scholarly journals Plasma heating power dissipation in low temperature hydrogen plasmas

2015 ◽  
Vol 22 (10) ◽  
pp. 103516 ◽  
Author(s):  
J. Komppula ◽  
O. Tarvainen
Keyword(s):  
Low Temperature ◽  
Power Dissipation ◽  
Plasma Heating ◽  
Heating Power ◽  
Hydrogen Plasmas

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

scholarly journals Safety Analysis of Solar Module under Partial Shading

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Wei He ◽  
Fengshou Liu ◽  
Jie Ji ◽  
Shengyao Zhang ◽  
Hongbing Chen
Keyword(s):  
Solar Cells ◽  
Power Dissipation ◽  
Hot Spot ◽  
Single Cells ◽  
Short Circuit ◽  
Heating Power ◽  
Maximum Point ◽  
Solar Module ◽  
Partial Shading ◽  
Efficient Alternative

Hot spot often occurs in a module when the qualities of solar cells mismatch and bypass diodes are proved to be an efficient alternative to reduce the effect of hot spot. However, these principles choosing a diode are based on the parameters of bypass diodes and PV cells without consideration of the maximum heating power of the shaded cell, which may cause serious consequences. On this basis, this paper presents a new approach to investigate partially shaded cells in different numbers of PV cells and different shading scenarios, including inhomogeneous illumination among solar cells and incomplete shading in one cell, which innovatively combines the same cells or divides one affected cell into many small single cells and then combines the same ones, and analyzes the shaded cell. The results indicate that the maximum power dissipation of the shaded cell occurs at short-circuit conditions. With the number of solar cells increasing, the shaded cell transfers from generating power to dissipating power and there is a maximum point of power dissipation in different shading situations that may lead to severe hot spot. Adding up the heat converted from solar energy, the heating power can be higher. In this case, some improvements about bypass diodes are proposed to reduce hot spot.

scholarly journals Terahertz power dissipation spectra of electrons in bulk GaAs under high electric fields at low temperature

2009 ◽  
Vol 58 (4) ◽  
pp. 2692
Author(s):  
Zhu Yi-Ming ◽  
Kaz Hirakawa ◽  
Chen Lin ◽  
He Bo-Yong ◽  
Huang Yuan-Shen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Electric Fields ◽  
Power Dissipation ◽  
Bulk Gaas ◽  
High Electric Fields

Effect of Zinc Pot Designs on Flow and Temperature Distribution in Hot-Dip Galvanizing Process

2016 ◽  
Vol 826 ◽  
pp. 99-104
Author(s):  
Guang Rui Jiang ◽  
Li Bin Liu ◽  
Huang Xiang Teng ◽  
Fang Qing Kong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Low Temperature ◽  
Zinc Level ◽  
Heating Power ◽  
Liquid Zinc ◽  
Base Case ◽  
Computational Fluid Dynamics Cfd ◽  
Temperature Liquid

s In this study, Computational Fluid Dynamics (CFD) was used to simulate the flow and temperature distribution in zinc pot of hot-dip galvanizing process. The flow and temperature distribution in a base-case zinc pot was compared to that in other two optimized zinc pots, one of which had a dam between ingot and snout and another one had a reduced heating power. The simulation shows that the dam impedes the flow of low temperature liquid zinc around zinc ingot to strip and increases the fluctuation of zinc level. By reducing the heating power, however, the fluctuation of zinc level could be suppressed.

scholarly journals Photoelectron emission induced by low temperature hydrogen plasmas

2018 ◽  
Author(s):  
Janne Laulainen ◽  
Taneli Kalvas ◽  
Hannu Koivisto ◽  
Risto Kronholm ◽  
Olli Tarvainen
Keyword(s):  
Low Temperature ◽  
Photoelectron Emission ◽  
Hydrogen Plasmas

Low Temperature In-Situ Processing for Si-MBE

1991 ◽  
Vol 220 ◽  
Author(s):  
Juergen Ramm ◽  
Eugen Beck ◽  
Albert Zueger
Keyword(s):  
Low Temperature ◽  
Hydrogen Plasma ◽  
Plasma Heating ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
Wafer Surface ◽  
Process Step ◽  
In Situ Processing

ABSTRACTA basic process sequence for low temperature in-situ processing of metal-insulator-semiconductor (MIS) structures in an ultra-high vacuum (UHV) multichamber system is presented. It includes conditioning of the process chamber by plasma heating, in-situ cleaning of silicon wafers, and conventional silicon molecular beam epitaxy (Si-MBE). The in-situ cleaning is achieved by an argon/hydrogen plasma treatment of the wafer surface at temperatures well below 400° C. The native oxide as well as carbon compounds are removed from the silicon surface. Etch rates for SiO2 are determined for various plasma parameters. Without additional cleaning procedures, silicon films are deposited in another process step using a quadrupole mass spectrometer controlled electron beam evaporator. Epitaxial films are obtained for substrate temperatures as low as 500°C on (100) and 600°C on (111) silicon for deposition rates of 0.05 nm/s.

scholarly journals Flow Field and Temperature Field in a Four-Strand Tundish Heated by Plasma

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 722
Author(s):  
Mengjing Zhao ◽  
Yong Wang ◽  
Shufeng Yang ◽  
Maolin Ye ◽  
Jingshe Li ◽  
...  
Keyword(s):  
Temperature Field ◽  
Flow Field ◽  
Molten Steel ◽  
Short Circuit ◽  
Plasma Heating ◽  
Three Dimensional ◽  
Heating Power ◽  
Flow State ◽  
Selection Of ◽  
Temperature Area

Tundish plasma heating is an effective method for achieving steady casting with low superheat and constant temperature. In order to study the flow field, temperature field in tundish heated by plasma, a three-dimensional transient mathematical model was established in the present work. A four-strand T-type tundish in a steelmaking plant was used to explore the changes in the flow field and temperature field of molten steel in the tundish under different plasma heating powers. The results showed that plasma heating affected the flow state of molten steel. It could eliminate the short-circuit flow at outlet. When the plasma heating was 500 kW, the molten steel had an obvious upward flow. The turbulence intensity was improved and distributed evenly with an increase in plasma heating power. In the prototype tundish, the temperature of the outlet was dropped by nearly 2–3 K within 300 s. With the increase of plasma heating power, the low temperature area in the tundish gradually was decreased. When the heating power was 1000 kW, the temperature difference of two outlets was 0.5 K and the overall temperature distribution was more uniform. The research results have a certain guiding significance for the selection of the actual plasma heating power on site.

Sign in / Sign up

Export Citation Format

Share Document