JPH0718138B2 - Shellfish removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a device for removing shellfish deposits which prevents shellfish deposits on the inner surface of plant piping of a nuclear power plant or the like and removes the shellfish deposits. In particular, the present invention relates to a device for removing shellfish deposits, which prevents shellfish deposits on the inner surface of seawater pipes and prevents pipe corrosion.

(Prior Art) In a nuclear power plant, steam generated in a nuclear reactor is sent to a steam turbine through a main steam system, and this steam turbine is driven to rotate a generator. The steam that has worked in the steam turbine is condensed in a condenser to become condensate, and this condensate is returned to the reactor again via the reactor condensate / water supply system.

On the other hand, the condenser that cools the turbine steam contains a heat exchanger inside, and seawater is mainly used as a cooling medium for the turbine steam in this heat exchanger. This seawater is forcibly supplied from the intake port to the heat exchanger by the circulating water pump via the seawater system inflow pipe, and the turbine steam is cooled by this seawater. The seawater that has cooled the turbine steam in the heat exchanger is discharged into the sea from the discharge port through the seawater system outflow pipe. By the way, in the seawater system piping that supplies seawater for turbine steam cooling to the condenser, shellfish such as Fuji jars and glass shells adhere to the inner surface of the piping, and the adhered shellfish gradually grows, blocking the piping flow path. Or reduce the flow path area,
In this case, sufficient cooling water could not be supplied to the condenser, and its heat exchange function might be impaired.

In this way, shellfish attach to seawater system piping of nuclear power plants, etc., and if the attached shellfish grows, various harmful effects will occur.Therefore, at present, at the time of regular inspection, the inside surface of the pipe is washed with a high-pressure jet stream, A work robot is sent inside to scratch and the shellfish attached to the inner surface of the pipe is forcibly removed.

(Problems to be Solved by the Invention) In a conventional shellfish removing device that removes shellfish attached to the inner surface of the pipe, the inner surface of the pipe may be damaged in order to remove the shellfish. Further, the adhesion of shellfish to the inner surface of the pipe has a great influence on the corrosion of the metal material of the pipe, and not only the corrosion and the damage of the pipe but also the problem of the blockage of the pipe flow path, etc., which is a big problem in the nuclear power plant. It was

In conventional nuclear power plants, removal of shellfish adhering to seawater pipes is the main target, and no special consideration has been given to preventive measures to prevent the attachment of shellfish.

On the other hand, the mechanism of shellfish's adhesion to the inner surface of the pipe is that if organic matter or plankton is attached to the inner wall of the pipe in any form, these will produce sticky metabolites and gradually grow, forming a matrix of organisms or bacteria. It is thought that shellfish may attach to this. The attached shellfish grow by eating microbes such as plankton.

The present invention has been made in consideration of the above-mentioned circumstances, and effectively prevents shellfish from adhering to the inner surface of the flow path, effectively prevents corrosion and damage of the piping flow path, and prevents blockage of the flow path. An object of the present invention is to provide a device for removing adhered shellfish.

Another object of the present invention is to provide a shellfish attachment removing device that can optically remove shellfish attached to an inner wall surface of a flow channel without damaging the inner wall surface of the flow passage.

Still another object of the present invention is to provide a shellfish attachment removing device that can prevent the growth of the shellfish even if the shellfish adheres to the inner surface of the flow path.

[Structure of Invention]

(Means for Solving the Problem) In order to solve the above-mentioned problems, the shellfish adhesion removing device according to the present invention is, as described in claim 1, used for cooling plant equipment from an intake of a sea or a river. Extend the flow path used,
A sterilization light source device for irradiating sterilization light is provided in the flow path, and the sterilization light source device has a sterilization light source that outputs sterilization light, and an optical fiber that guides the sterilization light from the sterilization light source, and the optical fiber is It is provided so that it can be moved and run freely in the flow channel, the inside of the flow channel and the inner wall surface of the flow channel can be irradiated freely, and microbes such as plankton are sterilized by irradiation of sterilizing light into the flow channel.

Further, in order to solve the above-mentioned problems, the shellfish attachment removing device according to the present invention has, as described in claim 2, a flow passage used for cooling plant equipment and the like extending from the intake port of the sea or river. , A sterilization light source device for irradiating sterilization light is provided in this flow path, and the sterilization light source device is a sterilization lamp device for outputting ultraviolet light having a wavelength of around 260 nm, a low pressure mercury lamp device for outputting ultraviolet light, or a laser for outputting laser light. An oscillating device, irradiating the sterilizing light from the sterilizing light source device into the flow path
It is sterilized by microorganisms such as plankton.

Furthermore, in order to solve the above-mentioned subject, as for the shellfish attachment removal device which concerns on this invention, in addition to the content of Claim 1 or 2, as described in Claim 3, chlorine is provided at the inlet side of a flow path. Alternatively, a replenishing device for injecting ozone is provided.

(Function) This device for removing adhesion of shellfish irradiates sterilizing light output from the sterilizing lamp device, the low-pressure mercury lamp device, or the sterilizing light source device of the laser oscillator into the channel to sterilize microbes such as plankton. It is possible to prevent microorganisms such as plankton from adhering to the inner wall surface of the channel, and consequently prevent shellfish from adhering to the inner wall surface of the channel.

In addition, since this attachment removing device sterilizes microbes such as underwater plankton and bacteria that pass through the flow path by sterilization light from the sterilization light source device, even if shellfish adhere to the inner surface of the flow path, the growth of the attached shellfish Can be prevented or delayed.

Further, by directly irradiating the sterilization light from the sterilization light source device to the shellfish attached to the inside of the flow path, the attached shellfish can be easily removed optically and in a non-contact state.

(Example) An example of the device for removing and attaching shellfish according to the present invention will be described with reference to the accompanying drawings.

1 and 2 show a typical example of a nuclear power plant of a boiling water reactor equipped with the shellfish deposit removing device of the present invention. This nuclear power plant comprises a reactor (composite) building 10 and a turbine building 11 arranged side by side. Reactor building 10
A reactor containment vessel 12 is housed therein, and a reactor pressure vessel 13 constituting a steam generator of the reactor is housed in the containment vessel 12.

On the other hand, the turbine building 11 includes a steam turbine 14, a generator 15 driven by the steam turbine 14, and a condenser 16 that drives the steam turbine 14 and cools the steam that has worked.

Then, the steam generated in the reactor pressure vessel 13 is sent to the steam turbine 14 via the reactor main steam system 18, drives the steam turbine 14 to perform work, and rotationally drives the generator 15. The steam that worked in the steam turbine 14 expands and the condenser
It is sent to 16 and cooled in this condenser 16 to become condensate. This condensate is supplied via the reactor condensate / water supply system 19 to the reactor pressure vessel.
Refluxed into 13.

Further, the condenser 16 has a casing 20 in which a heat exchanger 21 is housed, and a seawater system inflow pipe is provided at an inlet side of the heat exchanger 21.
22 is typically connected to the outlet side of a seawater system outflow pipe 23. The seawater system inflow pipe 22 is extended from an intake port 24 of the sea (may be a river), is connected to a heat exchanger 21 via a circulating water pump 25 on the way, and cools turbine steam with this heat exchanger 21. There is. The seawater that has cooled the turbine steam is discharged into the sea from a water discharge port 26 via a seawater system outflow pipe 23.

Further, another intake port 28 near the intake port 24 is connected to a seawater heat exchanger (not shown) housed in the seawater equipment building 31 via a seawater flow passage 30 as shown in FIG. It The seawater heat exchanger and the like form a part of the auxiliary equipment cooling system.

By the way, seawater system inflow pipe from the intake 24 to the condenser 20
As shown in FIG. 4, a sterilization light source device 36 for irradiating sterilization light is provided in a seawater flow passage 30 (hereinafter, referred to as a flow passage 35) connected to 22, the seawater heat exchanger or the like. The sterilization light source device 36 is preferably provided, for example, on the inlet side of the flow path 35 or near the water intake. A plurality of sterilization light source devices 36 are installed along the flow path 35 so that sterilization light is emitted in multiple stages.
A plurality of units may be installed around the flow path 35, and sterilizing light may be irradiated from around the flow path 35 so that the inside of the flow path 35 has a substantially uniform light intensity in consideration of attenuation of light in seawater. .

The sterilizing light source device 36 outputs sterilizing light having a wavelength that damages the ecological function of shellfish, and specifically, outputs sterilizing light having a wavelength capable of sterilizing aquatic plankton and bacterial microorganisms. There is. In the sterilization light source device 36, a sterilization lamp device that outputs an ultraviolet ray (sterilization line) near a wavelength of 260 nm, a laser oscillation device that outputs a powerful laser beam in a pulse oscillation mode or a CW oscillation mode, or a biological function of shellfish is reduced. A low-pressure mercury lamp device that emits ultraviolet rays, which has the action of killing shellfish, is suitable.

For example, the sterilization lamp device uses a special glass having a high sterilization transmittance of around 260 nm, and directly outputs 253.7 nm ultraviolet rays generated during mercury discharge in a low vapor pressure to the outside of the sterilization lamp. Therefore, the germicidal lamp is not coated with the phosphor. The relationship between the spectral distribution of this germicidal lamp and the specific germicidal effect is as shown in Fig. 5.
Ultraviolet rays near m have a great bactericidal effect as shown by the bactericidal effect curve a.

Next, the operation of the attachment removing device for shellfish will be described.

By driving the sterilization light source device 36 provided in the shellfish adhesion removing device, sterilization light is radiated from the sterilization light source device 36 almost uniformly over the entire surface of the flow path 35, and plankton existing in seawater passing through the flow path 35 and Sterilize microorganisms such as bacteria. By this sterilization treatment, seawater that is substantially free of microorganisms can be caused to flow in the flow channel, and microorganisms such as plankton can be effectively prevented from adhering to the inner wall surface of the flow channel. By the sterilization treatment of this microorganism, it is possible to effectively prevent the shellfish such as Fuji urn from adhering to the inner wall surface of the flow path. Even if juvenile molluscs attach to the inner wall of the flow path, the growth conditions are obstructed, so that the growth of the molluscs can be stopped and a sufficient amount of seawater can be supplied to the condenser and seawater heat exchange equipment. Can be supplied as cooling water.

Further, since the microorganisms are optically sterilized by the sterilizing light from the sterilization light source device 36, it is possible to effectively prevent the shellfish from adhering or growing on the inner wall surface of the flow path, and prevent the pipe corrosion.

In one embodiment of the shellfish adherence removing device, an example in which the sterilizing light from the sterilizing light source device 36 is applied to the entire surface of the flow path 35 is shown. However, as shown in FIG. 6, the sterilizing light output from the sterilizing light source device 36 is shown. (Laser light or ultraviolet light) may be guided into the flow path 35 through the optical fiber 38 and directly irradiated to the flow path 35 or the inner wall surface of the flow path. At that time, by providing the optical fiber 38 in the flow path 35 so that it can move freely, it may damage the biological function of the shellfish 39 attached to the inner surface of the flow path, or kill the shellfish 39 in an optically non-contact state. As a result, it is possible to effectively prevent damage and corrosion on the inner surface of the flow path.

The irradiation method using the optical fiber 38 includes a continuous irradiation method and an intermittent irradiation method, and the irradiation method, irradiation time, and irradiation light intensity are appropriately selected according to the degree of adhesion and growth of the shellfish 39, the irradiation application site, etc. To be done.

In addition, this shellfish adherence removal device can prevent shellfish from adhering to the inner surface of the flow path, and can remove the shellfish that adheres to the inner wall surface of the flow path without contact, but it interferes with the growth conditions of the shellfish. In order to do so, a chlorine replenishing device 40 is provided as shown in FIG. 7 on the inlet side of the flow passage 35, preferably on the upstream side of the circulating water pump 25, and the chlorine replenishing device 40 injects into the flow passage 35. Plankton and bacteria contained in seawater may be sterilized by chlorine (gas). When this chlorine supply device 40 is used together with the sterilization light source device 36, the sterilization effect of seawater can be further enhanced. Instead of chlorine sterilization, other substances such as ozone may be supplemented and sterilized if it does not adversely affect the ecosystem of the sea or river.

In addition, in one embodiment of the present invention, an example in which the shellfish adherence removing device is applied to a nuclear power plant is shown, but it can also be applied to other plants using seawater or river water, for example, a thermal power plant or a chemical plant. it can.

〔The invention's effect〕

As described above, in the device for removing adhesion of shellfish of the present invention, a sterilization light source that extends a channel used for cooling plant equipment from the intake of the sea or river and irradiates sterilizing light in this channel An apparatus is provided, and this sterilization light source device has a sterilization light source that outputs sterilization light, and an optical fiber that guides the sterilization light from this sterilization light source. Since it is possible to irradiate the inner wall surface and the inner wall surface
The germicidal light from the germicidal light source device is efficiently guided to the inside of the flow channel by suppressing the output decrease by the optical fiber as much as possible, and the germicidal light is radiated to the inside of the flow channel or the inner wall of the flow channel to allow microorganisms such as underwater plankton and bacteria Can be sterilized or damage the biological function of shellfish attached to the inner wall of the flow channel, and kill and remove the shellfish optically without contact, so that damage and corrosion of the inner wall of the flow channel can be effectively performed. It can be prevented.

Further, in the device for removing adhesion of shellfish according to the present invention, a flow path used for cooling plant equipment and the like is extended from the intake of the sea or river, and a sterilization light source device for irradiating sterilization light in this flow path is provided, This sterilization light source device is composed of a sterilization lamp device that outputs ultraviolet rays having a wavelength near 260 nm, a low-pressure mercury lamp device that outputs ultraviolet rays, or a laser oscillation device that outputs laser light.
Ultraviolet rays and laser light of wavelengths in the vicinity efficiently sterilize microbes such as underwater plankton and bacteria, and can guide almost sterile water into the channel, preventing shellfish from adhering to the inner wall of the channel. It is possible to effectively prevent the damage to the inner wall surface of the flow channel, and to effectively prevent the growth of the shellfish even if the shellfish adheres to the inner wall surface of the flow channel.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle diagram of a nuclear power plant to which the shellfish deposit removing device of the present invention is applied, and FIG. 2 is a diagram showing a sectional structure of a building provided in the nuclear power plant, and FIG.
Figure is a partial layout showing the layout of a nuclear power plant. Figure 4 is a diagram showing a shellfish removal device installed in the seawater flow passage of a nuclear power plant. Figure 5 is a shellfish removal device. Showing the relationship between the spectral distribution of the germicidal lamp of the germicidal light source device and the specific germicidal effect curve, and FIG. 6 is a diagram showing a second embodiment of the shellfish adhesion removing device of the present invention,
The drawing is a diagram showing a third embodiment of the shellfish removing device of the present invention. 10 …… Reactor building, 11 …… Turbine building, 13 …… Reactor pressure vessel, 14 …… Steam turbine, 15 …… Generator, 16 ……
Condenser, 21 ... Heat exchanger, 22 ... Seawater system inflow pipe (flow path), 23 ... Seawater system outflow pipe (flow path), 24 ... Intake port,
25 …… Circulating water pump, 26 …… Outlet, 30 …… Seawater flow passage (flow passage), 31 …… Seawater equipment building, 35 …… Flow passage, 36 …… Sterilization light source device, 38 …… Optical fiber, 39 …… Shellfish, 40 …… Chlorine supply device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Kubogawa 4-7-1, Kajiwara, Kamakura-shi, Kanagawa Inside Nomura Research Institute, Ltd. (72) Inventor Sakae Takagi 4-7-1, Kajiwara, Kamakura-shi, Kanagawa Nomura Co., Ltd. (56) References JP-A-51-96142 (JP, A) JP-A-3-8912 (JP, A)

Claims (3)

[Claims] 1. A sterilization light source device for extending sterilization light to irradiate sterilization light in a passage used for cooling plant equipment from an intake of a sea or a river. The sterilization light source device outputs sterilization light. The sterilization light source to perform, and an optical fiber that guides the sterilization light from the sterilization light source, the optical fiber is provided in the flow path so as to be freely movable, the flow path and the inner wall surface of the flow path can be illuminated, An apparatus for removing adhesion of shellfish, which is characterized in that microorganisms such as plankton are sterilized by irradiating sterilizing light into the road. 2. A sterilization light source device for irradiating sterilizing light is provided in the flow passage for cooling plant equipment from the intake of the sea or river, and the sterilization light source device has a wavelength near 260 nm. Of the sterilization lamp device that outputs ultraviolet rays, a low-pressure mercury lamp device that outputs ultraviolet rays or a laser oscillation device that outputs a laser beam, irradiating the sterilization light from the sterilization light source device into the flow path, to prevent microorganisms such as plankton. An apparatus for removing adhesion of shellfish characterized by being sterilized. 3. An apparatus for removing adhesion of shellfish according to claim 1, wherein a replenishing device for injecting chlorine or ozone is provided on the inlet side of the flow path.