JP2004019970A - Corrosion restricting method for boiler equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize a usage rate of the condensate treatment agent, when restricting corrosion to be generated in boiler equipment by using the condensate treatment agent. <P>SOLUTION: In the boiler equipment 1 provided with: a boiler 2 for generating steam by heating the supplied water; a water supply unit 3 for supplying water to the boiler 2; a steam supply unit 5 for supplying the steam generated by the boiler 2 to load equipment 4; and a condensate supply unit 6 for supplying the condensate of the steam used in the load equipment 4 to the water supply unit 3, a method of restricting corrosion in the condensate supply unit 6 by using the condensate treatment agent contains a measuring process for measuring concentration of the bicarbonate ion in the supplied water of the water supply unit 3, and a condensate treatment agent supply process for supplying the condensate treatment agent to, at least, any one of the water supply unit 3 and the steam supply unit 5 on the basis of a result of the measurement in the measuring process. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for suppressing corrosion of a boiler device, and in particular, to a boiler that generates steam by heating feed water, a water supply unit that supplies water to the boiler, and a steam supply that supplies steam generated by the boiler to load equipment. The present invention relates to a method for suppressing corrosion in a boiler apparatus including a unit and a condensate supply unit that supplies steam used in a load device as condensate water to a water supply unit.
[0002]
[Prior art]
Boiler equipment piping, especially condensate piping mainly made of steel pipes, for reusing condensate obtained by condensing steam from the boiler as feed water for boilers, may have to be replaced due to corrosion. . The corrosion of the condensate piping is mainly caused by the influence of carbon dioxide and dissolved oxygen in the condensate. Corrosion caused by carbon dioxide gas occurs when carbon dioxide gas generated by the thermal decomposition of feedwater containing carbonate ions in the boiler dissolves in the condensate and lowers the pH of the condensate, causing contact with the condensate. Since it progresses evenly to the inner surface portion of the pipe and reduces the wall thickness of the pipe, it has a characteristic that the progress speed is relatively slow. On the other hand, in the case of corrosion caused by dissolved oxygen, the oxygen dissolved in the condensate causes a partially intensive corrosion action on the pipe, especially on the lower part of the sludge such as the lower part of the horizontal pipe. Because it causes pitting corrosion (pitting) from the inside to the outside in the wall thickness direction of the pipe, the traveling speed is relatively high, causing fatal damage to the condensate pipe in a short time. Has features.
[0003]
For this reason, when condensate is reused, a condensate treatment agent is added to at least one of feed water and steam in order to suppress corrosion of the condensate supply unit, and corrosion is less likely to occur in the condensate supply unit. Like that. However, despite the fact that the condensate treatment agent is usually expensive, it is continuously or periodically added to at least one of feed water and steam, so that the amount used naturally increases and the boiler device This can increase operating costs.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems, and has an object to optimize the amount of a condensate treatment agent when suppressing corrosion occurring in a boiler device using the condensate treatment agent.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the problem, and the invention according to claim 1 is a boiler that heats water to generate steam, a water supply unit that supplies water to the boiler, In a boiler device including a steam supply unit that supplies steam generated by the boiler to a load device, and a condensate supply unit that supplies steam used in the load device as condensate water to the water supply unit, a condensate treatment agent is provided. A method for suppressing corrosion in the condensate supply unit using the water supply unit and the steam based on a measurement step of measuring the concentration of hydrogen carbonate ions in the feedwater of the water supply unit. A condensing agent supplying step of supplying the condensing agent to at least one of the supply units.
[0006]
The invention according to claim 2 is a boiler that generates steam by heating feed water, a water supply unit that supplies water to the boiler, a steam supply unit that supplies steam generated by the boiler to load equipment, In a boiler device including a condensate supply unit that supplies steam used in a load device as condensate to the water supply unit, a method for suppressing corrosion in the condensate supply unit using a condensate treatment agent, A measuring step of measuring the total carbonic acid concentration of the water supplied to the water supply unit, and supplying the condensate to at least one of the water supply unit and the steam supply unit based on a measurement result in the measurement step. Condensing agent supply step.
[0007]
Further, in the invention according to claim 3, the supply amount of the condensate is adjusted based on the measurement result in the measurement step.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
A boiler device according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, a boiler device 1 includes a boiler 2 that heats feed water to generate steam, a water feed device 3 that supplies water to the boiler 2 (an example of a water feed unit), and a load device 4 that uses steam. A steam pipe 5 (an example of a steam supply unit) that supplies the steam generated by the boiler 2 to the load equipment 4, and a condensate pipe 6 that supplies the steam used in the load equipment 4 as condensate water to the water supply device 3 ( An example of a condensate supply unit), a chemical supply device 7 for adding a condensate to the water supply device 3, and a measuring device 8 for measuring the concentration of hydrogen carbonate ions contained in the feed water.
[0009]
The water supply device 3 is configured to supply water to the boiler 2 with a water supply passage 9 for supplying makeup water, a water supply tank 10 for storing makeup water from the water supply passage 9, and a water supply stored in the water supply tank 10. A water supply channel 11 for supplying to the boiler 2 is mainly provided (see FIG. 1). Here, the water injection channel 9 includes a water softening device 12 and a deoxidizing device 13 in this order. The water softening device 12 replaces hardness components such as calcium ions and magnesium ions contained in makeup water with sodium ions and converts them into soft water. On the other hand, the deoxygenating device 13 mechanically removes dissolved oxygen contained in makeup water. In addition, the water supply channel 11 includes a water supply pump 14 that supplies water to the boiler 2.
[0010]
The load device 4 is a device that performs required heat exchange using steam from the boiler 2, that is, a load device in the boiler device 1, and is connected to a downstream side of the steam pipe 5.
[0011]
The medicine supply device 7 mainly includes a medicine tank 15 storing the condensed water treatment agent and a medicine supply passage 16 communicating with the water supply passage 11 in order to add the condensed water treatment agent to the water supply device 3. In preparation. The condensate treatment agent stored in the chemical tank 15 is not particularly limited as long as it has a function of suppressing the occurrence and growth of corrosion in the condensate pipe 6, and for example, a long chain Aliphatic amine compounds, aliphatic cyclic amine compounds, aliphatic amino alcohol compounds, and the like.
[0012]
On the other hand, the medicine supply path 16 includes a supply pump 17 that supplies the condensate treatment agent in the medicine tank 15 to the water supply path 11. The supply pump 17 is a constant-rate pump capable of supplying a predetermined amount of a condensate to a fixed amount of water moving in the water supply path 11 toward the boiler 2.
[0013]
The measuring device 8 is provided in the measurement sample supply passage 18 in the water supply passage 11 in order to measure the concentration of hydrogen carbonate ion contained in the supply water (see FIG. 1). Here, the measuring device 8 mainly includes a measuring cell 19, a measuring unit 20, a reagent supply device 21, and a control device 22, as shown in FIG.
[0014]
The measuring cell 19 is a transparent container formed of, for example, an acrylic resin in a cylindrical shape, and has an opening 23 at an upper portion. A sample introduction path 24 connected to the measurement sample supply path 18 is provided on a side surface near the bottom of the measurement cell 19. The sample introduction path 24 includes a filter 25, a constant flow valve 26, and a solenoid valve 27 in this order from the measurement sample supply path 18 side, and is supplied from the water supply path 11 through the measurement sample supply path 18. The water supply is set so that it can be supplied into the measurement cell 19. A sample discharge path 28 for discharging a measurement sample to the outside is provided near the opening 23 on the side of the measurement cell 19.
[0015]
A stirring device 29 is provided at the bottom of the measuring cell 19. This stirrer 29 includes a stirrer 30 and a stator 31. The stirrer 30 is rotatably arranged at the bottom of the measuring cell 19 and has a built-in magnet (not shown). The stator 31 is arranged outside the measurement cell 19 so as to surround the stirrer 30 and includes an electromagnetic induction coil (not shown). The current is supplied to the electromagnetic induction coil.
[0016]
The measurement unit 20 measures the transmitted light intensity of the water (hereinafter, referred to as “water supply sample”) stored in the measurement cell 19, and the light-emitting bodies 32 opposed to each other across the measurement cell 19. And a photoreceptor 33. Here, the light emitting body 32 is, for example, an LED, and the light receiving body 33 is, for example, a phototransistor.
[0017]
The reagent supply device 21 is detachably disposed in the opening 23. As shown in FIG. 3 (a vertical cross-sectional view of the reagent supply device 21 in the direction III in FIG. 2), the reagent cassette 34, It mainly includes a reagent cartridge 35 and a discharge device 36. The reagent cassette 34 is detachably mounted by a mounting tool (not shown) such that the bottom portion maintains an airtight state in the opening 23. A slit 37 extending in the up-down direction is formed in the wall of the reagent cassette 34. In the inside of the reagent cassette 34, a pressing member 38 is mounted on an inner surface facing the slit 37 in a vertical direction.
[0018]
The reagent cartridge 35 mainly includes a container 39 and a reagent container 40. The container 39 is mounted on the upper part of the reagent cartridge 35, and the housing 40 is housed in the container 39. The storage body 40 includes a storage section 41 storing a reagent (for example, methyl orange) and a buffer solution (for example, a phthalic acid buffer solution having a pH of 3.4) that change color by reacting with hydrogencarbonate ions, and the storage section 41. And a discharge section 42 for discharging the reagents and buffer therein. The discharge section 42 is made of, for example, a tube made of fluororubber, extends from the storage section 41, and has a discharge nozzle 43 at a distal end. The discharge section 42 extends vertically inside the reagent cartridge 35, and the discharge nozzle 43 is inserted into the measurement cell 19 from the opening 23. Here, the discharge nozzle 43 has a built-in check valve (not shown) for preventing the water supply sample in the measurement cell 19 from flowing backward.
[0019]
The discharge device 36 is for discharging the reagent and the buffer stored in the storage section 41, and mainly includes a rotary drive shaft 44, a drive arm 45, and a pressing roller 46 connected to a motor (not shown). Have. The rotary drive shaft 44 is disposed outside the slit 37 and is rotatable in a counterclockwise direction in FIG. One end of the drive arm 45 is connected to the rotary drive shaft 44, and the pressing roller 46 is rotatably mounted at the other end. The drive arm 45 is rotatable in the counterclockwise direction by the rotation of the rotary drive shaft 44 as shown by a two-dot chain line in FIG. 46 is set so as to be able to enter and exit from the reagent cassette 34.
[0020]
The reagent supply device 21 has substantially the same configuration as that of Japanese Patent No. 3186577 (name of the invention: liquid ejection device), which is a patent of the present applicant. I want to.
[0021]
The control device 22 controls the operation of the measurement device 8, and mainly includes a calculation device 47 and an input / output port 48 as shown in FIG. The arithmetic unit 47 includes a central control unit 49 (hereinafter, referred to as a “CPU 49”), a read-only storage device 50 (hereinafter, referred to as a “ROM 50”) that stores an operation program of the control unit 22, and a read / write unit. It mainly includes a possible storage device 51 (hereinafter, referred to as “RAM 51”).
[0022]
On the other hand, the input side of the input / output port 48 is connected to a switch 52 for inputting operating conditions and the like by the operator, the light receiving body 33 and the like. The output side is connected to an LCD 53 for displaying measurement results and the like, the light emitter 32, the solenoid valve 27, a motor (not shown) for driving the stator 31 and the rotary drive shaft 44, and the like.
[0023]
According to the operation program stored in the ROM 50, the control device 22 performs the arithmetic processing while the arithmetic device 47 appropriately stores various information input through the input / output port 48 in the RAM 51, The device 47 is set to transmit various operation commands to each member via the input / output port 48 based on the calculation result obtained therefrom.
[0024]
Next, the operation of the boiler apparatus 1 will be described, and a method for suppressing corrosion of the boiler apparatus 1 will be described. When operating the boiler device 1, make-up water is supplied from the water injection passage 9 to the water supply tank 10, and the make-up water is stored in the water supply tank 10 as water supply to the boiler 2. Here, the stored feedwater is that treated by the water softening device 12 and the deoxidizing device 13, that is, deoxygenated soft water. Then, the water supply pump 14 is operated to supply the water stored in the water supply tank 10 to the boiler 2 via the water supply path 11.
[0025]
Water supplied to the boiler 2 via the water supply channel 11 is stored in the boiler 2 as boiler water. The boiler water stored in the boiler 2 is heated and gradually turns into steam. The generated steam is supplied to the load device 4 via the steam pipe 5. The steam supplied to the load device 4 is then cooled and condensed, and is supplied to the water supply tank 10.
[0026]
By the way, the feed water supplied to the boiler 2 may include hydrogen carbonate ions. In this case, the feed water is heated in the boiler 2 to become steam, and the hydrogen carbonate ions generate carbon dioxide gas by thermal decomposition. The generated carbon dioxide gas is supplied to the load device 4 together with the steam, and is dissolved in the condensed water when the steam condenses. As a result, there is a possibility that the condensate pipe 6 may be corroded by the carbon dioxide gas and may be damaged.
[0027]
Therefore, the boiler device 1 uses the measuring device 8 to measure at regular time intervals whether or not the feedwater contains bicarbonate ions. Then, based on the measurement result of the measuring device 8, a condensate treatment agent is added from the chemical supply device 7 to the water supply. Hereinafter, this operation will be described in detail with reference to the operation flowcharts shown in FIGS.
[0028]
When the operation of the boiler device 1 is started, the program sets the elapsed time t of the internal timer of the control device 22 to zero (0) in step S1, and sets the elapsed time t in the next step S2. Fixed time t ₁ Is determined. Elapsed time t is constant time t ₁ Then, the program proceeds to step S3, and resets the elapsed time t to zero (0). Here, the fixed time t ₁ Is usually about 0.1 to 24 hours.
[0029]
After step S3, the program proceeds to step S4, and performs a pre-cleaning step in the measuring device 8. First, the water supply in the water supply channel 11 flows into the measurement cell 19 from the sample introduction channel 24 via the measurement sample supply channel 18. At this time, the dirt contained in the water supply is removed by the filter 25. The flow rate of the supply water flowing into the measurement cell 19 is controlled by the constant flow valve 26. The supply water continuously flowing into the measurement cell 19 fills the measurement cell 19 and is continuously discharged to the outside from the sample discharge path 28. At this time, the electromagnetic induction coil of the stator 31 is energized, and the magnetic field generated thereby is received by the magnet in the stirrer 30. Thereby, the stirrer 30 in the measuring cell 19 rotates, and the water supplied into the measuring cell 19 is stirred. As a result, the measuring cell 19 is washed by the continuously flowing water.
[0030]
After the pre-cleaning process as described above, the program proceeds to step S5, and measures the hydrogen carbonate ion concentration in the feed water (measuring process). Here, the current supply to the electromagnetic induction coil of the stator 31 is temporarily stopped, and the supply of water is also stopped. Thereby, the inflow of the water supply into the measurement cell 19 is cut off, and a predetermined amount of water supply is stored as a water supply sample in the measurement cell 19 up to the water level indicated by the one-dot chain line in FIG. The tip of the discharge nozzle 43 is located in the stored water supply sample. In this state, the measuring unit 20 is operated to irradiate light from the light emitting body 32 to the light receiving body 33. Then, the transmitted light intensity (A) of the water supply sample is measured.
[0031]
Next, energization of the electromagnetic induction coil of the stator 31 is started to restart the rotation of the stirrer 30, and while continuing the state, the motor of the discharge device 36 is driven to rotate the rotation drive shaft 44. Rotate. As a result, the drive arm 45 rotates in the counterclockwise direction in FIG. 3, and accordingly, the pressing roller 46 handles the discharging portion 42 downward in cooperation with the pressing member 38. As a result, a certain amount of the reagent and the buffer stored in the storage unit 41 are injected into the water supply sample in the measurement cell 19. When the rotational movement of the drive arm 45 is repeated a predetermined number of times, a fixed amount of a reagent and a buffer are intermittently injected into the measurement cell 19 every time the drive arm 45 rotates. (Injection step). Therefore, the reagent and the buffer are gradually injected. The reagent and the buffer solution thus injected into the measurement cell 19 are dissolved in the water supply sample stirred by the rotation of the stirrer 30 and change the color of the water supply sample.
[0032]
In the injection step as described above, the control device 22 continues the rotation of the stirrer 30 and, by the measurement unit 20, the transmitted light intensity of the water supply sample that changes its color due to the reagent and buffer gradually injected. B) is measured continuously. At this time, the control device 22 measures the amount of change in the transmitted light intensity with the increase in the amount of the reagent and the buffer solution injected into the water supply sample (change amount measuring step). The amount of change in transmitted light intensity measured here is usually the difference (ΔB) in transmitted light intensity before and after a certain amount of reagent and buffer is injected. For example, as shown in FIG. 8, the transmitted light intensity of the water supply sample gradually decreases according to the number of injections of the reagent and the buffer (that is, the number of rotations of the drive arm 45). Here, when all of the bicarbonate ions in the water supply sample have reacted with the reagent and the buffer solution injected before the X-th time, in the injection operation after the X-th time, more reagents and the buffer solution are injected. However, the discoloration of the water supply sample hardly progresses, and the transmitted light intensity of the water supply sample hardly changes. That is, the transmitted light intensity B after the X-th injection of the reagent and the buffer solution ₁ And transmitted light intensity B after the (X + 1) th injection ₂ Difference (B ₁ -B ₂ , Ie, ΔB) becomes a small difference. Therefore, when the ΔB is equal to or less than a predetermined amount, even if more reagents and buffers are injected into the water supply sample, the reagents and buffers do not participate in the reaction with the bicarbonate ions in the water supply sample, It will remain in the water sample as it is.
[0033]
Therefore, when the control device 22 determines that the ΔB has become equal to or less than the predetermined amount, the control device 22 stops the rotation operation of the drive arm 45. This stops additional injection of reagents and buffers into the water supply sample. Subsequently, the control device 22 controls the ratio between the transmitted light intensity (B) of the water supply sample at that time and the transmitted light intensity (A) before the injection of the reagent and the buffer solution (transmitted light intensity ratio: B / A). Ask for. Then, based on the calibration curve data of the transmitted light intensity ratio and the bicarbonate ion concentration prepared in advance, the control device 22 calculates the bicarbonate ion concentration in the water supply sample, and displays the result on the LCD 53. .
[0034]
After the above-described measurement process, the program proceeds to step S6, and in this step S6, it is determined whether hydrogen carbonate ions have been detected from the water supply sample. If it is determined in the measurement step of step S5 that bicarbonate ions have been detected (ie, if bicarbonate ions have been detected in the water supply sample), the program proceeds from step S6 to step S11, and the program proceeds to step S11. It is determined whether or not the ion detection identification flag is on (ON). If the bicarbonate ion detection identification flag is on (ON), the program proceeds to step S14, and performs a condensate treatment agent addition adjustment step.
[0035]
In this condensate treatment agent addition amount adjusting step, if the bicarbonate ion concentration measured in step S5 this time is different from the bicarbonate ion concentration measured in the previous step S5, in step S14, the program executes the program based on the bicarbonate ion concentration. Since the supply pump 17 is operated, the amount of the condensed water treatment agent added to the water supplied from the water supply passage 11 to the boiler 2 is changed.
[0036]
Then, the program proceeds to step S15, and performs a post-cleaning step. In the subsequent washing step, the program supplies water while rotating the stirrer 30. Here, the water supply sample containing the reagent and the buffer solution stored in the measurement cell 19 is pushed out by the newly supplied water from the sample introduction channel 24, and is discharged to the outside from the sample discharge channel 28. As a result, the measuring cell 19 is washed by the newly supplied water. After the end of step S15, the program returns to step S2.
[0037]
Conversely, when the bicarbonate ion detection identification flag is off (OFF), the program proceeds to step S12, and performs the condensate treatment agent adding step.
[0038]
In the step of adding the condensate, the control device 22 operates the supply pump 17 of the chemical supply device 7 to supply the condensate to the water supply channel 11. As a result, a condensate is added to the feedwater passing through the feedwater channel 11 toward the boiler 2. Here, the control device 22 controls the operation of the supply pump 17 based on the hydrogen carbonate ion concentration measured in step S5. More specifically, when the bicarbonate ion concentration measured in step S5 is low, the control device 22 adds a small amount of the condensate to the unit amount of water passing through the water supply passage 11. Thus, the supply pump 17 is operated continuously. On the other hand, when the bicarbonate ion concentration measured in step S5 is large, the supply pump 17 is controlled so that a relatively large amount of the condensate is added to a unit amount of water passing through the water supply channel 11. Operate continuously. That is, the control device 22 operates the supply pump 17 so that the amount of the condensate treatment agent added to the water supply is proportional to the hydrogen carbonate ion concentration measured in step S5. Here, the supply pump 17 continues to operate unless a stop command is received from the control device 22.
[0039]
Then, after the end of step S12, the program proceeds to step S13, and sets the bicarbonate ion detection identification flag to ON. Then, after performing post-cleaning in step S15, the process returns to step S2.
[0040]
As a result, in the water supplied from the water supply passage 11 into the boiler 2, an appropriate amount of the condensate treatment agent corresponding to the hydrogen carbonate ion concentration of the feed water is introduced. , Corrosion is effectively suppressed.
[0041]
On the other hand, if the bicarbonate ion concentration contained in the water supply sample obtained in the measurement step of step S5 is zero (0) (that is, if no hydrogen carbonate ion is detected in the water supply sample), the program proceeds from step S6 to step S6. The process proceeds to S7 (see FIG. 6) to determine whether or not the bicarbonate ion detection identification flag of the CPU 49 is ON. When the bicarbonate ion detection identification flag is off (OFF), the program proceeds to S10, performs the post-cleaning process as in step S15, and then returns to step S2.
[0042]
On the other hand, if the bicarbonate ion detection identification flag is on (ON) in step S7, the program proceeds to step S8 and stops the operation of the supply pump 17. As a result, the chemical supply device 7 stops supplying the condensate to the water supply channel 11. As a result, useless supply of the condensate treatment agent to feedwater containing no bicarbonate ions is prevented. After the end of step S8, the program proceeds to step S9, and sets the bicarbonate ion detection identification flag to OFF. Then, in step S10, after performing the post-cleaning process as in step S15, the process returns to step S2.
[0043]
Then, in step S2, the elapsed time t reset to zero (0) in step S3 is equal to the fixed time t. ₁ Is determined. Then, the elapsed time t becomes a certain time t ₁ Is reached, step S4 and subsequent steps are repeated again. Therefore, in the boiler device 1, the fixed time t ₁ Each time is passed, the bicarbonate ion concentration in the feed water is measured, and based on the result, the condensate treatment agent supplied from the chemical supply device 7 is supplied to the water supply via the water supply passage 11 as necessary. Will be added to the mixture.
[0044]
For example, even if hydrogen carbonate ions are detected from the water supply in step S5, if the hydrogen carbonate ions are not detected in step S5 in the next repetition process, the program proceeds from step S6 to step S7. Here, since the bicarbonate ion detection identification flag has been set to ON in step S13, the program proceeds to step S7, and returns to step S2 via steps S8 to S10. Therefore, the supply of the condensate to the water supply channel 11 is stopped. Conversely, even if hydrogen carbonate ions are not detected from the feed water in the previous step S5, if hydrogen carbonate ions are detected in the feed water in step S5 in the next repetitive process, the program proceeds from step S6 to step S11. Then, the process returns from step S12 to step S2 via step S15. Therefore, a condensate treatment agent is added to the water supplied from the water supply channel 11 to the boiler 2 based on the hydrogen carbonate ion concentration measured in step S5.
[0045]
On the other hand, if bicarbonate ions are detected from the feed water in the previous step S5 and bicarbonate ions are also detected in step S5 of the next repetition process, the program proceeds from step S6 to step S11, and the program proceeds to step S11. Continue supplying condensate. However, in this case, if the bicarbonate ion concentration measured in the subsequent step S5 is different from the bicarbonate ion concentration measured in the previous step S5, in step S14, the program executes the supply pump 17 based on the bicarbonate ion concentration. Is operated, the amount of the condensate treatment agent added to the water supplied from the water supply channel 11 to the boiler 2 changes. In other words, in this case, the supply amount of the condensate to the water supply channel 11 changes according to the concentration of hydrogen carbonate ions contained in the water supply.
[0046]
As described above, in the boiler apparatus 1, instead of continuously or periodically supplying the condensing agent, regardless of the presence of bicarbonate ions or the bicarbonate ion concentration in the feedwater, the feedwater is supplied with carbonic acid. Only when hydrogen ions are contained, and on the basis of the concentration of hydrogen carbonate ions, the condensing agent can be added to the water supply through the water supply channel 11, so that the amount of the condensing agent used is optimized. As a result, the cost required for controlling corrosion can be reduced. Further, the boiler apparatus 1 does not supply the condensing agent after the corrosion in the condensate pipe 6 has occurred, but focuses on the hydrogen carbonate ions in the feedwater that cause the corrosion. Since the treating agent is supplied, corrosion in the condensate pipe 6 can be prevented beforehand.
[0047]
[Other embodiments]
(1) In the above embodiment, the fixed time t ₁ The concentration of bicarbonate ion in the feed water is measured every time the water has passed, and the condensate is added to the feed water in the water supply channel 11 based on the result. Can be changed. For example, as shown in FIG. 7, step S16 is further set after step S15 in the operation flowchart, and the elapsed time t reset to zero (0) in step S3 is another fixed time t ₂ Is determined. Then, in step S16, the elapsed time t is equal to the fixed time t. ₂ When it is determined that the program has reached the time limit, the program is set to shift to step S3. Where t ₂ Is t ₁ Less time.
[0048]
In this case, if the bicarbonate ion is not detected in step S5, the boiler apparatus 1 sets a longer constant time t. ₁ The hydrogen carbonate ion concentration in the feed water is measured every time the time elapses, and if hydrogen carbonate ions are detected in step S5, a shorter fixed time t ₂ Since the hydrogen carbonate ion concentration in the feed water is measured every time elapses, the amount of the condensing agent added to the feed water can be optimized.
[0049]
(2) In the above embodiment, the measuring device 8 measures the concentration of hydrogen carbonate ions in the feedwater, and changes the amount of the condensate to be supplied to the feedwater channel 11 based on the result. However, the present invention is not limited to this. For example, the measuring device 8 simply measures whether or not the feedwater contains bicarbonate ions, and when the feedwater contains bicarbonate ions, a fixed amount of bicarbonate ions is independent of the bicarbonate ion concentration. May be added to the water supply in the water supply channel 11.
[0050]
(3) The measuring device 8 used in the above embodiment may be any other device as long as it can automatically measure the presence or absence of hydrogen carbonate ions in the feed water or the concentration of hydrogen carbonate ions. It can be changed. Here, as a method for automatically measuring the bicarbonate ion concentration in the feed water, for example, a measuring device using a TOC meter (organic carbon concentration meter) can be adopted.
[0051]
(4) In the above embodiment, the chemical supply device 7 is provided so as to supply the condensate treatment agent to the water supply channel 11, but as shown by the two-dot chain line in FIG. The present invention can be implemented in the same manner even when the chemical supply device 7 is provided so as to supply the condensate to 5. In this case, since the condensing agent can be directly supplied to the steam in the steam pipe 5, the corrosion in the condensing pipe 6 can be more effectively suppressed.
[0052]
Further, the condensate may be supplied to both the water supply passage 11 and the steam pipe 5 at the same time. In this case, in one medicine supply device 7, the medicine supply path 16 can be branched and connected to both the water supply path 11 and the steam pipe 5. The medicine supply device 7 may be provided for each of the steam pipes 5. Here, in the latter case, the amount of the condensed water condensing agent added is determined by the amount supplied from the medicine supply device 7 on the water supply channel 11 side and the amount supplied from the medicine supply device 7 on the steam pipe 5 side. It is preferable that the total is set to be an appropriate amount according to the concentration of hydrogen carbonate ions contained in the water supply.
[0053]
(5) In the above-described embodiment, when bicarbonate ions are contained in the feedwater, the condensate is supplied in accordance with the bicarbonate ion concentration. Only when the amount of the condensate is greater than or equal to the amount, the condensate may be supplied in a fixed amount or in an amount corresponding to the hydrogen carbonate ion concentration.
[0054]
(6) In the above embodiment, the measuring device 8 is provided in the boiler device 1, and based on the hydrogen carbonate ion concentration in the feed water automatically measured by the measuring device 8, Although the condensate treatment agent is supplied to at least one of the water supply channel 11 and the steam pipe 5, the corrosion suppressing method of the present invention is not limited to this. For example, the bicarbonate ion concentration in the feedwater is manually measured, and a condensate can be supplied to at least one of the water supply passage 11 and the steam pipe 5 based on the measurement result. . Here, as a method for manually measuring the hydrogen carbonate ion concentration in the feed water, for example, "calculation of the concentration of carbonic acid, hydrogen carbonate ion and carbonate ion" specified in JIS K0101: 1998 may be employed. it can.
[0055]
(7) In the above-described embodiment, the case where the bicarbonate ion concentration is measured is described as the measuring device 8, but the addition of the condensate treatment agent is performed using a device (not shown) for measuring the total carbonic acid concentration. Control is also suitable depending on the implementation.
[0056]
Here, depending on the structure of the load device 4 and the steam trap (symbols are omitted), the length and structure of the condensate pipe 6, the method of supplying the water to the water supply tank 10, etc. The forms of the bicarbonate ion and the carbonate ion are different, and their abundances are different. Therefore, by measuring the total carbon dioxide including these three forms, the total amount of carbon dioxide generated in the boiler 2 can be predicted. The use amount of the water treatment agent can be optimized. The apparatus for measuring the total carbonic acid concentration is not particularly limited as long as it can measure the presence or absence of the total carbonic acid in the feed water or the concentration of the total carbonic acid. For example, “calculation of concentrations of carbonate, hydrogen carbonate ion and carbonate ion” specified in JIS K0101: 1998 can be adopted.
[0057]
【The invention's effect】
As described above, according to the present invention, it is possible to optimize the amount of the condensate used in suppressing the corrosion generated in the boiler device using the condensate.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a boiler device applied to an embodiment of the present invention.
FIG. 2 is a schematic vertical sectional view of a measuring device used in the boiler device.
FIG. 3 is a schematic longitudinal sectional view of a reagent supply device part constituting the measuring device, as viewed from a direction III in FIG. 2;
FIG. 4 is a diagram showing a schematic configuration of a control device portion of the measurement device.
FIG. 5 is a flowchart showing a supply operation process of a condensate treatment agent in the boiler device.
FIG. 6 is a flowchart showing a supply operation process of a condensate treatment agent in the boiler device.
FIG. 7 is a flowchart showing a condensing agent supply operation process according to another embodiment.
FIG. 8 is a graph conceptually showing a determination table for measuring a hydrogen carbonate ion concentration based on the transmittance of light passing through a water supply sample.
[Explanation of symbols]
1 Boiler equipment
2 Boiler
3 Water supply department
4 Load equipment
5 Steam supply unit
6 Condensate supply section

Claims (3)

A boiler 2 for heating the supply water to generate steam, a water supply unit 3 for supplying water to the boiler 2, a steam supply unit 5 for supplying steam generated by the boiler 2 to a load device 4, And a condensate supply unit 6 for supplying the steam used in step 2 as condensate water to the water supply unit 3 in the boiler apparatus 1 using a condensate treatment agent to suppress corrosion in the condensate supply unit 6. hand,
A measuring step of measuring the hydrogen carbonate ion concentration of the feed water of the water supply unit 3;
A condensate treatment agent supply step of supplying the condensate treatment agent to at least one of the water supply unit 3 and the steam supply unit 5 based on the measurement result in the measurement step;
A method for suppressing corrosion of a boiler device, comprising: A boiler 2 for heating the supply water to generate steam, a water supply unit 3 for supplying water to the boiler 2, a steam supply unit 5 for supplying steam generated by the boiler 2 to a load device 4, And a condensate supply unit 6 for supplying the steam used in step 2 as condensate water to the water supply unit 3 in the boiler apparatus 1 using a condensate treatment agent to suppress corrosion in the condensate supply unit 6. hand,
A measuring step of measuring the total carbonic acid concentration of the water supplied to the water supply unit 3;
A condensate treatment agent supply step of supplying the condensate treatment agent to at least one of the water supply unit 3 and the steam supply unit 5 based on the measurement result in the measurement step;
A method for suppressing corrosion of a boiler device, comprising: The method according to claim 1 or 2, wherein the supply amount of the condensate is adjusted based on a measurement result in the measurement step.

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