Emiliano Casati

ETH Zurich | ETH Zürich · Department of Mechanical and Process Engineering

This work presents the first experimental results dealing with the direct absorption of concentrated solar energy by a body of glass contained in a solar cavity receiver. Container glass of various colors was adopted as working medium in a setup tested in the ETH’s High Flux Solar Simulator. Maximum radiative fluxes of 1.2 MWm⁻² and power input of...

This work presents the exploratory experimental results of a co-located solar receiver and thermal energy storage (TES) concept based on a pool of molten glass contained in a cavity, serving as solar receiver and TES medium simultaneously. Distinctive features of the system are the direct and volumetric absorption of solar radiation by the semi-tra...

Organic Rankine Cycle (ORC) power systems are receiving increased recognition for the conversion of thermal energy when the source potential and/or its temperature are comparatively low. Mini-ORC units in the power output range of 3–50 kWe are actively studied for applications involving heat recovery from automotive engines and the exploitation of...

The cumulative global capacity of organic Rankine cycle (ORC) power systems for the conversion of renewable and waste thermal energy is undergoing a rapid growth, and is estimated to be approx. 2,000 MW_e considering only installations that went into operation after 1995. The potential for the conversion into electricity of the thermal power coming...

Non-ideal compressible fluid dynamics (NICFD) are defined as compressible fluid flows occurring in the dense vapour, dense vapour-liquid equilibrium or supercritical thermodynamic region. This type of flow can occur in expanders of organic Rankine cycle power plants. In order to study NICFD, a Ludwieg tube-type facility has been designed and constr...

This paper describes the commissioning of the flexible asymmetric shock tube (FAST), a novel Ludwieg tube-type facility designed and built at Delft University of Technology, together with the results of preliminary experiments. The FAST is conceived to measure the velocity of waves propagating in dense vapours of organic fluids, in the so-called no...

Concentrated solar power plants are increasingly considered worldwide, in order to meet the demand for renewable power generation. A distinctive feature of these plants is the possibility of integrating thermal energy storage such that full-load operation can be sustained for several hours in the absence of solar radiation. A number of design softw...

The design of a hybrid test facility for the development of ORC turbomachinery is the subject of this technical report. The Organic Rankine Cycle Hybrid Integrated Device (ORCHID) is a continuous closed-circuit gas dynamic "wind tunnel" with the added capability of testing stationary and rotating cascades. Its purpose is to study the fundamentals o...

Complete thermodynamic models were developed for the estimation of thermodynamic properties of biphenyl (C12H10, CAS number 92-52-4), diphenyl ether (C12H10O, CAS number 101-84-8), and of their mixtures. These compounds are used as heat transfer fluids, both in the liquid and in the vapor phase, especially in the eutectic formulation (commercially...

Organic Rankine cycle (ORC) power systems are rapidly diffusing as a technology for the conversion of thermal energy sources in the small-to-medium power range, e. g., from 150 kW(e) up to several MWe. The most critical component is arguably the expander, especially if the power capacity is small or very small, as it is the case for innovative high...

Abstract This article presents a methodology to help in the definition of the optimal design of power generation systems. The innovative element is the integration of requirements on dynamic performance into the system design procedure. Operational flexibility is an increasingly important specification of power systems for base- and part-load opera...

The non-classical gas dynamics of binary mixtures of organic fluids in the vapour phase is investigated for the first time. A predictive thermodynamic model is used to compute the relevant mixture properties, including its critical point coordinates and the local value of the fundamental derivative of gas dynamics Gamma. The considered model is the...

Concentrated Solar Power CSP plants are increasingly being considered for construction worldwide, in order to meet the demand for renewable power generation. The most promising technology considered today employs a central receiver, illuminated by a heliostat field, using molten salts as working fluid. A distinctive feature of these plant is the po...

The feasibility of energy storage is of paramount importance for solar power systems, to the point that it can be the technology enabler. Regarding concentrated solar power (CSP) systems, the implementation of thermal energy storage (TES) is arguably a key advantage over systems based on photovoltaic (PV) technologies. The interest for highly effic...

Organic rankine cycles (ORC) are renowned to be attractive energy conversion systems for the thermal energy sources in the small-to-medium power range. A critical component in the ORC technology is the turbo-expander; the difficulties involved in the accurate thermodynamic modeling of organic fluids and, especially, the complex gasdynamic phenomena...

For fluids composed of complex molecules, a limited thermodynamic region exists, at high reduced temperature and pressure close to the dew-line (dense-vapour region), whereby the fundamental derivative of gas dynamics Γ assumes negative values. In such region the gas-dynamic flow features are reversed with respect to the gas dynamics of perfect gas...