Imperial College London
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Dr Asmaa A Harraz

Faculty of Engineering, Department of Chemical Engineering

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Location

 

B432ABCACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@inproceedings{Najjaran:2018,
author = {Najjaran, Kheirabadi A and Harraz, AA and Freeman, J and Mac, Dowell N and Markides, CN},
publisher = {ECOS},
title = {Numerical and experimental investigations of diffusion absorption refrigeration systems for use with low temperature heat sources},
url = {http://hdl.handle.net/10044/1/62182},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - CPAPER
AB  - he diffusion absorption refrigeration (DAR) cycle is a technology of increasing interest thanks to its suitabilityfor providing cooling  from a thermal  energyinputin  a  range  of  applications.  Itcan  bedistinguished  from  other absorption refrigeration cycles by its employment of a thermally-driven bubble pump to circulate the working fluid, which gives it anability to operate entirely off-gridwithout an electricity input. In this work,we present results from an  experimentalcampaign  aimed  atcharacterisingthe  performance  of  aprototypeammonia-water-hydrogen DAR system with a nominal cooling capacity of 100 W,over a range of operating conditions, specifically with a view ofadaptingthe system for use in low-temperature applications. In the experiments, the heat input to the DAR generator is provided over a range of temperatures from175to215°Cby using electrical cartridge heaters. The system is charged to 22 bar, and the ammonia mass concentration of the working fluid mixture is 30%. The resulting coefficient  of  performance  (COP)  of  the  system  is  measured  in  the  range 0.12to 0.26. A  new methodology for the selection of optimal working-fluid mixtures using the state-of-the-art, statistical associating fluid theory (SAFT) approach implemented within the process modelling software gPROMS®is also presented. The experimental results will be used for futurevalidation of a thermodynamic model of the cycle. Finally,the performance of the system in  a solar application  is  investigated,  with a thermal inputprovided by  an array  of evacuated tube heat pipe solar collectors. The system pressure and condensation temperature are found to be key factors in determining the performance of solar-DAR systems.
AU  - Najjaran,Kheirabadi A
AU  - Harraz,AA
AU  - Freeman,J
AU  - Mac,Dowell N
AU  - Markides,CN
PB  - ECOS
PY  - 2018///
TI  - Numerical and experimental investigations of diffusion absorption refrigeration systems for use with low temperature heat sources
UR  - http://hdl.handle.net/10044/1/62182
ER  -
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