Beam-plasma mechanism for anode plasma generation in a low-pressure two-stage self-sustained discharge with a cold hollow cathode

2003 ◽  
Vol 48 (9) ◽  
pp. 1145-1150 ◽  
Author(s):  
A. I. Stognij ◽  
N. N. Novitskii
Keyword(s):  
Hollow Cathode ◽  
Low Pressure ◽  
Two Stage ◽  
Plasma Generation ◽  
Beam Plasma ◽  
Anode Plasma ◽  
Sustained Discharge

Deposition of a multi-layer coating in a gas-metal beam-plasma formation at low pressure

2021 ◽  
Vol 64 (1) ◽  
pp. 125-129
Author(s):  
V.V. Denisov ◽  
◽  
Yu.A. Denisova ◽  
E.L. Vardanyan ◽  
E.V. Ostroverkhov ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Hollow Cathode ◽  
Multilayer Coating ◽  
Low Pressure ◽  
Plasma Formation ◽  
Vacuum Arc ◽  
Arc Spraying ◽  
Arc Plasma ◽  
Functional Coatings ◽  
Beam Plasma

The vacuum-arc plasma-assisted method was used to deposit a multilayer coating based on Ti and Al in two discharge systems - in a traditional plasma-assisted vacuum-arc spraying system and in a system for generating of gas-metal beam-plasma formation formed in a hollow cathode of a non-self-sustained low pressure glow discharge. The coatings obtained in the investigated discharge schemes are close in elemental and phase composition. In the coating deposited in the plasma-beam formation, the aluminum content is 8% lower, which is probably due to the overall higher average value of the ion flux density on the surface of the growing film in a non-self-sustained glow discharge. In the coating obtained by sputtering in a beam-plasma formation, there are no elements that are part of the material of the sputtered hollow cathode. Gas-metal beam-plasma formations, formed at low pressure, are promising in the processes of functional coatings deposition by the vacuum-arc plasma-assisted method.

Efficiency of two-stage heating of water on CHP plant with turbines of type T-250/300-240

2019 ◽  
Vol 12 (3) ◽  
pp. 213-219
Author(s):  
E. T. Ilin ◽  
S. P. Pechenkin ◽  
A. V. Svetushkov ◽  
J. A. Kozlova
Keyword(s):  
Transition Period ◽  
Steam Pressure ◽  
Low Pressure ◽  
Heat Extraction ◽  
Two Stage ◽  
Permissible Level ◽  
Lower Heat ◽  
Operational Modes ◽  
Extraction Section ◽  
Supply Water

During non-heating and transition period, most of cogeneration turbines operate with a lower heat extraction section actuated only due to a number of restrictions on the maximum and minimum pressure levels in the upper and lower heat extraction sections at operation of the turbine. For turbines of model T-250/300-240, the minimum permissible level of steam pressure in the upper heat extraction section, according to manufacturer data, is set to 0.06 MPa. During the non-heating and transition period, the supply water temperature is usually set in the range of 70–75°С. In order to maintain that temperature of supply water, the steam pressure in the upper heat extraction section should be below the minimum permissible level. As a result, the turbine operates with only the low-pressure heat extraction section actuated, which ensures operation without restrictions, but with a lower efficiency. The authors have introduced a set of measures, which enable to avoid those restrictions and implement two-stage heating of supply water. In this case, on connection of the upper heating extraction section, the pressure in the same is maintained at the minimum permissible level. Heat output characteristics are provided by having some of supply water delivered bypassing the group of network heaters. This operational mode enables to increase the turbine actual heat drop, to reduce the cooling steam flow into the low-pressure section and, accordingly, into the condenser, and to reduce temperature drops in network water heaters. Results of the research of operational modes for turbines of type T-250/300-240 in the non-heating and transition period with one and two-stage heating are provided. The economic efficiency of proposed operational modes was researched, which shows the effectiveness of those modes during non-heating and transition period. The limits of the efficiency of using these modes are determined.

Experimental investigations of glow discharges in hollow cathode geometries at low pressure

2005 ◽  
Vol 33 (2) ◽  
pp. 384-385 ◽  
Author(s):  
T. Callegari ◽  
F. Gegot ◽  
L.C. Pitchford ◽  
J. Galy ◽  
J.P. Boeuf
Keyword(s):  
Hollow Cathode ◽  
Low Pressure ◽  
Experimental Investigations ◽  
Glow Discharges
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