JP4443447B2 - Seawater cooling system configuration of strainer and power plant - Google Patents

Description

The present invention relates to a seawater cooling system configuration of a strainer and a power plant . In particular, the present invention relates to a technique suitable for removing foreign matters such as marine organisms contained in seawater in a seawater cooling system such as nuclear power and thermal power plants.

  Seawater cooling systems such as nuclear power plants and thermal power plants take seawater as cooling water and supply it to a heat exchanger. When foreign matter such as marine organisms contained in seawater flows into the heat exchanger in the system, the heat exchanger tube inlet of the heat exchanger is blocked, cooling water is reduced, or the heat exchanger tube adheres to the surface of the heat exchanger tube. Cause pitting and erosion.

  For this reason, in order to remove the foreign material contained in the seawater cooling water, a strainer is installed upstream of the heat exchanger (including the condenser) and the foreign material is removed upstream of the heat exchanger.

  The strainer is a filter that filters seawater within the casing of the strainer, a rotatable drift plate that controls the flow of seawater around the filter, an inlet nozzle that supplies seawater to the casing, and heats the filtered seawater. An outlet nozzle for supplying to the exchanger side and a discharge pipe for discharging foreign matter filtered from seawater by a filter to the outside of the casing are provided (for example, see Patent Document 1).

  In such a strainer, when the pressure difference between the inlet nozzle side and the outlet nozzle side of the strainer rises more than a specified value, the drift plate usually placed in a state parallel to the flow of seawater is set at an angle of 30. The water is rotated about 20 degrees to apply the flow of seawater to the drift plate, and the seawater is swirled around the outer periphery of the filter.

  With the force of the swirling flow, the foreign matter adhering to the filter can be removed from the filter, and the removed foreign matter can be discharged from the discharge pipe to the outside, so that the above-described differential pressure of the strainer can be returned within a specified range.

JP-A-55-157308

  However, when the flow in the strainer is observed, a swirl flow is generated on the outlet nozzle side of the filter, but the flow from the outside of the filter to the outlet nozzle side is strong, and the foreign matter is placed in the casing. Sometimes remained on the side.

  If foreign matter remains, the differential pressure between the inlet nozzle side and the outlet nozzle side of the strainer will increase, so the differential pressure may soon exceed the specified value. Must be reduced as much as possible.

  In the case of the prior art, even if the foreign matter captured by the filter in the strainer is discharged by the strainer, the foreign matter remains on the outlet nozzle side of the filter in the strainer, and the differential pressure of the strainer increases. There was a possibility of exceeding the specified value.

  The main object of the present invention is to provide a strainer capable of efficiently discharging foreign matters remaining in the strainer. Another object of the present invention is to provide a seawater cooling system configuration of a power plant that can efficiently discharge foreign matter in seawater.

  The first means for achieving the main object of the present invention includes a casing having an inlet nozzle and an outlet nozzle, and a filter that is contained in the casing and that flows in the inlet nozzle and flows into the outlet nozzle. And a plurality of discharge pipes that are connected to the casing and allow the foreign matter filtered out by the filter to flow out of the casing, and a swivel imparting unit that imparts an action of swirling the liquid around the outer periphery of the filter. It is a strainer characterized by having. According to this first means, in addition to the flow from the outside of the filter to the outlet nozzle side, the flow on the outlet nozzle side of the filter can flow on each discharge pipe side, and adheres to the filter surface where foreign substances are likely to adhere. Foreign matter can be discharged.

  Similarly, the second means is connected to the casing provided with an inlet nozzle and an outlet nozzle, a filter encapsulated in the casing and flowing from the inlet nozzle and flowing into the outlet nozzle, and connected to the casing. A strainer comprising: a discharge pipe through which foreign matter filtered out by the filter flows out of the casing; and swirl imparting means for swirling the liquid around the outer periphery of the filter. A strainer comprising: a plate and a rotating shaft attached to the drift plate, wherein the rotating shaft is inclined with respect to a center line of the casing. According to the second means, as a method for improving the discharge of foreign matters remaining on the outlet pipe side of the filter surface, the drift plate has an inclination of θ from the center line of the filter, outlet nozzle or casing installed in the strainer. The direction of the swirling flow generated in the drift plate is directed toward the outlet nozzle side of the filter surface, forcibly creating a flow around the filter part on the outlet nozzle side where foreign matter is likely to adhere, and adhering to the filter surface Foreign matter can be surely removed.

  Means for achieving another object of the present invention includes a cooling water supply pipe connected from a pump for driving seawater to an inlet nozzle of a strainer, and rotatable between the cooling water supply pipe and the inlet nozzle. The mounted drift plate, the cooling water outlet pipe connected from the outlet nozzle of the strainer to the heat exchanger, and the seawater that is connected to the heat exchanger and exchanges heat in the heat exchanger. A cooling water outlet line that leads to the outside, a discharge pipe that is connected from the strainer to the cooling water outlet line and that allows foreign matter in the seawater to flow out of the strainer, and is provided in the middle of the discharge pipe and the discharge pipe And a valve for controlling the flow of the power plant, wherein the strainer is a strainer according to any one of the first means and the second means. It is sea water cooling system configuration of a power plant that was. According to this third means, foreign matters that are likely to remain attached to the outer peripheral surface of the filter on the outlet nozzle side can be reliably discharged, so that an increase in pressure loss due to residual foreign matters is easily reduced, and the seawater cooling system configuration of the power plant Pressure loss can also be reduced.

  According to the strainer of the present invention, it is possible to improve the foreign matter discharge performance. In addition, according to the seawater cooling system configuration of the present invention, it is possible to suppress an increase in pressure loss in the strainer section, and therefore it is possible to reduce the pressure loss of the system.

The first embodiment is as follows. As shown in FIG. 1, the structure of the seawater cooling system of the power plant includes a pump 11 that supplies seawater to the strainer 13 through the cooling water supply pipe 12, and seawater filtered by the strainer 13 to the heat exchanger 17 as cooling water. The outlet pipe 16 to be supplied, the cooling water outlet line 18 for guiding the seawater subjected to heat exchange by the heat exchanger 17 to the outside of the seawater cooling system, and a flow path for discharging foreign matter in the strainer 13, Each valve 14 provided in the foreign matter discharge line 15 and the outlet nozzle side foreign matter discharge line 21 that connect the strainer 13 and the cooling water outlet line 18 by piping, the foreign matter discharge line 15 and the outlet nozzle side foreign matter discharge line 21, respectively. 20.

  As shown in FIGS. 2 and 3, the strainer 13 has the following configuration. That is, the filter 4 is built in the center of the strainer 13 with a gap serving as a seawater flow path from the inner surface of the strainer 13, and the outlet nozzle 5 is covered with the filter 4. The casing 3 installed on the support base B so that the center line A of the filter 4, the outlet nozzle 5, and the casing 3 is horizontal is arranged on the outlet nozzle 5, the inlet nozzle 2, the discharge pipe 6, and the outlet nozzle side discharge pipe 7. It has.

  The discharge pipe 6 is connected to the casing 3 at a position far from the outlet nozzle 5, and the outlet nozzle side discharge pipe 7 is connected to the casing 3 at a position closer to the outlet nozzle 5 as compared with it. One end side of the strainer outlet pipe 16 is connected to the outlet nozzle 5, and the other end side of the strainer outlet pipe 16 is connected to the heat exchanger 17.

  One end of the cooling water supply pipe 12 is connected to the seawater discharge port of the pump 11, and the other end of the cooling water supply pipe 12 is connected to the inlet nozzle 2 via the turning imparting means. The swivel imparting means includes a cylindrical body 30 connected to the other end of the cooling water supply pipe 12 and the inlet nozzle 2, a disc-shaped drift plate 1 disposed inside the trunk 30, and the drift plate. The drift plate rotating shaft 8 is fixed to 1, and the drift plate rotating shaft 8 is rotatably attached to the body 30. The center axis of the drift plate rotating shaft 8 is in a parallel relationship with the center line A of the casing 3.

  One end of a pipe of a foreign matter discharge line 15 constituted by piping is connected to the discharge pipe 6, and one end side of a pipe of the outlet nozzle side foreign matter discharge line 21 constituted by piping is connected to the outlet nozzle side discharge pipe 7. Has been. The other ends of the foreign matter discharge line 15 and the outlet nozzle side foreign matter discharge line 21 are connected to a pipe constituting a cooling water outlet line 18 constituted by a pipe.

  When the differential pressure between the outlet nozzle 5 side and the inlet nozzle 2 side of the strainer 13 is equal to or less than a specified value, the central axis C of the inlet nozzle 2 and the cooling water supply pipe 12 as shown in FIGS. The drift plate rotating shaft 8 is rotated and placed so that the plate surfaces of the drift plate 1 are parallel to each other. If it does in this way, the seawater sent with the pump 11 will not change the direction of a flow with the drift plate 1, but will enter in the casing 3, seawater will be filtered with the filter 4, and the filtered seawater will pass the filter 4 Then, it flows out from the outlet nozzle 5 to the strainer outlet pipe 16 and enters the heat exchanger 17 as cooling water. Seawater heat-exchanged by the heat exchanger 17 is discharged out of the seawater cooling system through the cooling water outlet line 18.

In this way, during normal operation of the seawater cooling system, the valves 14 and 20 are closed to supply seawater as cooling water to the heat exchanger 17 side.

  Due to the filtration of the seawater, foreign substances that have been accompanied by the seawater adhere to the outer peripheral surface of the filter 4. Since the flow of seawater in the casing 3 is dominant in the direction toward the outlet nozzle 5, a large amount of foreign matter tends to adhere to the filter 4 portion on the outlet nozzle 5 side. If many foreign substances adhere to the filter 4, the differential pressure between the outlet nozzle 5 side and the inlet nozzle 2 side exceeds the specified value.

  In that case, the operation is switched to the foreign matter discharging operation. That is, as shown in FIG. 5, the drift plate rotating shaft 8 is rotated so that the plate surface of the drift plate 1 is at an angle of about 30 degrees with respect to the central axis C of the inlet nozzle 2 and the cooling water supply pipe 12. Then, the drift plate 1 is rotated about 30 degrees. At the same time, the valves 14 and 20 are opened.

  In this case, the flow of seawater is guided to the drift plate 1 at an angle of about 30 degrees, and a flow as indicated by an arrow in FIG. 5 is generated in the flow path between the filter 4 and the casing 3. 3, a seawater flow swirling around the outer periphery of the filter 4 is generated. The foreign matter adhering to the filter 4 is peeled off by the force of the swirling flow of the seawater and is accompanied by the flow of the seawater. Since the seawater discharge port in the casing 3 occurs on the discharge pipe 6 side and the outlet nozzle side discharge pipe 7 side, the swirling flow of seawater is strong not only at a position far from the outlet nozzle 5 but also at a position close to the outlet nozzle 5 side. appear. For this reason, foreign matters attached to the filter 4 near the outlet nozzle 5 are also easily peeled off.

  The foreign matter peeled off from the filter 4 is accompanied by the flow of seawater and flows from the discharge pipe 6 to the foreign matter discharge line 15 or flows from the outlet nozzle side discharge pipe 7 to the outlet nozzle side foreign matter discharge line 21 and flows into the cooling water outlet line 18. Through the seawater cooling system.

  When the valves 14 and 20 are opened at the same time, if the distribution of the seawater flow to the heat exchanger 17 is insufficient, the valves 14 and 20 are alternately operated in reverse to solve the shortage. To open and close. If it does in this way, since each valve 14 and 20 is not opened simultaneously, the insufficient distribution of the seawater flow rate to the heat exchanger 17 side can be solved. In this case, when one valve 14 is opened and the other valve 20 is closed, a strong swirling flow is generated in the casing 3 on the discharge pipe 6 side, and one valve 20 is opened and the other valve 14 is closed. When this occurs, a strong swirling flow is generated in the casing 3 on the outlet nozzle side discharge pipe 7 side.

  Even when there is no concern about insufficient distribution of the seawater flow rate to the heat exchanger 17 side, the valves 14 and 20 are alternately opened and closed so as to perform the reverse operation, thereby removing the foreign matter from the filter 4. You may make it give strongly alternately.

  In this way, the swirl flow is surely generated even in the casing 3 on the outlet nozzle 5 side, and the foreign matter adhering to the portion of the filter 4 near the outlet nozzle 5 side is surely removed and discharged out of the seawater cooling system. It is possible to reduce residual foreign matter. Therefore, the seawater cooling system can be maintained in a low pressure loss state.

  The second embodiment is as follows. The second embodiment is an improvement of the first embodiment. The details of the improvement will be described below, and the description of the same contents as the first embodiment will be omitted.

  That is, in the second embodiment, the outlet nozzle side discharge pipe 7, the outlet nozzle side foreign matter discharge line 21 and the valve 20 are omitted. Instead, the drift plate rotating shaft 8 is inclined at an angle of θ degrees with respect to the center line A of the filter 4, the outlet nozzle 5 and the casing 3 as shown in FIG. 6. Other configurations are the same as those of the first embodiment.

  In the second embodiment, during normal operation of the seawater cooling system, the valve 14 is closed and the pump 11 is driven, the seawater is supplied to the strainer 13 and filtered, and the filtered seawater, as in the first embodiment. To the heat exchanger 17, and the operation of discharging the used seawater after heat exchange in the heat exchanger 17 from the seawater cooling system via the cooling water outlet line 18 is continued. In this case, the flow of seawater and the surface of the drift plate 1 are substantially parallel.

  During the foreign matter discharging operation, the valve is opened, and the drift plate 1 is rotated by rotating the drift plate rotating shaft 8 at an angle of about 30 degrees. In this way, the flow of seawater supplied from the cooling water supply pipe 12 to the casing 3 side by the pump 11 hits the drift plate 1 and has an inclination of θ with respect to the center line A of the casing 3 toward the outlet nozzle 5. The filter on the outlet nozzle 5 side that has conventionally entered the casing 3 and forcibly creates a swirling flow around the filter 4 on the outlet nozzle 5 side where foreign matter is likely to remain, and has conventionally become a foreign matter staying part. 4 From the surface part, it is possible to efficiently remove foreign substances and accompany them in the flow of seawater. The peeled foreign matter is accompanied by the flow of seawater, passes through the foreign matter discharge line 15 from the discharge pipe 6, passes through the cooling water outlet line 18, and is discharged out of the seawater cooling system.

  Also in this case, the foreign matter can be surely peeled off from the surface portion of the filter 4 on the outlet nozzle 5 side that has been a foreign matter staying portion, so that it is effective in reducing the residual foreign matter in the strainer 13. Therefore, the seawater cooling system can be maintained in a low pressure loss state.

  The third embodiment is as follows. The third embodiment is an improvement of the first embodiment. The details of the improvement will be described below, and the description of the same contents as those of the first embodiment will be omitted.

  In the third embodiment, as shown in FIGS. 9, 10, and 11, the drift plate rotation shaft 8 in the first embodiment is in relation to the filter 4, the outlet nozzle 5, and the center line A of the casing 3. As shown in FIG. 9, the angle is inclined by θ degrees. Other configurations are the same as those of the first embodiment.

  According to the third embodiment, during normal operation of the seawater cooling system, as in the first embodiment, the valves 14 and 20 are closed and the pump 11 is driven to supply seawater to the strainer 13 for filtration. Then, the filtered seawater is supplied to the heat exchanger 17, and the operation of discharging the used seawater after the heat exchange in the heat exchanger 17 from the seawater cooling system via the cooling water outlet line 18 is continued. In this case, the flow of seawater and the surface of the drift plate 1 are substantially parallel.

  During the foreign matter discharging operation, the valves 14 and 20 are opened, or the valves 14 and 20 are alternately opened and closed. At the same time, the drift plate rotating shaft 8 is rotated about 30 degrees to rotate the drift plate 1 to rotate. The flow of seawater is controlled so that the flow of seawater is applied to the plate 1 and a swirling flow is generated on the outlet nozzle 5 side.

  As a result, the flow of seawater controlled by the drift plate 1 becomes a swirling flow, the direction of the swirling flow can be directed to the outlet nozzle 5 side of the filter 4 surface, and the outlet nozzle on the surface of the filter 4 where foreign matter tends to remain. Forcibly creates a flow on the side 5, and the foreign matter staying part has been removed from the outlet nozzle 5 side portion on the surface of the filter 4 and the foreign matter separated from the outlet nozzle side discharge pipe 7 is discharged. I can flow.

  The present invention is applied to a seawater cooling system in a nuclear power plant or a thermal power plant.

It is a systematic diagram of the seawater cooling system of the nuclear power plant in 1st Example of this invention. FIG. 2 is an elevation view of the strainer shown in FIG. FIG. 3 is a top view of the strainer of FIG. 2. It is a right view of the strainer of FIG. It is the figure which showed the flow of the seawater at the time of the foreign material discharge | emission operation in the strainer in FIG. 4 with the arrow. It is a top view of the strainer in 2nd Example of this invention. FIG. 7 is an elevational view with a partial cross-sectional view of the strainer of FIG. 6. It is a right view of the strainer of FIG. It is a top view of the strainer in 3rd Example of this invention. FIG. 10 is an elevational view with a partial cross-sectional view of the strainer of FIG. 9. It is a right view of the strainer of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Diffusion plate, 2 ... Inlet nozzle, 3 ... Casing, 4 ... Filter, 5 ... Outlet nozzle, 6 ... Discharge pipe, 7 ... Outlet nozzle side discharge pipe, 8 ... Diffusion plate rotating shaft, 11 ... Pump, 12 ... Cooling Water supply pipe, 13 ... strainer, 14, 20 ... valve, 15 ... foreign matter discharge line, 16 ... strainer outlet pipe, 17 ... heat exchanger, 18 ... cooling water outlet line, 21 ... outlet nozzle side foreign matter discharge line.

Claims (3)

A casing with an inlet nozzle and an outlet nozzle;
Installed so that the center line of the outlet nozzle and the casing is horizontal;
A filter that is contained in the casing and that filters the liquid flowing from the inlet nozzle and flowing to the outlet nozzle;
A discharge pipe connected to the casing and flowing out the foreign matter filtered by the filter from the casing;
A swivel imparting means for imparting an action of swirling the liquid around the outer periphery of the filter;
The swivel imparting means comprises a drift plate and a rotating shaft attached to the drift plate;
A strainer characterized in that the rotating shaft is installed inclined with respect to the center line of the casing so that the liquid flowing in from the inlet nozzle hits the drift plate and the liquid flows in the direction of the outlet nozzle. . 2. The strainer according to claim 1, wherein a plurality of the discharge pipes are provided, and the plurality of discharge pipes are connected to the casing at intervals along a center line of the casing. A cooling water supply pipe connected from the pump for driving seawater to the inlet nozzle of the strainer;
The drift plate rotatably mounted between the cooling water supply pipe and the inlet nozzle;
A cooling water outlet pipe connected from the outlet nozzle of the strainer to a heat exchanger;
A cooling water outlet line that is connected to the heat exchanger and guides the seawater heat exchanged in the heat exchanger to the outside of the heat exchanger;
The discharge pipe connected to the cooling water outlet line from the strainer and causing the foreign matter in the seawater to flow out from the strainer;
In the seawater cooling system configuration of the power plant provided with a valve that is provided in the middle of the discharge pipe and controls the flow of the discharge pipe,
A seawater cooling system configuration of a power plant, wherein the strainer is the strainer according to any one of claims 1 to 2.

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