scholarly journals Analyses on the parameters affected to the output power density of a Faraday-type MHD generator

2014 ◽  
Vol 17 (2) ◽  
pp. 39-46
Author(s):  
Kien Chi Le
Keyword(s):  
Electrical Conductivity ◽  
Power Density ◽  
Output Power ◽  
Voltage Drop ◽  
Load Factor ◽  
Maximum Power Density ◽  
Mhd Generator ◽  
Hall Parameter ◽  
Electrode Voltage ◽  
Segmented Electrode

This paper has shown the power density of a Faraday-type Magnetohydrodynamic (MHD) generator considering the presence of electrode voltage drop. The electrode of the MHD generator used in this paper is a segmented type, therefore there is a reduction of electrical conductivity and Hall parameter. The paper has also defined a load factor to express the effects of voltage drop on the electrode to the output power of an MHD generator. The results obtained from this paper have been analyzed and compared to the previous results where the voltage drop of the electrode is not considered. As a result, the segmented electrode and the voltage drop have affected significantly to the characteristics of the output power. This result is significant for optimization of the MHD generator with respect to the maximum power density.

Characteristics of Output Power as a Function of Hall Parameter in Capacitive-coupled MHD Generator using Microwave Discharge Plasma

2020 ◽  
Vol 140 (10) ◽  
pp. 709-714
Author(s):  
Shunsuke Sakai ◽  
Shota Kon ◽  
Kazumasa Takahashi ◽  
Toru Sasaki ◽  
Takashi Kikuchi ◽  
...  
Keyword(s):  
Output Power ◽  
Discharge Plasma ◽  
Microwave Discharge ◽  
Mhd Generator ◽  
Hall Parameter

Development of High Performance Micro DMFCS and a DMFC Stack

2005 ◽  
Vol 3 (2) ◽  
pp. 131-136 ◽  
Author(s):  
G. Q. Lu ◽  
C. Y. Wang
Keyword(s):  
Power Density ◽  
Silicon Wafer ◽  
Output Power ◽  
Oxygen Transport ◽  
Maximum Output Power ◽  
Maximum Power ◽  
Membrane Electrode ◽  
Maximum Output ◽  
Maximum Power Density ◽  
Air Breathing

A silicon-based micro direct methanol fuel cell (μDMFC) for portable applications has been fabricated and its electrochemical characterization carried out. A membrane-electrode assembly (MEA) was specially fabricated to mitigate methanol crossover. The cell with active area of 1.625cm2 demonstrated a maximum power density of 50mW∕cm2 at 60°C. Since the silicon wafer is too fragile to compress for sealing, and a thicker layer of gold has to be coated on the silicon wafer to reduce contact resistance, further development of micro DMFCs for high power application was carried out using stainless steel as bipolar plate in which flow channels were fabricated by photochemical etching technology. The maximum power density of the micro DMFC reaches 62.5mW∕cm2 at 40°C and 100mW∕cm2 at 60°C with atmospheric pressure. An 8-cell air-breathing DMFC stack has been developed. Mass transport phenomena such as water transport and oxygen transport were investigated. By using a water management technique, cathode flooding was avoided in our air-breathing DMFC stack. Furthermore, it was found that oxygen transport in the air-breathing cathode is still very efficient. The DMFC stack produced a maximum output power of 1.33W at 2.21V at room temperature, corresponding to a power density of 33.3mW∕cm2. A passive DMFC using pure methanol was demonstrated with steady-state output power of 20-25mW∕cm2 over more than 10h without heat management.

Development of High Performance Micro DMFCs and a DMFC Stack

2005 ◽  
Author(s):  
Guoqiang Lu ◽  
Chao-Yang Wang
Keyword(s):  
Power Density ◽  
Silicon Wafer ◽  
Output Power ◽  
Oxygen Transport ◽  
Maximum Output Power ◽  
Maximum Power ◽  
Membrane Electrode ◽  
Maximum Output ◽  
Maximum Power Density ◽  
Air Breathing

A silicon-based micro direct methanol fuel cell (μDMFC) for portable applications has been fabricated and its electrochemical characterization carried out. A membrane-electrode assembly (MEA) was specially fabricated to mitigate methanol crossover. The cell with the active area of 1.625 cm2 demonstrated a maximum power density of 50 mW/cm2 at 60°C. Since silicon wafer is too fragile to compress for sealing, and a thicker layer of gold has to be coated on the silicon wafer to reduce contact resistance, further development of micro DMFCs for high power application was carried out using stainless steel plate as bipolar plate in which flow channels were fabricated by photochemical etching technology. The maximum power density of the micro DMFC reaches 62.5 mW/cm2 at 40 °C and 100 mW/cm2 at 60°C with atmospheric pressure. An 8-cell air-breathing DMFC stack has been developed. Mass transport phenomena such as water transport, and oxygen transport were investigated. By using a water management technique, cathode flooding was avoided in our air-breathing DMFC stack. Furthermore, it was found that oxygen transport in the air-breathing cathode is still very efficient. The DMFC stack produced a maximum output power of 1.33 W at 2.21 V at room temperature, corresponding to a power density of 33.3 mW/cm2. A passive DMFC using pure methanol was demonstrated with steady-state output power of 20–25 mW/cm2 over more than 10 hours without heat management.

scholarly journals Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Piezoelectric Patch ◽  
Piezoelectric Energy ◽  
Electromagnetic Transduction ◽  
Self Powered ◽  
Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

A 4.69-W/mm output power density InAlN/GaN HEMT grown on sapphire substrate

2011 ◽  
Vol 32 (12) ◽  
pp. 124003 ◽  
Author(s):  
Bo Liu ◽  
Zhihong Feng ◽  
Sen Zhang ◽  
Shaobo Dun ◽  
Jiayun Yin ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Sapphire Substrate ◽  
Gan Hemt

Thermoelectric module design to improve lifetime and output power density

2021 ◽  
Vol 18 ◽  
pp. 100391
Author(s):  
W. Sun ◽  
R. Sui ◽  
G. Yuan ◽  
H. Zheng ◽  
Z. Zeng ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Thermoelectric Module ◽  
Module Design

Carbon Nano Tube-Polymer Hybrid Nanocomposite Electrodes for Porous Polydimethylsiloxane Sponge-Based Flexible Triboelectric Nanogenerators

2021 ◽  
Vol 21 (9) ◽  
pp. 4680-4684
Author(s):  
Dae-Hyeon Kwon ◽  
Jaebum Jeong ◽  
Yongju Lee ◽  
Jun-Kyu Park ◽  
Suwoong Lee ◽  
...  
Keyword(s):  
Power Density ◽  
Output Voltage ◽  
Maximum Power ◽  
Maximum Power Density ◽  
Flexible Electrodes ◽  
Flexible Devices ◽  
Copper Electrodes ◽  
Polymer Hybrid ◽  
Triboelectric Nanogenerators ◽  
Carbon Nano Tube

Flexible triboelectric nanogenerators (TENGs) have attracted much attention because of its environmentally friendly, practical, and cost-producing advantages. In flexible TENGs, it is important to study the flexible electrodes in order to fabricate the fully flexible devices. Here, we compared electrical characteristics of the sponge porous polydimethylsiloxane (PDMS)-based flexible TENGs with two types of flexible electrodes, copper and carbon nanotube (CNT)-PDMS electrodes. The output voltage and maximum power density of sponge PDMS-based flexible TENGs with copper and CNTPDMS electrodes were compared. The voltage and power density of sponge PDMS-based flexible TENGs with CNT-PDMS electrodes were improved compare to those with copper electrodes. The output voltage and the maximum power density of sponge PDMS-based flexible TENGs with copper and CNT-PDMS electrodes increased 4 times and 7 times, respectively. It is attributed to higher electrical conductivity and stably flow electricity of CNT than those of copper.

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