SUMMARY
The range of COP for the Solar VAdRS is 0.2 - 0.7. The development of adsorption system for refrigeration is promising. An overall thermodynamics-based comparison of sorption systems shows that the performance of adsorption systems depends highly on both the adsorption pairs and processes. The technology continues to develop and the cost of producing power with solar thermal adsorption refrigeration is falling. If the costs of fossil fuels, transportation, energy conversion, electricity transmission and system maintenance are taken into account, the cost of energy produced by solar thermal adsorption systems would be much lower than that for conventional refrigeration systems.
The intermittent system has its simplicity and cost effectiveness. However, the main disadvantages such as long adsorption/desorption time have become obstacles for commercial production of the system. Hence, to compete with conventional vapor compression technologies, more efforts should be made in enhancing the COP and SCP. The environmental benefits of this technology and its non-dependence on conventional energy sources makes it highly attractive for further developments and a potential alternative to conventional systems in the future. The future of solar refrigeration and air conditioning seems to be a very good proposition and no doubt will find its place in future industrial applications. The major limiting factor at present is the shape of energy so as to make it available whenever it is required, for example at nights and extended cloudy days when we cannot attain a high enough temperature.
Structural Analysis and Design of Foundations: A Comprehensive Handbook for S...
“PRESENTATION ON SOLAR ASSISTED VAPOUR ADSORPTION REFRIGERATION SYSTEM”
1. UNDER THE GUIDANCE OF
PROF. R. R. KATWATE
PRESENTED BY
Mr. B. A. WADEKAR (8141)
A SEMINAR-II ON
“SOLAR ASSISTED VAPOUR ADSORPTION
REFRIGERATION SYSTEM”
2. • Introduction
• Classification of Solar Refrigeration Cycles
• Literature Review
• Methodology
• Thermodynamic Cycle of Solar VAdRS
• Components of VAdRS
• Types of Adsorption Processes And Adsorbents
• Working Pairs
• Performance of Solar VAdRS
• Summary
• Future Prospects
• References
CONTENTS
3. CURRENT TRENDS IN COOLING SYSTEM
Minimum Energy Consumption
Efficient Utilization of Non-renewable Natural Resources
Minimal Negative Impacts on Environment & Ecosystems
Montreal Protocol and
Kyoto Protocol
Maximum Quality of Indoor Environment
4. INTRODUCTION
Basics of VCC & VAC
Introduction to Solar Refrigeration
Need of Solar Energy Driven Refrigeration
Classification of Solar Refrigeration Cycle
Figure- Classification of Solar Refrigeration Cycle
5. LITERATURE REVIEW
S. N. Author Name Year Summary of Work
1
Ioan Sarbu,
Calin Sebarchievici
2015
- more suitable than VCC
- next several years will be decisive
2 M.S. Fernandes et al 2014
- intermittent Solar VAdRS
- Working Pair: AC-Methanol
- Solar COP 10% and 20%
3 Solmus et. al. 2012 - internal mass transfer resistances are focused
4 Tashtoush et. al. 2011
- many cylindrical tubes were used
- COP=0.616
5
Hamdeh and Al-
Muhtaseb
2010
- Minimum Te= 9°C & Tamb=26°C
- COP is found to be 0.688
6
Anyanwu and
Ogueke
2005
- Performance Analysis of VAdRS
- best COP’s (Solar) 0.16-0.3.
7
Rifat Ara Rouf et.
al.
2013
- Performance of an adsorption chiller with Heat
Stored in reserve tank
- Maximum COP=0.65 for direct solar coupling
while it is 0.6 for the heat storage
6. PRINCIPLE OF ADSORPTION REFRIGERATION
• Refrigerant
• Adsorbent
• Adsorption
• Desorption
a b
cd
7. BASIC SOLAR VAdRS
Figure- Simple Solar Adsorption Refrigeration System
(a) Schematic, intermittent cycle (b) constructive, continuous cycle
8. Processes Involved,
• Process (a-b)-Isosteric desorption
• Process (b-c)-Isobaric desorption
• Process (c-d)-Isosteric adsorption
• Process (d-a)-Isobaric adsorption
THERMODYNAMIC CYCLE
Figure- Schematic diagram Figure- Thermodynamic Cycle
Isosteric Process- Constant
Concentration Process
(Achieved by isolating the bed and
evaporator)
9. COMPONENTS
1. Solar Collector
2. Generator/Adsorber
3. Condenser
4. Condensate receiver tank
5. Expansion device
6. Evaporator
Figure- Components of VAdS
10. TYPES OF ADSORPTION PROCESSES & ADSORBENTS
1. PHYSICALADSORPTION
Physical Adsorbents
-Activated Carbon and Activated Carbon Fibre
-Silica Gel
-Zeolite
2. CHEMICALADSORPTION
Chemical Adsorbents
-Metal Chlorides
-Salt and Metal Hydrides
-Metal Oxides
3. COMPOSITE ADSORPTION
Composite Adsorbents
11. WORKING PAIRS
1. Activated Carbon(AC) fibre and Methanol
- most commonly used working pair
- large adsorption quantity
- lower adsorption heat
- suitable at around 100°C & not suitable above 120°C
- maximum value of X = 45% & disadvantage: requires vacuum inside the system
2. Activated Carbon(AC) fibre and Ammonia
- same adsorption heat
- suitable at and above 200°C
- small X (0.29 kg/kg) is compensated by large value of latent heat of NH3
- disadvantage: toxicity and pungent odour of ammonia
3. Silica Gel and Water
- Used where ability of water to act as a refrigerant
- Desorption temperature is very low, it can be up to 50°C
- disadvantage: Can not operate below 0°C & limited value of X=0.2 kg/kg
4. Zeolite and Water
- utilized in dehumidification & cooling, zeolites are stable at high temp. (>200°C)
- lower COP below 150°C and higher COP above 200°C, X=0.261kg/kg
5. Calcium Chloride and Ammonia
- most widely used chemical adsorption working pair
- adsorption quantity is higher 1 kg/kg, disadvantage: problem of swelling
12. PERFORMANCE
Figure- Experimental Setup (Schematic)Figure- Photographic view of Solar VAdRS
System Preliminary Setup
Procedure
-Heating and Desorption
-Cooling and Adsorption
13. The Carnot COP is given by,
The Solar COP is given by,
The Specific Cooling Power is given by,
EQUATIONS USED
14. Effect of Condenser Temperature on COP
Figure- Plot of COP vs Tcond, Qevap=1000 kJ/hr
15. Effect of Condenser Temperature on Carnot COP
Figure- Plot of COPCarnot vs Tcond, Qevap=1000 kJ/hr
16. Effect of Evaporator Temperature on COP
Figure- Plot of COP vs Tevap, Qevap=1000 kJ/hr
17. Effect of Evaporator Temperature on Carnot COP
Figure- Plot of COPCarnot vs Tevap, Qevap=1000 kJ/hr
18. Effect of Generation Temperature on COP
Figure- Plot of COP vs Tgen, Qevap=1000 kJ/hr
19. Effect of Generation Temperature on Carnot COP
Figure- Plot of COPCarnot vs Tgen, Qevap=1000 kJ/hr
20. MERITS & DEMERITS
Merits
1. Works on Renewable Energy Source
2. Method of Compression of the Refrigerant
3. Power Consumption Devices
4. Type of Energy Required
5. Running Cost
6. Foundations Required and Noise
7. Maintenance
8. Type of Refrigerant used and its Cost
9. Leakage of the Refrigerant
10. Greenhouse Effect
Demerits
1. Capital Cost
2. Corrosive Nature Adsorbents
3. Low Working Pressures
4. COP
5. Higher Heat Rejection
21. SUMMARY
• The range of COP for the Solar VAdRS is 0.2 - 0.7
• System works on renewable energy source.
• Performance of adsorption systems depends highly on both the
adsorption pairs and processes.
• Long adsorption/desorption time.
• To compete with conventional VCC efforts should be made to
increase COP and SCP.
• Limiting factor, shape of energy, i.e. at nights and extended
cloudy days.
• Recent advancements are in thermal energy storage
22. REFERENCES
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1999a
2. Ioan Sarbu and Calin Sebarchievici, “General review of solar-powered closed sorption refrigeration systems”, Energy Conversion and
Management 105 (2015) 403–422
3. M.S. Fernandes, G.J.V.N.Brites, J.J.Costa, A.R.Gaspar, V.A.F.Costa, “Review and future trends of solar adsorption refrigeration systems”,
Renewable and Sustainable Energy Reviews 39 (2014) 102–123.
4. Li M. and Wang R. Z., “Heat and mass transfer in a flat plate solar solid adsorption refrigeration ice maker”, Renewable Energy, Vol. 28,
no.4, pp. 613, 2003.
5. Anyanwu E. E., “Review of solid adsorption solar refrigeration I: An overview of refrigeration cycle”, Energy Conversion and
Management, vol.44, no.2, pp. 301-312, 2003.
6. Anyanwu E. E., “Review of solid adsorption solar refrigeration II: An overview of the principles and theory”, Energy Conversion and
Management, vol. 45, pp. 1279-1295, 2004.
7. Anyanwu, E. E., and Ogueke, N. V., “Thermodynamic design procedure for solid adsorption solar refrigerator”, Renewable Energy, vol.30,
no.1, pp. 81-96, 2005.
8. Hamdeh N. H. A. and Al-Muhtaseb M. A., “Optimization of Solar Adsorption Refrigeration System Using Experimental and Statistical
Techniques”, Energy Conversion and Management, vol.51, pp.1610-1615, 2010.
9. Tashtoush G.M., Al-Ata M., and Al-Khazali A., “Solar adsorption refrigeration (SAR) system modelling”, Energy Efficiency, vol.4, no.2,
pp. 247-56, 2011.
10. Solmus. I.‚ Rees D. A. S., Yamal C., Baker D. and Kaftanoglu B., “Numerical investigation of coupled heat and mass transfer inside the
adsorbent bed of an adsorption cooling unit”, International Journal of Refrigeration, vol. 35, pp. 652-662, 2012.
11. Buchter F., Dind P., Hilbrand C., and Pons M., “A new solar powered adsorption refrigerator with high performance”, Solar Energy, vol.77,
pp. 311-318. 2004.
12. Boubakri, A., Guillemiont, J. J., and Meunier, F., “Adsorptive solar powered icemaker: experiments and model”, Solar Energy, vol.69,
no.3, pp. 249-263, 2000.
13. Boubakri A.,“Performance of an adsorptive solar ice maker operating with a single double function heat exchanger
(evaporator/condenser)”, Renewable Energy, vol.31. pp 1799–812. 2006.
14. Buchter F., Dind P., Pons M., “An experimental solar-powered adsorptive refrigerator tested in Burkina-Faso”, International Journal of
Refrigeration, vol.26, pp.79– 86, 2003
15. Buchter F., Dind P., Hilbrand C., and Pons M., “A new solar powered adsorption refrigerator with high performance”, Solar Energy, vol.77,
pp. 311-318. 2004.