CN105570882A - Ultralow emission type circulating fluidized bed boiler system based on flow-state secondary reconstruction - Google Patents

Abstract

The invention relates to a circulating fluidized bed boiler and environmental protection system equipment, in particular to an ultra-low emission circulating fluidized bed boiler system based on secondary reconstruction of fluid state. The invention mainly solves the problem that the realization of ultra-low emission of the current coal-fired boiler is basically the simple superposition and integration of mature equipment. The present invention is an ultra-low-emission circulating fluidized bed boiler system based on the secondary reconstruction of the fluid state, which includes a circulating fluidized bed boiler furnace, a separator connected to the flue gas outlet of the furnace, and a material leg of the separator communicated with the furnace The return device, the secondary air pipe distributed on the front and rear walls of the furnace, and the SNCR flue gas denitrification system, the SNCR flue gas denitrification system consists of ammonia water unloading and storage system, ammonia water and dilution water delivery system, mixing distribution system and injection system Composition, among which: it also includes inlet valve group, limestone desulfurization conveying system in furnace, limestone desulfurization storage bin system in furnace, humidification spray gun, circulating fluidized bed desulfurization tower system, bag filter and return facility.

Description

An Ultra-low Emission Circulating Fluidized Bed Boiler System Based on Secondary Reconstruction of Fluid State

technical field

The patent of the present invention relates to circulating fluidized bed boilers and environmental protection system equipment, specifically an ultra-low emission circulating fluidized bed boiler system based on secondary reconstruction of fluid state.

Background technique

Coal-fired boilers achieve ultra-low emissions. The current technical route is basically the simple superposition and integration of mature equipment, including boilers that generate pollution sources, various desulfurization, denitrification, and dust removal equipment. The boiler island has not really gone through technological innovation and upgrading from the source. In order to reduce the original discharge of pollutants, it did not provide good chemical reaction conditions for the removal of pollutants. The environmental protection island did not fully integrate and interact with the boiler island, but only passively responded to various flue gas pollutants discharged from the boiler island. The desulfurization and denitrification equipment passed Continuously increasing the number of spray layers and catalyst layers improves the removal efficiency, and the smoke and dust emission is guaranteed by adding wet electrostatic precipitators. As the requirements for emission indicators are getting higher and higher, the capacity of the environmental protection island system is getting bigger and bigger, the chain is getting longer and longer, the investment and operating costs are getting higher and higher, and users are overwhelmed. If there is no fundamental technological innovation, the social, economic and environmental benefits of ultra-low emissions will be greatly reduced, and many new problems will be brought about.

Contents of the invention

The present invention mainly aims at the problem that realizing ultra-low emission of current coal-fired boilers is basically the simple superposition and integration of mature equipment, and provides an ultra-low emission circulating fluidized bed boiler system based on secondary reconstruction of fluid state.

The technical scheme that the present invention takes for solving the above problems is:

An ultra-low-emission circulating fluidized bed boiler system based on secondary reconfiguration of the fluid state, which includes a circulating fluidized bed boiler furnace, a separator connected to the flue gas outlet of the furnace, and a return valve connecting the separator legs to the furnace. Feeder, secondary air pipes distributed on the front and rear walls of the furnace and SNCR flue gas denitrification system, the SNCR flue gas denitrification system consists of ammonia water unloading and storage system, ammonia water and dilution water delivery system, mixing distribution system and injection system, Among them: it also includes the inlet valve group, the limestone desulfurization conveying system in the furnace, the limestone desulfurization storage bin system in the furnace, the humidification spray gun, the circulating fluidized bed desulfurization tower system, the bag filter and the return facility, the inlet valve group The output end is connected to the nozzle in the secondary air pipe, the input end of the inlet valve group is connected to the output end of the limestone desulfurization conveying system in the furnace, and the outlet of the storage bin of the limestone desulfurization storage system in the furnace is connected to the limestone in the furnace through the pipeline. The main inlet of the buffer bin of the desulfurization conveying system is connected, and the material outlet of the dust collector on the roof of the limestone desulfurization storage bin system in the furnace is connected with the auxiliary inlet of the buffer bin of the limestone desulfurization conveying system in the furnace through pipelines, increasing The wet spray gun is set in the flue outlet of the circulating fluidized bed boiler, the flue gas inlet of the circulating fluidized bed desulfurization tower system is connected with the flue outlet of the circulating fluidized bed boiler, and the flue gas outlet of the circulating fluidized bed desulfurization tower system is connected with the flue gas outlet of the circulating fluidized bed desulfurization tower system The flue gas inlet of the bag filter is connected, and the return facility connects the outlet of the bag filter with the return port of the circulating fluidized bed desulfurization tower system.

The separator of the present invention is an adiabatic cyclone separator with a downwardly inclined inlet flue and an eccentric center cylinder, and is arranged side by side in the flue gas outlet area of the furnace. The adiabatic cyclone separator is also equipped with a working temperature control system.

The feeder is equipped with a working temperature control system, and the return air of the feeder is high-pressure cold air, which is sent in by a small air cap, and a flow meter and a pressure gauge are installed on the main pipe of the inlet air duct.

Both the separator and the feeder are composed of an outer shell and a lining, the lining is a three-layer structure of refractory material, and the lining is respectively high-strength wear-resistant castable, lightweight castable and lightweight insulation from the outside to the inside. brick.

The nozzles in the secondary air pipe are arranged at the lower part of the furnace.

The inlet valve group is composed of an expansion joint and a valve, and the expansion joint is arranged at the input end of the valve.

The limestone desulfurization conveying system in the furnace is composed of a Roots fan, a mixer and a buffer bin. One inlet of the mixer is connected to the outlet of the Roots fan, and the other inlet of the mixer is connected to the discharge port of the buffer bin.

The limestone desulfurization storage system in the furnace is composed of a fluidization fan, an electric heater, a storage bin and a dust collector on the top of the warehouse. Opening at the top of the storage compartment.

The circulating fluidized bed desulfurization tower system includes a flue gas inlet, a Venturi nozzle, a process water nozzle, a material return port, a desulfurization tower body and a flue gas outlet, the outlet of the flue gas inlet is connected to the inlet of the Venturi nozzle, and the Venturi nozzle The outlet of the desulfurization tower body is connected to the inlet of the desulfurization tower body, the flue gas outlet is set on the top of the desulfurization tower body, and the process water nozzle and the return port are set at the bottom of the desulfurization tower body.

The material return facility is composed of an air conveying chute, a gasification fan and an electric heater. The bed desulfurization tower system is connected to the return port, and the gasification fan is connected to the air inlet of the air conveying chute through an electric heater.

The ammonia water unloading and storage system consists of an ammonia water tank truck, an ammonia water unloading pump device and an ammonia water storage tank.

The ammonia water and dilution water delivery system is composed of demineralized water, ammonia water metering pump device and dilution water metering pump device.

The mixing and distributing system consists of a static mixer and a reducing agent distributor.

The injection system consists of injection heads arranged in the inlet area of the separator, distributed to the entire flue section, and connected to a compressed air source.

The ammonia water storage tank is connected to the ammonia water metering pump device, the dilution water metering pump device and the ammonia water metering pump device are connected to the static mixer, the static mixer is connected to the reducing agent distributor, and the reducing agent A distributor is connected to the spray head.

The present invention adopts the above-mentioned technical scheme, further improves the bed quality, reduces the total bed stock, and increases the circulating fluidized bed boiler based on the low bed pressure and energy-saving circulating fluidized bed boiler based on the reconstruction of the fluid state, and rebuilds the flow state again, so that the boiler based on The redox atmosphere reforming in the furnace with improved bed quality realizes the ultra-low emission of nitrogen oxides and the desulfurization efficiency in the blast furnace under the low calcium-sulfur ratio. The breakthrough point of low-cost and ultra-low emission of circulating fluidized bed can be found in the third axis of circulating material particle size axis of circulating fluidized bed fluid state diagram, which is also the basic theoretical basis of flow state reconstruction.

The basic mechanism of the desulfurization efficiency in the blast furnace under the low calcium-sulfur ratio of the present invention: after the fluid state is reconfigured, the bed quality is improved, the total bed inventory is reduced, and the circulation volume is increased, which lays a fluid state foundation for improving the desulfurization efficiency in the furnace. After the bed quality is improved, the limestone can adopt a finer particle size, the specific surface area of the limestone is larger, and the corresponding desulfurization reaction area is larger. After improving the bed quality and increasing the circulation rate, the probability of material agglomeration increases, the residence time in the limestone furnace is prolonged, and the corresponding desulfurization reaction time is prolonged. The wear and surface renewal of the cycle process make the limestone further utilized. After reducing the total bed stock and increasing the circulation rate, it means that the amount of coarse particles in the lower part is greatly reduced, and the back pressure at the secondary air outlet is greatly reduced. In addition, the single-layer layout design of the secondary air has low resistance, large momentum, and strong penetrating power. The internal gas-solid mixing effect is greatly improved. The increase in circulation and the reasonable design of the heating surface keep the furnace temperature at the most suitable temperature level for desulfurization, 860-880°C. If the furnace temperature is lower than 820°C, it is not conducive to the calcination reaction of limestone; if the furnace temperature is higher than 920°C, the micropores in the calcium oxide will be quickly blocked to prevent the further utilization of limestone, and the generated CaSO ₄ will be re-decomposed into CaO And release SO ₂ . The increase in the circulation rate and the increase in the quality of the bed brings about an increase in the probability of particle agglomeration and the strengthening of the back-mixing of particles up and down, making the temperature of the upper and lower furnace more uniform.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The ultra-low emission circulating fluidized bed boiler system based on fluid state reconstruction enables the deep integration of the flue gas treatment environmental protection island with the boiler island system, breaking the gap between the boiler main engine, boiler island auxiliary system, desulfurization, denitrification, and dust removal subsystems Build a characteristic environmental protection system based on the characteristics of the boiler, realize intensification, integration, systematization and energy saving, and maximize the governance function of each link. Only this ultra-low emission concept of efficient and coordinated control of multiple pollutants can truly provide coal-fired boilers with a "package" solution from the boiler to the chimney with better operating indicators, simpler systems, and higher reliability. Minimize investment and operating costs for ultra-low emissions.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

detailed description

As shown in Figure 1, an ultra-low-emission circulating fluidized bed boiler system based on the secondary reconstruction of the fluid state, it includes a circulating fluidized bed boiler furnace 1, a separator 2 connected to the furnace flue gas outlet, separating The feeder 3 connected to the material leg and the furnace 1, the secondary air duct 4 distributed on the front and rear walls of the furnace, and the SNCR flue gas denitrification system. The SNCR flue gas denitrification system consists of an ammonia water unloading and storage system 12, ammonia water and dilution Water delivery system 13, mixing distribution system 14 and injection system 15, which also includes inlet valve group 5, furnace limestone desulfurization delivery system 6, furnace limestone desulfurization storage system 7, humidification spray gun 8, circulating fluidization Bed desulfurization tower system 9, bag filter 10 and material return facility 11, the output end of the inlet valve group 5 is connected to the nozzle in the secondary air pipe 4, the input end of the inlet valve group 5 is connected to the limestone desulfurization conveying system in the furnace 6, the output port of the storage bin 73 of the limestone desulfurization storage bin system 7 in the furnace is connected to the main feed port of the buffer bin 63 of the limestone desulfurization delivery system 6 in the furnace through a pipeline, and the limestone desulfurization storage bin in the furnace The material outlet of the dust collector 74 on the roof of the system 7 is connected with the secondary inlet of the buffer bin 63 of the limestone desulfurization conveying system 6 in the furnace through a pipeline, and the humidifying spray gun 8 is set in the flue outlet of the circulating fluidized bed boiler , the flue gas inlet 91 of the circulating fluidized bed desulfurization tower system 9 is connected with the flue outlet of the circulating fluidized bed boiler, the flue gas outlet 96 of the circulating fluidized bed desulfurization tower system 9 is connected with the flue gas inlet of the bag filter 10, The material return facility 11 connects the material outlet of the bag filter 10 with the material return port 94 of the circulating fluidized bed desulfurization tower system 9 . The separator 2 is an adiabatic cyclone separator with a downwardly inclined inlet flue and an eccentric central tube, and it is arranged side by side in the flue gas outlet area of the furnace 1. The adiabatic cyclone separator is also equipped with a working temperature control system. The feeder 3 is provided with a working temperature control system, and the return air of the feeder 3 adopts high-pressure cold air, which is sent in by a small wind cap, and a flow meter and a pressure gauge are installed on the main pipe of the inlet air duct. Both the separator 2 and the feeder 3 are composed of an outer shell and a lining, and the lining is a three-layer refractory material, and the lining is respectively high-strength wear-resistant castable, lightweight castable and lightweight castable from outside to inside. quality insulation bricks. The nozzles in the secondary air duct 4 are located at the bottom of the furnace. The inlet valve group 5 is composed of an expansion joint and a valve, and the expansion joint is arranged at the input end of the valve. The limestone desulfurization conveying system 6 in the furnace is composed of a Roots blower 61, a mixer 62 and a buffer bin 63. One inlet of the mixer 62 is connected to the air outlet of the Roots blower 61, and the other inlet of the mixer 62 is connected to the buffer bin. 63 outlet connection. The limestone desulfurization storage bin system 7 in the furnace is composed of a fluidizing fan 71, an electric heater 72, a storage bin 73 and a dust collector 74 on the roof of the warehouse. The fluidizing fan 71 is connected to the air inlet of the storage bin 73 through the electric heater 72 , The top dust collector 74 is located on the opening of the storage bin 73 top. The circulating fluidized bed desulfurization tower system 9 includes a flue gas inlet 91, a Venturi nozzle 92, a process water nozzle 93, a material return port 94, a desulfurization tower body 95 and a flue gas outlet 96, and the outlet of the flue gas inlet 91 is connected to the Venturi The inlet of the nozzle 92 is connected, the outlet of the Venturi nozzle 92 is connected with the inlet of the desulfurization tower body 95, the flue gas outlet 96 is arranged on the top of the desulfurization tower body 95, and the process water nozzle 93 and the return port 94 are arranged on the top of the desulfurization tower body 95. bottom. The material return facility 11 is composed of an air delivery chute 113, a gasification blower 111 and an electric heater 112. The discharge port is connected to the return port 94 of the circulating fluidized bed desulfurization tower system 9, and the gasification fan 111 is connected to the air inlet of the air delivery chute through the electric heater 112. The ammonia water unloading and storage system 12 is composed of an ammonia water tank truck 121 , an ammonia water unloading pump device 122 and an ammonia water storage tank 123 . The ammonia water and dilution water delivery system 13 is composed of a demineralized water 131 , an ammonia water metering pump device 132 and a dilution water metering pump device 133 . The mixing and distributing system 14 is composed of a static mixer 141 and a reductant distributor 142 . The injection system 15 is composed of an injection head 151 arranged at the inlet area of the separator, distributed to the entire flue section, and connected to a compressed air source. The ammonia water storage tank 123 is connected to the ammonia water metering pump device 132, the dilution water metering pump device and the ammonia water metering pump device 132 are connected to the static mixer 141, and the static mixer 141 is connected to the reducing agent distributor 142 , the reducing agent distributor 142 is connected to the injection head 151 .

Claims (10)

1. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary, it comprises boiler hearth of circulating fluidized bed (1), the separator (2) be communicated with burner hearth exhanst gas outlet, by the material returning device (3) that separator dipleg is communicated with burner hearth (1), be distributed in the secondary air channel (4) on burner hearth front-back wall and SNCR flue gas denitrification system, described SNCR flue gas denitrification system is unloaded and storage system (12) by ammoniacal liquor, ammoniacal liquor and dilution water induction system (13), mixing and dispensing system (14) and spraying system (15) composition, it is characterized in that: it also comprises inlet valve group (5), stove sodalime stone desulfurization induction system (6), stove sodalime stone desulfurization bin system (7), humidification spray gun (8), circulating fluidized bed desulfurization tower system (9), sack cleaner (10) and returning charge facility (11), the output of described inlet valve group (5) is connected with the nozzle in secondary air channel (4), the input of inlet valve group (5) is connected with the output of stove sodalime stone desulfurization induction system (6), the discharging opening of the warehouse (73) of stove sodalime stone desulfurization bin system (7) is connected by the main feeding mouth of pipeline with the buffering chamber (63) of stove sodalime stone desulfurization induction system (6), the material outlet in top dust-precipitator, the storehouse (74) of stove sodalime stone desulfurization bin system (7) is connected by the secondary feeding mouth of pipeline with the buffering chamber (63) of stove sodalime stone desulfurization induction system (6), humidification spray gun (8) is arranged in the flue outlet of CFBB, the smoke inlet (91) of circulating fluidized bed desulfurization tower system (9) is connected with the flue outlet of CFBB, the exhanst gas outlet (96) of circulating fluidized bed desulfurization tower system (9) is connected with the smoke inlet of sack cleaner (10), the discharging opening of sack cleaner (10) is communicated with the returning charge mouth (94) of circulating fluidized bed desulfurization tower system (9) by returning charge facility (11).

2. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described separator (2) is that inlet flue duct has a down dip, the Adiabatic Cyclone separator of central tube bias, and it is disposed in parallel in the exhanst gas outlet region of burner hearth (1), described Adiabatic Cyclone separator is also provided with operating temperature control system.

3. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described material returning device (3) is provided with operating temperature control system, and the returning charge elegance high pressure cold wind of material returning device (3), sent into by little blast cap, and flowmeter and pressure gauge are put in installing on the female pipe of entrance airduct.

4. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to any one of claims 1 to 3, it is characterized in that: described separator (2) and material returning device (3) are by shell and back boxing composition, back boxing is the refractory material of three-decker, and back boxing is respectively high-strength abrasion-proof castable, lightening casting material and light-weight insulating brick from outside to inside.

5. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, is characterized in that: the nozzle in described secondary air channel (4) is located at the bottom of burner hearth.

6. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, is characterized in that: described inlet valve group 5 is made up of expansion joint and valve, and expansion joint is located at the input of valve.

7. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described stove sodalime stone desulfurization induction system (6) is made up of roots blower (61), blender (62) and buffering chamber (63), an entrance of blender (62) is connected with the air outlet of roots blower (61), and another entrance of blender (62) is connected with the discharging opening of buffering chamber (63).

8. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described stove sodalime stone desulfurization bin system (7) is pushed up dust-precipitator (74) by fluidized air blower (71), electric heater (72), warehouse (73) and storehouse and formed, fluidized air blower (71) is connected by the air inlet of electric heater (72) with warehouse (73), and top dust-precipitator, storehouse (74) is located on the opening at warehouse (73) top.

9. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described circulating fluidized bed desulfurization tower system (9) comprises smoke inlet (91), Venturi nozzle (92), fresh water (FW) nozzle (93), returning charge mouth (94), desulfurizing tower body (95) and exhanst gas outlet (96), the outlet of smoke inlet (91) is connected with the entrance of Venturi nozzle (92), the outlet of Venturi nozzle (92) is connected with the entrance of desulfurizing tower body (95), exhanst gas outlet (96) is located at the top of desulfurizing tower body (95), fresh water (FW) nozzle (93) and returning charge mouth (94) are located at the bottom of desulfurizing tower body (95).

10. the minimum discharge type circulating fluidized bed boiler systems based on the reconstruct of fluidised form secondary according to claim 1, it is characterized in that: described returning charge facility (11) is by air conveyer flume (113), gasification blower fan (111) and electric heater (112) composition, the feeding mouth of air conveyer flume (113) is connected with the discharging opening of sack cleaner (10), the discharging opening of air conveyer flume (113) is connected with the returning charge mouth (94) of circulating fluidized bed desulfurization tower system (9), gasification blower fan (111) is connected with the air inlet of air conveyer flume by electric heater (112).