I. S. Anufriev

Conditions of explosive evaporation at the phase interface in an inhomogeneous droplet

The phenomenon of water boiling at a phase interface inside an inhomogeneous (containing a carbonaceous particle) water droplet heated in a high-temperature (above 650 K) gaseous medium has been studied by high-speed (up to 105 fps) video recording. Characteristic stages of intense evaporation from the external boundary, bubble formation on the particle surface, explosive vaporization at the phase interface inside the droplet, and disintegration of the droplet have been recognized.

Diagnostics of swirl flow spatial structure in a vortex furnace model

The method of laser Doppler anemometry was applied for study of the spatial structure of a swirl turbulent flow occurred in isothermal lab-scale model of a vortex furnace (“CBTI design”). The criterion of “minimum of total pressure” was applied for visualization of a vortex core; the latter possesses a W-shaped geometry. Velocity and pressure pulsation spectra were measured for a wide range of operational parameters; these spectra testify about zero precession of a vortex core.

Flow diagnostics in a vortex furnace by particle image velocimetry

The internal aerodynamics of a model vortex furnace for a steam generator with a horizontal axis of flow rotation and distributed input of fuel-air mixture jets has been studied. Average characteristics of the flow velocity field in various cross sections have been determined using a digital tracer imaging (particle image velocimetry) technique. Results are compared to data obtained by the method of laser Doppler anemometry.

Modeling of pulverized coal combustion processes in a vortex furnace of improved design. Part 1: Flow aerodynamics in a vortex furnace

Some results of the complex experimental and numerical study of aerodynamics and transfer processes in a vortex furnace, whose design was improved via the distributed tangential injection of fuel-air flows through the upper and lower burners, were presented. The experimental study of the aerodynamic characteristics of a spatial turbulent flow was performed on the isothermal laboratory model (at a scale of 1 : 20) of an improved vortex furnace using a laser Doppler measurement system. The comparison of experimental data with the results of the numerical modeling of an isothermal flow for the same laboratory furnace model demonstrated their agreement to be acceptable for engineering practice.

Steam-enhanced regime for liquid hydrocarbons combustion: velocity distribution in the burner flame

The lab-scale burner device with proprietary design was used for combustion of diesel fuel in a steam-enhanced regime. This operation mode ensures drastic intensification of liquid hydrocarbon combustion due to supply of superheated steam jet to the combustion zone. The particle image velocimetry technique was used for study of velocity field in the burner flame. The method of seeding of flow zone with new kind of tracers (micro-sized silica particles produced from silicon oil added to liquid fuel) was tested.

Visualization of flow structure in a vortex furnace

The spatial structure of a swirling flow in a model vortex furnace with distributed input of fuel-air-mixture jets has been studied. The results of experimental and numerical investigations of a three-dimensional (3D) field of time-averaged velocities in an isothermal laboratory model of a vortex furnace have been used to image the structure of flow. Vortex structures have been identified using λ2 and Q criteria, as well as the concept of “minimum total pressure.” The vortex core of the flow has a V-shaped 3D structure.

Aerodynamics of a promising vortex furnace design

The aerodynamics of a promising vortex furnace design with secondary top blasting has been studied. Flow velocity fields have been measured in an isothermal laboratory model of the furnace using a digital tracer imaging (particle image velocimetry) technique. Three-dimensional diagnostics of flow structure in the combustion chamber has been carried out by the method of laser Doppler anemometry. Processing of the obtained data using the criterion of “minimum total pressure” has been used to visualize the spatial structure of the vortex core.

Study of aerodynamic structure of flow in a model of vortex furnace using Stereo PIV method

The aerodynamic structure of flow in a lab model of a perspective design of vortex furnace was studied. The chamber has a horizontal rotation axis, tangential inlet for fuel-air jets and vertical orientation of secondary injection nozzles. The Stereo PIV method was used for visualization of 3D velocity field for selected cross sections of the vortex combustion chamber. The experimental data along with “total pressure minimum” criterion were used for reconstruction of the vortex core of the flow. Results fit the available data from LDA and simulation.

Characteristics of diesel fuel combustion in a burner with injection of a superheated steam jet

Basic characteristics of combustion of the diesel fuel in a novel autonomous burner with injection of superheated steam into the combustion region are studied. The temperature distribution in the flame is obtained. Calorimetric measurements of heat release and gas analysis of combustion products are performed. The environmental effects of fuel combustion are compared for regimes with injection of a steam jet and an air jet. It is demonstrated that the combustion regime with steam gasification ensures high combustion intensity and combustion efficiency; moreover, the combustion process becomes more environmentally friendly.

Modeling of pulverized coal combustion processes in a vortex furnace of improved design. Part 2: Combustion of brown coal from the Kansk-Achinsk Basin in a vortex furnace

This paper continues with the description of study results for an improved-design steam boiler vortex furnace, for the full-scale configuration of which the numerical modeling of a three-dimensional turbulent two-phase reacting flow has been performed with allowance for all the principal heat and mass transfer processes in the torch combustion of pulverized Berezovsk brown coal from the Kansk-Achinsk Basin. The detailed distributions of velocity, temperature, concentration, and heat flux fields in different cross sections of the improved vortex furnace have been obtained. The principal thermoengineering and environmental characteristics of this furnace are given.