JP2015117914A - Boiler system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler system capable of sufficiently suppressing corrosion of a boiler.SOLUTION: A boiler system includes a pure water manufacturing device 5, a supply water tank 2 to which pure water is supplied from the pure water manufacturing device 5 to store the pure water as supply water, a load device 9 utilizing steam, a sealed condensate tank 13 to which at least one of the condensate of the steam utilized in the load device and the supply water from the supply water tank is supplied to store at least one of the waters as boiler supply water, a first chemical agent injection device 1 for injecting a first chemical agent including volatile amine to the boiler supply water from the condensate tank 13, a boiler 3 to which the boiler supply water including the injected first chemical agent, is supplied to generate the steam to be supplied to the load device 9, and a control device 4 for controlling the first chemical agent injection device 1 to keep a pH value of the boiler water in the boiler 3 within a range of 9.0-10.3.

Description

  The present invention relates to a boiler system.

  2. Description of the Related Art Conventionally, there is a boiler system that collects steam condensate used in a load device in a sealed condensate water tank (see, for example, JP 2011-237065 A (Patent Document 1)). Condensed water in this closed type condensed water tank is used as boiler feed water. In a boiler system, a chemical containing a volatile amine may be added to boiler feed water in order to suppress corrosion of a boiler water pipe, a lower header, and the like (see, for example, JP 2011-174173 A (Patent Document 2)). ).

  In the above boiler system, the condensate water tank is connected to the make-up water tank via a water supply line, and make-up water is supplied from the make-up water tank when the water level in the condensate water tank decreases. . Further, the condensed water tank is connected to the makeup water tank via a flush steam guide line so that flush steam (re-evaporated steam) generated in the condensed water tank is exhausted toward the makeup water tank. It has become.

JP2011-237065A JP 2011-174173 A

  By the way, in the conventional boiler system, when a chemical containing a volatile amine is added to the boiler feed water, various disadvantages occur when the chemical is injected into the closed condensed water tank. For example, when the amount of flash steam exhausted toward the makeup water tank increases, the medicine is taken out along with the flash steam, and the concentration of the medicine in the boiler feed water decreases. Further, for example, when the water level in the condensed water tank is lowered and makeup water is supplied, the medicine is diluted and the concentration of the medicine in the boiler feed water is lowered. For this reason, boiler feed water having a low concentration of the chemical is supplied to the boiler, and there is a possibility that the effect of suppressing the corrosion of the boiler cannot be sufficiently obtained.

  In addition, when the supply amount of the chemical to the boiler feed water is set in consideration that the flash steam is exhausted from the condensed water tank, the chemical is supplied more than necessary to the boiler feed water when the flash steam is not generated. There is a possibility. Similarly, when the supply amount of the chemical to the boiler feed water is set in consideration of the supply of the makeup water to the condensed water tank, when the makeup water is not supplied, the medicine is supplied more than necessary to the boiler feed water. There is a possibility that.

  Then, the subject of this invention is providing the boiler system which can prevent that the chemical | medical agent is inject | poured wastefully while being able to make the suppression effect of corrosion of a boiler high.

In order to solve the above problems, the boiler system of the present invention is:
A source of pure water;
A pure water is supplied from the pure water supply source, and a makeup water tank for storing the pure water as makeup water,
A load device using steam;
At least one of steam condensate used in the load device and make-up water from the make-up water tank is supplied, and a sealed condensate water tank that stores at least one water as boiler feed water,
A first drug injection device for injecting a first drug containing a volatile amine into boiler feed water from the condensed water tank;
A boiler that is supplied with boiler feed water into which the first chemical has been injected and generates steam to be supplied to the load device;
And a controller for controlling the first drug injection device so that the pH value of the boiler water in the boiler falls within a range of 9.0 to 10.3.

  According to the above configuration, since the control device controls the first chemical injection device so that the pH value of the boiler water falls within the range of 9.0 to 10.3, the effect of suppressing boiler corrosion is enhanced. In addition, the first medicine can be prevented from being injected unnecessarily.

  When the pH value of the boiler water is adjusted to be more than 10.3, the effect of suppressing the corrosion of the boiler is not so much improved although the injection amount of the first chemical is increased. That is, the processing cost for suppressing the corrosion of a boiler will rise rapidly.

  On the other hand, when the pH value of the boiler water is adjusted to less than 9.0, the effect of suppressing boiler corrosion is greatly reduced.

  By the way, when a volatile amine having a low distribution ratio (= concentration in the gas phase / concentration in the liquid phase) is selected as the volatile amine contained in the first agent, it is easy to stay in the boiler water. However, it is difficult for volatile amines to transfer to steam. As a result, the concentration of the volatile amine in the condensed water is lowered, and the corrosion of the flow path for guiding the condensed water from the load device to the condensed water tank is likely to proceed.

Therefore, the boiler system of one embodiment is
A second drug injection device is provided that injects a second drug containing a volatile amine into the steam used by the load device.

  According to the above embodiment, a volatile amine having a low distribution ratio that easily stays in boiler water is selected as the volatile amine contained in the first agent, and the steam-condensed water system is used as the volatile amine contained in the second agent. It is possible to select volatile amines having different distribution ratios according to the pipe length. Therefore, the boiler system can further increase the effect of suppressing the corrosion of the boiler, and can make it difficult for the flow path for guiding the condensed water from the load device to the condensed water tank to progress.

  Moreover, the state where the electric conductivity of the boiler water is low (that is, the low concentration state) can be said to be a state where the pH value of the boiler water is low and the corrosion of the boiler is likely to proceed.

Therefore, the boiler system of one embodiment is
A first electrical conductivity measuring unit for measuring electrical conductivity of the boiler water;
The control device
The electric conductivity of the boiler water measured by the first electric conductivity measuring unit is compared with the first set value set in advance, and the electric conductivity of the boiler water becomes less than the first set value. First electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler water is less than the first set value, the electric conductivity of the boiler water is not less than a second set value that is greater than the first set value. Or a first medicine injection amount increasing means for increasing the injection amount of the first medicine per unit flow rate of boiler feed water from the condensate tank for a preset first time.

  According to the embodiment, when it is determined that the electric conductivity of the boiler water is less than the first set value, the first chemical injection amount increasing means has the electric conductivity of the boiler water having the first set value. The injection amount of the first chemical per unit flow rate of boiler feed water from the condensed water tank is increased until the second set value is greater than the second set value. Or in that case, a 1st chemical | medical agent injection quantity increase means increases the injection quantity of the 1st chemical | medical agent per unit flow volume of the boiler feed water from a condensed water tank for the preset 1st time. As a result, the pH value of the boiler water in a low concentration state is increased, and the effect of suppressing boiler corrosion is reliably increased.

The boiler system of one embodiment is
A first electrical conductivity measuring unit for measuring electrical conductivity of the boiler water;
The control device
The electric conductivity of the boiler water measured by the first electric conductivity measuring unit is compared with the first set value set in advance, and the electric conductivity of the boiler water becomes less than the first set value. First electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler water is less than the first set value, the electric conductivity of the boiler water is not less than a second set value that is greater than the first set value. Or a blow prohibiting means for prohibiting the blow of the boiler water for a preset second time.

  According to the above embodiment, when it is determined that the electric conductivity of the boiler water is less than the first set value, the blow prohibiting means is configured to increase the electric conductivity of the boiler water greater than the first set value. 2 Blowing of boiler water is prohibited until the set value is exceeded. Or in that case, a blow prohibition means prohibits the blow of boiler water for the 2nd time set beforehand. As a result, since the boiler water concentration proceeds rapidly, the pH value of the boiler water rises and the effect of suppressing boiler corrosion is reliably increased even if the injection amount of the first drug does not increase. In other words, the boiler system can reliably increase the pH value of boiler water without increasing the injection amount of the first drug.

  Moreover, when boiler feed water with a high dissolved oxygen value is supplied to the boiler, if the pH value of the boiler water is low, the corrosion of the boiler is more likely to proceed.

Therefore, the boiler system of one embodiment is
A first electrical conductivity measurement unit for measuring electrical conductivity of the boiler water;
A dissolved oxygen value measuring unit for measuring the dissolved oxygen value of boiler feed water supplied to the boiler,
The control device
Whether the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value by comparing the dissolved oxygen value of the boiler feed water measured by the dissolved oxygen value measuring unit with a preset third set value. Dissolved oxygen value determining means for determining whether or not,
When it is determined that the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value, the electric conductivity of the boiler water measured by the first electric conductivity measuring unit and a preset fourth value Unit of boiler water supply from the condensed water tank until the electric conductivity of the boiler water is equal to or higher than the fourth set value or a preset third time by comparing with the set value And a second drug injection amount increasing means for increasing the injection amount of the first drug per flow rate.

  According to the embodiment, when it is determined that the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value, the second drug injection amount increasing means is measured by the first electrical conductivity measuring unit. Unit flow rate of boiler feed water from the condensate tank until the electrical conductivity of the boiler water is equal to or higher than the fourth set value by comparing the electrical conductivity of the boiler water with the preset fourth set value. Increase the injection amount of the first drug per. Or in that case, the said 2nd chemical | medical agent injection amount increase means increases the injection | pouring amount of the 1st chemical | medical agent per unit flow rate of the boiler feed water from a condensed water tank for the preset 3rd time. As a result, the pH value of the boiler water rises, and even if the boiler feed water contains dissolved oxygen, the effect of suppressing boiler corrosion is reliably increased.

  In addition, when the electrical conductivity of the boiler feedwater (that is, the electrical conductivity of pure water before the chemical is injected) is high, the boiler feedwater contains many ions that promote corrosion such as chloride ions and sulfate ions. It is thought that. In this way, when the corrosion promoting ions are included in the boiler feed water, the possibility that the boiler corrodes increases.

Therefore, the boiler system of one embodiment is
A first electrical conductivity measurement unit for measuring electrical conductivity of the boiler water;
A second electrical conductivity measuring unit for measuring electrical conductivity of boiler feed water supplied to the boiler,
The control device
The electric conductivity of the boiler feed water measured by the second electric conductivity measuring unit is compared with a preset fifth set value, and the electric conductivity of the boiler feed water becomes equal to or higher than the fifth set value. Second electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler feed water is equal to or higher than the fifth set value, the electric conductivity of the boiler water measured by the first electric conductivity measuring unit and a preset sixth Unit of boiler water supply from the condensed water tank until the electric conductivity of the boiler water is equal to or higher than the sixth set value or a preset fourth time by comparing with the set value And third drug injection amount increasing means for increasing the injection amount of the first drug per flow rate.

  According to the embodiment, when it is determined that the electrical conductivity of the boiler feedwater measured by the second electrical conductivity measurement unit is equal to or higher than the fifth set value, the third medicine injection amount increasing means is Until the electric conductivity of the boiler water becomes equal to or higher than the sixth set value by comparing the electric conductivity of the boiler water measured by the first electric conductivity measuring unit with the preset sixth set value. The injection amount of the first chemical per unit flow rate of boiler feed water from the condensed water tank is increased. Or in that case, the said 3rd chemical | medical agent injection amount increase means increases the injection | pouring amount of the 1st chemical | medical agent per unit flow volume of the boiler feed water from a condensed water tank for the preset 4th time. As a result, the pH value of the boiler water is increased, and the possibility that the boiler is corroded reliably decreases even if the boiler feedwater contains corrosion promoting ions.

  A boiler system according to the present invention is provided with a first chemical injection device that injects a first chemical containing a volatile amine into boiler feed water from a condensed water tank, and a boiler feed water into which the first chemical is injected. A boiler that generates steam to be supplied to the boiler, and a control device that controls the first drug injection device so that the pH value of the boiler water in the boiler falls within the range of 9.0 to 10.3. In addition to maintaining the boiler corrosion suppression effect, it is possible to prevent the first medicine from being injected unnecessarily.

FIG. 1 is a schematic diagram of a boiler system according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a boiler system according to a second embodiment of the present invention. FIG. 3 is a schematic diagram of a boiler system according to a third embodiment of the present invention. FIG. 4 is a schematic diagram of a boiler system according to a fourth embodiment of the present invention. FIG. 5 is a schematic diagram of a boiler system according to a fifth embodiment of the present invention.

  Hereinafter, the boiler system of this invention is demonstrated in detail by embodiment of illustration.

[First Embodiment]
FIG. 1 is a schematic diagram showing a schematic configuration of a boiler system according to a first embodiment of the present invention. In the following description, “line” is a general term for a flow path, a path, a pipeline, and the like.

  The boiler system includes a first chemical injection device 1, a makeup water tank 2, a plurality of boilers 3, 3, a control device 4, a pure water production device 5, a steam header 8, a load device 9, and a condensation device. A water tank 13. The pure water production apparatus 5 is an example of a pure water supply source. The condensed water tank 13 is an example of a closed type condensed water tank.

The pure water production apparatus 5 is mainly composed of a demineralization unit and a deaeration unit, and generates degassed pure water. As the desalting unit, equipment using a reverse osmosis membrane method (for example, equipment using a reverse osmosis membrane device alone or equipment using a reverse osmosis membrane device and an electrodeionization device), an ion exchange method is used. Equipment (for example, equipment using a mixed bed type or two-bed / two-column type ion exchange apparatus) can be employed. The desalting unit is supplied with raw water such as tap water and industrial water through the raw water line L3, and generates pure water having an electrical conductivity of 1 μS / cm or less, for example, from the raw water. Moreover, as said deaeration part, the installation using deoxygenation apparatuses, such as a membrane type, a tower type, a nitrogen substitution type, can be employ | adopted, for example. The deaeration unit is supplied with pure water from the desalination unit, and generates pure water having a dissolved oxygen value of 1.0 mgO ₂ / L or less from the pure water. The deaerated pure water is guided to the makeup water tank 2 by the water supply line L1.

  The makeup water tank 2 is a tank that is open to the atmosphere, and stores the purified water supplied from the purified water production apparatus 5 as makeup water.

  The condensed water tank 13 is a hermetically sealed tank that satisfies the requirements for the first type pressure vessel stipulated in the Ordinance for Enforcement of the Industrial Safety and Health Law, and is connected to the load device 9 via the condensed water guide line L8. At the same time, it is connected to the makeup water tank 2 via a water supply line L4. More specifically, the condensed water tank 13 is supplied with condensed water generated by using steam in the load device 9 via the condensed water guide line L8, and stores this condensed water as boiler feed water. When the water level in the condensed water tank 13 is low, makeup water (pure water) in the makeup water tank 2 is supplied to the condensed water tank 13 via the water supply line L4 and stored as boiler feed water. That is, the condensed water tank 13 is supplied with at least one of steam condensed water used in the load device 9 and makeup water from the makeup water tank 2, and at least one (usually mixed water) is supplied to the boiler water. Store as.

  The flash steam generated in the condensed water tank 13 is guided to the make-up water tank 2 through the flash steam guide line L9. Note that flash steam refers to a part of condensed water that becomes steam when high-temperature and high-pressure condensed water (also called condensate or drain water) is exposed to a low-pressure atmosphere. be called.

Each boiler 3 is connected to the condensed water tank 13 via a water supply line L17 and a water distribution line L5. Each boiler 3 is provided with a first electric conductivity meter 7 for measuring the electric conductivity of the boiler water. The first electric conductivity meter 7 sends a signal indicating the electric conductivity of boiler water to the control device 4. Each boiler 3 generates steam using boiler feed water supplied from the condensed water tank 13. The steam generated in each boiler 3 flows through the steam collecting line L6 and collects in the steam header 8, and then is sent to the load device 9 through the steam supply line L7. Each boiler 3 in the present embodiment has a vapor pressure (gauge pressure) in a range of 0.5 to 3.0 MPa, for example, and an evaporation amount per hour in a range of 2 to 7 t / h, for example. It is a once-through boiler or a water tube boiler. The Industrial Safety and Health Law Enforcement Ordinance stipulates a special circulation boiler that is used at a gauge pressure of 1 MPa or less and has a heat transfer area of 10 m ² or less as a small once-through boiler. The first electric conductivity meter 7 is an example of a first electric conductivity measuring unit.

  Each boiler 3 is connected to one end of a blow line (not shown). This blow line is provided with a solenoid valve (not shown) that is opened and closed by a constant rate blow control or a high concentration blow control. When the solenoid valve is opened, boiler water is drained out of the boiler 3. The constant-rate blow control is a control for opening the solenoid valve for a predetermined time each time the combustion time in terms of high combustion state reaches a preset time. On the other hand, in the high concentration blow control, when the electric conductivity of boiler water exceeds a preset upper limit value, the electromagnetic valve is opened until the electric conductivity of boiler water reaches a preset lower limit value. It is a control to valve.

  The said 1st chemical | medical agent injection apparatus 1 inject | pours the 1st chemical | medical agent containing a volatile amine into the boiler feed water in the water supply line L17. Thereby, the boiler feed water containing the said 1st chemical | medical agent can flow in into the boiler 3. FIG. More specifically, the first drug injection device 1 includes a drug tank 10 for storing the first drug and a pump 11 provided in the drug injection line L2. By driving the pump 11, the first medicine is sent to the water supply line L17 via the medicine injection line L2. Examples of the volatile amine include diethanolamine (DEA), diethylethanolamine (DEEA), isopropanolamine (IPA), 2-amino-2-methyl-1-propanol (AMP), and monoethanolamine (MEA). , Cyclohexylamine (CHA), morpholine (MOR), and the like.

  A pump 12 and a flow rate sensor 6 are provided in the water supply line L17. The pump 12 is located on the downstream side of the connection point between the water supply line L17 and the medicine injection line L2, and is located on the upstream side of the flow rate sensor 6. The flow rate sensor 6 sends a signal indicating the flow rate of boiler feed water in the water supply line L17 to the control device 4.

  A pump 24 is provided in each of the water distribution lines L5. When the pump 12 and the pumps 24 and 24 are driven, boiler feed water stored in the condensed water tank 13 is supplied to the boilers 3 and 3.

  The pump 12 and the flow sensor 6 are connected to a condensed water tank 13 through a circulation line L15. The pump 12 is always driven during operation of each boiler 3. Therefore, when any of the pumps 24 is not driven (when any of the boilers 3 does not require water supply), the surplus boiler water that is not supplied to the boiler 3 is supplied to the condensed water tank 13 via the circulation line L15. Cycle back to.

  The load device 9 is supplied with steam generated in the boiler 3 and uses this steam as a heat source to exchange heat with the object to be heated. At this time, the condensed water of 80 ° C. to 90 ° C. generated by the condensation of the steam is guided to the condensed water tank 13 by the condensed water guide line L8 and collected. The load device 9 is provided in various manufacturing facilities such as paper industry, chemical industry, and food industry. The load device 9 may be a device that directly uses live steam for a product, or may be a device that does not directly use live steam for a product.

  The condensed water guide line L8 is provided with a steam trap 30 in the vicinity of the secondary side outlet of the load device 9. The steam trap 30 is a device that separates and discharges condensed water generated in the load device 9 from steam.

  The control device 4 is configured so that the injection amount of the first medicine is proportional to the flow rate of boiler feed water that flows downstream from the pump 12 of the water supply line L17 (the flow rate detected by the flow rate sensor 6). The medicine injection device 1 is controlled. Further, the control device 4 includes first electrical conductivity determination means 4a and first drug injection amount increase means 4b. The first electrical conductivity determination means 4a determines whether or not at least one of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7 and 7 is less than the first set value (that is, Whether any of the boilers 3 is in a low concentration state is determined. On the other hand, when it is determined that the electrical conductivity is less than the first set value, the first drug injection amount increasing unit 4b determines that the electrical conductivity is less than the first set value. The first chemical per unit flow rate of boiler feed water from the condensed water tank 13 (boiler feed water flowing downstream from the pump 12 of the water supply line L17) until the electrical conductivity of the boiler water becomes equal to or higher than the second set value. Increase the amount of injection. The first electrical conductivity determining means 4a and the first drug injection amount increasing means 4b are each configured by software. Here, the first set value is a value set in advance so as to correspond to the minimum pH value necessary to effectively prevent the corrosion of the boiler 3. On the other hand, the second set value is a value set in advance so as to be larger than the first set value.

  Moreover, the said control apparatus 4 controls the 1st chemical | medical agent injection | pouring apparatus 1 so that the pH value of the boiler water in each boiler 3 may enter into the range of 9.0-10.3. Specifically, when the pH value of the boiler water becomes less than 9.0 in any of the boilers 3, the first chemical injection device 1 is controlled to operate. Moreover, when the pH value of boiler water exceeds 10.3 in all the boilers 3, it controls so that the 1st chemical | medical agent injection apparatus 1 may be stopped. At this time, the pH value of the boiler water is detected by a pH meter (not shown) provided in each boiler 3.

  According to the boiler system having the above configuration, the boiler feed water into which the first medicine is injected by the first medicine injection device 1 is supplied to each boiler 3. At this time, the control device 4 controls the first chemical injection device 1 so that the pH value of the boiler water in each boiler 3 falls within the range of 9.0 to 10.3. In addition to being able to maintain a state where the suppression effect is increased, it is possible to prevent the drug from being injected unnecessarily.

  Further, it is determined by the first electrical conductivity determining means 4a that at least one of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7, 7 is less than the first set value. If it is, the first drug injection amount increasing means 4b has a second set value in which the electrical conductivity of the boiler water determined that the electrical conductivity is less than the first set value is greater than the first set value. Until this is reached, the injection amount of the first medicine per unit flow rate of boiler feed water from the condensed water tank 13 is increased. Therefore, the 1st chemical | medical agent injection amount increase means 4b can raise the pH value of the said boiler water, and can make high the inhibitory effect of the corrosion of the boiler 3 reliably.

  In the first embodiment, the first electrical conductivity determination unit 4a and the first drug injection amount increase unit 4b are each configured by software. However, at least one of them may be configured by hardware. .

  In the said 1st Embodiment, the 1st chemical | medical agent injection amount increase means 4b is the 1st per unit flow rate of the boiler feed water from the condensed water tank 13 until the electrical conductivity of boiler water becomes more than a 2nd setting value. Although the injection amount of the medicine has been increased, the injection amount of the first medicine per unit flow rate of boiler feed water from the condensed water tank 13 may be increased during a preset first time.

  In the first embodiment, at least one of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7 and 7 by the first electrical conductivity determination unit 4a is less than the first set value. When it is determined that the pump 24 of the boiler 3 determined to be in a low concentration state is being driven, the boiler in which the amount of the first chemical per unit flow rate of the boiler feed water from the condensed water tank 13 is increased. You may make it supply water supply. Then, when the pump 24 of the boiler 3 determined to be in the low concentration state is stopped and the pumps 24 of the other boilers 3 are driven, the amount of the first medicine is returned to the original set value.

[Second Embodiment]
FIG. 2 is a schematic diagram showing a schematic configuration of a boiler system according to a second embodiment of the present invention. 2, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  The boiler system is different from the first embodiment in that a control device 204 is provided.

  In the control device 204, the injection amount of the first chemical containing the volatile amine is proportional to the flow rate of boiler feed water (flow rate detected by the flow rate sensor 6) flowing downstream from the pump 12 of the water supply line L17. Thus, the 1st chemical injection device 1 is controlled. The control device 204 includes first electrical conductivity determination means 4a and blow prohibition means 204b. The first electrical conductivity determining means 4a determines whether or not at least one of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7 and 7 is less than the first set value. To do. On the other hand, when it is determined that the electrical conductivity is less than the first set value, the blow prohibiting unit 204b determines the electricity of the boiler water that is determined that the electrical conductivity is less than the first set value. Until the conductivity is equal to or higher than the second set value, the boiler water is prohibited from being blown. The first electrical conductivity determining means 4a and the blow prohibiting means 204b are each configured by software. Here, the first set value is a value set in advance so as to correspond to the minimum pH value necessary to prevent the corrosion of the boiler 3. On the other hand, the second set value is a value set in advance so as to be larger than the first set value. Further, the prohibition of the blow of boiler water by the blow prohibiting means 204b means prohibiting the opening of the solenoid valve of the blow line.

  Moreover, the said control apparatus 204 controls the 1st chemical | medical agent injection | pouring apparatus 1 so that the pH value of the boiler water in each boiler 3 may enter into the range of 9.0-10.3. Specifically, when the pH value of the boiler water becomes less than 9.0 in any of the boilers 3, the first chemical injection device 1 is controlled to operate. Moreover, when the pH value of boiler water exceeds all 10.3, it controls so that the 1st chemical | medical agent injection apparatus 1 may be stopped. At this time, the pH value of the boiler water is detected by a pH meter (not shown) provided in each boiler 3.

  According to the boiler system having the above configuration, at least one of the plurality of electrical conductivities measured by the first electrical conductivity meters 7 and 7 by the first electrical conductivity determination unit 4a is less than the first set value. If it is determined that the electrical conductivity of the boiler water is determined to be less than the first set value, the blow prohibiting means 204b has a second electrical conductivity greater than the first set value. Until the set value is exceeded, blow of the boiler water is prohibited. Thereby, the said boiler water concentration progresses rapidly and a 1st chemical | medical agent density | concentration becomes high. Therefore, the blow prohibiting means 204b forcibly raises the pH value of the low-concentrated boiler water even if the first drug injection device 1 does not increase the injection amount of the first drug, thereby suppressing the corrosion of the boiler 3. It can certainly be raised.

  In the second embodiment, the first electrical conductivity determination unit 4a and the blow prohibition unit 204b are each configured by software. However, at least one of them may be configured by hardware.

  In the second embodiment, the blow prohibiting means 204b prohibits the blowing of boiler water whose electrical conductivity is less than the first set value until the electrical conductivity of the boiler water becomes equal to or higher than the second set value. However, you may make it prohibit the blow of the boiler water whose electrical conductivity is less than 1st setting value during the 2nd time set beforehand.

[Third Embodiment]
FIG. 3 is a schematic diagram showing a schematic configuration of a boiler system according to a third embodiment of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals as those of the components in FIG.

  The boiler system is different from the first embodiment in that a control device 304 and a dissolved oxygen meter 341 are provided. The dissolved oxygen meter 341 is an example of a dissolved oxygen value measuring unit.

  The dissolved oxygen meter 341 is provided in the vicinity of the intake port of the condensed water tank 13 and measures the dissolved oxygen value of boiler feed water supplied to the boiler 3. The dissolved oxygen meter 341 sends a signal indicating the dissolved oxygen value of boiler feed water to the control device 304.

  In the control device 304, the injection amount of the first chemical containing the volatile amine is proportional to the flow rate of the boiler feed water that flows downstream from the pump 12 of the water supply line L17 (the flow rate detected by the flow rate sensor 6). Thus, the 1st chemical injection device 1 is controlled. The control device 304 includes a dissolved oxygen value determination unit 304a and a second medicine injection amount increase unit 304b. This dissolved oxygen value determination means 304a determines whether or not the dissolved oxygen value of the boiler feed water measured by the dissolved oxygen meter 341 is equal to or higher than the third set value. On the other hand, when it is determined that the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value, the second drug injection amount increasing unit 304b is measured by the plurality of first electric conductivity meters 7 and 7. The first per unit flow rate of boiler feed water from the condensed water tank 13 (boiler feed water flowing downstream from the pump 12 of the water supply line L17) until all of the plurality of electrical conductivities are equal to or higher than the fourth set value. Increase the amount of drug injection. The dissolved oxygen value determination means 304a and the second drug injection amount increase means 304b are each configured by software. Here, the third set value is a value set in advance so as to correspond to the dissolved oxygen value at which the possibility of corrosion of the boiler 3 starts to increase rapidly. On the other hand, the fourth set value is a value set in advance so as to correspond to the minimum pH value necessary to effectively prevent the corrosion of the boiler 3 in the presence of dissolved oxygen.

  Moreover, the said control apparatus 304 controls the 1st chemical | medical agent injection apparatus 1 so that the pH value of the boiler water in each boiler 3 may enter into the range of 9.0-10.3. Specifically, when the pH value of the boiler water becomes less than 9.0 in any of the boilers 3, the first chemical injection device 1 is controlled to operate. Moreover, when the pH value of boiler water exceeds 10.3 in all the boilers 3, it controls so that the 1st chemical | medical agent injection apparatus 1 may be stopped. At this time, the pH value of the boiler water is detected by a pH meter (not shown) provided in each boiler 3.

  According to the boiler system having the above-described configuration, when the dissolved oxygen value determination unit 304a determines that the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value, the second chemical injection amount increase unit 304b The first chemical per unit flow rate of boiler feed water from the condensed water tank 13 until all of the plurality of electric conductivities measured by the plurality of first electric conductivity meters 7 and 7 are equal to or higher than the fourth set value. Increase the amount of injection. Thereby, the quantity of the 1st chemical | medical agent per unit flow volume of the boiler feed water supplied to each boiler 3 increases, and the 1st chemical | medical agent density | concentration of boiler water becomes high. Therefore, the 2nd chemical | medical agent injection amount increase means 304b can raise the pH value of boiler water compulsorily, and can improve the corrosion inhibitory effect of the boiler 3 reliably, even if the said boiler feed water contains dissolved oxygen.

  In the third embodiment, the dissolved oxygen value determination unit 304a and the second medicine injection amount increase unit 304b are each configured by software, but at least one of them may be configured by hardware.

  In the third embodiment, boiler feed water from the condensed water tank 13 until all of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7 and 7 are equal to or higher than the fourth set value. Although the injection amount of the medicine per unit flow rate is increased, the injection amount of the medicine per unit flow rate of boiler feed water from the condensed water tank 13 may be increased during a preset third time.

  In the third embodiment, instead of the dissolved oxygen meter 341, for example, a dissolved oxygen meter provided in the middle of the water supply line L17 may be used. When doing in this way, it is preferable to connect the said dissolved oxygen meter through the connection line in the middle of the water supply line L17 between the condensed water tank 13 and the 1st chemical | medical agent injection apparatus 1. FIG.

[Fourth Embodiment]
FIG. 4 is a schematic diagram showing a schematic configuration of a boiler system according to a fourth embodiment of the present invention. 4, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  The boiler system is different from the first embodiment in that it includes a control device 404 and a second electric conductivity meter 441. The second electric conductivity meter 441 is an example of a second electric conductivity measuring unit.

  The second electrical conductivity meter 441 is provided in the vicinity of the intake port of the condensed water tank 13 and measures the electrical conductivity of boiler feed water supplied to the boiler 3. In addition, the second electrical conductivity meter 441 sends a signal indicating the electrical conductivity of boiler feed water to the control device 404.

  In the control device 404, the injection amount of the first chemical containing the volatile amine is proportional to the flow rate of the boiler feed water that flows downstream from the pump 12 of the water supply line L17 (the flow rate detected by the flow rate sensor 6). Thus, the 1st chemical injection device 1 is controlled. In addition, the control device 404 includes second electrical conductivity determination means 404a and third drug injection amount increase means 404b. This 2nd electrical conductivity determination means 404a determines whether the electrical conductivity of the boiler feed water measured with the 2nd electrical conductivity meter 441 is more than 5th setting value. On the other hand, the third medicine injection amount increasing means 404b, when it is determined that the electrical conductivity is equal to or higher than the fifth set value, the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7, 7. Injection of the first chemical per unit flow rate of boiler feed water from the condensate tank 13 (boiler feed water flowing downstream from the pump 12 of the water supply line L17) until all of the conductivity reaches the sixth set value or more. Increase the amount. Further, the second electrical conductivity determining means 404a and the third medicine injection amount increasing means 404b are each configured by software. Here, the fifth set value is a value set in advance so as to correspond to the electrical conductivity of the boiler feedwater corresponding to the corrosion accelerating ion concentration of the boiler feedwater at which the possibility of corrosion of the boiler 3 starts to increase rapidly. It is. On the other hand, the sixth set value is a value set in advance so as to correspond to the minimum pH value required to effectively prevent the corrosion of the boiler 3 in the presence of the corrosion promoting ion concentration. Note that the corrosion promoting ions in the present embodiment typically indicate chloride ions and sulfate ions. The corrosion promoting ion concentration is a total value of chloride ion concentration and sulfate ion concentration.

  Moreover, the said control apparatus 404 controls the 1st chemical | medical agent injection apparatus 1 so that the pH value of the boiler water in each boiler 3 may enter into the range of 9.0-10.3. Specifically, when the pH value of the boiler water becomes less than 9.0 in any of the boilers 3, the first chemical injection device 1 is controlled to operate. Moreover, when the pH value of boiler water exceeds 10.3 in all the boilers 3, it controls so that the 1st chemical | medical agent injection apparatus 1 may be stopped. At this time, the pH value of the boiler water is detected by a pH meter (not shown) provided in each boiler 3.

  According to the boiler system having the above configuration, it is determined by the second electrical conductivity determination unit 404a that the electrical conductivity of the boiler feedwater measured by the second electrical conductivity meter 441 is equal to or higher than the fifth set value. In this case, the third drug injection amount increasing unit 404b is configured to supply the condensed water tank 13 until all of the plurality of electrical conductivities measured by the plurality of first electrical conductivity meters 7 and 7 are equal to or higher than the sixth set value. Increase the injection amount of the first medicine per unit flow rate of boiler feed water from Thereby, the quantity of the 1st chemical | medical agent per unit flow volume of the boiler feed water supplied to each boiler 3 increases, and the 1st chemical | medical agent density | concentration of boiler water becomes high. Therefore, the control device 404 can forcibly increase the pH value of the boiler water and reliably increase the corrosion-inhibiting effect of the boiler 3 even if the boiler feedwater contains corrosion-promoting ions.

  In the fourth embodiment, the second electrical conductivity determination unit 404a and the third medicine injection amount increase unit 404b are each configured by software, but at least one of them may be configured by hardware. .

  In the fourth embodiment, when it is determined that the electrical conductivity of the boiler feed water is equal to or higher than the fifth set value, the third chemical injection amount increasing unit 404b has a plurality of first electrical conductivity meters 7 and 7. The amount of the first medicine injected per unit flow rate of the boiler feed water from the condensed water tank 13 was increased until all of the plurality of electrical conductivities measured in step 6 were equal to or higher than the sixth set value. During the fourth time, the injection amount of the first medicine per unit flow rate of boiler feed water from the condensed water tank 13 may be increased.

  In the fourth embodiment, instead of the second electrical conductivity meter 441, for example, an electrical conductivity meter provided in the middle of the water supply line L17 may be used. When comprised in this way, it is preferable that the said electric conductivity meter is connected to the middle of the water supply line L17 between the water supply tank 2 and the 1st chemical | medical agent injection apparatus 1 via a connection line.

[Fifth Embodiment]
FIG. 5 is a schematic diagram showing a schematic configuration of a boiler system according to a fifth embodiment of the present invention. 5, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  The boiler system is different from the first embodiment in that the boiler system includes a second medicine injection device 501 and a control device 504.

  The second medicine injection device 501 injects a second medicine containing a volatile amine into the steam used by the load device 9. That is, the second medicine injection device 501 injects the second medicine containing a volatile amine into the steam in the steam header 8. Thereby, the vapor | steam in which the said 2nd chemical | medical agent was inject | poured is supplied to the load apparatus 9, and the dissolved carbon dioxide gas contained in the condensed water generated with the load apparatus 9 is neutralized with a volatile amine. More specifically, the second drug injection device 501 includes a drug tank 510 that stores the second drug, and a pump 511 provided in the drug injection line L502. By driving the pump 511, the second medicine is sent to the steam header 8 through the medicine injection line L502. The second drug is different from the first drug. As the volatile amine contained in the first drug, for example, diethanolamine or 2-amino-2-methyl-1-propanol having a low distribution ratio (= gas phase concentration / liquid phase concentration) is used. Moreover, as a volatile amine which the said 2nd chemical | medical agent contains, when the piping length of a steam-condensed water system | strain is long, cyclohexylamine etc. are used, for example.

  The control device 504 is configured so that the injection amount of the first medicine is proportional to the flow rate of boiler feed water (flow rate detected by the flow rate sensor 6) flowing downstream from the pump 12 of the water supply line L17. The medicine injection device 1 is controlled. In addition, the control device 504 includes first electrical conductivity determination means 4a and first medicine injection amount increase means 4b.

  Moreover, the said control apparatus 504 controls the 1st chemical | medical agent injection apparatus 1 so that the pH value of the boiler water in each boiler 3 may enter into the range of 9.0-10.3. Specifically, when the pH value of the boiler water becomes less than 9.0 in any of the boilers 3, the first chemical injection device 1 is controlled to operate. Moreover, when the pH value of boiler water exceeds 10.3 in all the boilers 3, it controls so that the 1st chemical | medical agent injection apparatus 1 may be stopped. At this time, the pH value of the boiler water is detected by a pH meter (not shown) provided in each boiler 3.

  Moreover, the said control apparatus 504 controls the 2nd chemical | medical agent injection | pouring apparatus 501 so that the pH value of the condensed water in the condensed water guide line L8 may enter into the range of 6.5-9.0. Specifically, when the pH value of the condensed water becomes less than 6.5 at the end portion of the condensed water guide line L8, the second chemical injection device 1 is controlled to operate. In addition, when the pH value of the condensed water exceeds 9.0 at the end portion of the condensed water guide line L8, the second chemical injection device 1 is controlled to stop. At this time, the pH value of the condensed water is detected by a pH meter (not shown) provided at the end portion of the condensed water guide line L8.

  In the boiler system configured as described above, since the second drug is different from the first drug, for example, diethanolamine or 2-amino-2-methyl-1-propanol having a low distribution ratio is used as the volatile amine contained in the first drug. When the pipe length of the steam-condensed water system is long as the volatile amine used and contained in the second chemical, for example, cyclohexylamine can be used. As a result, the boiler system can further enhance the effect of suppressing the corrosion of the boiler 3 and can make the corrosion of the condensed water guide line L8 difficult to proceed.

[Modification]
In the fifth embodiment, the volatile amine included in the second drug is different from the volatile amine included in the first drug, but may be the same as the volatile amine included in the first drug. .

  In the first to fifth embodiments, a plurality of boilers 3 are installed, but a single boiler 3 may be installed.

  In the first to fifth embodiments, the control devices 4, 204, 304, 404, and 504 use the pH meter of the boiler 3 so that the pH value of the boiler water in each boiler 3 is 9.0 to 10.3. Although the 1st chemical | medical agent injection apparatus 1 was controlled so that it might enter into the range of this, using the 1st electric conductivity meter 7 of the boiler 3, the pH value of the boiler water in each boiler 3 is 9.0-. The first drug injection device 1 may be controlled so as to fall within the range of 10.3. Specifically, the relationship between the electrical conductivity of the boiler water and the pH value corresponding to the pressure in the boiler 3 is obtained in advance, and the injection amount of the first drug is increased as the electrical conductivity of the boiler water decreases. Then, the pH value of the boiler water is set within the range of 9.0 to 10.3.

  In the said 1st-5th embodiment, it is preferable that a boiler system sets and operates the blow rate of each boiler 3 to 5% or less, for example, 2-3%. By such an operation, a water saving effect and a heat loss reduction effect can be obtained, and both water and fuel costs can be suppressed.

  In the first to fifth embodiments, the deaerated pure water from the pure water production device 5 may pass through the dissolved oxygen monitoring device and flow into the water supply line L1.

  In the first to fifth embodiments, when the desalination unit of the pure water production device 5 is configured by a reverse osmosis membrane device, the reverse flow is performed so that the flow rate of the permeated water produced by the reverse osmosis membrane module becomes a target value. The driving frequency of the pressurizing pump that sends the pretreated water to the osmotic membrane module may be controlled by an inverter (see JP 2005-296945 A).

  In the said 1st-5th embodiment, the metal ion (for example, Fe, Cu, or Zn) density | concentration in the condensed water which flows through the condensed water guide line L8 is measured, and when this metal ion concentration is more than predetermined value, condensed water is used. You may make it discard, without sending to the condensed water tank 13. FIG. That is, when the condensed water is contaminated with metal ions eluted from the condensed water guide line L8 or the like and the metal ions may form a scale in each boiler 3, makeup water (pure water) in the makeup water tank 2 is used. Only the condensed water tank 13 may be supplied.

  As another method for controlling the first drug injection device 1, a distribution ratio data table using the pressure in the boiler 3 as a parameter is used for each type of volatile amine, and the distribution ratio obtained from this data table is used. Based on this, there is a method for controlling the first drug injection device 1. Specifically, the higher the distribution ratio (that is, the greater the amount of volatile amine transferred to the steam), the greater the injection amount of the first agent, and the pH value of the boiler water becomes 9.0-10. Within the range of .3.

  Although specific embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, a combination of the descriptions in the first to fifth embodiments as appropriate may be an embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 1st chemical | medical agent injection apparatus 2 Replenishment water tank 3 Boiler 4,204,304,404,504 Control apparatus 4a 1st electric conductivity determination means 4b 1st chemical | medical agent injection amount increase means 5 Pure water manufacturing apparatus 6 Flow rate sensor 7 1st Electrical conductivity meter 204b Blow prohibition means 304a Dissolved oxygen value determination means 304b Second drug injection amount increase means 404a Second electrical conductivity determination means 404b Third drug injection amount increase means 441 Second conductivity meter 501 Second drug injection apparatus

Claims (6)

A source of pure water;
A pure water is supplied from the pure water supply source, and a makeup water tank for storing the pure water as makeup water,
A load device using steam;
At least one of steam condensate used in the load device and make-up water from the make-up water tank is supplied, and a sealed condensate water tank that stores at least one water as boiler feed water,
A first drug injection device for injecting a first drug containing a volatile amine into boiler feed water from the condensed water tank;
A boiler that is supplied with boiler feed water into which the first chemical has been injected and generates steam to be supplied to the load device;
A boiler system comprising: a control device that controls the first drug injection device so that a pH value of boiler water in the boiler falls within a range of 9.0 to 10.3. The boiler system according to claim 1,
A boiler system comprising a second drug injection device that injects a second drug containing a volatile amine into the steam used by the load device. In the boiler system according to claim 1 or 2,
A first electrical conductivity measuring unit for measuring electrical conductivity of the boiler water;
The control device
The electric conductivity of the boiler water measured by the first electric conductivity measuring unit is compared with the first set value set in advance, and the electric conductivity of the boiler water becomes less than the first set value. First electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler water is less than the first set value, the electric conductivity of the boiler water is not less than a second set value that is greater than the first set value. Or a first drug injection amount increasing means for increasing the injection amount of the first drug per unit flow rate of boiler feed water from the condensed water tank for a preset first time. Boiler system. In the boiler system according to claim 1 or 2,
A first electrical conductivity measuring unit for measuring electrical conductivity of the boiler water;
The control device
The electric conductivity of the boiler water measured by the first electric conductivity measuring unit is compared with the first set value set in advance, and the electric conductivity of the boiler water becomes less than the first set value. First electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler water is less than the first set value, the electric conductivity of the boiler water is not less than a second set value that is greater than the first set value. Or a blow prohibiting means for prohibiting blow of the boiler water for a preset second time. In the boiler system according to claim 1 or 2,
A first electrical conductivity measurement unit for measuring electrical conductivity of the boiler water;
A dissolved oxygen value measuring unit for measuring the dissolved oxygen value of boiler feed water supplied to the boiler,
The control device
Whether the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value by comparing the dissolved oxygen value of the boiler feed water measured by the dissolved oxygen value measuring unit with a preset third set value. Dissolved oxygen value determining means for determining whether or not,
When it is determined that the dissolved oxygen value of the boiler feed water is equal to or higher than the third set value, the electric conductivity of the boiler water measured by the first electric conductivity measuring unit and a preset fourth value Unit of boiler water supply from the condensed water tank until the electric conductivity of the boiler water is equal to or higher than the fourth set value or a preset third time by comparing with the set value A boiler system comprising: a second medicine injection amount increasing means for increasing the injection amount of the first medicine per flow rate. In the boiler system according to claim 1 or 2,
A first electrical conductivity measurement unit for measuring electrical conductivity of the boiler water;
A second electrical conductivity measuring unit for measuring electrical conductivity of boiler feed water supplied to the boiler,
The control device
The electric conductivity of the boiler feed water measured by the second electric conductivity measuring unit is compared with a preset fifth set value, and the electric conductivity of the boiler feed water becomes equal to or higher than the fifth set value. Second electrical conductivity determination means for determining whether or not
When it is determined that the electric conductivity of the boiler feed water is equal to or higher than the fifth set value, the electric conductivity of the boiler water measured by the first electric conductivity measuring unit and a preset sixth Unit of boiler water supply from the condensed water tank until the electric conductivity of the boiler water is equal to or higher than the sixth set value or a preset fourth time by comparing with the set value A boiler system comprising: a third medicine injection amount increasing means for increasing the injection amount of the first medicine per flow rate.

Images