Cooling water sharing mechanism between multiple cooling water pressure reducing devices

Abstract

To provide a cooling water sharing mechanism among a plurality of cooling water decompression devices which prevents the occurrence of a malfunction of a strainer provided in a pressure regulation mechanism of a prescribed cooling water decompression device even if the quality of water which passes through a prescribed cooling water piping system deteriorates.SOLUTION: A branch pipe 80 branching from a pressure regulation pipe 71 of a second pressure regulation mechanism 70 of a cooling water decompression device 2 is connected to a pressure regulation pipe 61 of a first pressure regulation mechanism 60 of a cooling water decompression device 1 upstream of a strainer 62. An opening / closing valve 81 of the branch pipe 80 is opened, and a switching device 82 arranged at a connection between the pressure regulation pipe 61 of the first pressure regulation mechanism 60 and the branch pipe 80 is switched so that a source of water to the pressure regulation pipe 61 is located at the branch pipe 80 side from an upstream-side end side of the pressure regulation pipe 61 of the first pressure regulation mechanism 60, causing water to be sent to an upstream side relative to the strainer 62 of the pressure regulation pipe 61 of the first pressure regulation mechanism 60 from the pressure regulation pipe 71 of the second pressure regulation mechanism 70 via the branch pipe 80.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mechanism that allows cooling water from a desired cooling water piping system to be shared among multiple cooling water pressure reducing devices used to reduce the pressure of cooling water supplied to cooled equipment that requires cooling during operation of a water turbine generator before supplying the water to the cooled equipment. [Background technology]

[0002] When operating a water turbine generator, it is necessary to supply cooling water to certain equipment whose temperature rises, such as the water turbine metal (metal is also referred to as bearings, etc.; the same applies hereinafter), thrust metal, cooler, oil collection tank, sealing, etc. (hereinafter referred to as cooled equipment). As shown in Patent Document 1, this cooling water may be obtained by supplying water that has been sent from a specified water intake through a water conduit to a penstock, and then branching off from the penstock into a cooling water piping system.

[0003] However, the water that passes through the penstock from the intake port is subjected to the pressure (e.g., 0.9 MPa) required to turn the turbine of the turbine generator, so if this high water pressure is sent to the cooled equipment as cooling water, there is a risk that the cooled equipment will be damaged by the pressure of the cooling water, causing problems.

[0004] For this reason, as shown in Patent Document 1, a cooling water pressure reducing device is installed midway between the connection side (upstream side) of the cooling water piping system with the penstock and the equipment to be cooled (downstream side), and the pressure of the cooling water is reduced to a predetermined value (e.g., 0.5 MPa) by this cooling water pressure reducing device before it is sent to the equipment to be cooled as cooling water. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-89476 Summary of the Invention [Problem to be solved by the invention]

[0006] The cooling water pressure reducing device shown in Patent Document 1 has a strainer, but the position of the water intake through which the intake water is introduced into the cooling water piping system as cooling water is not specified, and if water taken from the river inlet point of the dam is introduced immediately, there is a risk that during heavy rain, muddy water from the river will be introduced almost directly into the cooling water piping system and sent to the cooling water pressure reducing device. For this reason, to prevent the strainer provided in the cooling water pressure reducing device from clogging, it becomes necessary to take measures such as frequently cleaning the strainer before, during, and after heavy rain, which may result in a problem in that it requires a great deal of effort and many personnel to ensure the pressure reducing function of the cooling water pressure reducing device.

[0007] 6 of the present application, a cooling water pressure reducing device that reduces the pressure of cooling water supplied to equipment to be cooled when a water turbine generator is in operation may have a configuration including a housing 500 that houses a pressure reducing mechanism such as a diaphragm and a valve stem, a pressure adjusting pipe 601 that has one end connected to a through hole 501 that communicates with the internal space of the housing 500 upstream of the pressure reducing mechanism and the other end connected to a through hole 502 that communicates with the internal space of the housing 500 downstream of the pressure reducing mechanism, a pressure adjusting device 602 provided in the pressure adjusting pipe 601, and a pressure adjusting mechanism 600 that has strainers 603, 603 that remove foreign matter from the water before it flows into the pressure adjusting device 602. Even in such a cooling water pressure reducing device, since the pressure adjusting mechanism 600 has the strainer 603, the strainer 603 will not be clogged by turbid water, as in Patent Document 1. Measures may be required to prevent this.

[0008] On the other hand, there may be multiple water intakes, penstocks, and cooling water piping systems depending on the number of turbine generators, and in such cases, a cooling water pressure reducing device is provided for each cooling water piping system. The position of the water intake through which the intake water is introduced into the cooling water piping system may also differ depending on the cooling water piping system. Accordingly, in a piping system provided with one of multiple cooling water pressure reducing devices, the water intake may be located relatively farther from the river inlet point of the dam than in a piping system provided with the other cooling water pressure reducing device, which may prevent the intake of muddy water from the river even during heavy rain.

[0009] The present invention has been made in consideration of the above-mentioned problems, and has as its main object to provide a cooling water sharing mechanism between multiple cooling water pressure reducing devices, in a case where multiple cooling water pressure reducing devices that reduce the pressure of water taken from a water intake to turn it into cooling water are provided in multiple cooling water piping systems, respectively, so that the cooling water sent to one cooling water pressure reducing device is also sent to the pressure adjustment mechanism of the other cooling water pressure reducing device, thereby preventing malfunctions in the pressure adjustment mechanism of the other cooling water pressure reducing device even if the quality of the water taken from the water intake to the other cooling water pressure reducing device deteriorates. [Means for solving the problem]

[0010] In order to achieve the above object, the cooling water sharing mechanism among a plurality of cooling water pressure reducing devices of the present invention is a plurality of cooling water pressure reducing devices used to reduce the pressure of cooling water supplied to cooled equipment that requires cooling in the operation of a hydroelectric generator before supplying the cooled equipment, wherein a first cooling water pressure reducing device, which is one of the plurality of cooling water pressure reducing devices, is provided in a first cooling water piping system that uses water taken from a first water intake for a first hydroelectric generator as cooling water, and has a housing that accommodates a pressure reducing mechanism, a pressure adjustment pipe that has one end connected to a through hole in the housing upstream of the pressure reducing mechanism and the other end connected to a through hole in the housing downstream of the pressure reducing mechanism, a pressure adjustment device provided in the pressure adjustment pipe, and a first pressure adjustment mechanism that has a strainer that removes foreign matter in the water before it flows into the pressure adjustment device, and a second cooling water pressure reducing device, which is the other of the plurality of cooling water pressure reducing devices, is provided in a first cooling water piping system that uses water taken from a second water intake for a second hydroelectric generator as cooling water, The cooling water pressure reducing device is provided in a second cooling water piping system that uses water taken for a machine as cooling water, and includes a housing that accommodates a pressure reducing mechanism, a pressure adjustment pipe having one end connected to a through hole of the housing upstream of the pressure reducing mechanism and the other end connected to a through hole of the housing downstream of the pressure reducing mechanism, a pressure adjusting device provided in the pressure adjustment pipe, and a second pressure adjustment mechanism having a strainer that removes foreign matter from the water before it flows into the pressure adjusting device, and a branch pipe branching from the pressure adjustment pipe of the second pressure adjustment mechanism of the second cooling water pressure reducing device is connected to the pressure adjustment pipe of the first pressure adjustment mechanism of the first cooling water pressure reducing device upstream of the strainer, so that under predetermined conditions, water passing through the second cooling water piping system is sent from the pressure adjustment pipe of the second pressure adjustment mechanism through the branch pipe to the pressure adjustment pipe of the first pressure adjustment mechanism upstream of the strainer. The cooling water pressure reducing device is, for example, an automatic pressure reducing valve. The pressure adjusting device is, for example, a pressure adjusting pressure reducing valve.

[0011] As a result, in the case where the first cooling water piping system is configured to introduce water taken from a first water intake located at a location closer to the river inlet of the dam than the second water intake that introduces water into the second cooling water piping system, the first pressure adjustment mechanism of the first cooling water pressure reducing device is normally supplied with cooling water that passes through the first cooling water piping system, but if it is determined that the cooling water passing through the first cooling water piping system has deteriorated more than the cooling water taken from the second water intake and passing through the second cooling water piping system under various conditions, such as when heavy rain causes the water to become polluted, or if such deterioration is expected, it is possible to supply cooling water taken from the second water intake and passing through the second cooling water piping system.

[0012] In the cooling water sharing mechanism for a plurality of cooling water pressure reducing devices of the present invention, one of the branch pipes One of the pressure adjustment pipes of the second pressure adjustment mechanism is characterized in that it branches off between the one end of the pressure adjustment pipe and the strainer, and an opening / closing device is disposed in the branch pipe to open and close the flow path of water sent from the one end of the pressure adjustment pipe. The opening / closing device is, for example, an opening / closing valve.

[0013] This makes it possible to send water passing through the second cooling water piping system that has been sent to the pressure adjustment pipe of the second pressure adjustment mechanism of the second cooling water pressure reducing device to the branch pipe by opening the opening / closing device arranged in the branch pipe.

[0014] In addition, in the cooling water sharing mechanism among multiple cooling water pressure reducing devices of the present invention, the other branch pipe is connected between one end of the pressure adjustment pipe of the first pressure adjustment mechanism and the strainer, and a switching device is disposed at a connection between the pressure adjustment pipe of the first pressure adjustment mechanism and the branch pipe, for switching the supply source of water sent to the strainer side between the one end side of the pressure adjustment pipe and the branch pipe side. The switching device is, for example, a three-way valve.

[0015] This makes it possible to make it so that under normal circumstances, water passing through the first cooling water piping system flows from one end of the pressure adjustment pipe of the first pressure adjustment mechanism to the first cooling water pressure reducing device, has foreign matter removed by the strainer, and is then sent to the pressure adjustment device.If the water passing through the first cooling water piping system is more deteriorated than the water passing through the second cooling water piping system, such as becoming muddy, or is expected to deteriorate, it is possible to stop the inflow from one end of the pressure adjustment pipe of the first pressure adjustment mechanism, and make the water passing through the second cooling water piping system pass through the pressure adjustment pipe and branch pipe of the second cooling water pressure reducing device and then pass through the pressure adjustment pipe of the first pressure adjustment mechanism. [Effects of the Invention]

[0016] As described above, according to the cooling water sharing mechanism between multiple cooling water pressure reducing valves of the present invention, when the first cooling water piping system is configured to introduce water taken from a first water intake located at a location closer to the river inlet of the dam than the second water intake that introduces water into the second cooling water piping system, cooling water passing through the first cooling water piping system is normally supplied to the first pressure adjustment mechanism of the first cooling water pressure reducing device, but when the cooling water passing through the first cooling water piping system is determined to have deteriorated more than the cooling water passing through the second cooling water piping system under various conditions, such as when pollution progresses due to heavy rain, or when this deterioration is expected, cooling water passing through the second cooling water piping system is supplied, thereby making it possible to reduce the risk of the strainer becoming clogged.

[0017] In particular, according to the cooling water sharing mechanism between multiple cooling water pressure reducing valves of the present invention described in claim 2, simply by switching the opening and closing device arranged in the branch pipe from closed to open, it is possible to send water passing through the second cooling water piping system that has been sent to the pressure adjustment pipe of the second pressure adjustment mechanism of the second cooling water pressure reducing device to the branch pipe.

[0018] In particular, according to the cooling water sharing mechanism between multiple cooling water pressure reducing valves described in claim 3, under normal circumstances, water passing through the first cooling water piping system flows from one end of the pressure adjustment pipe of the first pressure adjustment mechanism to the first cooling water pressure reducing device, and foreign matter is removed by a strainer before being sent to the pressure adjustment device. Furthermore, if the water passing through the first cooling water piping system is or is expected to deteriorate more than the water passing through the second cooling water piping system, such as becoming muddy, the inflow from one end of the pressure adjustment pipe of the first pressure adjustment mechanism can be stopped, and the water passing through the second cooling water piping system can pass through the pressure adjustment pipe of the second cooling water pressure reducing device, the branch pipe, and then the pressure adjustment pipe of the first pressure adjustment mechanism. This reduces the risk of the strainer becoming clogged even if the water passing through the first cooling water piping system deteriorates more than the water passing through the second cooling water piping system. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an explanatory diagram schematically showing a first cooling water piping system, a second cooling water piping system, a dam intake, a penstock, etc. to which the present invention is applied.

[0021] FIG. [Figure 2] 1 is an explanatory diagram showing the appearance of an example of a cooling water pressure reducing device to which the present invention can be applied, with a pressure adjusting mechanism removed; [Figure 3] 3 is a cross-sectional view of an example of the cooling water pressure reducing device shown in FIG. 2. FIG. [Figure 4] FIG. 2 is an explanatory diagram schematically illustrating an example of a second cooling water pressure reducing device among cooling water pressure reducing devices to which the present invention is applied, together with its pressure adjusting mechanism. [Figure 5] 1 is an explanatory diagram schematically illustrating an example of a first cooling water pressure reducing device among cooling water pressure reducing devices to which the present invention is applied, together with its pressure adjusting mechanism. [Figure 6] 1 is an explanatory diagram showing a schematic view of an example of a cooling water pressure reducing device to which the present invention is not applied, together with its pressure adjusting mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] 1, facilities, equipment, etc. related to the present invention are schematically shown, including a dam 100, a water turbine generator 105, a water turbine generator 110, a first cooling water piping system R1, a second cooling water piping system R2, and cooled equipment 120, 130. Note that facilities, equipment, etc. that are not related or only slightly related to the present invention are omitted from FIG. 1.

[0022] As shown in Fig. 1, water taken from a reservoir 101 of a dam 100 through an intake 102 passes through a penstock 103 where a predetermined pressure is applied due to the difference in elevation before being sent to a hydraulic turbine generator 105, where it rotates a hydraulic turbine 106 of the hydraulic turbine generator 105, and the resulting power drives a generator 107 to generate electricity. Also, as shown in Fig. 1, water taken from a reservoir 101 of the dam 100 through an intake 102' passes through a penstock 103' where a predetermined pressure is applied due to the difference in elevation before being sent to a hydraulic turbine generator 110, where it rotates a hydraulic turbine 111 of the hydraulic turbine generator 110, and the resulting power drives a generator 112 to generate electricity. That is, each hydraulic turbine generator 105, 110 has its own intake 102, 102' and penstock 103, 103'. In this embodiment, the intake 102' is provided at a location relatively farther from the river inlet of the dam 100 than the intake 102.

[0023] A first cooling water piping system R1 branches off from the penstock 103 so that part of the water passing through the penstock 103 can be used as cooling water for the equipment 120 to be cooled. The most downstream side of the first cooling water piping system R1 is connected to the equipment 120 to be cooled. A second cooling water piping system R2 branches off from the penstock 103' so that part of the water passing through the penstock 103' can be used as cooling water for the equipment 130 to be cooled. The first cooling water piping system R1 and the second cooling water piping system R2 will be described later.

[0024] In this embodiment, the cooled equipment 120 is, for example, a cooler 121, a thrust metal 122, a water turbine metal 123, an oil collection tank 124, and a ceiling 125. A pipe P1 extending from a cooling water pressure reducing device 1 described later branches into pipes P11, P12, P13, P14, and P15, and an on-off valve 126a or 126d is disposed in the branched pipes P11, P12, P13, and P14, so that cooling water supplied by opening the on-off valve 126a or 126d is sent to the cooler 121, the thrust metal 122, the water turbine metal 123, and the oil collection tank 124, and functions as a means for cooling the cooler 121, the thrust metal 122, the water turbine metal 123, and the oil collection tank 124, respectively. The branched pipe P15 further branches into pipes P15a and P15b, and on-off valves 126e and 126f are disposed in the pipes P15a and P15b. These pipes P15a and P15b are combined into one pipe P15c, and on-off valve 126f is disposed in the pipe P15c. The cooling water supplied by opening the on-off valves 126e or 126f and 126g of the pipes P15 is sent to the ceiling 125 side and functions as a means for cooling the ceiling 125.

[0025] In this embodiment, the cooled equipment 130 is similar to the cooled equipment 120. That is, for example, it includes a cooler 131, a thrust metal 132, a water turbine metal 133, an oil collection tank 134, and a ceiling 135. A pipe P2 extending from a cooling water pressure reducing device 2 (described later) branches into pipes P21, P22, P23, P24, and P25, and an on-off valve 136a or 136d is disposed in the branched pipes P21, P22, P23, and P24. Cooling water supplied by opening the on-off valve 136a or 136d is sent to the cooler 131, thrust metal 132, water turbine metal 133, and oil collection tank 134, and functions as a means for cooling the cooler 131, thrust metal 132, water turbine metal 133, and oil collection tank 134, respectively. In addition, the branched pipe P25 further branches into pipes P25a and P25b, and on-off valves 136e and 136f are placed in the pipes P25a and P25b, and these pipes P25a and P25b are combined into one pipe P25c, and on-off valve 136g is placed in the pipe P25c, and the cooling water supplied by opening on-off valve 136e or 136f and on-off valve 136g of these pipes P25 is sent to the ceiling 135 side and functions as a means for cooling the ceiling 135.

[0026] The first cooling water piping system R1 has one end connected to the downstream side of the penstock 103 (the side closer to the turbine generator 105), and in this embodiment, in the route leading to the cooling water pressure reducing device 1, two on-off valves 3 and 4, an STR device 5, and an on-off valve 6 are sequentially arranged upstream of the cooling water pressure reducing device 1. Note that the first cooling water piping system R1 shown in FIG. 1 omits parts other than the route leading to the cooling water pressure reducing device 1. In contrast, the second cooling water piping system R2 has one end connected to the downstream side of the penstock 103′ (the side closer to the turbine generator 110), and in this embodiment, in the route leading to the cooling water pressure reducing device 2, two on-off valves 7 and 8, an STR device 9, and an on-off valve 10 are sequentially arranged upstream of the cooling water pressure reducing device 2. Note that in the second cooling water piping system R2 shown in FIG. 1 , parts other than the route leading to the cooling water pressure reducing device 2 are also omitted.

[0027] In this embodiment, the cooling water pressure reducing device 1 and the cooling water pressure reducing device 2 use automatic pressure reducing valves as an example, and have the same basic configuration except for the pressure adjustment mechanisms 60 and 70 described below. Therefore, the cooling water pressure reducing device 1 and the cooling water pressure reducing device 2 will be described together using the external view of Fig. 2 and the cross-sectional view of Fig. 3 showing a state in which the pressure adjustment mechanisms 60 and 70 have been removed.

[0028] As shown in FIGS. 2 and 3, the cooling water pressure reducing devices 1 and 2 include a housing 31 that includes a valve box 32 and a cover 33.

[0029] The valve box 32 has a flange portion 32a around a pipe connection port 34 on one left-right side of the housing 31 for connection to cooling water piping systems R1 and R2, and a flange portion 32b around a pipe connection port 35 on the other left-right side of the housing 31 for connection to pipes P1 and P2. Inside the valve box 32, there are formed an upstream flow channel 36 that extends substantially left-right from the pipe connection port 34 through the housing 31 toward a pressure reducing mechanism 41 (described below), and a downstream flow channel 37 that extends substantially left-right from the pipe connection port 35 through the housing 31 toward the pressure reducing mechanism 41 (described below). The upstream flow channel 36 and the downstream flow channel 37 are separated by an internal partition wall 38 formed inside the housing 31, and the internal partition wall 38 has an opening 38a to which the pressure reducing mechanism 41 (described below) is attached.

[0030] The lid 33 has a protruding portion 33a that protrudes upward, and an air vent is provided at the top of the protruding portion 33a. A valve 39 is provided. A fluid chamber 40 is formed inside the cover 33.

[0031] In this embodiment, the pressure reducing mechanism 41 is basically composed of a seat member 42, a diaphragm receiver 43, a diaphragm holder 44, a diaphragm 45, a valve body holder 47, a valve stem 48, and a compression coil spring 51.

[0032] The seat member 42 is cylindrical and fitted into the opening 38a of the interior partition wall 38, with a ring-shaped valve seat 42a provided at the end of the seat member 42 facing the downstream flow channel 37. The upstream flow channel 36 and the downstream flow channel 37 communicate with each other via a hollow portion 42b located on the inner periphery of the seat member 42. That is, one axial end of the seat member 42 opens into the upstream flow channel 36, and the other axial end of the seat member 42 opens into the downstream flow channel 37.

[0033] The diaphragm receiver 43 is disposed above the seat member 42, and has a circular valve element 43a attached thereto, which seats on the valve seat 42a. The diaphragm holder 44 is disposed above the diaphragm receiver 43, and the central portion of a thin, disk-shaped diaphragm 45 is sandwiched between the diaphragm receiver 43 and the diaphragm holder 43. The peripheral portion of the diaphragm 45 is sandwiched between the valve box 32 and the cover 33, and is fixed to the valve box 32 and the cover 33 by a fixing device 46. The valve element holder 47 is disposed in a state where it is sandwiched between the seat member 42 and an expanded diameter portion 48a of the valve stem 48, which will be described below.

[0034] The valve stem 48 passes through the diaphragm holder 44, the diaphragm 45, and the diaphragm receiver 43 in that order, with one end supported by a bearing 49 and the other end supported by the cover 33 via a bushing 50. A compression coil spring 51 is disposed between the inner surface of the cover 33 on the bushing 50 side and the diaphragm holder 44, wrapping around the valve stem 48.

[0035] Next, a description will be given of the common configuration between the first pressure adjustment mechanism 60 of the cooling water pressure reducing device 1 and the second pressure adjustment mechanism 70 of the cooling water pressure reducing device 2. Note that the piping paths connecting the fluid chamber 40 in the cover 33 of the first pressure adjustment mechanism 60 and the second pressure adjustment mechanism 70 to the upstream side of the pressure adjustment devices 64 and 74 of the pressure adjustment pipes 61 and 71 are omitted. As shown in Figures 2 and 3, in the cooling water pressure reducing device 1 and the cooling water pressure reducing device 2, a through hole 321 opens at a position on the side of the valve box 32 that communicates with the upstream flow channel 36, and a through hole 322 opens at a position on the side of the valve box 32 that communicates with the downstream flow channel 37.

[0036] In the first pressure adjustment mechanism 60 of the cooling water pressure reduction device 1, one end (upstream end) of the pressure adjustment pipe 61 is connected to the through-hole 321, and in the second pressure adjustment mechanism 70 of the cooling water pressure reduction device 2, one end (upstream end) of the pressure adjustment pipe 71 is connected to the through-hole 321. In addition, in the first pressure adjustment mechanism 60 of the cooling water pressure reduction device 1, the other end (downstream end) of the pressure adjustment pipe 61 is connected to the through-hole 322, and in the second pressure adjustment mechanism 70 of the cooling water pressure reduction device 2, the other end (downstream end) of the pressure adjustment pipe 71 is connected to the through-hole 322.

[0037] In the first pressure adjustment mechanism 60, the pressure adjustment pipe 61 is divided into two pipe sections 61a and 61b midway, and a strainer 62 is disposed in the cooling water flow path of each of the pipe sections 61a and 61b. This configuration is used so that one of the pipe sections 61a and 61b and the strainer 62 provided in each of the pipe sections 61a and 61b is used primarily, and the other is used as an auxiliary (backup). On-off valves 65 and 66 are disposed upstream and downstream of the strainer 62 in the pipe sections 61a and 61b. For example, when performing maintenance on the strainer 62 in the pipe section 61a, the on-off valves 65 and 66 in the pipe section 61a can be closed and the on-off valves 65 and 66 in the pipe section 61b left open, allowing the strainer 62 in the pipe section 61b to be used. This eliminates the need to shut down the entire cooling water pressure reduction device 1, 2. Note that only the handles of the on-off valves 65 and 66 are shown in the figure. The piping sections 61a and 61b converge again into one piping section 61c downstream of the strainer 62, and a pressure adjusting device 64 is arranged on the cooling water flow path of this piping section 61c. The strainer 62 and the pressure adjusting device 64 may be well-known devices, so their configurations will not be described in detail. This also applies to the strainer 72 and the pressure adjusting device 74 described below. In this embodiment, for example, a pressure adjusting pressure reducing valve is used as the pressure adjusting device.

[0038] In the second pressure adjustment mechanism 70, the pressure adjustment pipe 71 is also divided into two piping sections 71a and 71b midway so that one section is used as the main section and the other as an auxiliary (backup) section, and a strainer 72 is disposed in the cooling water flow path of each of the piping sections 71a and 71b. Similar to the first pressure adjustment mechanism 60, on-off valves 75 and 76 are disposed upstream and downstream of the strainer 72 in the piping sections 71a and 71b, and only the handles of the on-off valves 75 and 76 are shown in the figure. Furthermore, similar to the first pressure adjustment mechanism 60, the piping sections 71a and 71b are converged again into a single piping section 71c downstream of the strainer 72, and a pressure adjustment device 74 is disposed in the cooling water flow path of this piping section 71c.

[0039] As a result, the pressure adjustment devices 64, 74 detect the differential pressure between the upstream pressure and the downstream pressure of the cooling water pressure reduction devices 1, 2, and provide the detected differential pressure to the pressure reduction mechanism 41, which adjusts the pressure of the pressure reduction mechanism 41 through the balance with the compression coil spring 51. Accordingly, the cooling water at a predetermined high pressure (e.g., 0.9 MPa) in the upstream flow channel 36 is reduced to the desired pressure (e.g., 0.5 MPa) when it passes through the pressure reduction mechanism 41 and reaches the downstream flow channel 37.

[0040] 1, 4, and 5, in the present invention, a branch pipe 80 branching off from the pressure adjustment pipe 71 of the second pressure adjustment mechanism 70 of the cooling water pressure reduction device 2 is connected to the pressure adjustment pipe 61 of the first pressure adjustment mechanism 60 of the cooling water pressure reduction device 1 upstream of the strainer 62. Although not shown, the branch pipe 80 is arranged, for example, to run from the position where the cooling water pressure reduction device 2 is installed toward the vertical wall of the building, route along the vertical wall of the building, and then be led from the vertical wall of the building to the position where the cooling water pressure reduction device 1 is installed.

[0041] 4, in this embodiment, one of the branch pipes 80 branches off immediately from a portion where it exits the housing 31 through the through hole 321 as one end of the pressure adjustment pipe 71 of the second pressure adjustment mechanism 70, and an opening / closing device 81 is disposed immediately where the branch pipe 80 branches off from the pressure adjustment pipe 71, for opening and closing the flow path of water sent from the through hole 321 via the one end of the pressure adjustment pipe 71. In this embodiment, an opening / closing valve 77 is disposed in the pressure adjustment pipe 71 at a portion before it branches off into the piping portion 71a and the piping portion 71b. Only the handle of the opening / closing valve 77 is shown.

[0042] A three-way valve 82 is disposed at a connection between one end of the pressure adjustment pipe 61 of the first pressure adjustment mechanism 60, immediately after exiting the housing 31 through the through hole 321, and the other end of the branch pipe 80. That is, the three-way valve 82 is connected on its upstream side to the pressure adjustment pipe 61 near the through hole 321 and the other end of the branch pipe 80, and is connected on its downstream side to the strainer 62 of the pressure adjustment pipe 61 and the downstream side connected to the pressure adjustment device 64. Therefore, the source of the water sent to the strainer 62 side of the pressure adjustment pipe 61 can be switched between the one end of the pressure adjustment pipe 61 connected to the through hole 321 and the branch pipe 80 side.

[0043] By adopting the above-described configuration and having the equipment, if the first cooling water piping system R1 is configured to introduce water taken from a position that is closer to the river inflow point of the dam 100 than the second cooling water piping system R2, during heavy rain, etc., muddy water will not flow into the second cooling water piping system R2, but muddy water will easily flow into the first cooling water piping system R1. In this situation, when no turbid water flows into the first cooling water piping system R1 and when turbid water flows into the first cooling water piping system R1 or when turbid water is expected to flow into the first cooling water piping system R1, the first pressure adjustment mechanism 60 of the cooling water pressure reduction device 1 and the second pressure adjustment mechanism 70 of the cooling water pressure reduction device 2 can handle the situation as follows.

[0044] (When muddy water does not flow into the first cooling water piping system R1) In the second pressure adjustment mechanism 70 of the cooling water pressure reducing device 2, by closing the opening and closing device 81, the cooling water that has flowed from the upstream flow channel 36 in the housing 31 of the cooling water pressure reducing device 2 through the through hole 321 into the pressure adjustment pipe 71 does not form a flow path through the branch pipe 80 as indicated by the thick arrow in Fig. 4. Then, in the first pressure adjustment mechanism 60 of the cooling water pressure reducing device 1, the inflow direction of the three-way valve 82 is adjusted so that the cooling water that has flowed from the upstream flow channel 36 in the housing 31 of the first cooling water pressure reducing device 1 through the through hole 321 into one end (upstream side) of the pressure adjustment pipe 61 is supplied to the strainer 62 and the pressure adjustment device 64 side, as indicated by the hollow arrow and thin arrow in Fig. 5.

[0045] (When muddy water has flowed into the first cooling water piping system R1 or when muddy water is expected to flow into the first cooling water piping system R1) In the second pressure adjustment mechanism 70 of the cooling water pressure reducing device 2, the on-off device 81 is opened so that the cooling water that flows from the upstream flow channel 36 in the housing 31 of the cooling water pressure reducing device 2 through the through hole 321 into the pressure adjustment pipe 71 forms a flow as shown by the bold arrows in Fig. 4. In this case, unless the on-off valve 77 is closed, the cooling water that flows into the pressure adjustment pipe 71 is also sent to the strainer 72 and pressure adjustment device 74 side as shown by the white arrows in Fig. 4. In the first pressure adjustment mechanism 60 of the cooling water pressure reducing device 1, the inflow direction of the three-way valve 82 is adjusted to stop the supply of cooling water that has flowed from the upstream flow channel 36 in the housing 31 of the first cooling water pressure reducing device 1 through the through hole 321 to one end (upstream side) of the pressure adjustment pipe 61 to the strainer 62 and pressure adjustment device 64 side, and as shown by the thick arrow and thin arrow in Figure 5, the cooling water that has flowed through the branch pipe 80 flows through the pressure adjustment pipe 61 and is supplied to the strainer 62 and pressure adjustment device 64 side.

[0046] Therefore, in the present invention, it is possible to prevent muddy water that has flowed into the first cooling water piping system R1 from flowing through the pressure adjustment pipe 61 downstream of the three-way valve 82 and being sent to the strainer 62 of the first pressure adjustment mechanism 60 of the cooling water pressure reduction device 1. Moreover, it is sufficient to modify only the first pressure adjustment mechanism 60 and the second pressure adjustment mechanism 70, and there is no need to modify the main bodies of the cooling water pressure reduction devices 1 and 2. Therefore, the present invention can be used with existing cooling water pressure reduction devices 1 and 2, and it is also possible to reduce the cost of applying the present invention. [Explanation of symbols]

[0047] 1 Cooling water pressure reducing device (first cooling water pressure reducing device) 2 Cooling water pressure reducing device (second cooling water pressure reducing device) 31 Housing 41 Pressure reducing mechanism 321, 322 through hole 60 First pressure adjustment mechanism 70 Second pressure adjustment mechanism 61, 71 Pressure adjustment pipe 62, 72 Strainer 64, 74 Pressure regulator 80 Branch Pipe 81 On-off valve (on-off device) 82 Three-way valve (switching device) 102 Intake (First Intake) 102´ Intake (Second Intake) 105 Water Turbine Generator (First Water Turbine Generator) 110 Water Turbine Generator (Second Water Turbine Generator) 120, 130 Cooled equipment R1 First cooling water piping system R2 Second cooling water piping system

Claims

1. In a plurality of cooling water pressure reducing devices used to reduce the pressure of cooling water supplied to cooled equipment that requires cooling during operation of a water turbine generator before the cooling water is supplied to the cooled equipment, a first cooling water pressure reducing device which is one of the plurality of cooling water pressure reducing devices, which is provided in a first cooling water piping system that uses water taken from a first water intake port for a first hydraulic turbine generator as cooling water, and which has a housing that houses a pressure reducing mechanism, a pressure adjusting pipe that has one end connected to a through hole in the housing that is upstream of the pressure reducing mechanism and the other end connected to a through hole in the housing that is downstream of the pressure reducing mechanism, a pressure adjusting device provided in the pressure adjusting pipe, and a first pressure adjusting mechanism that has a strainer that removes foreign matter from water before the water flows into the pressure adjusting device; a second cooling water pressure reducing device, which is the other of the plurality of cooling water pressure reducing devices, is provided in a second cooling water piping system that uses water taken from a second water intake port for a second hydraulic turbine generator as cooling water, and has a housing that houses a pressure reducing mechanism, a pressure adjusting pipe that has one end connected to a through hole in the housing that is upstream of the pressure reducing mechanism and the other end connected to a through hole in the housing that is downstream of the pressure reducing mechanism, a pressure adjusting device provided in the pressure adjusting pipe, and a second pressure adjusting mechanism that has a strainer that removes foreign matter from water before it flows into the pressure adjusting device; a branch pipe branching from the pressure adjustment pipe of the second pressure adjustment mechanism of the second cooling water pressure reduction device is connected to the pressure adjustment pipe of the first pressure adjustment mechanism of the first cooling water pressure reduction device upstream of the strainer, and under predetermined conditions, water passing through the second cooling water piping system is sent from the pressure adjustment pipe of the second pressure adjustment mechanism through the branch pipe to the pressure adjustment pipe of the first pressure adjustment mechanism upstream of the strainer.

2. one of the branch pipes branches off from the pressure adjustment pipe of the second pressure adjustment mechanism between the one end of the pressure adjustment pipe and the strainer, 2. The cooling water sharing mechanism for a plurality of cooling water pressure reducing devices according to claim 1, wherein an opening and closing device for opening and closing the flow path of water sent from one end of the pressure adjusting pipe is disposed in the branch pipe.

3. the other branch pipe is connected between one end of the pressure adjustment pipe of the first pressure adjustment mechanism and the strainer, 3. The cooling water sharing mechanism for a plurality of cooling water pressure reducing devices according to claim 1, wherein a switching device is disposed at a connection between the pressure adjustment pipe and the branch pipe of the first pressure adjustment mechanism, for switching the source of the water sent to the strainer side between one end side of the pressure adjustment pipe and the branch pipe side.

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