scholarly journals Neon turbo-Brayton cycle refrigerator for HTS power machines

2012 ◽  
Author(s):  
Hirokazu Hirai ◽  
M. Hirokawa ◽  
Shigeru Yoshida ◽  
N. Nara ◽  
S. Ozaki ◽  
...  
Keyword(s):  
Brayton Cycle ◽  
Cycle Refrigerator

Development of a Condensation Refueling Gas Recovery System Based on Turbo Brayton Refrigeration Technique

2014 ◽  
Vol 960-961 ◽  
pp. 595-598 ◽  
Author(s):  
Lian You Xiong ◽  
Wen Hai Lu ◽  
Zhi Yong Huo ◽  
Nan Peng
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Condensation Temperature ◽  
Brayton Cycle ◽  
Recovery Efficiency ◽  
Gas Recovery ◽  
Gasoline Vehicles ◽  
Recovery System ◽  
Volatile Organic ◽  
Cycle Refrigerator

Volatile organic compounds (VOCs) are emitted from the refueling of gasoline vehicles and trucks. Controlling these emissions has been an important issue since the late 2000s in China. We have recently developed a condensation refueling gas recovery system to recover the VOCs from gaseous wastes at a bulk gasoline terminal. In this system VOC vapor is condensed by a reversed turbo-Brayton cycle refrigerator. The recovery system has a capacity of 100 Nm3/hr at the lowest condensation temperature of 190K. It has been put into use since 2008. The achieved recovery efficiency is 96% and the emission of VOCs is less than 8 g/m3 at the exit of the recovery system.

Techno-economic Evaluation of Utility-Scale Power Plants Based on the Indirect sCO2 Brayton Cycle - Report

2017 ◽  
Author(s):  
Charles W. White ◽  
Walter Shelton ◽  
Nathan Weiland ◽  
Travis Shultz ◽  
John Plunkett ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
Power Plants ◽  
Brayton Cycle ◽  
Utility Scale

scholarly journals Comparative Exergy Analysis of Units for the Porous Ammonium Nitrate Granulation

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 280
Author(s):  
Dmytro Levchenko ◽  
Andrii Manzharov ◽  
Artem Artyukhov ◽  
Nadiya Artyukhova ◽  
Jan Krmela
Keyword(s):  
Ammonium Nitrate ◽  
Exergy Analysis ◽  
Evaporative Cooling ◽  
Energy Resources ◽  
Unit Mass ◽  
Brayton Cycle ◽  
Basic Scheme ◽  
Target Parameter ◽  
Effective Implementation ◽  
Nitrate Production

The article deals with the study on the efficiency of units for porous ammonium nitrate production. The ways which increase the effective implementation of energy resources are determined by including the ejector recycling module, heat and mass exchangers that utilize principles of regenerative indirect evaporative cooling, and the sub-atmospheric inverse Brayton cycle. Mixed exergy analysis evaluates all flows of the system contour as those of the same value. The target parameter for determining the efficiency of both systems is the ratio of the unit’s productivity to the exergy expenditures to produce the unit mass of the product. As a result, it is found that the mentioned devices and units enable to increase the efficiency of the basic scheme by 87%.

scholarly journals Numerical Study of Thermal-Hydraulic Performance of a New Spiral Z-Type PCHE for Supercritical CO2 Brayton Cycle

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4417
Author(s):  
Tingting Xu ◽  
Hongxia Zhao ◽  
Miao Wang ◽  
Jianhui Qi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Pressure Loss ◽  
Numerical Study ◽  
Hydraulic Performance ◽  
Optimal Structure ◽  
Original Structure ◽  
Brayton Cycle ◽  
Compact Structure ◽  
Spiral Angle

Printed circuit heat exchangers (PCHEs) have the characteristics of high temperature and high pressure resistance, as well as compact structure, so they are widely used in the supercritical carbon dioxide (S-CO2) Brayton cycle. In order to fully study the heat transfer process of the Z-type PCHE, a numerical model of traditional Z-type PCHE was established and the accuracy of the model was verified. On this basis, a new type of spiral PCHE (S-ZPCHE) is proposed in this paper. The segmental design method was used to compare the pressure changes under 5 different spiral angles, and it was found that increasing the spiral angle θ of the spiral structure will reduce the pressure drop of the fluid. The effects of different spiral angles on the thermal-hydraulic performance of S-ZPCHE were compared. The results show that the pressure loss of fluid is greatly reduced, while the heat transfer performance is slightly reduced, and it was concluded that the spiral angle of 20° is optimal. The local fluid flow states of the original structure and the optimal structure were compared to analyze the reason for the pressure drop reduction effect of the optimal structure. Finally, the performance of the optimal structure was analyzed under variable working conditions. The results show that the effect of reducing pressure loss of the new S-ZPCHE is more obvious in the low Reynolds number region.

Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

2018 ◽  
Author(s):  
Jinlan Gou ◽  
Wei Wang ◽  
Can Ma ◽  
Yong Li ◽  
Yuansheng Lin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Brayton Cycle ◽  
Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

High Efficiency Energy Conversion System Based on Modified Brayton Cycle

2005 ◽  
Author(s):  
Anatoli A. Borissov ◽  
Alexander A. Borissov ◽  
Kenneth K. Kramer
Keyword(s):  
High Efficiency ◽  
Fuel Efficiency ◽  
Brayton Cycle ◽  
Positive Displacement ◽  
Heat Engines ◽  
Current State ◽  
Technological Advances ◽  
First Results ◽  
Power Generation Systems ◽  
Vortex Combustion

Each year, the users in the U.S. alone spend over $100 billion on various type of engines to produce power — electrical, mechanical, and thermal. Despite technological advances, most all of these power generation systems have only been fine tuned: the engine efficiencies may have been improved slightly, but the underlying thermodynamic principles have not been modified to effect a drastic improvement. The result is that most engines in service today suffer from two major problems: low fuel efficiency and emission of high levels of polluting gases in the exhaust gases. The current state of propulsion engines or distributed generation technologies using heat engines shows an average efficiency of between 20% and 40%. These low efficiencies in a high–cost energy market indicate a great need for more efficient technologies. This paper describes a new method of achieving a very high efficiency, namely optimizing every stage of the thermodynamic process-Brayton cycle. Two modified processes, such as isothermal compression and recuperation, add about 35% efficiency to the conventional Brayton cycle, making 60% efficiency for modified Brayton cycle. By utilizing a positive displacement compressor and expander with a novel vortex combustion chamber and a vortex recuperator, high levels of efficiency with low emissions and noise are possible. The prototype engine with low RPM and high torque has been built which use continuous combustion of different fuels under a constant pressure. First results of the engine’s components testing are presented.

scholarly journals Pivoted-Pad Journal Gas Bearing Performance in Exploratory Operation of Brayton Cycle Turbocompressor

1968 ◽  
Vol 90 (4) ◽  
pp. 687-696 ◽  
Author(s):  
R. Y. Wong ◽  
W. L. Stewart ◽  
H. E. Rohlik
Keyword(s):  
Experimental Study ◽  
Journal Bearing ◽  
Inert Gas ◽  
Brayton Cycle ◽  
Ambient Conditions ◽  
Operating Characteristics ◽  
The Third ◽  
Loading Device ◽  
Bearing Design ◽  
Gas Bearing

This paper describes findings obtained to date in the area of journal gas bearings from an experimental study of a Brayton cycle turbocompressor designed for the requirements of a two-shaft 10-kw space power system. The journal bearing design utilizes three pads pivoted on conforming balls and sockets. Two of the pivots are rigidly mounted to the frame, and the third pivot is mounted to the frame through a low-spring-rate diaphragm. This paper describes the salient package and bearing design features and then presents the principal results obtained from testing the package in both a spin calibration rig and operation at design temperature conditions with an inert gas. The results discussed include (a) the successful use of a pneumatic loading device to vary pad load during operation, (b) the operating characteristics of the bearings as obtained over a range of pad loads and ambient conditions, (c) structural and dynamic behavior of the bearing-support system during design temperature operation and (d) a discussion of the wear characteristics of the conforming ball-and-socket pivot as obtained from the tests made to date.

Advanced Rotor Support Technologies for Closed Brayton Cycle Turbines

2005 ◽  
Author(s):  
Christopher DellaCorte ◽  
Steven Bauman ◽  
Kevin Radil ◽  
Malcolm Stanford ◽  
Samuel Howard ◽  
...  
Keyword(s):  
Brayton Cycle ◽  
Rotor Support
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