WO2019035344A1 - Power generation device - Google Patents

Abstract

This power generation device (100) is provided with: first and second energy conversion units (10a, 10b); first and second pumps (20a, 20b); a first main accumulator (50a); a second main accumulator (50b) having a capacity smaller than a predetermined capacity of the first main accumulator (50a); a first unload relief valve (60a); a second unload relief valve (60b) which opens when a working fluid stored in the second main accumulator (50b) reaches a predetermined pressure in a shorter amount of time than a working fluid stored in the first main accumulator (50b) reaches said predetermined pressure; a first pressure reducing valve (70a); a second pressure reducing valve (70b) which reduces the pressure of the working fluid guided from the second unload relief valve (60b) to the same pressure value as a predetermined pressure value reduced by the first pressure reducing valve (70a); and a motor (30) which is driven by the working fluid guided from a junction passage (3) and drives a power generator (40).

Description

Power generator

The present invention relates to a power generator.

Power generation using renewable energy is drawing attention as a countermeasure against environmental problems such as depletion of fossil fuels and global warming. JP2013-181433A discloses a power generation device that generates power using wave power. This power generation apparatus is driven by a floating body that is shaken by waves, a conversion mechanism that converts movement of the floating body into rotational motion, a pump that is driven by a rotational force extracted via the conversion mechanism, and hydraulic fluid discharged from the pump And a motor. The motor is connected to a generator, and the generator is driven by driving the motor.

In addition, the power generation device disclosed in JP2013-181433A further includes an accumulator for storing the hydraulic oil discharged by the pump. The accumulator supplies the stored hydraulic fluid to the motor when the wave height is small and the flow rate of the hydraulic fluid discharged from the pump is small. As a result, the motor can be driven at a desired number of revolutions, and a desired amount of power generation can be obtained.

In the power generation device disclosed in JP2013-181433A, when the wave height is long, the hydraulic oil stored in the accumulator decreases, and the hydraulic oil supply from the accumulator to the motor stops. In this case, the hydraulic fluid discharged from the pump needs to be stored in the accumulator, and the hydraulic fluid can not be supplied to the motor. Therefore, the motor can not be driven continuously, making stable power generation difficult.

An object of the present invention is to generate electric power stably using renewable energy.

According to the present embodiment, the power generation apparatus is connected to the first and second energy conversion units that convert renewable energy into mechanical energy, and the first energy conversion unit, and is driven by the first energy conversion unit. A first pump that discharges a working fluid, a second pump connected to the second energy conversion unit, which is driven by the second energy conversion unit to discharge the working fluid, and has a predetermined volume, the first pump A first main accumulator for storing a working fluid discharged from the pump, and a second main accumulator having a capacity smaller than a predetermined capacity of the first main accumulator and storing a working fluid discharged from the second pump; The working fluid stored downstream of the first pump and the first main accumulator and stored in the first main accumulator reaches a predetermined pressure The working fluid connected to the downstream side of the first unload relief valve, which is opened downstream of the second pump and the second main accumulator, and stored in the second main accumulator is stored in the first main accumulator A second unload relief valve which opens and reaches a predetermined pressure in a time shorter than the time for the working fluid to reach a predetermined pressure, and connected downstream of the first unload relief valve, from the first unload relief valve The first pressure reducing valve for reducing the pressure of the working fluid to be led to a predetermined pressure value, and the first pressure reducing valve connected to the downstream of the second unloading relief valve and working fluid led from the second unloading relief valve A second pressure reducing valve that reduces the pressure to the same pressure value as the predetermined pressure value to be reduced, the working fluid that has been reduced to the predetermined pressure value by the first pressure reducing valve, and the second pressure reducing And a motor for driving a generator is driven by hydraulic fluid directed from the confluent passage merges the working fluid has been depressurized to a predetermined pressure value by.

FIG. 1 is a circuit diagram of a power generation device according to an embodiment of the present invention. FIG. 2A is a graph showing changes in pressure of the working fluid in the first and second main accumulators. FIG. 2B is a graph showing the change in the total flow rate of the working fluid in the first and second supply passages. FIG. 2C is a graph showing changes in pressure of the working fluid in the sub-accumulator. FIG. 2D is a graph showing changes in the flow rate of the working fluid supplied to the motor.

Hereinafter, a power generation device 100 according to an embodiment of the present invention will be described with reference to the attached drawings.

First, the structure of the power generation device 100 will be described with reference to FIG.

As shown in FIG. 1, the power generation apparatus 100 includes first and second water turbines 10a and 10b as first and second energy conversion units for converting renewable energy into mechanical energy, and first and second water turbines 10a, 10b, The first and second pumps 20a and 20b connected to 10b are provided. The first and second water wheels 10a and 10b have a shaft 11 rotatably supported and a wing 12 provided on the outer periphery of the shaft 11, and are installed on the shore of the sea, a river or a lake . When the wing portion 12 receives a wave, the first and second water wheels 10a and 10b rotate around the shaft portion 11 in one direction. Thus, the first and second water turbines 10a and 10b convert wave energy as renewable energy into rotational energy as mechanical energy.

The rotational energy obtained by the first and second water wheels 10a and 10b is transmitted to the first and second pumps 20a and 20b via the first and second input shafts 21a and 21b. The first and second pumps 20 a and 20 b are rotationally driven by the transmitted rotational energy, and suck up and discharge the hydraulic oil stored in the storage unit 1.

The hydraulic oil discharged from the first pump 20 a is supplied to the motor 30 through the first supply passage 2 a and the merging passage 3 to drive the motor 30. Similarly, the hydraulic oil discharged from the second pump 20 b is supplied to the motor 30 through the second supply passage 2 b and the merging passage 3 to drive the motor 30. The output shaft 31 of the motor 30 is connected to the generator 40, and the generator 30 is driven by the motor 30 to generate power.

Thus, the power generation device 100 generates power using the energy of waves.

Further, the power generation apparatus 100 includes a first branch passage 4a branched from the first supply passage 2a, a first main accumulator 50a provided in the first branch passage 4a, and a first unload relief provided in the first supply passage 2a. And a valve 60a. The first branch passage 4a branches from the upstream of the first unload relief valve 60a in the first supply passage 2a.

The first main accumulator 50a is provided with an oil chamber 51a communicating with the first branch passage 4a and an air chamber 52a separated from the oil chamber 51a. The oil chamber 51a stores hydraulic oil discharged from the first pump 20a and guided through the first branch passage 4a. A gas such as nitrogen gas is sealed in the air chamber 52a. The gas sealed in the air chamber 52a is not limited to nitrogen gas, and may be another gas such as air. Further, the first main accumulator 50a may be formed to be able to adjust the amount of gas sealed in the air chamber 52a.

The air chamber 52a expands and contracts according to the amount of hydraulic fluid in the oil chamber 51a, and changes the pressure of the hydraulic fluid in the oil chamber 51a. Specifically, when the hydraulic oil flows into the oil chamber 51a and the hydraulic oil in the oil chamber 51a increases, the air chamber 52a shrinks. At this time, the gas in the air chamber 52a is compressed, and the pressure of the gas rises. As a result, the pressure of the hydraulic oil in the oil chamber 51a rises. When the hydraulic oil is released from the oil chamber 51a and the hydraulic oil in the oil chamber 51a decreases, the air chamber 52a expands. At this time, the gas in the air chamber 52a expands and the pressure of the gas decreases. As a result, the pressure of the hydraulic oil in the oil chamber 51a decreases. The sum of the volume of the oil chamber 51a and the volume of the air chamber 52a corresponds to the "volume" of the first main accumulator 50a.

As described above, the first main accumulator 50a has a predetermined volume, stores the hydraulic oil discharged from the first pump 20a, and at the same time, stores the pressure of the hydraulic oil stored according to the increase in the storage volume of the hydraulic oil. Raise it. Then, when the pressure of the hydraulic fluid in the first supply passage 2a is lower than the pressure of the hydraulic fluid in the first main accumulator 50a, the first main accumulator 50a discharges the hydraulic fluid and the first supply passage 2a. Supply hydraulic oil to

A first check valve 22a is provided upstream of the first branch passage 4a in the first supply passage 2a to allow only the flow of hydraulic oil from the first pump 20a to the first main accumulator 50a. Since the first check valve 22a blocks the flow of hydraulic oil from the first main accumulator 50a to the first pump 20a, the hydraulic oil in the first main accumulator 50a flows back to the reservoir 1 through the first pump 20a. You can prevent.

Further, the first relief passage 5a is connected upstream of the first unload relief valve 60a in the first supply passage 2a, and the first relief passage 23 is provided with a first relief valve 23a as a safety valve. The pressure in the first supply passage 2a can be prevented from exceeding the set pressure of the first relief valve 23a by the first relief valve 23a.

The first unload relief valve 60a is driven according to the pressure of the hydraulic fluid in the first main accumulator 50a.

Specifically, when the pressure of the hydraulic fluid in the first main accumulator 50a rises to a predetermined cutout pressure, the first unload relief valve 60a is opened, and the hydraulic fluid flowing from the first pump 20a to the motor 30 is Allow the flow. At this time, when the pressure in the first supply passage 2a is lower than the pressure of the hydraulic fluid in the first main accumulator 50a, the hydraulic fluid is supplied from the first main accumulator 50a to the first supply passage 2a. That is, in addition to the hydraulic fluid discharged from the first pump 20a, the hydraulic fluid discharged from the first main accumulator 50a is supplied to the motor 30, and the motor 30 is driven. As the hydraulic fluid in the first main accumulator 50a decreases, the pressure of the hydraulic fluid in the first main accumulator 50a decreases.

When the pressure of the hydraulic oil in the first main accumulator 50a decreases to a predetermined cut-in pressure lower than the cutout pressure, the first unload relief valve 60a closes, and the hydraulic oil directed from the first pump 20a to the motor 30 Block the flow of At this time, the hydraulic oil discharged from the first pump 20a is led to the first main accumulator 50a and stored in the first main accumulator 50a. As the hydraulic oil in the first main accumulator 50a increases, the pressure of the hydraulic oil in the first main accumulator 50a increases.

Thus, the first unload relief valve 60a is driven according to the pressure of the hydraulic fluid in the first main accumulator 50a, and controls the flow of hydraulic fluid in the first supply passage 2a. Therefore, it is possible to prevent the hydraulic oil from being supplied from the first main accumulator 50a to the motor 30 in a state where a sufficient amount of hydraulic oil is not stored in the first main accumulator 50a.

Further, the power generation device 100 includes the second branch passage 4b, the second main accumulator 50b, the second unload relief valve 60b, the second check valve 22b, the second relief passage 5b, and the second relief valve 23b. And. The structure of the second main accumulator 50b is substantially the same as the structure of the first main accumulator 50a except for the capacity. The structure of the second unload relief valve 60b is substantially the same as the structure of the first unload relief valve 60a, and the cut-in pressure and the cut-out pressure are also the same. Therefore, the description is omitted here. Further, the functions of the second check valve 22b, the second relief passage 5b and the second relief valve 23b are substantially the same as the functions of the first check valve 22a, the first relief passage 5a and the first relief valve 23a. , I omit their explanation here. The sum of the volume of the oil chamber 51b and the volume of the air chamber 52b in the second main accumulator 50b corresponds to the "volume" of the second main accumulator 50b.

The second main accumulator 50b has a smaller capacity than the predetermined capacity of the first main accumulator 50a. Therefore, when the first and second pumps 20a, 20b are driven under substantially the same conditions with the first and second unload relief valves 60a, 60b closed, the pressure of the hydraulic oil in the second main accumulator 50b Increases faster than the pressure of the hydraulic fluid in the first main accumulator 50a. The second unload relief valve 60b reaches the cut-out pressure in a time shorter than the time for the hydraulic oil stored in the second main accumulator 50b to reach the cutout pressure of the hydraulic oil stored in the first main accumulator 50a Open.

In other words, the pressure of the hydraulic fluid in the first and second main accumulators 50a, 50b rises to the cut-out pressure of the first and second unload relief valves 60a, 60b at different timings and falls to the cut-in pressure. . Therefore, the first and second unload relief valves 60a and 60b open and close at different timings. Therefore, the hydraulic oil can be supplied to the motor 30 from the other while storing the hydraulic oil in one of the first and second main accumulators 50a, 50b.

In addition, the power generation device 100 is provided downstream of the first pressure reducing valve 70a provided downstream of the first unload relief valve 60a in the first supply passage 2a and downstream of the second unload relief valve 60b in the second supply passage 2b. And a second pressure reducing valve 70b. The first pressure reducing valve 70 a reduces the hydraulic oil in the first supply passage 2 a to a predetermined pressure value. The second pressure reducing valve 70 b reduces the hydraulic oil in the second supply passage 2 b to the same pressure value as the predetermined pressure value reduced by the first pressure reducing valve 70 a. Therefore, even if the pressure of the hydraulic oil in the first and second main accumulators 50a, 50b is different, the pressure downstream of the first and second pressure reducing valves 70a, 70b in the first and second supply passages 2a, 2b is substantially It will be the same. Therefore, when the first and second unload relief valves 60a and 60b are opened, it is possible to prevent the hydraulic oil from being led from one of the first and second supply passages 2a and 2b to the other. It is possible to reduce the fluctuation of the flow rate of hydraulic oil led to 3. As a result, the motor 30 can be stably driven, and stable power generation becomes possible.

Third, between the first unloading relief valve 60a and the first pressure reducing valve 70a in the first supply passage 2a, only the flow of hydraulic fluid from the first unloading relief valve 60a to the first pressure reducing valve 70a is permitted A check valve 24a is provided. Since the third check valve 24a shuts off the flow of hydraulic fluid from the first pressure reducing valve 70a to the first unloading relief valve 60a, the first unloading pressure relief valve 60a is opened from the first pressure reducing valve 70a when the first unloading relief valve 60a is opened. It is possible to prevent the hydraulic oil from flowing back to the main accumulator 50a.

Similarly, between the second unloading relief valve 60b and the second pressure reducing valve 70b in the second supply passage 2b, only the flow of hydraulic oil from the second unloading relief valve 60b toward the second pressure reducing valve 70b is permitted. A fourth check valve 24b is provided. The fourth check valve 24b can prevent hydraulic fluid from flowing back from the second pressure reducing valve 70b to the second main accumulator 50b when the second unloading relief valve 60b is opened.

The merging passage 3 is provided with a flow control valve 80 for controlling the flow rate of hydraulic oil to a constant value. The flow rate control valve 80 adjusts the flow rate of the hydraulic oil in the merging passage 3 to a predetermined set flow rate. Therefore, the hydraulic fluid can be supplied to the motor 30 at a predetermined flow rate, and the rotational speed of the motor 30 can be stabilized to enable stable power generation.

A sub accumulator 90 is provided upstream of the flow control valve 80 in the merging passage 3 via a branch passage 91. The sub accumulator 90 stores the hydraulic oil led from the first and second supply passages 2 a and 2 b and supplies the stored hydraulic oil to the merging passage 3. Specifically, when the flow rate of the hydraulic oil in the first and second supply passages 2a and 2b exceeds the set flow rate of the flow control valve 80, the sub-accumulator 90 stores the surplus hydraulic oil. When the flow rate of the hydraulic oil in the first and second supply passages 2 a and 2 b is smaller than the set flow rate of the flow control valve 80, the sub accumulator 90 supplies the hydraulic oil to the flow control valve 80. Therefore, the hydraulic oil can be supplied to the motor 30 at a constant flow rate, and stable power generation becomes possible.

Next, the operation of the power generation device 100 will be described with reference to FIGS. 1 to 2D. Here, it is assumed that hydraulic oil is not stored in the first and second main accumulators 50a and 50b and the sub-accumulator 90 at time T0 when the first and second pumps 20a and 20b start operating. Moreover, after time T0, the first and second pumps 20a and 20b operate under the same condition. The cut-out pressures of the first and second unload relief valves 60a and 60b are set to a value P1, and the cut-in pressure is set to a value P2. The flow rate Q1 of hydraulic fluid led from the first pump 20a and the first main accumulator 50a to the first unload relief valve 60a when the first unload relief valve 60a is open substantially matches the set flow rate Q0 of the flow control valve 80. It shall be. In addition, the flow rate Q2 of hydraulic fluid led from the second pump 20b and the second main accumulator 50b to the second unload relief valve 60b when the second unload relief valve 60b is opened is the set flow rate Q0 of the flow control valve 80. It is assumed that it substantially matches.

At time T0, since the hydraulic oil is not stored in the first main accumulator 50a, the pressure of the hydraulic oil in the first main accumulator 50a is lower than the cut-in pressure P2 of the first unload relief valve 60a. Therefore, the first unload relief valve 60a is closed to shut off the flow of hydraulic fluid. Therefore, the hydraulic oil discharged from the first pump 20a is stored in the first main accumulator 50a. As the hydraulic oil stored in the first main accumulator 50a increases, the pressure of the hydraulic oil in the first main accumulator 50a increases.

Similar to the first main accumulator 50a, at time T0, no hydraulic oil is stored in the second main accumulator 50b, so the pressure of the hydraulic oil in the second main accumulator 50b is equal to that of the second unload relief valve 60b. Lower than cut-in pressure P2. Therefore, the second unload relief valve 60b is closed, and the hydraulic oil discharged from the second pump 20b is stored in the second main accumulator 50b. As the hydraulic oil stored in the second main accumulator 50b increases, the pressure of the hydraulic oil in the second main accumulator 50b increases. Since the capacity of the second main accumulator 50b is smaller than the capacity of the first main accumulator 50a, the pressure of the hydraulic fluid in the second main accumulator 50b rises faster than the pressure of the hydraulic fluid in the first main accumulator 50a. .

The time T1 is the time when the pressure of the hydraulic fluid in the second main accumulator 50b rises to the cut-out pressure P1 of the second unload relief valve 60b. At time T1, the pressure of the hydraulic fluid in the first main accumulator 50a has not risen to the cut-out pressure P1 of the first unload relief valve 60a.

From time T0 to time T1, the pressure of the hydraulic fluid in the first and second main accumulators 50a and 50b is lower than the cut-out pressure P1 of the first and second unload relief valves 60a and 60b. Therefore, the first and second unload relief valves 60a and 60b maintain the closed state and shut off the flow of hydraulic oil. Therefore, no hydraulic oil is supplied to the motor 30 from any of the first and second pumps 20a and 20b and the first and second main accumulators 50a and 50b.

Also, no hydraulic oil is stored in the sub accumulator 90 at time T0. Therefore, the hydraulic fluid is not released from sub accumulator 90 from time T0 to time T1. Therefore, no hydraulic oil is supplied to the motor 30 from the sub accumulator 90 as well.

Thus, from time T0 to time T1, no hydraulic oil is supplied to the motor 30 from any of the first and second pumps 20a, 20b, the first and second main accumulators 50a, 50b, and the sub-accumulator 90. . Therefore, the generator 40 is not driven and power generation is not performed.

At time T1, the pressure of the hydraulic fluid in the second main accumulator 50b rises to the cut-out pressure P1 of the second unload relief valve 60b, so the second unload relief valve 60b is opened to flow the hydraulic fluid. Tolerate. Therefore, the hydraulic oil in the second main accumulator 50b is discharged to the second supply passage 2b. As the hydraulic oil in the second main accumulator 50b decreases, the pressure of the hydraulic oil in the second main accumulator 50b decreases.

The time T2 is the time when the pressure of the hydraulic fluid in the first main accumulator 50a rises to the cut-out pressure P1 of the first unload relief valve 60a. At time T2, the pressure of the hydraulic fluid in the second main accumulator 50b is not lowered to the cut-in pressure P2 of the second unload relief valve 60b.

From time T1 to time T2, the pressure of the hydraulic fluid in the second main accumulator 50b does not decrease to the cut-in pressure P2 of the second unload relief valve 60b. Therefore, the second unload relief valve 60b remains open to allow the flow of hydraulic oil. Therefore, hydraulic oil is supplied from the second pump 20 b and the second main accumulator 50 b to the motor 30 through the second supply passage 2 b and the merging passage 3. Thereby, the generator 40 is driven and power generation is performed.

On the other hand, from time T1 to time T2, the pressure of the hydraulic fluid in the first main accumulator 50a does not rise to the cut-out pressure P1 of the first unload relief valve 60a. Therefore, the first unload relief valve 60a remains closed to shut off the flow of hydraulic oil. Therefore, the hydraulic oil is not supplied to the motor 30 from the first pump 20a and the first main accumulator 50a.

That is, from time T1 to time T2, the hydraulic oil is supplied to the motor 30 only from the second pump 20b and the second main accumulator 50b. Then, the flow rate Q2 of the hydraulic oil led from the second pump 20b and the second main accumulator 50b to the second unload relief valve 60b substantially matches the set flow rate Q0 of the flow control valve 80. Is supplied to the motor 30. Therefore, the hydraulic oil is not led to the sub accumulator 90, and the hydraulic oil in the sub accumulator 90 does not increase.

At time T2, since the pressure of the hydraulic fluid in the first main accumulator 50a rises to the cut-out pressure P1 of the first unload relief valve 60a, the first unload relief valve 60a is opened to flow the hydraulic fluid. Tolerate. Therefore, the hydraulic oil in the first main accumulator 50a is discharged to the first supply passage 2a, and the pressure of the hydraulic oil in the first main accumulator 50a decreases.

Time T3 is the time when the pressure of the hydraulic fluid in the second main accumulator 50b has dropped to the cut-in pressure P2. At time T3, the pressure of the hydraulic fluid in the first main accumulator 50a has not dropped to the cut-in pressure P2 of the first unload relief valve 60a.

From time T2 to time T3, the pressure of the hydraulic fluid in the first main accumulator 50a does not decrease to the cut-in pressure P2 of the first unload relief valve 60a, so the first unload relief valve 60a remains open. , Allow the flow of hydraulic oil. Therefore, the hydraulic oil is supplied from the first pump 20 a and the first main accumulator 50 a to the motor 30 through the first supply passage 2 a and the merging passage 3.

Similarly, from time T2 to time T3, the pressure of the hydraulic oil in the second main accumulator 50b does not decrease to the cut-in pressure P2 of the second unload relief valve 60b, so the second unload relief valve 60b is opened. Keep the condition and allow the flow of hydraulic oil. Therefore, hydraulic oil is supplied from the second pump 20 b and the second main accumulator 50 b to the motor 30 through the second supply passage 2 b and the merging passage 3.

That is, from time T2 to time T3, the hydraulic oil is supplied from the first pump 20a and the first main accumulator 50a to the motor 30, and the hydraulic oil is supplied from the second pump 20b and the second main accumulator 50b to the motor 30 Be done. Therefore, the generator 40 is driven and power generation is performed.

From time T2 to time T3, the pressure of the hydraulic fluid in the first main accumulator 50a is higher than the pressure of the hydraulic fluid in the second main accumulator 50b. Even in such a case, the pressure downstream of the first and second pressure reducing valves 70a and 70b in the first and second supply passages 2a and 2b is reduced to substantially the same pressure by the first and second pressure reducing valves 70a and 70b. . Therefore, the hydraulic fluid can be prevented from being introduced from the first supply passage 2a to the second supply passage 2b, and fluctuations in the flow rate of the hydraulic fluid introduced to the merging passage 3 can be reduced. As a result, the motor 30 can be stably driven, and stable power generation becomes possible.

Also, from time T2 to time T3, the combined flow rate of the hydraulic fluid flow rate Q1 in the first supply passage 2a and the hydraulic fluid flow rate Q2 in the second supply passage 2b exceeds the set flow rate Q0 of the flow control valve 80. . Specifically, the combined flow rate of the flow rate Q1 and the flow rate Q2 is approximately twice the set flow rate Q0 of the flow control valve 80 (see FIG. 2B). Therefore, half of the flow rate of the hydraulic oil introduced from the first and second supply passages 2 a and 2 b is supplied to the motor 30 through the flow control valve 80. The remaining half is led to the sub accumulator 90 and stored in the sub accumulator 90 (see FIG. 2C).

As described above, in the power generation device 100, the flow rate control valve 80 adjusts the flow rate of the hydraulic oil in the merging passage 3 to a predetermined set flow rate Q0. Therefore, the hydraulic fluid can be supplied to the motor 30 at a predetermined flow rate, and the rotational speed of the motor 30 can be stabilized to enable stable power generation.

At time T3, the pressure of the hydraulic oil in the second main accumulator 50b decreases to the cut-in pressure P2 of the second unload relief valve 60b, so the second unload relief valve 60b closes and the flow of hydraulic oil Cut off. Therefore, the hydraulic fluid discharged from the second pump 20b is stored in the second main accumulator 50b, and the pressure of the hydraulic fluid in the second main accumulator 50b rises.

Further, at time T3, the pressure of the hydraulic fluid in the first main accumulator 50a is not lowered to the cut-in pressure P2 of the first unload relief valve 60a, so the first unload relief valve 60a is in the open state. Maintain and allow hydraulic oil flow. Therefore, the hydraulic fluid is released from the first main accumulator 50a to the first supply passage 2a, and the pressure of the hydraulic fluid in the first main accumulator 50a is reduced.

Time T4 is the time when the pressure of the hydraulic fluid in the first main accumulator 50a has dropped to the cut-in pressure P2 of the first unload relief valve 60a. At time T4, the pressure of the hydraulic fluid in the second main accumulator 50b does not rise to the cut-out pressure P1 of the second unload relief valve 60b.

From time T3 to time T4, the pressure of the hydraulic fluid in the first main accumulator 50a does not decrease to the cut-in pressure P2 of the first unload relief valve 60a. Therefore, the first unload relief valve 60a remains open to allow the flow of hydraulic oil. Therefore, the hydraulic oil is supplied from the first pump 20 a and the first main accumulator 50 a to the motor 30 through the first supply passage 2 a and the merging passage 3. Thereby, the generator 40 is driven and power generation is performed.

On the other hand, from time T3 to time T4, the pressure of the hydraulic oil in the second main accumulator 50b does not rise to the cutout pressure P1 of the second unload relief valve 60b. Therefore, the second unload relief valve 60b remains closed to shut off the flow of hydraulic oil. Therefore, the hydraulic oil is not supplied to the motor 30 from the second pump 20 b and the second main accumulator 50 b.

Thus, in the power generation apparatus 100, the pressure of the hydraulic oil in the first and second main accumulators 50a, 50b rises to the cutout pressure P1 of the first and second unload relief valves 60a, 60b at different timings. The pressure drops to the cut-in pressure P2. Therefore, the first and second unload relief valves 60a and 60b open and close at different timings. Therefore, the hydraulic oil can be supplied to the motor 30 from the other while storing the hydraulic oil in one of the first and second main accumulators 50a, 50b.

From time T3 to time T4, hydraulic oil is supplied to the motor 30 only from the first pump 20a and the first main accumulator 50a. Then, the flow rate Q1 of the hydraulic oil led from the first pump 20a and the first main accumulator 50a to the first unload relief valve 60a substantially matches the set flow rate Q0 of the flow control valve 80. Is supplied to the motor 30. Therefore, the hydraulic oil is not led to the sub accumulator 90, and the hydraulic oil in the sub accumulator 90 does not increase.

At time T4, the pressure of the hydraulic fluid in the first main accumulator 50a decreases to the cut-in pressure P2 of the first unload relief valve 60a, so the first unload relief valve 60a closes and the flow of hydraulic fluid It is cut off. Therefore, the hydraulic fluid discharged from the first pump 20a is stored in the first main accumulator 50a, and the pressure of the hydraulic fluid in the first main accumulator 50a rises.

Further, at time T4, the pressure of the hydraulic fluid in the second main accumulator 50b does not rise to the cut-out pressure P1 of the second unload relief valve 60b, so the second unload relief valve 60b is closed. Hold and shut off the flow of hydraulic fluid. Therefore, the hydraulic fluid discharged from the second pump 20b continues to be stored in the second main accumulator 50b, and the pressure of the hydraulic fluid in the second main accumulator 50b continues to rise.

Time T5 is the time when the pressure of the hydraulic fluid in the second main accumulator 50b rises again to the cut-out pressure P1 of the second unload relief valve 60b. At time T5, the pressure of the hydraulic fluid in the first main accumulator 50a does not rise to the cut-out pressure P1 of the first unload relief valve 60a.

From time T4 to time T5, the pressure of the hydraulic fluid in the first and second main accumulators 50a, 50b does not rise to the cut-out pressure P1 of the first and second unload relief valves 60a, 60b. Therefore, the first and second unload relief valves 60a and 60b maintain the closed state and shut off the flow of hydraulic oil. Therefore, no hydraulic oil is supplied to the motor 30 from any of the first and second pumps 20a and 20b and the first and second main accumulators 50a and 50b.

As described above, from time T2 to time T3, half of the flow rate of the hydraulic oil led from the first and second supply passages 2a and 2b is led to the sub accumulator 90 and stored in the sub accumulator 90. Since the hydraulic oil is supplied to the motor 30 only from the first pump 20a and the first main accumulator 50a from time T3 to time T4, no hydraulic oil is released from the sub accumulator 90. That is, at time T4, the hydraulic fluid is stored in the sub accumulator 90. Therefore, from time T4 to time T5, hydraulic oil is supplied from the sub accumulator 90 to the motor 30 through the merging passage 3. Therefore, the generator 40 is driven and power generation is performed.

As described above, in the power generation device 100, when the flow rate of the hydraulic oil in the first and second supply passages 2a and 2b exceeds the set flow rate of the flow control valve 80, the sub accumulator 90 stores the surplus hydraulic oil. . When the flow rate of the hydraulic oil in the first and second supply passages 2 a and 2 b is smaller than the set flow rate of the flow control valve 80, the sub accumulator 90 supplies the hydraulic oil to the flow control valve 80. Therefore, the hydraulic oil can be supplied to the motor 30 at a constant flow rate, and stable power generation becomes possible.

At time T5, the pressure of the hydraulic fluid in the second main accumulator 50b rises to the cut-out pressure P1, so the second unload relief valve 60b is opened to allow the flow of hydraulic fluid. Therefore, the hydraulic fluid is discharged from the second main accumulator 50b to the second supply passage 2b, and the pressure of the hydraulic fluid in the second main accumulator 50b is reduced.

Time T6 is the time when the pressure of the hydraulic fluid in the first main accumulator 50a rises again to the cut-out pressure P1 of the first unload relief valve 60a. At time T6, the pressure of the hydraulic fluid in the second main accumulator 50b is lowered to the cut-in pressure P2 of the second unload relief valve 60b.

The operation of the power generation device 100 from time T5 to time T6 is substantially the same as the operation of the power generation device 100 from time T1 to time T2, and thus the description thereof is omitted here.

According to the above-described embodiment, the following effects can be obtained.

In the power generation apparatus 100, the pressure of the hydraulic oil in the first and second main accumulators 50a, 50b rises to the cutout pressure of the first and second unload relief valves 60a, 60b at different timings and falls to the cut-in pressure. Do. Therefore, the first and second unload relief valves 60a and 60b open and close at different timings. Therefore, the hydraulic oil can be supplied to the motor 30 from the other while storing the hydraulic oil in one of the first and second main accumulators 50a, 50b.

Further, even when the pressure of the hydraulic oil in the first and second main accumulators 50a, 50b is different, the pressure downstream of the first and second pressure reducing valves 70a, 70b in the first and second supply passages 2a, 2b is The first and second pressure reducing valves 70a and 70b are substantially the same. Therefore, when the first and second unload relief valves 60a and 60b are opened, it is possible to prevent the hydraulic oil from being led from one of the first and second supply passages 2a and 2b to the other. It is possible to reduce the fluctuation of the flow rate of hydraulic oil led to 3. As a result, the motor 30 can be stably driven, and stable power generation becomes possible.

The flow rate control valve 80 adjusts the flow rate of the hydraulic oil in the merging passage 3 to a predetermined set flow rate. Therefore, the hydraulic fluid can be supplied to the motor 30 at a predetermined flow rate, and the rotational speed of the motor 30 can be stabilized to enable stable power generation.

The sub accumulator 90 stores the hydraulic oil led from the first and second supply passages 2 a and 2 b and supplies the stored hydraulic oil to the merging passage 3. Therefore, the hydraulic oil can be supplied to the motor 30 at a constant flow rate, and stable power generation becomes possible.

Hereinafter, the configuration, operation, and effects of the embodiment of the present invention will be collectively described.

The power generation apparatus 100 is connected to the first and second water turbines 10a and 10b for converting wave energy into rotational energy, and the first water pump 10a connected to the first water turbine 10a and driven by the first water turbine 10a to discharge hydraulic fluid. And a second pump 20b connected to the second water wheel 10b and driven by the second water wheel 10b to discharge the hydraulic fluid, and having a predetermined capacity and storing the hydraulic fluid discharged from the first pump 20a A second main accumulator 50b having a capacity smaller than a predetermined capacity of the main accumulator 50a and the first main accumulator 50a and storing hydraulic oil discharged from the second pump 20b, the first pump 20a and the first main accumulator A first valve connected downstream of 50a and opened when the hydraulic oil stored in the first main accumulator 50a reaches a predetermined pressure The hydraulic oil stored in the second main accumulator 50b is connected downstream of the relief valve 60a and the second pump 20b and the second main accumulator 50b, and the hydraulic oil stored in the first main accumulator 50a reaches a predetermined pressure. The second unload relief valve 60b which opens to reach a predetermined pressure in a time shorter than the time and the downstream of the first unload relief valve 60a are connected, and the hydraulic oil guided from the first unload relief valve 60a is set to a predetermined value. A predetermined pressure value at which the first pressure reducing valve 70a reduces the pressure of the hydraulic oil connected to the downstream of the first pressure reducing valve 70a that reduces the pressure value and the second unload relief valve 60b and led from the second unload relief valve 60b. The second pressure reducing valve 70b which reduces the pressure to the same pressure value as that of It includes a motor 30 for driving the generator 40 is driven by hydraulic oil introduced from the confluent passage 3 which joins the hydraulic fluid whose pressure is reduced to a predetermined pressure value by the second pressure reducing valve 70b, the.

In this configuration, the second main accumulator 50b has a smaller capacity than the predetermined capacity of the first main accumulator 50a, and the second unload relief valve 60b is configured so that the hydraulic oil stored in the second main accumulator 50b is the first The hydraulic pressure stored in the main accumulator 50a reaches the predetermined pressure in a time shorter than the time when the hydraulic fluid reaches the predetermined pressure and opens. Therefore, the first and second unload relief valves 60a and 60b open at different timings. Further, the second pressure reducing valve 70b reduces the hydraulic oil introduced from the second unload relief valve 60b to a pressure value equal to the predetermined pressure value at which the first pressure reducing valve 70a reduces the pressure. Therefore, when the first and second unload relief valves 60a and 60b are opened, the hydraulic oil can be prevented from being led from one of the first and second unload relief valves 60a and 60b to the other. Fluctuations in the flow rate of hydraulic oil led to the motor 30 can be reduced. Therefore, the hydraulic oil can be supplied to the motor 30 from the other while the hydraulic oil is stored in one of the first and second main accumulators 50a and 50b, and the motor 30 can be stably driven. This enables stable power generation using wave energy.

In addition, the power generation device 100 further includes a flow control valve 80 that controls the flow rate of hydraulic oil in the merging passage 3 to a constant value.

In this configuration, hydraulic fluid can be supplied from the flow control valve 80 to the motor 30 at a constant flow rate even when the first and second unload relief valves 60a and 60b are open. Therefore, the motor 30 can be driven at a desired number of revolutions, and power can be generated stably.

In addition, the power generation apparatus 100 further includes a sub-accumulator 90 that stores the hydraulic oil reduced to a predetermined pressure value by the first and second pressure reducing valves 70a and 70b and supplies the stored hydraulic oil to the flow rate control valve 80.

In this configuration, if the flow rate of the hydraulic oil led from the first and second pressure reducing valves 70 a and 70 b is smaller than the flow rate of the hydraulic oil passing through the flow control valve 80, the sub accumulator 90 runs short to the flow control valve 80. A minute of hydraulic oil is supplied. Therefore, the hydraulic oil can be supplied to the motor 30 at a constant flow rate, and power can be generated stably.

As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only a part of application example of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

In the above embodiment, the hydraulic fluid is used as the hydraulic fluid, but instead of the hydraulic fluid, an incompressible fluid such as water or an aqueous solution may be used.

In the above embodiment, the hydraulic oil from the two first pumps 20a is led to the first main accumulator 50a, but the hydraulic oil may be led from the one first pump 20a to the first main accumulator 50a. The hydraulic oil may be led from three or more first pumps 20a. Similarly, hydraulic oil may be led to the second main accumulator 50b from one second pump 20b, or hydraulic oil may be led from three or more second pumps 20b.

In the above embodiment, the first and second main accumulators 50a and 50b and the first and second unload relief valves 60a and 60b are provided, but three or more main accumulators and three or more unload relief valves are provided. It may be provided.

In the above embodiment, the first and second water turbines 10a and 10b that convert wave energy into rotational energy are used, but instead of the first and second water turbines 10a and 10b, wind turbines are used to convert wind energy to rotational energy May be converted to The wind power also changes in wind power generation, but the first and second pumps 20a and 20b are driven by the wind turbine to store the hydraulic oil in one of the first and second main accumulators 50a and 50b, and the other is activated to the motor 30 Oil can be supplied. Therefore, power can be generated stably by utilizing the energy of the wind.

The first and second unload relief valves 60a and 60b may be solenoid valves.

In the above embodiment, the cut-out pressure P1 and the cut-in pressure P2 of the first unload relief valve 60a are set to substantially coincide with the cut-out pressure P1 and the cut-in pressure P2 of the second unload relief valve 60b, respectively. However, these settings may be different.

The present application claims priority based on Japanese Patent Application No. 2017-156660 filed on August 14, 2017 to the Japanese Patent Office, and the entire contents of this application are incorporated herein by reference.

Claims (3)

First and second energy conversion units that convert renewable energy into mechanical energy;
A first pump connected to the first energy converter and driven by the first energy converter to discharge working fluid;
A second pump connected to the second energy conversion unit and driven by the second energy conversion unit to discharge the working fluid;
A first main accumulator having a predetermined volume and storing a working fluid discharged from the first pump;
A second main accumulator having a capacity smaller than a predetermined capacity of the first main accumulator and storing a working fluid discharged from the second pump;
A first unload relief valve connected downstream of the first pump and the first main accumulator and opening when the working fluid stored in the first main accumulator reaches a predetermined pressure;
It is connected downstream of the second pump and the second main accumulator, and the working fluid stored in the second main accumulator is shorter than the time when the working fluid stored in the first main accumulator reaches a predetermined pressure And a second unload relief valve that opens and reaches a predetermined pressure at
A first pressure reducing valve connected downstream of the first unloading relief valve for reducing the pressure of the working fluid led from the first unloading relief valve to a predetermined pressure value;
A second pressure reducing valve connected downstream of the second unloading relief valve and reducing the pressure of the working fluid led from the second unloading pressure relief valve to the same pressure value as the predetermined pressure value reduced by the first pressure reducing valve; ,
The generator is driven by a working fluid led from a merging passage that combines the working fluid reduced to a predetermined pressure value by the first pressure reducing valve and the working fluid reduced to a predetermined pressure value by the second pressure reducing valve. And an electric motor. The power generation apparatus according to claim 1,
The power generator further comprising a flow control valve that controls the flow rate of the working fluid in the merging passage to a constant value. The power generation device according to claim 2,
A power generator further comprising: a sub-accumulator that stores the working fluid that has been depressurized to a predetermined pressure value by the first and second pressure reducing valves and supplies the stored working fluid to the flow control valve.

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