Denitration ash clogging detection system

Abstract

The utility model relates to the field of denitration, in particular to a denitration ash blockage detection system which comprises a catalyst pressure sensor, a catalyst ash blower, a standby ash blower, a pre-coating layer, a pre-coating layer pressure sensor, a pre-coating layer ash blower, a controller and an alarm. The catalyst pressure sensors, the catalyst soot blower, the standby soot blower, the pre-coating layer pressure sensors, the pre-coating layer soot blower and the alarm are all electrically connected with the controller, the catalyst pressure sensors are arranged above and below the catalyst, the pre-coating layer is arranged above the catalyst, and the alarm is electrically connected with the controller. The precoating layer pressure sensors are arranged above and below the precoating layer, the catalyst soot blower and the standby soot blower are arranged above the catalyst and used for blowing soot to the catalyst, and the precoating layer soot blower is arranged above the precoating layer and used for blowing soot to the precoating layer. According to the utility model, the ash blocking problem of the catalyst can be found and solved in time as soon as possible.

Description

Technical Field

[0001] The utility model relates to the field of denitration, in particular to a denitration ash blocking detection system. Background Art

[0002] Denitrification refers to the process of removing nitrogen oxides from combustion flue gas. The denitrification processes are divided into SCR and SNCR. Among them, the selective catalytic reduction method (SCR) refers to the use of reducing agents such as NH3, liquid ammonia, urea, etc. under the action of a catalyst to "selectively" react with nitrogen oxides in the flue gas to generate non-toxic and non-polluting nitrogen and water.

[0003] An important part of SCR flue gas denitrification technology is the catalyst used in the reaction. The original flue gas enters the SCR reactor from the top, passes through multiple layers of catalysts and reacts, and finally the clean flue gas is discharged from the bottom of the SCR reactor. As the operating time increases, the catalyst will gradually be blocked due to the deposition of fly ash in the flue gas. After the catalyst is blocked by ash, it will not only hinder the effective contact between the flue gas and the catalyst, but also affect the reaction of nitrogen oxides and reductants on the catalyst surface, resulting in a significant decrease in the conversion efficiency of nitrogen oxides, causing excess ammonia to be directly discharged without reaction, increasing the ammonia escape rate. It will also increase the resistance of the flue gas through the catalyst bed and increase the system pressure drop. In addition, the flue gas flow rate near the ash blocking area is reduced, and heat transfer is hindered, which may cause the local temperature to be too high, thereby damaging the activity of the catalyst and accelerating the aging of the catalyst. Long-term ash blocking may cause permanent deactivation of the catalyst, and a new catalyst must be replaced, increasing the operation and maintenance cost. Therefore, it is necessary to discover and solve the ash blocking problem of the catalyst as soon as possible to avoid permanent deactivation of the catalyst and reduce the replacement cost of the catalyst. Utility Model Content

[0004] The utility model aims to provide a denitration ash blocking detection system so as to find out and solve the catalyst ash blocking problem as early as possible.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A denitrification soot blockage detection system comprises a catalyst pressure sensor, a catalyst soot blower, a spare soot blower, a pre-coating layer, a pre-coating layer pressure sensor, a pre-coating layer soot blower, a controller and an alarm. The catalyst pressure sensor, the catalyst soot blower, the spare soot blower, the pre-coating layer pressure sensor, the pre-coating layer soot blower and the alarm are all electrically connected to the controller. The catalyst pressure sensor is arranged above and below the catalyst, the pre-coating layer is arranged above the catalyst, the pre-coating layer pressure sensor is arranged above the pre-coating layer, the catalyst soot blower and the spare soot blower are arranged above the catalyst for blowing soot on the catalyst, and the pre-coating layer soot blower is arranged above the pre-coating layer for blowing soot on the pre-coating layer.

[0007] Preferably, as an improvement, the catalyst soot blower, spare soot blower and pre-coating layer soot blower are connected to a heater, and temperature sensors are installed in the nozzles of the catalyst soot blower, spare soot blower and pre-coating layer soot blower, and the temperature sensor and the heater are electrically connected to the controller.

[0008] Preferably, as an improvement, the nozzle of the standby soot blower is arranged vertically on the surface of the catalyst.

[0009] Preferably, as an improvement, flow detectors are provided in the nozzles of the catalyst soot blower, the pre-coating layer soot blower and the spare soot blower, and the flow detectors are electrically connected to the controller.

[0010] Preferably, as an improvement, the pre-coating layer is a wire mesh, and the mesh openings of the wire mesh are larger than the pores of the catalyst.

[0011] The principles and beneficial effects of this scheme are:

[0012] 1. This solution can timely detect the ash blockage of the catalyst, and can also take corresponding countermeasures in different ash blockage situations, which can effectively extend the life of the catalyst. Specifically: The pressure sensor is used to monitor the changes in the pressure difference between the upper and lower parts of the catalyst in real time. If the catalyst is blocked, it will increase the resistance of the flue gas flowing through the catalyst bed. Therefore, the pressure difference between the upper and lower parts of the catalyst will increase accordingly. When the pressure difference exceeds the normal range, it means that the catalyst is blocked. When the pressure difference is greater than 100pa and less than 150pa, the controller controls the catalyst soot blower to blow the catalyst to reduce dust accumulation; when the pressure difference increases to 150pa or above, it means that the catalyst is blocked, and the controller controls the catalyst soot blower and the standby soot blower to blow the catalyst at the same time to remove the blocked dust and regenerate the catalyst; after blowing, if the pressure difference continues to increase to 200pa, it means that a more serious ash blockage has occurred, and the controller controls the alarm to remind the staff to stop the machine for inspection and cleaning.

[0013] 2. The nozzle of the standby soot blower is arranged vertically on the surface of the catalyst, so that the airflow can directly act on the pores of the catalyst to blow out the dust blocked in the pores. Combined with the soot blowing effect of the catalyst soot blower, the two soot blowers work together to achieve a strong soot blowing effect.

[0014] 3. This solution sets a pre-coating layer above the catalyst to intercept large dust particles in the flue gas, which can prevent large dust particles from falling into the catalyst and effectively delay the catalyst clogging process. On this basis, this solution also sets a pre-coating layer pressure sensor above and below the pre-coating layer to monitor the pressure difference of the pre-coating layer in real time, which can detect the clogging of the pre-coating layer in time. When the pre-coating layer is clogged with dust, the controller controls the pre-coating layer soot blower to blow the pre-coating layer, which can effectively extend the service life of the pre-coating layer.

[0015] 4. This scheme sets temperature sensors in the nozzles of the catalyst sootblower, spare sootblower and pre-coating layer sootblower to monitor the temperature of the sootblowing gas in real time. When the temperature is lower than 130°C, the controller controls the heater to heat the sootblowing gas to avoid the water vapor carried in the sootblowing gas reacting with the dust to cause dust compaction and ash blockage.

[0016] 5. In addition, this solution also sets flow detectors in the nozzles of the catalyst soot blower, spare soot blower and pre-coating layer soot blower to monitor the flow of the catalyst soot blower, spare soot blower and pre-coating layer soot blower in real time, which can effectively avoid the blockage of the catalyst soot blower, spare soot blower and pre-coating layer soot blower themselves. When blockage is found, the controller controls the alarm to alert the staff to come and deal with it. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of Example 1 of the utility model.

[0018] Figure 2 This is a logic block diagram of Example 1 of the utility model.

[0019] Figure 3 This is a logic block diagram of Example 2 of the present utility model. DETAILED DESCRIPTION

[0020] The following is further described in detail through specific implementation methods:

[0021] The figure marks in the drawings of the specification include: reactor 1, spare catalyst mounting frame 11, catalyst 12, catalyst soot blower 13, spare soot blower 14, catalyst pressure sensor 15, pre-coating layer 2, pre-coating layer soot blower 21, pre-coating layer pressure sensor 22, heater 3.

[0022] The arrows in the figure indicate the direction of flue gas flow.

[0023] like Figure 1 and Figure 2As shown, a denitration ash blockage detection system includes a catalyst pressure sensor 15, a catalyst soot blower 13, a spare soot blower 14, a pre-coating layer 2, a pre-coating layer pressure sensor 22, a pre-coating layer soot blower 21, a controller and an alarm. The catalyst pressure sensor 15, the catalyst soot blower 13, the spare soot blower 14, the pre-coating layer pressure sensor 22, the pre-coating layer soot blower 21 and the alarm are all electrically connected to the controller. The catalyst 12 is installed in the denitration reactor 1. The catalyst 12 adopts a honeycomb catalyst 12. In this embodiment, four layers of catalyst mounting frames are installed from top to bottom in the denitration reactor 1. The catalyst 12 is installed in the lower two layers, and a pre-coating layer 2 is installed above each layer of catalyst 12 to intercept large particles of dust. The upper two layers are spare catalyst mounting frames 11 for spare installation of the catalyst 12. In this embodiment, the pre-coating layer 2 adopts a wire mesh, the mesh of which is larger than the pores of the catalyst 12, and each pre-coating layer 2 is installed with a pre-coating layer pressure sensor 22 above and below. The catalyst soot blower 13 and the spare soot blower 14 are installed above the catalyst 12 for soot blowing the catalyst 12, wherein the nozzle spray direction of the catalyst soot blower 13 is set at a certain angle with the bottom surface of the catalyst 12, which is specifically 30 degrees in this embodiment, and can also be set to other angles according to needs in actual use. The spray direction of the nozzle of the spare soot blower 14 is set perpendicular to the surface of the catalyst 12, that is, the spray direction of the nozzle of the spare soot blower 14 is aligned with the pores of the catalyst 12. The pre-coating layer soot blower 21 is installed above the pre-coating layer 2, and the spray direction of the nozzle of the pre-coating layer soot blower 21 is also set at a 30-degree angle with the surface of the pre-coating layer 2. In this embodiment, the catalyst soot blower 13, the spare soot blower 14 and the pre-coating layer soot blower 21 all adopt air rake soot blowers.

[0024] The catalyst soot blower 13, the standby soot blower 14 and the pre-coating layer soot blower 21 are connected to a heater 3, the heater 3 is connected to a compressed air storage tank, temperature sensors are installed in the nozzles of the catalyst soot blower 13, the standby soot blower 14 and the pre-coating layer soot blower 21, and the temperature sensor and the heater 3 are electrically connected to the controller.

[0025] In actual use, the original flue gas enters the reactor 1 from the top, passes through the catalyst 12 in sequence and reacts to form clean flue gas which is discharged from the bottom of the reactor 1, thus completing the denitrification of the flue gas.

[0026] During the flow of flue gas, the pre-coating layer 2 intercepts large dust particles above the catalyst 12 in advance, which can effectively prevent large dust particles from entering the catalyst 12 and effectively alleviate the ash blockage of the catalyst 12. On this basis, the pre-coating layer pressure sensor 22 monitors the pressure difference between the upper and lower parts of the pre-coating layer 2 in real time. When the pressure difference exceeds the preset range, it indicates that the pre-coating layer 2 is blocked by ash. At this time, the controller controls the pre-coating layer soot blower 21 to blow the pre-coating layer 2, which can effectively extend the life of the pre-coating layer 2.

[0027] During the denitration process, the catalyst pressure sensor 15 also monitors the pressure difference above and below the catalyst 12 in real time. When the pressure difference is greater than 100Pa and less than 150Pa, the catalyst pressure sensor 15 sends a conventional soot blowing signal to the controller, and the controller controls the catalyst soot blower 13 to blow the catalyst 12 alone to achieve conventional soot blowing, and perform conventional maintenance and cleaning on the catalyst 12. When the pressure difference reaches above 150Pa, the catalyst pressure sensor 15 sends a strong soot blowing signal to the controller, and the controller controls the catalyst soot blower 13 and the spare soot blower 14 to blow the catalyst 12 together to achieve strong soot blowing and solve the problem of catalyst 12 ash blockage. Since the spare soot blower 14 is added, and the spare soot blower 14 blows vertically on the surface of the catalyst 12, the dust in the pores of the catalyst 12 can be effectively blown out to achieve a good soot blowing effect. When the pressure difference reaches 200Pa, it means that the catalyst 12 is seriously blocked. At this time, the pressure sensor sends an alarm signal to the controller, and the controller controls the alarm to issue a catalyst maintenance alarm to remind the staff to come for maintenance.

[0028] During the sootblowing process, the temperature sensor monitors the temperature of the sootblowing gas in the catalyst sootblower 13, the standby sootblower 14 and the pre-coating layer sootblower 21 in real time. When the temperature is lower than 130°C, the temperature sensor sends a signal to the controller, and the controller controls the heater 3 to heat the compressed air to ensure that the temperature of the sootblowing gas remains above 130°C to avoid the reaction of water vapor carried in the sootblowing gas with dust to cause dust to clog the catalyst 12. This can also effectively alleviate the ash blockage of the catalyst 12.

[0029] Embodiment 2:

[0030] Combination Figure 3 As shown, the difference between this embodiment and embodiment 1 is that flow detectors are installed in the nozzles of the catalyst soot blower 13, the pre-coating layer soot blower 21 and the spare soot blower 14, and the flow detectors are electrically connected to the controller.

[0031] The flow controller monitors the flow in the nozzles of the catalyst soot blower 13, the pre-coating layer soot blower 21 and the spare soot blower 14 in real time. When the flow is found to be lower than the normal range, it means that the soot blower may be blocked. At this time, the temperature sensor sends a signal to the controller, and the controller controls the alarm to issue a soot blower blockage alarm to remind the staff to come and deal with it.

[0032] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A denitrification ash blocking detection system, characterized in that: It includes a catalyst pressure sensor, a catalyst sootblower, a spare sootblower, a pre-coating layer, a pre-coating layer pressure sensor, a pre-coating layer sootblower, a controller and an alarm. The catalyst pressure sensor, the catalyst sootblower, the spare sootblower, the pre-coating layer pressure sensor, the pre-coating layer sootblower and the alarm are all electrically connected to the controller. The catalyst pressure sensor is arranged above and below the catalyst, the pre-coating layer is arranged above the catalyst, the pre-coating layer pressure sensor is arranged above the pre-coating layer, the catalyst sootblower and the spare sootblower are arranged above the catalyst for blowing soot on the catalyst, and the pre-coating layer sootblower is arranged above the pre-coating layer for blowing soot on the pre-coating layer.

2. A denitrification ash blockage detection system according to claim 1, characterized in that: The catalyst soot blower, the spare soot blower and the pre-coating layer soot blower are connected with a heater, and temperature sensors are installed in the nozzles of the catalyst soot blower, the spare soot blower and the pre-coating layer soot blower. The temperature sensor and the heater are electrically connected to the controller.

3. A denitrification ash blocking detection system according to claim 2, characterized in that: The nozzle of the spare soot blower is arranged vertically on the surface of the catalyst.

4. A denitrification ash blockage detection system according to claim 3, characterized in that: A flow detector is arranged in the nozzles of the catalyst soot blower, the pre-coating layer soot blower and the spare soot blower, and the flow detector is electrically connected to the controller.

5. A denitrification ash blockage detection system according to claim 4, characterized in that: The pre-coating layer is a wire mesh, and the mesh openings of the wire mesh are larger than the pores of the catalyst.

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