Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

A novel retrofittable solar cooler/heater based on adsorption cycle for domestic application

Crema L., Bozzoli A., Cicolini G., Zanetti A.

Polska Energetyka Słoneczna

2009

nr 1-4

43-53

Solar driven cooling machines have been employed until recent years only in niche markets due to a series of reasons: dimensions of the machines, cooling power storage, production costs, and others. At present times there's a high request for a reliable technology :veloped for domestic applications at distributed level. The solar heating is a rapidly growing market and the available technologies ire almost consolidated, but a strong limitation to the application of solar collectors is due to the waste heat available in summer leriods, which limit the sizing of solar domestic installations, limit the capacity to provide not only support to hot sanitary water, but even to indoor space heating. The objective of the present work is to suggest a possible solution and try to give a contribution to the iescribed problem. The R&D performed at FBK-REET labs has produced a new concept of solar driven cooling/heating machine )ased on a double adsorption/desorption cycle acting between two small tanks. The machine, working cyclically between desorption nd adsorption, is provided of an heat storage to separate the cooling energy availability from the solar radiation. Thus the system is Je to provide not only cooling power in hot periods, but even heating in colder times or for hot sanitary water production. The system maybe scaled up or down in cooling capacity, sizing properly the porous adsorbing material volumes, and in cooling power, changing the air mass flow through the system. A prototype has been built, provided of a cooling capacity of about 25 kWh|h and wling power retrofittable until a max of 4 kWlh in the range of cold temperatures of about 8-M2°C. The overall COP is in the range of 0,6^-0,7. The system is patent pending (Publication number: WO2008099262).

Modal analysis as a damage detection tool a research and educational proposal

Crema L., Castellani A.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

1998

nr 8

131-136

This paper outlines the main methods proposed in the last years and developed by a working group of the Aerospace Department of the University of Rome "La Sapienza" in order to evaluate the operative possibilities offered by analysis as a damage detection method in structures. The basic idea is very clear: the dynamic characteristics of a structure represent a signature of the same structure so each non in the structure, even if it is very small as it ens in a damage detection research, creates a variation m die dynamic characteristics. As a consequence by the different dynamic behaviour of a structure its operative life it is possible to detect and to the position and the magnitude of a localized Of course it is possible to consider the ureroents of the frequency response function, FRF, which are very often the data directly measured by a test or the measurements of the natural frequencies, mode shapes and damping coefficients which ie classical modal parameters. A mixed approach may be considered too, which uses together FRF's and modal and numerous alternative have been suggested. time domain data, as the impulse response IR, may be because IR permits to avoid some errors in the connected with the frequency domain data as for example the ones due to the truncation and permits a evaluation of the natural frequencies during operative life of the structure. Of course the achievable results depend on several factors: the measurements of accurate data certainly but also the number of the obtained data. A crucial point is connected to characteristics of the aeronautical structure under study use of the possibility to introduce significant errors in the same measurement procedure. The peculiar characteristics, both by the theoretical andexperimental point of view, of this topic permit to consider a very appealing one for a research activity and an educational action.