Perfection of technology and equipment for heating of steel ladles lining at horizontal stands

To change or repair sliding gates, steel ladles are installed in horizontal position, in which they are heated to keep a working temperature of lining. Peculiarities of a steel ladle heating in horizontal position considered. Description of the lining heating process presented, necessity of elaboration a method of its numeral simulation justified. The method should enable to make studies of influence of various methods of burner location on the ladle cover and torch parameters on efficiency of heating for a particular ladle and time available for the heating. A method of mathematical simulation of heat- and mass-exchange processes of lining heating in nonstationary conditions described. Based on examples of various variants of torch power calculation, dynamics of a ladle walls heating was shown. Results of calculation of temperature distribution over a ladle lining presented, as well as the map of gases flow in the ladle volume for various parameters of torch and heating process stages. Taking into consideration, that calculation costs related to simulation of nonstationary ladle heating are very high, a simplified one-dimensional model of calculation of lining heating process was elaborated. In the model correction factors are used, obtained as a result of numeral simulation. The model enables to make calculations in real time conditions and to use them for control at a practical steel ladle heating in horizontal position at a modern automized heating facility.

Research on Thermal Protection of One Gas Generator

The thermal protection is a key factor to keep the gas generator work longtime under high temperature condition steadily. The main heat transfer paths are analyzed. A numeral simulation of the combustor and its nozzle shows the pipe outside temperature distribution with the change of time, position and thickness. According to the numeral simulation results, two thermal protection measures are bring forward, reduce the temperature, choosing proper thickness and heat resisting material. At last, an experiment results validate that the numeral simulation is credibility; the improvement of the structure is effective. With a longtime run, the outside wall temperature is 870K, which satisfies the operation needs.

Numerical Simulation of 3D Solid-Liquid Turbulent Flow in a Low Specific Speed Centrifugal Pump: Flow Field Analysis

For numerically simulating 3D solid-liquid turbulent flow in low specific speed centrifugal pumps, the iteration convergence problem caused by complex internal structure and high rotational speed of pump is always a problem for numeral simulation researchers. To solve this problem, the combination of three measures of dynamic underrelaxation factor adjustment, step method, and rotational velocity control means according to residual curves trends of operating parameters was used to improve the numerical convergence. Numeral simulation of 3D turbulent flow in a low specific speed solid-liquid centrifugal pump was performed, and the results showed that the improved solution strategy is greatly helpful to the numerical convergence. Moreover, the 3D turbulent flow fields in pumps have been simulated for the bottom ash-particles with the volume fraction of 10%, 20%, and 30% at the same particle diameter of 0.1 mm. The two-phase calculation results are compared with those of single-phase clean water flow. The calculated results gave the main region of the abrasion of the impeller and volute casing and improve the hydraulic design of the impeller in order to decrease the abrasion and increase the service life of the pump.

Nonlinear Vibration Forces of Rotor-Bearing-Support System

The nonlinear vibration forces of rotor-bearing-supports system are important to the structural vibration and sound. Based on nonlinear vibration analysis of the system, the vibration equations were solved and the vibration forces were given by numeral simulation. The results show that the motions of forces are complex with the changing of rotary speed. The results could be used to determine the vibration and acoustic radiation of underwater vehicle under complex excitations.