Lorenzo Damiani

BIOMASS GASIFICATION MODELLING: AN EQUILIBRIUM MODEL, MODIFIED TO REPRODUCE THE OPERATION OF ACTUAL REACTORS

This paper presents a modified equilibrium simulation model for biomass gasification performance prediction. The model, implemented in the Matlab-Simulink® environment, is able to calculate the reactor main operating parameters, such as reaction temperature, gas composition, gas flow rate and solid product (typically charcoal). The comparison of model output with experimental data puts in evidence the insufficient precision of equilibrium models, due to their incapability of taking into account the non equilibrium effects always present in the gasification process. To obtain a better prediction of measured values the pure equilibrium model has been modified on the basis of literature experimental data, introducing semi-empirical correlations with the aim to consider the most meaningful effects of non-equilibrium. The results demonstrate that this modification leads to an increased precision of the model in reproducing experimental data.Copyright

Simulation Model for the Analysis of Road Vehicles Global Efficiency

This paper will discuss how, along with the rapid growth of energy shortage and environmental pollution, the improvement of road vehicles’ overall efficiency has become a major research topic argument in automotive areas. A significant contribution towards this goal, apart from modifying the powertrain layout and optimizing engine and mechanical components, could be provided by the development of computer-aided energy management systems. Vehicular powertrain is a nonlinear dynamic integrated system of electrical, mechanical, chemical and thermodynamic devices, whose primary objective is providing the power needed to move vehicles. In order to analyze such a complex system, a simulation platform for a generic vehicle powertrain has been developed in the Matlab/Simulink environment, on the basis of vehicle characteristics and loads. The paper studies the development of a validated powertrain simulation model, able to test different on-board power and energy management strategies. The paper also identifies a series of key parameters useful for the study of the overall vehicle efficiency, highlighting the energy losses associated to each powertrain component and plotting energy flows balance diagram. The models of the different powertrain components have been characterized and cascade-connected. The powertrain operational logics has been implemented in a control system including power distribution and advanced energy management strategies (e.g. overdrive, Stop&Start system, regenerative braking). The simulation model has been validated with New European Driving Cycle literature data and experimental road tests.

Simulation Model of a Passive Decay Heat Removal System for Lead-Cooled Fast Reactors

The generation IV lead cooled fast reactors are of particular interest for the Italian research: several influential companies (Ansaldo Nucleare, ENEA) are involved in these important European RD according to the latest guidelines, ALFRED final configuration will be characterized by a secondary loop providing bayonet-tube steam generators. The Authors have addressed the issue of bayonet-tube steam generators proposing the EBBSG (External Boiling Bayonet Steam Generator) system, in which the reaction heat is extracted from the lead by means of coolant under vapor phase. This is possible thanks to an external feed-water boiling, based on the known Loeffler scheme, coupled to the bayonet tube concept. In the present paper, the Authors propose a decay heat removal (DHR) system to match the EBBSG scheme. The DHR system is fully passive, exploiting natural circulation phenomena. The performance of the proposed DHR system is investigated through a Matlab-Simulink model. The results are satisfactory since, according to the simulations, the proposed DHR system is able to keep the primary coolant temperature within a safety range for a sufficient time, avoiding the lead freezing or over-heating.© 2012 ASME

Simulation Model of a Node for Smart Grid Applications, Equipped with Photovoltaic Panel, Energy Storage and Electric Vehicle

The improvement of renewable energy sources exploitation is a central topic of the present studies in the energetic field. One of the main obstacles to the renewable energy increase in the global energetic mix is represented by the fluctuating nature of renewable power sources. The power fluctuations are cause of stress for the electric grid to which the individual nodes are connected. A wider exploitation of renewable power is possible through the implementation of a “smart grid”, constituted by an interconnection of several smart nodes consisting in a user and a renewable source. To reduce the stochastic effects of the renewable energy source it is possible to introduce in the nodes composing the smart grid an energy storage, finalized to smooth the power peaks, rending the node itself less disturbing for the electric grid. This paper presents a simulation model of a smart node, consisting in a user power profile, a photovoltaic panel, an electric vehicle and a battery. Through the simulation model it is possible to evaluate the node effect on the electric grid, with a quantitative approach. Tests were worked out in different node configurations: basic (the only user power profile), basic with photovoltaic panel, basic with storage, basic with panel and storage and finally the complete configuration including also the electric vehicle. The tests were repeated for a domestic and an industrial user to evaluate the size influence over the parameters of interest.

Numerical Exergetic Analysis of Different Biomass and Fossil Fuels Gasification

In this paper, the effect of fuel composition on gasification exergetic efficiency is investigated with the aid of equilibrium and non-equilibrium models. The work aims at comparing, for different fuels, the second principle theoretical efficiencies of air gasification and oxygen-steam gasification.

Energy Requirements Estimation Models for Iron and Steel Industry Applied to Electric Steelworks

The price of electric energy depends on additional factors since the introduction of renewable energy sources, which has changed the basics of electricity production and the determination of its price. Iron and steel industries strongly require forecasting procedures for the energy amount of their production cycles: today production planning is performed without taking into account that the difference in electricity price between night and day can overcome 500%. The aim of this work is to create a model allowing to estimate energy requirements for steel industry; the model correctness is assessed, for both energy and power analysis, by comparison with real data. A planning tool is employed to provide data to a computer platform able to assess, on the basis of required energy, the best market on which power can be purchased ensuring money saving for the steelworks.

Transportation Safety Improvements Through Video Analysis: An Application of Obstacles and Collision Detection Applied to Railways and Roads

Obstacles detection systems are essential to obtain a higher safety level on railways. Such systems has the ability to contribute to the development of automated guided trains. Even though some laser equipments have been used to detect obstacles, short detection distance and low accuracy on curve zones make them not the best solution. In this paper, after an assessment of the risks related to railway accidents and their possible causes, computer vision combined with prior knowledge is used to develop an innovative approach. A function to find the starting point of the rails is proposed. After that, bottom-up adaptive windows are created to focus on the region of interest and ignore the background. The whole system can run in real time thanks to its linear complexity. Experimental tests demonstrated that the system performs well in different conditions.

An Innovative Analytical Network Process Model for Evaluation and Management of Maintenance Projects in Engineering Plant Field

The proposed paper presents: the description and the analysis of an Analytic Network Process Model for the evaluation and the management of maintenance projects in engineering plant field. The study was made in Ansaldo Energia (AEN), Italian company active in the energy sector, one of the world’s major power plant producers. The test cases are three power plants belonging to three important Service customers. Three service contracts that respectively represent, from an HSE (Health Safety Environment) point of view, the “as was”, the “as is” and the “to be” are presented and discussed aiming to demonstrate that HSE could be improved in a systematic way. These three examples are characterized by an increase in HSE preventive activities more than the simple actions required to be compliant with HSE laws and rules. The complex of the HSE measures, known in Ansaldo as “HSE package”, are generally proposed in service contracts with the aim of improving the overall Customer Satisfaction that, recently, is strictly connected with HSE. Due to a rising general awareness of HSE, many general contractors are facing the complex trade-off among HSE performances improvement and other project KPI (Key Performance Indicator) related to cost saving, making this business even harder than expected. Finally this paper tries to answer these research questions: Is the HSE project with more preventive actions effectively the best project to be implemented by Ansaldo? How much does an improvement of Customer Satisfaction and HSE cost to the company in terms of time and effort?

AN INNOVATIVE MODEL FOR SUPPORTING FMEA/FMECA ANALYSIS ON COMPLEX COAL FIRED POWER PLANTS

Failure analysis through simulation is a useful practice to predict a system availability, maintenance times and costs over even long time periods. So far, computational tools for failure analysis have been designed mainly for electronic components. This paper presents a software tool aimed at carrying out the failure analysis of complex plants composed by a large number of different mechanical components. The proposed software, named TARAS, is described in detail, highlighting the features which make it particularly suitable for the mechanical components failure analysis. To demonstrate the software potential, a test-case is provided, consisting in the failure analysis of the transport line required to feed a pulverized coal steam plant for electric power production. The transportation plant consists in several belt conveyors, unloading machines, stacker-reclaimer machines etc. The work demonstrates a satisfactory capability of the software TARAS to cope with very complex mechanical systems.