JPH05306676A - Solid phase thermal energy generating system - Google Patents

Abstract

PURPOSE:To carry out power generation by using heat at an ordinary temperature or in a comparatively low temperature range near to the ordinary temperature. CONSTITUTION:This system is constituted of a reciprocating motion engine 1 carrying out reciprocating motion with a shape memory alloy as working elements 11,... 11, a motion converter 3 to convert the reciprocating motion of this reciprocating motion engine 1 and a generating device 4 rotated by this motion converter 3, and it is devised to realize a high density and compact generating system by acquiring small reciprocating motion by the reciprocating motion engine 1 by way of using comparatively low temperature heat and rotating the generating device 4 by this small reciprocating motion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state thermal energy power generation system. More specifically, the present invention includes, for example, city heat exhaust heat power generation, waste heat power generation of various industries, thermal heat power generation power generation of thermal power plants, cogeneration waste heat power generation, fuel cell waste heat power generation, The present invention relates to a solid-phase thermal energy power generation system used for power generation using a solar water heater.

[0002]

2. Description of the Related Art A large amount of relatively high temperature combustion gas is discharged from a power generation system or an industrial plant. For example, the combustion gas discharged from a gas turbine for thermal power generation reaches as high as 500 ° C or higher. Further, the gas discharged from a general industrial plant or the like also has heat of about 200 ° C to 400 ° C.

Therefore, the heat of the gas that has been conventionally discarded is recovered (cogeneration) so that it can be used as the heat itself in an exhaust heat boiler or a heat exchanger that operates even at a relatively low temperature, temperature difference power generation, etc. It is considered to be used to improve the thermal efficiency.

[0004]

However, in all cases, exhaust heat has been recovered to the extent that a sufficient temperature difference can be obtained, for example, to the extent that heat can be efficiently recovered by the exhaust heat boiler, heat exchanger, etc. In a state in which the temperature cannot be offset, for example, heat at room temperature or higher and less than about 100 ° C. is not recovered, but is directly discharged to the natural world. In particular, there has never been a conventional apparatus that continuously generates power using heat of less than about 100 ° C., which is industrially low temperature close to room temperature. For this reason, the heat from the power plant and various industrial equipment is still discharged at a temperature close to room temperature.

It is an object of the present invention to provide a solid-state thermal energy power generation system capable of generating electric power by utilizing heat in a room temperature or a relatively low temperature range close to it.

[0006]

In order to achieve the above object, the solid-state thermal energy power generation system of the present invention includes a reciprocating engine that reciprocates using a shape memory alloy as an actuating element, and a reciprocating motion of the reciprocating engine. It is composed of a motion conversion device for converting the motion into rotational motion and a power generation device rotated by the motion conversion device. Here, a heat transfer material and a heat pipe are inserted in the operating element of the reciprocating engine and its surroundings so that the heat supplied by the heat pipe is transferred to the operating element directly and via the heat transfer member. preferable. Alternatively, the actuating element of the reciprocating engine preferably transfers the heat supplied by the water directly to the actuating element. Further, it is more preferable to have a displacement amplification device that amplifies linear displacement and force of the reciprocating motion engine and transmits the force to the motion conversion device.

In the solid-state thermal energy power generation system of the present invention, a plurality of reciprocating motion engines are connected in cascade.

[0008]

The shape memory alloy operates with a relatively narrow temperature difference.
Moreover, the strain energy accumulated in this shape memory alloy is proportional to the volume of the shape memory alloy. However, the life of the shape memory alloy sharply shortens as the amount of strain increases. Therefore,
In order to prolong the life and increase the strain energy, this shape memory alloy is used as an actuating element for reciprocating motion, and it is mounted in a reciprocating engine with high density and a range of minute strain amount change, for example, 0.2. The actuating element is activated at .about.0.5%. The actuating element obtains strain by using a heat source at a relatively low temperature within the range of minute strain amount change. And
This strain is amplified by a displacement amplifying device and a force amplifying device as needed, or is converted into a rotary motion by a motion converting device as it is. This rotating motion rotates the generator to generate electricity.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows the principle of the solid-state thermal energy power generation system of the present invention. This power generation system includes a reciprocating engine 1 for converting solid-phase heat energy into reciprocating motion, a displacement amplifying device 2 for amplifying the reciprocating motion, a motion converting device 3 for converting the reciprocating displacement into rotation, and a motion converting device 3 And a generator 4 driven by the rotation obtained by.

The reciprocating engine 1 uses a shape memory alloy such as Nitinol alloy (NiTi) as the operating element 11, and heats the operating element 11 to a temperature near the transformation temperature and heat to cool it to a temperature lower than the transformation temperature. And at least heat sources 12 supplied alternately. For example, as shown in FIG. 2, a movable insulating partition wall 15 that is movable in the axial direction is provided between two insulating partition walls 13 and 14, and one or a plurality of pistons 16 are provided in this movable partition wall 15. Is fixed so that the movement of the movable partition wall 15 is transmitted to the piston 16, while actuating elements 11, 11 made of shape memory alloy are provided in the left and right chambers that sandwich the movable partition wall 15, respectively.
It is stuck between 5.

The actuating elements 11, 11 are partition walls 13, 1 respectively.
It is fixed to Nos. 4 and 15 and is provided so as to supply heat from both ends. Further, a heat pipe 18 is installed at an intermediate portion of the actuating element 11, and the heat pipe 18 supplies a predetermined amount of heat. And this movable partition wall 1
One of the left and right shape memory alloy actuating elements 11, 11 is heated at a temperature equal to or higher than the transformation temperature, while the other is heated at a lower temperature. The shape-memory alloy actuating element 11 is memorized in a shape such that it contracts when heat below the transformation temperature is applied and extends when heat above the transformation temperature is applied. The expansion / contraction rate at the transformation point of this shape memory alloy is 10 to 1 times that of phosphor bronze springs.
Since the force is 00 times and the force reaches 85 kg / mm ² , the movable partition wall 15 can be easily moved. The method of deforming the shape memory alloy is not particularly limited to expansion and contraction in the axial direction, and displacement in the axial direction may be obtained by bending or the like.

As a method of transferring heat to the shape memory alloy actuating element 11, for example, heat pipes 18 that come into contact with the shape memory alloy are respectively arranged, and the heat pipes 18 are used to heat heat above the transformation temperature or to heat it. Also, low cold heat can be applied alternately. In order to help transfer of heat by the heat pipe 18, a material having good thermal conductivity, for example, a filament 19 made of copper or the like is filled around the shape memory alloy rod 11. The heat is supplied to the heat pipe 18 by the heat switch 56 by switching between low temperature and high temperature.

The shape memory alloy actuating element 11 is not particularly limited. For example, as shown in FIG. 4, a rod-shaped plate [see (C)] and a gutter-shaped plate [see (A)]. , Flat plate [see (B)] or corrugated plate [see (D)]
Etc., and a large number of them are arranged in the vertical and horizontal directions between the partition walls 13, 15 and 14, 15. It is also possible to employ the actuating element 11 formed in a honeycomb shape having a hole in the displacement direction [see (E) of FIG. 4]. Two sets of partition walls 13 and 15 connected by the actuating element 11,
Fix the outer partitions 13 and 14 of 14 and 15, respectively,
By making the movable partition 15 at the center movable, the piston 16 fixed to the partition 15 at the center is displaced.

The displacement amplifying device 2 is not particularly limited, but in this embodiment, a combination of two sets of fluid pressure cylinders 21 and 22 having greatly different piston diameters is mentioned. That is, the piston rod 16 of the reciprocating engine 1 drives the piston 23 of the large-diameter fluid pressure cylinder 21, and the fluid pressure cylinder 22 having a diameter much smaller than the fluid pressure cylinder 21 is driven by the reciprocating engine 1. The displacement is amplified by driving the discharged working fluid 27. Since the shape of the shape-memory alloy actuating element 11 can be restored in a moment and a considerable force can be obtained, a large-diameter piston can be easily moved. The displacement amplifying device 2 is not limited to the combination of the fluid pressure cylinders 21 and 22, but may be a gear train or a lever. Reference numeral 24 is a piston, 25
Is a piston rod, 26 is a rack, 27 is a working fluid, 2
Reference numeral 8 is a return conduit.

As the motion converting device 3, in this embodiment, the piston rod 2 of the fluid pressure cylinder 22 of the displacement amplifying device 2 is used.
Two sets of unidirectional rotating gears 31 that change the linear motion of 5 into a rotary motion are adopted. These two sets of unidirectional rotating gears 31
Is arranged coaxially with one that transmits rotation when the piston rod 25 is pushed out and one that transmits rotation when the piston rod 25 is pulled back. Rotate in the direction. That is, the one-way rotating gear 3 has a built-in one-way clutch that transmits rotation only in the direction in which the generator 4 is rotated, and rotates on the opposite side without idling without rotating. Regarding the rotation in the opposite direction, another gear rotates like the gear 31. A rack 26 formed on the piston rod 25 of the displacement amplification device 2 is meshed with the gear 31 to convert a linear motion into a rotary motion. The rotation of the unidirectional rotating gear 31 is generated by, for example, the idle gear 32 through the generator 4
Is transmitted to the gear 42 that is coaxial with the rotor shaft 41 of FIG. The motion converting device 3 is not particularly limited to the above-mentioned one-way rotating gear.

A known generator is used as the generator 4. At this time, the rotation of the generator 4 is provided so that electricity of a predetermined frequency can be generated with a small number of rotations by increasing the number of poles.

With the above-mentioned structure, linear displacement is caused by alternately applying hot and cold heat having a temperature difference of about 10 ° C. which is higher than the transformation temperature and lower than the transformation temperature to the actuating element 11 of the reciprocating engine 1. This can be amplified by the displacement amplifying device 2 as necessary, or can be converted into rotary motion by the motion converting device 3 without being amplified, and the generator 4 can be driven. At this time, NiTi
The transformation point variable temperature of the alloy is in the range of 95 ° C to 10 ° C, and the shape memory alloy is used within that range because the shape memory effect disappears when the transformation point temperature exceeds 30 ° C.
For example, a box-shaped nitinol alloy having a size (0.45 m × 0.25 m × 0.25 m) is used as the actuating element 11, and the temperature is 95 ° C. to 10 ° C.
Reciprocating engine 1 with a temperature difference of 13 ° C in the heat input temperature range of
When heat is supplied to the
An output of 1.6 kw is theoretically obtained when the frequency is Hz, the theoretical efficiency is 2.6%, and the change in strain amount of the shape memory alloy actuating element is 0.5%.

It should be noted that the above-described embodiment is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, the reciprocating engine 1 is not particularly limited to the piston type, and as shown in FIG. 6, a band 60 of a shape memory alloy is wound around a pair of drums 61 and 62 and fixed at one place, It is also possible to heat the drum 61 and cool the other drum 62 to expand / contract the shape memory alloy strip 60 to obtain a reciprocating motion and rotate the generator 4. Here, the supply of heat is provided so as to be switched by the heat switch 63 that alternately switches the flow of the heat fluid.

As the reciprocating device 1, as shown in FIG. 3, a container 5 is provided around the actuating element 11 of shape memory alloy.
The container 50 may be sealed at 0, and hot water and cold water at a predetermined temperature may be alternately passed through the container 50. A part of the container 50 has expandable bellows parts 51, 51, and the movable partition wall 15 is connected to the bellows parts 51, 51 to movably connect the partition wall 15. The container 50 is fixed except for the bellows part 51 and the movable partition wall 15, and a water supply port 52 and a drain port 53 are provided to alternately flow hot water or cold water into the container 50 to transform the actuating element 11 of the shape memory alloy into a piston. The rod 16 may be displaced in the axial direction.

A fluid pressure motor (not shown) can be used as the motion conversion device 3. The working fluid discharged from the fluid pressure cylinder constituting the displacement amplifying device 2 is introduced into this fluid pressure motor to rotate the rotor. The rotor of the generator 4 is coaxially connected to the fluid pressure motor.

Further, as shown in FIG. 5, a plurality of reciprocating engines 1, ..., 1 described above are connected in cascade, so that heat can be efficiently utilized, and high efficiency and high output can be achieved. .. In this case, each reciprocating engine 1,1,
…, A high temperature water tank 54 that stores high temperature water in the piston 1
Hot water and cold water are alternately flowed from the low temperature water tank 55 storing the low temperature water and the low temperature water in the same manner as described above, and the reciprocating engine 1 ,.
Reciprocate the piston rod of.

Further, as shown in FIG. 7, there is also an example in which the linear displacement is obtained by the lever 69, the displacement is amplified through the force amplifying device 70, and the generator 4 is rotated. In this case, high temperature water and low temperature water are alternately flown from the high temperature water tank 64 and the low temperature water tank 65 to the two pistons 67 and 68 through the pipe switching device / control device 66 to obtain the linear displacement by using the lever 69. ing.
The piston rods of the two pistons 67, 68 are made of a shape memory alloy, and linear displacement is obtained by supplying high-temperature water above the transformation point temperature or low-temperature water below it to the cylinder.

[0024]

As is apparent from the above description, the solid-state thermal energy power generation system of the present invention rotates the reciprocating motion of the reciprocating motion engine that reciprocates using the shape memory alloy as an actuating element. Since it is composed of a motion conversion device that converts into motion and a power generation device that is rotated by this motion conversion device, a minute reciprocating motion is obtained using heat at a relatively low temperature, and by rotating the generator with this A high-density, compact power generation system can be realized.

Here, the life of the shape memory alloy suddenly shortens as the amount of strain increases, but when a displacement amplification device that amplifies the linear displacement of the reciprocating motion engine and transmits it to the motion conversion device is provided, a minute strain is generated. Since the reciprocating engine can be operated within the range of the amount change, for example, within the range of 0.2% to 0.5%, there is no fear of shortening the life.

Further, since the strain energy stored in the shape memory alloy is proportional to the volume, when a piston type reciprocating motion engine is adopted, the shape memory alloy actuating elements can be packed at a high density and a high output and a high output can be obtained. Density Compact drive source.

[Brief description of drawings]

FIG. 1 is a principle diagram showing an example of a solid-state thermal energy power generation system of the present invention.

FIG. 2 is a perspective view showing an embodiment of a reciprocating engine used in the power generation system of the present invention.

FIG. 3 is a perspective view showing another embodiment of the reciprocating engine used in the power generation system of the present invention.

FIG. 4 is a view showing an example of an operating element of a reciprocating engine,
(A) is an arc-shaped actuating element, (B) is a flat-shaped actuating element,
(C) rod-shaped actuating element, (D) corrugated actuating element,
(E) shows a honeycomb-shaped actuating element.

FIG. 5 is a principle view showing an example in which the solid-phase thermal energy power generation system of the present invention is cascade-connected.

FIG. 6 is a perspective view showing still another embodiment of the reciprocating engine used in the power generation system of the present invention.

FIG. 7 is a block diagram showing still another embodiment of the reciprocating engine used in the power generation system of the present invention.

[Explanation of symbols]

 1 Reciprocating motion engine 2 Displacement amplification device 3 Motion conversion device 4 Generator

Claims (6)

[Claims] 1. A reciprocating engine that reciprocates using a shape memory alloy as an actuating element, a motion converting device that converts the reciprocating motion of the reciprocating engine into a rotary motion, and a power generation device that is rotated by the motion converting device. A solid-state thermal energy power generation system comprising: 2. A heat transfer material and a heat pipe are inserted in and around the operating element of the reciprocating engine, and the heat supplied by the heat pipe is transferred to the operating element directly and via the heat transfer member. The solid-state thermal energy power generation system according to claim 1, which is characterized in that. 3. The solid-state thermal energy power generation system according to claim 1, wherein the reciprocating engine operates by directly transferring heat supplied by water to the actuating element. 4. The solid-state thermal energy power generation system according to claim 1, further comprising a displacement amplification device that amplifies a linear displacement of the reciprocating motion engine and transmits the linear displacement to the motion conversion device. .. 5. The solid phase thermal energy according to claim 1 or 2, further comprising a force amplification device and a displacement amplification device for amplifying a force and a direct displacement of the reciprocating motion engine and transmitting the amplified displacement to the motion conversion device. Power generation system. 6. The solid-state thermal energy power generation system according to claim 1, wherein a plurality of reciprocating engines are connected in cascade.