scholarly journals Thermoacoustic Energy Conversion Devices: Novel Insights

2020 ◽  
Vol 77 (2) ◽  
pp. 130-144
Author(s):  
Mahmoud A. Alamir
Keyword(s):  
Energy Conversion ◽  
Operating Conditions ◽  
Geometric Parameters ◽  
Power Sources ◽  
Thermoacoustic Engines ◽  
Design Characteristics ◽  
And Performance ◽  
Optimisation Methods ◽  
Energy Conversion Devices ◽  
Thermoacoustic Refrigeration

Thermoacoustic engines and refrigerators have many advantages. They use environment-friendly working gases, their design is simple, and they can operate quietly. However, they have many design characteristics from geometric parameters and operating conditions. Besides this, they still have low efficiencies and performance. This paper summarises important considerations of the design and presents the state-of-the-art developments in thermoacoustic energy conversion devices. This includes recent studies and designs of the thermoacoustic refrigeration devices towards more efficient thermoacoustic engines and refrigerators. New insights into the design of resonators, the different sources of the power sources, the different stack geometries and working mediums were considered. The challenges that face the development of thermoacoustic devices were also discussed. Far too little attention has been paid to looking at these devices comprehensively. In further research, the use of neural networks and metadata as optimisation methods could be a means of significantly increasing the performance of these devices. There is also abundant room for further progress in enhancing oscillatory heat transfer. Moreover, further recommendations and studies were proposed for a better understanding of the interrelationship between the geometric parameters and operating conditions.

scholarly journals A Steady-State Equivalent Circuit of TSCAOI Configured Induction Generator for Renewable Energy Conversion Systems

2021 ◽  
Vol 6 (1) ◽  
pp. 20-30
Author(s):  
Zhijia Wang ◽  
Keyword(s):  
Renewable Energy ◽  
Steady State ◽  
Energy Conversion ◽  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Operating Conditions ◽  
Voltage Unbalance ◽  
Energy Conversion Systems ◽  
State Behaviour ◽  
And Performance

3-phase cage induction machines, operated in two series-connected and one-isolated (TSCAOI) winding configuration, have been proposed to generate standalone single-phase electricity at variable speeds for renewable energy conversion systems. However, the steady-state behaviour and performance of this particular generator are not yet to be theoretically investigated. This paper therefore presents the first theoretical investigation based on the steady-state equivalent circuit model for standalone TSCAOI configured generators. Moreover, this paper is the first to adopt the winding function approach to derive a dynamic mathematical model for TSCAOI configured generators. This approach not only eliminates the cumbersome mathematical manipulation required in all previous papers related to TSCAOI configured generators but also provides a visual insight into the resulting winding distribution of the machine. In order to investigate the load and excitation characteristics pertinently, the dynamic model is transformed into two different equivalent circuit models by appropriate selected transformation matrix. Using these two models, this paper identified the impacts of system parameters on the load and excitation characteristics, as well as on the level of voltage unbalance. Experimental results of a prototype generator under various operating conditions are presented, together with simulated results, to demonstrate the accuracy of the proposed investigations.

scholarly journals Radioisotope Thermophotovoltaic Generator Design and Performance Estimates for Terrestrial Applications

2017 ◽  
Author(s):  
Xiawa Wang ◽  
Walker Chan ◽  
Veronika Stelmakh ◽  
Peter Fisher
Keyword(s):  
Heat Source ◽  
Energy Conversion ◽  
Heat Sink ◽  
Electrical Power ◽  
Equivalent Circuit Model ◽  
Operating Conditions ◽  
And Performance ◽  
Heat Sink Design ◽  
Performance Estimates ◽  
Source Number

This work provides the design methods and performance estimates of the radioisotope thermophotovoltaic system (RTPV) for terrestrial applications. The modeling is based on an experimentally tested prototype using two-dimensional high temperature photonic crystal to realize spectral control. The design efforts focus on the optimization of the system efficiency and contain the heat source number, the size of the energy conversion elements, the insulation configuration, and the heat sink design. An equivalent circuit model was developed for the thermal and electrical performances. Based on a specific output requirement, an optimized heat source number and energy conversion area can be computed for a certain cell type and insulation design. The selection and characterization of the low bandgap thermophotovoltaic (TPV) cells applicable to the generator are compared and discussed. The generator’s heat sink design uses extended fins and the performance is estimated based on the external operating conditions. Finally, the work provides a design example of a terrestrial RTPV generator with an output level of ∼40 W electrical power (We) using InGaAsSb cell, reaching an efficiency of 8.26%.

On the Coupling Between Standing-Wave Thermoacoustic Engine and Piezoelectric Transducer

2007 ◽  
Author(s):  
Konstantin I. Matveev ◽  
Andy Wekin ◽  
Cecilia D. Richards ◽  
Najmeddin Shafrei-Tehrany
Keyword(s):  
Mathematical Model ◽  
Energy Conversion ◽  
Standing Wave ◽  
Electric Energy ◽  
Small Scale ◽  
Thermoacoustic Engine ◽  
Power Sources ◽  
Thermoacoustic Engines ◽  
Piezoelectric Elements ◽  
Simplified Mathematical Model

Small thermoacoustic engines integrated with piezoelectric elements can be effective small-scale power sources to convert heat to electricity. A simplified mathematical model is developed to illustrate the effect of transducer parameters on the frequency and onset temperature difference in a standing-wave engine and to estimate efficiencies of energy conversion. Results of sample calculations show that efficiencies for the acoustic-electric energy conversion on the order of 10% are feasible.

Картофелекопатель с ротационной сепарирующей поверхностью

2018 ◽  
Author(s):  
V.M. Alakin ◽  
G.S. Nikitin
Keyword(s):  
Performance Data ◽  
Pilot Studies ◽  
Research Results ◽  
Operating Modes ◽  
Analysis Of Results ◽  
Design Characteristics ◽  
And Performance ◽  
Definition Of

Приведены результаты исследований экспериментального картофелекопателя с ротационной сепарирующей поверхностью. Особое внимание уделяется обоснованию конструктивных параметров и определению рабочих характеристик нового сепарирующего устройства. На основе анализа результатов экспериментальных исследований определены наиболее оптимальные режимы работы экспериментального картофелекопателя.Research results of an experimental potato digger with rotational separating web are published in this article. Special attention is paid to definition of design characteristics and performance data of the new separating device. Admissible operating modes are defined on the basis of the analysis of results of pilot studies of the experimental potato digger.

MODERN EQUIPMENT FOR DETERMINING TRACTOR-SPEED PROPERTIES OF THE VEHICLE: CHARACTERISTICS’ ANALYSIS IN LABORATORY CONDITIONS

2019 ◽  
Vol 16 (3) ◽  
pp. 276-289
Author(s):  
N. V. Savenkov ◽  
V. V. Ponyakin ◽  
S. A. Chekulaev ◽  
V. V. Butenko
Keyword(s):  
Environmental Performance ◽  
Operating Conditions ◽  
Special Role ◽  
Development Stages ◽  
Advantages And Disadvantages ◽  
Force Transfer ◽  
Characteristics Analysis ◽  
And Performance ◽  
Loading Devices ◽  
Structural Solutions

Introduction. At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.Materials and methods. The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.Discussion and conclusions. The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.

Application of vacuum belt press filters for cane mud filtration and performance comparison with rotary filters

2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit
Keyword(s):  
Electricity Consumption ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Vacuum Filter ◽  
Sugar Mill ◽  
Belt Press ◽  
Vacuum Belt ◽  
And Performance ◽  
Mud Filtration ◽  
The Impact

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

Sign in / Sign up

Export Citation Format

Share Document