Variable Compression Ratio Engine Research Articles

Modelling and evaluation of combustion emission characteristics of COME biodiesel using RSM and ANN—a lead for pollution reduction

Nowadays, the emissions from the diesel engines are focused lot to minimise the environmental pollutions in accordance with the emission standards. In this regard, biodiesels are found to be efficient for the diesel engines due to their higher energy contents and low exhaust emissions. Use of biofuel in association with diesel will be an efficient way for the cost-effective performance of the diesel engines with reduced pollutions. The COME is an efficient combustible oil, in which the diesel is blended at different proportions to identify their suitability in the diesel engines. In this regard, the properties of the COME-Diesel blends are determined and analysed for their influence on the combustion characteristics. To understand the performance and emission characteristics of blends, experiments are carried out on the variable compression ratio (VCR) engine keeping the blend, compression ratio, load, and speed as variables. The response surface methodology (RSM) used as a tool for designing and conducting the experiments according to the predetermined variables. The experimental sets generated are performed to determine the NO and HC emissions (response functions). The adequacy of the models is verified through ANOVA and through the p and F tests. The experimental design matrix is also used in training the artificial neural network (ANN) to develop the empirical models. The models from RSM and ANN are experimented and the results obtained from both the models are compared for their accuracy levels. Once the hypothesis is developed for the biodiesel and engine setup, the emission models will be used for the optimising the engine operating parameters and blends to minimise the pollutions from engine for wide operating conditions.

Influence of Cissus quadrangularis as biofuel additive on the performance of VCR diesel engine fueled with palm oil

Although many bio-fuels (neat vegetable oils) including palm oil, were found suitable for diesel replacement in internal combustion engines, none of them ever tested so far had better performance than diesel and therefore bio-fuels are commercially not viable to date. Hence in this research work, a novel bio-fuel additive derived from naturally available herbal species known as Cissus quadrangularis (Vajravalli) has been proposed. This herbal juice in liquid form is added with palm oil in different volumetric proportions and is used as fuel to test the performance of single-cylinder, 4-stroke, compression-ignition water-cooled, direct-injection, variable compression ratio engine. The experimental results witness a significant advancement in the brake thermal efficiency of the engine operating with palm oil using Cissus quadrangularis as an additive when it is compared to neat palm oil fuel operation. At rated load with an engine compression ratio of 18, the fall in brake thermal efficiency for palm oil operation is 7% in comparison to diesel operation. This reduction in BTE has been improved to only 3% for 2V98P fuel. Also, there is a decrease in brake specific fuel consumption. Furthermore, the performance characteristics of 2V98P fuel are in close concurrence with diesel operation. The maximum mechanical efficiency obtained at rated load for palm oil, 1V99P, 2V98P, 3V97P, and 4V96P fuels is respectively 7%, 5.8%, 4.8%, 4%, and 3% greater than that of diesel. Also, the exhaust gas temperatures obtained for 2V98P, 3V97P, and 4V96P are less than that of diesel operation while for palm oil and 1V99P it is greater than that of diesel. The maximum BTE and minimum BSFC obtained for 2V98P fuel is 32.05% and 0.3255 kg/kWh respectively as against 32.8% and 0.3126 kg/kWh for the diesel operation at a rated load with a compression ratio of 20.

The Coupled Dynamic Behavior Analysis of the Link Parts and the Application to the Design of the Multi-link Crank Mechanism for Variable Compression Ratio Engine

The Coupled Dynamic Behavior Analysis of the Link Parts and the Application to the Design of the Multi-link Crank Mechanism for Variable Compression Ratio Engine

Investigation on performance and emission characteristics of jack fruit peel biodiesel in VCR using single hole nozzle

In this experiment, the investigation on performance and emission characteristics of Jack fruit peel biodiesel is done in single cylinder, constant speed, water cooling system Variable Compression Ratio engine using single hole nozzle at various loads. Jack fruit peel Biodiesel is prepared by transesterification process. Analysis is done with three combination of Jack fruit bio-oil with diesel as 20:80, 40:60 and 60:40. From the study it is found that the emission characteristics of Carbon monoxide, Hydrocarbon and Oxygen in biodiesel are less. On the other hand Nitrogen oxide and Carbon dioxide are less for diesel. The specific fuel consumption (SFC) and Break thermal efficiency (BTE) of these blends are high for biodiesel.

Effect of compression ratio and fuel injection pressure on the characteristics of a CI engine operating with butanol/diesel blends

The fast reduction of fossil fuels is making it imperative to search for renewable fuels to be used in the IC engines. The use of alcohols as fuel in the CI engines either directly or as blends of diesel requires some modification of the engine operating parameters to minimize the emissions without affecting the performance. Among the different operating parameters, Compression ratio (CR) and Fuel injection pressure (FIP) strongly affect the performance characteristics of the CI engine. In this paper, the influence of CR and FIP on the combustion, performance and emission characteristics of a CI engine fuelled with butanol/diesel (B/D) blends is presented. Experiments were performed on a Variable Compression Ratio (VCR) engine by varying the CR (CRs of 14:1, 15:1, 16:1, 17.5:1and 18:1) and the FIP (FIP of 200 bar, 220 bar, 240 bar, 260 bar and 280 bar) with three different (B/D) blends (butanol fraction of 0%, 20% and 40% by volume). The experimental outcomes showed that for all the (B/D) blends, with increase in the CR from 14 to 18, the in-cylinder pressure, net heat release (NHR) and Brake Thermal Efficiency (BTE) increased. The soot, CO and UBHC emissions decreased, while the NOx emissions increased with increase in the CR from 14 to 18. Similarly, the effect of FIP was to increase the in-cylinder pressure, net heat release (NHR), BTE and the NOx, and reduce the soot CO and UBHC emissions. The effect of CR and FIP for different butanol/diesel blends was experimentally evaluated. There existed an optimum value of FIP for each test fuel, corresponding to which the best performance was obtained. For the Bu00 (diesel) and Bu20 test fuels this optimum value was 260 bar, whereas for the Bu40 test fuel, it was 240 bar. At the higher CR of 18, Bu40 gave the best performance with BTE of 30.14%.

Modeling of Properties and SI Engine Pollution of Associated Petroleum Gas in Iraq

Modeling and simulation of process performance has been conducted around the use of theIraqi associated petroleum gas as fuel for the spark-ignition engine. The study included astatistical evaluation of the effect of each component on the total properties of the gas.Finally, the gas was tested as a possible fuel for the spark-ignition engine from theemission point of view. This was done numerically using commercial software wellestablished and verified for modeling the operation and performance of spark-ignitionengines.The study was conducted on Ricardo E6/T variable compression ratio engine. The range ofthe speed studied was 1000-3000 rpm and was limited to a lean range 0.8-0.95. It was alsofound that the presence of Methane in higher quantity helped in improving the calorificvalue (on a mass basis) but at the cost of gas density. The presence of higher carbon valuegasses did not help improve the fuel heating value.The highest negative impact on the heating value is CO, H2S, and C2H6 respectively. Thestudy also showed that the associated gas can be used as a fuel after removing sulfur fromit.

Performance Evaluation of Diesel Engine Using Novel Variable Compression Ratio Mechanism

Increasingly stringent emission and fuel economy standards brings opportunities and research in automobile engine technology development to make it more efficient and less polluting. There are various performance improvement strategies adopted by different researchers in order to get maximum power from the minimum quantity of fuel alongside substantial reduction in exhaust gas emission. The techniques such as CRDI (Common Rail Direct Injection), VVT (Variable valve timing) and such more are commercially viable and successfully incorporated in vehicles. Along the similar track, this paper highlights the importance of variable compression ratio diesel engine, method of achieving the variable compression ratio (VCR) as per load and speed conditions. Variable compression ratio (VCR) technology is one of the method for improving the automobile engine performance, efficiency, fuel economy with reduced emission for range of fuels. The basis of the VCR engine is to operate at different compression ratio, by altering the combustion chamber volume, as per need of most suitable operating conditions. Apart from this, the fuel injection location needs to be varied as per load and speed conditions. The synchronization of both VCR and variable fuel injector location (VFIL) becomes important. Knowing this fact, the study for the diesel Comet engine (3.7 kW@2100 RPM) is undertaken for variable clearance volume accompanied with VIPL. The work consists of design and development of mechanism consisting of auxiliary cylinder and auxiliary piston which will operate in and out of combustion chamber as per load and speed conditions. The detailed drawings and complete experimentation will be carried out to judge the improvement of performance of diesel engine with modification of variable clearance volume concept. The performance parameters consist of brake power, brake thermal efficiency and brake specific fuel consumption under various load conditions.

Performance Comparison of Microalgae Biodiesel Blends with Petro–Diesel on Variable Compression Ratio Engine

In the present paper, the performance evaluation of a variable compression ratio single-cylinder engine with 20% blend of microalgae biodiesel with petro–diesel is presented. Microalgae biodiesel is prepared at the laboratory scale from microalgae oil (Schizochytrium sp.), and its evaluated physical and chemical properties are observed to be comparable with petro–diesel. Further, it was observed that at a comparable compression ratio there is no significant performance variation between petro–diesel and its blended version that contains 20% of microalgae biodiesel. In addition to that, the experiment results show a reduction in the CO, un-burnt HC and smoke emissions with biodiesel blend as compared to petro–diesel fuel. Keeping the above points into consideration, it can be said that the promotion of microalgae biodiesel for 20% blending with petro–diesel for use in existing diesel engines should be taken up. Thus, the target set to be achieved by present Indian biofuel policy of blending 5% biodiesel with petro–diesel in the existing diesel engines by 2030 seems to be on the lower side and should be considered for the upward revision.

Type Synthesis of Variable Compression Ratio Engine Mechanisms

Type synthesis of two-degrees-of-freedom (DOF) planar mechanisms has been carried out using graph theory to determine the possible kinematic structures of variable compression ratio (VCR) engine mechanisms with two to three independent loops, and has resulted in the structures of 87 mechanisms satisfying search specification. By applying evaluation criteria to the enumerated mechanisms, the kinematic structures of three mechanisms are selected as suitable VCR engine mechanisms and verified by analysis results. In this research, VCR engine mechanisms with revolute joints and only one prismatic joint are enumerated, and the basic method to determine the VCR engine mechanisms with higher pairs is discussed. The procedure used in this research can be utilized to determine the kinematic structures of desired mechanisms and the results can be used as an atlas of two-DOF adjustable slider-crank mechanisms.

Optimization of performance and emission parameters of direct injection diesel engine fuelled with microalgae Spirulina (L.) – Response surface methodology and full factorial method approach

The closeness of the characteristics of biodiesel with that of diesel during combustion can be achieved through variations in compression ratios of the engine coupled with different biodiesel blends. The simplest approach towards attaining an optimal combination can be achieved through design of experiments (DOE). The present study has been greatly focussed on the usage of blends of microalgae Spirulina (L.) with conventional diesel in a variable compression ratio engine at varying loads, compression ratios (CR) and concentration of blends. L64 orthogonal array using full factorial method was used in designing the experiments and the corresponding multiple responses were studied using response surface methodology (RSM). The effects of load, CR and blends along with the correlation between the performance parameters (brake specific fuel consumption and brake thermal efficiency) and emission parameters (carbon dioxide, particulate matter and oxides of nitrogen) were studied. The model validation has been performed using the adjusted value of R2, which resulted in the decrease of unnecessary terms in the designed mode. The regression model explained the mechanism by delivering the response variable of R2 by more than 80%. The model predicted that the load of 64.634, CR of 16.50 and 20% blend would provide BTE of 31.357% and BSFC of 274.97 g/kWh with lower values of CO2 (869.075 g/kWh), PM (0.2807 g/kWh) and NOx (1804.97 ppm), respectively. The confirmation test showed the closeness of the predicted results with those of experimental values.

Enhancement in Combustion, Performance, and Emission Characteristics of a Diesel Engine Fueled with Ce-ZnO Nanoparticle Additive Added to Soybean Biodiesel Blends

This study considered the impacts of diesel–soybean biodiesel blends mixed with 3% cerium coated zinc oxide (Ce-ZnO) nanoparticles on the performance, emission, and combustion characteristics of a single cylinder diesel engine. The fuel blends were prepared using 25% soybean biodiesel in diesel (SBME25). Ce-ZnO nanoparticle additives were blended with SBME25 at 25, 50, and 75 ppm using the ultrasonication process with a surfactant (Span 80) at 2 vol.% to enhance the stability of the blend. A variable compression ratio engine operated at a 19.5:1 compression ratio (CR) using these blends resulted in an improvement in overall engine characteristics. With 50 ppm Ce-ZnO nanoparticle additive in SBME25 (SBME25Ce-ZnO50), the brake thermal efficiency (BTE) and heat release rate (HRR) increased by 20.66% and 18.1%, respectively; brake specific fuel consumption (BSFC) by 21.81%; and the CO, smoke, and hydrocarbon (HC) decreased by 30%, 18.7%, and 21.5%, respectively, compared to SBME25 fuel operation. However, the oxides of nitrogen slightly rose for all the nanoparticle added blends. As such, 50 ppm of Ce-ZnO nanoparticle in the blend is a potent choice for the enhancement of engine performance, combustion, and emission characteristics.

Performance and exhaust emission analysis of a variable compression ratio (VCR) dual fuel CI engine fuelled with producer gas generated from pistachio shells

In the current scenario, interest in harvesting energy from non-conventional sources such as biomass has mount due to appalling increase in energy demand. In this research work, performance and emission characteristics of VCR engine operating with PG originated from pistachio shells gasification has been determined. During experimentation, results have been acquired by altering CR and brake power and then compared with standard diesel run results. Apart from emission and performance analysis, engine sound level and diesel saving have also been observed. The maximum diesel substitution of 46.66% has been observed in case of dual mode. In addition, NOX fraction in exhaust during dual mode has been measured as 12.06–37.27% lower than diesel run. The results suggested that brake thermal efficiency (ηbth) of 25.71% and 23.81% have been obtained during diesel and DF run. CO2 emission has been measured in DF mode as 17.62–67.14% (at 3.44 kW brake power) more than diesel run. Under similar conditions, CO emission in diesel mode has been decreased (ranging from 63.06 to 73.37%) when compared with DF run. Further, hydrocarbon emission level in DF mode has been discerned as 473–593% higher when compared with diesel run.

Study on the efficiency of a spark-ignition variable displacement and compression ratio engine

A variable stroke engine was proposed as a promising solution for improving the efficiency of flex-fuel engines by adjusting the compression ratio; this prevents knock onset for fuels with different octane numbers. Similarly, the displacement was adjusted by varying stroke length with the objective of mitigating cylinder pumping losses. This article compares the efficiency of a spark-ignition, port-fuel injection engine, with variable displacements and compression ratios; a conventional engine with a fixed compression ratio; and an engine with variable compression ratios. A simulation-based calibration was performed for each engine, using the results from a phenomenological model to predict the engine performance. The calibration maps were obtained by maximising efficiency through determining the optimal combination of available engine parameters such as spark timing, compression ratio, displacement, and throttle actuation. A comparison of the efficiencies of the different types of engines showed an improvement of approximately 15% for the engine under partial load conditions and with variable displacement and compression ratio, compared to a conventional engine.

Extraction of algae biodiesel for power generation and comparison of sustainable fuels using MCDM

ABSTRACT Current research talks about the extraction of green crude from algae using fast pyrolysis, comparison of properties of biofuel derived from various feedstocks, analysis of biofuels using multi-criteria decision-making (MCDM) method, performance on Variable Compression Ratio (VCR) engine. 2.11 mm2/sec (kinematic viscosity at 40°C) of biodiesel is cause ease in atomisation of fuel in engine and hence better thermal efficiency (η thb) and lower value of BSFC is observed. Analysis using MCDM proves algae biodiesel as best among the other feedstock. The fast pyrolyser is designed for the derivation of green crude from any feedstock. Response Surface Methodology (RSM) technique having a set of large numbers of runs is adapted to gain analytical results very close to the actual performance tests. The result for B0, B20, and B40 shows, the lowest value of BSFC of 0.34kg/kWh, the highest value of η thb = 27.59% and the highest value of mechanical efficiency = 48.56% are achieved at B20, with CR 17, the injection pressure of 200bar and at full load i.e. at 11 kg-f. Thus algae biodiesel as a cleaner and greener fuel is proven as a futuristic fuel for the automobile and power generation sector.

Emulsified nano Al2O3 – Jatropha methyl ester blends: application in variable compression ratio engine

Purpose The purpose of this paper is to assess the influence of blends of Jatropha methyl ester (JME) and its nano Al2O3 emulsion on variable compression ratio diesel engine. The oxygen in alumina contributed for the smooth burning and resulted in improved performance and emissions. Design/Methodology/Approach The biodiesel (methyl ester) is prepared from the raw Jatropha oil. The B10, B20 and B30 blends of and their nanoemulsions are prepared with the 25, 50, 75 and 100 ppm of nano Al2O3. The prepared JME blends and its nanoemulsions are tested in a variable compression ratio (VCR) diesel engine to evaluate the engine performance and emission characteristics. Findings The nanoemulsion B20 + 50 ppm has given maximum brake thermal efficiency (BTE), and with the increased proportion of nanoparticle, the BTE was reduced. Also, the specific fuel consumption is lowest (0.2826 kg/kWh) for B20 + 50 ppm at the compression ratio 16.5 and full load which is 4.10% lower than the diesel and 5.8% lower than the B20 blend. As the load increases, NOx emission increases owing to higher peak temperatures in the combustion chamber. The JME-nano Al2O3 emulsion reduces the HC and CO emission compared with all other fuels. Originality/Value Novel nano emulsions are prepared, characterized and tested on VCR engine.

Impact of compression ratio and effect of biodiesel blends in performance, combustion and emission characteristics of VCR DI diesel engine

The work has been carried out to use mahua oil methyl ester (MOME) in variable compression ratio (VCR) engine with three compression ratios (CR) 17:1, 17.5:1 and 18:1 was used for the experiment. Also the blend ratios are (M10, M20 and M30) mahua biodiesel blends at zero to maximum load with a constant speed 1500 rpm. The MOME properties are identical to diesel. The characteristics that means brake thermal efficiency (BTE), specific fuel consumption (SFC), hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx), smoke, cylinder pressure (CP) and heat release rate (HRR) were superior at CR 18:1 and the blend B20, but considering the engine vibration and noise of the CR is limited to a value of 18:1.

Emission profiling of a common rail direct injection diesel engine fueled with hydrocarbon fuel extracted from waste high density polyethylene as a partial replacement for diesel with some modifications

A hydrocarbon fuel extracted from waste high-density polyethylene (WHDPE) by catalytic pyrolysis in a batch scale reactor is blended with diesel by 30% vol. (called as D70H30) is tested in a variable compression ratio engine equipped with a common rail system. Experiments were conducted at three compression ratios (16:1, 17.5:1, and 19:1) and exhaust gas re-circulation (EGR) rates (0%, 10%, and 20%) at the engine’s rated power to evaluate its combustion, performance and emission characteristics. The results revealed that, increasing the compression ratio resulted in higher peak cylinder pressure (PCP) and heat release rates (HRR). Introduction of EGR diminished both PCP and HRR peaks. The brake thermal efficiency of D70H30 blend was 4% lower than diesel at same operating conditions which got better at higher compression ratio without EGR. NOx emission was highest when injected at compression ratio 19:1 and at 0% EGR rate which was 6% and 3% higher than diesel and D70H30 blend operated at engine stock settings. In comparison with baseline diesel smoke opacity remained lower at all operating conditions, where lowest smoke emission was recorded at CR19 and at 0% EGR rate. UHC and CO emission followed the similar trend of smoke opacity. Whereas CO2 emission increased with compression ratio and reduced with induction of EGR. It can be concluded from the study that at higher compression ratio and low EGR rates D70H30 blend can be effectively utilized in a CRDi engine.

Performance, emission characteristics of compressed ignition engine with alternative fuel

The primary study is to take the alternative fuel using cashew nut shell liquid as bio-diesel and to moderate the continuous issues posed by the reducing petroleum backup. Cashew nut shell is pulverized and the oil is extracted. The CNSL is then converted in to bio-diesel by transesterification process. The properties of liquid thus accomplished are characterized. The investigational results verified the fact that CNSL consists mostly phenolic compounds. The bio-diesel thus obtained is blended with neat diesel in the ratios 2080 (B20) and 6040 (B60) per litre. The blended mixture is then tested for performance and combustion using Variable Compression Ratio (VCR) Engine set up. The emission characteristics are tested using computerized AVL Smoke Metre.

Optimization of performance and emission characteristics of VCR engine with biodiesel using response surface methodology

Due to an increase in the population and over-exploitation of fossil fuels, give us a prospect to discover environmentally friendly and clean fuels for the existing unmodified diesel engines for automobiles to reduce the air pollution. The aim of this study is to optimize the performance and emission characteristics of biodiesel (i.e.,) Plastic and Castor oil in Variable Compression Ratio (VCR) engine using Box-Behnken Design (BBD) of Response Surface Methodology (RSM). 15 Experimental runs were carried out with the input parameters as Blend (B), Compression Ratio (CR) and Load (L) ranges from B0, B10, B20 and 15, 16, 17 and 0, 5, 10 respectively for the responses like Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE), Hydro-Carbon (HC), Carbon-monoxide (CO), Oxides of Nitrogen (NOX). From RSM, mathematical models and optimizer plots were employed to find the optimal parameters for the BSFC, BTE and HC, CO, NOx. Highest desirability for maximum 1.0 is observed for BSFC, 0.91 for BTE and for minimum 0.95 for NOx, 0.68 for HC and 0.55 for CO. Composite desirability of 0.79 is observed for blend B10 CR 16:1 and Load 5 kg. The outcomes of the test carried out for the validation test with the estimated values were observed from the model and almost coincided with the validation results with smaller deviations.

Effect of Shorea robusta methyl ester biodiesel blends on the exergy and sustainability analysis of diesel engine

ABSTRACT In this experimental investigation, the impact of engine load, compression ratio, and percentage blends of biofuel on exergy, energy, and sustainability parameters for the samples of diesel based (10–40% v/v) biodiesel blends were performed on variable compression ratio engine. The brake thermal efficiency, exergy efficiency, engine sustainability, exergy destruction rate, and other exergy parameters were found to escalate with the escalating engine load, compression ratio, and percentage of Shorea robusta methyl ester biodiesel fuel blends. The exergy and energy efficiency of the engine with diesel fuel were 2.05%, 6.98%, and 10.63%, respectively higher than 10%, 30%, and 40% Shorea robusta methyl ester fuel and 2.23%, 8.67%, and 9.22%, respectively at 50% engine load and 1500 rpm engine speed. The influence of compression ratio, engine load, and fuel blends on the exergetic performance parameters revealed a similar trend with energetic parameters, but the magnitude of exergy parameters was found lower than the energetic parameters. The application of Shorea robusta methyl ester biodiesel blends improved the combustion characteristics with a small drop in energy and exergy performance parameters and sustainability of the engine. The exergy destruction rate and entropy generation rate for shorea robusta methyl ester biodiesel blend were found lower than the conventional fuel. Therefore, the fuel blend have a high potential to be an alternate to the conventional fuel without any design modification of diesel engines.