The analysis of the dust system of the TП-10 boiler with the Ш-12 mill at the Dobrotvir Termal Power Plant
Students Name: Kharechko Ruslan Yuriiovych
Qualification Level: magister
Speciality: Thermal Power Plants
Institute: Institute of Power Engineering and Control Systems
Mode of Study: full
Academic Year: 2020-2021 н.р.
Language of Defence: ukrainian
Abstract: Kharechko R.Y., Zayats M.F. (supervisor). The analysis of the dust system of the TП-10 boiler with the Ш-12 mill at the Dobrotvir Termal Power Plant. Master’s thesis. - Lviv Polytechnic National University, Lviv, 2020. Extended abstaract. In the master’s qualification work the question of increase of efficiency of work of the a ball drum mill is considered. The analysis of the dust system was performed according to the results of its testing with the mill type KBM 287/410 (Ш-12) during grinding of coal grade G, it was found that the level of ball loading of the drum significantly affects the reliability and efficiency of the dust preparation system [1]. The work is performed on the basis of tests of the dust system with different loading of the drum of the mill Dobrotvirskaya TPP [2]. Study object - is a boiler TП-10 and a dust system with a mill type KBM 287/410 (Ш-12) with different ball loading. Scope of research - is to determine the optimal regimes, economic indicators of the vacuum cleaner system, the rate of wear of grinding balls and correction factors to the specific consumption of balls. Scope of research - the study is to determine the correction factors experimentally - by the calculation method to the specific consumption of grinding balls, which take into account the increase in coal moisture and decrease in the ball load of the mill drum. Goal of research: describes the design features of the high pressure steam boiler TП-10 equipped with two individual dust preparation systems with ball drum mills (KBM), dust hopper, closed cycle of hot air drying and pneumatic transport of coal dust mill to burners. KBM is designed for grinding to a pulverized state of coal and is designed for continuous operation in dust preparation systems at thermal power plants. The work of grinding hard coal of poor quality and irregular supply of grinding balls is also analyzed, the operating conditions of vacuum cleaners with KBM do not meet the design characteristics of mills and the requirements of the rules of technical operation (PTE) for dust preparation systems [3]. Therefore, the norms [4] recommend to calculate the actual values of the specific costs of grinding balls with additional consideration of the correction factors to reduce the ball load of the mill drum and increase the humidity of the coal. Correction factors should be determined using an experimental calculation method[5]. In MKR mode and economic calculations of a vacuum cleaner system at various spherical loading of a drum of a mill are executed. It is investigated that the level of ball loading of the drum significantly affects the reliability and efficiency of the dust preparation system, namely the rate of wear of grinding balls and the fractional composition of the finished dust. Based on the analysis, the operation of the vacuum cleaner should be within the allowable range of changes in the ball load of the mill drum from the minimum = 25 tons to the maximum = 27 tons. In this case, the ball load should be determined by the power of the electric motor of the mill. According to the average daily rate of wear of grinding balls and periodic five percent replenishment of ball loading of the drum, it is advisable to carry out approximately every eight days of continuous operation of the mill. The paper also developed an automated process control system for automatic control of fuel and air supply using modern automation tools, namely: pressure transducer, actuators of the actuator shaft, actuators, starters, which also help increase the efficiency of the boiler TП-10. In particular, conclusions are made about the technological feasibility of modernization of the ball drum mill in the dust preparation system and the economic effect of its implementation. By performing KBM tests in the dust preparation system, it is possible to achieve capital savings without reducing the efficiency of the ball drum mill, and thus obtain an economic effect from the proposed measures to improve the dust preparation system [6]. Key words – vacuum cleaner, ball drum mill, coal, grinding ball, correction factor, specific fuel consumption. References: 1. Anikeev V.A., Kopp I.Z., Skalkin F.V. Technological aspects of environmental protection. - Leningrad: Gidrometeoizdat, 1982. - P. 287. 2. Omelyanovsky P., Mysak J.S. Thermal energy. New challenges of time. Lviv. Scientific and Production Enterprise "Ukrainian Technologies". - P. 660. 3. Zdamovsky V.T. "Modernization of boilers of a thermal power plant". - K. Technique, 1990. - P. 253. 4. Lebedev A.N. Preparation and grinding of fuel at power plants. M .: Energy, 1969p. - P. 175. 5. Vukalovich M.P., Kirilin V.A. etc. Thermodynamic properties of gases. Heat energy. M., 1989p. - P. 232. 6. Ryzhkin V. Y. Thermal power plants. Edited by V. Ya. Gіrshfeld. - M., 1987p. - P. 328.