Diagnosis of internal combustion engine through vibration and acoustic pressure non-intrusive measurements

The present study proposes a diagnosis methodology for internal combustion engines (I.C.E.) working conditions, by means of non-invasive measurements on the cylinder head, such as acoustic and vibration, related to the internal indicated mean effective pressure. The experimental campaign was carried out on the internal combustion engine of the cogeneration plant at the Faculty of Engineering – University of Perugia (Italy), for different values of the engine load. Results show that both the vibration and acoustic signals measured on the cylinder head are strictly related to the phenomena inside the cylinder, depending on the engine load and the combustion frequency. Some vibration and acoustic indexes were introduced, in order to evaluate the working regimen of the engine. Their values, obtained for different engine loads, constitute the reference values; when the methodology was implemented, the evaluation of such indexes allows to estimate the combustion quality, comparing measured and reference values.     

Diagnosis methodology and technique for solid oxide fuel cells: A review

The present study aims to identify and recollect the articles existing in literature that deal malfunction or failure causes of SOFC cells and relative diagnostic systems. This work is motivated by the increasing demand for diagnostic techniques aimed at both increasing durability and fully exploiting SOFC benefits throughout system lifetime. This paper reviews SOFC cells degradation phenomena and relevant fault detection methodologies already available, having found a gap in literature, above all relative to SOFC electrode microstructural degradation related, specifically, to sintering of the electrode microstructure, poisoning of the cathode microstructure with chromium products outgassed from the interconnect plates, carbon deposition in the anode, anode sulfur poisoning and boron SOFC cathodes' poisoning. It is therefore encouraged a future effort of the research activity in this specific sector.     

Study of the carbonation–calcination reaction applied to the hydrogen production from syngas

In the last years the interest in hydrogen as an energy carrier is significantly increased both for vehicle fuelling and stationary energy production by fuel cells. The benefits of a hydrogen energy policy are the reduction of the greenhouse effect and the centralization of the emission sources. Moreover, an improvement to the environmental benefits can be achieved if hydrogen is produced from renewable sources, as biomass.     

Production of hydrogen through the carbonation–calcination reaction applied to CH4/CO2 mixtures

The production of hydrogen combined with carbon capture represents a possible option for reducing CO₂ emissions in atmosphere and anthropogenic greenhouse effect. Nowadays the worldwide hydrogen production is based mainly on natural gas reforming, but the attention of the scientific community is focused also on other gas mixtures with significant methane content. In particular mixtures constituted mainly by methane and carbon dioxide are extensively used in energy conversion applications, as they include land-fill gas, digester gas and natural gas. The present paper addresses the development of an innovative system for hydrogen production and CO₂ capture starting from these mixtures. The plant is based on steam methane reforming, coupled with the carbonation and calcination reactions for CO₂ absorption and desorption, respectively. A thermodynamic approach is proposed to investigate the plant performance in relation to the CH₄ content in the feeding gas. The results suggest that, in order to optimize the hydrogen purity and the efficiency, two different methodologies can be adopted involving both the system layout and operating parameters. In particular such methodologies are suitable for a methane content, respectively, higher and lower than 65%.