CN215428230U

CN215428230U - Novel in-furnace high-efficiency flue gas denitration device of power plant boiler

Info

Publication number: CN215428230U
Application number: CN202121933262.5U
Authority: CN
Inventors: 赵建
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-08-17
Filing date: 2021-08-17
Publication date: 2022-01-07
Anticipated expiration: 2031-08-17

Abstract

The utility model provides a novel in-furnace high-efficiency flue gas denitration device of a power plant boiler; the device comprises a material storage assembly, a transmission assembly and a gun assembly; the storage bin of the storage assembly is provided with a feeding hole and a discharging hole, the discharging hole of the storage bin is communicated with the transmission assembly, the transmission assembly comprises a first control valve, a transmission hard tube and a pressure switch, an inlet of the transmission hard tube is communicated with the discharging hole of the storage bin, the first control valve is installed at the inlet of the transmission hard tube, and the pressure switch is arranged at the outlet of the transmission hard tube; the spray gun subassembly includes spray gun seat, venturi nozzle and spray tube, is equipped with in the spray gun seat and sprays the chamber, and the venturi nozzle stretches into and sprays the intracavity, and the venturi nozzle communicates with outside high pressurized air source, and the one end of spray tube stretches into and sprays the intracavity, and the other end of spray tube stretches into power plant boiler inner chamber, and the spray gun seat lateral wall is opened have with the through-hole that sprays the chamber intercommunication, through-hole and the export intercommunication of transmission hard tube. The denitration device has low equipment cost investment. The maintenance cost is low, and the catalyst of different manufacturers can be used.

Description

Novel in-furnace high-efficiency flue gas denitration device of power plant boiler

Technical Field

The utility model relates to a flue gas denitration device, in particular to a novel in-furnace high-efficiency flue gas denitration device of a power plant boiler.

Background

The existing mainstream denitration device comprises a PNCR (pneumatic nitrogen reduction reactor) device for denitration in a furnace, an SNCR device for denitration in the furnace and an SCR device for denitration outside the furnace, wherein the denitration devices have the following advantages and disadvantages:

firstly, denitration in a furnace: a PNCR device;

the PNCR equipment is equipment such as a Roots blower, a feeding device, a suction material or a storage material and the like arranged on the ground. The high-pressure gas generated by the Roots blower is used for blowing powdery (particle) materials into the pipeline by a Venturi nozzle or directly. If the venturi nozzle is used for conveying, the later boiler nozzle must be thick, otherwise, negative pressure cannot be generated at the venturi nozzle for sucking materials. With thick nozzles, the boiler water wall needs to be treated by a yielding pipe, so that the reconstruction cost is high. And is conveyed upwards through a pipeline to a branch at a position of 20 to 30 meters, and powder is conveyed to each nozzle through the branch.

The advantages of PNCR are mainly that gas transportation is adopted, solid urea particles and powdery catalyst are transported, so that ammonia slip is smaller than that of SNCR. Since solid urea particles are a physical process from solid to gas, there is no liquid state in between. Unreacted solid urea particles are carried to the fly ash collection system. Does not become ammonia slip. As the solid urea particles are used as the reducing agent, the urea is not a flammable and explosive article, and has no potential safety hazard.

However, the disadvantages of PNCR are: 1, the material conveying pipeline of the PNCR is divided into two or three branches (according to the size of the boiler) from 0 meter of the outlet ground of the Roots blower to the position near the height of 30 meters of the nozzle of the boiler, and each branch is divided into 4 to 5 nozzles. The length of the pipe, the number of bends and the height of the branch will create a pressure drop, and the pressure and flow into the branch will be less than at the outlet of the roots blower. The pressure and flow to the boiler from the multiple nozzle outlets behind the branch is further reduced. Resulting in a spray distance that is not SNCR-free. It is only suitable for small power plants. 2, the nozzle is selected to be thick because the nozzle is larger than the distance between the boiler water-cooled walls. Therefore, the water wall of the boiler at each nozzle needs to be processed by a yielding pipe, and the reconstruction cost of the boiler is high. 3, the nozzle opening is big, and the material velocity of flow of export can further diminish, and reaction area is little, only is fit for early, miniature waste incineration power plant. 4, the selected nozzle is thin, the water-cooled wall of the boiler does not need to be treated by a pipe, but the distance is long, the flow rate is slow, materials can be adhered to the pipeline, and the phenomenon of material blockage is easily formed on the pipeline at the position of the branch and the nozzle. Because no blockage monitoring equipment is arranged on the pipeline, the blockage at the position cannot be known. The blowing-assisting device is needed at the nozzle, so that the material cannot be blocked. And 5, selecting a thin nozzle, wherein the outlet of the fan cannot be conveyed by using a Venturi nozzle, and arranging a hopper on the ground. 6, no matter which nozzle, the actual flow rate condition of the individual nozzle can be known. 7, if the hopper is arranged on the ground, compressed air can blow back air into the hopper from the rotary blanking valve because the air has certain humidity. The powder can form the wall built-up phenomenon because the hopper inner wall wets. 8, because the air has certain humidity, the high molecular catalyst can be out of work for a long time. 9, the total spraying amount can be controlled only at the outlet of the fan, and the flow of a single gun or a plurality of guns cannot be controlled. If one or more nozzles are blocked or the material flow is slow, the central control room cannot know. 10, the fan is large in size and weight and can only be installed on the ground. 11, if a Venturi nozzle is used for conveying, the later nozzle must be thick, otherwise, negative pressure cannot be generated at the Venturi nozzle for sucking materials. And 12, the energy consumption is higher than that of the SNCR system.

Secondly, denitration in the furnace: the SNCR equipment uses ammonia water or urea solution as a material;

the SNCR equipment has the advantages that: 1, since the liquid is delivered to the distribution cabinet by means of a water pump under a certain pressure, the cabinet has branches leading to the respective spray guns, one float flow meter being provided on each branch. The reducing agent is delivered to the dual fluid spray gun by a float flow meter. The flow of each spray gun can be observed through the float flowmeter, and whether the spray gun is blocked or not can be judged. 2, the double-fluid spray guns are adopted to work, and each double-fluid spray gun is provided with an independent gas pressure regulating valve and a gas conveying pipeline, so that the gas pressure of each spray gun is ensured to be consistent. The liquid spray distance at the nozzle is further than that of the PNCR solid. The reaction area in the furnace is large, and the method is suitable for denitration in the furnace of a large-scale waste incineration power plant.

However, the disadvantages of SNCR devices are: 1, ammonia slip is higher than PNCR. Because it is transported through a liquid, the unreacted reductant (ammonia or urea solution) can mix with the flue gas and become ammonia slip. 2, when ammonia water is used as a reducing agent, the ammonia water is an inflammable and explosive article and has potential safety hazard. And 3, the holes at the nozzle are too small and are easily blocked by impurities. 4, the gun head is inserted into the boiler to a certain depth, and if the depth is insufficient, the water-cooled wall of the boiler is burst, so that the large fault that the garbage power plant stops running is caused. And 5, periodically pulling out the gun head for inspection, and cleaning foreign matters at the gun head. If the gun is not checked for a long time, the gun may not be pulled out and replaced. 6, the spray holes at the gun head become large after being used for a period of time due to abrasion. The atomization effect is poor, the reducing agent is changed into a water drop shape from a mist shape, and the reaction is insufficient in a proper temperature. After the use amount is increased, the original denitration effect can be achieved. Ammonia slip and reductant build-up can result. Increasing the operating cost of the plant and causing losses to the equipment. 7, the flue gas system adopts ammonia process desulfurization, and when ammonia escapes too much, the ammonium bicarbonate produced by the desulfurization system can not be crystallized. Economic value cannot be generated.

Thirdly, denitration SCR equipment outside the furnace, wherein the SCR equipment is reacted by ammonia water, and noble metal is used as a catalyst;

the advantages of the SCR device are: the denitration efficiency is high, and the ultralow emission requirement of nitrogen oxides can be met. NOX <100Nm 3/mg.

The disadvantages of the SCR device are: 1, the equipment investment is large in advance. And 2, the later operation cost is high. Mainly the cost of replacing the SCR catalyst is high. 3, when the sulfide in the flue gas is too high, the SCR catalyst is easy to lose efficacy and shorten the service life after being poisoned by sulfur. 4, under the condition that harmful substances such as sulfide in the flue gas do not exceed the standard, the service time of the SCR catalyst is only twenty thousand hours, and the service time can be increased only for a short time after heating and regeneration. And 5, the denitration efficiency after regeneration is low. 6, the good SCR catalyst is foreign, and domestic efficiency and service time cannot reach foreign. 7, procurement is carried out by using a large amount of foreign currencies every year. 8, when the SCR catalyst is used in the middle and later periods, the denitration efficiency is reduced. The operation of the apparatus is unstable. 9, the flue gas at the inlet of the SCR catalyst needs to be reheated, so that the energy consumption is high (the flue gas of the high-temperature catalyst and the flue gas of the low-temperature catalyst need to be heated).

The SNCR energy consumption among the three denitration devices is the lowest, the PNCR is the second, and the highest is the SCR. The lowest nitrogen oxide emissions are PNCR and SCR followed by SNCR. The long-term usage of the device is PNCR, SNCR. The SCR is influenced by the sulfur content in the flue gas, so that the time is shortest. Under normal use (sulfide does not exceed standard), the time is only two years.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of providing a novel in-furnace high-efficiency flue gas denitration device of a power plant boiler, which has a reasonable structure and can flexibly control materials.

In order to solve the technical problems, the utility model provides a novel in-furnace high-efficiency flue gas denitration device of a power plant boiler;

the device comprises a storage assembly, at least one group of conveying assemblies and at least one group of spray gun assemblies;

the storage assembly at least comprises a storage bin, the storage bin is provided with a feeding hole and a discharging hole respectively, the discharging holes of the storage bin are communicated with the transmission assembly respectively, the transmission assembly comprises a first control valve, a transmission hard pipe and a pressure switch, an inlet and an outlet are arranged on two sides of the transmission hard pipe respectively, the inlet of the transmission hard pipe is communicated with the discharging hole of the storage bin, the first control valve is installed at the inlet of the transmission hard pipe, and the pressure switch is arranged at the outlet of the transmission hard pipe;

at least a set of transmission assembly and at least a set of spray gun subassembly are the one-to-one relation, the spray gun subassembly includes spray gun seat, venturi nozzle and spray tube, is equipped with in the spray gun seat and sprays the chamber, and the venturi nozzle stretches into and sprays the intracavity to venturi nozzle and outside high pressurized air source intercommunication, the one end of spray tube stretches into and sprays the intracavity, and the other end of spray tube runs through power boiler lateral wall and stretches into power boiler inner chamber, and spray gun seat lateral wall is opened have with the through-hole that sprays the chamber intercommunication, the export intercommunication of through-hole and transmission hard tube.

In order to more clearly understand the technical content of the utility model, the novel in-furnace high-efficiency flue gas denitration device of the power plant boiler is simply referred to as the denitration device below.

As this denitrification facility's preferred, storage component still include gear motor and helical agitator, the discharge gate setting of feed bin is in the feed bin bottom, gear motor fixed connection is in the feed bin upside, helical agitator stretches into inside the feed bin, gear motor drive helical agitator rotates.

As the optimization of this denitrification facility, storage subassembly still include first spacing meter and the spacing meter of second, first spacing meter and the spacing meter setting of second are inside the feed bin, first spacing meter is in the position of being close to the feed bin discharge gate, the spacing meter of second is in the position of being close to the feed bin feed inlet.

Preferably, the denitration device employs a rotation-resistant level gauge for both the first limit gauge and the second limit gauge.

As the optimization of this denitrification facility, the transmission subassembly still includes the conveying hose, and conveying hose one end and through-hole intercommunication, the conveying hose other end and the export intercommunication of transmission hard tube.

Preferably, the spray gun assembly further comprises a connecting pipe, the venturi nozzle is communicated with an external high-pressure air source through the connecting pipe, and a second control valve and an air pressure regulating valve are arranged on the connecting pipe.

As this denitrification facility's preferred, the spray gun subassembly still includes locating piece and puller bolt, locating piece and power plant boiler lateral wall fixed connection, the locating piece be equipped with spray tube complex hole, the spray tube runs through the hole of locating piece and power plant boiler lateral wall in proper order and stretches into power plant boiler inner chamber, the locating piece lateral wall open have with the communicating screw hole of hole, puller bolt supports on the spray tube lateral wall with screw hole cooperation and puller bolt's tip.

As this denitrification facility's preferred, this power plant boiler's novel high-efficient flue gas denitrification facility in stove includes three transmission assembly of group and three spray gun subassemblies of group, and three transmission assembly's of group transmission hard tube import is through cross to one side and feed bin discharge gate intercommunication, and three spray gun subassemblies of group are even circumference along power plant boiler axis and distribute.

Preferably, the denitration device further includes a plurality of air cannons provided at positions below the first limit gauge.

The denitration device adopts a brand new process design, eliminates the defects of PNCR, SCR and SNCR equipment, and integrates the advantages of a plurality of equipment.

The spray gun assembly comprises a spray gun seat, a Venturi nozzle and a spray pipe

The denitration device selects the factory compressed air, and an independent gas pressure regulating valve and a venturi nozzle are arranged from the factory compressed air main pipe to each group of spray gun assemblies. And the sufficient gas pressure and flow of each group of spray gun components are ensured. The outlet of the transmission hard pipe is provided with a pressure switch, and the outlet of the transmission hard pipe is negative pressure due to the Venturi principle during normal work, and is normal pressure only when the material is blocked. The pressure switch will actuate. Whether each set of spray gun assemblies is plugged can be known remotely.

The flow control is carried out by adopting a special first control valve (powder switch valve). Flow control of each group of spray gun components can be achieved. The flow rate of the powder is controlled by the on-off time of the first control valve in unit time or the opening of the control valve. If the left temperature and the right temperature of the boiler are too different, left control and right control can be achieved. The above devices are not accessible.

When only the solid urea particles are used, the denitration device can be used as an SNCR device. Urea granules are added into the bin after being crushed, so that the reaction time is faster and the reaction is more sufficient.

The water-cooled wall of the boiler does not need to be processed by a pipe, the existing SNCR open pore can be utilized for equipment transformation, and the existing boiler can be transformed under the condition of not stopping the boiler.

The denitration device achieves ammonia escape of PNCR and SCR, because PNCR is a physical reaction process from solid to gas, and no liquid state exists in the middle. The SNCR is obtained by spraying liquid into a furnace for reaction, is unreacted, can be completely changed into gaseous ammonia water, and the ammonia escapes into flue gas. SPNCR is a reactive, non-reactive urea particle injected into the furnace with solid urea, which is fed into the fly ash system.

The urea particles of the denitration device are crushed and then the reaction area is increased. The reaction time is reduced and the maximum effect can be achieved with the minimum amount.

Compared with SNCR equipment, the gun head used by the SNCR is expensive, and the spray pipe used by the denitration device can be processed on site. Can be processed and replaced on site at any time. And this denitrification facility reaches the effect of SCR, and at present SCR mostly adopts foreign catalyst, and there are a lot of rare metals in the SCR catalyst, and the price is expensive, and life is short, and when the sulphide in the flue gas was too high, the SCR catalyst became invalid easily. When the SCR catalyst is out of service, the replacement cost is hundreds of thousands per cubic meter, and the cost is calculated according to the volume by replacing the SCR catalyst of one boiler by about millions. The running cost is too high. The maintenance cost is high. The denitration device has low equipment cost investment. The maintenance cost is low, and the catalyst of different manufacturers can be used.

Drawings

FIG. 1 is a schematic structural diagram of a storage assembly in an embodiment of the denitration device.

FIG. 2 is a diagram showing the state of use of the transport assembly and the lance assembly in the embodiment of the denitration apparatus.

Detailed Description

As shown in fig. 1 to 2

This denitrification facility includes storage subassembly, three group's transmission subassemblies and three group's spray gun subassemblies.

Storage component sets up in power plant boiler top position, and storage component includes feed bin 11, gear motor 12, helical agitator 13, first spacing meter 14 and the spacing meter 15 of second, and feed bin 11 is equipped with feed inlet 11a and discharge gate 11b respectively, and feed inlet 11a of feed bin 11 sets up at 11 tops of feed bin, and 11b settings in 11 bottoms of feed bin of discharge gate of feed bin 11.

Speed reducer 12 fixed mounting is in 11 upsides in feed bin, and helical agitator 13 is the auger agitator, and helical agitator 13 is vertical to stretch into 11 insides in feed bin and to extend to the discharge gate 11b position that is close to feed bin 11, and speed reducer 12 drives helical agitator 13 and rotates, and helical agitator 13 is in 11 top central point in feed bin and from upwards turning over the material down, when preventing the vibration of power boiler, likepowder material is to sinking, and the granule material is upwards, causes the interior material of feed bin 11 uneven.

The first limit gauge 14 and the second limit gauge 15 are arranged inside the bin 11, the first limit gauge 14 and the second limit gauge 15 both adopt a rotation-resisting type material level gauge, the first limit gauge 14 is positioned at a position close to a discharge hole 11b of the bin 11, the second limit gauge 15 is positioned at a position close to a feed hole 11a of the bin 11, and the first limit gauge 14 is at a low material level and is used for feeding; the second limit gauge 15 is used for stopping feeding at a high material level, an air cannon 16 is arranged between the discharge hole 11b of the storage bin 11 and the first limit gauge 14, and the air cannon 16 prevents the phenomenon of material wall hanging.

The powdery materials filled into the bin 11 are a high molecular catalyst and urea particles, and urea particles with different urea contents can be used (the urea content is low, the use amount can be increased, and the maximum use amount is 46.3%).

The storage bin 11 of the storage assembly is not additionally provided with a heating or a dehumidifier, and the body temperature of the boiler is utilized for drying. Because of installing the top position at the boiler, can utilize the heat radiation and the heat-conduction that produce when the boiler barbecue (have the contact of large tracts of land with the boiler when using heat-conduction, the centre can not have the heat preservation), the feed bin 11 is dried.

The transmission assembly comprises a first control valve 22, an air-operated valve 23, a transmission hard pipe 21, a conveying hose 25 and a pressure switch 24, the two sides of the transmission hard pipe 21 are respectively an inlet and an outlet, the first control valve 22 is installed at the inlet of the transmission hard pipe 21, the air-operated valve 23 is also installed at the inlet of the transmission hard pipe 21, the pressure switch 24 is arranged at the outlet of the transmission hard pipe 21, the transmission hard pipe 21 is a transparent glass pipe, and the flow rate of materials can be conveniently checked by personnel.

The spray gun assembly comprises a spray gun seat 31, a venturi nozzle 32, a spray pipe 36, a connecting pipe 33, a positioning block 37 and a puller bolt 38, wherein a spray cavity 31a is arranged in the spray gun seat 31, the venturi nozzle 32 is in threaded fit with the spray gun seat 31, the venturi nozzle 32 extends into the spray cavity 31a, the venturi nozzle 32 is communicated with an external high-pressure air source through the connecting pipe 33, a second control valve 34 and a gas pressure regulating valve 35 are arranged on the connecting pipe 33, one end of the spray pipe 36 extends into the spray cavity 31a, the other end of the spray pipe 36 penetrates through a side wall 41 of the boiler of the power plant and extends into an inner cavity of the boiler of the power plant, a through hole communicated with the spray cavity 31a is formed in the side wall of the spray gun seat 31, the through hole is communicated with an outlet of a transmission hard pipe 21 through a conveying hose 25, the inlet of the spray gun seat 31 is designed to be thickened, and blockage can be effectively prevented.

The positioning block 37 is fixed to the side wall of the power plant boiler through four brackets in a welding mode, an inner hole matched with the spray pipe 36 is formed in the positioning block 37, the spray pipe 36 penetrates through the inner hole of the positioning block 37 and the side wall 41 of the power plant boiler in sequence and extends into an inner cavity of the power plant boiler, a threaded hole communicated with the inner hole is formed in the side wall of the positioning block 37, the jacking bolt 38 is matched with the threaded hole, and the end portion of the jacking bolt 38 abuts against the side wall of the spray pipe 36.

The inlets of the conveying hard pipes 21 of the three groups of conveying assemblies are communicated with the discharge port 11b of the storage bin 11 through an inclined four-way joint 17, the three groups of spray gun assemblies are uniformly and circumferentially distributed along the axis of the boiler of the power plant, and the three groups of conveying assemblies and the three groups of spray gun assemblies are in one-to-one correspondence.

The above description is only one embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the principle of the present invention, and these should also be considered as falling within the protection scope of the present invention.

Claims

1. The utility model provides a high-efficient flue gas denitration device in novel stove of power plant boiler, characterized in that:

2. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 1, which is characterized in that:

storage assembly still include gear motor and helical agitator, the discharge gate setting of feed bin is in the feed bin bottom, gear motor fixed connection is at the feed bin upside, helical agitator stretches into inside the feed bin, gear motor drive helical agitator rotates.

3. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 2, which is characterized in that:

the storage assembly further comprises a first limit gauge and a second limit gauge, the first limit gauge and the second limit gauge are arranged inside the storage bin, the first limit gauge is located at a position close to a discharge port of the storage bin, and the second limit gauge is located at a position close to a feed port of the storage bin.

4. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 3, which is characterized in that:

the first limit gauge and the second limit gauge both adopt a rotation-resisting type material level gauge.

5. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 1, which is characterized in that:

the transmission assembly further comprises a conveying hose, one end of the conveying hose is communicated with the through hole, and the other end of the conveying hose is communicated with an outlet of the transmission hard pipe.

6. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 1, which is characterized in that:

the spray gun assembly further comprises a connecting pipe, the Venturi nozzle is communicated with an external high-pressure air source through the connecting pipe, and a second control valve and an air pressure regulating valve are arranged on the connecting pipe.

7. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 1, which is characterized in that:

the spray gun subassembly still includes locating piece and puller bolt, locating piece and power plant boiler lateral wall fixed connection, the locating piece be equipped with spray tube complex hole, the spray tube runs through the hole of locating piece and power plant boiler lateral wall in proper order and stretches into power plant boiler inner chamber, the locating piece lateral wall open have with the communicating screw hole of hole, the puller bolt supports on the spray tube lateral wall with screw hole cooperation and puller bolt's tip.

8. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 1, which is characterized in that:

this high-efficient flue gas denitration device in novel stove of power plant boiler includes three transmission component of group and three spray gun subassemblies of group, and three transmission component's of group transmission hard tube import is through oblique cross and feed bin discharge gate intercommunication, and three spray gun subassemblies of group are even circumference along power plant boiler axis and distribute.

9. The novel in-furnace high-efficiency flue gas denitration device for the power plant boiler as claimed in claim 3, which is characterized in that:

and a plurality of air cannons are arranged at the lower side of the first limit gauge.