3 June 2010 Solar Air Conditioning 1
K. Gommed & G. GrossmanFaculty of Mechanical Engineering, Technion, I. I. T.
Haifa 32000, ISRAEL
"Solar Air Conditioning Based on Liquid Desiccant Open Absorption Cycle".
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Direct Utilization of Solar Heat to Perform Some of the Air Conditioning Tasks
Why Air Conditioning ?Air conditioners are big electric consumersAvailability of solar energy when air conditioning (cooling) is needed
Direct Vs. IndirectHigh efficiency (COP) Vs. low efficiency Example: Solar Power (thermal) Electric Power Cooling Power (thermal)
What Tasks & Benefits ?
The Objective
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Air Conditioning ??
• Temperature control
Sensible Heat Load
• Humidity control
Latent Heat Load
Conventional AC: Air is (over) cooled below dew-point,
Then the dry-air is reheated to supply conditions
�������� a Coupled AC-process - where w = w (T)
���� Complex control of T & w
���� Need Low Coil Temperature (below dew-point)
Hybrid AC: Air is first dried to optimal humidity level,
Using the Proposed Liquid Desiccant Open Absorption Cycle
to deal with Latent Heat Load by Solar
Then air is cooled to optimal convenient conditions
Using Conventional High Temperature Cooling Coil
to deal with Sensible Heat load Electrically
�������� an inherent Decoupled & optimized AC-process
Prior artPrior art
* O2 in , CO2 out
* Dust particles filtration
* Air-born microbes filtration
• Clean/Fresh air supply*
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European approach to A/C
• Quality central air conditioning
– Minimum air circulation
– Maximum dryness
– Independent control of humidity and temp
• Method of implementation
– Radiant cooling (chilled ceiling) to handle sensible load
– Deep dehumidification of make-up air and low-velocity distribution to handle latent load
It is different from common US practice…
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Liquid Desiccant Cooling System Diagram
Absorber
Solution Pump
M
C
Blower Fresh Air
Option "B" Diagram
Auxiliaryelectrical
heat pump
HX
Desorber
Solution Pump
H
M
Air-Air HX
Exhaust Air
Exhaust Air
Blower
Fresh Air
SupplyAir
Air-Air HX
Hybrid approach to A/C
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Typical Liquid Desiccant Dehumidification System
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0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
10:19:12 12:43:12 15:07:12 17:31:12 19:55:12
Time
Hu
mid
ity
Win Wout_1 Wout_2
Results – Humidity
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The New Dehumidification System
Ambient Air
Supply
Air
Absorber
Blower
Solution Pump
Cold-Water
Pump
Water/Solution H.X.
Cold Water
From Cooling
Tower
to Cooling
Tower
78
5 6
13
12
14
Air/Air H.X.
Ambient
Air
Exhaust
AirBlower
Solution Pump
Hot-Water
Pump
Water/Solution H.X.
Hot Water
From Storage
Tank
to Storage
Tank
3 4
12
FA15
11
GA 16
Desorber
Concentration Driven Mass
Exchanger
910
3 June 2010 Solar Air Conditioning 12
Reactor Assembly
ריאק טור . 1
ת ע לת כניס ת אוו יר. 2
מת א� למח לי� חו� . 4
מח לי� חו� . 5
ת ע לת יצי את אוו יר . 3
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Regenerator Reactor
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Regenerator & Dehumidifier
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Thank you