JP2015117627A - Power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation system using a gas turbine, capable of ensuring less load on environment, and improved in heat efficiency.SOLUTION: A power generation system includes: a heating unit heating a working medium without mixing fuel with the working medium to burn the mixture; a turbine generating rotational energy by expanding the working medium heated by the heating unit; a regenerator that includes a first channel in which the working medium expanded by the turbine flows and a second channel in which the working medium directed toward the heating unit flows, and implementing heat exchange between the working medium flowing in the first channel and the working medium flowing in the second channel; a decompressor reducing a pressure of an outlet of the turbine by inhaling the working medium passing through the first channel of the regenerator; and a circulation pipe introducing the working medium discharged from the decompressor into the second channel of the regenerator.

Description

  The present invention relates to a power generation system using a gas turbine.

  Conventional gas turbine power generation facilities include a compressor that compresses air in the atmosphere, a combustor that mixes and burns fossil fuels such as coal and oil with high-pressure air compressed by the compressor, and burns with a combustor And a turbine that expands the high-temperature and high-pressure air that is generated, and the high-temperature air discharged from the turbine is released into the atmosphere (see, for example, Patent Document 1).

  By the way, in recent years, adverse effects on the environment caused by burning fossil fuels (for example, consumption of non-renewable fossil fuels, greenhouse effect due to emission of carbon dioxide, etc.) have been problems. In particular, there are arid areas called sunbelt areas with abundant solar radiation over a wide area such as the United States, Southern Europe, Australia, Africa, and Central Asia. In such arid areas, new combustors are installed. When installed, there is a problem that the environment is further deteriorated by adding a new heat source.

  In view of this, it has been proposed to employ a solar heating system that heats air without mixing and burning fossil fuel in a conventional gas turbine power generation facility instead of a heating system using a combustor. In particular, an arid region called a sunbelt zone is suitable for the use of a solar heating method because of the large amount of solar radiation.

  However, in a conventional gas turbine power generation facility, simply replacing the heating method by the combustor with the heating method by solar heat releases the high-temperature air discharged from the turbine to the atmosphere, resulting in a large environmental load. There is.

  In order to solve this problem, the high-temperature air exhausted from the turbine and the air going to the solar heat collection facility are exchanged through a regenerator, and the high-temperature air exhausted from the turbine is cooled and then returned to the atmosphere. It is also possible to release it. However, since the compressed air heading for the solar heat collecting facility is already heated by being compressed by the compressor, the air discharged from the turbine cannot be effectively cooled in the regenerator.

JP 2006-118368 A

  The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a power generation system using a gas turbine, which has a small environmental load and is improved in terms of thermal efficiency.

  The present invention includes a heating unit that heats the working gas without mixing the fuel with the working gas and combusts, a turbine that generates rotational energy by expanding the working gas heated by the heating unit, A first flow path through which the working gas expanded by the turbine passes, and a second flow path through which the working gas toward the heating unit passes, and the working gas and the second flow path that pass through the first flow path. A regenerator for exchanging heat with the working gas passing through the pressure reducing device, a pressure reducing device for reducing the pressure at the outlet of the turbine by sucking the working gas that has passed through the first flow path of the regenerator, and the pressure reducing device And a circulation pipe for introducing the working gas discharged from the second flow path of the regenerator.

  According to the present invention, the working gas discharged from the decompression device passes through the circulation pipe and the second flow path of the regenerator in order to be returned to the heating unit, and in the heating unit, fuel is returned to the returned working gas. The working gas is reheated without being mixed and burned. Thereby, since a high temperature working gas is not discharged | emitted to air | atmosphere, the raise of the atmospheric temperature by exhaust gas is suppressed and the load to an environment reduces. This effect is remarkably useful when the power generation system according to the present invention is used in an arid region called a sun belt area. Further, since the high temperature working gas is not released to the atmosphere, the amount of heat released to the outside of the system is reduced, and the thermal efficiency of the entire system is improved.

  Further, according to the present invention, since the turbine expands the uncompressed working gas, the element efficiency is not easily lowered even if the turbine is small. Further, since the uncompressed working gas passes through the second flow path of the regenerator, the working gas discharged from the turbine and passing through the first flow path is effectively cooled by the working gas passing through the second flow path. . Furthermore, since the working gas effectively cooled through the first flow path is introduced into the decompression device, the work amount in the decompression device is reduced. As a result, the thermal efficiency of the entire system is further improved.

  Preferably, the heating unit heats the working gas using solar heat as a heat source. According to such an aspect, it is easy to heat the working gas to a higher temperature without mixing the fuel with the working gas and burning it.

  Preferably, the working gas is air. According to such an aspect, there is an advantage that the cost is low and even if an accident occurs in which the working gas leaks out of the system, there is no load on the environment.

  Preferably, the third flow path includes a third flow path through which the working gas passing through the first flow path and going to the decompression device passes, and a fourth flow path through which a cooling fluid passes. And a heat exchanger for exchanging heat between the working gas passing through and the cooling fluid passing through the fourth flow path. According to such an aspect, since the working gas further cooled through the third flow path of the heat exchanger is introduced into the decompression device, the work in the decompression device is further reduced, and as a result, the entire system This leads to further improvement of the thermal efficiency of the. In addition, when the cooling fluid heated through the fourth flow path of the heat exchanger is effectively used outside, the overall efficiency of the entire system is also improved.

  In this case, preferably, the cooling fluid is cooling water. According to such an aspect, since heat is exchanged between the cooling water (liquid) and the working gas (gas) in the heat exchanger, heat exchange is performed compared to the case where heat is exchanged between the gases. The structure of the vessel is simple and the equipment cost is low. Moreover, the cooling water (hot water) heated by the heat exchanger can be effectively used in a wide range of applications such as a cooling heat source in an adsorption refrigerator and a domestic hot water supply.

  Alternatively, the cooling fluid may be a cooling gas. In this case, the cooling gas heated by the heat exchanger can be effectively used in a wide range of applications such as air conditioning.

  According to the present invention, the working gas discharged from the decompression device passes through the circulation pipe and the second flow path of the regenerator in order to be returned to the heating unit, and in the heating unit, fuel is returned to the returned working gas. The working gas is reheated without being mixed and burned. Thereby, since high temperature working gas is not discharged | emitted to air | atmosphere, the raise of the temperature by exhaust gas is suppressed and the load to an environment reduces. This effect is remarkably useful when the power generation system according to the present invention is used in an arid region called a sun belt area. Further, since the high temperature working gas is not released to the atmosphere, the amount of heat released to the outside of the system is reduced, and the thermal efficiency of the entire system is improved.

  Further, according to the present invention, since the turbine expands the uncompressed working gas, the element efficiency is not easily lowered even if the turbine is small. Further, since the uncompressed working gas passes through the second flow path of the regenerator, the working gas discharged from the turbine and passing through the first flow path is effectively cooled by the working gas passing through the second flow path. . Furthermore, since the working gas effectively cooled through the first flow path is introduced into the decompression device, the work amount in the decompression device is reduced. As a result, the thermal efficiency of the entire system is further improved.

FIG. 1 is a schematic configuration diagram showing a power generation system according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing a power generation system according to the second embodiment of the present invention. FIG. 3 is a flow sheet showing an embodiment using the power generation system of FIG. FIG. 4 is a schematic configuration diagram illustrating a power generation system as a comparative example in which a circulation pipe is omitted. FIG. 5 is a flow sheet showing a first comparative example using the power generation system of FIG. FIG. 6 is a flow sheet showing a second comparative example using the power generation system of FIG.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing a power generation system according to a first embodiment of the present invention.
As shown in FIG. 1, the power generation system 10 a according to the present embodiment includes a heating unit 11 that heats the working gas without mixing the working gas with fuel and burns, and the working gas heated by the heating unit 11. And a first flow path 131 through which the working gas expanded by the turbine 12 passes, and a second flow path 132 through which the working gas toward the heating unit 11 passes. Then, the regenerator 13 that exchanges heat between the working gas passing through the first flow path 131 and the working gas passing through the second flow path 132 and the working gas that has passed through the first flow path 131 of the regenerator 13 are sucked. Thus, the pressure reducing device 14 for reducing the pressure at the outlet of the turbine 12 and the circulation pipe 15 for introducing the working gas discharged from the pressure reducing device 14 into the second flow path 132 of the regenerator 13 are provided. In the present embodiment, the working gas is the same air as that contained in the atmosphere.

  As shown in FIG. 1, the heating unit 11 of the present embodiment is a tower-type solar heat collecting facility, and heats the working gas using solar heat as a heat source.

  More specifically, as shown in FIG. 1, the heating unit 11 includes a tower 113 erected on the ground, a heat collector 112 provided at the upper end of the tower 113, and sunlight toward the heat collector 112. And a heating flow path 114 that is heated by receiving heat from the heat collector 112.

  A plurality of reflectors 111 are installed around the tower 113 on the ground, and the sunlight reflected by each reflector 111 is collected in the heat collector 112. The heat collector 112 efficiently converts the collected sunlight into heat (solar heat).

  The heat collector 112 may be provided with a heat storage device (not shown). As the heat storage device, for example, molten salt, ceramics, or the like is used. Since the heat generated by the heat collector 112 is stored in the heat storage device, the heat can be used even in a time zone without sunlight.

  As shown in FIG. 1, the inlet 114 a of the heating channel 114 is connected to the outlet 132 b of the second channel 132 of the regenerator 13, and the inlet 132 a of the second channel 132 passes through the circulation pipe 15. Are connected to the outlet 14b of the decompression device 14. As will be described later, the normal-pressure air discharged from the outlet 14 b of the decompression device 14 passes through the second flow path 132 and then flows into the inlet 114 a of the heating flow path 114. And while flowing through the heating flow path 114, it is heated to a high temperature by receiving heat from the heat collector 112. In this specification, “normal pressure” refers to atmospheric pressure in the installation environment of the power generation system 10a, and pressure lower than that is referred to as “negative pressure”.

  As shown in FIG. 1, the outlet 114 b of the heating channel 114 is connected to the inlet 12 a of the turbine 12. The pressure at the outlet 12 b of the turbine 12 is reduced to a negative pressure by the pressure reducing device 14. The turbine 12 generates rotational energy by expanding the atmospheric air heated in the heating unit 11 to a negative pressure.

  A decompressor 14 and a generator 19 are coaxially connected to the turbine 12, and the rotational energy generated by the turbine 12 is used as drive energy for the generator 19 and the decompressor 14. Yes. As the decompression device 14, for example, an axial flow compressor or a centrifugal compressor can be used.

  The outlet 12 b of the turbine 12 is connected to the inlet 131 a of the first flow path 131 of the regenerator 13, and the negative pressure air expanded by the turbine 12 enters the inlet 131 a of the first flow path 131 of the regenerator 13. Inflow.

  As the regenerator 13, for example, a heat transfer heat exchanger is used. In the present embodiment, the first flow path 131 and the second flow path 132 are adjacent to each other via a partition wall in such a direction that the flow directions face each other, and negative pressure passing through the first flow path 131. Heat exchange is performed between the air and normal pressure air passing through the second flow path 132 via a partition wall. More specifically, the negative pressure air passing through the first flow path 131 is cooled by heat recovery by the normal pressure air passing through the second flow path 132, and the normal pressure air passing through the second flow path 132 is Heat is recovered by recovering heat from negative-pressure air passing through the first flow path 131.

  As shown in FIG. 1, the outlet 131 b of the first flow path 131 is connected to the inlet 14 a of the decompression device 14. Specifically, for example, an axial flow compressor or a centrifugal compressor is used as the decompression device 14. The decompression device 14 is driven by the rotational energy of the turbine 12 and sucks air that has passed through the first flow path 131 from the inlet 14a, and discharges atmospheric air from the outlet 14b. The air that has passed through the first flow path 131 is sucked by the decompression device 14, whereby the pressure at the outlet 12 b of the turbine 12 is reduced to a negative pressure.

  As described above, the outlet 14 b of the decompression device 14 is connected to the inlet 132 a of the second flow path 132 of the regenerator 13 via the circulation pipe 15. As a result, normal pressure air discharged from the outlet 14 b of the decompression device 14 passes through the circulation pipe 15 and the second flow path 132 in order, and is returned to the heating unit 11.

Next, the operation of the present embodiment having such a configuration will be described.
First, as shown in FIG. 1, the air in the first flow path 131 is sucked from the inlet 14 a of the decompression device 14, so that the pressure at the outlet 12 b of the turbine 12 is reduced to a negative pressure and the decompression device 14. Normal pressure air is discharged from the outlet 14b.

  Normal-pressure air discharged from the outlet 14 b of the decompression device 14 flows into the inlet 132 a of the second flow path 132 of the regenerator 13 through the circulation pipe 15.

  In the regenerator 13, the temperature of the negative pressure air flowing into the inlet 131 a of the first flow path 131 is higher than the temperature of the normal pressure air flowing into the inlet 132 a of the second flow path 132. Therefore, heat moves from negative pressure air passing through the first flow path 131 to normal pressure air passing through the second flow path 132. Thus, the negative pressure air passing through the first flow path 131 is cooled by heat recovery by the normal pressure air passing through the second flow path 132. On the other hand, the normal pressure air passing through the second flow path 132 is heated by recovering heat from the negative pressure air passing through the first flow path 131.

  Normal pressure air flowing out from the outlet 132 b of the second flow path 132 flows into the inlet 114 a of the heating flow path 114.

  In the heating unit 11, the sunlight reflected by the reflector 111 is collected in the heat collector 112 provided at the upper end of the tower 113, and the sunlight is efficiently converted into heat (solar heat) in the heat collector 112. The The atmospheric air flowing through the heating channel 114 is heated to a high temperature by receiving heat from the heat collector 112.

  In the present embodiment, the normal pressure air flowing into the inlet 114 a of the heating channel 114 is preheated through the second channel 132 of the regenerator 13. Even if the amount of heat generated (i.e., the size of the heat source) is small, the heat can be easily heated to a high temperature (e.g., 800C to 1000C) while passing through the heating flow path 114.

  Normal-pressure air that flows out from the outlet 114 b of the heating channel 114 flows into the inlet 12 a of the turbine 12.

  In the turbine 12, normal pressure air flowing in from the inlet 12a is expanded to a negative pressure to generate rotational energy. Part of the generated rotational energy is used as driving energy for the decompression device 14, and the rest is used as driving energy for the generator 19.

  The negative pressure air discharged from the outlet 12 b of the turbine 12 flows into the inlet 131 a of the first flow path 131 of the regenerator 13.

  As described above, in the regenerator 13, heat is transferred from the negative pressure air passing through the first flow path 131 to the normal pressure air passing through the second flow path 132, and the negative pressure passing through the first flow path 131 is reduced. The air is cooled.

  Negative pressure air flowing out from the outlet 131 b of the first flow path 131 of the regenerator 13 flows into the inlet 14 a of the decompression device 14.

  In the decompression device 14, the negative pressure air flowing from the inlet 14a is decompressed until it reaches a normal pressure. Then, the decompressed normal pressure air is discharged from the outlet 14 b of the decompression device 14. As described above, the normal pressure air discharged from the outlet 14 b of the decompression device 14 flows into the inlet 132 a of the second flow path 132 of the regenerator 13 through the circulation pipe 15.

  According to the present embodiment as described above, the working gas discharged from the decompression device 14 is returned to the heating unit 11 through the circulation pipe 15 and the second flow path 132 of the regenerator 13 in order, and heated. In the part 11, the working gas is reheated without being mixed with the returned working gas and burned. Thereby, since a high temperature working gas is not discharged | emitted to air | atmosphere, the raise of the atmospheric temperature by exhaust gas is suppressed and the load to an environment reduces. This effect is remarkably useful when the power generation system 10a according to the present embodiment is used in an arid region called a sun belt area. Further, since the high temperature working gas is not released to the atmosphere, the amount of heat released to the outside of the system is reduced, and the thermal efficiency of the entire system is improved.

  Moreover, according to this Embodiment, since the turbine 12 expands the working gas which is not compressed, even if it is small, element efficiency does not fall easily. Further, since the uncompressed working gas passes through the second flow path 132 of the regenerator 13, the working gas discharged from the turbine 12 and passing through the first flow path 131 is more effective than the working gas passing through the second flow path 132. Cooled. Furthermore, since the working gas effectively cooled through the first flow path 131 is introduced into the decompression device 14, the work amount in the decompression device 14 is reduced. As a result, the thermal efficiency of the entire system is further improved.

  Further, according to the present embodiment, since the working gas is air, the cost is low, and even if an accident occurs in which the working gas leaks out of the system, there is an advantage that no environmental load is generated. There is.

  Further, according to the present embodiment, the heating unit 11 is configured to heat the working gas using solar heat as a heat source. It is easy to heat to high temperature. Moreover, it is also possible to respond | correspond to the time shift electric power generation in the time slot | zone without sunshine by attaching a thermal storage apparatus to the heating part 11. FIG.

  In the present embodiment, a tower-type solar heat collecting facility is used as the heating unit 11. However, the present invention is not limited to this, and other types of solar collectors such as a dish type, a trough type, and a Fresnel type are used. Thermal equipment may be used. A method in which sunlight is collected at a single point, such as a tower type or a dish type, is preferable because high temperatures are easily obtained.

  In the present embodiment, the heating unit 11 is configured to heat the working gas using solar heat as a heat source. However, the heating unit 11 is not limited to this, and for example, the heating unit 11 is configured to heat the working gas using magma as a heat source. Also good. Also in this case, it is easy to heat the working gas to a high temperature without mixing the fuel with the working gas and burning it. In this case, it is possible to stably generate power regardless of the time of day or the weather.

  In the present embodiment, air is used as the working gas. However, the present invention is not limited to this. For example, helium gas or ammonia gas having a higher specific heat than air may be used as the working gas. In this case, the thermal efficiency of the entire system can be further improved.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 2 is a schematic configuration diagram showing a power generation system 10b according to the second embodiment of the present invention.

  As shown in FIG. 2, in the power generation system 10b according to the second embodiment, in addition to the configuration of the first embodiment shown in FIG. A third flow path 161 through which the working gas passes and a fourth flow path 162 through which the cooling fluid passes, between the working gas passing through the third flow path 161 and the cooling fluid passing through the fourth flow path 162. Further, a heat exchanger 16 for exchanging heat is provided.

  As the heat exchanger 16, for example, a heat transfer heat exchanger is used. In the present embodiment, the third flow path 161 and the fourth flow path 162 are adjacent to each other via a partition wall in such a direction that the flow directions are opposed to each other, and the working gas passing through the third flow path 161. And a cooling fluid passing through the fourth flow path 162, heat exchange is performed via a partition wall.

  As shown in FIG. 2, the inlet 161 a of the third channel 161 is connected to the outlet 131 b of the first channel 131, and the outlet 161 b of the third channel 161 is connected to the inlet 14 a of the decompression device 14. . On the other hand, the inlet 162a of the fourth channel 162 is connected to a cooling water supply unit (not shown), and the outlet 162b of the fourth channel 162 is connected to an adsorption refrigerator (not shown). As the decompression device 14, for example, an axial flow compressor or a centrifugal compressor can be used as in the first embodiment.

  The temperature of the cooling water flowing into the inlet 162a of the fourth flow path 162 is set to be lower than the temperature of the negative pressure air flowing into the inlet 161a of the third flow path 161. Therefore, heat moves from the negative pressure air passing through the third flow path 161 to the cooling water passing through the fourth flow path 162. Thereby, the negative pressure air passing through the third flow path 161 is cooled by heat recovery by the cooling water passing through the fourth flow path 162. On the other hand, the cooling water passing through the fourth flow path 162 is heated by recovering heat from negative pressure air passing through the third flow path 161.

  In the present embodiment, the cooling water (warm water) flowing out from the outlet 162b of the fourth channel 162 is effectively used as a cold heat source in an adsorption refrigerator (not shown).

  Other configurations are substantially the same as those of the first embodiment shown in FIG. In FIG. 2, the same parts as those of the first embodiment shown in FIG.

  According to the second embodiment as described above, in addition to the same effects as those of the first embodiment, it is further cooled through the third flow path 161 of the heat exchanger 16. Since the working gas is introduced into the decompression device 14, the amount of work in the decompression device 14 is further reduced, and as a result, the thermal efficiency of the entire system is improved. Further, the cooling fluid heated through the fourth flow path of the heat exchanger 16 is effectively used outside, so that the overall efficiency of the entire system is improved.

  Moreover, according to this Embodiment, in the heat exchanger 16, since heat exchange is carried out between cooling water (liquid) and working gas (gas), compared with the case where heat exchange is carried out between gases. The structure of the heat exchanger 16 is simple and the equipment cost is small. Further, the cooling water (hot water) heated by the heat exchanger 16 can be effectively used in a wide range of applications such as a cooling heat source in an adsorption refrigerator and a domestic hot water supply.

  In the present embodiment, the cooling water is used as the cooling fluid. However, the present invention is not limited to this, and a cooling gas may be used as the cooling fluid. In this case, the cooling gas heated by the heat exchanger 16 can be effectively used in a wide range of applications such as air conditioning.

Next, specific examples will be described.
First, as an example according to the second embodiment, the atmospheric temperature: 35 ° C., the cooling water temperature at the fourth channel inlet: 45 ° C., the cooling water temperature at the fourth channel outlet: 90 ° C., and the turbine inlet temperature: 900 A predetermined amount of working gas (air) flowing between each element based on thermodynamics, on the preconditions of: ° C, compression ratio: 3, regenerator efficiency: 80%, turbine efficiency: 90%, pressure reducing device efficiency: 90% ) State change was calculated.

  As a result, as shown in the flow sheet of FIG. 3, at the inlet 132a of the second channel 132 (the outlet 14b of the decompression device 14), the pressure is 1 barA, the temperature is 190 ° C., and the outlet 132b of the second channel 132 The pressure is 1 barA, the temperature is 557 ° C., the pressure is 1 barA and the temperature is 900 ° C. at the inlet 12a of the turbine 12, and the pressure is 0.3 barA and the temperature is 648 ° C. at the outlet 12b of the turbine 12. At the outlet 131b of the first flow path 131, the pressure was 0.3 barA and the temperature was 282 ° C., and at the inlet 14a of the decompression device 14, the pressure was 0.3 bar A and the temperature was 60 ° C.

In order to evaluate the example according to the second embodiment, the work in the turbine 12 is W _T , the work in the decompression device 14 is W _C , the heat input from the heating unit 11 is ΔQ, and the heat recovery amount by the cooling water is ΔQ. In the case of ', the following formula (1)
η = (W _T −W _C ) / ΔQ (1)
The plant thermal efficiency η expressed by the following formula (2)
η ′ = (W _T −W _C + ΔQ ′) / ΔQ (2)
The plant overall efficiency η ′ shown in FIG. The plant overall efficiency η ′ indicates the efficiency when all the cooling water (hot water) flowing out from the outlet 162b of the fourth flow path 162 is effectively used.

  As a result, in the example according to the second embodiment, the plant thermal efficiency η: 35.3% and the plant overall efficiency η ′: 93.5%.

  FIG. 4 is a schematic configuration diagram illustrating a power generation system 100 as a comparative example. In FIG. 4, the same parts as those of the second embodiment shown in FIG.

  As shown in FIG. 4, in the power generation system 100 as a comparative example, the circulation pipe 15 is omitted from the configuration of the second embodiment, and the inlet 132a of the second flow path 132 and the outlet 14b of the decompression device 14 are provided. Each is open to the atmosphere.

  Next, as a first comparative example using the power generation system 100 as the comparative example, a predetermined amount (second implementation) flowing between the elements is assumed on the precondition that the value is the same as that of the example according to the second embodiment. The change in state of the working gas (air) at the same flow rate as in the example according to the form was calculated.

  As a result, as shown in the flow sheet of FIG. 5, at the inlet 132a of the second flow path 132, the pressure is 1 barA and the temperature is 35 ° C., and at the outlet 132b of the second flow path 132, the pressure is 1 barA and the temperature is: At the inlet 12a of the turbine 12, the pressure is 1 barA and the temperature is 900 ° C. At the outlet 12b of the turbine 12, the pressure is 0.3 barA and the temperature is 648 ° C. In 131b, the pressure is 0.3 barA, and the temperature is 158 ° C. In the inlet 14a of the decompression device 14, the pressure is 0.3 barA and the temperature is 52 ° C. In the outlet 14b of the decompression device 14, the pressure is 1 barA and the temperature. 179 ° C.

  In order to evaluate the first comparative example, similarly to the example according to the second embodiment, the plant thermal efficiency η represented by the above equation (1), and the overall plant efficiency η ′ represented by the above equation (2) , Respectively.

  As a result, in the first comparative example, the plant thermal efficiency η was 33.2% and the plant overall efficiency η ′ was 58.6%. That is, in the first comparative example, it was confirmed that the plant thermal efficiency was reduced by 2.1% and the overall plant efficiency was reduced by 35% as compared with the example according to the second embodiment.

  In the example according to the second embodiment and the first comparative example, the same values are adopted as the element efficiency and the flow rate of the working gas as preconditions, so that the amount of heat input from the heating unit 11 in the first comparative example. (That is, the temperature difference between the inlet 114a and the outlet 114b of the heating channel 114) is larger than the amount of heat input from the heating unit 11 in the example according to the second embodiment. Care must be taken.

  By the way, in an actual power generation system, planning, construction, and the like are performed on the assumption that a heat source (amount of heat input) or a power generation amount of a predetermined size. Therefore, as a comparative example in which the heat generation system 10b according to the second embodiment having the circulation pipe 15 and the circulation pipe 15 are omitted when a heat source or a power generation system with a power generation amount of a predetermined size is planned and constructed. Next, which power generation system 100 is advantageous will be discussed.

  First, when the same value is adopted for each element efficiency as a precondition, as in the example according to the second embodiment and the first comparative example, if the flow rate of the working gas is the same, the heat input amount of the first comparative example is Therefore, in order to make the size of the heat source (heat input amount) the same, it is necessary to reduce the flow rate of the working gas of the first comparative example. In this case, the amount of power generation in the first comparative example is reduced by the amount of decrease in the flow rate. In other words, in order to make the power generation amount the same, it is necessary to make the flow rate of the working gas the same. Therefore, the size of the heat source (heat input amount) required in the first comparative example becomes larger, that is, In the first comparative example, a larger heating unit 11 is required.

  Next, as a second comparative example using the power generation system 100 as a comparative example, the heat input amount from the heating unit 11 is the same value as the heat input amount from the heating unit 11 in the example according to the second embodiment. Except for increasing the regenerator efficiency to 85%, a pre-determined amount of flow between each element is assumed with the same value as the example according to the second embodiment (the example according to the second embodiment). The change in the state of the working gas (air) at the same flow rate was calculated.

  As a result, as shown in the flow sheet of FIG. 6, at the inlet 132a of the second flow path 132, the pressure is 1 barA and the temperature is 35 ° C., and at the outlet 132b of the second flow path 132, the pressure is 1 barA and the temperature is: At the inlet 12a of the turbine 12, the pressure is 1 barA and the temperature is 900 ° C, and at the outlet 12b of the turbine 12, the pressure is 0.3 barA and the temperature is 648 ° C. In 131b, pressure: 0.3 barA, temperature: 282 ° C., in the inlet 14a of the decompression device 14, pressure: 0.3 barA, temperature: 60 ° C., and in the outlet 14b of the decompression device 14, pressure: 1 barA, temperature : 190 ° C.

  In order to evaluate the second comparative example, the plant thermal efficiency η represented by the above equation (1) and the plant represented by the above equation (2), similarly to the example and the first comparative example according to the second embodiment. The total efficiency η ′ was calculated respectively.

  As a result, in the second comparative example, the plant thermal efficiency η was 36.5%, and the overall plant efficiency η ′ was 56.5%. In the second comparative example, the temperature of the inlet 14a of the decompression device 14 decreases, so that the plant thermal efficiency η increases compared to the example according to the second embodiment, but the recovered heat quantity of the cooling water decreases. It has been confirmed that the overall plant efficiency η ′ decreases as compared with the example according to the second embodiment.

  In the second comparative example, the plant thermal efficiency η is increased as compared with the example according to the second embodiment, but the regenerator efficiency is increased to 85% as a precondition for the second comparative example. It is necessary to pay attention to. The actual regenerator 13 has a complicated structure in order to exchange heat between gases. Therefore, in order to increase the regenerator efficiency in the actual regenerator 13, there is a disadvantage that a large cost is required. That is, according to the second embodiment, it is possible to obtain an advantageous effect of low cost while achieving a plant thermal efficiency of 35% or more.

10a power generation system 10b power generation system 11 heating unit 111 reflector 112 collector 113 tower 114 heating channel 114a heating channel inlet 114b heating channel outlet 12 turbine 12a turbine inlet 12b turbine outlet 13 regenerator 131 first flow Path 131a first channel inlet 131b first channel outlet 132 second channel 132a second channel inlet 132b second channel outlet 14 decompression device 14a decompression device inlet 14b decompression device outlet 15 circulation pipe 16 Heat exchanger 161 Third flow path 161a Third flow path inlet 161b Third flow path outlet 162 Fourth flow path 162a Fourth flow path inlet 162b Fourth flow path outlet 19 Generator

Claims (6)

A heating unit that heats the working gas without mixing the fuel with the working gas and burning it;
A turbine that generates rotational energy by expanding the working gas heated by the heating unit;
A first flow path through which the working gas expanded by the turbine passes, and a second flow path through which the working gas toward the heating unit passes, and the working gas and the second flow through the first flow path. A regenerator for exchanging heat with the working gas passing through the path;
A pressure reducing device for reducing the pressure at the outlet of the turbine by sucking the working gas that has passed through the first flow path of the regenerator;
A circulation pipe for introducing the working gas discharged from the decompression device into the second flow path of the regenerator;
A power generation system comprising: The power generation system according to claim 1, wherein the heating unit heats the working gas using solar heat as a heat source. The power generation system according to claim 1, wherein the working gas is air. A third flow path through which the working gas passing through the first flow path and toward the decompression device passes, and a fourth flow path through which a cooling fluid passes, and a working gas passing through the third flow path; 4. The power generation system according to claim 1, further comprising a heat exchanger that exchanges heat with a cooling fluid that passes through the fourth flow path. 5. The power generation system according to claim 4, wherein the cooling fluid is cooling water. The power generation system according to claim 4, wherein the cooling fluid is a cooling gas.

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