JP2002354854A - Generating equipment and power generation system using thermal-photovoltaic power generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the power generation efficiency of generating equipment and a power generation system using thermal-photovoltaic power generation to practical level. SOLUTION: Generating equipment 1 comprises a radiating portion 10 which discharges radiant energy by heating of working fluid or heating by a heater; thermal storage layers 20; a means for changing the direction of flow of the working fluid in the thermal storage layers; and photovoltaic power generation elements 30. The thermal storage layers 20 use a radiation wavelength selective material having permeability to wavelength ranges in which the photovoltaic power generation elements 30 effectively generate power, and the photovoltaic power generation elements 30 are placed in positions where radiant light which permeated the thermal storage layers 20 is received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Photovoltaic) and a power generation device and a power generation system.

[0002]

2. Description of the Related Art A power generating apparatus using thermophotovoltaic power generation is composed of a heat source, an emitter that generates radiation by receiving heat from the heat source, and a photovoltaic element, and includes an emitter heated to a high temperature. In this system, emitted radiation is incident on the photovoltaic element to obtain an electromotive force. Unlike solar cell power generation, this power generation device is expected to have a high future potential because, for example, the general radiation emitted from a high-temperature substance can be used as a light source.

[0003] US Pat. No. 4,683,862 discloses that
An example of a power generation device using thermoelectric power generation is described. Here, zirconia globules are arranged in the gas combustion zone to form a heat storage layer, the sensible heat of the combustion gas is recovered by the zirconia globules, and the combustion air is preheated there. The heat recovery is performed by switching the flow direction in the heat storage layer. On the other hand, the radiation radiated from the heat storage layer passes through a filter made of quartz glass and enters the photovoltaic element. By passing through the quartz glass, only radiation in a specific wavelength range, that is, a wavelength range in which the photovoltaic element effectively generates power, reaches the photovoltaic element.

[0004] US Pat. No. 5,555,992 describes:
Another example of a power generation device using thermoelectric power generation is described.
Here, two types of filters are used in combination to heat the emitter to which the rare earth metal is added by gas combustion and to pass radiation of a specific wavelength range radiated from the rare earth metal toward the photovoltaic element. The emitter is a disk with holes and has a structure in which these are stacked in multiple stages.By stacking the holes so that the positions of the holes are shifted, a turbulent flow is generated in the combustion gas to improve the electrothermal efficiency. I have. In addition, a heat exchanger having a similar structure is provided, and heat is recovered from combustion exhaust gas.

[0005]

As described above, a power generation apparatus using thermophotovoltaic power generation emits light in a wavelength range in which a photovoltaic element can effectively generate power by using a filter made of a material having wavelength selectivity. Selection is made by transmitting light. However, most of the radiation that does not pass through the filter (radiation that is ineffective for power generation) is absorbed by the filter itself and converted into thermal energy. This heat energy is usually released by the cooling means of the filter.
Radiation is emitted out of the system as reactive energy that does not contribute to power generation, or radiation is re-emitted from the filter by raising the temperature of the filter.As a result, wavelength components of radiation that do not contribute to power generation become light. The light is incident on the power generation element, and the power generation efficiency is reduced.

For example, in the thermophotovoltaic power generator described in US Pat. No. 4,868,622, a part of energy in a wavelength range that cannot pass through a quartz glass as a filter is absorbed by the quartz glass, and the quartz glass is heated to a temperature. Is re-emitted from the quartz glass toward the photovoltaic element. As a result, an invalid radiation wavelength component that cannot be effectively converted into electric power by the photovoltaic element enters the photovoltaic element. The same applies to the thermophotovoltaic power generator described in U.S. Pat. No. 5,555,992. Even if two types of filters are used, the energy of the radiation wavelength component absorbed by the filters cannot be effectively used.

From the above situation, in a conventional power generation system using thermophotovoltaic power generation, most of the energy input to the radiation radiating portion is limited due to the narrow wavelength range in which the photovoltaic element can be effectively used for power generation. It is used to raise the temperature of the photovoltaic element or causes heat loss to the outside of the system, and the rate of contribution to actual power generation is small, and the power generation efficiency is not high. In addition, energy for cooling is required to prevent the temperature of the photovoltaic element from rising above a specified value, and the efficiency is further reduced. As a result, the actual situation is that power generation efficiency at a practical level has not yet been obtained. The present invention
The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the power generation efficiency of a power generation device and a power generation system using thermo-light power generation to a level that can be practically used.

[0008]

According to the present invention, there is provided a power generating apparatus comprising: a radiation radiating section for emitting radiation energy by generating heat of a working fluid or heating by a heating device; a heat storage layer; and a flow direction of the working fluid in the heat storage layer. Switching means, and a power generation device configured with a photovoltaic element, using, as the heat storage layer, an emission wavelength-selective material that is transparent to a wavelength range in which the photovoltaic element effectively generates power, In addition, a photovoltaic element is arranged at a position capable of receiving radiation transmitted through the heat storage layer.

In the present invention, the working fluid is not particularly limited as long as it contains a combustible gas and a supporting gas (such as oxygen) when the working fluid is used to heat the radiation radiating section. When a heating device is used for heating the radiation radiating portion, any gas having fluidity may be used, and there is no particular limitation. Further, the power generator according to the present invention can be effectively used as a working fluid even if the concentration of the flammable gas is extremely low for the reason described below.

The radiation radiator is not particularly limited as long as it effectively converts the combustion heat of the working fluid into radiation. For example, a foamed porous body, a fiber-shaped porous body, and a plate-like solid having vent holes are used. Those to which rare earth elements such as neodymium, erbium, ytterbium, and phosphene are added are more preferable because they emit a large amount of radiation in a wavelength range that the photovoltaic element can effectively convert into electric power.

The photovoltaic element is made of Si, GaSb, InGa
As, Ge, CdTe, InAs, GaAs, InS
b, InP, AlSb, AlAs, GaP, AlP, Z
A conventionally known device such as nSe may be used as it is. As the radiation wavelength-selective material that is the material of the heat storage layer, a material such as quartz glass, crystallized glass, or low expansion glass is used. In an actual machine, a material having an appropriate radiation wavelength selectivity is selected and used according to the power generation wavelength characteristics of the photovoltaic element used.

In the power generation device according to the present invention, the radiation wavelength-selective material for selectively transmitting radiation in the wavelength range in which the photovoltaic element effectively generates power also serves as a heat storage layer, and does not transmit therethrough, ie, does not transmit light. Radiation in an invalid wavelength range that does not contribute to power generation by the power generation element is absorbed by the heat storage layer. The energy heats the heat storage layer. The heat storage layer is also heated by the flow of the working fluid (combustion gas), and the temperature of the heat storage layer is highest near the radiation radiating section and lowest on the side facing the photovoltaic element.

On the other hand, since the flow direction of the working fluid in the heat storage layer is switched, the working fluid is preheated when passing through the already heated heat storage layer. That is, the energy having an invalid wavelength range that does not contribute to power generation by the photovoltaic element is effectively recovered by the working fluid passing through the heat storage layer. Then, the preheated working fluid flows into the radiation radiating portion and burns, and the thermal energy of the combustion gas heats the radiation radiating portion and releases the radiation energy from the radiation radiating portion. Thereby, the power generation by the photovoltaic element occurs, and the energy in the wavelength region that does not contribute to the power generation of the photovoltaic element heats the heat storage layer as described above. Hereinafter, this is repeated every time the flow direction of the working fluid is switched. That is, in the power generation device according to the present invention, only the wavelength range effective for power generation is mainly incident on the photovoltaic element, and the energy of the other wavelength ranges is used for preheating the working fluid using the heat storage layer as a medium. The amount of heat generated, that is, the flow rate of the working fluid or the concentration of the flammable component, or the amount of fuel to be supplied to the heating device can be reduced, and the efficiency of the system is improved. In addition, since the working fluid is effectively preheated, power is generated by using a description containing a low-concentration flammable gas that is discharged or generated from industrial equipment, industrial facilities, or the natural world and is not normally usable as the working fluid. Can be performed.

The temperature of the heated heat storage layer is highest near the radiation radiating portion, and lowest on the side facing the photovoltaic element. Then, radiation is re-emitted from the heat storage layer region close to the radiation radiating portion. Among the radiation, radiation in an invalid wavelength range is absorbed by another region of the heat storage layer and does not reach the photovoltaic element. For this reason, it is possible to avoid a decrease in power generation efficiency due to absorption and re-emission in a filter for wavelength selectivity as in a conventional photovoltaic element, and the system efficiency is also improved here.

[0015] Preferably, the power generation device is characterized in that two heat storage layers are arranged opposite to the radiation radiating portion, and a photovoltaic element is arranged outside each of the heat storage layers. By adopting such a configuration, both the heat recovery by switching the flow direction of the working fluid in the heat storage layer and the power generation efficiency can be improved.

[0016] In a preferred embodiment, the heat storage layer has a shape obtained by combining square rod-shaped radiation wavelength-selective materials in parallel or in a lattice, and more preferably, the end face of the square rod-shaped radiation wavelength-selective material is It is polished to a roughness less than the wavelength range transmitting therethrough. In another embodiment, the heat storage layer has a shape in which a plurality of flat-plate-shaped radiation wavelength-selective materials provided with a plurality of gas-passing holes provided with a plurality of gas passage holes are arranged in parallel. The inner surface of the gas passage hole provided in the plate-shaped radiation wavelength-selective material is polished to a roughness equal to or less than the wavelength range through which the gas passes.

[0017] By forming the heat storage layer in the shape described above, of the radiation radiated from the radiation radiating portion, the directional component not directed to the photovoltaic element is reflected at the end face or the inner surface, and is transmitted to the photovoltaic element. It is possible to increase the input amount of radiation. A reflector may be further provided between the heat storage layer and the photovoltaic element, the reflector having reflectivity to radiation in a wavelength range where the photovoltaic element cannot effectively generate power. Thereby, the reflected radiation is absorbed by the heat storage layer or the radiation radiating portion, and can be effectively used for preheating the working fluid or heating the radiation radiating portion, so that the energy efficiency can be increased.

As described above, in the power generation device according to the present invention, the heat storage layer is made of a radiation wavelength-selective material that is transparent to the wavelength region in which the photovoltaic element effectively generates power, thereby achieving high power generation efficiency. Can be obtained. However, it is practically difficult to cut all the materials having a required short wavelength (for example, 2 μm) or more with only the radiation wavelength selective material constituting the heat storage layer. For this purpose, in a preferred embodiment of the power generation device according to the present invention, an infrared light filter that is transparent between the heat storage layer and the photovoltaic element for radiation in a wavelength range in which the photovoltaic element effectively generates power, and / or Alternatively, a reflector having reflectivity for radiation in a wavelength range where the photovoltaic element cannot generate power effectively is further provided. By providing such a filter, it becomes possible to make radiation in the wavelength range in which power is generated effectively incident on the photovoltaic element more restrictively, and it is possible to suppress a decrease in efficiency due to a rise in temperature of the photovoltaic element.

In order to avoid the temperature rise of the photovoltaic element,
It is effective to provide a radiation fin in thermal contact with the photovoltaic element, or to provide a cooling medium flow path in thermal contact with the photovoltaic element to allow the cooling medium to flow down. Further, a working fluid that is a heating source of the radiation radiating section can be used as the cooling medium. In that case, when the working fluid passes through the cooling flow path, heat exchange is performed between the photovoltaic element and the working fluid to preheat the working fluid, which is supplied to the radiation radiating portion. Therefore, the efficiency as a whole is improved. A Peltier element may be stacked on the surface opposite to the light receiving side of the photovoltaic element such that the low-temperature side faces, and the Peltier element may be used as a means for transporting heat from the photovoltaic element to the working fluid. In this case, while maintaining the photovoltaic element at a relatively low temperature with high power generation efficiency,
There is an advantage that the working fluid can be preheated to a relatively high temperature. The power supplied to the Peltier element is used for heating the radiation radiating portion, and therefore does not cause a loss.

The working fluid after heating the radiation radiating section is:
It is discharged outside the system while preheating the heat storage layer. The working fluid (e.g., combustion gas) after passing through the heat storage layer usually still has high thermal energy, and discharging as it is results in a decrease in efficiency. Therefore, in a preferred embodiment, the power generation device according to the present invention further includes a second heat storage layer using a material having no radiation wavelength selectivity on the low temperature side of the first heat storage layer having the radiation wavelength selectivity. In this embodiment, the working fluid (for example, combustion gas) passes through the second heat storage layer and is discharged out of the system, and the working fluid (for example, the unburned mixture) is preheated to the second heat storage layer. And is introduced into the system. Thereby, the thermal efficiency is further improved. One second heat storage layer may be provided for one first heat storage layer, or a plurality of second heat storage layers may be arranged in series or in parallel.

The present invention also discloses a power generation system using the above power generation device. As described above, the power generation device according to the present invention can effectively perform preheating of the working fluid, so that power generation can be continued even if a combustible component lean mixture that does not burn in a normal state is used as the working fluid. Can be. Therefore, in a preferred embodiment of the power generation system according to the present invention, a gas containing a lean combustible component which is not combusted in a normal state, which is discharged and generated from other industrial equipment, industrial facilities, or nature is used as all or a part of the working fluid. To do. At this time, after the flammable components of the lean flammable gas are concentrated, they may be introduced as a working fluid into the power generator.

The gas containing a dilute flammable component discharged or generated from the other industrial equipment or facility described above is a gas having a flammable limit or less, such as an exhaust fluid from a fixed electrolyte fuel cell or an exhaust fluid from an internal combustion engine. Fluids that contain hydrocarbons, hydrogen, carbon monoxide, etc. as flammable components, human waste treatment plants, sewage treatment plants, sludge treatment plants, landfill plants, livestock breeding plants, compost heaps, and grain heaps And a fluid containing a small amount of hydrocarbons such as methane generated from coal mines and lakes.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on several embodiments with reference to the accompanying drawings. FIG. 1 shows an embodiment of a power generating apparatus according to the present invention. The power generating apparatus 1 is arranged so as to face a radiation radiating section 10 which emits radiation energy by generating heat by a working fluid. A pair of heat storage layers 20A, 2
0B and a photovoltaic element 30 disposed on the back side of the heat storage layers 20A and 20B. Further, although not shown, a means for switching the flow direction of the working fluid in the heat storage layer is provided.

The working fluid is a mixture of a combustible gas such as hydrocarbon, hydrogen and carbon monoxide and a supporting gas such as oxygen. The working fluid is supplied to the radiation radiating section 10 or in the vicinity thereof and burns. The radiation radiating section 10 is heated by the combustion heat.
The radiation radiating section 10 is a porous or fibrous solid in this example, and has air permeability and high heat transfer. Then, the combustion heat of the working fluid is effectively converted to radiation. A rare earth element such as neodymium, erbium, ytterbium, and phosphene may be added to increase the radiation conversion rate.

The heat storage layers 20A and 20B are made of a material such as quartz glass, crystallized glass, low-expansion glass, and low-temperature heat-reflection glass, and allow the passage of a working fluid and a required radiation wavelength range. Has a selective transmission property, and absorbs radiation in other wavelength ranges. The absorbed radiation is converted into heat energy to heat the heat storage layer. Upon reaching a predetermined temperature, radiation is re-emitted. The photovoltaic element 30 is conventionally known, and a description thereof will be omitted. The means for switching the flow direction of the working fluid in the heat storage layer may also be a conventionally known appropriate flow path switching means, and a description thereof will be omitted.

The operation of the power generator 1 shown in FIG. 1 will be described. A working fluid, for example, a lean mixture of methane and air, is supplied from the rear side of the heat storage layer 20A to the radiation radiating section 10 by operating the switching means (arrow A1). The supplied air-fuel mixture is burned in the radiation radiating section 10 and the temperature of the radiation radiating section 10 is raised to, for example, about 1500 ° C. by the combustion heat. Thereby, radiation in many wavelength ranges is emitted.
The combustion gas passes through the other heat storage layer 20B while being heated by heat exchange, and is released from the backside of the system (arrow A).
2).

After a lapse of a predetermined time, the switching means is operated to reverse the flow direction of the air-fuel mixture. Thereby, the working fluid flows from the back side of the heated heat storage layer 20B toward the radiation radiating section 10 (arrow B1), and is preheated during that time. The preheated air-fuel mixture is burned in the radiation radiating section 10 and causes the radiation radiating section 10 to radiate radiation in many wavelength ranges. The combustion gas passes through the other heat storage layer 20A while being heated by heat exchange, and is released from the back surface to the outside of the system (arrow B2). By switching the flow direction of the air-fuel mixture, a temperature is formed in the heat storage layers 20A and 20B such that the radiation radiating section 10 has a high temperature and the photovoltaic element 30 has a low temperature.

The emitted radiation is stored in the heat storage layers 20A and 20B.
And a part of the wavelength region where the photovoltaic element 30 effectively generates power passes through the heat storage layer 20 and enters the photovoltaic element 30 to contribute to power generation, as indicated by an arrow X. . Those in other wavelength ranges are absorbed by the heat storage layer 20 and converted into heat as shown by the arrow Y, and do not enter the photovoltaic element 30. Thereby, the heating of the photovoltaic element 30 is suppressed, and a decrease in the power generation efficiency of the photovoltaic element due to the temperature rise can be avoided. .

The heat storage layer 2 absorbs radiation in an invalid wavelength range and
0 is heated and re-injects radiation. Of the re-emitted radiation, an effective wavelength region passes through the heat storage layer and enters the photovoltaic element 30 to contribute to power generation. However, radiation in an invalid wavelength range is also absorbed by other portions of the heat storage layer, and does not enter the photovoltaic element 30. Since the energy converted into heat in the heat storage layer 20 preheats the air-fuel mixture (working fluid), radiation other than the wavelength range that contributes to power generation is effectively used, and the overall thermal efficiency is greatly improved.
The photovoltaic element 30 is preferably composed of a plurality of photovoltaic elements each having a power terminal, and connecting the power terminals of the individual photovoltaic elements in series or in series / parallel,
I try to get the boosted voltage.

FIGS. 2 and 3 show some examples of the inside of the heat storage layer 20. In FIG. 2a, a large number of square rod-shaped radiation wavelength-selective materials 21 are arranged in parallel at intervals, and in FIG. 2b, the same square rod-shaped radiation wavelength-selective materials 21 are arranged in grids at intervals. It is a shape in which many are combined. Although not essential, in any case, the surface is polished to a roughness equal to or less than the wavelength range that transmits the end face 22 parallel to the radiation direction component 27 from the radiation radiating portion of the rectangular rod-shaped radiation wavelength-selective material 21 toward the photovoltaic element. . By adopting such a shape, of the radiation radiated from the radiation radiating portion, a component in a direction in which the radiation is not directed toward the photovoltaic element but is absorbed by the flow path wall surface is reflected by the end face 22. It is possible to increase the amount of radiation incident on the element.

FIG. 3A shows a coarse shape in which a plurality of circular gas passage holes 24 are provided in a plate-shaped radiation wavelength-selective material 23, and FIG. 3B shows an elongated slot 25 as a gas passage hole. FIG. 3C shows a case where a plurality of substantially square gas passage holes 26 are formed.
FIG. 3d shows these planar radiation wavelength-selective materials 23.
Among them, a plurality of the same type or different types are arranged in parallel to form the heat storage layer 20. FIG. 3d
, 29 indicates a direction component of the radiation toward the photovoltaic element. In FIG. 3d, preferably, each plate-shaped radiation wavelength-selective material 23 is arranged so that a gas passage space communicating in the axial direction is not formed. Further, the peripheral side surface of each plate-shaped radiation wavelength-selective material 23 and the inner surfaces of the gas passage holes 24, 25 and 26 are polished to a roughness of a wavelength range not more than the wavelength range to be transmitted. Also in the heat storage layer 20 having this shape, the component of the radiation radiated from the radiation radiating portion that is not directed to the photovoltaic element but is absorbed by the flow path wall surface is reflected by the end faces 24, 25, and 26. Thus, the amount of radiation incident on the photovoltaic element can be increased. Note that the shape and configuration of the radiation wavelength-selective material shown in FIGS. 2 and 3 are preferred embodiments, and the intended purpose is achieved even when the heat storage layer is simply formed of a block-like radiation wavelength-selective material. Needless to say.

FIG. 4 shows another embodiment of the power generation device according to the present invention. In this embodiment, a wavelength range in which the photovoltaic element 30 effectively generates power is provided between the heat storage layer 20 and the photovoltaic element 30. Infrared filter 35 that is transparent to radiation
Is different from the one shown in FIG. In an actual machine, it is practically difficult to cut all radiation wavelength-selective materials constituting the heat storage layer 20, for example, those having a wavelength range of 2 μm or more. Is inevitable to pass through the heat storage layer 20. As described above, by arranging the infrared light filter 35 having a transmittance with respect to the wavelength range in which the photovoltaic element 30 effectively generates power,
It is possible to prevent radiation having a long wavelength from being incident on the photovoltaic element 30 and to prevent the temperature of the photovoltaic element 30 from rising more than necessary. As the infrared light filter 35, for example, a dielectric filter is used.

In place of, or in addition to, the infrared light filter 35, which is transparent to radiation in a wavelength range in which the photovoltaic element 30 effectively generates power, a wavelength at which the photovoltaic element cannot generate power effectively. A reflector 36 having reflectivity (arrow Z) to the radiation in the area may be provided. Also in this case, for the same reason, a decrease in efficiency due to a rise in the temperature of the photovoltaic element 30 is suppressed. As the reflector 36, for example, a low-temperature heat ray reflective glass, a dielectric filter, a metal or metal oxide thin film, or the like is used.

Further, a reflector (not shown) having reflectivity to radiation in a wavelength range in which the photovoltaic element effectively generates power may be further provided on a wall surface surrounding the flow path of the working fluid. By arranging such a reflector, it is possible to prevent radiation in a wavelength range effective for power generation from radiating outside the system. As the reflector, for example, a heat ray reflective glass, a dielectric filter, a metal or metal oxide thin film, or the like is used.

FIG. 5 shows still another embodiment of the power generation device according to the present invention.
The radiating fins 31 are provided in a state in which they are in thermal contact with the back surface of the
It differs from that shown in FIG. 1 in that a cooling medium flow path 32 of the photovoltaic element 30 is provided. In this embodiment, since the photovoltaic element 30 can be actively cooled, a decrease in power generation efficiency due to a rise in temperature of the photovoltaic element 30 can be reliably suppressed. The cooling medium may be a gas such as air or a liquid such as cooling water. Further, the working fluid (air-fuel mixture) can be used as a cooling medium.

FIG. 6 shows a case where a working fluid (air-fuel mixture) is used as a cooling medium. In this case, the air-fuel mixture passes through the flow path 32 formed on the back surface of the photovoltaic element 30 (arrow AP), and flows from the back side of the heat storage layer 20A toward the radiation radiating section 10 (arrow A1). If the photovoltaic element 30 is heated to a temperature equal to or higher than the temperature of the air-fuel mixture at that time, heat exchange is performed there, and the temperature of the photovoltaic element 30 drops, and the air-fuel mixture is preheated. Since the preheated air-fuel mixture directly flows into the heat storage layer 20A, a high heat recovery rate is obtained, and the efficiency is improved. When the flow direction of the air-fuel mixture is switched, the arrow B
Similar heat recovery is performed by the flows indicated by A and B1.

FIG. 7 shows still another embodiment of the power generation device according to the present invention. Here, the radiation wavelength selectivity is provided on the low temperature side of the first heat storage layer 20 having the radiation wavelength selectivity. The above-described embodiment is further provided with a second heat storage layer 40 using a material that does not have the same, and the working fluid (air-fuel mixture and combustion gas) is configured to pass through the second heat storage layer 40 as well. Is different. FIG. 7 also shows a piping system for the working fluid and a flow direction switching unit.

In this example, a partition plate 41 made of quartz glass is attached between the heat storage layer 20 and the photovoltaic device 30, and a closed box 42 (cooling of the photovoltaic device 30) is provided on the back of the partition plate 41. (Which functions as a flow path 32 for an application medium), and the photovoltaic element 30 is accommodated therein. Preferably, as shown, an infrared light filter 35 is also provided on the front surface of the photovoltaic element 30. One end of each of the left and right sealed boxes 42A and 42B is connected to inflow conduits 51A and 51B branched from a supply line 50 for a working fluid (air mixture), and the other end is connected to outflow conduits 52A and 52B. are doing. The other ends of the outlet pipes 52A and 52B are connected to a pipe 53.
And two branch pipes 5 are connected from the pipe 53.
4A and 54B are branched. The other end of each branch pipe is connected to the second heat storage layer 40A via the inflow-side on-off valves 55A and 55B.
40B, and is connected to one end of the second heat storage layer 40B.
The other ends of the heat storage layers A and 40B communicate with the back sides of the heat storage layers 20A and 20B via conduits 56A and 56B, respectively.
Further, one ends of exhaust pipes 57A, 57B provided with outflow-side on-off valves 58A, 58B are connected to the second heat storage layers 40A, 40B, and the other ends of the exhaust pipes 57A, 57B are connected to the other end. It is connected to a common working fluid (combustion gas) discharge line 59.

An operation state of the power generator 1 shown in FIG. 7 will be described. Working fluid (mixture) from the supply line 50 (usually,
(At room temperature of about 25 ° C.) flows into the left and right sealed boxes 42A and 42B through the branched inflow pipes 51A and 51B. When passing therethrough, heat exchange is performed with the photovoltaic element 30 (preferably maintained at 100 ° C. or lower where high power generation efficiency is obtained) and the infrared light filter 35, and the air-fuel mixture is preheated (for example, 50 ° C.). ° C). Here, as shown in the figure, it is assumed that the inflow-side on-off valve 55A is set to the open state, the inflow-side on-off valve 55B is closed, the outflow-side on-off valve 58A is closed, and the outflow-side on-off valve 58B is set to the open state. The preheated air-fuel mixture passes through the pipes 52A, B and 53A, B, through the pipe 54A and the on-off valve 55A, and passes through the second heat storage layer 4.
Flow into OA. The second heat storage layer 40A has already been preheated to a temperature equal to or higher than the temperature of the inflowing air-fuel mixture by the passage of the working fluid (combustion gas) in the opposite direction in the previous round, and by passing through the second heat storage layer 40A The mixture is then preheated to a higher temperature. The air-fuel mixture thus preheated flows in from the rear side of the heat storage layer 20A. The preheated air-fuel mixture
The mode when passing through the heat storage layer 20A, the radiation radiating section 10, and the heat storage layer 20B, and the mode of power generation by the photovoltaic element 30 are the same as those of the above-described power generation device.

Discharged from the other heat storage layer 20B (arrow A2)
The temperature of the working fluid (combustion gas) at the time of
OB but still high temperature (400 ° C
), And if it is released outside the system as it is, heat loss will occur. Therefore, in the power generation device of this embodiment, the combustion gas is caused to flow into the second heat storage layer 40B through the conduit 56B, where heat exchange is performed and exhaust heat recovery is performed. The combustion gas from which the heat has been recovered is discharged out of the system via the exhaust pipe 57B and the discharge line 59. After the required time has elapsed, the state is switched to a state in which the on-off valve 55A is closed, the on-off valve 55B is opened, the second on-off valve 58A is opened, and the second on-off valve 58B is closed. Thereby, the flow direction of the working fluid in the heat storage layer 20 and the second heat storage layer 40 is switched, and the pattern of heat release and heat recovery is reversed.
However, power generation by the photovoltaic element 30 is performed continuously. In the power generator of this aspect, heat recovery can be performed with high efficiency, and the air-fuel mixture before combustion can be preheated to a high temperature, so that high-efficiency operation can be performed. Even if it is an ultra-lean mixture below the flammable limit, it can be used as a working fluid without any problem.

FIG. 8 shows still another embodiment of the power generation device according to the present invention.
Is different from the above-described power generation device in that a Peltier element 60 is stacked as a heat transport means on the back surface of the power generation device. In addition,
The Peltier elements 60 are stacked such that the low-temperature side is in contact with the back surface of the photovoltaic element 30. As already mentioned,
It is desirable that the heat energy not effectively used for power generation in the photovoltaic element 30 (heat enough to heat the photovoltaic element) be used for preheating the working fluid as much as possible. now,
It is assumed that an amount of heat enough to raise the temperature of the working fluid by 40 ° C. is transferred from the photovoltaic element 30 to the working fluid. Assuming that the working fluid (air-fuel mixture) flows in at room temperature 25 ° C, to preheat the working fluid temperature to (25 ° C + 40 ° C =) 65 ° C,
If the temperature of the photovoltaic element 30 has not reached 65 ° C. or higher, heat cannot be transported. On the other hand, the photovoltaic element 3
0, the lower the temperature, the higher the efficiency.
If the required heat transport can be performed on the working fluid while maintaining 0 at a lower temperature, the most preferable power generation mode is obtained.

The above can be achieved by laminating the Peltier device 60 as a heat transport means on the back surface (the surface opposite to the light receiving side) of the photovoltaic device 30. That is, when the temperature difference between the high-temperature side and the low-temperature side is about 10 ° C., the efficiency of the Peltier element is COP = 4 (the power of 4 can be moved from the low-temperature side to the high-temperature side by supplying 1 power). Even if the temperature of the photovoltaic element 30 is, for example, 55 ° C. (a high power generation efficiency is obtained), the working fluid (the temperature of the photovoltaic element 30 (Above) It becomes possible to preheat. Since the electric power input for operating the Peltier element is used for heating the radiation radiating portion and the heat storage layer, no heat loss occurs.

In the example shown in FIG. 8, an infrared light filter 35 is disposed between the heat storage layer 20 and the photovoltaic element 30, and the rear surface thereof is in thermal contact with the closed box 42 (photovoltaic element 30). Which functions as a flow path 32 for a cooling medium), in which a Peltier element 60 is stacked such that the low-temperature side is opposite to the light-receiving side of the photovoltaic element 30. The element 30 is housed. One end of each of the left and right closed boxes 42A, 42B is connected to inflow conduits 51A, 51B branched from a supply line 50 for a working fluid (air mixture), and the other ends are communicated by a common outflow conduit 53. ing. Two branch pipes 54A, 54 are provided from the outflow pipe 53.
B is branched, and the other end of each branch pipe is connected to the heat storage layers 20A, 20A via the inflow-side on-off valves 55A, 55B, respectively.
B communicates with one end on the back side. Thermal storage layer 20A, 20
One end of exhaust pipes 57A, 57B provided with outflow-side on-off valves 58A, 58B is connected to the other end on the back side of B, and the other ends of the exhaust pipes 57A, 57B share a common operation. It is connected to a fluid (combustion gas) discharge line 59.

The operation of the power generator 1 shown in FIG. 8 will be described. The working fluid (air-fuel mixture) from the supply line 50 passes through the branched inflow pipes 51A and 51B, and the left and right sealed boxes 42
A, 42B. When passing therethrough, the mixture is preheated by the transfer of heat by the Peltier element 60. Here, as shown in FIG.
Assuming that the inflow-side on-off valve 55B is closed, the outflow-side on-off valve 58A is closed, and the outflow-side on-off valve 58B is open, the preheated air-fuel mixture flows through the pipelines 53, 54A,
The heat flows from the back side of the heat storage layer 20A through the on-off valve 55A. The mode when the flowing preheated air-fuel mixture passes through the heat storage layer 20A, the radiation radiating section 10, and the heat storage layer 20B, and the mode of power generation by the photovoltaic element 30 are the same as those of the above-described power generation device. The working fluid (combustion gas) discharged from the other heat storage layer 20B is supplied to the exhaust pipe 57B
8B, discharged through the discharge line 59 to the outside of the system. After the required time has elapsed, the operation is switched to the state of closing the inflow-side on-off valve 55A, opening the inflow-side on-off valve 55B, opening the outflow-side on-off valve 58A, and closing the outflow-side on-off valve 58B. Same as for the device.

FIG. 9 shows still another embodiment of the power generating apparatus according to the present invention. Here, a heating burner 61 is provided in the vicinity of the radiation radiating section 10 in FIG. Is different from By heating the radiation radiating section 10 in advance by the combustion heat of the burner 61 at the time of startup, a lean mixture having a low concentration of combustible components can be used as a working fluid from the beginning of operation. Alternatively, the radiation radiating unit 10 may be continuously heated by the burner 61.

FIG. 10 illustrates an example of a power generation system that generates power using the above-described power generation device. Here, a conventional power generation device is used as an example of another industrial device or facility, and exhaust gas discharged therefrom is used as a working fluid of the power generation device according to the present invention. That is, the existing power generation device 100 generates electric power 111, heat 121, and exhaust gas 102 using the fuel 101 as an energy source. Existing power generation devices include those using an internal combustion engine as a drive source, fuel cells, and the like.
Flammable gas (hydrocarbons, hydrogen, C
O etc.). The exhaust gas 102 is sent as a working fluid to the power generator 1 according to the present invention, and becomes a fuel source. The power generation device 1 generates electric power 112, heat 122, and exhaust gas 103.

As described above, the power generation device according to the present invention can effectively preheat the working fluid, and therefore, the power generation can be continued even if a mixture that is not combustible under normal conditions and is less than the flammable limit is used as the working fluid. Power generation can be performed with high efficiency. Furthermore, since the exhaust gas 102 from the existing power generation device 100 is subjected to the combustion processing in the power generation device 1, the final exhaust gas 103 becomes cleaner. Thus, the power generator 1 according to the present invention and the existing power generator 10
By combining with 0, highly efficient energy recovery can be performed while purifying the exhaust gas.

The exhaust heat generated by the power generator according to the present invention can be used not only for preheating the working fluid described above but also for various heats according to the temperature level. Table 1 shows usage examples at each exhaust gas temperature. For details on how to use waste heat, see the Natural Gas Cogeneration Waste Heat Utilization Design Manual.
(Edited by The Japan Institute of Energy, Japan Industrial Publishing Company). Naturally, high-temperature exhaust gas can be used in a low-temperature-side usage form through a cooling process. In addition, if steam and hot water are produced,
Needless to say, it can be used for various heat processes and equipment such as an absorption heat pump using hot water, distillation / separation technology, and desiccant air conditioning.

[0049]

[Table 1]

FIG. 11 is an example showing the form of heat utilization when the exhaust gas generated by the power generator according to the present invention is at a high temperature. The steam boiler is driven by the exhaust gas generated from the power generator according to the present invention. In this example, a spare fuel (combustor) is provided as a backup when the heat of the exhaust gas is insufficient. The produced steam is used to drive a (back pressure) steam turbine to obtain power. The steam after obtaining the electric power drives a steam-fired absorption heat pump to obtain cold and hot water. on the other hand,
Since the exhaust gas that has undergone heat exchange in the steam boiler has a temperature sufficient for use, the hot water boiler is driven to obtain hot water.

FIG. 12 shows an example of heat utilization when the hot water boiler is driven with a low exhaust heat temperature. The hot water obtained in the hot water boiler is absorbed and cooled by a hot / cold water heater (refrigerator), for example, a hot water absorption cold / hot water heater (refrigerator), a single double absorption cold / hot water heater (refrigerator), and a waste heat input type absorption cold / hot water heater (refrigeration) Machine). In this case, the hot water is used in the process of regenerating the absorbent, and the energy efficiency of the entire system is improved. It is needless to say that even if the generated hot water is used for purposes other than the absorption chiller / heater, that is, for hot water supply and heating, the energy efficiency of the entire system is increased. FIG. 13 shows a heat utilization method when the exhaust gas temperature is low and the hot water boiler cannot be driven. In this case, the heat of the exhaust gas is directly used for regeneration of the desiccant air conditioner. As a result, even low-temperature heat of about 55 ° C. can be effectively used.

[0052]

As described above, in the present invention, the photovoltaic element is formed by using, as the heat storage layer, an irradiating wavelength-selective material that is transparent to the wavelength range in which the photovoltaic element generates power effectively. Ineffective radiation that cannot generate power is absorbed by the heat storage layer and raises the temperature of the heat storage layer. A part of the radiation energy absorbed in the heat storage layer is re-emitted due to this temperature rise, but radiation in an invalid wavelength range that does not contribute to power generation is accumulated as heat in other parts of the heat storage layer.
These stored ineffective radiation energies are effectively used for preheating of the working fluid by providing a means for switching the flow direction of the working fluid in the heat storage layer, thereby increasing the temperature of the radiation radiating portion, thereby increasing the short wavelength region. (I.e., in the wavelength range where the photovoltaic element effectively generates power). From these, power generation efficiency is greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a power generation device according to the present invention.

FIG. 2 is a diagram illustrating some forms of an emission wavelength-selective material constituting a heat storage layer.

FIG. 3 is a view for explaining still some other forms of the radiation wavelength-selective material constituting the heat storage layer.

FIG. 4 is a diagram illustrating another embodiment of the power generator according to the present invention.

FIG. 5 is a view for explaining still another embodiment of the power generator according to the present invention.

FIG. 6 is a diagram illustrating still another embodiment of the power generator according to the present invention.

FIG. 7 is a diagram illustrating still another embodiment of the power generation device according to the present invention.

FIG. 8 is a view for explaining still another embodiment of the power generator according to the present invention.

FIG. 9 is a diagram illustrating still another embodiment of the power generation device according to the present invention.

FIG. 10 is a diagram illustrating an example of a power generation system according to the present invention.

FIG. 11 is a diagram showing an example of a mode using waste heat from a power generation device according to the present invention.

FIG. 12 is a diagram showing another example of a mode using waste heat from a power generation device according to the present invention.

FIG. 13 is a diagram showing still another example of a mode using waste heat from a power generator according to the present invention.

[Explanation of symbols]

Reference numeral 1 denotes a power generator, A1, A2, B1, B2: a flow of a working fluid, X: radiation in a wavelength region which passes through a heat storage layer and is incident on a photovoltaic element to contribute to power generation, Y: radiation in another wavelength region, 10
... radiation radiating portions, 20A and 20B ... heat storage layer, 21 ... square rod-shaped radiation wavelength-selective material, 22 ... parallel to the radiation direction component from the radiation radiating portion of the square rod-shaped radiation wavelength-selective material toward the photovoltaic element 23, flat plate-like radiation wavelength-selective material, 24, 25, 26 ... gas-passing holes of flat plate-like radiation wavelength-selective material, 27, 29 ... component of radiation direction toward photovoltaic element, 35 ... infrared Light filter, 30 ...
Photovoltaic element, 31 radiating fin, 32 cooling medium flow path, 40 second heat storage layer using material having no irradiation wavelength selectivity

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F051 AA01 AA07 JA14 JA16 JA20

Claims (17)

[Claims] 1. A radiation radiating unit that emits radiation energy by generating heat of a working fluid or heating by a heating device, a heat storage layer, a means for switching a flow direction of the working fluid in the heat storage layer, and a photovoltaic element. A radiation wavelength-selective material having a transmittance with respect to a wavelength region in which the photovoltaic element effectively generates power, and receives radiation transmitted through the heat storage layer as the heat storage layer. A photovoltaic device, wherein a photovoltaic element is arranged at a position where it can be performed. 2. The power generation system according to claim 1, wherein two heat storage layers are arranged to face the radiation radiating portion, and a photovoltaic element is arranged outside each of the heat storage layers. apparatus. 3. The power generation device according to claim 1, wherein the heat storage layer has a shape obtained by combining square-shaped rod-shaped radiation wavelength-selective materials in parallel or in a lattice. 4. The power generating apparatus according to claim 3, wherein the end face of the square rod-shaped radiation wavelength-selective material is polished to a roughness equal to or less than a transmission wavelength range. 5. The heat storage layer according to claim 1, wherein the heat storage layer has a shape in which a plurality of flat-plate-shaped radiation wavelength-selective materials provided with a plurality of gas-passing holes provided with a plurality of gas passage holes are arranged in parallel. 2. The power generator according to 2. 6. The power generator according to claim 4, wherein an inner surface of the gas passage hole provided in the plate-shaped radiation wavelength-selective material is polished to a roughness of a wavelength range that allows transmission. 7. An infrared light filter between the heat storage layer and the photovoltaic element, the infrared light filter being transparent to radiation in a wavelength range in which the photovoltaic element effectively generates power. 7. The power generator according to any one of claims 6 to 6. 8. The photovoltaic device according to claim 1, further comprising a reflector between the heat storage layer and the photovoltaic element, the reflector having reflectivity to radiation in a wavelength range in which the photovoltaic element cannot generate power effectively. The power generating device according to any one of claims 1 to 3. 9. The apparatus according to claim 1, further comprising a reflector on a wall surrounding the flow path of the working fluid, the reflector having a reflectivity to radiation in a wavelength range in which the photovoltaic element generates power effectively. A power generator as described. 10. The power generating apparatus according to claim 1, wherein a flow path of a cooling medium is provided in thermal contact with the photovoltaic element. 11. The cooling medium is a working fluid, and heat exchange is performed between the photovoltaic element and the working fluid by passing through the flow path. Power generator. 12. A Peltier device is disposed on a surface of the photovoltaic device opposite to the light receiving side.
Or the power generator according to 11. 13. A second heat storage layer using a material having no radiation wavelength selectivity is further provided on a low temperature side of the first heat storage layer having the radiation wavelength selectivity, and the working fluid is a second heat storage layer.
The power generation device according to claim 1, wherein the power generation device is configured to pass through the heat storage layer. 14. The power generator according to claim 1, wherein the radiation radiator includes a heating burner. 15. A power generation system using the power generation device according to claim 1. 16. The power generation system according to claim 15, wherein a lean flammable gas discharged or generated from another industrial device or facility or from the natural world is used as all or a part of the working fluid. 17. The power generation system according to claim 16, wherein the flammable component of the lean flammable gas is concentrated and then introduced as a working fluid into the power generation device.