JP4683958B2 - Pump shaft lubrication water supply system - Google Patents

Description

  The present invention relates to a pump shaft lubricating water supply system that supplies lubricating water to a shaft seal portion of a pump that supplies seawater. More specifically, the present invention relates to a pump shaft lubricating water supply system in which a part of seawater discharged from a pump is used as the shaft lubricating water of its own pump.

  In a thermal power plant, a steam turbine is driven using steam generated by a boiler, and power is generated by a generator connected to the steam turbine. The steam that exits the steam turbine is cooled by a condenser to become condensate, and is sent to a boiler by a condensate pump for circulation. In the condenser, seawater is used to cool the steam. Moreover, in a LNG (liquid natural gas) -fired power plant, seawater is used to vaporize LNG.

  The cooling seawater is supplied to the condenser by pumping the seawater taken from the intake channel, and this pump is called a circulation pump or a cooling water supply pump. In the circulation pump, a self-lubricating water line for using a part of the discharged seawater is provided in the lubricating water at the shaft seal portion. The pump that feeds seawater to the LNG vaporizer to vaporize LNG is called the LNG vaporizer seawater pump. Like the circulation pump, the pump that uses a part of the discharged seawater as the lubricating water for the shaft seal is used. A lubricating water line is provided.

When seawater is used as the lubrication water for the shaft seal of the circulation pump or LNG vaporizer seawater pump, the adhering larvae of the shellfish floating in the seawater will adhere to the inner surface of the pipe and propagate, providing sufficient shaft lubrication. In some cases, a technique for mounting a filter in the middle of a self-lubricating water line of a circulation pump is disclosed (for example, see Patent Document 1). At this power plant, strainers are installed in the middle of the self-lubricating water line of the circulation pump and the LNG vaporizer seawater pump, and the strainer is periodically washed to prevent clogging of pipes due to shellfish adhesion. Yes.
JP 9-94414 A

  While installing a strainer in the middle of the self-lubricating water line of the circulation pump and the LNG vaporizer seawater pump and periodically washing the strainer, it is possible to prevent clogging of the piping due to adhesion of shellfish, etc. These are not perfect methods, and shellfish may adhere and grow during long-term operation. If shaft lubrication water cannot be sufficiently secured due to the growth of shellfish attached to the pipe, the pipe is disassembled and mechanically cleaned and then assembled. During this time, seawater (discharge water) cannot be used as shaft lubrication water, so the shaft is lubricated using backup water.

  In order to prevent clogging of the pipeline that supplies the lubricating water and to supply the lubricating water stably to the shaft seal of the pump, it is desirable to use industrial water, but using industrial water constantly increases costs. Connected. From the above, development of a system that is superior in cost and that stably supplies lubricating water to the shaft seal portion of the pump is awaited.

  An object of the present invention is to provide a system that is superior in cost and that stably supplies shaft lubricating water to a shaft seal portion of a pump.

  The present inventor has found that there is a margin in the amount of industrial water that can be used in the power plant, and the shaft lubrication of the pump that can be used by switching between industrial water and seawater as the shaft lubrication water of the pump A water supply system was developed.

That is, the present invention is a shaft lubrication water supply system for a pump that supplies seawater installed in a power plant, and includes a strainer, and a part of discharged water is taken out, filtered by the strainer, and supplied to a shaft seal portion of the pump. A shaft lubricating water supply for a pump comprising: a self-lubricating water supply line; and an in- house water line for supplying in-house water consisting of treated water treated with industrial water or treated water or mixed water to the shaft seal portion. In the system, an industrial water supply line is further provided for supplying industrial water to the shaft seal by filtering the industrial water with the strainer. When there is sufficient industrial water in the power plant, the industrial water is supplied from the industrial water supply line to the inside of the power plant. When there is no room for industrial water, seawater is supplied from the self-lubricating water supply line. Water, which is the axis lubricant supplying system of the pump, characterized in that supplied to the shaft sealing portion.

In the shaft lubricating water supply system of the pump according to the present invention , the unsteady time is when the pump is started, when the pump is stopped, or when the strainer is disassembled and cleaned .

The shaft lubricating water supply system of the pump of the present invention is a pump lubricating oil supply line for the pump, in addition to a self-lubricating water supply line that filters a part of the pump discharge water with a strainer and supplies it to the shaft seal portion of the pump, with industrial water supply line for supplying filtered industrial water in the strainer, resulting is a margin in industrial water power plant, when it is possible to use industrial water pump shaft lubricating water, using industrial water When there is not enough room for industrial water in the power plant, self-lubricating water (seawater) is used for the shaft lubrication water of the pump, so maintenance of the shaft lubrication water supply line of the pump becomes easy and stable shaft lubrication water is supplied. It becomes possible to supply .

Or industrial water, since only be used when the industrial water plant can afford, not the cost, as much maintenance axes lubricant supplying line of the pump is easy to reduce the total cost it can. The shaft lubricating water supply system of the pump according to the present invention further includes an in-house water line for supplying in-house water consisting of treated water or clean water obtained by treating industrial water with a treatment device or mixed water thereof to the shaft seal portion. It is conceivable to replace the industrial water or supply the industrial water with the industrial water as the shaft lubrication water. However, the industrial water is more expensive than the industrial water, so it is more cost-effective to use the industrial water. .

According to the present invention, when the pump is started, when the pump is stopped, or when the strainer is disassembled and cleaned, the in-house water is supplied from the in-house water line to the shaft seal of the pump, so that the strainer can be disassembled and cleaned. The shaft lubricating water can be supplied stably .

  FIG. 1 is a system diagram showing a schematic configuration of a circulating pump shaft lubricating water supply system 1 according to an embodiment of the present invention. A shaft lubricating water supply system 1 of the present circulation pump supplies circulating water to a shaft sealing portion (not shown) of a circulation pump 2 that supplies seawater for cooling to a condenser. 10, roughly divided into a backup facility water line 30, an industrial water supply line 40, and a washing water supply line 50.

  The self-lubricating water supply line 10 is a piping system for taking out part of the water discharged from the circulation pump 2 and supplying it to the shaft seal portion of the circulation pump 2. The circulation pump 2 takes seawater from the intake passage via the suction pipe 3 and feeds seawater to the condenser through the discharge pipe 4. The discharge pipe 4 is provided with a branch pipe 11 for taking out discharge water, and the self-lubricating water supply line 10 obtains the discharge water from the branch pipe 11.

  The outlet of the branch pipe 11 is provided with a seawater take-off valve 12, and discharged water can be taken out by opening it. Pipes 13, 14, 15, 16, and 17 are connected to the outlet side of the seawater extraction valve 12, and seawater is supplied to the shaft seal portion of the circulation pump 2 through these pipes. The pipe line 13 is connected to the seawater gate valve 12 and one end is connected to the check valve 18. The check valve 18 is for preventing a backflow of industrial water described later. The pipe 14 has one end connected to the check valve 18 and the other end connected to a strainer 19 that removes shellfish larvae and solids contained in the seawater. Moreover, the pipe line 14 is provided with a strainer inlet valve 20 in the middle, and further includes a branch part for receiving industrial water described later.

  A pipe line 15 is connected to the outlet of the strainer 19, and one end of the pipe line 15 is connected to the strainer outlet valve 21. The strainer outlet valve 21 is connected to the pipe line 16, and the pipe line 16 is further connected to a pipe line 17 that connects the shaft seal portion and one end of the circulation pump 2. A flow rate detector 22 for detecting the flow rate is provided in the middle of the pipeline 17. A part of the discharge water of the circulation pump 2 can be supplied to the shaft seal through the self-lubricating water supply line configured as described above.

  Further, the shaft lubrication water supply system 1 of the present circulation pump includes a backup in-house water line 30 that supplies lubrication water to the shaft seal portion when the circulation pump 2 is started, stopped, or in an emergency. Since the discharge water cannot be used when the circulation pump 2 is started and stopped, the shaft seal portion is lubricated by using the backup in-house water line 30. The backup station water line 30 includes a pipe 31 and an automatic valve 32 in the middle of the pipe 31, and a check valve 33 for preventing a backflow at the outlet of the automatic valve 32. The check valve 33 includes a pipe line 34 at the outlet, and the pipe line 34 is connected to the pipe line 16 at one end.

  The in-house water used here is treated water or clean water obtained by treating industrial water with a pretreatment device to remove solids, or mixed water thereof. The water in the backup station is used as shaft lubricating water not only when the circulation pump 2 is started and stopped as described later, but also when the strainer of the self-lubricating water supply line 10 is disassembled and washed. Since the water in the backup station is used as shaft lubricating water without passing through the strainer, it is necessary to use industrial water treated with a pre-treatment device or treated water from which solid content has been removed or clean water or a mixture of these. is there.

  Further, the shaft lubrication water supply system 1 of the present circulation pump has an industrial water supply line 40 for supplying industrial water to the shaft seal portion of the circulation pump 2. The industrial water supply line 40 receives industrial water through a branch pipe 42 of a pipe 41 that receives industrial water. The branch pipe 42 is connected to an industrial water supply valve 43, and the industrial water supply valve 43 includes a pipe line 44 at the outlet. Further, the pipe 44 is connected at one end to a check valve 45 for preventing seawater backflow. The check valve 45 includes a pipe 46 at the outlet, and the pipe 46 is connected to a branch portion of the pipe 14.

  As described above, the industrial water supply line 40 is connected to the upstream side of the strainer 19 provided in the self-lubricated water supply line 10. Although it is possible to connect the industrial water supply line 40 to the downstream side of the strainer 19 provided in the self-lubricating water supply line 10, the industrial water is not pretreated unlike the water in the backup station. For this reason, since the case where solid content is contained in industrial water is assumed, it is desirable to connect the industrial water supply line 40 to the upstream side of the strainer 19 provided in the self-lubricating water supply line 10.

  The industrial water is also used as cleaning water used when cleaning the strainer 19. The cleaning water supply line 50 for supplying the cleaning water includes a pipe 41 and an automatic valve 51 at one end of the pipe 41, and supplies the cleaning water through a pipe 52 connecting the automatic valve 51 and the strainer 19.

  Next, an example of using seawater as shaft lubricating water will be described as a method of using the shaft lubricating water supply system 1 of the present circulation pump. When the circulation pump 2 is started, the discharge water cannot be used as shaft lubricating water, so the automatic valve 32 of the backup in-house water line 30 is opened and the in-house water is supplied as shaft lubricating water. After the circulation pump 2 is activated, the seawater extraction valve 12, the strainer inlet valve 20 and the strainer outlet valve 21 are opened, and seawater is supplied from the self-lubricating water supply line 10.

  After the supply of seawater to the shaft seal is started and the flow rate detector 22 detects that the flow rate of the discharge water (seawater) is a predetermined flow rate, the automatic valve 32 of the backup site water line 30 is closed, and the inside of the backup site Stop supplying water. Thereafter, the shaft of the circulation pump 2 is lubricated with seawater through the self-lubricating water supply line 10. However, when the flow rate detector 22 detects that the strainer is blocked and the flow rate of the discharge water (seawater) has decreased, the automatic valve 32 is opened again, and the in-house water is supplied through the backup in-house water line 30. . Even when the circulation pump is stopped, the in-house water is supplied through the backup in-house water line 30.

  After the circulation pump 2 is activated, seawater is supplied to the shaft seal portion through the self-lubricating water supply line 10 and the strainer 19 attached to the self-lubricating water supply line 10 is cleaned at a predetermined interval. Since the strainer 19 has solid content removing means for removing larvae and solid contents of shellfish contained in seawater, the solid content removing means is clogged during a long operation. When the degree of clogging of the solid content removing means increases, the pressure loss of the strainer increases, and a predetermined amount of seawater cannot be supplied as shaft lubricating water. Therefore, at a predetermined interval, the automatic valve 51 mounted on the cleaning water supply line 50 is opened, and the cleaning water is sent to the strainer for a predetermined time to clean the solid content removing means. After supplying the washing water to the strainer 19 for a predetermined time, the automatic valve 51 is closed and the washing is finished.

  The solid matter may adhere to the wall surface of the strainer with the operation for a long time, and the cleaning of the strainer may not be sufficient only by periodic cleaning with cleaning water. In such a case, after switching the lubricating water of the shaft to the water in the backup station, the strainer inlet valve 20 and the strainer outlet valve 21 are closed, and the strainer 19 is disassembled and cleaned.

  Next, an example of using industrial water as shaft lubricating water will be described as a method of using the shaft lubricating water supply system 1 of the present circulation pump. When supplying industrial water, the seawater take-off valve 12 is closed, the industrial water supply valve 43 is opened, and the shaft 14, the strainer 19, the pipe 15, the strainer outlet valve 21, and the pipes 16 and 17 are supplied to the shaft seal. Supply water.

  By supplying industrial water instead of seawater, shellfish will not adhere to the wall surface of the strainer and the like, and it becomes unnecessary to disassemble and clean the strainer. By using industrial water in this way, maintenance of the self-lubricating water supply line 10 including the strainer 19 becomes easy. On the other hand, because industrial water is charged, using industrial water may increase costs.

  A certain amount of industrial water used at the power plant is purchased by predetermining the supply source and usage amount outside the power plant. For this reason, there are cases where there is a margin in industrial water depending on the season. Only in such a case, industrial water is used as shaft lubricating water, and seawater is used as self-lubricating water when there is no room for using industrial water in the power plant. Thus, by using seawater and industrial water in combination, the maintenance of the self-lubricating water supply line 10 is facilitated, and the shaft lubricating water can be stably supplied. In addition, the amount of industrial water used is suppressed, and the overall cost can be reduced. Further, switching between industrial water and seawater can be performed only by opening and closing the valve, and can be easily performed.

  Existing shaft lubrication water supply systems used in power plants are often composed of a self-lubricating water supply line, a backup-station water line, and a cleaning water line. Since the shaft lubricating water system 1 of the present invention can be regarded as a system in which an industrial water supply line is arranged in the existing shaft lubricating water supply system, in the existing shaft lubricating water supply system, By providing an industrial water supply line, a main shaft lubricating water supply system can be obtained.

  If the existing shaft lubrication water supply system consists of a self-lubricated water supply line, a backup site water line, and a cleaning water line, the site water is sealed off through the backup site water line instead of industrial water. A method of sending water to the department is also conceivable. However, in-house water uses treated water obtained by filtering industrial water, clean water, or a mixture of these waters, which increases costs compared to industrial water. In addition, the water supply line in the backup station is basically a line for starting and stopping the circulation pump and supplying shaft lubrication water in an emergency, and the automatic valve opening and closing is controlled so that it can be opened and closed only under predetermined conditions. ing. For this reason, in order to supply in-house water through back-up in-house water, it is necessary to change the control method, which is troublesome.

  FIG. 2 is a system diagram showing a schematic configuration of a circulating pump shaft lubricating water supply system 100 as another embodiment of the present invention. The parts corresponding to those in FIG. The shaft lubricating water supply system 1 of the circulating pump shown in FIG. 1 is manually switched between the self-lubricating water supply line 10 and the industrial water supplying line 40, whereas the shaft lubricating water supply system of the circulating pump shown in FIG. Reference numeral 100 denotes a system that automatically switches between the self-lubricating water supply line 10 and the industrial water supply line 40.

  For this reason, in the axial lubrication water supply system 100 of the circulation pump, the seawater extraction valve 61 disposed in the self-lubricating water supply line 10 and the industrial water supply valve 62 disposed in the industrial water supply line 40 receive signals. It is an automatic valve that opens and closes. In addition, the shaft lubrication water supply system 100 for the circulation pump includes an industrial water usage measuring device 70, a calculation unit 80, and a control unit 90 which are measuring units for measuring the usage amount of industrial water in the power plant.

  The calculation means 80 calculates the industrial water margin from the industrial water usage data in the power plant measured by the industrial water usage measuring device 70 and the contract amount of industrial water. Further, the control means 90 sends an opening / closing signal to the seawater extraction valve 61 and the industrial water supply valve 62 in the following manner based on the calculation data of the calculation means 80. When the control means 90 determines that the amount of industrial water used is sufficient based on the calculation data of the calculation means 80, the control means 90 controls to close the seawater extraction valve 61 and open the industrial water supply valve 62. If it is determined that the amount of industrial water used is not sufficient based on the calculation data of the computing means 80, the seawater extraction valve 61 is opened and the industrial water supply valve 62 is closed. The calculation means 80 and the control means 90 can be realized using a computer.

  If the margin of industrial water is given a certain range and the margin value exceeds the upper limit (the margin is large), the seawater extraction valve 61 is closed and the industrial water supply valve 62 is opened, and the margin value is the lower limit ( It is the same as the ordinary control method that the seawater extraction valve 61 can be opened and the industrial water supply valve 62 can be closed when the marginal amount is less than or less than the marginal amount.

  With the above configuration, the shaft lubrication water supply system 100 of the circulation pump can automatically switch the shaft lubrication water to seawater or industrial water. At this time, the control means 90 enables supply of industrial water if it is determined from the calculation data of the calculation means 80 that there is an allowance in the amount of industrial water used, and enables supply of seawater if it is determined that there is no allowance in the use of industrial water. Thus, the cost is not increased, and the total cost can be reduced by the amount that facilitates the maintenance of the shaft lubricating water supply line of the pump.

  In the above embodiment, the circulation pump has been described as an example, but the pump is not limited to the circulation pump. The present invention can be used as long as it is a pump that uses a part of the seawater that feeds seawater and discharges it to the shaft seal as lubricating water. For example, the shaft lubricating water supply system of the pump of the present invention can be used for an LNG vaporizer seawater pump.

1 is a system diagram showing a schematic configuration of a circulating pump shaft lubricating water supply system 1 as one embodiment of the present invention. FIG. It is a systematic diagram which shows the schematic structure of the axial-lubricated-water supply system 100 of the circulation pump as other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Axis lubricating water supply system 2 Circulation pump 4 Discharge pipe 10 Self-lubricating water supply line 11 Branch pipe 12 Seawater extraction valve 13, 14, 15, 16, 17 Pipe 40 Industrial supply lines 42, 44, 46 Industry Industrial water supply valve 61 Industrial water supply valve 61 Automatic seawater extraction valve 62 Automatic industrial water supply valve 70 Industrial water consumption measuring device 80 Calculation means 90 Control means

Claims (2)

Self-lubricating water supply system for a shaft lubrication water supply system for pumping seawater installed in a power plant, comprising a strainer, taking out a part of the discharged water , filtering it through the strainer and supplying it to the shaft seal of the pump And an in- house water line for supplying in-house water consisting of treated water or clean water obtained by treating industrial water with a treatment device or a mixed water thereof to the shaft seal portion, in a shaft lubricating water supply system for a pump,
Further, an industrial water supply line is provided for filtering industrial water through the strainer and supplying the shaft seal to the shaft seal. When there is sufficient industrial water in the power plant, industrial water is supplied from the industrial water supply line to the industrial water in the power plant. When there is no allowance, seawater is supplied from the self-lubricating water supply line, and in the non-steady state, in-house water is supplied from the in-house use water line to the shaft seal portion even if there is room in industrial water in the power plant. The shaft lubrication water supply system of the pump. 2. The shaft lubricating water supply system for a pump according to claim 1, wherein the unsteady time is when the pump is started, when the pump is stopped, or when the strainer is disassembled and cleaned .

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