Idle Speed Research Articles

Improving idle performance of a hydrogen-gasoline rotary engine at stoichiometric condition

Because of the unusual structure chamber compared with traditional engines, gasoline rotary engine always encounters partial burning and increased noxious emissions at the idle. Hydrogen-addition could enhance the characteristics of combustion and emissions of sparked-ignited engines at idle. A modified gasoline rotary engine with electronic spark control and fuel (gasoline and hydrogen) port-injection system was developed to study the impact of hydrogen-addition on idle performance of a gasoline rotary engine. A hybrid electronic control unit was invented to manage the spark, fuel injection, hydrogen volume fraction of the total intake and overall excess air ratio. In this study, the engine was operating at the idle speed of 2400 rpm and stoichiometric conditions. The hydrogen volume fraction was gradually varied from 0% to 6.8%. Results showed that the coefficient of variation in speed and fuel energy flow rate were both decreased after the hydrogen-addition. Flame development and propagation periods were shortened owning to hydrogen-addition. The peak chamber temperature was enhanced after the hydrogen-addition due to the high adiabatic flame temperature of hydrogen. Cooling loss was dropped when hydrogen was added into gasoline. HC, CO and CO2 emissions were reduced by 79.4%, 86.0% and 25.9% when hydrogen volume fraction were raised from 0% to 6.8%.

Exergetic analysis of an LPG evaporator/regulator with thermal storage

In this study, the efficiency of an LPG evaporator/regulator (E/R) is investigated on both energy and exergy concept. The E/R, which is a key part of LPG conversion systems that enables gasoline engines to be operated on LPG when desired, has been transformed to a thermal energy storage (TES) system using an adequate amount of phase change material (PCM) to be able to store waste energy of the engine coolant, so that the engine can be operated on LPG rather than gasoline even at cold start to decrease fuel consumption and exhaust emissions. The engine has been tested at idle speed at 4 °C environment temperature. The PCM application provided the engine to be operated on LPG at cold start and increased the efficiency of the E/R in a considerable extent on both energy and exergy bases. It was observed that using PCM in the E/R for thermal storage, the net efficiency differences of the E/R with PCM application reach to the values of 20% and 10%, respectively for the energy and exergy calculations. The net 2nd law efficiencies were lower than the ones that of 1st law with the values of about 11% for gasoline operation, and 8% for LPG operation of the engine.

THE STUDY OF POSSIBILITIES FOR REDUCING FUEL CONSUMPTION FOR NATURAL GAS ENGINE BASED ON DIESEL AT IDLE SPEED

Diesel-to-natural gas engine conversion is an important economic task. In this modification the gas engine has some fundamental differences from the diesel: forced ignition is replaced by Compression ignition; as a rule, external mixture formation instead internal mixture formation; the quantitative load control using throttle - instead quality load control. The latter is one of the main reasons for the deterioration of the fuel economy of the gas engine especially at low loads, because of the significant increase in pumping losses when reducing the load by throttling. The greatest value of such losses is on the idle speed. The authors considered the possibility of increasing the efficiency of the gas modification due to the implementation of the Miller cycle, where the load reduction is achieved by variable valve timing - mainly the valve Duration and intake valve closing angle. In this case, the load reduction is achieved without the use of throttling the fuel / air mixture. The analysis is performed using a calculation method, which was developed a special program takes into account the main physical processes of the gas engine at low operating conditions. The authors considered several options for improving fuel economy at engine low load operation for the engine KAMAZ-820.74-300, including the possibility of using lean air fuel mixture, increasing the compression ratio, load management using changing valve timing. The authors defined the values of temperature and pressure at characteristic points of the pressure volume diagram, and the values of indicated thermal efficiency of an engine, fuel consumption and other parameters for the five variants of idling. The authors presented the calculated pressure volume diagrams of a Miller cycle at idle. The authors have shown the best option, where possible fuel economy improvement at idle is 25 % compared to the base engine.

Adaptive neurofuzzy control of engine idle speed

Adaptive neurofuzzy control of engine idle speed

Experimental Study on Electrostatic Spray Combustion Technology to Reduce the Fuel Consumption of Engine Idle Speed

Electrostatic spray can apparently improve the fuel atomization. Based on the Santana 2000AFE engine, the engine test equipment was built to experimentally study the effect of the electrostatic spray combustion technology on the fuel consumption and the emission in the case of engine idle speed. Entry in the injector bracket installed a OCS electrostatic atomization devices, electronics, said exhaust gas analyzer and other related equipment with static electricity on the front of the engine idle fuel consumption and emissions tested, The results show that the electrostatic spray combustion technology can obviously improve the oil saving and emission. Below at 1000r/min engine speed, fuel economy of up to 3%; in all idle speed, HC emissions decrease of up to 10% ~ 17%, CO emissions increase up to 5% to 25%.

An improved startup mode using clutch coupling for in-wheel electric vehicle drives

ABSTRACTBy introducing a new type of clutch into the driveline system of an in-wheel drive electric vehicle, a flexible connection has been developed to replace the rigid one between the hub and the motor. The driving motor can realize variable idling, unlike the internal combustion engine, which needs a minimum rotational speed. This paper proposes a new startup method that utilizes the initial kinetic energy of the motor to achieve a smooth and fast acceleration of the wheel speed from zero to the expected motor speed. First, the powertrain system, including the driving motor, the clutch and the vehicle resistance, is modelled. Second, factors influencing the starting current and the jerk level during the starting process are investigated. In consequence, the idle speed can be interpreted as a tunable variable that determines the tradeoff between the torque capacity and the jerk level. Finally, simulation and experiments on a laboratory test rig are performed. The results validate that the proposed variable-idle speed control strategy has a lower jerk level and lower starting current when compared with those using a direct start under the same load condition.

Распределение вибраций по несущей системе станков при шарико-стержневом упрочнении узлов колесных пар

Introduction. Acoustic field in the allowable zone of the equipment operators, and, in particular, under ball-rod hardening of wheelpairs, is generated by the simultaneous emission of sound energy from two sources. The first one is the acoustic subsystem of “hardenable workpiece - reinforcer”. The second source includes all elements of the supporting machine system, in particular, spindle head housings, foundation slab, etc. When measuring sound pressure levels, it is practically impossible to detect the contribution from each separate source, therefore it is needed to carry out experimental studies on the distribution of vibrations throughout the entire machine carrier system both at idle speed and under the process implementation. Materials and Methods. Measurements of the vibration levels were carried out under certain technological operations. Roll surface machining was performed on a wheel-turning lathe on which ball-rod reinforcers were installed instead of cutting tools. Hard-facing of the landing surfaces of the wheelpair axles was carried out on a purpose-designed axle turning lathe on which the ball-rod reinforcers were installed in place of the cutters. Hard-facing of the wheel landing surface was carried out on a boring-and-turning lathe. In all these cases, octave vibration levels were measured at idle and under hardening. Comparison of the vibration spectra and noise spectra makes it possible to determine implicitly the contribution of the machine carrier system elements to the sound field at the operators' workplaces. Research Results. The research objectives, the results of which are given, consisted in studying the regularities in the distribution of vibration levels throughout the elements of the bearing systems of the ball-rod hardening equipment for wheelpairs. A qualitative assessment of the contribution of each source (hardenable part, reinforcer, and elements of the supporting system) can be performed on the basis of comparing the noise and vibration spectra. Measurements were carried out on three types of machines: special wheel-turning lathe on which the rolling surface is hardened; purpose-designed axle turning lathe on which the landing surface of the wheelpair axle is strengthened; and boring-and-turning lathe on which the wheel opening is reinforced. Discussion and Conclusions. The results of vibration measurements show that the intensity of sound emission of the machine carrier system elements does not cause excess over the sanitary norms of noise. Thus, the development of a noise-vibration protection system can be limited to the “hardenable workpiece - reinforcer” subsystem.

Particulate Matter Emission Characteristics of a Biodiesel Fueled Engine at Idling Speed

Automotive and transportation sectors will be inclined towards the renewable or green energy in the near future. One of the green energy sources discovered recently is biodiesel. Biodiesel is a source of clean alternative fuel for internal combustion engines, which reduces the exhaust emissions significantly. Like diesel, biodiesel also emits exhaust particulate matter (PM), which is responsible for the black soot coming out from the diesel engine. However, it is not clear that what will be the size of PM formed during the idle speed of a biodiesel fueled engine. In this study, the characteristics of the exhaust particulate during the idling speed of a biodiesel fueled single cylinder diesel engine is analyzed. Biodiesel showed a positive result in terms of the concentration of emitted PM. However, particle sizes were smaller in case of biodiesel than diesel. Further studies should be carried out to improve the properties of biodiesel to ensure that the emitted particle sizes are not toxic to human health.

Investigations on emission of nanoparticulates under free acceleration test condition

Considering the dangerous effects of ultrafine particles and air quality concerns worldwide, this work investigates the possibility of identifying operating criterion over which there is a greater tendency of formation of nanoparticle emissions in Diesel engines. The objective of this analysis is to study the emission of particles in the size range of 10 nm to 700 nm by subjecting a diesel engine to free acceleration tests. Details on the emission characteristics such as Particulate number, Particle mass, Particle diameter and the Lung deposition surface area in the size range 10–700 nm during specific conditions of acceleration and deceleration has been studied in this work. Maximum effect of the particles occurs during rapid acceleration. At idle speed, the Particle number, particle mass and Lung deposition surface area are very low indicating that the nanoparticle formation is low at idle condition. With increase in Particulate number, there is an increase in the Particulate mass and the LDSA. The particulate diameter is distributed across the PN range.

Investigations on emission of nanoparticulates under free acceleration test condition

Considering the dangerous effects of ultrafine particles and air quality concerns worldwide, this work investigates the possibility of identifying operating criterion over which there is a greater tendency of formation of nanoparticle emissions in Diesel engines. The objective of this analysis is to study the emission of particles in the size range of 10 nm to 700 nm by subjecting a diesel engine to free acceleration tests. Details on the emission characteristics such as Particulate number, Particle mass, Particle diameter and the Lung deposition surface area in the size range 10–700 nm during specific conditions of acceleration and deceleration has been studied in this work. Maximum effect of the particles occurs during rapid acceleration. At idle speed, the Particle number, particle mass and Lung deposition surface area are very low indicating that the nanoparticle formation is low at idle condition. With increase in Particulate number, there is an increase in the Particulate mass and the LDSA. The particulate diameter is distributed across the PN range.

Adaptive idling control scheme and its experimental validation for gasoline engines

In this paper, the idle speed control problem is investigated for spark-ignition (SI) engines. To scope with physical model parameter-free control scheme, a nonlinear adaptive control law is proposed for the speed regulation loop. The stability analysis result shows that the idle speed converges to the set value and the estimated parameter converges to an equivalent static value of the intake manifold. Furthermore, the proposed fuel injection control law consists of a feedforward and a simple feedback loop. Finally, the proposed control scheme is validated based on a full-scaled six-cylinder gasoline engine test bench.

Experimental study on the effect of alternator speed to the car charging system

In this paper, we present our work, which is doing an energy audit on alternator’s current output and battery’s voltage based on alternator speed. Up until today, the demand for power in automobile is ever increasing. As technology advances, more and more electrical devices were produced and being installed in vehicles. To cope with the demand, alternator has been designed and modified so that it can produce enough power. This research is to study the effect of alternator speed to the charging system. The car used in this experiment is Proton Preve 1.6 Manual. In both ISO 8854 and SAE J 56, alternator testing and labelling standards indicate that the rated output an alternator is the amount of current that it is capable of producing at 6,000 RPM. Three different constant speed of engine which is 750 RPM as idle speed, 1500 RPM and 3000 RPM as cruise speed were taken as parameter. The speed of the alternator was measured using tachometer, digital multi-meter was used to measure battery’s voltage, and AC/DC Clamp was used to measure alternator current output. The result shows that the faster the alternator spin, the more power it can produce. And when there is more power, the faster the charging rate of the battery.

밸브트레인용 롤러태핏 하우징의 제작 공정 개발 및 시제품 평가

본 연구에서는 엔진의 밸브트레인에 적용되는 롤러 태핏 하우징의 냉간단조 공정을 개발하였다. 시제품을 제작하였으며, 태핏 하우징의 내구성 평가를 통하여 작동성을 확인하였다. 소재 시편의 압축시험을 통하여 태핏에 사용되는 소재의 물성을 확보하고 상용 소프트웨어인 Deform-3D을 이용하여 단조해석을 수행하였다. 해석결과를 바탕으로 냉간단조 공정을 설계하였으며, 실제 금형을 제작하고 시제품을 제작하였다. 제작한 시제품의 평가를 위하여 치수정밀도, 표면조도, 평행도, 동심도를 확인하였으며, 목표한 항목에 모두 부합하는 결과를 확인하였다. 또한 제품의 작동성 및 내구성 평가를 수행하기 위하여, 엔진 밸브트레인의 구동을 모사하는 별도의 시험장치 개발을 완료하였다. 디젤엔진의 아이들 상태를 가정하여 작동성을 평가하고, 엔진의 최고 회전수를 가정하여 내구성 시험을 진행하였다. 시험결과 태핏하우징의 마모는 시험 전, 후 외경 치수 0.002 mm 감소로, 미소한 마모를 보였다. 본 연구를 통하여 정밀 냉간단조 기술을 이용한 제품개발 프로세스를 정립하였다. 또한 본 연구에서 개발한 작동성 평가 시험기를 통해 밸브트레인용 부품의 작동성 및 내구성 평가 시험이 가능할 것으로 사료된다. In this study, a cold forging process was developed for the roller tappet housing of an engine valvetrain system. A tappet sample was manufactured and subjected to an endurance test. The material properties were obtained from a compression test, and forging analysis was carried out to design a forging process using a commercial program, Deform-3D. The forging process was set up based on the analysis results, and a die set and sample tappet housing were manufactured. To evaluate the sample, the dimensional accuracy, surface roughness, parallelism, and concentricity were measured and confirmed. To evaluate the actuation and durability, a special test rig was developed to simulate the valvetrain system of the engine. An actuation test was performed based on the idle speed of a general diesel engine, and an endurance test was done based on the maximum speed. The results show minor wear of 0.002 mm. The developed test rig will be used to evaluate the actuation and durability of other valvetrain parts.

Safety and interaction of patients with implantable cardiac defibrillators driving a hybrid vehicle

BackgroundElectromagnetic interference (EMI) can affect the function of implantable cardioverter defibrillators (ICD). Hybrid electric vehicles (HEV) have increased popularity and are a potential source of EMI. Little is known about the in vivo effects of EMI generated by HEV on ICD. ObjectiveThis study evaluated the in vivo interaction between EMI generated by HEV with ICD. Methods and resultsThirty patients (73±9 y/o; 80% male) with stable ICD function were exposed to EMI generated by a Toyota Prius Hybrid®. The vehicle was lifted above the ground, allowing safe changes in engine rotation and consequent variations in electromagnetic emission. EMI was measured (NARDA STS® model EHP-50C) and expressed in A/m (magnetic), Volts/m (electrical), and Hertz (frequency). Six positions were evaluated: driver, front passenger, right and left back seats, outside, at the back and front of the car. Each position was evaluated at idle, 30 mph, 60 mph and variable speeds (acceleration-deceleration-brake). All ICD devices were continuously monitored during the study.The levels of EMI generated were low (highest mean levels: 2.09A/m at right back seat at 30 mph; and 3.5V/m at driver seat at variable speeds). No episode of oversensing or inadvertent change in ICD programming was observed. ConclusionIt is safe for patients with ICD to interact with HEV. This is the first study to address this issue using an in vivo model. Further studies are necessary to evaluate the interaction of different models of HEV or electric engine with ICD or unipolar pacemakers.

COMPARATIVE PERFORMANCE BETWEEN R134a AND R152a IN AN AIR CONDITIONING SYSTEM OF A PASSENGER CAR

The present study investigates numerically the performances of an automotive air conditioning (A/C) system using R134a and R152a as working fluids for various engine running speeds. There are three engine rotation variations, i.e., 1000 rpm, 2000 rpm and 3000 rpm that represent idle, city and high speed conditions, respectively. The compressor volumetric efficiencies for 1000 rpm, 2000 rpm and 3000 rpm are 0.75, 0.65 and 0.55, respectively. The results show that the cooling capacities of R152a are slightly lower than that of R134a at the condensing temperatures of 40oC and 45oC. However, at the condensing temperature of 50oC, the cooling capacity of R152a is higher than that of R134a up to 5.0%. In addition, COPs of R152a are higher than that of R134a for all the condensing temperature. The increase of condensing temperature is more dominant to the COP improvement rather than the increase in engine rotation. The highest COP improvement is 13.5%.

Comparison of Model-based Vs. Data-driven Methods for Fault Detection and Isolation in Engine Idle Speed Control System

An internal combustion engine operating at idle is regulated by a feedback controller so that it runs at a preset idle speed without stalling when no acceleration is requested from the driver. Idle speed control is affected by numerous disturbances, ranging from accessory loads to environmental conditions. Because of the regulating behavior of the controller, faults, especially actuator faults, may affect sensor measurements in a way very similar to disturbances, system uncertainty or noise. This poses a challenge to the fault detection and isolation (FDI) problem for this system. In this paper, two fundamentally different fault diagnoses approaches are used to detect and isolate faults. A model-based residual generation scheme as well as a data-driven linear discriminant analysis scheme is developed to solve the FDI problem even when faults are concurring in addition to system uncertainty, disturbance and noise. Their performances are compared side by side using data gathered from an experimentally validated simulator for an engine idle system that considers an actuator fault, a sensor fault, several system uncertainties and disturbance (operating conditions), and sensor noise. The results show that comparable performance can be achieved with both schemes and some comments are made about each approach.

Estudio comparativo de gases contaminantes en un vehículo M1, utilizando gasolina de la Comunidad Andina

La contaminación ambiental es una problemática que afecta a todos los países alrededor del mundo como resultado de esta contaminación se producen los fenómenos de cambio climático, efecto invernadero, lluvia acida, y enfermedades sobre el ser humano. Para delimitar la problemática en estudio, se seleccionó los países que integran la comunidad Andina, siendo el objetivo del proyecto comparar mediante pruebas estáticas y dinámicas los valores de emisiones de gases contaminantes, con el combustible que se distribuye en cada uno de los países seleccionados. El proceso de medición y ensayo de las pruebas estáticas se desarrollaron bajo la norma NTE INEN 2203:1999, considerándose las condiciones a ralentí (820 RPM) y régimen de alto giro (2500 RPM), en ambos casos, a una temperatura del aceite del motor constante de 94º C y las pruebas dinámicas se ejecutaron, según los ciclos americanos ASM 25/25 y 50/15, confrontando los resultados obtenidos con los diferentes combustibles en un vehículo Chevrolet modelo Sail, uno de los más vendidos en el medio nacional. Con base a las pruebas desarrolladas, el vehículo evaluado podrá circular sin ningún inconveniente utilizando cualquiera de los combustibles de la Comunidad Andina cumpliendo con la norma NTE INEN 2204:2002, en consecuencia, el combustible con los niveles más bajos de emisiones gaseosas es el distribuido en Perú.

Idle speed controller based on active disturbance rejection control in diesel engines

This study proposes a design for an idle speed controller to compensate for varying engine load and friction torque in passenger car diesel engines. An active disturbance rejection control (ADRC) framework, comprised of a disturbance compensator and a feedback controller, is applied to an idle speed controller to compensate for disturbances such as engine load and friction torque. In addition, a feedforward compensator is designed into the ADRC framework to improve disturbance rejection performance. The proposed controller is validated by engine and vehicle experiments and the experiment results are compared with a commercial controller.

Effect of DOC/CCRT Aging on Gaseous Emission Characteristics of an In-used Diesel Engine Bus

Based on heavy chassis dynamometer, an experimental study was conducted in diesel bus with China Stage Ⅲ, which investigated the effects of gaseous emission characteristics under CCBC driving cycle, such as carbon monoxide (CO), total hydrocarbons (THC), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxides (NO<i>x</i>) and carbon dioxide (CO2) with the fresh/aged oxidized catalyst (DOC) and oxidation catalysts coupled catalyzed particulate trap (DOC+CDPF, referred CCRT). The results showed that using fresh and aged DOC/CCRT, the diesel bus could reduce CO, THC and NO emissions, meanwhile increase NO2 emissions, but NO<i>x</i> and CO2 emissions remained basically unchanged. In idle speed, acceleration, deceleration and constant speed of working conditions, the diesel bus using the fresh DOC had better oxidation efficiency of the CO and THC emissions than the bus using the aged DOC. The diesel bus using the fresh CCRT had higher oxidation efficiency of THC emissions, but lower oxidation efficiency of CO emissions than the bus using the aged CCRT. The diesel bus using the fresh DOC/CCRT had a higher rate of NO emissions reductions and NO2 emissions increments than the bus using the aged DOC/CCRT, but it did not basically affect the NO<i>x</i> emissions.

Thermodynamic analysis of indexes of operation of the engine with direct fuel injection for idle speed and acceleration

Contemporary requirements for combustion engines are aimed mainly at obtaining significant parameter values of their operation at simultaneously low fuel consumption and reduced exhaust emission. Despite the fact that combustion engines utilize diverse load conditions, the idle speed share in the whole range of their operation is significant. The percentage of combustion engines with spark-ignition direct injection (SI DI) in the total number of spark-ignition engines is increasing. It means that the method of the mixture preparation is an important factor in SI DI engine, also for idle speed. In the tests was analysed the SI engine preparing the mixture with a dose of injected fuel (air-guided type) in conditions of the idle speed. Idle speed control is a critical issue in engine control fields. Essentially, it is a highly nonlinear and time-varying problem. Its performance has a significant impact on fuel economy and emission levels. The engine operation indexes were determined, and with the use of coefficient of variation, the variation of the cycle was estimated. Article contains the three-stage division, taking into account the variable measuring modes where was analysed the work condition during the idling, free acceleration of combustion engine and car acceleration. From numerous operational indexes of the engine operation were selected those, which in the best way characterize engine operation for idle speed.