Design Construction and Performance of 10W Thermoacoustic Refrigerators

2017 ◽  
Vol 25 (03) ◽  
pp. 1750023 ◽  
Author(s):  
B. G. Prashantha ◽  
M. S. Govinde Gowda ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham
Keyword(s):  
Comparative Analysis ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Small Diameter ◽  
Cooling Power ◽  
Experimental Measurements ◽  
And Performance ◽  
Assembly Procedure ◽  
Design Construction ◽  
Thermoacoustic Refrigerators

In this paper, the construction and performance of the 10[Formula: see text]W cooling power thermoacoustic refrigerators designed for a temperature difference of 120 K at 3% drive ratio are discussed. The construction and assembly procedure of the optimized thermoacoustic refrigerator components viz. spiral stack, heat exchangers, 0.28[Formula: see text]-taper, small diameter tube and divergent section with hemispherical end (TSDH) and 0.24[Formula: see text]-taper and divergent section with hemispherical end (TDH) resonator designs and loudspeaker found in the published literature, and instrumentation are discussed. The performance of the 0.28[Formula: see text]-TSDH, and 0.24[Formula: see text]-TDH resonator designs, and the uncertainties involved in the experimental measurements are discussed. Both the resonator designs show good behavior. A decent low temperature of [Formula: see text]11.3[Formula: see text]C and [Formula: see text]8.7[Formula: see text]C at 10[Formula: see text]W cooling power is achieved at the cold heat exchanger for the 0.28[Formula: see text]-TSDH and 0.24[Formula: see text]-TDH resonator designs, respectively. The comparative analysis of the experimental results with the theoretical and DeltaEC results is discussed.

Prediction and Performance of Compact Latent Heat Recovery Heat Exchanger With Small Diameter Tubes

2007 ◽  
Author(s):  
Masahiro Osakabe
Keyword(s):  
Heat Exchanger ◽  
Power System ◽  
Latent Heat ◽  
Heat Recovery ◽  
Small Diameter ◽  
Cooling Water ◽  
Prediction Method ◽  
Outer Diameter ◽  
Exhaust Gas ◽  
And Performance

The most part of energy losses in power system such as fuel cells is due to the heat released by the exhaust gas to atmosphere. The exhaust gas consists of non-condensable gas and steam with sensible and latent heat. As a lot of latent heat is included in the exhaust gas, its recovery is very important to improve the power system efficiency. Based on the previous basic studies, a thermal hydraulic prediction method for latent heat recovery exchangers was proposed. For the condensation of steam on heat transfer tubes, the modified Sherwood number taking account of the mass absorption effect on the wall was used. Two kinds of compact heat exchanger with staggered banks of bare tubes of 10.5 or 4mm in outer diameter was designed with the prediction method. The more compactness was obtained with the smaller tubes at a designed heat recovery. The thermal hydraulic behavior in the compact heat exchangers was experimentally studied with air-steam mixture gas. In the parametric experiments varying the steam mass concentration, the temperature distributions of cooling water and mixture gas were measured. The experimental results agreed well with the prediction proposed in this study and the more compactness with the smaller tubes was proved.

Design and Analysis of Thermoacoustic Refrigerators Using Air as Working Substance

2019 ◽  
Vol 27 (01) ◽  
pp. 1950008 ◽  
Author(s):  
B. G. Prashantha ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham ◽  
M. R. Praveen Kumar
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Low Cost ◽  
Design Strategies ◽  
Software Simulation ◽  
Design And Optimization ◽  
Theoretical Design ◽  
Resonator Design ◽  
Simulation Results ◽  
Thermoacoustic Refrigerators

In this paper, the design of 50 W thermoacoustic refrigerators operating with air as working substance at 10 bar pressure and 3% drive ratio for a temperature difference of 28 K is described. The design strategies discussed in this paper help in design and development of low cost thermoacoustic coolers compared to helium as the working substance. The design and optimization of spiral stack and heat exchangers, and the promising 0.2[Formula: see text] and 0.15[Formula: see text] resonator design with taper and divergent section with hemispherical end are discussed. The surface area, volume, length and power density of the hemispherical end design with air as working substance is found better compared to the published 10 and 50 W coolers using helium as the working substance. The theoretical design results are validated using DeltaEC software simulation results. The DeltaEC predicts 51.4% improvement in COP (1.273) at the cold heat exchanger temperature of [Formula: see text]C with air as working substance for the 50[Formula: see text]W 0.15[Formula: see text]TDH resonator design compared to the published 50[Formula: see text]W 0.25[Formula: see text]TDH resonator design with helium as working substance.

A Continuous Heat Regenerative Adsorption Refrigerator Using Spiral Plate Heat Exchanger as Adsorbers: Improvements

1999 ◽  
Vol 121 (1) ◽  
pp. 14-19 ◽  
Author(s):  
R. Z. Wang ◽  
J. Y. Wu ◽  
Y. X. Xu
Keyword(s):  
Activated Carbon ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Plate Heat Exchanger ◽  
Cooling Power ◽  
Thermal Cycles ◽  
Plate Heat ◽  
Spiral Plate ◽  
Continuous Heat

Spiral plate heat exchangers as adsorbers have been proposed, and a prototype heat regenerative adsorption refrigerator using activated carbon-methanol pair has been developed and tested. Various improvements have been made, at last we get a specific cooling power for 2.6 kg-ice/day-kg adsorbent at the condition of generation temperature lower than 100°C. Discussions on the arrangements of thermal cycles and influences of design are shown.

Experimental and Numerical Analyses of Friction Factors in Offset Strip Fin Heat Exchangers

2007 ◽  
Author(s):  
Aihua Wang ◽  
Samir F. Moujaes ◽  
Yitung Chen ◽  
Valery Ponyavin
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Experimental Measurements ◽  
Test Rig ◽  
Compact Heat Exchangers ◽  
Friction Factors ◽  
Offset Strip Fin

Heat transfer in compact heat exchangers is augmented by the introduction of the offset strip fins. With the breakdown of the thermal and hydro boundary layers to boost heat transfer, the fins increase the friction power. Two heat exchangers of different fin geometries structures were built and tested. The results of the study show that the round-edge-fin heat exchanger has the smaller friction factor. A test rig was constructed to measure the friction factor of the offset strip fin heat exchangers with air. A modified hydraulic diameter was used to calculate the main parameters. The computational fluid dynamics package FLUENT was used to predict the flow in the heat exchanger. The numerical investigation was conducted and compared with experimental measurements.

Air-Side Heat Transfer and Friction Correlations for Plain Fin-and-Tube Heat Exchangers With Staggered Tube Arrangements

1999 ◽  
Vol 121 (3) ◽  
pp. 662-667 ◽  
Author(s):  
N. H. Kim ◽  
B. Youn ◽  
R. L. Webb
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Small Diameter ◽  
Tube Diameter ◽  
Heat Transfer Correlation ◽  
Multiple Regression Technique ◽  
Geometric Variables ◽  
Tube Pitch ◽  
Fin Spacing

This paper deals with heat exchangers having plain fins on a staggered array of circular tubes. Correlations are developed to predict the air-side heat transfer coefficient and friction factor as a function of the Reynolds number and geometric variables of the heat exchanger such as tube diameter, tube pitch, fin spacing, etc. A multiple regression technique was used to correlate 47 sets of heat exchanger data to develop the heat transfer and friction correlation. The correlations are applicable to heat exchangers having small diameter tubes (or large tube pitch to tube diameter ratio), whose performance previous correlations failed to predict adequately. The heat transfer correlation applicable to three or more row configuration predicts 94 percent of the data within ±20 percent, and the heat transfer correlation applicable to one- or two-row configuration predicts 94 percent of the data within ±20 percent. The friction correlation predicts 90 percent of the data within ±20 percent.

Development of a Plate Heat Exchanger for High-Temperature and High-Pressure

2013 ◽  
Author(s):  
Kiyoshi Ishihama ◽  
Seiichi Matsumura ◽  
Takahisa Funabiki ◽  
Yukiko Kushima ◽  
Junichi Nakamura ◽  
...  
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Heat Removal ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Thermal Transients ◽  
Higher Temperature ◽  
Water Reactors ◽  
And Performance

A gasketed plate heat exchanger that has a seal pressure of 6.5 MPa or more has been developed. This heat exchanger can be applied to heat exchangers (design temperature: 182°C, design pressure: 3.43 MPa) for the residual heat removal (RHR) systems of boiling water reactors (BWR). Practical use of gasketed plate heat exchangers under the condition of higher temperature and higher pressure has been achieved by developing a high-pressure-retaining plate and frame, as well as a heat- and radiation-resistant gasket. Various element tests related to strength and performance were conducted in the process of this development. A verification test using a prototype heat exchanger was also conducted, and pressure resistance, heat resistance, radiation resistance, endurance against thermal transients, and heat transfer performance have been confirmed. As a result of this development, gasketed plate heat exchangers can be applied for use under the condition of higher temperature and higher pressure, and various effects such as lower system flow, smaller footprint, easier maintenance, and lower cost for weld inspection are expected, compared to conventional shell & tube heat exchangers.

High Temperature Heat Exchangers (HTHX) for Nuclear Applications

2006 ◽  
Author(s):  
James C. Govern ◽  
Cila V. Herman ◽  
Dennis C. Nagle
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Heat Exchanger Design ◽  
Performance Requirements ◽  
Starting Point ◽  
Temperature Heat ◽  
And Performance ◽  
Design Challenges

Many nuclear engineering applications, current and future, require heat exchangers operating at high temperatures. The operating conditions and performance requirements of these heat exchangers present special design challenges. This paper considers these challenges with respect to a simple heat exchanger design manufactured of a novel carbon material. Heat transfer and effectiveness calculations are performed for several parametric studies regarding heat exchanger parameters. These results are used to better understand the design challenges of high temperature heat exchangers as well as provide a starting point for future optimization work on more complex heat exchanger designs.

Sign in / Sign up

Export Citation Format

Share Document