The use of VO blends has been found to reduce NO emissions, especially at higher engine loads. However, HC emissions decrease with the addition of 5% ethanol and increase with the addition of 10% ethanol in the VO20 mixture.
Nomenclature
33 2.26 Variation of heat release rate at full load (Misra and Murthy Effects of vegetable oil blending on engine CO emissions. 61 5.9 Variation of ignition delay with engine load 61 5.10 Variation of maximum cylinder pressure with engine load.
List of Tables
Introduction
- Inspiration
- Global and Indian Energy Overview
- Reciprocating Internal Combustion Engines
- Vegetable Oil as a Fuel to CI Engines
- Emissions Standards
- Present Objectives
- Organization of the Thesis
Thus, the chemical energy of the fuel is converted into mechanical energy in the internal combustion engine. In the following years, other strict emission standards were introduced (Euro 2, Euro 3, Euro 4, Euro 5 and Euro 6).
Literature Review
Vegetable Oil
The typical composition of common FAs for different feeds is shown in Table 2.2. This variation in composition may be due to the cultivation of raw materials in different parts of the world with different climatic and geographical conditions.
Impacts of Neat VO in CI Engines
- Brake Thermal Efficiency
- Brake Specific Fuel Consumption
- Exhaust Gas Temperature
- Combustion Analysis
- Carbon Monoxide Emissions
- Carbon Dioxide Emissions
- Oxides of Nitrogen
- Hydrocarbon Emissions
The poor combustion properties of VO result in the higher EGT due to its high viscosity (Pramanik 2003; Chauhan et al. 2010). Compared to diesel, the use of VO in the engine reduces NOX emissions, as shown in Figure 2.11.
Effects of Preheated Neat VO in CI Engines
- Brake Thermal Efficiency
- Brake Specific Fuel Consumption
- Exhaust Gas Temperature
- Carbon Monoxide Emissions
- Oxides of Nitrogen
- Hydrocarbon Emissions
- Smoke Emissions
However, in the study by Nwafor (2003), the use of preheated oil degrades the BTE of the engine. It indicates a reduction in CO emissions with preheating, especially at higher engine loads (Hazar and Sevinc 2019).
Effects of Vegetable Oil Blends in CI Engines
- Brake Thermal Efficiency
- Brake Specific Fuel Consumption
- Exhaust Gas Temperature
- Combustion Analysis
- Oxides of Nitrogen
- Hydrocarbon Emissions
Increasing percentage of VO in the mixture increases engine EGT (Pramanik 2003; Hebbal et al. Engine CO emissions increase with increasing amount of VO in the mixture.
Use of Ethanol as Additives on VO-diesel Blends
Engine BTE is improved by blending ethanol with the VO-diesel blend. Unburnt HC emissions in the engine exhaust were found to increase with increasing ethanol content in the VO-diesel blend.
Summary and Scope of Work
A significant amount of HC emissions is observed when vegetable oil is used in the engine. The efficiency was even better than with diesel when mixing less than 20% in the engine. The increase in the percentage of VO in the mixture increases the HC emissions in the engine.
This review reveals that pure VO can be used in the engine, although some additional engine maintenance may be required due to the higher viscosity of the oil.
Production and Characterization of Fuel
- Introduction
- Oil Production
- Characteristics of Mesua ferrea Linn Oil
- Composition
- Heating Value
- Viscosity
- Other Properties
- Diesel Engine Test Setup
- Experimental Procedure
- Instruments on Engine Setup
- Air and Fuel Flow Measurement
- Pressure-crank Angle Measurement
- Temperature Measurement
- Emissions Measurement
- Concluding Remark
A Physica MCR 101 rheometer (manufactured by Anton Paar) is used to measure the oil viscosity. In this study, the viscosity of Mesua ferrea Linn oil is determined for the temperature range of 25 to 122 ºC. The schematic diagram of the experimental setup is shown in figure 4.1 and the photographic view is shown in figure 4.2.
Specifications of transmitters and sensors are shown in table 4.2, and flow meters in table 4.3.
Results of Binary Blends of VO and Diesel
- Introduction
- Performance Analysis
- Combustion Analysis
- Emissions Analysis
- Summary
This reduction increases with the increase in the volume of Mesua ferrea Linn oil in the mixture. This tends to increase with the increase in the amount of Mesua ferrea Linn oil in the mixture. The differences in the RoPR between the fuels increase with the increase in engine load.
VO blends show higher PCP compared to diesel fuel up to 80% engine load, which is higher with higher amount of VO in the blend.
Results of Ternary Blend of VO, Diesel and Ethanol
Introduction
The study of Mesua ferrea Linn oil blends (VO10, VO20 and VO30) reveals a deterioration of engine performance with increase in the amount of Mesua ferrea Linn oil in the blend. The higher viscosity and density of Mesua ferrea Linn oil constitutes an obstacle to go for higher composition of Mesua ferrea Linn oil in the binary mixture with diesel. To remove this obstacle, the simplest and best way is to use an additive in the binary mixture.
In this part of the experimental investigation, ethanol is used as an additive in the binary oil-diesel mixture of Mesua ferrea Linn.
Module I with VO20 .1 Performance Analysis
- Combustion Analysis
- Emissions Analysis
- Summary of Module I
The unburnt HC emitted in the engine exhaust when using the tested fuels is shown in Figure 6.15. By using 10% ethanol in the blend, the engine produces higher HC emissions compared to other fuels. As shown in Figure 6.16, engine CO2 emissions increase with increasing engine load for all test fuels.
However, HC emissions decrease with the addition of 5% ethanol and increase with the use of 10% ethanol in the VO20 mixture.
Module II with VO30 .1 Performance Analysis
- Combustion Analysis
- Emissions Analysis
- Summary of Module II
The BTE of the tested fuels depicted in Figure 6.18 shows an increase in engine BTE with increasing load. The variation of engine volumetric efficiency at different loads for the test fuels is shown in Figure 6.21. With the addition of ethanol in VO30, the combustion of fuels is improved, which leads to the increase in cylinder pressure compared to neat VO30, as shown in Figure 6.22.
The NO engine emissions increase with the increase in engine load for all the test fuels as shown in Figure 6.26.
Overall Summary
The EGT of the engine registers a slight increase when using ethanol in the VO20 mixture, which is in the range of 7 to 12 °C and 8 to 14 °C when using the 5 and 10% ethanol mixture, respectively. The use of ethanol in VO30 results in an increase in CO and HC emissions.
Results of Ternary Blend of VO, Diesel and DEE
Introduction
Engine BTE is improved while CO emissions are reduced by blending ethanol with VO20 and VO30. In this part of the study, the focus is to examine the impact of low viscosity additive (even lower than ethanol) on VO20 and VO30 blends. Diethyl Ether (DEE) having a very low viscosity and high cetane number is considered as an additive for the two blends ie VO20 and VO30.
The properties of test fuels for Modules I and II are shown in Table 7.2 and Table 7.3 respectively.
Module I with VO20 .1 Performance Analysis
- Combustion Analysis
- Emissions Analysis
- Summary of Module I
This shorter ID results in an earlier onset of fuel burn and pressure stage progression with mixed fuels as shown in Figures 7.7 and 7.8. With increasing load, the duration of combustion increases for all test fuels, as shown in Figure 7.12. NO emissions increase with increasing load for all test fuels as shown in Figure 7.14.
The variation in the emissions of unburnt HC at different loads for the test fuels is shown in Figure 7.15.
Module II with VO30 .1 Performance Analysis
- Combustion Analysis
- Emissions Analysis
- Summary of Module II
The change in ignition delay (ID) of the test fuels at different engine loads is shown in Figure 7.26. The differences in CO emissions for the test fuels at different engine loads are shown in Figure 7.29. Mixing DEE into VO30 reduces NO emissions compared to pure VO30.
The unburnt HC emission from the engine increases with increasing load as revealed in Figure 7.31.
Overall Summary
By mixing 5 and 10% of DEE and VO30 respectively, CO emissions in the exhaust gases are reduced by 8 and 13%, respectively. However, HC emissions increase with the addition of DEE with VO20 and VO30 blends. In Table 7.4 and Table 7.5, a direct comparison of the additives was made regarding the efficiency and emission behavior of a CI engine operating at VO20 and VO30.
The use of DEE as an additive in VO20 and VO30 shows a better overall performance compared to ethanol.
Energy and Exergy Analyses
- Introduction
- Energy Analysis
- Exergy Analysis
- Summary
The availability of input fuel increases with the increase in the amount of VO in the VO-diesel mixture. The exergy efficiency decreases with the increase in the content of VO in the VO-diesel blend. This difference in the energy and exergy efficiency reflects the effective use of fuel in the engine.
Exergy efficiency decreases with increasing VO content in the VO-diesel mixture.
Conclusion and Future Scopes
Contribution of the Present Work
- Characteristics of Mesua ferrea Linn Oil
- VO-diesel Blends
- VO-diesel-ethanol Blends
- VO-diesel-diethyl ether Blends
- Energy and Exergy Analyses
The BSFC of engine increases with the use of the ethanol in both V2O and VO30 blends and is found to be higher with higher amount of ethanol in the blend. The use of ethanol in VO30 leads to an increase in CO and HC emissions. An increase in the EGT is observed with the addition of DEE in VO20 mixture which increases to 3.4 and 4.4% with the use of 5 and 10% DEE respectively.
There is no major change in EGT when using DEE in the VO30 blend.
Application Potential of the Work
Future Scopes
However, it must be ensured that these fuels do not affect the engine during long-term operation. Similarly, IT must be optimized to achieve the best engine performance. However, it should be understood that these parameters change if the engine load exceeds full load.
Thus, there is a need to test the engine under overload conditions to obtain the inflection point of parameters such as BTE, BSFC and others.
Machacon HTC, Shiga S, Karasawa T, Nakamura H, (2001), Performance and emission characteristics of a diesel engine fueled with coconut oil-diesel fuel blend. Nwafor OMI, (2004), Emission Characteristics of Diesel Engine Running on Vegetable Oil with Elevated Fuel Inlet Temperature. Saleh HE, Selim MYE, (2017), Improvement of the performance and emission characteristics of a diesel engine fueled by jojoba-methyl ester-diesel-ethanol ternary blends.
Venu H, Madhavan V, (2017), Effect of addition of diethyl ether (DEE) to ethanol-biodiesel-diesel (EBD) and methanol-biodiesel-diesel (MBD) blends in a diesel engine.
Appendix A
Expressions for Performance and
Performance analysis
- Brake Power (BP)
- Brake Thermal Efficiency (BTE)
- Brake Specific Fuel Consumption (BSFC)
- Air Flow Rate
- Stoichiometric Reaction
This is the rate at which the air is introduced into the engine during the suction stroke. The airflow rate is determined using the following expression where Cd is discharge coefficient, d opening diameter (m), g acceleration due to gravity (9.81 m/s2) and h the manometer reading across opening meter (m is water) ). The following equation was used for the calculations of the stoichiometric fuel-air or air-fuel ratio.
Combustion Analysis 1. Net Heat Release Rate
- Smoothing Pressure
- Rate of Pressure Rise
For each complete engine cycle, data acquisition device 720 records pressure and volume data at the rate of one pressure and volume data per one degree of rotation of crank. The equation for calculating net heat release rate is based on the first law of thermodynamics and ideal gas law which is expressed as (Heywood 2011; Debnath et al 2014; Bora and Saha 2015; Bora and Saha 2016a; Sarkar and Saha 2018b). It has been observed that when differentiating the raw pressure data recorded by the data acquisition shows a noisy trend with the successive values (Debnath et al. 2014; Bora and Saha 2015; Bora and Saha 2016; Sarkar and Saha 2018b).
The change in pressure per unit change in crank angle (dP d/ ) was determined using a first-order finite difference equation with fourth-order accuracy (Debnath et al. 2014; Bora and Saha 2015; Bora and Saha 2016b ; Stone 1992) which is expressed as.
Appendix B
Equation A2 shows that the thermal efficiency of the brakes is the function of BP, mf and LHVf with uncertainties of 0.7, 1 and 1% respectively.
Appendix C
Expressions for Energy and Exergy Analyses
Energy Analysis
Energy in the exhaust per unit of time Energy loss through the exhaust per unit of time. Cpe is the specific heat of the exhaust gas, which is evaluated from the energy balance of the exhaust gas calorimeter using the following equation.
Exergy Analysis
List of Publications
