Variable Compression Ratio Research Articles

Experimental analysis of the effect of zinc oxide nano additive diesel-ethanol blend on the performance and emission characteristics of a variable compression ratio diesel engine at various compression ratios

The two significant challenges facing the world are growing pollution issues and fossil fuel depletion. Emissions emanating and consumption of fossil fuels in diesel engines are reduced by modifying engine operating parameters and by developing more efficient alternative fuels. In view of this, the current work evaluates the effect of ZnO nanoparticles mixed with diesel-ethanol blend on the working characteristics of diesel engine at different CR’s and loads. The test fuels selected for the experimental work are pure diesel, DE10, DE10ZnO50 and DE10ZnO100, and the compression ratios are 16.5, 17.5 and 18.5. Using ultrasonic agitation, ZnO nanoparticles were incorporated in fuel blends in the presence of 2% surfactant span80. All fuel blends were tested for their physicochemical properties, and it was noted that the fuel properties improved when ZnO nanoparticles were added to the test blends. The results showed that at CR 18.5, the DE10ZnO100 fuel blend shown maximum improvement in engine working characteristics as compared to other blends. In comparison to diesel at CR 18.5 for DE10ZnO100 blend, BTE enhanced by 5.73% and BSFC was reduced by 8.31%. CO, NOx and UHC emissions are reduced by 21.96%, 6.41% and 12.07%, whereas CO2 emissions have increased by 7.44%, respectively. HIGHLIGHTS Different concentration of ZnO nanoparticles incorporated diesel-ethanol blend is prepared. The effect of ZnO nanoparticles diesel-ethanol blend at various compression ratios of diesel engine was investigated Optimal results are noted for the DE10ZnO100 blend at compression ratio 18.5. Improvements in BTE and BSFC is 5.73% and 8.31% as compared to diesel at CR 18.5 for DE10ZnO100 blend. CO, UHC and NOx reduced by 21.96%, 12.07% and 6.41%.

The effects of nanoparticles as a biodiesel ingredient on the performance of a VCR diesel engine

The combustion, efficiency, and emission properties of a single-cylinder variable compression ratio diesel engine were examined in this research (B100A30C30). To create a homogeneous solution, the ultrasonicator was used in conjunction with a 30 ppm concentration of silicon carbide and carbon nanotubes, two common nanoparticles found in fuel combinations. The increased mixing and chemical reactivity offered by nanoparticles' greater surface area to volume ratio during combustion improved the combustion, performance, and emission characteristics of diesel engines. The engine with nanoparticles (B20A30C30) had a thermal efficiency of braking that is 20% higher than the engine with regular particles (B100). Following that, nitrogen oxide emissions reduced by 38%, carbon monoxide emissions by 68%, hydrocarbon emissions by 52%, and smoke emissions by 48%.

Study on Performance and Emission Characteristics of CI Diesel Engine by adding liquid additives with Dual Fuel

For an extensive stretch of time, diesel motors have turned into the world’s “Central player” of transportation. However, fuel consumption, late natural concerns, and accordingly consistently expanding fuel costs have made the quest for another fuel basic. Scientists have shown an enormous interest in testing different plant and vegetable oils as an enhancement for diesel. This foundation Nox discharge is conveyed during the ignition of energizes at high temperatures. Inordinate NOx discharge has a scope of consequences for human wellbeing and the environment. In this article, we will talk about elective energy sources in contrast with petroleum derivatives utilizing the ASTM standard. Thus, in this specific occasion, we’re subbing waste cooking oil and Juliflora oil for nano-added substances like magnesium oxide (MgO) and ferrofluid (Fe3O4). The two oils are mixed in the accompanying rates: 10%, 20%, 30%, and 40%. The SBU Variable Compression Ratio Engine was utilized to execution examination, burning, and outflow attributes. Therefore, we can see a diminishing in HC, a break in warm execution, and an increment in NOx.

Impact of additive ethylene glycol diacetate on diesel engine working with jatropha-karanja dual biodiesel

The present study investigates ethylene glycol diacetate as a prospective oxygenated additive for jatropha-karanja dual blended biodiesel for enhanced engine characteristics of a diesel engine. The experiments have been conducted at constant speed of 1500 rpm on a variable compression ratio diesel engine working with biodiesel having 10–30% of Jatropha and karanja oil methyl ester and 1–3% of additive. The brake thermal efficiency increased by 3.6–4.2% while the brake specific fuel consumption reduced by 0.08–0.24 kg/kWh for fuel blends by adding 3% additive. The hydrocarbon and carbon monoxide emissions reduced by a maximum of 7 ppm and 0.02% respectively with slight increase in nitrogen oxide over entire range of fuel blends. The peak cylinder pressure attained 53.2 bar with maximum heat release rate 63.7 J/oCA by addition of 3% additive. Thus, the ethylene glycol diacetate can be adopted as a suitable additive for jatropha-karanja blend dual biodiesel to achieve improved engine characteristics of diesel engines.

Sustainable biodiesel from flex-mix feedstock and its combustion in a VCR-CRDI engine with variable exhaust gas recirculation and injection pressure

Biodiesel produced from single feedstocks has many challenges due to variations in the oil properties. The flex-mix approach is a long-term solution for turning mixed feedstock into high-quality biodiesels. In this investigation, a pre-mixed used cooking oil and animal fat (pig fat) mixture (from 20% to 80%) was transesterified to produce flex-mix methyl ester (FMME). The FMME fuel characteristics were tested and compared to biodiesel standards. Generally, biodiesel emits higher oxides of nitrogen (NO x ) gas due to the presence of highly unsaturated compounds and oxygen. The present study aims to address this issue by adopting the flex-mix approach in combination with fuel injection strategies (400, 500 and 600 bar), exhaust gas recirculation (EGR 10%, 20% and 30%) and variable compression ratio (CR 17.5:1, 20:1 and 22:1). At a CR of 22 and an injection pressure (P inj) of 600 bar, the FMME fuel without EGR shows a minimum reduction in brake thermal efficiency of 0.15% when compared to diesel. Nitric oxide gas emissions decreased by nearly 50% for all P inj and EGR values, but they rose when the compression ratio was increased to 20 and 22. Smoke and hydrocarbon emissions also increased with the exhaust gas proportion. The engine performance with FMME fuel was found to be equivalent to that with fossil diesel fuel. According to the findings, the flex-mix approach could be a long-term alternative to producing renewable fuel for off-road diesel engine application.

Techno‐economic studies on the variable compression ratio dual fuel diesel‐producer gas CI engine utilizing different biomass feedstocks

AbstractIn this study, a techno‐economic analysis for a 3.75 kW biomass gasification power generation system (BMPGS) was conducted by exploiting available biomass resources such as rice husk, coconut shell, and rubber shell as feedstock. Payback time (PBT), net present value (NPV), and life cycle cost are the economic criteria that are delivered by an economic model for a BMPGS. Experimental results obtained on the technical parameters of a BMPGS, show that the rubber shell operated BMPGS has the highest overall efficiency (15.5%), maximum diesel savings (48%), and least biomass consumption (3.3 kg/h). Even though the capital cost of the producer gas driven dual fuel CI engine is higher than the standalone diesel genset power production system, it has the lowest running cost and cost savings per year, making it an excellent choice for power generation in remote locations. The rubber shell operated BMPGS system show a minimum PBT of 2.9 years which is desirable as the cost for installation of the proposed system can be regained within a short period of time. A positive NPV of Rs. 3,90,000 is attained for rubber shell, which clearly indicates in acceptance of rubber shell as biomass feedstock for BMPGS. The sensitivity analysis proves that the uncertainty in input parameters such as the cost of a biomass gasifier, dual fuel VCR engine, labor cost, and the cost of biomass feedstock influence the output parameters of the capital cost, operating cost, and PBT.

Preparation, Characterization, and Evaluation of Emission and Performance Characteristics of Thumba Methyl Ester (Biodiesel).

Thumba oil with a higher triglyceride content can be a promising feed for synthesizing a fatty acid alkyl ester as an alternative to pure diesel. The current study investigates the emission and performance characteristics of thumba methyl ester (TME) in compression ignition (CI) engines corresponding to variable loads and compression ratios (CRs), respectively. TME was prepared at an optimized pressure of 5 bar by hydrodynamic cavitation. The properties of TME-diesel blends with varied volume percentages of biodiesel, such as 5, 10, 15, 20, and 25, denoted B5, B10, B15, B20, and B25, respectively, were compared to pure TME (100% biodiesel) and pure diesel (100%). The B20 biodiesel blend has been observed as the optimal one based on the lower emission composition and higher brake thermal efficiency. For B20 fuel, injection at 23° before the top dead center (TDC) and a CR of 18 resulted in the lowest brake specific fuel consumption of 0.32 kg/kW h and a maximum brake thermal efficiency of 36.5%. Using titanium dioxide nanoparticles in the pre-stage of TME manufacturing has ultimately reduced the nitrogen oxide, hydrocarbon, and carbon monoxide emissions. At a CR of 18 and advanced injection 23° before TDC for a CI engine, TME derived from thumba oil has the potential to be a viable diesel substitute.

Assessment of the co-combustion process of ammonia with hydrogen in a research VCR piston engine

The presented work concerns experimental research of a spark-ignition engine with variable compression ratio (VCR), adapted to dual-fuel operation, in which co-combustion of ammonia with hydrogen was conducted, and the energy share of hydrogen varied from 0% to 70%. The research was aimed at assessing the impact of the energy share of hydrogen co-combusted with ammonia on the performance, stability and emissions of an engine operating at a compression ratio of 8 (CR 8) and 10 (CR 10). The operation of the engine powered by ammonia alone, for both CR 8 and CR 10, is associated with either a complete lack of ignition in a significant number of cycles or with significantly delayed ignition and the related low value of the maximum pressure pmax. Increasing the energy share of hydrogen in the fuel to 12% allows to completely eliminate the instability of the ignition process in the combustible mixture, which is confirmed by a decrease in the IMEP uniqueness and a much lower pmax dispersion. For 12% of the energy share of hydrogen co-combusted with ammonia, the most favorable course of the combustion process was obtained, the highest engine efficiency and the highest IMEP value were recorded. The conducted research shows that increasing the H2 share causes an increase in NO emissions, for both analyzed compression ratios.

Optimization of diesel engine performance and emission characteristics with cerium oxide nanoparticles mixed waste cooking oil biodiesel blends

The study investigates the performance and emission characteristics of a four-stroke, single-cylinder, and direct injection diesel engine with variable compression ratio using nanoparticles blended biofuel. The cerium Oxide (CeO2) nanoparticles have been blended in corresponding ratios with waste cooking oil (WCO) biodiesel. Further, response surface methodology (RSM) based Box-Behnken design (BBD) approach was used to evaluate engine performance parameters such as brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and emission characteristics (such as NOx, CO, and CO2 emission). In addition, the quadratic models were obtained to investigate the influence of input parameters on each output response with analysis of variance (ANOVA). The desirability approach was used to obtain the optimal engine performance and emission characteristics. The analysis revealed that WCO blended with CeO2 nanoparticles fuel improves CI engines’ performance and reduces their hazardous emissions. The compression ratio of 14:1 at 10.29% blend composition and 50 ppm concentration level of nanoparticles with composite desirability of 0.858 was found to be the engine’s optimal operating conditions. At optimal conditions, BTE, BSFC, NOx, CO, and CO2 were 36.62%, 0.2204 kg/kW-h, 168 ppm, 0.0192%, and 1.132% respectively.

An evaluation of biosynthesized nanoparticles in biodiesel as an enhancement of a VCR diesel engine

• Homogeneous solution is made by mixing nanoparticles such as titanium oxide (TiO 2 ) and zinc oxide (ZnO). • Enhanced mixing and improved reactivity of such nanoparticles. • Higher surface area to volume ratio is observed. • Improved engine’s performance and higher efficiency is resulted. Using three different fuel sequences –biodiesel–diesel (B20), biodiesel–chemically and biologically synthesized nanoparticles(B20A30C30), and biodiesel–chemically and biologically synthesized nanoparticles (B20A30C30). This study investigates a single-cylinder variable compression ratio diesel engine's combustion, efficiency, and emission characteristics (B100A30C30). The ultrasonicator is employed in concert with 30 parts per million (ppm) concentration of titanium oxide (TiO 2 ) and zinc oxide (ZnO), two typical nanoparticles found in fuel mixtures, to form a homogenous solution. As a result of the greater mixing and chemical reactivity offered by nanoparticles' higher surface area to volume ratio during combustion, diesel engines' combustion, performance, and emission characteristics have all been improved. The engine with nanoparticles (B20A30C30) has a 16% higher brake thermal efficiency than the engine with conventional particles (B100). Following that, nitrogen oxide emissions were reduced by 32%, carbon monoxide emissions were reduced by 62%, hydrocarbon emissions were reduced by 48%, and smoke emissions were reduced by 40%.

Effect of using spirulina algae methyl ester on the performance of a diesel engine with changing compression ratio: an experimental investigation

Diesel engine characteristics were investigated experimentally while adding different concentrations of third generation biodiesel spirulina algae methyl ester (SAME). Three volumetric blends of SAME are added to standard Iraqi diesel, namely 10% SAME, 20% SAME, and 30% SAME. The properties of the fuels were found according to the American Society for Testing and Materials standards (ASTM). Experimental work was conducted on a single-cylinder diesel engine under variable load and compression ratio. Three compression ratios are used, starting from 14.5, 15.5, and 16.5. Based on the results obtained, the presence of SAME along with diesel caused an increase in Brake specific fuel consumption (BSFC), carbon dioxide (CO2), and nitrogen oxides (NOx) while decreasing both brake thermal efficiency (BTE) and exhaust gas temperature (EGT). Hydrocarbon (HC) emissions decreased by 7.14%, 8.57%, and 10.71%, for 10% SAME, 20% SAME, and 30% SAME, respectively, compared to the original neat diesel fuel. The dramatic carbon monoxide (CO) emission reduction was at full load point. The addition of SAME from (10 to 30)% reported a decrease in CO by (6.67–20)%. NOx, as well as CO2 emission, are increased as a result of SAME addition. The compression ratio change from (14.5/1 to 16.5/1) led to increased BTE, NOx, and decreased BSFC and all carbon emissions. The experimental results are validated with other studies' findings, and minor divergence is reported.

Compressor operated sorption system for high temperature thermochemical energy storage using Mg based hydrides

Thermal energy storage based on sorption technology has been flourishing due to its high storage density, wide operating temperatures, and long-term storage. In this work, an innovative compressor operated sorption thermochemical energy storage (CSTES) system is proposed and investigated for high temperature (≥250 °C) thermal energy storage with a large heat upgradation. The system uses magnesium-based metal hydrides as energy storage material due to their high hydrogen absorption capacity and good reversibility. The proposed CSTES system stores energy in the temperature range between 228 and 587 °C with a maximum heat upgradation of 78 °C. The highest coefficient of performance and energy storage density of 0.91 and 1991.843 kJ/kg is obtained using Mg–Al–Ti and Mg–Al–Ni alloys, respectively. Variation of compression ratio and heat source temperature on the performance of the CSTES system is studied.

Experimental investigation on impact of water in diesel emulsion in a single-cylinder research diesel engine

The current study focuses on assessing the impact of water-emulsified fuel on single-cylinder diesel engine. The effect of water concentration, homogeniser speed and surfactant concentration on the stability of water in diesel emulsion is studied. The performance, emission, and combustion analysis have been carried out by varying compression ratio, injection timing, and injection pressure. It is noted from stability analysis that for 10% water at 15,000 RPM homogeniser speed, 1% surfactant mixture is the optimal parameter to achieve stability of WD emulsion. Ignition delay period and combustion duration increase as water concentration is increased in the emulsion. At a compression ratio of 18, injection timing 23bTDC and pressure 210 bar show reduced carbon monoxide, hydrocarbon, oxides of nitrogen, and smoke emission by 8.3%, 8.57%, 21.25%, and 43.07%, respectively, compared to standard diesel. The injection pressure of 250 bar shows enhanced brake thermal efficiency compared to 210 and 230 bar.

Impact of variable compression ratios on engine performance and unregulated HC emitted from a research single cylinder engine fueled with commercial gasoline

Un burned hydrocarbon determination analysis of toxic of unregulated HC chemical species staring from C5 to C11, using different compression ratios in one-cylinder gasoline research engine using (GC- MS) instrument, tests were carried out under variable engine conditions with different sizes of compression ratios. Engine characteristics showed a potential fuel economy and a promising exhaust emissions. A great reduction of un regulated HC,CO, and NOx emissions were achieved. Impact of adding H2 in to the inlet manifold was also analyzed. Maximum HC emissions was presented with smaller engine compression ratio at lower engine loads. Driving to higher compression ratios leads to a lower level of unburdened HC, changing to larger compression ratios has the ability to remove an un regulated HC compounds to lower levels (under permissible exposure limits), except for naphthalene and methyl naphthalene which is classified as carcinogenic and harmful compounds for health and environment, these organic compounds were presented with larger concentrations at lower load and lower compression ratio (C1). However, hydrogen addition helps decreasing methyl-naphthalene and naphthalene to acceptable level. Aromatic Species such as toluene and pexlene are mainly found in the engine exhaust operating in C5 mode aside with engine load operation, and reduced slightly at higher load., changing compression ratio did not much influence benzene and ethely benzene concentrations in all engine conditions. Bmep, Bp, and Bsfc, were analyzed under different compression ratios. Larger compression ratios have increased Bmep and engine power and reduced Bsfc.

Performance analysis of vibration characteristics on VCR engine using hybrid honeycomb structure

There are a number of techniques available to reduce the engine vibration, and vibration isolation is one among those techniques. Such vibrations can be isolated using hybrid engine mounts that absorb the forces caused by vibration. Consequently, the present work proposes a hybrid aluminium mount filled with silica gel to isolate the engine vibration. Experiments were carried out on the variable compression ratio engine mounted on the hybrid honeycomb structure, and the free, forced vibrations, and frequency domains were analysed. The test results portrayed that the performance of the engine with a hybrid mount is found to be better than the conventional rubber mount. The hybrid sandwich panel with a honeycomb structure crowded with silica gel as fibrous material was utilized to isolate the engine vibrations. Compared with conventional mount (1.502 m/s2), high amount of vibration was reduced by honeycomb structured mount (0.814 m/s2) using different load conditions and fuel input pressure of 150 bar. Vibration in conventional mount for blower closing condition was 1.546 m/s2 and that in honeycomb structured mount was 1.4 m/s2.

Study of the effects of trapped compression ratio on the heavy fuel operation of a spark ignition unmanned aerial vehicle engine

PurposeThis paper aims to present experimental experience of heavy fuelling of a spark ignition crankcase scavenged two-stroke cycle unmanned aerial vehicle (UAV) engine, particularly focusing on the effects of compression ratio variation, and to cross-correlate with the results of fluid dynamic modelling of the engine and fuels used.Design/methodology/approachOne-dimensional modelling of the engine has been conducted using WAVE software supported by experimental dynamometer testing of a spark ignition UAV engine to construct a validated computational model using gasoline and kerosene JET A-1 fuels.FindingsThe investigation into the effects of compression ratio variation via fluid dynamic simulation and experimental testing has allowed an assessment of the approach for improving heavy fuel operation of UAV engines using auxiliary transfer port fuel injection. The power level achieved with reduced compression ratio heavy fuel operation is equal to 15.35 kW at 6,500 revolutions per minute compared to 16.27 kW from the standard gasoline engine or a reduction of 5.7%.Practical implicationsThe studied engine is specifically designed for UAV applications. The validation of the computational models to explore the effects of compression ratio and heavy fuel injection on the solution and cost is supported by experimental tests.Originality/valueThe application of auxiliary port fuel injection of heavy fuel and associated compression ratio optimisation offers an alternative approach to achieve the safety and logistical challenges of the single fuel policy for UAVs. The application of WAVE to simulate crankcase scavenged two-stroke cycle engines has been applied in very few cases. This study shows further exploratory work in that context.

Experimental investigation on performance of cotton seed biofuel blended with diesel on variable compression ratio diesel engine

The reasons for the fuel energy crisis are the rapid increase in the global population and changing human lives. Fossil fuel is a leading factor involved in atmospheric pollutants. However, biofuel plays an important role in boosting engine efficiency and lowering emissions. Present research work contributes to enhancing the performance of diesel engines. In this work, cottonseed oil is used and converted into biofuel through the transesterification process. Raw cotton seed oil comes under the category of vegetable oils, both edible and non-edible. The calorific value and viscosity of biodiesel fuel are two distinct characteristics. The biofuel blends with diesel in variable proportions by volume of 20%–40 % are used. The performance was monitored, analysed and verified against pure diesel and biofuel using CB20, CB30, and CB40. The performance obtained using biofuel with varying loads at different fuel blends on the VCR engine improves BTE and BSFC. When the CR is changed from 18 to 22, the BSFC decreases by 0.310 to 0.290 kg/kwh, while the BTE increases by 0.72 percent.

Exergy and energy analysis of compression ignition engine using diesel and karanja oil blends under varying compression ratio and engine load

The present investigation aims to analyse the effective utilisation and losses of available energy in a compression ignition (CI) engine using diesel,10% and 20% blends of karanja oil (K10, K20) with different engine loads and compression ratios. Exergy and energy analysis is carried out and performance parameters are compared. The results show that thermal efficiency for K10 was 6.08% higher compared to diesel. Exergy efficiency for diesel, K10 and K20 was recorded as 25.87%, 27.36% and 25.26%, respectively. For K10 exergy efficiency was 5.76% higher compared to diesel. Exergy analysis shows that the maximum fuel chemical exergy is lost in the engine, which represents about 65–70% of the total exergy in the overall system for all tested fuels. The K10 blend is recommended as fuel for CI engines based on its optimum results compared to diesel. HIGHLIGHTS From the present investigation the following points should be noted: Using exergy and energy analysis, efficient utilisation of fuel input energy and various losses are measured directly. Thermal efficiency and exergy efficiency (EE) were found to be improved by 6.08% and 5.76%, respectively, for the lower fuel blend (K10) compared to base fuel diesel under full load condition at a compression ratio of 18:1. Specific fuel consumption is remarkably reduced for all test fuels. K10 results in optimum reduction in fuel consumption which was 2.94% lower compared to base fuel diesel. From exergy and energy analysis, K10 showed better energetic performance (fuel energy input, heat loss and exhaust loss) with equivalent exergetic performance (fuel exergy input, exergetic efficiency and exergy losses) in response to variation in compression ratio and engine load.

Overall Performance Investigation and Optimization of a Multi-fuel Operated Compression Ignition Engine Using Coupled Taguchi and Grey Relational Analysis.

Biofuels are regarded as the best diesel fuel substitute due to their low sulfur concentration, reduced aromatic hydrocarbon content, renewable nature, and higher oxygen content. In this research article, the impact of producer gas, Calophyllum inophyllum oil, diesel, and a blend of C. inophyllum–producer gas fuel on a variable compression ratio (VCR) compression ignition (CI) engine, and the performance and emission parameters are evaluated. Several test runs are undertaken at a constant speed of 1500 rpm to predict the performance and emission characteristics of the test engine by changing input parameters such as engine load, CR, and fuel mode of operation. The brake thermal efficiency, BTE, is considered the performance characteristic, and CO, HC, NOX, and opacity are considered the emission characteristics for the present study. The biofuel, or producer gas, employed in this study is prepared from waste biomasses, such as leaves, small tree branches, vegetable waste, and cow dung, aiding waste management for a sustainable environment. In addition, a coupled Taguchi–Grey relational analysis technique is used to predict the best possible combination of control factors for optimizing the overall output responses. 12 kg load, a CR of 18, and diesel fuel are found to be the optimum input parameters of an engine toward optimum performance. A confirmation test is performed at the end to validate the outcome of the experiment. An enhancement in performance of 22.75% is observed with the considered Grey relational grade model.

Optimization of operating conditions in a homogeneous charge compression ignition engine with variable compression ratio

Optimization of operating conditions in a homogeneous charge compression ignition engine with variable compression ratio