CN111989483A

CN111989483A - Cooling water supply system and cooling water supply method in hydraulic power generation system

Info

Publication number: CN111989483A
Application number: CN201980026820.9A
Authority: CN
Inventors: 余田充; 田熊康秀
Original assignee: Organo Corp
Current assignee: Organo Corp
Priority date: 2018-05-18
Filing date: 2019-05-09
Publication date: 2020-11-24
Anticipated expiration: 2039-05-09
Also published as: JP7015208B2; WO2019220991A1; JP2019199854A; CN111989483B

Abstract

The purpose of the present invention is to use external water as cooling water for a generator or a main shaft and to reduce the size of the apparatus. A hydroelectric power generation system (1) is provided with a runner (3), a generator (4), a main shaft (7) that connects the generator (4) and the runner (3), and a bearing part (11) of the main shaft (7). The cooling water supply system (20) is provided with: a cooling water supply line (21a) for supplying cooling water to the generator (4) and the bearing section (11); a return line (21b) that returns the cooling water discharged from the generator (4) and the bearing (11) to the cooling water supply line (21a) and forms a circulation path (21) together with the cooling water supply line (21 a); a cooling unit (29) for cooling water, which is provided in the circulation path (21); and an external water collection unit (22) that collects external water and introduces the collected external water into the circulation path (21) as a part of the cooling water, wherein the cooling unit (22) has a heat pump (29a) that cools the cooling water flowing through the circulation path (21).

Description

Cooling water supply system and cooling water supply method in hydraulic power generation system

Technical Field

The present application is based on japanese application filed on 18/5/2018, namely japanese patent application 2018-. This application is incorporated by reference in its entirety into the present application.

The present invention relates to a cooling water supply system and a cooling water supply method in a hydroelectric power generation system.

Background

A generator of a hydro generator and a bearing portion of a main shaft connecting the generator and a runner (runner) require continuous cooling during operation, and river water is generally used as cooling water for the cooling. Patent document 1 discloses a lubrication system for an underwater bearing, which includes: a water supply pipe branched from a hydraulic iron pipe for supplying river water; a foreign body classifier installed at the water supply pipe; and a storage tank for storing water in which the amount of foreign matters is reduced by the foreign matter classifier, wherein the lubricating system of the underwater bearing uses clean water overflowing from an outlet of the storage tank for lubricating and cooling the underwater bearing. Further, patent document 2 discloses a cooling system for a generator bearing for a hydroelectric power station, which includes: a circulation path through which cooling water circulates; a water heat exchanger provided in the circulation path; and a refrigerant heat exchanger for cooling the water heat exchanger.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2008-95585

Patent document 2: japanese patent laid-open No. 2008-104355

Disclosure of Invention

The method disclosed in patent document 2 uses cold water, and therefore, the bearing can be cooled efficiently. However, the cooling water in the circulation passage is gradually lost, and therefore, needs to be replenished. In general, in a hydroelectric power plant, restrictions on land use are large, and there are cases where downsizing of equipment for replenishment is desired.

The invention aims to provide a cooling water supply system which can use external water as cooling water of a generator or a main shaft and can realize the miniaturization of equipment.

The present invention relates to a cooling water supply system in a hydroelectric power generation system including a runner, a generator, a main shaft connecting the generator and the runner, and a bearing portion of the main shaft. The cooling water supply system comprises: a cooling water supply line that supplies cooling water to the generator and the bearing portion; a return line that returns the cooling water discharged from the generator and the bearing portion to the cooling water supply line and forms a circulation path together with the cooling water supply line; a cooling unit for cooling water provided in the circulation path; and an external water collecting unit that collects external water and introduces the collected external water into the circulation path as a part of the cooling water, wherein the cooling unit includes a heat pump that cools the cooling water flowing through the circulation path.

According to the present invention, since the external water is used as the cooling water for the generator or the bearing portion, the cooling water can be easily supplied. Further, since the heat pump has a very high cooling effect, the flow rate and flow rate of the cooling water can be reduced, and the size of the entire apparatus can be reduced. Therefore, according to the present invention, it is possible to provide a cooling water supply system capable of using external water as cooling water for a generator or a main shaft and realizing downsizing of equipment.

The above and other objects, features and advantages of the present application will become apparent from the following detailed description with reference to the accompanying drawings which illustrate the present application.

Drawings

Fig. 1 is a schematic configuration diagram of a hydraulic power generation system according to an embodiment of the present invention.

Detailed Description

A hydraulic power generation system according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows a schematic structure of a hydro-power generation system. In the figure, the broken line indicates a portion normally provided in a conventional hydroelectric power generation system, and the solid line indicates a portion unique to the present embodiment. As described later, the present invention can be used to retrofit an existing hydro-power generation system, and in this case, the retrofitting can be performed by appropriately adding the piping and equipment shown by the solid line to the existing hydro-power generation system shown by the broken line. In the figure, the dot portions indicate portions where river water or cooling water is present.

The hydro-power generation system 1 has a hydro-generator 2 including a runner 3 and a generator 4. The runner 3 is accommodated in a casing 5 connected to a hydraulic iron pipe 6. A main shaft 7 is attached to the runner 3, and the main shaft 7 penetrates the housing 5. The upper end of the main shaft 7 is coupled to the generator 4 via a coupling (not shown). The runner 3 is rotated by the river water supplied from the hydraulic iron pipe 6, and the generator 4 generates electricity. The hydraulic iron pipe 6 is provided with an inlet valve 8 for stopping the supply of river water when the hydraulic generator 2 is maintained. A drain pipe 9 is connected to a lower end of the casing 5, and the river water that rotates the runner 3 is discharged to a river or the like through the drain pipe 9.

The main shaft 7 is provided with an upper bearing 11a, a lower bearing 11b, and a turbine bearing 11c (hereinafter, these are collectively referred to as a bearing 11) from top to bottom. The generator 4 and the bearing portion 11 have a coil 12 (a coiled pipe), and cooling water is passed through the coil 12 to be cooled (only the coil 12 of the generator 4 is shown in the figure). A seal portion 14 for shaft sealing the through portion 13 of the main shaft 7 of the housing 5 is provided below the turbine bearing 11 c. The seal portion 14 includes a bearing water tank 15 and a shaft seal portion 16 provided in the through portion 13 of the main shaft 7 of the bearing water tank 15. The bearing water tank 15 is filled with cooling water described later. An underwater bearing 17 is housed in the bearing water tank 15, and the underwater bearing 17 is lubricated and cooled by cooling water.

The hydro-power generation system 1 includes: a cooling unit 29 for cooling water; a circulation path 21 through which cooling water for cooling the generator 4 and the bearing 11 circulates; and a river water collecting unit 22 connected to the circulation path 21. The circulation path 21 is constituted by a cooling water supply line 21a and a return line 21b, the cooling water supply line 21a supplies cooling water to the generator 4 and the bearing portion 11, and the return line 21b returns cooling water discharged from the generator 4 and the bearing portion 11 to the cooling water supply line 21a, and forms the circulation path 21 together with the cooling water supply line 21 a. The cooling water supply line 21a extends from a first merging portion M1 where the river water collecting line 22b of the river water collecting unit 22 merges with the return line 21b to the generator 4 and the bearing portion 11. The return line 21b extends from the generator 4 and the bearings 11a, 11b, and 11c to a first branch portion D1 at which a drain line 23 that discharges the cooling water to the river branches, and further extends from the first branch portion D1 to a first joining portion M1. The return line 21b is provided with a first valve V1, and the drain line 23 is provided with a second valve V2, the first valve V1 being normally opened and the second valve V2 being closed. When the cooling water is not flowing to the downstream side of the first branch portion D1 of the return line 21b for some reason, the first valve V1 is closed and the second valve V2 is opened, whereby the cooling water flowing through the circulation path 21 is discharged from the discharge line 23 to the outside of the system. The cooling water supply line 21a and the return line 21b have branch pipes 21d (only the branch pipe 21d of the generator 4 is shown in the figure) connected to the generator 4 and the respective bearing portions 11. The branch pipe 21d of the cooling water supply line 21a includes the coil 12. A water supply pump 24 is provided on the cooling water supply line 21 a. The cooling water is supplied from the cooling water supply line 21a to the generator 4 and the bearing 11, discharged from the generator 4 and the bearing 11 to the return line 21b, and returned to the cooling water supply line 21 a. That is, the cooling water of the generator 4 and the bearing 11 circulates along the circulation path 21.

The river water collection unit 22 includes: a river water collecting part 22a provided in the water discharge pipe 9; a river water collecting line 22b extending from the collecting section 22a to the first merging section M1; and a water intake pump 22c provided in the river water collection line 22b, wherein the river water collection unit 22 supplies the river water collected by the collection unit 22a to the circulation path 21. The flow rate of the river water introduced from the river water sampling line 22b into the circulation path 21 can be adjusted by controlling the output of the water extraction pump 22 c. The collecting part 22a of the river water collecting unit 22 may be provided in the hydraulic iron pipe 6 or may be provided in the river itself. In the present embodiment, the source of the river water is the drain pipe 9, but the source may be any source capable of supplying the river water. In addition, the water source is not limited to river water, and may be any external water, and the river water collecting unit 22 may be more colloquially understood as an external water collecting unit.

A seal water supply line 25 for supplying seal water to the seal portion 14 is branched from the cooling water supply line 21a of the circulation path 21. The water pressure of the river water flowing into the housing 5 acts on the shaft seal portion 16. Therefore, in order to prevent or suppress leakage of the river water from the shaft seal portion 16 of the housing 5, high-pressure seal water is supplied to the seal portion 14. The sealing water gradually leaks from the shaft seal portion 16, flows out to the housing 5, and is finally discharged to a river. The seal water supply line 25 supplies cooling water to the seal portion 14 to fill up seal water lost in the seal portion 14. That is, the river water collecting means 22 collects the river water at a flow rate substantially equal to the flow rate of the seal water, and introduces the collected water into the circulation path 21.

The circulation path 21 is provided with a cooling unit 29 for cooling the cooling water. The cooling unit 29 includes a heat pump 29a, a heat exchanger 29b that exchanges heat with the cooling water in the circulation path 21, a circulation pump 29c, and a circulation tank 29d, and the cooling circulation water flowing through the cooling circulation line 29e is circulated between the heat pump 29a and the heat exchanger 29b by the circulation pump 29 c. The cooling unit 29 cools the cooling water having an increased temperature by removing heat from the generator 4 and the bearing 11. The cooling unit 29 is provided on the cooling water supply line 21a, but may be provided at any position of the circulation path 21 or may be provided on the return line 27. The cooling unit 29 can keep the cooling circulation water at a low temperature by a refrigeration cycle in which the refrigerant of the heat pump 29a is compressed and expanded, and can increase the temperature difference before and after cooling of the cooling water by the heat exchanger 29 b. In other words, low-temperature cooling water can be easily produced. Therefore, the flow rate of the cooling water can be suppressed, and thus, the diameter of the circulation path 21 can be reduced, the flow rate of the cooling water can be reduced, the purifier 26 can be downsized, and the installation space can be reduced. The cooling unit 29 preferably has such characteristics that the temperature difference before and after cooling of the cooling water is maximized and the flow rate is minimized.

The heat taken from the cooling water by the cooling unit 29 is used not only for a hot water load (not shown) inside the power plant but also for a hot water load (not shown) outside the power plant. Examples of the hot water load in the power plant include hot water supply, heating, and snow melting in the land. Examples of the hot water load outside the power station include hot water supply, heating, snow melting, and the like, and applications such as agricultural water and heating of a vinyl house, but are not limited thereto.

The hydro-power generation system 1 has a bypass line 30 of the cooling module 29. The bypass line 30 branches from the circulation path 21 at a fourth branch point D4 on the upstream side of the cooling module 29, and merges with the circulation path 21 at a fourth merging portion M4 on the downstream side of the cooling module 29. Normally, the seventh valve V7 of the circulation path 21 is opened, the eighth valve V8 of the bypass line 30 is closed, and the cooling water bypasses the cooling module 29 by closing the seventh valve V7 and opening the eighth valve V8. Similarly to the bypass line 28 of the purification apparatus 26, when the cooling module 29 fails, the cooling water is caused to flow into the bypass line 30, whereby the supply of the cooling water to the generator 4 and the bearing portion 11 and the supply of the seal water to the seal portion 14 can be continued, and the power generation can be continued.

A purification device 26 for cooling water is provided in the river water collection line 22. In the circulation path 21 and the seal water supply line 25, a flow path may be partially or completely blocked due to foreign matter contained in the river water. This tendency is particularly remarkable in a pipe such as the coil 12 which is bent in a small diameter. The clogging of the flow path causes a decrease in the amount of cooling water and cooling efficiency, and makes it difficult to stably operate the power plant. The inventors of the present application found that the clogging of the flow path is mainly caused by sludge contained in the river water. Once attached to the surface of the pipe, the sludge is difficult to remove by the water flow. The content of sludge in river water tends to increase due to rainstorm or the like, but sludge is also contained in river water in general. The purification device 26 of the present embodiment effectively removes sludge. This makes it difficult to cause clogging of the piping, and can extend the inspection cycle of the cooling system of the generator 4 and the bearing 11, thereby reducing the cost required for inspection or cleaning of the inside of the piping. In addition, in some cases, the periodic inspection period of the power plant can be shortened, and the operating rate can be improved (the amount of power generation can be increased) accordingly.

Further, since the heat pump 29a has a very high cooling effect, the pipe diameter of the circulation path 21 can be reduced as described above, and the flow rate of the cooling water can also be reduced. Therefore, the pipe can be reduced in diameter and the cooling water pump can be reduced in size. However, sand or gravel in the cooling water, rust generated by corrosion of the pipe, scale components (calcium, silicon oxide, and the like), ion components (iron, manganese, and the like), microorganisms (slime, and the like), and other pipe-clogging substances are likely to accumulate in the pipe due to a small diameter of the pipe or a decrease in the flow rate of the cooling water. In addition, since the viscosity of the water increases due to the decrease in the temperature of the cooling water (for example, when the temperature is decreased from 25 ℃ to 10 ℃, the viscosity increases by about 1.4 times), the viscosity of the clay containing a large amount of water such as sludge also increases, and there is a possibility that the clogging of the pipe is easily caused. Therefore, when the cooling module 29 including the heat pump 29a is used, it is extremely effective to provide the purification device 26 for removing the pipe clogging substance in the circulation path 21 in order to suppress the occurrence of the pipe clogging.

A return line 27 is connected to the circulation path 21 and the river water collection line 22. The return line 27 branches from the circulation path 21 at a second branch point D2 located on the downstream side of the purification device 26, and merges with the river water collection line 22 at a second merging portion M2 located on the upstream side of the purification device 26. The return line 27 returns a part of the cooling water purified by the purification apparatus 26 to the upstream side of the purification apparatus 26. A third valve V3 is provided downstream of the second branch point D2 of the circulation path 21, a fourth valve V4 is provided in the return line 27, and the opening degrees of the third valve V3 and the fourth valve V4 are appropriately set, whereby a predetermined proportion of the cooling water flowing through the circulation path 21 can be made to flow into the return line 27.

The flow rates of the cooling water or the river water in the circulation path 21, the river water collecting unit 22 (the river water collecting line 22b), and the return line 27 are as follows. First, the flow rate of the cooling water supply line 21a on the downstream side of the second branch portion D2 is Q1+ Q2. Here, Q1 is the flow rate of the cooling water in the generator 4 and the bearing 11, and Q2 is the flow rate of the seal water supplied to the seal 14. As described above, since the sealing water flows out to the case 5 and is not recovered, the flow rate of the return line 21b becomes Q1. In the present embodiment, since the cooling water discharged from the drain line 23 is zero, the flow rate of the return line 21b is also Q1 on the downstream side of the first branch portion D1. The flow rate Q2 of the sealing water lost in the sealing portion 14 is filled by collecting the river water from the river water collecting means 22 at the flow rate Q2. The flow rate Q3 of the return line 27 can be appropriately set within a range satisfying Q3 < Q1. That is, since the cooling water is repeatedly treated by the purification device 26 to have high cleanliness, it is not necessary to treat the entire amount by the purification device 26 every time. However, since the content of the iron clad layer or the like gradually increases during the circulation in the circulation path 21, a part of the cooling water is treated by the purification device 26. The cooling water taken out from the circulation path 21 to the return line 27 and the river water collected by the river water collecting unit 22 flow into the purification apparatus 26. Therefore, the flow rate in the purge device 26 is Q2+ Q3. Since the purification device 26 is provided in the river water collection unit 22, the entire amount of the river water collected by the river water collection unit 22 is treated by the purification device 26. Since the cooling water and the river water treated by the purification apparatus 26 are merged with the cooling water flowing through the return line 21b at the first merging portion M1, the flow rate of the circulation path 21 between the first merging portion M1 and the second branch D2 becomes Q1+ Q2+ Q3. Further, since a part of the cooling water (flow rate Q3) is taken out to the return line 27 at the second branch portion D2, the flow rate of the cooling water supply line 21a on the downstream side of the second branch portion D2 is Q1+ Q2.

Thus, a part of the cooling water flowing through the circulation path 21 passes through the return line 27 and is purified by the purifying device 26, and the remaining part is supplied from the cooling water supply line 21a to the generator 4, the bearing portion 11, and the seal portion 14. This can always maintain the water quality of the cooling water circulating through the circulation path 21. Further, since the cooling water of the generator 4 and the bearing 11 is not substantially lost from the circulation path 21 and the supply of the river water from the river water collecting means 22 is limited to the amount of the lost sealing water, the intake amount of the river water can be reduced compared to the conventional case. The amount of cooling water depends on the output of the hydroelectric power plant, and in some cases, a flow rate of several hundred tons/hour of water is required, and the amount of water intake can be significantly reduced as compared with a conventional instantaneous cooling system (a system in which the obtained cooling water is directly discharged without being recirculated). When the river water collecting part 22a is provided in the hydraulic iron pipe 6, the flow rate of the river water that can be used for power generation is increased compared to the instantaneous type, and therefore the power generation amount can be increased.

The hydro-power generation system 1 has a bypass line 28 of the cleaning device 26. The bypass line 28 branches from the river water collecting line 22b at a third branch point D3 located upstream of the purification device 26 and downstream of the second confluence portion M2, and merges with the river water collecting line 22b at a third confluence portion M3 located upstream of the first confluence portion M1 and downstream of the purification device 26. Normally, the fifth valve V5 of the river water collecting line 22b is opened, the sixth valve V6 of the bypass line 28 is closed, but by closing the fifth valve V5 and opening the sixth valve V6, the cooling water bypasses the purification device 26. When the purifier 26 fails, the cooling water is caused to flow into the bypass line 28, whereby the supply of the cooling water to the generator 4 and the bearing 11 and the supply of the seal water to the seal portion 14 can be continued, and the power generation can be continued. Since a part of the water flowing between the second merging portion M2 of the river water collection line 22b and the purification device 26 has already been purified by the purification device 26, even if the purification device 26 is temporarily not operated, the cooling water with a certain degree of cleanliness can be supplied to the generator 4, the bearing portion 11, and the seal portion 14 in a short time. Therefore, power generation can be continued even when the purification device 26 is temporarily stopped.

As is clear from the above description, the circulation path 21 of the cooling water, the river water collecting unit 22, the seal water supply line 25, the purification device 26 of the cooling water provided in the river water collecting unit 22, the bypass line 28 of the purification device 26, the return line 27, the cooling module 29, and the bypass line 30 of the cooling module 29 constitute the cooling water supply system 20 in the hydro-power generation system. The cooling water supply system 20 of the present embodiment can also be realized by adding a circulation path 21 for cooling water, a purification device 26 for cooling water provided in the river water collection line 22 (above the river water collection line 22 b), a bypass line 28 for the purification device 26, a return line 27, a cooling module 29, and a bypass line 30 for the cooling module 29 to the existing hydro-power generation system. At this time, since the portions of the cooling water supply line 21a and the return line 21b up to the first branch portion D1 are usually installed in the existing hydroelectric power generation system, the circulation path 21 can be realized only by installing a portion of the return line 21b that connects the first branch portion D1 to the connection point (first junction M1) between the cooling water supply line 21a and the river water collecting line 22.

The purification device 26 and the cooling module 29 may be provided so as to be detachable from the circulation path 21. In general, hydroelectric power plants have a small amount of flat land due to site restrictions, and it is sometimes difficult to secure a site for installation of equipment materials during inspection and repair works. By making the purification device 26 and the cooling module 29 detachable, it is sometimes easy to secure an installation place for equipment materials.

Although several preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications could be made therein without departing from the spirit or scope of the appended claims.

Description of the symbols

1 hydroelectric power generation system

3 rotating wheel

4 electric generator

5 casing

7 Main shaft

9 drainpipe (river water source)

11 bearing part

14 sealing part

20 cooling water supply system

21 circulation path

21a cooling water supply line

21b return line

22 river water collecting unit (external water collecting unit)

23 drainage line

24 water supply pump

25 sealed water supply line

26 purification device

27 return line

28 bypass line of a purification device

29 Cooling component (Cooling Unit)

29a heat pump

30 cooling the bypass line of the assembly.

Claims

1. A cooling water supply system in a hydroelectric power generation system having a runner, a generator, a main shaft connecting the generator and the runner, and a bearing portion of the main shaft,

the cooling water supply system includes: a cooling water supply line that supplies cooling water to the generator and the bearing portion; a return line that returns the cooling water discharged from the generator and the bearing portion to a cooling water supply line and forms a circulation path together with the cooling water supply line; a cooling unit for the cooling water provided in the circulation path; and an outside water collecting unit that collects outside water and introduces the collected outside water into the circulation path as a part of the cooling water, wherein the cooling unit includes a heat pump that cools the cooling water flowing through the circulation path.

2. The cooling water supply system according to claim 1,

the system for hydroelectric power generation comprises: a housing that houses the runner and through which the spindle passes; and a sealing part for shaft sealing of the through part of the main shaft in the housing,

the cooling water supply system includes a seal water supply line that branches from the cooling water supply line and supplies a part of the cooling water to the seal portion as seal water, and the external water collecting unit collects external water at a flow rate substantially equal to a flow rate of the seal water and introduces the collected external water to the circulation path.

3. The cooling water supply system according to claim 1 or 2,

the cooling water supply system includes a purification device that is provided in the circulation path and removes a pipe clogging substance in the cooling water.

4. The cooling water supply system according to claim 3,

the cooling water supply system includes a return line that branches from the circulation path downstream of the purification device, merges with the external water collection unit upstream of the purification device, and returns a part of the cooling water purified by the purification device to the upstream side of the purification device.

5. The cooling water supply system according to claim 3 or 4,

the purification apparatus treats the entire amount of the outside water collected by the outside water collection unit and a part of the cooling water circulating in the circulation path.

6. A cooling water supply method in a hydroelectric power generation system having a runner, a generator, a main shaft connecting the generator and the runner, and a bearing portion of the main shaft, the method comprising:

supplying cooling water to the generator and the bearing portion through a cooling water supply line;

returning the cooling water discharged from the generator and the bearing portion from a return line forming a circulation path together with the cooling water supply line to the cooling water supply line, thereby circulating the cooling water within the circulation path;

collecting external water and introducing the collected external water into the circulation path as a part of the cooling water; and

cooling the cooling water by a cooling unit provided in the circulation path,

the cooling water is cooled by a heat pump of the cooling unit.