Application Analysis of Vortex TubeTemperature Difference Phenomenon in High-Temperature Cyclone Separator

The compressed gas for ambient temperature in vortex tube can be separated into two streams of different temperature gas, which phenomenon is unapparent for non-compressed gas. However, for non-compressed high-temperature gas, it can produce temperature difference of more than 20°C in vortex tube, which has been ignored by researchers. In this paper, basic principle of temperature difference effect in vortex tube is described firstly, and cooling effect produced by different inlet temperature in the condition of low pressure ratio is analyzed, which results that obvious cooling effect can still be produced for high temperature and low pressure ratio. Combined with factual operation conditions of cyclone separator for circulating fluidized bed (CFB) boiler, a design and renovation method of cyclone separator is proposed firstly according to temperature difference effect principle of high-temperature gas in vortex tube. According to the analysis, the separation efficiency and boiler performance will be enhanced by using temperature difference effect in vortex tube to design and reconstruct the existing cyclone separator.

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Numerical Analysis of Flow Behavior in Vortex Tube for Different Gases

Mechanical Engineering Research ◽

10.5539/mer.v7n2p18 ◽

2017 ◽

Vol 7 (2) ◽

pp. 18

Author(s):

Kiran Dattatraya Devade ◽

Ashok T. Pise ◽

Atul R. Urade

Keyword(s):

High Temperature ◽

Numerical Analysis ◽

Vortex Tube ◽

Flow Behavior ◽

Three Dimensional ◽

Energy Separation ◽

Separation Device ◽

Compressed Gas ◽

Turbulent Models ◽

Different Gases

The vortex tube is an energy separation device that separates compressed gas stream into a low and a high temperature stream. Present work reports the flow behavior inside the vortex tube for different commonly used fluids with varied properties like Air, He, N2, CO2 and NH3. Flow behavior investigation for three-dimensional short straight-diverging vortex tube is done with CFD code (ANSYS 16.0). Different turbulent models, standard k-epsilon, Realizable k-epsilon and RNG k-epsilon are tested. Realizable k-epsilon model was then used for analysis. Flow behavior of gases with varied multi-atomic number is analyzed and compared with literature. The effect on temperature for N2 is found to be better, followed by He, CO2, Air and NH3. Energy separation for N2 is 46 % higher than all other gases. Energy separation and flow behavior inside vortex tube is analyzed and compared with literature.

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Experimental Study and Energy-Saving Analysis on Cooling Effect with Large Temperature Difference and High Temperature of Chilled Water System in Data Center

Environmental Science and Engineering - Proceedings of the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019) ◽

10.1007/978-981-13-9524-6_97 ◽

2020 ◽

pp. 933-942

Author(s):

Zhibo Kang ◽

Zhenhua Shao ◽

Lin Su ◽

Kaijun Dong ◽

Hongxian Liu

Keyword(s):

Experimental Study ◽

High Temperature ◽

Energy Saving ◽

Temperature Difference ◽

Data Center ◽

Water System ◽

Cooling Effect ◽

Large Temperature ◽

Large Temperature Difference ◽

Chilled Water

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The Application of System CFD to the Design and Optimization of High-Temperature Gas-Cooled Nuclear Power Plants

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2835057 ◽

2008 ◽

Vol 130 (3) ◽

Cited By ~ 1

Author(s):

Gideon P. Greyvenstein

Keyword(s):

Steady State ◽

High Temperature ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Low Pressure ◽

Critical Parameters ◽

Wide Range ◽

Component Models ◽

High Temperature Gas

The objective of this paper is to model the steady-state and dynamic operation of a pebble-bed-type high temperature gas-cooled reactor power plant using a system computational fluid dynamics (CFD) approach. System CFD codes are 1D network codes with embedded 2D or even 3D discretized component models that provide a good balance between accuracy and speed. In the method presented in this paper, valves, orifices, compressors, and turbines are modeled as lumped or 0D components, whereas pipes and heat exchangers are modeled as 1D discretized components. The reactor is modeled as 2D discretized system. A point kinetics neutronic model will predict the heat release in the reactor. Firstly, the layout of the power conversion system is discussed together with the major plant parameters. This is followed by a high level description of the system CFD approach together with a description of the various component models. The code is used to model the steady-state operation of the system. The results are verified by comparing them with detailed cycle analysis calculations performed with another code. The model is then used to predict the net power delivered to the shaft over a wide range of speeds from zero to full speed. This information is used to specify parameters for a proportional-integral-derivative controller that senses the speed of the power turbine and adjusts the generator power during the startup of the plant. The generator initially acts as a motor that drives the shaft and then changes over to a generator load that approaches the design point value as the speed of the shaft approaches the design speed. A full startup simulation is done to demonstrate the behavior of the plant during startup. This example demonstrates the application of a system CFD code to test control strategies. A load rejection example is considered where the generator load is suddenly dropped to zero from a full load condition. A controller senses the speed of the low pressure compressor/low pressure turbine shaft and then adjusts the opening of a bypass valve to keep the speed of the shaft constant at 60rps. The example demonstrates how detailed information on critical parameters such as turbine and reactor inlet temperatures, maximum fuel temperature, and compressor surge margin can be obtained during operating transients. System CFD codes is a powerful design tool that is indispensable in the design of complex power systems such as gas-cooled nuclear power plants.

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Effective thermal conductivity of gas–solid composite materials and the temperature difference effect at high temperature

International Journal of Heat and Mass Transfer ◽

10.1016/s0017-9310(98)00287-7 ◽

1999 ◽

Vol 42 (10) ◽

pp. 1885-1893 ◽

Cited By ~ 40

Author(s):

X.-G. Liang ◽

W. Qu

Keyword(s):

Thermal Conductivity ◽

High Temperature ◽

Composite Materials ◽

Effective Thermal Conductivity ◽

Temperature Difference ◽

Difference Effect

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An Environmental Wet Cell For High Voltage Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070539 ◽

1973 ◽

Vol 31 ◽

pp. 18-19

Author(s):

N.J. Tighe ◽

H.M. Flower ◽

P.R. Swann

Keyword(s):

Electron Microscopy ◽

High Temperature ◽

Image Quality ◽

Inelastic Scattering ◽

High Voltage ◽

High Voltage Electron Microscopy ◽

Voltage Electron ◽

Environmental Cell ◽

Water Saturated ◽

High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

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