0000000000122041
AUTHOR
F. Butera
EXPERIMENTAL VALIDATION OF A FINITE DIFFERENCES TROMBE WALL MODEL
ABSTRACT The paper describes a finite differences Trombe wall model validation, based on experimental data recorded at a passive systems test station in Central Italy. The computer code has been checked step by step, due to the different reliability of the data and to the various algorithms used in the code. Thus, cloudy and clear nights with no thermocirculation were simulated and compared with experimental data, then evening hours with thermocirculation, but no sun and, finally, a full day was simulated and compared. Some inaccuracy has been found in the simulation of wind effect on outer glass convective heat transfer coefficient. The code, however, has been found to provide data in reas…
Update on desiccant wheel model
This short communication presents the update on the desiccant wheel models, developed earlier by the present authors. It is to be mentioned here that the psycrometric model presented earlier (Int. J. Energy Res., 2003; 27:17) is valid only for the desiccant wheel running with identical volume air-flows in supply and regeneration sides. However, when system runs with volume air flow ratio between supply and regeneration side (α), different from 1 (one), the model need further modifications. In the present work, correction factors were developed and incorporated in order to update the earlier model for predicting correctly the temperature and humidity of processed air at the outlet of desicca…
Simplified models for the performance evaluation of desiccant wheel dehumidification
In the present communication, simple models have been presented to evaluate the performance of rotary desiccant wheels based on different kind of solid desiccants e.g. silica gel and LiCl. The first part of the paper presents ‘Model 54’ which is developed for silica gel desiccant rotor. The model has been derived from the interpolation of experimental data obtained from the industry and the correlations have been developed for predicting outlet temperature and absolute humidity. The ‘Model 54’ consists of 54 coefficients corresponding to each correlation for outlet absolute humidity and temperature and it is found that the model predicts very well the performance of silica gel desiccant rot…
COOLING OF COMMERCIAL BUILDINGS BY MEANS OF LARGE COLD RADIANT CEILINGS
ABSTRACT The possibility of using different cooling tools working with lower radiant temperatures and higher air velocity is explored. Lower energy consumptions may be achieved in specific climates with reasonable levels of thermal comfort.
Simplified thermal analysis of naturally ventilated dwellings
Abstract A simplified comprehensive methodology for thermal comfort prediction in a naturally crossventilated room is described. The methodology mainly consists of the following three steps: • - analysis of the dynamic thermal behaviour of the given room, by means of the admittance procedure; • - evaluation of the air flows rates and their velocities in the room, by means of a new simplified method; • - thermal comfort prediction by means of the Fanger's theory. The results obtained appear satisfactory and the simplified methodology makes itself a useful tool for the identification of appropriate choices at the early stages of the design process, regarding naturally ventilated buildings. Th…