Turbocharged Diesel Engine Research Articles

Experimental investigation on effects of fuel injection and intake parameters on combustion and performance of a turbocharged diesel engine at different altitudes

Matching characteristics between fuel injection and intake control parameters significantly affect overall performances in diesel engine at variable altitudes. Prior to optimizing the control parameters of diesel engines operating at high altitudes areas, there is a necessity to identify the influence law of fuel injection and intake parameters on engine performance. This study focused on the effects of main injection timing (MIT), fuel injection pressure (FIP), EGR rate, and variable nozzle turbocharger (VNT) opening on the combustion, performances and NOx and smoke emissions in a turbocharged diesel engine at different altitudes (2000, 1,000, and 0 m). Strategies for optimization of engine performance and the coupling relationship between these parameters were analyzed. The results showed that as the altitude increased from 0 m to 2000 m, the engine torque dropped by 2.9%, the BSFC increased by 2.6%, the NOx emissions reduced by 11.8%, and the opacity smoke increased by 26.2%. The effects of MIT, FIP, EGR rate and VNT opening on engine performances were more significant at high altitudes. As the MIT was advanced at 2000 m altitude, the engine torque increased by 5.6%, the BSFC reduced by 5.9%, the opacity smoke decreased by 55%, while the NOx emissions increased by 54%%. Advance the injection timing properly can overcome the altitude effect on engine power. With the FIP increased from 105 to 130 MPa at 2000 m, the engine torque reduced by 1.7%, the BSFC increased by 1.6%, the opacity smoke dropped by 44.5%, and the NOx emissions increased by 17.5%. When the EGR rate increases by 5%, the NOx emission reduces by 16.4%,17.9 and 21.9 respectively at 0, 1,000 and 2000 m altitude. The EGR rate should be properly reduced to obtain the recovery of engine power at plateau. As the VNT vane opening decreased from 40% to 20%, the NOx emission increase by 9.4% and 9.9% at 0 m and 1,000 m respectively, and it reduces by 3.9% at 2000 m, while the opacity smoke reduces by 38.9% at different altitudes. The optimization of VNT vane opening requires a balance between combustion performance and pumping losses. The multi-objective collaborative optimization technique should be applied to optimize these parameters to help improve engine efficiency and emissions at high altitudes.

Performance, emissions, and combustion in turbocharged diesel engines: The effect of rapeseed oil biodiesel-diesel blends

The need for sustainable alternative fuels is becoming increasingly urgent because to the rapidly expanding demand for automobiles and the growing concerns over the fossil fuel diminution. This research looks into how biodiesel, specifically blends made from rapeseed oil (RSO), can fill this new need. The RSO is created through transesterification, which yields a biodiesel with characteristics that meet ASTM requirements. In a 5.1 kW, single-cylinder, turbocharged Diesel engine (Turbo-DE), the performance, emissions, and combustion (P-E-C) characteristics of several RSO-diesel blends (B20, B40, B60, and B80) are examined and contrasted with those of pure diesel. According to the findings, brake thermal efficiency slightly decreases as biodiesel proportion in the blend rises. The environmental advantages of these blends are offset by a sizable decrease in smoke, CO, and hydrocarbon emissions. On the other hand, greater biodiesel ratios result in higher emissions of NOx and CO2. The thermal efficiencies of the brakes for diesel, B20, B40, B60, and B80 blends were found to be 29.3%, 28.6%, 27.9%, 27.2%, and 26.9%, respectively, in the detailed results. While smoke emissions decreased from 55% (diesel) to 40% (B80), NOx emissions ranged from 1556 ppm (diesel) to 1718 ppm (B80). The B20 blend?s combustion characteristics closely resemble those of diesel, with maximum cylinder pressures and ignition delay of 78 bar, 73 bar, 20%, and 18%, respectively, for diesel and B20. These results offer a good starting point for additional investigation into sustainable alternative fuels by shedding light on the prospective performance and ecological impact of biodiesel-diesel mixes.

Model-based Performance Study of Electrically Assisted Turbocharging Diesel Engine

Under the low load conditions, the motor drives the compressor to increase the intake of the engine, and under the high load conditions, the motor recovers the excess exhaust energy, which greatly improves the performance of the diesel engine in all aspects. In this paper, the one-dimensional simulation prediction model of TBD620V16 diesel engine is established and checked. On this basis, the external electric auxiliary turbocharging system of motor is established. The influence of motor power on the performance of diesel engine under different working conditions is studied by simulation, and the control strategy is put forward according to the influence of power and economy of diesel engine under low load. Based on this control strategy, the improvement effect of power performance and economy under low load conditions is studied. The results show that there is an optimal motor power in each load condition to make the comprehensive thermal efficiency of diesel engine reach the maximum value. Under low load condition, with the increase of diesel engine speed, the pressure ratio of electrically assisted turbocharged diesel engine is higher and the fuel consumption is lower. When the diesel engine is accelerated from 25% to 30% load condition, the supercharged pressure of electrically assisted turbocharged diesel engine is stabilized for about 3s, and the supercharged pressure is higher when it is stable, and BSFC is significantly lower than that of traditional turbocharged diesel engine.

Total loss torque waveform estimation for a turbocharged diesel engine

The indicated (gas) torque is a key parameter for reciprocating engine. It reports on various aspects of the engine, such as the quality of the combustion process, the fuel combustion rate and the average effective pressure. This is a good indicator of the stability of the engine at work. The form of the instantaneous indicated torque is precious information for the control and diagnosis of the engine. The study of the simulation of crankshaft dynamics illustrates the need to know the total loss torque (i.e. the addition of friction torque, auxiliary torque and load torque) to achieve the indicated torque. To date, it has proven difficult to obtain an accurate predictive expression of the instantaneous total loss torque. This expression includes adequate simulation of friction of all moving parts of the engine (piston ring and skirt, crankshaft bearings, valve gear...), auxiliaries and load. Based on experimental results conducted on a four-cylinder turbocharged diesel engine, this work offers a simple and practical solution for estimating the total torque loss. The proposed method makes it possible to successfully estimate total torque losses under a wide range of engine operating conditions. The result prediction has been confronted to experimental data.

Simulation of Sequential Turbocharging Switching Control System for Low Speed Diesel Engines

In order to study the sequential turbocharging switching process of low-speed diesel engine, this paper uses GT-power software to establish a simulation model of sequential turbocharging low-speed diesel engine. It is enhanced and improved into a model of a sequential supercharged diesel engine. Modules such as load, governor, valve control, and surge margin are set up in the simulation model. Then parameters such as switching speed, valve opening time and response time are set in the model. Through the above preparations, the thesis has carried out the simulation calculation of the sequential supercharging transient switching process and verified the rationality of the setting parameters and the accuracy of the module setting. This provides a certain reference for the valve control strategy of the sequential supercharging switching system of low-speed diesel engines.

Assessment of the impact of the number and the arrangement of cylinders of the KAMAZ disel engines on their fuel efficiency

Most of the natural aspirated truck diesel engines had an eight-cylinder V-twin (V8) configuration. Modern turbocharged diesel engines have a six-cylinder in-line configuration (L6), although some V8 diesel engines continue to be produced. A comparison was made of the performance of the KAMAZ-740 (V8) diesel engine with two turbochargers and KAMAZ-910 (L6) diesel engines with one turbocharger, having almost the same displacement with the same pattern of torque along the full load characteristic. The AVL BOOST software and experimental compressor and turbine maps were used. The factors influencing fuel efficiency were analyzed: indicated efficiency, friction and gas exchange losses, turbocharger efficiency. The L6 diesel engine had a uniform pressure pulsation in the exhaust manifold and at the turbine inlet. In the V8 diesel engine, the pulsations were uneven and had higher amplitude, which led to higher gas exchange losses and a decrease in turbine efficiency. The L6 diesel engine had a higher indicated efficiency but also higher friction losses. On average, the brake specific fuel consumption of the L6 diesel engine was by 5.5 % lower than that of the V8 diesel engine. Keywords V8 and P6 diesel engines; modeling in AVL BOOST; pressure pulsations in the exhaust system; turbocharger efficiency; friction and gas exchange losses

Numerical analysis of energy recovery system for turbocharged internal combustion engines via a parallel compounding turbine

Increasing energy efficiency requirements mandatory ask for optimizing energy utilization in many devices, which include internal combustion engines. One of the most investigated subjects is the energy recovery from the exhaust, such as turbo-compound systems, which usually consist in a secondary turbine located afterward the turbocharger. Here an alternative arrangement is proposed and analysed via a numerical model. The recovery turbine works in parallel to the main turbine and uses the gasses which would be otherwise wasted through the waste-gate valve, once the set-point boost pressure is reached. The reference case analysed is a 12.4L turbocharged diesel engine, commonly used in marine, road and light railroad applications, with a nominal power of 380kW. The results showed that an overall 8% of power can be gained, without nor increasing the fuel mass flow rate, neither requiring significant modifications to the baseline engine. Moreover, in the case of the recovery system failure, the operation of the engine is not affected, thus resulting in no engine availability reduction. This work also shows a feasible way to convert the mechanical energy delivered by the recovery turbine into electrical energy, by making use of a high-speed electrical generator.

Effect of palm biodiesel blends on cold start performance and emissions of common rail turbocharged engine at moderately cold ambient temperatures

AbstractPalm biodiesel fuel is limited to 7% (v/v), that is, B7 in petroleum diesel used at Malaysian highlands due to concerns over poor flow characteristics. This article investigated the cold start performance of a common rail direct injection turbocharged diesel engine using B7, B10, B20, and B30 blends in a simulated cold climatic chamber at 5, 10, 15, and 20°C. All the blends passed the startability test at 20°C but failed at 5°C. Higher biodiesel blend of B20 could withstand moderate cold temperature (15°C) without startability issue, while B7 and B10 were usable beyond 15°C. Engine workability after start‐up was insignificantly affected though, on average, 23% increase and 56% reduction observed in engine starting time and speed stability between B7 (standard) and other blends. Emissions of CO was noticeable, <0.1%, while CO2 and NOx were reduced by 13% and 18%, respectively during cold start‐up using B10 and B20. It is expected that B20 could be destined for at the Malaysian highlands with the coldest temperature not exceeding 15°C threshold for more than 5 h. Considering the importance of cold filter plugging point, it is suggested for inclusion in existing diesel standards to minimize issues while deploying high biodiesel blends at highlands commercially.

Experimental and Theoretical Investigations of a Plate-Fin Water Intercooler Equipped in a Boosted Diesel Engine

Abstract Intercoolers utilized in turbocharged engines are critically essential to efficiently improve the engine volumetric efficiency and therefore the engine specific power. Although boosting the internal combustion engines has been extensively investigated, further studies are required to provide relevant approaches to optimize the heat transfer coefficient. This paper experimentally and theoretically investigates the influence of inlet coolant velocity on heat transfer characteristics of an air-to-water intercooler equipped in a turbocharged diesel engine. This aims to optimize the heat transfer rate from water to air under typical engine operating conditions. The experiment has been conducted using a fully equipped engine testbed. The engine is turbocharged with a plate-fin intercooler. The intercooler is a perpendicular air–water heat transfer system that could be suitable for boosted marine engines or power generators. A simulation model was also developed using the finite volume model in the ansysfluent package. The distributions of inlet and outlet temperature, pressure, and velocity of air and coolant under various inlet water velocity and engine operating conditions are examined. The optimal heat transfer rate from air to water was achieved for this intercooler. The outlet air temperature after the intercooler decreases by about 10 °C, engine thermal efficiency increases by 0.7% approximately, engine power enhances by 2.5%, and the specific fuel consumption decreases by 0.82%. The CFD simulation and experiment model developed in this study for the plate-fin water intercooler could be a useful approach to optimize other intercooler systems. In this study, with a 270 × 270 × 10 mm plate-fin perpendicular air–water intercooler, an optimal cooling water velocity of 1.0 m/s, corresponding with a flowrate of 1780 liter/hr, is achieved.

Potential of emission reduction of a turbo-charged non-road diesel engine without aftertreatment under multiple operating scenarios

In this study, the bench test of a non-road diesel engine was conducted under universal conditions, non-road steady-state cycle (NRSC) and non-road transient cycle (NRTC). To reduce the raw emissions of the tested non-road diesel engine, some improvement measures, such as pre-injection, smoke limit, and intake throttle degree control strategy, were applied to the optimized engine. The experiment results showed that particulate matter (PM) emissions are reduced significantly at medium-high speed and low load. The maximum and average proportion of PM emissions reduction at 0–30% load and 1400–2200 r/min are 68.4% and 47.5%, respectively. However, the optimized nitrogen oxide (NOx) emissions are higher than that of the original engine, particularly under low load working conditions. Nevertheless, at medium-high speed and load, NOx emissions of the optimized engine were reduced. PM and NOx emissions decreased by 12.3% and 2.4%, respectively, under NRSC. Under NRTC, PM and NOx emissions decreased by 5.2% and 5.5%, respectively. Unburned hydrocarbon (HC) and carbon monoxide (CO) were always maintained at extremely low emission levels. Furthermore, the fuel consumption almost remained constant under all operating conditions. Thus, this study demonstrates the emission reduction potential in non-road diesel engines without considerable payment.

Full energy recovery from exhaust gases in a turbocharged diesel engine

Energy recovery has become an important solution that drives the transition to more sustainable propulsion, since the amount of thermal energy available from exhaust gases is huge. This energy can be transformed into electrical energy (without significantly affecting the powertrain) and directly used, for instance, in hybrid propulsion or driving auxiliaries.A turbocharged diesel engine equipped with a variable geometry turbine (VGT) was tested to assess the maximum energy recoverable from exhaust gases through two different recovery stages. The first was achieved using the pressure difference between the value at the exhaust valves and the atmospheric datum (turbo-compounding). The second recovery stage was achieved thanks to the temperature of the exhaust gases after the first recovery, and performed using an organic Rankine cycle (ORC)-based power unit.Therefore, these two combined stages of energy recovery were experimentally investigated in the medium–low load region of the ESC-13 homologation test, which is representative for real driving of heavy-duty engines. The first stage was performed on the turbocharging system by recovering the energy lost inside the VGT, through an additional turbine that operates in parallel with the main turbine that drives the compressor. It facilitates the recovery of a mechanical power of up to 3 kW, which was approximately equal to 5 % of the engine brake power at a specific medium–low load. The second stage was performed with an ORC-based unit bottomed to the first recovery section, exploiting the fact that after the first recovery, exhaust gases still have a high temperature, which can be used to feed the additional ORC based recovery unit. This second stage adds up to 3.5 kW of recovered mechanical energy, which represents 5 % of the engine brake power at the same medium–low engine load operating points. Therefore, a total of 10 % of the engine power was recovered in the two stages, which are characterized by proven technologies. Considering the engine working point at maximum power, the value was also higher, the combined recovery achieved a mechanical power of approximately 14 % of the engine brake power.In this study, the detrimental effects related to the engine backpressure produced by the two recovery units and the additional weight of the vehicle were assessed, demonstrating a net overall specific fuel consumption reduction of approximately 5–7% in the medium–low operating region of the engine considered, and higher than 8% at the maximum engine power. The increase in complexity related to the two recovery stages invites to consider this technology for heavy-duty engines for long-hauling vehicles, in which the detrimental effects does not significantly affects fuel consumption.

Lyapunov matrix‐based method to global robust practical exponential r‐stability for a class of delayed continuous‐time nonlinear systems: Theory and applications

AbstractThis article involves the problem of global robust practical exponential ‐stability for a class of delayed continuous‐time nonlinear systems. By proposing a method based on Lyapunov matrix, a global robust practical exponential ‐stability criterion of the considered systems is established. The criteria are expressed as uncomplicated linear matrix inequalities. Therefore, standard calculation software can be used for verification. In addition, the proposed method is applied to the practical stabilization problem of three‐state turbocharged diesel engine model, and a good control effect is obtained.

Performance and Emission Characterstics of Diesel Engine Using Milk Waste Water Bio-diesel

Due to increased usage of petroleum products, fossil fuels are getting exhausted. After discussions, scientists came to a conclusion that there should be an alternative fuel source which can be used instead of diesel. Through this experiment, the authors are going to investigate the possibilities of using milk waste water bio-diesel as an alternative source. The milk waste water methyl ester blends are added with fuels at ratio of 10% and 20% and a turbo charged diesel engine is used to test it. The engine is running under steady condition. The concentration of nitrogen oxide (NOx), carbon monoxide (CO), total particulate matter (PM) and unburned hydro carbon are mainly observed in this experiment. From the recorded results, it is concluded that the milk waste water methyl ester (MWME) did not encounter with the engine thermal efficiency when comparing with the diesel engine. The outcomes of MWME upon CO and HC emissions were depended upon the load given to the engine. This resulted in poor breakup and evaporation properties. While comparing with soya bean bio-diesel, the milk waste water bio fuel emitted less NOx. A same test with milk waste water with milk waste water and soya bean fuel was done with high and low load conditions to absorb the particulate matter emissions. The results exposed that at lower load conditions, the level of PM emission was very high for milk waste water bio-diesel blend when comparing with soyabean blends and the fossil diesel.

Effects of different main injection timings and injection pressures on combustion and emissions of diesel-THF-ethanol blended fuel

ABSTRACT The effects of additives tetrahydrofuran (THF) and ethanol on combustion, performance and emissions were researched on a six-cylinder turbocharged diesel engine with varying injection strategies. Four fuels were tested, i.e. pure diesel, T15E0, T5E10, and T5E20. Under low load, the maximum cylinder pressure of blended fuel decreased and that of T15E0 decreased with the maximum decrease of 3.35%, from 6.56 MPa to 6.34 MPa. The maximum cylinder pressure was also reduced by 4.24% at most under high load, from 9.90 MPa to 9.48 MPa. With the addition of tetrahydrofuran, the brake specific fuel consumption (BSFC) increased, and the brake thermal efficiency (BTE) decreased. In comparison to pure diesel, the addition of 20% ethanol increased BTE from 35.4% to 35.9%, which was a 1.34% rise. For various injection strategies, the optimized soot emissions of T5E20 decreased by 66.94%, from 0.00289 g/kW·h to 0.00096 g/kW·h, while the maximum increase ratio of NOx emissions was 9.67%, from 9.88 g/kW·h to 10.84 g/kW·h. T5E20 has the potential to increase BTE while decreasing NOx and soot emissions concurrently. The results indicate that tetrahydrofuran is a good cosolvent for diesel-ethanol blended fuel, and ethanol exhibits good performance as the principal component of the blended fuel.

Smart cooling design using dual loop cooling to increase engine efficiency and decrease fuel emissions with artificial intelligence

In this study, smart cooling design and optimization, which is based on dual loop cooling system, is used to increase the efficiency of the engine and decrease the fuel emission levels with the artificial intelligence approach. Dual circuit cooling system is used to cool down the charged air and condenser for the 1.6 lt turbocharged diesel engine. The main objective is to increase the efficiency of the engine and decrease the fuel emission levels with smart cooling system design using 1D analysis, experimental tests and neural networks. Water-cooled air charger and condenser are placed separately on engine bay. Whereas, similar applications have been used for these modules integrated on the engine itself. Artificial Neural Network approach is applied in order to optimize the water cooled air charger sizing. Input data is generated by using 1D model within the correlation of experimental test results both on dyno and road conditions. Experimental and 1D analysis data comparison shows that they are very coherent. Results showed that efficiency of the engine is increased and CO2 (g/km) emission levels are decreased about 4,1% in WLTP cycle. It's obtained with efficient dual loop cooling system and optimization based on 1D model and ANN approach.

Structural Comparison of Naturally Aspirated and Turbocharged Diesel Engine for Steel and Aluminium Made Radiator: A Finite Element Study

The current study is based on the structural analysis of radiators made of different materials to compare their effectiveness in the case of naturally aspirated and turbocharged diesel engines. For the analysis of the radiator structure, ABAQUS software was used. In the ABAQUS, static structural analysis was made to calculate the strength of the radiator. The said software is capable of calculating the strength of the radiator considering the boundary conditions (i.e., fixing at corners) as well as the loading conditions. It was observed that stresses generated while using an aluminium radiator were very high than those produced by steel radiators. According to the study, the following are the key findings for the steel and aluminium radiators. In the first case, while three corners were fixed, the steel radiator showed a deflection of 1.86 mm while aluminium exhibited 5.65 mm. However, in the second case in which the radiator had four fixed corners, the deflection of the steel radiator was 1.10 mm, while that of aluminium was 3.36 mm. Additionally, based on the deflections obtained from all investigations, it was found that radiators made of aluminium were more sensitive than those made of steel in both naturally aspirated and turbocharged applications. However, due to aluminium’s strong thermal conductivity, it is compatible with naturally aspirated engines in terms of thermal capacity. To combat turbocharged engine complications caused by high temperatures, such as thermal cracking, engine wear and tear, and so on, a steel-made radiator is more suitable than an aluminium radiator, hence mitigating the issues.

Retracted: Structural Strength and Reliability Analysis of Important Parts of Marine Diesel Engine Turbocharger

Retracted: Structural Strength and Reliability Analysis of Important Parts of Marine Diesel Engine Turbocharger

An approach to select an appropriate turbocharger for matching with an internal combustion engine

The present paper proposes a novel methodology of turbocharging automotive engines to reach targeted performance. The actual method is tested and validated against simulation test results of two turbocharged diesel engines; engine I, three cylinders, 1.5 L, and engine II, six cylinders, 5.9 L. The present procedure is subdivided into four key parts; namely, database construction, selection procedure, turbocharger preliminary design, and engine modeling. Based on geometric dimensions and aerodynamic parameters provided by the preliminary design procedure, 3D geometries of the turbine and compressor are generated for each studied engine. After integrating previous data into a constructed turbocharger database, two turbochargers are selected for the engine I, while only one turbocharger for the engine II. The findings show that, at the engine speed of 4000 rpm, engine I matched with the adequate turbocharger reached a target power about 2.7%, compared to the original turbocharger equipping engine I. Furthermore, engine II reached a rated power of 299.3 kW at 2500 rpm which is slightly under the original one by 2.64 kW. The superimposition of the engine operating area on compressor and turbine maps provided satisfactory results in terms of turbocharger-engine output performance, fuel consumption, secure functioning and engine thermal strength. Finally, the main advantage of the developed methodology consists of its ability to be applied at both earlier and last stages of the engine turbocharging process or to find new adequate turbochargers to replace the original one for economic, mechanical or for safety reasons.

Computational Investigation on the Performance Increase of a Small Industrial Diesel Engine Regarding the Effects of Compression Ratio, Piston Bowl Shape and Injection Strategy

This paper describes the simulative approach to calibrate an already extremely highly turbocharged industrial diesel engine for higher low-speed torque. The engine, which is already operating at its cylinder-pressure maximum, is to achieve close to 30 bar effective mean pressure through suitable calibration between the compression ratio, piston-bowl shape and injection strategy. The basic idea of the study is to lower the compression ratio for even higher injection masses and boost pressures, with the resulting disadvantages in the area of emissions and fuel consumption being partially compensated for by optimizations in the areas of piston shape and injection strategy. The simulations primarily involve the use of the 3D CFD software Converge CFD for in-cylinder calibration and a fully predictive 1D full-engine model in GT Suite. The simulations are based on a two-stage turbocharged 1950 cc four-cylinder industrial diesel engine, which is used for validation of the initial simulation. With the maximum increase in fuel mass and boost pressure, the effective mean pressure could be increased up to 28 bar, while specific consumption increased only slightly. Depending on the geometry, NOx or CO and UHC emissions could be reduced.

Application of methanol and optimization of mixture design over the full operating map in an intelligent charge compression ignition (ICCI) engine

Application of methanol and mixture design of the dual-fuel intelligent charge compression ignition (ICCI) was investigated over the full operating range. ICCI engine (an originally 5.3 L turbocharged diesel engine) equipped with two direct-injection systems and a supercharged system realized real-time design of dual-fuel stratification and was investigated compared with conventional diesel combustion (CDC). Engine operating map and control strategy was obtained, and combustion characteristics and original emissions were analyzed. Results showed that the thermal efficiency of ICCI was 1% to 3% higher than that of CDC in the load range of 6–14 bar IMEP. Increasing load over 14 bar IMEP, a triple-injection strategy of methanol was applied where the last injection was near the top dead center. Except for high speed and low load conditions, ICCI mode realized controllable combustion (coefficient of cyclic variation below 5%, maximum pressure rise rate below 15 bar/°CA, and peak pressure below 180 bar). The maximum thermal efficiency was 53% under low speed and high load conditions, while the minimum NOx emissions were 0.17 g/kWh occurring in the same conditions. Nucleation particles dominated the formation of particle emissions and were minimized under high speed and medium load conditions (below 1.3 × 106/cm3).