scholarly journals Performance of Thermoelectric Power-Generation System for Sufficient Recovery and Reuse of Heat Accumulated at Cold Side of TEG with Water-Cooling Energy Exchange Circuit

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5542
Author(s):  
Zhe Zhang ◽  
Yuqi Zhang ◽  
Xiaomei Sui ◽  
Wenbin Li ◽  
Daochun Xu
Keyword(s):  
Energy Loss ◽  
Energy Conversion ◽  
Energy Exchange ◽  
Control Variable ◽  
Load Resistance ◽  
Variable Method ◽  
Water Cooling ◽  
Cold Side ◽  
Thermoelectric Conversion ◽  
The Stability

Aiming to reduce thermal energy loss at the cold side of a thermoelectric generator (TEG) module during thermoelectric conversion, a thermoelectric energy conversion system for heat recovery with a water-cooling energy exchange circuit was devised. The water-cooling energy exchange circuit realized sufficient recovery and reuse of heat accumulated at the cold side of the TEG, reduced the danger of heat accumulation, improved the stability and output capacity of thermoelectric conversion, and provided a low-cost and high-yield energy conversion strategy in energy conversion and utilization. Through the control variable method to adjust the heat generation of the heat source in the thermoelectric conversion, critical parameters (e.g., inner resistance of the TEG, temperatures of thermoelectric modules, temperature differences, output current, voltage, power, and efficiency of thermoelectric conversion) were analyzed and discussed. After using the control variable method to change the ratio of load resistance and internal resistance, the impacts of the ratio of load resistance to inner resistance of the TEG on the entire energy conversion process were elaborated. The results showed that the maximum value of output reached 397.47 mV with a current of 105.56 mA, power of 41.96 mW, and energy conversion efficiency of 1.16%. The power density of the TEG module is 26.225 W/m2. The stability and practicality of the system with a water-cooling energy exchange circuit were demonstrated, providing an effective strategy for the recovery and utilization of heat energy loss in the thermoelectric conversion process.

scholarly journals Structural tuning of heterogeneous molecular catalysts for electrochemical energy conversion

2021 ◽  
Vol 7 (13) ◽  
pp. eabf3989
Author(s):  
Jiong Wang ◽  
Shuo Dou ◽  
Xin Wang
Keyword(s):  
Energy Conversion ◽  
Model Systems ◽  
Structural Variations ◽  
Metal Centers ◽  
Electrochemical Energy Conversion ◽  
Electronic Configurations ◽  
Coordination Spheres ◽  
The Stability ◽  
Molecular Catalysts ◽  
Electrochemical Energy

Heterogeneous molecular catalysts based on transition metal complexes have received increasing attention for their potential application in electrochemical energy conversion. The structural tuning of first and second coordination spheres of complexes provides versatile strategies for optimizing the activities of heterogeneous molecular catalysts and appropriate model systems for investigating the mechanism of structural variations on the activity. In this review, we first discuss the variation of first spheres by tuning ligated atoms; afterward, the structural tuning of second spheres by appending adjacent metal centers, pendant groups, electron withdrawing/donating, and conjugating moieties on the ligands is elaborated. Overall, these structural tuning resulted in different impacts on the geometric and electronic configurations of complexes, and the improved activity is achieved through tuning the stability of chemisorbed reactants and the redox behaviors of immobilized complexes.

scholarly journals Numerical and Experimental Study on the Internal Flow of the Venturi Injector

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 64 ◽  
Author(s):  
Hao Li ◽  
Hong Li ◽  
Xiuqiao Huang ◽  
Qibiao Han ◽  
Ye Yuan ◽  
...  
Keyword(s):  
Energy Loss ◽  
Internal Flow ◽  
Hydraulic Performance ◽  
Mixing Process ◽  
Cavitation Model ◽  
Precise Control ◽  
Mixing Chamber ◽  
Numerical Simulation Methods ◽  
The Stability ◽  
Good Agreement

To study the appropriate numerical simulation methods for venturi injectors, including the investigation of the hydraulic performance, mixing process, and the flowing law of the two internal fluids, simulations and experiments were conducted in this study. In the simulations part, the cavitation model based on the standard k–ε turbulence and mixture models was added, after convergence of the calculations. The results revealed that the cavitation model has good agreement with the experiment. However, huge deviations occurred between the experimental results and the ones from the calculation when not considering the cavitation model after cavitation. Thus, it is inferred that the cavitation model can exactly predict the hydraulic performance of a venturi injector. In addition, the cavitation is a crucial factor affecting the hydraulic performance of a venturi injector. The cavitation can ensure the stability of the fertilizer absorption of the venturi injector and can realize the precise control of fertilization by the venturi injector, although it affects the flow stability and causes energy loss. Moreover, this study found that the mixing chamber and throat are the main areas of energy loss. Furthermore, we observed that the internal flow of the venturi injector results in the majority of mixing taking place at the diffusion and outlet sections.

scholarly journals Onset of centrifugal filtration convection: departure from thermal equilibrium

2013 ◽  
Vol 469 (2154) ◽  
pp. 20120655 ◽  
Author(s):  
S. Saravanan ◽  
D. Brindha
Keyword(s):  
Linear Theory ◽  
Thermal Equilibrium ◽  
Convective Instability ◽  
Energy Exchange ◽  
Body Force ◽  
Field Model ◽  
Centrifugal Filtration ◽  
Alternating Direction ◽  
Filtration Convection ◽  
The Stability

This paper deals with convective instability in a fluid-saturated, rotating porous layer subject to alternating direction of the centrifugal body force, when the layer fails to exhibit thermal equilibrium. The Darcy model is used to describe the flow, and a two-field model is used to take care of the energy exchange. The normal mode approach of the linear theory and the energy approach of the nonlinear theory are used to find the stability characteristics. Unconditional and sharp nonlinear thresholds are found. The study brings out the failure of the linear theory in describing the instability in most parts of the parameter space of interest where possible subcritical instabilities may arise. The stability boundaries are presented graphically and it is found that the inter-phase heat transfer coefficient has a significant effect in the thermal non-equilibrium regime.

scholarly journals The effect of plate design and fixation type on primary stability after open wedge high tibial osteotomy

2013 ◽  
Vol 60 (4) ◽  
pp. 37-41
Author(s):  
Zeljko Stepanovic ◽  
Miroslav Zivkovic ◽  
Snezana Vulovic ◽  
Srbislav Aleksandrovic ◽  
Branko Ristic
Keyword(s):  
High Tibial Osteotomy ◽  
Primary Stability ◽  
Load Resistance ◽  
Tibial Osteotomy ◽  
Open Wedge ◽  
Hybrid Fixation ◽  
Initial Stiffness ◽  
Wedge High Tibial Osteotomy ◽  
The Difference ◽  
The Stability

Background: The stability of the open wedge high tibial osteotomy is dependent on an undamaged cortical hinge and design of the plate. Aims: We evaluated the primary stability of two internal fixation devices for open wedge high tibial osteotomy. Methods: Five pairs of cadaveric tibia with 10? valgus correction were stabilized with a newly designed plate with hybrid fixation and 10 mm spacer block and with conventional T plate with 10 mm spacer block. Static axial loads were applied until ultimate failure of the construct. Results: The average load at initial failure of the new plate construct was 4757.7 N compared to 3022.43 N obtained with the T plate, (p<0.01). The difference in initial stiffness of both constructs was not significant (p=0.27). The mean ultimate load at failure of the new plate construct was 5280.6 N compared to 3635.3N obtained with the T plate, (p=0.001). Conclusion: The new plate with hybrid fixation, provides substantial load resistance but similar stiffness when compared to standard T plate.

Inelastic Scattering and Interference

1997 ◽  
Vol 3 (S2) ◽  
pp. 1033-1034
Author(s):  
D. Van Dyck
Keyword(s):  
Electron Diffraction ◽  
Energy Loss ◽  
Inelastic Scattering ◽  
Energy Exchange ◽  
Position Vector ◽  
Inelastic Electron ◽  
Global System ◽  
Interference Fringes ◽  
Energy Exchanges ◽  
Generating System

Recently it has been a matter of controversy whether inelastically scattered electrons can yield interference fringes so as to obtain holograms, and in particular whether compensation of energy loss in the object by energy gain in the source will maintain coherence [1]. In discussions about coherence (and wave mechanisms in general) it is always dangerous to rely on intuitive arguments (exchange of energy, time of interaction, etc.). In this work we will start from the most general approach, which is inspired by the treatment of inelastic electron diffraction crystals by Yoshioka in 1957 [2]. Energy exchanges are always described quantummechanically by an Hamiltonian. Therefore we can only investigate the balance between energy exchange properly if electron, object, and source are described by one global Hamiltonian. With source we mean the whole electron generating system (emitter, accelerator, condensor).Consider a global system consisting of an electron, with position vector r, an object with particle vectors ri, and a source with particles at rα.

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