Publications associées à Cycle transcritique

Experimental Investigation of a Small-Scale Organic Rankine Cycle Turbo-Generator Supported on Gas-Lubricated Bearings

Waste heat recovery (WHR) is expected to contribute to reducing CO2 emissions from trucks. Organic Rankine cycle (ORC) systems show the highest potential for this application, but still lack efficient small-scale expansion devices, in practice. A novel tur ...

2021

Scale limitations of gas bearing supported turbocompressors for vapor compression cycles

Jürg Alexander Schiffmann

An analysis of single-stage centrifugal compressors supported on dynamic, gas lubricated bearings for driving vapor compression cycles suggests that the maximum feasible compressor power is limited, primarily by the bearing load capacity, in the range from ...

2020

New Approach to Synthesis of Tetralin via Naphthalene Hydrogenation in Supercritical Conditions Using Polymer-Stabilized Pt Nanoparticles

Lioubov Kiwi

Supercritical (SC) fluid technologies are well-established methods in modern green chemical synthesis. Using SC fluids as solvents instead of traditional liquids gives benefits of higher diffusivity and lower viscosity, which allows mass transfer intensifi ...

2020

Printing of NiO-YSZ nanocomposites: from continuous synthesis to inkjet deposition

Andreas Stephan Lesch, Victor Costa Bassetto, Massimo Rosa

Water-based inks, containing nanometric NiO and YSZ particles in 66/34 vol. % ratio, are produced by colloidal stabilization of a binary dispersion obtained via continuous hydrothermal synthesis at supercritical conditions, i.e. 280 bar and 400 °C. The met ...

2019

Supercritical water anomalies in the vicinity of the Widom line

Christian Ludwig

Supercritical water is used in a variety of chemical and industrial applications. As a consequence, a detailed knowledge of the structure-properties correlations is of uttermost importance. Although supercritical water was considered as a homogeneous fluid ...

Nature Research2019

Generic superstructure synthesis of organic Rankine cycles for waste heat recovery in industrial processes

François Maréchal, Ivan Daniel Kantor, Maziar Kermani, Anna Sophia Wallerand

Waste heat accounts for up to 70% of input energy in industrial processes which enunciates the importance of energy recovery measures to improve efficiency and reduce excessive energy consumption. A portion of the energy can be recovered within the process ...

2018

Multi-objective optimization of turbo-ORC systems for waste heat recovery on passenger car engines

Jürg Alexander Schiffmann, Kévin Rosset, Eliott Philippe Guenat, Violette Mounier

Waste heat recovery from passenger car internal combustion engines by means of an organic Rankine cycle (ORC) system is promising for reducing CO2 emissions. In this study, different cycle configurations capable of converting waste heat from both coolant a ...

2018

Methodologies for simultaneous optimization of heat, mass, and power in industrial processes

Maziar Kermani

Efficient consumption of energy and material resources, including water, is the primary focus for process industries to reduce their environmental impact. The Conference of Parties in Paris (COP21) highlighted the prominent role of industrial energy effici ...

EPFL2018

Multiple Inflow Branches at Supercritical-Type Vortex Drop Shaft

Michael Pfister, Jean-Marc Ribi, Corrado Gisonni, Gaetano Crispino, Thierry Fuchsmann

Vortex drop shafts serve to overcome important elevation differences in drainage systems. If well designed, they are performant in terms of energy dissipation and safety. However, the standard design requires well-defined approach flow conditions to ensure ...

ASCE-AMER SOC CIVIL ENGINEERS2018

Dimensionless correlations and performance maps of scroll expanders for micro-scale Organic Rankine Cycles

Jürg Alexander Schiffmann, Violette Mounier, Luis Carlos Mendoza Toledo, Luis Eric Olmedo Ocampo

In the endeavor towards distributed power systems, not seasonal-dependent micro-power generation technologies are expected to integrate the energy scenario in the years to come. In this context, the Organic Rankine Cycle (ORC) in the (1e10) KWe scale has c ...

2018

Thermo-economic analysis of transcritical CO2 cycles with bounded and unbounded reheats in low-temperature heat recovery applications

Ali Amini

Performance of transcritical CO2 Rankine cycles with and without reheat process is investigated thermo-economically in low-grade waste heat recovery applications. Two reheating scenarios are proposed to evaluate the effect of bounded and unbounded reheats ...

Pergamon-Elsevier Science Ltd2017

Pressure drop prediction in annular two-phase flow in macroscale tubes and channels

John Richard Thome, Andrea Cioncolini

A new prediction method for the frictional pressure drop in annular two-phase flow is presented. This new prediction method focuses on the aerodynamic interaction between the liquid film and the gas core in annular flows, and explicitly takes into account ...

Pergamon-Elsevier Science Ltd2017

Energy integration on a gasoline engine for a vehicular application

François Maréchal, Zlatina Kirilova Dimitrova

The internal combustion engines are the most applied energy converters in the passenger cars. In order to increase their efficiency, energy integration techniques are used to recover the waste heat. An adapted methodology is required to design the ORC as a ...

2017

Multi-temperature heat pumps: A literature review

Jürg Alexander Schiffmann

This review highlights the major advantages and challenges of mechanically driven heat pumps and refrigeration systems with focus on multi-temperature applications. Different design strategies are presented, including cycles with multi-stage compressors, e ...

Elsevier2016

Supercriticality conditions for asymmetric zero-range process with sitewise disorder

Thomas Mountford

We discuss necessary and sufficient conditions for the convergence of disordered asymmetric zero-range process to the critical invariant measure. ...

Brazilian Statistical Association2015

Integration of Organic Rankine Cycles for Waste Heat Recovery in Industrial Processes

Matthias Bendig

Developing a methodology that allows identifying maximumelectricity production with the help of Organic Rankine Cycles (ORC) from the waste heat of an industrial process, at the lowest specific cost, without jeopardising the increase of the industrial proc ...

EPFL2015

Methodology for Identification of Suitable ORC-Cycle and Working-Fluid using Integration with Multiple Objectives

François Maréchal, Daniel Favrat, Matthias Bendig

In recent times the interest in electricity production with Organic Rankine Cycles (ORC) has increased. A look into recent publications shows that the identification of suitable working fluids is in general done by a look at a more or less small number of ...

Aidic Servizi Srl2014

Isothermal transcritical CO2 cycles with TES (thermal energy storage) for electricity storage

Daniel Favrat, Young Min Kim

Recently, TEES (thermo-electric energy storage) systems have been proposed as a new method for large-scale energy storage wherein electric power is stored as thermal energy by using a heat pump and retrieved from the TES (thermal energy storage) by using a ...

Elsevier2013

Transcritical or supercritical CO2 cycles using both low- and high-temperature heat sources

Daniel Favrat

In CO2 cycles with high-temperature heat sources that are used in applications such as nuclear power, concentrated solar power, and combustion, partial condensation transcritical CO2 (T-CO2) cycles or recompression supercritical CO2 (S-CO2) cycles are cons ...

2012

Theoretical and Experimental Study of a Thermally Driven Heat Pump Based on a Double Organic Rankine Cycle

Jonathan Demierre

Nowadays, one of the main alternatives for a more rational use of energy in heating applications is the heat pumping technologies. The market is dominated by two kinds of heat pump systems: the electrically driven vapor compression heat pumps (EHP), which ...

EPFL2012