Here too, the fuel properties of the preheated biodiesel (POME/COME) at different fuel inlet temperatures were determined and compared with biodiesel standards (ASTM 6751, EN14214 and IS15607) and diesel fuel. In this experimental analysis, first the fuel properties of the preheated biodiesel/diesel blends were determined and compared with mixed biodiesel standards (ASTM D7467 and BIS) and diesel fuel.
Contents
Effect of compression ratio on combustion characteristics Effect of compression ratio on emission characteristics 185 8.3.2 Effect of fuel injection pressure on diesel engine parameters 189. Effect of fuel injection pressure on exhaust emissions 192 8.3.3 Effect of fuel injection timing on combustion diesel engine parameters Effect of fuel injection timing on performance parameters Effect of fuel injection timing on exhaust emissions 199.
Nomenclature
ASTM America Society of Testing Materials IC Internal Combustion atTDC To Top Dead Center (degree) ICE Internal Combustion Engine. EN European committee standardization POME Palm Oil Methyl Ester FPT Fuel Preheat temperature (°C) PPBD Preheat Palm Biodiesel.
158 7.1 Variation engine parameters with intake air preheated temperature: (a) BSFC, (b) BTHE 166 7.2 Comparisons of combustion parameters with crank angle for test: (a) Cylinder pressure,. 167 7.3 Variation of combustion parameters with inlet air temperature: (a) PCP; (b) ID 170 7.4 Variation of engine exhaust gases with intake air preheated temperatures: (a) CO, (b).
List of Tables
CHAPTER -1
Introduction
Overview
Preface
Because of the higher oxygen atom present in biodiesel, it is accepted as an oxidized hydrocarbon. With different IP and CR fuels, many researchers have found improved results for engine performance parameters (Celikten et al., 2010).
Alternative Fuels
The cold flow properties of biodiesel are also poor compared to diesel (Isioma et al., 2013). The kinematic viscosity of methyl ester (biodiesel) is usually higher than diesel fuel by almost a factor of two (Hoekman et al., 2012).
Fuel Modification Technique
- Blending Technique
- Preheating Technique
- Preheating and Blending Techniques
- Intake Air Preheating
The preheating of the biodiesel improves the injection characteristics by improving the fuel properties of biodiesel (surface tension, density, kinematic viscosity and poor flow properties). Of the fuel properties, the use of biodiesel or its mixtures effects on fuel droplet formation.
Engine Parameter Modification Techniques
- Variable Compression Ratio
- Fuel Injection Pressure
- Fuel Injection Timing
While the condition of the air into which the fuel is injected changes as the injection timing is varied, and thus the ignition delay will vary, these effects are predictable. If the injection starts earlier (advanced injection timing), the initial air temperature and pressure are lower, the ignition delay will increase.
Emission Control Norms
- Excess Air Supply
- Exhaust Gas Recirculation
This also reduces the oxygen concentration in the combustion chamber, increases the heat capacity (specific heat) of the intake charge. As the content of exhaust gases in the combustion chamber increases, this affects the formation of the mixture.
Objective of the Dissertation
Exhaust gas recirculation (EGR) is a useful technique to reduce NOx formation in the combustion chamber. There is therefore a reduction in the cylinder's peak temperature rise and consequently the formation of NOx is reduced due to the lower combustion temperature.
Organization of the Thesis
To study the combined effect of intake air preheating and preheated blends of biodiesel on performance, combustion and emission characteristics of CI engine. Investigation of performance, combustion and emission characteristics of preheated blends of biodiesel in a VCR-CI engine at different CRs, fuel IPs and ITs.
Characterization of fuel blend properties with increasing biodiesel ratios (by volume) was performed to evaluate engine performance and emission test results. In this study, the effects of intake air preheating on engine performance parameters and exhaust gas emissions were investigated.
CHAPTER-2
Preface
This chapter presents a brief review of the main studies on biodiesel, engine performance, combustion and exhaust emission characteristics of diesel engines operating with different types of biodiesel blends, preheated biodiesel, preheated biodiesel blend with diesel and intake air preheating. diesel engine. A critical review of the effects of CR, fuel IP and IT on the engine performance, combustion and exhaust emission characteristics of diesel engines fueled with biodiesel and biodiesel blends is also provided in the section.
Biodiesel
Finally, the key studies related to the use of exhaust gas recirculation (EGR) to reduce the NOx exhaust gases of diesel engines are also presented. Thus, it is essential to increase the performance of biodiesel in CI engines by modifying the engine parameters, i.e. compression ratio (CR), fuel injection timing (IT), fuel injection pressure (IP) etc.
Fuel Modification Technique
- Diesel engines fueled with Biodiesel Blends
- Diesel engines fueled with Preheated Biodiesel
- Diesel engines fueled with Preheated Biodiesel–Diesel Blends
- Diesel Engine run with Intake Air Preheating Mode
Fuels were evaluated in the engine at two elevated intake air temperatures at 30 °C and 85 °C. The resulting emissions indicate that the high heat of vaporization of methanol significantly affects CO and HC emissions. Thermal efficiency of the brake and specific fuel consumption increase as the injection pressure increases. the tests show B20 blend fuel has a higher brake thermal efficiency of 31.3% compared to 32.7% for diesel, but marginally at a higher specific fuel consumption than diesel.
Exhaust NOx Emission Treatment
2015), dealt with the impact of exhaust gas recirculation on the performance and emission characteristics of a biogas diesel engine, with an emphasis on reducing harmful exhaust gas emissions while maintaining high thermal efficiency. EGR was found to reduce exhaust gas temperature by up to 7.6% at minimum engine load and up to 2.3% at maximum load.
Thermodynamic and Thermoeconomic Analysis of Diesel Engine
Saleh (2009) in his studies used the jojoba methyl ester (JME) as a renewable fuel in two-cylinder diesel engine. Canakci and Hosoz (2006), performed a comparative energy and exergy analysis of a turbocharged diesel engine with different biodiesel fuels and diesel fuel tested at 100% load and 1400 rpm. 2013), performed energy and exergy analyzes in a single-cylinder, four-stroke diesel engine operated with diesel and palm biodiesel.
Limitations of the previous research
The studies on the combined effect of compression ratio, fuel injection pressure and timing of engines using preheated biodiesel blends with charge air preheat mode are limited. However, limited findings have been reported on the thermodynamics and thermoeconomic analysis for engines fueled with biodiesel blends or preheated biodiesel blends with diesel in a direct injection and compression ignition variable compression ratio engine mode.
Research gap
The combined effects of fuel preheating and intake air with EGR rates on variable compression ratio direct injection, compression ignition engine performance, emission, and combustion parameters are not fully discussed. The reviewed literature shows that the study of VCR DI CI engine using preheated biodiesel blends with intake air preheating mode is very limited.
Scopes of Work
However, the studies on the application of EGR in with/without blending with diesel or preheated biodiesel/diesel blend fueled CI engines are very limited. In this regard, the use of preheated biodiesel/diesel blends is rare and can alternatively fuel CI engines.
Summary
The use of POME and its preheating and mixing with diesel fuel as the main fuel in the study of compression ignition direct injection engine with variable compression ratio with intake air preheating mode is almost nil. Therefore, there is ample scope to investigate POME and its preheating and mixing effect at different fuel mix ratios with different engine performance parameters (CRs-IPs-ITs) in a VCR DI CI engine.
CHAPTER-3
Preface
Using any alternative fuel in a variable compression ratio (VCR) direct injection (DI) compression ignition (CI) engine requires proper engine and instrument selection. An experimental test rig was developed to evaluate the performance, combustion and emission characteristics of a variable compression ratio compression ignition engine running on diesel fuel and preheated biodiesel/diesel blend fuels.
The Experimental Setup
- The VCR Compression Ignition Engine
- Instrumentations for Measurements
- Emission Measurement
- Fuel Supply System
A photographic image of the tilting cylinder block mounted on the engine cylinder is given in Figure 3.3. Adjust the nut until the desired injection point is reached. The injection point can be varied in the range of 0-25° bTDC.
Engine Conversion Methodology
- Fuel Preheater
- Intake Air Preheater
- Exhaust Gas Recirculation System
The schematic layout diagram of the modified experimental setup comprising a fabricated helical heat exchanger is shown in Figure 3.11. The modified experimental setup consisting of intake air preheater “Hx2” and fuel preheater “Hx1” is shown in Figure 3.13.
Experimental Methodology and Procedure
- Methodology
- Experimental Procedure
The developed preheater was attached to the engine to complete the trial setup. The device specifications and test procedure are in accordance with American Society for Testing Materials (ASTM D6751), European Union (EN14214) and Indian Standard (IS15607). b) Different blends of preheated biodiesel were tested in a diesel engine operating at standard (CR 17.5, IP = 200 bar and IT = 23° bTDC) conditions.
Analysis Procedure
Uncertainty Analysis
Summary
For convenience, the details of base diesel and various biodiesel-diesel blend modes for operational procedures are prepared separately. The later chapter discussed estimation of blend ratios and calculated performance and emission results of biodiesel-diesel blends running the engine.
CHAPTER-4
Estimation of Optimum Blend Ratios of Biodiesel for Diesel Engine
Preface
Typically, the energy content of biodiesel fuel is less than that of mineral oil due to different chemical compositions, which affect the energy content of the blended fuel as the ratio of biodiesel fuel in the blend with mineral oil increases. The investigation of the engine characteristics was carried out with the blended fuel meeting the standard fuel specifications.
Methodology and Methods
- Characteristics and Properties of Biodiesel
- The Ultimate and Proximate Analysis of Fuels
- Biodiesel Diesel Blending
- Engine Test
The tested physical properties of the different biodiesels and diesel fuel are shown in Table 4.1. The temperature at the bottom of the test pot (i.e. the temperature at which the biodiesel starts to pour) is taken as the pouring point.
Results and Discussion
- Analysis of Biodiesel-Diesel Blend Properties
- Engine Performance Analysis
- Effect of COME and POME Biodiesels on Engine Knock
- Analysis of Engine Emission
It has been clearly shown that increasing the biodiesel content in the fuel blend will increase the density of the fuel. It is clear that increasing the content of biodiesel in the blended mixture increases the density of the blended fuel (Figure 4.5 and Table 4.4).
Uncertainty Analysis
Due to these facts, the calculated accuracy of the performance and combustion study for both COME blend (CBD10), POME blend and diesel engines is within ±3.6%.
Summary
The mixing ratio of the COME is recommended up to 10% volume (CBD0) and POME up to 20% volume (PBD10−PBD20), which is remarkably beneficial and meets the blended fuel standard (ASTM D7467 and BIS). Consequently, the blending ratio of the POME biodiesel/diesel blended fuel is recommended up to 20% (PB20), while COME biodiesel/diesel blended fuel is recommended up to 10% (CBD10) and can replace diesel in diesel engines to provide better performance than a comparable fuel up to mineral diesel with smoother engine operation.
CHAPTER-5
Results and Discussion: Preheated Biodiesel Run Engine
- Preface
- Materials and Methodology
- Results and Discussion
- Fuel Characterization .1 Test Fuel Properties
- Effect of Fuel Preheating on Engine performance parameters
- Effect of Fuel Preheating on Engine Exhaust Emissions
- Summary
It is indicated that the kinematic viscosity and density are gradually reduced as the fuel preheating temperature increases from 54 °C to 138 °C, respectively. The result showed that the kinematic viscosity and density of biodiesel gradually decrease as the fuel inlet temperature increases from 54 to 138 °C.
CHAPTER-6
Results and Discussion: Preheated Biodiesel Blends Run Engine
Preface
The effect of exhaust gas recirculation (EGR) on performance and emission characteristics of diesel engine fueled with 20%. The effect of EGR on NOx emission from diesel engines operating with different biodiesel-diesel blends of fuel was investigated by (Saravanan, 2015).
Material and Methods
- Preheated Biodiesel/Diesel Blend Fuels
- Facilities and Test Procedures
Further, the effect of fuel preheating and blend ratio on engine performance and emission evaluation of diesel engines operated with blended blends has been investigated (Patel and Shrivastava, 2016). Finally, the optimized preheated biodiesel blends were compared to diesel fuel for performance and emission characteristics.
Result and Discussion
- Characterization of Preheated POME Biodiesel Blends
- Effect of Preheated Biodiesel Blends on Engine Performance Parameters
- Effect of Preheated Biodiesel Blends on Combustion Characteristics
- Effect of Preheated Biodiesel Blends on Engine Emission Levels
- Comparative Overall Engine Performance and Emission Analysis
The effect of increasing EGR rates on BSFC for preheated biodiesel/diesel POME blends at full engine load is shown in Figure 6.4(b). The effect of increasing EGR rates on preheated POME biodiesel/diesel blends at full engine load (12 kg) was presented in Figure 6.5(b).
Uncertainty Analysis
The variations in the evaluated β values for preheated biodiesel blends with diesel samples (PBD0, PPBD20, PPBD40, PPBD60, PPBD80 and PPBD100) at full load are shown graphically in Figure 6.13 and Figure 6.14 for the engine performance and emission parameters, respectively. It is observed that the EGT decreases as the percentage of EGR of preheated biodiesel in the blend ratio increases, indicating poor combustion of the fuel.
Summary
BTHE decreases for all preheated POME biodiesel/diesel blends at increasing EGR rates, with the loss greater for the PPBD100 blends. CO and HC emissions increased with increasing EGR rates for all preheated POME/diesel biodiesel blends.
CHAPTER-7
Results and Discussion: Preheated Biodiesel Blends with Intake Air Preheating Mode Run Engine
- Preface
- Materials and methodology
- Experimental Facilities
- Methodology
- Results and Discussion
- Effect of Fuel and Intake Air Preheating on Engine Performance Parameters
- Effect of Fuel and Intake Air Preheating on Engine Combustion Characteristics The primary purpose of preheating intake air is to improve combustion efficiency with shorter
- Effect of Fuel and Intake Air Preheating on the Engine Exhaust Emissions
- Summary
Figure 7.3(a) shows that the PCP for all tested fuels increases at a higher intake air preheat temperature. According to Figure 7.4(b), the change in CO2 emissions shows a marginal increase in the amount of CO2 with intake air preheating.
CHAPTER-8
Results and Discussion: Modified Operating Parameters on a Diesel Engine using Preheated Intake Air and Blend Ratios
Preface
It is therefore possible that an air and fuel mixture is not homogeneous and that the engine performance decreases. Increases in the temperature and pressure of the air-fuel mixture in the combustion chamber, together with turbulence effects, are the direct result of increasing CR in a diesel engine.
Experimental Setup and Procedures
