| Abstrakt: |
Purpose. Development of scientific foundations and generalization of experience in development and implementation of technical solutions for conversion of CHPP anthracite boilers with steam productivity up to 250 t/h for combusting sub-bituminous coal with maximum use of existing equipment. Methodology. Consumption and heat calculations of pulverizing systems, aerodynamic calculations of pulverized coal pipes and burners, thermal calculations of boilers and combustion chambers. Calculation justification of technical solutions to eliminate the risk of coal ignition in pulverizing systems and in the burners. Industrial tests on CHPP boiler units. Findings. Different types of pulverizing systems of anthracite CHPP boilers with ball-drum mills, an intermediate pulverized coal hopper and with hot air as a drying agent were considered, and a classification of pulverizing systems by the method of pulverized coal transport to the burners (with drying agent or hot air), and boilers – by the type and location of the burners and the geometry of the furnace, was performed. The problems were analyzed, the calculations of pulverizing systems, pipes, burners, and boilers were performed according to the applied technical solutions, and the experience was summarized of conversion from anthracite to sub-bituminous coal in the boilers of Myronivska, Darnytska CHPP and of the first line of Slovianska TPP. Recommendations are given on methods of conversion of anthracite boilers with a steam capacity of up to 250 t/h with different types of pulverizing systems for burning sub-bituminous coal with maximum use of existing equipment. Originality. For pulverizing systems with ball-drum mills and an intermediate hopper for pulverized coal with hot air as a drying agent classification was made for the first time by the type of transporting agent, and it was shown that when converting from anthracite to sub-bituminous coal with the air transport of pulverized coal to the burners, it is necessary to use the selection of slightly heated air from the first stage of the air heater. It is substantiated that maintaining the temperature conditions of molten slag removal while reducing the share of hot air consumption to the furnace requires the preferential operation of pulverizing systems in a single-mill mode, which is possible due to the greater grindability of sub-bituminous coal. Practical value. Based on the experience of approving technical solutions at Myronivska, Darnytska CHPPs, and at the first line of Slovianska TPP, recommendations are given on how to transfer anthracite boilers with a steam capacity of up to 250 t/h with different types of pulverizing systems for burning sub-bituminous coal with maximum use of existing equipment. [ABSTRACT FROM AUTHOR] |
