High energy conversion composites based on graphene material with excellent healing performances

2021 ◽  
pp. 51690
Author(s):  
Peishuang Xiao ◽  
Guanghao Li ◽  
Suping Ma ◽  
Zhihao Cai ◽  
Lu Huang ◽  
...  
Keyword(s):  
Energy Conversion ◽  
High Energy ◽  
Graphene Material

Current progress and performance improvement of Pt/C catalysts for fuel cells

2020 ◽  
Vol 8 (46) ◽  
pp. 24284-24306
Author(s):  
Xuefeng Ren ◽  
Yiran Wang ◽  
Anmin Liu ◽  
Zhihong Zhang ◽  
Qianyuan Lv ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Energy Conversion ◽  
Performance Improvement ◽  
Electric Energy ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Carnot Cycle ◽  
High Energy Conversion Efficiency ◽  
And Performance

Fuel cell is an electrochemical device, which can directly convert the chemical energy of fuel into electric energy, without heat process, not limited by Carnot cycle, high energy conversion efficiency, no noise and pollution.

scholarly journals Performance Characteristics in Runner of an Impulse Water Turbine with Splitter Blade

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 303
Author(s):  
Lingdi Tang ◽  
Shouqi Yuan ◽  
Yue Tang ◽  
Zhijun Gao
Keyword(s):  
Energy Conversion ◽  
Flow Direction ◽  
Mechanical Energy ◽  
Experimental Tests ◽  
High Energy ◽  
Negative Energy ◽  
Water Turbine ◽  
Conversion Performance ◽  
Water Turbines ◽  
Current Energy

The impulse water turbine is a promising energy conversion device that can be used as mechanical power or a micro hydro generator, and its application can effectively ease the current energy crisis. This paper aims to clarify the mechanism of liquid acting on runner blades, the hydraulic performance, and energy conversion characteristics in the runner domain of an impulse water turbine with a splitter blade by using experimental tests and numerical simulations. The runner was divided into seven areas along the flow direction, and the power variation in the runner domain was analyzed to reflect its energy conversion characteristics. The obtained results indicate that the critical area of the runner for doing the work is in the front half of the blades, while the rear area of the blades does relatively little work and even consumes the mechanical energy of the runner to produce negative work. The high energy area is concentrated in the flow passage facing the nozzle. The energy is gradually evenly distributed from the runner inlet to the runner outlet, and the negative energy caused by flow separation with high probability is gradually reduced. The clarification of the energy conversion performance is of great significance to improve the design of impulse water turbines.

In situ lithiated FeF3/C nanocomposite as high energy conversion-reaction cathode for lithium-ion batteries

2016 ◽  
Vol 307 ◽  
pp. 435-442 ◽  
Author(s):  
Xiulin Fan ◽  
Yujie Zhu ◽  
Chao Luo ◽  
Tao Gao ◽  
Liumin Suo ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
High Energy ◽  
Conversion Reaction

Direct-Write Piezoelectric Polymeric Nanogenerator with High Energy Conversion Efficiency

Nano Letters ◽  
2010 ◽  
Vol 10 (2) ◽  
pp. 726-731 ◽  
Author(s):  
Chieh Chang ◽  
Van H. Tran ◽  
Junbo Wang ◽  
Yiin-Kuen Fuh ◽  
Liwei Lin
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Direct Write ◽  
High Energy Conversion Efficiency

scholarly journals Metal-Water mixtures for Propulsion and Energy-Conversion Applications: Recent Progress and Future Directions

2018 ◽  
Vol 20 (1) ◽  
pp. 53 ◽  
Author(s):  
Dilip Sundaram
Keyword(s):  
Particle Size ◽  
Energy Conversion ◽  
Experimental Studies ◽  
High Energy ◽  
High Energy Density ◽  
Full Potential ◽  
Predictive Tool ◽  
Practical Applications ◽  
Relative Safety ◽  
Metal Water

The metal-water system is attractive for propulsion and energy-conversion applications. Of all metals, aluminum is attractive due to its high energy density, relative safety, and low cost. Experimental studies provide new insight on the combustion and propulsive behaviors. The burning rate is found to be a strong function of both pressure and particle size. Furthermore, there is a wide scatter in the measured pressure exponents due to differences in particle size, pressure, pH, and equivalence ratio. A major problem with Al/H2O mixtures is incomplete combustion and poor impulses, thereby rendering Al/H2O mixtures unsuitable for practical applications. Efforts to improve the performance of Al/H2O mixtures have only met with moderate success. Although experiments have revealed these new trends, not much is offered in terms of the underlying physics and mechanisms. To explore the combustion mechanisms, theoretical models based on energy balance analysis have been developed. These models involve numerous assumptions and many complexities were either ignored or treated simplistically. The model also relies on empirical inputs, which makes it more a useful guide than a predictive tool. Future works must endeavor to conduct a more rigorous analysis of metal-water combustion. Empirical inputs should be avoided and complexities must be properly treated to capture the essential physics of the problem. The model should help us properly understand the experimental trends, offer realistic predictions for unexplored conditions, and suggest guidelines and solutions in order to realize the full potential of metal-water mixtures.

Thermal Model of a Thin Film Pulsed Pyroelectric Generator

2016 ◽  
Author(s):  
Nicholas R. Jankowski ◽  
Andrew N. Smith ◽  
Brendan M. Hanrahan
Keyword(s):  
Thin Film ◽  
Power Generation ◽  
Energy Conversion ◽  
High Speed ◽  
High Energy ◽  
High Energy Density ◽  
Working Fluid ◽  
Film Material ◽  
Thermodynamic Cycles ◽  
The Impact

Recent high energy density thin film material development has led to an increased interest in pyroelectric energy conversion. Using state-of-the-art lead-zirconate-titanate piezoelectric films capable of withstanding high electric fields we previously demonstrated single cycle energy conversion densities of 4.28 J/cm3. While material improvement is ongoing, an equally challenging task involves developing the thermal and thermodynamic process though which we can harness this thermal-to-electric energy conversion capability. By coupling high speed thermal transients from pulsed heating with rapid charge and discharge cycles, there is potential for achieving high energy conversion efficiency. We briefly present thermodynamic equivalent models for pyroelectric power generation based on the traditional Brayton and Ericsson cycles, where temperature-pressure states in a working fluid are replaced by temperature-field states in a solid pyroelectric material. Net electrical work is then determined by integrating the path taken along the temperature dependent polarization curves for the material. From the thermodynamic cycles we identify the necessary cyclical thermal conditions to realize net power generation, including a figure of merit, rEC, or the electrocaloric ratio, to aid in guiding generator design. Additionally, lumped transient analytical heat transfer models of the pyroelectric system with pulsed thermal input have been developed to evaluate the impact of reservoir temperatures, cycle frequency, and heating power on cycle output. These models are used to compare the two thermodynamic cycles. This comparison shows that as with traditional thermal cycles the Ericsson cycle provides the potential for higher cycle work while the Brayton cycle can produce a higher output power at higher thermal efficiency. Additionally, limitations to implementation of a high-speed Ericsson cycle were identified, primarily tied to conflicts between the available temperature margin and the requirement for isothermal electrical charging and discharging.

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