570 likes | 831 Views
Graduation Project II. Green Cooling. Design of Thermoacoustic Refrigerator . Advisor Name: Dr. Emad Elnajjar Group members Azeeza Saeed 200321817 Basma Abu-Baker 200302708 Haniya Awad 200337204
E N D
Graduation Project II Green Cooling
Design of Thermoacoustic Refrigerator • Advisor Name:Dr. Emad Elnajjar • Group members • Azeeza Saeed 200321817 • Basma Abu-Baker 200302708 • Haniya Awad 200337204 • Shamma Sultan 200321100
Outlines • Introduction • Environmental and Economical Aspects • Design and Manufacturing • Project Budget • Testing and Results • Conclusion and Recommendations
Objectives Applying engineering knowledge and sense to design and implement thermoacoustic refrigeration system Building and characterizing this system using systematic design method Gaining a practical experience in: How to purchase, select material, instrumentation, read equipments specifications, and prepare design drawings to be built in the workshop
Objectives Training ourselves on creating an entrepreneur opportunities for small business ideas and exploring marketing opportunities and looking for a sponsorship Improving different personal skills and encouraging the team work spirit between all group members Looking for a sponsorship
Environmental Aspect Today the earth plant suffering from two serious environmental problems: Global warming Ozone depletion
2nd Law of thermodynamics (Clausius statement). • Sound waves are pressure waves.
Assumptions The acoustic medium is frictionless. The sound wave compression and expansion processes are isentropic. The sound wave propagates in horizontal direction. The resonator tube walls are rigid.
Governing Equations Coefficient of Performance : Coefficient of performance : Cooling power, KW : Acoustic power, KW : Dimensionless/ Normalized cooling power : Dimensionless/ Normalized acoustic power : Sound velocity, m/s : stack cross sectional area, mm2 : Average pressure, KPa
Design and Manufacturing Specify operation, working gas and stack parameters Design Choices: Average Pressure, Frequency, Dynamic Pressure, Working gas, Stack material and Stack geometry Design of the resonator Optimization of the stack Design of the stack Design of heat exchanger Design of acoustic driver
Stack • Stack and stack holder shape • Stack material • Stack holder material
Stack and Stack Holder Shape circular sticks with holes
Stack and Stack Holder Shape cont. Parallel plates with rectangular gaps
Stack and Stack Holder Shape cont. Spiral stack with fishing line Parallel plates with finishing line
Stack Material • Stack material characteristics: 1. Low thermal conductivity. 2. Heat capacity larger than helium heat capacity. 3. Easy to manufacture and shaped.
Stack Holder Material • Stack holder material characteristics: 1. Low thermal conductivity 2. Rigidity
Resonator • Shape • Material • AutoCAD Drawing
Resonator Shape • Length equal to λ/2 or λ/4 • Power losses: • λ/4 resonator will dissipate half of energy dissipated by λ/2 resonator
Resonator Shape Cont. • Spherical end to simulate the open end • Buffer to reduce turbulence • Tapered section to reduce turbulence
Resonator Material • The tube should stand high pressure • Should be rigid • Made of available metal • Suggested Material: • Aluminum • Advantages: • It is available in our workshop
Heat Exchangers • Material • Size • Weight • Heat transfer rate
Heat Exchanger AutoCAD Layout` Piped heat exchanger Sinusoidal heat exchanger
Acoustic Driver • Loud speaker specifications • Housing of the Acoustic Driver • Housing material and specifications • Electroacoustic Power & Efficiency
Acoustic Driver Design The selection of the driver is based on : 1.Compactness 2. Lightweight 3. Low losses 4. Bl-factor
Mathematical Equations • The acoustic output power is : Where: Amplitude of the dynamic pressure Volume velocity amplitude Phase difference
Results and Analysis • What we were expecting and what we end with • Results gained • Analysis
Results and Analysis • What we were expecting and what we end with? • Results • Analysis
Expected TcR System Buffer
Expected TcR System Buffer Pressure Gage
Expected TcR System Buffer Valve Pressure Gage Valve