阅读说明：本技术 一种在线监测的电站锅炉水冷壁及其监测方法 (On-line monitoring water cooled wall of power station boiler and monitoring method thereof ) 是由 王洋 汪华剑 房凡 马翔 吴庆龙 陈煜� 刘笑 于 2021-08-05 设计创作，主要内容包括：本发明一种在线监测的电站锅炉水冷壁及其监测方法,水冷壁包括水冷壁管、水冷壁侧管、温度感应器组、水冷壁近壁面烟气取样管、数据传输系统和上位机；水冷壁管相互之间通过设置的鳍片依次连接形成电站锅炉水冷壁；水冷壁侧管垂直设于一个水冷壁管外侧；沿水冷壁侧管轴线方向设有伸入水冷壁管管内的堵头；温度感应器组中的水冷壁向火侧壁温度感应器设在连接水冷壁侧管的水冷壁管上；温度感应器组中的水冷壁管内工质温度感应器沿堵头轴线设在堵头内；水冷壁近壁面烟气取样管入口穿过鳍片设置,出口连接烟气成分分析仪器输入端；水冷壁向火侧壁温度感应器、水冷壁管内工质温度感应器和烟气成分分析仪器输出端通过数据传输系统连接上位机。(The invention relates to a power station boiler water-cooled wall for on-line monitoring and a monitoring method thereof, wherein the water-cooled wall comprises a water-cooled wall pipe, a water-cooled wall side pipe, a temperature sensor group, a water-cooled wall near-wall surface flue gas sampling pipe, a data transmission system and an upper computer; the water wall pipes are connected in sequence through the arranged fins to form a water wall of the utility boiler; the water wall side pipe is vertically arranged on the outer side of one water wall pipe; a plug extending into the water wall pipe is arranged along the axis direction of the water wall side pipe; the water wall fire facing side wall temperature sensor in the temperature sensor group is arranged on a water wall pipe connected with the water wall side pipe; working medium temperature sensors in water-cooled wall tubes in the temperature sensor group are arranged in the plugs along the axis of the plugs; an inlet of a water-cooled wall near-wall flue gas sampling tube penetrates through the fins, and an outlet of the water-cooled wall near-wall flue gas sampling tube is connected with an input end of a flue gas component analysis instrument; the water-cooled wall fire-facing side wall temperature sensor, the working medium temperature sensor in the water-cooled wall tube and the output end of the flue gas component analysis instrument are connected with an upper computer through a data transmission system.)

1. A power station boiler water-cooled wall with on-line monitoring is characterized by comprising a water-cooled wall tube (2), a water-cooled wall side tube (5), a temperature sensor group, a water-cooled wall near-wall surface flue gas sampling tube (10), a data transmission system (9) and an upper computer (4);

the water wall tubes (2) are sequentially connected with each other through the arranged fins (1) to form a water wall of the utility boiler;

the water wall side pipe (5) is vertically arranged on the outer side of one water wall pipe (2); a plug (7) extending into the water wall tube (2) is also arranged along the axial direction of the water wall side tube (5);

the temperature sensor group comprises a water wall fire facing side wall temperature sensor (3) and a working medium temperature sensor (8) in a water wall tube; the water-cooled wall fire-facing side wall temperature sensor (3) is arranged on the water-cooled wall pipe (2) connected with the water-cooled wall side pipe (5); the working medium temperature sensor (8) in the water-cooled wall pipe is arranged in the plug (7) along the axis of the plug (7);

the inlet of the water-cooled wall near-wall flue gas sampling tube (10) penetrates through the fin (1), and the outlet is connected with the input end of a flue gas component analyzer (14); the output ends of the water-cooled wall fire-facing side wall temperature sensor (3), the working medium temperature sensor (8) in the water-cooled wall tube and the flue gas component analysis instrument (14) are connected with the upper computer (4) through a data transmission system (9).

2. An on-line monitoring utility boiler waterwall according to claim 1, characterized in that the waterwall side tubes (5) are forged integrally with the waterwall tubes (2); the water wall side pipe (5) is provided with a first temperature measuring hole at the fin (1) towards the fire side direction, the thickness between the inner wall of the first temperature measuring hole and the inner wall of the water wall pipe (2) meets the minimum safe wall thickness, and a water wall fire side wall temperature sensor (3) is arranged in the first temperature measuring hole.

3. An on-line monitoring utility boiler waterwall according to claim 1, characterized in that the said plug (7) is T-shaped, its long end is set along the axis of the waterwall side tube (5), and the end extending into the waterwall tube (2) is set with a tip.

4. An on-line monitoring power boiler water-cooled wall according to claim 3, characterized in that the plug (7) is provided with a second temperature measuring hole from the short end to the tip of the long end, the second temperature measuring hole is deep into the inner wall of the water-cooled wall tube (2), and a working medium temperature sensor (8) in the water-cooled wall tube is arranged in the second temperature measuring hole.

5. An on-line monitoring power station boiler water-cooled wall according to claim 1, characterized in that the plug (7) is made of the same material as the water-cooled wall tube (2) and is welded and fixed with the water-cooled wall side tube (5).

6. The on-line monitoring power station boiler water-cooled wall according to claim 1, characterized in that a flue gas filter (12) and a flue gas cooler (13) are arranged between the water-cooled wall near-wall flue gas sampling tube (10) and the flue gas component analyzer (14).

7. An on-line monitoring power boiler water-cooled wall according to claim 6, characterized in that the flue gas filter (12) is connected with the water-cooled wall near-wall flue gas sampling tube (10) through a flexible sealing joint (11).

8. An on-line monitoring power station boiler water-cooled wall according to claim 1, characterized in that a flue gas tail gas treatment device (15) is arranged at a flue gas outlet of the flue gas component analysis instrument (14).

9. A method for monitoring the water wall of a power station boiler by on-line monitoring, which is characterized in that based on the system of any one of the above claims 1-8, the method comprises the following steps,

the upper computer (4) is used for monitoring and storing water-cooled wall temperature data acquired by a water-cooled wall fire-facing side wall temperature sensor (3) and a water-cooled wall tube internal working medium temperature sensor (8) which are input by a data transmission system (9), and H at the position of a water-cooled wall near-wall surface flue gas sampling tube (10)₂S concentration data;

when the monitored temperature of the water cooling wall fire facing side wall temperature sensor (3) exceeds a preset limit value, the upper computer (4) sends out an alarm signal;

when H is transmitted by the flue gas component analysis instrument (14)₂When the concentration of S exceeds a preset limit value, the upper computer (4) sends out an alarm signal.

10. An on-line monitoring method for the water wall of the utility boiler in accordance with claim 8 or 9, characterized in that the working medium temperature sensor (8) in the water wall tube monitors and stores the temperature data of the working medium in the water wall tube (2) when the metal wall temperature of the water wall is abnormally increased.

Technical Field

The invention relates to the technical field of coal-fired power generation, in particular to an on-line monitoring water-cooled wall of a power station boiler and a monitoring method thereof.

Background

The water wall is the main heated part of the boiler, and is composed of a plurality of rows of steel pipes, distributed around the boiler furnace and generally vertically laid on the inner wall surface of the furnace wall. The inside of the furnace is flowing water or steam, and the outside receives the heat of the flame of the boiler furnace. Mainly absorbs the radiation heat of high-temperature combustion products in the hearth, and the working medium rises in the hearth and is heated and evaporated. The water-cooled wall is a boiler heating surface for absorbing radiant heat emitted by flame and high-temperature flue gas in the boiler, is a main type of evaporation heating surfaces of various modern boilers, is also a basic component in a boiler water circulation loop, and has the functions of cooling and protecting the boiler wall.

The high-temperature corrosion phenomenon of the near wall surface of the water-cooled wall causes the reduction of the wall of the tube and even the overtemperature tube explosion, and the operation safety of the power station boiler is seriously influenced. In order to meet the requirement of ultralow emission, the current power station boiler generally adopts low-nitrogen combustion technologies such as air staged combustion and the like, a main combustion area operates in a reducing atmosphere, and meanwhile, the risk of high-temperature corrosion of a water-cooled wall is aggravated by the increase of sulfur content of fire coal.

Research shows that the high-temperature corrosion mainly depends on the temperature of the wall of the water wall and the concentration of the near-wall reducing atmosphere, and H is generated under the high-temperature condition₂And S and other corrosive gases and the water wall tube undergo chemical reaction, so that the tube wall is thinned and even the tube is burst. However, at present, the high-temperature corrosion condition of the water wall pipe has no mature online monitoring method, the experimental test adjustment method has obvious hysteresis, and meanwhile, after the operation mode or the coal-fired components are changed, the research results of the experimental adjustment are mostly not applicable any more.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the power station boiler water-cooled wall with the on-line monitoring function and the monitoring method thereof, the design is reasonable, the structure is simple, the accuracy and the timeliness of the high-temperature corrosion monitoring of the water-cooled wall are effectively ensured, and the operation safety of the water-cooled wall is improved.

The invention is realized by the following technical scheme:

a power station boiler water wall with on-line monitoring comprises a water wall pipe, a water wall side pipe, a temperature sensor group, a water wall near-wall surface flue gas sampling pipe, a data transmission system and an upper computer;

the water-cooled wall pipes are connected in sequence through the arranged fins to form a water-cooled wall of the utility boiler;

the water wall side pipe is vertically arranged on the outer side of one water wall pipe; a plug extending into the water wall tube is also arranged along the axis direction of the water wall side tube;

the temperature sensor group comprises a water-cooled wall fire-facing side wall temperature sensor and a working medium temperature sensor in a water-cooled wall pipe; the water-cooled wall fire-facing side wall temperature sensor is arranged on a water-cooled wall pipe connected with the water-cooled wall side pipe; the working medium temperature sensor in the water wall tube is arranged in the plug along the axis of the plug;

the inlet of the water-cooled wall near-wall flue gas sampling tube penetrates through the fins, and the outlet of the water-cooled wall near-wall flue gas sampling tube is connected with the input end of a flue gas component analyzer; the output ends of the water-cooled wall fire-facing side wall temperature sensor, the water-cooled wall tube working medium temperature sensor and the flue gas component analysis instrument are connected with an upper computer through a data transmission system.

Further, the water wall side tube and the water wall tube are integrally forged; the water wall side tube is provided with a first temperature measuring hole at the fin towards the fire side direction, the thickness between the inner wall of the first temperature measuring hole and the inner wall of the water wall tube meets the minimum safe wall thickness, and a water wall fire side wall temperature sensor is arranged in the first temperature measuring hole.

Furthermore, the plug is T-shaped, the long end of the plug is arranged along the axis of the side pipe of the water wall, and the tip is arranged at one end extending into the water wall pipe.

Furthermore, a second temperature measuring hole is formed in the plug from the short end to the tip of the long end vertically, the depth of the second temperature measuring hole extends into the inner wall of the water wall tube, and a working medium temperature sensor in the water wall tube is arranged in the second temperature measuring hole.

Furthermore, the plug is made of the same material as the water wall tube and is welded and fixed with the water wall side tube.

Furthermore, a flue gas filter and a flue gas cooler are arranged between the water-cooled wall near-wall surface flue gas sampling tube and the flue gas component analysis instrument.

Furthermore, the flue gas filter is connected with the water-cooled wall surface-near flue gas sampling pipe through a flexible sealing joint.

Furthermore, a flue gas tail gas treatment device is arranged at a flue gas outlet of the flue gas component analysis instrument.

A method for monitoring the water-cooled wall of a power station boiler by on-line monitoring comprises the following steps,

monitoring and storing water wall temperature data acquired by a water wall fire facing side wall temperature sensor and a working medium temperature sensor in a water wall tube, which are input by a data transmission system, and HS concentration data at a position of a water wall near-wall surface flue gas sampling tube by an upper computer;

when the monitored temperature of the water cooling wall fire facing side wall temperature sensor exceeds a preset limit value, the upper computer sends out an alarm signal;

when the HS concentration transmitted by the flue gas component analysis instrument exceeds a preset limit value, the upper computer sends out an alarm signal.

Furthermore, when the temperature of the metal wall of the water wall is abnormally increased, the working medium temperature sensor in the water wall tube monitors and stores the temperature data of the working medium in the water wall tube.

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

the invention combines the generation of high-temperature corrosion of the water-cooled wall with the metal temperature of the wall of the water-cooled wall and the concentration (CO, H) of reducing gas near the wall surface₂S, etc.) directly related to the theoretical foundation, and the water wall is arranged by arranging a side pipe of the water wallThe fire facing side wall temperature sensor is arranged in the water-cooled wall tube, and the water-cooled wall near-wall flue gas sampling tube is also arranged, so that the metal wall temperature of the fire facing side of the water-cooled wall and the reducing atmosphere concentration of the water-cooled wall near-wall can be tested and recorded at the same time, and the risk of high-temperature corrosion of the water-cooled wall is monitored in real time through the data transmission system, the upper computer and the flue gas component analysis instrument; when the system gives an alarm, an operator can take effective combustion adjustment or hydrodynamic force adjustment measures in time to reduce the temperature of the metal wall or reducing atmosphere in the water wall area, and the method is favorable for finding and eliminating the high-temperature corrosion of the water wall in time, so that the high-temperature corrosion of the water wall pipe is relieved or eliminated, and the functions of real-time, accurate and online monitoring and early warning of the high-temperature corrosion state of the water wall pipe of the boiler are realized; meanwhile, the on-line monitoring of the working medium temperature sensor in the water-cooled wall pipe can be realized, the analysis of the reason of sudden rise of the wall temperature can be timely carried out, reliable data support is provided for guaranteeing the safe operation adjustment of the water-cooled wall, and the on-line monitoring system has important significance for the safe operation of the water-cooled wall of the power station boiler.

Furthermore, the water wall side tube is integrally forged by the same material as the water wall tube, so that the stability and the reliability of the system are effectively ensured, and the accuracy of data is further improved; meanwhile, the first temperature measuring holes are formed in the fins of the water wall side tube towards the fire side, and the thickness between the inner wall of each first temperature measuring hole and the inner wall of the tube is guaranteed to meet the minimum safe wall thickness, so that the water wall side tube is safe and reliable.

Furthermore, the water wall adopts a mode that the plug is vertically provided with a second temperature measuring hole from the short end to the long end tip, and the second temperature measuring hole is deep into the inner wall of the water wall tube, so that the accurate measurement in the tube can be carried out under the condition of ensuring the sealing safety of the whole water wall tube, and the reliability is strong.

Furthermore, the water wall adopts the same material for finish machining as the water wall tube for the plug, and the water wall side tube and the plug are fixedly connected by welding, so that the safety and the stability of the whole system can be effectively enhanced.

Furthermore, the water-cooled wall adopts a mode of arranging the flue gas filter and the flue gas cooler, so that impurities can be effectively prevented from entering the flue gas analysis instrument and the temperature of entering gas can be effectively reduced, the measurement accuracy is ensured, meanwhile, the safety and the reliability of the flue gas analysis instrument can be ensured, and the service life of the flue gas analysis instrument is further prolonged.

Furthermore, the water-cooled wall is connected with the flue gas filter and the flue gas sampling tube on the near wall surface of the water-cooled wall through the flexible sealing joint, so that the device is flexible, convenient and fast, has good sealing performance, and can effectively ensure the safe reliability of the operation of the system.

Furthermore, the water-cooled wall adopts a flue gas tail gas treatment device to treat the flue gas at the outlet of the flue gas component analysis instrument, and is environment-friendly, economical, reasonable and safe.

The water-cooled wall monitoring method starts from the principle of high-temperature corrosion and key monitoring parameters, forms an online monitoring system for simultaneously monitoring the temperature of the fire-facing side wall of the water-cooled wall, the temperature of working medium in the water-cooled wall pipe, the concentration of reducing gas on the near wall surface of the water-cooled wall and the concentration of reducing gas on the near wall surface of the water-cooled wall, and aims to accurately monitor the concentration of the metal wall on the fire-facing side and the reducing gas on the near wall surface of the water-cooled wall of the boiler in real time, provide accurate and timely data support for timely adjusting and eliminating the high-temperature corrosion phenomenon, effectively ensure the accuracy and timeliness of monitoring the high-temperature corrosion of the water-cooled wall and improve the running safety of the water-cooled wall; meanwhile, the temperature of the working medium temperature sensor in the water wall tube is monitored and stored, data support is provided for analysis and adjustment of abnormal working conditions such as sudden temperature rise of the metal wall of the water wall, and the aim of long-period safe operation of the water wall of the boiler is fulfilled.

Drawings

FIG. 1 is a schematic structural diagram of the water wall in the embodiment of the invention.

In the figure: the device comprises fins 1, a water wall tube 2, a water wall fire-facing side wall temperature sensor 3, an upper computer 4, a water wall side tube 5, a welding seam 6, a plug 7, a working medium temperature sensor in the water wall tube 8, a data transmission system 9, a water wall near-wall flue gas sampling tube 10, a flexible sealing joint 11, a flue gas filter 12, a flue gas cooler 13, a flue gas component analyzer 14 and a flue gas tail gas treatment device 15.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

The invention relates to a power station boiler water-cooled wall for on-line monitoring, which is shown in figure 1 and comprises a water-cooled wall tube 2, fins 1, a water-cooled wall fire-facing side wall temperature sensor 3 and a water-cooled wall tube working medium temperature sensor 8, a water-cooled wall side tube 5, a plug 7, a water-cooled wall near-wall surface flue gas sampling tube 10, a flue gas filter 12, a flue gas cooler 13, a flue gas component analysis instrument 14, a flue gas tail gas treatment device 15, a data transmission system 9 and an upper computer 4, wherein the water-cooled wall tube is a water-cooled wall tube;

the number of the water wall tubes 2 is multiple, and the water wall tubes 2 are sequentially connected through fins 1 to form a water wall of the utility boiler;

the water wall side pipe 5 is integrally forged by the same material as the water wall pipe 2 and is vertically arranged on the outer side of one water wall pipe 2; the plug 7 is made of the same material as the water wall tube 2 in a finish machining mode, the plug 7 is T-shaped, the long end of the plug is arranged along the axis of the water wall side tube 5, and a tip is arranged at one end extending into the water wall tube 2; the water wall side tube 5 and the plug 7 are fixed by welding, and a welding seam 6 is formed at the welding position;

the wall thickness of the water wall side tube 5 is thickened and forged, a first temperature measuring hole is formed in the water wall side tube 5 at the fin 1 towards the fire side direction, and the thickness between the inner wall of the first temperature measuring hole and the inner wall of the water wall tube 2 meets the minimum safe wall thickness; a second temperature measuring hole is formed in the plug 7 from the short end to the tip of the long end vertically, and the depth of the second temperature measuring hole is deep into the inner wall of the water wall tube 2; the water cooling wall fire facing side wall temperature sensor 3 is arranged in the first temperature measuring hole; the working medium temperature sensor 8 in the water wall tube is arranged in the second temperature measuring hole;

the water-cooled wall near-wall flue gas sampling tube 10 extends into the fins 1 among the water-cooled wall tubes 2 and is connected with a flue gas filter 12 through a flexible sealing joint 11, and an outlet of the flue gas filtering system 12 is connected with a flue gas cooler 13;

the temperature and smoke component data tested by the water wall fire facing side wall temperature sensor 3, the water wall tube working medium temperature sensor 8 and the smoke component analyzer 14 are transmitted into the upper computer 4 in real time through the data transmission system 9, so that the on-line monitoring of the high-temperature corrosion state of the water wall near wall surface is realized.

Preferably, the upper computer 4 has temperature, CO concentration and H₂And the S concentration data display and storage functions are realized, and the S concentration data display and storage functions are provided with a judgment module and an alarm function. When the monitored temperature of the water wall fire facing side wall temperature sensor 3 and the H transmitted by the flue gas component analysis instrument 14₂And when the concentration of S exceeds a preset limit value, the upper computer 4 sends out an alarm signal.

Preferably, the upper computer 4 simultaneously monitors and stores the temperature of the working medium temperature sensor 8 in the water cooling wall tube and the temperature of the fire facing side wall temperature sensor 3 of the water cooling wall tube for analyzing and researching the reason of the over-temperature of the tube wall of the water cooling wall tube 2, so that effective control measures can be taken from the working medium side and the smoke side.

Preferably, the flue gas outlet of the flue gas component analysis instrument 14 is further provided with a flue gas tail gas treatment device 15 for treating harmful substances in the flue gas.

For further understanding of the system of the present invention, the operation thereof will now be described:

the system breaks through the technical idea of the traditional fixed working condition test adjustment optimization, provides the on-line water-cooled wall for monitoring the metal wall temperature of the water-cooled wall tube 2, the working medium temperature in the tube and the near-wall surface reducing atmosphere on line, obtains the real-time monitoring results of the metal wall temperature of the water-cooled wall and the near-wall surface reducing gas concentration through the water-cooled wall fire-facing side wall temperature sensor 3 and the water-cooled wall near-wall surface flue gas sampling tube 10 under the actual operation state, and adopts the upper computer 4 to judge and early warn the risk of the high-temperature corrosion of the water-cooled wall near a measuring point so as to guide the actual operation optimization adjustment. Meanwhile, the monitoring result of the temperature of the working medium in the water wall tube under the working condition that the temperature of the metal wall of the water wall is abnormally increased is obtained through the working medium temperature sensor 8 in the water wall tube, so that the reason for sudden increase of the wall temperature can be more accurately analyzed, and a releasing or eliminating measure with stronger pertinence can be formulated, and finally, the long-period safe and stable operation of the water wall of the boiler is realized.

Based on any one of the systems, the invention also provides an on-line monitoring method for the water cooled wall of the power station boiler, which comprises the following steps,

the upper computer 4 monitors and stores the water-cooled wall temperature data which are input by the data transmission system 9 and are collected by the water-cooled wall fire-facing side wall temperature sensor 3 and the working medium temperature sensor 8 in the water-cooled wall tube, and the H at the position of the water-cooled wall near-wall surface flue gas sampling tube 10₂S concentration data;

when the monitored temperature of the water cooling wall fire facing side wall temperature sensor 3 exceeds a preset limit value, the upper computer 4 sends out an alarm signal;

h when the flue gas component analysis instrument 14 transmits₂And when the concentration of S exceeds a preset limit value, the upper computer 4 sends out an alarm signal.

When the temperature of the metal wall of the water wall is abnormally increased, the working medium temperature sensor 8 in the water wall tube monitors and collects temperature data of the working medium in the water wall tube 2.