Begell House Inc.
International Journal of Energy for a Clean Environment
IJECE
2150-3621
20
2
2019
NUMERICAL MODELING OF REAL-TIME GAS INFLUX MIGRATION IN VERTICAL WELLBORES DURING DRILLING OPERATION
95-111
10.1615/InterJEnerCleanEnv.2019029547
Sridharan
Chandrasekaran
Petroleum Engineering Program, Department of Ocean Engineering,
IIT-Madras, Chennai-600036, India
Suresh Kumar
Govindarajan
Indian Institute of Technology- Madras
drift flux
gas kick
multiphase flow
numerical model
well control
In this work, a mathematical one-dimensional two-phase model (liquid + gas) has been developed to simulate the dynamic flow system in the event of a gas kick during vertical drilling. The flow system is a drift-flux model where the fluid properties are represented by averaged mixture properties rather than by two independent formulations. With this model, different flow scenarios and influx fluid propagation are investigated in vertical wells. The numerical solution is based on finite volume staggered discretization solved implicitly by a first-order upwind scheme. A sensitivity analysis of the influx model parameters, namely, the gas slip velocity, was performed and its impact on the bottom hole pressure and kick propagation is demonstrated. This model is further extended to predict the kick velocity and pressure in the annulus at the bit based on surface flow measurements in real-time drilling. This paper details on the model development of transient two-phase flow along with validation with experimental results. It is found from the study that the developed light-weight simulation model could be employed in real-time drilling to model influx events, and the drift-flux simulation approach is comparable with the experimental and analytical results.
PERSPECTIVES FOR DEVELOPING AND USING THE TORREFACTION TECHNOLOGY IN UKRAINE
113-134
10.1615/InterJEnerCleanEnv.2019026643
Myroslav
Panchuk
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
S.
Kryshtopa
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
A.
Panchuk
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
L.
Kryshtopa
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
B.
Dolishnii
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
I.
Mandryk
Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk,
Ukraine
A.
Sladkowski
Silesian Polytechnic University, Gliwice, Poland
torrefaction technology
bioenergy
biofuels
cellulose
hemicellulose
lignin
pyrolysis
Ukraine refers to countries that only partially provide themselves with traditional types of energy resources, and it is forced to import about 65% of fossil fuels. This article shows the possibility of increasing the biomass energy using through introduction of torrefaction technology as a relatively new process that allows converting raw material to highly efficient fuels with properties close to fossil fuels increasing amount of processing of raw materials geography of its delivery, reducing the cost of transportation, storage what will be enable to save traditional fuel and energy resources, diversify sources of energy supplies, strengthen energy independence of the state and improve the environment. There are a number of applications for torrefaction products, the most promising of which are: combustion in pellet boilers, cofiring with coal, gasification of raw biomass for fuel production, and the production of composite wood-based materials. Estimation of the efficiency of considered technologies is carried out.
VALIDATION AND COMPARISON OF DISCRETE ELEMENT MODEL AND TWO-FLUID MODEL FOR DENSE GAS-SOLID FLOW SIMULATION IN A FLUIDIZED BED
135-151
10.1615/InterJEnerCleanEnv.2019025595
Ling
Zhou
Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, No. 301 Xuefu Road, Zhenjiang 212013, China
Ling
Bai
Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, No. 301 Xuefu Road, Zhenjiang 212013, China
Lingjie
Zhang
Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, No. 301 Xuefu Road, Zhenjiang 212013, China
Weidong
Shi
School of Mechanical Engineering, Nantong University, No. 9 Seyuan Road,
Nantong 226019, China
Ramesh K.
Agarwal
Department of Mechanical Engineering and Materials Science, Washington
University in St. Louis, 1 Brookings Dr., St. Louis, MO 63130
discrete element method
gas-solid flow
two-fluid model
numerical simulation
Two-fluid model (TFM) and discrete element model (DEM) are the two most widely used methods for numerical simulation of dense gas-solid flow in a fluidized bed. It is of great interest to investigate the differences in the physics of these two models and their applicability regime in modeling the dense gas-solid flow accurately. In this study, a quasi-2D spouted fluidized bed was simulated by DEM and TFM separately. In DEM, the hydrodynamic flow field is computed by solving the incompressible continuity and Navier-Stokes equations, while the motion of the solid particles is modeled by the Newtonian equations of motion. The results show that the TFM cannot predict the evolution of the bubbles in the fluidized bed accurately, but it could predict the height of the bed better in the initial period of fluidization. Compared to the TFM, it is found that the DEM is closer to the experiment in determining the changes in the bubble shape, bed pressure fluctuations, and particle velocity; however, the bed height predicted by DEM is slightly lower than the experimental value. The TFM simulations based on the Eulerian approach although computationally more efficient are not very accurate in capturing the flow features of the fluidized bed. It is concluded that for accurate simulation of transient dense gas-solid flow simulation of a fluidized bed, DEM should be used and not the TFM based on the kinetic theory of granular flow.
ASSESSMENT OF ENERGY EFFICIENCY OF THE MODERNIZED MAIN FAN UNIT FOR AN UNDERGROUND MINE
153-165
10.1615/InterJEnerCleanEnv.2019026505
Ayaal
Egorov
EiAPP Department, Mirny Polytechnic Institute (branch), M.K. Ammosov
North-Eastern Federal University, Mirny, Russia
Alexander
Semenov
EiAPP Department, Mirny Polytechnic Institute (branch), M.K. Ammosov
North-Eastern Federal University, Mirny, Russia
Yuriy
Bebikhov
EiAPP Department, Mirny Polytechnic Institute (branch), M.K. Ammosov
North-Eastern Federal University, Mirny, Russia
Alexander
Sigaenko
PVS and VR Mine "Internatsionalnyi," Mirny GOK AK "ALROSA" (PJSC),
Mirny, Russia
ventilation
mine
main fan unit (MFU)
modernization
energy effi ciency
modeling
MatLab
The present paper is focused on comparison and analysis of two different main fan units (MFUs) for the "Internatsionalnyi" mine from the viewpoint of ensuring energy efficiency of mining equipment. The mathematical models of the two unit systems were created in terms of the MatLab/ Simulink package to analyze the energy efficiency. The results of calculations were compared with the real parameter obtained with the help of instrumental control. Graphical relationships were established between the static pressure, volumetric flow rate, power, and angular speed. The annular power consumption has been computed.
It has been proven that replacement of MFU resulted in a higher reliability of the mine ventilation system. At the same time, it brought about a significant increase in the energy efficiency of the unit due to the more advanced equipment and adequate management system.
EXPERIMENTAL AND THEORETICAL STUDIES OF THE HEAT TRANSFER CHARACTERISTICS OF THE LAB-SCALE SENSIBLE HEAT STORAGE SYSTEM
167-193
10.1615/InterJEnerCleanEnv.2019025350
Ajitanshu
Vedrtnam
Vinoba Bhave Research Institute, Allahabad, UP, 211004, India; Department of Mechanical Engineering, Invertis University, Bareilly, UP,
243001, India; Translational Research Centre, Institute of Advanced Materials, VBRI,
Linkoping 58330, Sweden
Mon Prakash
Upadhyay
Department of Mechanical Engineering, Invertis University, Bareilly, UP, 243001, India
Kishor
Kalauni
Department of Mechanical Engineering, Invertis University, Bareilly, UP,
243001, India
computational fluid dynamics
sensible heat storage
temperature profile
heat transfer characteristics
solar thermal power plant
Sensible heat storage in a passive mode is in the phase of development and has a significant potential for improvement. The present work includes the composition of a computational fluid dynamics (CFD) model for predicting the heat transfer characteristics of the sensible heat storage system (SHSS) followed by the validation of the numerical model with experimental data obtained using a lab-scale facility constructed for investigating the heat transfer characteristics of the SHSS. A concrete structure with an embedded steel pipe having the maximum energy storage capacity of 1.12 MJ was considered for numerical modeling and experimentation. For the 90-min charging period, the stored energy was 1.01 MJ during experimentation, and the numerical model has predicted the stored energy to be equal to 0.99 MJ. The charging/discharging time, pipe and concrete temperature profiles were also predicted with considerable accuracy by the numerical model. The dependence of storage performance on operating temperature range, thermophysical properties of sensible heat storage material, and heat transfer fluid has also been established. The excellent agreement between experimental and theoretical results ensured the applicability of the numerical model for higher temperature full-scale applications.