Flavio Fucci

Planning and automated management of a horticultural station.

This paper presents a simulated environment for a horticultural station composed of storage cells, precooling systems and refrigerators. The numerical model developed for the simulation of the station is based on an object oriented structure that allows separately verifying the reliability of the results of each functional block.

Physical model and demonstration of an aquifer thermal energy store

Abstract An experimental loop has been set up to demonstrate the technical feasibility of a hot water aquifer store and to validate an original physical model and code as well as the engineering based on it. The model applies to a “reference aquifer” and an appropriate exploitation system, as defined in the text. Experiments have been carried out for a period of 37 days, 15 days for injection of hot water at 40°C, 7 days of storage at rest, 15 days for pumping out stored hot water. The system has worked perfectly at the specified performance. Measured temperatures show a very good accordance with temperatures predicted by the numerical model. The rated 52% efficiency has been confirmed. Although more extended experiments shall be performed, one can conclude that the engineering of the system is appropriate and the physical model and numerical code developed by the authors are satisfactory.

Vibration analysis using a contactless acquisition system

The problem of vibration measurement has assumed increasing importance in recent years for different aspects. In the first phase of this study an analysis of vibrations by means of contact accelerometers was carried out to study a tree shaking machine used in the mechanical harvesting of olives. Then a kinematic analysis of motion with a contactless method was carried out on a belt transmission system equipped with three pulleys: a high speed camera was used, able to capture up to 500 frames per second thus to follow the position of any moving point of the mechanical system under investigation. Vibrations were acquired detecting the positions during time of a marker fixed on the belt. The proposed method made it possible to analyse the mechanism and verify both known behaviours and neglected aspects in the usual kinematic analysis carried out using acceleration measurements.

Adsorption phenomena in porous media in presence of moist air

Abstract In the present study the authors show the experimental results for some building materials as concrete, gypsum, brick, neapolitan yellow tuff, prestressed pine wood. These results are connected, during isothermal conditions, with the adsorbed water content and with a relative humidity variation of the medium air. The authors, considering previous results showed, suggest an empirical correlation describing, for some materials, the percentual weight variation of the adsorbed water higher than 1.0 kg/kg, for a 0.40–0.90 relative humidity range.

Renewable and integrative sources of energy: Aspects and technological applications: evaluation of the contribution to the energetic needs provided by the passive solar system

Abstract Aim of the article is the description and the evaluation of the contribution of energetic need provided by the passive solar system in relation to the acclimatisation of residential environment. The applicability of innovative solutions capable of sustaining, energetically, autonomous electrical structures of rural and/or isolated premises is also studied. The realisation of a prototype (wooden prefabricated volume) to test passive solar systems for a bioclimatic and environmental control has been done; experimental tests had been carried out and the results are shown.

Climate effect on the evaluation of the heat transfer through the perimetral structures of refrigerating stores

Numerical simulation gives the possibility to evaluate, with the approximation peculiar to the method, the temperature trend and the heat exchange through the outside perimetral structures of the refrigerating stores, under different climatic conditions. Specifically, two types of structural panels used in the refrigerating stores building are analysed. Taking in account the climatic sectors under which our national country could be divided, the authors evaluated the sun and the outside temperature influence on the structures thermal behaviour. Using numerical simulation, the thermal power exchange and the temperature field had been determined, under different climatic situations and for a seasonal mean day, related to the exposition and the thermophysical characteristics of the materials. The obtained results show the difference of the thermal behaviour of the two different structures considered and have been utilized for a comparison with the ASHRAE method.

Experimental study of a mechanical ventilation system in a greenhouse

Greenhouse cultivation is one of the most energy intensive activities in agriculture. This is especially true in cold climate zone. Generally heating systems involves boilers fed with fossil fuels. This means low yields of the heat generator and high pollutant emissions. Moreover, the increase of annual crop yield in greenhouses is possible only through a very close control of the internal conditions. Ventilation systems could allow proper control of temperature, relative humidity and CO2 rate. For this purpose a prototype of a mechanical ventilation unit was installed at service of a mini-tunnel greenhouse. The recovery unit is equipped with a heat pump and is able to increase the thermal energy recovered, by the flow of exhaust air, through a high efficiency heat exchanger. A first study was carried out to evaluate the thermophysical and energy performances of the system during the heating season. The experimental apparatus consists of mechanical ventilation system, a perforated duct for air distribution, a fog system to adjust humidity and a supervision system to acquire the field data. Another dedicated supervision system allows to measure and collect all the parameters of the prototype, such as thermophysical parameter of the air flow, thermophysical parameter of the refrigerant circuit of the heat pump, status and alarms of the unit. To characterize the whole system under investigation the main data measured are temperature, relative humidity and carbon dioxide inside the greenhouse and temperature in all section of the prototype. Other two mini-tunnel greenhouses are monitored as references. One is heated with radiant tubes placed on the bench and humidified with a fog system, the other is completely passively heated (without heating system) and humidified with the same fog system. A First test was performed to evaluate the ability of the system to regulate the indoor temperature of the greenhouse with a set point of 27 °C. By using a temperature probe installed on the return side of the machine, the results shown an appropriate temperature regulation.