CN202074513U - Circulating fluidized-bed boiler for burning rice hulls - Google Patents

Abstract

The utility model provides a circulating fluidized bed boiler for burning rice husks, which enables the separator to return materials smoothly. A boiler drum is installed above the furnace, and a superheater, an economizer, an air preheater, and a boiler outlet flue are installed in the direction of the flue gas flow in the furnace, and the feature is that a double-screw feeder is externally connected to the bottom side of the furnace , The rice husk feeding pipe, the double screw feeder, the rice husk feeding pipe leading to the combustion chamber inside the furnace, the rice husk inlet of the rice husk feeding pipe is provided with an air inlet device blowing toward the furnace, and the lower part of the combustion chamber is arranged with a slag discharge There is an under-bed ignition device outside the combustion chamber, wall-wrapped tubes are installed between the channels connecting the furnace to the superheater, and a circular steam-cooled high-temperature cyclone separator is arranged vertically in the space where the furnace leads to the wall-wrapped tubes. The bottom of the high-temperature cyclone separator is connected with a return channel, and the return channel is connected to the combustion chamber of the furnace. The saturated steam outlet pipe of the drum is connected to the upper pipeline inlet of the circular steam-cooled high-temperature cyclone separator through a connecting pipe.

Description

A circulating fluidized bed boiler burning rice husk

technical field

The utility model relates to the technical field of mechanical mechanisms of boilers, in particular to a circulating fluidized bed boiler for burning rice husks.

Background technique

The development and utilization of pollution-free renewable energy has become an urgent problem in today's world. Among them, biomass energy has attracted the attention of the world because of its renewability and low pollution. In biomass energy, rice husk has the advantages of abundant reserves, relatively simple transportation, and easy pretreatment. However, due to the low density of rice husk and inconvenient stacking, its transportation, storage, and processing costs are relatively high, and its utilization radius is generally 80~120km, which greatly limits the effective use of large power plants. The above disadvantages have prompted the generation of biomass combustion technology in small power plants. the

The content of sulfur and nitrogen in rice husk is not high, and the burning of rice husk has little environmental pollution. The CO ₂ emitted during the combustion process is almost as much as that absorbed during the growth process, so the net effect of rice husk burning on air CO ₂ Emissions are zero. Making full use of rice husk incineration to generate electricity has the social benefits of saving energy and preventing environmental pollution, as well as good economic benefits. Therefore, burning biomass (rice husk) to generate electricity is currently one of the most economically feasible means of reducing CO ₂ emissions.

Since the carbon content of the fly ash in the fluidized bed combustion of rice husk is significantly higher than that of the furnace ash, the rice husk volatilizes quickly, but the coke is difficult to burn. At present, the domestic use of biomass rice husk Circulating fluidized bed boilers generally have many problems such as separator coking and poor material return.

Contents of the invention

In view of the above problems, the utility model provides a circulating fluidized bed boiler for burning rice husks, which prevents the separator from coking and returns materials smoothly.

A circulating fluidized bed boiler burning rice husks, its technical scheme is as follows: it includes a drum, a furnace, a superheater, an economizer, an air preheater, and a boiler outlet flue; The boiler drum and the flue gas flow direction of the furnace are sequentially installed with the superheater, economizer, air preheater, and boiler outlet flue, and it is characterized in that: the bottom side of the furnace is externally connected with double helix The feeder and the rice husk feeding pipe, the double-screw feeder and the rice husk feeding pipe lead to the combustion chamber inside the furnace, and the rice husk inlet of the rice husk feeding pipe is provided with an air inlet blowing toward the furnace. device, a slag discharge pipe is arranged at the lower part of the combustion chamber, an under-bed ignition device is externally connected to the lower part of the combustion chamber, a wall pipe is installed between the channels connecting the furnace to the superheater, and the furnace leads to the wall A circular gas-cooled high-temperature cyclone separator is vertically arranged in the space of the tube, and the bottom of the circular gas-cooled high-temperature cyclone separator is connected with a return passage, and the return passage communicates with the combustion chamber of the furnace. The saturated steam outlet pipe of the drum is connected to the upper pipeline inlet of the circular steam-cooled high-temperature cyclone separator through a connecting pipe, and the lower pipeline outlet of the circular steam-cooled high-temperature cyclone separator is connected to the cladding wall through a pipeline. The inlet of the pipe, the outlet of the wall-clad pipe leads to the inlet of the superheater, and the outlet of the superheater communicates with the steam outlet header.

It is further characterized in that: the superheater includes a low-temperature superheater and a high-temperature superheater, the high-temperature superheater and the low-temperature superheater are sequentially arranged in the flue gas flow direction of the furnace, and the outlet of the wall-clad pipe leads to the The low-temperature superheater, the outlet of the low-temperature superheater is connected to the inlet of the high-temperature superheater through a spray desuperheater, and the outlet of the high-temperature superheater is connected to the steam outlet header;

The water inlet of the boiler is connected to the economizer, the outlet of the economizer is connected to the water inlet of the drum through a pipeline, and the water outlet of the drum is connected to the water inlet of the furnace membrane wall through a downcomer , the water outlet on the upper part of the furnace membrane wall is connected to the drum through a water inlet pipe;

An upward primary air device is arranged below the combustion chamber, a secondary air device and a tertiary air device are arranged above the combustion chamber, and the tertiary air device is arranged above the secondary air device;

The air preheater includes a cold air inlet, a central pipe, a primary air outlet, and a secondary air outlet, the primary air outlet is connected to the sequential air device, and the secondary air outlet is respectively connected to the secondary air device, Tertiary wind device.

After adopting the structure of the utility model, the rice husk is transported to the combustion chamber inside the furnace through the double screw feeder, and the high-temperature flue gas is generated after the fuel is burned, and the heat is sequentially transferred to the membrane wall of the furnace and the circular steam-cooled high-temperature cyclone separator , clad wall pipe, etc., where the high-temperature flue gas generated after fuel combustion is separated in the circular steam-cooled high-temperature cyclone separator, and the finer particles enter the tail convection heating surface with the flue gas, and the larger particles are separated and passed through the return material The channel is sent into the combustion chamber area of the furnace to form a circulation, so it keeps the separator from coking and the material is returned smoothly.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the front view of the utility model.

Detailed ways

See Fig. 1, it includes drum 1, furnace 2, superheater, economizer 9, air preheater, boiler outlet flue 19, superheater includes low-temperature superheater 8, high-temperature superheater 7, high-temperature superheater 7, The low-temperature superheater 8 is sequentially arranged in the direction of the flue gas flow of the furnace 2, and the drum 1 is installed above the furnace 2, and the superheater, the economizer 9, the air preheater, and the boiler are installed in sequence in the direction of the flue gas flow of the furnace 2 Outlet flue 19, double screw feeder 16, rice husk pipe 17 are externally connected to the bottom side of furnace 2, and double screw feeder 16, rice husk pipe 17 lead to combustion chamber 22 inside furnace 2, feed rice The rice husk inlet of the shell pipe 17 is provided with an air inlet device 30 blowing toward the furnace, a slag discharge pipe 18 is arranged at the lower part of the combustion chamber 22, an under-bed ignition device 12 is connected outside the combustion chamber 22, and the furnace 2 is connected to the superheater. There is a wall pipe 6, and a circular vapor-cooled high-temperature cyclone separator 4 is vertically arranged in the space where the furnace 2 leads to the wall pipe 6. The bottom of the circular vapor-cooled high-temperature cyclone separator 4 is connected with a return passage 5, and the return The material channel 5 communicates with the combustion chamber 20 of the furnace 2, and the saturated steam outlet pipe of the drum 1 is connected to the upper pipeline 24 inlet of the circular steam-cooled high-temperature cyclone separator 4 through the connecting pipe 23, and the inlet of the circular steam-cooled high-temperature cyclone separator 4 The outlet of the lower pipeline 25 is connected to the inlet of the cladding tube 6 through the pipeline 26, the outlet of the cladding tube 6 leads to the low-temperature superheater 8, and the outlet of the low-temperature superheater 8 and the inlet of the high-temperature superheater 7 are cooled by spraying water The outlet of the high-temperature superheater 7 is connected to the steam outlet header 20;

The water inlet of the boiler is connected to the economizer 9, and the outlet of the economizer 9 is connected to the water inlet of the drum 1 through a pipeline (not shown in the figure, which belongs to the existing mature technology), and the water outlet of the drum 1 passes through the downpipe 3 Connect the water inlet of the furnace membrane wall, and the upper water outlet of the furnace membrane wall is connected to the drum 1 through the water inlet pipe 27;

An upward primary air device 13 is arranged below the combustion chamber 22, and a secondary air device 14 and a tertiary air inlet device 15 are arranged above the combustion chamber 22, and the tertiary air device 15 is arranged above the secondary air device 14;

The air preheater includes a cold air inlet 28, a central pipe 29, a primary air outlet 11, and a secondary air outlet 10. The primary air outlet 11 is connected to the sequential air device, and the secondary air outlet 12 is respectively connected to the secondary air device 14 and the tertiary air device. 15.

It works as follows:

The boiler feed water enters the economizer 9, and enters the drum 1 after being heated by the flue gas. The boiler water in the drum 1 enters the membrane wall of the furnace 2 respectively through the downcomer 3, and the furnace water in the membrane wall of the furnace 2 is heated by the flue gas The steam-water mixture enters the drum 1, and the steam-water separation device divides the steam-water mixture into saturated steam and saturated boiler water in the drum 1, and the boiler water enters the downcomer; the saturated steam is introduced into the circular steam-cooled high-temperature cyclone separator 4 through the connecting pipe , the heated saturated steam at the outlet of the circular air-cooled high-temperature cyclone separator 4 becomes superheated steam, which is introduced into the superheater wall pipe 6 and the low-temperature superheater 8 through the connecting pipe, and then enters the spray desuperheater 21 and the high-temperature superheater 7 in sequence The superheated steam that reaches the boiler rated parameters is introduced into the steam outlet header 20 through the connecting pipe and output to the boiler, and then enters the steam turbine to generate power.

The rice husk is transported by wind from the rice husk pipe 17 in front of the furnace to the combustion chamber 22 at the bottom of the furnace 2, and the supplementary bed material is sent from the feeder to the furnace by the screw feeder 16 to supplement the ash. After the fuel is burned, high-temperature flue gas will be The heat is transmitted to the membrane wall of the furnace chamber, the circular steam-cooled high-temperature cyclone separator 4, the high-temperature superheater 7, the low-temperature superheater 8, the economizer 9, and the air preheater 10. After cooling, the flue gas is discharged through the outlet flue 19 For the boiler, after dust removal, desulfurization and other treatments, the flue gas that meets the national emission standards is discharged from the chimney, and the slag after fuel combustion is discharged from the boiler through the slag discharge pipe 18 .

After the fuel is burned, the high-temperature flue gas is separated in the circular steam-cooled high-temperature cyclone separator 4. The finer particles enter the convection heating surface at the tail with the flue gas, and the larger particles are separated and sent to the furnace 2 by the return device 5. The combustion chamber 22 forms a cycle, during which the hot particles transfer heat to the high-temperature cyclone separator 4 and the heating surface of the furnace membrane wall. The under-bed ignition device 12 uses light diesel oil, which is used when the boiler is ignited.

In order to organize the good combustion of fuel in the boiler and reduce the generation of NOx, the primary air device 13, the secondary air device 14 and the tertiary air device 15 are arranged respectively. The secondary air outlet 10 enters the primary air device 13, the secondary air device 14 and the tertiary air device 15 and sends them into the furnace 2 respectively.

Claims (5)

1. the CFBB of a combusting rice hull, it comprises drum, burner hearth, superheater, economizer, air preheater, the boiler export flue, the top of described burner hearth is equipped with described drum, the flue gas flow direction direction of described burner hearth is equipped with described superheater successively, economizer, air preheater, the boiler export flue, it is characterized in that: the bottom sidepiece of described burner hearth is circumscribed with double-spiral feeder, to the rice husk pipe, described double-spiral feeder, the combustion chamber of leading to described burner hearth inside to the rice husk pipe, the described rice husk mouth that advances to the rice husk pipe is provided with towards the air-intake device of burner hearth blowing, described combustion chamber lower disposed has residue outlet, below, described combustion chamber is circumscribed with the ignition under bed device, the interchannel that described burner hearth connects described superheater is equipped with enclosure wall tube, described burner hearth leads in the space of described enclosure wall tube vertically to being furnished with the cold high temperature cyclone separator of circular vapour, the bottom of the cold high temperature cyclone separator of described circular vapour is communicated with the returning charge passage, the combustion chamber of the described burner hearth of described returning charge channel connection, the saturated vapor of described drum goes out pipe connects the cold high temperature cyclone separator of described circular vapour by tube connector upper pipeline import, the lower tube way outlet of the cold high temperature cyclone separator of described circular vapour connects the import of described enclosure wall tube by pipeline, the import of described superheater is led in the outlet of described enclosure wall tube, and the outlet of described superheater is communicated with described steam (vapor) outlet collection case.

2. the CFBB of a kind of combusting rice hull according to claim 1, it is characterized in that: described superheater comprises low temperature superheater, high temperature superheater, described high temperature superheater, low temperature superheater are arranged in the flue gas flow direction direction of described burner hearth in turn, described low temperature superheater is led in the outlet of described enclosure wall tube, connect by direct-contact desuperheater between the outlet of described low temperature superheater and the import of described high temperature superheater, the outlet of described high temperature superheater is communicated with described steam (vapor) outlet collection case.

3. the CFBB of a kind of combusting rice hull according to claim 2, it is characterized in that: the boiler feed water import connects described economizer, the outlet of described economizer connects the water inlet of described drum by pipeline, the delivery port of described drum connects the water inlet of described burner hearth membrane wall by down-comer, and described burner hearth membrane wall top delivery port connects described drum by water inlet pipe.

4. the CFBB of a kind of combusting rice hull according to claim 3, it is characterized in that: described combustion chamber arranged beneath has a wind apparatus up, the top of described combustion chamber is furnished with overfire air device, tertiary air device, and described tertiary air device is arranged in the top of described overfire air device.

5. the CFBB of a kind of combusting rice hull according to claim 4, it is characterized in that: described air preheater comprises inlet of cold air, middle part pipeline, air outlet, secondary air outlet, a described air outlet is communicated with described wind apparatus successively, and described secondary air outlet is communicated with described overfire air device, tertiary air device respectively.

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