阅读说明：本技术 一种凝汽器阴极保护机构及凝汽器阴极保护电位监测系统 (Condenser cathodic protection mechanism and condenser cathodic protection potential monitoring system ) 是由 薛飞 林斌 秦铁男 王亚东 张磊 林泽泉 于 2019-12-11 设计创作，主要内容包括：本发明涉及一种凝汽器阴极保护机构及凝汽器阴极保护电位监测系统,阴极保护机构包括多组牺牲阳极,牺牲阳极包括阳极本体、与阳极本体固定连接的安装件,阳极本体具有第一侧表面和第二侧表面,牺牲阳极安装在凝汽器水室内壁上时,第一侧表面靠近凝汽器内的钛换热管,第二侧表面远离凝汽器内的钛换热管,第一侧表面与安装件长度方向上的中心线之间的距离大于第二侧表面与安装件长度方向上的中心线之间的距离；本发明通过牺牲阳极的结构优化设计,使得牺牲阳极设计使用寿命至少达到18个月(1轮次检修周期时间),能够在设计使用周期内为凝汽器水室内壁提供有效保护,确保其有效保护寿命能够满足电厂检修周期的更换要求。(The invention relates to a condenser cathodic protection mechanism and a condenser cathodic protection potential monitoring system, wherein the cathodic protection mechanism comprises a plurality of groups of sacrificial anodes, each sacrificial anode comprises an anode body and a mounting piece fixedly connected with the anode body, each anode body is provided with a first side surface and a second side surface, when the sacrificial anode is mounted on the inner wall of a water chamber of a condenser, the first side surface is close to a titanium heat exchange tube in the condenser, the second side surface is far away from the titanium heat exchange tube in the condenser, and the distance between the first side surface and the center line of the mounting piece in the length direction is greater than the distance between the second side surface and the center line of the mounting piece in the length direction; according to the invention, through the structural optimization design of the sacrificial anode, the service life of the sacrificial anode is at least 18 months (1-time maintenance cycle time), the effective protection can be provided for the inner wall of the water chamber of the condenser in the design service life, and the effective protection life can meet the replacement requirement of the maintenance cycle of a power plant.)

1. The utility model provides a condenser cathodic protection mechanism, cathodic protection mechanism is including locating multiunit sacrificial anode on the condenser hydroecium inner wall, sacrificial anode include the anode body, with anode body fixed connection's installed part, its characterized in that: the utility model discloses a sacrificial anode, including positive pole body, installed part, sacrificial anode, titanium heat exchange tube, first side surface and distance between the last central line of installed part length direction are greater than the second side surface with distance between the last central line of installed part length direction.

2. The condenser cathodic protection mechanism of claim 1, wherein: establish the second side surface with the distance between the central line on the installed part length direction is a, the first side surface with the distance between the central line on the installed part length direction is a +4mm ~ a +6 mm.

3. The condenser cathodic protection mechanism of claim 1, wherein: the cross section profile of the long block-shaped anode body is trapezoidal, and the center line of the anode body in the length direction does not coincide with the center line of the mounting piece in the length direction in the width direction of the anode body.

4. The condenser cathodic protection mechanism of claim 3, wherein: when the sacrificial anode is arranged on the inner wall of the water chamber of the condenser, a gap is formed between the bottom surface of the anode body and the inner wall of the water chamber of the condenser.

5. The condenser cathodic protection mechanism of claim 1, wherein: the mounting part is provided with a buried section buried in the anode body and metallurgically combined with the anode body, and a mounting section connected to two ends of the buried section and positioned outside the anode body, and a plurality of through holes are sequentially arranged on the buried section at intervals.

6. The condenser cathodic protection mechanism of claim 1, wherein: the anode body is made of aluminum-zinc-indium-magnesium-titanium-aluminum alloy.

7. The utility model provides a condenser cathodic protection potential monitoring system which characterized in that: the monitoring system is used for monitoring and judging the protection effect of the cathode protection mechanism recited in any one of claims 1 to 6.

8. The condenser cathodic protection potential monitoring system according to claim 7, characterized in that: the monitoring system comprises a potential monitoring sensor for sensing potential difference signals of coupling potentials among the potential monitoring sensor, the titanium heat exchange tube and the heat exchange tube plate in the water chamber of the condenser, carbon steel on the inner wall of the water chamber and the sacrificial anode, an AD expansion module for performing analog-to-digital conversion on the potential difference signals, a data processing module for performing logic calculation on digital signals converted by the AD expansion module, and an upper computer for displaying calculation results of the data processing module.

9. The condenser cathodic protection potential monitoring system according to claim 8, characterized in that: the potential monitoring sensor is provided with a silver/silver chloride reference electrode.

10. The condenser cathodic protection potential monitoring system according to claim 8, characterized in that: the both ends of condenser hydroecium all are provided with the electric potential monitoring sensor, by the wire that the electric potential monitoring sensor was drawn is connected with AD expansion module's negative pole electricity, the both ends of condenser hydroecium still are fixed with the copper nose, AD expansion module's positive pole pass through the wire with the copper nose electricity is connected.

Technical Field

The invention relates to the field of corrosion prevention of inner walls of water chambers of condensers, in particular to a cathode protection mechanism of a condenser and a cathode protection potential monitoring system of the condenser.

Background

The condenser is a heat exchange device for converting water vapor discharged after the drive turbine applies work into condensed water, and is an important component of the turbine unit. The working medium state change in the power plant operation follows a Rankine cycle. The condenser is one of the important components of the cycle and functions as a heat sink in the thermodynamic cycle of the turbine plant. Firstly, high vacuum is established and maintained at the steam exhaust port of the steam turbine, and secondly, water condensed from the steam exhaust of the steam turbine is used as system water supply to form a complete cycle. The exhaust temperature and the exhaust pressure of the steam turbine are reduced, the heat cycle efficiency can be improved, and meanwhile, the condenser keeps higher vacuum degree.

The condenser mainly comprises a carbon steel cylinder and a titanium alloy material cooling pipe, the heat exchange medium is seawater, the condenser has large geometric dimension, and the heat exchange process of internal steam flowing and condensing is complex. In terms of material corrosion, the conditions can be summarized into a strong corrosive couple pair, a strong corrosive medium, a complex vapor/liquid two-phase mass transfer condition and a complex stable change rule, and the factors directly cause the inner wall of the water chamber of the condenser to have a very high corrosion tendency. At present, the protection of the inner wall of a water chamber of a condenser mainly adopts a physical isolation and electrochemical protection mode, specifically, single rubber lining, rubber lining + impressed current cathodic protection, rubber lining + sacrificial anode cathodic protection and the like. Based on the extreme corrosive environment in the condenser water chamber, once the protective measures of the condenser water chamber fail, the corrosion perforation of the water chamber shell is caused, and the safe operation of a unit is influenced.

The cathodic protection is to apply a certain cathodic current to the protected metal to make the electrode potential of the protected metal deviate from the equilibrium electrode potential in the negative direction, so that the reaction process of the anode is inhibited, and the corrosion of the metal is effectively controlled. The cathodic protection technology is divided into an impressed current protection technology and a sacrificial anode protection technology. By sacrificial anodic protection is meant the connection of the protected metal to another metal or alloy of lower electrode potential so that the metal or alloy is preferentially consumed as the anode and the protected metal is protected by the cathodic current. The sacrificial anode protection system has the advantages of stable protection effect, mature installation process and no need of frequent maintenance and management in the later operation process, is suitable for the working conditions without maintenance conditions or the working conditions that the outside cannot provide power supply, and is widely used in the engineering at present.

In the existing related patents, CN203890445U "condenser cathode protection device", CN205722818U "electrochemical protection device for condenser water chamber of nuclear power plant", and CN205122201U "sacrificial anode block device for condenser of nuclear power plant all adopt zinc alloy as the sacrificial anode of the inner wall of the condenser water chamber, and the sacrificial anode containing the steel sleeve iron core is installed and welded on the screw rod of the inner wall of the water chamber, so that the sacrificial anode and the inner wall of the water chamber are tightly installed and electrically connected by using a single installation bolt. However, when the zinc alloy sacrificial anode is used in the field, the problem that the sacrificial anode is too fast to be dissolved for a plurality of times and cannot meet the design protection age of the anode is solved, and even after the zinc alloy anode is exhausted, a cross iron core in the anode is corroded and broken to scratch a heat exchange tube plate.

Disclosure of Invention

The invention aims to provide a condenser cathode protection mechanism for overcoming the defects of the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a condenser cathodic protection mechanism, cathodic protection mechanism is including locating the multiunit sacrificial anode on the condenser hydroecium inner wall, sacrificial anode includes the anode body, with anode body fixed connection's installed part, the anode body is long blocky, the installed part is long slabby, the installed part runs through the anode body along the length direction of anode body, the anode body has along its length direction extension and corresponding first side surface and second side surface, when sacrificial anode installs on condenser hydroecium inner wall, first side surface is close to the titanium heat exchange tube in the condenser, the titanium heat exchange tube in the condenser is kept away from to second side surface, distance between the central line on first side surface and the installed part length direction is greater than the distance between the central line on second side surface and the installed part length direction.

Preferably, let a be the distance between the second side surface and the central line of installed part length direction, the distance between the first side surface and the central line of installed part length direction be a +4mm ~ a +6 mm.

Preferably, the cross-sectional profile of the anode body in an elongated block shape is trapezoidal, and the center line in the length direction of the anode body and the center line in the length direction of the mounting member do not coincide in the width direction of the anode body.

Preferably, when the sacrificial anode is installed on the inner wall of the water chamber of the condenser, a gap is formed between the bottom surface of the anode body and the inner wall of the water chamber of the condenser.

Preferably, the mounting member has a buried section buried in the anode body and metallurgically bonded to the anode body, and a mounting section connected to both ends of the buried section and located outside the anode body, and the buried section is sequentially provided with a plurality of through holes at intervals.

Preferably, the length and the width of the bottom surface of the anode body are 395-405 mm and 130-140 mm respectively; the length and the width of the top surface of the anode body are 375-385 mm and 110-120 mm respectively; the height of the anode body is 125-135 mm.

Preferably, the anode body is made of aluminum-zinc-indium-magnesium-titanium-aluminum alloy.

The invention discloses a monitoring system for the cathodic protection potential of a condenser, which is used for monitoring and judging the protection effect of a cathodic protection mechanism.

Preferably, the monitoring system comprises a potential monitoring sensor for sensing potential difference signals of coupling potentials between the potential monitoring sensor and the titanium heat exchange tube and the heat exchange tube plate in the water chamber of the condenser as well as carbon steel and the sacrificial anode on the inner wall of the water chamber, an AD expansion module for performing analog-to-digital conversion on the potential difference signals, a data processing module for performing logic calculation on digital signals converted by the AD expansion module, and an upper computer for displaying calculation results of the data processing module.

Preferably, the potentiometric monitoring sensor is provided with a silver/silver chloride reference electrode.

Preferably, both ends of the condenser water chamber are provided with potential monitoring sensors, a lead led out by the potential monitoring sensors is electrically connected with a negative electrode of the AD expansion module, both ends of the condenser water chamber are further fixed with copper noses, and a positive electrode of the AD expansion module is electrically connected with the copper noses through the lead.

Due to the implementation of the technical scheme, compared with the prior art, the invention has the following advantages:

according to the invention, through the eccentric design of the anode body and the mounting part, the volume of the anode body close to the titanium heat exchange tube side is increased, and the anode body on the titanium tube plate side is prevented from being dissolved, consumed and dropped off preferentially.

Drawings

FIG. 1 is a schematic view of a main-direction cross-sectional structure of a sacrificial anode installed on the inner wall of a water chamber of a condenser according to the present invention;

FIG. 2 is a schematic view of a top view structure of a sacrificial anode mounted on the inner wall of a water chamber of a condenser in accordance with the present invention;

FIG. 3 is a schematic diagram of a side view structure of a sacrificial anode mounted on the inner wall of a water chamber of a condenser according to the present invention;

FIG. 4 is a schematic diagram of a side view structure of a potential monitoring sensor of the present invention installed on the inner wall of a water chamber of a condenser;

FIG. 5 is a schematic diagram of the structure of the potential monitoring system according to the present invention;

wherein: 100. the inner wall of the water chamber of the condenser; 10. an anode body; 11. a mounting member; 1001. a through hole; 101. a first side surface; 102. a second side surface; 20. a potential monitoring sensor; 21. a copper nose; m1, potential isolation transmitter; m2, AD extension module; m3, a data processing module; m4 and an upper computer; l1, bolt bar.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples.

As shown in fig. 1 to 5, a cathode protection mechanism for a condenser comprises a plurality of sets of sacrificial anodes disposed on an inner wall 100 of a water chamber of the condenser, each sacrificial anode comprises an anode body 10 and a mounting member 11 (iron core) fixedly connected to the anode body 10, the anode body 10 is in a long block shape, the cross-sectional profile of the long block-shaped anode body 10 is trapezoidal, the mounting member 11 is in a long plate shape, the mounting member 11 penetrates through the anode body 10 along the length direction of the anode body 10, the anode body 10 has a first side surface 101 and a second side surface 102 extending along the length direction and corresponding to each other, when the sacrificial anode is mounted on the inner wall 100 of the water chamber of the condenser, the first side surface 101 is close to a titanium heat exchange tube in the condenser, the second side surface 102 is far away from the titanium heat exchange tube in the condenser, the distance between the first side surface 101 and the center line of the mounting member 11 in the length direction is greater than the distance, the center line in the length direction of the anode body 10 and the center line in the length direction of the mount 11 are spaced apart in the width direction of the anode body 10, i.e., do not coincide.

The anode body 10 is made of aluminum-zinc-indium-magnesium-titanium-aluminum alloy, the capacitance of the anode body is 3 times that of a zinc alloy sacrificial anode, the material and the components of the anode body 10 meet the requirements of GB/T4948, and the length and the width of the bottom surface of the anode body 10 are 400mm and 135mm respectively; the length and width of the top surface of the anode body 10 are 380mm and 115mm, respectively; the height of the anode body 10 is 130mm, the net weight is 16.4kg, and the gross weight is 18.5 kg;

specifically, let a be the distance between the second side surface 102 and the center line in the longitudinal direction of the mounting member 11, and a +5mm be the distance between the first side surface 101 and the center line in the longitudinal direction of the mounting member 11. That is, the distance between the center line of the anode body 10 in the longitudinal direction and the center line of the mounting member 11 in the longitudinal direction is deviated by 5mm, and the eccentric design of the anode body 10 and the mounting member 11 increases the volume of the anode body 10 near the titanium heat exchange tube side, thereby preventing the anode body 10 on the titanium tube plate side from being preferentially dissolved, consumed and dropped.

The mounting member 11 has a buried section buried in the anode body 10 and metallurgically bonded to the anode body 10, and a mounting section connected to both ends of the buried section and located outside the anode body 10, and a plurality of through holes 1001 are sequentially provided at intervals in the buried section (1 through hole 1001 of ∅ 10mm is opened at an interval of 50mm, increasing the area of fusion connection of the anode bodies 10 on the upper and lower sides of the iron core). When the sacrificial anode is arranged on the inner wall 100 of the water chamber of the condenser, a gap is formed between the bottom surface of the anode body 10 and the inner wall 100 of the water chamber of the condenser,

mounting holes are formed in the mounting sections on the two sides and are fixedly connected with the inner wall 100 of the water chamber of the condenser through bolt rods L1, namely a T-shaped sacrificial anode structure mounted by a two-point type support is adopted, a larger anode body 10 can be supported, the bottom surface of the anode body 10 can be suspended, and the consumption of the anode body 10 is slower and uniform;

the sacrificial anodes to be installed are installed on M20 installation bolts on the inner wall 100 of the water chamber of the condenser one by one and are fastened by M20 nuts, 8 groups of sacrificial anodes are installed in each water chamber, and the first side surface 101 of the anode body 10 is close to the side of a titanium heat exchange tube in the water chamber of the condenser when the sacrificial anodes are installed;

in addition, 316L stainless steel with the length, width and height of 600mm, 50mm and 10mm is used as the material of the mounting piece 11 (iron core), and the bending surface of the iron core is reduced through the structural form of the iron core;

in order to ensure that the anode body 10 and the iron core are completely metallurgically fused, the fusion contact area of the anode body 10 and the iron core is microscopically increased, the part (embedded section) of the stainless steel iron core poured in the anode body 10 is subjected to surface sand blasting before the anode body 10 is poured, the surface cleanliness is not lower than Sa2.5, and the surface roughness is Ra12.5. The iron core embedding section is provided with a through hole 1001 structure and surface spraying treatment, so that the falling of the anode caused by uneven dissolution of the anode can be prevented;

the invention aims at the defects in the prior art, and starts from multiple aspects such as sacrificial anode material, sacrificial anode iron core structure, anode service life calculation and the like, the invention increases the volume of the anode body 10 close to the titanium heat exchange tube side through the eccentric design of the anode body 10 and the mounting piece 11, and prevents the anode body 10 on the titanium tube plate side from being dissolved, consumed and dropped preferentially, through the structural optimization design of the sacrificial anode, the service life of the sacrificial anode design at least reaches 18 months (1-round maintenance cycle time), the effective protection can be provided for the inner wall 100 of the water chamber of the condenser in the design service cycle, and the effective protection service life can meet the replacement requirement of the power plant maintenance cycle.

In addition, the monitoring system is used for monitoring and judging the protection effect of the cathodic protection mechanism. The monitoring system comprises a potential monitoring sensor 20 for sensing a potential difference signal of a coupling potential between the potential monitoring sensor and a titanium heat exchange tube and a heat exchange tube plate in a water chamber of the condenser, carbon steel on the inner wall of the water chamber and a sacrificial anode, a potential isolation transmitter M1 for isolating and filtering the potential difference signal transmitted by the potential monitoring sensor 20, an AD expansion module M2 for performing analog-to-digital conversion on the potential difference signal, a data processing module M3 for performing logic calculation on a digital signal converted by the AD expansion module M2, and an upper computer M4 for displaying a calculation result of the data processing module M3.

Potential monitoring sensors 20 are arranged at two ends of the condenser water chamber (the potential monitoring sensors 20 are arranged at openings in the inner walls of the two ends of the condenser water chamber by using hexagon bolts of M18), a lead led out from the potential monitoring sensors 20 is electrically connected with a negative electrode of the AD expansion module M2, a copper nose 21 is further fixed at one end of the condenser water chamber, and the positive electrode of the AD expansion module M2 is electrically connected with the copper nose 21 through a lead.

In this example, the potential monitoring sensor 20 is provided with a silver/silver chloride reference electrode. The potential difference of the coupling potentials of the reference electrode, the 100 titanium heat exchange tube on the inner wall of the water chamber of the condenser, the heat exchange tube plate, the carbon steel on the inner wall of the water chamber and the sacrificial anode is measured to judge the cathodic protection potential of the inner wall 100 of the water chamber of the condenser so as to monitor and evaluate the protection effect of the sacrificial anode. The recording, storage, inquiry and alarm of the measured potential data can be realized.

The above embodiments are merely illustrative of the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the content of the present invention and implement the invention, and not to limit the scope of the invention, and all equivalent changes or modifications made according to the spirit of the present invention should be covered by the scope of the present invention.