Integration of heat recirculating microreactors with thermoelectric modules for power generation: A comparative study using CFD

2021 ◽  
Author(s):  
Neha Yedala ◽  
Niket S. Kaisare
Keyword(s):  
Power Generation ◽  
Comparative Study ◽  
Thermoelectric Generator ◽  
Operating Conditions ◽  
Thermoelectric Modules ◽  
Wide Range

Heat recirculating microreactors are being investigated for coupling with thermoelectric generator (TEG) for power generation since they facilitate sustained combustion over a wide range of operating conditions. A major challenge...

scholarly journals Power quality improvement of smart microgrids using EMS-based fuzzy controlled UPQC

2019 ◽  
pp. 1181-1197 ◽  
Author(s):  
AHMED A. HOSSAM-ELDIN ◽  
AHMED A. MANSOUR ◽  
MOHAMMED EL-GAMAL ◽  
KARIM H. YOUSSEF
Keyword(s):  
Power Generation ◽  
Power Quality ◽  
Distribution Systems ◽  
Current Control ◽  
Operating Conditions ◽  
Superior Performance ◽  
Voltage Sag ◽  
Nonlinear Load ◽  
Wide Range ◽  
Voltage Swell

The prevalent power quality problems in smart microgrids and power distribution systems are voltage sag, voltage swell, and harmonic distortion. The achievement of pure sinusoidal waveform with proper magnitude and phase is currently a great research and development concern. The aim of this paper is to evaluate and mitigate the smart microgrid harmonics, voltage sag, and voltage swell throughout a 24-h cycle, taking into consideration the variation in solar power generation due to changes in irradiation received by photovoltaic cells, the variation in wind power generation due to changes in wind speed, and the variation of linear and nonlinear load profiles during the day’s cycle. The mitigation of the power quality issues manifested in current harmonics, voltage sag, and voltage swell is achieved through the implementation of a new fully fuzzy controlled unified power quality conditioner (UPQC). It is controlled by an energy management system (EMS). This paper introduces a new control system for the UPQC using full fuzzy logic control. Moreover, fuzzy control is used in current control instead of proportional integral controllers so that it has acceptable performance over a wide range of operating points. The novel approach of an EMS-connected UPQC activates the UPQC at the required time only into the grid. This approach has many benefits by increasing the UPQC lifetime. The effect of the proposed system on the aforementioned issues has been validated through simulation by MATLAB/Simulink. The results are compared with those obtained by conventional methods. The results verify the superior performance of the proposed UPQC to mitigate the problems of current total harmonic distortions, voltage sag, and voltage swell under different operating conditions during the monitoring period.

Development of a Test Stand for the Characterization of Thermoelectric Modules for Power Generation

2007 ◽  
Author(s):  
Kevin Smith ◽  
Emil Sandoz-Rosado ◽  
Crisson Jno-Charles ◽  
Clement Henry ◽  
Erik Herrmann ◽  
...  
Keyword(s):  
Power Generation ◽  
Electrical Power ◽  
Thermoelectric Module ◽  
Test Stand ◽  
Electrical Performance ◽  
Cold Side ◽  
Thermoelectric Modules ◽  
Senior Design ◽  
Wide Range

The characterization of thermoelectric modules for power generation applications has only received minimal attention by researchers. This paper describes the development of a test stand for the characterization of the thermoelectric power modules. The test stand has the ability to provide constant temperatures on the hot and cold side of thermoelectric modules and measure the amount of electrical power generated. Great care was taken to provide a uniform temperature on both the hot side and cold side of the module, with the hot side having the capability to provide temperatures of up to 600°C and the cold side able to be maintained at room temperature. The system is able to deliver a controlled heat flux of 140 kW/m2 to a thermoelectric module. A data acquisition system was developed to record the electrical performance of tested modules under a wide range of operating temperatures regulated by the control system. Using the collected data it will be possible to compare many modules and evaluate their performance with one another as well as provide module power generation parameters which can be useful for thermoelectric system design. This project was commissioned through the RIT Multidisciplinary Senior Design program as a capstone to the undergraduate degree curricula.

Design, Manufacturing and Testing of a New Family of Steam Turbine Low Pressure Stages

2007 ◽  
Author(s):  
Lorenzo Cosi ◽  
Jonathon Slepski ◽  
Steven DeLessio ◽  
Michele Taviani ◽  
Amir Mujezinovic´
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Low Pressure ◽  
Full Scale ◽  
Operating Conditions ◽  
Test Facility ◽  
Steam Turbines ◽  
Wide Range ◽  
The Family ◽  
Last Stage

New low pressure (LP), stages for variable speed, mechanical drive and geared power generation steam turbines have been developed. The new blade and nozzle designs can be applied to a wide range of turbine rotational speeds and last stage blade annulus areas, thus forming a family of low pressure stages—High Speed (HS) blades and nozzles. Different family members are exact scales of each other and the tip speeds of the corresponding blades within the family are identical. Thus the aeromechanical and aerodynamic characteristics of the individual stages within the family are identical as well. Last stage blades and nozzles have been developed concurrently with the three upstream stages, creating optimised, reusable low pressure turbine sections. These blades represent a step forward in improving speed, mass flow capability, reliability and aerodynamic efficiency of the low pressure stages for the industrial steam turbines. These four stages are designed as a system using the most modern design tools applied on Power Generation and Aircraft Engines turbo-machineries. The aerodynamic performance of the last three stage of the newly designed group will be verified in a full-scale test facility. The last stage blade construction incorporates a three hooks, axial entry dovetail with improved load carrying capability over other blade attachment methods. The next to the last stage blade also uses a three hooks axial entry dovetail, while the two front stage blades employ internal tangential entry dovetails. The last and next to the last stage blades utilize continuous tip coupling via implementation of integral snubber cover while a Z-lock integral cover is employed for the two upstream stages. Low dynamic strains at all operating conditions (off and on resonance speeds) will be validated via steam turbine testing at realistic steam conditions (steam flows, temperatures and pressures). Low load, high condenser pressure operation will also be verified using a three stage test turbine operated in the actual steam conditions as well. In addition, resonance speed margins of the four stages have been verified through full-scale wheel box tests in the vacuum spin cell, thus allowing the application of these stages to Power Generation applications. Stator blades are produced with a manufacturing technology, which combines full milling and electro-discharge machining. This process allows machining of the blades from an integral disc, and thus improving uniformity of the throat distribution. Accuracy of the throat distribution is also improved when compared to the assembled or welded stator blade technology. This paper will discuss the aerodynamic and aeromechanical design, development and testing program completed for this new low pressure stages family.

Experimental study on thermoelectric modules for power generation at various operating conditions

Energy ◽  
2012 ◽  
Vol 45 (1) ◽  
pp. 874-881 ◽  
Author(s):  
Wei-Hsin Chen ◽  
Chen-Yeh Liao ◽  
Chen-I Hung ◽  
Wei-Lun Huang
Keyword(s):  
Power Generation ◽  
Experimental Study ◽  
Operating Conditions ◽  
Thermoelectric Modules

An Efficiency Entitlement Study for Thermoelectric Generators

2007 ◽  
Author(s):  
H. Peter J. De Bock ◽  
Vladimir Novak
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Material Properties ◽  
Thermoelectric Generator ◽  
Operating Conditions ◽  
Thermoelectric Generators ◽  
Thermoelectric Power Generation ◽  
Closed Form Solutions ◽  
Recent Developments ◽  
System Operating

Recent developments in thermoelectric materials and systems have led to renewed interest in thermoelectric devices for power generation. Operating conditions of the heat source and heat sink are essential in evaluating the conversion efficiency of such thermoelectric generator systems. This study provides a method for evaluating efficiency entitlement for thermoelectric power generation when thermoelectric material properties and system operating conditions are specified. The efficiency entitlement in closed form solutions for the most commonly used thermoelectric power generation configurations are presented followed by results and discussion.

scholarly journals Electrical Modelling and Mismatch Effects of Thermoelectric Modules on Performance of a Thermoelectric Generator for Energy Recovery in Diesel Exhaust Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3189
Author(s):  
Samir Ezzitouni ◽  
Pablo Fernández-Yáñez ◽  
Luis Sánchez Rodríguez ◽  
Octavio Armas ◽  
Javier de las Morenas ◽  
...  
Keyword(s):  
Thermoelectric Generator ◽  
Flow Direction ◽  
Electric Energy ◽  
Electric Circuit ◽  
Operating Conditions ◽  
Thermoelectric Generators ◽  
Thermoelectric Modules ◽  
Light Duty ◽  
Negative Effect ◽  
Light Duty Vehicle

Thermoelectric generators harvesting energy from exhaust gases usually present a temperature mismatch between modules, due to the gradual cooling of the gases along the flow direction. The way modules that produce unequal voltages are connected has a deep impact on the overall power output. A further step in the prediction of thermoelectric production is to consider the complete layout of the thermoelectric modules and not consider them as isolated systems. In this work, a model to predict the electric behavior of thermoelectric generators for automotive applications at different points of operation is presented. The model allows testing of serial-parallel connection configurations. The results present good agreement with experimental data. This model could be used on similar light duty vehicles with similar engines as the engine used in this work and using similar configuration of thermoelectric generators. Simulated scenarios considering realistic operating conditions in a light duty vehicle allow stating that thermoelectric modules interconnection under heterogenous thermal surface conditions has a significant negative effect (more than 17%) on electric energy production. Moreover, the proposed model shows the need to protect the electric circuit of the thermoelectric generator to avoid the negative effect of possible malfunction of some thermoelectric modules.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

EXPERIMENTAL INVESTIGATION TO ENHANCE THE POWER GENERATION FOR THERMOELECTRIC GENERATOR UNIT

2019 ◽  
Vol 50 (5) ◽  
pp. 451-462
Author(s):  
Abhishek Khanchi ◽  
Mani Kanwar Singh ◽  
Harkirat Sandhu ◽  
Satbir Sehgal
Keyword(s):  
Power Generation ◽  
Experimental Investigation ◽  
Thermoelectric Generator ◽  
Generator Unit

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

Nitrogen Removal from Anaerobically-Treated Leachate

1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis
Keyword(s):  
Nitrogen Removal ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Anaerobic Filter ◽  
Ph Values ◽  
Wide Range ◽  
Ammonia Desorption ◽  
Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

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