JP2024084091A - Power Generation System - Google Patents

Abstract

[Problem] To develop a system that can generate electricity by effectively utilizing low-temperature heat from the sun, air, geothermal energy, river water heat, seawater heat, and various types of exhaust heat.
The above-mentioned low-temperature heat of about 10° C. to 30° C. is collected in a heat exchanger by a pump or a heat pipe, and heat is exchanged with a heat medium.
The heat exchanger heats the low-temperature heat medium, which is about 10 to 30°C, to about 80°C by compressing and heating it in a compressor. The compressed and heated heat medium is then passed through a hemispherical heat ray concentrating unit to heat the heat receiving part of the Stirling engine generator to about 300 to 800°C, generating electricity.
The heat transfer medium that has passed through the heat radiation unit passes through the expansion valve and becomes low-pressure and low-temperature, and flows into the cold air inlet to cool the cooling section of the Stirling engine generator. The heat transfer medium, which has been heated by the cooling effect, flows out from the warm air outlet.
The heat transfer medium that flows out of the warm air outlet of the Stirling engine generator flows into a vortex tube that can separate it into low and high temperature parts, and the low temperature part is sent to a heat exchanger where it is exchanged with solar heat, atmospheric heat, earth heat, river water heat, sea water heat, and various types of exhaust heat, and then flows into a compressor where it is compressed and heated. The high temperature part flows directly into the compressor where it is compressed and heated.
There is an abundance of low-temperature heat from the sun, air, geothermal energy, river water heat, seawater heat, and various types of waste heat, and we will build a locally distributed, locally produced and locally consumed power generation system as a clean energy source.

Description

The present invention relates to a power generation system incorporating a concentrated heat ray radiation unit, which utilizes low-temperature heat from the sun, air, earth, river water, seawater, and various types of exhaust heat, exchanges heat with a heat medium in a heat exchanger, compresses and heats the heat in a compressor, and further generates electricity by concentrating and radiating heat rays from the heat medium to the heat receiving part of a Stirling engine generator.

The power generation using the low-temperature heat has low power generation efficiency and is not effectively utilized.

Problem to be solved by the invention

The challenge is to build a system that can effectively utilize this low-temperature heat to generate electricity.

Means for solving the problem

This low-temperature heat is utilized to exchange heat with a heat medium in a heat exchanger, compressed and heated in a compressor, and then the heat rays from the heat medium are concentrated on the heat receiving part of a Stirling engine generator to heat it, thus building a power generation system that effectively utilizes low-temperature heat.

Effect of the invention

The above-mentioned low-temperature heat is abundant and can be used as clean energy to provide locally distributed, locally produced and locally consumed electricity.

FIG. 1 is a schematic diagram of a Stirling engine power generation system incorporating a heat concentrating radiator unit. 3A and 3B are a cross-sectional view and a front view of a heat ray concentrating radiation unit. FIG. 2 is a front view of the heat ray concentrating radiation unit. 1 is a cross-sectional view and a front view of the first bowl. 1 is a front view and a cross-sectional view of a second bowl. 3A and 3B are a cross-sectional view and a front view of the cap.

The details of the embodiment of the present invention will be described with reference to Fig. 1 to Fig. 6. Note that the following embodiment is merely an example of the present invention, and is not intended to limit the scope of the present invention, its applications, or its uses.

A Stirling engine generator heats the heat receiving part of the generator to about 300 to 800 degrees Celsius, and moves the working gas (such as helium gas) with a displacer piston. The working gas expands and contracts, converting the power piston into mechanical reciprocating motion, and the kinetic energy is used to drive the generator and generate electricity.

A Stirling engine power generation system incorporating a heat ray concentrating radiation unit 1 shown in Figures 1 to 3 uses low-temperature heat of about 10°C to 30°C from solar heat, atmospheric heat, geothermal heat, river water heat, seawater heat, and various types of exhaust heat as a medium, for example air or water, to collect the heat in a heat exchanger by a pump or heat pipe and exchange it with the heat medium. Since the low-temperature heat changes depending on the season and time, a switching valve is provided to switch and control high-temperature heat, for example atmospheric heat during the day and geothermal heat at night, allowing effective use of the composite heat source.

In order to heat the heat medium, which has a low temperature of about 10 to 30 degrees Celsius, to about 80 degrees Celsius, a reverse Carnot cycle is applied to compress and heat the heat medium in a compressor, which produces thermal energy several times higher than the input energy. For example, a small, quiet scroll compressor is used as the compressor.
The heat medium compressed by the compressor and heated to about 80° C. flows into the heat medium flow passage 1b from the heat medium inlet 1a at the top of the hemispherical heat ray concentration radiation unit 1 shown in FIGS.

The heat ray concentrating radiation unit 1 shown in Figures 2 and 3 has the first bowl 2 shown in Figure 4, the second bowl 3 shown in Figure 5, and the cap 4 shown in Figure 6 aligned in center by flanges 2d, 3c, and 4b, with the second bowl 3 positioned inside the first bowl 2 and the cap 4 positioned on the end face of the second bowl 3, which are overlapped to form a single unit and fastened with bolts 1i, making for a structure that is easy to disassemble and reinstall.
The concentrated heat radiation unit 1 is made of, for example, stainless steel to provide corrosion resistance.

2 and 3, a heat medium flow path 1b is formed between first bowl body 2a of first bowl 2 and second bowl body 3a of second bowl 3, and a first packing 1e is installed to prevent leakage of the heat medium between flange 2d of first bowl 2 and flange 3c of second bowl 3. A heat-resistant O-ring, for example, is used as the packing.

Heat ray concentrating radiation unit 1 shown in Figures 2 and 3 is assembled so as to cover the heat receiving section of the Stirling engine generator, and the heat of the heat medium of about 80°C that flows into heat medium flow path 1b from heat medium inlet 1a is transferred to second bowl body 3a and fins 3b of second bowl 3, causing the temperature to rise.

The first bowl 2 shown in Figures 2, 3, and 4 has a double structure between the first bowl main body 2a and the outer bowl 2b, and this space serves as a bowl vacuum layer 2c in order to suppress heat conduction to the outer periphery of the outer bowl 2b and heat conduction due to convection.
The inner surface of the hemispherical shape of the first bowl body 2a is made into a mirror surface to suppress radiant heat to the outside and to concentrate and reflect the heat toward the second bowl body 3a and fins 3b of the second bowl 3. To achieve the mirror surface, for example, a stainless steel mirror sheet is attached to the inner surface.

Inside the flange 2d of the first bowl 2 shown in Figures 2, 3, and 4, a number of orifices 2e are provided radially at equal angles to allow the heat medium to flow uniformly over the entire surface of the heat medium flow path 1b from the heat medium inlet 1a, and a manifold 2f is provided on the outer periphery of the flange 2d to collect the heat medium from the orifices 2e to the heat medium outlet 1c.
A double structure is formed between the manifold body 2g and the manifold outer rim 2h, and in order to suppress heat transfer due to conduction to the outer periphery of the manifold outer rim 2h and heat transfer due to convection, this space is made into a manifold vacuum layer 2i, which is connected to the bowl vacuum layer 2c through a vacuum layer connecting small hole 2j, and a vacuum is drawn through a vacuum check valve 1h installed in the vacuum check valve port 2k, thereby improving thermal efficiency and reducing the number of parts by integrating each function.

2, 3 and 5, the heat medium flows uniformly over the entire outer surface of the outer surface of the second bowl body 3a of the second bowl 3, and in order to improve heat transfer efficiency, the same number of fins 3b in length as the orifices 2e of the first bowl 2 are provided radially from the center of the apex of the second bowl 3, midway between the orifices 2e. Furthermore, in order to ensure the width of the heat medium flow path 1b at the top of the second bowl 3, the fins 3b are shortened by omitting part of the apex area every other fin 3b.
The hemispherical outer surface of the second bowl body 3a of the second bowl 3 is made black to increase the heat ray absorption rate, and the hemispherical inner surface is made black to increase the heat ray emissivity, for example a carbon nanotube blackbody surface.

The cap 4 shown in Figs. 2 and 6 closes the second bowl 3 to the heat receiving portion of the Stirling engine generator, forming a heat ray concentrated radiation chamber 1d.
The heat ray intensive radiation chamber 1d is constructed as a vacuum structure in order to suppress heat transfer due to conduction and convection, and to suppress attenuation of heat ray radiation due to atmospheric gas.
The cap body 4a has a cylindrical curved surface to withstand a vacuum, thereby reducing the number of components and making it lighter. A vacuum check valve 1h provided in the vacuum check valve port 4d draws a vacuum in the heat ray concentration radiation chamber 1d.

The inner surface of the cap body 4a on the heat ray concentration radiation chamber 1d side is made mirror-finished to suppress radiant heat to the outside, and in order to achieve this mirror-finish, for example, a stainless steel mirror-finish sheet is attached to the inner surface.
The heat ray concentrated irradiation unit 1 is attached to the heat receiving portion of the Stirling engine generator by a boss 4c provided in the center of the cap 4, and is attached to the stand of the Stirling engine generator by a base 4e for supporting the weight.
The specifications and shape of the cap 4 can be adapted to suit the model of the Stirling engine generator.

In order to prevent vacuum leakage between the flange 3c of the second bowl 3 and the flange 4b of the cap 4, and between the boss 4c of the cap 4 and the heat receiving part of the Stirling engine generator, a second packing 1f and a third packing 1g are respectively installed. For example, a heat-resistant O-ring is used as the packing.

A heat medium at about 80°C enters from heat medium inlet 1a into heat medium flow path 1b between first bowl 2 and second bowl 3, and is transferred along fins 3b of second bowl 3 to second bowl body 3a. While this heat transfer is uniform over the entire surface, it flows towards a number of orifices 2e provided at equal angles, and gathers in manifold 2f.

Second bowl body 3a of second bowl 3 shown in FIG. 2 has a hemispherical shape, and heat rays radiated from its inner surface pass through heat ray intensive radiation chamber 1d having a vacuum structure and are intensively radiated to the heat receiving part of the Stirling engine generator, heating it to about 300° C. to 800° C., thereby generating electricity.

The heat transfer medium collected in the manifold 2f passes through the expansion valve from the heat transfer medium outlet 1c and becomes low pressure and low temperature, then flows in from the cold air inlet to cool the cooling part of the Stirling engine generator. The heat transfer medium, which has been heated by the cooling effect, flows out from the warm air outlet. The cooling cost can be reduced because the cooling part of the Stirling engine generator is cooled with the heat transfer medium at a low temperature.

The heat transfer medium flowing out of the warm air outlet of the Stirling engine generator flows into a vortex tube that can separate it into low and high temperatures, and the low temperature heat transfer medium, for example below 5°C, is sent to a heat exchanger where it is heat exchanged with solar heat, atmospheric heat, geothermal heat, river water heat, seawater heat, and various types of exhaust heat, and then flows into a compressor where it is compressed and heated. The high temperature heat transfer medium, for example above 30°C, flows directly into the compressor where it is compressed and heated. The flow rate is controlled by a flow control valve depending on the operating conditions. By providing a vortex tube, the heat of the heat transfer medium can be used efficiently.

Heat transfer media that efficiently transport heat are non-flammable, non-toxic, and safe, and have an extremely small impact on global warming compared to fluorocarbon heat transfer media, such as _CO2 heat transfer media. To reduce heat loss when transferring the heat transfer media, insulated materials such as vacuum double piping, insulated piping, and insulated hoses are used, and each device is connected by piping as shown in Figure 1.

The control system is linked to the control of the Stirling engine generator and the system incorporating various sensors and devices such as a temperature sensor, and controls the Stirling engine power generation system incorporating the heat ray concentration radiation unit shown in Figure 1.

Reference Signs List 1: Heat ray concentrated radiation unit 1a: Heat medium inlet 1b: Heat medium flow path 1c: Heat medium outlet 1d: Heat ray concentrated radiation chamber 1e: First packing 1f: Second packing 1g: Third packing 1h: Vacuum check valve 1i: Bolt 2: First bowl 2a: First bowl body 2b: Outer bowl 2c: Bowl vacuum layer 2d: Flange 2e: Orifice 2f: Manifold 2g: Manifold body 2h: Manifold outer rim 2i: Manifold vacuum layer 2j: Vacuum layer connecting small hole 2k: Vacuum check valve port 3: Second bowl 3a: Second bowl body 3b: Fin 3c: Flange 4: Cap 4a: Cap body 4b: Flange 4c: Boss 4d: Vacuum check valve port 4e: Base

Claims (6)

A power generation system equipped with a heat exchanger, a compressor, a heat radiation concentrated unit, and a Stirling engine generator.
The heat exchanger is configured to be able to exchange low-temperature heat from solar heat, atmospheric heat, geothermal heat, river water heat, seawater heat, and various types of exhaust heat with a heat medium.
The compressor is configured to compress and heat the heat medium, and then supply it to the heat ray concentration radiation unit.
The heat radiation unit is hemispherical and is attached to the heat receiving part of the Stirling engine generator.
A power generation system that generates electricity by concentrating and radiating heat rays from a heat medium supplied to a heat ray concentrating unit onto the heat receiving part of a Stirling engine generator. 2. The power generation system according to claim 1, wherein the heat ray concentrating radiation unit has a first bowl, a second bowl, and a cap, the second bowl is disposed inside the first bowl so that their centers are aligned, the cap is disposed on an end face of the second bowl, and a flow path through which a heat medium passes is provided between the first bowl and the second bowl, and heat rays based on the supplied heat medium are radiated in a concentrated manner to heat a heat receiving portion of the Stirling engine generator. The first bowl of the heat ray concentrated radiation unit has a double structure, with the space made into a vacuum layer to suppress heat conduction to the outside, and the inner surface is made into a mirror surface to suppress radiated heat to the outside, and is configured to concentrate and reflect the heat rays based on the heat medium passing through the flow path toward the second bowl.
The outer surface of the second bowl is black to increase the absorption rate of heat rays, and the inner surface is black to increase the efficiency of concentrated radiation of heat rays.
2. The power generating system according to claim 1, wherein a vacuum structure is formed between the second bowl and the cap to suppress thermal conduction and to suppress attenuation of heat ray radiation, and heat rays based on the supplied heat medium are concentrated and radiated to the heat receiving part of the Stirling engine generator for heating. 2. The power generation system according to claim 1, wherein the low-temperature heat medium is compressed and heated by the compressor by application of the reverse Carnot cycle, and the heat is concentrated and radiated to the heat receiving portion of the Stirling engine generator by the heat ray concentration unit. 2. The power generation system according to claim 1, further comprising an expansion valve, wherein the heat medium that has passed through the heat ray concentrating radiation unit passes through the expansion valve and becomes low-pressure and low-temperature, thereby cooling a cooling section of the Stirling engine generator. The power generation system according to claim 1, further comprising a vortex tube, the heat medium flowing out of the warm air outlet of the Stirling engine generator can be separated into low temperature and high temperature by the vortex tube, the low temperature heat medium is sent to the heat exchanger and after heat exchange, flows into the compressor to be compressed and heated, and the high temperature heat medium is directly flowed into the compressor to be compressed and heated.

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