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Project Title
Evaluation of the use of Solar Flat Plate
Collectors for Solar Thermal Refrigeration
Student Name-Dinesh Kha...
Contents
• INTRODUCTION
• PROJECT OBJECTIVE
• LITERATURE SURVEY
• COP CALCULATIONS FOR THE STVARS
• DESIGN OF STVARS
• FAB...
1.Introduction
1.1 Refrigeration
• Refrigeration is the thermodynamic process to
produce cooling effect below the atmosphe...
• Refrigeration may be defined as the process of
achieving and maintaining a temperature
below that of the surroundings, t...
1.2 Types of Vapour Refrigeration
Cycle
1. Compression Refrigeration Cycle.
• The most popular and widely used system in
r...
1.3 Problems with VCRS
• The major share of electricity that is being
supplied with a refrigerator is consumed by the
comp...
2. Absorption Refrigeration Cycle.
• The vapour absorption system replaces the
compressor with a generator absorber set.
•...
Fig.2 VARS
1.4 Solar Energy for Cooling
• Solar energy is the most readily available source
among renewable energy sources.
• With th...
1.4.1 PV Operated Refrigeration Cycle
• PV involve the direct conversion of solar
radiation to direct current (DC) electri...
Fig.3 PV operated Refrigeration
1.4.2 Solar Thermal Refrigeration
• Solar thermal systems use solar heat rather than
solar electricity to produce refriger...
Fig.4 Solar thermal NH3-H2O VARS
2.Project Objective
• The main objective of this project work is to
design and fabricate a solar thermal vapour
absorption...
3.Literature Survey
3.1 VCR
Sl.No Author Title Year
1 Eng. Naser R. M. AL-
Ajmi
Coefficient of Performance Enhancement of
...
3.2 PV operated refrigeration
Sl.No Author Title Year
1 Navneet Kumar
Sharma, Hari Singh
,Madan Kumar
Sharma and B. L.
Gup...
3.3 Solar Thermal VARS
Sl.No. Author Title Year
1 D.S. Kima and C.A.
Infante Ferreirab
Solar refrigeration options – a sta...
Sl.No Author Title Year
6 Dr. Adel et al. The use of Direct Solar Energy in
Absorption Refrigeration Employing NH3-
H2O Sy...
Literature survey
Sl.No Author Title Year
12 V.K.Bajpai Design of Solar Powered Vapour Absorption
System
2012
13 Sameh Als...
Observation from Literature Review
• Replacing the electrical energy with solar
energy will reduce the consumption of high...
• Thermal cooling technology is preferred to PV-
based cooling systems because it can utilize
more incident sunlight than ...
• Aqua-ammonia VAR system integrated with solar
collector that can be used small and large scale
cooling applications.
• T...
4. COP Calculations for the STVARS
• The Coefficient of performance (COP) of the
system as theoretically known is given by...
• Let m = mass flow rate of refrigerant, kg/s
• Q=Heat
• Heat absorbed at generator Qg= m (h3-h2)
• COP=3.516/m (h3-h2)
• ...
• At Pump (Aqua ammonia liquid state), Pressure = 7 bar, X2= 0.55
Temperature = 40°C, h2= 130 kj/kg
• At Evacuated tube (A...
5. Design of STVARS
The design of solar thermal refrigeration designed considering
various criteria and assumptions. The d...
Fig.6 STVARS 3D model
5.1 Absorber Tank
• Absorber tank is designed according the volume of
evacuated tube collectors (6ltrs) and specification ...
Fig.7 Designed Absorber tank
WEAK SOLUTION IN
VAPOUR IN
TO PUMP
5.2 Pump
• Pump is used to pump the ammonia hydroxide
from the absorber to the generator tank attached
to the evacuated tu...
5.3 Generator Tank
Generator tank is designed to maintain steady
state level for continuous discharge and act as
accumulat...
• All dimensions in cm
Fig.8 Generator tank
OUTLET
INLET
5.4 Evacuated Tubes
• To get higher temperature to vaporize ammonia
refrigerant, Evacuated tube collectors are used
instea...
All dimensions in cm
Fig.9 Design of Evacuated tube collectors
5.5 Rectifier Tank
• Rectifier tank is designed according to the volume of
absorber, evacuated tube collectors and cooling...
Fig.10 Design of Rectifier tank
WEAK SOLUTION OUT
VAPOUR OUT
5.6 Condenser
• Condenser is selected to withstand the
temperature and pressure and that amount of
heat to be removed from...
5.7 Capillary tube
• Capillary tube has very small internal diameter
and it is of very long in length. It is coiled to
sev...
5.8 Evaporator
• In evaporator low temperature, low pressure
refrigerant extract the heat from the cabin or system
which w...
6. Fabrication of STVARS
The solar vapour absorption refrigeration system is
fabricated with reference to the designed det...
• The fabrication process is done in Gajanana
machine works, Bunder Mangaluru
Fig.11 Fabricated STVARS
6.1 Fabricated Absorber Tank
• Absorber tank is fabricated with reference to
the designed details of capacity 20 litres. T...
6.2 Diaphragm Pump
• Pump is fixed between absorber tank and
generator tank using union coupling parts of ¾
inch stainless...
6.3 Generator Tank with Evacuated Tubes
• Tank is fabricated with reference to designed model
of generator tank that can a...
6.4 Fabricated Rectifier Tank
• Rectifier tank is made up of mild steel of capacity
6.28 litres is fabricated according to...
6.5 Wire and Tube Condenser
• The condenser is selected depending upon the area of the
condenser that able to give require...
6.6 Copper Capillary Tube
• A capillary tube is selected by its length and
diameter for capacity one ton refrigeration
and...
6.7 Evaporator tank
• Evaporator tank is fabricated according to the
design details of capacity 9.42 litres, material used...
6.8 Instrumentations
• Two pressures gauges of 150psi are installed, one
pressure gauge is threaded in 20mm diameter
stain...
6.9 Modification
• Modification is done after testing of fabricated
system.
Fig.20 Modified System
6.10 Ammonium Hydroxide as Working fluid
• Ammonium hydroxide (NH3+H2O) solution (13 litres) is
filled in absorber tank wh...
7.Optimization of Design
• The fabricated system was found to be not
holding the system pressure in evacuated tube
collect...
7.1 Stainless tube Collectors
• Maximum temperature of 65 to 70°C can obtain by using
stainless tube collector.
• Specific...
• All dimensions in mm
Fig.22 Designed stainless tube collector
7.2 Insulation
• Insulation is done to rectifier tank and the
stainless steel pipe connections to maintain the
required te...
7.3 Finned tube Condenser
• Finned tube condenser is a type of natural convection heat
exchanger (condenser), it is sugges...
• Assuming heat transfer co-efficient, h =10W/(m^2×K)
• The heat flow rate is the mass flow rate times the latent heat of
...
7.4 Optimized Instrumentations
• For calculating COP of the system, temperature and
pressure of refrigerant flow is requir...
8.Result and Discussion
• Literature review is done on different type refrigeration system mostly based on solar
thermal r...
9. Conclusion
• The new solar thermal refrigeration has been introduced with
ammonia as working fluid Evacuated tubes main...
10.References
• [01] Prof. Dr. Adel A. Al-Hemiri and Ahmed Deaa Nasiaf, ‘‘The use of direct Solar energy
in Absorption Ref...
References
• [8] Subi Salim and Rajesh V. R., ‘‘Thermodynamic analysis of Aqua-Ammonia based miniaturized vapour
Absorptio...
THANK YOU
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Solar Flat Plate Collectors for Solar Thermal Refrigeration

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3rd year project done with collaboration of a M.tech seniour of NMAM institute of technology college.

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Solar Flat Plate Collectors for Solar Thermal Refrigeration

  1. 1. Project Title Evaluation of the use of Solar Flat Plate Collectors for Solar Thermal Refrigeration Student Name-Dinesh Khanna Reg. No.-4NM15MES03 M.Tech in Energy Systems Engineering. NMAMIT, Nitte. Project guide: Mr. Aneesh Jose(Asst. Professor) NMAMIT, Nitte.
  2. 2. Contents • INTRODUCTION • PROJECT OBJECTIVE • LITERATURE SURVEY • COP CALCULATIONS FOR THE STVARS • DESIGN OF STVARS • FABRICATION OF STVARS • OPTIMIZATION OF DESIGN • RESULT AND DISCUSSION • CONCLUSIONS • REFERENCES
  3. 3. 1.Introduction 1.1 Refrigeration • Refrigeration is the thermodynamic process to produce cooling effect below the atmospheric temperature.
  4. 4. • Refrigeration may be defined as the process of achieving and maintaining a temperature below that of the surroundings, the aim being to cool some product or space to the required temperature. • Refrigeration has many applications, including household refrigerators, industrial freezers and air conditioning . • The performance of refrigeration system is evaluated in terms in Coefficient of Performance (COP) .
  5. 5. 1.2 Types of Vapour Refrigeration Cycle 1. Compression Refrigeration Cycle. • The most popular and widely used system in refrigeration and air conditioning both for industrial and domestic applications. Fig.1 VCR
  6. 6. 1.3 Problems with VCRS • The major share of electricity that is being supplied with a refrigerator is consumed by the compressor. • Since a refrigerator is operated 24 hours a day, there is considerable energy consumption. • The refrigerants used in these refrigerators are environmentally hazardous. • The Freon gases that are popularly used in compression refrigerators are ozone depleting and add on to global warming. • The performance of vapour compressing system is very poor at partial load.
  7. 7. 2. Absorption Refrigeration Cycle. • The vapour absorption system replaces the compressor with a generator absorber set. • The first NH3-H2O absorption refrigeration system was developed by Ferdinand Carre in 1860. • Combination of refrigerant and absorbent. • Most widely use NH3-H2O & LiBr-H2O. • In addition, the VARS use natural substances which do not cause ozone depletion as working fluids
  8. 8. Fig.2 VARS
  9. 9. 1.4 Solar Energy for Cooling • Solar energy is the most readily available source among renewable energy sources. • With the use of solar energy, usage of conventional energy sources and its peak demand will be reduced. • Utilization of solar energy for cooling was an attractive one, as the demand for cooling is some what in tune with the availability of heat. • The VARS being a heat operated system, is especially suited for refrigeration using solar energy.
  10. 10. 1.4.1 PV Operated Refrigeration Cycle • PV involve the direct conversion of solar radiation to direct current (DC) electricity using semiconducting materials. • DC electrical power that can be either used to operate a dc motor, which is coupled to the compressor • Inverter can be used to convert this DC current to AC current for running the compressor of a vapour compression refrigeration system.
  11. 11. Fig.3 PV operated Refrigeration
  12. 12. 1.4.2 Solar Thermal Refrigeration • Solar thermal systems use solar heat rather than solar electricity to produce refrigeration effect. • The thermal component of solar energy is taken up the working fluids in solar collector. • The heat energy will be supplied to generator unit that has a strong solution of refrigerant- absorbent mixture, wherein the concentration of refrigerant is high. • This heat energy heats up the mixture and the mixture should be chosen in such that, the refrigerant has a lower boiling point than the absorbent, so the refrigerant boils and gets converted to vapour phase.
  13. 13. Fig.4 Solar thermal NH3-H2O VARS
  14. 14. 2.Project Objective • The main objective of this project work is to design and fabricate a solar thermal vapour absorption system using ammonia as refrigerant and water as absorbent. • A solar flat plate collector will be used, that is capable of providing the thermal energy required to operate vapour absorption refrigeration unit. • A detailed analysis on solar radiation, collector area has to be done. After which the vapour absorption system is to be designed and fabricated. • This new solar thermal refrigeration system should prove better than PV refrigeration system.
  15. 15. 3.Literature Survey 3.1 VCR Sl.No Author Title Year 1 Eng. Naser R. M. AL- Ajmi Coefficient of Performance Enhancement of Refrigeration Cycles 2015 2 M. Krishna Prasanna & P. S. Kishore Enhancement of COP in Vapour Compression Refrigeration System 2014 3 Shoyab hussan Improve the cop of Vapour compression cycle with change in Evaporator and Condenser pressure 2015 4 F. Memet A Performance Analysis on a Vapour Compression Refrigeration System Generated by the Replacement of R134a 2014 5 Dr. A.C. Tiwari and Shyam kumar Barode Performance Analysis of Vapour Compression Refrigeration Systems Using Hydrofluorocarbon Refrigerants 2012
  16. 16. 3.2 PV operated refrigeration Sl.No Author Title Year 1 Navneet Kumar Sharma, Hari Singh ,Madan Kumar Sharma and B. L. Gupta Performance Analysis of Vapour Compression and Vapour Absorption Refrigeration Units Working on Photovoltaic Power Supply 2016 2 S. R. Kalbande and Sneha Deshmukh Photovoltaic Based Vapour Compression Refrigeration System for Vaccine Preservation 2015 3 Armand Noël Ngueche Chedop, Noël Djongyang and Zaatri Abdelouahab Modelling of the Performance of a Solar Electric-Vapour Compression Refrigeration System in Dry Tropical Regions 2012 4 Kapil K. Samar, S. Kothari and S. Jindal Thermodynamic and economic analysis of solar photovoltaic operated vapour compressor refrigeration system 2014 5 Mehmet Azmi Aktacir Experimental study of a multi-purpose PV- refrigerator system 2011
  17. 17. 3.3 Solar Thermal VARS Sl.No. Author Title Year 1 D.S. Kima and C.A. Infante Ferreirab Solar refrigeration options – a state- of-the-art review 2008 2 Preethu Johnson and K. B. Javare Gowda Fabrication of Solar of Thermal Vapour Asorption Refrigeration System 2015 3 Subi Salim and Rajesh V Thermodynamic Analysis of Aqua- Ammonia Based Miniaturized Vapor Asorption Refrigeration System Utilizing Solar Thermal Energy 2016 4 Narale Pravin et al. Vapour Absorption Refrigeration System by using Solar Energy 2016 5 Anadi Mondal et al. Design & Construction of a Solar Driven Ammonia Absorption Refrigeration System 2015
  18. 18. Sl.No Author Title Year 6 Dr. Adel et al. The use of Direct Solar Energy in Absorption Refrigeration Employing NH3- H2O System 2010 7 Jasim Abdulateef et al. Experimental Investigation on Solar Absorption Refrigeration System in Malaysia 2009 8 Rahul Yadav and Mohini Sharma Analytical Study of Ammonia –Water (NH3-H2O) Vapor Absorption Refrigeration System Based On Solar Energy 2016 9 K.V.N. Srinivasa Rao Low Cost Solar Cooling System 2013 10 Moreno-Quintanar et al. Development of a solar intermittent refrigeration system for ice production 2011 11 Abhishek Sinha and S.R Karale A review on Solar Powered Refrigeration and the Various Cooling Thermal Energy Storage (CTES) Systems 2013
  19. 19. Literature survey Sl.No Author Title Year 12 V.K.Bajpai Design of Solar Powered Vapour Absorption System 2012 13 Sameh Alsaqoor & S. AlQdah Performance of a Refrigeration Absorption Cycle Driven by Different Power Sources 2014 14 O. Babayigit et al. Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey 2013 15 Dillip Kumar and Abhijit Padhiary Thermodynamic Performance Analysis of a Solar Vapour Absorption Refrigeration System 2015 16 K Karthik Design, Fabrication and Analysis of Solar Vapour Absorption Refrigeration System 2014 17 N.D. Hingawe and R.M. Warkhedkar Design and Analysis of Solar Electrolux Vapour Absorption Refrigeration System 2015 18 K.R. Ullah et al. A review of solar thermal refrigeration and cooling methods 2013
  20. 20. Observation from Literature Review • Replacing the electrical energy with solar energy will reduce the consumption of high grade electrical energy. • Also the replacement of compression system with absorption system eliminates the energy consumption by compressors. • The overall system energy efficiency of PV operated refrigerator was found low because of energy conversion efficiency and exergy efficiency of the photovoltaic system was low.
  21. 21. • Thermal cooling technology is preferred to PV- based cooling systems because it can utilize more incident sunlight than a PV system. • Evacuated collectors have less heat loss and perform better at high temperatures. • Solar thermal Vapour absorption refrigeration technology has great potential to offer economical and innovative solutions to various refrigeration requirements. • Using ammonia as refrigerant in VARS has many advantages.
  22. 22. • Aqua-ammonia VAR system integrated with solar collector that can be used small and large scale cooling applications. • The COP depends primarily on the temperatures of the evaporator and the condenser. Also depends on Refrigerant and the model of generator used in VARS. • The detailed study of these papers gave a good idea about solar thermal vapour absorption system. • It was observed that the accumulation of ammonia, solar collector efficiency, clearness of sky played great factor for overall efficiency.
  23. 23. 4. COP Calculations for the STVARS • The Coefficient of performance (COP) of the system as theoretically known is given by • COP= Heat Absorbed in the Evaporator / (Work done by pump +Heat Supplied in the evacuated tube ) or COP =Qe/(Qg+Wp). • Negelecting pump work, Theoretical COP = Qe/Qg • Assumed values as follows. High pressure = 7 bar Generator temperature (max) = 110°C Evaporator temperature (max) = -5°C Qe= 1TR = 3.516 KW (Theoretical valve)
  24. 24. • Let m = mass flow rate of refrigerant, kg/s • Q=Heat • Heat absorbed at generator Qg= m (h3-h2) • COP=3.516/m (h3-h2) • Mass Concentrations: X1 = X2 = 0.55 X3=X5= X6 = X7= X8 = 1 X4 = 0.42 Figure 5 Circuit of STVARS
  25. 25. • At Pump (Aqua ammonia liquid state), Pressure = 7 bar, X2= 0.55 Temperature = 40°C, h2= 130 kj/kg • At Evacuated tube (Ammonia vapour state), X3=1 and temperature =110°C Pressure =7 bar, h3= 1716.4 kj/kg • At Evaporator, taking concentration X7=1 and temperature = -5°C, Pressure =3 bar Applying the Energy balance • Qe = Refrigerating effect =3.516kW = m (h8 – h7) • = m× (1461.56-176.9) • m=3.788/ (1461.56-176.9) = 2.94×10^-3 kg/s • m =2.94×10^-3 kg/s = mass flow rate of refrigerant. • Now circulation ratio, λ= X4/(X1-X4) = 3.23 • Strong solution, m1=m2= λ× m= 9.49×10^-3 kg/s • Weak solution, m4=(1+ λ)m= 12.43×10^-3 kg/s • So, Qg= m(h3-h2)= 2.94×10^-3 (1716.4-130) =4.66 kj/sec = 4.66 KW • Theoretical COP=3.516/4.66 = 0.75 Statement: For such a design circuit the refrigeration system produce a cooling capacity of COP 0.75 which a good value for applications such as air conditioning where the temperature is not much of concern.
  26. 26. 5. Design of STVARS The design of solar thermal refrigeration designed considering various criteria and assumptions. The design is done to get the refrigeration capacity of 1 ton with required COP. The calculated COP of the system is 0.75.Design depends on the individual components used in the system. Following are the individual components used in STVARS are as follows. • Absorber tank • Pump • PV panel • Generator tank • Evacuated Tubes • Rectifier tank • Condenser • Capillary tube • Evaporator tank
  27. 27. Fig.6 STVARS 3D model
  28. 28. 5.1 Absorber Tank • Absorber tank is designed according the volume of evacuated tube collectors (6ltrs) and specification of the pump (5ltrs/min). Specifications: • Type: cylindrical tank • Material used: Mild Steel • Refrigerant= R717 (Ammonia) • Absorber = Water • Inner diameter of the tank = 260mm • Outer diameter of the tank = 263mm • Length of the tank = 370mm • Total volume of the tank = V = π r^2 h= π×(0.153m)^2×0.4m= 0.02m^3= 20.10 litres • Volume of ammonia water solution used= V = π r^2 h = π×(0.13m)^2×0.3m= 16 litres
  29. 29. Fig.7 Designed Absorber tank WEAK SOLUTION IN VAPOUR IN TO PUMP
  30. 30. 5.2 Pump • Pump is used to pump the ammonia hydroxide from the absorber to the generator tank attached to the evacuated tube. It is used according to the maximum pressure rate required and also maintain adequate discharge flow rate at the refrigerant. • Specifications: • Type: Auto Diaphragm DC pump • 0.08 Hp = 60 W • Pump flow rate = 5 ltrs/min • Rated pressure = max 8bar • Dimensions: 165×95×60mm
  31. 31. 5.3 Generator Tank Generator tank is designed to maintain steady state level for continuous discharge and act as accumulator above the evacuated tube. Figure 8 shows design of a generator tank . • Specifications: • Type: Cylindrical tank • Inner Diameter= 100mm • Thickness = 2mm • Length = 300mm • Volume=πr^2h=π×(50)^2×300= 2.3litres
  32. 32. • All dimensions in cm Fig.8 Generator tank OUTLET INLET
  33. 33. 5.4 Evacuated Tubes • To get higher temperature to vaporize ammonia refrigerant, Evacuated tube collectors are used instead of solar flat collectors. Figure 9 shows the design of evacuated tube collectors. Specifications: • No. of Tubes = 2 • Length of the Tube = 1500mm • Outer diameter of the tube = 58mm • Inner diameter of the Tube = 48mm • Volume of one tube = V = π r^2 h= π×(23.5)^2×1500= 2.6 litres
  34. 34. All dimensions in cm Fig.9 Design of Evacuated tube collectors
  35. 35. 5.5 Rectifier Tank • Rectifier tank is designed according to the volume of absorber, evacuated tube collectors and cooling required converting water vapour to liquid state. Figure 10 shows a design of rectifier tank. Specifications: • Type: Water cooled tank • Material used = Mild steel • Inner diameter of tank one = 200mm • Outer diameter of the tank= 203mm • Length of the tank = 200mm • Thickness of inner tank = 3mm • Capacity of the tank = V = π r^2 h = π ×(0.115m)^2×0.3m= 6.28 litres • Copper coil length= 3m • Copper tube diameter= 9mm
  36. 36. Fig.10 Design of Rectifier tank WEAK SOLUTION OUT VAPOUR OUT
  37. 37. 5.6 Condenser • Condenser is selected to withstand the temperature and pressure and that amount of heat to be removed from ammonia vapour and convert it into liquid state. Specification: • Type: Wire and tube coil • Material: Mild steel • No. of turns = 26 • Outer diameter of condenser pipe= 6mm • Thickness = 1mm • Area of the condenser = 0.95m × 0.4 m = 0.38 m^2
  38. 38. 5.7 Capillary tube • Capillary tube has very small internal diameter and it is of very long in length. It is coiled to several turns, so that it would occupy less space. This device connects between condenser and evaporator to reduce the pressure. The refrigerant comes out of capillary tube to evaporator this change in diameter drops the refrigerant pressure there by reducing its temperature. Specifications • Material: Copper • Inner diameter = 0.3mm • Thickness = 0.1mm • Capillary tube length = 3m
  39. 39. 5.8 Evaporator • In evaporator low temperature, low pressure refrigerant extract the heat from the cabin or system which we have to cool. Evaporator should be designed to get capacity of 1 ton as the heat input is of 4.65 KW (from COP calculations). • Specifications: • Material : Mild steel • Cylinder inner diameter = 200mm • Cylinder length = 300mm • Cylinder thickness= 3mm • Volume of the thank V = π r^2 h = π×(100)^2×2= 9.42 litres • Coil material= Copper • Coil length = 3m • Coil outer diameter = 6mm
  40. 40. 6. Fabrication of STVARS The solar vapour absorption refrigeration system is fabricated with reference to the designed details using available parts and materials in market, which is cost effective. The following are steps involved in Fabrication. • 1. Selecting the type of materials and parts to be used. • 2. Fabricating the cylinders and modifying the parts. • 3. Assembling the system as per design and installing the instruments. • 4. Sealing done at required spots in the system. • 5. Testing and modifying the assembly.
  41. 41. • The fabrication process is done in Gajanana machine works, Bunder Mangaluru Fig.11 Fabricated STVARS
  42. 42. 6.1 Fabricated Absorber Tank • Absorber tank is fabricated with reference to the designed details of capacity 20 litres. The material used to fabricate is galvanized mild steel and the thickness is 3mm. Operations performed: • Arc Welding • Drilling • Brazing • Sealing Fig.12 Absorber tank
  43. 43. 6.2 Diaphragm Pump • Pump is fixed between absorber tank and generator tank using union coupling parts of ¾ inch stainless steel, both in inlet and outlet of pump. • 60W DC pump Operation performed: • Threading on coupling parts Fig.13 60W pump
  44. 44. 6.3 Generator Tank with Evacuated Tubes • Tank is fabricated with reference to designed model of generator tank that can attached to evacuated tubes with the help of bush, so there will be no leakage . Operation Performed: • Drilling • Welding • Sealing Fig.14 Generator tank with Evacuated tubes
  45. 45. 6.4 Fabricated Rectifier Tank • Rectifier tank is made up of mild steel of capacity 6.28 litres is fabricated according to the design details. Operations performed: • Welding • Drilling • Soldering • Brazing • Sealing Fig.15 Rectifier tank
  46. 46. 6.5 Wire and Tube Condenser • The condenser is selected depending upon the area of the condenser that able to give required condensation to the system. • A wire and tube type condenser used to household refrigerator of system 1TR is purchased in micro refrigeration bunder, Mangalore. • Wire and tube condenser is a type of natural convection condenser used in small capacity refrigeration systems. Fig.16 Wire and tube condenser
  47. 47. 6.6 Copper Capillary Tube • A capillary tube is selected by its length and diameter for capacity one ton refrigeration and fabricated in Christal refrigeration, Surathkal Mangalore. Operations performed: • Brazing • Soldering Fig. 17 Capillary tube
  48. 48. 6.7 Evaporator tank • Evaporator tank is fabricated according to the design details of capacity 9.42 litres, material used is mild steel. • It is insulated by asbestos webbing tape. • A 6mm diameter of 2m copper coil is used. Operation Performed : • Welding • Brazing • Drilling • Sealing Fig.18 Evaporator tank
  49. 49. 6.8 Instrumentations • Two pressures gauges of 150psi are installed, one pressure gauge is threaded in 20mm diameter stainless steel pipe after the pump and other one between evaporator and absorber tank. • Three digital thermometers rated from -50°C to +300°C is installed in the system, one in absorber tank and other two in rectifier tank and evaporator tank . Fig.19 Pressure gauge
  50. 50. 6.9 Modification • Modification is done after testing of fabricated system. Fig.20 Modified System
  51. 51. 6.10 Ammonium Hydroxide as Working fluid • Ammonium hydroxide (NH3+H2O) solution (13 litres) is filled in absorber tank where ammonia is the refrigerant and water acts as absorber. • Ammonia Solubility in H2O = 47% at 0°C , 31% at 25°C and 18% at 50 °C Fig.21 Ammonium hydroxide
  52. 52. 7.Optimization of Design • The fabricated system was found to be not holding the system pressure in evacuated tube collectors. The following are the areas where new modification is put in the place due to the above reasons. • Design of solar collector area. • Connective areas of generator tank. • Identification of valves • Proper insulation in the system. • Better instrumentations in the system.
  53. 53. 7.1 Stainless tube Collectors • Maximum temperature of 65 to 70°C can obtain by using stainless tube collector. • Specification: • Rectangular box dimensions = L×W×H= 347.09mm×291.24mm×150mm • Absorber plate area (copper)= 342mm×286mm = 0.097m^2 • Tube material used = Stainless steel • Number of tubes = 2 • Length of the tube = 150mm • Outer diameter of the tube= 64mm • Thickness = 2mm • Volume of generator tank = 2.97 litres • Volume of the two tubes = 0.96 litres • Quantity of ammonium hydroxide used in absorber tank = 6 litres
  54. 54. • All dimensions in mm Fig.22 Designed stainless tube collector
  55. 55. 7.2 Insulation • Insulation is done to rectifier tank and the stainless steel pipe connections to maintain the required temperature in the system. • Asbestos tapes can be used for insulation the components.
  56. 56. 7.3 Finned tube Condenser • Finned tube condenser is a type of natural convection heat exchanger (condenser), it is suggested to a solar vapour absorption refrigeration system. • Calculations: • The optimum heat and mass transfer area can be calculated using A= Q/(F×h×ΔT) • t1= 70°C, t2= 45°C, T1= 30°C and T2 = 35°C • P = 0.62 and R= 0.2, from graph F= 0.97 Fig.23 Correction factor F chart
  57. 57. • Assuming heat transfer co-efficient, h =10W/(m^2×K) • The heat flow rate is the mass flow rate times the latent heat of condensation of the ammonia = Q = m×Δh • Mass flow rate of refrigerant = 2.94×10^-3 kg/s • If ammonia vapour entering condenser at maximum temperature of 70°C then • Δh = (1484-545) = 939 kj/kg • The log mean temperature difference ΔT = (Tc-Tai)×(Tc-Tao) / log((Tc-Tai)/(Tc-Tao)) • Tc is Condenser temperature = 45°C = 318 K • Tai is air inlet temperature = 30°C = 303 K • Tao is air outlet temperature = 35°C = 308 K • ΔT = (318-303)× (318-308)/log((318-303)/(315-308) = 851.83 K • A = (2.94×10^-3 × 939)/ (0.97×10×851.83) = 330.93 (kj/sec×m^2/w)= 0.34 m^2
  58. 58. 7.4 Optimized Instrumentations • For calculating COP of the system, temperature and pressure of refrigerant flow is required to be noted at each point. • High pressure P1=P2=P3=P5 • Low pressure= P6=P7 • T1=Absorber temperature • T2=Generator temperature • T3=Rectifier temperature • T4=Condenser temperature • T5= Evaporator temperature Fig.24 Circuit diagram of STVARS for instrumentations
  59. 59. 8.Result and Discussion • Literature review is done on different type refrigeration system mostly based on solar thermal refrigeration. • Solar thermal refrigeration is designed and fabricated with reference to the COP calculation. • System fabrication components had drilling, welding, brazing and other operations. • Fabrication model is tested, and find out that there is leakage in pump outlet coupling part due to pressure as the pump in working condition. • Modification is done by removing pump from the system and changing the position of absorber and generator setup, also replacing the stainless steel pipes to flexible pipe. • Ammonia solution is filled successfully as per the procedure of handling ammonium hydroxide. • As the absorber tank valve is opened the solution entering evacuated tubes by generator is failed to hold up the pressure developed by ammonia vapour and there was gas leakage in bush to that connects generator tank and evacuated tubes. • Design has optimized on the system by replacing evacuated tube collector by stainless steel flat plate collectors and some minor modifications in piping and insulations. • Optimized design is better to the system’s new design which can deal with pressure and leakage problems and quantity of ammonia ammonium hydroxide is used is 6 litres. • Instrumentations like new pressure gauges and ball valve has been introduced to be used in the system as per the requirements.
  60. 60. 9. Conclusion • The new solar thermal refrigeration has been introduced with ammonia as working fluid Evacuated tubes mainly to replace the high grade electricity. • Reviews of different area of solar thermal refrigeration system have been carried out, designed components used in solar thermal refrigeration system are shown in detailed with its pictures. • To find the performance parameter of refrigeration system instrumentation studies has been carried out and different types of gauges and exact locations have been represented. • The designed refrigeration system is fabricated, tested and modified as per the requirement. • The fabricated system when tested it was found incapable of holding the system pressure and the evacuated tubes could not keep itself in place. The evacuated tubes lost its vacuum pressure not suitable for ammonia solution for present design. • Considering the factor a new design has been introduced after optimization which takes care of problems encountered in the earlier design.
  61. 61. 10.References • [01] Prof. Dr. Adel A. Al-Hemiri and Ahmed Deaa Nasiaf, ‘‘The use of direct Solar energy in Absorption Refrigeration employing NH3 – H2O system’’, Iraqi Journal of Chemical and Petroleum Engineering, Vol.11 No.4 (December 2010) 13-21. • [02] Preethu Johnson and K. B. Javare Gowda, ‘‘Fabrication of Solar Thermal Vapour Absorption Refrigeration System’’, International Research Journal of Engineering and Technology, Volume: 02 Issue: 05 | Aug-2015. • [03] Shireesha Mary Ch, Nandini Ch, Divya Samala, Siva Kumar B and Parthasarathy Garre, ‘‘A Review: Increase in Performance of Vapour Compression Refrigeration System Using Fan’’, International Journal of Engineering and Applied Sciences (IJEAS) ISSN: 2394-3661, Volume-2, Issue-4, April 2015. • [04] F. Memet, ‘‘A Performance Analysis on a Vapour Compression Refrigeration System Generated by the Replacement of R134a’’, Journal of maritime research, Vol XI. No. III (2014) pp 83–87. • [05] Shubham Srivastava, Ravi Kumar Sen, Arpit Thakur and Manish Kumar Tated, ‘‘Review paper on analysis of Vapour Absorption Refrigeration System’’, International Journal of Research in Engineering and Technology, Volume: 04 Issue: 06 June 2015. • [06] Sachin Kaushik and Dr. S. Singh, ‘‘Thermodynamic Analysis of Vapour Absorption Refrigeration System and Calculation of COP’’, International journal for research in applied science and engineering technology’’, Vol. 2 Issue II, February 2014. • [07] Jose  FernaÂndez-Seara and Manuel VaÂzquez, ‘‘Study and control of the optimal generation temperature in NH3-H2O absorption refrigeration systems’’, Applied Thermal Engineering 21 343±357 @ Elsevier Science Ltd., March 2000.
  62. 62. References • [8] Subi Salim and Rajesh V. R., ‘‘Thermodynamic analysis of Aqua-Ammonia based miniaturized vapour Absorption Refrigeration system utilizing solar thermal energy’’, ARPN Journal of Engineering and Applied Sciences, VOL. 11, NO. 9, MAY 2016. • [09] K.V.N. Srinivasa Rao, ‘‘Low Cost Solar Cooling System’’, International Journal of Engineering and Innovative Technology (IJEIT) Volume 3, Issue 4, October 2013. • [10] N.D. Hingawe and R.M. Warkhedkar, ‘‘Design and Analysis of Solar Electrolux Vapour Absorption Refrigeration System, International Journal of Advance Research in Science and Engineering’’, IJARSE, Vol. No.4, Issue 04, April 2015. • [11] O. Babayigit,a, M. H. Aksoy, M. Ozgoren and O. Solmaz, ‘‘Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey’’, EPJ Web of Conferences DOI: 10.1051/ C _ Owned by the authors, published by EDP Sciences,2013. • [12] Satish Raghuvanshi and Govind Maheshwari, ‘‘Analysis of Ammonia –Water (NH3-H2O) Vapour Absorption Refrigeration System based on First Law of Thermodynamics’’, International Journal of Scientific & Engineering Research Volume 2, Issue 8, August-2011. • [13] Sanford A. Klein, Ph.D., Fellow ASHRAE, and Douglas T. Reindl, Ph.D., ‘‘ Solar Refrigeration’’, © 2005, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. ASHRAE Journal, (Vol. 47, No. 9, September 2005). • [14] K.R. Ullah , R.Saidur , H.W.Ping , R.K.Akikur and N.H.Shuvo, ‘‘A review of solar thermal refrigeration and cooling methods’’, Renewable and Sustainable Energy Reviews 24 (2013) 499–513 @ Elsevier journals, March 2013. • [15] Amar Rouag, Adel Benchabane and Adnane Labed “Thermal design of air cooled condenser of a solar adsorption refrigerator” Laboratoire de Génie Energétique et Matériaux (LGEM), Université de Biskra, B.P. 145 R.P. 07000, Biskra, Algeria
  63. 63. THANK YOU

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