LASER DOPPLER ANEMOMETRY STUDY OF SWIRLING FLOW IN AN IMPROVED FOUR-VORTEX FURNACE MODEL
- PDF / 1,995,116 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 6 Downloads / 213 Views
LASER DOPPLER ANEMOMETRY STUDY OF SWIRLING FLOW IN AN IMPROVED FOUR-VORTEX FURNACE MODEL E. Yu. Shadrin∗ , I. S. Anufriev∗ , and O. V. Sharypov
UDC 621.18, 533.6.08
Abstract: The aerodynamics of a laboratory model of an improved four-vortex coal combustion furnace is studied using laser Doppler anemometry. For the isothermal case, the distributions of the averaged velocity and velocity pulsations are obtained for various flow regimes. The main features of the flow are established. The experimental results are compared with previous particle image velocimetry measurements, showing good agreement. Keywords: four-vortex furnace, isothermal model, internal aerodynamics, laser Doppler anemometry. DOI: 10.1134/S0021894420050168
Currently, combustion equipment for thermal power plants (TPPs) is designed mainly to burn high-quality standard coal fuel. At the same time, during coal mining and processing, huge reserves of low-grade coal have been accumulated, which are not yet in demand [1]. Forced combustion of substandard fuel at TPPs leads to a decrease in boiler power and to problems with equipment operation, imposes additional requirements for fuel preparation systems, ash and slag collectors, flue gas cleaners, etc. The effective use of such fuels in compliance with environmental standards requires new scientific-based technological solutions. A promising approach to solving this problem is to improve equipment by using vortex technologies for pulverized coal combustion. Flow swirling promotes intense mixing of the fuel–air mixture with the burning flow, stable ignition of low-reactive fuel, and high combustion efficiency with multiple circulation of fuel particles in the combustion chamber. Implementing the vortex flow structure reduces the formation of harmful combustion products and slagging of heat-exchange surfaces [2–6]. An important step in the development and validation of such technologies is to study the aerodynamics of laboratory models in order to verify mathematical models for full-scale calculations taking into account combustion processes. The aim of this work is to experimentally study the internal aerodynamics of an improved furnace device with a four-vortex flow structure. Furnaces of this type at operating TPPs have drawbacks associated primarily with intense slagging of heat-exchange surfaces. The improvement of the design seeks to eliminate these drawbacks by establishing favorable aerodynamic conditions in the combustion chamber. The laboratory model is made on a scale of 1 : 25 (internal dimensions 290 × 880 × 730 mm) from transparent Plexiglas for optical flow diagnostics. A schematic diagram of the model is shown in Fig. 1a. Two diagonally oriented 28 × 50 mm nozzles corresponding to the burner nozzles are mounted at three tiers on the side walls. Their axes are oriented horizontally and inclined to the vertical axis of the furnace at an angle of 6◦ . The front nozzles (for supplying
Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia; ∗ evgen
Data Loading...
