CN212068340U - Flue gas decarbonization denitration treatment system - Google Patents
Flue gas decarbonization denitration treatment system Download PDFInfo
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Abstract
The utility model discloses a flue gas decarbonization denitration treatment system, this system is including CO reactor and SCR reactor. And the flue gas inlet pipe is connected with the air inlet of the CO reactor according to the trend of the flue gas. And the exhaust port of the CO reactor is connected with the air inlet of the SCR reactor through a first pipeline. And an exhaust port of the SCR reactor is connected with a flue gas exhaust pipe. A first heating device is arranged on the smoke inlet pipe, and a second heating device is arranged on the first pipeline. According to the scheme, organic combination is realized when CO catalytic oxidation removal is cooperated with SCR denitration, so that the CO catalyst and the SCR catalyst can be in a high-efficiency catalytic working state for a long time, and meanwhile, system heat is fully utilized, and unnecessary energy consumption is avoided. The reaction temperature of the system can be accurately regulated, the catalyst is protected, and the stable and efficient operation of the system is guaranteed.
Description
Technical Field
The utility model relates to a flue gas treatment facility technique, concretely relates to flue gas decarbonization denitration treatment system belongs to flue gas purification technical field.
Background
The ultra-low emission modification of the thermal power industry is basically completed, and the non-electric field is mainly characterized by the ultra-low emission modification of steel sintering flue gas. The sintering flue gas dedusting and desulfurization process is mature, and the key and difficult point of ultralow emission is denitration, because the sintering flue gas is low in temperature, the medium-high temperature (200-350 ℃) SCR technology widely applied to the thermal power industry needs to heat the flue gas when being applied to denitration of the sintering flue gas, and a large amount of flue gas is heated to bring huge energy consumption.
The sintering flue gas contains CO (6000 mg/Nm) with higher concentration3Left and right), CO is converted to CO by catalytic oxidation2And meanwhile, a large amount of heat can be released, if the CO catalytic oxidation technology is coupled with the SCR denitration technology, the heat emitted in the CO catalytic oxidation process is fully utilized, and the heat supplement of an external heat source to the flue gas is reduced or even avoided, the mature medium-high temperature SCR technology is expected to be directly transplanted and applied to the denitration of the sintering flue gas, and the medium-high temperature SCR denitration catalyst is low in price and easy to obtain, high in denitration efficiency, strong in sulfur poisoning resistance and long in service life, so that the sintering flue gas is efficiently, economically and environmentally-friendly to denitrate.
When the CO catalyst components are different, the reaction characteristics are different. For example, the commercial Pt/Al catalyst reaction is characterized by a typical catalytic combustion reaction, namely, when the reaction temperature reaches a certain value, the CO catalytic oxidation process is vigorously carried out, the temperature is called as the light-off temperature of the catalyst, and the light-off temperature is just like a catalytic combustion 'fuse', and the reaction is vigorously carried out after the critical point; and non-noble metal catalysts such as metal oxide catalyst systems of Cu, Co or Mn, the reaction characteristics are as follows: the reaction efficiency gradually increases to a plateau with a gradual increase in temperature, and the rate of increase in catalytic activity gradually slows down during the temperature increase.
The CO catalytic oxidation removal and SCR denitration of the sintering flue gas are respectively carried out under the action of corresponding catalysts, and the catalysts with different components have specific catalytic activity temperature windows. When the two are used for the synergistic decarbonization and denitration, the principle of selecting the CO catalytic oxidation catalyst and the SCR denitration catalyst is as follows: the optimal catalytic activity temperature windows of the two are close to each other as much as possible so as to ensure that the CO and the NOx simultaneously realize the optimal removal effect. However, the decarburization and the denitration are difficult to perfectly match in the engineering operation due to the fluctuation of the actual working conditions, the self properties of the catalyst and the like.
SUMMERY OF THE UTILITY MODEL
To prior art not enough, the utility model provides a flue gas decarbonization denitration treatment system, when this scheme aims at solving CO catalytic oxidation desorption SCR denitration in coordination, the two realizes the system and the control method of organic combination. The CO catalyst and the SCR catalyst are ensured to be in a high-efficiency catalytic working state for a long time, and meanwhile, the system heat is fully utilized, so that unnecessary energy consumption is avoided. The scheme can accurately regulate and control the reaction temperature of the system, protects the catalyst, and ensures stable and efficient operation of the system.
In order to achieve the above object, the utility model discloses the technical scheme who adopts specifically as follows:
according to the utility model discloses a first embodiment provides a flue gas decarbonization denitration treatment system, and this system is including CO reactor and SCR reactor. And the flue gas inlet pipe is connected with the air inlet of the CO reactor according to the trend of the flue gas. And the exhaust port of the CO reactor is connected with the air inlet of the SCR reactor through a first pipeline. And an exhaust port of the SCR reactor is connected with a flue gas exhaust pipe. A first heating device is arranged on the smoke inlet pipe, and a second heating device is arranged on the first pipeline.
Preferably, the system further comprises a GGH heat exchanger. The GGH heat exchanger is respectively connected with the flue gas inlet pipe and the flue gas exhaust pipe. The flue gas conveyed by the flue gas inlet pipe is subjected to heat exchange by the GGH heat exchanger and then conveyed to the gas inlet of the CO reactor. And the clean flue gas discharged by the SCR reactor is subjected to heat exchange by the GGH heat exchanger and then discharged by the flue gas exhaust pipe, and the first heating device is positioned at the downstream of the connecting position of the GGH heat exchanger and the flue gas inlet pipe.
Preferably, m layers of CO catalytic oxidation layers are arranged in the CO reactor. And n layers of SCR denitration layers are arranged in the SCR reactor.
Preferably, m and n are each independently 1 to 5, preferably 2 to 4.
Preferably, a first temperature detector, a first flow rate detector and a first CO concentration detector are arranged on a flue gas inlet pipe between the first heating device and the GGH heat exchanger.
Preferably, a second temperature detector is arranged at the air inlet of the CO reactor or at one end of the flue gas inlet pipe close to the CO reactor.
Preferably, a third temperature detector, a second flow detector and a second CO concentration detector are arranged at the exhaust port of the CO reactor or at one end of the first pipeline close to the CO reactor.
Preferably, a fourth temperature detector is disposed on the first pipeline downstream of the second heating device.
Preferably, a first cooling medium delivery pipe is externally connected to the flue gas inlet pipe between the first heating device and the second temperature detector. And a first flow control valve is arranged on the first cooling medium conveying pipe.
Preferably, a second cooling medium delivery pipe is externally connected to the first pipeline between the second heating device and the fourth temperature detector. And a second flow control valve is arranged on the second cooling medium conveying pipe. And/or
Preferably, the air inlet of the SCR reactor is further provided with a rectifier. And/or
Preferably, an ammonia spraying device is further arranged in the first pipeline between the second heating device and the rectifier.
According to the utility model discloses a second embodiment provides and adopts first embodiment flue gas decarbonization denitration treatment system's flue gas decarbonization denitration treatment method, its characterized in that: the method comprises the following steps:
1) when the system is started:
1a) the original flue gas is heated by a first heating device from a flue gas inlet pipe to reach the temperature required by decarburization and then is conveyed to a CO reactor. And carrying out decarburization treatment on the raw flue gas by a CO catalytic oxidation layer in the CO reactor, and discharging the decarburized flue gas after the decarburization treatment from an exhaust port of the CO reactor.
1b) The decarbonized flue gas discharged from the exhaust port of the CO reactor is heated by a second heating device or not and then is conveyed to the SCR reactor through a first pipeline. Denitration treatment is carried out layer by SCR denitration in the SCR reactor, and the clean flue gas after denitration is discharged through a flue gas exhaust pipe after heat exchange and temperature reduction of the GGH heat exchanger.
2) In the operation process:
2a) the original flue gas is heated by heat exchange of a flue gas inlet pipe through a GGH heat exchanger, optionally heated to the temperature required by decarburization through or without a first heating device, and then conveyed to a CO reactor. In the CO reactor, the raw flue gas is decarbonized by a CO catalytic oxidation layer, and the decarbonized flue gas after the decarbonization is discharged from an exhaust port of the CO reactor 1.
2b) The decarbonized flue gas discharged from the exhaust port of the CO reactor is heated by a second heating device or not and then is conveyed to the SCR reactor through a first pipeline. Denitration treatment is carried out layer by SCR denitration in the SCR reactor, and the clean flue gas after denitration is discharged through a flue gas exhaust pipe after heat exchange and temperature reduction of the GGH heat exchanger.
Preferably, step 1a) further comprises: a first CO concentration detector is arranged on a flue gas inlet pipe between the first heating device and the GGH heat exchanger, and the initial concentration of CO in the original flue gas is detected to be a1, mg/Nm3. And a second temperature detector is arranged at the air inlet of the CO reactor or at one end of the flue gas inlet pipe close to the CO reactor, and the original flue gas temperature before decarburization is detected to be t2 and DEG C in real time. The exhaust port of the CO reactor or the first pipeline is close to the CO reactorOne end of the reactor is provided with a second CO concentration detector for detecting the concentration of CO in the decarbonized flue gas in real time to be a2 mg/Nm3。
Preferably, the optimum temperature for detecting the flue gas decarburization is t0, DEG C, and specifically comprises the following steps:
1a1) when the catalytic reaction of the catalyst adopted by the CO catalytic oxidation layer is characterized by catalytic combustion (namely when the reaction temperature reaches a certain value, the CO catalytic oxidation process is vigorously carried out): the first heating device is turned on to continuously heat the raw flue gas entering the CO reactor until the following formula is satisfied:
(a1-a2)/a1 ═ k1..
Wherein, k1 is more than or equal to 5% and less than or equal to 20% (preferably, k1 is more than or equal to 8% and less than or equal to 15%). When the formula I is established, the synchronously detected temperature value t2 is the optimal temperature t0 for the smoke decarburization.
1a2) When the catalytic reaction of the catalyst adopted by the CO catalytic oxidation layer is characterized in that the CO removal efficiency is in a slow increasing trend along with the temperature: the first heating device is turned on to continuously heat the raw flue gas entering the CO reactor until the following formula is satisfied:
(a1-a2)/a1 ═ k2..
Wherein k2 is more than or equal to 90 percent (preferably k2 is more than or equal to 95 percent), and the temperature value of t2 synchronously detected when the formula II is established is the optimal temperature t0 for the flue gas decarburization.
Preferably, step 2a) further comprises: a first temperature detector is arranged on a flue gas inlet pipe between the first heating device and the GGH heat exchanger to detect that the original flue gas temperature is t1 and DEG C. Meanwhile, a first flow detector is arranged to detect the flow of the original flue gas as q1, L/s. And a first cooling medium conveying pipe is externally connected to the flue gas inlet pipe between the first heating device and the second temperature detector, and a first flow control valve is arranged on the first cooling medium conveying pipe. Setting the safety temperature t for the decarbonization of the flue gasCarbon (C)，℃。
Preferably, 2a1) when t1 < t0, the first heating device is started to heat the raw smoke so that the temperature of the raw smoke is t 2-t 0.
Preferably, 2a2) when t 0. ltoreq.t 1 < tCarbon (C)When the first heating device is not started, the system maintains the stateAnd continuing to operate.
Preferably, 2a3) at t1 ≧ tCarbon (C)When the first heating device is not started, the first cooling medium conveying pipe is started to input cooling medium to cool the raw flue gas, so that the temperature of the raw flue gas is lower than tCarbon (C)。
Preferably, in step 2a3), the heat dissipated when the high-temperature raw flue gas in the system is cooled to t0 is equal to the heat absorbed when the cooling medium is heated to t0, according to the heat balance principle:
C1*q1(t1-t0)＝Ccold*q3(t0-tCold)...III。
Wherein C1 is the specific heat capacity of the smoke, and J/(kg ℃). CColdThe specific heat capacity of the cooling medium is J/(kg ℃). t is tColdThe temperature of the cooling medium is measured in degrees centigrade. q3 is the input amount of the cooling medium, L/s.
Preferably, formula III converts to:
q3＝[C1*q1(t1-t0)]/[Ccold(t0-tCold)]...IV。
By controlling the first flow rate control valve on the first cooling medium delivery pipe, the total flow rate of the cooling medium delivered through the first cooling medium delivery pipe is q 3.
Preferably, step 1b) and step 2b) further comprise: and a third temperature detector is arranged at the exhaust outlet of the CO reactor or at one end of the first pipeline close to the CO reactor to detect the temperature of the decarbonized flue gas to be t3 and DEG C. Meanwhile, a second flow detector is arranged to detect the flow of the decarbonized flue gas as q2, L/s. The first pipeline is internally provided with a fourth temperature detector for detecting the temperature t4 and DEG C of the flue gas before denitration. And a second cooling medium conveying pipe is externally connected to the first pipeline between the second heating device and the fourth temperature detector, and a second flow control valve is arranged on the second cooling medium conveying pipe. The optimal temperature for flue gas denitration is set to t5 and DEG C. Setting the safe temperature of flue gas denitration as tMirabilite，℃。
Preferably, 301) when t3 < t5, the second heating device is started to heat the decarbonized flue gas so that the temperature of the decarbonized flue gas is t 4-t 5.
Preferably, 302) when t5 ≦ t3 < tMirabiliteAnd when the second heating device is not started, the system maintains the state and continues to operate.
Preferably, 303) when t3 ≧ tMirabiliteWhen the second heating device is not started, the second cooling medium conveying pipe is started to input the cooling medium to cool the decarburized flue gas so that the temperature of the decarburized flue gas is lower than tMirabilite。
Preferably, in step 303), the heat quantity dissipated when the high-temperature decarbonized flue gas in the system is cooled to t5 is equal to the heat quantity absorbed when the cooling medium is heated to t5, according to the heat balance principle:
C2*q2(t3-t5)＝Ccold*q4(t5-tCold)...V。
Wherein C2 is the specific heat capacity of the decarbonized flue gas, and J/(kg ℃). CColdThe specific heat capacity of the cooling medium is J/(kg ℃). t is tColdThe temperature of the cooling medium is measured in degrees centigrade. q4 is the input amount of the cooling medium, L/s.
Preferably, formula V is converted to:
q4＝[C2*q2(t3-t5)]/[Ccold(t5-tCold)]...VI。
By controlling the second flow control valve on the second cooling medium delivery pipe, the total flow rate of the cooling medium delivered through the second cooling medium delivery pipe is q 4.
Preferably, the decarbonized flue gas is subjected to ammonia injection treatment in the first duct. And/or
Preferably, the safety temperature t for the decarbonization of the flue gasCarbon (C)380 ℃ and 420 ℃.
Preferably, the flue gas denitration safe temperature tMirabilite380 ℃ and 420 ℃.
Generally, the temperature of the flue gas after desulfurization is about 120 ℃, and the temperature of the flue gas required for CO catalytic oxidation decarburization and SCR catalytic denitration is often higher than that of the raw flue gas itself, so that in order to improve the treatment effect of the raw flue gas for decarburization and denitration, the raw flue gas is heated by an external heat source before the raw flue gas is subjected to CO catalytic oxidation decarburization or before the raw flue gas is subjected to SCR catalytic denitration so that the raw flue gas reaches the optimal temperature range for CO catalytic oxidation decarburization or the optimal temperature range for SCR catalytic denitration.
The utility model discloses in, all be provided with heating device through flue gas pipeline before the CO reactor and the flue gas pipeline before the SCR reactor, can in time heat up the flue gas to CO catalytic oxidation optimum temperature window before carrying out the decarbonization, heat up the flue gas to SCR catalytic oxidation optimum temperature window before carrying out the denitration simultaneously and realize the desorption effect of optimization simultaneously with CO and the NOx of guaranteeing former flue gas.
The utility model discloses in, the GGH heat exchanger is connected with flue gas intake pipe and flue gas exhaust pipe respectively. The flue gas conveyed by the flue gas inlet pipe is subjected to heat exchange by the GGH heat exchanger and then conveyed to the gas inlet of the CO reactor. And the clean flue gas discharged by the SCR reactor is subjected to heat exchange by the GGH heat exchanger and then discharged through a flue gas exhaust pipe. Generally, the clean flue gas subjected to denitration by the SCR reactor has the temperature of about 180-300 ℃, partial heat of the clean flue gas can be exchanged to the low-temperature desulfurized flue gas by arranging the GGH heat exchanger so as to improve the temperature of the desulfurized flue gas, so that firstly, the emission temperature of the clean flue gas can be further reduced, the environmental pollution is reduced, and simultaneously, the consumption and the heating time of energy sources required by the following steps of heating the desulfurized flue gas to the optimal temperature window required by CO catalytic oxidation or the optimal temperature window for SCR denitration treatment are reduced after the temperature of the desulfurized flue gas is increased.
The utility model discloses in, in order to further improve the decarbonization effect of CO reactor and the denitration effect of SCR reactor, the accessible be equipped with a plurality of CO catalytic oxidation layer in the CO reactor and be equipped with a plurality of SCR denitration layers in the SCR reactor, only having avoided only probably causing the not thorough problem of flue gas decarbonization denitration and played the purpose that can continue to play catalytic action when other catalyst layer after certain one deck catalyst layer catalysis saturation inactivation, set up the multilayer catalysis layer simultaneously and also can improve the life cycle of CO reactor and SCR reactor, can also reduce the number of times of changing the catalysis layer, the reinforcing lasts the ability of production.
The utility model discloses in, because CO catalytic oxidation is a constantly exothermic process, and the heat of system can constantly transmit for former flue gas through the GGH reactor moreover, therefore the temperature of former flue gas is a constantly changeable process, for the temperature variation of more convenient accurate monitoring flue gas around the decarbonization denitration, and then judge whether the temperature of flue gas is in the best temperature range of decarbonization denitration, and then judge whether start or not start the hot device and heat up to decarbonization or flue gas before the denitration, consequently through be provided with first temperature detection meter in the flue gas intake pipe between first heating device and the GGH heat exchanger. And a second temperature detector is arranged at the air inlet of the CO reactor or at one end of the flue gas inlet pipe close to the CO reactor. And a third temperature detector is arranged at the exhaust port of the CO reactor or at one end of the first pipeline close to the CO reactor. And a fourth temperature detector is arranged at the downstream of the first pipeline on the second heating device. The result through above-mentioned temperature detection feedback and then can be swiftly effectual messenger's flue gas no matter be before the decarbonization or before the denitration all be in optimum temperature range, can also the energy saving simultaneously, avoid causing unnecessary extravagant (general CO catalyst is after reaching the uniform temperature, catalytic activity has become stable, continues to heat up, and its catalytic activity changes and also is little, but does so undoubtedly can consume the energy, causes the waste).
Further, in order to prevent that the flue gas from continuously rising temperature (the continuous accumulation of system temperature or the CO concentration increase in the flue gas leads to the exothermic increase of CO catalytic oxidation, and then causes the system temperature to further rise), the safety and stability operation of assurance system, the utility model discloses still through be provided with first flow detection meter in the flue gas intake pipe between first heating device and the GGH heat exchanger the gas vent department of CO reactor or first pipeline are close to CO reactor one end department and are provided with the second flow detection meter be located the flue gas intake pipe between first heating device and the second temperature detection meter is gone up to external first cooling medium conveyer pipe that has. And a first flow control valve is arranged on the first cooling medium conveying pipe. And a second cooling medium conveying pipe is externally connected to the first pipeline between the second heating device and the fourth temperature detector. And a second flow control valve is arranged on the second cooling medium conveying pipe. When the temperature of the flue gas before decarburization is detected to be higher than the safe temperature of the CO catalyst, the first cooling medium conveying device conveys the cooling medium to reduce the temperature of the flue gas to the temperature required by the optimal CO catalytic oxidation, and the input amount of the cooling medium is determined by the detected flow of the flue gas and is accurately controlled by the first flow control valve. When the detected flue gas temperature before denitration is higher than the safe temperature of the SCR catalyst, the cooling medium is conveyed by the second cooling medium conveying device to reduce the flue gas temperature to the optimal temperature required by SCR catalytic oxidation, and the input amount of the cooling medium is determined by the detected flow of the flue gas and is accurately controlled by the second flow control valve.
In the present invention, since there are two types of reaction characteristics in the catalytic oxidation of CO, for example, when a noble metal catalyst such as Pt/Al system is used, the reaction is a catalytic combustion characteristic, and the emphasis of such a reaction is the determination of the light-off temperature, and generally, the temperature at which the conversion rate of the reactant reaches 5 to 20% is defined as the light-off temperature, which is represented by t0, and the catalytic oxidation of CO can be rapidly performed until the conversion of CO is completed. At this point, even if the flue gas temperature continues to be increased above the catalyst light-off temperature, there is no significant contribution to CO conversion, while the flue gas inlet temperature is below the light-off temperature, and little CO conversion occurs. When the non-noble metal catalyst is adopted, the temperature of the flue gas entering the CO reactor needs to be ensured to reach the temperature required by the maximum CO conversion value. No matter which catalyst is adopted, the temperature of the flue gas at the inlet of the CO reactor has an optimal value, when the temperature is lower, the requirement of the removal rate is difficult to meet, when the temperature is higher, unnecessary energy consumption is brought, and if the temperature of the flue gas at the inlet is higher than 400 ℃, the CO catalyst is easy to be damaged by thermal sintering and the like when being operated at a higher temperature for a long time.
Further, when the CO reaction is characterized by catalytic combustion reaction, when the system is started, the heating device in front of the CO reactor is started, the concentrations a1 and a2 of CO in front of and behind the CO reactor are monitored, when (a1-a2)/a1 is equal to k1 (k 1 is equal to or greater than 5% and equal to or less than 20%, preferably k1 is equal to or greater than 8% and equal to or less than 15%), the corresponding temperature is the ignition temperature t0, at the moment, the temperature of the flue gas at the CO inlet is t0, the flue gas is subjected to CO catalytic oxidation reaction in the CO reactor, and simultaneously emits heat to raise the temperature of the flue gas, at the moment, whether the heating device in back of the CO reactor is started and started according to the requirement of the SCR catalyst for the reaction temperature, so that the flue gas before denitration meets the requirement of. And after passing through the SCR reactor, the flue gas enters the GGH heat exchanger to transfer heat to cold flue gas at the inlet end, so that the temperature of the cold flue gas is raised, the relation between the temperature of the flue gas before decarburization and t0 is judged, and a front heating device of the CO reactor is adjusted in time. When T1 is less than T0, adjusting the heating device to ensure that T2 is T0; when t1 is more than or equal to t0, the heating device is closed.
Further, when the CO reaction is characterized in that the removal efficiency is in a slowly increasing trend along with the temperature, when the system is started, the front heating device of the CO reactor is started, the front and rear CO concentrations a1 and a2 of the CO reactor are monitored, when the (a1-a2)/a1 is equal to or more than 90% and preferably k2 is equal to or more than 95%, the CO catalyst reaches the efficient removal effect at the temperature of t2, the flue gas generates CO catalytic oxidation reaction in the CO reactor, and heat is released to increase the temperature of the flue gas at the same time, at the moment, whether the rear heating device of the CO reactor is started or not and the size of the rear heating device of the CO reactor is adjusted according to the requirement of the SCR catalyst on the reaction temperature, so that t4 meets the requirement of the SCR reaction. After passing through the SCR reactor, the flue gas enters the GGH heat exchanger to transfer heat to inlet-end cold flue gas, so that the cold flue gas is heated before decarburization, the relation between the flue gas before decarburization and t0 is judged at the moment, and the heating device is adjusted in time. When T1 is less than T0, adjusting the heating device to ensure that T2 is equal to T0; when t1 is more than or equal to t0, the heating device is closed.
In the present invention, since the catalysts used for the CO catalytic oxidation are different, the optimum catalytic temperature t0 may be different.
When the catalytic reaction of the catalyst adopted by the CO catalytic oxidation layer is characterized by catalytic combustion (namely when the reaction temperature reaches a certain value, the CO catalytic oxidation process is vigorously carried out): the first heating device is turned on to continuously heat the raw flue gas entering the CO reactor until the following formula is satisfied:
(a1-a2)/a1 ═ k1..
Wherein, k1 is more than or equal to 5% and less than or equal to 20% (preferably, k1 is more than or equal to 8% and less than or equal to 15%). When the formula I is established, the synchronously detected temperature value t2 is the optimal temperature t0 for the smoke decarburization.
When the catalytic reaction of the catalyst adopted by the CO catalytic oxidation layer is characterized in that the CO removal efficiency is in a slow increasing trend along with the temperature: the first heating device is turned on to continuously heat the raw flue gas entering the CO reactor until the following formula is satisfied:
(a1-a2)/a1 ═ k2..
Wherein k2 is more than or equal to 90 percent (preferably k2 is more than or equal to 95 percent), and the temperature value of t2 synchronously detected when the formula II is established is the optimal temperature t0 for the flue gas decarburization.
Furthermore, a first temperature detector is arranged on a flue gas inlet pipe between the first heating device and the GGH heat exchanger to detect that the original flue gas temperature is t1 and DEG C. Meanwhile, a first flow detector is arranged to detect the flow of the original flue gas as q1, L/s. And a first cooling medium conveying pipe is externally connected to the flue gas inlet pipe between the first heating device and the second temperature detector, and a first flow control valve is arranged on the first cooling medium conveying pipe. Setting the safety temperature t for the decarbonization of the flue gasCarbon (C)，℃。
When t1 < t0, the first heating device 5 is started to heat the raw smoke so that the temperature of the raw smoke is t 2-t 0.
When t0 is not less than t1 < tCarbon (C)In this case, the system is maintained in this state without starting the first heating device 5.
When t1 is more than or equal to tCarbon (C)In the process, the first heating device 5 is not required to be started, the first cooling medium conveying pipe is started to input cooling medium to cool the raw flue gas, so that the temperature of the raw flue gas is lower than tCarbon (C)。
The utility model discloses in, the heat that scatters and disappears when the former flue gas of high temperature in the system cools down to t0 equals the absorbed heat when cooling medium heaies up to t0, according to the heat balance principle:
C1*q1(t1-t0)＝Ccold*q3(t0-tCold)...III。
Wherein C1 is the specific heat capacity of the smoke, and J/(kg ℃). CColdThe specific heat capacity of the cooling medium is J/(kg ℃). t is tColdThe temperature of the cooling medium is measured in degrees centigrade. q3 is the input amount of the cooling medium, L/s.
Formula III converts to:
q3＝[C1*q1(t1-t0)]/[Ccold(t0-tCold)]...IV。
By controlling the first flow rate control valve on the first cooling medium delivery pipe, the total flow rate of the cooling medium delivered through the first cooling medium delivery pipe is q 3.
The utility model discloses in the exhaust vent department of CO reactor or first pipeline are close to CO reactor one end department and are provided with the third temperature and detect that the flue gas temperature is t3, degree C after the decarbonization is detected to the meter. Meanwhile, a second flow detector is arranged to detect the flow of the decarbonized flue gas as q2, L/s. The first pipeline is internally provided with a fourth temperature detector for detecting the temperature t4 and DEG C of the flue gas before denitration. And a second cooling medium conveying pipe is externally connected to the first pipeline between the second heating device and the fourth temperature detector, and a second flow control valve is arranged on the second cooling medium conveying pipe. The optimal temperature for flue gas denitration is set to t5 and DEG C. Setting the safe temperature of flue gas denitration as tMirabilite，℃。
When t3 is less than t5, the second heating device 6 is started to heat the decarbonized flue gas so that the temperature of the decarbonized flue gas is t4 to t 5.
When t5 is not less than t3 < tMirabiliteIn this case, the second heating device 6 is not required to be started, and the system is maintained in this state and continues to operate.
When t3 is more than or equal to tMirabiliteIn the process, the second heating device 6 does not need to be started, the second cooling medium conveying pipe 8 is started to input the cooling medium to cool the decarburized flue gas, so that the temperature of the decarburized flue gas is lower than tMirabilite。
The utility model discloses in, the heat that scatters and disappears when the high temperature decarbonization flue gas cooling reaches t5 in the system equals the absorbed heat when cooling medium heaies up to t5, according to the heat balance principle:
C2*q2(t3-t5)＝Ccold*q4(t5-tCold)...V。
Wherein C2 is the specific heat capacity of the decarbonized flue gas, and J/(kg ℃). CColdThe specific heat capacity of the cooling medium is J/(kg ℃). t is tColdThe temperature of the cooling medium is measured in degrees centigrade. q4 is the input amount of the cooling medium, L/s.
Formula V is converted to:
q4＝[C2*q2(t3-t5)]/[Ccold(t5-tCold)]...VI。
By controlling the second flow control valve on the second cooling medium delivery pipe, the total flow rate of the cooling medium delivered through the second cooling medium delivery pipe is q 4.
Through the technical scheme of the utility model, through the temperature of flue gas before the control entering CO reactor that first heating device can be accurate, along with the operation of system, can in good time adjust opening of first heating device and stop and heating power, the temperature of flue gas reaches the optimum temperature of CO conversion before can getting into the CO reactor through first heating device to avoid the emergence of catalytic poisoning in the CO reactor, and then guarantee the decarbonization effect of CO reactor to the flue gas. In addition, through the setting of first cooling medium conveyer pipe, can avoid getting into the high temperature of flue gas before the CO reactor to the safety of catalyst in the guarantee CO reactor. In short, the temperature of the flue gas before entering the CO reactor is ensured to be in a proper range through the arrangement of the first heating device and the first cooling medium conveying pipe.
Through the technical scheme of the utility model, through the temperature of flue gas before the control entering SCR reactor that second heating device can be accurate, along with the operation of system, can in good time adjust opening of second heating device and heat power, can make the temperature that gets into flue gas before the SCR reactor reach the optimum temperature of SCR conversion through second heating device to avoid the emergence of catalytic poisoning in the SCR reactor, and then guarantee the denitration effect of SCR reactor to the flue gas. In addition, through the setting of second cooling medium conveyer pipe, can avoid getting into the temperature of flue gas too high before the SCR reactor to the safety of catalyst in the guarantee SCR reactor. In short, the temperature of the flue gas before entering the SCR reactor is ensured to be in a proper range through the arrangement of the second heating device and the second cooling medium conveying pipe.
In the present invention, the height of the CO reactor is 1 to 50m, preferably 2 to 30m, more preferably 3 to 20 m.
In the present invention, the height of the SCR reactor is 1 to 50m, preferably 2 to 30m, more preferably 3 to 20 m.
In the present invention, the first heating device is an electric heating device or a gas heating device.
The utility model discloses in, the second heating device is electric heater unit or gas heater unit.
Compared with the prior art, the utility model discloses a beneficial technological effect as follows:
1. when the CO catalyst reaction is characterized by catalytic combustion reaction, the ignition temperature is related to physical properties such as reactant concentration, flue gas working condition of the catalyst, whether dust is deposited on the surface of the catalyst, and ammonium sulfate product adhesion besides the catalyst active components. The utility model discloses can in time differentiate the light-off temperature of catalyst under the specific operating mode, feed back to the system heating module, make system's flue gas entry temperature keep at catalyst light-off temperature, the stable, high-efficient operation of guarantee system.
2. The utility model discloses can guarantee that CO catalyst and SCR catalyst are in high-efficient catalytic operating condition for a long time, avoid the unnecessary energy consumption simultaneously, make full use of the system heat simultaneously, reduce the energy consumption, improve economic benefits.
3. The utility model discloses can effectively avoid because the CO catalytic oxidation process acutely releases heat and lead to the system to take place unfavorable phenomena such as hot sintering, accurate regulation and control system reaction temperature has protected the catalyst simultaneously, has ensured the security and the stability of system.
Drawings
FIG. 1 is a structural diagram of a flue gas decarburization and denitration treatment system;
FIG. 2 is a structural diagram of a flue gas decarburization and denitration treatment system provided with a CO concentration detection device;
FIG. 3 is a structural diagram of a flue gas decarburization and denitration treatment system provided with a cooling mechanism.
Reference numerals: 1: a CO reactor; 101: a CO catalytic oxidation layer; 2: an SCR reactor; 201: an SCR denitration layer; 202: a rectifier; 3: an ammonia injection device; 4: a GGH heat exchanger; 5: a first heating device; 6: a second heating device; 7: a first cooling medium delivery pipe; 8: a second cooling medium delivery pipe; 9: a flue gas inlet pipe; 10: a flue gas exhaust pipe; l1: a first conduit; a1: a first CO concentration detector; a2: a second CO concentration detector; q1: a first flow detector; q2: a second flow rate detector; t1: a first temperature detector; t2: a second temperature detector; t3: a third temperature detector; t4: a fourth temperature detector; m1: a first flow control valve; m2: a second flow control valve.
Detailed Description
The technical solution of the present invention is illustrated below, and the claimed invention includes but is not limited to the following embodiments.
A flue gas decarbonization and denitration treatment system comprises a CO reactor 1 and an SCR reactor 2. According to the trend of the flue gas, a flue gas inlet pipe 9 is connected with the air inlet of the CO reactor 1. The exhaust of the CO reactor 1 is connected to the inlet of the SCR reactor 2 via a first conduit L1. And an exhaust port of the SCR reactor 2 is connected with a flue gas exhaust pipe 10. The flue gas inlet pipe 9 is provided with a first heating device 5, and the first pipeline L1 is provided with a second heating device 6.
Preferably, the system further comprises a GGH heat exchanger 4. The GGH heat exchanger 4 is respectively connected with a flue gas inlet pipe 9 and a flue gas outlet pipe 10. The flue gas conveyed by the flue gas inlet pipe 9 is subjected to heat exchange by the GGH heat exchanger 4 and then conveyed to the gas inlet of the CO reactor 1. And the clean flue gas discharged from the SCR reactor 2 is subjected to heat exchange by the GGH heat exchanger 4 and then discharged through the flue gas exhaust pipe 10, and the first heating device 5 is positioned at the downstream of the connecting position of the GGH heat exchanger 4 and the flue gas inlet pipe 9.
Preferably, m layers of the CO catalytic oxidation layer 101 are arranged in the CO reactor 1. And n layers of SCR denitration layers 201 are arranged in the SCR reactor 2.
Preferably, m and n are each independently 1 to 5, preferably 2 to 4.
Preferably, a first temperature detector T1, a first flow rate detector Q1, and a first CO concentration detector a1 are provided in the flue gas intake pipe 9 between the first heating device 5 and the GGH heat exchanger 4.
Preferably, a second temperature detector T2 is arranged at the air inlet of the CO reactor 1 or at one end of the flue gas inlet pipe 9 close to the CO reactor 1.
Preferably, a third temperature detector T3, a second flow rate detector Q2 and a second CO concentration detector a2 are provided at the gas outlet of the CO reactor 1 or at one end of the first pipe L1 near the CO reactor 1.
Preferably, a fourth temperature detector T4 is provided on the first conduit L1 downstream of the second heating device 6.
Preferably, the flue gas inlet pipe 9 between the first heating device 5 and the second temperature detector T2 is externally connected with a first cooling medium conveying pipe 7. The first cooling medium feed pipe 7 is provided with a first flow rate control valve M1.
Preferably, the second cooling medium delivery pipe 8 is externally connected to the first pipe L1 between the second heating device 6 and the fourth temperature detector T4. The second cooling medium delivery pipe 8 is provided with a second flow rate control valve M2. And/or
Preferably, the air inlet of the SCR reactor 2 is further provided with a rectifier 202. And/or
Preferably, an ammonia injection device 3 is further arranged in the first pipeline L1 between the second heating device 6 and the rectifier 202.
Example 1
As shown in fig. 1-3, a system for decarbonizing and denitrating flue gas comprises a CO reactor 1 and an SCR reactor 2. According to the trend of the flue gas, a flue gas inlet pipe 9 is connected with the air inlet of the CO reactor 1. The exhaust of the CO reactor 1 is connected to the inlet of the SCR reactor 2 via a first conduit L1. And an exhaust port of the SCR reactor 2 is connected with a flue gas exhaust pipe 10. The flue gas inlet pipe 9 is provided with a first heating device 5, and the first pipeline L1 is provided with a second heating device 6.
Example 2
Example 1 is repeated except that the system further comprises a GGH heat exchanger 4. The GGH heat exchanger 4 is respectively connected with a flue gas inlet pipe 9 and a flue gas outlet pipe 10. The flue gas conveyed by the flue gas inlet pipe 9 is subjected to heat exchange by the GGH heat exchanger 4 and then conveyed to the gas inlet of the CO reactor 1. And the clean flue gas discharged from the SCR reactor 2 is subjected to heat exchange by the GGH heat exchanger 4 and then discharged through the flue gas exhaust pipe 10, and the first heating device 5 is positioned at the downstream of the connecting position of the GGH heat exchanger 4 and the flue gas inlet pipe 9.
Example 3
Example 2 was repeated except that the CO reactor 1 was provided with 2 CO catalytic oxidation layers 101. And 2 layers of SCR denitration layers 201 are arranged in the SCR reactor 2.
Example 4
Example 3 was repeated except that a first temperature detector T1, a first flow rate detector Q1, and a first CO concentration detector a1 were provided in the flue gas intake pipe 9 between the first heating device 5 and the GGH heat exchanger 4.
Example 5
Example 4 is repeated, except that a second temperature detector T2 is arranged at the inlet of the CO reactor 1 or at the end of the flue gas inlet 9 close to the CO reactor 1.
Example 6
Example 5 was repeated except that a third temperature detector T3, a second flow rate detector Q2 and a second CO concentration detector a2 were provided at the gas outlet of the CO reactor 1 or at the end of the first pipe L1 near the CO reactor 1.
Example 7
Example 6 was repeated except that a fourth temperature detecting gauge T4 was provided on the second heating means 6 downstream of the first conduit L1.
Example 8
Embodiment 7 is repeated, and the flue gas inlet pipe 9 between the first heating device 5 and the second temperature detector T2 is externally connected with a first cooling medium conveying pipe 7. The first cooling medium feed pipe 7 is provided with a first flow rate control valve M1.
Example 9
Example 8 was repeated except that the second cooling medium feed pipe 8 was circumscribed to the first pipe L1 between the second heating means 6 and the fourth temperature detector T4. The second cooling medium delivery pipe 8 is provided with a second flow rate control valve M2.
Working example 10
Example 9 is repeated, except that the inlet of the SCR reactor 2 is also provided with a rectifier 202.
Example 11
Example 10 is repeated except that an ammonia injection device 3 is further provided in the first conduit L1 between the second heating device 6 and the rectifier 202.
Claims (9)
1. The utility model provides a flue gas decarbonization denitration treatment system which characterized in that: the system comprises a CO reactor (1) and an SCR reactor (2); according to the trend of the flue gas, a flue gas inlet pipe (9) is connected with an air inlet of the CO reactor (1); the exhaust port of the CO reactor (1) is connected with the air inlet of the SCR reactor (2) through a first pipeline (L1); the exhaust port of the SCR reactor (2) is connected with a flue gas exhaust pipe (10); a first heating device (5) is arranged on the flue gas inlet pipe (9), and a second heating device (6) is arranged on the first pipeline (L1); wherein: the height of the CO reactor is 1-50 m.
2. The system of claim 1, wherein: the system further comprises a GGH heat exchanger (4); the GGH heat exchanger (4) is respectively connected with a flue gas inlet pipe (9) and a flue gas outlet pipe (10); the flue gas conveyed by the flue gas inlet pipe (9) is subjected to heat exchange by the GGH heat exchanger (4) and then conveyed to the gas inlet of the CO reactor (1); and the clean flue gas discharged from the SCR reactor (2) is discharged from a flue gas exhaust pipe (10) after being subjected to heat exchange by a GGH heat exchanger (4), and the first heating device (5) is positioned at the downstream of the connecting position of the GGH heat exchanger (4) and a flue gas inlet pipe (9).
3. The system of claim 2, wherein: m layers of CO catalytic oxidation layers (101) are arranged in the CO reactor (1); n layers of SCR denitration layers (201) are arranged in the SCR reactor (2); wherein: m and n are each independently 1 to 5.
4. The system of claim 3, wherein: m and n are each independently 2 to 4.
5. The system according to any one of claims 2-4, wherein: a first temperature detector (T1), a first flow rate detector (Q1) and a first CO concentration detector (A1) are arranged on a flue gas inlet pipe (9) between the first heating device (5) and the GGH heat exchanger (4); a second temperature detector (T2) is arranged at the air inlet of the CO reactor (1) or at one end of the flue gas inlet pipe (9) close to the CO reactor (1); a third temperature detector (T3), a second flow detector (Q2) and a second CO concentration detector (A2) are arranged at the air outlet of the CO reactor (1) or at one end of the first pipeline (L1) close to the CO reactor (1); a fourth temperature detector (T4) is arranged on the first pipeline (L1) downstream of the second heating device (6).
6. The system of claim 5, wherein: a first cooling medium conveying pipe (7) is externally connected to the flue gas inlet pipe (9) between the first heating device (5) and the second temperature detector (T2), and a first flow control valve (M1) is arranged on the first cooling medium conveying pipe (7); and a second cooling medium conveying pipe (8) is externally connected to a first pipeline (L1) between the second heating device (6) and the fourth temperature detector (T4), and a second flow control valve (M2) is arranged on the second cooling medium conveying pipe (8).
7. The system according to any one of claims 1-4, 6, wherein: the air inlet of the SCR reactor (2) is also provided with a rectifier (202).
8. The system of claim 5, wherein: the air inlet of the SCR reactor (2) is also provided with a rectifier (202).
9. The system of claim 8, wherein: an ammonia spraying device (3) is also arranged in the first pipeline (L1) between the second heating device (6) and the rectifier (202).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921889250.XU CN212068340U (en) | 2019-11-05 | 2019-11-05 | Flue gas decarbonization denitration treatment system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921889250.XU CN212068340U (en) | 2019-11-05 | 2019-11-05 | Flue gas decarbonization denitration treatment system |
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| CN212068340U true CN212068340U (en) | 2020-12-04 |
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