TWI557314B - Energy conversion apparatus - Google Patents

Description

Energy extraction device

The present invention relates to an energy extraction device, and more particularly to an energy extraction device for extracting energy from fluid fluctuations.

With the rapid decline of the world's crude oil reserves, renewable energy with clean, sustainable, low carbon content, low pollution, such as: solar energy, wind power, geothermal energy, ocean energy, biomass energy and fuel cells, etc. It has gradually received the attention of the world. In these clean energy sources, wave power generation uses the energy of wave fluctuations to convert to the rotational kinetic energy of the turbine, and then use the generator to generate electricity or directly output shaft power.

In general, the types of wave power generation equipment are Oscillating water column, Oscillating Wave Surge, Overtopping device, Submerged pressure differential, and point absorption type (Point). Absorber, Attenuator. However, in the above-mentioned system, in the energy transfer, the efficiency of the conversion of kinetic energy into electrical energy is ineffective due to the complexity of the mechanism system.

In addition, the ocean wave energy is affected by wind and climate. In different seasons and regions, the wave height and cycle are probabilistic, and the wave energy external force will also be different. Therefore, how to effectively extract wave energy under various environmental conditions has also been studied.

In summary, one can reduce the loss of energy conversion and can have The energy extraction device that takes advantage of the fluid fluctuation energy is highly demanded.

In view of the above, it is an object of the present invention to provide an energy extraction device for extracting energy from fluid fluctuations.

An energy extraction device according to an embodiment of the present invention includes a fixed structure, a floating member, a connecting member, and a power module. The fixed structure is configured to be stationary relative to the fluid. The floating member is configured to float on the fluid. The connecting member has a front end pivoting portion and a rear end pivoting portion. The connecting member is pivotally connected to the floating member by the front end pivoting portion, and the connecting member is pivotally connected to the fixing structure by the rear end pivoting portion. The power module is configured to draw energy generated when the connecting member pivots relative to the floating member and the fixed structure.

In the above embodiment, the floating member includes the rod member and the body. One end of the rod is pivotally connected to the connecting member and is pivotable about the front pivot axis. The body is coupled to the other end of the rod. And, the body extends toward opposite sides in a direction parallel to the first pivot axis.

In the above embodiment, the ratio of the distance between the front end pivot portion and the rear end pivot portion to the length of the rod is between about 0.2 and about 1.

In the above embodiment, the cross section of the body may be any shape, and the extended section of the body may be a non-uniform section.

In the above embodiment, the 撷 energy module includes a front end energy absorbing member disposed between the floating member and the connecting member.

In the above embodiment, the 撷 energy module includes a rear end energy absorbing member disposed between the fixed structure and the connecting member.

In the above embodiment, the first elastic member is disposed on the floating member Between the connecting member and the connecting member to maintain the position of the floating member.

In the above embodiment, the connecting member includes a front end portion adjacent to the front end pivot portion and a rear end portion adjacent to the rear end pivot portion, wherein the position at which the connecting member connects the first elastic member is located at a front end portion thereof and a front end pivot portion thereof Between, to control the frequency response of the energy extraction device.

In the above embodiment, the energy extraction device further includes a second elastic member disposed between the fixed structure and the connecting member to maintain the position of the connecting member.

An energy extraction device according to another embodiment of the present invention includes a suspension member, a floating member, a connecting member, and a power module. The suspension member and the floating member are configured to float on the fluid. The connecting member has a front end pivoting portion and a rear end pivoting portion. The connecting member is pivotally connected to the floating member by the front end pivoting portion, and the connecting member is pivotally connected to the floating member by the rear end pivoting portion. The power module is configured to draw energy generated when the connecting member pivots relative to the floating member and the floating member.

In the above embodiment, the ratio of the distance between the front end pivot portion and the rear end pivot portion to the length of the rod is between about 0.2 and about 1.

In the above embodiment, the cross section of the body may be any shape, and the extended section of the body may be a non-uniform section.

In the above embodiment, the 撷 energy module includes a front end energy absorbing member disposed between the floating member and the connecting member.

In the above embodiment, the 撷 energy module includes a rear end energy absorbing member disposed between the suspension member and the connecting member.

In the above embodiment, the first elastic member is disposed on the floating member Between the connecting member and the connecting member to maintain the position of the floating member.

In the above embodiment, the connecting member includes a front end portion adjacent to the front end pivot portion and a rear end portion adjacent to the rear end pivot portion, wherein the position at which the connecting member connects the first elastic member is located at a front end portion thereof and a front end pivot portion thereof between.

In the above embodiment, the energy extraction device further includes a second elastic member disposed between the suspension member and the connecting member to control the frequency response of the energy extraction device.

In the above embodiment, the weight ratio of the suspension member to the floating member needs to be greater than or equal to 3.

The energy extraction device can effectively extract the energy of the floating member in the direction of the surge and the heave, thereby improving the energy conversion efficiency of the energy extraction device, thereby reducing the power generation cost.

1, 2‧‧‧ power generation system

30‧‧‧Fan

50‧‧‧ plane (seabed)

51‧‧‧ Fluid (seawater)

60‧‧‧ breakwater

61‧‧‧ top

70‧‧‧Architecture

100, 100a, 100b, 100c‧‧‧ energy extraction equipment

110, 110a, 110b‧‧‧ fixed structure

111‧‧‧Bottom

113, 113a‧‧‧ upper end

120, 120a, 120b‧‧‧ connecting members

121‧‧‧ front end

123‧‧‧ Back end

125, 125a, 125b‧‧‧ front end pivot

127, 127a, 127b‧‧‧ back end pivot

130, 130a, 130b‧‧‧ floating components

131, 131a, 131b‧‧‧ rods

1311‧‧‧ Back end

1313‧‧‧ front end

133, 133a, 133b‧‧‧ ontology

1331‧‧‧Base

1335‧‧‧ Floating elements

140‧‧‧First elastic member

140a‧‧‧Flexible components

150‧‧‧Second elastic member

160‧‧‧Enable module

161‧‧‧ front-end energy components

163‧‧‧ Back-end energy components

170‧‧‧suspension components

D1‧‧‧ undulation direction

D2‧‧‧ directional direction

L1‧‧‧ spacing

L2‧‧‧ length

M1‧‧‧First motion track

M2‧‧‧Second motion track

P1‧‧‧ front pivot shaft

P2‧‧‧Back end pivot shaft

Figure 1 shows a schematic diagram of an energy harvesting device in accordance with one embodiment of the present invention.

Fig. 2 is a graph showing the relationship between the energy absorption rate of the floating body of the present invention and the fluid motion period.

Fig. 3 is a view showing a power generation system of an embodiment of the present invention.

Fig. 4 is a view showing a power generation system according to another embodiment of the present invention.

Fig. 5 is a view showing an energy extraction device according to another embodiment of the present invention.

In the following, a number of specific preferred embodiments will be described in detail with reference to the accompanying drawings, which illustrate several embodiments. However, the invention can be embodied in many different forms and is not limited to the embodiments described below, which are provided herein. The examples are intended to provide a more thorough and complete disclosure of the invention, and the scope of the invention is fully disclosed to those skilled in the art.

Referring to Figure 1, there is shown a schematic diagram of an energy extraction device 100 in accordance with one embodiment of the present invention. The energy extraction device 100 is used to extract energy from a fluid fluctuation, such as wave fluctuation energy. In one embodiment, the energy extraction device 100 includes a fixed structure 110 , a connecting member 120 , a floating member 130 , a first elastic member 140 , a second elastic member 150 , and a thermal module 160 .

The fixed structure 110 is secured to a plane 50 (e.g., the sea floor) and is stationary relative to the fluid 51. A portion of the fixed structure 110 adjacent to its lower end portion 111 is immersed in a fluid 51 (e.g., seawater), and a portion of the fixed structure 110 adjacent to its upper end portion 113 extends perpendicularly from the surface of the fluid 51 (e.g., a seawater surface). In one embodiment, the length of the fixed structure 110 extending from the fluid 51 is greater than the height difference between the maximum height and the lowest height of the fluid 51. For example, the length of the fixed structure 110 extending from the fluid 51 is greater than the tidal range of the sea area set by the energy extraction device 100. Therefore, when the fluid is at the maximum height, the portion of the fixed structure 110 adjacent to its upper end portion 113 is not immersed in the fluid 51. The effect of this feature will be described later with respect to the method of operation of the energy extraction device 100.

The connecting member 120 includes a front end pivoting portion 125 and a rear end pivoting portion 127. In an embodiment, the front end pivot portion 125 is adjacent to the front end portion 121 of the connecting member 120. The front end pivot portion 125 is spaced apart from the front end portion 121 by a distance. The rear end pivot portion 127 is located on the rear end portion 123 of the connecting member 120. The connecting member 120 is pivotally connected to the floating member 130 by the front end pivoting portion 125 , and the connecting member 120 is pivotally connected to the fixing structure 110 by the rear end pivoting portion 127 . With the above configuration, the connecting member 120 The pivoting member 130 is pivotable relative to the floating member 130 about a front pivot axis P1, and the connecting member 120 is pivotable relative to the fixed structure 110 about a rear pivot axis P2. In an embodiment, the front end pivot axis P1 and the rear end pivot axis P2 are parallel to each other. However, the present invention is not limited thereto, and the front end pivot shaft P1 may also be skewed with respect to the rear end pivot axis P2. With the above configuration, the energy extraction device 100 has two degrees of freedom of motion.

The connecting member 120 can be pivoted with the fixed structure 110 and the floating member 130 in various ways, for example, by a single pivot point or a plurality of pivot points about the front pivot axis P1 or the rear pivot axis P2. Additionally, the connecting member 120 can be pivotally coupled to the fixed structure 110 and the floating member 130 using a hinge structure or any other pivotable structure.

The floating member 130 includes a rod 131 and a body 133. The rear end portion 1311 of the rod member 131 is pivotally connected to the front end pivot portion 125 of the connecting member 120, and the front end portion 1313 of the rod member 131 is coupled to the body 133. In an embodiment, the distance L1 between the front end pivot portion 125 and the rear end pivot portion 127 of the connecting member 120 is smaller than the length L2 of the rod 131. In an embodiment, the ratio of the distance L1 between the front end pivot portion 125 and the rear end pivot portion 127 of the connecting member 120 to the length L2 of the rod member 131 is between about 0.2 and about 1, thereby increasing energy. Learn efficiency.

The body 133 is configured to float on the fluid 51. In an embodiment, the body 133 has a circular cross section and has a substantially strip shape. Specifically, the body 133 extends in two opposite directions from the front end portion 1313 of the rod member 131 in a direction parallel to the front end pivot axis P1. However, the length and cross-sectional shape of the body 133 can be adjusted depending on the application and is not limited by the above embodiments. In another embodiment, the cross section of the body 133 can be any shape, and the extension of the body 133 The face can be a non-uniform section.

It should be noted that in an embodiment, the body 133 is fixed to the front end portion 1313 of the rod member 131, and the body 133 and the rod member 131 have no movement capability. A portion or the entirety of the rod member 131 and the body 133 may be formed in an integrally formed manner. Alternatively, body 133 can be secured to front end 1313 of lever member 131 by any suitable means (e.g., locking).

The first elastic member 140 is disposed between the connecting member 120 and the floating member 130. In one embodiment, the first elastic member 140 is a linear spring, and one end thereof is coupled to a portion of the connecting member 120 between the front end pivot portion 125 and the front end portion 121, and the other end thereof is coupled to the rod member 131. The first elastic member 140 is configured to provide the floating member 130 with a restoring force, thereby improving the energy extraction efficiency and controlling the frequency response of the energy extraction device 100.

The second elastic member 150 is disposed between the connecting member 120 and the fixed structure 110. In one embodiment, the second elastic member 150 is a linear spring having one end coupled to the fixed structure 110 and the other end coupled to the connecting member 120. The second resilient member 150 is configured to provide a restoring force to the connecting member 120, thereby controlling the frequency response of the energy extraction device 100.

It should be noted that, in the above embodiment, although the energy extraction device 100 includes the first elastic member 140 and the second elastic member 150, it is not limited thereto. In another embodiment, the energy extraction device 100 includes only the first resilient member 140. The movement of the connecting member 120 relative to the fixed structure 110 is not limited. In another embodiment, the energy extraction device 100 includes only the second resilient member 140, and the movement of the floating member 130 relative to the connecting member 120 is not limited.

In another embodiment not shown, the first elastic member 140 and The second elastic members 150 are respectively a torsion spring, and the first elastic members 140 and the second elastic members 150 are respectively disposed in the front end pivot portion 125 and the rear end pivot portion 127.

The 模组 energy module 160 is configured to capture kinetic energy generated when the connecting member 120 pivots relative to the floating member 130 or the fixed structure 110. The power module 160 can include one or more piezoelectric components. In one embodiment, the xenon module 160 includes a front end energy member 161 and a rear end energy member 163. The front end energy absorbing member 161 is disposed between the connecting member 120 and the floating member 130 and configured to capture the kinetic energy generated when the connecting member 120 pivots relative to the floating member 130. The rear end energy component 163 is disposed between the fixed structure 110 and the connecting member 120 and configured to capture the kinetic energy generated when the connecting member 120 pivots relative to the fixed structure 110. It can be understood that the number of the 撷 energy components of the 模组 module 160 is not limited by the above embodiments. Depending on the application, the number of components can be increased or decreased as appropriate. In addition, the type of the power module 160 should not be limited by the above embodiments. The energy module 160 can be any energy conversion device that converts mechanical energy into electrical energy, such as a linear generator, a torsion generator, or a hydraulic generator.

In one embodiment, the front end energy component 161 and the rear end energy component 163 each comprise a drive-through generator that utilizes energy from the fluid 51 to generate electrical power or other available energy. In another embodiment, the front end energy component 161 and the rear end energy component 163 each include a hydraulic generator that utilizes energy from the fluid 51 to generate electrical power or other available energy. In one embodiment, the xenon module 160 is not immersed in the fluid 51 to increase the life of the xenon module 160 and facilitate maintenance.

With continued reference to FIG. 1, in accordance with one embodiment of the present invention, the operation of the energy extraction device 100 is illustrated as follows: when the energy extraction device 100 is used to extract energy fluctuating from the fluid 51, the floating member 130 floats on the fluid 51. . In an embodiment, the direction of extension of the floating member 130 is perpendicular to the direction of travel of the fluid 51, thereby increasing the amount of power generated by the energy extraction device 100.

Then, when the fluid 51 fluctuates, the fluid 51 can drive the floating member 130 to pivot relative to the connecting member 120 about the front pivot axis P1, and/or the fluid 51 can drive the connecting member 120 to pivot about the rear end relative to the fixed structure 110. P2 pivots. In this way, the driving function module 160 can capture the kinetic energy generated when the connecting member 120 pivots relative to the floating member 130 or the fixed structure 110, thereby generating electric power or other available energy.

In an embodiment, since the energy extraction device 100 has two degrees of freedom of motion, the floating member 130 can appropriately adjust its motion trajectory according to different movement modes of the fluid 51. For example, when the kinetic energy of the fluid 51 in the heave direction D1 is greater than the kinetic energy of the fluid 51 in the longitudinal direction D2, the center of the floating member 130 will move along a substantially elliptical first motion trajectory M2. . The floating member 130 has a higher energy absorption rate for the fluid 51 in the undulating direction D1. When the energy of the fluid 51 in the longitudinal direction D2 is greater than the energy of the fluid 51 in the undulating direction D1, the floating member 130 will move along a substantially elliptical second motion trajectory M1. The floating member 130 has a higher energy absorption rate for the fluid 51 in the longitudinal direction D2.

Please refer to FIG. 1 and FIG. 2 together. FIG. 2 is a graph showing the relationship between the energy absorption rate (%) of a floating body and the motion period (t) of the fluid 51. As can be seen from Fig. 2, when the fluid 51 is moved in different cycles, the floating member 130 has different energy absorption rates in various directions. Due to the floating member of the embodiment 130 has the property of adjusting its motion trajectory adaptively, and the efficiency of energy extraction by the energy extraction device 100 will not be affected by the motion cycle of the fluid 51, and a significant difference will occur.

The structural features of the energy extraction device 100 of the present invention may be varied as needed. The following may exemplarily provide a possible implementation of the energy extraction device 100: Please refer to FIG. 1 and FIG. 3 together, and FIG. 3 shows A schematic diagram of a power generation system 1 of one embodiment of the invention. The power generation system 1 includes a fan 30 and an energy extraction device 100a. In FIG. 3, the same or similar components of the energy extraction device 100a and the energy extraction device 100 will be given similar reference numerals, and their features will not be described again to simplify the description. The energy extraction device 100a includes a fixing structure 110a, a connecting member 120a, a floating member 130a, an elastic member 140a, and a heat dissipation module (not shown in FIG. 3). The energy module 160a is twisted. The generator is hidden in the front end pivot portion 125a or the rear end pivot portion 127a. The fan 30 is disposed at an upper end 113a of the fixed structure 110a and configured to convert wind energy into electrical energy or other applicable energy.

The connecting member 120a is pivotally connected to the fixing structure 110a by a rear end pivoting portion 127a, and the connecting member 120a is pivotally connected to the floating member 130a by a front end pivoting portion 125a. In an embodiment, the front end pivoting portion 125a and the rear end pivoting portion 127a respectively have two pivoting points for pivotal connection with the fixed structure 110a and the floating member 130a. In one embodiment, the snubber module (not shown in FIG. 3) is a torsion generator disposed in the front end pivoting portion 125a or the rear end pivoting portion 127a and configured to capture the connecting member 120a. The kinetic energy generated when pivoting relative to the floating member 130a or the fixed structure 110a.

In an embodiment, the floating member 130a of the energy extraction device 100a A rod member 131a and a body 133a are included. Also, the body 133a includes a base 1331 and a floating element 1335. The rod member 131a and the base 1331 are integrally formed. The floating element 1335 is coupled to the opposite side of the base 1331 connecting the rods 131a. The base 1331 and the floating element 1335 can be made of different materials. For example, the rod member 131a and the base member 1331 may be made of a material having a high rigidity, for example, a steel for marine engineering; and the floating member 1335 may be made of a material having a small specific gravity, such as a plastic float.

In one embodiment, the fan 30 of the power generation system 1 and the energy extraction device 100a operate simultaneously. Since the power generation system 1 simultaneously draws wind energy by the wind turbine 30 and draws energy of the fluctuation of the fluid 51 by the energy extraction device 100a, the power generation amount of the power generation system 1 can be improved.

Referring to Figures 1 and 4 together, Figure 4 shows a schematic diagram of a power generation system 2 in accordance with an embodiment of the present invention. The power generation system 2 includes a plurality of energy extraction devices 100b. In FIG. 4, the same or similar components of the energy extraction device 100b and the energy extraction device 100 will be given similar reference numerals, and their features will not be described again to simplify the description. In one embodiment, the energy extraction device 100b includes a fixed structure 110b, a connecting member 120b, a floating member 130b, an elastic member (not shown in FIG. 4), and an energy module (not shown). Shown in Figure 4).

In an embodiment, the fixed structure 110b is disposed on the top 61 of a breakwater 60. Since the breakwater 60 is fixed above the plane 50, the fixed structure 110b is stationary relative to the fluid 51. The connecting member 120b is pivotally connected to the fixing structure 110b by a rear end pivoting portion 127b, and the connecting member 120b is pivotally connected to the floating member 130b by a front end pivoting portion 125b. The floating member 130b includes a rod 131b and A body 133b. The body 133b floats on the fluid 51 and has a hexagonal cross section. The elastic member (not shown in Fig. 4) is provided inside the front end pivot portion 125b. The snoring module (not shown in FIG. 4) is a torsion generator disposed in the front end pivoting portion 125b or the rear end pivoting portion 127b and configured to draw the connecting member 120b relative to the floating member 130b or The kinetic energy generated when the fixed structure 110b is pivoted.

In an embodiment, since the power generation system 2 simultaneously utilizes the energy of the fluctuations of the fluid 51 by the plurality of energy extraction devices 100b, the power generation amount of the power generation system 2 can be improved. On the other hand, with the arrangement of the breakwater 60, the power generation system 2 simultaneously has the purpose of attenuating the fluctuating energy of the fluid 51 to protect the building 70 from the fluctuating energy of the fluid 51.

Referring to Figure 5, there is shown a schematic diagram of an energy extraction device 100c in accordance with an embodiment of the present invention. In FIG. 5, the same or similar components of the energy extraction device 100c and the energy extraction device 100 will be given similar reference numerals, and their features will not be described again to simplify the description. The energy extraction device 100c differs from the energy extraction device 100 in that the energy extraction device 100c replaces the fixed structure 110 with a suspension member 170.

The suspension member 170 is configured to float on the fluid 51 and pivotally connect with the rear end pivot portion 127 of the connecting member 120. In an embodiment, the weight ratio of the suspension member 170 to the floating member 130 needs to be greater than or equal to 3. With the above configuration, when the floating member 130 and the suspension member 170 are driven by the fluid 51, the floating member 130 relatively moves relative to the suspension member 170, and generates electric power or other available energy by the energy module 160.

It should be understood that the number of the connecting member 120 and the floating member 130 The amount should not be limited by the above embodiments. In another embodiment not shown, the energy extraction device 100c includes a suspension member 170 and a plurality of connection members 120 and a floating member 130. Each connecting member 120 is pivotally connected to a floating member 130 , and the floating member 170 is pivotally connected to the plurality of connecting members 120 . With the above configuration, the energy extraction performance of the energy extraction device 100c will be further improved.

Although the present invention has been disclosed in its preferred embodiments, it is not intended to limit the invention, and the invention may be modified by those skilled in the art without departing from the spirit and scope of the invention. The scope of the present invention is defined by the scope of the appended claims.

50‧‧‧ plane (seabed)

51‧‧‧ Fluid (seawater)

100‧‧‧Energy extraction equipment

110‧‧‧Fixed structure

111‧‧‧Bottom

113‧‧‧Upper end

120‧‧‧Connecting components

121‧‧‧ front end

123‧‧‧ Back end

125‧‧‧ front-end pivoting

127‧‧‧Back end pivoting

130‧‧‧Floating components

131‧‧‧ rods

1311‧‧‧ Back end

1313‧‧‧ front end

133‧‧‧Ontology

140‧‧‧First elastic member

150‧‧‧Second elastic member

160‧‧‧Enable module

161‧‧‧ front-end energy components

163‧‧‧ Back-end energy components

D1‧‧‧ undulation direction

D2‧‧‧ directional direction

L1‧‧‧ spacing

L2‧‧‧ length

M1‧‧‧First motion track

M2‧‧‧Second motion track

P1‧‧‧ front pivot shaft

P2‧‧‧Back end pivot shaft

Claims (9)

An energy extraction device for extracting energy of a fluid fluctuation, comprising: a fixed structure configured to be stationary with respect to the fluid; a floating member configured to float on the fluid; and a connecting member having a front end a pivoting portion and a rear end pivoting portion, wherein the connecting member is pivotally connected to the floating member by the front end pivoting portion, and the connecting member is pivotally connected to the fixing structure by the rear end pivoting portion; An elastic member disposed between the floating member and the connecting member to maintain a position of the floating member; a second elastic member disposed between the fixed structure and the connecting member to control the frequency of the energy extracting device Responding to; and an energy module configured to capture energy generated when the connecting member pivots relative to the floating member or the fixed structure, wherein the energy module comprises: a front end energy component, Between the floating member and the connecting member; and a rear end energy member disposed between the fixed structure and the connecting member. The energy extraction device of claim 1, wherein the floating member comprises: a rod member pivotally connected to the connecting member and pivotable about a front pivot axis; and a body coupled to the body The other end of the rod, wherein the body extends toward opposite sides in a direction parallel to the front pivot axis. An energy extraction device as claimed in claim 2, wherein the former The ratio of the distance between the end pivoting portion and the rear end pivoting portion to the length of the rod is between about 0.2 and about 1. The energy extraction device of claim 1, wherein the connecting member comprises a front end adjacent to the front end pivot portion and a rear end portion adjacent to the rear end pivot portion, wherein the connecting member connects the first An elastic member is positioned between the front end portion and the front end pivot portion to control the frequency response of the energy extraction device. An energy extraction device for extracting energy of a fluid fluctuation, comprising: a suspension member and a floating member configured to float on the fluid; a connecting member having a front end pivot portion and a rear end pivot a connecting portion, wherein the connecting member is pivotally connected to the floating member by the front end pivoting portion, and the connecting member is pivotally connected to the floating member by the rear end pivoting portion; a first elastic member is disposed on the floating member Between the member and the connecting member to maintain the position of the floating member; a second elastic member disposed between the fixed structure and the connecting member to control the frequency response of the energy extracting device; and an energy module And configured to capture energy generated when the connecting member pivots relative to the floating member or the floating member, wherein the energy module includes: a front end energy member disposed on the floating member and the connecting member And a rear end energy component disposed between the fixed structure and the connecting member. An energy extraction device as claimed in claim 5, wherein the bleaching device The floating member includes: a rod member pivotally connected to the connecting member and pivotable about a front pivot shaft; and a body coupled to the other end of the rod, wherein the body pivots parallel to the front end The direction extends towards the opposite sides. The energy extraction device of claim 6, wherein a ratio of a distance between the front end pivot portion and the rear end pivot portion to a length of the rod is between about 0.2 and about 1. The energy extraction device of claim 5, wherein the weight ratio of the suspension member to the floating member is greater than or equal to 3. The energy extraction device of claim 5, wherein the connecting member comprises a front end adjacent to the front end pivot portion and a rear end portion adjacent to the rear end pivot portion, wherein the connecting member connects the first An elastic member is positioned between the front end portion and the front end pivot portion to control the frequency response of the energy extraction device.