Post on 16-Apr-2017
Comparison of Solar Sorption Cooling Systems Using TRNSYS Software
Rebecca SelwynMarie-Esther GuillermDr Hind Saidani-Scott
Outline
•Traditional Refrigeration•Problems with Vapour Compression Cycles•Sorption Cycles
Introduction
•Aims•Context•System Layout•Comparisons
TRNSYS Simulation
•Results•Discussion
Conclusions
•Improving the SimulationNext Steps
Traditional Refrigeration• Vapour
compression cycle• High efficiency (COP
>3)
• Replace compressor with sorption cycle
Heat based compression instead of electric compressor
Condenser
Expansion Valve
Evaporator
Compressor
Qc
W
Qe
Vapour Compression vs. Sorption Cycles: Refrigerant
Traditional Refrigerants• Ozone depletion• Montreal Protocol to
eliminate use of traditional refrigerants
Need to find suitable replacement refrigerants
Sorption Refrigerants• Sorbent-refrigerant
working pair• Range of working pairs
give range of characteristics
Vapour Compression vs. Sorption Cycles: Compression
Sorption Generator• Pressure increased
through heat cycle• Requires low grade heat
input (>170°C), e.g. Solar thermal or waste industrial heat
Electric Compressor• Climate change• Kyoto protocol to reduce
greenhouse gas emissions
Need to find alternatives to traditional electric compressors
Outline
•Traditional Refrigeration•Problems with Vapour Compression Cycles•Sorption Cycles
Introduction
•Aims•Context•System Layout•Comparisons
TRNSYS Simulation
•Results•Discussion
Conclusions
•Improving the SimulationNext Steps
TRNSYS Simulation: Aims
Simulation of Sorption
Cooling Systems
Connect pre-defined
components together to model
simple system
Create adsorption chiller component
in Matlab
Use real weather data for heat
source
Compare adsorption and
absorption under identical
conditions
TRNSYS Simulation: Context
Malaysian weather dataHuman cooling:– Air conditioned office
environment: ‘Seated, light work, typing’
– PCs, lighting, windows
Food cooling:– Refrigerated storage– Heats of respiration of
fruit and veg.
2m
10m10m
TRNSYS Simulation: System Layout
Weather Data
Solar PanelSorption System
Cooling Load
TRNSYS Simulation: Comparisons
Cooling System• Absorption– LiBr-water
• Adsorption– Activated carbon-
methanol– Zeolite-methanol– Silica gel-water
Cooling Application• Human cooling (air
conditioning)• Food cooling
(refrigeration)
Outline
•Traditional Refrigeration•Problems with Vapour Compression Cycles•Sorption Cycles
Introduction
•Aims•Context•System Layout•Comparisons
TRNSYS Simulation
•Results•Discussion
Conclusions
•Improving the SimulationNext Steps
Results: Human Cooling
Sorbent volume (m3) COP0
0.10.20.30.40.50.60.70.80.9
Human Cooling
Zeolite-methanol Silica gel-water Activated carbon-methanol LiBr-water
Results: Food Cooling
Sorbent volume (m3) COP0
0.10.20.30.40.50.60.70.80.9
Food Cooling
Zeolite-methanol Silica gel-water Activated carbon-methanol LiBr-water
Discussion
• Ratio of COP to required adsorbent volume
• For freezing use activated carbon-methanol
Human cooling Food coolingZeolite-methanol 3.40 3.05Silica gel-water 3.35 4.30Activated carbon-methanol 2.84 3.33
Outline
•Traditional Refrigeration•Problems with Vapour Compression Cycles•Sorption Cycles
Introduction
•Aims•Context•System Layout•Comparisons
TRNSYS Simulation
•Results•Discussion
Conclusions
•Improving the SimulationNext Steps
Next Steps
Extending the simulation scope
Effect of non-equilibrium
conditions in sorption process
Effect of different climates
Ionic liquids as possible sorbents
Thank You
Any Questions?