평균값 모델을 활용한 WGT 디젤엔진의 과급압력 및 EGR율 보정 방법 개발

<div class="section abstract"><div class="htmlview paragraph">Diesel engine is vital in the industry for its characteristics of low fuel consumption, high-torque, reliability, and durability. Existing diesel engine technology has reached the upper limit. It is difficult to break through the fuel consumption and emission of diesel engines. VVA (Variable Valve Actuation) is a new technology in the field of the diesel engines. In this paper, GT-Suite and ANN (artificial neural network) model are established based on engine experimental data and DoE simulation results. By inputting Intake Valve Opening crake angle (IVO), Intake Valve Angle Multiplier (IVAM) and Exhaust Valve Angle Multiplier (EVAM) into the ANN Model, and by using SA (simulated annealing algorithm), the optimized results of intake and exhaust valve lift under the target conditions are obtained. According to the optimized results, the fuel consumption of BSFC (brake specific fuel consumption) can be saved by 3.9%, 0.9%, and 7.3% at three different target working conditions, respectively (1000r/min with 50% load, 2000 r/min with 35% load, and 3000r/min with 20% load. Under the three conditions, the intake valve lifts are 1.10, 0.96, 1.10 times as the original respectively and the exhaust valve lifts are 0.98,0.94 and 1.10 times respectively. In addition, by adding the secondary opening strategy of the exhaust valve lift, internal exhaust gas recycling (IEGR) can be achieved. The exhaust gas temperature increased by 9.55% (66.64K) under low-speed working condition, and fuel consumption increased slightly by 6.15%, which is also important for exhaust thermal management and external emission control in the cold start phase of diesel engines. By changing the intake and exhaust valve control, there are obvious differences in the optimal valve lift under different working conditions. Therefore, the application of the VVA system in the diesel engine is of great significance.</div></div>

The steady and reliable operation of a ship’s diesel engine is important to the ship’s electrical power system and the engine’s performance, and stable control of rotational speed is crucial to a diesel engine’s emission, economy and power performance. A ship’s diesel engine is a nonlinear and time-varying system. A traditional proportional–integral–derivative (PID) controller cannot regulate the speed under different working conditions. In this paper, a nonlinear mathematical model for speed regulation of diesel engines is established according to experiments and a multi-sliding surface variable structure controller for speed regulation of diesel engine is established by sliding mode control. A bulk cargo ship 500-I was analysed as an example. The MATLAB/Simulink simulation took the navigation environment and the effect of the ship propeller on the diesel engine into consideration. A simulation model considering the whole ship–engine–propeller system is built and some conclusions can be drawn from the simulation. The multi-sliding surface control can restrain the overshoot and realize a quick track of the targeted value with high accuracy and strong robustness. In addition, the fuel consumption and CO2 emission of this sliding mode variable structure control is reduced by 4.6% compared with traditional PID control.

To broaden the application range of hardware in loop simulation for electronic controlled unit, study on model simulation of electronic unit pump diesel engine oriented to control is made, the requirement and selection of simulation model oriented to control in electronic unit pump diesel engine is provided, model of simplified nonlinearity in diesel engine and electronic unit pump system are established in Matlab/Simulink, model verification shows that this model can achieve relative accuracy, by means of calculation time and parameter, different calculation step and method affecting model output is analyzed and compared. Real engine model is applied into hardware-in-loop simulation test, its results show that model can perform real-time ECU hardware-in-loop simulation test accurately.

A Physics-based mean value model that predicts engine combustion, heat transfer, gas exchange, and friction loss has been developed. The model is developed starting from the thermodynamic principles of an ideal gas standard limited pressure cycle concept. The idealized assumptions that are typically used in a limited pressure cycle concept are relieved to enhance the fidelity of the model by introducing variables that account for the in-cylinder heat transfer and the combustion characteristics that change under varying EGR rate as well as the engine speed and load while minimal number of empirical correlations are used to ensure the compactness and flexibility of the physics-based mean value model. The model is calibrated and validated with the simulation results from a detailed GT-Power® engine model previously calibrated with experimental results from a Ford 6.7 liter Diesel engine. The comparison shows good agreement between the results from the mean value model and the GT-Power® model. The mean value model developed in this study is a flexible simulation tool that provides excellent computational efficiency without sacrificing critical physical details of the Diesel combustion process required by the control design development.

Modern cars operate in various climatic conditions and have a number of problems, one of which is fuel overheating at elevated ambient temperatures. This article is devoted to solving the problem of improving the reliability of the fuel supply system of a high-speed diesel engine by controlling the temperature of the fuel. Keywords: cooling, power supply system, heat exchanger, fuel equipment

Various systems have been suggested for the generation of electricity from biomass that aim to improve on the low efficiency, capital intensive steam turbine cycles that are currently used. While the integrated gasification combined cycle (IGCC) system using gas turbines has been favoured at large scale (above 30 MWe), diesel engine systems are more suitable at smaller scales because their investment costs and efficiencies are less sensitive to scale. Diesel engines could be driven by liquids produced in fast pyrolysis, a technology that is rapidly gaining acceptance as a means of producing high yields of a liquid fuel. Models have been developed that calculate the costs of producing electricity from biomass via fast pyrolysis and diesel engines. It is expected that such systems would compete with atmospheric gasification and diesel engine systems and these systems have also been evaluated for comparison. Initial analyses have shown that electricity production costs are very similar for the two systems where the conversion (fast pyrolysis or gasification) stage is directly connected to the generating stage. However, fast pyrolysis may be de-coupled from the generator and this could give pyrolysis an advantage over gasification. Three de-coupling options are assessed in this paper to evaluate how de-coupling could be used to improve the economics of fast pyrolysis and hence increase the opportunities for its application in small-scale electricity generation.

Nowadays, with the increasing cost of shipping and fuel oil, more and more countries pay attention to the energy saving and emission reduction of marine main diesel engine. The application of marine intelligent diesel engine is more and more extensive. This paper studies the common rail fuel system of intelligent diesel engine represented by RT-flex, and analyses the comparison between marine traditional diesel engine and marine intelligent diesel engine, Simultaneous analysis the advantages of intelligent diesel engine. Based on the characteristics of electronic control common rail of RT-flex diesel engine, the structure and principle of fuel common rail and servo common rail are analyzed. On this basis, the intelligent diesel engine control system is mainly studied. At the same time, the application of flex View software of control system is also studied.

Development and validation of a new turbocharger simulation methodology for marine two stroke diesel engine modelling and diagnostic applications

A steady state and transient simulation model for an underwater diesel engine system, including governor, diesel engine, and pipe systems after turbine, is developed and verified. A two-phase flow of exhaust gas and water at the tail pipe is studied with three-dimensional fluid dynamics calculation. A water flooding criterion for an underwater engine is also given by these models and related experiments. Safe operation ranges of the engine are also studied. The histories of relative engine speed, pressure, and Froude number of the tail pipe exhaust gas under starting and stopping processes are studied. The Froude number of the tail pipe exhaust gas is an oscillating phenomena when the engine is starting, which is likely to cause sea water to flow backward into the tail pipe. The opening of the tongue valve must be controlled according to engine back pressure during the stopping process to prevent sea water flooding on the one hand and high back pressure on the other. The underwater diesel engine operating control strategy can be given on the basis of the research work.

In order to research the High Pressure Common— Rrail System(HPCRS) for a large power diesel engine. In this paper, based on establishing a physical and math model of the system, the control manner of Proportional oil-in Control for fuel pressure control has been discussed and framed; the structure of the fuel injection system which adapt to this control manner has been design. The real time control system of large power diesel engine simulation model has been established though the fuel system simulation software and Matlab/Simulink software; the effects of the structural parameters to common-rail pressure were simulated. Finally, the high pressure common—rail system for a large power diesel engine was designed. As the result, it is turned out that the common—rail fuel pressure controlled by the control manner of Proportional oil-in Control and the strategy of PID could be setup less than 0.42s and stabilize by the range of 3% under manifold enactment pressure and the consistency of injection meet the challenge.

In this paper, two types of intelligent controllers are designed based on the RBF neural network algorithm and active disturbance rejection control (ADRC) technology to solve the problem that the dynamic speed is difficult to control for diesel engine. In order to verify the speed regulation performance of the intelligent control system a mean value modeling (MVM) of D6114 generation diesel engine was established for off-line simulation, and the above two intelligent algorithms were compared with PID. The results show that the ADRC has a relatively small overshoot and quick dynamic response for diesel engine speed control. Radial basis function (RBF) intelligent algorithm can real-timely optimize the control parameters and has good adaptability in speed control, the transient rate decreased by 1.6% and stable time is shortened by 1.46s compared with common PID algorithm. The control performance under condition of start-up, idle speed and mutation load is compared. The results show that RBF neural network controller has good learning and adaptive capabilities for speed control of diesel engine. It can balance the stability at different speed and output of large rack displacement in a short time when the load changes to reduce the influence of load change on the rotational speed. For ADRC controller, it maintains good effect when the nonlinearity in the system increases. Improvement of PID using TD has fast response at startup and under disturbances. With NLSEF and ESO, NLSEF can automatically adjust the output according to the speed deviation to reduce interference while ESO can correct the control amount to improve the control effect of load change.

Over the past two decades considerable effort has been taken to develop and introduce new alternate source of energy for the conventional gasoline and diesel. Environmental pollution and uncertainty in cost of petroleum products are the principal driving forces for this movement. The major pollutants from an Diesel engine system are NOx, Smoke, particulate matter, Soot. Several alternative fuels were tried but all of them are carbon based fuels, therefore net carbon based pollutants cannot be reduced. One alternative to carbon-based fuels is hydrogen. Hydrogen a non-carbon fuel only can meet zero emission vehicles standards in future. Hydrogen can be commercially used as a fuel even though it is having a number of technical and economical barriers. Numerous techniques are available for use in C.I. engine such as dual fuel made, by using spark plug, glow plug, DEE as an ignition enhancer. Hydrogen was used in a diesel engine in the dual fuel mode-using diesel as an ignition source in neat form using DEE. In neat form the DEE was introduced in the manifold. In order to have a precise control of hydrogen flow and to avoid the backfire and pre – ignition problems hydrogen was injection in to intake manifold; DEE injection follows the hydrogen injection. DEE mixed with air and flows into the combustion chamber as DEE auto ignites first followed by hydrogen combustion. A single cylinder-four stroke water-cooled naturally aspirated constant speed D.I. diesel engine with a rated output of 3.7 kW at 1500 rpm was used for the experimental purpose. Measurements were taken with respect to the performance, combustion and emission studies.

Problem. Modern requirements for internal combustion engines are becoming ever more stringent, and current trends require the manufacturer to have high power and economy. This pushes the manufacturer to create and upgrade the design of the internal combustion engine and its systems. Modern technologies allow the creation of high-tech internal combustion engines with electronic control systems that increase the efficiency of resource use, and improve environmental parameters. As a result, modern engines can dynamically change their parameters and adjust to the needs of consumers. One of the main systems that affect the performance of an internal combustion engine is the cooling system. The regulation of the cooling system allows maintaining the optimum temperature of the coolant. The low or periodically increasing and decreasing temperature of the coolant and oil leads to such consequences as increased wear of parts in friction pairs, an increase in fuel consumption and ineffective operation of the cooling system. Goal. Analyze and justify the need to regulate the diesel engine cooling system of the ground transport vehicle. Methodology. Based on the experimental data, an analysis of the change in the temperature of the heat transfer media was carried out and a comparison was made with the optimum recommended temperature. Result. It is determined that with a change in the speed of the diesel engine's crankshaft and load, the temperature deviates, indicating that there are no measures aimed at regulating the temperature state of the diesel and the need to develop and implement a system for regulating the temperature of the heat carriers of the internal combustion engine. Originality. To a diesel engine of type 5TDF, an estimation of a temperature condition and a substantiation of necessity of regulation of temperatures of heat carriers was not applied earlier. Practical value. This assessment will lay the foundation for the rationale for the development of a cooling system control system for domestic diesel engines of the 5TDF type.

Recent increases in petroleum fuel costs, CAFE standards, and environmental concerns about CO2 emissions from petroleum based fuels have created an increased opportunity for diesel engines and renewable alternative fuels such as biodiesel. Additionally, the Environmental Protection Agencies Tier II heavy duty and light duty emissions regulations require significant reductions in NOx and diesel particulate matter emissions for diesel engines. As a result, the diesel engine and aftertreatment system is a highly calibrated system that is sensitive to changing fuel characteristics. This study focuses on the impact of soy methyl ester biodiesel blends on combustion performance, carbonaceous soot matter and NOX emissions. Tests were completed with an I4 1.9L, turbocharged, high speed, direct injection diesel engine using commercially available 15 ppm ultra low sulfur diesel, a soy methyl ester B20 (20% biodiesel and 80% ultra low sulfur diesel) biodiesel blend and a pure soy methyl ester biodiesel. Results show a reduction in NOx and carbonaceous soot matter emissions and an increase in brake specific fuel consumption with the use of biodiesel. Further, traditional methodology assumes that diesel fuels with a high cetane number have a reduced ignition delay. However, results from this study show the cetane number is not the only parameter effecting ignition delay.

<div class="htmlview paragraph">A kinetic carbon monoxide (CO) emission model is developed to simulate engine out CO emissions for conventional diesel combustion. The model also incorporates physics governing CO emissions for low temperature combustion (LTC). The emission model will be used in an integrated system level model to simulate the operation and interaction of conventional and low temperature diesel combustion with aftertreatment devices. The Integrated System Model consists of component models for the diesel engine, engine-out emissions (such as NOx and Particulate Matter), and aftertreatment devices (such as DOC and DPF). The addition of CO emissions model will enhance the capability of the Integrated System Model to predict major emission species, especially for low temperature combustion.</div> <div class="htmlview paragraph">In this work a CO emission model is developed based on a two-step global kinetic mechanism [<span class="xref">8</span>]. In addition, effect of physical parameters such as start of injection (SOI) and ignition delay are studied and modeled to develop a phenomenological CO emission model. This includes development of a simple spray model to compute amount of fuel missing the bowl in case of PCCI and HCCI type combustion. Results from the spray model are used to simulate the motion of fuel in the cylinder bowl during various stages of combustion. Ignition delay effects are analyzed and modeled to change the activation temperature of CO oxidation reaction to simulate the affect of increasing peak temperatures with advancing SOI. The results from the CO emission model are compared with experimental data from a multi-cylinder conventional diesel engine as well as a single cylinder version of a low temperature combustion diesel engine. For the LTC engine, the start of injection is advanced using two different injection strategies (single and two-step injection). Overall the results show good agreement of the trends between the experiments and model predictions.</div>