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[en] At present one of the most promising methods to remanufacture worn-out machine parts is plasma spraying. The paper describes the selection of the optimum plasma spraying technique to coat the worn-out wall surface of the diesel engine cylinder liners. All the data have been MathCad processed and the regression models equivalent to the algoristic-type model of plasma spraying have been developed. The experiments have resulted in achieving the optimization parameters, the mean value of which is presented in the paper. The given plasma spraying mode allows one not only to remanufacture the worn-out wall surface of the diesel engine cylinder liners but also to obtain the best coating properties. (paper)
[en] Selection of diagnosis data, troubleshooting table(symptom/diagnosis/remedy) - visiting Uljin 2 times, Yeonggwang once, examination of monitoring system, data collection of piping system, analysis of operation parameter for Pielstic DMDS, analysis of DMDS trial data for Uljin 5/6 EDG, embodiment of diagnosis knowledge for diesel engine(class/method/member), framing roubleshooting for Pielstic PC2-5V. Development of display module for monitoring and diagnosis - system classification of EDGS, design of system GUI based on in-touch, development of interface to diagnosis module. Development of diagnosis module - expression of EDG object using Java language, development of inference engine based on ILOG Jrules, development of interface to in-touch
[en] Highlights: • A complex EMR model of a new railcar range has been developed. • A satisfactory assessment of the fuel consumption of the railcar. • The significant potential benefits are attainable by hybridizing the original railcar. • The regenerative braking can provide up to 240 kW h saving. - Abstract: Energetic Macroscopic Representation (EMR) modelling approach is proposed to perform model-based reverse-engineering of a new railcar range, having six propulsion units, each consisting of a diesel engine and a traction motor. Particularly, EMR intrinsic features were exploited to perform phenomenological structuration of power flows, thus allowing proper and comprehensive modelling of complex systems, such as the under-study railcar. Based on some prospective real trips, selected in such a way as to enable realistic evaluation of effective railcar effort, EMR-based prediction of railcar energy consumption is performed. Furthermore, physical consistency of each powertrain component operation was carefully verified. The suitability of EMR approach was thus proven effective to perform reverse-engineering of known specifications and available experimental data, with the final aim of reconstructing a high fidelity computational tool that meets computational burden requirements for subsequent model-based tasks deployment. Finally, specific simulation analyses were performed to evaluate the potential benefits attainable through electric hybridization of the original powertrain.
[en] Aiming the electrical system reliability improvement, the Angra-1 energy electric system has been modified. The two original Diesel generators were replaced by two new ones, and the former were configured as standby generators. The purpose of this work is to quantify the electric system reliability improvement under the mentioned modifications by using Markovian analysis. It was found that the new configuration for the emergency Diesel system improves significantly the power supply to the safety buses. (author). 8 refs., 3 figs., 5 tabs
[en] In this paper the results of a series of tests on a spark-ignition engine using both gasoline and natural gas as fuels are reported. The engine used was a 4-cylinder Toyota model 3-TC with hemispherical combustion chamber and central ignition. (author)
[en] The importance of emergency diesel generator (EDG) has confirmed in the safety evaluation of PSA and the study on aging of EDG has been progressed actively as a part of the project of nuclear plant aging research in the U.S.A.. As the result, the concept of performance evaluation is being transferred from statistical analysis of test results to performance monitoring and trending analysis for monitoring of aging and reliability. Recently, the study related aging characteristic and reliability for EDGS has begun in Korea. And the performance monitoring of diesel engine and procedures related reliability program of EDG introduced in recent is recommended to be complemented. Consequently, the efficient performance monitoring based systematic and integrated monitoring and failure diagnostic technology is necessary. Especially, because the operating hours of EDG for nuclear power plant is brief extremely, ordinary monitoring is liable to be negligent and it is difficult to adopt a high degree expert, too. Therefore, it is important for duty engineer to cope with an emergency state easily as a system displays the results of condition monitoring and failure diagnosis. Putting the goal of this research on a development of monitoring and diagnostic system, diagnosis parameters of EDG is analyzed before anything else. And the prototype monitoring and diagnosis system is developed with this analysis result for a basis
[en] Highlights: ► The effect of in-cycle speed fluctuation on cylinder pressure measurement is investigated. ► A phasing error is introduced when sampling cylinder pressure at constant time intervals. ► The phasing error increases with the increase of engine load and decrease of engine speed. ► Measurement using constant sampling rate affects estimation of HRR, ignition angle etc. - Abstract: Diesel engine cylinder pressure measurements are widely used in field and lab applications to support among other control, monitoring and diagnostic applications. There are two methods to measure cylinder pressure, the use of a crank angle encoder, which guarantees pressure samples at fixed crank angles, and the use of constant time sampling rate. The last is frequently used due to its simplicity or because of practical restrictions. However, in order to perform thermodynamic calculations it is necessary to attribute a crank angle value to each measured pressure value. But if the in-cycle rotational speed fluctuates and this is neglected, an error will result in the values derived from the processing of the measured cylinder pressure. For this reason in the present work an experimental investigation is conducted on a single cylinder diesel test engine to identify the aforementioned problem. During the tests cylinder pressure and instantaneous speed were recorded using an accurate crank angle reference. These where then used to simulate the measurement of cylinder pressure digitized using a fixed time step. The comparison of the two cylinder pressure traces and the thermodynamic parameters derived from them, reveals the introduction of an error which depends on engine load and speed.
[en] The increment of the mechanical properties (surface hardness) of engine cylinder is one of the principal goals for foundry company, to increase the competitiveness of their products in the local and foreign market. This study focused on the characterization of the gray cast iron used in the production of engine cylinder liners and metallurgical parameters determination in the design of conventional quenching heat treatment. The characterization was performed by material hardenability evaluation using Grossmann method, and Jominy test; the austenitizing temperature and the severity of cooling medium to a proper hardening of material were selected. Results revealed that the excellent hardness value obtained is attributed to the suitable hardenability of the gray cast iron and adequate severity selection for hardening treatment.
[es]El aumento de las propiedades mecánicas (dureza superficial) de las camisas de cilindro es uno de los objetivos de las empresas de fundición especializadas, en miras de aumentar la competitividad de sus productos en el mercado local y extranjero. El objetivo de este estudio se centró en la caracterización de la fundición gris utilizada en la producción de las camisas y en la determinación de los parámetros metalúrgicos en el diseño del tratamiento térmico de temple convencional. Lo anterior, se realizó mediante la evaluación de la templabilidad del material por el método de Grossman y el ensayo Jominy, la selección de la temperatura de austenización y la severidad del medio de enfriamiento para un adecuado endurecimiento del material. Los resultados revelaron que el excelente valor de dureza obtenido luego del tratamiento es atribuido a la adecuada templabilidad de la fundición y a la severidad de temple seleccionada.