CN212618251U - Controllable quantity material returning device of low-emission circulating fluidized bed boiler - Google Patents

Abstract

The controllable amount material returning device of the low-emission circulating fluidized bed boiler comprises a vertical material pipe, a material returning valve, a material returning leg, an air cap and an air chamber; the controllable quantity material returning device comprises a material returning valve, a material standing pipe, a material returning leg, a blast cap, a controllable quantity material returning device, an ash discharging pipe, an ash discharging adjusting valve, a fan, a material returning air pipe, a material returning air quantity adjusting valve and a cold ash slag remover, wherein the material standing pipe is arranged at the lower part of the existing separator; the inlet end of the ash discharge pipe extends into the air chamber and is communicated with the bottom of the return material valve, the outlet end of the ash discharge pipe is connected with the cold ash slag remover, the ash discharge pipe is provided with an ash discharge regulating valve, and the return material air pipe is provided with a return material air pipeReturn air volume regulating valve. The utility model discloses make the boiler when low-load or fuel sudden change, adjust through the wide range, guarantee best returning charge ash volume, realize high-efficient burning and steady operation, make NO_XAnd SO₂Initial ultra low emissions.

Description

Controllable quantity material returning device of low-emission circulating fluidized bed boiler

Technical Field

The utility model relates to a return feeder device, in particular to controllable volume return feeder device of low emission type circulating fluidized bed boiler.

Background

With the wide application of the low-emission circulating fluidized bed boiler adopting the self-balancing material returning device, a better low-emission effect of pollutants is obtained, but the safe and stable operation, the energy-saving combustion and the ultralow emission of pollutants can be influenced by the replacement of fuel and sudden load. The traditional material returning device can not adjust the material returning amount, the material returning amount is greatly changed when the boiler is used for replacing fuel and sudden load change, the material returning amount is increased or reduced, the problem of excessive material returning amount when the load of the boiler is reduced or the heat value of the fuel is reduced is solved, the temperature of a bed in a hearth is too low, unstable combustion and flameout can occur, the fuel is not completely combusted, the desulfurization efficiency in the boiler is reduced, and the like, and the stable operation of the boiler, energy-saving combustion and the ultralow emission of pollutants are not facilitated.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve the problem that the returning charge ash volume changes by a wide margin when current low emission type circulating fluidized bed boiler load descends or the fuel calorific value reduces, and then provide a controllable volume returning charge ware device of low emission type circulating fluidized bed boiler. The controllable quantity material returning device is adopted, the problem that the material returning quantity is too large when the boiler is under low load or fuel mutation is solved by controlling the material returning quantity, the bed temperature of the hearth reaches a design value, the phenomena that the boiler is shut down due to unstable combustion and flameout or coking, the environmental-friendly emission is not up to standard due to low desulfurization efficiency in the boiler, the boiler efficiency is reduced due to incomplete combustion of fuel and the like are avoided, and the boiler can be safely, stably and efficiently operated for a long time.

The technical scheme of the utility model is that: the controllable quantity material returning device of the low-emission circulating fluidized bed boiler comprises a material returning device, wherein the material returning device comprises a vertical material pipe, a material returning valve, a material returning leg, a hood and an air chamber; the vertical material pipe is arranged at the lower part of the existing separator, the vertical material pipe is arranged at the upper part of the material returning valve, the material returning leg is arranged on the side surface of the material returning valve, and the material returning leg is communicated with the rear lower part of the existing hearth; the vertical material pipe is provided with a plurality of observation holes, the blast cap is arranged at the bottom of the material returning valve, the air chamber is arranged at the lower part of the material returning valve, and the material returning leg is provided with a limestone desulfurization interface;

the quantity-controllable material returning device also comprises an ash discharging pipe, an ash discharging regulating valve, a fan, a material returning air pipe, a material returning air quantity regulating valve and a cold ash slag remover; the inlet end of the ash discharge pipe extends into the air chamber and is communicated with the bottom of the material return valve, the outlet end of the ash discharge pipe is connected with the ash cooling slag remover, the ash discharge pipe is provided with an ash discharge adjusting valve, one end of the material return air pipe is fixedly arranged in the air chamber and is communicated with the inner pipe core of the air cap, the material return air port of the fan is connected with the other end of the material return air pipe, and the material return air pipe is provided with a material return air volume adjusting valve.

The utility model discloses compare prior art's beneficial effect is:

1. the utility model discloses a controllable volume returning charge ware device through control returning charge ash volume, realizes that the boiler returns the charge ash volume when low-load or fuel sudden change steerable, makes furnace inner temperature reach the design value, and is steerable in 800 supplyes one's food and drink 900 ℃ within range, avoids taking place the environmental protection that the burning unstability is put out flame or the coking leads to and discharges not up to standard, the boiler efficiency that the incomplete combustion of fuel leads to reduces etc. in the environmental protection that desulfurization efficiency in the stove leads to, makes the boiler can the high-efficient operation of long-term safety and stability. Has better social benefit and economic benefit.

2. The utility model adopts the return material air quantity regulating valve to regulate the return material air quantity in the return material device, adjusts the height of the return material ash in the vertical material pipe by controlling the return material air quantity, controls the amount of the return material ash, ensures the amount of the return material ash when the boiler is under low load or the fuel suddenly changes, and realizes the stable operation of the boiler;

3. the utility model discloses a arrange grey governing valve and adjust row returning charge ash mode, adjust the returning charge ash height in the riser, control returning charge ash volume makes furnace bed temperature reach the design value, realizes that the burning is complete, guarantees the energy-conserving operation of boiler, NO_XInitial ultra-low emission;

4. the utility model adopts the mode of controlling the return material air quantity and discharging the return material ash to control the return material ash quantity, adjust the height of the return material ash in the vertical material pipe, avoid the furnace shutdown caused by unstable combustion flameout or coking, and ensure the safe operation of the boiler;

5. the utility model discloses an integrated lime stone desulfurization interface on the returning charge leg, lime stone pyrolysis in advance in the returning charge leg, the desulfurization after calcining in furnace has the desulfurization efficiently, and investment cost is low, and running cost is few and area is little technical advantage, SO₂The stripping efficiency is improved to more than 99.8 percent, and the method has better economic benefit and social benefit. Realizes the conversion from treatment outside the furnace to low emission in the furnace, reduces the pollutant emission from the source in the furnace, and further ensures that the SO of the boiler₂Initial ultra low emissions.

The invention will be further described with reference to the accompanying drawings and embodiments:

drawings

FIG. 1 is an overall schematic view of a controlled amount returning feeder apparatus of a low emission type circulating fluidized bed boiler according to the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at I;

FIG. 3 is a diagram of the connection between the ash discharge pipe and the air chamber in FIG. 1;

FIG. 4 is a cross-sectional view taken along line C-C of FIG. 3;

FIG. 5 is a connection diagram of the ash discharge pipe and the ash cooler and the return air pipe and the blower in FIG. 1;

FIG. 6 is a schematic view of the present invention relating to the application of the quantity-controllable material returning device to a circulating fluidized bed boiler of low emission type;

FIG. 7 is a schematic view of the assembly of a low emission circulating fluidized bed boiler using the amount-controllable material returning device of the present invention.

Detailed Description

Referring to fig. 1 to 5, the controllable quantity material returning device of the low-emission circulating fluidized bed boiler of the present embodiment comprises a material returning device 3, wherein the material returning device comprises a vertical pipe 3-1, a material returning valve 3-2, a material returning leg 3-3, an air cap 3-5 and an air chamber 3-6; the vertical material pipe 3-1 is arranged at the lower part of the existing separator 2, the vertical material pipe 3-1 is arranged at the upper part of the material return valve 3-2, the material return leg 3-3 is arranged at the side surface of the material return valve 3-2, and the material return leg 3-3 is communicated with the rear lower part of the existing hearth 1; a plurality of observation holes 3-4 are formed in the vertical material pipe 3-1, a blast cap 3-5 is installed at the bottom of the material return valve 3-2, an air chamber 3-6 is installed at the lower part of the material return valve 3-2, and a limestone desulfurization interface 3-7 is arranged on the material return leg 3-3;

the quantity-controllable material returning device also comprises an ash discharging pipe 12, an ash discharging regulating valve 13, a fan 16, a material returning air pipe 17, a material returning air quantity regulating valve 18 and a cold ash slag remover;

the inlet end of an ash discharge pipe 12 extends into the air chamber 3-6 to be communicated with the bottom of a material return valve 3-2, the outlet end of the ash discharge pipe 12 is connected with a cold ash slag remover, an ash discharge adjusting valve 13 is arranged on the ash discharge pipe 12, one end of a material return air pipe 17 is fixedly arranged in the air chamber 3-6 and is communicated with an inner pipe core of an air cap 3-5, the material return air outlet of a fan 16 is connected with the other end of the material return air pipe 17, and a material return air quantity adjusting valve 18 is arranged on the material return air pipe 17.

Alternatively, as shown in fig. 1 and 5, the cold ash slag remover comprises a cold ash machine 14 and an ash slag remover 15; the outlet end of the ash discharge pipe 12 is connected with an ash cooler 14, and the ash cooler 14 is connected with an ash remover 15. The blast caps 3-5 can be selected from the prior art patent documents: CN 205299504U.

As shown in fig. 1, 6 and 7, the separated ash in the separator 2 flows into the vertical material pipe 3-1 and then enters the return material valve 3-2, and under the fluidization effect of return material wind entering through the blast cap 3-5, the return material ash flows into the lower part of the hearth 1 through the return material leg 3-3, and the fuel fed from the feeding device 5 is ignited;

as shown in the figures 1 and 5, the blower 16 is a Roots blower, return air provided by the Roots blower enters the air chamber 3-6 through the return air pipe 17 and then enters the return valve 3-2 through the air cap 3-5 to fluidize return ash, the height of the return ash in the material standing pipe 3-1 is adjusted through the return air volume, and the return air volume in the return valve 3-2 is adjusted through controlling the return air volume adjusting valve 18.

The ash discharge pipe 12 penetrates through the air chamber 3-6 to be communicated with the bottom of the return valve 3-2, the height of the return ash in the vertical pipe 3-1 is ensured by discharging the return ash in the return valve 3-2, the ash discharge pipe 12 is provided with an ash discharge adjusting valve 13, the height H of the return ash in the vertical pipe 3-1 is controlled by adjusting the ash discharge adjusting valve 13, the visible range of the height H of the return ash in the vertical pipe 3-1 can be judged by the observation hole 3-4 to be 2-3m, the ash in the return valve 3-2 enters the ash cooler 14 through the ash discharge pipe 12 to be cooled, and the redundant return ash discharged by the ash discharge pipe 12 enters the ash remover 15 after being cooled by the ash cooler 14 and is conveyed to the slag bin. The ash discharge pipe 12 of this embodiment adopts inner tube overcoat outer tube structure, and the center forms the air intermediate layer, and outer tube external application heat preservation reaches thermal-insulated heat preservation effect, the dangerous source that ash discharge pipe high temperature formed when preventing the ash discharge. The ash discharge pipe of this embodiment adopts inner tube overcoat outer tube structure, and the inner tube carries out the transitional coupling with the outer tube through the metal expansion joint sealed, absorbs the expansion volume difference that inner tube and outer tube lead to because of being heated the difference.

Alternatively, as shown in FIG. 3, the ash discharge pipe 12 comprises an inner pipe 12-1, an outer pipe 12-2, an insulating layer 12-3 and an expansion joint 12-4; the outer pipe 12-2 is sleeved outside the inner pipe 12-1, the inlet end of the inner pipe 12-1 penetrates through the air chamber 3-6 to be communicated with the bottom of the material returning valve 3-2, one end of the outer pipe 12-2 is welded with the outer wall of the air chamber 3-6, the other end of the outer pipe 12-2 is in transitional connection with the inner pipe 12-1 through an expansion joint 12-4, the outer part of the outer pipe 12-2 is coated with the heat insulation layer 12-3, the outlet end of the inner pipe 12-1 is provided with an ash discharge adjusting valve 13, and the outlet end of the inner pipe 12-1 is connected.

Alternatively, as shown in fig. 1 and 2, the number of the observation holes 3-4 is three, three observation holes 3-4 are vertically arranged in a straight line, and the distance H1 between two adjacent observation holes is 0.5 m. Further, the height H of the returned ash in the vertical material pipe 3-1 ranges from 2m to 3m, H is 2m when the top of the returned ash is positioned at the position of the observation hole 3-4 at the lower part, and H is 3m when the top of the returned ash is positioned at the position of the observation hole 3-4 at the upper part. In the embodiment, the amount of the returned ash is controlled in a wide range, so that the height H of the returned ash in the vertical material pipe is ensured to be more than or equal to 2.5m, and the ash collapse is preventedFlameout and flue gas back-flowing coking, the temperature in the hearth is controlled within the range of 800-900 ℃, the temperature is more suitable for the desulfurization of limestone in the hearth, a wide-range controllable amount material returning device provides a suitable temperature range, sufficient reaction time and the like, the utilization rate of limestone is increased, the desulfurization efficiency in the hearth is improved, and the pollutant SO is realized₂And (4) ultralow emission. In the embodiment, the height of the returned ash in the vertical material pipe is ensured by controlling the amount of the returned ash in a wide range, and the temperature in the hearth is controlled within the range of 800-_XGenerating, realizing low-nitrogen combustion in a hearth and realizing pollutant NO_xAnd (4) ultralow emission.

Fig. 6-7 are exemplary views of the present invention applied to a low-emission type circulating fluidized bed boiler, which may be based on the prior art patent document CN 207146381U.

The controllable method of the return material air quantity and the return material ash quantity is explained by combining with the figures 1-7, the height H of the return material ash in the vertical material pipe is adjusted to be more than or equal to 2.5m by adjusting the return material air quantity supplied by the Roots blower and the return material ash quantity discharged by the ash discharge pipe, so that the problem that the return material ash quantity of the boiler is greatly changed under low load or when fuel suddenly changes is solved, the hearth bed temperature reaches a design value, the boiler shutdown caused by unstable combustion and flameout or coking is avoided, the environmental-friendly discharge caused by low desulfurization efficiency in the boiler is not up to standard, the boiler efficiency caused by incomplete combustion of fuel is reduced, and the like, so that the boiler can be safely, stably and efficiently operated for a long time, two independent quantity control methods are respectively provided, and after the two independent quantity control methods are combined, a combined quantity control method.

The first independent quantity control method comprises the following steps: after returning air supplied by Roots air enters an air chamber 3-6 through a returning air pipe 17, returning ash flows into a returning valve 3-2 through an air cap 3-5, the height of the returning ash in a vertical material pipe 3-1 is adjusted through the returning air quantity, and a returning air adjusting valve 18 is arranged on the returning air pipe 17 to adjust the returning air quantity;

and (2) an independent quantity control method II: the ash discharge pipe 12 passes through the air chamber 3-6 to be communicated with the bottom of the return valve 3-2, the height H of the return ash in the vertical pipe 3-1 is more than or equal to 2.5m by discharging the return ash in the return valve 3-2, the return ash in the return valve 3-2 enters the ash cooler 14 through the ash discharge pipe 12 to be cooled, and the ash discharge pipe 12 is provided with an ash discharge regulating valve 13 to regulate the amount of the discharged return ash;

the combined quantity control method comprises the following steps: when the amount of the returned ash is excessive, in order to ensure that the height H of the returned ash in the vertical material pipe 3-1 is more than or equal to 2.5m, the opening degree of a returned air volume regulating valve is increased to increase the amount of the returned ash, if the returned air volume regulating valve is fully opened, the height H of the returned ash in the vertical material pipe 3-1 is still more than 3m, the opening degree of an ash discharge regulating valve 13 is increased to perform ash discharge regulation, the ash discharge amount of an ash discharge pipe 12 is increased, and the height H of the returned ash in the vertical material pipe 3-1 is ensured to be more than or equal to 2.5 m; when the amount of the returned ash is too small, in order to ensure that the height H of the returned ash in the vertical material pipe 3-1 is more than or equal to 2.5m, the height H of the returned ash in the vertical material pipe 3-1 can be reduced by reducing the opening degree of an ash discharge regulating valve to perform ash discharge regulation and reduce the ash discharge amount of the ash discharge pipe 1, and if the ash discharge regulating valve 13 is completely closed, the height H of the returned ash in the vertical material pipe is still less than 2m, the height H of the returned ash in the vertical material pipe 3-1 can be ensured to be more than or equal to 2.5m by reducing the opening degree of;

limestone desulfurization ports 3-7 arranged on the return legs 3-3 ensure that the fed limestone and return ash simultaneously enter the hearth 1, and the main component CaCO in the limestone₃Is rapidly heated and undergoes a calcination reaction to produce CaO and CO₂Porous and loose CaO is generated after calcination reaction, and SO is generated by fuel combustion₂Diffusing to the surface and inner holes of CaO, and absorbing SO by CaO in the presence of oxygen₂And generates CaSO₄Realize the in-furnace desulfurization and the SO₂Initial ultra low emissions.

The present invention has been disclosed in the above embodiments, but not limited to the embodiments of the present invention, and any person skilled in the art can easily modify, change and modify the above embodiments according to the technical spirit of the present invention without departing from the scope of the present invention.

Claims (5)

1. The controllable amount material returning device of the low-emission type circulating fluidized bed boiler comprises a material returning device (3), wherein the material returning device comprises a vertical material pipe (3-1), a material returning valve (3-2), a material returning leg (3-3), an air cap (3-5) and an air chamber (3-6); the vertical material pipe (3-1) is arranged at the lower part of the existing separator (2), the vertical material pipe (3-1) is arranged at the upper part of the return valve (3-2), the return leg (3-3) is arranged on the side surface of the return valve (3-2), and the return leg (3-3) is communicated with the rear lower part of the existing hearth (1); the blast cap (3-5) is arranged at the bottom of the return valve (3-2), the air chamber (3-6) is arranged at the lower part of the return valve (3-2), and the return leg (3-3) is provided with a limestone desulfurization interface (3-7);

the method is characterized in that: the quantity-controllable material returning device also comprises an ash discharging pipe (12), an ash discharging adjusting valve (13), a fan (16), a material returning air pipe (17), a material returning air quantity adjusting valve (18) and a cold ash slag remover;

a plurality of observation holes (3-4) are vertically arranged on the vertical material pipe (3-1), the inlet end of an ash discharge pipe (12) extends into an air chamber (3-6) and is communicated with the bottom of a return material valve (3-2), the outlet end of the ash discharge pipe (12) is connected with an ash cooling slag remover, an ash discharge adjusting valve (13) is installed on the ash discharge pipe (12), one end of a return material air pipe (17) is fixedly installed in the air chamber (3-6) and is communicated with an inner pipe core of an air cap (3-5), a return material air outlet of a fan (16) is connected with the other end of the return material air pipe (17), and a return material air quantity adjusting valve (18) is installed on the return material air pipe (17).

2. The controlled amount returning device for a low emission type circulating fluidized bed boiler according to claim 1, wherein: the cold ash slag remover comprises a cold ash machine (14) and an ash slag remover (15); the outlet end of the ash discharge pipe (12) is connected with an ash cooler (14), and the ash cooler (14) is connected with an ash and slag remover (15).

3. The controlled amount returning device for a low emission type circulating fluidized bed boiler according to claim 2, wherein: the ash discharge pipe (12) comprises an inner pipe (12-1), an outer pipe (12-2), a heat insulation layer (12-3) and an expansion joint (12-4); the outer pipe (12-2) is sleeved outside the inner pipe (12-1), the inlet end of the inner pipe (12-1) penetrates through the air chamber (3-6) and is communicated with the bottom of the return material valve (3-2), one end of the outer pipe (12-2) is welded with the outer wall of the air chamber (3-6), the other end of the outer pipe (12-2) is in transitional connection with the inner pipe (12-1) through an expansion joint (12-4), the outer part of the outer pipe (12-2) is coated with a heat insulation layer (12-3), the outlet end of the inner pipe (12-1) is provided with an ash discharge regulating valve (13), and the outlet end of the inner pipe (12-1) is connected with an ash cooler (14).

4. The controlled amount returning device for a low emission type circulating fluidized bed boiler according to claim 3, wherein: the number of the observation holes (3-4) is three, the three observation holes (3-4) are vertically arranged in a straight line, and the distance (H1) between every two adjacent observation holes is 0.5 m.

5. The controlled amount returning device for a low emission type circulating fluidized bed boiler according to claim 4, wherein: the height H of the returned ash in the vertical material pipe (3-1) can be seen within the range of 2-3m, when the top of the returned ash is positioned at the position of the observation hole (3-4) at the lower part, H is 2m, and when the top of the returned ash is positioned at the position of the observation hole (3-4) at the upper part, H is 3 m.

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