2. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Contents
Introduction
Solar Desiccant Evaporative Cooling System
Solar thermal tile system
NovelAire desiccant evaporative cooling systems
Hybrid Solar Desiccant Evaporative Cooling System
Advantages
Application
Conclusion
References
[2]
3. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Introduction
Using excess summer heat from solar collectors to drive desiccant cooling systems .
.This technology is use to improves system efficiency.
These technologies convert primary energy into heating or cooling with COP’s
between 2 and 5.
Here three technologies include solar thermal heating, evaporative cooling, and
desiccant drying.
[3]
4. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Desiccant
A desiccant material naturally attracts moisture from gases and liquid. The material
becomes as moisture by collecting the moisture on the surface.
solid desiccant include silica gel, activated alumina, lithium chlorate salt and
molecular sieves.
Liquid desiccant include lithium chlorate, lithium bromide, calcium chloride and
triethylene glycol solution.
the desiccant can be regenerated by the thermal energy.
[4]
5. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Solar desiccant evaporative cooling system
With the solar, desiccant and evaporative cooling industries each targeting there has
been little joint development.
Solar thermal work is concentrated on flat plate water heating systems, which are
generally not cost effective for space heating applications.
It can provide a significant portion of the space heating, hot water heating and space
cooling needs of residential and commercial consumers.
[5]
6. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Solar thermal tile system
The solar thermal tile system is a mid temperature air heating collector.
It is design such way that The collector was at a slope of 20 degrees from the
horizontal, an angle that would roughly equal a roof pitch of 4 in 12. The sun was at
an angle of 37 degrees below perpendicular to the collector.
This system support desiccant regeneration with the large quantities of excess
summer heat. Because the system is an air heating system, it is well suited for direct
delivery of solar heated air for desiccant regeneration
[6]
10. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
The cycle uses excess air passing through the desiccant wheel to create excess dry air.
After leaving the desiccant wheel (B), the hot dry air is cooled by heat exchanger (c).
The warm dry air is then split into two air streams.
The first stream (C-CX-CY) supports an indirect evaporative cooling of the second
stream (C-C’).
This cools the second stream without adding any humidity at state point C’.
The final direct evaporative cooling stage from point C’ to D can adjust the
temperature and humidity to any point on the line CD.
The regeneration side of the NovelAire cycle begins by recovering heat via the
exhaust side of the heat exchange.
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12. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Here the Psychometric Representation Of cycle along line A,B,C & 2 wheel limit
line.
The regeneration cycle is shown along E, G, I and J.
2 wheel limit line” in Figure represents the temperature and humidity possible by
evaporative cooling.
The line C’ D represents one such cooler drier condition.
E is original state point.
[12]
13. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Hybrid Desiccant Evaporative Cooling System
This system includes following system
1) A solar thermal tile system.
2) A NovelAire desiccant evaporative cooling systems.
3) One additional evaporative cooling system between state points E and F,
4) A hot water heating system using the waste heat from the desiccant
regeneration at state point J.
[13]
15. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
In hybrid desiccant does not use recovered heat from the heat exchanger for
desiccant regeneration.
Instead of this tile roof is used as the primary heating source for desiccant
regeneration.
Supplemental gas heat is used to desiccant regeneration during cloudy days.
The hot water heating systems uses waste heat from the desiccant regeneration to
heat water via an air-to-water heat exchanger.
[15]
16. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Integrated SOLAR-DES-EVAP psychometrics
The increased cooling for the heat exchanger by the building air can be seen from
the change in state point temperature from E to F.
The first stage cooling of the heat exchanger from A to L can also
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17. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Advantage
Direct indirect and evaporative cooling system is less expensive than vapour
compression system.
It decreases the electrical demand.
Hybrid system can provide year round comfort.
removes moisture from the air without the use of ozone-depleting compounds.
reduce initial capital investment.
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20. NalandaInstituteOfTechnology
Technical Seminar Presentation-2013
Presented By: Abhinav Anand 1001297081
Conclusion
The hybrid cycle can use less energy than a normal vapour compression unit.
Considering a case of high effectiveness hybrid cycle meeting the high sensible
load.
The average energy saving in the summer and winter conditions are considered is
24%.
The saving in resource energy are at least equal to and typically higher than this
(27% and40% respectively)
saving is depending on the size of the solar energy system associated with the
hybrid cycle.
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