtaining test conditions that allow auto-ignition of gasoline biodiesel blended fuel after so-called pre-combustion. The temperature immediately after the pre-combustion must wait for the heat loss to reduce the chamber condition because the ambient temperature is too high to simulate the actual engine. When conditions are met, fuel is injected
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
190 4
and main combustion occurs. The gas composition inside the chamber after pre-combustion can be controlled to simulate different operating conditions. E.g. Use of EGR (Exhaust Gas Recirculation). Fuel Type
GB05, GB20
Orifice Diameter (mm)
0.33 mm
Density Range Tested, ρamb
10kg/㎥
Injection Pressure Range Tested, Pinj
400-800-1200 bar
Ambient temperature range tested
700-800-900 K
Injection duration
1200 μs
Fuel temperature
Ambient
Table 2. Non-vaporizing spray experimental condition 3. Experimental Test and Analysis Procedure 3.1 Spray combustion experiment Two different sets of experimental conditions have been implemented to visualize the fuel injection and evaporation process. Using a premixed combustion method in a constant volume combustion chamber (CVCC), simulated experimental in-cylinder engine conditions similar to compression ignition engines during fuel injection. Condition of experiment is shown in Table 2. Although it is assumed that complete combustion occurs during premix combustion, the residual gas after pre-combustion combustion is not similar to a diesel engine, but the oxygen concentration that helps to ignite the fuel spray is accurate. Composition of the pre-combustion reactants is controlled by program, which already calculated. In this study, target is 15% of oxygen in 10 kg/㎥. Figure 4. shows target of composition. Table 3. Target of composition
3.2 Fuel characteristics Fuel characteristics are the most important parameters affecting most processes during the spraying and combustion of compression ignition engines. The standard fuel specification is developed to ensure that fuel has a certain quality and ensures safe use and to distribute specific fuel from all suppliers. Biodiesel and petroleum diesel have very similar chemical and thermodynamic characteristics, but with slight differences, affecting spray and combustion characteristics and emission characteristics. Therefore, the experiment was carried out by referring to the characteristics of gasoline and biodiesel in K-petro. 3.3 Combustion characteristics Combustion characteristics are associated with the combustion process, and different fuels will exhibit different properties based on their characteristics and chemical composition. 3.3.1 Heat release rate
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
191 5
The Heat Release Rate (HRR) is calculated from the first law of thermodynamics for an open system at the rate at which the chemical energy of the fuel is converted to thermal energy when the fuel is burned [John b. Heywood]. 3.3.2 Ignition delay Ignition delay is an important characteristic for injection system design and injection timing adjustment. Delay period in the diesel engine exerts a very great influence on both engine design and performance. The delay period has been found to be different when diesel and biodiesel are used individually. The ignition delay is defined as the time between the start of injection and the start of combustion. In this study, the ignition delay will be calculated by the MFB method [8]. Figure 4 shows ignition delay tends to decrease with increasing oxygen concentration in all fuels.
Figure4. Ignition delay as a function of ambient oxygen concentration for the diesel and emulsified fuels. 3.4 Experiment This experiment measured the ignition delay when the temperature was in the range of 700 to 900K with a density of 10kg/m3 and an oxygen concentration of 15% with gasoline biodiesel blended condition GB05 and GB20. The measured values were as follows Figure 5.
Figure 5. Plots of measured ignition delays of GB05 and GB20 at different ambient gas temperature ranging from 700-900K at 10 kg/m3 and 15% O2 concentration 4. Conclusion This paper investigates the combustion characteristics of gasoline biodiesel blended fuels and studies whether they can serve as alternative fuels. Experimental results show that biodiesel is not significantly different from existing combustion characteristics even when it is mixed with gasoline. The higher the content of biodiesel, the shorter the ignition delay, which is the result of increased oxygen content in the biodiesel.
192 6
Shubhra Kanti Das et al. / Energy Procedia 145 (2018) 187–192 Author name / Energy Procedia 00 (2018) 000–000
Acknowledgements This research was supported by The Leading Human Resource Training Program of Regional Neo industry through the National Research Foundation of Korea (NRF) funded by The Ministry of Science, ICT and Future Planning (2016H1D5A1908826). This research was financially supported by the CEFV(Center for Environmentally Friendly Vehicle) as Global-Top Project of KMOE(Ministry of Environment, Korea). References [1] Bardi M, Bazyn T, Bruneaux G, Johnson J, Lee S-Y, Malbec LM, et al. Engine Combustion Network (Ecn): Characterization and Comparison of Boundary Conditions for Different Combustion Vessels. At Sprays 2012;22:777–806. doi:10.1615/AtomizSpr.2012006083. [2] Bardi M, Payri R, Malbec LM, Bruneaux G, Pickett LM, Manin J, et al. Engine Combustion Network: Comparison of Spray Development, Vaporization, and Combustion in Different Combustion Vessels. At Sprays 2012;22:807–42. doi:10.1615/AtomizSpr.2013005837. [3] Upatnieks A, Mueller CJ, Martin GC. The influence of charge-gas dilution and temperature on DI diesel combustion processes using a short-ignition-delay, oxygenated fuel. SAE Trans 2005;114:773–85. doi:10.4271/2005-01-2088. [4] Espey C, E. DJ. Diesel engine combustion studies in a newly designes optical-access engin using high-speed visualization and 2-d laser imaging. Sae 1993;SAE-930971. doi:10.4271/930971. [6] Sung C-J, Curran HJ. Using rapid compression machines for chemical kinetics studies. Prog Energy Combust Sci 2014;44:1–18. doi:10.1016/j.pecs.2014.04.001. [5] Pastor JV, Payri R, Garcia-Oliver JM, Nerva J. Schlieren Measurements of the ECN-Spray A Penetration under Inert and Reacting Conditions. SAE Tech Pap 2012-01-0456 2012. doi:10.4271/2012-01-0456. [6] Phan A. Development of a Rate of Injection Bench and Constant Volume Combustion Chamber for Diesel Spray Diagnostics. 2009. [7] Pickett LM, Genzale CL, Bruneaux G, Malbec L-M, Hermant L, Christiansen C, et al. Comparison of Diesel Spray Combustion in Different High-Temperature, High-Pressure Facilities. SAE Int J Engines 2010;3:156–81. doi:10.4271/2010-01-2106. [8] Park SH, Lee D, Lee CS. Influence of gas-to-liquid fuel on the combustion and pollutant emission characteristics. Proc Inst Mech Eng Part D J Automob Eng 2013;228:85–93. doi:10.1177/0954407013504743. [9] Tie Li, Xiao-Qing Zhang, Bin Wang, Tao Guo, Qi Shi, Ming Zheng. Characteristics of non-evaporating, evaporating and burning sprays of hydrous ethanol diesel emulsified fuels. Fuel 191 (2017) 251–265 Biography Ocktaeck Lim received his B.S. and M.S degrees in Mechanical Engineering from Chonnam National University, Korea, in 1998 and 2002, respectively. He received his Ph.D. degree from Keio University in 2006. Dr. Lim is currently a Professor at the School of Automotive and Mechanical Engineering at Ulsan University in Ulsan, Korea. Dr. Lim’s research interests include Internal Combustion Engines, Alternative Fuel and Thermodynamics. email: [email protected]