CN115430213A

CN115430213A - Intelligent control anti-condensation type saturated wet flue gas flow mixing system and method

Info

Publication number: CN115430213A
Application number: CN202211077994.8A
Authority: CN
Inventors: 邱国志; 冯晓峰; 汪子寒; 刘贵云; 罗波; 徐玉珍; 李建华
Original assignee: Zhongye Changtian International Engineering Co Ltd
Current assignee: Zhongye Changtian International Engineering Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2022-12-06
Anticipated expiration: 2042-09-05
Also published as: CN115430213B

Abstract

An intelligent control anti-condensation saturated wet flue gas mixed flow system comprises a mixer (1), a mixed flow cylinder (2) and a dust remover (3); the mixed flow cylinder (2) is arranged above the exhaust end of the mixer (1), and an exhaust port of the mixer (1) is connected with a flue gas inlet of the mixed flow cylinder (2) through a pneumatic valve (K); the heat medium conveying pipeline (L1) is connected to a heat medium inlet of the mixed flow cylinder (2); the flue gas outlet of the mixed flow cylinder (2) is connected to the dust remover (3) through a dust removal pipeline (L2). The mixed flow system can effectively control the temperature of the flue gas entering the dust remover, avoids the problem that the flue gas is still below the dew point temperature at the initial stage of hot air influx in the prior art, can thoroughly solve the problem that the moisture-containing flue gas dews and blocks the inner wall of a pipeline, and ensures the long-term stable operation of the system.

Description

Intelligent control anti-condensation type saturated wet flue gas flow mixing system and method

Technical Field

The invention relates to an anti-condensation dedusting system and process for wet flue gas, in particular to an intelligent control anti-condensation type saturated wet flue gas mixed flow system and method, and belongs to the technical field of flue gas dedusting.

Background

The quicklime digestion process in the primary mixer is a process of violent exothermic reaction with water after water is added, and the reaction equation is as follows:

CaO+H ₂ O＝Ca(OH) ₂ +6489.15J

slaked lime Ca (OH) generated after slaking quicklime ₂ Particles, further absorbing water, in air with CO ₂ Reaction to form CaCO ₃ Precipitation, bulk CaCO ₃ The precipitate is easy to form hard scale and harden. Therefore, the flue gas of the sintering primary mixer has the following characteristics: (1) the moisture content in the flue gas is higher; (2) The dust in the flue gas has strong adhesion and is easy to adhere to the inner wall of the exhaust funnel, a pipeline, equipment and the like; (3) The content of quicklime in the flue gas is high (accounting for more than 30 percent of the weight of the dust); (4) The temperature of the flue gas is higher than the ambient temperature, so that the flue gas is easy to condense, especially in winter; (5) The dust concentration in the flue gas exceeds the standard and the fluctuation range is larger, even the lower level is far beyond the 10mg/Nm required by the national standard ³ And (4) limiting values.

The saturated wet flue gas generated after the quicklime is digested has the temperature higher than the ambient temperature and the dew point temperature is high, the moisture condensed and separated from the flue gas is subjected to chemical exothermic reaction with the unreacted quicklime in the process of conveying in a pipeline if the temperature is reduced too fast, and the generated CaCO ₃ After the substances are deposited on the inner wall of the pipeline, the inner wall of the pipeline is scaled and blocked, and the dust removal effect is influenced.

The existing mode for controlling the dew point of the flue gas and the defects thereof are as follows:

(1) The mixed hot air is adopted to prevent the scaling of the pipeline. This mode is through setting up the branch pipe and introducing the hot-blast dust removal pipeline that converges of one strand, and the control dew point temperature can be guaranteed to the mixing temperature who calculates theoretically, and hot-blast direct heating saturation wet flue gas, and it is effectual to heat, but because of its temperature that can't guarantee the heat source at the in-process of in-service use, and converge hot-blast initial stage, the flue gas still probably is below dew point temperature, and in the long term, the problem of pipeline inner wall jam can't thoroughly be solved.

(2) The wet flue gas is heated by adopting an electric tracing mode. The electric tracing band is arranged on the outer side of the pipeline, the outer wall of the dust removal pipeline is heated through electric energy, and heat is conducted to the inner wall of the dust removal pipeline to heat wet flue gas through the action of metal heat conduction. This mode energy consumption is big, and there is certain heat consumption after heat conduction several times, and the heating of wet flue gas needs a process, consequently, the problem of pipe blockage can only be alleviated, still can not thoroughly solve.

(3) The wet flue gas is heated by adopting a steam heat tracing mode. The principle of the mode for preventing the condensation is the same as that of the mode (2), the mode has the advantages that redundant steam resources of industrial factories are utilized, the defects are that the mode is the same as the second mode, the heat conduction is needed for multiple times, the manufacturing and construction requirements are high due to the fact that the steam pipeline is a pressure pipeline, heat conduction mud for heat conduction of the steam pipeline is inconvenient to purchase, and the like, and the mode for preventing the condensation cannot be popularized and used on a large scale.

Therefore, the existing device or process cannot well solve the problems of condensation and pipeline blockage of the saturated wet flue gas in a dust removal system.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an intelligent control anti-condensation saturated wet flue gas mixed flow system. The system introduces a mixing barrel, the mixing barrel is arranged above the exhaust end of the mixer and is connected through a pneumatic valve, and the downstream of the mixing barrel is connected to a dust remover through a dust removing pipeline. And introducing a heat medium into the mixed flow cylinder, and when the temperature in the mixed flow cylinder rises to be higher than the dew point temperature of the wet flue gas in the mixer, the wet flue gas in the mixer enters the mixed flow cylinder, so that the problem that the wet flue gas is likely to be condensed to block a pipeline at the initial stage of hot air convergence in the prior art can be avoided, and the temperature of the mixed flue gas entering the dust remover is ensured to be higher than the dew point temperature of the flue gas in the whole process.

Based on the mixed flow system, the invention also provides an intelligent control anti-condensation type saturated wet flue gas mixed flow method. The method comprises the steps of determining the dew point temperature of wet flue gas based on state parameters of the wet flue gas in a mixer, and enabling the mixed flue gas to enter a dust remover for dust removal treatment when the temperature of the mixed flue gas of the wet flue gas and a heat medium in a mixed flow cylinder is higher than the dew point temperature of the wet flue gas. The mixed flow method can effectively control the temperature of the flue gas entering the dust remover, avoid the problem that the flue gas is still below the dew point temperature at the initial stage of hot air influx in the prior art, and can thoroughly solve the problem that the moisture-containing flue gas is condensed to block the inner wall of the pipeline, thereby ensuring the long-term stable operation of the system.

According to a first embodiment of the invention, an intelligent control anti-condensation type saturated wet flue gas mixed flow system is provided.

An intelligent control anti-condensation type saturated wet flue gas mixed flow system comprises a mixing machine, a mixed flow cylinder and a dust remover. The mixed flow cylinder is arranged above the exhaust end of the mixer, and the exhaust port of the mixer is connected with the flue gas inlet of the mixed flow cylinder through a pneumatic valve. The heat medium conveying pipeline is connected to the heat medium inlet of the mixing barrel. The flue gas outlet of the mixed flow cylinder is connected to a dust remover through a dust removing pipeline.

In the present invention, the system further comprises a gas delivery conduit. The gas conveying pipeline is connected to the input end of the heat medium conveying pipeline.

Preferably, the heat medium conveying pipeline is provided with a first switch valve and a booster fan. Preferably, the gas transmission pipeline is provided with a second switch valve.

In the present invention, the system further comprises a preheater. The preheater is connected to the input end of the heat medium conveying pipeline via a first heat supply pipeline. Preferably, the first heat supply pipeline is provided with a third switch valve. Preferably, the preheater is a hot blast stove.

In the invention, the system also comprises a device for producing waste heat. The production waste heat device is connected to the input end of the heat medium conveying pipeline through a second heat supply pipeline. Preferably, a fourth switch valve is arranged on the second heat supply pipeline.

In the invention, a bypass pipeline is separated from the heat medium conveying pipeline, and the bypass pipeline bypasses the first switch valve and the booster fan and then is combined to the heat medium conveying pipeline. Preferably, a fifth switch valve is arranged on the bypass pipeline.

Preferably, the heat medium delivery pipe is provided with a first pressure sensor and a second pressure sensor. Wherein the first pressure sensor is located upstream of the location on the heat medium transport pipe from which the bypass pipe branches. The second pressure sensor is located downstream of the location where the bypass conduit merges into the thermal medium delivery conduit.

In the invention, the heat medium conveying pipeline is provided with a first temperature sensor. The first temperature sensor is located on the heat medium transport pipe upstream of the location of the branch bypass pipe. And a second temperature sensor and a humidity sensor are arranged on the mixer. And a third temperature sensor is arranged on the mixed flow cylinder. And a fourth temperature sensor is arranged on the dust removal pipeline.

Preferably, the heat medium delivery pipe is provided with a first regulating valve. The first regulating valve is located downstream of the point where the bypass line merges into the heat medium conveying line. And a second regulating valve is arranged on the dust removing pipeline.

Preferably, the system comprises n mixers. A mixing cylinder is correspondingly arranged above the exhaust end of each mixer. Each mixing machine is connected with the mixing cylinder through a pneumatic valve. And the downstream of the position where the bypass pipeline is merged to the heat medium conveying pipeline, the heat medium conveying pipeline is divided into n heat medium branch pipes which are respectively connected to the heat medium inlets of the n mixed flow cylinders. The flue gas outlet of each mixed flow cylinder is respectively connected to a dust remover through a respective dust removing pipeline. Preferably, n is from 1 to 10, preferably from 2 to 6.

Preferably, a second temperature sensor and a humidity sensor are provided on each mixer. And a third temperature sensor is arranged on each mixed flow cylinder. And a fourth temperature sensor and a second regulating valve are arranged on the dust removal pipeline respectively connected with each mixed flow cylinder. Each thermal medium branch pipe is provided with a first regulating valve.

Preferably, the dust removal pipelines connected with each flow mixing cylinder are connected to the dust remover through the dust removal header pipe after being combined. Preferably, a fifth temperature sensor is arranged on the dust removal header pipe.

In the present invention, the system further comprises a control device. The control device is connected with the pneumatic valve, the first switch valve, the second switch valve, the third switch valve, the fourth switch valve, the fifth switch valve, the first pressure sensor, the second pressure sensor, the first temperature sensor, the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor, the humidity sensor, the first regulating valve and the second regulating valve, and controls the operation of each valve and each sensor.

According to a second embodiment of the invention, an intelligent control anti-condensation type saturated wet flue gas mixed flow method is provided.

An intelligent control anti-dewing type saturated wet flue gas flow mixing method or a flow mixing method using the system in the first embodiment comprises the following steps:

1) The dew point temperature of the moist flue gas contained in the mixer was determined.

2) And (3) introducing a heat medium into the mixed flow cylinder through a heat medium conveying pipeline, and when the temperature in the mixed flow cylinder is higher than the dew point temperature of the wet flue gas in the step 1), opening the pneumatic valve, so that the wet flue gas in the mixer enters the mixed flow cylinder.

3) Mixing the wet flue gas and a heat medium in a mixing cylinder to obtain mixed flue gas, and when the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the step 1), enabling the mixed flue gas to enter a dust remover through a dust removal pipeline for dust removal treatment.

According to a third embodiment of the invention, an intelligent control anti-condensation type saturated wet flue gas mixed flow method is provided.

An intelligent control anti-condensation type saturated wet flue gas mixed flow method or a mixed flow method using the system in the first embodiment comprises the following steps:

1) The dew point temperature of the wet flue gas contained in the n mixers was determined.

2) And respectively introducing a heat medium into each mixed flow cylinder through a heat medium branch pipe separated from the heat medium conveying pipeline, and opening a pneumatic valve when the temperature in each mixed flow cylinder is higher than the dew point temperature of the wet flue gas in the corresponding mixing machine, so that the wet flue gas in each mixing machine enters the corresponding mixed flow cylinder.

3) The wet flue gas and the heat medium are mixed in each mixed flow cylinder to obtain mixed flue gas, and when the temperature of the mixed flue gas in each mixed flow cylinder is higher than the dew point temperature of the wet flue gas in the corresponding mixer, the mixed flue gas in each mixed flow cylinder is merged to a dust removal header pipe through respective dust removal pipelines and then enters a dust remover for dust removal treatment.

In the invention, the step 2) further comprises a step of detecting and cleaning ash, which specifically comprises the following steps: before the heat medium is introduced into the mixed flow cylinder, the pressure on the heat medium conveying pipeline is detected by adopting a first pressure sensor and a second pressure sensor. If the pressure detection is abnormal, a system ash removal program is started, at the moment, external air is introduced into the gas conveying pipeline and the heat medium conveying pipeline through the booster fan, and the heat medium conveying pipeline and the mixed flow cylinder are cleaned by the external air in a back flushing mode. And ending the ash removal program of the system until the pressures detected by the first pressure sensor and the second pressure sensor are recovered to be normal.

In the invention, in the step 2), the introduction of a heat medium into the mixing flow cylinder specifically comprises the following steps: at the beginning of the system operation, the heat medium is provided to the heat medium conveying pipeline through the preheater. When the process production state is stable, the production waste heat device can provide effective waste heat, and at the moment, the production waste heat device provides heat medium for the heat medium conveying pipeline.

In the invention, the determination of the dew point temperature of the wet flue gas in the mixer in step 1) specifically comprises the following substeps:

(1) collecting humidity and temperature data of a large amount of wet flue gas in engineering, obtaining the dew point temperature of the flue gas under corresponding working conditions through an enthalpy-humidity diagram (namely, the relationship among various parameters of the wet air is represented by a graph and can be consulted for application), and establishing a flue gas dew point temperature database.

(2) And respectively measuring the humidity and the temperature of the wet flue gas in the mixing machine by adopting a humidity sensor and a second temperature sensor, and acquiring the dew point temperature of the wet flue gas in the corresponding mixing machine from a flue gas dew point temperature database.

In the invention, the amount of the heat medium required to be introduced into the mixer cylinder in the step 2) is calculated, and the method specifically comprises the following substeps:

a) Calculating the heat required by the wet flue gas in the preheating mixer:

the amount of wet flue gas in the mixer is V _{Cigarette with heating means} ，m ³ H is used as the reference value. Detecting the temperature of the wet flue gas as T _{Cigarette with heating means} At deg.C. The dew point temperature of the flue gas is T ₀ At deg.C. Setting the temperature of mixed flue gas obtained after mixing wet flue gas and heat medium to be T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ + (5-30) DEG C. The heat Q to be absorbed thereby for preheating the moist flue gas in the mixer _{Cigarette with heating means} Comprises the following steps:

Q _{cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρΔT _{Cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )。

In the formula: c _{Cigarette with heating means} The specific heat capacity of the wet flue gas is kJ/(kg-DEG C). Rho _{Cigarette with heating means} Density of wet smoke, kg/m ³ 。

b) Calculating the heat released by the heat medium entering the flow mixing cylinder:

the quantity of the heat medium entering the mixing tube is set as V _{Heat generation} ，m ³ H is used as the reference value. Detecting the temperature T of the heat medium _{Heat generation} At deg.C. Thereby, the heat Q released by the heat medium entering the mixed flow cylinder _{Heat generation} Comprises the following steps:

Q _{heat generation} ＝C _{Heat generation} V _{Heat generation} ρΔT _{Heat generation} ＝C _{Heat generation} V _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )。

In the formula: c _{Heat generation} The specific heat capacity of the heat medium is kJ/(kg. Multidot. Multidot.C.). ρ is a unit of a gradient _{Heat generation} Density of the heat medium, kg/m ³ 。

c) The heat Q to be absorbed by preheating the moist flue gas _{Cigarette with heating means} With the heat Q released by the heat medium entering the mixing tube _{Heat generation} Equality, we can get:

C _{cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )＝C _{Heat generation} V _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )。

Obtaining the following components:

V _{heat generation} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )/[C _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )]。

Adjusting the opening degree of a first adjusting valve on the heat medium conveying pipeline or a heat medium branch pipe separated from the heat medium conveying pipeline to ensure that the quantity of the heat medium introduced into the mixed flow cylinder in the step 2) is V _{Heat generation} 。

Preferably, in step 3), the opening degree of the second regulating valve on the dust removing pipeline is regulated so that the air volume of each dust removing point meets the requirement, and the dust does not escape from each dust removing point. Meanwhile, a fourth temperature sensor detects the temperature T of the mixed flue gas on the dust removal pipeline on line and adjusts the opening degree of a first adjusting valve on the heat medium conveying pipeline or the heat medium branch pipe, so that T is equal to T _{Is provided with} 。

The invention provides an intelligent control anti-condensation type saturated wet flue gas mixed flow system, aiming at the problem that flue gas of a primary sintering mixer is easy to condense and block a pipeline in the dedusting and cooling processes because the flue gas of the primary sintering mixer in the prior art has high moisture content and high dust concentration. The mixed flow system comprises a mixer, a mixed flow cylinder and a dust remover. The mixed flow barrel is arranged above the exhaust end of the mixer, and a pneumatic valve is arranged at the exhaust port of the mixer, namely, the exhaust port of the mixer is connected with the flue gas inlet of the mixed flow barrel through the pneumatic valve. The heat medium conveying pipeline is connected to a heat medium inlet of the mixing barrel, namely the heat medium conveying pipeline provides heat medium for preheating the mixing barrel and heating wet flue gas in the mixer. The dust remover is arranged at the downstream of the mixed flow cylinder, and the flue gas outlet of the mixed flow cylinder is connected to the dust remover through a dust removal pipeline. In the in-service use in-process, let in hot medium in to the mixed flow section of thick bamboo, treat that the temperature in the mixed flow section of thick bamboo rises to mix above the wet flue gas dew point temperature in the machine, the pneumatic valve is opened this moment, and the wet flue gas that contains in the mixer gets into the mixed flow section of thick bamboo to can avoid among the prior art the problem that contains wet flue gas at the hot-blast initial stage of joining in still probably the dewfall and block up the pipeline, and then ensure that the mixed flue gas gets into the temperature of dust remover and all be above the flue gas dew point temperature in the whole journey.

Preferably, the invention further comprises a gas conveying pipeline, and the gas conveying pipeline is connected with the input end of the heat medium conveying pipeline. The heat medium conveying pipeline is also provided with a booster fan. The pressure on the heat medium conveying pipeline is detected through the pressure sensors (including the first pressure sensor and the second pressure sensor), so that whether the heat medium conveying pipeline and the mixed flow cylinder are in the dust deposition state or not is judged. If the pressure detection is abnormal, a system ash removal program is started, external air is introduced into the gas conveying pipeline and pressurized through the booster fan, and the external air performs back-flushing cleaning on the heat medium conveying pipeline and the mixed flow cylinder in sequence, so that the ash accumulation blockage of the pipeline is avoided, and the system can stably run for a long time.

In the invention, the mixed flow system also comprises a preheater and a device for producing waste heat. The preheater and the production waste heat device are respectively connected to the input end of the heat medium conveying pipeline through a first heat supply pipeline and a second heat supply pipeline. At the beginning of the system operation, the heat medium is provided to the heat medium conveying pipeline through the preheater. Wherein, the preheater can select a hot blast stove. When the process production state is stable, the production waste heat device can provide an effective heat source, the preheater stops running at the moment, and the production waste heat device is adopted to provide a heat medium for the heat medium conveying pipeline. The process waste heat provided by the waste heat production device is not limited to a specific process, and may be waste heat generated in a sintering process, or waste heat generated in processes such as glass calcination, pellet production and the like. The invention adopts the preheater as a standby heat source, and when the waste heat in the production process is judged to be available (the judgment can be carried out through the measured value of the thermal resistance arranged at the heat source, after a period of time operation, the control can be carried out according to the time in the later period), the waste heat generated in the production process of the process can be preferentially utilized, the cascade utilization of energy is realized, and the energy is saved. In addition, the booster fan arranged on the heat medium conveying pipeline can boost the external air for ash removal and can also be used as a standby power source, so that the phenomenon of pressure imbalance caused by overlarge resistance of the heat medium conveying pipeline is avoided, the introduction of a heat medium is more stable, and the subsequent stability of the temperature of the dedusting flue gas is facilitated.

Preferably, the bypass pipeline is separated from the heat medium conveying pipeline, bypasses the booster fan and then is combined to the heat medium conveying pipeline. When the resistance of the heat medium conveying pipeline is small and the introduction of the heat medium is stable, the heat medium can be conveyed to the mixed flow cylinder through the bypass pipeline without passing through the pipeline position where the booster fan is located.

In the invention, a first pressure sensor and a second pressure sensor are arranged on the heat medium conveying pipeline. Wherein the first pressure sensor is located upstream of the location on the heat medium transport pipe from which the bypass pipe branches. The second pressure sensor is located downstream of the location where the bypass conduit merges into the thermal medium delivery conduit. The first pressure sensor and the second pressure sensor are used for detecting the pressure on the heat medium conveying pipeline, so that whether the heat medium conveying pipeline and the mixed flow cylinder are in a dust deposition state or not is judged, and whether a system dust cleaning program needs to be started or not is judged. Generally, under the normal working condition that the pipeline has no accumulated dust, the pressure in the heat medium conveying pipeline ranges from-100 Pa to 0Pa. The specific detection and judgment of the pressure condition in the pipeline is related to the position of the pressure measuring point, for example, when the pressure difference (pressure difference) detected by the first pressure sensor and the second pressure sensor is greater than 100Pa, the pressure abnormality in the heat medium conveying pipeline can be judged, namely, the ash deposition exists in the pipeline or the mixing flow cylinder, and a system ash cleaning program needs to be started to avoid further sedimentation.

The invention is provided with a first temperature sensor on the heat medium conveying pipeline. The first temperature sensor is located on the heat medium transport pipe upstream of the location of the branch bypass pipe. The first temperature sensor is used for detecting the temperature of the heat medium. And a second temperature sensor and a humidity sensor are arranged on the mixer. The second temperature sensor is used for detecting the temperature of the wet flue gas in the mixer, and the humidity sensor is used for detecting the humidity of the wet flue gas in the mixer. And a third temperature sensor is arranged on the mixed flow cylinder. The third temperature sensor is used for monitoring the temperature in the mixed flow cylinder in real time, on one hand, the time node of the wet flue gas entering the mixed flow cylinder in the mixing machine can be accurately judged through real-time monitoring, and on the other hand, the temperature of the mixed gas obtained after the wet flue gas is mixed with the heat medium can be ensured to reach the temperature above the dew point of the flue gas and then enter the dust remover for treatment. And a fourth temperature sensor is arranged on the dust removal pipeline. The fourth temperature sensor detects the temperature of the mixed flue gas on the dust removal pipeline on line, and further ensures that the temperature of the flue gas entering the dust remover is above the dew point temperature of the flue gas, so that the problem that the inner wall of the pipeline is easily condensed and blocked by the wet flue gas of the sintering primary mixer in the dust removal process in the prior art is thoroughly solved.

Preferably, the present invention is provided with a first regulating valve on the heat medium transporting pipe. The first regulating valve is located downstream of the location where the bypass conduit merges into the heat medium conveying conduit. The first regulating valve is used for regulating the amount of the heat medium entering the mixing barrel through the heat medium conveying pipeline. And a second regulating valve is arranged on the dust removing pipeline. The second regulating valve is used for regulating the air volume (or the flue gas volume) on the dust removal pipeline, so that the air volume of the dust removal point meets the requirement, namely, the dust removal point has no phenomenon of dust escape.

Preferably, the mixed flow system comprises n mixers. A mixing cylinder is correspondingly arranged above the exhaust end of each mixer. Each mixing machine is connected with the mixing cylinder through a pneumatic valve. And the downstream of the position where the bypass pipeline is merged to the heat medium conveying pipeline, the heat medium conveying pipeline is divided into n heat medium branch pipes which are respectively connected to the heat medium inlets of the n mixed flow cylinders. The flue gas outlet of each flow mixing cylinder is respectively connected to a dust remover through a respective dust removing pipeline. Wherein n is 1-10, preferably 2-6, for example n =3, n =4, or n =6.

When a plurality of mixers are included in the mixed flow system, correspondingly, a second temperature sensor and a humidity sensor are arranged on each mixer. And a third temperature sensor is arranged on each mixed flow cylinder. And a fourth temperature sensor and a second regulating valve are arranged on the dust removal pipeline respectively connected with each mixed flow cylinder. Each thermal medium branch pipe is provided with a first regulating valve. At this time, the first regulating valve on each thermal medium branch pipe is used for regulating the amount of the thermal medium entering the corresponding flow mixing cylinder. The second regulating valve is used for regulating the air volume (or the flue gas volume) on the dust removal pipeline connected with the corresponding mixed flow cylinder, and further balancing the resistance of each dust removal point, so that the air volume of each dust removal point meets the requirement, namely, each dust removal point has no phenomenon of dust escape. In the application, the dust concentration of each dust removing point (such as each mixer) can be monitored in real time by observing or arranging a corresponding dust concentration detector on site, so that the corresponding dust removing point is ensured to have no dust escape phenomenon. The second governing valve is used for balanced system resistance, generally can not do the adjustment after the aperture of second governing valve is set for to accomplish, only when the raise dust condition appear adjust as required can.

Preferably, the dust removal pipelines connected with each mixing flow cylinder are combined and then connected to the dust remover through the dust removal header pipe. In order to further ensure that the temperature of the mixed flue gas entering the dust remover is above the dew point temperature, the dust removal header pipe is provided with a fifth temperature sensor so as to ensure the stable operation of the system. Based on this, the application mixed flow system can handle the wet flue gas that contains of a plurality of machines of mixing simultaneously to ensure that the flue gas temperature that gets into the dust remover is above flue gas dew point temperature, can thoroughly solve the problem that contains wet flue gas dewfall and block up the dust removal pipeline promptly, ensure the long-term steady operation of system.

Further preferably, the flow mixing system further comprises a control device. The control device is connected with the pneumatic valve, the first switch valve, the second switch valve, the third switch valve, the fourth switch valve, the fifth switch valve, the first pressure sensor, the second pressure sensor, the first temperature sensor, the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor, the humidity sensor, the first regulating valve and the second regulating valve, and controls the operation of each valve and each sensor. The detection signals of all detection points are connected to the control device for analysis/feedback, and the running state of the saturated wet flue gas mixed flow system is displayed in the control device, so that the intelligent control of the mixed flow system is realized.

Based on the intelligent control anti-condensation type saturated wet flue gas flow mixing system, the invention also provides an intelligent control anti-condensation type saturated wet flue gas flow mixing method. The mixed flow method mainly comprises the steps of determining the dew point temperature of the wet flue gas in the mixer, judging the time node of the wet flue gas entering the mixed flow cylinder, judging the time node of the mixed flue gas of the wet flue gas and the heat medium entering the dust remover, performing dust removal treatment and the like. Firstly, establishing a flue gas dew point database through a large amount of engineering measured data, acquiring the humidity and the temperature of wet flue gas in a mixer, and analyzing and comparing to obtain the dew point temperature of the wet flue gas in the mixer. Then, a heat medium is introduced into the mixing cylinder through a heat medium conveying pipeline (or a heat medium branch pipe separated from the heat medium conveying pipeline), when the temperature in the mixing cylinder is higher than the dew point temperature of the wet flue gas in the corresponding mixing machine, the pneumatic valve is opened, and the wet flue gas in the mixing machine enters the mixing cylinder. The wet flue gas and the heat medium are mixed in the mixed flow cylinder to obtain mixed flue gas, and when the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the corresponding mixer, the mixed flue gas enters a dust remover through a dust removal pipeline for dust removal treatment. The amount of the heat medium to be introduced into the mixing flow cylinder can be calculated through heat balance. The temperature that this application can set for mixed flue gas in the system operation control mixed flow section of thick bamboo is higher than containing wet flue gas dew point temperature more than 10 ℃, guarantees that mixed flue gas does not condense the dewfall at the dust removal in-process. Simultaneously, this application still can be based on containing wet flue gas dew point temperature and control mixed flue gas temperature and above dew point temperature and calculate minimum heat medium volume, the heat that the heat medium provided only makes the temperature of mixed flue gas reach not condense the dewfall in dust removal process can, and do not need unnecessary heat to reduce the energy consumption.

In the actual application process, the control flow of the intelligent mixed flow control method is shown in fig. 4. Firstly, pressure detection is carried out on the heat medium conveying pipeline through the first pressure sensor and the second pressure sensor, and if the pressure detection is abnormal, a pipeline ash removal program is started. And opening the first switch valve and the second switch valve, introducing outdoor air into the gas conveying pipeline and the heat medium conveying pipeline and pressurizing the outdoor air through the booster fan, and enabling the air to sequentially pass through the heat medium conveying pipeline and the mixed flow cylinders until the pressure signal of the heat medium conveying pipeline is recovered to be normal, namely completely finishing the ash removal of the mixed flow cylinders. And then the hot blast stove (namely a preheater) is operated, the third switch valve and the fifth switch valve are opened, meanwhile, the first switch valve and the second switch valve are closed, and the system introduces hot air provided by the hot blast stove. The humidity and the temperature of the moisture-containing flue gas are measured by the humidity sensor and the temperature sensor which are arranged on each mixing machine, and the measured humidity and the measured temperature of the moisture-containing flue gas are transmitted into a flue gas dew point temperature database for analysis, so that the dew point temperature of the moisture-containing flue gas in the corresponding mixing machine is determined. When the third temperature sensor on each mixing cylinder detects that the temperature in the mixing cylinder reaches above the dew point temperature of the wet flue gas in the corresponding mixing machine, the pneumatic valve between the exhaust port of the mixing machine and the flue gas inlet of the mixing cylinder can be opened, and the wet flue gas in the mixing machine enters the mixing cylinder. The wet flue gas and the hot medium are mixed in the mixed flow cylinder to form mixed flue gas, and when the third temperature sensor on the mixed flow cylinder detects that the temperature of the mixed flue gas reaches above the dew point temperature of the wet flue gas, the mixed flue gas enters the dust remover through the dust removal pipeline to be treated. When the air volume of the respective dedusting pipeline connected with each mixing tube meets the requirement, the opening conditions of the first regulating valve and the second regulating valve are kept when no dust is raised on site. When the posts appear dust on site, the adjusting program is started, and the resistance of each point is balanced by adjusting the second adjusting valve on each dust removing pipeline, so that the air quantity entering each dust removing pipeline meets the requirement, namely, no dust escapes from the posts. It should be noted that, when the first adjusting valve is used for adjusting the air volume, the temperature of the mixed flue gas in the mixed flow cylinder or the dust removal pipeline may change, and the requirement that the temperature of the mixed flue gas is above the dew point temperature of the wet flue gas is no longer met, and at this time, the amount of the heat medium entering the heat medium conveying pipeline or the mixed flow cylinder is adjusted by adjusting the first adjusting valve on the heat medium conveying pipeline (or a heat medium branch pipe branched from the heat medium conveying pipeline), so that the temperature of the mixed flue gas is above the dew point temperature of the wet flue gas. And after the fourth temperature sensor circularly operates to the post position and does not generate dust and the temperature detected by the dust removing pipeline reaches the dew point temperature of the wet flue gas, the opening state of each valve in the system at the moment is recorded. When the process production state is stable and the device for producing the waste heat can provide effective waste heat for the system to use, the fourth switch valve is opened, the third switch valve is closed, the hot blast stove stops running, the system uses the process production waste heat at the moment, the energy gradient utilization is realized, and the starting program of the intelligent control system is finished.

Compared with the prior art, the invention has the following beneficial technical effects:

1. the invention introduces the mixed flow cylinder which is arranged above the exhaust end of the mixer and connected through the pneumatic valve, when the temperature in the mixed flow cylinder rises to be higher than the dew point temperature of the wet flue gas in the mixer, the wet flue gas in the mixer enters the mixed flow cylinder, thereby avoiding the problem that the wet flue gas still possibly forms dew to block a dust removal pipeline at the initial stage of hot air convergence in the prior art, and further ensuring that the temperature of the mixed flue gas entering the dust remover is all higher than the dew point temperature of the flue gas in the whole process.

2. The invention judges whether the heat medium conveying pipeline and the mixed flow cylinder are in the dust deposition state or not through pressure detection, and introduces outside air through the booster fan to carry out back flushing cleaning, thereby avoiding the dust deposition blockage of the pipeline and leading the system to stably run for a long time.

3. The invention adopts the preheater as a standby heat source, and when judging that the waste heat in the production process can be utilized, the waste heat generated in the production process of the process can be preferentially utilized, thereby realizing the gradient utilization of energy and saving energy. The booster fan arranged on the heat medium conveying pipeline can boost the external air in the ash removal procedure and can also be used as a standby power source, so that the phenomenon of pressure imbalance caused by too large resistance of the heat medium conveying pipeline is avoided, the introduction of a heat medium is more stable, and the subsequent stability of the temperature of the dedusting flue gas is facilitated.

4. The invention judges the dew point temperature of the flue gas through the detection data of humidity, temperature and the like, and is used for calculating the minimum amount of thermal medium required for controlling the temperature of the flue gas entering the dust remover to be above the dew point temperature, namely, the energy consumption can be reduced to the maximum degree on the premise of ensuring that the flue gas is not condensed and dewed in the dust removing process.

5. The mixed flow system can treat moisture-containing flue gas of a plurality of mixers at the same time, and ensure that the temperature of the flue gas entering the dust remover is above the dew point temperature of the flue gas, thus thoroughly solving the problem that the moisture-containing flue gas is condensed to block a dust removal pipeline and ensuring the long-term stable operation of the system. Moreover, the mixed flow system is provided with a plurality of measuring points, a plurality of sensors and a plurality of valves are arranged at a plurality of positions, the amount or the temperature of the smoke at each position can be regulated and controlled, the control is accurate and flexible, and the intelligent degree is high.

Drawings

FIG. 1 is a schematic structural diagram of an intelligently controlled anti-dewing saturated wet flue gas mixing system according to the invention;

FIG. 2 is a schematic view of a mixing system of the present invention having a plurality of mixers and mixing barrels;

FIG. 3 is a schematic view of a control device according to the present invention;

FIG. 4 is a control flow chart of the method for intelligently controlling the anti-dewing type saturated wet flue gas flow mixing according to the invention.

Reference numerals:

1: a mixer; 2: a mixing barrel; 3: a dust remover; 4: a booster fan; 5: a preheater; 6: a waste heat production device; 701: a first pressure sensor; 702: a second pressure sensor; 801: a first temperature sensor; 802: a second temperature sensor; 803: a third temperature sensor; 804: a fourth temperature sensor; 805: a fifth temperature sensor; 9: a humidity sensor; 10: a control device;

k: a pneumatic valve; s1: a first on-off valve; s2: a second on-off valve; s3: a third on/off valve; s4: a fourth switching valve; s5: a fifth on-off valve; z1: a first regulating valve; z2: a second regulating valve;

l1: a thermal medium delivery conduit; l2: a dust removal pipeline; l3: a gas delivery conduit; l4: a first heat supply pipeline; l5: a second heat supply pipeline; l6: a bypass conduit; l7: a thermal medium branch pipe; l8: a dust removal header pipe.

Detailed Description

The technical solutions of the present invention are illustrated below, and the claimed scope of the present invention includes, but is not limited to, the following examples.

According to the first embodiment of the invention, an intelligent control anti-condensation type saturated wet flue gas flow mixing system is provided.

The utility model provides an intelligent control anti-condensation type saturated wet flue gas mixed flow system, this system includes mixes quick-witted 1, mixed flow section of thick bamboo 2, dust remover 3. The mixed flow cylinder 2 is arranged above the exhaust end of the mixer 1, and the exhaust port of the mixer 1 is connected with the flue gas inlet of the mixed flow cylinder 2 through a pneumatic valve K. The heat medium delivery pipe L1 is connected to the heat medium inlet of the mixing cylinder 2. The flue gas outlet of the mixing flow cylinder 2 is connected to a dust remover 3 via a dust removing pipeline L2.

In the present invention, the system further comprises a gas delivery line L3. The gas delivery pipe L3 is connected to the input end of the heat medium delivery pipe L1.

Preferably, the heat medium transport pipe L1 is provided with a first switching valve S1 and a booster fan 4. Preferably, the gas transmission pipeline L3 is provided with a second on-off valve S2.

In the present invention, the system further comprises a preheater 5. The preheater 5 is connected to the input of the heat medium supply line L1 via a first heat supply line L4. Preferably, the third on/off valve S3 is disposed on the first heat supply pipeline L4. Preferably, the preheater 5 is a hot blast stove.

In the present invention, the system further comprises a waste heat production device 6. The production waste heat device 6 is connected to the input end of the heat medium conveying pipeline L1 through a second heat supply pipeline L5. Preferably, the second heat supply pipeline L5 is provided with a fourth switching valve S4.

In the present invention, the bypass line L6 is branched from the heat medium transport line L1, and the bypass line L6 bypasses the first switching valve S1 and the booster fan 4 and is then merged into the heat medium transport line L1. Preferably, a fifth switching valve S5 is provided on the bypass line L6.

Preferably, the heat medium transport pipe L1 is provided with a first pressure sensor 701 and a second pressure sensor 702. Wherein the first pressure sensor 701 is located upstream of the position of the heat medium transport pipe L1 from which the bypass pipe L6 branches off. The second pressure sensor 702 is located downstream of the location where the bypass line L6 merges into the heat medium delivery line L1.

In the present invention, the heat medium transport pipe L1 is provided with a first temperature sensor 801. The first temperature sensor 801 is located upstream of the position on the heat medium conveying pipe L1 from which the bypass pipe L6 branches out. The mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. The mixed flow cylinder 2 is provided with a third temperature sensor 803. And a fourth temperature sensor 804 is arranged on the dust removal pipeline L2.

Preferably, the heat medium transport pipe L1 is provided with a first regulating valve Z1. The first regulating valve Z1 is located downstream of the point at which the bypass line L6 merges into the heat medium feed line L1. And a second regulating valve Z2 is arranged on the dust removal pipeline L2.

Preferably, the system comprises n mixers 1. A mixing cylinder 2 is correspondingly arranged above the exhaust end of each mixer 1. Each mixer 1 is connected with the mixing cylinder 2 through a pneumatic valve K. Downstream of the position where the bypass pipeline L6 merges into the heat medium delivery pipeline L1, the heat medium delivery pipeline L1 branches n heat medium branch pipes L7 and is connected to the heat medium inlets of the n mixing barrels 2, respectively. The flue gas outlet of each mixed flow cylinder 2 is respectively connected to a dust remover 3 through a respective dust removing pipeline L2. Preferably, n is from 1 to 10, preferably from 2 to 6.

Preferably, each mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. Each mixer cylinder 2 is provided with a third temperature sensor 803. And a fourth temperature sensor 804 and a second regulating valve Z2 are arranged on the dust removal pipeline L2 connected with each mixing tube 2. Each thermal medium branch pipe L7 is provided with a first regulating valve Z1.

Preferably, the dust removal pipe L2 connected to each of the mixing flow cylinders 2 is connected to the dust remover 3 via the dust removal header pipe L8 after being combined. Preferably, a fifth temperature sensor 805 is disposed on the dust collection manifold L8.

In the present invention, the system further comprises a control device 10. The control device 10 is connected to the air-operated valve K, the first switching valve S1, the second switching valve S2, the third switching valve S3, the fourth switching valve S4, the fifth switching valve S5, the first pressure sensor 701, the second pressure sensor 702, the first temperature sensor 801, the second temperature sensor 802, the third temperature sensor 803, the fourth temperature sensor 804, the fifth temperature sensor 805, the humidity sensor 9, the first adjustment valve Z1, and the second adjustment valve Z2, and controls operations of the respective valves and the respective sensors.

Example 1

As shown in figure 1, the intelligent control anti-condensation type saturated wet flue gas mixing system comprises a mixer 1, a mixing cylinder 2 and a dust remover 3. The mixed flow cylinder 2 is arranged above the exhaust end of the mixer 1, and the exhaust port of the mixer 1 is connected with the flue gas inlet of the mixed flow cylinder 2 through a pneumatic valve K. The heat medium delivery pipe L1 is connected to the heat medium inlet of the mixing cylinder 2. The flue gas outlet of the flow mixing cylinder 2 is connected to a dust remover 3 via a dust removing pipeline L2.

Example 2

Example 1 is repeated except that the system further comprises a gas delivery line L3. The gas delivery pipe L3 is connected to the input end of the heat medium delivery pipe L1.

Example 3

Example 2 was repeated except that the heat medium conveying pipe L1 was provided with the first switching valve S1 and the booster fan 4.

Example 4

Example 3 was repeated except that the gas delivery pipe L3 was provided with the second switching valve S2.

Example 5

Example 4 is repeated except that the system further comprises a preheater 5. The preheater 5 is connected to the input of the heat medium conveying line L1 via a first heat supply line L4. The preheater 5 is a hot blast stove.

Example 6

Embodiment 5 is repeated except that the third switching valve S3 is provided on the first heat supply pipeline L4.

Example 7

Example 6 is repeated except that the system further comprises a waste heat production device 6. The production waste heat device 6 is connected to the input end of the heat medium conveying pipeline L1 through a second heat supply pipeline L5.

Example 8

Example 7 is repeated except that the fourth switching valve S4 is provided on the second heat supply line L5.

Example 9

Example 8 was repeated except that the bypass line L6 was branched from the heat medium transport line L1, and the bypass line L6 was merged into the heat medium transport line L1 after bypassing the first switching valve S1 and the booster fan 4.

Example 10

Example 9 was repeated except that the bypass line L6 was provided with the fifth switching valve S5.

Example 11

Embodiment 10 is repeated except that the heat medium transport pipe L1 is provided with the first pressure sensor 701 and the second pressure sensor 702. Wherein the first pressure sensor 701 is located upstream of the position of the heat medium transport pipe L1 from which the bypass pipe L6 branches off. The second pressure sensor 702 is located downstream of the location where the bypass line L6 merges into the heat medium delivery line L1.

Example 12

Example 11 was repeated except that the heat medium transport pipe L1 was provided with the first temperature sensor 801. The first temperature sensor 801 is located upstream of the position on the heat medium conveying pipe L1 from which the bypass pipe L6 branches out. The mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. The mixed flow cylinder 2 is provided with a third temperature sensor 803. And a fourth temperature sensor 804 is arranged on the dust removal pipeline L2.

Example 13

Example 12 was repeated except that the heat medium transporting pipe L1 was provided with the first regulating valve Z1. The first regulating valve Z1 is located downstream of the position where the bypass line L6 merges into the heat medium delivery line L1. And a second regulating valve Z2 is arranged on the dust removal pipeline L2.

Example 14

As shown in fig. 2, example 13 is repeated, except that the system comprises 3 mixers 1. A mixing cylinder 2 is correspondingly arranged above the exhaust end of each mixer 1. Each mixer 1 is connected with the mixing cylinder 2 through a pneumatic valve K. Downstream of the position where the bypass line L6 merges into the heat medium delivery line L1, the heat medium delivery line L1 branches off 3 heat medium branch lines L7 and is connected to the heat medium inlets of the 3 mixing cylinders 2, respectively. The flue gas outlet of each mixed flow cylinder 2 is respectively connected to a dust remover 3 through a respective dust removing pipeline L2.

Example 15

Example 14 was repeated except that each mixer 1 was provided with the second temperature sensor 802 and the humidity sensor 9. Each mixing cylinder 2 is provided with a third temperature sensor 803. A fourth temperature sensor 804 and a second regulating valve Z2 are arranged on the dust removal pipeline L2 connected with each flow mixing cylinder 2. Each thermal medium branch pipe L7 is provided with a first regulating valve Z1.

Example 16

The embodiment 15 is repeated except that the dust removal pipes L2 respectively connected with each flow mixing cylinder 2 are connected to the dust remover 3 through the dust removal header pipe L8 after being combined. A fifth temperature sensor 805 is disposed on the dust collection header L8.

Example 17

As shown in fig. 3, the embodiment 16 is repeated except that the system further comprises a control device 10. The control device 10 is connected to the air-operated valve K, the first switching valve S1, the second switching valve S2, the third switching valve S3, the fourth switching valve S4, the fifth switching valve S5, the first pressure sensor 701, the second pressure sensor 702, the first temperature sensor 801, the second temperature sensor 802, the third temperature sensor 803, the fourth temperature sensor 804, the fifth temperature sensor 805, the humidity sensor 9, the first regulating valve Z1, and the second regulating valve Z2, and controls operations of the valves and the sensors.

Example 18

An intelligent control anti-condensation type saturated wet flue gas flow mixing method uses the system in embodiment 13, and comprises the following steps:

1) The dew point temperature of the moist flue gas contained in the mixer 1 is determined.

2) And (3) introducing a heat medium into the mixed flow cylinder 2 through a heat medium conveying pipeline L1, and when the temperature in the mixed flow cylinder 2 is higher than the dew point temperature of the wet flue gas in the step 1), opening a pneumatic valve K, so that the wet flue gas in the mixer 1 enters the mixed flow cylinder 2.

3) The wet flue gas and the heat medium are mixed in the mixed flow cylinder 2 to obtain mixed flue gas, and when the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the step 1), the mixed flue gas enters a dust remover 3 through a dust removal pipeline L2 for dust removal treatment.

Example 19

As shown in fig. 4, an intelligent control anti-dewing type saturated wet flue gas mixing method using the system described in embodiment 17 includes the following steps:

1) The dew point temperature of the moist flue gas in the 3 mixers 1 was determined.

2) The hot medium branch pipes L7 divided from the hot medium conveying pipeline L1 respectively introduce the hot medium into the mixed flow cylinders 2, when the temperature in each mixed flow cylinder 2 is higher than the dew point temperature of the wet flue gas in the corresponding mixer 1, the pneumatic valve K is opened at the moment, and the wet flue gas in each mixer 1 enters the corresponding mixed flow cylinder 2.

3) The wet flue gas and the heat medium are mixed in each mixed flow cylinder 2 to obtain mixed flue gas, and when the temperature of the mixed flue gas in each mixed flow cylinder 2 is higher than the dew point temperature of the wet flue gas in the corresponding mixer 1, the mixed flue gas in each mixed flow cylinder 2 is merged to a dust removal header pipe L8 through a dust removal pipeline L2, and then enters a dust remover 3 for dust removal treatment.

Example 20

Example 19 is repeated, except that step 2) further includes a step of detecting ash removal, specifically: before the heat medium is introduced into the mixing cylinder 2, the pressure on the heat medium conveying pipe L1 is detected by using the first pressure sensor 701 and the second pressure sensor 702. If the pressure detection is abnormal, a system ash cleaning program is started, at the moment, outside air is introduced into the gas conveying pipeline L3 and the heat medium conveying pipeline L1 through the booster fan 4, and the outside air performs back flushing cleaning on the heat medium conveying pipeline L1 and the mixed flow cylinder 2. And ending the ash removal program of the system until the pressures detected by the first pressure sensor 701 and the second pressure sensor 702 return to normal.

Example 21

The embodiment 20 is repeated, except that the heat medium is introduced into the mixed flow cylinder 2 in the step 2), specifically: at the beginning of the system operation, the heat medium is supplied to the heat medium transport line L1 through the preheater 5. When the process production state is stable, the production waste heat device 6 can provide effective waste heat, and at the moment, the production waste heat device 6 provides heat medium for the heat medium conveying pipeline L1.

Example 22

Example 21 is repeated, except that the determination of the dew point temperature of the humid flue gas contained in the mixer 1 as described in step 1) specifically comprises the following substeps:

(1) collecting humidity and temperature data of a large amount of moisture-containing flue gas in engineering, obtaining the dew point temperature of the flue gas under corresponding working conditions through an enthalpy-humidity diagram, and establishing a flue gas dew point temperature database.

(2) The humidity sensor 9 and the second temperature sensor 802 are adopted to respectively measure the humidity and the temperature of the wet flue gas in the mixer 1, and the dew point temperature of the wet flue gas in the corresponding mixer 1 is obtained from the flue gas dew point temperature database.

Example 23

The embodiment 22 is repeated, except that the amount of the heat medium which needs to be introduced into the mixer barrel 2 in the step 2) is calculated, and the method specifically comprises the following substeps:

a) Calculating the heat required for preheating the wet flue gas in the mixer 1:

the amount of the wet flue gas contained in the mixer 1 is V _{Cigarette with heating means} ，m ³ H is the ratio of the total weight of the catalyst to the total weight of the catalyst. Detecting the temperature of the wet flue gas as T _{Cigarette with heating means} DEG C. The dew point temperature of the flue gas is T ₀ DEG C. Setting the temperature of mixed flue gas obtained after mixing wet flue gas and heat medium to be T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ +10 ℃. Thereby, the heat Q to be absorbed for preheating the moisture-containing flue gas in the mixer 1 _{Cigarette with heating means} Comprises the following steps:

In the formula: c _{Cigarette with heating means} Is the specific heat capacity of wet flue gas, kJ/(kg. DEG C). Rho _{Cigarette with heating means} Is the density of wet smoke, kg/m ³ 。

b) Calculating the heat released by the heat medium entering the mixing flow cylinder 2:

the quantity of the heat medium entering the mixed flow cylinder 2 is set as V _{Heat generation} ，m ³ H is the ratio of the total weight of the catalyst to the total weight of the catalyst. Detecting the temperature T of the heat medium _{Heat generation} DEG C. Thereby, the heat Q released by the heat medium entering the mixing tube 2 _{Heat generation} Comprises the following steps:

c) The heat Q to be absorbed by preheating the moist flue gas _{Cigarette with heating means} With the heat medium entering the mixing tubeHeat of release Q _{Heat generation} Equality, we can get:

Obtaining the following components:

Adjusting the opening degree of a first adjusting valve Z1 on a heat medium branch pipe L7 divided from the heat medium conveying pipeline L1 to ensure that the amount of the heat medium introduced into the mixed flow cylinder 2 in the step 2) is V _{Heat generation} 。

Example 24

Example 23 is repeated except that in step 3), the opening degree of the second adjusting valve Z2 on the dust removal pipeline L2 is adjusted so that the air volume of each dust removal point meets the requirement, and each dust removal point has no phenomenon of dust escape. Meanwhile, the fourth temperature sensor 804 detects the temperature T of the mixed flue gas on the dedusting pipeline L2 on line, and adjusts the opening degree of the first adjusting valve Z1 on the heat medium branch pipe L7, so that T is equal to T _{Is provided with} 。

Application example 1

An intelligent control anti-condensation type saturated wet flue gas flow mixing method comprises the following steps:

1) The method for determining the dew point temperature of the wet flue gas in the mixer 1 specifically comprises the following substeps:

(1) collecting actually measured humidity and temperature data of a large amount of moisture-containing flue gas in engineering, obtaining the dew point temperature of the flue gas under corresponding working conditions through an enthalpy-humidity diagram, and establishing a flue gas dew point temperature database.

(2) The humidity sensor 9 is adopted to measure the relative humidity d =85% of the wet flue gas in the mixer 1, and the second temperature sensor 802 is adopted to measure the temperature T of the wet flue gas in the mixer 1 _{Cigarette with heating means} =49 ℃, and the dew point temperature T of the wet flue gas in the corresponding mixer 1 is obtained from the flue gas dew point temperature database ₀ ＝45℃。

2) The pressure on the heat medium delivery pipe L1 is detected using the first pressure sensor 701 and the second pressure sensor 702. The first pressure sensor 701 displays the pipeline pressure P1= -60Pa at the corresponding position, the second pressure sensor 702 displays the pipeline pressure P2= -500Pa at the corresponding position, that is, the pressure difference detected by the two is greater than 200Pa, so that it is determined that the pressure in the heat medium conveying pipeline L1 is abnormal, and the system ash removal program is started. At this time, the external air is introduced into the gas conveying pipeline L3 and the heat medium conveying pipeline L1 through the booster fan 4, and the heat medium conveying pipeline L1 and the mixed flow cylinder 2 are cleaned by the external air in a back flushing manner. And ending the ash removal program of the system until the pressures detected by the first pressure sensor 701 and the second pressure sensor 702 return to normal.

At the beginning of the operation of the system, the heat medium is supplied to the heat medium delivery pipe L1 through the preheater 5. The heat medium conveying pipeline L1 introduces heat medium into the mixing cylinder 2, when the temperature in the mixing cylinder 2 is higher than the dew point temperature of the wet flue gas in the corresponding mixing machine 1, the pneumatic valve K is opened, and the wet flue gas in the mixing machine 1 enters the corresponding mixing cylinder 2.

Calculating the quantity of the heat medium required to be introduced into the mixer barrel 2, and specifically comprising the following substeps:

a) The heat required to preheat the humid flue gas in the mixer 1 is calculated:

the amount of the wet flue gas contained in the mixer 1 is V _{Cigarette with heating means} ＝20000m ³ H is used as the reference value. The second temperature sensor 802 detects the temperature of the moisture-containing flue gas as T _{Cigarette with heating means} =49 ℃. The dew point temperature of the flue gas is T ₀ =45 ℃. Setting the temperature of mixed flue gas obtained after mixing wet flue gas and heat medium to be T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ +15 ℃ and =60 ℃. The heat Q to be absorbed thereby to preheat the moist flue gas in the mixer 1 _{Cigarette with heating means} Comprises the following steps:

Q _{cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρΔT _{Cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )＝240999kJ/h。

In the formula: c _{Cigarette with heating means} Specific heat capacity of moist flue gas, C _{Cigarette with heating means} ＝1.005kJ/(kg·℃)。ρ _{Cigarette with heating means} Density of the wet flue gas, p _{Cigarette with heating means} ＝1.09kg/m ³ 。

b) Calculating the heat quantity released by the heat medium entering the mixing flow cylinder 2:

let the quantity of the heat medium entering the mixing tube 2 be V _{Heat generation} ，m ³ H is used as the reference value. The first temperature sensor 801 detects the temperature T of the heat medium _{Heat generation} =150 ℃. Thereby, the heat Q released by the heat medium entering the mixing tube 2 _{Heat generation} Comprises the following steps:

In the formula: c _{Heat generation} Is the specific heat capacity of the heat medium, C _{Heat generation} ＝1.005kJ/(kg·℃)。ρ _{Heat generation} Is the density of the thermal medium, p _{Heat generation} ＝0.78kg/m ³ 。

c) The heat Q to be absorbed by preheating the moist flue gas _{Cigarette with heating means} With the heat Q released by the heat medium entering the flow mixing cylinder _{Heat generation} Equality, we can get:

Obtaining the following components:

V _{heat generation} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )/[C _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )]＝3416m ³ /h。

Adjusting the opening degree of a first adjusting valve Z1 on the heat medium conveying pipeline L1 to ensure that the quantity of the heat medium introduced into the mixed flow cylinder 2 in the step 2) is V _{Heat generation} 。

3) The wet flue gas and the hot medium are mixed in the mixed flow cylinder 2 to obtain mixed flue gas, and when the temperature of the mixed flue gas in the mixed flow cylinder 2 is higher than the dew point temperature of the wet flue gas in the corresponding mixer 1, the mixed flue gas in the mixed flow cylinder 2 enters the dust remover 3 through the dust removal pipeline L2 for dust removal treatment.

In the step 3), the opening degree of a second adjusting valve Z2 on the dust removal pipeline L2 is adjusted, so that the air volume of each dust removal point meets the requirement, and each dust removal point has no phenomenon of dust escape. At the same time, the firstThe four temperature sensors 804 detect the temperature T of the mixed flue gas on the dedusting pipeline L2 on line, and adjust the opening degree of the first adjusting valve Z1 on the heat medium conveying pipeline L1, so that T is equal to T _{Is provided with} . And recording the opening state of each valve in the system at the moment.

When the process production state is stable, the production waste heat device 6 can provide effective waste heat, and at the moment, the production waste heat device 6 provides heat medium for the heat medium conveying pipeline L1.

Claims

1. An intelligent control anti-condensation saturated wet flue gas mixed flow system comprises a mixer (1), a mixed flow cylinder (2) and a dust remover (3); the mixed flow cylinder (2) is arranged above the exhaust end of the mixer (1), and an exhaust port of the mixer (1) is connected with a flue gas inlet of the mixed flow cylinder (2) through a pneumatic valve (K); the heat medium conveying pipeline (L1) is connected to a heat medium inlet of the mixed flow cylinder (2); the flue gas outlet of the mixed flow cylinder (2) is connected to the dust remover (3) through a dust removal pipeline (L2).

2. The system of claim 1, wherein: the system further comprises a gas delivery duct (L3); the gas conveying pipeline (L3) is connected to the input end of the heat medium conveying pipeline (L1);

preferably, a first switch valve (S1) and a booster fan (4) are arranged on the heat medium conveying pipeline (L1); preferably, a second switch valve (S2) is arranged on the gas conveying pipeline (L3).

3. The system according to claim 1 or 2, characterized in that: the system further comprises a preheater (5); the preheater (5) is connected to the input end of the heat medium conveying pipeline (L1) via a first heat supply pipeline (L4); preferably, a third switch valve (S3) is arranged on the first heat supply pipeline (L4); preferably, the preheater (5) is a hot blast stove; and/or

The system also comprises a device (6) for producing waste heat; the waste heat production device (6) is connected to the input end of the heat medium conveying pipeline (L1) through a second heat supply pipeline (L5); preferably, a fourth switch valve (S4) is arranged on the second heat supply pipeline (L5).

4. A system according to claim 2 or 3, characterized in that: a bypass pipeline (L6) is branched from the heat medium conveying pipeline (L1), and the bypass pipeline (L6) bypasses the first switch valve (S1) and the booster fan (4) and then is combined to the heat medium conveying pipeline (L1); preferably, a fifth switch valve (S5) is arranged on the bypass pipeline (L6);

preferably, a first pressure sensor (701) and a second pressure sensor (702) are arranged on the heat medium conveying pipeline (L1); wherein the first pressure sensor (701) is located upstream of the location of the branching off bypass line (L6) on the heat medium conveying line (L1); the second pressure sensor (702) is located downstream of the point at which the bypass line (L6) merges into the heat medium supply line (L1).

5. The system of claim 4, wherein: a first temperature sensor (801) is arranged on the heat medium conveying pipeline (L1); the first temperature sensor (801) is positioned on the heat medium conveying pipeline (L1) and is upstream of the position of the branch bypass pipeline (L6); a second temperature sensor (802) and a humidity sensor (9) are arranged on the mixer (1); a third temperature sensor (803) is arranged on the mixed flow cylinder (2); a fourth temperature sensor (804) is arranged on the dust removal pipeline (L2);

preferably, a first regulating valve (Z1) is arranged on the heat medium conveying pipeline (L1); the first regulating valve (Z1) is positioned downstream of the position where the bypass pipeline (L6) merges into the heat medium conveying pipeline (L1); and a second regulating valve (Z2) is arranged on the dust removing pipeline (L2).

6. The system of claim 5, wherein: the system comprises n mixers (1); a mixing cylinder (2) is correspondingly arranged above the exhaust end of each mixer (1); each mixer (1) is connected with the mixing cylinder (2) through a pneumatic valve (K); downstream of the position where the bypass pipeline (L6) is merged to the heat medium conveying pipeline (L1), n heat medium branch pipes (L7) are branched from the heat medium conveying pipeline (L1) and are respectively connected to heat medium inlets of the n mixed flow barrels (2); the flue gas outlet of each mixed flow cylinder (2) is connected to a dust remover (3) through a dust removing pipeline (L2) respectively; preferably, n has a value of 1 to 10, preferably 2 to 6.

7. The system of claim 6, wherein: each mixer (1) is provided with a second temperature sensor (802) and a humidity sensor (9); each mixed flow cylinder (2) is provided with a third temperature sensor (803); a fourth temperature sensor (804) and a second regulating valve (Z2) are arranged on the dust removal pipeline (L2) which is respectively connected with each mixed flow cylinder (2); each heat medium branch pipe (L7) is provided with a first regulating valve (Z1);

preferably, the dust removal pipeline (L2) connected with each mixed flow cylinder (2) is connected to the dust remover (3) through a dust removal header pipe (L8) after being combined; preferably, a fifth temperature sensor (805) is arranged on the dust removing header pipe (L8).

8. The system according to any one of claims 1-7, wherein: the system further comprises a control device (10); the control device (10) is connected with the pneumatic valve (K), the first switch valve (S1), the second switch valve (S2), the third switch valve (S3), the fourth switch valve (S4), the fifth switch valve (S5), the first pressure sensor (701), the second pressure sensor (702), the first temperature sensor (801), the second temperature sensor (802), the third temperature sensor (803), the fourth temperature sensor (804), the fifth temperature sensor (805), the humidity sensor (9), the first regulating valve (Z1) and the second regulating valve (Z2), and controls the operation of each valve and each sensor.

9. An intelligent control anti-condensation type saturated wet flue gas flow mixing method or a flow mixing method using the system of any one of claims 1 to 8, wherein the method comprises the following steps:

1) Determining the dew point temperature of wet flue gas contained in the mixer (1);

2) Introducing a heat medium into the mixed flow cylinder (2) through a heat medium conveying pipeline (L1), and opening a pneumatic valve (K) when the temperature in the mixed flow cylinder (2) is higher than the dew point temperature of the wet flue gas in the step 1), so that the wet flue gas in the mixer (1) enters the mixed flow cylinder (2);

3) Mixing the wet flue gas and a heat medium in a mixed flow cylinder (2) to obtain mixed flue gas, wherein the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the step 1), and then the mixed flue gas enters a dust remover (3) through a dust removal pipeline (L2) for dust removal treatment.

10. An intelligent control anti-condensation type saturated wet flue gas flow mixing method or a flow mixing method using the system of any one of claims 1 to 8, wherein the method comprises the following steps:

1) Determining the dew point temperature of wet flue gas in the n mixers (1);

2) Respectively introducing a heat medium into each mixed flow cylinder (2) through a heat medium branch pipe (L7) separated from the heat medium conveying pipeline (L1), and opening a pneumatic valve (K) when the temperature in each mixed flow cylinder (2) is higher than the dew point temperature of wet flue gas contained in the corresponding mixer (1), so that the wet flue gas contained in each mixer (1) enters the corresponding mixed flow cylinder (2);

3) The wet flue gas and the heat medium are mixed in each mixed flow cylinder (2) to obtain mixed flue gas, and when the temperature of the mixed flue gas in each mixed flow cylinder (2) is higher than the dew point temperature of the wet flue gas in the corresponding mixer (1), the mixed flue gas in each mixed flow cylinder (2) is merged to a dust removal header pipe (L8) through a dust removal pipeline (L2) and then enters a dust remover (3) for dust removal treatment.

11. The method according to claim 9 or 10, characterized in that: the step 2) also comprises a step of detecting and cleaning ash, which specifically comprises the following steps: before introducing a heat medium into the mixing flow cylinder (2), a first pressure sensor (701) and a second pressure sensor (702) are adopted to detect the pressure on a heat medium conveying pipeline (L1); if the pressure is detected to be abnormal, starting a system ash removal program, introducing external air into the gas conveying pipeline (L3) and the heat medium conveying pipeline (L1) through the booster fan (4), and performing back flushing cleaning on the heat medium conveying pipeline (L1) and the mixed flow cylinder (2) by the external air; until the pressures detected by the first pressure sensor (701) and the second pressure sensor (702) are recovered to normal, ending the ash removal program of the system; and/or

In the step 2), introducing a heat medium into the mixed flow cylinder (2) specifically comprises the following steps: at the beginning of the system operation, a heat medium is provided for the heat medium conveying pipeline (L1) through a preheater (5); when the process production state is stable, the production waste heat device (6) can provide effective waste heat, and at the moment, the production waste heat device (6) provides heat medium for the heat medium conveying pipeline (L1).

12. The method according to any one of claims 9-11, wherein: the step 1) of determining the dew point temperature of the wet flue gas in the mixer (1) specifically comprises the following substeps:

(1) collecting humidity and temperature data of a large amount of moisture-containing flue gas in engineering, obtaining the dew point temperature of the flue gas under corresponding working conditions through an enthalpy-humidity diagram, and establishing a flue gas dew point temperature database;

(2) and a humidity sensor (9) and a second temperature sensor (802) are adopted to respectively measure the humidity and the temperature of the wet flue gas in the mixer (1), and the dew point temperature of the wet flue gas in the corresponding mixer (1) is obtained from a flue gas dew point temperature database.

13. The method according to any one of claims 9-12, wherein: calculating the amount of the heat medium required to be introduced into the flow mixing cylinder (2) in the step 2), and specifically comprising the following substeps:

a) Calculating the heat required for preheating the wet flue gas in the mixer (1):

the amount of the wet flue gas contained in the mixer (1) is V _{Cigarette with heating means} ，m ³ H; detecting the temperature of the wet flue gas as T _{Cigarette with heating means} DEG C; the dew point temperature of the flue gas is T ₀ DEG C; setting the temperature of mixed flue gas obtained after mixing wet flue gas and heat medium to be T _{Is provided with} ，℃；T _{Is provided with} ＝T ₀ + (5-30) DEG C; thereby, the heat Q absorbed by the wet flue gas in the preheating mixer (1) _{Cigarette with heating means} Comprises the following steps:

Q _{cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρΔT _{Cigarette with heating means} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )；

In the formula: c _{Cigarette with heating means} The specific heat capacity of the wet flue gas is kJ/(kg DEG C); ρ is a unit of a gradient _{Cigarette with heating means} Is the density of wet smoke, kg/m ³ ；

b) Calculating the heat quantity released by the heat medium entering the mixing flow cylinder (2):

the quantity of the heat medium entering the mixed flow cylinder (2) is set as V _{Heat generation} ，m ³ H; detecting the temperature T of the heat medium _{Heat generation} DEG C; thereby, the heat Q released by the heat medium entering the mixed flow cylinder (2) _{Heat generation} Comprises the following steps:

Q _{heat generation} ＝C _{Heat generation} V _{Heat generation} ρΔT _{Heat generation} ＝C _{Heat generation} V _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )；

In the formula: c _{Heat generation} kJ/(kg. DEG C), which is the specific heat capacity of the heat medium; rho _{Heat generation} Density of the heat medium, kg/m ³ ；

c) The heat Q absorbed by the preheated wet flue gas _{Cigarette with heating means} With the heat Q released by the heat medium entering the mixing tube _{Heat generation} Equality, we can get:

C _{cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )＝C _{Heat generation} V _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )；

Obtaining the following components:

V _{heat generation} ＝C _{Cigarette with heating means} V _{Cigarette with heating means} ρ _{Cigarette with heating means} (T _{Is provided with} -T _{Cigarette with heating means} )/[C _{Heat generation} ρ _{Heat generation} (T _{Heat generation} -T _{Is provided with} )]；

Adjusting the opening degree of a first adjusting valve (Z1) on a heat medium conveying pipeline (L1) or a heat medium branch pipe (L7) separated from the heat medium conveying pipeline (L1) to ensure that the amount of the heat medium introduced into the mixed flow cylinder (2) in the step 2) is V _{Heat generation} 。

14. The method of claim 13, wherein: in the step 3), the opening degree of a second regulating valve (Z2) on the dust removing pipeline (L2) is regulated, so that the air volume of each dust removing point meets the requirement, and each dust removing point has no phenomenon of dust escape; meanwhile, a fourth temperature sensor (804) detects the temperature T of the mixed flue gas on the dust removal pipeline (L2) on line, and adjusts the opening degree of a first adjusting valve (Z1) on the heat medium conveying pipeline (L1) or the heat medium branch pipe (L7) to enable T to be equal to T _{Is provided with} 。