FOSSA , Marco

Calculations are performed to study the behavior of air-water mixtures in vertical flows employing a simple model for the description of mass, momentum, and energy transfer in annular gas-liquid flows. The model is applied to various flow conditions including thermal nonequilibrium and variable cross section ducts. Theoretical results agree...

The performance of impedance probes for measuring the conductance of gas–liquid mixtures in horizontal pipes is here studied by means of the numerical solution of Laplace problem. In particular the work is aimed at optimising the probe geometry in order to improve the probe response both in terms of linearity and in terms of spatial resolution...

Borehole heat exchangers (BHEs) are the most frequently adopted solution for ground coupled heat pump applications. In most installations, BHEs also represent the most important cost item, and a careful design analysis is needed to either assure long time performance or reduce the payback period, both parameters related to overall BHE length....

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Tesi di Dottorato, Roma

Nel presente articolo si intendono descrivere i principi fisici di base che regolano il processo di scambio termico tra il terreno ed un sistema di scambiatori interrati nelle applicazioni a pompa di calore a circuito chiuso (Ground Coupled Heat Pumps, GCHP). Questa breve analisi riguarderà gli scambiatori interrati verticali (Borehole Heat...

Ground coupled heat pumps are systems combining a heat pump with a ground heat exchanger for building heating and cooling purposes. Borehole heat exchangers (BHE) are the most frequently adopted solution for ground-assisted heat pump applications, and in most installations, they represent the most important cost item. For this reasons, a...

In this article, the ASHRAE method for borehole heat exchanger field design is deeply discussed in order to trace its theory and physical meaning. The aim of the article is corroborate previous studies in order to demonstrate that the current version of the method is not suitable for a reliable sizing of the borehole field since the criteria...

CERN Report, 1992

Experiments have been carried out to analyze the evolution of the air/water flow structure along a horizontal 60 mm i.d. straight pipe. Plug and slug flow regimes were observed. In order to investigate the local structure of the flow, dynamic void fraction measurements have been performed by means of ring impedance probes. From dynamic void...

tAmong the strategies for borehole heat exchanger (BHE) field design, the Ashrae method is a powerfuland fast procedure for the prediction of the BHE field length required by the building monthly heat loadprofile. The method needs the calculation of the Temperature Penalty, a key parameter that takes intoaccount the error introduced by the...

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Borehole heat exchangers (BHE) are the most common solution for ground coupled heat pumps (GCHP).The thermal interactions with ground and the GCHP performance are strictly related to a number of fac-tors, including the ground properties, the BHE field geometry, the sequence and strength of heat loadsrequired by the building. A typical...

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