Energy-saving and environment-friendly flue gas waste heat pulverized coal preparation system

Abstract

An energy-saving and environment-friendly flue gas waste heat pulverized coal preparation system comprises a belt coal feeder, a raw coal bunker, a coal feeder, a coal mill and a powder recovery bunker, wherein the dry air inlet of the coal mill communicates with the outlet of a first induced draft fan which is used for inputting high-temperature flue gas at the tail part of a boiler to the coal mill; an inert gas input passage is arranged in front of the dry air inlet of the coal mill; a first control valve is mounted on the inert gas input passage; the outlet of the coal mill communicates with the inlet of the powder recover bunker; a gas temperature detector and a gas concentration detector are mounted behind the outlet of the coal mill and connected with an alarm controller; a pulverized coal collection device is arranged in the powder recovery bunker; a second induced draft fan is mounted behind the flue gas outlet of the powder recovery bunker; and the outlet of the second induced draft fan communicates with the inlet of a flue gas desulfurization device or a chimney. The energy-saving and environment-friendly flue gas waste heat pulverized coal preparation system is a special production line for providing coal dust fuels for the pulverized coal boiler, the security of the pulverized coal preparation system can be guaranteed while the waste heat of flue gas at the tail part of the boiler is effectively utilized, energy saving and consumption reduction are realized and the environment is protected.

Description

technical field [0001] The invention belongs to the technical field of fuel preparation for small and medium-sized pulverized coal boilers, and in particular relates to an energy-saving and environment-friendly pulverized coal preparation system for waste heat of flue gas. Background technique [0002] Burning coal to obtain energy is still one of the main ways of obtaining energy in my country at present, and its proportion accounts for more than 50% of the total energy. Therefore, it is of great significance to promote the clean and efficient use of fossil energy such as coal at this stage . High-efficiency and environmentally friendly pulverized coal boiler is a key energy-saving technology project promoted by the state. It has the characteristics of high efficiency and energy saving, clean emission, high level of automation, and environmental friendliness. It is economical, environmentally friendly, and energy-saving. It is of great significance to promote the clean and ...

AI Technical Summary

Problems solved by technology

[0004] 1. The pulverized coal boiler needs to be equipped with a pulverized coal preparation system, and the pulverized coal preparation system is relatively complicated, with relatively large investment and land occupation. The pulverized coal preparation system for large boilers is reasonable and economical, but because of people's livelihood issues, such as the need for heating and steam supply , some small boilers cannot be replaced

And if these small boilers are equipped with a pulverized coal preparation system, the boiler unit system will be much more complicated and the economy will not be high

[0005] 2. The current conventional pulverized coal preparation system mainly uses the hot blast stove that burns self-produced pulverized coal to provide heat source, which has low combustion efficiency, most of them do not have desulfurization and denitrification settings, the pollutant emission index is high, and the height of the exhaust pipe is generally low , the diffusion of pollutants is not good, etc.

[0006] 3. Most of the conventional pulverizing systems use hot air to dry coal powder. If the system is overheated, the coal powder is prone to explosion and other problems.

Therefore, although the existing milling system has adopted various safety measures and approaches, there are still hidden dangers of accidents due to the use of hot air or hot air containing certain oxygen in the drying process.

[0007] 4. The flue gas temperature at the tail of the boiler behind the induced draft fan in a conventional power plant is still about 130°C. Because there are not many ways to utilize the waste heat of this part of the flue gas, most of it will be directly sent to the desulfurization system, and will be directly wasted after being sprayed and cooled by the desulfurization tower. It's a waste of energy and water

[0008] The pulverized coal preparation system in the existing boiler units generally only uses a small amount of flue gas at the tail of the boiler, and needs to feed high-temperature furnace flue gas as a desiccant, so it consumes more energy and has not yet solved the problem of flammability in the pulverized coal preparation process. Explosive and other safety issues

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