CN214700765U - SCR denitration high-temperature air mixing device for low-load operation of reciprocating chain grate coal-fired boiler - Google Patents

Abstract

The utility model relates to a reciprocating type chain grate coal fired boiler equipment technical field just discloses a be used for reciprocating type chain grate coal fired boiler low-load operation SCR denitration high temperature to mix wind device, and it includes the boiler, the boiler is inside to be provided with furnace and burns out the cinder room, just intercommunication between furnace and the cinder room, through-hole A's one end is seted up to the indoor lateral wall of burn out, just through-hole A's the other end extends to the boiler surface, through-hole A open end outer wall fixedly connected with high temperature flue A's one end. This high temperature mixes wind device and is applied to SCR denitration when reciprocating type chain grate coal-fired heating boiler low-load operation, mixes the service temperature that gets into SCR denitration reactor and satisfy the catalyst through extracting boiler burn-out room high temperature flue gas and boiler final stage convection bank export flue gas, guarantees SCR denitration normal operating, satisfies NOx's ultralow emission requirement, and device simple structure and practicality are stronger, are fit for being extensively promoted and use.

Description

SCR denitration high-temperature air mixing device for low-load operation of reciprocating chain grate coal-fired boiler

Technical Field

The utility model belongs to the technical field of reciprocating type chain grate coal fired boiler equipment, specifically be a be used for reciprocating type chain grate coal fired boiler low-load operation SCR denitration high temperature to mix wind device.

Background

SCR denitration is the most mature flue gas denitration technology at present, and is widely applied to power station boiler flue gas denitration project engineering at home and abroad. Under the increasingly strict background of smoke emission, the ultralow emission of NOx is less than or equal to 50mg/Nm³The application of the SCR denitration technology in the coal-fired boiler flue gas treatment project in the heating industry also becomes a mainstream. The catalyst used in SCR is mostly made into three types of honeycomb type, plate type or corrugated type by taking TiO2 as a carrier and V2O5, V2O 5-WO3 or V2O5-MoO3 as active ingredients. The reaction temperature suitable for different catalysts is different, if the reaction temperature is lower, the activity of the catalyst is reduced, so that the denitration efficiency is reduced, and if the catalyst is continuously operated at low temperature, the catalyst is permanently damaged; if the reaction temperature is too high, NH3 is easily oxidized, the amount of NOx produced increases, and phase transition of the catalyst material is also caused, degrading the activity of the catalyst.

The SCR denitration technology of the reciprocating chain grate coal-fired boiler is a difficult point in the industry, and even if the smoke temperature of an outlet of a heating surface of a final-stage tube bundle of the boiler is about 250 ℃ during full-load operation, the use temperature of an SCR catalyst cannot be met; in general, a short circuit is generally carried out on a smoke folding wall of a convection tube bundle of a boiler, the flow direction of smoke is changed to increase the outlet smoke temperature under 80% -100% of boiler load, the smoke temperature reaches 310-360 ℃ and meets the use temperature of a catalyst, but the load change often occurs in the actual operation process of a heating boiler, the outlet smoke temperature is lower than 300 ℃ under the condition of lower than 80% of load and can not meet the use temperature of the catalyst, the denitration efficiency is seriously influenced, and the NOx emission concentration is increased along with the outlet smoke temperature and can not meet the emission requirement; in general, when a power station boiler is operated in SCR denitration under the condition of low load, a bypass flue is connected to an inlet of an economizer and introduced into an inlet of a reactor for flue gas mixing to reach the service temperature of a catalyst, and obviously, the scheme is not suitable for a reciprocating type chain grate boiler.

The reaction temperature range of the catalyst used in the domestic heating industry at present is 310-400 ℃. When the reciprocating chain grate coal-fired boiler operates at high load, the flue gas temperature can reach the reactor region of the catalyst by partially short-circuiting the smoke-folding wall of the convection tube bundle of the boiler, but the flue gas temperature is still lower when the boiler operates at low load.

SUMMERY OF THE UTILITY MODEL

To the above-mentioned condition, for overcoming prior art's defect, the utility model provides a be used for reciprocating type chain grate coal fired boiler low-load operation SCR denitration high temperature to mix wind device, the effectual problem of having solved on the existing market.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a be used for reciprocating type chain grate coal fired boiler low-load operation SCR denitration high temperature to mix wind device, includes the boiler, inside furnace and the burn-out room of being provided with of boiler, and communicate between furnace and the burn-out room, the one end of through-hole A is seted up to the indoor lateral wall of burn-out, and the other end of through-hole A extends to the boiler surface, through-hole A open end outer wall fixedly connected with high temperature flue A's one end, and high temperature flue A's the other end extends to reactor entry flue inside wall, reactor entry flue's one end and boiler inside wall fixed connection, and reactor entry flue's the other end extends to inside the denitration reactor.

Preferably, the high-temperature air mixing fan A is installed in the middle of the high-temperature flue A, an air inlet electric baffle door is arranged at the left side of the high-temperature air mixing fan A, and an exhaust electric baffle door is installed at the right side of the high-temperature air mixing fan A.

Preferably, one end of the through hole B is formed in the inner side wall of the burnout chamber, and the other end of the through hole B extends to the outer surface of the boiler.

Preferably, through-hole B open end outer wall fixedly connected with high temperature flue B's one end, just inside high temperature flue B's the other end extended to reactor entry flue, high temperature flue B intermediate position was provided with high temperature and mixes wind fan B, just high temperature flue B's structure is the same with high temperature flue A's structure.

Preferably, the exhaust ends of the high-temperature flue A and the high-temperature flue B are provided with temperature sensors, and the signal output ends of the temperature sensors are in telecommunication connection with the signal input ends of the high-temperature air mixing fan A, the high-temperature air mixing fan B, the air inlet electric baffle door and the exhaust electric baffle door.

Compared with the prior art, the beneficial effects of the utility model are that:

1) in the operation, firstly, materials are added in the hearth to enable the boiler to operate in a combustion mode, then, flue gas generated after the materials in the hearth are combusted flows into the burn-out chamber, then, the flue gas after sufficient combustion flows into the denitration reactor along the inlet flue of the reactor to be subjected to denitration treatment, meanwhile, the temperature sensor is switched on and controlled to operate, when the temperature sensor senses that the temperature in the inlet flue of the reactor is lower than 310 ℃, the temperature sensor transmits signals to the air inlet electric baffle door, the air exhaust electric baffle door and the high-temperature air mixing fan A, then, the air inlet electric baffle door and the air exhaust electric baffle door are opened, the high-temperature air mixing fan A operates to extract the high-temperature flue gas in the burn-out chamber from the interior of the through hole A, and then, the high-temperature flue gas in the burn-out chamber can be transported to the interior of the inlet flue of the reactor through the high-temperature flue A, meanwhile, high-temperature flue gas in the burn-out chamber can be conveyed to the interior of an inlet flue of the reactor through the through hole B and the high-temperature flue B under the matched operation of the high-temperature air mixing fan B, in this way, through detailed thermodynamic calculation, holes are formed in the burn-out chamber of the boiler, the high-temperature air mixing fan A and the high-temperature air mixing fan B extract high-temperature flue gas with the temperature of more than 520 ℃ to be mixed with the flue gas in the inlet flue of the reactor, the temperature of the mixed flue gas reaches about 330 ℃, the use temperature of a catalyst is met, and under the interlocking action of an air inlet electric baffle door, an exhaust electric baffle door, the high-temperature air mixing fan A and the high-temperature air mixing fan B and a temperature sensor, when the temperature of the inlet flue gas of the reactor is lower than 310 ℃, the electric baffle door and the fan are automatically opened, and the power of the fan can be automatically adjusted according to the temperature by selecting a variable frequency motor at the last stage, so that the mixed power of the high-temperature air fan B and the high-temperature flue gas in the burn-out chamber of the boiler and the outlet flue of the convection tube bundle of the boiler can be effectively realized The flue gas enters an SCR denitration reactor to meet the use temperature of a catalyst, the normal operation of SCR denitration is ensured, the ultralow emission requirement of NOx is met, the temperature of the obtained denitration inlet flue gas is about 250 ℃ when the load of a boiler is 50 percent through calculation, the temperature requirement of a denitration process cannot be met, a short-circuit flue gas hole needs to be formed near the inlet position of a burn-out chamber, about 35 percent of the total flue gas amount of a short-circuit burn-out chamber is needed, the temperature of the high-temperature flue gas at the position is about 527 ℃, the short-circuit high-temperature flue gas is led out by a high-temperature fan and then is sent to the front of the inlet of a denitration device, the temperature of the low-temperature flue gas at the position is about 250 ℃, the high-temperature flue gas and the low-temperature flue gas at the position are mixed and then enter the denitration device, the temperature of the mixed flue gas is about 330 ℃, the flue gas is actually operated, and when the load of the boiler is 50 percent, the short-circuit high-temperature flue gas is led out by the high-temperature fan and then is sent to the front of the inlet of the denitration device, and the mixed flue gas is mixed with the low-temperature flue gas, the temperature of the mixed flue gas is about 340 ℃, the use of a catalyst is met, the denitration efficiency is ensured, meanwhile, the device is interlocked with the temperature, the automatic start is realized, the manual operation is not needed, and the operation is safe and reliable.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic structural view of a high-temperature flue A of the present invention;

in the figure: 1. a boiler; 2. a hearth; 3. a burn-out chamber; 4. a through hole A; 5. an intake electric flapper door; 6. a high-temperature flue A; 7. a high-temperature flue B; 8. a high-temperature air mixing fan A; 9. an exhaust electric flapper door; 10. a through hole B; 11. a high-temperature air mixing fan B; 12. a temperature sensor; 13. a reactor inlet flue; 14. a denitration reactor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments; based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

First embodiment, as shown in fig. 1-2, the utility model comprises a boiler 1, a hearth 2 and a burn-out chamber 3 are arranged inside the boiler 1, the hearth 2 and the burn-out chamber 3 are communicated, one end of the inner side wall of the burn-out chamber 3 is provided with a through hole A4, and the other end of the through hole A4 extends to the outer surface of the boiler 1, the outer wall of the opening end of the through hole A4 is fixedly connected with one end of a high-temperature flue A6, and the other end of the high-temperature flue A6 extends to the inner side wall of the reactor inlet flue 13, one end of the reactor inlet flue 13 is fixedly connected with the inner side wall of the boiler 1, the other end of the reactor inlet flue 13 extends to the inside of the denitration reactor 14, the boiler 1 is burnt and operated by adding materials into the hearth 2, at the moment, the flue gas generated after the materials in the hearth 2 are burnt flows into the burnout chamber 3, subsequently, the flue gas after sufficient combustion flows into the denitration reactor 14 along the reactor inlet flue 13 to be subjected to denitration treatment.

Referring to fig. 1 and 2, a high-temperature air mixing fan A8 is installed in the middle of the high-temperature flue a6, an air inlet electric damper 5 is installed at the left side of the high-temperature air mixing fan A8, and an exhaust electric damper 9 is installed at the right side of the high-temperature air mixing fan A8, so that high-temperature flue gas inside the burn-out chamber 3 can be extracted from the inside of the through hole a4 by opening the air inlet electric damper 5 and the exhaust electric damper 9 and operating the high-temperature air mixing fan A8, and the high-temperature flue gas inside the burn-out chamber 3 can be transported to the inside of the reactor inlet flue 13 by the high-temperature flue a 6.

Referring to fig. 1 and 2, one end of the inner side wall of the ember chamber 3, which is provided with a through hole B10, is provided, and the other end of the through hole B10 extends to the outer surface of the boiler 1, so that the high-temperature flue gas inside the ember chamber 3 can be transported to the inside of the reactor inlet flue 13 through the through hole B10 and the high-temperature flue B7 under the matching operation of the high-temperature air mixing fan B11.

Referring to fig. 1 and 2, one end of a high-temperature flue B7 is fixedly connected to the outer wall of the opening end of the through hole B10, the other end of the high-temperature flue B7 extends into the reactor inlet flue 13, a high-temperature air mixing fan B11 is arranged in the middle of the high-temperature flue B7, the structure of the high-temperature flue B7 is the same as that of the high-temperature flue a6, a hole is formed in the position of the burnout chamber 3 of the boiler 1 through detailed thermodynamic calculation, and high-temperature flue gas at 520 ℃ is extracted by the high-temperature air mixing fan A8 and the high-temperature air mixing fan B11 to be mixed with the flue gas in the reactor inlet flue 13, so that the temperature of the mixed flue gas reaches about 330 ℃, and the use temperature of the catalyst is met.

Referring to fig. 1 and 2, a temperature sensor 12 is arranged at the exhaust end of the high-temperature flue a6 and the high-temperature flue B7, the signal output end of the temperature sensor 12 is in telecommunication connection with the signal input ends of the high-temperature air mixing fan A8, the high-temperature air mixing fan B11, the air inlet electric damper door 5 and the exhaust electric damper door 9, and when the temperature of the inlet smoke of the reactor is lower than 310 ℃, the electric damper door and the fan are automatically opened under the interlocking action of the air inlet electric damper door 5, the exhaust electric damper door 9, the high-temperature air mixing fan A8, the high-temperature air mixing fan B11 and the temperature sensor 12, and the power of the fan can be automatically adjusted according to the temperature by using a variable frequency motor.

The high-temperature flue A6 and the high-temperature flue B7 are made of 304 materials, so that the high-temperature use requirement is met; the high-temperature air mixing fan A8 and the high-temperature air mixing fan B11 both adopt an integral damping support structure, a bottom frame at the lower part of a damper is welded at an installation position during installation, and the part above the damper can move, so that the maintenance is facilitated; the fan transmission mode adopts belt transmission, the belt pulley adopts a detachable belt pulley (with a taper sleeve), and the triangular belt adopts an SPB tooth-shaped strong belt; the fan adopts a double-layer heat-preservation shell, the inner shell is made of heat-resistant steel, the outer shell is made of carbon steel, and aluminum silicate refractory fiber cotton is filled in the shell, so that the radiation and the conduction of heat in the fan are effectively prevented; the cooling mode of the fan bearing is as follows: water cooling + air cooling, bearing brand NSK; materials: impeller: 321, blade thickness: 6mm, main axis: 304, maximum diameter: 115mm, double-layer heat preservation shell inner shell: 304, thickness of side plate and volute plate: 5 mm.

The working principle is as follows: when the device works, firstly, materials are added into a hearth 2 to enable a boiler 1 to operate in a combustion mode, then, flue gas generated after the materials in the hearth 2 are combusted flows into an ember chamber 3, then, the flue gas after full combustion flows into a denitration reactor 14 along a reactor inlet flue 13 to be subjected to denitration treatment, meanwhile, a power supply is switched on and a temperature sensor 12 is controlled to operate, when the temperature sensor 12 senses that the temperature in the reactor inlet flue is lower than 310 ℃, the temperature sensor 12 transmits signals to an air inlet electric baffle door 5, an exhaust electric baffle door 9 and a high-temperature air mixing fan A8, then, the air inlet electric baffle door 5 and the exhaust electric baffle door 9 are opened, the high-temperature air mixing fan A8 operates to extract high-temperature flue gas in the ember chamber 3 from the inside of a through hole A4, and then, the high-temperature flue gas in the ember chamber 3 can be transported to the reactor inlet flue 13 through a high-temperature flue 6, meanwhile, under the matching operation of a high-temperature air mixing fan B11, high-temperature flue gas in the burnout chamber 3 can be conveyed to the interior of a reactor inlet flue 13 through a through hole B10 and a high-temperature flue B7, in this way, through detailed thermodynamic calculation, a hole is selected to be formed in the position of the burnout chamber 3 of the boiler 1, the high-temperature air mixing fan A8 and the high-temperature air mixing fan B11 extract high-temperature flue gas at a temperature of more than 520 ℃ to be mixed with the flue gas in the reactor inlet flue 13, so that the temperature of the mixed flue gas reaches about 330 ℃, the service temperature of a catalyst is met, in this way, under the interlocking action of an air inlet electric baffle door 5, an exhaust electric baffle door 9, the high-temperature air mixing fan A8 and the high-temperature air mixing fan B11 and a temperature sensor 12, when the temperature of the reactor inlet flue gas is lower than 310 ℃, the electric baffle door and the fan are automatically opened, and the high-temperature fan can also automatically adjust the power according to the temperature, the effective realization mixes the service temperature that gets into SCR denitration reactor and satisfy the catalyst through extracting boiler burn-out room high temperature flue gas and boiler last stage convection bank export flue gas, guarantees SCR denitration normal operating, satisfies NOx's minimum emission requirement.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (5)

1. The utility model provides a be used for reciprocating type chain grate coal fired boiler low-load operation SCR denitration high temperature to mix wind device, includes boiler (1), its characterized in that: boiler (1) is inside to be provided with furnace (2) and burn out room (3), just intercommunication between furnace (2) and the burn out room (3), the one end of through-hole A (4) is seted up to burn out room (3) inside wall, just the other end of through-hole A (4) extends to boiler (1) surface, the one end of through-hole A (4) open end outer wall fixedly connected with high temperature flue A (6), just the other end of high temperature flue A (6) extends to reactor entry flue (13) inside wall, the one end and the boiler (1) inside wall fixed connection of reactor entry flue (13), just the other end of reactor entry flue (13) extends to inside denitration reactor (14).

2. The SCR denitration high-temperature air mixing device for the low-load operation of the reciprocating chain grate coal-fired boiler according to claim 1, is characterized in that: the high-temperature air mixing device is characterized in that a high-temperature air mixing fan A (8) is installed in the middle of the high-temperature flue A (6), an air inlet electric baffle door (5) is arranged at the left side position of the high-temperature air mixing fan A (8), and an exhaust electric baffle door (9) is installed at the right side position of the high-temperature air mixing fan A (8).

3. The SCR denitration high-temperature air mixing device for the low-load operation of the reciprocating chain grate coal-fired boiler according to claim 2, is characterized in that: one end of a through hole B (10) is formed in the inner side wall of the burnout chamber (3), and the other end of the through hole B (10) extends to the outer surface of the boiler (1).

4. The SCR denitration high-temperature air mixing device for the low-load operation of the reciprocating chain grate coal-fired boiler according to claim 3, characterized in that: through-hole B (10) open end outer wall fixedly connected with high temperature flue B (7) one end, just inside the other end of high temperature flue B (7) extended to reactor entry flue (13), high temperature flue B (7) intermediate position is provided with high temperature and mixes wind fan B (11), just the structure of high temperature flue B (7) is the same with the structure of high temperature flue A (6).

5. The SCR denitration high-temperature air mixing device for the low-load operation of the reciprocating chain grate coal-fired boiler according to claim 4, is characterized in that: and the exhaust ends of the high-temperature flue A (6) and the high-temperature flue B (7) are provided with temperature sensors (12), and the signal output ends of the temperature sensors (12) are in telecommunication connection with the signal input ends of the high-temperature air mixing fan A (8), the high-temperature air mixing fan B (11), the air inlet electric baffle door (5) and the exhaust electric baffle door (9).

Images