JP7380303B2 - Cooling device for power generation equipment - Google Patents

Description

The present invention relates to a cooling device for cooling the heat-generating parts of power generation equipment such as a water turbine generator, and in particular, a cooling device that circulates lubricating oil to be supplied to the sliding parts of the power generation equipment through cooling piping arranged in the oil. The present invention relates to a cooling device that cools the air by cooling the air.

For example, in a water turbine generator, in order to ensure smooth sliding between the rotating part and the bearing that supports it, a bearing oil tank is provided around the bearing, and the lubricating oil stored in this bearing oil tank is transferred to the bearing. We try to provide a constant supply. Frictional heat is generated between such rotating parts and the bearings, so during long-term continuous operation, the temperature of the lubricating oil in the bearing oil tank may rise and the sufficient viscosity required for lubrication may not be obtained. There is. Therefore, in order to cool the lubricating oil, conventionally, a cooling pipe is disposed in the lubricating oil in a bearing oil tank, and cooling water is made to flow through the cooling pipe to cool the lubricating oil. The cooling water that has flowed through the cooling pipes is discharged directly into the river unless a particular problem occurs.

However, if the thickness of the cooling water piping in the bearing oil tank becomes thin over many years of use, pinholes may occur on the surface of the piping. If such pinholes are formed in the cooling water piping, there is concern that the lubricating oil in the bearing oil tank will flow into the cooling water in the piping through the pinholes and flow directly into the river, causing environmental pollution. Ru.

Therefore, if pinholes are found in the cooling water piping, it is necessary to stop the water turbine generator, disassemble and repair it, and eliminate the pinhole before restarting operation. This has the disadvantage that it takes time and unexpected costs are incurred.

In order to avoid such inconveniences, it is possible to use self-cooled bearings that do not have cooling piping installed in the bearing oil tank, but if a self-cooled bearing is used, the bearing oil tank needs to be larger. Therefore, it is physically impossible in most cases, and even if it is possible to upgrade to a self-cooled bearing, it would require a design change or new manufacturing of the main parts, which would incur significant costs. be.
Therefore, conventionally, as shown in Patent Document 1, a refrigerant circulation cycle (closed circulation cooling system) is used to circulate liquid refrigerant through the cooling piping, and the route of the refrigerant supplied to the cooling piping is set to a penstock or a water discharge channel. A cooling device has been proposed that is independent from the above and does not communicate with them.

Japanese Patent Application Publication No. 2015-180151

However, in a cooling system using the above-mentioned refrigerant circulation cycle (closed circulation cooling system), it is possible to prevent oil from leaking outside the premises even if a pinhole occurs, but liquid refrigerant (water ), and this liquid refrigerant is circulated by a pump, so if a pinhole occurs and the liquid refrigerant in the refrigerant circulation cycle (closed circulation cooling system) leaks into the lubricating oil, the lubricating oil is stored. There is an inconvenience that the oil level in the bearing oil tank rises and the abnormality detection sensor is activated, causing the generator to stop. Furthermore, when the pump stops, there is also the problem that the lubricating oil in the bearing oil tank flows back into the cycle pipe.

Furthermore, if liquid refrigerant (water) leaks into the lubricating oil, there is a concern that the lubricating oil will deteriorate due to the liquid refrigerant, and if liquid refrigerant is mixed in the lubricating oil, there is also a concern that the lubrication function will deteriorate. .

Therefore, if a pinhole is found to have formed, it is not possible to continue operation, and the power generation equipment must be shut down and the cooling water piping repaired. If it is determined that the lubricating oil has deteriorated, it will be necessary to completely replace the lubricating oil.
Furthermore, in order to reuse current equipment as much as possible, it is necessary to lower the pressure on the low-pressure side sufficiently, and to avoid using refrigerants that have environmental impacts (artificial refrigerants such as fluorocarbons, CO2 _, etc.). It is desirable to construct a cooling system that uses natural refrigerants that have no environmental impact.

The present invention was made in view of the above circumstances, and does not require major changes to the current equipment, and even if a pinhole occurs in the cooling pipe, if it is minor, the equipment can continue to operate. The main object of the present invention is to provide a cooling device for power generation equipment that can use a natural refrigerant that does not cause problems and has no environmental impact.

In order to achieve the above object, a cooling device for power generation equipment according to the present invention circulates a refrigerant through a cooling pipe arranged in the lubricating oil in order to cool the lubricating oil that lubricates the sliding parts of the power generation equipment. A cooling device for power generation equipment equipped with a refrigerant circulation cycle,
The refrigerant is dry air, and the refrigerant circulation cycle includes an expander-integrated compressor in which a compressor that compresses the refrigerant and an expander that expands the refrigerant are coaxially connected, and the compressor and , a heat radiating device that radiates heat from the refrigerant compressed by the compressor, the expander that expands the refrigerant that has passed through the heat radiating device, a pressure regulating valve that adjusts the refrigerant pressure to a predetermined pressure range, and the pressure regulating valve. The cooling pipe for supplying the refrigerant whose pressure has been adjusted by the cooling pipe and the check valve provided on the downstream side of the cooling pipe are connected to each other in at least this order.

Therefore, in converting the refrigerant circulation cycle into a heat pump cycle, we used an expander-compressor that integrated a compressor and an expander, and used dry air as the refrigerant, so the refrigerant could be pressurized to the desired pressure. By appropriately adjusting the refrigerant pressure, even if a pinhole occurs in the cooling piping installed in the lubricating oil in the bearing oil tank, the inconvenience of lubricating oil infiltrating into the cooling piping is eliminated. . Further, even if the compressor is stopped, the pressurized state of the refrigerant is maintained, so there is no problem of lubricating oil flowing back through the pinhole.

In addition, since dry air is used as the refrigerant, even if the refrigerant in the refrigerant circulation cycle leaks into the lubricating oil in the bearing oil tank through a pinhole, there will be no impact on the environment. The discharged refrigerant passes through the lubricating oil and is released from the oil level to the atmosphere, so there is no problem of raising the lubricating oil level and detecting an abnormality. This also eliminates the inconvenience of deteriorating lubrication performance.

Furthermore, the pressure of the refrigerant supplied to the cooling piping can be set using a pressure regulating valve to a pressure that puts less strain on the cooling piping, so existing cooling piping can be used as is, making it possible to make major changes to the current equipment. There's no need to.
Furthermore, a check valve is provided on the downstream side of the cooling piping, so even if the expander-compressor does not have a check valve function, the high-pressure refrigerant will be cooled when the expander-compressor stops. This makes it possible to avoid the inconvenience of backflow into the piping.

The expander-integrated compressor is connected to a motor, the compressor that is connected to the output shaft of the motor and is driven by the motor to compress the refrigerant, and the compressor that is connected to the output shaft of the motor, and The expander is configured to expand the refrigerant and recover the expansion energy generated at that time as power for the output shaft, and the compressor and expander are of a turbo type, Expansion energy generated by the expander can be used as auxiliary power for the compressor, increasing energy efficiency and making it possible to obtain sufficient cooling capacity even when dry air is used as the refrigerant.

In particular, in the case where a water turbine is provided below the generator as power generating equipment and the generator and the water turbine are rotatably supported on the main shaft, the above configuration is arranged in lubricating oil. a first cooling pipe disposed in the lubricating oil of an upper bearing provided at the upper part of the generator, and a first cooling pipe disposed in the lubricating oil of a lower bearing provided at the lower part of the generator. It is preferable that the cooling pipe is configured by a second cooling pipe provided in the water wheel, and a third cooling pipe disposed in the lubricating oil of the water wheel bearing provided at the upper part of the water turbine.

Here, the first cooling pipe, the second cooling pipe, and the third cooling pipe are provided on parallel passages connected in parallel to the compressor and the heat radiating device, and Each of the passages may be provided with a flow rate regulating valve that regulates the flow rate of the refrigerant.
In such a configuration, cooling pipes (first cooling pipe, second cooling pipe, third cooling pipe) for cooling lubricating oil supplied to each of the upper bearing, lower bearing, and water turbine bearing of the water turbine generator are used. The amount of refrigerant supplied to each cooling pipe can be roughly adjusted by adjusting the pipe diameter of the parallel passages, and the amount of refrigerant supplied to each cooling pipe can be adjusted by adjusting the flow rate adjustment valve provided in each parallel passage. Fine adjustments can be made, and adjustments can be made to obtain the cooling capacity required for each bearing.

Further, even if the pressure regulating valve is disposed on the downstream side of the expander in the refrigerant circulation cycle and upstream of a portion where the refrigerant is divided into the parallel passages, It may be arranged such that the
According to the former configuration, the pressure of the refrigerant supplied to the cooling pipes is collectively managed by a common pressure regulating valve, but according to the latter configuration, it can be adjusted for each cooling pipe.

Here, a refrigerant filling valve for charging the gas refrigerant is preferably provided downstream of the pressure regulating valve in the refrigerant circulation cycle.
By placing the refrigerant filling valve on the downstream side of the pressure regulating valve in this way, it is possible to fill the refrigerant in the low pressure line downstream of the pressure regulating valve, making it easier to fill and work safely. It becomes possible to do this.

Furthermore, the generator includes a rotor fixed to a rotating shaft, a stator provided around the rotor, and air provided around the stator and circulating through the rotor and the stator. In the case where the refrigerant is provided with an air cooler for cooling the air cooler, the refrigerant whose pressure is regulated by a pressure regulating valve may also be circulated to the air cooler.
Since the air cooler is not installed in lubricating oil, the above-mentioned disadvantages do not occur even if liquid refrigerant (water) is supplied. For this reason, liquid refrigerant may be supplied to the air cooler, but if a separate path for supplying liquid refrigerant to the air cooler is provided separately from the heat pump cycle, the structure becomes complicated. be. Therefore, by configuring the air cooler to circulate the gas refrigerant (dry air) of the heat pump cycle, it is possible to simplify the structure.

As described above, according to the cooling device for power generation equipment according to the present invention, there is a refrigerant circulation cycle in which the refrigerant is circulated through the cooling pipes arranged in the lubricating oil in order to cool the lubricating oil that lubricates the sliding parts. When using a heat pump cycle using dry air as the refrigerant and a turbo-type expander-integrated compressor, the pressure in the low-pressure line downstream of the expander can be sufficiently suppressed and sufficient cooling capacity can be achieved. This makes it possible to use existing equipment as is without major changes. In addition, since dry air is used as the refrigerant, even if a pinhole occurs in the cooling piping in the bearing oil tank, if it is minor, it will not cause any trouble to the environment or equipment, even if the operation continues. This makes it possible to suppress the occurrence of unexpected costs as much as possible.

In other words, even if a pinhole occurs in the cooling pipe installed in the lubricating oil in the bearing oil tank, the refrigerant can be adjusted to the desired pressure using dry air, so the lubricating oil will not enter the cooling pipe. This makes it possible to avoid inconveniences.

Additionally, since dry air is used as the refrigerant, even if the refrigerant in the refrigerant circulation cycle leaks into the lubricating oil through a pinhole, it will simply be released into the atmosphere without mixing with the lubricating oil. Therefore, it is possible to avoid inconveniences such as deterioration of the lubricating oil or deterioration of lubrication performance due to the presence of refrigerant in the lubricating oil.

FIG. 1 is an overall configuration diagram showing a cooling device when the power generating equipment is a water turbine generator, and shows an example in which a pressure regulating valve of a refrigerant circulation cycle is arranged upstream from a branch part of a parallel passage. FIG. 2 is a cross-sectional view showing a configuration example of each bearing of the water turbine generator according to the present invention and a cooling pipe accommodated in a bearing oil tank. FIG. 3 is a flowchart illustrating an example of the operation of notifying a decrease in the amount of refrigerant charged by the control unit. FIG. 4 is an overall configuration diagram showing a cooling device when the power generating equipment is a water turbine generator, and shows an example in which pressure regulating valves for the refrigerant circulation cycle are arranged on each parallel passage. FIG. 5 is an overall configuration diagram showing a cooling device when the power generating equipment is a water turbine generator, and is a diagram showing an example in which refrigerant whose pressure is regulated by a pressure regulating valve is also supplied to the air cooler of the generator. .

Embodiments of the present invention will be described below with reference to the accompanying drawings.
In FIG. 1, an example of hydroelectric power generation equipment is shown as the power generation equipment.

The hydroelectric power generation facility 1 includes a water turbine 2, a penstock 3 as a water pipe, an inlet valve 4 provided on the penstock 3 to open and close water guided to the water turbine 2, and a suction pipe 5 provided directly below the water turbine. A generator 10 placed above the water turbine 2, a water turbine generator main shaft 6 provided from the water turbine 2 to the generator 10, and various bearings (upper bearing 20, lower bearing 30, It is configured to include a water wheel bearing 40), an air cooler 15 provided in the generator 10, and a refrigerant circulation cycle 50.

The penstock 3 is a water pipe that guides water from the reservoir to the water wheel 2 using a head difference, and is connected to the water wheel 2 to supply water from the reservoir via the inlet valve 4. The water wheel 2 is configured to rotate due to the reaction when flowing water flows through the penstock 3. The water that has passed through the water turbine 2 is discharged into the waterway through the suction pipe 5.

The generator 10 includes a rotor 11 connected to the main shaft 6 of the water turbine generator, a stator 12 provided around the rotor 11, and a stator 12 provided on the rotor 11 and integrated with the rotor 11. It includes a rotating cooling fan 13 and an air cooler 15 provided around a stator. The rotation of the rotor 11 generates an electromotive force in the coil of the stator 12, and also rotates the cooling fan 13 to cause the air around the generator to pass through the rotor 11, stator 12, and air cooler 15. I try to circulate it.
The rotor 11 of the generator 10 and the water turbine 2 are coaxially fixed by a water turbine generator main shaft 6.

As shown in FIG. 2, the water turbine generator main shaft 6 includes an upper bearing 20 as a thrust bearing that suspends the generator 10 and the water turbine 2 above the generator 10, and an upper bearing 20 below the generator 10. The water turbine 2 is rotatably supported by a lower bearing 30 as a radial bearing supported at the lower bearing 30 and a water turbine bearing 40 as a radial bearing provided below the lower bearing 30 and above the water turbine 2 .

The upper bearing 20, the lower bearing 30, and the water wheel bearing 40 are provided with corresponding bearing oil tanks (upper bearing oil tank 21, lower bearing oil tank 31, and water wheel bearing oil tank 41) around the respective bearing oil tanks. Lubricating oil is stored in each of the bearing oil tanks 21, 31, and 41, and this lubricating oil is constantly supplied to the upper bearing 20, the lower bearing 30, and the water wheel bearing 40.

Each of the bearing oil tanks 21, 31, and 41 has a lubricating oil that suppresses the temperature of the lubricating oil from rising due to frictional heat between the upper bearing 20, the lower bearing 30, and the water turbine bearing 40 due to the rotation of the water turbine generator main shaft 6. Cooling pipes (first cooling pipe 22, second cooling pipe 32, and third cooling pipe 42) are provided for this purpose. These cooling pipes 22, 32, 42 are provided so as to be immersed in lubricating oil over the entire circumference of the bearing oil tanks 21, 31, 41. For example, a large number of pipes are arranged in parallel in the vertical direction and in the radial direction. It is configured as follows.

A plurality of air coolers 15 provided in the generator 10 are provided at intervals around the stator 12 of the generator 10, and air is circulated through the rotor 11 and the stator 12 by rotation of the cooling fan 13. It is supposed to cool down.

The refrigerant circulation cycle 50 is a heat pump cycle using dry air as a refrigerant, and includes a first cooling pipe 22 arranged in the upper bearing oil tank 21 and a second cooling pipe 32 arranged in the lower bearing oil tank 31. The lubricating oil in each bearing oil tank is cooled by circulating a refrigerant through a third cooling pipe 42 disposed in the water turbine bearing oil tank 41.

The refrigerant circulation cycle includes a compressor 51a that compresses the refrigerant, a heat radiator 52 that radiates heat by exchanging the compressed refrigerant with water flowing through the penstock 3, and an expansion that decompresses and expands the refrigerant radiated by the heat radiator 52. a pressure regulating valve 53 that adjusts the refrigerant depressurized and expanded by the expander 51b to a predetermined pressure range, and the refrigerant whose pressure has been adjusted by the pressure regulating valve 53 is stored in each bearing oil tank 21, 31, 41. The cooling pipes 22, 32, and 42, which exchange heat with the lubricating oil, and the backflow prevention valve 54 provided on the downstream side of the cooling pipes are connected at least in this order.

The compressor 51a is an expander-integrated compressor 51 in which an expander 51b is coaxially connected and integrated, and is well known in itself, as shown in, for example, Japanese Patent Application Laid-Open No. 2015-94259. be. The expander-compressor 51 includes a motor 51c, a compressor 51a connected to one end of the output shaft of the motor 51c, and driven by the motor 51c to compress refrigerant, and a compressor 51a connected to the other end of the output shaft of the motor 51c. The expander 51b is connected to the refrigerant and expands the refrigerant and recovers the expansion energy generated at that time as power for the output shaft. The discharge port of the compressor 51 a of the expander-compressor 51 is connected to the inlet of the heat radiating device 52 .

The heat dissipation device 52 is made by contacting and fixing piping along the surface of the penstock 3, and various configurations can be adopted for its form. It is recommended to adopt it. The outflow section of the heat radiating device 52 is connected to the inflow section of the expander 51b of the expander-integrated compressor 51, and the low-temperature, high-pressure refrigerant cooled by the heat radiating device 52 is supplied to the expander 51b, where it is decompressed and expanded. Ru.

The refrigerant expanded under reduced pressure by the expander 51b is supplied to the pressure regulating valve 53, where the refrigerant supplied to the cooling pipes 22, 32, and 42 is set to a predetermined pressure. In this example, since the existing cooling piping is used, the refrigerant pressure (P _L ) will be 1.5 [kgf/cm ² ] (0.147 [MPa]) or less, taking into consideration the durability of the cooling piping, etc. Also, even if a pinhole is formed in the cooling piping 22, 32, 42, the lubricating oil in the bearing oil tank will not flow into the piping at 1.0 [kgf/cm ² ] (0.098 [ (1.0 [kgf/cm ² ]≦ _PL ≦1.5 [kgf/cm ² ]) (0.098 [MPa]≦ _PL ≦0.147 [MPa] ]).

An outgoing main pipe 100 is connected to the outflow side of the pressure regulating valve 53, and a refrigerant filling valve 55 for filling refrigerant is disposed in the middle of this outgoing main pipe 100.

The downstream side of the refrigerant filling valve 55 of the outbound main pipe 100 is branched into an upstream branch pipe 101a and an upstream branch pipe 102a by a branch part A, and the upstream branch pipe 101a is a cooling pipe accommodated in the upper bearing oil tank 12. 22, and the upstream branch pipe 102a is connected to a cooling pipe 32 housed in a lower bearing oil tank 31. Further, on the downstream side of the refrigerant filling valve 55 of the outgoing main pipe 100, an upstream branch pipe 103a is branched by a branch part B, and this upstream branch pipe 103a is connected to a cooling pipe 42 housed in a water turbine bearing oil tank 41. has been done.

The outlet side of the first cooling pipe 22 is connected to the downstream branch pipe 101b, the outlet side of the second cooling pipe 32 is connected to the downstream branch pipe 102b, and the outlet side of the third cooling pipe 42 is connected to the downstream branch pipe 101b. These downstream branch pipes 101b, 102b, and 103b are joined at merging portions C and D, and connected to the suction port of the compressor 51a via the return main pipe 104.
The check valve 54 is disposed downstream of the confluence D of the return main pipe 104, so that when the expander-integrated compressor 51 stops, the high-pressure refrigerant flowing back from the compressor 51a flows through each cooling pipe 22. , 32, and 42.

The upstream branch pipe 101a and the downstream branch pipe 101b constitute a parallel passage 101 in which the first cooling pipe 22 is disposed, and the upstream branch pipe 102a and the downstream branch pipe 102b constitute the second cooling pipe 32. The upstream branch pipe 103a and the downstream branch pipe 103b constitute a parallel passage 103 in which the third cooling pipe 42 is arranged. The integrated compressor 51 and the heat dissipation device 52 are connected in parallel to a pressure regulating valve 53, a check valve 54, and a refrigerant filling valve 55 in this example.

Therefore, the high-temperature, high-pressure refrigerant compressed by the compressor 51a is cooled by exchanging heat with the water flowing in the penstock 3 in the heat dissipation device 52 to become a low-temperature, high-pressure refrigerant, and after being expanded in the expander 51b, the pressure is adjusted. It becomes a low-temperature refrigerant at the desired pressure in the valve 53, and by exchanging heat with the lubricating oil in each bearing oil tank 21, 31, 41 in each cooling pipe 22, 32, 42 and absorbing heat, it becomes a high-temperature, low-pressure refrigerant, and reverse flow occurs. It is returned to the compressor 51a via the prevention valve 54.

Note that even if a pinhole is formed on the air cooler 15's piping surface, the oil will not be released into the oil. 56 or the like, and the water that has exchanged heat with the air that has passed through the air cooler 15 may be discharged to the outlet (discharge channel) of the suction pipe 5.

In the refrigerant circulation cycle 50 described above, a pressure sensor P1 that detects the pressure of the high-temperature and high-pressure refrigerant is provided at the discharge port of the compressor 51a or in the piping between the compressor 51a and the heat radiator 52, and the pressure sensor P1 detects the pressure of the high temperature and high pressure refrigerant. A pressure sensor P2 that detects the pressure of the low-temperature high-pressure refrigerant is installed in the piping between the machine 51b and the outgoing main pipe 100 on the downstream side of the pressure regulating valve 53. P3 is provided, and a pressure sensor P4 for detecting the pressure of the high temperature and low pressure refrigerant is provided in the return path main pipe 104 that is downstream of the suction port of the compressor 51a or each cooling pipe.

Further, the upper bearing oil tank 21 is provided with a temperature sensor T1 that detects the temperature of the upper bearing 20 or the temperature of the lubricating oil in the upper bearing oil tank 21, and the lower bearing oil tank 31 is provided with a temperature sensor T1 that detects the temperature of the upper bearing 20 or the temperature of the lubricating oil in the upper bearing oil tank 21. , a temperature sensor T2 that detects the temperature of the lubricating oil in the lower bearing oil tank 31 is provided, and a temperature sensor T3 that detects the temperature of the water turbine bearing 40 or the temperature of the lubricating oil in the water turbine bearing oil tank 41 is provided in the water turbine bearing oil tank 41. is provided.

These pressure sensors (P1 to P4) and temperature sensors (T1 to T3) are connected to the control unit 60, and the pressure data and temperature data detected by each sensor are taken into the control unit 60, processed as appropriate, and It is used as a guide for replenishing water, a guide for adjusting the pressure of the pressure regulating valve 53, etc.

In the above configuration, it is assumed that the cooling pipes 22, 32, 42 housed in each bearing oil tank 21, 31, 41 to cool the lubricating oil become thin due to long-term use, and pinholes occur on the pipe surface. Then, the refrigerant circulating in the cooling pipes 22, 32, and 42 is dry air, and although the pressure is reduced by the pressure regulating valve 53, it is pressurized above atmospheric pressure, and the expander Even if the compressor 51 is stopped, the pressurized state is maintained, so although refrigerant (air) may leak into the lubricant from the pinhole, the lubricant will not enter the cooling piping. There is no. Therefore, there is no problem that the compressor 51a compresses the liquid or that the lubrication performance deteriorates due to a decrease in the amount of oil.

Furthermore, even if the refrigerant leaks into the lubricating oil in the bearing oil tank through a pinhole, since dry air is used for the refrigerant, it will not remain in the oil and will simply be released from the oil surface into the atmosphere. There is no inconvenience that the lubricating oil level rises and an abnormality is detected, and there is no inconvenience that the lubricating oil deteriorates or is mixed in the lubricating oil and deteriorates the lubricating performance. Therefore, there is no need to immediately stop the refrigerant circulation cycle when a pinhole is formed.
Although there is a possibility that the amount of refrigerant in the cycle will decrease due to a refrigerant leak, it is possible to understand the decrease in the amount of refrigerant in the cycle by looking at changes in the refrigerant pressure in various parts of the cycle and the temperature of bearings, etc. There is no need to intentionally stop the cooling device as long as the cooling ability of the lubricating oil is not affected, and it is therefore possible to suppress unexpected costs associated with repairs.

During regular patrols, workers measure and monitor the refrigerant pressure on the high temperature high pressure side, low temperature high pressure side, low temperature low pressure side, and high temperature low pressure side of the refrigerant circulation cycle, and also measure the temperature of each bearing, etc. By monitoring the progress, if there is a tendency for the refrigerant pressure in the cycle to decrease and a tendency for the bearing temperature to increase, it is considered that the refrigerant is decreasing, so the refrigerant is Refill refrigerant.
At this time, since the refrigerant filling valve 55 is provided on the low-pressure path downstream of the pressure regulating valve 53, the refrigerant filling operation can be easily performed and the refrigerant can be filled safely.

In addition, in the cooling system mentioned above, it is also possible to automate to some extent. For example, in the control unit 60, as shown in FIG. 3, based on the pressure data taken in from the pressure sensors P1 to P4 and the temperature data taken in from the temperature sensors T1 to T3 (step 210), various parts of the cycle are controlled. It is determined whether the refrigerant pressure is decreasing and the temperature of the lubricating oil in each bearing or bearing oil tank is increasing (steps 220, 230). If it is determined that the temperature of the bearing or the lubricating oil in the bearing oil tank is on the rise, it may be determined that the refrigerant in the cycle has decreased to the extent that it requires replenishment, and a notification may be sent (a warning will be displayed on the control monitor). The information may be displayed or an alarm may be sounded: step 240).

Note that the amount of refrigerant to each cooling pipe is determined in advance by adjusting the pipe diameter of the parallel passage (branch pipe), and the amount of refrigerant is determined in advance by adjusting the pipe diameter of the parallel passage (branch pipe). In order to increase the amount of refrigerant supplied to the pipe 22, the pipe diameter of the parallel passage 101 is set to be larger than the other parallel passages 102 and 103, but each parallel passage has flow rate regulating valves 101c, 102c, 103c may be provided (indicated by a broken line in the figure), and the flow rate of the refrigerant flowing into each cooling pipe 22, 32, 42 may be finely adjusted by the flow rate adjustment valves 101c, 102c, and 103c.

Further, the pressure of the refrigerant supplied to the cooling pipes 22, 32, and 42 is adjusted in advance when the refrigerant circulation cycle 50 is assembled to the water turbine generator 1, but the refrigerant pressure downstream of the pressure regulating valve 53 is monitored. (by monitoring P3), within a predetermined pressure range (1.0 [kgf/cm ² ]≦P _L ≦1.5 [kgf/cm ² ]) (0.098 [MPa]≦P _L ≦0.147 [MPa]) It is also possible to automatically adjust the opening degree of the pressure regulating valve 53.

In the above configuration, the pressure regulating valve 53 is provided in the outgoing main pipe 100, and the refrigerant whose pressure is regulated by the pressure regulating valve is supplied to each of the parallel passages 101, 102, 103. In this configuration, the pressure and temperature of the refrigerant supplied to each parallel passage are the same in any parallel passage, so the variation in the amount of heat generated in each bearing is due to the amount of refrigerant supplied to the cooling pipes 22, 32, 42. This will be dealt with by adjustment. That is, the pipe diameters of the parallel passages (branch pipes) are adjusted in advance, or the flow rate adjustment valves 101c, 102c, and 103c are provided in each parallel passage to adjust the flow rate of each parallel passage. Therefore, the control range is limited because the pressure and temperature of the refrigerant supplied to each cooling pipe cannot be individually adjusted.

Therefore, as shown in FIG. 4, pressure regulating valves 53a, 53b, and 53c may be provided for each of the parallel passages, and the cooling capacity may be adjusted by adjusting the refrigerant pressure for each of the parallel passages. In such a configuration, it is possible to adjust the cooling capacity of each parallel passage using the respective pressure regulating valves 53a, 53b, and 53c, so that more fine-grained temperature control is possible than in the configuration shown in FIG. At the same time, it becomes possible to expand the control range.
Note that the refrigerant filling valve 55 is preferably provided on the downstream side of the pressure regulating valve on any of the parallel passages (in the figure, it is provided on the downstream side of the pressure regulating valve 53c of the parallel passage 103).

Furthermore, in the above configuration, the air is cooled by the air cooler 15 of the generator 10 by passing water through the air cooler 15, but in this configuration using a heat pump cycle, as shown in FIG. As shown in FIG. 2, a parallel passage 105 in which the air cooler 15 is arranged may be provided in the refrigerant circulation cycle 50, and the gas refrigerant may be provided in the air cooler 15. That is, the upstream branch pipe 105a is connected to the outgoing main pipe 100 via the branch E, the upstream branch pipe 105a is connected to the inflow part of the air cooler 15, and the downstream pipe is connected to the outflow part of the air cooler 15. The side branch pipe 105b is connected, and this downstream side branch pipe 105b is merged into the return main pipe 104 via the merging part F, and the gas refrigerant whose pressure is adjusted by the pressure adjustment valve 53d provided in the upstream side branch pipe 105a is supplied. It may also be supplied to the air cooler 15.
In such a configuration, there is no need for equipment to supply water to the air cooler 15, and the cooling air for the generator 10 can also be cooled using the same heat pump cycle. It becomes possible to simplify the device.

In addition, in the above example, a case was explained in which a gas refrigerant is supplied to cooling piping installed in the lubricating oil in order to cool the lubricating oil that lubricates the bearings of hydroelectric power generation equipment. A similar configuration can be adopted in other cooling devices that circulate refrigerant through provided cooling pipes.

1 Hydroelectric power generation equipment 2 Water turbine 6 Water turbine generator main shaft 10 Generator 20 Upper bearing 21 Upper bearing oil tank 22 First cooling pipe 30 Lower bearing 31 Lower bearing oil tank 32 Second cooling pipe 40 Water turbine bearing 41 Water turbine bearing oil tank 42 Third Cooling piping 50 Refrigerant circulation cycle 51 Expander-compressor integrated 51a Compressor 51b Expander 52 Heat dissipation device 53, 53a, 53b, 53c, 53d Pressure adjustment valve 54 Backflow prevention valve 55 Refrigerant filling valve 100 Outgoing main pipe 101, 102 , 103, 105 Parallel passage 104 Main pipe for return route

Claims (7)

A cooling device for power generation equipment equipped with a refrigerant circulation cycle that circulates a refrigerant through cooling piping arranged in the lubricating oil in order to cool the lubricating oil that lubricates the sliding parts of the power generation equipment,
The refrigerant is dry air,
The refrigerant circulation cycle includes an expander-integrated compressor in which a compressor that compresses the refrigerant and an expander that expands the refrigerant are coaxially connected,
the compressor; a heat radiator that radiates heat from the refrigerant compressed by the compressor; an expander that expands the refrigerant that has passed through the heat radiator; and a pressure regulating valve that adjusts the refrigerant pressure to a predetermined pressure range. A power generation device characterized in that the cooling piping that supplies the refrigerant whose pressure has been adjusted by the pressure regulating valve and the backflow prevention valve provided on the downstream side of the cooling piping are connected at least in this order. Equipment cooling system. The expander-integrated compressor is
motor and
the compressor connected to the output shaft of the motor and driven by the motor to compress the refrigerant;
the expander that is connected to the output shaft of the motor and expands the refrigerant and recovers the expansion energy generated at that time as power for the output shaft;
2. The cooling device for power generation equipment according to claim 1, further comprising: The power generation equipment is a water turbine generator in which a water turbine is provided below a generator, and the generator and the water turbine are rotatably supported by a main shaft,
The cooling pipe arranged in the lubricating oil is
A first cooling pipe disposed in lubricating oil supplied to an upper bearing that rotatably supports the main shaft above the generator, and a lower bearing that rotatably supports the main shaft below the generator. a second cooling pipe disposed in the lubricating oil supplied; and a third cooling pipe disposed in the lubricating oil supplied to the water turbine bearing provided below the lower bearing and above the water turbine. The cooling device for power generation equipment according to claim 1 or 2, characterized in that it has the following. The first cooling pipe, the second cooling pipe, and the third cooling pipe are provided on parallel passages connected in parallel to the compressor and the heat radiating device,
4. The cooling device for power generation equipment according to claim 3, wherein each of the parallel passages is provided with a flow rate adjustment valve that adjusts the flow rate of the refrigerant. The pressure regulating valve is disposed downstream of the expander in the refrigerant circulation cycle and upstream of a portion where the refrigerant is divided into the parallel passages, or is disposed on each of the parallel passages. 5. The cooling device for power generation equipment according to claim 4. 6. The cooling device for power generation equipment according to claim 1, further comprising a refrigerant filling valve provided downstream of the pressure regulating valve in the refrigerant circulation cycle. The generator includes a rotor fixed to a rotating shaft, a stator provided around the rotor, and a device provided around the stator to cool air circulating through the rotor and the stator. The cooling device for power generation equipment according to any one of claims 1 to 6, further comprising an air cooler having a pressure adjusted by the pressure regulating valve, wherein the refrigerant whose pressure is regulated by the pressure regulating valve is also circulated to the air cooler. .

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