scholarly journals Experimental Study on Desorption Characteristics of Anthracite in Positive Pressure Environments

2021 ◽  
Author(s):  
Zheng Gao ◽  
Chong Chen
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Pressure Drop ◽  
Inhibitory Effect ◽  
Methane Adsorption ◽  
Positive Pressure ◽  
Desorption Rate ◽  
Experimental Equipment ◽  
Equilibrium Pressure ◽  
Anthracite Coal

In order to investigate the desorption characteristics of methane adsorption in coal under positive pressure conditions, methane adsorption and successive desorption experiments of anthracite coal under positive pressure conditions were conducted on the developed experimental equipment, and the experimental data were analyzed. In the process of desorption of coal samples with the same adsorption equilibrium pressure and the same pressure drop gradient, the phase desorption rate decreased with the increase of pressure, and the positive pressure environment had a significant inhibitory effect on the desorption of methane in coal.

Experimental Study on Resistance Characteristics in a 3 × 3 Rod Bundle

2014 ◽  
Author(s):  
Chaoxing Yan ◽  
Changqi Yan ◽  
Licheng Sun ◽  
Yang Wang
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Local Resistance ◽  
Local Pressure ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Rod Bundle

Experimental study on resistance of air-water two-phase flow in a vertical 3 × 3 rod bundle was carried out under normal temperature and pressure. The rod diameter and pitch were 8 mm and 11 mm, respectively. The ranges of gas and liquid superficial velocity were 0.013∼3.763 m/s and 0.076∼1.792 m/s, respectively. The result indicated that the existing correlations for calculating frictional coefficient in the rod bundle and local resistance coefficient could not give favorable predictions on the single-phase experimental data. For the case of two-phase flow, eight correlations for calculating two-phase equivalent viscosity poorly predicted the frictional pressure drop, with the mean absolute errors around 60%. Meanwhile, the eight classical two-phase viscosity formulae were evaluated against the local pressure drop at spacer grid. It is shown that Dukler model predicted the experimental data well in the range of Rel<9000 while McAdams correlation was the best for Rel⩾9000. For all the experimental data, Dukler model provided the best prediction with MRE of 29.03%. Furthermore, approaches to calculate two-phase frictional pressure drop and local resistance were proposed by considering mass quality, two-phase Reynolds number and densities in homogenous flow model, resulting in a good agreement with the experimental data.

scholarly journals An experimental study on the subcooled flow boiling pressure drop of R141b in the system of two microchannels

2021 ◽  
Vol 2119 (1) ◽  
pp. 012053
Author(s):  
A. S. Shamirzaev
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Heat Flux ◽  
Pressure Drop ◽  
Flow Boiling ◽  
Nucleate Boiling ◽  
Copper Block ◽  
Subcooled Flow Boiling ◽  
Subcooled Flow ◽  
Boiling Incipience

Abstract An experimental study of the pressure drop under subcooled flow boiling of the refrigerant R141b in a system with two slotted microchannels was carried out. A copper block with two microchannels 2 mm wide, 0.4 mm deep, and 16 mm long was used as an experimental section for testing. The mass flow rate varied in the range from 1 to 4 g/s, the initial subcooling from 20°C to 50°C. Experimental data show a significant decrease in the pressure drop when the critical heat flux is reached. The experimental data are compared with the model known from the literature. Experimental data show that the occurrence of nucleate boiling incipience at subcooled boiling corresponds to a larger heat flux than that given by the recommended correlation.

Prediction of Darcy Permeability and Forchheimer’s Coefficient of Porous Structures Relevant to Regenerator of a Stirling Cryocooler Using a Correlation Based Method

2017 ◽  
Vol 25 (02) ◽  
pp. 1750014
Author(s):  
V. V. Kishor Kumar ◽  
Biju T. Kuzhiveli
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Porous Media ◽  
Pressure Drop ◽  
Friction Factor ◽  
Steady Flow ◽  
Wire Mesh ◽  
Pressure Amplitude ◽  
Regenerative Heat ◽  
Inertial Coefficient

A regenerative heat exchanger is the most vital component in the design of a Stirling cryocooler. Computational Fluid Dynamics (CFD) is the best technique for the design and prediction of the performance of a regenerator. The reliability of the simulation results depend on the accuracy of the Darcy permeability [Formula: see text] and Forchheimer’s inertial coefficient [Formula: see text] used for modeling the momentum transfer in porous media. Usually these coefficients are calculated from pressure drop data obtained from experiment. Because of the requirement of sophisticated equipments for the measurement and analysis of data, experimental study becomes expensive. This paper proposes a friction factor correlation-based method for the prediction of directional permeability and Forchheimer’s inertial coefficient of wire mesh structures relevant to Stirling cryocooler. The friction factor for the flow of helium through #325, #400 and #635 SS wire matrices with porosities of 0.6969, 0.6969 and 0.6312 are calculated using standard correlations and compared with the friction factor given by Clearman et al. based on steady flow experimental study. The friction factor obtained from Blass and Tong/London correlations are in agreement with that of Clearman et al. The viscous and inertial resistances are calculated from the friction factor obtained from Blass and Tong/London correlations. Using these values, the regenerator was modeled as a porous media in Fluent. From the steady flow simulation, pressure drop at different mass flow rates (0.08–1.44[Formula: see text]g/s) is obtained. The maximum deviation of predicted pressure drop from the reported experimental data is 15.14%. The Darcy permeability [Formula: see text] and Forchheimer’s inertial coefficient [Formula: see text] obtained from correlation-based method was used for modeling the oscillatory flow of helium through a #400 regenerator. The pressure amplitude and phase at regenerator exit were obtained at different frequencies. The average deviation of predicted pressure amplitude from the experimental data is 15.83%. The model could predict the phase angle also accurately. Therefore, the proposed method can be used to calculate the hydrodynamic parameters of woven wire screen matrices applied to Stirling cryocoolers.

Measurement of Pressure Drop in a Full-Scale Fuel Assembly of a Liquid Metal Reactor

2003 ◽  
Vol 125 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Seok Ki Choi ◽  
Il Kon Choi ◽  
Ho Yun Nam ◽  
Jong Hyeun Choi ◽  
Hoon Ki Choi
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Pressure Drop ◽  
Liquid Metal ◽  
Fuel Assembly ◽  
Diameter Ratio ◽  
Pressure Drops ◽  
Liquid Metal Reactor ◽  
The Wire ◽  
Measured Pressure

An experimental study has been carried out to measure the pressure drop in a 271-pin fuel assembly of a liquid metal reactor. The rod pitch to rod diameter ratio P/D of the fuel assembly is 1.2 and the wire lead length to rod diameter ratio H/D is 24.84. Measurements are made for five different sections in a fuel assembly; inlet orifice, fuel assembly inlet, wire-wrapped fuel assembly, fuel assembly outlet and fuel assembly upper region. A series of water experiments have been conducted changing flow rate and water temperature. It is shown that the pressure drops in the inlet orifice and in the wire-wrapped fuel assembly are much larger than those in other regions. The measured pressure drop data in a wire-wrapped fuel assembly region is compared with the existing four correlations. It is shown that the correlation proposed by Cheng and Todreas fits best with the present experimental data among the four correlations considered.

scholarly journals An experimental study on two-phase pressure drop in small diameter horizontal, downward inclined and vertical tubes

2015 ◽  
Vol 19 (5) ◽  
pp. 1791-1804 ◽  
Author(s):  
Arun Autee ◽  
Srinivasa Rao ◽  
Ravikumar Puli ◽  
Ramakant Shrivastava
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Pressure Drop ◽  
Small Diameter ◽  
Working Fluid ◽  
Water Mixture ◽  
Two Phase ◽  
New Correlation ◽  
Vertical Tubes ◽  
Phase Pressure

An experimental study of two-phase pressure drop in small diameter tubes orientated horizontally, vertically and at two other downward inclinations of ?= 300 and ? = 600 is described in this paper. Acrylic transparent tubes of internal diameters 4.0, 6.0, and 8.0 mm with lengths of 400 mm were used as the test section. Air-water mixture was used as the working fluid. Two-phase pressure drop was measured and compared with the existing correlations. These correlations are commonly used for calculation of pressure drop in macro and mini-microchannels. It is observed that the existing correlations are inadequate in predicting the two-phase pressure drop in small diameter tubes. Based on the experimental data, a new correlation has been proposed for predicting the two-phase pressure drop. This correlation is developed by modification of Chisholm parameter C by incorporating different parameters. It was found that the proposed correlation predicted two-phase pressure drop at satisfactory level.

EXPERIMENTAL STUDY OF THE KINEMATIC PARAMETERS OF MOVEMENT OF CARS FORCED IDLE MOTION

2018 ◽  
pp. 52-57
Author(s):  
Ivelin Kostov
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Experimental Research ◽  
Kinematic Parameters ◽  
Research Results ◽  
Software Product

In the work brought some experimental data of kinematic parameters of movement of cars forced idle, as the software product was used to diagnose 900 ATS, which recorded kinematic parameters of vehicle. On the basis of the conducted experimental research results are shown tabulated and analysed.

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