Control system and method for preparation and drying process of high volatile pulverized coal

Abstract

The invention discloses a control system and method of a high-volatility-component pulverized coal preparation and drying technology. The control system comprises a raw coal bin, wherein a weighing and coal feeding machine is arranged at a discharging port of the raw coal bin; the output end of the weighing and coal feeding machine is connected to a feeding port of a coal grinding machine; a discharging port in the top part of the coal grinding machine communicates with a feeding port of a pulverized coal collector through a pipeline; an air inlet of the coal grinding machine is connected to an air outlet of a hot blast heater through a pipeline; a circulating fan is arranged between an air inlet of the hot blast furnace and an air outlet of the pulverized coal collector; a low-pressure nitrogen channel and a dry fresh air pipeline are arranged on a pipeline through which the air outlet of the hot blast furnace is connected to the air inlet of the coal grinding machine; and the controlsystem further comprises a relative humidity control unit, an oxygen content control unit and an assistant control unit. Compared with a traditional production technology, the control system and method have the advantages of being efficient and energy saving; and meanwhile, the environmental pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of pulverized coal production, in particular to a control system and method for the preparation and drying process of high volatile pulverized coal. Background technique [0002] The geological reserves of lignite in the world are about 4 trillion tons, accounting for 40% of the global coal reserves. However, lignite has the characteristics of loose structure, high volatile content, high moisture, low calorific value, and is not suitable for transportation. Therefore, the utilization of lignite is mainly used in: the nearest conversion into electrical energy for outward transportation; the nearest gasification or liquefaction conversion into chemical products; drying and other upgrading processes to improve the quality of lignite before delivery. In the above several fields, coal pulverization and drying processes are widely used, but the current existing coal pulverization and drying techniques have certain...

AI Technical Summary

Problems solved by technology

[0005] 1) The moisture content of pulverized coal after drying is not monitored, and the moisture content of pulverized coal after drying is difficult to control within the specified index when dealing with raw coal with different moisture content

[0006] 2) Oxygen content monitoring and fire protection measures of the drying system are not set up, only suitable for coal types with low volatile content, high ignition point, and relatively stable, and directly blown into the furnace for combustion under positive pressure

[0010] 2) Oxygen and moisture monitoring and control facilities are set independently. When the system fires nitrogen and replenishes nitrogen, the temperature of the circulating inert gas system remains unchanged, resulting in additional loss of heat energy; when the moisture in the circulating inert gas system exceeds the standard, the system directly replenishes fresh dry gas. In order to maintain the system temperature, it causes additional waste of heat energy

[0012] 4) The production drying load fluctuates, and the amount of fresh drying gas entering the system fluctuates, which in turn causes fluctuations in the oxygen content of the system, causing frequent interlocking actions of the fire-fighting nitrogen filling system and poor system stability

[0013] 5) After drying, the finished pulverized coal is tested offline and in batches, and the product index does not automatically control the production process, so it is difficult to ensure that the moisture content of the finished pulverized coal continues to meet the standard

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