Examinatal Study on Common Rail Diesel Engine for Multi-injection Strategies
Based on diesel engine equipped with common rail, the multi-injection strategies common rail diesel engine test bed is established with NI test system. In this test bed, the influences of optimized multi-injection strategies to diesel engine performances are studied. The test results show that by using multi-injection strategies, the diesel engine exhaust temperature can reduce 50???, and noises can reduce 15dB, and emission improve obviously.
More than one decade with development of common-rail diesel engine management systems: a literature review on modelling, control, estimation and calibration
Diesel engines are becoming more popular owing to their low fuel consumption and low emissions. The performance and emissions of diesel engines are strictly influenced by the injection pattern and the induced air quality. Utilization of diesel engines with mechatronic systems together with the advent of common-rail injection systems, which promotes the flexibility of injection control, has further increased diesel engine favourability and decreased the level of relevant emissions and noise. Development of mechatronic systems is a hierarchical procedure; in particular, in the case of common-rail diesel engine control, the extent and diversity of involved topics lead to a complex multi-stage development procedure. Many research studies have been carried out, thereby providing much literature in this field, which addresses different aspects of the development procedure for diesel engine management systems. Investigation of the existing literature will help researchers in the field to obtain a better understanding of the whole development procedure of diesel engine management systems and to make them familiar with new trends, state-of-the-art technologies and research fields. In this article, the control strategy development of common-rail diesel engine management systems is considered using the existing literature, i.e. the related literature was collected and categorized into the five main categories of modelling, sensitivity analysis, controller design, estimation and calibration. A brief description of every category followed by the relevant literature is given in the paper, and the common methods as well as the state-of-the-art techniques are discussed in each section. Finally, the strengths and weaknesses of the existing methods and the potential for further advancement are mentioned for each stage of the development of the engine management system, and a road map for the development of a common-rail diesel engine management system is presented.
Numerical tools applied to power reactor noise analysis
In order to be able to calculate the space- and frequency-dependent neutron noise in real inhomogeneous systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic transfer function) of such systems. This paper reports on the development as well as the test and application of the numerical tools employed. The code that was developed yields the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the two-group diffusion approximation and in a two-dimensional representation of heterogeneous systems, for both critical systems and non-critical systems with an external source. Some applications of these tools to power reactor noise analysis are then described, including the unfolding of the parameters of the noise source from the induced neutron noise, measured at a few discrete locations throughout the core. Other concrete applications concern the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of the beam- and shell-mode core-barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems driven by an external source. In most of these applications, calculations performed using the code are compared with at-power plant measurements. Power reactor noise analysis applications of the above type, i.e. core monitoring without disturbing plant operation, is of particular interest in the framework of the extensive program of power uprates worldwide.