Power generation system

Abstract

The present invention realizes a power generation system capable of producing a larger amount of power by using a temperature-sensitive magnetic fluid. A power generation system (100) comprises: an upper storage unit (20) in which a temperature-sensitive magnetic fluid (G) is stored; a power generation unit (40) that generates power by using the temperature-sensitive magnetic fluid descending from the upper storage unit; a lower storage unit (30) in which the temperature-sensitive magnetic fluid flowing down from the power generation unit is stored; a flow path (10) through which the temperature-sensitive magnetic fluid circulates and which is partially open to the atmosphere; a fluid drive unit (50) that is disposed between the lower storage unit and the upper storage unit on the flow path, applies a magnetic field to the temperature-sensitive magnetic fluid in the flow path, and heats and drives the temperature-sensitive magnetic fluid in the circulation direction; and an opening / closing unit (70) that controls the descent of the temperature-sensitive magnetic fluid from the upper storage unit.

Description

Power Generation System

[0001] The present invention relates to a power generator system using a temperature-sensitive magnetic fluid.

[0002] Conventionally, magnetic fluid pumps (thermomagnetic pumps) for cooling and heat transport of CPUs and other devices have been developed. A magnetic fluid pump uses a magnetic fluid (temperature-sensitive magnetic fluid), and converts thermal energy into kinetic energy to cause the magnetic fluid to flow by applying a magnetic field to the magnetic fluid and heating the magnetic fluid.

[0003] Patent Document 1 discloses a magnetic fluid power generation device that uses a magnetic fluid pump as a drive unit for circulating a magnetic fluid. The magnetic fluid power generation device includes a circulation flow path for the magnetic fluid, a drive unit for circulating the magnetic fluid, and a power generation unit interposed in the circulation flow path.

[0004] Japanese Patent No. 6474217

[0005] However, although the technology disclosed in Patent Document 1 can convert thermal energy into kinetic energy in a system where the entire flow path is sealed, it does not convert thermal energy into potential energy to extract the energy for power generation.

[0006] In addition, in Patent Document 1, a configuration in which a water turbine (turbine) is installed in the sealed flow path is also conceivable. However, in an example disclosed in Patent Document 1, when the pipe diameter of the flow path is about 5 mm and the flow velocity of the magnetic fluid is about 40 mm / s, the calculated flow rate of the magnetic fluid is about 0.8 mL / s, which is extremely low. With such a flow rate, there is a possibility that power cannot be generated even if a water turbine (turbine) is installed in the flow path. Furthermore, even if power generation is possible, only very little electric power can be obtained.

[0007] Here, there is also a method of charging and storing the slightly generated electric power in a storage battery, but storage batteries have problems of service life and deterioration, and there is also a risk of natural discharge. Furthermore, since there is a limit to the electric power that can be instantaneously extracted from a storage battery, it is not suitable for use in situations where large electric power is required instantaneously.

[0008] One aspect of the present invention aims to implement a power generation system capable of extracting larger electric power by using a temperature-sensitive magnetic fluid.

[0009] To solve the above problems, a power generation system according to embodiment 1 of the present invention comprises: an upper storage section for storing a thermosensitive magnetic fluid; a power generation section for generating electricity with the thermosensitive magnetic fluid falling from the upper storage section; a lower storage section for storing the thermosensitive magnetic fluid flowing down from the power generation section; a flow path, partially open to the atmosphere, through which the thermosensitive magnetic fluid circulates from the lower storage section to the upper storage section and from the upper storage section to the lower storage section via the power generation section; a fluid drive section disposed between the lower storage section and the upper storage section in the flow path, which applies a magnetic field to the thermosensitive magnetic fluid in the flow path and heats the thermosensitive magnetic fluid to drive it in the circulation direction; and an opening / closing section for controlling the falling of the thermosensitive magnetic fluid from the upper storage section.

[0010] According to one aspect of the present invention, a power generation system that can extract greater power using a temperature-sensitive magnetic fluid can be realized.

[0011] This is a schematic diagram showing an example of the configuration of the power generation system of the first embodiment, along with the installation environment. This is a schematic diagram showing an example of the configuration of the fluid drive unit of the power generation system shown in Figure 1. This is a diagram showing the magnetic field distribution in the flow direction of the pumping channel in the fluid drive unit shown in Figure 2. This is a schematic diagram showing an example of the configuration of the power generation system of the second embodiment. This is a schematic diagram showing an example of the configuration of the power generation system of the third embodiment. This is a schematic diagram showing a portion of the fluid drive unit in the power generation system of the fourth embodiment. This is a schematic diagram showing a portion of the fluid drive unit in the power generation system of the fifth embodiment.

[0012] [First Embodiment] Hereinafter, one embodiment of the present invention will be described in detail. Figure 1 is a schematic diagram showing an example of the configuration of the power generation system 100 of the first embodiment, along with the installation environment. As shown in Figure 1, the power generation system 100 is installed in a facility 200 such as a factory or plant, and is located inside a building 201.

[0013] In the following explanation, thermosensitive magnetic fluid will be likened to water, and the act of lifting the thermosensitive magnetic fluid to a high position will be referred to as "water pumping," the act of forcefully releasing the thermosensitive magnetic fluid from a high position will be referred to as "water discharge," and the liquid level of the thermosensitive magnetic fluid will be referred to as "water level."

[0014] As shown in Figure 1, the power generation system 100 includes a fluid channel (flow path) 10 through which a thermosensitive magnetic fluid G circulates, with a portion open to the atmosphere, and an upper storage section 20, a lower storage section 30, a power generation section 40, a fluid drive section 50, an opening / closing section 70, and a temperature stabilization section 60, which are arranged (interposed) at required positions in the fluid channel 10.

[0015] (Thermosensitive magnetic fluid) The thermosensitive magnetic fluid G is a fluid that circulates within the fluid channel 10. The thermosensitive magnetic fluid G is driven by the difference in magnetic volume force when a magnetic field is applied and a temperature difference is given, and moves within the fluid channel 10 to be pumped up. The thermosensitive magnetic fluid G makes it possible to convert the given thermal energy into potential energy. The thermosensitive magnetic fluid G has relatively high magnetization in the low temperature range or room temperature range, and its magnetization decreases as it rises towards the Curie temperature.

[0016] As the thermosensitive magnetic fluid G, a solution can be used in which magnetic nanoparticles are dispersed as the dispersion phase, water or oil (such as kerosene) as the dispersion medium (mother liquor), and a surfactant is included. The thermosensitive magnetic fluid G reacts to a magnetic field at low temperatures and room temperature, but stops reacting to a magnetic field at high temperatures. Even if the thermosensitive magnetic fluid G is heated to a high temperature, as long as it remains below the Curie temperature, it will become reactive to a magnetic field again after cooling.

[0017] Examples of magnetic nanoparticles that can be used include iron oxide-based spinel ferrite (MFe2O4: M=Fe, Mn, Ni, MnZn), γ-hematite (γ-Fe2O3), etc. Examples of dispersion media that can be used include water, hydrocarbon oils (kerosene, alkylnaphthalene, etc.), and fluorine-based oils (purple polyether, etc.).

[0018] As an example of a water-based temperature-sensitive magnetic fluid G using water as a dispersion medium, products such as TC3030W manufactured by Ferrotec Holdings Corporation can be used.

[0019] As an example of an oil-based temperature-sensitive magnetic fluid G using oil as a dispersion medium, TS-50K manufactured by Ichinen Chemicals Co., Ltd. can be used. However, the temperature-sensitive magnetic fluid G is not limited to the examples given.

[0020] (Fluid flow path) The fluid flow path 10 has a discharge flow path 11 and a pumping flow path 12, and circulates the thermosensitive magnetic fluid G in the circulation direction indicated by the arrow Y in Figure 1. The discharge flow path 11 connects the bottom of the upper storage section 20 and the lower storage section 30. The thermosensitive magnetic fluid G in the upper storage section 20 falls (flows down) through the discharge flow path 11.

[0021] The discharge channel 11 is provided with an opening / closing section 70 that controls the flow of the temperature-sensitive magnetic fluid G from the upper storage section 20. In Figure 1, a valve that opens and closes the channel is shown as an example of the opening / closing section 70, but the opening / closing section 70 is not limited to a valve and may be, for example, an opening / closing door. In short, any configuration that can control the flow of the temperature-sensitive magnetic fluid G falling from the upper storage section 20 is acceptable.

[0022] The pumping channel 12 connects the bottom of the lower storage section 30 and the upper storage section 20. The temperature-sensitive magnetic fluid G in the lower storage section 30 is sent to the upper storage section 20 through the pumping channel 12 and pumped up. In this embodiment, the bottom of the lower storage section 30 and the upper storage section 20 are connected, but the location of the connection is not limited to the bottom; it may also be connected to the side of the lower storage section 30, or, in the case of a suction type, to the top surface of the lower storage section 30.

[0023] The fluid channel 10 is partially open to the atmosphere between the pumping channel 12 and the upper storage section 20. While Figure 1 shows an example where the thermosensitive magnetic fluid G from the pumping channel 12 pours down from above the upper storage section 20, the system is not limited to this. For example, the pumping channel 12 may be connected to the upper storage section 20, and an opening communicating with the outside may be provided at the top of the upper storage section 20, allowing the fluid channel 10 to be open to the atmosphere.

[0024] Thus, the fluid channel 10 allows the thermosensitive magnetic fluid G to circulate from the lower storage section 30 to the upper storage section 20, and from the upper storage section 20 to the lower storage section 30 via the power generation section 40, with a portion of it being open to the atmosphere.

[0025] In the case of closed or sealed fluid channels, it is impossible to store and release potential energy through storage and discharge. However, by creating a system in which a portion of the channel is open to the atmosphere, as in fluid channel 10, it becomes possible to store and release potential energy.

[0026] The fluid channel 10 is composed of, for example, piping. In this case, the portion of the piping in the water pumping channel 12 that is heated by the heating section 52 of the fluid drive section 50 (described later) is preferably made of a non-magnetic metal such as copper, which has excellent thermal conductivity. The non-heated portion may be made of a resin, such as a fluororesin, which has low thermal conductivity.

[0027] (Upper storage section, lower storage section) The upper storage section 20 stores the thermosensitive magnetic fluid G that is transported from the lower storage section 30 through the pumping channel 12. The upper storage section 20 enables the accumulation of potential energy by storing the thermosensitive magnetic fluid G that has been transported to a higher position.

[0028] When the opening / closing section 70 is opened, the temperature-sensitive magnetic fluid G in the upper storage section 20 falls through the water discharge channel 11, and when the opening / closing section 70 is closed, the falling of the temperature-sensitive magnetic fluid G stops.

[0029] Here, the opening / closing section 70 may be adjustable in terms of the amount of opening / closing. This allows the amount of temperature-sensitive magnetic fluid G to fall per unit time to be adjusted by adjusting the amount of opening / closing, and consequently, the amount of power generated by the power generation section 40 to be adjusted. In other words, by controlling the discharge of water from the upper storage section 20, the amount of potential energy extracted and the timing of extraction can be controlled, enabling stable power generation in the power generation system 100.

[0030] The lower storage section 30 collects and stores the temperature-sensitive magnetic fluid G that falls from the upper storage section 20 and flows down from the power generation section 40. The capacity of the lower storage section 30 is set to be larger than the capacity of the upper storage section 20, so that it can store the temperature-sensitive magnetic fluid G even when the upper storage section 20 is empty. In this embodiment, the lower storage section 30 is located on the ground 202.

[0031] (Power Generation Unit) The power generation unit 40 is located in the water discharge channel 11 and converts the potential energy of the thermosensitive magnetic fluid G falling through the water discharge channel 11 into electrical energy. In other words, the power generation unit 40 generates electricity using the thermosensitive magnetic fluid G falling from the upper storage unit 20. For this purpose, although not shown in the figures, the power generation unit 40 includes, for example, a turbine such as a water wheel that rotates with the thermosensitive magnetic fluid G falling through the water discharge channel 11, and a generator that is rotated by the turbine. By rotating the turbine of the power generation unit 40 with the potential energy of the thermosensitive magnetic fluid G, the potential energy can be extracted as electrical energy.

[0032] Here, the greater the vertical distance between the upper storage section 20 and the power generation section 40, the greater the potential energy that can be extracted. For this reason, the power generation section 40 is positioned near the top (upper surface) of the lower storage section 30. Furthermore, the potential energy extracted by the power generation section 40 increases as the flow rate of the thermosensitive magnetic fluid G falling from the upper storage section 20 to the power generation section 40 increases.

[0033] In this example, the power generation unit 40 is located in the water discharge channel 11. However, if the water discharge channel 11 is a pipe whose upper end is connected to the upper storage unit 20, the lower end of the pipe may be open toward the turbine of the power generation unit 40. In this case, the thermosensitive magnetic fluid G that has rotated the turbine may fall directly into the lower storage unit 30, or be introduced into the lower storage unit 30 via another pipe.

[0034] (Fluid Drive Unit) The fluid drive unit 50 is located between the lower storage unit 30 and the upper storage unit 20 in the fluid flow path 10. It applies a magnetic field to the thermosensitive magnetic fluid G in the fluid flow path 10 and heats the thermosensitive magnetic fluid G to drive it in the circulation direction. Specifically, the fluid drive unit 50 is a magnetic fluid pump located in the pumping flow path 12. It applies a magnetic field to the thermosensitive magnetic fluid G in the pumping flow path 12 and heats it, converting thermal energy into kinetic energy to drive the thermosensitive magnetic fluid G. To this end, the fluid drive unit 50 includes a magnetic field application unit 51 that applies a magnetic field to the thermosensitive magnetic fluid G and a heating unit 52 that heats the thermosensitive magnetic fluid G.

[0035] Figure 2 is a schematic diagram showing an example of the configuration of the fluid drive unit 50 of the power generation system 100 shown in Figure 1. Figure 3 is a diagram showing the magnetic field distribution in the circulation direction Y in the pumping channel 12 of the fluid drive unit 50 shown in Figure 2. In Figure 3, the horizontal axis indicates the position in the circulation direction Y of the fluid drive unit 50, and the vertical axis indicates the applied magnetic field in the fluid drive unit 50.

[0036] As shown in Figure 2, the fluid drive unit 50 includes a pair of magnetic field applying units 51 that apply a magnetic field to the thermosensitive magnetic fluid G in the pumping channel 12, and a heating unit 52 that heats the thermosensitive magnetic fluid G in the pumping channel 12.

[0037] <Magnetic Field Application Section> The magnetic field application section 51 applies a magnetic field to the thermosensitive magnetic fluid G in the fluid drive section 50, which is a magnetic fluid pump, thereby locally applying a magnetic volume force to the thermosensitive magnetic fluid G. As shown in Figure 2, the magnetic field application section 51 is equipped with permanent magnets 511 and a yoke 512, and the permanent magnets 511 and the yoke 512 are in close contact. Two permanent magnets 511, which have easy magnetization axes perpendicular to the circulation direction Y of the pumping channel 12, are arranged relative to the yoke 512 such that their magnetic pole surfaces facing the pumping channel 12 are different from each other.

[0038] The pair of magnetic field application units 51 are positioned opposite each other across the water pumping channel 12, and the magnetic pole surfaces of the four permanent magnets 511 facing each other across the water pumping channel 12 are arranged so that they are the same for each other. The space between the two permanent magnets 511 aligned in the circulation direction Y, shown by the dashed line X, is the center position in the circulation direction Y of the fluid drive unit 50.

[0039] By arranging the pair of magnetic field application units 51 in this manner, as shown in Figure 3, an axisymmetric magnetic field is generated, for example, a Mexican hat type (a type with a positive peak and negative depressions on both sides near the peak), with the center of the magnetic field application unit 51, indicated by the dashed line X, as the axis. The centers of the negative depressions on both sides in the Mexican hat type correspond to the outer ends of the two permanent magnets 511 aligned in the circulation direction Y.

[0040] As the permanent magnet 511, for example, neodymium magnets, samarium-cobalt magnets, ferrite magnets, etc. can be used. Neodymium magnets, which have the highest magnetic force and can generate a high magnetic field, are preferred. By using a neodymium magnet, no electric power is required for magnetic field application. The permanent magnet 511 may have any shape, but prismatic, cylindrical, and elliptical cylindrical shapes can be used. Further, a hollow cylindrical magnet that surrounds the pipe forming the pumped water flow path 12 can also be used. In addition, an electromagnet can be used if low power consumption is required.

[0041] The peak magnetic flux intensity shown in FIG. 3 can be increased by bringing the pair of magnetic field applying units 51 closer to reduce the distance between the permanent magnets 511 respectively provided therein. However, when the permanent magnet 511 becomes high temperature due to heat from the heating unit 52, the magnetic flux density decreases, and the magnetic field intensity also decreases.

[0042] Therefore, as shown in FIG. 2, the pair of magnetic field applying units 51 are preferably arranged spaced apart between the permanent magnet 511 and the heating unit 52 such that an air layer C of several millimeters is formed therebetween. Thereby, the air layer C functions as a heat insulating portion, and a decrease in magnetic field intensity caused by the permanent magnet 511 becoming high temperature can be suppressed.

[0043] Although the air layer C is exemplified as a measure for suppressing the permanent magnet 511 from becoming high temperature, a heat insulating material or the like may be arranged between the permanent magnet 511 and the heating unit 52. As the heat insulating material, one that does not affect (or only slightly affects) the magnetic field generated by the permanent magnet 511 is selected. In short, it is only necessary that a heat insulating portion is provided between the magnetic field applying unit 51 (the permanent magnet 511) and the heating unit 52.

[0044] Further, instead of the heat insulating portion, a configuration in which the permanent magnet 511 is cooled by some method may be adopted. In addition, even if the permanent magnet 511 is heated by the heating unit 52, there is no need to provide a heat insulating portion or a cooling configuration as long as the heating is performed at a low temperature at which a decrease in magnetic field intensity does not cause a problem.

[0045] <Heating Section> In the fluid drive unit 50 which is a magnetic fluid pump, the heating unit 52 reduces the saturation magnetization of the temperature-sensitive magnetic fluid G by heating the downstream side of the magnetic field applying unit 51, and makes the magnetic volume force in a non-equilibrium state, thereby applying a driving pressure in the water pumping direction to the temperature-sensitive magnetic fluid G. The heating unit 52 heats the temperature-sensitive magnetic fluid G in the fluid channel 10 on the downstream side in the circulation direction Y of the magnetic field applying unit 51.

[0046] The heating unit 52 is disposed on the downstream side in the circulation direction Y of the magnetic field applying unit 51. More specifically, the heating unit 52 partially overlaps the permanent magnet 511 on the downstream side in the circulation direction Y among the two permanent magnets 511 arranged along the circulation direction Y in the magnetic field applying unit 51, and is disposed so as to extend beyond the downstream permanent magnet 511. As shown in FIG. 3, the heating unit 52 heats beyond the negative depression on the downstream side in the circulation direction Y relative to the peak of the Mexican hat-shaped magnetic field.

[0047] The heating unit 52 may be in any form as long as it can heat the temperature-sensitive magnetic fluid G. For example, the heating unit 52 may be a heating element such as a planar heater disposed to be wound around the water pumping channel 12. Alternatively, a configuration may be adopted that uses exhaust heat (waste heat) generated in the facility 200. By using exhaust heat, electric power for heating is not required. In addition, using exhaust heat leads to lowering the ambient temperature in the facility 200, and an effect of reducing the physical burden on workers in a high-temperature environment can also be expected.

[0048] In the present embodiment, the fluid drive unit 50 is disposed on the ground 202 similarly to the lower reservoir 30.

[0049] <Operation of Fluid Drive Unit> The fluid drive unit 50 applies a magnetic field from the magnetic field applying unit 51 to the temperature-sensitive magnetic fluid G in the water pumping channel 12, and heats the fluid by the heating unit 52 to impart a temperature difference thereto. By heating, the magnetization of the temperature-sensitive magnetic fluid G decreases, an imbalance in the magnetic volume force acting on the temperature-sensitive magnetic fluid G occurs, and driving force is generated. With this driving force, the temperature-sensitive magnetic fluid G in the water pumping channel 12 moves in the circulation direction Y, is pumped up, and is stored in the upper reservoir 20.

[0050] The thermosensitive magnetic fluid G can be either water-based or oil-based, but by using an oil-based thermosensitive magnetic fluid, the heating range can be set to 100°C or higher and the cooling range to below freezing point. This expands the temperature range that can be applied in the heating section 52 to create a difference in magnetic volume force, and allows for a reduction in the strength of the magnetic field applied from the magnetic field application section 51 (magnetic field strength) required to drive the thermosensitive magnetic fluid G.

[0051] By the way, in order for the fluid drive unit 50 to drive the thermosensitive magnetic fluid G in the pumping channel 12 by creating an imbalance in magnetic volume force, at least the following condition (1) must be satisfied. Condition (1) At the start of driving, the downstream end of the thermosensitive magnetic fluid G in the pumping channel 12 in the circulation direction Y is located downstream of the upstream end of the circulation direction Y in the heating unit 52 in the circulation direction Y. In other words, the downstream end of the thermosensitive magnetic fluid G in the pumping channel 12 in the circulation direction Y is the tip of the thermosensitive magnetic fluid G that comes out of the lower storage unit 30 and moves within the pumping channel 12.

[0052] In other words, in order for the fluid drive unit 50 to drive the thermosensitive magnetic fluid G in the pumping channel 12, the leading edge of the thermosensitive magnetic fluid G in the pumping channel 12 must extend beyond the upstream end in the circulation direction Y of the superposition region where the magnetic field application unit 51 and the heating unit 52 are superimposed. This creates an imbalance in magnetic volume force in the thermosensitive magnetic fluid G, thereby providing a driving force to the thermosensitive magnetic fluid G.

[0053] More preferably, the following condition (2) is satisfied. Condition (2) At the start of operation, the leading edge of the thermosensitive magnetic fluid G in the pumping channel 12 reaches the downstream end of the magnetic field application unit 51 in the circulation direction Y. Specifically, the downstream end of the magnetic field application unit 51 in the circulation direction Y is the downstream end of the permanent magnet 511 located downstream in the circulation direction Y.

[0054] In other words, because the leading edge of the thermosensitive magnetic fluid G in the pumping channel 12 reaches the downstream end in the circulation direction Y of the aforementioned superimposed region, an imbalance in magnetic volume force can be created in the thermosensitive magnetic fluid G throughout the entire superimposed region. This allows a greater driving force to be imparted to the thermosensitive magnetic fluid G.

[0055] The position of the tip of the thermosensitive magnetic fluid G in the pumping channel 12 that satisfies either condition (1) or condition (2) above can be set, for example, by arranging the magnetic field application section 51 and the lower storage section 30 to satisfy a predetermined relationship. In this embodiment, the magnetic field application section 51 and the lower storage section 30 are arranged as follows to satisfy condition (2) above.

[0056] As shown in Figure 1, the magnetic field application unit 51 and the lower storage unit 30 are configured such that, at the start of operation, the downstream end of the permanent magnet 511 located on the downstream side in the circulation direction Y (the downstream end in the circulation direction Y of the magnetic field application unit 51) is positioned below the liquid level E in the lower storage unit 30.

[0057] When the fluid drive unit 50 is positioned in the vertically upward portion of the pumping channel 12, the upper end of the permanent magnet 511 provided by the fluid drive unit 50 corresponds to the downstream end of the permanent magnet 511 positioned downstream in the circulation direction Y.

[0058] Furthermore, as shown in Figure 4, for example, the fluid drive unit 50 may be positioned lower than the bottom of the lower storage unit 30. Figure 4 is a schematic diagram showing an example of the configuration of the power generation system 100A of the second embodiment. The power generation system 100A of the second embodiment differs from the power generation system 100 of the first embodiment in the position of the fluid drive unit 50.

[0059] By positioning the fluid drive unit 50 at a lower position than the bottom of the lower storage unit 30, the above condition (2) is always satisfied when the temperature-sensitive magnetic fluid G is stored in the lower storage unit 30. In this case, as shown in Figure 4, the fluid drive unit 50 may be buried underground.

[0060] Furthermore, as shown in Figure 5, an auxiliary pump P may be provided in the pumping channel 12 to adjust the position of the tip of the thermosensitive magnetic fluid G in the pumping channel 12 so as to satisfy the above condition (1) or the above condition (2). Figure 5 is a schematic diagram showing an example of the configuration of the power generation system 100B of the third embodiment. The power generation system 100B of the third embodiment differs from the power generation system 100 of the first embodiment in the arrangement of the lower storage section 30 and the inclusion of an auxiliary pump P.

[0061] The auxiliary pump P is used to adjust the position of the tip of the thermosensitive magnetic fluid G in the pumping channel 12. Since the auxiliary pump P is only used when the fluid drive unit 50 starts operating (at the start of operation), the energy loss due to the use of the auxiliary pump P is small.

[0062] By providing the auxiliary pump P, it becomes unnecessary to configure the magnetic field application unit 51 and the lower storage unit 30 to satisfy the above condition (1) or condition (2) in a predetermined relationship, and it becomes possible to bury the lower storage unit 30 underground. In the example of Figure 5, the auxiliary pump P is provided on the upstream side in the circulation direction Y with respect to the fluid drive unit 50, but it may also be provided on the downstream side. The auxiliary pump P may be detachable and provided in the power generation system 100 as needed.

[0063] (Temperature Constantization Unit) The temperature constantization unit 60 improves the performance of the fluid drive unit 50 in converting thermal energy to kinetic energy. However, the temperature constantization unit 60 is not necessarily required in the power generation system 100.

[0064] The temperature stabilization unit 60 stabilizes the temperature of the thermosensitive magnetic fluid G reaching the fluid drive unit 50 within a predetermined temperature range lower than the temperature of the thermosensitive magnetic fluid G after heating by the fluid drive unit 50. In other words, it maintains the thermosensitive magnetic fluid G upstream of the heating unit 52 in the circulation direction Y of the fluid drive unit 50 at a relatively low constant temperature. The temperature stabilized by the temperature stabilization unit 60 is, for example, a single temperature within the temperature range of 15°C to 20°C. This ensures a stable temperature difference in the fluid drive unit 50 and improves the drive pressure.

[0065] The temperature stabilization unit 60 may be provided in the lower storage unit 30, or in at least one of the pumping channel 12 between the lower storage unit 30 and the fluid drive unit 50.

[0066] In the power generation system 100 (100A, 100B), a temperature constant section 60 is realized by burying the pumping channel 12 upstream of the heating section 52 of the fluid drive section 50 in the ground in the circulation direction Y. Since the temperature in the ground is kept relatively stable at a low temperature, it can be used as a temperature constant section 60. By configuring the temperature constant section 60 using natural energy such as geothermal energy in this way, electricity for cooling is not required. In other words, the temperature constant section utilizes geothermal energy. Utilizing geothermal energy means utilizing the ground. For example, the temperature constant section 60 maintains a constant temperature of the thermosensitive magnetic fluid G reaching the fluid drive section 50 by radiating heat into the ground or absorbing heat from the ground.

[0067] (Operation of the power generation system) Next, the operation of the power generation system 100 will be described with reference to Figure 1. First, the fluid drive unit 50 is started to move the thermosensitive magnetic fluid G in the lower storage unit 30 to the upper storage unit 20 via the pumping channel 12 (pumping process). The fluid drive unit 50 is driven until the upper storage unit 20 is full, at which point the fluid drive unit 50 is stopped. As a result, the thermal energy supplied from the heating unit 52 is converted into potential energy and stored as potential energy. The fluid drive unit 50 may be controlled based on the water level of the upper storage unit 20 so that the upper storage unit 20 is always kept full.

[0068] When power is needed in the equipment 200, the opening / closing section 70 provided in the water discharge channel 11 is opened, and the thermosensitive magnetic fluid G in the upper storage section 20 is allowed to fall through the water discharge channel 11 (water discharge process). The power generation section 40 generates electricity using the thermosensitive magnetic fluid G falling through the water discharge channel 11. As a result, the stored potential energy is converted into kinetic energy and then into electrical energy, which is then extracted.

[0069] Here, by suddenly opening the opening / closing section 70 and causing the thermosensitive magnetic fluid G in the upper storage section 20 to fall out all at once, the thermosensitive magnetic fluid G can vigorously rotate the turbine (not shown) of the power generation section 40. This allows a large amount of potential energy to be extracted and a large amount of electricity to be obtained.

[0070] When the required power is low, the amount of opening and closing of the opening / closing section 70 is adjusted to control the momentum of the falling temperature-sensitive magnetic fluid G. This reduces the amount of potential energy extracted, thereby adjusting the amount of power generated. Also, when power is no longer needed, the opening / closing section 70 is closed. This stops power generation by the power generation section 40.

[0071] The thermosensitive magnetic fluid G from which potential energy has been extracted in the power generation unit 40 is recovered in the lower storage unit 30 and, upon activation of the fluid drive unit 50, is sent again to the upper storage unit 20 via the pumping channel 12.

[0072] (Effects) In the above power generation system, since an open-air fluid channel 10 is used, potential energy can be extracted not by simple circulation of fluid in the channel, but by pumping up the temperature-sensitive magnetic fluid G and letting it fall.

[0073] Furthermore, by accumulating the pumped temperature-sensitive magnetic fluid G in the upper storage section 20 and then releasing and dropping it all at once, a large amount of potential energy can be extracted to obtain a large amount of electricity.

[0074] Furthermore, since a thermosensitive magnetic fluid is stored in the upper storage section 20 and conserved as potential energy, no energy loss occurs as long as the thermosensitive magnetic fluid in the upper storage section 20 does not volatilize.

[0075] Furthermore, as mentioned above, by suddenly releasing and dropping the temperature-sensitive magnetic fluid G stored in the upper storage section 20, a large amount of electrical energy can be extracted instantaneously. Therefore, it becomes possible to supply large amounts of electrical energy that would be impossible with a battery.

[0076] [Other Embodiments] Other embodiments of the present invention are described below. For the sake of convenience of explanation, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0077] In the aforementioned power generation systems 100, 100A, and 100B, the fluid drive unit 50 was configured to have one set SE consisting of a pair of magnetic field application units 51 and one heating unit 52. However, as shown in Figures 6 and 7, it may also be configured to have multiple sets SE.

[0078] Figure 6 is a schematic diagram showing the fluid drive unit 50C portion of the power generation system 100C of the fourth embodiment. Figure 7 is a schematic diagram showing the fluid drive unit 50D portion of the power generation system 100D of the fifth embodiment. In Figures 6 and 7, the parts other than the fluid drive unit 50C and the fluid drive unit 50D are not shown, but the parts other than the fluid drive unit 50C and the fluid drive unit 50D are the same as the configuration of the power generation systems 100, 100A, and 100B described above.

[0079] As shown in Figure 6, in the power generation system 100C of the fourth embodiment, multiple set SEs (two in this example) are arranged in series with respect to the pumping channel 12. When the set SEs are connected in series, the driving force for moving the temperature-sensitive magnetic fluid G is the sum of the driving forces of each set SE. Therefore, with this configuration, the head of the fluid drive unit 50C can be raised higher than that of the fluid drive unit 50.

[0080] As shown in Figure 7, in the power generation system 100D of the fifth embodiment, multiple set SEs (two in this example) are arranged in parallel with respect to the pumping channel 12. Specifically, the pumping channel 12 is branched into multiple branch channels 121 along its course (two branches in this example), and a set SE is placed in each branch channel 121.

[0081] When the set SEs are connected in parallel, the flow rate of the temperature-sensitive magnetic fluid G is the sum of the flow rates of each set SE. Therefore, by using the above configuration, the flow rate of the fluid drive unit 50D can be increased compared to that of the fluid drive unit 50.

[0082] Although not shown in the diagram, the set SEs may also be arranged in series and in parallel with respect to the pumping channel 12. This makes it possible to improve both the head and flow rate compared to the fluid drive unit 50.

[0083] In the above embodiment, power generation systems 100 to 100D installed in facility 200 were illustrated, but they may also be installed on a smaller scale than facility 200.

[0084] [Summary] In order to solve the above problems, the power generation system according to embodiment 1 of the present invention comprises: an upper storage section for storing a thermosensitive magnetic fluid; a power generation section for generating electricity with the thermosensitive magnetic fluid falling from the upper storage section; a lower storage section for storing the thermosensitive magnetic fluid flowing down from the power generation section; a flow path, partially open to the atmosphere, through which the thermosensitive magnetic fluid circulates from the lower storage section to the upper storage section and from the upper storage section to the lower storage section via the power generation section; a fluid drive section disposed between the lower storage section and the upper storage section in the flow path, which applies a magnetic field to the thermosensitive magnetic fluid in the flow path and heats the thermosensitive magnetic fluid to drive it in the circulation direction; and an opening / closing section for controlling the falling of the thermosensitive magnetic fluid from the upper storage section.

[0085] In the power generation system according to embodiment 2 of the present invention, in embodiment 1, the fluid drive unit comprises a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, wherein at the start of driving, the downstream end of the thermosensitive magnetic fluid in the circulation direction may be located downstream in the circulation direction of the heating unit than the upstream end of the heating unit in the circulation direction.

[0086] A power generation system according to embodiment 3 of the present invention, in embodiment 1, comprises a fluid drive unit, a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side in the circulation direction of the magnetic field application unit, wherein at the start of driving, the downstream end in the circulation direction of the thermosensitive magnetic fluid may reach the downstream end in the circulation direction of the magnetic field application unit.

[0087] A power generation system according to embodiment 4 of the present invention, in embodiment 1, comprises a fluid drive unit, a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side in the circulation direction of the magnetic field application unit, wherein the magnetic field application unit and the lower storage unit may be arranged such that, at the start of driving, the downstream end of the magnetic field application unit in the circulation direction is below the liquid level in the lower storage unit.

[0088] A power generation system according to embodiment 5 of the present invention, in embodiment 1, comprises a fluid drive unit which applies a magnetic field to the thermosensitive magnetic fluid in the flow path and a heating unit which heats the thermosensitive magnetic fluid in the flow path on the downstream side in the circulation direction of the magnetic field application unit, and a heat insulating unit may be provided between the magnetic field application unit and the heating unit.

[0089] In embodiment 6 of the present invention, the power generation system in embodiment 1 comprises a plurality of sets of a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, and the plurality of sets may be arranged in series with respect to the flow path.

[0090] In embodiment 7 of the present invention, the power generation system in embodiment 1 comprises a plurality of drive sets, each having a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, wherein the flow path is branched between the lower storage unit and the upper storage unit, and the plurality of drive sets may be arranged in the branched flow path.

[0091] The power generation system according to embodiment 8 of the present invention may further include, in embodiment 1, a pump separate from the fluid drive unit for adjusting the position of the downstream end in the circulation direction of the thermosensitive magnetic fluid in the flow path.

[0092] In embodiment 9 of the present invention, the power generation system may include a temperature stabilization unit that stabilizes the temperature of the thermosensitive magnetic fluid reaching the fluid drive unit within a predetermined temperature range lower than the temperature of the thermosensitive magnetic fluid after heating by the fluid drive unit, in embodiment 1.

[0093] In the power generation system according to embodiment 10 of the present invention, in embodiment 9, the temperature constant unit may be provided in the lower storage unit, or in at least one of the flow path between the lower storage unit and the fluid drive unit.

[0094] In the power generation system according to embodiment 11 of the present invention, the temperature constant unit may utilize geothermal energy in embodiment 9 or 10.

[0095] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0096] 10 Fluid flow path (flow path) 11 Discharge flow path 12 Pumping flow path 20 Upper storage section 30 Lower storage section 40 Power generation section 50, 50C, 50D Fluid drive section 51 Magnetic field application section 52 Heating section 60 Temperature stabilization section 70 Switching section 100, 100A, 100B, 100C, 100D Power generation system 121 Branch flow path (branched flow path) 200 Equipment SE set (set)

Claims

1. A power generation system comprising: an upper storage section for storing a thermosensitive magnetic fluid; a power generation section for generating electricity using the thermosensitive magnetic fluid falling from the upper storage section; a lower storage section for storing the thermosensitive magnetic fluid flowing down from the power generation section; a flow path, partially open to the atmosphere, through which the thermosensitive magnetic fluid circulates from the lower storage section to the upper storage section and from the upper storage section to the lower storage section via the power generation section; a fluid drive section positioned between the lower storage section and the upper storage section in the flow path, which applies a magnetic field to the thermosensitive magnetic fluid in the flow path and heats the thermosensitive magnetic fluid to drive it in the circulation direction; and an opening / closing section for controlling the fall of the thermosensitive magnetic fluid from the upper storage section.

2. The power generation system according to claim 1, wherein the fluid drive unit comprises a magnetic field application unit for applying a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit for heating the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, wherein at the start of operation, the downstream end of the thermosensitive magnetic fluid in the circulation direction is located downstream in the circulation direction of the heating unit than the upstream end of the heating unit in the circulation direction.

3. The power generation system according to claim 1, wherein the fluid drive unit comprises a magnetic field application unit for applying a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit for heating the thermosensitive magnetic fluid in the flow path on the downstream side in the circulation direction of the magnetic field application unit, wherein at the start of driving, the downstream end of the thermosensitive magnetic fluid in the circulation direction reaches the downstream end of the magnetic field application unit in the circulation direction.

4. The power generation system according to claim 1, wherein the fluid drive unit comprises a magnetic field application unit for applying a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit for heating the thermosensitive magnetic fluid in the flow path on the downstream side in the circulation direction of the magnetic field application unit, wherein the magnetic field application unit and the lower storage unit are provided such that, at the start of operation, the downstream end of the magnetic field application unit in the circulation direction is located below the liquid level in the lower storage unit.

5. The power generation system according to claim 1, wherein the fluid drive unit comprises a magnetic field application unit for applying a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit for heating the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, and an insulating unit is provided between the magnetic field application unit and the heating unit.

6. The power generation system according to claim 1, wherein the fluid drive unit comprises a plurality of sets of a magnetic field application unit that applies a magnetic field to the thermosensitive magnetic fluid in the flow path, and a heating unit that heats the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, and the plurality of sets are arranged in series with respect to the flow path.

7. The power generation system according to claim 1, wherein the fluid drive unit comprises a plurality of drive sets, each having: a magnetic field application unit for applying a magnetic field to the thermosensitive magnetic fluid in the flow path; and a heating unit for heating the thermosensitive magnetic fluid in the flow path on the downstream side of the magnetic field application unit in the circulation direction, the flow path is branched between the lower storage unit and the upper storage unit, and the plurality of drive sets are arranged in the branched flow path.

8. The power generation system according to claim 1, further comprising a pump, separate from the fluid drive unit, for adjusting the position of the downstream end in the circulation direction of the thermosensitive magnetic fluid in the flow path.

9. The power generation system according to claim 1, further comprising a temperature stabilization unit that stabilizes the temperature of the thermosensitive magnetic fluid reaching the fluid drive unit within a predetermined temperature range lower than the temperature of the thermosensitive magnetic fluid after heating by the fluid drive unit.

10. The power generation system according to claim 9, wherein the temperature stabilization unit is provided in the lower storage unit, or in the flow path, at least in the lower storage unit and the fluid drive unit.

11. The power generation system according to claim 9 or 10, wherein the temperature stabilization unit utilizes geothermal energy.

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