Power generation system

Abstract

To provide a power generation system capable of effectively utilizing heat of compressed air.SOLUTION: A power generation system 10 has a plurality of compression tanks 12, 13, and a power generation device 76 that generates power with kinetic energy of water discharged from the plurality of compression tanks 12, 13. The power generation system 10 has a heat exchanger that generates water vapor by transferring heat of compressed air discharged from a compressor 14 to water, and a power generation device 100 that uses water vapor generated by the heat exchanger to generate power.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a power generation system that utilizes the kinetic energy of water and converts it into electrical energy using a generator.

Background Art

[0002] An example of a power generation system that utilizes the kinetic energy of water and converts it into electrical energy using a generator is described in Patent Document 1. The power generation device described in Patent Document 1 includes a cylinder filled with compressed air, a first water storage tank and a second water storage tank for storing water, a turbine for power generation, a pipe for supplying water in the first water storage tank to the inlet of the turbine, a pipe for supplying the water supplied from the second water storage tank to the turbine to the first water storage tank, a pipe for supplying the water in the second water storage tank to the inlet of the turbine, and a pipe for supplying the water supplied from the first water storage tank to the turbine to the second water storage tank. The power generation device described in Patent Document 1 supplies the compressed air in the cylinder to the first water storage tank or the second water storage tank by switching a switching valve, thereby pressurizing and ejecting the water in the first water storage tank and the water in the second water storage tank respectively, and rotating the turbine with the water to generate electricity.

[0003] In the power generation device described in Patent Document 1, a route switching valve that can switch the pressure feeding route of the compressed air from the cylinder to each water storage tank is provided, and the compressed air supplied from the cylinder is supplied to the air inlet at the upper part of the first water storage tank. Then, the water ejected from the first water storage tank is supplied to the turbine, and power generation is performed by the turbine. The water supplied from the first water storage tank to the turbine is discharged from the turbine and supplied to the turbine inlet of the second water storage tank. Therefore, the amount of water in the second water storage tank increases. When water is supplied to the turbine inlet of the second water storage tank, the air in the second water storage tank is discharged from the air vent valve.

[0004] When the water volume in the first water storage tank decreases, the switching valve is switched, and the compressed air supplied from the cylinder is supplied to the air inlet at the upper part of the second water storage tank. Then, the water ejected from the second water storage tank is supplied to the turbine, and power generation is performed by the turbine. The water supplied from the second water storage tank to the turbine is discharged from the turbine and supplied to the turbine inlet of the first water storage tank. For this reason, the water volume in the first water storage tank increases. When water is supplied to the turbine inlet of the first water storage tank, the air in the first water storage tank is discharged from the air vent valve. In this way, in the power generation device described in Patent Document 1, the compressed air in the cylinder is alternately supplied to the first water storage tank and the second water storage tank, and power generation is performed by the turbine with the water discharged from the first water storage tank and the second water storage tank.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The inventor of the present application recognized the problem that there is still room for improvement in the power generation device described in Patent Document 1 in terms of effectively utilizing the heat of compressed air.

[0007] An object of the present disclosure is to provide a power generation system capable of performing power generation by effectively utilizing the heat of compressed air.

Means for Solving the Problems

[0008] The present disclosure relates to a power generation system having: a plurality of compression tanks arranged in parallel with each other and discharging stored water pressurized by compressed air; a first power generation device that generates power using the kinetic energy of the water discharged from the plurality of compression tanks and discharges the water used for power generation. The power generation system further includes: a water storage pit for storing water to be supplied to the plurality of compression tanks; a first water passage for supplying the water discharged from a first compression tank among the plurality of compression tanks to the first power generation device; a second water passage for supplying the water stored in the water storage pit to a second compression tank that is not being supplied with water by the first power generation device when power generation is being performed by the first power generation device among the plurality of compression tanks; a compressor that inhales air and discharges compressed air; a first air passage for sending the air in the second compression tank to the compressor; a second air passage for sending the compressed air discharged from the compressor to the first compression tank; a third water passage for supplying the water discharged from the second compression tank to the first power generation device; a first valve for opening and closing the first water passage; a second valve for opening and closing the third water passage; a determination unit for determining the remaining amount of water that can be supplied from the first compression tank to the first power generation device; a first control unit for causing the first power generation device to generate power by supplying the water discharged from the first compression tank to the first power generation device via the first water passage; a second control unit for controlling the first valve to close the first water passage and controlling the second valve to open the second water passage when the remaining amount of water that can be supplied from the first compression tank to the first power generation device decreases to a predetermined amount while the water discharged from the first compression tank is being supplied to the first power generation device and power generation is being performed by the first power generation device; a fourth water passage through which the water discharged from the water storage pit passes; a heat exchanger for transferring the heat of the compressed air discharged from the compressor to the water passing through the fourth water passage to generate steam; and a second power generation device for generating power using the steam generated by the heat exchanger.

Effect of the Invention

[0009] According to the power generation system of the present disclosure, compressed air is discharged from a compressor that sucks in air in a first compression tank, and the compressed air can be supplied to a second compression tank. In addition, it is possible to effectively utilize the heat of the compressed air.

Brief Description of the Drawings

[0010]

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0011] (Summary) Several embodiments included in the power generation system will be described below with reference to the drawings. In the drawings for explaining the embodiments of the power generation system, the same components are denoted by the same reference numerals, and repeated explanations are omitted.

[0012] (First Embodiment) The power generation system 10 shown in FIG. 1A includes a water storage pit 11, a compression tank 12, a compression tank 13, a compressor 14, a waterwheel 15, a generator 16, and a control unit 17. The water storage pit 11 is a tank that stores water as a compressible fluid. The water storage pit 11 has a volume capable of simultaneously supplying water to the compression tank 12 and the compression tank 13 and storing a first predetermined amount of water in each of the compression tank 12 and the compression tank 13. The water storage pit 11 has a water inlet 18 and a drain outlet 19. The water inlet 18 is connected to a passage 20. The drain outlet 19 is connected to passages 21 and 22. The drain outlet 19 is provided at a position lower than the water inlet 18 in the direction of the action of gravity. The direction of the action of gravity is the vertical direction.

[0013] The compression tank 12 can store water and air and can pressurize and discharge the stored water. Both water and air are compressible fluids. Inside the compression tank 12, air accumulates in a region above the region where water accumulates in the direction of the action of gravity. The lower end of the water storage pit 11 is provided at a position higher than the upper end of the compression tank 12 in the direction of the action of gravity. The compression tank 12 has a water inlet 23, a drain outlet 24, an air inlet 25, an exhaust port 26, and a ventilation port 59. The water inlet 23 is connected to the passage 21, and a valve 27 is provided in the passage 21. The air inlet 25, the exhaust port 26, and the ventilation port 59 are provided at positions higher than the water inlet 23 and the drain outlet 24 in the direction of the action of gravity. A passage 60 is connected to the ventilation port 59, and a valve 61 for opening and closing the passage 60 is provided. The passage 60 is provided for discharging the air inside the compression tank 12 to the outside of the compression tank 12 when storing water in the compression tank 12. The valve 61 is, for example, an electromagnetic valve, and the operation of the valve 61 is electrically controlled.

[0014] The compression tank 13 can store water and air, and can pressurize and discharge the stored water. Inside the compression tank 13, air is stored in a region above the region where water is stored in the direction of the action of gravity. The lower end of the water storage pit 11 is provided at a position higher than the upper end of the compression tank 13 in the direction of the action of gravity. In the present disclosure, an example will be described in which the upper end of the compression tank 12 and the upper end of the compression tank 13 are provided at the same position, and the lower end of the compression tank 12 and the lower end of the compression tank 13 are provided at the same position in the direction of the action of gravity.

[0015] The compression tank 13 has a water inlet 28, a drain outlet 29, an air inlet 30, an exhaust port 31, and a ventilation port 62. The water inlet 28 is connected to the passage 22, and a valve 32 is provided in the passage 22. The air inlet 30, the exhaust port 31, and the ventilation port 62 are provided at positions higher than the water inlet 28 and the drain outlet 29 in the direction of the action of gravity. A passage 63 is connected to the ventilation port 62, and a valve 64 for opening and closing the passage 63 is provided. The passage 63 is provided for discharging the air in the compression tank 13 to the outside of the compression tank 13 when storing water in the compression tank 13. The valve 64 is, for example, an electromagnetic valve, and the operation of the valve 64 is electrically controlled.

[0016] The compressor 14 is an air machine that pressurizes the sucked air and discharges it as compressed air. The compressor 14 has an air inlet 33 and a discharge port 34. Further, an electric motor 35 for driving the compressor 14 is provided. The electric motor 35 is a prime mover that rotates when power is supplied. When the rotational speed of the electric motor 35 is controlled, the pressure of the compressed air discharged from the discharge port 34 of the compressor 14 is adjusted. When the electric motor 35 is stopped, the compressor 14 is stopped.

[0017] The intake port 33 of the compressor 14 is connected to the passage 36 and the passage 37. A valve 39 for connecting the passage 36 to the exhaust port 26 or the outside air intake passage 38 is provided. The valve 39 is, for example, an electromagnetic valve, and the operation of the valve 39 is electrically controlled. The passage 36 is connected to the exhaust port 31, and a valve 40 is provided in the passage 37. The valve 40 is, for example, an electromagnetic valve, and the operation of the valve 40 is electrically controlled.

[0018] The discharge port 34 of the compressor 14 is connected to the passages 41 and 42. The passage 41 is connected to the intake port 25 of the compression tank 12, and a valve 43 is provided in the passage 41. The valve 43 is, for example, an electromagnetic valve, and the operation of the valve 43 is electrically controlled. The passage 42 is connected to the intake port 30 of the compression tank 13, and a valve 44 is provided in the passage 42. The valve 44 is, for example, an electromagnetic valve, and the operation of the valve 44 is electrically controlled. The compressed air discharged from the compressor 14 passes through the passages 41 and 42.

[0019] The ventilation path 72 is constituted by the passages 36 and 41. The ventilation path 72 is constituted by the passages 37 and 42. The ventilation path 72 is connected to the intake port 33 and the discharge port 34 of the compressor 14. The ventilation path 73 is connected to the intake port 33 and the discharge port 34 of the compressor 14. The ventilation paths 72 and 73 are arranged in parallel with respect to the compressor 14.

[0020] The drain port 24 of the compression tank 12 is connected to the inlet 46 of the waterwheel 15 via the passage 45. A valve 47 is provided in the passage 45. The drain port 29 of the compression tank 13 is connected to the inlet 46 of the waterwheel 15 via the passage 48. A valve 49 is provided in the passage 48. The outlet 50 of the waterwheel 15 is connected to the water supply port 18 of the water storage pit 11 via the passage 20. The water passage 70 is constituted by the passage 21, the passage 45, and the compression tank 12. The water passage 71 is constituted by the passage 22, the passage 48, and the compression tank 13.

[0021] The waterwheel 15 has an inlet 46, an outlet 50, and a rotating shaft. The waterwheel 15 is a fluid machine that converts the kinetic energy of the water entering the inlet 46 into the mechanical energy of the rotating shaft. The waterwheel 15 may be any of a Francis waterwheel, a propeller waterwheel, a Pelton waterwheel, etc. The rotating shaft of the waterwheel 15 is connected to the rotor of the generator 16. The generator 16 may be either a DC generator or an AC generator. The generator 16 has, for example, a rotor, a stator, a permanent magnet attached to the stator, and a coil wound around the rotor. When the rotor rotates, an electric current flows through the coil according to the principle of electromagnetic induction.

[0022] In this way, the generator 16 converts the rotational energy (mechanical energy) applied to the rotor into electrical energy and outputs it. The waterwheel 15 and the generator 16 constitute a power generation device 76. All of the power generation device 76 is provided outside the compression tank 12 and outside the compression tank 13. FIG. 1A shows an example in which the power generation device 76 is provided at a position higher than the water supply port 18 of the water storage pit 11. The electric power generated by the generator 16 is supplied to the power supply destination 51. The power supply destination 51 includes a secondary battery, electrical equipment, etc. The secondary battery is a power storage device capable of charging and discharging. The electrical equipment is a device that consumes electric power to operate or function. The power of the secondary battery can be supplied to the electrical equipment. The electrical equipment supplied with power from the secondary battery may include an electric motor 35.

[0023] In addition, the power generation system 10 shown in FIG. 1A includes a power generation device 100, a pump 101, and a heat exchanger 102 as shown in FIG. 1B. Also, as shown in FIG. 2, a discharge amount sensor 201 is provided to detect the amount of water discharged from the pump 101 and output a signal. The power generation device 100, the pump 101, and the heat exchanger 102 are respectively provided corresponding to the compression tanks 12 and 13. In FIG. 1A, both power generation devices 100 are shown in an inclusive manner. The power generation device 100 includes a steam engine 103 and a generator 104. The pump 101 is driven (rotated) by, for example, an electric motor. When the pump 101 is driven, the pump 101 sucks water from the passages 21 and 22 and discharges the sucked water to the passage 105. The heat exchanger 102 serves as a steam generator that raises the temperature of the water in the passage 105, that is, boils it to generate steam, by transferring the heat of the compressed air supplied from the compressor 14 to the compression tanks 12 and 13 to the water in the passage 105.

[0024] The steam generated in the heat exchanger 102 is at high temperature and high pressure, and the steam is sent to the steam engine 103 via the passage 106. The steam engine 103 includes, for example, a steam turbine and a steam engine. The steam turbine is a device that ejects and expands high-temperature and high-pressure steam through a nozzle or a fixed blade, or changes the direction to generate a high-speed steam flow, and sprays the steam flow onto the blades attached to the rotating shaft to rotate the rotating shaft. A reciprocating steam engine, which is an example of a steam engine, has a configuration in which steam is inhaled and exhausted into a cylinder to reciprocate a piston in the cylinder, and a rotating shaft connected to the piston via a crankshaft is rotated. The steam engine may be a turbine-type steam engine. Note that the steam whose temperature and pressure have decreased in the steam engine 103 is sent to the water storage pit 11 through the passage 107.

[0025] The generator 104 is connected to the rotating shaft of the steam engine 103 so as to be able to transmit power. The configuration and function of the generator 104 are the same as those of the generator 16. The electric power generated by the generator 104 is supplied to the power supply destination 51.

[0026] Figure 2 shows the control system of the power generation system 10. The power generation system 10 has a computer 200, and the computer 200 has a control unit 52, a storage unit 53, an operation unit 74, and a display unit 75. The control unit 52 can also be defined as a control circuit or a processing circuit. The control unit 52 has an input port, an output port, a timer for measuring the elapsed time, a central processing unit, etc. Further, a water volume sensor 54 that detects the water volume in the water storage pit 11 and outputs a signal, a water volume sensor 55 that detects the water volume in the compression tank 12 and outputs a signal, and a water volume sensor 56 that detects the water volume in the compression tank 13 and outputs a signal are provided. Also, a flow rate sensor 57 that detects the flow rate of the water supplied to the inlet 46 of the waterwheel 15 and outputs a signal is provided. Further, an air pressure sensor 65 that detects the air pressure in the compression tank 12 and outputs a signal, and an air pressure sensor 66 that detects the air pressure in the compression tank 13 and outputs a signal are provided. Further, a water pressure sensor 108 that detects the water pressure in the compression tank 12 and outputs a signal, and a water pressure sensor 109 that detects the water pressure in the compression tank 13 and outputs a signal are provided.

[0027] Furthermore, the control unit 52 is connected to the operation unit 74 and the display unit 75. The operation unit 74 is operated by an operator. The operator can operate the operation unit 74 to input information, data, conditions, etc. used in the power generation system 10. The operation unit 74 includes a mouse, a keyboard, a scanner, a liquid crystal panel, etc. The control unit 52 stores the information and data input by the operation of the operation unit 74 in the storage unit 53. The display unit 75 is, for example, a liquid crystal monitor, and the operator can visually observe the display unit 75. The display unit 75 can display the air pressure detected by the air pressure sensors 65, 66, the flow rate detected by the flow rate sensor 57, the water volume detected by the water volume sensors 54, 55, 56, the water pressure detected by the water pressure sensors 108, 109, etc. Further, the control unit 52 is connected to the power supply destination 51, and performs a process of determining the required power at the power supply destination 51 by processing the signal from the power supply destination 51. When the power supply destination 51 includes a secondary battery, the control unit 52 performs a process of determining the voltage of the secondary battery.

[0028] Furthermore, a storage unit 53 is connected to the control unit 52. The storage unit 53 stores information and data input by operations of the operation unit 74, and information used for processes, judgments, etc. performed by the control unit 52, conditions for determining the rotation and stop of the pump 101, non-temporary programs, etc. The control unit 52 reads and activates a non-temporary program, and based on the operation content of the operation unit 74, signals from the water volume sensors 54, 55, 56, signals from the flow rate sensor 57, signals from the air pressure sensors 65, 66, signals from the water pressure sensors 108, 109, signals from the discharge amount sensor 201, the determination result of the required power, the voltage of the secondary battery, information stored in the storage unit 53, conditions for determining the rotation and stop of the pump 101, etc., it can control the power generation amounts of the generators 16, 104, the rotation speed of the electric motor 35, the opening and closing of the valves 27, 32, 39, 40, 43, 44, 49, 61, 64 respectively, the rotation and stop of the pump 101, etc.

[0029] The valves 27, 32, 47, 49 are, for example, solenoid valves, and the operations of the valves 27, 32, 47, 49 are controlled by the control unit 52. In addition to being valves that open and close passages, the valves 27, 32, 47, 49 may be flow control valves that control the flow rate of water. That is, the control unit 52 can control the flow rate of water supplied from the water storage pit 11 to the compression tank 12 by controlling the valve 27. Also, the control unit 52 can control the flow rate of water discharged from the compression tank 12 by controlling the valve 47. Also, the control unit 52 can control the flow rate of water supplied from the water storage pit 11 to the compression tank 13 by controlling the valve 32. Also, the control unit 52 can control the flow rate of water discharged from the compression tank 13 by controlling the valve 49.

[0030] As shown in Fig. 1A, in the power generation system 10, two water flow paths 70 and 71 are arranged in parallel between the drain port 19 of the water storage pit 11 and the inlet 46 of the waterwheel 15. One compression tank 12 is arranged in the water flow path 70, and one compression tank 13 is arranged in the water flow path 71. Also, two air flow paths 72 and 73 are connected in parallel to the intake port 33 and the discharge port 34 of the compressor 14. The compression tank 12 is arranged in the air flow path 72, and the compression tank 13 is arranged in the air flow path 73.

[0031] (Example of process performed in the power generation system) The control example, that is, the process example performed in the power generation system 10 of the present disclosure is as follows. For convenience, first, an example will be described in which the water stored in the compression tank 12 is supplied to the waterwheel 15 to generate power with the generator 16, and when the water volume in the compression tank 12 decreases, the water stored in the compression tank 13 is supplied to the waterwheel 15 to generate power with the generator 16.

[0032] [First step] In the first step, the control unit 52 controls the power generation system 10 as follows. In the first step, the control unit 52 supplies the water in the water storage pit 11 to the compression tank 12 and the compression tank 13. The valve 27 shown in Fig. 1A opens the passage 21, and the valve 47 closes the passage 45. Also, the valve 32 opens the passage 22, and the valve 49 closes the passage 48. Further, the valve 39 connects the outside air intake passage 38 and the intake port 33 of the compressor 14, and blocks the passage 36 and the intake port 33. Also, the valve 40 closes the passage 37. Further, the valve 43 opens the passage 41, and the valve 44 closes the passage 42. Further, the valve 61 opens the passage 60, and the valve 64 opens the passage 63.

[0033] As shown in Fig. 1A, the water in the water storage pit 11 is supplied into the compression tank 12 through the passage 21 by gravity, and the amount of water in the compression tank 12 increases. Also, the amount of water in the water storage pit 11 decreases. The pressure of the water supplied into the compression tank 12 is determined based on the pressure obtained by multiplying the planar area and the water level of the water storage pit 11, and the pressure corresponding to the potential energy due to the height difference between the drain port 19 and the water supply port 23. In this way, in the process of storing the water in the water storage pit 11 into the compression tank 12, the air in the compression tank 12 is discharged to the outside of the compression tank 12 through the ventilation port 59.

[0034] Also, the water in the water storage pit 11 is supplied into the compression tank 13 through the passage 22 by gravity, and the amount of water in the compression tank 13 increases. The pressure of the water supplied into the compression tank 13 is determined based on the pressure obtained by multiplying the planar area and the water level of the water storage pit 11, and the pressure corresponding to the potential energy due to the height difference between the drain port 19 and the water supply port 28. In this way, in the process of storing the water in the water storage pit 11 into the compression tank 13, the air in the compression tank 13 is discharged to the outside of the compression tank 13 through the ventilation port 62. Then, when the control unit 52 detects that the amount of water in the compression tank 12 and the compression tank 13 has increased to the first predetermined amount respectively, it shifts to the second step.

[0035] [Second Step] In the second step, the control unit 52 controls the valve 61 shown in FIG. 1A to close the passage 60 and controls the valve 27 to close the passage 21. Further, the control unit 52 controls the valve 39 to connect the outside air intake passage 38 and the intake port 33 of the compressor 14 and to block the exhaust port 26 of the compression tank 12 and the intake port 33. Furthermore, the control unit 52 rotates the electric motor 35 to drive the compressor 14. Then, as shown in FIG. 3A, the air existing outside the compression tank 12 and the compression tank 13, that is, the outside air, is sucked into the intake port 33 of the compressor 14 through the outside air intake passage 38. The air sucked into the compressor 14 is at atmospheric pressure (1 atm = 1013.25 Pa). The compressor 14 compresses the sucked air and discharges the compressed air from the discharge port 34. The compressed air discharged from the discharge port 34 is supplied into the compression tank 12 from the intake port 25. Therefore, the air pressure in the compression tank 12 rises. When the control unit 52 detects that the air pressure in the compression tank 12 has risen to the first predetermined pressure, it proceeds to the third step.

[0036] [Third Step] In the third step, the control unit 52 controls the valve 47 shown in FIG. 1A to connect the drain port 24 and the inlet 46 of the waterwheel 15. Then, as shown in FIG. 3A, the water in the compression tank 12 is discharged from the drain port 24 by the air pressure in the compression tank 12, and the amount of water in the compression tank 12 decreases. Also, the electric motor 35 is being driven, and the compressed air discharged from the compressor 14 is being supplied into the compression tank 12. The water drained from the compression tank 12 is supplied to the inlet 46 of the waterwheel 15.

[0037] For this reason, the rotating shaft of the waterwheel 15 rotates and power generation is performed by the generator 16, and the electric power generated by the generator 16 is sent to the power supply destination 51. The control unit 52 controls the output of the generator 16 based on the required power determined by the required power determination unit 58, the information stored in the storage unit 53, and the data. Furthermore, the water discharged from the outlet 50 of the waterwheel 15 is sent to the water storage pit 11 through the passage 20. When the air pressure in the compression tank 12 drops to the second predetermined pressure, the control unit 52 proceeds to the fourth step.

[0038] [Fourth Step] In the fourth step, the control unit 52 controls the valve 47 shown in FIG. 1A to block the drain port 24 of the compression tank 12 and the water turbine 15. Also, the control unit 52 controls the valve 27 to open the passage 21. Thus, as shown in FIG. 3B, the water in the water storage pit 11 is supplied to the compression tank 12, and the amount of water in the compression tank 12 increases. Also, the control unit 52 controls the valve 64 to close the passage 63, and controls the valve 44 to connect the discharge port 34 of the compressor 14 and the intake port 30 of the compression tank 13. Further, the control unit 52 controls the valve 39 to connect the exhaust port 26 of the compression tank 12 and the intake port 33 of the compressor 14, and blocks the outside air intake passage 38 and the intake port 33. Further, the control unit 52 controls the valve 40 to block the intake port 33 and the exhaust port 31. Thus, the air in the compression tank 12 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 13. Further, the control unit 52 controls the valve 49 to connect the compression tank 13 and the water turbine 15.

[0039] Then, as shown in FIG. 3B, the water discharged from the compression tank 13 is supplied to the water turbine 15, and power generation is performed by the generator 16. The electric power generated by the generator 16 is sent to the power supply destination 51. The control unit 52 controls the output of the generator 16 based on the required power determined by the required power determination unit 58, the information stored in the storage unit 53, and the data. Further, the water discharged from the outlet 50 of the water turbine 15 is sent to the water storage pit 11. When water is discharged from the compression tank 13 and power generation is performed by the generator 16, and the air pressure in the compression tank 13 drops to the second predetermined pressure, and the air pressure in the compression tank 12 rises to the first predetermined pressure, the control unit 52 proceeds to the fifth step.

[0040] [Fifth Step] In the fifth step, the control unit 52 controls the valve 27 to close the passage 21. Then, the water in the water storage pit 11 is no longer supplied to the compression tank 12. Also, the control unit 52 closes the valve 49 shown in FIG. 1A to cut off the compression tank 13 and the water turbine 15. Further, the control unit 52 closes the valve 49. Therefore, as shown in FIG. 4A, no water is discharged from the compression tank 13. Furthermore, the control unit 52 opens the valve 32 to supply the water in the water storage pit 11 to the compression tank 13. For this reason, the amount of water in the compression tank 13 increases.

[0041] Also, the control unit 52 controls the valve 40 to connect the exhaust port 31 and the intake port 33. Further, the control unit 52 controls the valve 44 to cut off the passage 42. Furthermore, the control unit 52 controls the valve 39 to cut off the intake port 33 and the exhaust port 26, and to cut off the intake port 33 and the outside air intake passage 38. Furthermore, the control unit 52 controls the valve 43 to connect the discharge port 34 and the intake port 25. Then, as shown in FIG. 4A, the air in the compression tank 13 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 12. Further, the control unit 52 controls the valve 47 shown in FIG. 1A to connect the drain port 24 of the compression tank 12 and the inlet 46 of the water turbine 15. For this reason, the water discharged from the compression tank 12 is supplied to the water turbine 15, and power generation is performed by the generator 16.

[0042] Also, the water discharged from the outlet 50 of the water turbine 15 is supplied to the water storage pit 11. When the air pressure in the compression tank 12 drops to the second predetermined pressure and the air pressure in the compression tank 13 rises to the first predetermined pressure, the control unit 52 proceeds to the fourth step described above. Thereafter, by alternately repeating the fourth step and the fifth step, power generation by the generator 16 continues, that is, power generation is continuously performed.

[0043] Note that instead of controlling various valves based on the air pressure in the compression tank 12 and the air pressure in the compression tank 13 and executing the first to fifth steps, the control unit 52 can also control various valves based on the amount of water in the compression tank 12 and the amount of water in the compression tank 13 and execute the first to fifth steps.

[0044] Specifically, in the first step, when the control unit 52 detects that the water levels in the compression tanks 12 and 13 have increased to the first predetermined amounts respectively, it can shift from the first step to the second step. Also, in the fourth step, when water is discharged from the compression tank 13 and power generation is being performed by the generator 16, and the water level in the compression tank 13 has decreased to the second predetermined amount, and the water level in the compression tank 12 has increased to the first predetermined amount, the control unit 52 can shift from the fourth step to the fifth step. In the fifth step, when the water level in the compression tank 12 has decreased to the second predetermined amount, and the water level in the compression tank 13 has increased to the first predetermined amount, the control unit 52 proceeds to the aforementioned fourth step. The first predetermined amount exceeds the second predetermined amount.

[0045] Furthermore, instead of controlling various valves based on the air pressures in the compression tanks 12 and 13 and executing the first to fifth steps, the control unit 52 can also control various valves based on the water pressures in the compression tanks 12 and 13 and execute the first to fifth steps.

[0046] Specifically, in the first step, when the control unit 52 detects that the water pressures in the compression tanks 12 and 13 have risen to the first predetermined pressures respectively, it can shift from the first step to the second step. Also, in the fourth step, when water is discharged from the compression tank 13 and power generation is being performed by the generator 16, and the water pressure in the compression tank 13 has dropped to the second predetermined pressure, and the water level in the compression tank 12 has risen to the first predetermined pressure, the control unit 52 can shift from the fourth step to the fifth step. In the fifth step, when the water pressure in the compression tank 12 has dropped to the second predetermined pressure, and the water pressure in the compression tank 13 has risen to the first predetermined pressure, the control unit 52 proceeds to the aforementioned fourth step. The first predetermined pressure exceeds the second predetermined pressure.

[0047] The control unit 52 of the present disclosure can directly determine the remaining amount of water that can be supplied from each compression tank 12, 13 to the waterwheel 15 from the signals of the water volume sensors 55, 56. Further, the control unit 52 can indirectly determine the remaining amount of water that can be supplied from each compression tank 12, 13 to the waterwheel 15 from the signals of the air pressure sensors 65, 66. The higher the air pressure detected by the air pressure sensors 65, 66, the relatively larger the remaining amount of water that can be supplied to the waterwheel 15. Further, the control unit 52 can indirectly determine the remaining amount of water that can be supplied from each compression tank 12, 13 to the waterwheel 15 from the signals of the water pressure sensors 108, 109. The higher the water pressure detected by the water pressure sensors 108, 109, the relatively larger the remaining amount of water that can be supplied to the waterwheel 15.

[0048] The storage unit 53 stores information that can directly determine the remaining amount of water that can be supplied from the compression tanks 12, 13 to the waterwheel 15 by processing the signals of the water volume sensors 55, 56. Further, the storage unit 53 stores information that can indirectly determine the remaining amount of water that can be supplied from the compression tanks 12, 13 to the waterwheel 15 by processing the signals of the air pressure sensors 65, 66. Furthermore, the storage unit 53 stores information that can indirectly determine the remaining amount of water that can be supplied from the compression tanks 12, 13 to the waterwheel 15 by processing the signals of the water pressure sensors 108, 109.

[0049] (Effect of the First Embodiment) The power generation system 10 can pressurize the air sucked from inside the compression tank 12 with the compressor 14 and supply it to the compression tank 13. Further, the power generation system 10 can pressurize the air sucked from inside the compression tank 13 with the compressor 14 and supply it to the compression tank 12. That is, in the second step and subsequent steps, the power generation system 10 can effectively utilize the compressed air by circulating and pressurizing the air in the compressor 14, the compression tank 12, and the compression tank 13 without newly sucking in air at atmospheric pressure from the outside into the compressor 14. Therefore, in the compressor 14, the time for pressurizing the air from atmospheric pressure to generate compressed air can be shortened, and the compression efficiency of the compressor 14 is improved.

[0050] In addition, the power generation device 76 of the power generation system 10 can convert the kinetic energy of water into the mechanical energy of the waterwheel 15, and the generator 16 can convert the mechanical energy into electrical energy. Further, a water storage pit 11 is provided for storing the water supplied to the power generation device 76 before returning it to the compression tank 12 or the compression tank 13 which is the discharge source of the water. The water storage pit 11 is provided at a position higher than the compression tank 12 and the compression tank 13 in the direction of the action of gravity. Therefore, the water in the water storage pit 11 is sent to the compression tank 12 and the compression tank 13 by the potential energy corresponding to its own weight and height. Thus, it is not necessary to provide a power source for sending the water in the water storage pit 11 to the compression tank 12 and the compression tank 13.

[0051] Also, since the water passage 70 and the water passage 71 are provided in parallel, the water in the water storage pit 11 can be surely distributed to the compression tank 12 and the compression tank 13. Further, since the ventilation passage 72 and the ventilation passage 73 are provided in parallel, the air sucked from one of the compression tanks can be compressed by the compressor 14 and surely supplied to the other compression tank. Further, all of the power generation device 76 is provided outside the compression tank 12 and the compression tank 13. Therefore, it is possible to suppress the supply of water and air to the compression tank 12 from being inhibited, and it is possible to suppress the supply of water and air to the compression tank 13 from being inhibited.

[0052] Furthermore, when the valves 27, 49 each have a function as a flow control valve, in the fourth step, by controlling the flow rate of the water supplied to the compression tank 12 and the flow rate of the water discharged from the compression tank 13, the timing when the water volume in the compression tank 12 increases to the first predetermined amount and the timing when the water volume in the compression tank 13 decreases to the second predetermined amount can be made to substantially coincide. Therefore, in the process of the control unit 52 switching from the fourth step to the fifth step, it is possible to suppress a temporary decrease in the water volume supplied to the waterwheel 15 and to suppress a decrease in the power generation function by the generator 16.

[0053] Also, when valves 32 and 47 each have a function as a flow control valve, in the fifth step, by controlling the flow rate of water supplied to the compression tank 13 and the flow rate of water discharged from the compression tank 12, the timing at which the water volume in the compression tank 13 increases to a first predetermined amount and the timing at which the water volume in the compression tank 12 decreases to a second predetermined amount can be made to substantially coincide. Therefore, when the control unit 52 switches from the fifth step to the fourth step, it is possible to suppress a temporary decrease in the amount of water supplied to the waterwheel 15 and suppress a decrease in the power generation function of the generator 16.

[0054] Furthermore, when the pump 101 of the power generation device 100 shown in FIG. 1B is driven, in the heat exchanger 102, the heat of the compressed air discharged from the compressor 14 is transferred to the water discharged from the pump 101. For this reason, the temperature of the compressed air discharged from the compressor 14 decreases, and the volume expands as it is sent to the compression tanks 12 and 13. Therefore, in the process where the air in the compression tanks 12 and 13 is sucked into the compressor 14 again and compressed, the compression efficiency can be increased.

[0055] On the other hand, the water discharged from the pump 101 has its temperature raised by the heat of the compressed air in the heat exchanger 102 and boils, generating steam. The steam is sent to the steam engine 103, and power generation is performed by the generator 104. In this way, power generation can be performed by effectively using the heat of the compressed air discharged from the compressor 14. Also, the steam coming out of the steam engine 103 has a lower temperature and a lower pressure. The steam is sent to the water storage pit 11 and is cooled by the water in the water storage pit 11, or returns to its original volume in the water storage pit 11 and is cooled by cold air and liquefies.

[0056] Furthermore, the power generation system 10 of the present disclosure can efficiently cool the steam when returning it to water. Also, since it takes away the heat of the compressed air, the air becomes cold air when it expands, and this air is used to cool the steam, thereby increasing the power generation efficiency. Note that, for example, the control unit 52 continues the operation of the pump 101 while the valve 39 provided in the outside air intake passage 38 is open. Further, the control unit 52 stops the pump 101, for example, while the valve 39 is closed. Furthermore, in the power generation system 10 having the power generation device 130 shown in FIG. 1C, the control unit 52 may perform control to stop the pump 101 even if the valve 39 is open when a predetermined time has elapsed since the start of the operation of the pump 101. The storage unit 53 stores a predetermined time used for the control to close the valve 39. Furthermore, in the power generation system 10 having the power generation device 130 shown in FIG. 1C, the control unit 52 may perform control to stop the pump 101 even if the valve 39 is open when the discharge amount of the pump 101 reaches a predetermined discharge amount from the time when the operation of the pump 101 is started. The storage unit 53 stores a predetermined discharge amount of the pump 101 used for the control to close the valve 39. The air discharge amount per predetermined time of the compressor 14 shown in FIG. 1C is constant, and the water storage amount of the compression tank 120 is constant. However, when these controls are performed, it is possible to prevent water exceeding the water storage amount of the compression tank 120 from being supplied to the compression tank 123. In addition, a proximity switch for detecting the open / closed state of the valve 39 is provided. When the control unit 52 controls the opening and closing of the valve 39 using the signal of the proximity switch, if the proximity switch fails, it may affect the driving and stopping of the pump 101. On the other hand, when the control unit 52 stops the pump 101 based on the predetermined time or the predetermined discharge amount stored in the storage unit 53, it is possible to avoid the pump 101 being driven with the valve 39 closed.

[0057] (Second Embodiment) The second embodiment of the power generation system is shown in FIGS. 2 and 5A. In the second embodiment of the power generation system 10, components having the same configuration as those in the first embodiment of the power generation system 10 are denoted by the same reference numerals as in the first embodiment of the power generation system 10. The second embodiment of the power generation system 10 has a compression tank 80 in addition to the compression tanks 12 and 13. The basic configuration and function of the compression tank 80 are the same as those of the compression tanks 12 and 13. A passage 81 for supplying the water in the water storage pit 11 to the compression tank 80 is provided, and as shown in FIG. 2, a valve 82 for opening and closing the passage 81 is provided.

[0058] Also, a passage 83 for sending the water in the compression tank 80 to the inlet 46 of the waterwheel 15 is provided. A valve 84 shown in FIG. 2 is provided in the passage 83. The valves 82 and 84 are, for example, solenoid valves, and the valves 82 and 84 are each controlled by the control unit 52. When the valve 82 opens the passage 81, the water in the water storage pit 11 is supplied to the compression tank 80. When the valve 82 closes the passage 81, the water in the water storage pit 11 is not supplied to the compression tank 80. When the valve 84 opens the passage 83, the water discharged from the compression tank 80 is sent to the waterwheel 15. When the valve 84 closes the passage 83, the water in the compression tank 80 is not sent to the waterwheel 15.

[0059] Furthermore, a passage 85 for sending the air in the compression tank 80 to the intake port 33 of the compressor 14 is provided. Furthermore, a passage 86 for supplying the compressed air discharged from the compressor 14 to the compression tank 80 is provided. A valve 87 shown in FIG. 2 is provided in the passage 85, and a valve 88 for opening and closing the passage 86 is provided. The valves 87 and 88 are, for example, solenoid valves, and the valves 87 and 88 are each controlled by the control unit 52. When the valve 87 opens the passage 85, the air in the compression tank 80 is sucked into and compressed by the compressor 14. When the valve 87 closes the passage 85, the air in the compression tank 80 is not sucked into the compressor 14. When the valve 88 opens the passage 86, the compressed air discharged from the compressor 14 is supplied to the compression tank 80. When the valve 88 closes the passage 86, the compressed air of the compressor 14 is not supplied to the compression tank 80.

[0060] In addition to being valves that open and close passages, valves 82 and 84 may also be flow control valves that control the flow rate of water. That is, the control unit 52 can control the flow rate of water supplied from the water storage pit 11 to the compression tank 80 by controlling valve 82. Further, the control unit 52 can control the flow rate of water sent from the compression tank 80 to the waterwheel 15 by controlling valve 84. Furthermore, a valve 89 is provided that opens and closes a passage for discharging the air in the compression tank 80 to the atmosphere. Valve 89 is, for example, a solenoid valve, and valve 89 is controlled by the control unit 52. A water volume sensor 90 is provided that detects the water volume in the compression tank 80 and outputs a signal. An air pressure sensor 91 is provided that detects the air pressure in the compression tank 80 and outputs a signal. A water pressure sensor 110 is provided that detects the water pressure in the compression tank 80 and outputs a signal.

[0061] Also, the power generation system 10 shown in FIG. 5A has the power generation device 100 shown in FIG. 1B. The heat exchanger 102 serves as a steam generator that raises the temperature of the water in passage 105, that is, boils it to generate steam, by transferring the heat of the compressed air supplied from the compressor 14 to the compression tank 80 to the water in passage 105. Also, the pump 101 sucks in a part of the water sent from the water storage pit 11 to passage 81 and discharges it to passage 105.

[0062] The control system shown in FIG. 2 can also be applied to the second embodiment of the power generation system 10. The control unit 52 processes the signals of the water volume sensors 54, 55, 56, 90, the signal of the water pressure sensor 110, the signals of the air pressure sensors 65, 66, 91, and the signal of the discharge amount sensor 201, and based on the information, data, etc. stored in the storage unit 53, can control valves 27, 32, 39, 40, 43, 44, 49, 61, 64, 82, 84, 87, 88, 89, and can control the electric motor 35.

[0063] In the second embodiment of the power generation system 10, the compression tanks 12, 13, 80 are arranged in parallel with respect to the water storage pit 11. Further, the compression tanks 12, 13, 80 are arranged in parallel with respect to the waterwheel 15. Furthermore, the compression tanks 12, 13, 80 are arranged in parallel with respect to the compressor 14. Further, a water passage 92 is formed by the passage 81, the passage 83, and the compression tank 80. And the water passages 70, 71, 92 are arranged in parallel.

[0064] (Example of process performed in the power generation system) The control example, that is, the process example performed in the second embodiment of the power generation system 10 is as follows. For convenience, first, the water stored in the compression tank 12 is supplied to the waterwheel 15 to generate power with the generator 16. Next, the water stored in the compression tank 13 is supplied to the waterwheel 15 to generate power with the generator 16. After that, an example in which the water stored in the compression tank 80 is supplied to the waterwheel 15 to generate power with the generator 16 will be described.

[0065] [Step 11] In the 11th step, the control unit 52 performs the same control on the power generation system 10 as in the first step, and stores water from the water storage pit 11 into the compression tank 12 and the compression tank 13 as shown in FIG. 5A. When the control unit 52 detects that the air pressure in the compression tank 12 and the air pressure in the compression tank 13 have each risen to the first predetermined pressure, it shifts to the 12th step.

[0066] [Step 12] The control unit 52 closes the passages 21 and 22 and opens the passage 81 in the 12th step. Also, the control unit 52 opens the passages 41 and 85 and rotates the electric motor 35 to drive the compressor 14. Then, as shown in FIG. 5B, the water in the water storage pit 11 is supplied to the compression tank 80, and the water volume in the compression tank 80 increases. Also, the air in the compression tank 80 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 12. Further, the water discharged from the compression tank 12 is sent to the waterwheel 15, and power generation is performed by the generator 16. When the control unit 52 detects that the air pressure in the compression tank 12 has dropped to the second predetermined pressure and the air pressure in the compression tank 80 has risen to the first predetermined pressure, it proceeds to the 13th step.

[0067] [13th step] In the 13th step, the control unit 52 opens the passages 21 and 48 and closes the passages 45 and 81. Also, the control unit 52 opens the passages 36 and 42 and closes the passages 41 and 85. For this reason, as shown in FIG. 6A, the water in the water storage pit 11 is supplied to the compression tank 12, and the water volume in the compression tank 12 increases. Also, the air in the compression tank 12 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 13. Further, the water discharged from the compression tank 13 is sent to the waterwheel 15, and power generation is performed by the generator 16. When the control unit 52 detects that the air pressure in the compression tank 13 has dropped to the second predetermined pressure and the air pressure in the compression tank 12 has risen to the first predetermined pressure, it proceeds to the 14th step.

[0068] [14th step] In the 14th step, the control unit 52 opens passages 22 and 83 and closes passages 21 and 48. Also, the control unit 52 opens passages 37 and 86 and closes passages 36 and 42. For this reason, as shown in Fig. 6B, the water in the water storage pit 11 is supplied to the compression tank 13, and the amount of water in the compression tank 13 increases. Also, the air in the compression tank 13 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 80. Further, the water discharged from the compression tank 80 is sent to the waterwheel 15, and power generation is performed by the generator 16. When the control unit 52 detects that the air pressure in the compression tank 80 has dropped to the second predetermined pressure and the air pressure in the compression tank 13 has risen to the first predetermined pressure, it proceeds to the 15th step.

[0069] [15th step] In the 15th step, the control unit 52 opens passages 45 and 81 and closes passages 22 and 83. Also, the control unit 52 opens passages 41 and 85 and closes passages 37 and 86. For this reason, as shown in Fig. 7, the water in the water storage pit 11 is supplied to the compression tank 80, and the amount of water in the compression tank 80 increases. Also, the air in the compression tank 80 is sucked into the compressor 14 and compressed, and the compressed air discharged from the compressor 14 is supplied to the compression tank 12. Further, the water discharged from the compression tank 12 is sent to the waterwheel 15, and power generation is performed by the generator 16. When the control unit 52 detects that the air pressure in the compression tank 12 has dropped to the second predetermined pressure and the air pressure in the compression tank 80 has risen to the first predetermined pressure, it proceeds to the 13th step. Thereafter, by repeating the 13th step, 14th step, and 15th step, power generation by the generator 16 continues, that is, is continuously performed.

[0070] Note that instead of controlling various valves based on the air pressures of the compression tanks 12, 13, and 80 and executing the 11th to 15th steps, the control unit 52 can also control various valves based on the water amounts in the compression tanks 12, 13, and 80 and execute the 11th to 15th steps.

[0071] Specifically, in the 11th step, when the control unit 52 detects that the water volume in the compression tank 12 and the water volume in the compression tank 13 have each increased to the first predetermined amount, it proceeds to the 12th step. Also, in the 12th step, when the control unit 52 detects that the water volume in the compression tank 12 has decreased to the second predetermined amount and the water volume in the compression tank 80 has increased to the first predetermined amount, it proceeds to the 13th step. In the 13th step, when the control unit 52 detects that the water volume in the compression tank 13 has decreased to the second predetermined amount and the water volume in the compression tank 12 has increased to the first predetermined amount, it proceeds to the 14th step. In the 14th step, when the control unit 52 detects that the water volume in the compression tank 80 has decreased to the second predetermined amount and the water volume in the compression tank 13 has increased to the first predetermined amount, it proceeds to the 15th step. In the 15th step, when the control unit 52 detects that the water volume in the compression tank 12 has decreased to the second predetermined amount and the water volume in the compression tank 80 has increased to the first predetermined amount, it proceeds to the 13th step.

[0072] Furthermore, when the valves 27, 32, 47, 49, 82, and 84 each have a function as a flow control valve, by controlling the flow rate of water supplied to the compression tanks 12, 13, and 80 respectively, and the flow rate of water discharged from the compression tanks 12, 13, and 80 respectively, it is possible to substantially match the timing when the water volume in the compression tanks 12, 13, and 80 increases to the first predetermined amount and the timing when the water volume in the compression tanks 12, 13, and 80 decreases to the second predetermined amount. Therefore, it is possible to suppress a temporary decrease in the water volume supplied to the waterwheel 15 and suppress a decrease in the power generation function by the generator 16.

[0073] Furthermore, instead of controlling various valves based on the air pressure in the compression tank 80 and executing the 11th to 55th steps, the control unit 52 can also control various valves based on the water pressure in the compression tank 80 and execute the 11th to 15th steps.

[0074] Specifically, in the 11th step, when the control unit 52 detects that the water pressure in the compression tank 80 has risen to the first predetermined pressure respectively, it can shift from the 11th step to the 12th step. Also, in the 14th step, when water is discharged from the compression tank 80 and power generation is performed by the generator 16, and the water pressure in the compression tank 13 has dropped to the second predetermined pressure, and the water volume in the compression tank 12 has risen to the first predetermined pressure, the control unit 52 can shift from the 14th step to the 15th step. In the 15th step, when the water pressure in the compression tank 12 has dropped to the second predetermined pressure and the water pressure in the compression tank 13 has risen to the first predetermined pressure, the control unit 52 proceeds to the 14th step described above. The first predetermined pressure exceeds the second predetermined pressure.

[0075] The control unit 52 of the present disclosure can directly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 based on the signal of the water volume sensor 90. Also, the control unit 52 can indirectly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 based on the signal of the air pressure sensor 91. The higher the air pressure detected by the air pressure sensor 91, the relatively more the remaining amount of water that can be supplied to the waterwheel 15. Further, the control unit 52 can indirectly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 based on the signal of the water pressure sensor 110. The higher the water pressure detected by the water pressure sensor 110, the relatively more the remaining amount of water that can be supplied to the waterwheel 15.

[0076] In the storage unit 53, information is stored that allows the control unit 52 to directly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 by processing the signal of the water volume sensor 90. In the storage unit 53, information is stored that allows the control unit 52 to indirectly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 by processing the signal of the air pressure sensor 91. Furthermore, in the storage unit 53, information is stored that allows the control unit 52 to indirectly determine the remaining amount of water that can be supplied from the compression tank 80 to the waterwheel 15 by processing the signal of the water pressure sensor 110.

[0077] Furthermore, the temperature of the compressed air discharged from the compressor 14 decreases, and it is sent to the compression tank 80 where its volume expands. Therefore, in the process where the air in the compression tank 80 is sucked into the compressor 14 again and compressed, the compression efficiency can be increased. Note that the control unit 52 drives the pump 101 at the timing described above, and the control unit 52 stops the pump 101 at a timing different from the above.

[0078] (Another example of the power generation device) Another example of the power generation device is shown in FIG. 1C. The power generation device 130 shown in FIG. 1C includes a compression tank 120, a waterwheel 121, and a generator 104. Also, a pump 101 and a heat exchanger 102 are provided. The compression tank 120 can store water and air, and can pressurize and discharge the stored water. The drain port 19 of the water storage pit 11 is connected to the compression tank 120 via a passage 122. The heat exchanger 102 is connected to the compression tank 120. The drain port of the compression tank 120 is connected to the inlet of the waterwheel 121 via a passage 124.

[0079] The waterwheel 121 is a fluid machine that converts the kinetic energy of the water entering the inlet into the mechanical energy of the rotating shaft. The waterwheel 121 may be any of a Francis waterwheel, a propeller waterwheel, a Pelton waterwheel, etc. The rotating shaft of the waterwheel 121 is connected to the rotor of the generator 104. When the rotating shaft of the waterwheel 121 rotates, the generator 104 generates electricity. The water exiting from the outlet of the waterwheel 121 is sent to the water storage pit 11 through a passage 107.

[0080] The operation example of the power generation device 130 in FIG. 1C is as follows. The high-temperature and high-pressure steam discharged from the heat exchanger 102 is sent to the compression tank 120. The steam sent to the compression tank 120 is cooled by the water in the compression tank 120, and its temperature and pressure decrease. The waterwheel 121 is rotated by the water discharged from the compression tank 120, and power generation is performed by the generator 104. The water discharged from the outlet of the waterwheel 121 is sent to the water storage pit 11 through the passage 107. Therefore, the power generation system 10 having the power generation device 130 in FIG. 1C can generate power by effectively using the heat of the compressed air discharged from the compressor 14.

[0081] (Third Embodiment) FIG. 8 shows a third embodiment of the power generation system. The third embodiment of the power generation system 10 includes a plurality of, for example, three sets of compression systems C1, C2, C3, and a plurality of, for example, two sets of plants P1, P2. The compression systems C1, C2, C3 each include the electric motor 35 and the compressor 14 shown in FIG. 2. That is, the power generation system 10 includes a plurality of electric motors 35 and a plurality of compressors 14. The plants P1, P2 each include the water storage pit 11 shown in FIG. 1A, the power generation device 76 shown in FIG. 2, the power supply destination 51, the air pressure sensors 65, 66, 91, the water volume sensors 54, 55, 56, 90, the flow rate sensor 57, and the valves 27, 32, 39, 40, 43, 44, 61, 64, 49, 82, 84, 87, 88, 89. The control unit 52 controls the plants P1, P2 and the compression systems C1, C2, C3.

[0082] When the compression systems C1, C2, C3 are each driven, the compression systems C1, C2, C3 can each suck air from the plant P1 and supply the compressed air discharged from the compression systems C1, C2, C3 to the plant P1 respectively. Also, when the compression systems C1, C2, C3 are each driven, the compression systems C1, C2, C3 can each suck air from the plant P2 and supply the compressed air discharged from the compression systems C1, C2, C3 to the plant P2 respectively.

[0083] In the third embodiment of the power generation system 10, as modes for the control unit 52 to control the power generation system 10, the first mode, the second mode, and the third mode can be switched and selected. When the first mode for controlling the power generation system 10 is selected, as shown in the upper part of FIG. 8, the compression systems C1 and C2 are driven and the compression system C3 is stopped. When the second mode for controlling the power generation system 10 is selected, as shown in the middle part of FIG. 8, the compression systems C1 and C3 are driven and the compression system C2 is stopped. When the third mode for controlling the power generation system 10 is selected, as shown in the lower part of FIG. 8, the compression systems C2 and C3 are driven and the compression system C1 is stopped.

[0084] Then, when a predetermined time, for example, 4 hours, has elapsed since the control unit 52 selects the first mode, the control unit 52 can switch from the first mode to the second mode. Also, when a predetermined time, for example, 4 hours, has elapsed since the control unit 52 selects the second mode, the control unit 52 can switch from the second mode to the third mode. Further, when a predetermined time, for example, 4 hours, has elapsed since the control unit 52 selects the third mode, the control unit 52 can switch from the third mode to the first mode. Thus, the control unit 52 can alternately switch and select the first mode, the second mode, and the third mode. Then, the three sets of compression systems C1, C2, and C3 are each intermittently driven and stopped. When the control unit 52 alternately switches the first mode, the second mode, and the third mode, the three sets of compression systems C1, C2, and C3 are each driven for 8 hours and each stopped for 4 hours in a repeating state. Therefore, power generation can always be performed in the plants P1 and P2, and maintenance of the compression systems that are stopped can be carried out.

[0085] (Included control example) The flowchart of FIG. 4B comprehensively shows an example of control performed in the power generation system 10. In step S20, the control unit 52 reads and activates a non-temporary program, and processes input signals, information, data, etc. In step S21, the control unit 52 can control the plants P1 and P2 respectively, or can control the various valves 27, 32, 39, 40, 43, 44, 49, 61, 64, 82, 84, 87, 88, 89 separately. In step S22, the control unit 52 can control the compression systems C1, C2, C3 respectively, or can control the electric motor 35 and the pump 101. In step S23, the control unit 52 controls the plants P1 and P2 respectively, or controls the generator 16 alone, and ends the control example of FIG. 4B. Note that the order in which the control unit 52 executes steps S20, S21, S22, and S23 is not limited.

[0086] (Supplementary Explanation) This embodiment is not limited to what is disclosed using the drawings, and various modifications can be made without departing from the gist thereof. For example, the second predetermined pressure used by the control unit 52 for control is the lower limit pressure at which power generation can be performed by the generator 16 when the water discharged from the compression tank is supplied to the waterwheel 15. The first predetermined pressure and the second predetermined pressure are higher than the atmospheric pressure, and the first predetermined pressure is higher than the second predetermined pressure. The first predetermined pressure and the second predetermined pressure are stored in the storage unit 53. The second predetermined quantity used by the control unit 52 for control is the lower limit water quantity at which power generation can be performed by the generator 16 when the water discharged from the compression tank is supplied to the waterwheel 15. The first predetermined quantity is more than the second predetermined quantity, and the first predetermined quantity and the second predetermined quantity are stored in the storage unit 53.

[0087] Instead of shifting from the currently executing process to another process based on the air pressure or water quantity in each compression tank, the control unit 52 can measure the elapsed time since the start of any process using a timer, and when the elapsed time reaches or exceeds a predetermined time, shift to another process. The predetermined time used by the control unit 52 for switching between processes is stored in the storage unit 53.

[0088] Also, each valve disclosed in this embodiment may be structured to be manually operable, and an operator may manually operate to switch the opening and closing of each valve. Note that the waterwheel 15 shown in FIG. 1A may be of a type that can ensure the pressure for the water discharged from the outlet 50 to reach the water inlet 18 of the water storage pit 11 through the passage 20, and the power generation device 76 may be provided at a position lower than the water inlet 18 of the water storage pit 11.

[0089] An example of the technical meaning of the matters described in this embodiment is as follows. The power generation system 10 is an example of a power generation system, the power generation device 76 is an example of a first power generation device, and the power generation devices 100 and 130 are each an example of a second power generation device. The heat exchanger 102 is an example of a heat exchanger. The generator 104 is an example of a generator. The compression tanks 12, 13, and 80 are examples of a plurality of compression tanks. The compression tanks 12, 13, and 80 may each correspond to a first compression tank and a second compression tank. The water storage pit 11 is an example of a water storage pit. The compressor 14 is an example of a compressor. The passages 45, 48, and 83 may each correspond to a first water passage. The passages 21, 22, and 81 may each correspond to a second water passage. The passages 45 and 48 may correspond to a third water passage. The passage 105 may correspond to a fourth water passage.

[0090] The passages 36, 37, and 85 may correspond to a first air passage. The passages 41, 42, and 86 may correspond to a second air passage. The valves 47, 49, and 84 may correspond to a first valve. The valves 47, 49, and 84 may correspond to a second valve. The control unit 52 is an example of a first control unit, a second control unit, a determination unit, and a pump control unit. The compression tank 120 is an example of a water storage tank. The waterwheel 121 is an example of a waterwheel. The steam engine 103 is an example of a steam engine. The pump 101 is an example of a pump.

Industrial Applicability

[0091] The present disclosure can be used as a power generation system that converts the kinetic energy of water into electrical energy.

Explanation of Reference Numerals

[0092] 10…Power generation system, 11…Water storage pit, 12, 13, 80…Compression tank, 14…Compressor, 20, 21, 22, 36, 37, 41, 42, 61, 64, 48, 81, 83, 85, 86…Passage, 47, 49, 84…Valve, 52…Control unit, 76, 100, 130…Power generation device, 101…Pump, 102…Heat exchanger, 103…Steam engine, 104…Generator, 121…Waterwheel

Claims

1. A plurality of compression tanks arranged in parallel with each other and pressurizing and discharging stored water with compressed air; A first power generation device that generates electricity using the kinetic energy of the water discharged from the plurality of compression tanks and discharges the water used for power generation; A power generation system comprising: A water storage pit for storing water supplied to the plurality of compression tanks; A first water passage for supplying the water discharged from the first compression tank among the plurality of compression tanks to the first power generation device; A second water passage for supplying the water stored in the water storage pit to a second compression tank that is not supplying water to the first power generation device among the plurality of compression tanks when power generation is being performed by the first power generation device; A compressor that inhales air and discharges compressed air; A first ventilation passage for sending the air in the second compression tank to the compressor; A second ventilation passage for sending the compressed air discharged from the compressor to the first compression tank; A third water passage for supplying the water discharged from the second compression tank to the first power generation device; A first valve for opening and closing the first water passage; A second valve for opening and closing the third water passage; A determination unit for determining the remaining amount of water that can be supplied from the first compression tank to the first power generation device; A first control unit for causing the first power generation device to generate electricity by supplying the water discharged from the first compression tank to the first power generation device via the first water passage; A second control unit that, when the remaining amount of water that can be supplied from the first compression tank to the first power generation device decreases to a predetermined amount while the water discharged from the first compression tank is being supplied to the first power generation device and power generation is being performed by the first power generation device, controls the first valve to close the first water passage and controls the second valve to open the second water passage; A fourth water passage through which the water discharged from the water storage pit passes; A heat exchanger that transfers the heat of the compressed air discharged from the compressor to the water passing through the fourth water passage to generate water vapor; A second power generation device that generates electricity using the water vapor generated by the heat exchanger; A power generation system comprising the above.

2. The power generation system according to Claim 1, wherein the second power generation device comprises a steam engine rotated by the kinetic energy of the water vapor generated by the heat exchanger, and a generator that converts the rotational energy of the steam engine into electrical energy. A power generation system comprising the above.

3. The power generation system according to Claim 1, wherein the second power generation device A water storage tank that is supplied with water vapor generated by the heat exchanger and stores water supplied from the water storage pit; A waterwheel rotated by the kinetic energy of the water discharged from the water storage tank; A generator that converts the rotational energy of the waterwheel into electrical energy; A power generation system comprising the above.

4. The power generation system according to claim 1, further comprising: A pump that sucks water from the water storage pit and discharges it into the fourth water passage; A pump control unit that controls the driving and stopping of the pump; A power generation system comprising the above.

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