A solar powered liquid-desiccant cooling system for greenhouses

George Lychnos, Philip A. Davies

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Liquid desiccant systems are of potential interest as a means of cooling greenhouses to temperatures below those achieved by conventional means. However, only very little work has been done on this technology with previous workers focussing on the cooling of human dwellings using expensive desiccants such as lithium salts. In this study we are designing a system for greenhouse cooling based on magnesium chloride desiccant which is an abundant and non-toxic substance. Magnesium chloride is found in seawater, for example, and is a by-product from solar salt works. We have carried out a detailed experimental study of the relevant properties of magnesium rich solutions. In addition we have constructed a test rig that includes the main components of the cooling system, namely a dehumidifier and solar regenerator. The dehumidifier is a cross-flow device that consists of a structured packing made of corrugated cellulose paper sheets with different flute angles and embedded cooling tubes. The regenerator is of the open type with insulated backing and fabric covering to spread the flow of desiccant solution. Alongside these experiments we are developing a mathematical model in gPROMS® that combines and simulates the heat and mass transfer processes in these components. The model can be applied to various geographical locations. Here we report predictions for Havana (Cuba) and Manila (Philippines), where we find that average wet-bulb temperatures can be lowered by 2.2 and 3°C, respectively, during the month of May.
Original languageEnglish
Title of host publicationInternational Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions
EditorsC. Kubota, M. Kacira
Place of PublicationLeuven (BE)
PublisherInternational Society for Horticultural Science
Pages95-102
Number of pages8
Volume797
ISBN (Print)978-90-66055-81-0
Publication statusPublished - 30 Sep 2008
EventISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions - Tucson, AZ, United States
Duration: 20 Oct 200824 Oct 2008

Publication series

NameISHS Acta Horticulturae
Volume797
ISSN (Print)0567-7572

Conference

ConferenceISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions
CountryUnited States
CityTucson, AZ
Period20/10/0824/10/08

Fingerprint

Greenhouses
Cooling systems
Cooling
Magnesium
Regenerators
Liquids
Salts
Seawater
Byproducts
Cellulose
Lithium
Mass transfer
Mathematical models
Heat transfer
Temperature
Experiments

Bibliographical note

The original publication is available at http://www.actahort.org/members/showpdf?booknrarnr=797_11

Keywords

  • greenhouse cooling
  • liquid desiccant
  • solar energy

Cite this

Lychnos, G., & Davies, P. A. (2008). A solar powered liquid-desiccant cooling system for greenhouses. In C. Kubota, & M. Kacira (Eds.), International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions (Vol. 797, pp. 95-102). (ISHS Acta Horticulturae; Vol. 797). Leuven (BE): International Society for Horticultural Science.
Lychnos, George ; Davies, Philip A. / A solar powered liquid-desiccant cooling system for greenhouses. International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions. editor / C. Kubota ; M. Kacira. Vol. 797 Leuven (BE) : International Society for Horticultural Science, 2008. pp. 95-102 (ISHS Acta Horticulturae).
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Lychnos, G & Davies, PA 2008, A solar powered liquid-desiccant cooling system for greenhouses. in C Kubota & M Kacira (eds), International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions. vol. 797, ISHS Acta Horticulturae, vol. 797, International Society for Horticultural Science, Leuven (BE), pp. 95-102, ISHS International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions, Tucson, AZ, United States, 20/10/08.

A solar powered liquid-desiccant cooling system for greenhouses. / Lychnos, George; Davies, Philip A.

International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions. ed. / C. Kubota; M. Kacira. Vol. 797 Leuven (BE) : International Society for Horticultural Science, 2008. p. 95-102 (ISHS Acta Horticulturae; Vol. 797).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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Lychnos G, Davies PA. A solar powered liquid-desiccant cooling system for greenhouses. In Kubota C, Kacira M, editors, International Workshop on Greenhouse Environmental Control and Crop Production in Semi-Arid Regions. Vol. 797. Leuven (BE): International Society for Horticultural Science. 2008. p. 95-102. (ISHS Acta Horticulturae).