CN201715533U - Powder feeding device of pulverized coal boiler at power station - Google Patents

Abstract

The utility model discloses a powder feeding device for pulverized coal boiler at power station which can solve deficiency of lowering ignition heat of prior art device. The utility model comprises a powder tank and a powder feeding air duct, wherein inlet end of the powder feeding air duct is communicated with a flue which is between a low temperature superheater of the pulverized coal boiler and en coal economizer, the outlet end being communicated with a burner of the pulverized coal boiler; wherein the powder outlet of the powder tank is communicated with the powder feeding air duct through a powder feeder, the powder feeding air duct being provided with a regulating valve and a circulating fan, one section of the powder feeding air duct which is between the regulating valve and the circulating fan being communicated with an adjacent boiler high temperature fuel gas pipeline and a vapour line; wherein one section of the powder feeding air duct which is between the circulating fan and the outlet end is provided with an outside-tube heating device. The utility model can effectively lower ignition heat of pulverized air duct and increase utilization efficiency of heat energy by making the most of partial waste heat of exhaust flue gas of the boiler, combined with simple structure.

Description

A kind of feeding pulverized coal in power station pulverized-coal fired boiler device

Technical field

The utility model relates to a kind of feeding pulverized coal in power station pulverized-coal fired boiler device, and being suitable for the coal dust is the boiler of fuel.

Technical background

In station boiler start and stop and the low-load combustion-stabilizing process, all need to reduce by every means the ignition heat of breeze airflow, light the purpose of smooth combustion to reach coal dust fast.

For power plant, under the situation of specific coal and coal powder size distribution, the method for reduction ignition heat commonly used: 1, pulverized coal carried by hot air: the employing temperature is the hot-air powder feeding about 300 ℃, but temperature can not be too high, otherwise can make coal dust in powder feeding pipes, burn in advance, accidents caused; 2, improve coal powder density: a normal wind powder feeding concentration is about 0.6kg/kg, excessive concentrations makes coal dust deposit easily, stop up powder feeding pipe, the inner light-dark separation device that increases of burner so be everlasting, coal powder density is divided into deep or light two strands, light the dense phase pulverized coal air-flow earlier, refire whole breeze airflow, the increase of light-dark separation device makes the structure complicated of burner; 3, add imflammable gas: studies show that the adding of a spot of imflammable gas can significantly reduce the ignition heat of breeze airflow, so there is the researcher to adopt the mode of water electrolysis to produce Blang's gas, carry out powder feeding, or with in the gas point ignition combustor on the coal gasification apparatus, to reduce ignition heat, this dual mode all needs extra water electrolysis or coal gasification apparatus.

Summary of the invention

The purpose of this utility model is at the deficiencies in the prior art, and a kind of feeding pulverized coal in power station pulverized-coal fired boiler device that can effectively reduce ignition heat is provided.

The utility model comprises powder storehouse and powder feeding gas flow tube, and the arrival end of powder feeding gas flow tube and the low temperature superheater of generating plant pulverized coal boiler system are communicated with flue between the economizer, and the port of export is communicated with the burner of generating plant pulverized coal boiler system; The meal outlet in powder storehouse is communicated with the powder feeding gas flow tube by machine supplying powder, the powder feeding gas flow tube is provided with control valve and circulating fan, wherein circulating fan is arranged on the powder feeding gas flow tube between powder feeding gas flow tube and machine supplying powder junction and the arrival end, control valve is arranged on the powder feeding gas flow tube between circulating fan and the arrival end, is communicated with adjacent stove high temperature flue gas pipeline and steam pipework on one section powder feeding gas flow tube between control valve and the circulating fan; Powder feeding gas flow tube between the circulating fan and the port of export is outside equipped with the outer heater of pipe.

Described adjacent stove high temperature flue gas pipeline and the low temperature superheater of adjacent stove generating plant pulverized coal boiler system are communicated with flue between the economizer; The middle pressure steam pipeline connection at the public station of described steam pipework and power plant.

The outer heater of described pipe is resistive heating device or the frequency heating device that is nested with outside pipeline.

The utility model is simple in structure, and the high-temperature flue gas that can utilize generating plant pulverized coal boiler system to produce is brought up to 0.8～2kg/kg with a wind breeze airflow concentration, effectively reduces the ignition heat of breeze airflow.In this process, breeze airflow enters and produces pyrolysis before burner catches fire, and separates out the part volatile matter, and makes the CO in the powder feeding air-flow ₂, H ₂O, O ₂Produce partial gasification Deng gas and coal tar, generate CO, H ₂Deng imflammable gas, also can effectively reduce the ignition heat of breeze airflow.Reaction equation is as follows:

C+H ₂O→CO+H ₂-135kJ

2C+O ₂→2CO+221kJ

C+CO ₂→2CO-170kJ

Because separating out in a large number of volatile matter, the pore area on pulverized coal particle surface increases greatly, has promptly strengthened the response area of coal dust surface with oxygen, also makes breeze airflow be easier to light.

Simultaneously, the utility model utilizes the part of waste heat of boiler tail flue gas, has saved energy, has improved utilization efficiency of heat energy.And can effectively reduce CO in the boiler emission tail gas ₂And NO _X

Description of drawings

Fig. 1 is a structural representation of the present utility model.

The specific embodiment

As shown in Figure 1, a kind of feeding pulverized coal in power station pulverized-coal fired boiler device comprises powder storehouse 9 and powder feeding gas flow tube 7.The arrival end of powder feeding gas flow tube 7 and the low temperature superheater 2 of generating plant pulverized coal boiler system 1 are communicated with flue between the economizer 3, and the port of export is communicated with the burner 12 of generating plant pulverized coal boiler system 1.The meal outlet in powder storehouse 9 is communicated with powder feeding gas flow tube 7 by machine supplying powder 10.Powder feeding gas flow tube 7 is provided with control valve 4 and circulating fan 8, wherein circulating fan 8 is arranged on the powder feeding gas flow tube 7 between powder feeding gas flow tube and machine supplying powder junction and the arrival end, and control valve 4 is arranged on the powder feeding gas flow tube 7 between circulating fan 8 and the arrival end.Be communicated with adjacent stove high temperature flue gas pipeline 5 and steam pipework 6 on one section powder feeding gas flow tube 7 between control valve 4 and the circulating fan 8, adjacent stove high temperature flue gas pipeline 5 and the low temperature superheater of adjacent stove generating plant pulverized coal boiler system are communicated with the middle pressure steam pipeline connection at steam pipework 6 and the public station of power plant with flue between the economizer.Powder feeding gas flow tube 7 between the circulating fan 8 and the port of export is outside equipped with the outer heater 11 of pipe, and managing outer heater is resistive heating device or the frequency heating device that is nested with outside pipeline.

Extract the part high-temperature flue gas as the powder feeding flue gas by circulating fan 8 by powder feeding gas flow tube 7 in the work, in the powder feeding flue gas, sneak into water vapour then and form the powder feeding gaseous mixture by steam pipework 6, utilize the outer heater 11 of pipe with the heating of powder feeding gaseous mixture, make it keep 800～1000 ℃ of high temperature.Machine supplying powder 10 is sent into the coal dust in the powder storehouse 9 in the powder feeding gas flow tube 7, utilizing the powder feeding gaseous mixture after the heating is that the coal dust of 0.8～2kg/kg is sent in the burner of generating plant pulverized coal boiler with concentration, heater 11 heated outside continuation was used and managed in the powder feeding process, and keeping powder feeding gaseous mixture air-flow temperature is 800～1000 ℃.

When generating plant pulverized coal boiler system starts, the powder feeding flue gas by adjacent stove high temperature flue gas pipeline 5 by extracting in the adjacent stove generating plant pulverized coal boiler system that is moving; When generating plant pulverized coal boiler system stable operation, the powder feeding flue gas comes from the generating plant pulverized coal boiler system of self.

Claims (3)

1. A pulverized coal boiler powder feeding device of a power station, comprising a powder bin and a powder feeding airflow pipe, characterized in that: the smoke between the inlet end of the powder feeding airflow pipe and the low-temperature superheater and the economizer of the pulverized coal boiler system of the power station The outlet end is connected with the burner of the pulverized coal boiler system of the power station; the powder outlet of the powder bin is connected with the powder feeding air flow pipe through the powder feeding machine, and the powder feeding air flow pipe is equipped with a regulating valve and a circulation fan, and the circulation fan is set On the powder feeding air pipe between the connection between the powder feeding air pipe and the powder feeder and the inlet end, the regulating valve is set on the powder feeding air pipe between the circulating fan and the inlet end, and the section between the regulating valve and the circulating fan The high-temperature flue gas pipeline and steam pipeline of the adjacent furnace are connected to the powder feeding airflow pipe; an external heating device is arranged outside the powder feeding airflow pipe between the circulating fan and the outlet end. 2. A power plant pulverized coal boiler powder feeding device as claimed in claim 1, characterized in that: between the high-temperature flue gas pipeline of the adjacent furnace and the low-temperature superheater and economizer of other power plant pulverized coal boiler systems The flue is connected; the steam pipeline is connected with the medium-pressure steam pipeline of the utility station of the power plant. 3. A power plant pulverized coal boiler powder feeding device as claimed in claim 1, characterized in that: said external heating device is a resistance heating device or an intermediate frequency heating device sleeved outside the pipeline.

Images