3D Visualization of the Results of Using Modern Ofa Technology on the Example of Real Boiler

The leading place in the world for environmental protection is currently occupied by the protection of the air basin. And the main sources of atmospheric pollution are industrial enterprises, motor transport and thermal power plants. Thus, there is an obvious need to increase attention to the problems of the innovation sector, mainly in the areas of technical improvement of heat and power industry enterprises. Therefore, the study of the problems of reducing the amount of harmful emissions into the atmosphere, control and regulation of its quality, as well as the study of new various methods of innovative development of thermal power is an urgent task at present, requiring a serious scientific approach. In the proposed work, computer experiments were carried out in the field of innovative energy production technologies (the use of modern "sharp blast" OFA technology) at a specific thermal power facility of the enterprise of the Republic of Kazakhstan. During the experiment, various ways of supplying additional air through OFA nozzles were investigated: OFA=0% (basic version without additional air supply), OFA=10% and OFA=18%. For these three modes, a comparative analysis of the aerodynamics of the furnace part of the boiler was performed according to the obtained distributions of the temperature and concentration fields of nitrogen oxide NO over the entire volume of the combustion chamber. The results obtained were compared with experimental data obtained during experiments conducted directly at the CHP.

Optimal Estimation of Thermal Diffusivity in a Thermal Energy Transfer Problem with Heat Generation, Convection Dissipation and Lateral Heat Flow

This work focuses on determining the coefficient of thermal diffusivity in a one-dimensional heat transfer process along a homogeneous and isotropic bar, embedded in a moving fluid with heat generation. A first type (Dirichlet) condition is imposed on one boundary and a third type (Robin) condition is considered at the other one. The parameter is estimated by minimizing the squared errors where noisy observations are numerically simulated at different positions and instants. The results are evaluated by means of the relative errors for different levels of noise. In order to enhance the estimation performance, an optimal design technique is chosen to select the most informative data. Finally, the improvement of the estimate is discussed when an optimal design is used.

Geomechanical Hazards related to River Hydraulics and Remedial Measures: Selected Case Studies in India

River science and engineering has been one of the important study areas for geologists, hydrologists and engineers. The open channel flow and associated hydraulics often initiate several geomechanical hazards including silting and scouring, meandering and migration, floods, etc. Such hazards may lead to disastrous consequences if adequate remedial measures are not undertaken by proper river training works. This paper presents selected case studies in northern and north-eastern parts of India where such hazards occurred due to migration of river channel and flooding of adjacent lands. The two study areas have been the Kosi and the Brahmaputra river basins. In the former study area, hazards took place due to eastward migration, whereas in the latter case, significant damages occurred due to scouring and erosion. The descriptions of the hazards occurred, and the mitigation techniques adopted have been briefly summarized in this paper. A critical analysis with prediction techniques for flood occurrence probability and erosion potential has been conducted as well. The relevant conclusions are drawn therefrom.

Effects of Physical Coordinate Clustering on Boundary Vorticity Approximations in von Mises Coordinates

Forward finite difference expressions of first-order accuracy for boundary vorticity on a solid boundary are evaluated in this work when the physical coordinates are clustered and mapped using von Mises coordinates. Results show that schemes using in-field grid points do not improve solutions obtained. Results also show that the finer the grid used in the physical domain, and the more clustered it is, improves the boundary vorticity values in the computational domain. The “best” expressions forward finite difference expressions are identified when two, three, four and five grid points are used.

Simulation of Nitrogen Oxides Formation as Air Pollution on the Example of Real Combustion Furnace

As in other countries in Central and West Asia, most of Kazakhstan's power plants have reached their potential as they were built mainly during the Soviet era. In this regard, it is important today to optimize coal consumption processes, introduce new environmentally friendly technologies and reduce emissions. And it is impossible without conducting detailed studies of the combustion of fuels in the combustion chambers of energy devices. It can provide complete information about the nature of complex processes of heat and mass transfer without special financial, time and labor costs. The existing models of the formation and destruction of nitrogen-containing substances NOx do not have a universal nature of use, since the fuel and combustion conditions are different. In this regard, the proposed work considered two models that are widely used. The aim of this work is to select a model that actually can describe the processes of dioxin formation in the combustion chamber of a real CHP boiler when high ash content coal is burned in it. The results of the simulation were verified with the data of field experiments, which allows an objective conclusion to be made. The obtained research data and the method of applying the selected optimal kinetic scheme of dioxin formation contribute to the development of new and optimization of existing measures to control environmental pollution

Analysis of the Strong and Weak Monotonic External Stability of the Resonance in a Perturbed Dynamical System

A perturbed dynamical system involving two ordinary differential equations is under review. Whereupon, the differential equation for determining the fast phase contains the ratio of the two frequencies. When these frequencies coincide for a long time, a resonance is implemented in this system. The aim of this paper is to obtain the conditions of monotonic external stability and instability of this resonance. The sufficient conditions for the external stability and instability of the resonance defined in this paper assume that the signs of the analyzed derivatives remain unchanged in the non-resonant section of the change in the independent variable. This paper gives a new classification of the phenomenon of external stability of resonance, which includes weak, linear, and strong stability. It should be noted that the conditions of monotonic external stability and instability of the resonance presented in this paper can be used in various scientific and technological problems, in which resonances are observed. Particularly, the concluding part of the paper considers the application of the results obtained within the framework of the problem of the perturbed motion of a rigid body relative to a fixed point.

Ultrasonic Exposure of the Liquid Film for Highly Efficient Gas Absorption

A model of ultrasonic intensification of the absorption process is proposed, developed, and analyzed. For the first time, the model takes into account the effect of wave-like capillary perturbations of the liquid-gas surface and the acceleration of diffusion in the liquid volume on the absorption rate due to cavitation. According to the results of the model researches, the need for uniform sounding of the extended surface of the liquid film is established to accelerate the absorption of carbon dioxide and other harmful and target gaseous impurities by at least 3 times. The designs and layout of ultrasonic vibration radiators with an extended radiation surface are proposed. The results of measurements of the vibration amplitudes of the invented transducers showed that they have a relative deviation of the amplitude of no more than 0.2. The proposed approaches to the implementation of the process can be recommended for further research, the selection of optimal designs, and industrial applications to accelerate the absorption of gaseous impurities

Effects of Rotation Speeds on Electrical Submersible Pump Performance under Two-Phase Flow

The effects of the wall shear stress on an Electrical Submersible Pump (ESP) was investigated in this paper. A CFD model in ANSYS Fluent was proposed to simulate actual single-phase and two-phase flow. The bottom hole pressure was minimized by utilizing the artificial lift methods. The flowing fluids in pumps and pipes causes shear stress on surface interacting. In multiphase flow application pump damages on head degradation as well as shear stress affects. The K-ω turbulence model and the multiphase Mixture approach with the sliding technique used to solve the Navier-Stokes equation. To study the effects of gas-liquid (air-water) flow on the ESP and the pump handle ability, the rotation speeds were varied while the other parameters were kept constant. The rotation speeds simulated were at 500, 900, 1500, 2000 and 2500 rpm meanwhile the water flow rate and gas flow rate were kept constant with 20 L/min and 1% fraction, respectively. The results obtained show that as the rotation speeds were increased, the less concentration of the bubbles were observed, moreover the wall shear stress (WSS) increases. Although, the wall shear stress in both single-phase and two-phase flow were tend to increase as the blades length increased, however for the single-phase flow the WSS was found higher in all the simulated rotational speeds.

Numerical Prediction and Reduction of Pressure Loss of Air Flow Inside a Sharp 90˚ Elbow Using Turning Vanes

The aim of this study is to calculate the pressure loss and the effect of turning vanes on the pressure loss incurred by the flow in a duct with a 90˚ sharp elbow using numerical fluid mechanics. The main focus this study was to calculate the effects of the number of turning vanes and the length of the turning vanes on the pressure loss. Computational Fluid Dynamics calculations have been carried out using ANSYS Workbench software. Two turbulence models have been used in these calculations. They are the standard k- and the k- turbulence models. The number and length of the vanes were changed in the study to calculate their effects on pressure loss. The length of the vanes was varied from 0mm to 400mm in steps of 100mm on both sides of the bend and the number of vanes was changed from 0 to 3. It was found that a single curved turning vane can reduce the pressure loss significantly. The pressure loss does not reduce further when the length of the vanes was extended. As the number of turning vanes increased beyond one, the predicted pressure loss starts increasing. The turning vanes in duct systems can be used in industries and factories to reduce the pressure loss.

The Functioning of The Hybrid Integrated Partially Solar-Vapor-Compression Fridge

The main purpose of our research is to increase the utilization of solar thermal energy to supply a refrigerator with vapor compression and reduce the refrigeration power needed for cooling. Combined Hybrid Solar - the vapor- compression refrigerating unit has been built and operates under Mutah University's environment in Jordan. The systems were made up of a capillary tube, condenser, evaporator, and collector. The vapor-pressure refrigerator was incorporated with the classic water-solar system to minimize the compressor's duty and to reduce power consumption in heating the amount of water held in the pipe to be sent along the tube outside the evaporator. After that, it will be returned to the compressor, But at a lesser temperature, to minimize compressor workload and enhance cooling performance. Before the compressor was developed, a solar collector system had been created to maximize its temperature before reaching the compressor to improve C.O.P, and the difference in temperature was remarkable. The vapor-compression refrigerator unit was powered by many generators: solar collector that has been discharged, photovoltaic system, flat plate solar collector. Two groups of tests have been performed experimentally on the partial solar compression refrigerator integrated into a hybrid system. First in the vapor compression refrigerator only, and the second in the Hybrid solar compression refrigerator incorporated. Total sunlight and different temperatures, current, and voltage were measured for many months each hour of the day. The performance coefficient was determined found 2.019, 2.432 respectively. Many auxiliary instruments are utilized to measure the temperature in irradiation networks, voltage, and night-time current every hour.