DESIGN AND ANALYSIS OF THERMOACOUSTIC REFRIGERATOR

2013 ◽  
Vol 21 (01) ◽  
pp. 1350001 ◽  
Author(s):  
B. G. PRASHANTHA ◽  
M. S. GOVINDE GOWDA ◽  
S. SEETHARAMU ◽  
G. S. V. L. NARASIMHAM
Keyword(s):  
Boundary Layer ◽  
Power Density ◽  
Gas Pressure ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Boundary Layer Approximation ◽  
Resonator Design ◽  
Quarter Wavelength ◽  
Calculation Results ◽  
Thermoacoustic Refrigerator

This paper deals with the design and analysis of a quarter-wavelength, 10 W capacity, thermoacoustic refrigerator using short stack boundary layer approximation assumptions. The effect of operating frequency on the performance of the refrigerator is studied using dimensional normalization technique. The variation of stack diameter with average gas pressure and cooling power is discussed. The resonator optimization is discussed and the calculation results show a 9% improvement in the coefficient of performance and 201% improvement in power density for the optimized quarter-wavelength resonator compared to published optimization studies. The optimized resonator design is tested with DeltaEC software and the results show better performance compared to past established resonator designs.

DESIGN AND OPTIMIZATION OF A LOUDSPEAKER DRIVEN 10-W COOLING POWER THERMOACOUSTIC REFRIGERATOR

2014 ◽  
Vol 22 (03) ◽  
pp. 1450015 ◽  
Author(s):  
B. G. PRASHANTHA ◽  
M. S. GOVINDE GOWDA ◽  
S. SEETHARAMU ◽  
G. S. V. L. NARASIMHAM
Keyword(s):  
Surface Area ◽  
Optimization Procedure ◽  
Cooling Power ◽  
Design And Optimization ◽  
Resonator Design ◽  
Quarter Wavelength ◽  
Optimum Diameter ◽  
Minimum Heat ◽  
Good Agreement ◽  
Thermoacoustic Refrigerator

The design and optimization procedure for a loudspeaker driven 10-W cooling power thermoacoustic refrigerator components with a temperature difference of 120 K has been discussed using the linear thermoacoustic theory. The resonator losses are proportional to surface area and the optimum diameter ratio of small and large resonator tubes for minimum heat loss for a quarter-wavelength hemispherical ended resonator design is discussed. The hemispherical ended resonator design is further analytically optimized to increase COP, cooling effect at cold heat exchanger and power density by decreasing total resonator surface area and volume. An alternate convergent-divergent resonator design is proposed which is found to be more efficient compared to previous published designs. Resonator designs are tested with DeltaEC software, which predicts a lowest temperature of -48°C and -47°C for the improved hemispherical and convergent-divergent resonator designs, respectively. Theoretical results are in good agreement with DeltaEC results.

Resonator Optimization and Studying the Effect of Drive Ratio on the Theoretical Performance of a 10-W Cooling Power Thermoacoustic Refrigerator

2015 ◽  
Vol 23 (03) ◽  
pp. 1550020 ◽  
Author(s):  
B. G. Prashantha ◽  
M. S. Govinde Gowda ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham
Keyword(s):  
Dynamic Pressure ◽  
Optimization Procedure ◽  
Cooling Power ◽  
Pressure Amplitude ◽  
Performance Simulation ◽  
Resonator Design ◽  
Working Principle ◽  
Simulation Results ◽  
Theoretical Performance ◽  
Thermoacoustic Refrigerator

This paper deals with the basic insight of thermoacoustic refrigeration concepts, and the working principle, history and the role of linear thermoacoustic theory in designing a thermoacoustic refrigerator system are discussed. Resonator design optimization procedure for a 10W cooling power thermoacoustic refrigerators is discussed. The optimized resonator designs proposed in this paper are found to be efficient compared to published resonator designs. The effects of drive ratio on the theoretical performance by varying dynamic pressure amplitude from 0.2 bar to 0.4 bar in the steps of 0.05 bar on the optimized resonator designs are discussed. Performance simulation results for the optimized resonator designs using DeltaEC software are discussed. Simulation results are in agreement with theoretical results.

Miniaturized Traveling-Wave Thermoacoustic Refrigerator Driven by Loudspeaker: Numerical Design

2020 ◽  
Vol 28 (04) ◽  
pp. 2050035
Author(s):  
Oday S. Mahmood ◽  
Abdul Mun’em A. Karim ◽  
Samir Gh. Yahya ◽  
Itimad D. J. Azzawi
Keyword(s):  
Traveling Wave ◽  
New Technology ◽  
Acoustic Power ◽  
Inert Gases ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Vapor Compression ◽  
Sound Waves ◽  
Numerical Design ◽  
Thermoacoustic Refrigerator

Ordinary refrigeration systems such as vapor-compression refrigerators are the commonly used devices in industry, mostly for their high efficiencies. However, they make a significant contribution to the depletion of Ozone and global warming due to their operational refrigerants. Hence, thermoacoustic refrigeration can be a great alternative candidate which uses inert gases such as air, helium and nitrogen as the primary refrigerant. Thermoacoustic refrigerators convert the acoustic power (sound waves) into a thermal effect (cooling power). Thermoacoustics can be counted as a new technology that has a strong potential toward the development of the thermal applications. This study aims to design and fabricate miniaturized traveling wave thermoacoustic refrigerator which can be driven by an ordinary loudspeaker. The optimized numerical design of the refrigerator shows an overall efficiency (cooling power over input electricity) of nearly 66% at a temperature difference of 25[Formula: see text]K (between cold and ambient heat exchangers). The maximum estimated cooling power is 65[Formula: see text]W at coefficient of performance (COP) of 2.65.

SIMULTANEOUS OPTIMIZATION OF FOUR PARAMETERS IN THE STACK UNIT OF A THERMOACOUSTIC REFRIGERATOR

2014 ◽  
Vol 22 (02) ◽  
pp. 1450011 ◽  
Author(s):  
NOR ATIQAH ZOLPAKAR ◽  
NORMAH MOHD-GHAZALI ◽  
ROBIAH AHMAD
Keyword(s):  
Cooling System ◽  
Acoustic Power ◽  
Optimization Techniques ◽  
Simultaneous Optimization ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Multi Objective Genetic Algorithm ◽  
Parametric Studies ◽  
Discrete Values ◽  
Thermoacoustic Refrigerator

Thermoacoustic refrigerators are environmentally friendly cooling systems that use no refrigerants. Optimization of the performance of any cooling system is crucial for an efficient energy management. Most of the optimization techniques in thermoacoustic systems utilized to date involved experimental and numerical parametric studies which are generally limited to the variations of the parameters to be optimized at discrete values. This study reports on the optimization of a thermoacoustic refrigerator using multi-objective genetic algorithm (MOGA). The study introduces the ability of MOGA to optimize four different variables which are length of stack, center position of stack, blockage ratio and drive ratio simultaneously. The four variables are optimized to achieve the two objectives; a maximum cooling and minimum acoustic power required at the stack and provide the optimum coefficient of performance, COP. The results show that the optimum COP = 1.35 with a cooling power of Qc = 6.57 W, acoustic power of Wn = 4.86 W and with the resonator diameter of D = 3.8 cm.

Effect of Stack Spacing on the Performance of Thermoacoustic Refrigerators Using Helium and Air as Working Substances

2019 ◽  
Vol 27 (02) ◽  
pp. 1950016 ◽  
Author(s):  
B. G. Prashantha ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham ◽  
M. R. Praveen Kumar
Keyword(s):  
Heat Exchanger ◽  
Penetration Depth ◽  
Power Density ◽  
Cooling Power ◽  
Quarter Wavelength ◽  
Thermal Penetration Depth ◽  
Theoretical Results ◽  
Theoretical Performance ◽  
Thermoacoustic Refrigerators

This paper deals with the design of thermoacoustic refrigerators using linear thermoacoustic theory. The refrigerator components are designed at 3% drive ratio by considering the practical limitations of providing sufficient spacing for attaching the loudspeaker to the resonator tube and accommodating instrumentation. The effects of spiral stack spacing in terms of thermal penetration depth on the theoretical performance of refrigerator using helium and air as working substances are discussed. The quarter-wavelength resonator designs with taper and divergent section terminated with hemispherical end are optimized with helium and air for better performance. Theoretical results are validated with DeltaEC software results and are in agreement with each other. Helium shows better performance compared to air but lacks power density. The DeltaEC predicts COP 0.514 at the cold heat exchanger temperature of [Formula: see text]C with helium compared to air (COP 0.616 at [Formula: see text]C) for the 50[Formula: see text]W cooling power 100[Formula: see text]mm diameter quarter-wavelength resonator designs.

scholarly journals Design Analysis of Thermoacoustic Refrigerator Using Air and Helium as Working Substances

2017 ◽  
Vol 13 (2) ◽  
Keyword(s):  
Heat Exchanger ◽  
Low Temperature ◽  
Sheet Thickness ◽  
Design Strategy ◽  
Cooling Power ◽  
Resonator Design ◽  
Helium Gas ◽  
Penetration Depths ◽  
Shape And Size ◽  
Thermoacoustic Refrigerator

In this paper, thermoacoustic refrigerator design strategy with parameters normalization and literature review covering the recent development in the modification of the resonator shape and size is discussed. The design of a 10 W cooling power thermoacoustic refrigerator using air as working substance and the effect of operating frequency on viscous and thermal penetration depths, and on stack sheet thickness and spacing are discussed. The promising 10 W cooling power TDH (Taper and Divergent section with Hemispherical end) resonator design operating with air and helium gases as working substances is analyzed using DeltaEC software. The analysis results show that the TDH resonator design using helium as working substance operates at lower drive ratio (14%) compared to air (25%). In comparison, DeltaEC predicts a decent low temperature of -35.4 o C at cold heat exchanger with a COP of 0.5294 when operated using helium gas, and for air is -9 oC and 0.8113 respectively, and the results are discussed.

High cooling power density SiGe/Si micro-coolers

2001 ◽  
Vol 37 (2) ◽  
pp. 126 ◽  
Author(s):  
X. Fan ◽  
G. Zeng ◽  
E. Croke ◽  
C. LaBounty ◽  
C.C. Ahn ◽  
...  
Keyword(s):  
Power Density ◽  
Cooling Power

scholarly journals Absorption and adsorption chillers applied to air conditioning systems

2010 ◽  
Vol 31 (2) ◽  
pp. 77-94 ◽  
Author(s):  
Agnieszka Kuczyńska ◽  
Władysław Szaflik
Keyword(s):  
Heat Source ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Geothermal Heat ◽  
Pump System ◽  
Desorption Process ◽  
Heat Pump System ◽  
Adsorption Chiller ◽  
Air Conditioning Systems

Absorption and adsorption chillers applied to air conditioning systemsThis work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperatureTdes= 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling waterTc= 25 °C and temperature in evaporatorTevap= 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

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