A boiler top large cover protection monitoring system and method

Abstract

The present invention discloses a protection monitoring system and method for a large boiler top cover, including a controller, a large plate girder, a furnace top cover, a ceiling tube and its seal, a corrugated plate at the top of the cover, a heat-insulating castable layer at the top of the cover, a plastering at the top of the cover, and a platen superheater inlet header, a platen superheater outlet header, a final superheater inlet header, a final superheater outlet header, a high-temperature reheater inlet header, a high-temperature reheater outlet header, a low-temperature reheater outlet header, and a low-temperature superheater outlet header which are arranged in sequence from the front of the furnace to the rear of the furnace and are disposed inside the furnace top cover. The system and method can prevent personnel from falling into the furnace top cover and the risk of casualties, and improve the safety of the staff. In addition, through analysis and confirmation by the operating personnel, the system can detect the equipment with burst pipes inside the furnace top cover in advance and take measures as early as possible to prevent the further expansion of the fault.

Description

Technical Field

[0001] The present invention belongs to the field of thermal power generation, and relates to a protection monitoring system and method for a large boiler top cover. Background Art

[0002] In the boiler design, in order to reduce heat loss and the amount of thermal insulation used, the pipes and the header of the heating surface at the top of the boiler are integrally arranged inside the boiler casing. The boiler roof casing adopts a membrane wall structure to form a membrane tube screen airtight chamber. The bottom of the boiler casing is the ceiling tube, and the height from the ceiling tube to the top of the boiler casing is about 7m. During the operation of the unit, the temperature inside the boiler casing is about 450°C.

[0003] During the unit maintenance period, power plant staff need to go to the upper part of the large boiler top cover to check the equipment. However, in actual situations, there are also staff entering the upper part of the boiler top cover during the operation of the unit, and there have been multiple accidents where people fell into the inside of the boiler top cover and lost their lives. During the shutdown maintenance process, if a staff member falls from the boiler top cover, the height from the boiler top cover to the ceiling tube is about 7m, and the person will be injured. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art, and provides a protection monitoring system and method for a large boiler top cover, which can effectively reduce the risk of personnel falling and improve the safety of staff.

[0005] To achieve the above purpose, the protection monitoring system for the large boiler top cover of the present invention includes a controller, a large plate girder, a boiler top cover, a ceiling tube and its seal, a corrugated plate at the top of the cover, a heat-insulating castable layer at the top of the cover, a plastering at the top of the cover, and a platen superheater inlet header, a platen superheater outlet header, a final superheater inlet header, a final superheater outlet header, a high-temperature reheater inlet header, a high-temperature reheater outlet header, a low-temperature reheater outlet header, and a low-temperature superheater outlet header arranged in sequence from the front of the furnace to the rear of the furnace inside the boiler top cover;

[0006] The large plate girder is located above the boiler top cover, the ceiling tube and its seal are located at the bottom of the boiler top cover, the corrugated plate at the top of the cover is fixed to the top of the boiler top cover, and the heat-insulating castable layer at the top of the cover and the plastering at the top of the cover are sequentially laid on the top of the corrugated plate at the top of the cover;

[0007] A plurality of corrugated plate wall temperature sensors are installed on the corrugated plate at the top of the cover. A sensor protection device is arranged at the bottom of the corrugated plate at the top of the cover. The sensor protection device is suspended from the large plate girder. The output ends of each corrugated plate wall temperature sensor are connected to the input end of the DCS system through the controller.

[0008] The output ends of each corrugated plate wall temperature sensor are connected to the DCS system through a communication bus and the controller.

[0009] The wall temperature sensors of each corrugated plate are distributed in a matrix pattern, and a high-temperature resistant protection net is arranged between adjacent two columns of wall temperature sensors of corrugated plates. The high-temperature resistant protection net is fixed on the sensor protection device.

[0010] A method for protecting and monitoring the large cover at the top of a boiler includes the following steps:

[0011] The controller measures the wall temperature data T of different areas in the corrugated plates at the top of the large cover through the wall temperature sensors of each corrugated plate i,j , where i is the row number, from the front wall to the rear wall of the boiler, and j is the column number, from the left wall to the right wall of the boiler. Then, the wall temperature data T of different areas in the corrugated plates at the top of the large cover i,j is compared with the historical data at the same load under normal conditions to determine whether the wall temperature data corresponding to each area is normal. When the wall temperature data corresponding to any area is abnormal, then this area is listed as a dangerous area. When, within a statistical period, the cumulative duration of the abnormal wall temperature data corresponding to any area exceeds the preset duration, then personnel are prohibited from entering this area from the upper part of the large cover at the top of the furnace. At the same time, during the unit maintenance period, maintenance personnel enter the interior of the large cover at the top of the furnace to replace the corrugated plates at the top of the large cover in this area, and at the same time, repair or replace the high-temperature resistant protection net in this area.

[0012] Compare the wall temperature data measured by the wall temperature sensors of the corrugated plates with the historical wall temperature values at the same load in the DCS system read by the controller to obtain the wall temperature data T i,j of the area with a high deviation. When T i,j is greater than the preset maximum temperature Ty, then the corresponding area of T i,j is recorded as a dangerous area. Within the statistical period, the longer the cumulative time when T i,j is greater than Ty, the higher the danger level of this dangerous area. When the cumulative duration when T i,j corresponding to any area is greater than or equal to the preset duration, then personnel are prohibited from entering this area from the upper part of the large cover at the top of the furnace. At the same time, during the unit maintenance period, maintenance personnel enter the interior of the large cover at the top of the furnace to replace the corrugated plates at the top of the large cover in this dangerous area, and at the same time, repair or replace the high-temperature resistant protection net in this area.

[0013] Compare the wall temperature data measured by the wall temperature sensors of the corrugated plates with the historical wall temperature values at the same load in the DCS system read by the controller to obtain the area where the wall temperature T i,j is low. Within the statistical period, when the duration when T i,j is less than the preset minimum temperature value exceeds the preset duration, then this area is listed as a dangerous area, and personnel are prohibited from entering this area from the upper part of the large cover at the top of the furnace. At the same time, during the unit maintenance period, maintenance personnel enter the interior of the large cover at the top of the furnace to replace the corrugated plates at the top of the large cover in the dangerous area, and repair or replace the high-temperature resistant protection net in this area.

[0014] Judge the wall temperature T of the corrugated plate at the top of the large hood i,j For the mutation area, then use the principal component analysis method to confirm the associated equipment with the wall temperature mutation, analyze whether the associated equipment has burst pipes, and have the operator confirm it to detect the burst pipes of the equipment in advance.

[0015] The present invention has the following beneficial effects:

[0016] When the boiler top large hood protection monitoring system and method of the present invention are specifically operated, the wall temperature data of different areas in the corrugated plate at the top of the large hood are measured by multiple corrugated plate wall temperature sensors, and then compared with the wall temperature data under the same load to judge whether the wall temperature data corresponding to each area is normal. When the wall temperature data corresponding to any area is abnormal, then this area is listed as a dangerous area. When the cumulative duration of the abnormal wall temperature data corresponding to any area exceeds the preset duration within a statistical period, personnel are prohibited from entering this area from the upper part of the furnace top large hood, thus avoiding the risk of personnel falling and ensuring the personal safety of the staff. At the same time, during the unit maintenance period, the maintenance personnel enter the inside of the furnace top large hood to replace the corrugated plate at the top of the large hood in this area, and at the same time repair or replace the high-temperature protection net in this area to improve the reliability and safety of the equipment. In addition, through analysis and confirmation by the operator, the present invention can detect the burst pipe equipment in the furnace top large hood in advance and take measures as early as possible to prevent the further expansion of the fault. Description of the drawings

[0017] Figure 1 is the structural schematic diagram of the present invention;

[0018] Figure 2 is the schematic diagram of measurement data communication;

[0019] Figure 3 is the schematic diagram of the high-temperature protection net 18.

[0020] Among them, 1 is the furnace top large hood, 2 is the ceiling tube and its seal, 3 is the corrugated plate at the top of the large hood, 4 is the insulating castable layer at the top of the large hood, 5 is the plastering at the top of the large hood, 6 is the platen superheater inlet header, 7 is the platen superheater outlet header, 8 is the final superheater inlet header, 9 is the final superheater outlet header, 10 is the high-temperature reheater inlet header, 11 is the high-temperature reheater outlet header, 12 is the low-temperature reheater outlet header, 13 is the low-temperature superheater outlet header, 14 is the corrugated plate wall temperature sensor, 15 is the sensor protection device, 16 is the DCS system, 17 is the controller, 18 is the high-temperature protection net, 19 is the large plate girder. Specific embodiments

[0021] The following further describes the present invention in detail with reference to the drawings:

[0022] Reference Figures 1 to 3, the boiler top hood protection monitoring system described in the present invention includes a controller 17, a large plate girder 19, a furnace top hood 1, a ceiling tube and its seal 2, a corrugated plate at the top of the hood 3, a castable insulation layer at the top of the hood 4, a plaster finish at the top of the hood 5, and a platen superheater inlet header 6, a platen superheater outlet header 7, a final superheater inlet header 8, a final superheater outlet header 9, a high-temperature reheater inlet header 10, a high-temperature reheater outlet header 11, a low-temperature reheater outlet header 12, and a low-temperature superheater outlet header 13 arranged in sequence from the front of the furnace to the back of the furnace and located inside the furnace top hood 1; the large plate girder 19 is located above the furnace top hood 1, the ceiling tube and its seal 2 are located at the bottom of the furnace top hood 1, the corrugated plate at the top of the hood 3 is fixed to the top of the furnace top hood 1, and the castable insulation layer at the top of the hood 4 and the plaster finish at the top of the hood 5 are laid in sequence on the top of the corrugated plate at the top of the hood 3; a number of corrugated plate wall temperature sensors 14 are installed on the corrugated plate at the top of the hood 3, and a sensor protection device 15 is provided at the bottom of the corrugated plate at the top of the hood 3. The sensor protection device 15 is suspended from the large plate girder 19, and the output ends of the corrugated plate wall temperature sensors 14 are connected to the input end of the DCS system 16 through the controller 17.

[0023] The output ends of the corrugated plate wall temperature sensors 14 are connected to the DCS system 16 through a communication bus and the controller 17; the corrugated plate wall temperature sensors 14 are arranged in a matrix, and a high-temperature resistant protection net 18 is provided between two adjacent columns of corrugated plate wall temperature sensors 14. The high-temperature resistant protection net 18 is fixed on the sensor protection device 15.

[0024] A method for protecting and monitoring the boiler top hood includes the following steps:

[0025] The controller 17 measures the wall temperature data T of different regions in the corrugated plate at the top of the hood 3 through the corrugated plate wall temperature sensors 14 i,j , where i is the row number, from the front wall to the back wall of the boiler, and j is the column number, from the left wall to the right wall of the boiler. Then, the wall temperature data T of different regions in the corrugated plate at the top of the hood 3 i,j is compared with the historical data of the same load under normal conditions to determine whether the wall temperature data corresponding to each region is normal. When the wall temperature data corresponding to any region is abnormal, that region is listed as a dangerous region. When the cumulative duration of the abnormal wall temperature data corresponding to any region exceeds the preset duration within a statistical period, personnel are prohibited from entering the upper part of the furnace top hood 1 in this region. At the same time, during the unit maintenance period, maintenance personnel enter the inside of the furnace top hood 1 to replace the corrugated plate at the top of the hood 3 in this region, and at the same time, repair or replace the high-temperature resistant protection net 18 in this region.

[0026] Specifically, the measured wall temperature data of the corrugated plate wall temperature sensors 14 is compared with the historical wall temperature values of the same load in the DCS system 16 read by the controller 17 to obtain the wall temperature data T i,jIn the area with a relatively high temperature, when T i,j is greater than the preset maximum temperature Ty, then T i,j of the corresponding area is marked as a dangerous area. During the statistical period, the longer the cumulative time when T i,j is greater than Ty, the higher the danger level of this dangerous area. When the cumulative duration when T i,j of any area is greater than or equal to the preset duration, personnel are prohibited from entering this area from the upper part of the furnace top hood 1. At the same time, during the unit maintenance period, maintenance personnel enter the inside of the furnace top hood 1 to replace the corrugated plate 3 at the top of the hood in this dangerous area, and at the same time, repair or replace the high-temperature resistant protection net 18 in this area.

[0027] Compare the wall temperature data measured by the corrugated plate wall temperature sensor 14 with the historical wall temperature values of the same load read by the controller 17 from the DCS system 16 to obtain the wall temperature T i,j In the area with a relatively low temperature, during the statistical period, when the duration when T i,j is less than the preset minimum temperature value exceeds the preset duration, then this area is listed as a dangerous area, and personnel are prohibited from entering this area from the upper part of the furnace top hood 1. At the same time, during the unit maintenance period, maintenance personnel enter the inside of the furnace top hood 1 to replace the corrugated plate 3 at the top of the hood in the dangerous area, and repair or replace the high-temperature resistant protection net 18 in this area.

[0028] Judge the mutation area of the wall temperature T i,j of the corrugated plate 3 at the top of the hood, and then use the principal component analysis method to confirm the associated equipment with the wall temperature mutation, analyze whether the associated equipment has burst pipes, and have the operating personnel confirm it to detect equipment burst pipes in advance. Among them, check T i+1,j , T i,j+1 , T i-1,j , T i,j-1 the change of the wall temperature. If only a single wall temperature T i,j mutates, then the thermal measurement points need to be checked. The specific process is as follows:

[0029] Conduct principal component analysis of the wall temperature of each equipment with respect to the wall temperature T i,j of the corrugated plate 3 at the top of the hood, establish a principal component model composed of process variables. The equipment closer to the wall temperature measurement point of the corrugated plate 3 at the top of the hood radiates more heat, and the first n principal components can analyze more than 80% of the data change characteristics. During the 3-month statistical period, when the change of the wall temperature measurement point of the corrugated plate 3 at the top of the hood is the largest, then the corresponding T 2 statistic also has a highest point at this time. The moment when the wall temperature T i,j of the corrugated plate 3 at the top of the hood changes greatly corresponds to the moment when the T 2 statistic is relatively large. By calculating the T 2 statistic of the principal component, it can reflect the wall temperature T i,jBased on the changes of, the contribution of each wall temperature measurement point of the equipment to the T 2 statistic can be calculated, reflecting the change of the T 2 statistic. The change of the statistic is mainly caused by the wall temperature changes of several pieces of equipment. The change of the unit load will cause the change of the equipment wall temperature and the wall temperature T i,j of the corrugated plate 3 at the top of the large hood. Perform principal component analysis under steady-state load and variable load respectively to reflect the influence of the wall temperature changes of each equipment on the wall temperature of the corrugated plate 3 at the top of the large hood, and determine the associated equipment and wall temperature measurement points of the wall temperature Ti,j of the corrugated plate 3 at the top of the large hood.

[0030] The wall temperature T i,j mutation area of the corrugated plate 3 at the top of the large hood. Based on the determined associated equipment and wall temperature measurement points of the wall temperature T i,j of the corrugated plate 3 at the top of the large hood, analyze whether there are abnormalities in the wall temperature measurement points of the associated equipment. The operator checks the large hood 1 at the furnace top on site to confirm whether there is a tube burst in the equipment and detect the tube burst in advance.

[0031] A high-temperature resistant protection net 18 is arranged between the two rows of corrugated plate wall temperature sensors 14. The high-temperature resistant protection net 18 belongs to a backup protection measure. When the staff is working on the upper part of the large hood 1 at the furnace top, in case of a safety accident that the corrugated plate 3 at the top of the large hood fails to bear the load and is about to fall into the interior of the large hood 1, it can protect personal safety.

Claims

1. A method for protecting and monitoring a large cover at the top of a boiler, characterized in that, Boiler top cover protection monitoring system, the boiler top cover protection monitoring system includes a controller (17), a DCS system (16), a large plate girder (19), a furnace top cover (1), a ceiling tube and its seal (2), a corrugated plate at the top of the cover (3), a thermal insulation casting layer at the top of the cover (4), a plaster finish at the top of the cover (5), and a platen superheater inlet header (6), a platen superheater outlet header (7), a final superheater inlet header (8), a final superheater outlet header (9), a high-temperature reheater inlet header (10), a high-temperature reheater outlet header (11), a low-temperature reheater outlet header (12), and a low-temperature superheater outlet header (13) arranged in sequence from the front of the furnace to the back of the furnace and disposed inside the furnace top cover (1); The large plate girder (19) is located above the furnace top cover (1), the ceiling tube and its seal (2) are located at the bottom of the furnace top cover (1), the corrugated plate at the top of the cover (3) is fixed to the top of the furnace top cover (1), and the thermal insulation casting layer at the top of the cover (4) and the plaster finish at the top of the cover (5) are sequentially laid on the top of the corrugated plate at the top of the cover (3); A number of corrugated plate wall temperature sensors (14) are installed on the corrugated plate at the top of the cover (3), a sensor protection device (15) is provided at the bottom of the corrugated plate at the top of the cover (3), the sensor protection device (15) is suspended from the large plate girder (19), and the output ends of the respective corrugated plate wall temperature sensors (14) are connected to the input end of the DCS system (16) via the controller (17); Including the following steps: The controller (17) measures the wall temperature data T of different regions in the corrugated plate (3) at the top of the large hood through each corrugated plate wall temperature sensor (14). i,j , where i is the row number from the front wall to the rear wall of the boiler, and j is the column number from the left wall to the right wall of the boiler. Then, the wall temperature data T of different regions in the corrugated plate (3) at the top of the large hood i,j is compared with the historical data at the same load under normal conditions to determine whether the wall temperature data corresponding to each region is normal. When the wall temperature data corresponding to any region is abnormal, that region is listed as a dangerous area. When the cumulative duration of abnormal wall temperature data corresponding to any region exceeds the preset duration within a statistical period, personnel are prohibited from entering this region from the upper part of the large hood (1) on the furnace top. At the same time, during the unit maintenance period, maintenance personnel enter the inside of the large hood (1) on the furnace top to replace the corrugated plate (3) at the top of the large hood in this region, and at the same time, repair or replace the high-temperature protection net (18) in this region; Compare the measured wall temperature data of the corrugated plate wall temperature sensor (14) with the historical wall temperature values of the same load in the DCS system (16) read by the controller (17) to obtain the wall temperature data T i,j In the area with a relatively high temperature, when T i,j is greater than the preset maximum temperature Ty, then the corresponding area of T i,j is recorded as a dangerous area. During the statistical period, the longer the cumulative time when T i,j is greater than Ty, the higher the danger level of this dangerous area. When the cumulative duration when T corresponding to any area i,j is greater than Ty is greater than or equal to the preset duration, then personnel are prohibited from entering this area from the upper part of the furnace top hood (1). At the same time, during the unit maintenance period, maintenance personnel enter the inside of the furnace top hood (1) to replace the corrugated plate (3) at the top of the hood in this dangerous area, and at the same time, repair or replace the high-temperature protection net (18) in this area.

2. The boiler top cover protection monitoring method according to claim 1, characterized in that Compare the measured wall temperature data of the corrugated plate wall temperature sensor (14) with the historical wall temperature values of the same load read by the controller (17) from the DCS system (16) to obtain the wall temperature T i,j For the area with a relatively low temperature, within the statistical period, when T i,j is lower than the preset minimum temperature value for a duration exceeding the preset duration, then list this area as a dangerous area, prohibit personnel from entering this area from the upper part of the furnace top hood (1). At the same time, during the unit maintenance period, maintenance personnel enter the inside of the furnace top hood (1) to replace the corrugated plate (3) at the top of the hood in the dangerous area, and repair or replace the high-temperature protection net (18) in this area.

3. The boiler top hood protection monitoring method according to claim 1, characterized in that Judge the wall temperature T of the corrugated plate (3) at the top of the large hood i,j in the mutation area, then use the principal component analysis method to confirm the associated equipment with the wall temperature mutation, analyze whether the associated equipment has burst pipes, and then have the operator confirm it to detect the burst pipes of the equipment in advance.

4. The boiler top cover protection monitoring method according to claim 1, characterized in that, The output ends of the respective corrugated plate wall temperature sensors (14) are connected to the DCS system (16) via a communication bus and the controller (17).

5. The boiler top hood protection monitoring method according to claim 1, characterized in that The respective corrugated plate wall temperature sensors (14) are arranged in a matrix pattern, and a high-temperature resistant protection net (18) is provided between adjacent two columns of corrugated plate wall temperature sensors (14), and the high-temperature resistant protection net (18) is fixed to the sensor protection device (15).

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