Heat generation / power generation combined system

Abstract

To provide a system having simple structure and converting rotation energy into thermal energy and electric energy.SOLUTION: A heat generation / power generation combined system comprises: a fluid type heat generator 3 which has an annular pump 7 connected to a power source 5 and rotates, an annular turbine 8 arranged opposite the pump 7, and an annular stator 9 arranged between the pump 7 and turbine 8, and causes working fluid 10 to circulate among the pump 7, turbine 8 and stator 9 by the rotation of the pump 7, thereby generating heat; a power generator 4 which has a rotor 4a connected to the turbine 8 of the fluid type heat generator 3, and is connected to the fluid type heat generator 3 in series; and a case 2 which houses the fluid type heat generator 3 and power generator 4 in such a manner that the case 2 holds inside, a stator 4b of the power generator 4 surrounding the rotor 4, wherein the combined system further comprises a brake mechanism 19 optionally allows or disallows the turbine 8 and rotor 4a, and the case 2 to rotate relatively.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a combined heat and power generation system comprising a fluid-type heater having an annular pump connected to a power source and rotating, an annular turbine arranged opposite the pump, and an annular stator removably fixed to the turbine and arranged between the pump and the turbine, and which generates heat by circulating a working fluid between the pump, the turbine, and the stator as the pump rotates, and a generator connected in series to the fluid-type heater, having a rotor connected to the turbine of the fluid-type heater. [Background technology]

[0002] As described in Patent Document 1, a combined heat and power generation system is known that switches between a power generation mode in which the rotational energy of a wind turbine, which is a power source, is converted into electrical energy, and a heat generation mode in which the rotational energy of the wind turbine is converted into thermal energy, stored in a heat storage device, and then converted into electrical energy through thermal power generation, depending on the power supply and wind conditions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Publication No. 2015-46984 Summary of the Invention [Problem to be solved by the invention]

[0004] The system described in Patent Document 1 mentioned above has an induction rotating machine connected to the rotating shaft of a wind turbine, and when power demand is at its peak and the wind turbine is rotating due to the wind, the induction rotating machine operates as a normal generator, while when power demand is off-peak and the wind turbine is rotating due to the wind, a power conversion device connected to the induction rotating machine applies a load torque that hinders rotation to the induction rotating machine, causing the induction rotating machine to operate as a heat generator. The generated heat is stored in a heat accumulator through a heat medium circulation mechanism, and when power demand is at its peak but the wind turbine is not rotating, the heat stored in the heat accumulator is used to generate electricity in a thermal generator.

[0005] However, this system requires the use of an induction motor, a power converter, and a thermal generator, which results in a complex, large-scale structure and high costs. In addition, when the induction motor is used as a heat generator, a current must be continuously supplied to the induction motor to prevent it from rotating, resulting in a lot of power waste.

[0006] The present invention has been proposed in view of the above, and aims to provide a combined heat and power generation system that can generate heat and power with a compact structure, making the entire device lightweight and inexpensive, and capable of operating at high efficiency at all times, particularly when the power source is a wind turbine. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a combined heat generation / power generation system comprising a fluid-type heater having an annular pump connected to a power source and rotating, an annular turbine arranged opposite the pump, and an annular stator arranged between the pump and the turbine, and which generates heat by circulating a working fluid between the pump, the turbine and the stator through the rotation of the pump, a generator having a rotor connected to the turbine of the fluid-type heater and connected in series to the fluid-type heater, and a case that houses the fluid-type heater and the generator so as to hold the stator of the generator surrounding the rotor inside, and whose first feature is that it has a brake mechanism that can arbitrarily switch between allowing or preventing the turbine and rotor from rotating relative to the case.

[0008] In addition to the first feature, the present invention has a second feature in that the fluid heater has a clutch that can mechanically connect and disconnect the pump and the turbine.

[0009] Furthermore, in addition to the first or second feature, the present invention has a third feature in that the stator of the fluid type heater is fixed to the turbine or the case in a detachable or replaceable manner. Effect of the Invention

[0010] According to a first feature of the present invention, a fluid-type heater having an annular pump connected to a power source, an annular turbine arranged opposite the pump, and an annular stator arranged between the pump and the turbine, and a generator having a rotor connected to the turbine of the fluid-type heater are connected in series, and the fluid-type heater and generator are housed within a case that holds the stator of the generator surrounding the rotor inside, thereby making it possible to compactly arrange a mechanism for converting the rotational power of the power source into thermal energy and electrical energy.

[0011] Furthermore, the brake mechanism can be used to freely switch the turbine, rotor, and case between a state in which they can rotate relative to one another and a state in which they cannot rotate relative to one another.This makes it possible to easily switch between a heat generation mode in which the brake mechanism is activated to fix the turbine and rotor to the case and rotate only the pump of the fluid-type heater, causing the working fluid circulating between the pump, turbine, and stator to generate heat, and a heat generation / power generation mode in which the brake mechanism is released to rotate the pump, turbine, and rotor together, and combines heat generation by the working fluid circulating through the fluid-type heater with power generation by the generator due to rotation of the rotor.

[0012] Furthermore, when a heater is connected to a wind turbine, the efficiency of the wind turbine can be maximized by adjusting the pump capacity of the heater so as to obtain a circumferential speed ratio (ratio of the tip speed of the wind turbine blades to the wind speed) at which the power coefficient of the wind turbine is maximized, but since the fluid type heater of the present invention has a fluid coupling structure in which the input torque is proportional to the square of the rotation speed, the output torque of the wind turbine connected to the power transmission shaft of the heater can always be proportional to the square of the rotation speed of the wind turbine. Therefore, once the pump capacity of the fluid type heater is adjusted to obtain a circumferential speed ratio at which the power coefficient of the wind turbine is maximized, it is possible to obtain a circumferential speed ratio at which the power coefficient is always maximized even if the wind speed changes, and so the wind turbine can always be operated at maximum efficiency without special control of the wind turbine.

[0013] According to a second feature of the present invention, in addition to the brake mechanism, the fluid heater has a clutch that can mechanically connect or disconnect the pump and turbine, so that when the fluid heater of the present invention is not used as a heater, the pump and turbine can be mechanically connected by operating the clutch with the brake mechanism released, and the rotational power of the power source can be transmitted directly from the turbine connected to the pump to the rotor of the generator. In this case, the fluid heater can function as a torque converter with a lock-up mechanism, so that the torque required to start rotation can be kept small at the beginning of the rotation of the power source, while power transmission loss between the pump and the turbine can be eliminated when the power source is in a steady state of rotation.

[0014] Furthermore, according to a third feature of the present invention, the stator of the fluid-type heat generator is fixed to the turbine or case in a detachable or replaceable manner, so that the pump capacity of the fluid-type heat generator can be changed to suit the characteristics of various wind turbines simply by changing the stator. This makes it possible to easily configure a combined heat generation / power generation system that is compatible with a wide variety of wind turbines, each of which has a different circumferential speed ratio that maximizes the power coefficient, without having to change the blade shape of the pump and turbine. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a configuration in which the heat generation / power generation combined system of the first embodiment is applied to a vertical axis wind turbine. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing a configuration in which the heat generation / power generation combined system of the second embodiment is applied to a vertical axis wind turbine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] First and second embodiments of the present invention will be described below with reference to the accompanying drawings.

[0017] As shown in FIG. 1, the heat generation / power generation combined system 1 of the first embodiment has a fluid type heater 3 and a generator 4, each of which is disposed in a case 2. The fluid type heater 3 has an annular pump 7 connected to a vertical axis type windmill 5, which is a power source, via a power transmission shaft 6, an annular turbine 8 disposed opposite the pump 7, and an annular stator 9 disposed between the pump 7 and the turbine 8. An upper half constituting the turbine 8 and a lower half extending downward from the outer periphery of the turbine 8 and covering the entire pump 7 from the outside form a sealed space. By the rotation of the pump 7 receiving the rotational power of the windmill 5, oil 10 as a working fluid filled in the fluid type heater 3 is circulated in a spiral passage 3a between the pump 7, the turbine 8, and the stator 9 to generate heat. Note that other fluids, such as water, can also be used as the working fluid.

[0018] The power transmission shaft 6 extends downward from the wind turbine 5 in the direction of gravity, is inserted into the case 2 through a through hole 2a in the top surface of the case 2, and passes through the central axis 8a of the turbine 8 and the central axis 9a of the stator 9 of the fluid-type heater 3, and is connected to the pump 7 of the fluid-type heater 3 which is placed on the top surface of the generator 4 within the case 2.

[0019] The central shaft 8a of the turbine 8 surrounds the central shaft 9a of the stator 9 so as to form a hub of the turbine 8 and is rotatable relative to the central shaft 9a, and one end 9a1 of the central shaft 9a of the stator 9 is detachably fixed to the periphery of the through hole 2a of the case 2 by a bolt 2a1 or the like. The other end 9a2 of the central shaft 9a of the stator 9 is connected to a hub 9c of the stator 9 via a one-way clutch 9b, and the power transmission shaft 6 is held inside the central shaft 9a of the stator 9 so as to be rotatable relative to the central shaft 9a.

[0020] The one-way clutch 9b, like the one-way clutch of the stator hub of a normal torque converter, fixes the stator 9 to the case 2 so as not to rotate up to a specific speed range of the wind turbine 5, and allows the stator 9 to rotate freely when the specific speed range is reached, thereby amplifying the torque at the beginning of the rotation of the wind turbine 5 and keeping the torque required at the start of the rotation small, but if such a one-way clutch 9b is not required, it can be omitted. Also, in the first embodiment, the stator 9 is attached to the case 2, but it is also possible to detachably attach it to the central shaft 8a, which is the hub of the turbine 8, without using a one-way clutch.

[0021] A circulation pipe 12 is connected inside the fluid-type heater 3 to circulate the oil 10 inside the fluid-type heater 3 between the oil 10 and an external heat storage unit 11, and a circulation pump 13 is interposed midway along the circulation pipe 12. The heat storage unit 11 is for storing heat generated inside the fluid-type heater 3, and releases the stored heat where necessary.

[0022] The generator 4 has a rotor 4a connected to the turbine 8 of the fluid heater 3 and a stator 4b surrounding the rotor 4a, the rotor 4a being arranged coaxially with the power transmission shaft 6, and the stator 4b being held inside the case 2 by a fixing means 2b that coaxially surrounds the rotor 4a. A wiring 14 for sending generated power to the outside is connected to the stator 4b of the generator 4, and a wiring 16 for connecting power to a power storage unit 15 branches off from the wiring 14 as needed. The case 2, the power storage unit 15, and the above-mentioned heat storage unit 11 are fixedly arranged on a floor 17, roof, ground, or the like of a building.

[0023] In order to connect the generator 4 to the turbine 8, a disk 18 coaxial with the rotor 4a is fixed to the upper surface of the rotor 4a of the generator 4, and a fixed portion 3c that is fixed to the disk 18 is formed on the lower surface of the lower half of the fluid heater 3. A brake mechanism 19 is disposed around the disk 18 and is fixed to the case 2 and includes brake pads 19a that sandwich the peripheral surface of the disk 18 from above and below.

[0024] The brake mechanism 19 can arbitrarily switch the turbine 8 and the rotor 4a relative to the case 2 between a state in which they can rotate relative to each other and a state in which they cannot rotate relative to each other. By activating the brake mechanism 19 and clamping the circumferential surface of the disk 18 from above and below with brake pads 19a, the turbine 8 and the rotor 4a can be fixed to the case 2, and by releasing the operation of the brake mechanism 19 and moving the circumferential surface of the disk 18 away from the brake pads 19a, the fixation of the turbine 8 and the rotor 4a to the case 2 can be released.

[0025] As a result, by operating the brake mechanism 19 and fixing the turbine 8 and the rotor 4a to the case 2, only the pump 7 of the fluid heater 3 can be rotated, thereby obtaining a heat generation mode in which the oil 10 circulating between the pump 7, the turbine 8, and the stator 9 is effectively heated. Also, by releasing the brake mechanism 19 and rotating the pump 7, the turbine 8, and the rotor 4a together, a heat generation / power generation mode can be obtained in which heat is generated by the oil 10 circulating through the fluid heater 3 and power is generated by the generator 4 due to the rotation of the rotor 4a. These two modes can be easily switched by simply operating the brake mechanism 19.

[0026] Next, the operation of the first embodiment of the present invention having the above configuration will be described.

[0027] In this embodiment, a fluid-type heater 3 having an annular pump 7 connected to the wind turbine 5, which is the power source, by a power transmission shaft 6, an annular turbine 8 arranged opposite the pump 7, and an annular stator 9 arranged between the pump 7 and the turbine 8, and a generator 4 having a rotor 4a connected to the turbine 8 of the fluid-type heater 3 are connected in series, and the fluid-type heater 3 and generator 4 are stored within a case 2 that holds the stator 4b of the generator 4 surrounding the rotor 4a inside, so that the mechanism for converting the rotational power of the wind turbine 5, which is the power source, into thermal energy or electrical energy can be compactly constructed.

[0028] In addition, the brake mechanism 19 can be used to freely switch the turbine 8 and rotor 4a against the case 2 between a state in which they can rotate relative to one another and a state in which they cannot rotate relative to one another. This makes it possible to easily switch between a heat generation mode in which the brake mechanism 19 is operated to fix the turbine 8 and rotor 4a to the case 2 and rotate only the pump 7 of the fluid-type heater 3, thereby causing heat to be generated by the oil 10 circulating between the pump 7 and the turbine 8 and the stator 9, and a heat generation / power generation mode in which the brake mechanism 19 is released to rotate the pump 7, turbine 8 and rotor 4a together and use both heat generation by the oil 10 circulating through the fluid-type heater 3 and power generation by the generator 4 due to the rotation of the rotor 4a.

[0029] When wind energy is converted into mechanical power by the wind turbine 5 as in this embodiment, it is desirable to maximize the power coefficient Cp, which is the conversion efficiency. The power coefficient Cp of the wind turbine 5 changes parabolically in response to the tip speed ratio λ, which is the ratio (Vr / V) of the wind turbine blade tip speed Vr to the wind speed V, and so there is a tip speed ratio λ at which the power coefficient Cp is maximized somewhere along the way. However, in conventional wind turbines, when the wind speed V changes, the wind turbine rotation speed N changes, which in turn changes the tip speed ratio λ. Therefore, even if the tip speed ratio λ at which the power coefficient Cp is maximized at a specific wind speed V is obtained, the tip speed ratio λ at which the power coefficient Cp is maximized cannot be obtained when the wind speed V changes.

[0030] However, in this embodiment, the rotational energy of the wind turbine 5 is converted into thermal energy by the fluid heater 3 using a fluid coupling, so even if the wind speed V changes, it is possible to obtain a peripheral speed ratio λ that always maximizes the power coefficient Cp, and the wind turbine can always be operated at maximum efficiency without special control of the wind turbine. The reason for this is explained below.

[0031] The output power E of a wind turbine is given by the following equation, where Cp is the power coefficient, ρ is the air density, A is the pressure-receiving area of ​​the blade, and V is the wind speed. E=Cp×(1 / 2)×ρ×A×V 3 ...(1) It can be expressed as: Here, d is the diameter of the rotor blade, λ is the tip speed ratio, Vr is the tip speed of the wind turbine blade, and N is the rotation speed of the wind turbine. V=Vr / λ Vr=πdN / 60 Since, V=πdN / 60λ Therefore, equation (1) can be expressed as follows: E=Cp×(1 / 2)×ρ×A×(πdN / 60λ) 3 ...(2) Furthermore, if the output torque of the wind turbine is T, the output torque T is expressed as follows: T = 60E / 2πN (3) Therefore, from equations (2) and (3), the relationship between T and N can be expressed as follows: T=60×(Cp×(1 / 2)×ρ×A×(πdN / 60λ) 3 / 2πN = {(Cp × ρ × A × π 2 d 3 ) / (4×60 2 ×λ 3 )}×N 2 ...(4) It can be expressed as:

[0032] Equation (4) is (Cp×ρ×A×π 2 d 3 ) / (4×60 2 ×λ 3 ) is constant, the output torque T of the wind turbine 5 is proportional to the square of the rotation speed N of the wind turbine 5. However, conversely, if the output torque T of the wind turbine 5 is made proportional to the square of the rotation speed N of the wind turbine, then (Cp×ρ×A×π 2 d 3 ) / (4×60 2 ×λ 3 ) is a proportional constant and is fixed at a constant value, that is, T ∝ N 2 If this is the case, it also shows that the power coefficient Cp and the tip speed ratio λ, which change correspondingly, can always be fixed to constant values ​​regardless of the wind speed V.

[0033] However, as is well known, since the input torque of a fluid coupling is proportional to the square of the rotation speed N, if a fluid coupling is connected to the wind turbine 5 as a member that receives the output of the wind turbine 5, the output torque T of the wind turbine 5 can be made to be always proportional to the square of the rotation speed N of the wind turbine 5. Since the fluid type heater 3 of this embodiment has a fluid coupling structure in which the input torque T is proportional to the square of the rotation speed N, the output torque of the wind turbine 5 connected to the power transmission shaft 6 of the fluid type heater 3 can be made to be always proportional to the square of the rotation speed N of the wind turbine 5. Therefore, once the pump capacity of the fluid type heater 3 is adjusted to obtain a peripheral speed ratio at which the power coefficient of the wind turbine is maximized, a peripheral speed ratio at which the power coefficient is always maximized can be obtained even if the wind speed changes, and therefore the wind turbine can be always operated at maximum efficiency without special control of the wind turbine.

[0034] Next, a heat generation / power generation combined system according to a second embodiment of the present invention will be described with reference to FIG.

[0035] The combined heat generation / power generation system of the second embodiment of the present invention differs from the combined heat generation / power generation system of the first embodiment in that the fluid heater 3 has a clutch 20 that can mechanically connect or disconnect the pump 7 and the turbine 8.

[0036] This clutch 20 is disposed between the pump 7 in the fluid heater 3 and the bottom wall of the lower half 3b of the fluid heater 3 connected to the turbine 8, and has a structure similar to that of a lock-up clutch in a normal torque converter. That is, this clutch 20 is attached to the pump 7 so as to be non-rotatable relative to the pump 7 and movable in the axial direction, and in the normal open state is separated from the bottom wall of the lower half 3b of the fluid heater 3, but by applying hydraulic pressure or the like between the pump 7 and the clutch 20, it moves toward the bottom wall and enters a connected state in which the pump 7 and the turbine 8 connected to the fluid heater 3 are mechanically connected.

[0037] Since the combined heat generation / power generation system of the second embodiment has the configuration as described above, when the fluid type heater 3 of the second embodiment is used as a heater, by releasing the clutch 20, it is possible to obtain the same modes as the combined heat generation / power generation system of the first embodiment, i.e., a heat generation mode in which the brake mechanism 19 is operated to rotate only the pump 7 and effectively generate heat in the oil 10 circulating between the pump 7 and the turbine 8 and the stator 9, and a heat generation / power generation mode in which the operation of the brake mechanism 19 is released and heat generation by the circulation of the oil 10 and power generation by the generator 4 due to the rotation of the rotor 4a are used in combination. Furthermore, when the fluid type heater 3 of the second embodiment is not used as a heater, by operating the clutch 20 with the brake mechanism 19 released, the pump 7 and the turbine 8 are mechanically connected, and the rotational power of the windmill 5 can be directly transmitted from the turbine 8 connected to the pump 7 to the rotor 4a of the generator 4.

[0038] In this way, the combined heat generation / power generation system of the second embodiment can cause the fluid heater 3 to function as a torque converter with a lock-up mechanism when it is not being used as a heat generator. By using this in combination with the one-way clutch 9b, it is possible to keep the torque required to start rotation low at the beginning of the rotation of the wind turbine 5, while eliminating power transmission loss between the pump 7 and the turbine 8 when the rotation of the wind turbine 5 is in a steady state.

[0039] Moreover, in both the first and second embodiments of the combined heat generation / power generation systems, the stator 9 of the fluid-type heater 3 is fixed to the case 2, so that even if a differential rotation occurs between the pump 7 and the turbine 8 when transmitting power to the generator 4, the characteristics of the fluid-type heater 3 can be kept constant, and because the stator 9 is detachable or replaceable from the case 2, the pump capacity of the fluid-type heater 3 can be changed to suit the characteristics of various wind turbines simply by changing the stator, making it possible to easily configure a combined heat generation / power generation system that is compatible with a wide variety of wind turbines each having different circumferential speed ratios that maximize the power coefficient, without changing the blade shape of the pump and turbine.

[0040] Furthermore, if the one-way clutch 9b is not required, the stator 9 can be easily changed to one that does not use the one-way clutch 9b, so that the characteristics of the fluid-type heater 3 can be easily changed in accordance with the characteristics of the power source.

[0041] As described above, in the heat generation / power generation combined systems of the first and second embodiments, the stator 9 of the fluid type heater 3 can also be detachably or replaceably fixed to the turbine 8 without using the one-way clutch 9b. In this case, the fluid type heater 3 cannot function as a normal torque converter, but similar to the case where the stator 9 is fixed to the case 2, the pump capacity of the fluid type heater 3 can be changed to suit the characteristics of various wind turbines 5 simply by changing the stator, and the pump capacity of the fluid type heater 3 can also be changed simply by changing the phase (relative mounting angle) of the stator with respect to the turbine 8, so that the pump capacity can be easily changed just by changing the phase.

[0042] Although the embodiment of the present invention has been described above, various design changes can be made to the present invention without departing from the gist of the present invention. For example, the direction in which the power transmission shaft 8 extends may be horizontal, and the power source is not limited to the wind turbine 9. [Explanation of symbols]

[0043] 2. Case 3. Fluid type heater 4. Generator 4a Rotor 4b Stator 5. Windmills as a power source 7. Pump 8. Turbine 9. Stator 10. Oil as a working fluid 19. Brake mechanism 20. Clutch

Claims

1. a fluid heater having an annular pump that is connected to a power source and rotates, an annular turbine that is disposed opposite the pump, and an annular stator that is disposed between the pump and the turbine, and which generates heat by circulating a working fluid between the pump, the turbine, and the stator as the pump rotates; a generator having a rotor connected to the turbine of the fluid-type heat generator and connected in series to the fluid-type heat generator; a case that houses the fluid-type heater and the generator so as to hold a stator of the generator surrounding the rotor therein, A combined heat generation / power generation system comprising a brake mechanism that can arbitrarily switch between allowing relative rotation between the turbine and rotor and the case or preventing relative rotation between the turbine and rotor and the case.

2. 2. The combined heat and power generation system according to claim 1, wherein the fluid type heat generator has a clutch capable of mechanically connecting or disconnecting the pump and the turbine.

3. 3. The combined heat and power generation system according to claim 1, wherein the stator of the fluid type heat generator is fixed to the turbine or the case in a detachable or replaceable manner.

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