JPH07117355B2 - How to control dirt on copper alloy parts - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling contamination of a copper alloy member, and more particularly to a copper alloy cooling pipe in equipment such as condensers and heat exchangers using seawater as cooling water. The present invention relates to a method capable of partially and in real time grasping the degree of dirt such as slime formed on the surface of a tube sheet or the like (hereinafter referred to as a copper alloy member) and managing the dirt.

[0002]

2. Description of the Related Art The inner surface of a copper alloy member in facilities such as condensers and heat exchangers that use seawater as cooling water is apt to be corroded by inlet water flow and deposit attack due to the flow of cooling water. Therefore, as a means for suppressing such corrosion, a combination of a cathodic protection method such as an external power supply method and a method of supplying iron ions into cooling water to form an iron film on the surface of a copper alloy member has been widely used in recent years. There is.

However, in such equipment, since seawater or the like is used as cooling water, microorganisms (usually plankton) in the cooling water and manganese ions floating from the sea bottom adhere to the inner surface of the copper alloy member ( (Generally referred to as slime), there is a problem such as a decrease in the anticorrosion effect of the iron film and a decrease in the heat transmission efficiency of the equipment.

Therefore, it is necessary to appropriately remove stains on the member due to such slime by a cleaning method such as soft ball cleaning, hard ball cleaning, jet cleaning and brush cleaning. However, in order to perform brush cleaning or jet cleaning, it is necessary to stop the equipment for a long time (several days),
Also, soft ball cleaning and hard ball cleaning can be performed during operation, but it is necessary to suspend the equipment for cleaning evaluation. Furthermore, the above-mentioned stain generation condition is susceptible to various factors such as water temperature and season, and is not regular.

Therefore, in order to minimize the downtime of the equipment required for cleaning and to effectively clean the dirt of the copper alloy member concerned, it is necessary to grasp the condition of dirt properly and without stopping the equipment. is there.

However, in order to visually grasp the state of dirt, the equipment must be stopped, and a quantitative judgment cannot be made. In addition, it takes a considerable amount of time and effort to collect and analyze the deposits and obtain the results, and since the equipment must be stopped during the collection, the state of dirt can be directly grasped from the amount of deposits. Is also difficult.

As a method of grasping such dirt, a method of utilizing a vacuum deviation value has been generally used conventionally. This method uses the fact that if the copper alloy member is contaminated with dirt, it causes a reduction in heat transmission efficiency and affects the degree of vacuum on the steam side of equipment such as a power plant. It has been empirically found that the vacuum degree deviation value is closely related to the degree of contamination.
The vacuum degree deviation value is a value of (measured vacuum degree)-(estimated vacuum degree), and the expected vacuum degree is a value calculated by each facility based on the capacity of the facility, the number of pumps, cooling water temperature, and the like.

By the way, facilities such as a condenser and a heat exchanger are usually provided with a plurality of heat exchange units (condenser; each unit is generally provided with a plurality of cooling pipes and two water chambers). It is known that the state of dirt is different for each. However, in the case of using the above-mentioned vacuum degree deviation value, since the steam side of the equipment is usually one in the whole equipment, the state of contamination can be grasped only on average in the whole equipment. Therefore, conventionally, it is difficult to detect when dirt is concentrated on a part of the equipment, and even if it is sufficient to wash only one unit with a soft ball early, as a result, all units are brush-washed as a result. There were times when I was forced to do so.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and relates to a copper alloy member in equipment such as condensers and heat exchangers that use seawater or the like as cooling water. Provided is a method capable of efficiently maintaining the equipment in an appropriate operating state by grasping the degree of dirt such as slime formed on the surface for each unit of the equipment in real time and managing the dirt. That is the purpose.

[0010]

Means and Actions for Solving the Problems As a result of intensive studies conducted by the present inventors to solve the above problems, the spontaneous potential of the copper alloy member has a very close relationship with the degree of contamination of the copper alloy member. The inventors have found that and reached the present invention.

That is, the method for controlling the contamination of a copper alloy member of the present invention is a method for preventing corrosion of a copper alloy member used for equipment that requires cooling water by performing an anticorrosion method and forming an iron film on the surface of the member. In controlling the contamination of the copper alloy member during corrosion prevention in combination with the method, a current circuit for energizing the copper alloy member from the electrode provided in the cooling water through the cooling water and the potential of the copper alloy member Using a current-carrying device having a potential measuring circuit for measuring, a step of obtaining a natural potential at which the potential of the cathode (copper alloy member) is attenuated and stabilized after the current is temporarily cut off, and the natural potential is previously set. The method is characterized by comprising a step of comparing with a predetermined reference value and a step of cleaning dirt of the copper alloy member when the natural potential becomes nobler than the reference value.

The copper alloy member which is the object of the present invention has its surface in contact with cooling water such as seawater or fresh water, and is protected from corrosion by using both the anticorrosion method and the corrosion prevention method using an iron coating. The above-mentioned cathodic protection method and anticorrosion method using an iron film are not particularly limited. For example, as an anticorrosion method using an iron film, there is a method of supplying iron ions for forming an iron film by introducing a ferrous sulfate solution or an iron electrolysis method using an iron electrode.

In the present invention, the natural potential obtained as an index of the degree of contamination is the potential of the copper alloy member (cathode) when not energized (depolarization stable potential), that is, it is attenuated and stabilized after the energization is cut off. It is the cathode potential of the place where it did.
Usually, it takes about 5 minutes after the power supply is cut off for the cathode potential to reach the true natural potential.

In the present invention, the above-mentioned spontaneous potential may be actually measured, but from the viewpoint of the effect of anticorrosion and measurement work, it is preferable to shorten the energization interruption time as much as possible to obtain the spontaneous potential. The following formula (1) En = E ₆₀ + (E ₆₀ −E ₅₀ ) (1) [In the formula (1), En is a natural potential, E ₅₀ is a cathode potential after 50 seconds from interruption of energization, E ₆₀ Is the cathode potential 60 seconds after the power supply is cut off.] Is most preferable. Since the natural potential calculated based on the following equation (1) substantially matches the actually measured value, it is possible to calculate the natural potential in about 1 minute by this method.

The energizing device used in the present invention is
As long as it has a current circuit for energizing the copper alloy member from the electrode provided in the cooling water through the cooling water and a potential measuring circuit for measuring the potential of the copper alloy member, it can also serve as a cathodic protection device by an external power supply method. It is preferable to use one because the apparatus does not become complicated. Further, such an energization device may be provided separately from the cathodic protection device. When the target equipment is composed of a plurality of units, it is preferable that the energizing device is provided for each unit to obtain the natural potential of each unit.

In the present invention, the natural potential is compared with a predetermined reference value, and when the natural potential is nobler than the reference value, the copper alloy member is cleaned. Since the above-mentioned reference value changes depending on operating conditions, environmental conditions, etc., it is difficult to set it uniformly, and it is necessary to set it for each equipment or each unit. In setting the above-mentioned reference value, it is preferable to empirically determine such that the reduction of the anticorrosion effect of the iron coating and / or the reduction of the heat transmission efficiency of the equipment does not exceed the allowable range. Specifically, for example, the amount of deposits on the copper alloy member may be measured for a certain period of time and set from the data, or may be set with reference to the conventional vacuum degree deviation value. When the equipment is to be managed more strictly, the reference value may be set to a more base value. Further, the above reference value may be set with a certain width in consideration of variations in the natural potential, and cleaning may be performed when the value falls within the range, and cleaning may be performed immediately when the value becomes higher than the range.

The method for cleaning the dirt is not particularly limited and may be selected according to the degree of dirt, etc., but the equipment can be used for a short period of time (several hours), so soft ball cleaning or hard ball cleaning is possible. Washing is preferred, and soft ball washing is most preferred, with less risk of removing good iron coatings.

Although the above-described method for controlling the contamination of the copper alloy member of the present invention can sufficiently control the contamination, of course, in order to be more careful, the conventional method of utilizing the deviation value of the degree of vacuum is used. You may perform it together with.

Further, it is more preferable to use the method for controlling the contamination of the copper alloy member of the present invention together with the method for measuring the resistance of the iron film by the present applicants (Japanese Patent Application Laid-Open No. 59-147247). This method for measuring the resistance of the iron film is such that, when measuring the resistance value of the iron film formed on the surface of the copper alloy member, the iron film resistance value (Rf), the polarization resistance value (Rd), and the measured IR are superimposed and measured. It is possible to separate and measure only the iron film resistance value (Rf) from the third component resistance value (Rx) including the drop, and grasp the state of the iron film based on the iron film resistance value (Rf). It's a way to be able to.

That is, the method for measuring the iron film resistance is as follows.
In the control of the anticorrosion iron film when the anticorrosion method is used in combination with the anticorrosion method and the anticorrosion method by forming the iron film on the surface of the copper alloy member used for equipment requiring cooling water Using an energizing device having a current measuring circuit and a potential measuring circuit, the cathode potential and energizing current value I during energization
And a step of measuring the cathodic potential, which is temporarily cut off and attenuated, until the cathodic potential reaches a natural potential at which the cathodic potential is stable or until the natural potential can be predicted. And a step of obtaining a potential change value V, which is a difference between the cathode potential after the power supply is cut off and the natural potential, at each time after the power supply is cut off, and an attenuation curve with respect to a time of logarithm logV of the potential change value ( A), a step of obtaining a regression line (b) with respect to time of the logarithm logV after the attenuation curve (a) has changed from an exponential decreasing tendency to a linear decreasing tendency, and the attenuation curve The step of obtaining the iron film resistance component potential Vf, which is the difference between (a) and the regression line (b), at each time after the current is cut off, and the regression with respect to the time of the logarithm logVf of the iron film resistance component potential Vf. A step of obtaining a straight line (C), Using the process of obtaining the iron film resistance component potential Vf (t = 0) at the moment when the energization is cut off from the return line (C) and the obtained iron film resistance component potential Vf (t = 0) and the energization current value I From the following formula Rf = {Vf (t = 0) / I} × {S / K} [in the formula, Rf is the resistance value of the iron film, S is the area to be energized, and K is the distribution ratio of the energized current] Resistance value R
and a step of obtaining f. The iron film resistance value Rf is closely related to the iron film state, so the iron film resistance value Rf is used to grasp the state of the iron film, and the iron film can be controlled by adjusting the amount of energizing current. This is a possible method.

In the above method of measuring the resistance of the iron film, the spontaneous potential is obtained in the process, but it has not been found that the spontaneous potential is closely related to the degree of contamination. It was a value merely required for obtaining the iron film resistance value Rf.

By performing such a method for measuring the resistance of the iron film and the method for controlling the contamination of the copper alloy member of the present invention, the contamination can be controlled from the natural potential, and the resistance of the iron coating can be determined from the resistance Rf of the iron coating. The state can be grasped by the same device and at the same time, and the equipment can be more efficiently maintained in the proper operating state.

Hereinafter, the case where the method for controlling the contamination of the copper alloy member of the present invention and the method for measuring the iron film resistance are performed together will be described in more detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of an energizing device for carrying out the control method of the present invention in a condenser for carrying out an anticorrosion method by an external power supply method as an anticorrosion method.

In FIG. 1, an electrode 1 for energization and a zinc reference electrode 4 for detecting the potentials of the tube plate surface 2 and the cooling pipe 3 (copper alloy member) are installed in a water chamber 5.
The DC power supply 6 is a current measuring circuit (A in the figure).
And a potential measuring circuit (E in the figure), and the energizing current is adjusted so as to maintain the proper potential checked by the reference electrode 4. Further, 7 in FIG. 1 is a measuring device described later. Further, although not shown, an iron electrolysis device, a ferrous sulfate introduction device, or an iron electrode is provided in the condenser to supply iron ions into the cooling water.

In carrying out the method for controlling contamination of a copper alloy member according to the present invention, the spontaneous potential is measured by the potential measuring circuit after the current is temporarily cut off. When the natural potential is calculated based on the above equation (1),
The cathode potential 50 seconds and 60 seconds after the power supply is cut off is measured by the potential measuring circuit, and the natural potential is obtained by the measuring device 7 from the data. Then, the measuring device 7 compares the natural potential with a predetermined reference value, and when the natural potential becomes nobler than the reference value, a means (not shown) for cleaning the contamination of the copper alloy member is activated. The means for activating the cleaning means is not particularly limited, and a signal may be generated in such a case, and the cleaning means may be manually activated or automatically activated.

When the above-mentioned iron film resistance measuring method is also performed, the current measuring circuit and the potential measuring circuit measure the cathode potential during energization, the energizing current value I and the cathode potential after energization interruption. Data from measuring device 7
Thus, the iron film resistance value Rf is obtained.

FIG. 2 is a block diagram of an example of the measuring device 7.

In FIG. 2, reference numeral 8 denotes a central processing unit (CPU) for performing arithmetic operations and control of the entire measuring apparatus, 9 denotes a measurement processing procedure, various parameters such as measured cathode potential, and predetermined reference values. A storage unit for storing, 10 is a switcher for an analog signal of electric potential and current input at a plurality of points, 11 is an analog-to-digital signal converter for converting an analog signal of electric potential and current into a digital signal, 12 is a measurement result, an operation command A dial that can display information such as a character, a keyboard portion 13 for inputting various parameters to the measuring device, and a reference numeral 14
Is a channel select switch unit used when performing measurement, 15 is a printer unit that can print the measurement result or the contents of setting parameters on paper, and 16 is a power supply unit that supplies power to the measuring device.

FIG. 3 shows the natural potential En and the iron film resistance value R.
It is a conceptual diagram for grasping the state of dirt and an iron film simultaneously from f.

There is a close relationship that the natural potential En becomes noble when the dirt due to slime or the like becomes large. Further, there is a close relation that the iron film resistance value Rf increases as the iron film becomes thicker and the corrosion resistance increases. Therefore, if a certain reference value is preset for the natural potential and the iron film resistance value,
Based on these values, as shown in FIG. 3, it is divided into four areas (divided by broken lines) in which the condition of the iron film and the dirt can be grasped.

Therefore, if a relationship diagram between the natural potential and the iron film resistance value as shown in FIG. 3 is prepared for each facility or unit and the target reference values thereof are set in advance, the measured natural potential and the iron film resistance value are determined. By plotting the values in the figure, it is possible to easily and simultaneously grasp the state of the contamination and the iron film of the copper alloy member of the target equipment.

If the resistance of the iron film is below the reference value, iron ions are supplied to strengthen the iron film, and if the natural potential is nobler than the reference value, dirt is removed by ball cleaning or the like. It is possible to give instructions.

FIG. 4 shows an example of a flow for carrying out the method of controlling the contamination of the copper alloy member of the present invention together with the method of measuring the iron film resistance and the method of utilizing the vacuum degree deviation value.

In FIG. 4, En is the natural potential (mV),
Rf is the iron film resistance (Ω · m ² ), Rd is the polarization resistance (Ω
M ² ), ΔH is the degree of vacuum deviation, t is the inlet water chamber temperature (° C.), grade A cleaning is brush cleaning, grade B cleaning is hard ball cleaning, and normal cleaning is soft ball cleaning.

As shown in the flow chart of FIG. 4, the natural potential En
, The iron film resistance value Rf, the vacuum deviation value ΔH, etc. are automatically measured, stored, calculated, commanded and the like. Natural potential En
And the iron film resistance value Rf are measured for each unit of the target equipment, and those values are plotted on a conceptual diagram based on the respective reference values as shown in FIG. 3 and the time transition of the plot is observed to observe the contamination. The condition and the condition of the iron film are grasped. Then, depending on the position of the plot in the above conceptual diagram, that is, the degree of contamination and the state of the iron film, it is determined for each unit whether or not to clean the inside of the pipe based on the degree of contamination such as slime and the operation or stop of the iron ion supply device. , It is possible to give qualified instructions in real time without stopping the operation of the equipment. In addition, the vacuum degree deviation value ΔH is also used to control the degree of contamination of the entire equipment, and if the vacuum degree deviation value ΔH exceeds the reference value, the entire equipment is completely stopped and brush cleaning is performed. is there. The reference values shown in FIG. 4 are examples of actual equipment and are empirically determined for each equipment or each unit.

[0037]

The present invention will be described in more detail based on the following examples, but the present invention is not limited thereto.

[0038] applying the management method of the present invention for one unit of Embodiment external power supply method sacrificial apparatus and condenser thermal power plant provided with an iron ion supply device according to the iron electrolysis by. In this example, the vacuum degree deviation value ΔH of only that unit was measured, so that the other units were closed. The target condenser uses seawater as cooling water, and is equipped with an aluminum brass cooling pipe and a Naval brass tube plate.

(Setting of Reference Value) First, a preliminary investigation was carried out for obtaining the reference values of the natural potential En and the iron film resistance value Rf of the subject condenser.

The interior of the condenser pipe in which organisms and slime deposits such as manganese scale were accumulated was jet-cleaned by performing cathodic protection and supplying iron ions for 6 months. After that, the cathodic protection and the iron ion supply were restarted, and the deposits in the tube were periodically collected for about 3 months to measure the deposit amount. At the same time as the collection, the self-potential E
n, the iron film resistance value Rf and the vacuum degree deviation value ΔH were measured.

The natural potential En is the saturated sweet potato electrode (SC
E) Based on the above equation (1) on the basis of the reference, as is clear from Table 1, the value is sufficiently coincident with the measured natural potential (cathode potential 5 minutes after the interruption of energization). It was

[0042]

[Table 1] .

FIG. 5 is a graph showing the relationship between the amount of deposits, the natural potential En and the iron film resistance value Rf, FIG. 6 is a graph showing the relationship between the amount of deposits and the vacuum deviation ΔH, and FIG. 7 is the vacuum degree. Deviation ΔH, spontaneous potential En and iron film resistance Rf
The graphs showing the relationship with are respectively shown.

As is clear from FIG. 5, the natural potential En has a close relationship with the amount of deposits, and as the amount of deposits in the tube (the amount of slime such as organisms and manganese scale) increases, the spontaneous potential En becomes more noble. The iron film resistance value Rf is decreasing.

Further, the vacuum degree deviation value ΔH has been widely used as an index for grasping the degree of contamination of the entire equipment in actual operation, and is closely related to the amount of deposits as shown in FIG. (However, since the amount of deposits is not uniform in all units in ordinary equipment that includes multiple units, it is not possible to determine the degree of contamination for each unit).

Therefore, in this embodiment, the spontaneous potential En and the iron film resistance value Rf are referred to with reference to the vacuum degree deviation value ΔH.
Determine the standard value of. That is, conventionally, the degree of vacuum deviation ΔH
When it is preferable to perform ball cleaning when the value becomes 2 to 3 mmHg, the vacuum degree deviation value ΔH = 3 mmHg is used as a reference. The amount of deposits corresponding to that value is 4.5 mg / cm ² from FIG. Therefore, the amount of deposit is 4.5 mg /
It can be seen from FIG. 5 that the reference value of the natural potential En can be set to −150 mV (SCE) in order to control the value to be cm ² or less. The iron film resistance value Rf is 0.6
It may be 5 Ω · m ² .

Further, based on the relationship between the vacuum degree deviation value ΔH, the natural potential En and the iron film resistance value Rf shown in FIG.
Each reference value may be determined directly from the vacuum degree deviation value ΔH.

When the respective reference values are set in this way, as is apparent from FIG. 5, as the spontaneous potential En becomes nobler than -150 mV, the contamination becomes remarkable (the amount of deposits is more than 4.5 mg / cm ² ) and the heat flow-through occurs. This leads to a decrease in efficiency, and the iron film resistance value Rf is less than 0.
When it is less than 65 Ω · m ² , it can be understood that the anticorrosion effect of the iron film is reduced due to the accumulation of dirt due to slime adhesion, so it becomes a warning notification standard for cleaning the inside of the pipe by ball cleaning or the like.

Therefore, based on each of the above reference values, a conceptual diagram can be obtained in which the states of the dirt and the iron film can be grasped at the same time from the natural potential En and the iron film resistance value Rf (FIG. 8). Then, by plotting the measured values of the self-potential and the resistance value of the iron film in the figure, it is possible to easily and simultaneously grasp the stains on the target member and the state of the iron film, and take appropriate action in real time. be able to.

In the case where the control is made more strict, for example, with reference to the vacuum deviation value ΔH = 2 mmHg, the natural potential En = −200 mV and the iron film resistance value R corresponding to that value are used.
The reference value may be f = 0.7Ω · m ² .

(Operation Management of Condenser) Next, the operation management of the condenser was actually performed using the above-mentioned reference value.

From the state in which the inside of the condenser pipe was jet-cleaned to clean the inner surface, the electrocorrosion and the iron ion supply were started, and the self-potential En, the iron film resistance value Rf, and the vacuum degree deviation were measured using the above-mentioned measuring device. The value ΔH was measured for about 4 months.

A graph obtained by plotting the measured values of the natural potential En and the iron film resistance value Rf in FIG. 8 is shown in FIG. In FIG. 9, black circles (•) indicate measured values, and arrow lines (→) indicate elapsed time after the start of measurement and operation of the condenser. It should be noted that the measurement was started in the late spring, and it is a record from the summer when the slime is easily generated to the early autumn.

When the measured values in FIG. 9 are viewed with time, the measured values are band-shaped and shifted, and can be roughly divided into 4 blocks. That is, immediately after the start of measurement (late spring), the inner surface of the tube was clean, the spontaneous potential En was about -400 mV, and the iron film resistance value Rf was 0.65 Ω · m ² or less, so the anticorrosion effect due to galvanic protection was effective. You can understand that you are working. During this period, iron ions are also supplied at the same time, so that the iron film resistance value Rf increases with the passage of time. Further, the spontaneous potential En gradually becomes noble with the formation of the iron film, but at this time, the anticorrosion effect by the electrocorrosion is dominant.

In early summer, the resistance value Rf of the iron film rapidly increases, and the spontaneous potential En is also becoming more noble. Therefore, it can be understood that the formed iron film is solidified and the adhesion of slime is started. It can be seen that during this period, the corrosion protection by the electrolytic protection gradually shifts to the corrosion protection by the iron film.

In the summer, the spontaneous potential En is remarkably noble and the iron film resistance value Rf is rapidly decreased from the peak value. Therefore, it is understood that the slime is prominent and the contamination is remarkable. it can. At the end of this period, the iron film resistance value Rf became 0.65 Ω · m ² or less, and the natural potential En also became noble from -150 mV, so ball cleaning (softening) was carried out according to the flow of FIG. At the end of the above period, the vacuum degree deviation value ΔH also exceeded 3 mmHg.

As a result of ball cleaning, in the late summer, the spontaneous potential En and the resistance value Rf of the iron film were restored to almost the same level as in the early summer (hatched portion in the figure), and the dirt and the iron film were restored to a good state. I can understand.

Table 2 shows the vacuum deviation ΔH, the iron film in the cooling pipe, and the degree of contamination during the above measurement period.

[0059]

[Table 2] .

As is clear from Table 2, the state of the dirt and the iron film is grasped from the spontaneous potential En and the iron film resistance value Rf by performing the dirt management method of the present invention and the iron film resistance measuring method together. The obtained results correspond well with the conventionally used vacuum degree deviation value ΔH and the iron film in the cooling pipe and the degree of contamination, and it is understood that the degree of contamination is particularly well understood.

Furthermore, when the cleaning was carried out according to the method for controlling dirt of the present invention, the dirt and the iron film were recovered to a good state, which shows that the method of the present invention is effective.

[0062]

As described above, according to the management method of the present invention, it is formed on the surface of a copper alloy member such as a cooling pipe or a tube plate in a condenser such as a condenser or a heat exchanger that uses seawater as cooling water. It becomes possible to grasp in real time how dirty the slime is. Then, by controlling the contamination, it is possible to prevent the deterioration of the anticorrosion effect of the iron film and the reduction of the heat transmission efficiency of the equipment for each unit, and it is possible to efficiently maintain the equipment in an appropriate operating state.

Since the self-potential according to the present invention can be measured for each unit in equipment such as a condenser, heat exchanger, etc., which comprises a plurality of units, according to the present invention, the state of contamination can be grasped for each unit. Therefore, the equipment can be managed very efficiently for each unit.

Furthermore, the method for controlling dirt of the present invention can be carried out together with the method for measuring the resistance of the iron film, and by doing so, the management of dirt and the state of the iron film can be grasped simultaneously by the same device. It becomes possible to maintain the equipment in a proper operating state more efficiently.

Therefore, according to the present invention, the trouble of the equipment can be prevented in advance, and the processing can be immediately performed even if an abnormality should occur, so that the equipment can always be operated safely and efficiently.

[Brief description of drawings]

FIG. 1 is a block diagram of an example of a power supply device for implementing a management method of the present invention.

FIG. 2 is a block diagram of an example of a measuring device 7.

FIG. 3 is a conceptual diagram for simultaneously grasping the states of dirt and an iron film from the natural potential and the resistance value of the iron film.

FIG. 4 is an example of a flow for performing the method for controlling the contamination of the copper alloy member of the present invention together with the method for measuring the iron film resistance and the method for utilizing the vacuum deviation value.

FIG. 5: Amount of deposit, natural potential En and iron film resistance value R
It is a graph showing the relationship with f.

FIG. 6 is a graph showing the relationship between the amount of deposits and the vacuum degree deviation value ΔH.

FIG. 7 is a graph showing the relationship between the vacuum deviation value ΔH, the natural potential En, and the iron film resistance value Rf.

FIG. 8 is a conceptual diagram for simultaneously grasping the states of dirt and iron film from the natural potential and the resistance value of the iron film.

FIG. 9 is a graph in which the measured values of the natural potential and the resistance value of the iron film are plotted in FIG.

[Explanation of symbols]

 1 energizing electrode 2 tube plate surface 3 cooling tube 4 reference electrode 5 water chamber 6 DC power supply device 7 measuring device A current measuring circuit E potential measuring circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Hachiya 1-172-8 Fujiwara, Funabashi City, Chiba (56) References JP-A-59-147247 (JP, A) JP-A-1-139998 (JP, A)

Claims (5)

[Claims] 1. A copper alloy used for corrosion protection of a copper alloy member used in equipment requiring cooling water, using both an anticorrosion method and a corrosion prevention method by forming an iron film on the surface of the member. In controlling the contamination of a member, using a current-carrying device having a current circuit for supplying current to the copper alloy member from the electrode provided in the cooling water through the cooling water, and a potential measuring circuit for measuring the potential of the copper alloy member. , A step of obtaining a natural potential where the potential of the cathode (copper alloy member) is attenuated and stabilized after the current is temporarily cut off, a step of comparing the natural potential with a predetermined reference value, A method for controlling contamination of a copper alloy member, which comprises a step of cleaning the contamination of the copper alloy member when the potential becomes nobler than the reference value. 2. The natural potential is expressed by the following formula (1) En = E ₆₀ + (E ₆₀ −E ₅₀ ) (1) [In the formula (1), En is a natural potential (mV) and E ₅₀ is a current. The cathode potential (mV) 50 seconds after the interruption, E ₆₀ represents the cathode potential (mV) 60 seconds after the interruption of the energization, respectively]. A method for controlling contamination of a copper alloy member as described. 3. The cleaning method according to claim 1, wherein the step of cleaning the dirt is performed by at least one cleaning method selected from the group consisting of soft ball cleaning, hard ball cleaning and jet cleaning. For controlling the contamination of copper alloy parts of. 4. The reference value is empirically determined such that a reduction in the anticorrosion effect of the iron coating and / or a reduction in the heat transmission efficiency of the equipment does not exceed an allowable range. 4. A method for controlling contamination of a copper alloy member according to any one of 3 to 3. 5. The method for controlling contamination of a copper alloy member according to claim 1, wherein the energizing device is an external power source type anticorrosion device.