Search results for "Desiccant"

Energy performance evaluation of a demo solar desiccant cooling system with heat recovery for the regeneration of the adsorption material

2012

Abstract Since July 2008, a Solar Desiccant Evaporative Cooling (DEC) system has been operating as a test plant at the solar laboratory of the Dipartimento di Energia (ex DREAM) of the University of Palermo. The system is composed of an air handling unit (AHU) designed for ventilation of the laboratory coupled with a radiant ceiling that provides most of the required sensible cooling/heating energy. Flat plate collectors deliver part of the regeneration heat of the desiccant wheel during the summertime and are used for space heating during the wintertime. The system was designed for high humidity loads because of the typical climate conditions at the site and the need to support a radiant c…

DISPOSITIVO E METODO PER IL CONDIZIONAMENTO DELL’ARIA

2012

Energy performance improvements of a DEC system due to wet heat exchangers

2011

This work concerns an innovative desiccant and evaporative cooling (DEC) system for building air conditioning. The original system is an experimental DEC air handling unit installed at the Solar Laboratory of the University of Palermo and recently modified and updated. With the aim to increase the cooling effect due to water evaporation in the return air flow rate, the sensible heat exchanger was replaced with two cross flow flat plate heat exchangers installed in series, with continuous humidification of the secondary air flow. The new thermodynamic cycle is theoretically described and the realization of the real application is shown. Detailed operational data and energy performance indica…

Odesse: A New Tool for Simulation and Design of Solar Desiccant Cooling Systems in Energy Efficient Buildings

2010

Simplified models for the performance evaluation of desiccant wheel dehumidification

2002

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…

Experimental results on adsorption beds for air dehumidification

2016

Desiccant rotors are commonly used in large scale solar cooling open cycle applications. As is well known, adsorption heat sensibly reduces the dehumidification capacity of the desiccant material and results in lower system performance. The aim of this work is to describe an innovative solution that permits simultaneous mass and heat transfer. In particular, two components working with silica gel fixed beds were studied and compared. The first component is a simple packed bed containing silica gel grains. The second component is a fin and tube heat exchanger commonly used in several air conditioning applications wherein the spaces between the fins are filled with silica gel grains. In this …

Monitoring Results and Energy Performances Evaluation of Freescoo Solar DEC Systems

2016

Abstract This work addresses the energy saving performances of some solar Desiccant and Evaporative Cooling (DEC) systems working with the freescoo technology. The innovative freescoo concept is based on the use two fixed and cooled adsorption beds and advanced indirect evaporative cooling processes. The main feature of this new adsorption bed concept is to allow the simultaneous dehumidification and cooling of air. The systems analyzed have been installed in Italy last here and results based on field monitoring data are here presented. A description of the monitored systems and comparisons between the energy performances based on the main performance indicators such as EER, thermal COP, co…

Life Cycle Assessment of a compact Desiccant Evaporative Cooling system: The case study of the “Freescoo”

2016

Abstract The paper aims at exploring the performances of a compact Desiccant Evaporative Cooling system called “Freescoo” (Free Solar Cooling) in comparison to standard conventional technologies. The Freescoo – that aims at applications in the residential sector and in small office buildings and includes a photovoltaic–thermal system – is analyzed, its monitored performance discussed and reported: under cooling conditions an Energy Efficiency Ratio of 12.8 is calculated, that reaches 50.7 if also photovoltaic generation is considered. To assess the performance of the proposed system a Life Cycle Assessment study was performed to investigate the system covering all its life, from the product…

ADVANCED SOLAR ASSISTED DESICCANT AND EVAPORATIVE COOLING SYSTEM EQUIPPED WITH WET HEAT EXCHANGERS

2011

Abstract This work concerns an innovative solar assisted desiccant and evaporative cooling (DEC) system for building air conditioning. In this system, air-to-air packaged wet heat exchangers are used to maximize the exploitation of the evaporative cooling potential associated with the exhaust air stream. The thermodynamic cycle is first theoretically described, and then an example of a real application is shown. The system presented is an experimental DEC system originally installed at the beginning of 2008 at the Solar Laboratory of the University of Palermo and recently modified and updated. These modifications have been implemented with the aim to foster some problems related to the conv…

Update on desiccant wheel model

2004

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…