Paolo Iora

Paolo Iora
Università degli Studi di Brescia | UNIBS · Department of Mechanical and Industrial Engineering

About

61
Publications
15,428
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1,609
Citations
Citations since 2016
30 Research Items
878 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (61)
Article
The carbonation of alkaline wastes is an interesting research field that may offer opportunities for CO2 reduction. However, the literature is mainly devoted to studying different waste sequestration capabilities, with lame attention to the reliability of the data about CO2 reduction, or to the possibilities to increase the amount of absorbed CO2....
Conference Paper
Full-text available
The adoption of CO2-based mixtures as power block working fluid for CSP plant can turn supercritical CO2 cycles into efficient transcritical cycles even at high ambient temperature, with significant performance improvement and potential power block cost reduction. In this work, the use of CO2+C6F6 mixture as working fluid for a power cycle coupled...
Article
Full-text available
Organic Rankine cycles are often the best solution for the conversion of thermal energy. The many working fluids include silicon oils. One crucial issue that determines the choice of a working fluid is its thermochemical stability, as this sets a limit to the maximum temperature at which the fluid can be used in a power plant. A second subject, muc...
Article
Full-text available
Nowadays supercritical CO2 cycles are considered as a promising alternative to the traditional steam cycle for the power block in CSP plants with the aim of enhancing the system efficiency and reducing costs. This work deals with the experimental characterisation of a CO2 blend as working fluid in transcritical cycle: the addition of C6F6 as a dopa...
Article
Full-text available
This paper focuses on the use of the CO2 + SO2 binary mixture as innovative working fluid for closed transcritical power cycles with a minimum temperature above 50 °C. Starting from a literature review of the available experimental data on the mixture, the PC-SAFT EoS is identified as a suitable model to characterize the mixture behavior. Once the...
Conference Paper
Full-text available
Supercritical CO 2 cycles are a promising technology, but their performance drops for hot cold source, in hot and arid environments, typical of a CSP field. The adoption of CO 2 -based mixtures as working fluid can turn supercritical CO 2 cycles into transcritical cycles even at high temperatures, with performance improvement and significant power...
Article
Full-text available
Electrified vehicles have undergone great evolution during the last decade because of the increasing attention paid on environmental sustainability, greenhouse gas emissions and air pollution. Emission regulations are becoming increasingly tight, and governments have been allocating multiple funds to facilitate the spreading of the so-called green...
Article
Full-text available
The present paper explores the utilisation of dopants to increase the critical temperature of Carbon Dioxide (sCO2) as a solution towards maintaining the high thermal efficiencies of sCO2 cycles even when ambient temperatures compromise their feasibility. To this end, the impact of adopting CO2-based mixtures on the performance of power blocks repr...
Conference Paper
Full-text available
Supercritical Carbon Dioxide (sCO2) power cycles have been proposed for Concentrated Solar Power (CSP) applications as a means to increase the performance and reduce the cost of state-of-the-art CSP systems. Nevertheless, the sensitivity of sCO2 systems to the usually hot ambient temperatures found in solar sites compromises the actual thermodynami...
Article
Full-text available
The Tesla turbine is an original expander working on the principle of torque transmission by wall shear stress. The principle – demonstrated for air expanders at lab scale has some attractive features when applied to two-phase expanders: it is suitable for handling limited flow rates (as is the case for machines in the range from 500W to 5 kW), it...
Article
Nowadays supercritical CO2 cycles are considered as a promising alternative to the traditional steam cycle for the power block in CSP plants with the aim of enhancing the system efficiency and reducing costs. This work deals with the experimental characterisation of a CO2 blend as working fluid in transcritical cycle: the addition of C6F6 as a dopa...
Conference Paper
The future of Concentrated Solar Power technology relies on significant cost reduction to be competitive against both fossil fuel power stations and renewable technologies as photovoltaics and wind. Most of the research activity on concentrated solar power focuses on supercritical CO2 cycles to increase the solar plant efficiency together with a co...
Article
Full-text available
This study aims to provide a thermodynamic comparison between supercritical CO2 cycles and ORC cycles utilizing flue gases as waste heat source. Moreover, the possibility of using CO2 mixtures as working fluids in transcritical cycles to enhance the performance of the thermodynamic cycle is explored. ORCs operating with pure working fluids show hig...
Article
Full-text available
In the last years, several fluids have been proposed to replace steam as working fluid in power cycle for converting thermal power into electricity. This paper describes the procedure to be adopted for the selection of any innovative fluid which can be even mixtures of fluids. The first step consists of the working fluid characterization in terms o...
Article
Full-text available
In this paper we compare energy performance and environmental impact of four nominal weight classes of commercial vehicles with different powertrain solutions: conventional diesel internal combustion engine (ICE), Plug-In Electric Vehicle (PHEV), Battery Electric Vehicle (BEV) and Plug-In Fuel Cell Vehicle (PFCV). First, the sizing of the various p...
Article
Full-text available
This study investigates the use of pure and hydrocarbons binary mixtures as potential alternatives working fluids in a usual biomass powered organic Rankine cycle (ORC). A typical biomass combined heat and power plant installed in Cremona (Italy) is considered as the benchmark. Eight pure hydrocarbons (linear and cyclic) and four binary mixtures of...
Article
Full-text available
This work explores the possibility to adopt in organic Rankine cycle (ORC) plants mixtures of water (acting as solvent) plus an organic compound (acting as solute) as the working fluid. Initially an evaluation of the thermodynamic properties of the mixtures is performed, in order to assess their properties, and to point out the molar fractions whic...
Article
This paper discusses the adoption of CO2 mixtures for improving the thermal-to-power efficiency conversion in solar tower plants and reducing the Levelized Cost of Electricity. Two different fluids are considered for blending the CO2: N2O4 and TiCl4. The main advantage of the innovative mixtures relies in a higher critical temperature with respect...
Article
The competitiveness of concentrated solar power technology in the near-future electricity generation scenario, requires a substantial reduction of the Levelized Cost of Energy which can be achieved with an increase of the energy conversion efficiencies while maintaining or reducing the investment costs. This paper discusses the use of pure Dinitrog...
Article
Full-text available
In this paper, a general quasi-steady backward-looking model for energy consumption estimation of electric vehicles is presented. The model is based on a literature review of existing approaches and was set up using publicly available data for Nissan Leaf. The model has been used to assess the effect of ambient temperature on energy consumption and...
Article
A thermal stability test-rig for organic Rankine cycles working fluids was designed and commissioned at the Laboratory of Compressible-fluid dynamics for Renewable Energy Applications (CREA Lab) of Politecnico di Milano, in collaboration with the University of Brescia. The set-up is composed by a vessel containing the fluid, heated for about 80 h a...
Article
Full-text available
Real time matching of electric power generation is a crucial aspect in off-grid systems as well as in case of use of renewable intermittent sources. In this paper, with reference to 1 MWel Turboden biomass ORC plants operating in off-grid systems, we study the possibility to store thermal energy in the form of sensible heat within a storage compose...
Article
This article analyzed the potential energy recovery from rather small quantities of associated gas (<2000 m3/h), where the on-site electricity generation within the oil extraction field may represent a cost-effective solution as an alternative to flare combustion. Various power plant technologies were considered and compared from both the economic...
Article
In this paper, Titanium tetrachloride (TiCl4) is analyzed/assessed and proposed as a new potential working fluid in Rankine Cycles. Besides its good thermodynamic properties, TiCl4 is in fact a fairly low cost, non-carcinogenic fluid, with zero Global Warming Potential (GWP) and Ozone Depleting Potential (ODP) and it is currently employed in high t...
Article
In this paper we investigate the potential replacement of HFC-134a in ORC applications by two low-GWP refrigerant fluids, namely HFO-1234yf and HFO-1234ze(E). After revising and discussing their main thermo-physical properties, we adopted in our calculations the Peng Robinson EOS available in Aspen Plus v7.3, integrated with literature data. By ass...
Article
Full-text available
Power generation using Organic Rankine Cycle was studied in this paper in case of both low and high temperature cycles, exploiting respectively a geothermal heat source available at 167 °C, and heat available at 300 °C from the combustion of biomass. In particular we assess the feasibility of employing mixture of working fluids, in the case of repl...
Article
Full-text available
The thermal stability analysis of perfluorohexane (C6F14)is presented in this paper as a preliminary evaluation of the potential application of the binary mixture CO2 – C6F14 as innovative working fluid for transcritical-CO2 power cycles. After presentinga description of the experimental apparatus, saturation pressure models are compared and calibr...
Conference Paper
This work proposes a process simulation of high efficiency intermediate-temperature (660–730°C) SOFC systems for promising applications in the foreseeable future distributed power generation sector. Two case-studies have been considered: the kW-scale unit proposed by Ceramic Fuel Cell Limited (CFCL), which reaches up to 68% stack DC efficiency, and...
Article
Full-text available
This work evaluates the thermodynamic performances of two oxygen separation technologies, Pressure Driven Electrolytic Membranes (PDEM) and Solid Electrolyte Oxygen Pumps (SEOP), focusing on the application to small scale oxygen production. We show that PDEM systems operated with a specific flux of 5 liters of oxygen per minute per square meter of...
Article
Full-text available
In this work we present an improved survey method for the evaluation of the thermal stability of working fluids for organic Rankine cycles. The method presented here represents an improvement of a test methodology already used in literature, based on the analysis of temperature and pressure measurements of a fluid subjected to increasing thermal st...
Technical Report
In questo documento sono riportate le attività svolte e attivate dal Dipartimento di Energia nell'ambito del progetto di ricerca dal titolo "Verifica del comportamento del TiCl4 come possibile fluido di lavoro" giunto al secondo anno di indagini. Le attività di questo secondo anno sono descritte in due rapporti distinti. La prima dal titolo "Propri...
Article
This paper presents a new CHP solution based on a double shaft intercooled gas cycle with external combustion (EFGT cycle). This configuration exploits the turbocharger technology widely diffused in the automotive industry, taking advantage of the capital cost reduction due to the economy of scale typical of the automotive market. Thermodynamic cal...
Article
In this paper we present a one dimensional dynamic model of a PEM fuel cell applied to the design of a mobile backup system for uninterruptable power units. The fuel cell is modeled using a finite difference approach where mass and energy balance equations are applied locally together with the pertinent equations of the electrochemical model yieldi...
Article
This paper presents a finite difference one-dimensional (1D) model of a single unit SOFC–SOEC stack, a novel technology based on the integration of a solid oxide fuel cell (SOFC) and solid oxide electrolyzer (SOEC), and a promising candidate for the high efficiency production of oxygen and/or hydrogen, especially for small scale applications. The m...
Article
Oxygen is used for a wide range of applications. Depending on the economic range and the required purity, various methods are used to extract oxygen; for the medium to large production scale, cryogenic air separation is preferred with relatively low energy consumption and high purity, whilst for the small scale, adsorption-based devices are widely...
Article
In this paper, a novel process for the production of pure hydrogen from natural gas based on the integration of solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs) is presented. In this configuration, the SOFC is fed by natural gas and provides electricity and heat to the SOEC, which carries out the separation of steam into hy...
Article
The paper presents a model for the off-design analysis of a hybrid plant based on a MCF4C and a gas-turbine. The model is used to define a possible regulation strategy for the power plant, minimizing the performance decay at partial load and allowing investigation of the interaction issues among the different plant components. The hybrid plant refl...
Conference Paper
Full-text available
This paper compares the different incentive systems in support to the photovoltaic power generation in force in six countries of the European Union: Austria, France, Germany, Italy, Portugal and Spain. For the proper solar radiation of each location and two different plant sizes (one, from 1 to 3 kWp, typical of domestic installations, the other la...
Conference Paper
Full-text available
This paper deals with the performance comparison over simulated micro-cogeneration units based on polymer electrolyte membrane fuel cells (PEMFC or PEM), when the fuel is processed by means of two contrasting techniques. On the one hand with the use of conventional natural gas steam reforming (SR), and on the other, the adoption of an innovative pa...
Article
This paper presents a novel system for production of pure oxygen based on the integration of a solid oxide fuel cell (SOFC) and a solid oxide electrolyzer (SOEC). In the proposed arrangement, the SOFC provides electricity, heat and H2O in vapour phase to the SOEC which carries out the inverse reactions of the SOFC, that is the separation of H2O int...
Article
This work presents a computational thermofluid-dynamic analysis of circular-planar type intermediate-temperature solid oxide fuel cells (SOFCs), based on the Hexis design. A single cell, representative of the average conditions of a real stack, is simulated in detail considering the real anode and cathode channel design, featuring an array of squar...
Conference Paper
This paper analyzes the dynamic behaviour of a 5 kW fuel cell system based on planar co-flow Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) stack, with internal reforming. The system is composed by the SOFC stack, a combustor of the cell exhausts, two heat exchangers for fuel and air preheating and the related control valves, where the ai...
Article
A computer model of a solid oxide fuel cell (SOFC) was implemented with a number of operational options to evaluate the best use of the cell waste heat. The simplest solution for heat recovery is represented by adopting a pressurized fuel cell with the eventual expansion of the exhaust stream in a gas turbine. Other alternatives feature the adoptio...
Article
In this paper, a three-dimensional finite volume model of a molten carbonate fuel cell (MCFC) is presented. The model applies a detailed electrochemical and thermal analysis to a planar MCFC stack of given geometry and assigned input flows conditions, material properties and assigned external heat losses, calculating global energy balances and reac...
Article
This work presents an experimental analysis of circular-planar type intermediate-temperature solid oxide fuel cells, and the interpretation of the experimental results with a finite volume model. The model is developed to generate cell mass and energy balances and internal cell profiles for all the relevant thermodynamic or electrochemical variable...
Article
This paper investigates the thermodynamic potential of the integration of molten carbon fuel cell (MCFC) technology with gas turbine systems for small-scale (sub-megawatt or sub-MW) as well as large-scale (multi-MW) hybrid cycles. Following the proposals of two important MCFC manufacturers, two plant layouts are discussed, the first based on a pres...
Article
This paper investigates the possibility of enhancing the performances of micro-gas turbines through the addition of a bottoming organic Rankine cycle which recovers the thermal power of the exhaust gases typically available in the range of 250–300 °C. The ORC cycles are particularly suitable for the recovery of heat from sources at variable tempera...
Article
The coproduction of electrical, thermal and refrigerating power is a well-known strategy which can significantly improve the efficiency of energy systems. Often in such tri-generation systems the refrigerating power is obtained by means of absorption cycles. This paper deals with the potential use of ejector-powered refrigerating cycles for heat re...
Article
This paper compares two dynamic, one-dimensional models of a planar anode-supported intermediate temperature (IT) direct internal reforming (DIR) solid oxide fuel cell (SOFC): one where the flow properties (pressure, gas stream densities, heat capacities, thermal conductivities, and viscosity) and gas velocities are taken as constant throughout the...
Article
This paper discusses the development of a finite volume model for a planar solid oxide fuel cell. Two different levels of detail for the definition of the basic cell elements are considered, the first with the assumption of isothermal behavior for a finite volume, defined by a portion of the cell PEN structure with pertinent air and fuel channels,...
Article
A finite volume model of a solid oxide fuel cell has been developed. The model applies a detailed electrochemical and thermal analysis to a tubular SOFC of given geometry, material properties and assigned input flows. Electrochemical modeling includes an evaluation of ohmic, activation and diffusion losses as well as a kinetic model of hydrocarbon...
Article
SOMMARIO In questo lavoro viene proposto un sistema innovativo per la produzione di ossigeno costituito da un sistema integrato SOFC-SOEC, dove SOFC (Solid Oxide Fuel Cell) è una cella a combustibile ad alta temperatura alimentata con idrogeno ed aria in grado di produrre energia elettrica, energia termica e H 2 O in fase vapore, mentre il componen...

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Projects (3)
Project
Modeling and simulations of ORCs
Project
At the moment we are carrying out a series of measures to analyse the "heat resistance" of working fluids potentially usable in Rankine cycles. The greater the thermal stability, the greater is the maximum temperature at which the fluid can be used. Higher operating temperatures extend the field of applications of the engines and their efficiency increases too. The Organic Rankine Cycle power systems can offer viable solutions to generate electric/mechanical power from a wide variety of energy sources. Different applications need different working fluids.