A TRAVELING WAVE THERMOACOUSTIC ENGINE - DESIGN AND TEST

2021 ◽  
pp. 1-9
Author(s):  
Mitchell McGaughy ◽  
Chengshi Wang ◽  
Eric Boessneck ◽  
Thomas Salem ◽  
John R Wagner
Keyword(s):  
Acoustic Wave ◽  
Traveling Wave ◽  
System Analysis ◽  
Waste Heat ◽  
Electrical Power ◽  
Performance Testing ◽  
Cost Effective ◽  
Acoustic Power ◽  
Consumer Products ◽  
Thermoacoustic Engine

Abstract The demand for clean, sustainable, and cost-effective energy continues to increase due to global population growth and corresponding use of consumer products. The provision of heat to a thermoacoustic prime mover results in the generation of an acoustic wave that can be converted into electrical power. Thermoacoustic devices offer highly reliable and transportable power generation with low environmental impact using a variety of fuel sources. This paper focuses on the design and testing of a single stage, traveling wave, thermoacoustic engine. The system configuration, component design, and integration of sensors will be described. Performance testing and system analysis shows that for a 300 W heat source, the thermoacoustic machine generates a 54 Hz acoustic wave with a thermal efficiency of 7.8%. The system's acoustic power output may be increased by 84% through improved heat exchanger design. Tuning of the acoustic system and optimization of the bi-directional turbine merit attention to realize an applicable waste heat energy harvesting system.

scholarly journals The effect of mean pressure on the performance of a single-stage heat-driven thermoacoustic cooler

2020 ◽  
Vol 15 (3) ◽  
pp. 471-476
Author(s):  
Irna Farikhah
Keyword(s):  
High Efficiency ◽  
Waste Heat ◽  
Heating Temperature ◽  
Acoustic Power ◽  
Environmental Issue ◽  
Thermoacoustic Engine ◽  
Limit Value ◽  
The World ◽  
Mean Pressure ◽  
Thermoacoustic Cooler

Abstract Waste heat is an environmental issue in the world. There are some technologies that can be used to recovery the waste heat, one of which is thermoacoustic cooler technology. Thermoacoustic technology can be divided into two parts: one is thermoacoustic engine and cooler. To design the cooler system having high efficiency and lower onset heating temperature, the effect of mean pressure is investigated. By increasing mean pressure from 0.5 to 3 MPa, the heating temperature generating acoustic power can be decreased from 831 to 580 K. Moreover, 15% of Thermodynamic upper limit value of the whole cooler system is achieved.

Design and Experimental Study of a Cascade Thermoacoustic Engine for Remote and Rural Communities

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Isares Dhuchakallaya ◽  
Patcharin Saechan
Keyword(s):  
Rural Communities ◽  
Rural Areas ◽  
Traveling Wave ◽  
Low Frequency ◽  
Acoustic Power ◽  
Point Of View ◽  
Working Fluid ◽  
Thermoacoustic Engine ◽  
The People ◽  
In Series

The design, construction, and experimental evaluation of a cascade thermoacoustic engine are presented in this paper. The system was designed and built under the constraint of an inexpensive device to meet the energy needs of the people based in remote and rural areas. From the cost and straightforward system point of view, the air at atmospheric pressure was applied as a working fluid, and the main resonator tubes were then constructed of conventional polyvinyl chloride (PVC) pipes. Such device consists of one standing-wave unit and one traveling-wave unit connected in series. This topology is preferred because the traveling-wave unit provides an efficient energy conversion, and a straight-line series configuration is easy to build and allows no Gedeon streaming. The system was designed to operate at a low frequency of about 57 Hz. The measured results were in a reasonably good agreement with the predicted results. So far, this system can deliver up to 61 W of acoustic power, which was about 17% of the Carnot efficiency. In the further step, the proposed device will be applied as the prime mover for driving the thermoacoustic refrigerator.

Economic Feasibility of Application Semiconductor Heat Pumps

2020 ◽  
pp. 63-66
Author(s):  
Stanislav S. Trunov ◽  
Aleksey V. Kuzmichev
Keyword(s):  
System Analysis ◽  
Waste Heat ◽  
Economic Effect ◽  
Cost Effective ◽  
Electrical Energy ◽  
Heat Pumps ◽  
Economic Feasibility ◽  
Research Purpose ◽  
Electrical Network ◽  
Thermoelectric Heat

Energy consumption around the world is growing continuously and more rapidly. There are three ways to solve the energy problem in the future: the use of new and more efficient use of existing energy sources and the rational use of extracted energy. Modern technologies for developing fuel deposits allow extracting on average no more than 40 percent of the subsurface content, the level of science and technology does not allow achieving a greater level of its extraction with sufficient economic effect. The most cost-effective, simple and feasible way to efficiently use the extracted energy is to utilize the waste heat. The article considers the advantages and possibility of using thermoelectric heat pumps based on Peltier elements. (Research purpose) The research purpose is in justifying the effectiveness of using semiconductor heat pumps in thermal technological processes at livestock facilities. (Materials and methods) During the study, the authors used methods of system analysis and synthesis of existing knowledge in the field of research on the development of thermoelectric heat pumps. (Results and discussion) The article presents the adjusted methodology for calculating the efficiency of thermoelectric heat pumps. The heat energy withdrawn by the hot circuit, and directed to heating the air, exceeds the energy consumed from the electrical network. (Conclusions) The utilization coefficient in most modern thermoelectric installations is at the level of 3-5, which means that one kilowatt-hour of electrical energy consumed produces 3-5 times more thermal energy. Heat pumps are efficient because they allow to use renewable energy, and therefore they are economically feasible.

Effect of phase adjustment on the acoustic field of a cascade thermoacoustic engine

2017 ◽  
Vol 231 (4) ◽  
pp. 317-327
Author(s):  
Patcharin Saechan ◽  
Isares Dhuchakallaya
Keyword(s):  
Acoustic Field ◽  
Traveling Wave ◽  
Acoustic Impedance ◽  
Acoustic Power ◽  
Phase Region ◽  
Thermoacoustic Engine ◽  
Flow Area ◽  
Resonator Length ◽  
Phase Adjustment ◽  
Tuning Methods

This study set out to explore the influence of phase adjustment on the acoustic field of a cascade thermoacoustic engine. The system consists of one standing wave unit and one traveling wave unit arranged in series. The straight-line configuration allows suppressing a time-averaged mass flow or Gedeon streaming, which causes some unwanted convective heat transport and reduces the efficiency of the system. Theoretically, the regenerator of the traveling wave unit must be operated within the traveling wave phasing and high impedance region in order to achieve an efficient performance. The various techniques of phase adjustment by modifying the configurations and geometrical dimensions of the system are investigated both numerically and experimentally to adjust the position of the sweet spot as well as to achieve the high acoustic impedance in the regenerator. The effective tuning methods with less modification here are accomplished by changing the volume of the down-cavity and reducing the flow area of the down-resonator by inserting the pencil. However, the pencil insertion scheme causes an extra loss due to viscous dissipation that should be taken into account. The change of the down-resonator length has a strong effect on the acoustic field in the system. After the phase-adjustment schemes are completely implemented, the performance of the proposed system is significantly improved, in which the regenerator of the traveling wave unit operates within the traveling wave phase region with high acoustic impedance. This prototype operated with air at atmospheric pressure can supply acoustic power up to 33 W to the down-resonator, which is about 9.5% of Carnot efficiency.

Design and Construction of a Four-Stage Travelling-Wave Thermo-Acoustic System for Power Generation

2020 ◽  
Author(s):  
Miniyenkosi Ngcukayitobi ◽  
Lagouge Tartibu ◽  
Samuel Gqibani
Keyword(s):  
Sound Wave ◽  
Traveling Wave ◽  
Electricity Generation ◽  
Waste Heat ◽  
Acoustic Power ◽  
Travelling Wave ◽  
Low Grade ◽  
Wave System ◽  
Acoustic System ◽  
Design And Construction

Abstract This work describes the design and construction of a four-stage traveling-wave thermo-acoustic system for electricity generation. The thermo-acoustic conversion consists of using a sound-wave for the transfer of heat from a low to high-temperature medium or the use of heat energy to generate a sound wave. Both the absence of moving parts and the simplicity of thermo-acoustic systems make the technology sustainable for converting low-grade waste heat into acoustic power. Many existing studies have pointed out the acoustic-to-electric potential of thermo-acoustic systems. Hence in this work, a thermo-acoustic system has been developed. The traveling-wave system has a total length of 3 560 mm. The distance between each thermo-acoustic engine is 640 mm. Each engine stage had four cartridge heaters used to generate the heat required. A commercial loudspeaker was used to convert sound into electricity. The minimum temperature difference necessary to induce a voltage at the terminals of the loudspeaker was approximately 200°C. The four-stage traveling-wave system generated the highest output voltage of 4.218 V.

Analysis of Surface Waste Heat Recovery in IC Engine by Using TEG

2015 ◽  
Vol 787 ◽  
pp. 782-786 ◽  
Author(s):  
R. Prakash ◽  
D. Christopher ◽  
K. Kumarrathinam
Keyword(s):  
Waste Heat ◽  
Electrical Power ◽  
Electrical Energy ◽  
Surface Heat ◽  
Heat Energy ◽  
Ic Engine ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Heat Energy Recovery

The prime objective of this paper is to present the details of a thermoelectric waste heat energy recovery system for automobiles, more specifically, the surface heat available in the silencer. The key is to directly convert the surface heat energy from automotive waste heat to electrical energy using a thermoelectric generator, which is then regulated by a DC–DC Cuk converter to charge a battery using maximum power point tracking. Hence, the electrical power stored in the battery can be maximized. Also the other face of the TEG will remain cold. Hence the skin burn out accidents can be avoided. The experimental results demonstrate that the proposed system can work well under different working conditions, and is promising for automotive industry.

scholarly journals Polycrystalline SnSe with a thermoelectric figure of merit greater than the single crystal

2021 ◽  
Author(s):  
Chongjian Zhou ◽  
Yong Kyu Lee ◽  
Yuan Yu ◽  
Sejin Byun ◽  
Zhong-Zhen Luo ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
High Performance ◽  
Figure Of Merit ◽  
Waste Heat ◽  
Electric Energy ◽  
Cost Effective ◽  
Tin Selenide ◽  
Tin Oxides ◽  
Thermally Conductive

AbstractThermoelectric materials generate electric energy from waste heat, with conversion efficiency governed by the dimensionless figure of merit, ZT. Single-crystal tin selenide (SnSe) was discovered to exhibit a high ZT of roughly 2.2–2.6 at 913 K, but more practical and deployable polycrystal versions of the same compound suffer from much poorer overall ZT, thereby thwarting prospects for cost-effective lead-free thermoelectrics. The poor polycrystal bulk performance is attributed to traces of tin oxides covering the surface of SnSe powders, which increases thermal conductivity, reduces electrical conductivity and thereby reduces ZT. Here, we report that hole-doped SnSe polycrystalline samples with reagents carefully purified and tin oxides removed exhibit an ZT of roughly 3.1 at 783 K. Its lattice thermal conductivity is ultralow at roughly 0.07 W m–1 K–1 at 783 K, lower than the single crystals. The path to ultrahigh thermoelectric performance in polycrystalline samples is the proper removal of the deleterious thermally conductive oxides from the surface of SnSe grains. These results could open an era of high-performance practical thermoelectrics from this high-performance material.

scholarly journals Capturing Waste Heat Energy with Charge-Transfer Organic Thermoelectrics

Synthesis ◽  
2018 ◽  
Vol 50 (19) ◽  
pp. 3833-3842 ◽  
Author(s):  
Vladimir Dimitrov ◽  
Simon Woodward
Keyword(s):  
Waste Heat ◽  
Electrical Power ◽  
Structure Property ◽  
Future Perspectives ◽  
New Materials ◽  
Organic Salts ◽  
Electrically Conducting ◽  
Structure Property Relationships ◽  
Device Applications ◽  
Key Aspects

Electrically conducting organic salts, known for over 60 years, have recently demonstrated new abilities to convert waste heat directly into electrical power via the thermoelectric effect. Multiple opportunities are emerging for new structure–property relationships and for new materials to be obtained through synthetic organic chemistry. This review highlights key aspects of this field, which is complementary to current efforts based on polymeric, nanostructured or inorganic thermoelectric materials and indicates opportunities whereby mainstream organic chemists can contribute.1 What Are Thermoelectrics? And Why Use Them?2 Current Organic and Hybrid Thermoelectrics3 Unique Materials from Tetrathiotetracenes4 Synthesis of Tetrathiotetracenes5 Materials and Device Applications6 Future Perspectives

scholarly journals EFFECTIVE USE OF ROTARY FURNACE SHELL HEAT

2014 ◽  
Vol 54 (6) ◽  
pp. 414-419
Author(s):  
Julius Lisuch ◽  
Dusan Dorcak ◽  
Jan Spisak
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Raw Materials ◽  
Significant Proportion ◽  
Rotary Furnace ◽  
Cost Effective ◽  
Total Energy Expenditure ◽  
Heat Losses ◽  
Controlled Cooling ◽  
Effective Use

<pre><pre>Significant proportion of the total energy expenditure for the heat treatment of raw materials are heat losses through the shell of rotary furnace. Currently, the waste heat is not used in any way and escapes into the environment. Controlled cooling system for rotary furnace shell (<span>CCSRF</span>) is a new solution integrated into the technological process aimed at reducing the heat loss of the furnace shell. Based on simulations and experiments carried out was demonstrated a significant effect of controlled cooling shell to the rotary furnace work. The proposed solution is cost-effective and operationally undemanding.</pre></pre>

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