شماره ركورد كنفرانس :
4567
عنوان مقاله :
Experimental Study of a Diffusion Absorption Refrigeration Unit at Different Charge-Pressures
Author/Authors :
Ahmad Najjaran Clean Energy Processes (CEP) Laboratory & Centre for Process Systems Engineering (CPSE) - Department of Chemical Engineering - Imperial College London, London SW7 2AZ, UK , Asmaa A. Harraz Clean Energy Processes (CEP) Laboratory & Centre for Process Systems Engineering (CPSE) - Department of Chemical Engineering - Imperial College London, London SW7 2AZ, UK , James Freeman Clean Energy Processes (CEP) Laboratory & Centre for Process Systems Engineering (CPSE) - Department of Chemical Engineering - Imperial College London, London SW7 2AZ, UK , Raymond Sacks Clean Energy Processes (CEP) Laboratory & Centre for Process Systems Engineering (CPSE) - Department of Chemical Engineering - Imperial College London, London SW7 2AZ, UK , Christos N Markides Clean Energy Processes (CEP) Laboratory & Centre for Process Systems Engineering (CPSE) - Department of Chemical Engineering - Imperial College London, London SW7 2AZ, UK
كليدواژه :
cooling power , COP , DAR , solar cooling , pressure
عنوان كنفرانس :
ششمين كنفرانس ملي ساليانه انرژي پاك
چكيده لاتين :
Diffusion absorption refrigeration (DAR) is a cooling technology without moving
parts or the need for electrical input and can be driven purely by thermal energy,
such as renewable- or waste-heat. In this work, the performance of an ammoniawater-
hydrogen DAR unit was investigated experimentally at three different chargepressures
(15 bar, 18 bar, and 21 bar), two cooling temperatures (5 °C and 23 °C),
and an ammonia concentration of 30%. The thermal power was supplied by an
electrical heat-source to the generator and varied between 150 W and 700 W. The
highest coefficient of performance (COP) was observed at a charge pressure of
15 bar, and was found to be 0.25 for a cooling temperature of 5 °C and 0.31 for a
cooling temperature of 23 °C. In part-load operation, when the generator power was
below 250 W, an increase in the charge pressure reduced both the cooling power and
the COP. For a generator power between 250 W and 500 W, an increase in the charge
pressure reduced the cooling power for a cooling temperature of 23 °C, but had no
effect on the system’s cooling power for a cooling temperature of 5 °C, while no
effect was observed on the COP. For a generator power above 500 W, an increase in
charge pressure increased both the cooling power and the COP. Finally, a solarpowered
DAR prototype, developed based on the above findings, was also tested.
The diurnal performance of this unit is presented, showing the potential for activating
DAR systems using low-cost solar heat-pipes.