JP4102737B2 - Method and system for inhibiting the attachment and growth of marine organisms - Google Patents

Description

  The present invention relates to a method and a system for suppressing adhesion and growth of marine organisms in a cooling water flow path for supplying seawater as cooling water to a cooling target facility such as a condenser of a thermal power plant.

In thermal power plants that use seawater as cooling water, shells, etc. are placed inside the intake channel that takes seawater from the ocean and supplies it to the condenser, and the discharge channel that releases the seawater that has passed through the condenser to the ocean. The marine life is easy to adhere. When the adhesion amount of such marine organisms increases, there is a risk of causing problems such as blocking the cooling water flow path and lowering the cooling performance. Therefore, conventionally, as disclosed in, for example, Patent Document 1 and Patent Document 2, by injecting a chlorine-based chemical such as sodium hypochlorite solution or chlorine dioxide into the flow path of cooling water, Suppression of the attachment and growth of marine organisms has been carried out.
JP-A-7-265867 Japanese Patent Laid-Open No. 11-37666

  As mentioned above, seawater after being used as cooling water in thermal power plants is released to the sea, but for environmental conservation, the chlorine concentration (residual chlorine concentration) contained in the discharged water to the sea is constant. It is required to be below the agreed value. Therefore, the injection amount of the chlorinated chemical for removing marine organisms must be limited so as to satisfy the above requirements, and it is not easy to obtain a sufficient removal effect within the limits.

  The present invention has been made in view of the above points, and when cooling a facility to be cooled with seawater, the adhesion and growth of marine organisms are effectively suppressed with a chlorine-based chemical in the cooling water flow path, while entering the sea. The purpose is to make it possible to keep the chlorine concentration in the released seawater low.

In order to achieve the above object, the invention described in claim 1 is for taking seawater from the sea as cooling water and supplying it to the facility to be cooled, and discharging the seawater after passing through the facility to be cooled to the sea. A method for suppressing the attachment and growth of marine organisms in the cooling water flow path of
A plurality of drug injection parts for injecting a chlorinated drug are provided along a cross-sectional wall surface at a predetermined position of the cooling water flow path, and the cooling is performed by the drug injection part selected by sequentially switching among the plurality of drug injection parts. A chlorinated chemical is injected into the water flow path.

  According to the present invention, a plurality of drug injection portions are provided along a cross-sectional wall surface at a predetermined position of the cooling water flow path, and the chlorine injection into the cooling water flow path is performed by the drug injection portions selected by sequentially switching among the drug injection portions. Inject drugs. For this reason, the residual chlorine concentration becomes high in the vicinity of the drug injection position, and the adhesion and growth of marine organisms on the wall surface can be effectively suppressed. Moreover, since the chemical | medical agent injection | pouring part which inject | pours a chlorine type | system | group chemical | medical agent is switched sequentially, adhesion and growth of a marine organism can be suppressed over the whole wall surface of a flow path. As described above, according to the present invention, since a high residual chlorine concentration can be realized locally in the cooling water flow path, it is possible to reduce the residual chlorine concentration of seawater discharged to the sea while keeping the concentration of the shells and the like in the cooling water flow path. The adhesion and growth of marine organisms can be effectively suppressed.

  The invention described in claim 2 is characterized in that, in the method according to claim 1, sodium hypochlorite is injected as the chlorinated drug.

  According to a third aspect of the present invention, in the method according to the first or second aspect, the predetermined position is a position in the vicinity of a water intake port for taking seawater into the cooling water flow path.

In the invention described in claim 4, seawater is taken from the sea as cooling water and supplied to the equipment to be cooled, and the seawater after passing through the equipment to be cooled is discharged into the cooling water flow path for discharging the seawater to the sea. A system for removing attached marine life,
A plurality of drug injection parts for injecting chlorine-based drugs provided along the cross-sectional wall surface at a predetermined position of the cooling water flow path,
Control means for injecting a chlorine-based medicine into the cooling water flow path by a medicine injection section selected by switching sequentially from the plurality of medicine injection sections.

  According to the present invention, when cooling the facility to be cooled with seawater, the chlorine concentration in the seawater released to the sea can be reduced while effectively suppressing the adhesion and growth of marine organisms with the chlorine-based chemical in the cooling water flow path. It can be kept low.

  FIG. 1 is a schematic plan view of a thermal power plant 10 according to an embodiment of the present invention. As shown in the figure, the thermal power plant 10 is constructed on a site facing the sea 2. The thermal power plant 10 is provided with various facilities such as a fuel storage facility 12, an LNG tank 14, and a power generation facility 16. In the present embodiment, the condenser 18 provided in the power generation facility 16 is cooled with seawater. A water discharge channel 22 for discharging the seawater that has passed through to the sea 2 is installed. Seawater is taken in from the water intake 24 at the tip of the intake channel 20, flows through the water intake channel 20, passes through the condenser 18, flows through the water discharge channel 22, and is discharged from the water discharge port 26 at the tip thereof to the sea 2. The intake channel 20 and the discharge channel 22 correspond to the “cooling water channel” of the present invention.

  As described above, since seawater flows through the intake channel 20 and the discharge channel 22, marine organisms such as shellfish are easily attached and propagated in the channel. If a large amount of marine organisms adhere to the flow path, the flow performance may be reduced because the flow path is blocked and a sufficient flow rate cannot be obtained. In particular, with regard to the intake channel 20, since the intake 24 is provided offshore far away from the land so that low temperature seawater can be taken in, the intake channel 20 becomes very long and is affected by the attachment of marine organisms. easy.

  Therefore, in this embodiment, by injecting sodium hypochlorite solution as a chlorinated chemical into the intake channel 20 at a point near the intake port 24 of the intake channel 20, the inner wall surfaces of the intake channel 20 and the discharge channel 22. To suppress the adhesion and growth of marine organisms such as shellfish. However, it is not limited to sodium hypochlorite, and other chlorinated chemicals such as chlorine dioxide may be used.

  FIG. 2 schematically shows a cooling water system 28 including a water intake channel 20 and a water discharge channel 22. As shown in the figure, a seawater pump 30 is provided at a connection portion between the condenser 18 and the intake channel 20, and seawater is drawn into the intake channel 20 from the intake port 24 by the seawater pump 30. In addition, a drug injection part 32 is provided in the vicinity of the water intake 24 of the water intake channel 20. The drug injection part 32 is provided at a plurality of locations along the cross-sectional wall surface of the intake channel 20. Further, a residual chlorine concentration meter 34 for detecting the residual chlorine concentration in the seawater discharged to the sea 2 is provided in the vicinity of the water outlet 26 of the water discharge channel 22. The detection signal from the residual chlorine concentration meter 34 is sent wirelessly or by wire to a monitoring device provided on land.

  FIG. 3 shows a detailed configuration of the drug injection unit 32. As shown in the figure, the drug injection section 32 includes an injection pipe 40 having an injection port 41 inside the intake channel 20, a drug supply tank 42 for supplying a sodium hypochlorite solution to the injection pipe 40, and an injection pipe 40. The opening and closing of the valve 44 is controlled by a control device 46. In the example shown in FIG. 3, the tip of the injection tube 40 is bent toward the downstream side of the seawater, and an injection port 41 is provided at the tip. In addition, as shown in FIG. 4, you may comprise so that the cross section of the front-end | tip part of the injection tube 40 may spread toward the injection port 41 gradually. Further, as shown in FIG. 5, a hole provided on the downstream side surface may be used as the injection port 41 without bending the injection tube 40. Thus, various structures can be considered as the injection port 41.

  FIG. 6 shows an example of a plurality of drug injection portions 32 provided along the cross-sectional wall surface of the intake channel 20. In this example, the case where five drug injection parts 32A, 32B, 32C, 32D, and 32E are provided is shown, but the number of drug injection parts 32 is not limited to this, and is along the cross-sectional wall surface of the intake channel 20. A plurality of drug injection portions 32 may be provided. In addition, the medicine supply tank 42 and the control device 46 are provided in common in the medicine injection units 32A to 32E. In the following description, the water injection tube 40 and the water injection port 41 included in the drug injection units 32A to 32E may be also referred to as the water injection tubes 40A to 40E and the water injection ports 41A to 41E, respectively.

  As shown in FIG. 6, the injection ports 41 </ b> A to 41 </ b> E of the drug injection parts 32 </ b> A to 32 </ b> E are arranged along both side surfaces and the upper surface of the cross section of the intake channel 20. The reason why the water injection pipe 40 is not disposed on the bottom surface of the intake channel 20 is that the sludge accumulates on the bottom of the intake channel 20, so that the sodium hypochlorite solution is injected at a position avoiding this. . In addition, in the example of FIG. 6, although the intake channel 20 shall have a rectangular cross-sectional shape, the water inlet 41 should just be arrange | positioned avoiding the lower position where sludge accumulates similarly in the case of a circular cross section.

  FIG. 7 shows the change over time of the open / close state of the valve 44 of the drug injection sections 32A to 32E controlled by the control device 46 (that is, the on / off state of drug injection). As shown in the figure, in this embodiment, the sodium hypochlorite solution is injected from any one of the drug injection units 32 selected by sequentially switching the five drug injection units 32A to 32E. In this way, by sequentially switching the plurality of drug injection parts 32A to 32E and injecting the sodium hypochlorite solution, the residual chlorine concentration distribution in the cross section of the intake channel 20 is the injection position of the sodium hypochlorite solution. As a result, the density becomes uneven.

  FIG. 8 shows an example of the residual chlorine concentration distribution in the cross section of the intake channel 20 when the sodium hypochlorite solution is injected by the drug injection part 32A. In the figure, the darker the color, the higher the residual chlorine concentration. Since there are almost no obstacles that disturb the water flow inside the intake channel 20, at least the flow of seawater is kept in a laminar flow within the intake channel 20, and the non-uniform residual chlorine concentration as illustrated in FIG. Distribution is almost maintained. On the other hand, the residual chlorine concentration of the seawater discharged from the water outlet 26 to the sea 2 becomes a value averaged over the entire cross section of the water discharge channel 22, and is thus kept low.

  Thus, in this embodiment, by injecting the sodium hypochlorite solution from any one of the drug injection parts 32A to 32C provided along the cross-sectional wall surface of the intake channel 20, a high residual chlorine concentration is locally produced. Realizing it, it is possible to keep the residual chlorine concentration of the seawater released to the sea 2 low while effectively suppressing the adhesion and growth of marine organisms in that part. Then, by sequentially switching the drug injection part 32 for injecting the sodium hypochlorite solution, the attachment and growth of marine organisms can be suppressed over the entire wall surface excluding the bottom surface of the intake channel 20. In addition, about the bottom face of the intake channel 20, when sludge accumulates and marine organisms do not adhere as mentioned above, there is no problem even if the sodium hypochlorite solution is not injected.

  In the above-described embodiment, the sodium hypochlorite solution is injected from any one of the plurality of drug injection units 32. However, the present invention is not limited to this, and the plurality of drug injection units 32 is used. The sodium hypochlorite solution may be injected at the same time. For example, in the above-described embodiment, it is assumed that the drug injection units 32A and 32E and the drug injection units 32B and 32D perform injection simultaneously, respectively (drug injection units 32A and 32E) → (drug injection unit 32C) → (drug injection) The case where switching is performed as in (Parts 32B, 32D) → (Pharmaceutical injection units 32A, 32E) is also included in the scope of the present invention.

  In the above embodiment, the condenser of the thermal power plant is cooled as the equipment to be cooled. However, the present invention is not limited to the condenser and is widely applied when cooling various equipment using seawater. Is possible.

1 is a schematic plan view of a thermal power plant according to an embodiment of the present invention. It is a figure which shows typically the cooling water system which consists of a water intake channel and a water discharge channel. It is a figure which shows the detailed structure of a chemical | medical agent injection | pouring part. It is a figure which shows the structural example of the injection port of an injection tube. It is a figure which shows another structural example of the injection inlet of an injection tube. It is a figure which shows the time change of the opening / closing state (namely, on / off state of a chemical | medical agent injection | pouring) of the valve | bulb of the chemical | medical agent injection | pouring parts 32A-32E controlled by a control apparatus. It is a figure which shows an example of residual chlorine concentration distribution in the cross section of an intake channel. It is a figure which shows an example of residual chlorine concentration distribution in the cross section of an intake channel.

Explanation of symbols

2 Sea 10 Thermal Power Plant 18 Condenser 20 Intake Channel 22 Inlet Channel 24 Inlet 26 Outlet 28 Cooling Water System 30 Seawater Pump 32 (32A to 32E) Drug Injection Portion 40 (40A to 40E) Infusion Tube 41 (41A to 41A to 41A 41E) Inlet 42 Drug supply tank 44 Valve 46 Control device

Claims (4)

This is a method for suppressing the adhesion and growth of marine organisms in the cooling water flow path for taking seawater from the sea as the cooling water and supplying it to the equipment to be cooled, and discharging the seawater that has passed through this equipment to the sea. And
A plurality of drug injection parts for injecting a chlorinated drug are provided along a cross-sectional wall surface at a predetermined position of the cooling water flow path, and the cooling is performed by the drug injection part selected by sequentially switching among the plurality of drug injection parts. A method comprising injecting a chlorinated drug into a water flow path.   The method according to claim 1, wherein sodium hypochlorite is injected as the chlorinated drug.   The method according to claim 1, wherein the predetermined position is a position in the vicinity of a water intake port for taking seawater into the cooling water flow path. It is a system that suppresses the adhesion and growth of marine organisms in the cooling water flow path for taking seawater from the sea as the cooling water and supplying it to the equipment to be cooled and discharging the seawater that has passed through this equipment to the sea. And
A plurality of drug injection parts for injecting chlorine-based drugs provided along the cross-sectional wall surface at a predetermined position of the cooling water flow path,
And a control means for injecting a chlorine-based medicine into the cooling water flow path by a medicine injection section selected by switching sequentially from among the plurality of medicine injection sections.

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