CN115430213B

CN115430213B - Intelligent control anti-condensation saturated wet flue gas mixed flow system and method

Info

Publication number: CN115430213B
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: 2023-06-23
Anticipated expiration: 2042-09-05
Also published as: CN115430213A

Abstract

An intelligent control condensation-proof saturated wet flue gas mixed flow system comprises a mixer (1), a mixed flow cylinder (2) and a dust remover (3); the mixing drum (2) is arranged above the exhaust end of the mixer (1), and the exhaust port of the mixer (1) is connected with the smoke inlet of the mixing drum (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 removing pipeline (L2). The mixed flow system 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 inflow in the prior art, namely thoroughly solve the problem that the inner wall of a pipeline is blocked by dew condensation of wet flue gas, and ensure long-term stable operation of the system.

Description

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

Technical Field

The invention relates to a moisture-containing flue gas anti-condensation dust removal system and a process, in particular to an intelligent control moisture-condensation-resistant saturated flue gas mixed flow system and method, and belongs to the technical field of flue gas dust removal.

Background

The quicklime slaking process in the primary mixer is a process of carrying out a severe exothermic reaction with water after adding water, and the reaction equation is as follows:

CaO+H ₂ O＝Ca(OH) ₂ +6489.15J

Slaked lime Ca (OH) produced after slaking quicklime ₂ Particles, further absorbing water and then mixing with CO in the air ₂ Reacting to generate CaCO ₃ Precipitation, large amount of CaCO ₃ The precipitate is easy to form hard scale and harden. Therefore, the flue gas of the primary sintering mixer has the following characteristics: (1) the moisture content in the flue gas is higher; (2) The dust in the flue gas has strong adhesiveness and is easy to adhere to the inner wall of the exhaust funnel, the pipeline, the equipment and the like; (3) The content of quicklime in the flue gas is higher (more than 30 percent of the weight of dust); (4) The flue gas temperature is higher than the ambient temperature, so that dew condensation is easy, especially in winter; (5) The dust concentration in the flue gas exceeds the standard and the fluctuation range is large, and even the lower level is far beyond the national standard required 10mg/Nm ³ A limit value.

The saturated wet flue gas temperature generated after the quicklime is digested is higher than the ambient temperature, the dew point temperature is high, dew condensation is easily caused in the process of conveying in a pipeline if the temperature is reduced too quickly, the moisture precipitated by condensing the flue gas and unreacted quicklime react with chemical exothermicity, and CaCO is generated ₃ After the substances are deposited on the inner wall of the pipeline, the scaling and blocking on the inner wall of the pipeline are caused, and the dust removal effect is affected.

The existing mode for controlling the dew point of the flue gas has the following defects:

(1) The mixed hot air is used to prevent pipeline scaling. According to the mode, a branch pipe is arranged to introduce a hot air stream into the dust removal pipeline, the theoretically calculated mixed temperature can ensure the control of the dew point temperature, and the hot air directly heats saturated wet flue gas, so that the heating effect is good, but the temperature of a heat source cannot be ensured in the actual application process, and the flue gas is still possibly below the dew point temperature in the initial stage of the hot air injection, and the problem of blockage of the inner wall of the pipeline cannot be thoroughly solved over time.

(2) The wet flue gas is heated by adopting an electric tracing mode. An electric tracing band is arranged on the outer side of the pipeline, the outer wall of the dust removing pipeline is heated by electric energy, and heat is conducted to the inner wall of the dust removing pipeline to heat wet flue gas through the effect of metal heat conduction. The mode is high in energy consumption, certain heat consumption exists after heat energy is conducted for several times, and one process is needed for heating wet flue gas, so that the problem of pipeline blockage can be only relieved, and the problem cannot be thoroughly solved.

(3) And heating the wet flue gas by adopting a steam tracing mode. The condensation prevention principle of the mode is the same as (2), the advantage is that the redundant steam resources of the industrial factory are utilized, and besides the fact that the mode is the same as the second mode in that heat conduction is needed for many times, because the steam pipeline is a pressure pipeline, the manufacturing and construction requirements are high, the heat conduction mud for heat conduction of the steam pipeline is inconvenient to purchase, and the like, the condensation prevention mode cannot be popularized and used on a large scale all the time.

Therefore, the existing device or process can not well solve the problem of condensation and pipeline blockage of 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 drum, the mixing drum is arranged above the exhaust end of the mixer and is connected with the exhaust end of the mixer through a pneumatic valve, and the downstream of the mixing drum is connected with a dust remover through a dust removing pipeline. And (3) introducing a heat medium into the mixed flow cylinder, and raising the temperature in the mixed flow cylinder to be higher than the dew point temperature of the wet flue gas in the mixer, wherein the wet flue gas in the mixer enters the mixed flow cylinder at the moment, so that the problem that the wet flue gas is still likely to be condensed to block a pipeline at the initial stage of hot air converging in the prior art can be avoided, and the whole process of 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.

Based on the mixed flow system, the invention further provides an intelligent control anti-condensation saturated wet flue gas mixed flow method. The method is characterized in that the dew point temperature of wet flue gas is determined based on state parameters of the wet flue gas in a mixer, the temperature of mixed flue gas of the wet flue gas and a heat medium in a to-be-mixed flow cylinder is higher than the dew point temperature of the wet flue gas, and the mixed flue gas enters a dust remover for dust removal treatment. 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 inflow in the prior art, namely thoroughly solve the problem that the inner wall of a pipeline is blocked by dew condensation of the wet flue gas, and ensure long-term stable operation of the system.

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

An intelligent control dew-proof saturated wet flue gas mixed flow system comprises a mixer, a mixed flow cylinder and a dust remover. The mixing flow cylinder is arranged above the exhaust end of the mixer, and the exhaust port of the mixer is connected with the smoke inlet of the mixing flow cylinder through a pneumatic valve. The heat medium delivery pipe is connected to the heat medium inlet of the mixed flow cylinder. The flue gas outlet of the mixed flow cylinder is connected to the dust remover through a dust removing pipeline.

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

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

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

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

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 is combined to the heat medium conveying pipeline. Preferably, the bypass pipeline is provided with a fifth switch valve.

Preferably, the heat medium transfer pipe is provided with a first pressure sensor and a second pressure sensor. Wherein the first pressure sensor is located upstream of the position of the branching bypass line on the heat medium transfer line. The second pressure sensor is located downstream of the point where the bypass conduit merges into the heat medium delivery conduit.

In the present invention, a first temperature sensor is provided in the heat medium pipe. The first temperature sensor is located upstream of the position of the branching bypass line on the heat medium transfer line. The mixer is provided with a second temperature sensor and a humidity sensor. The mixed flow cylinder is provided with a third temperature sensor. The dust removing pipeline is provided with a fourth temperature sensor.

Preferably, the heat medium transfer pipe is provided with a first regulating valve. The first regulating valve is located downstream of the point where the bypass conduit merges into the heat medium transfer conduit. The dust removal pipeline is provided with a second regulating valve.

Preferably, the system comprises n mixers. And a mixing drum is correspondingly arranged above the exhaust end of each mixer. The mixers are connected with the mixing drum through pneumatic valves. Downstream of the position where the bypass pipe merges into the heat medium conveying pipe, the heat medium conveying pipe branches n heat medium branch pipes respectively connected to the heat medium inlets of the n mixed flow cylinders. The flue gas outlets of the mixed flow cylinders are respectively connected to the dust remover through respective dust removing pipelines. Preferably, n has a value of 1 to 10, preferably 2 to 6.

Preferably, each mixer is provided with a second temperature sensor and a humidity sensor. And each mixing drum is provided with a third temperature sensor. And a fourth temperature sensor and a second regulating valve are arranged on the dust removing pipeline respectively connected with each mixing drum. Each heat medium branch pipe is provided with a first regulating valve.

Preferably, the dust removal pipes respectively connected with each mixed flow cylinder are connected to the dust remover through the dust removal main pipe after being combined. Preferably, a fifth temperature sensor is arranged on the dust collection main 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 saturated wet flue gas mixed flow method is provided.

An intelligent control dew prevention saturated wet flue gas mixed flow method or a mixed flow method using the system described in the first embodiment, the method comprising the steps of:

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

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

3) Mixing the wet flue gas and the heat medium in a mixed flow cylinder 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 the mixed flue gas enters a dust remover through a dust removing pipeline to carry out dust removing treatment.

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

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

2) And (3) respectively introducing a heat medium into each mixing drum through the heat medium branch pipes separated by the heat medium conveying pipelines, and opening the pneumatic valve when the temperature in each mixing drum is higher than the dew point temperature of the wet flue gas in the corresponding mixer, and enabling the wet flue gas in each mixer to enter the corresponding mixing drum.

3) Mixing the wet flue gas and the heat medium 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, merging the mixed flue gas in each mixed flow cylinder into a dust collection main pipe through respective dust collection pipelines, and then entering a dust collector for dust collection treatment.

In the invention, the step 2) also comprises the step of detecting and cleaning ash, which is specifically as follows: 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 external air carries out back blowing cleaning on the heat medium conveying pipeline and the mixed flow barrel. And (5) ending the ash cleaning 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 heating medium is introduced into the mixed flow cylinder, specifically: at the beginning of the system operation, the heat medium is supplied to the heat medium conveying pipeline through the preheater. When the process production state is stable, the waste heat production device can provide effective waste heat, and at the moment, the waste heat production device provides heat medium for the heat medium conveying pipeline.

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

(1) and collecting humidity and temperature data of a large amount of wet flue gas in engineering, obtaining the flue gas dew point temperature under corresponding working conditions through an enthalpy-humidity diagram (namely, the relation among various parameters of wet air is represented by a graph line and can be referred to and applied), 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 mixer by adopting a humidity sensor and a second temperature sensor, and acquiring the dew point temperature of the wet flue gas in the corresponding mixer from a flue gas dew point temperature database.

In the invention, the calculation of the amount of the heat medium required to be introduced into the mixed flow cylinder in the step 2) specifically comprises the following substeps:

a) The heat required for preheating the wet flue gas in the mixer is calculated:

the amount of wet flue gas in the mixer is V _{Cigarette with smoke} ，m ³ And/h. Detecting the temperature of the wet flue gas to be T _{Cigarette with smoke} And (3) the temperature is lower than the temperature. The dew point temperature of the flue gas is T ₀ And (3) the temperature is lower than the temperature. Setting the temperature of the mixed flue gas obtained by mixing the wet flue gas with the heat medium as T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ ++ (5-30) deg.C. Thereby, the heat Q required to be absorbed by the wet flue gas in the preheating mixer _{Cigarette with smoke} The method comprises the following steps:

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

Wherein: c (C) _{Cigarette with smoke} The specific heat capacity of the wet flue gas is kJ/(kg. DEG C.). ρ _{Cigarette with smoke} Density of wet flue gas, kg/m ³ 。

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

let the amount of the heat medium entering the mixed flow cylinder be V _{Heat of the body} ，m ³ And/h. Detecting the temperature of the heat medium as T _{Heat of the body} And (3) the temperature is lower than the temperature. Thereby, the heat Q released by the heat medium entering the mixed flow cylinder _{Heat of the body} The method comprises the following steps:

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

Wherein: c (C) _{Heat of the body} The specific heat capacity of the heat medium, kJ/(kg. DEG C.). ρ _{Heat of the body} For density of the heat medium, kg/m ³ 。

c) Heat Q absorbed by pre-heating wet flue gases _{Cigarette with smoke} Heat Q released by heat medium entering mixed flow cylinder _{Heat of the body} Equal, can be obtained:

C _{cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )＝C _{Heat of the body} V _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} -T _{Is provided with} )。

The preparation method comprises the following steps:

V _{heat of the body} ＝C _{Cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )/[C _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} -T _{Is provided with} )]。

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

Preferably, in step 3), the opening degree of the second regulating valve on the dust removing pipeline is regulated, so that the air quantity of each dust removing point meets the requirement, and each dust removing point has no phenomenon of dust escaping. Meanwhile, a fourth temperature sensor detects the temperature T of the mixed flue gas on the dust removing pipeline on line and adjusts the opening degree of the first regulating valve on the heat medium conveying pipeline or the heat medium branch pipe so that T is equal to T _{Is provided with} 。

Aiming at the problems that in the prior art, the flue gas of the primary sintering mixer is easy to form condensation and block a pipeline in the dedusting and cooling process due to high moisture content and high dust concentration, the invention provides an intelligent control condensation-prevention saturated wet flue gas mixed flow system. The mixed flow system comprises a mixer, a mixed flow cylinder and a dust remover. The mixing drum is arranged above the exhaust end of the mixer, and a pneumatic valve is arranged at the position of the exhaust port of the mixer, namely the exhaust port of the mixer is connected with the smoke inlet of the mixing drum through the pneumatic valve. The heat medium conveying pipeline is connected to the heat medium inlet of the mixed flow cylinder, namely, the heat medium conveying pipeline provides heat medium for preheating the mixed flow cylinder and heating wet flue gas in the mixer. The dust remover sets up in the low reaches of mixed flow section of thick bamboo, and the flue gas outlet of mixed flow section of thick bamboo is connected to the dust remover through dust removal pipeline. In the actual application process, a heat medium is introduced into the mixed flow cylinder, the temperature in the mixed flow cylinder rises to be higher than the dew point temperature of wet flue gas in the mixer, at the moment, the pneumatic valve is opened, and the wet flue gas in the mixer enters the mixed flow cylinder, so that the problem that the wet flue gas is still likely to be condensed and blocked in the initial stage of hot air converging in the prior art can be avoided, and the whole process of 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.

Preferably, the invention further comprises a gas feed line, which is connected to the inlet end of the heat medium feed line. And a booster fan is also arranged on the heat medium conveying pipeline. The pressure sensor (comprising a first pressure sensor and a second pressure sensor) is used for detecting the pressure on the heat medium conveying pipeline, so as to judge whether the heat medium conveying pipeline and the mixing drum are in an ash accumulation state or not. If the pressure detection is abnormal, a system ash removal program is started, external air is introduced into the gas conveying pipeline and is boosted by the booster fan, and the external air sequentially carries out back-blowing cleaning on the heat medium conveying pipeline and the mixed flow cylinder, so that the ash accumulation and blockage of the pipeline are avoided, and the system is enabled to stably operate for a long time.

In the invention, the mixed flow system further comprises a preheater and a waste heat production device. The preheater and the waste heat production device are connected to the input end of the heat medium conveying pipeline through a first heat supply pipeline and a second heat supply pipeline respectively. At the beginning of the system operation, the heat medium is supplied to the heat medium conveying pipeline through the preheater. Wherein, the preheater can select the hot blast stove. When the process production state is stable, the production waste heat device can provide an effective heat source, and 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 does not limit a specific process, and can be waste heat generated in the sintering process, or waste heat generated in the processes of glass calcination, pellet production and the like. The invention adopts the preheater as a standby heat source, when judging that the waste heat is available in the production process (can be judged by the thermal resistance measured value arranged at the heat source, can be controlled according to time in the later period after a period of operation), the waste heat generated in the production process can be preferentially utilized, the energy cascade utilization 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 be used as a standby power source, so that the phenomenon of unbalanced pressure caused by overlarge resistance of the heat medium conveying pipeline is avoided, the introduction of the heat medium is more stable, and the subsequent stability of the temperature of dust removal flue gas is also facilitated.

Preferably, the invention branches off a bypass line from the heat medium transfer line, which bypasses the booster fan and merges into the heat medium transfer line. When the resistance of the heat medium conveying pipeline is smaller 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 present invention, a first pressure sensor and a second pressure sensor are provided in the heat medium pipe. Wherein the first pressure sensor is located upstream of the position of the branching bypass line on the heat medium transfer line. The second pressure sensor is located downstream of the point where the bypass conduit merges into the heat 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 as to judge whether the heat medium conveying pipeline and the mixed flow cylinder are in an ash accumulation state or not, and whether a system ash cleaning program needs to be started or not. In general, under normal working conditions without ash deposition in the pipeline, 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 are related to the position of the pressure measuring point, for example, in the application, when the pressure difference (pressure difference) detected by the first pressure sensor and the second pressure sensor is greater than 100Pa, the abnormality of the pressure in the heat medium conveying pipeline can be judged, that is, ash accumulation exists in the pipeline or the mixed flow cylinder, and the ash removal program of the system needs to be started so as to avoid further sedimentation.

The invention is provided with a first temperature sensor on a heat medium conveying pipeline. The first temperature sensor is located upstream of the position of the branching bypass line on the heat medium transfer line. The first temperature sensor is used for detecting the temperature of the heat medium. The mixer is provided with a second temperature sensor and a humidity sensor. 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. The mixed flow cylinder is provided with a third temperature sensor. 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 in the mixer entering the mixed flow cylinder can be accurately judged through real-time monitoring, and on the other hand, the mixed gas temperature obtained after the wet flue gas and the heat medium are mixed can be ensured to reach the temperature above the dew point temperature of the flue gas and then enter the dust remover for treatment. The dust removing pipeline is provided with a fourth temperature sensor. 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, thereby thoroughly solving the problem that wet flue gas of the primary sintering mixer is easy to dew and block the inner wall of the pipeline in the dust removal process in the prior art.

Preferably, the present invention is provided with a first regulating valve in the heat medium transfer pipe. The first regulating valve is located downstream of the point where the bypass conduit merges into the heat medium transfer conduit. The first regulating valve is used for regulating the quantity of the heat medium entering the mixed flow cylinder through the heat medium conveying pipeline. The dust removal pipeline is provided with a second regulating valve. The second regulating valve is used for regulating the air quantity (or flue gas quantity) on the dust removing pipeline, so that the air quantity of the dust removing point meets the requirement, namely, the dust removing point has no phenomenon of dust escaping.

Preferably, the mixed flow system comprises n mixers. And a mixing drum is correspondingly arranged above the exhaust end of each mixer. The mixers are connected with the mixing drum through pneumatic valves. Downstream of the position where the bypass pipe merges into the heat medium conveying pipe, the heat medium conveying pipe branches n heat medium branch pipes respectively connected to the heat medium inlets of the n mixed flow cylinders. The flue gas outlets of the mixed flow cylinders are respectively connected to the dust remover through respective dust removing pipelines. Wherein n has a value of 1-10, preferably 2-6, for example n=3, n=4, or n=6.

When the mixed flow system comprises a plurality of mixers, a second temperature sensor and a humidity sensor are correspondingly arranged on each mixer. And each mixing drum is provided with a third temperature sensor. And a fourth temperature sensor and a second regulating valve are arranged on the dust removing pipeline respectively connected with each mixing drum. Each heat medium branch pipe is provided with a first regulating valve. At this time, the first regulating valve on each heat medium branch pipe is used to regulate the amount of heat medium entering the corresponding mixing drum. The second regulating valve is used for regulating the air quantity (or smoke quantity) on the dedusting pipeline connected with the corresponding mixed flow cylinder, so that the resistance of each dedusting point is balanced, and the air quantity of each dedusting point meets the requirement, namely, each dedusting point has no phenomenon of dust escaping. In the application, the dust concentration of each dust removing point (such as each mixer) can be monitored in real time by on-site observation or setting of a corresponding dust concentration detector, so that no dust escaping phenomenon of the corresponding dust removing point is ensured. The second regulating valve is used for balancing the system resistance, and the opening degree of the second regulating valve can be generally not adjusted after the setting of the opening degree is finished, and only the dust raising condition is required to be adjusted.

Preferably, the dust removal pipes respectively connected with each mixed flow cylinder are connected to the dust remover through the dust removal main pipe after being combined. In order to further ensure that the temperature of the mixed flue gas entering the dust remover is above the dew point temperature, a fifth temperature sensor is arranged on the dust removing main pipe so as to ensure the stable operation of the system. Based on this, mixed flow system can handle the wet flue gas of containing of a plurality of mixers 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 wet flue gas dew point problem of jam dust removal pipeline promptly, ensure the long-term steady operation of system.

Still preferably, the mixed flow system of the present invention further includes 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 into 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 saturated wet flue gas mixed flow system, the invention also provides an intelligent control anti-condensation saturated wet flue gas mixed flow method. The mixed flow method mainly comprises the steps of determining dew point temperature of wet flue gas in a mixer, judging time nodes when the wet flue gas enters a mixed flow cylinder, judging time nodes when the wet flue gas and mixed flue gas of a heat medium enter a dust remover, carrying out dust removal treatment and the like. Firstly, a flue gas dew point database is established through a large amount of engineering actual measurement data, the humidity and the temperature of the wet flue gas in the mixer are obtained, and the dew point temperature of the wet flue gas in the mixer is obtained through analysis and comparison. Then, heat medium is introduced into the mixed flow cylinder through a heat medium conveying pipeline (or a heat medium branch pipe separated from the heat medium conveying pipeline), the temperature in the mixed flow cylinder is higher than the dew point temperature of wet smoke in a corresponding mixer, at the moment, a pneumatic valve is opened, and the wet smoke in the mixer enters the mixed flow cylinder. The wet flue gas and the heat medium are mixed in the mixed flow cylinder to obtain mixed flue gas, the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the corresponding mixer, and the mixed flue gas enters the dust remover through the dust removing pipeline to carry out dust removing treatment. The amount of the heat medium to be introduced into the mixed-flow tube can be calculated by heat balance. The temperature that this application can set for the mixed flue gas in the mixed flow section of thick bamboo of control in the system operation is higher than wet flue gas dew point temperature more than 10 ℃, guarantees that mixed flue gas does not condense the dewfall in the dust removal process. Meanwhile, the minimum thermal medium quantity can be calculated according to the dew point temperature of the wet flue gas and the temperature of the mixed flue gas above the dew point temperature, namely, the heat provided by the thermal medium only enables the temperature of the mixed flue gas to reach the temperature that the mixed flue gas is not condensed and condensed in the dust removal process, and redundant heat is not needed, so that the energy consumption is reduced.

In the actual application process, the control flow of the intelligent control mixed flow method is shown in fig. 4. Firstly, pressure detection is carried out on a heat medium conveying pipeline through a first pressure sensor and a second pressure sensor, and if the pressure detection is abnormal, a pipeline ash cleaning program is started. And opening the first switch valve and the second switch valve, wherein outdoor air is introduced into the gas conveying pipeline and the heat medium conveying pipeline and is boosted by the booster fan, and the air sequentially passes through the heat medium conveying pipeline and each mixed flow cylinder until the pressure signal of the heat medium conveying pipeline is recovered to be normal, namely, the ash removal of each mixed flow cylinder is completely finished. And then the hot blast stove (i.e. the preheater) operates, the third switch valve and the fifth switch valve are opened, the first switch valve and the second switch valve are closed at the same time, and the system introduces hot blast provided by the hot blast stove. And the humidity and temperature of the measured wet flue gas are transmitted into a flue gas dew point temperature database for analysis through humidity sensors and temperature sensors arranged on each mixer, so as to determine the dew point temperature of the wet flue gas in the corresponding mixer. When the third temperature sensor on each mixing drum detects that the temperature in the mixing drum reaches above the dew point temperature of the wet smoke in the corresponding mixer, the pneumatic valve between the air outlet of the mixer and the smoke inlet of the mixing drum can be opened, and the wet smoke in the mixer enters the mixing drum. The wet flue gas and the heat 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 for treatment through the dust removal pipeline. When the air quantity of the respective dust removing pipelines connected with the mixing drums meets the requirement, the opening conditions of the first regulating valve and the second regulating valve are maintained when dust is not raised on site. When dust is raised at the on-site posts, an 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, the posts have no dust escaping. It should be noted that when the air quantity is adjusted by the first adjusting valve, the temperature of the mixed flue gas in the mixed flow cylinder or the dust removing pipeline may be changed, so that 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 the heat medium branch pipe separated 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 detection temperature of a fourth temperature sensor on the dust-free and dust-removing pipeline of the station reaches above the dew point temperature of the wet flue gas, the opening states of all valves in the system are recorded. When the process production state is stable, the production waste heat device 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, and at the moment, the system uses the process production waste heat to realize energy cascade utilization, and the intelligent control system starts up the program to finish.

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

1. according to the invention, the mixed flow cylinder is introduced, the mixed flow cylinder is arranged above the exhaust end of the mixer and is connected through the pneumatic valve, the temperature in the mixed flow cylinder rises to be higher than the dew point temperature of wet flue gas in the mixer, and the wet flue gas in the mixer enters the mixed flow cylinder at the moment, so that the problem that the wet flue gas is still likely to be condensed and block a dust removing pipeline at the initial stage of hot air inflow in the prior art can be avoided, and the whole process of 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.

2. According to the invention, whether the heat medium conveying pipeline and the mixed flow cylinder are in an ash accumulation state is judged through pressure detection, and the outside air is introduced through the booster fan to carry out back blowing cleaning, so that the ash accumulation blockage of the pipeline is avoided, and the system stably operates for a long time.

3. The invention adopts the preheater as a standby heat source, and when the waste heat is judged to be available in the production process, the waste heat generated in the production process can be preferentially utilized, so that the energy cascade utilization is realized, and the energy is saved. The booster fan arranged on the heat medium conveying pipeline can boost the external air in the ash removal procedure and can be used as a standby power source, so that the phenomenon of unbalanced pressure caused by overlarge resistance of the heat medium conveying pipeline is avoided, the introduction of the heat medium is more stable, and the subsequent stabilization of the temperature of the dust removal flue gas is also facilitated.

4. The invention judges the dew point temperature of the flue gas according to the detection data such as humidity, temperature and the like, and is used for calculating and controlling the minimum heat medium amount required by the flue gas temperature entering the dust remover above the dew point temperature, namely, the energy consumption can be reduced to the greatest extent on the premise of ensuring that the flue gas is not condensed and condensed in the dust removing process.

5. The mixed flow system can treat the wet flue gas of a plurality of mixers at the same time, ensures that the temperature of the flue gas entering the dust remover is above the dew point temperature of the flue gas, can thoroughly solve the problem that the wet flue gas is condensed to block a dust removing pipeline, and ensures the long-term stable operation of the system. In addition, 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 flue gas quantity or the temperature 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 diagram of a structure of an intelligent control anti-condensation saturated wet flue gas mixed flow system;

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

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

fig. 4 is a control flow chart of an intelligent control anti-condensation saturated wet flue gas mixed flow method.

Reference numerals:

1: a mixer; 2: a mixing drum; 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 switching valve; s2: a second switching valve; s3: a third switching valve; s4: a fourth switching valve; s5: a fifth switching valve; z1: a first regulating valve; z2: a second regulating valve;

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

Detailed Description

The following examples illustrate the technical aspects of the invention, and the scope of the invention claimed includes but is not limited to the following examples.

An intelligent control dew-proof saturated wet flue gas mixed flow system comprises a mixer 1, a mixed flow cylinder 2 and a dust remover 3. The mixing drum 2 is arranged above the exhaust end of the mixer 1, and the exhaust port of the mixer 1 is connected with the smoke inlet of the mixing drum 2 through a pneumatic valve K. The heat medium delivery pipe L1 is connected to a heat medium inlet of the mixed flow drum 2. The flue gas outlet of the mixing drum 2 is connected to a dust remover 3 via a dust removal pipe L2.

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

Preferably, the heat medium transfer pipe L1 is provided with a first on-off valve S1 and a booster fan 4. Preferably, the gas delivery pipe 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 transfer line L1 via a first heat supply line L4. Preferably, the first heat supply line L4 is provided with a third switching valve S3. Preferably, the preheater 5 is a hot blast stove.

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

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

Preferably, the heat medium transfer 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 on the heat medium delivery pipe L1 where the bypass pipe L6 branches off. The second pressure sensor 702 is located downstream of the point where the bypass line L6 merges into the heat medium carrying line L1.

In the present invention, the heat medium transfer pipe L1 is provided with a first temperature sensor 801. The first temperature sensor 801 is located upstream of the position of the bypass line L6 on the heat medium conveyance line L1. The mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. The mixing drum 2 is provided with a third temperature sensor 803. The dust removal pipe L2 is provided with a fourth temperature sensor 804.

Preferably, the heat medium transfer pipe L1 is provided with a 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 carrying line L1. The dust removal pipeline L2 is provided with a second regulating valve Z2.

Preferably, the system comprises n mixers 1. A mixing drum 2 is correspondingly arranged above the exhaust end of each mixer 1. The mixers 1 and the mixing drums 2 are connected through pneumatic valves K. Downstream of the position where the bypass line L6 merges into the heat medium transfer line L1, the heat medium transfer line L1 branches out into n heat medium branch lines L7, which are connected to the heat medium inlets of the n mixing drums 2, respectively. The flue gas outlets of the mixed flow cylinders 2 are respectively connected to the dust collectors 3 through respective dust collecting pipelines L2. Preferably, n has a value of 1 to 10, preferably 2 to 6.

Preferably, each mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. A third temperature sensor 803 is provided on each mixing drum 2. A fourth temperature sensor 804 and a second regulating valve Z2 are respectively arranged on the dust removing pipeline L2 connected with each mixing drum 2. Each of the heat medium branch pipes L7 is provided with a first regulating valve Z1.

Preferably, the dust removal pipe L2 to which each mixing drum 2 is connected individually is connected to the dust remover 3 via the dust removal manifold L8 after being combined. Preferably, the dust collecting main pipe L8 is provided with a fifth temperature sensor 805.

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 regulating valve Z1, and the second regulating valve Z2, and controls the operations of the valves and the sensors.

Example 1

As shown in fig. 1, the 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 mixing drum 2 is arranged above the exhaust end of the mixer 1, and the exhaust port of the mixer 1 is connected with the smoke inlet of the mixing drum 2 through a pneumatic valve K. The heat medium delivery pipe L1 is connected to a heat medium inlet of the mixed flow drum 2. The flue gas outlet of the mixing drum 2 is connected to a dust remover 3 via a dust removal pipe 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 an input end of the heat medium delivery pipe L1.

Example 3

Example 2 was repeated except that the heat medium transfer pipe L1 was provided with the first on-off 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 on-off 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 transfer line L1 via a first heat supply line L4. The preheater 5 is a hot blast stove.

Example 6

Example 5 was repeated except that the third switching valve S3 was provided on the first heating pipe 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 of the heat medium conveying line L1 via a second heat supply line L5.

Example 8

Example 7 was repeated except that the fourth switching valve S4 was 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 carrying line L1, and the bypass line L6 was combined into the heat medium carrying line L1 after bypassing the first switching valve S1 and the booster fan 4.

Example 10

Example 9 is repeated except that the bypass line L6 is provided with a fifth on-off valve S5.

Example 11

Embodiment 10 is repeated except that a first pressure sensor 701 and a second pressure sensor 702 are provided on the heat medium delivery pipe L1. Wherein the first pressure sensor 701 is located upstream of the position on the heat medium delivery pipe L1 where the bypass pipe L6 branches off. The second pressure sensor 702 is located downstream of the point where the bypass line L6 merges into the heat medium carrying line L1.

Example 12

Example 11 is repeated except that the first temperature sensor 801 is provided on the heat medium conveyance pipe L1. The first temperature sensor 801 is located upstream of the position of the bypass line L6 on the heat medium conveyance line L1. The mixer 1 is provided with a second temperature sensor 802 and a humidity sensor 9. The mixing drum 2 is provided with a third temperature sensor 803. The dust removal pipe L2 is provided with a fourth temperature sensor 804.

Example 13

Example 12 was repeated except that the heat medium transfer 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 carrying line L1. The dust removal pipeline L2 is provided with a second regulating valve Z2.

Example 14

As shown in fig. 2, example 13 is repeated except that the system comprises 3 mixers 1. A mixing drum 2 is correspondingly arranged above the exhaust end of each mixer 1. The mixers 1 and the mixing drums 2 are connected through pneumatic valves K. Downstream of the position where the bypass line L6 merges into the heat medium transfer line L1, the heat medium transfer line L1 branches 3 heat medium branch lines L7, which are connected to the heat medium inlets of the 3 mixing drums 2, respectively. The flue gas outlets of the mixed flow cylinders 2 are respectively connected to the dust collectors 3 through respective dust collecting pipelines L2.

Example 15

Example 14 was repeated except that a second temperature sensor 802 and a humidity sensor 9 were provided on each mixer 1. A third temperature sensor 803 is provided on each mixing drum 2. A fourth temperature sensor 804 and a second regulating valve Z2 are respectively arranged on the dust removing pipeline L2 connected with each mixing drum 2. Each of the heat medium branch pipes L7 is provided with a first regulating valve Z1.

Example 16

Example 15 was repeated except that the dust removing pipes L2 to which each of the mixing drums 2 was individually connected were connected to the dust remover 3 via the dust removing header pipe L8 after being combined. A fifth temperature sensor 805 is provided on the dust collection manifold L8.

Example 17

As shown in fig. 3, example 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 the operations of the valves and the sensors.

Example 18

An intelligent control condensation-prevention saturated wet flue gas mixed flow method, which uses the system of the embodiment 13, and comprises the following steps:

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

2) And (2) introducing a heat medium into the mixed flow cylinder 2 through a heat medium conveying pipeline L1, wherein the temperature in the mixed flow cylinder 2 is higher than the dew point temperature of the wet flue gas in the step (1), and opening a pneumatic valve K at the moment, 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, the temperature of the mixed flue gas is higher than the dew point temperature of the wet flue gas in the step 1), and the mixed flue gas enters the dust remover 3 through the dust removing pipeline L2 to carry out dust removing treatment.

Example 19

As shown in fig. 4, an intelligent control anti-condensation saturated wet flue gas mixed flow method, using the system described in embodiment 17, comprises the following steps:

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

2) And a heat medium branch pipe L7 separated through a heat medium conveying pipeline L1 respectively introduces heat medium into each mixing drum 2, and when the temperature in each mixing drum 2 is higher than the dew point temperature of the wet smoke in the corresponding mixer 1, the pneumatic valve K is opened, and the wet smoke in each mixer 1 enters the corresponding mixing drum 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 combined to a dust collection main pipe L8 through a respective dust collection pipeline L2 and then enters a dust collector 3 for dust collection treatment.

Example 20

Example 19 was repeated except that step 2) further comprises the step of detecting ash removal, specifically: before the heat medium is introduced into the mixing drum 2, the pressure in the heat medium pipe L1 is detected by the first pressure sensor 701 and the second pressure sensor 702. If the pressure detection is abnormal, a system ash removal program is started, and at the moment, external air is introduced into the gas conveying pipeline L3 and the heat medium conveying pipeline L1 through the booster fan 4, and the external air carries out back blowing cleaning on the heat medium conveying pipeline L1 and the mixed flow cylinder 2. And (5) ending the system ash removal procedure until the pressures detected by the first pressure sensor 701 and the second pressure sensor 702 are recovered to be normal.

Example 21

Example 20 was repeated except that the heat medium was introduced into the mixing drum 2 as described in step 2), specifically: at the beginning of the system operation, the heat medium is supplied to the heat medium delivery pipe L1 through the preheater 5. When the process production state is stable, the waste heat production device 6 can provide effective waste heat, and at the moment, the waste heat production device 6 provides heat medium for the heat medium conveying pipeline L1.

Example 22

Example 21 was repeated except that the determination of the dew point temperature of the wet flue gas in the mixer 1 described in step 1) specifically comprises the following sub-steps:

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

(2) The humidity and the temperature of the wet flue gas in the mixer 1 are measured by adopting a humidity sensor 9 and a second temperature sensor 802 respectively, 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.

Example 23

Example 22 was repeated, except that the amount of the heat medium required to be introduced into the mixed-flow cartridge 2 in step 2) was calculated, and specifically comprising the following substeps:

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

the amount of wet flue gas in the mixer 1 is V _{Cigarette with smoke} ，m ³ And/h. Detecting the temperature of the wet flue gas to be T _{Cigarette with smoke} And (3) the temperature is lower than the temperature. The dew point temperature of the flue gas is T ₀ And (3) the temperature is lower than the temperature. Setting the temperature of the mixed flue gas obtained by mixing the wet flue gas with the heat medium as T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ +10℃. Thereby, the heat Q to be absorbed by the wet flue gas in the pre-heating mixer 1 _{Cigarette with smoke} The method comprises the following steps:

b) Calculate the heat released by the heat medium entering the mixing drum 2:

let the amount of the heat medium entering the mixing drum 2 be V _{Heat of the body} ，m ³ And/h. Detecting the temperature of the heat medium as T _{Heat of the body} And (3) the temperature is lower than the temperature. Thereby, the heat Q released by the heat medium entering the mixed flow tube 2 _{Heat of the body} The method comprises the following steps:

The preparation method comprises the following steps:

The opening degree of the first regulating valve Z1 on the heat medium branch pipe L7 separated by the heat medium conveying pipeline L1 is regulated to ensure that the quantity of the heat medium introduced into the mixed flow cylinder 2 in the step 2) is V _{Heat of the body} 。

Example 24

Example 23 was repeated except that in step 3), the opening degree of the second regulating valve Z2 on the dust removing pipe L2 was adjusted so that the air volume of each dust removing point satisfied the requirement, and each dust removing point had no phenomenon of dust escaping. Meanwhile, the fourth temperature sensor 804 detects the temperature T of the mixed flue gas on the dust removal pipe L2 on line and adjusts the opening 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 condensation-proof saturated wet flue gas mixed flow 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) and collecting humidity and temperature measured data of a large amount of wet flue gas in engineering, obtaining the flue gas dew point temperature under corresponding working conditions through an enthalpy-humidity diagram, and establishing a flue gas dew point temperature database.

(2) The relative humidity d=85% of the wet flue gas in the mixer 1 is measured with the humidity sensor 9, and the second temperature sensor 802 measures the temperature T of the wet flue gas in the mixer 1 _{Cigarette with smoke} 49 ℃ and acquiring the dew point temperature T of the wet flue gas in the corresponding mixer 1 from a flue gas dew point temperature database ₀ ＝45℃。

2) The pressure on the heat medium conveyance pipe L1 is detected using the first pressure sensor 701 and the second pressure sensor 702. The first pressure sensor 701 displays the corresponding position pipeline pressure p1= -60Pa, and the second pressure sensor 702 displays the corresponding position pipeline pressure p2= -500Pa, that is, the pressure difference detected by the two pressure sensors is greater than 200Pa, so as to judge that the pressure in the heat medium conveying pipeline L1 is abnormal, and start the system ash cleaning program. 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 external air performs back-blowing cleaning on the heat medium conveying pipeline L1 and the mixed flow cylinder 2. And (5) ending the system ash removal procedure until the pressures detected by the first pressure sensor 701 and the second pressure sensor 702 are recovered to be normal.

At the beginning of the system operation, the heat medium is supplied to the heat medium delivery pipe L1 through the preheater 5. The heat medium conveying pipeline L1 is used for introducing heat medium into the mixing drum 2, the temperature in the mixing drum 2 is higher than the dew point temperature of the wet smoke in the corresponding mixer 1, at the moment, the pneumatic valve K is opened, and the wet smoke in the mixer 1 enters the corresponding mixing drum 2.

The method for calculating the quantity of the heat medium required to be introduced into the mixed flow barrel 2 specifically comprises the following substeps:

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

the amount of wet flue gas in the mixer 1 is V _{Cigarette with smoke} ＝20000m ³ And/h. The second temperature sensor 802 detects the temperature of the wet flue gas as T _{Cigarette with smoke} =49℃. The dew point temperature of the flue gas is T ₀ =45℃. Setting the temperature of the mixed flue gas obtained by mixing the wet flue gas with the heat medium as T _{Is provided with} ，℃。T _{Is provided with} ＝T ₀ +15℃=60℃. Thereby, the heat Q to be absorbed by the wet flue gas in the pre-heating mixer 1 _{Cigarette with smoke} The method comprises the following steps:

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

Wherein: c (C) _{Cigarette with smoke} Specific heat capacity of wet flue gas, C _{Cigarette with smoke} ＝1.005kJ/(kg·℃)。ρ _{Cigarette with smoke} To density of wet flue gas ρ _{Cigarette with smoke} ＝1.09kg/m ³ 。

b) Calculate the heat released by the heat medium entering the mixing drum 2:

let the amount of the heat medium entering the mixing drum 2 be V _{Heat of the body} ，m ³ And/h. The first temperature sensor 801 detects the temperature of the heat medium as T _{Heat of the body} ＝150DEG C. Thereby, the heat Q released by the heat medium entering the mixed flow tube 2 _{Heat of the body} The method comprises the following steps:

Wherein: c (C) _{Heat of the body} Specific heat capacity of heat medium, C _{Heat of the body} ＝1.005kJ/(kg·℃)。ρ _{Heat of the body} For density of the heat medium ρ _{Heat of the body} ＝0.78kg/m ³ 。

The preparation method comprises the following steps:

V _{heat of the body} ＝C _{Cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )/[C _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} -T _{Is provided with} )]＝3416m ³ /h。

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

3) The wet flue gas and the heat medium are mixed in the mixed flow cylinder 2 to obtain mixed flue gas, 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, and at the moment, the mixed flue gas in the mixed flow cylinder 2 enters the dust remover 3 through the dust removing pipeline L2 to carry out dust removing treatment.

In the step 3), the opening degree of the second regulating valve Z2 on the dust removing pipeline L2 is regulated, so that the air quantity of each dust removing point meets the requirement, and each dust removing point has no phenomenon of dust escaping. Meanwhile, the fourth temperature sensor 804 detects the temperature T of the mixed flue gas on the dust removal pipe L2 on line and adjusts the opening of the first regulating valve Z1 on the heat medium conveying pipe L1 so that T is equal to T _{Is provided with} . The opening states of the valves in the system at this time are recorded.

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

Claims

1. An intelligent control condensation-proof saturated wet flue gas mixed flow system comprises a mixer (1), a mixed flow cylinder (2) and a dust remover (3); the mixing drum (2) is arranged above the exhaust end of the mixer (1), and the exhaust port of the mixer (1) is connected with the smoke inlet of the mixing drum (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 a dust remover (3) through a dust removing pipeline (L2); the system further comprises a gas delivery conduit (L3); the gas delivery pipe (L3) is connected to the input end of the heat medium delivery pipe (L1); a first switch valve (S1) and a booster fan (4) are arranged on the heat medium conveying pipeline (L1); a second switch valve (S2) is arranged on the gas conveying pipeline (L3);

the system further comprises a preheater (5); the preheater (5) is connected to the input of the heat medium transfer line (L1) via a first heat supply line (L4); a third switch valve (S3) is arranged on the first heat supply pipeline (L4); the system also comprises a production waste heat 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); a fourth switch valve (S4) is arranged on the second heat supply pipeline (L5);

A bypass pipeline (L6) is separated from the heat medium conveying pipeline (L1), and the bypass pipeline (L6) bypasses the first switch valve (S1) and the booster fan (4) and is combined into the heat medium conveying pipeline (L1); a fifth switch valve (S5) is arranged on the bypass pipeline (L6); 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 position on the heat medium delivery pipe (L1) at 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); 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) at the upstream of the position of the bypass pipeline (L6); the mixer (1) is provided with a second temperature sensor (802) and a humidity sensor (9); a third temperature sensor (803) is arranged on the mixed flow cylinder (2); a fourth temperature sensor (804) is arranged on the dust removing pipeline (L2); 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 pipe (L6) merges into the heat medium conveying pipe (L1); the dust removing pipeline (L2) is provided with a second regulating valve (Z2).

2. The system according to claim 1, wherein: the preheater (5) is a hot blast stove.

3. The system according to claim 1, wherein: the system comprises n mixers (1); a mixing drum (2) is correspondingly arranged above the exhaust end of each mixer (1); the mixers (1) are connected with the mixing drum (2) through pneumatic valves (K); downstream of the position where the bypass pipe (L6) merges into the heat medium conveying pipe (L1), the heat medium conveying pipe (L1) branches n heat medium branch pipes (L7) which are respectively connected to the heat medium inlets of the n mixing drums (2); the flue gas outlets of the mixed flow cylinders (2) are respectively connected to the dust remover (3) through respective dust removing pipelines (L2).

4. A system according to claim 3, characterized in that: n has a value of 1-10.

5. The system according to claim 4, wherein: n has a value of 2-6.

6. A system according to claim 3, characterized in that: each mixer (1) is provided with a second temperature sensor (802) and a humidity sensor (9); a third temperature sensor (803) is arranged on each mixing drum (2); a fourth temperature sensor (804) and a second regulating valve (Z2) are arranged on the dust removing pipeline (L2) connected with each mixing drum (2); each heat medium branch pipe (L7) is provided with a first regulating valve (Z1).

7. The system according to claim 6, wherein: the dust removing pipeline (L2) connected with each mixing drum (2) is connected to the dust remover (3) through the dust removing main pipe (L8) after being combined; a fifth temperature sensor (805) is arranged on the dust collection main pipe (L8).

8. The system according to claim 6, wherein: the system further comprises a control device (10); the control device (10) is connected with a pneumatic valve (K), a first switching valve (S1), a second switching valve (S2), a third switching valve (S3), a fourth switching valve (S4), a fifth switching valve (S5), a first pressure sensor (701), a second pressure sensor (702), a first temperature sensor (801), a second temperature sensor (802), a third temperature sensor (803), a fourth temperature sensor (804), a fifth temperature sensor (805), a humidity sensor (9), a first regulating valve (Z1) and a second regulating valve (Z2), and controls the operation of each valve and each sensor.

9. A mixed flow method using the system of any one of claims 1-8, the method comprising the steps of:

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

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

3) Mixing 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 the mixed flue gas enters a dust remover (3) through a dust removing pipeline (L2) to carry out dust removing treatment;

wherein: the step 2) also comprises the step of detecting ash removal, and specifically comprises the following steps: before the heat medium is introduced into the mixed 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 detection is abnormal, a system ash removal program is started, at the moment, external air is introduced into the gas conveying pipeline (L3) and the heat medium conveying pipeline (L1) through the booster fan (4), and the external air carries out back blowing cleaning on the heat medium conveying pipeline (L1) and the mixed flow cylinder (2); until the pressure detected by the first pressure sensor (701) and the second pressure sensor (702) is recovered to be normal, ending the ash cleaning program of the system; and/or

In the step 2), a heat medium is introduced into the mixed flow cylinder (2), and the method specifically comprises the following steps: at the beginning of the system operation, a heat medium is provided for a 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 a heat medium for the heat medium conveying pipeline (L1).

10. The method according to claim 9, 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 wet flue gas in the engineering, obtaining the flue gas dew point temperature under the corresponding working condition through an enthalpy-humidity diagram, and establishing a flue gas dew point temperature database;

(2) the humidity and the temperature of the wet flue gas in the mixer (1) are respectively measured by adopting a humidity sensor (9) and a second temperature sensor (802), 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.

11. The method according to claim 9 or 10, characterized in that: calculating the amount of the heat medium required to be introduced into the mixed flow barrel (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 in the mixer (1) is V _{Cigarette with smoke} ，m ³ /h; detecting the temperature of the wet flue gas to be T _{Cigarette with smoke} C, controlling the temperature; the dew point temperature of the flue gas is T ₀ C, controlling the temperature; setting the temperature of the mixed flue gas obtained by mixing the wet flue gas with the heat medium as T _{Is provided with} ，℃；T _{Is provided with} =T ₀ ++ (5-30) DEG C; thereby, the heat Q required to be absorbed by the wet flue gas in the mixer (1) is preheated _{Cigarette with smoke} The method comprises the following steps:

Q _{cigarette with smoke} = C _{Cigarette with smoke} V _{Cigarette with smoke} ρ∆T _{Cigarette with smoke} = C _{Cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )；

Wherein: c (C) _{Cigarette with smoke} The specific heat capacity of the wet flue gas is kJ/(kg. DEG C); ρ _{Cigarette with smoke} Density of wet flue gas, kg/m ³ ；

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

the amount of the heat medium entering the mixed flow cylinder (2) is V _{Heat of the body} ，m ³ /h; detecting the temperature of the heat medium as T _{Heat of the body} C, controlling the temperature; thereby, the heat Q released by the heat medium entering the mixed flow cylinder (2) _{Heat of the body} The method comprises the following steps:

Q _{heat of the body} = C _{Heat of the body} V _{Heat of the body} ρ∆T _{Heat of the body} = C _{Heat of the body} V _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} - T _{Is provided with} )；

Wherein: c (C) _{Heat of the body} kJ/(kg. Deg.C) is the specific heat capacity of the heat medium; ρ _{Heat of the body} For density of the heat medium, kg/m ³ ；

C _{cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )= C _{Heat of the body} V _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} - T _{Is provided with} )；

The preparation method comprises the following steps:

V _{heat of the body} = C _{Cigarette with smoke} V _{Cigarette with smoke} ρ _{Cigarette with smoke} (T _{Is provided with} -T _{Cigarette with smoke} )/[ C _{Heat of the body} ρ _{Heat of the body} (T _{Heat of the body} - T _{Is provided with} )]；

The opening degree of a first regulating valve (Z1) on a heat medium conveying pipeline (L1) or a heat medium branch pipe (L7) separated by the heat medium conveying pipeline (L1) is regulated so that the amount of the heat medium introduced into the mixed flow cylinder (2) in the step 2) is V _{Heat of the body} 。

12. The method according to claim 11, wherein: in the step 3), the opening degree of a second regulating valve (Z2) on the dust removing pipeline (L2) is regulated to ensure that the air quantity of each dust removing point meets the requirement and each dust removing point has no phenomenon of dust escaping; at the same time, the fourth temperature sensor (804) detects the temperature T of the mixed flue gas on the dust removing pipeline (L2) on line and adjusts the opening degree of the first adjusting valve (Z1) on the heat medium conveying pipeline (L1) or the heat medium branch pipe (L7) to ensure that T is equal to T _{Is provided with} 。

13. A mixed flow method using the system of any one of claims 1-8, the method comprising the steps of:

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

2) The heat medium branch pipes (L7) separated through the heat medium conveying pipelines (L1) respectively introduce heat medium into the mixing drums (2), when the temperature in each mixing drum (2) is higher than the dew point temperature of the wet flue gas in the corresponding mixer (1), the pneumatic valve (K) is opened, and the wet flue gas in each mixer (1) enters the corresponding mixing drum (2);

3) Mixing the wet flue gas and a heat medium in each mixing drum (2) to obtain mixed flue gas, and when the temperature of the mixed flue gas in each mixing drum (2) is higher than the dew point temperature of the wet flue gas in the corresponding mixer (1), merging the mixed flue gas in each mixing drum (2) into a dust collection main pipe (L8) through a respective dust collection pipeline (L2) and then entering a dust collector (3) for dust collection treatment;

14. The method according to claim 13, wherein: the step 1) of determining the dew point temperature of the wet flue gas in the mixer (1) specifically comprises the following substeps:

15. The method according to claim 13 or 14, characterized in that: calculating the amount of the heat medium required to be introduced into the mixed flow barrel (2) in the step 2), and specifically comprising the following substeps:

The preparation method comprises the following steps:

16. The method according to claim 15, wherein: in the step 3), the opening degree of a second regulating valve (Z2) on the dust removing pipeline (L2) is regulated to ensure that the air quantity of each dust removing point meets the requirement and each dust removing point has no phenomenon of dust escaping; at the same time, the fourth temperature sensor (804) detects the temperature T of the mixed flue gas on the dust removing pipeline (L2) on line and adjusts the opening degree of the first adjusting valve (Z1) on the heat medium conveying pipeline (L1) or the heat medium branch pipe (L7) to ensure that T is equal to T _{Is provided with} 。