a Section of Thermal Energy, Department of Mechanical Engineering, Technical University of Denmark, Building 403, Nils Koppels Allé, 2800 Kongens Lyngby, Denmark b Industrial Process and Energy Systems Engineering Laboratory, École Polytechnique Fédérale de Lausanne, Station postale 9, 1015 Lausanne, Switzerland c Energy Department, International Research Institute of Stavanger, Professor Olav ...

We present a thermo-economic evaluation of binary power plants based on the Organic Rankine Cycle (ORC) for geothermal power generation. The focus of this study is to analyse if an efficiency increase by using zeotropic mixtures as working fluid overcompensates additional requirements regarding the major power plant components. The optimization approach is compared to systems with pure media. B...

Exergy and economic analysis is often used to find and identify the most efficient process configuration for proton exchange membrane fuel cell from the thermo-economic point of view. This work gives an explicit account of the synergetic effect of exergetic and economic analysis of proton exchange membrane fuel cell (PEMFC) using methanol and methane as fuel sources. This was carried out throug...

We established the Arctic System Science/Thermokarst (ARCSS/TK) project in 2008 with the intent to use a systems approach to address hypotheses about how upland thermo-erosional features influence the structure and function of the foothill and mountainous landscape in the vicinity of the Brooks Range in arctic Alaska. We found that the common thermo-erosional features in this region are thaw sl...

Large scale power production benefits from the high efficiency of gas-steam combined cycles. In the lower power range, fuel cells are a good candidate to combine with gas turbines. Such systems can achieve efficiencies exceeding 60%. High temperature Solid Oxide Fuel Cells (SOFC) offer good opportunities for this coupling. In this paper, a systematic method to select a design according to user ...

Within the context of Finite-Time Thermodynamics (FTT) a simplified thermal power plant model (the so-called Novikov engine) is analyzed under economical criteria by means of the concepts of profit function and the costs involved in the performance of the power plant. In this study, two different heat transfer laws are used, the so called Newton’s law of cooling and the Dulong-Petit’s law of co...

Converting wood to grid quality methane allows to distribute a CO 2 free, renewable energy resource in a conventional energy distribution system and use it in transportation applications. Applying a multi-objective optimisation algorithm to a previously developed thermo-economic process model for the thermochemical production of synthetic natural gas from wood, the present paper assesses the pr...

This paper addresses a methodology for the optimal conceptual design of thermochemical fuel production processes from biomass. A decomposed modelling approach with separate energy-flow, energy-integration and economic models are coupled with a multi-objective optimisation strategy. It is applied to the design of a process that produces synthetic natural gas (SNG) from lignocellulosic materials....

A recent work reported a local stability analysis of a thermo-economical model of an irreversible heat engine working under maximum power conditions. That work showed that after small perturbations to the working temperatures, the system decreases exponentially to the steady state characterized by two different relaxation times. This work extends the local stability analysis considering other p...