JP5241875B2 - Water removal system and water removal method - Google Patents

Description

  The present invention relates to a water removal system and a water removal method, and more particularly, to a water removal system and method for removing water leaked in a drainage tank in a hydroelectric power plant to the outside of the power plant.

  FIG. 5 is a diagram illustrating the configuration of a conventional hydroelectric power plant. The hydroelectric power plant 10 includes an upper pond (not shown) for storing water, such as a dam, a power generation water turbine 12 that rotates using the drop energy of water supplied from the upper pond, and a main shaft 52 attached to the power generation water turbine 12. And a generator 50 connected to the hydraulic power plant 10. The deepest portion of the hydroelectric power plant 10 is configured as a drainage basin 16 which is a portion for storing water leakage from facilities such as the water turbine 12. In such a hydroelectric power plant, the power generation water turbine 12 rotates with the head energy of water supplied from the upper pond, and power is generated by the generator 50 using this rotational energy. Further, the water used for the rotational drive of the power generation water turbine 12 is sucked from the draft pipe 14 provided at the lower part of the power generation water turbine 12 and discharged outside the power plant 10.

  The drainage basin 16 includes a power-driven water removal pump (ordinary pump) 30, a power-driven auxiliary water removal pump (reserve pump) 32, and a jet pump for removing the stored leakage outside the power plant 10. 34 is provided. Normally, the leakage water stored in the drain 16 is drained to the outside by using the service pump 30 and the backup pump 32. The jet pump 34 is used as an auxiliary when the water is not in time. In addition, when oil leak is detected by the oil leak detector 40 provided in the drain 16, the leak is stored in the drain 16 so that the oil does not flow out of the power plant 10. Even in the state, the operation of each pump 30, 32, 34 is temporarily stopped.

On the other hand, the power generation water turbine 12 for power generation rotates at a high speed of, for example, 257 min ^{−1 to} 900 min ⁻¹ , and negative pressure is generated in the draft pipe 14 due to such high speed rotation, and abnormal vibration of the water turbine occurs. Etc. may occur. In order to prevent this, it is necessary to apply pressure so that the negative pressure in the draft tube 14 is eliminated. The pressurization in the draft pipe 14 is performed by providing a pipe communicating with the outside in the draft pipe 14 so that the draft pipe is brought into contact with the outside air, and particularly when the pressure drop in the draft pipe 14 is remarkable, This is performed by using a separate device for pressurizing.

JP 2002-202043 A

  In the hydroelectric power plant as described above, the power-driven water removal pump 30 and the standby electric water removal pump 32 have a high power consumption during operation when a large amount of water leakage is stored and the required amount of drainage is increased. Improvements should be desired for such a large amount of power consumption for operating the pump.

  On the other hand, as described above, in the case where a pipe communicating with the outside is provided in the draft pipe in order to alleviate the pressure drop of the draft pipe, the negative pressure elimination effect in the draft pipe may not be sufficient, and abnormal vibration of the water turbine may occur. There is a risk that it cannot be prevented. Further, if a device for pressurizing in the draft tube is used separately, power consumption for driving the device is also generated.

  The present invention has been made in view of such circumstances, and an object thereof is generated in the draft region while suppressing power consumption for driving a water removal device such as a water removal pump in a drainage basin. An object of the present invention is to provide a water removal system and a water removal method that can contribute to the elimination of negative pressure.

  In order to solve the above-mentioned problem, a water removal system according to claim 1 is a hydroelectric power generation comprising a water turbine for power generation, a draft region formed below the water turbine, and a drainage basin for storing water leakage. In the dewatering system for removing water stored in the drainage basin outside, a communication pipe for connecting the inside of the draft area and the drainage basin is provided.

  According to this, the leaked water stored in the drainage can be sucked using the negative pressure state generated in the draft region by the water turbine rotating during power generation via the communication pipe. Therefore, the suction of water leakage using the negative pressure in the draft area replaces the water removal by the water removal device such as an electrically driven pump or assists the water removal device to reduce the power consumption for operating the water removal device. Can be reduced. Moreover, the negative pressure state of the draft region is relieved by using the negative pressure generated in the draft region in this manner for raising the water leakage. That is, it contributes to the elimination of the negative pressure in the draft region described above.

  According to a second aspect of the present invention, in the dewatering system according to the first aspect, the opening / closing means for closing the communication pipe when oil leakage is detected by the oil leakage detector provided in the drainage basin. It is characterized by having.

  As a result, when oil leakage is detected in the drainage basin, the communication pipe is closed and water removal using the negative pressure in the draft area is stopped, so that leakage from the draft area is stopped. Oil can be prevented from leaking outside the power plant.

  According to a third aspect of the present invention, in the dewatering system according to the second aspect, the open / close means opens and closes the communication pipe, and opens the open / close valve during operation of the water wheel. Control means for performing opening / closing control of the opening / closing valve so as to close the opening / closing valve when the water turbine is stopped.

  According to this, by opening the on-off valve during the water turbine operation, the power-driven water removal pump can be reliably assisted by water removal using the negative pressure in the draft region. On the other hand, for example, when the water level in the drainage basin exceeds a predetermined reference value, the main engine of the power plant is stopped and the operation of the water turbine is stopped. The water removal used is stopped.

  According to a fourth aspect of the present invention, in the water removal method according to the third aspect, the communication pipe is provided with a check valve. Thereby, for example, when the operation of the water turbine is stopped and the negative pressure state in the draft area is being eliminated, it is possible to prevent the leakage of water from flowing back from the draft area side to the drainage tank side.

  In addition, the water removal method according to claim 5 is an interior of a hydroelectric power plant comprising a water turbine for power generation, a draft region formed below the water turbine, and a drainage basin in which leakage from the water turbine is stored. In the dewatering method for removing water stored in the drainage basin to the outside, a communication pipe is provided for communicating the drainage basin with the drainage basin. The leakage water stored in the drainage basin is sucked into the draft area and removed outside the power plant.

  According to this, the leaked water stored in the drainage can be sucked using the negative pressure state generated in the draft region by the water turbine rotating during power generation via the communication pipe. Therefore, the suction of water leakage using the negative pressure in the draft area replaces the water removal by the water removal device such as an electrically driven pump or assists the water removal device to reduce the power consumption for operating the water removal device. Can be reduced. Moreover, the negative pressure state of the draft region is relieved by using the negative pressure generated in the draft region in this manner for raising the water leakage. That is, it contributes to the elimination of the negative pressure in the draft region described above.

  According to the present invention, it is possible to suck water leaked in a drainage basin using a negative pressure generated in a draft region by a water turbine rotating during power generation via a communication pipe. Therefore, the suction of water leakage using the negative pressure in the draft area replaces the water removal by the water removal device such as an electrically driven pump or assists the water removal device to reduce the power consumption for operating the water removal device. Can be reduced. Moreover, the negative pressure state of the draft region is relieved by using the negative pressure generated in the draft region in this manner for raising the water leakage.

  In other words, by using the pump effect due to the negative pressure that inevitably arises in the draft area due to the operation of the power generation water turbine, the leakage water stored in the drainage basin is drained, so that the existing water leakage can be removed. In addition to reducing the operating power of the dewatering equipment, the negative pressure state in the draft region is also alleviated, and abnormal vibration of the water turbine due to the negative pressure is also reduced.

It is a figure which shows schematic structure of the hydroelectric power station concerning this Embodiment. It is a block diagram explaining the structure for performing control of the waste_water | drain concerning this Embodiment. It is a flowchart which shows the control aspect of the water removal method concerning this Embodiment. It is a flowchart which shows the process at the time of oil leak being detected within the drain. It is a figure explaining a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a schematic configuration of a hydroelectric power plant according to the present embodiment, and FIG. 2 is a block diagram illustrating a hardware configuration for performing water removal control. As shown in the figure, a power plant 10 according to the present embodiment includes a power generation turbine 12 that is rotated by the drop energy of water supplied from an upper portion of a power plant such as a dam (not shown), and a main shaft of the power generation turbine 12. 52, a draft pipe 14 formed below the power generation water turbine 12, a drainage basin 16 in which leakage from the power generation water turbine 12 is stored, a service pump 30, and a spare pump 32. And it is common with the structure of the conventional hydroelectric power station mentioned above by the point provided with the jet pump 34 and the oil leak detector 40. FIG. Therefore, detailed description of this common configuration is omitted.

  The power generation turbine 12 includes, for example, a Francis turbine that includes a plurality of runner blades formed of a metal material such as stainless cast steel, and rotates when the runner blades are pushed by the water flow flowing into the rotation center. It is comprised and rotates on a horizontal surface with the main shaft 52 as a rotation axis. Moreover, in this Embodiment, the water turbine driving | operation detection means 42 which detects whether this power generation water turbine 12 is driving | running is provided.

  In the present embodiment, the communication pipe 20 is provided in a state where the draft pipe 14 and the drainage pit 16a below the drainage basin 16 are communicated with each other. In particular, the communication pipe 20 in the present embodiment communicates from a position directly below the water wheel 12 inside the draft pipe 14 to a portion below a reference water level HWL1 (described later) in the drain pit 16a. The communication pipe 20 includes an electromagnetic valve 22 that opens and closes the communication pipe 20 based on a control signal from a control unit 46 described later, and a check that prevents water from flowing back from the draft pipe 14 side to the drainage pipe 16 side. A valve 24 is provided. The opening / closing control of the electromagnetic valve 22 will be described in detail later.

  Further, the drainage basin 16 operates the reference water level HWL0 as a reference for stopping the pumps 30, 32, 34 and closing the solenoid valve 22, the reference water level HWL1 as a reference for operating the service pump 30, and the standby pump 32. A reference water level HWL2 that serves as a reference for the operation and a reference water level HWL3 that serves as a reference for operating the jet pump 34 are set. Further, a reference water level that serves as a reference for stopping the main engine of the power plant 10 above the drain pit 16a of the drainage basin 16 HWL 4, the reference water level HWL 5 ′ serving as a reference for stopping the pumps 30, 32, 34 when oil leaks are detected in the drainage layer 16, and the pumps 30 when oil leaks are detected in the drainage layer 16. , 32, and 34, a reference water level HWL5 serving as a reference for resuming operation, and a reference water level HWL6 serving as a reference for executing a complete power failure of the power plant 10 facility are set.

  Further, the drainage basin 16 is provided with a water level gauge 44 for detecting that the stored water leak has reached these reference water levels. And this system receives the water level information by the water level gauge 44, the information on whether the water turbine is operated by the water turbine operation detecting means 42, and the oil leakage detection information by the oil leakage detector 40, and according to the information. Control means 46 for controlling the opening / closing of the pumps 30, 32, 34 and the motor-operated valve 22 is provided. In the present embodiment, the control means 46 performs control so as to close the motor-operated valve 22 when the water turbine for power generation 12 is stopped and when oil leakage is detected in the drainage basin.

  With the above configuration, in the present embodiment, in addition to drainage by the normal pump 30, the spare pump 32, and the jet pump 34, the drain pipe 16 is operated by the operation of the power generation water turbine 12 through the communication pipe 20. The drainage basin 16 can be dewatered using the negative pressure generated in the interior 14.

  Hereinafter, detailed control of the water leakage removal method according to the present embodiment, that is, operation of each pump 30, 32, 34 and control of opening / closing of the electromagnetic valve 22 performed by the control means 46 will be described. FIG. 3 is a flowchart showing a control mode of the water removal method according to the present embodiment.

  As shown in the drawing, first, in step S101, when the current water level in the drainage basin 16 becomes equal to or higher than the reference water level HWL1, determination of oil leakage detection is performed in step S102.

  If no oil leakage is detected, the operation status of the power generation water turbine 12 is determined in step S103. If it is determined that the power generation turbine 12 is not in operation, the process proceeds to step S108 described later.

  If it is determined that the power generation water turbine 12 is in operation, the electromagnetic valve 22 is opened in step S104. As described above, when the electromagnetic valve 22 is opened, the draft tube 14 and the drain 16 are in communication with each other. The pressure of the drainage basin 16 is approximately atmospheric pressure, and the draft pipe 14 is negatively pressured by the rotation of the power generation water turbine 12. Accordingly, when the draft pipe 14 and the drainage basin 16 are in communication with each other, the water leakage stored in the drainage basin 16 is pulled up to the draft pipe 14 by this pressure difference.

  When the electromagnetic valve 22 is opened as described above, it is determined in step S105 whether or not the current water level in the drainage basin 16 is equal to or higher than the reference water level HWL2. When it is determined that the water level of the drainage basin 16 is not equal to or higher than the reference water level HWL2, in step S106, the electromagnetic valve 22 is kept open until the water level becomes equal to or lower than the reference water level HWL0, and the negative pressure of the draft pipe 14 is maintained. The drainage of the drainage basin 16 is sucked by the above. When the water level of the drainage basin 16 becomes equal to or lower than the reference water level HWL0 due to this water leakage, the electromagnetic valve 22 is closed in step S107, and the process is terminated.

  On the other hand, when it is determined that the water level of the drainage basin 16 is equal to or higher than the reference water level HWL2 (step S105), the service pump 30 is operated in step S108. Even when it is determined in step S103 described above that the power generation water turbine 12 is not operating, the service pump 30 is similarly operated.

  Then, when the service pump 30 is operated in this way, in step S109, it is determined whether or not the current water level in the drainage basin 16 is equal to or higher than the reference water level HWL2. If it is determined that the water level of the drainage basin 16 is not equal to or higher than the reference water level HWL2, in step S110, the operation of the service pump 30 and the solenoid valve 22 are maintained open until the water level of the basin 16 becomes lower than the reference water level HWL0. Is done. When it is determined in step S103 that the power generation water turbine 12 is not operating, the electromagnetic valve 22 remains in the closed state.

  When the water level of the drainage basin 16 becomes equal to or lower than the reference water level HWL0, in step S111, the service pump 30 is stopped, and if the electromagnetic valve 22 is open, it is closed and water removal is completed.

  On the other hand, when it is determined that the water level of the drainage basin 16 is equal to or higher than the reference water level HWL2 (step S109), the preliminary pump 32 is operated in step S112.

  Then, after the predetermined time has elapsed after the standby pump 32 is operated in this way, in step S113, it is determined whether or not the current water level in the drainage basin 16 is equal to or higher than the reference water level HWL3.

  If it is determined that the water level of the drainage basin 16 is not equal to or higher than the reference water level HWL3, the service pump 30 and the standby pump 32 are operated until the water level of the drainage basin 16 becomes equal to or lower than the reference water level HWL0 in step S114. An open state is maintained. When it is determined in step S103 that the power generation water turbine 12 is not operating, the electromagnetic valve 22 remains in the closed state.

  When the water level of the drainage basin 16 becomes equal to or lower than the reference water level HWL0, in step S115, the service pump 30 and the backup pump 32 are stopped, and if the electromagnetic valve 22 is open, it is blocked and water removal is completed. To do.

  On the other hand, when it is determined that the water level of the drainage basin 16 is equal to or higher than the reference water level HWL3 (step S113), the jet pump 34 is operated in step S116.

  Then, after the jet pump 34 is operated in this way, in step S117, it is determined whether or not the current water level in the drainage basin 16 is equal to or higher than the reference water level HWL4.

  If it is determined that the water level of the drainage basin 16 is not equal to or higher than the reference water level HWL4, the service pump 30, the spare pump 32, and the jet pump 34 are operated until the water level of the basin 16 becomes equal to or lower than the reference water level HWL0 in step S118. And the open state of the solenoid valve 22 is maintained.

  If it is determined in step S102 that the power generation water turbine 12 is not operating, the electromagnetic valve 22 remains closed.

  When the water level of the drainage basin 16 becomes equal to or lower than the reference water level HWL0, in step S119, the service pump 30 and the backup pump 32 are stopped, and if the electromagnetic valve 22 is open, it is closed and the water removal ends.

  On the other hand, when it is determined that the water level of the drainage basin 16 is equal to or higher than the reference water level HWL4 (step S117), the main engine of the power plant 10 is stopped and the water turbine 12 for power generation is stopped in step S120. In other words, water leakage from the power generation turbine 12 is prevented. Accordingly, the electromagnetic valve 22 is closed and water removal is performed using a device that does not affect the stop of the main engine such as the jet pump 34 (a device that does not use the power generated by the operation of the power generation turbine 12). In addition, when the service pump 30 and the backup pump 32 are configured to receive power from other power systems in the power plant and operate, the service pump 30 and the backup pump 32 can be connected even if the main engine is stopped. The used water removal is possible. Furthermore, when it is determined that the current water level in the drainage basin 16 is equal to or higher than the reference water level HWL6, a power failure of all the facilities of the power plant 10 is performed. This is an emergency measure to prevent disasters such as fires caused by high-voltage short circuits due to the water level reaching a dangerous level.

  On the other hand, a case where oil leakage is detected by the oil leakage detector 40 in step S102 will be described. When oil leakage is detected, processing in steps S201 to S207, which is oil leakage processing, is performed.

  FIG. 4 is a flowchart showing a control mode during the oil leakage process. As shown in the figure, when oil leakage is detected, all the operations of the pumps 30, 32, and 34 are stopped and the solenoid valve 22 is closed in step S201. That is, the water removal in the drain 16 is completely stopped. This is a measure for preventing the leakage of water containing oil from being discharged outside the power plant 10.

  In step S202, the water removal stop state is maintained until the water level reaches the reference water level HWL5.

  When the water level reaches the reference water level HWL5, the service pump 30, the backup pump 32, and the jet pump 34 are operated in step S203. That is, water removal is resumed.

  As described above, the reason for resuming the water removal is that oil having a small specific gravity does not remain in the drain pit 16a due to the fact that the water level has reached the reference water level HWL5. This is because oil does not flow out of the power plant 10 even if water is removed using the water pump 32 and the jet pump 34.

  After step S203, water removal by the service pump 30, the spare pump 32, and the jet pump 34 is performed until the water level of the drainage basin 16 reaches the reference water level HWL5 ′ in step S204.

  Thereafter, when the water level of the drainage basin 16 reaches the reference water level HWL5 ′, the service pump 30, the standby pump 32, and the jet pump 34 are stopped in step S205, and water removal is stopped.

  Then, after the oil removal work of the leaked water stored in the drain 16 is performed, the process proceeds to step S102 again.

  As described above, in the present embodiment, the negative pressure condition that is inevitably generated in the draft pipe 14 due to the operation of the power generation water turbine 12 is used via the communication pipe 20 that connects the draft pipe 14 and the drainage pipe 16. The leaked water stored in the drain 16 can be pulled up to the draft pipe 14. Accordingly, it is possible to assist the service pump 30 and the spare pump 32 by raising the water leakage due to the negative pressure generated in the draft pipe 14, and to reduce the power consumption for operating the pumps 30 and 32.

  In addition, by using the negative pressure generated in the draft pipe 14 for raising the leakage, the negative pressure state of the draft pipe 14 is relieved, that is, it contributes to the elimination of the negative pressure in the conventional draft pipe 14 region. To do.

  Further, in the present embodiment, the electromagnetic valve 22 is closed when oil leakage is detected by the oil leakage detector 40 provided in the drain 16 (see step S201). If it is considered that oil may flow out of the power plant 10 through the draft pipe 14 in which leakage is detected, the electromagnetic valve 22 is closed and water leakage using the negative pressure of the draft pipe 14 is removed. This stops the oil leakage from the draft pipe 14 to the outside of the power plant 10.

  In particular, in the present embodiment, the electromagnetic valve 22 is basically opened when the power generation water turbine 12 is in operation, and is controlled to close the electromagnetic valve 22 when the water turbine is stopped and when oil leakage is detected. ing. Therefore, execution and stop of water removal using the negative pressure of the draft pipe 14 can be appropriately switched as necessary. Further, the check valve 24 provided in the communication pipe 20 prevents the backflow of water leakage from the drainage pipe 16 to the draft pipe 14.

  In addition, this invention is not limited to the said embodiment, A various change is possible within the range of the summary of invention. For example, in the present embodiment, the case has been described in the present embodiment where water removal using the negative pressure of the draft pipe 14 and water removal using the pumps 30, 32, and 34 are assisted. It is not restricted to this, and when the storage rate of water leakage in the drain 16 is not so high, only the water removal using the negative pressure of the draft pipe 14 is performed without using the pumps 30, 32, 34. Anyway. In this case, various auxiliary devices for assisting the suction force by the negative pressure may be used.

DESCRIPTION OF SYMBOLS 10 Power plant 12 Power generation turbine 14 Draft pipe 16 Drainage basin 20 Communication pipe 22 Solenoid valve (open / close valve)
24 check valve 30 service pump (power-driven dewatering pump)
32 Preliminary pump (power-driven dewatering pump)
40 Oil leakage detector (oil leakage detection means)
42 Waterwheel operation state detection means 44 Water level detection means

Claims (5)

Water stored in the drainage basin in a hydroelectric power plant comprising a water turbine for power generation, a draft region formed below the turbine, and a drainage basin in which leakage from facilities such as the turbine is stored In the water removal system that removes water to the outside,
A water removal system comprising a communication pipe for communicating the inside of the draft area with the drainage basin.   2. The water removal system according to claim 1, further comprising opening / closing means for closing the communication pipe when oil leakage is detected by an oil leakage detector provided in the drain. The opening / closing means includes
An on-off valve for opening and closing the communication pipe;
Control means for opening and closing the on-off valve so as to open the on-off valve during operation of the water wheel and to close the on-off valve when the water wheel is stopped;
The water removal system according to claim 2, further comprising:   The water removal system according to any one of claims 2 and 3, wherein the communication pipe is provided with a check valve. The water stored in the drainage basin is externally provided in a hydroelectric power plant comprising a water turbine for power generation, a draft region formed below the turbine, and a drainage basin in which leakage from the turbine is stored. In the water removal method of removing water,
A communication pipe for communicating the drainage basin with the drainage basin is provided, and the water leaked in the drainage basin is sucked into the draft basin by the negative pressure generated in the drafting region by the operation of the water turbine, Water removal method characterized by removing water.

Images