JP6712672B1 - Power generation device and power generation system using supercritical CO2 gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a supercritical CO2 gas turbine having high engineering feasibility, low construction cost, high economy, easy maintainability, easy manufacturability, high adaptability as a commercial power source, and high safety. Provide a power generation system. A supercritical CO2 gas turbine (1) includes an elongated rotary shaft body (3) rotatable about one rotary shaft. The rotary shaft body 3 is uniaxial so that the low-pressure compressor 4, the high-pressure compressor 5, and the bypass compressor 6 rotate at the same rotation speed in series in the direction in which the supercritical CO 2 gas flows along the rotary shaft body 3. Be connected. These compressors include a plurality of step structures, and the step structures have blade portions extending in the radial direction. The power generator 2 includes a gas turbine 1 and a power generator 15 connected to the gas turbine 1 in a housing, and constitutes a closed circulation system 30 for supercritical CO 2 gas. The closed circulation system 30 includes a main heat exchanger 20 for obtaining heat energy, pipes 21 to 21, first and second regenerative heat exchangers 26a and 26b, and coolers 28 and 29. [Selection diagram] Fig. 3

Description

The present invention relates to a power generation device and a power generation system using supercritical CO ₂ gas.

Patent Document 1 below pays attention to the fact that the compression work is reduced by the peculiarity of the intermolecular force of gas in the vicinity of the supercritical point, with respect to the conventional power generation method using a steam turbine, a high temperature gas turbine, or the like. A new supercritical CO ₂ gas turbine power generation system has been proposed. In this supercritical CO ₂ gas turbine power generation system, it is said that the compression work is halved as compared with the same closed cycle high temperature gas reactor power generation, and the cycle thermal efficiency is about 5% higher in the middle and high temperature regions. In addition, compared with the light water power generation system in the low to medium temperature range, which is an open Rankine cycle, the compression work is large, but the turbine efficiency is high, so the thermal efficiency is about the same at the same turbine inlet temperature. As described above, the supercritical CO ₂ gas turbine power generation is a compact power generation method with the highest power generation efficiency in the medium temperature range. Further, in the application of supercritical CO ₂ gas turbine to nuclear power generation, since water is not used, hydrogen in water molecules is converted to tritium which is a radioactive isotope by high-energy neutrons radiated from a nuclear reactor, and it is in the environment. It is possible to provide a safer power generation system that has no risk of leaking into the interior of the vehicle and is free from the risk of hydrogen and steam explosion due to abnormal heating of cooling water.

However, Patent Document 1 does not disclose a specific configuration and design method of a supercritical CO ₂ gas turbine for achieving engineering feasibility, effects, and economical efficiency/manufacturability/commerciality. For example, in Patent Document 1, it was not clear how the plurality of compressors and the gas turbine were connected. Further, although Patent Document 1 discloses that the compressor is a centrifugal pump, in the case of a centrifugal pump, in order to achieve the prescribed recompression pressure described by one unit, (1) high speed rotation Or (2) it is necessary to make multiple units. However, in the case of solving in (1), problems such as securing the compression ratio of the compressor capable of processing a large capacity fluid of CO ₂ fluid 1 ton/sec class and structural strength such as material newly occur, and at this stage It becomes impossible to match the rotational harmony with other structures such as turbines and rotating equipment. In the case of solving in (2), it becomes impossible to design with a single shaft, because it becomes independent operation in which a motor is attached to each of a plurality of compressors.

On the other hand, there has been proposed a technique in which a compressor and a turbine are uniaxially integrated for the purpose of downsizing a gas turbine. However, since a single-axis design combining a compressor and a gas turbine is established as a high-speed rotating body power generation system, it has not been clear what kind of compressor can be combined with what can be achieved.

JP 2012-145092A

The present invention has been made to solve the above problems, and (1) engineering feasibility having a thermal efficiency of 45.63% or more , (2) miniaturization of the entire power generation system and/or vertical installation low construction cost by equal, high efficiency high economic efficiency due to power generation, (4) easy maintenance due to the compact single-axis design, (5) easy manufacturing due to prior manufacturing techniques and materials, (6) as a commercial power source (3) It is to provide a power generation device and a power generation system using a supercritical CO ₂ gas turbine that can simultaneously realize all the requirements such as high adaptability and (7) high safety by adopting an inert/non-toxic cooling medium. To aim.

In order to solve the above-mentioned problems, a power generator using supercritical CO ₂ gas of the present invention is a supercritical CO ₂ gas turbine having an elongated rotary shaft body rotatable around one rotary shaft, and the supercritical CO ₂ gas turbine. A generator that is uniaxially connected to the end of the rotating shaft of a _two- gas turbine and a supercritical CO ₂ gas that is heated by an external heat energy source through a main heat exchanger through the supercritical CO ₂ gas turbine. A closed circulation system for supercritical CO ₂ gas, which is circulated, wherein the supercritical CO ₂ gas turbine comprises a single low pressure compressor in series in a direction in which the supercritical CO ₂ gas flows along the rotating shaft body. Machine, one high-pressure compressor, one bypass compressor, and the low-pressure compressor, the high-pressure compressor, and the bypass compressor are arranged to be rotated by supercritical CO ₂ gas sequentially compressed And a single gas turbine section as a constituent device, and the inlet temperature of the supercritical CO ₂ gas from the main heat exchanger to the supercritical CO ₂ gas turbine in the closed circulation system is 550° C. or higher. In order to achieve the thermal efficiency target of 45.63% or more and the miniaturization of the cycle thermal efficiency of the power generator under the conditions, the constituent devices are integrated with the rotary shaft body so as to rotate in the same direction at the same rotation speed. Uniaxially connected to each other, and the constituent devices each include a plurality of step structures arranged in series in the rotation axis direction, and each of the plurality of step structures extends in the radial direction from the rotation shaft body. The bypass compressor has a configuration of an axial flow type in which a plurality of blades are arranged in the circumferential direction, the bypass compressor can be operated at a higher temperature than the low pressure compressor and the high pressure compressor, and a compression work for supercritical CO ₂ gas is performed. The ratio is higher, the rotating shaft is controlled to rotate at a specific rotation speed that is uniquely determined by a predetermined relationship in accordance with the generated power that the power generation device targets, and the low pressure compressor and the high pressure compressor are controlled. And the design limit range of each of the constituent devices having sufficient structural strength and material strength for achieving the adiabatic efficiency of 80% or more in the bypass compressor and the adiabatic efficiency of 90% or more in the gas turbine unit, Limited by the generated power, the design limit range becomes narrower as the generated power becomes larger, and the design limit range of each of the constituent devices is at least an allowable flow rate, an allowable inlet temperature range, an allowable stage number range of the stage structure, The present invention relates to the number of blades per step structure, and various conditions such as the axial length and diameter of each component, and achieves the thermal efficiency target and compactness of the power generator. As described above, the values of various conditions of each of the constituent devices are selected from the performance limit range of the constituent device, and the specific rotation speed falls within the allowable rotation speed of all of the constituent devices, and the rotating shaft body The flow rate of the supercritical CO ₂ gas flowing along is within the allowable flow rate of each component.
An example and a preferred embodiment of the present invention are as follows.

The performance limit range of each of the constituent devices in the case where the generated power per one power generation device is 100 MW is described in Table 1 of the present specification. Further, the performance limit range of each of the constituent devices when the generated power per one power generation device is 3 GW is described in Table 2 of the present specification.

Table 3 of the present specification shows the axial length and the axial diameter of the entire one power generating device which is made compact according to the present invention.
The various conditions further include strength of each blade of the component, inlet/outlet temperature/pressure/flow velocity, pressure loss, and critical speed of the component at start-up.
To support the rotary shaft, magnetic journal bearings are provided at both ends of the rotary shaft, and magnetic thrust bearings are provided at one end.

The low pressure compressor, the high pressure compressor, the bypass compressor, and a balance piston for relieving the press-fitting between the gas turbine unit, thereby providing a full shaft on the magnetic journal bearing and the magnetic thrust bearing. Reduce the directional force.
The generator is separably connected to the rotating shaft so as to rotate at the same rotation speed.

The power generator is configured to generate the generated power derived from the predetermined relationship with respect to a specific rotation speed of 3600 rpm corresponding to a common power supply frequency of 50 to 60 Hz.
The supercritical CO _Two The closed gas circulation system is a heat exchange pipe provided inside the main heat exchanger, and the main heat exchanger is a supercritical CO flowing in the heat exchange pipe. _Two The heat exchange pipe for applying heat energy from the heat energy source to the gas, and the supercritical CO heated by the heat energy source. _Two A first pipe connecting the outlet side of the heat exchange pipe and the inlet side of the gas turbine unit for supplying gas to the gas turbine unit to rotate the rotating shaft body, and the outlet of the gas turbine unit Supercritical CO from the side _Two A second pipe that guides gas to the inlet side of the low-pressure compressor, and a supercritical CO gas that exits from the bypass compressor. _Two In order to return a part of the gas to the main heat exchanger, a third pipe connecting the outlet side of the bypass compressor and the inlet side of the heat exchange pipe, and an extra gas discharged from the outlet side of the gas turbine section are connected. Critical CO _Two In order to return a part of the gas to the bypass compressor, a fourth pipe, which branches from the second pipe and is connected to the inlet side of the bypass compressor, and a path of the second pipe are provided. The first regenerative heat exchanger provided, wherein the third pipe passes through the inside of the first regenerative heat exchanger, whereby the supercritical CO discharged from the outlet side of the gas turbine unit _Two Supercritical CO returning from the bypass compressor to the main heat exchanger by gas _Two Supercritical CO compressed by the first regenerator and the high pressure compressor, which reheats the gas. _Two A fifth pipe extending from the outlet side of the high-pressure compressor to join a part of the gas to the main heat exchanger, and joins the third pipe at a position upstream of the first regenerative heat exchanger. A second regenerative heat exchanger provided downstream of the first regenerative heat exchanger on the path of the second pipe and upstream of a branch point of the fourth pipe, Before passing through the second regenerative heat exchanger before joining the third pipe, the supercritical CO 2 exiting from the outlet side of the gas turbine section _Two Supercritical CO returning from the high pressure compressor to the main heat exchanger by gas _Two The second regenerative heat exchanger for further regenerative heating of the gas; a precooler provided in the second pipe between the second regenerative heat exchanger and the low pressure compressor; A sixth pipe connecting from the outlet side of the low pressure compressor to the inlet side of the high pressure compressor;
An intercooler provided in the sixth pipe for cooling a part of the gas compressed by the low pressure compressor and supplying the gas to the high pressure compressor.
The supercritical CO _Two It further comprises a container covering the gas turbine, the generator, and the entire closed circulation system. The supercritical CO _Two The gas turbine and the generator are housed vertically in the container. The container has a lid that can be opened and closed, and by opening the lid, at least the supercritical CO _Two The gas turbine and the generator can be taken in and out of the container. The closed circulation system is a supercritical CO _Two It further comprises an openable/closable jet outlet for jetting gas as a coolant to the outside.

The power generator of the present invention supplies the commercial power source to the generator at the time of start-up, thereby causing the generator to function as a motor to operate the supercritical CO. _Two Rotate the gas turbine.
The power generation system of the present invention including the power generation device, the thermal energy source is a nuclear fission reactor, a nuclear fusion reactor, a thermal power source, or a heat source of natural energy of solar heat or geothermal, the fusion reactor, It is either a tokamak reactor, a helical reactor, a laser implosion reactor, a tandem mirror reactor, or a cold fusion reactor. In the power generation system, in a mode in which the thermal energy source is solar heat, at least a heat collecting part heated by sunlight, a primary circulation system for circulating a molten salt in at least the heat collecting part, and a primary circulation system. A tower provided with a part thereof, wherein the heat collecting portion is provided on the head of the tower, and reflects the sunlight by following the operation of the tower and the sun to the heat collecting portion. A high temperature molten salt tank connected to the inlet side of the main heat exchanger for storing a heliostat for collecting light and the molten salt heated in the heat collecting section and supplying the molten salt to the main heat exchanger. Connected to the outlet side of the main heat exchanger, and the supercritical CO _Two A low-temperature molten salt tank for storing molten salt that has exchanged heat with a gas, wherein the primary circulation system is a supercritical CO flowing through the closed circulation system which is a secondary circulation system. _Two In order to exchange heat with gas, the main heat exchanger is interposed and the molten salt is FLiNaK.

In an aspect in which the thermal energy source is a fusion reactor, the fusion reactor includes a blanket, a primary circulation system in which FLiNaK circulates is arranged in the blanket, and the primary circulation system is a secondary circulation system. Supercritical CO flowing through the closed circulation system _Two In order to perform heat exchange with gas, the primary circulation system can be switched so that heat is supplied from either the thermal power source or the fusion reactor through the main heat exchanger.

FIG. 1 is a side view of a supercritical CO ₂ gas turbine having a minimized single-shaft rotating shaft, which is provided in a power generator according to a first embodiment of the present invention. FIG. 2 is a perspective view of a part of a supercritical CO ₂ gas turbine having a minimized single-shaft rotating shaft, which is provided in the power generator according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a power generator/power generation system using the supercritical CO ₂ gas turbine of FIG. 1 according to the first embodiment of the present invention. FIG. 4 shows the temperature of the supercritical CO ₂ gas of each component when the power generation apparatus of FIG. 3 is designed as one power generation system that generates power from a 100 MW class thermal energy source in the 100 MW to 3 GW high temperature external heat source range , It is an example of pressure, flow rate, power consumption, or generated power. FIG. 5 shows the temperature of the supercritical CO ₂ gas of each component when the power generation device of FIG. 3 is designed as one power generation system that generates power from a 3 GW class thermal energy source in the 100 MW to 3 GW high temperature external heat source range , It is an example of pressure, flow rate, power consumption, or generated power. FIG. 6 is a flowchart showing a method for starting/operating/stopping the power generation system according to the second embodiment shown in FIG. FIG. 7 is a diagram showing the superiority of the present invention compared to the prior art, (A) shows the cycle thermal efficiency with respect to the turbine inlet temperature, and (B) shows the sizes of the gas turbine of the present invention and the conventional steam turbine. A comparison is shown, and (C) shows a comparison between the steam power generation building and the power generation system building of the present invention. FIG. 8 is a graph showing the control rotation speed (rpm) of the rotary shaft body 3 with respect to the input electric power (GW) in one power generator of the present invention. FIG. 9: is a side view which shows the connection aspect of a gas turbine and a generator which concern on the 4th Embodiment of this invention. FIG. 10 is a schematic view showing an example of a maintenance method for a 100 MW class power generator according to the fifth embodiment of the present invention. FIG. 11 is a diagram showing a specific example of the thermal energy source of the power generation system according to each embodiment of the present invention, in which (A) is a thermal power source, (B) is a power generation system using the thermal power source, and (C). Shows a power generation system using a helical furnace. FIG. 12 is a schematic diagram of a power generation system according to the third embodiment that uses solar heat as a heat energy source.

Hereinafter, a supercritical CO ₂ gas turbine according to an embodiment of the present invention, and a power generation device and a power generation system using the same will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows an axial flow type supercritical CO ₂ gas turbine 1 according to a first embodiment of the present invention. The supercritical CO ₂ gas turbine 1 is provided with an elongated rotary shaft body 3 rotatable around one rotary axis A. The arrow B direction is the direction in which the supercritical CO ₂ gas flows along the surface of the rotating shaft body 3. A low pressure compressor 4, a high pressure compressor 5, a bypass compressor 6, and a gas turbine unit 7 are uniaxially connected to the rotary shaft body 3 in series in the direction of arrow B. One end of the rotating shaft body 3 is rotatably supported by a journal bearing 9, and the other end of the rotating shaft body 3 is supported by the journal bearing 10 and the thrust bearing 14 (oil bearing or magnetic bearing (especially for a heat source). It is effective to prevent oil contamination)) and is rotatably supported. In addition, a balance piston 11 is provided between the constituent devices (4,5, 6, 7) to reduce the pressure between the compressor side and the gas turbine side. The balance piston 11 balances the gas pressures of the chambers (not shown) on both sides of the piston that slides in the axial direction by controlling the opening/closing of control valves provided in the pipes that connect the chambers on both sides. So that the total axial force on the bearings 9, 10 , 14 is reduced.

Since the rotating shaft body 3 is a rigid body, when the rotating shaft body 3 is rotated around the rotation axis A, the low pressure compressor 4, the high pressure compressor 5, the bypass compressor 6 and the gas turbine unit which are connected to the rotating shaft body 3 are rotated. 7 rotates in the same direction at the same rotation speed.

The gas turbine section 7 is rotated by the supercritical CO ₂ gas compressed by the low-pressure compressor 4, the high-pressure compressor 5 and the bypass compressor 6, and this rotation causes the low-pressure compressor 4, the high-pressure compressor 5 and the bypass compressor 6 to rotate. Since it also rotates, it will perform the compression work of the supercritical CO ₂ gas supplied to the gas turbine section 7. As will be described later, the gas turbine unit 7 is also rotated by the supercritical CO ₂ gas supplied from the components other than the compressors 4 to 7.

As shown in FIG. 1, the low-pressure compressor 4, the high-pressure compressor 5, the bypass compressor 6, and the gas turbine unit 7 each include a plurality of stage structures 8 arranged in series in the rotation axis A direction. .. As shown in FIG. 2, in each of the plurality of step structures 8, a plurality of blade portions 12 extending in the radial direction from the rotary shaft body 3 are arranged in the circumferential direction. The supercritical CO ₂ gas turbine 1 is covered with a housing 13 and constitutes a closed circulation system in a power generation system for supercritical CO ₂ gas described later.

FIG. 3 shows a power generation device 2 using the supercritical CO ₂ gas turbine 1. As shown in the figure, a generator 15 is connected to one end of the rotary shaft body 3, and the generator 15 is also rotated by the rotation of the rotary shaft body 3 to generate electric power . Since the generator 15 has different inspection requirements from a turbo device such as a compressor at the time of overhaul and a different working place, it is preferable that the generator 15 be configured to be separable from the compressor groups 4 to 7. In the example of FIG. 3, the generator 15 is connected to the end of the rotary shaft 3 on the gas turbine section 7 side, but is connected to the opposite end of the rotary shaft 3 on the low pressure compressor 4 side. May be. Furthermore, when increasing the size of the supercritical CO ₂ gas turbine 1, it is preferable that the compressor groups 4 to 7 and the gas turbine section 7 are separable.

The power generator 2 further includes a closed circulation system 30 for supercritical CO ₂ gas. Closed circulation system 30 includes a main heat exchanger 20 for providing heat energy from the external heat energy source (not shown) to the supercritical CO ₂ gas, the gas turbine unit supercritical CO ₂ gas heated by the thermal energy source 7, to rotate the rotary shaft body 3, the first pipe 21 that connects the outlet side of the heat exchange pipe in the main heat exchanger 20 and the inlet side of the gas turbine unit 7, and the gas turbine unit 7 The second pipe 22 for guiding the supercritical CO ₂ gas that has exited from the outlet side to the inlet side of the low-pressure compressor 4.

Further, the closed circulation system 30 of the supercritical CO ₂ gas, for returning a portion of the supercritical CO ₂ gas exiting the bypass compressor 6 to the primary heat exchanger 20, the outlet side and the main heat exchanger bypass the compressor 6 In order to return a part of the supercritical CO ₂ gas discharged from the outlet side of the gas turbine section 7 to the bypass compressor 6, the third pipe 23 connecting the inlet side of the heat exchange pipe in the vessel 20 And a fourth pipe 24 branched from the pipe 22 and connected to the inlet side of the bypass compressor 6.

Further, the closed circulation system 30 for the supercritical CO ₂ gas includes a first regenerative heat exchanger 27 a on the path of the second pipe 22. The third pipe 23 passes through the inside of the first regenerative heat exchanger 27 a, whereby the supercritical CO ₂ gas that exits from the outlet side of the gas turbine unit 7 and passes through the second pipe 22 causes the bypass compressor. The supercritical CO ₂ gas returning from 6 to the main heat exchanger 20 is regenerated and heated.

The closed supercritical CO ₂ gas circulation system 30 extends from the outlet side of the high pressure compressor 5 to return a part of the supercritical CO ₂ gas compressed by the high pressure compressor 5 to the main heat exchanger 20, and A fifth pipe 25 that joins the third pipe 23 at a position upstream of the first regenerative heat exchanger 27a is further provided.

The closed circulation system 30 for the supercritical CO ₂ gas includes a second regenerative heat exchanger downstream of the first regenerative heat exchanger 27 a on the path of the second pipe 22 and upstream of the branch point of the fourth pipe 24. 27b is further provided. The fifth pipe 25 passes through the inside of the second regenerative heat exchanger 27b before joining with the third pipe 23, whereby the supercritical CO ₂ gas emitted from the outlet side of the gas turbine unit 7 is used. , The supercritical CO ₂ gas returning from the high-pressure compressor 5 to the main heat exchanger 20 is regenerated and heated. The supercritical CO ₂ gas from the high-pressure compressor 5, which has joined the third pipe 23, exits from the bypass compressor 6 and passes through the third pipe 23 together with the supercritical CO ₂ gas to generate the first regenerative heat exchanger 27a. Is further heated by regeneration.

The closed circulation system 30 of the supercritical CO ₂ gas is a supercritical CO flowing through the second pipe 22 between the second regenerative heat exchanger 27b and the inlet side of the low pressure compressor 4. _It further comprises a precooler 28 for cooling the _two gases. As a result, the lower temperature supercritical CO ₂ gas can be supplied to the supercritical CO ₂ gas turbine 1.

The closed supercritical CO ₂ gas circulation system 30 further includes a sixth pipe 26 that connects the outlet side of the low pressure compressor 4 to the inlet side of the high pressure compressor 5, and the sixth pipe 26 is a low pressure compressor. An intercooler 29 is further provided for cooling a part of the gas compressed by 4 and supplying it to the high-pressure compressor 5.

The main purpose of the compressors 4 to 6 here is to restore the pressure with as little work as possible, and the compression efficiency decreases at high temperatures, so it is necessary to lower the temperature and operate under the minimum power. Therefore, the low pressure compressor 4 and high pressure After the pressure is restored in the compressor 5, it is reheated to the required return temperature by the regenerative heat exchangers 27a and 27b. However, the bypass compressor 6 is an exception, and is designed to enable high temperature operation. In the bypass compressor 6, although the processing amount is small, the required power becomes large accordingly. Therefore, the required number of stages of the bypass compressor is larger than that of the low/high pressure compressor.

According to the present invention, a power generation system can be constructed by combining the power generation device 2 and the thermal energy source described above. The heat energy source to be combined with the power generation device 2 may be any one of heat sources such as thermal power, a nuclear fission reactor, a nuclear fusion reactor, and natural energy described later. Here, as the natural energy, solar heat or geothermal heat described later can be used. As for the fusion reactor, various reactor systems such as a helical reactor, a tokamak reactor, a laser furnace, a tandem mirror reactor, and a cold fusion reactor described later can be applied.

For example, when the thermal power source 50 shown in FIG. 11(A) is used as a 100 MW class thermal energy source, as shown in FIG. 11(B), the power generation system 90 includes a power generation device 2 and a turbine for thermal power generation. 53, the boiler 52, and the CO ₂ pipe of the main heat exchanger 20 arranged inside the boiler 52 . Further , it is possible to construct a power generation system 90a using the helical furnace 51 shown in FIG. 11(C) as a 3 GW class thermal energy source. The example of FIG. 11C will be described later in the second embodiment.

Each of the components of the low-pressure compressor 4, the high-pressure compressor 5, the bypass compressor 6, and the gas turbine unit 7 should satisfy the respective allowable ranges of conditions in order to achieve the desired parameters in the target generated electric power. Is designed to. In this design, the constituent devices 4 to 7 rotate at the same number of revolutions, so that the allowable number of revolutions of all the constituent devices 4 to 7 is restricted. In addition, since the supercritical CO ₂ gas flows through the constituent devices 4 to 7 in sequence, the flow rate of the supercritical CO ₂ gas allowable for all of the constituent devices 4 to 7 is also restricted.

Table 1 shows the performance limit range of each component in one 100 MW class power generation system within the range of the external heat source capacity of 100 MW to 3 GW . As a desired parameter of each component, in order to achieve higher cycle thermal efficiency, the low-pressure compressor 4, the high-pressure compressor 5, and the bypass compressor 6 have adiabatic efficiency of 80% or more, and the gas turbine section 7 has an adiabatic efficiency. 90% or more.

From Table 1, when designing one power generator 2 of 100 MW class, it can be determined that there is design feasibility at a supercritical CO ₂ fluid flow rate of 200 Kg/s and a common rotation speed of 10,000 rpm. That is, according to the first embodiment of the present invention, in the 100 MW class power generation system, the compressors 4 to 6 and the gas turbine unit 7 are configured to include a plurality of stage structures having a plurality of blades, and thus are high. Achieving adiabatic efficiency, it enables a uniaxial design that rotates at an acceptable common speed while using an acceptable supercritical CO ₂ gas flow rate.

Table 2 shows the performance limit range of each component in the 3 GW class power generation system within the range of the external heat source capacity of 100 MW to 3 GW . As a desired parameter of each component, in order to achieve higher cycle thermal efficiency, the adiabatic efficiency of the low pressure compressor 4, the high pressure compressor 5, and the bypass compressor 6 is 80% or more, as in the case of the 100 MW class power generation system. The heat insulation efficiency of the gas turbine section 7 is set to 90% or more.

From Table 2, when designing one power generation device 2 of 3 GW class, it can be judged that there is design feasibility at a supercritical CO ₂ fluid flow rate of 15,000 Kg/s and a common rotation speed of 2,000 rpm. .. That is, according to the first embodiment of the present invention, in the 3 GW class power generation system, the compressors 4 to 6 and the gas turbine unit 7 are configured to include a plurality of stage structures having a plurality of blades, and thus are high. Achieving adiabatic efficiency, it enables a uniaxial design that rotates at an acceptable common speed while using an acceptable supercritical CO ₂ gas flow rate.

In the above-described design, as Table 1 and Table 2 show various allowable conditions for each of the constituent devices 4 to 7, the number of blades per step structure of each of the constituent devices 4 to 7, the strength of the blades, the entrance and exit The temperature/pressure/flow rate, pressure drop, as well as the critical speed of the components 4-7 at start-up can be further taken into account.

Next, the operation of the first embodiment of the present invention will be described.
When the power generation device 2 is started, an external thermal energy source is operated, and the power of the external commercial power source is supplied to the power generator 15 so that the power generator 15 functions as a motor to rotate the supercritical CO ₂ gas turbine 1 . .. With the rotation of the gas turbine 1, the supercritical CO ₂ gas starts to circulate in the piping of the closed circulation system 30 while being pressurized by the compressor . Thermal energy is transferred to the supercritical CO ₂ gas flowing through the main heat exchanger 20 from an external heat energy source, and the heated supercritical CO ₂ gas passes through the first pipe 21 and enters the gas turbine section 7. Supplied to the side. The gas turbine section 7 is rotated by the supplied supercritical CO ₂ gas, and this rotation is transmitted to the low pressure compressor 4, the high pressure compressor 5, and the bypass compressor 6 through the rotating shaft body 3, and these compressors 4-6 and the gas turbine part 7 rotate at the same rotation speed. When it is determined that the supercritical CO ₂ gas turbine 1 can be operated independently, the power supply from the commercial power source to the generator 15 is turned off, and the generator 15 is switched to the power generation mode.

The supercritical CO ₂ gas is sequentially compressed along with the rotating shaft body 3 into a higher temperature and higher pressure gas while passing through the low pressure compressor 4, the high pressure compressor 5 and the bypass compressor 6 which are rotationally driven, The supercritical CO ₂ gas emitted from the bypass compressor 6 rotates the gas turbine unit 7. As a result, the generator 15 connected to the rotating shaft 3 rotates to generate electricity. The supercritical CO ₂ gas that has performed the work of rotating the gas turbine unit 7 passes through two pipes 22 and two regenerative heat exchangers (27a, 27b), and at that time, to a main heat exchanger 20 described later. By applying heat energy to the supercritical CO ₂ gas flowing through the return path, the temperature of the supercritical CO ₂ gas is lowered, and further cooled by the precooler 28 and sent to the low pressure compressor 4 in a low temperature and low pressure state. It is recompressed by the group and serves to rotate the gas turbine section 7. Some of the supercritical CO ₂ gas exiting the regenerative heat exchanger 27b is sent to the bypass compressor 6 through the pipe 24, a portion of the supercritical CO ₂ gas compressed by a bypass compressor 6, the pipe 23 Through which heat energy is given through the regenerative heat exchanger 27a, returns to the main heat exchanger 20 and is further heated, and is sent to the gas turbine section 7 through the pipe 21. A part of the supercritical CO ₂ gas compressed by the high-pressure compressor 5 is also sequentially passed through the pipe 25 and the regenerative heat exchangers 27b and 27a to be heated and sent to the main heat exchanger 20. That is, in the low-pressure compressor 4 and the high-pressure compressor 5, in order to reduce the operating power, the supercritical CO ₂ gas is recompressed at a low temperature, and in the bypass compressor 6, the operating power increases, but the supercritical CO ₂ becomes high in temperature. The pressure of the CO ₂ gas is restored.

According to the first embodiment of the present invention, since the supercritical CO ₂ gas is used as the medium for rotating the compressor and the gas turbine, the compression work is caused by the peculiarity of the intermolecular force of gas near the supercritical point. In addition to the above, the following bypass routes and bypass compressors have been introduced to reduce the low/high compressor operating power. Compression work is halved compared to the same closed cycle helium gas turbine. Furthermore, about half and a half of the main CO ₂ medium fluid that passed through the two regenerative heat exchangers (27a, 27b) from the outlet of the gas turbine section 7 (low/high pressure compressor flow rate 275.8815kg/s, bypass flow rate 205.1797) was used. kg/s), part of which is cooled by the precooler 28, and then the path (second pipe 22) for recompressing by the low compressor 4 and the remaining CO ₂ medium are directly bypassed at the same temperature and pressure. By adopting the bypass system with the path (the fourth pipe 24) for charging the compressor 6 to restore the pressure, the power generation efficiency which has been about 20 to 35% in the Brayton cycle system without the bypass route is leap forward. Can be improved. Further, since a part of the gas flowing from the low pressure compressor 4 to the high pressure compressor 5 is bypassed by the sixth pipe 26 and cooled by the intercooler 29 before being returned to the high pressure compressor 5, low/high pressure is achieved. It is possible to reduce the driving power of the compressor. Further, a part of the gas compressed by the high-pressure compressor 5 is heated through the fifth pipe 25 by passing through the second regenerative heat exchanger 27b and the first regenerative heat exchanger 27a to heat it. By returning to the vessel 20, it becomes possible to meet the temperature required specifications for the primary system thermal cycle (550°C/384°C).

The effective work of the closed cycle gas turbine cycle is the turbine work minus the compressor work. Since the ratio of the effective work to the heat input is the cycle thermal efficiency, comparing the same turbine inlet gas temperature, Fig. 7(A) As shown in, a cycle thermal efficiency as high as about 5% is obtained. Compared to an open Rankine cycle steam turbine, the compression work is large, but the turbine efficiency is high, so the thermal efficiency is about the same at the same turbine inlet temperature.

FIG. 4 shows a power generation system 90 including a thermal energy source corresponding to 100 MW class electric power and a power generation device 2 designed corresponding thereto. FIG. 4 shows an example of the temperature, pressure, flow rate, power consumption, or generated power of the supercritical CO ₂ gas of each component device. In the power generator 2 of FIG. 4, the compression power of the low-pressure compressor 4 is 1.55 MW, the compression power of the high-pressure compressor 5 is 5.5 MW, and the compression power of the bypass compressor 6 is 13.8 MW. The rotation power given to the gas turbine section 7 by the supercritical CO ₂ gas compressed by the compressors 4 to 6 is 66.45 MW. Therefore, the power generated by the generator 15 is 66.45 MW-(1.55 MW+5.5 MW+13.8 MW)=45.6 MW (in FIG. 4, using the correct value, 66.4482-(1.554+5.493+13.MW). 77)=45.63 MW). The power that the external heat energy gives to the main generator 20 is 100 MW, so that the power generation system shown in FIG. 4 achieves a cycle thermal efficiency of 45.63/100=45.63%. The configuration of the piping system and the heat exchanger shown in FIG. 4 is only an example, and the primary system heat source operating temperature via the main heat exchanger 20 is 550° C./384° C. It goes without saying that the thermal efficiency improves as the system specifications change depending on the temperature (for example, 600°C/400°C).

FIG. 5 shows a power generation system 90a including a thermal energy source corresponding to 3 GW class electric power and a power generation device 2 designed corresponding thereto. In the power generator 2 of FIG. 5, the compression power of the low-pressure compressor 4 is 48.3 MW, the compression power of the high-pressure compressor 5 is 163.3 MW, and the compression power of the bypass compressor 6 is 412.9 MW. The rotating power given to the gas turbine part 7 by the supercritical CO ₂ gas compressed by the compressors 4 to 6 is 2010.7 MW. Therefore, the power generated by the generator 15 is 2010.7 MW-(48.3 MW + 163.3 MW + 412.9 MW) = 1.386 GW. Since the power that the external heat energy gives to the main heat exchanger 20 is 3 GW, the power generation system shown in FIG. 4 achieves a cycle thermal efficiency of 1.386/3=46.2%.

Table 3 shows specific numerical values of the typical minimum various dimensions shown in FIG. 1 of the supercritical CO ₂ gas turbine 1 designed in each of 100 MW class and 3 GW class based on Tables 1 and ₂ . .. In addition, in various dimensions, L represents length and D represents diameter.

From Table 3, in the 100 MW class power generation system, the length L = 2.5 m and the maximum diameter L _ByC = 0.98 m, and in the 3 GW class power generation system, the minimum shaft length L = 10.0 m and the maximum diameter L _ByC = It will be 5.0 m, and it can be seen that a very compact supercritical CO ₂ gas turbine can be realized using the configuration of the present invention.

Comparing the present invention and the prior art with respect to the size of the gas turbine, in the steam turbine, the outlet size is enormous in order to expand the steam from the inlet pressure of about 10 MPa to the outlet pressure of 0.005 MPa, that is, about 2000 times. Become. On the other hand, since the expansion ratio of the supercritical CO ₂ gas turbine is about 2.5, the turbine size is remarkably small as shown in FIG. 7(B). Also, in the system configuration, the steam turbine requires a large number of stages of feed water heating, a deaerator, etc., but the newly required equipment is only a regenerative heat exchanger, which is very simple. In addition, the vertical arrangement of the power generation system saves space and can significantly reduce the volume of the power generation facility , thus saving capital costs. Figure 7(C) shows a comparison of buildings when applied to a 600MW class Na-cooled fast reactor and a 3GW class fusion reactor power generation system. The volume of the turbine building will be significantly reduced by 60%.
(Second embodiment)
The second embodiment relates to the power generation system 90a shown in FIG. 5 including a 3 GW class fusion reactor.

As shown in FIG. 5, a power generation system 90a according to the second embodiment switches between a 3 GW external thermal power source 50 (or a commercial power source) and a 3 GW fusion reactor 51 as a thermal energy source. The main heat exchanger 20 is provided with a primary system loop 31 that circulates FLiNaK as a molten salt, and the FLiNaK flowing through the FLiNaK circulation primary system loop 31 is either the external heat source 50 or the fusion reactor 51. By circulating the above, those heat energy is brought to the closed circulation system 30 (secondary circulation system) of supercritical CO ₂ via the main heat exchanger 20. Here, the temperature on the inlet side of the primary circulation system 31 to the main heat exchanger 20 is 600° C., and the temperature on the outlet side is 400° C., whereas the inlet side of the main heat exchanger of the secondary circulation system 30 is The temperature is 382° C. and the temperature on the outlet side is 550° C., which suppresses the heat loss.

The nuclear fusion reactor 51 is, for example, a helical reactor that can be continuously operated. As shown in FIG. 11C, a blanket 55 is arranged on the side of the helical reactor 51, and inside the blanket 55, The piping of FLiNaK primary circulation system loop 31 is arranged, and FLiNaK is heated by the high temperature plasma in the furnace.

Next, a method of starting/operating/stopping the power generation system 90a according to the second embodiment will be described with reference to the flowchart of FIG.
As shown in the flow chart of FIG. 6, in the state before activation, the molten salt FLiNaK is stored in the reservoir tank 32 (FIG. 5) at room temperature/normal pressure, and CO ₂ is stored in the reservoir tank 33 (FIG. 5) at room temperature/normal pressure. It is stored under pressure, and the helical furnace 51 is in a stopped state (normal temperature/normal pressure) (step 100). This state is maintained until a start request is made (No at Step 102). When there is a start request (affirmative determination in step 102), CO ₂ is supplied from the reservoir tank 33 (FIG. 5) to the supercritical state and then supplied to the secondary circulation system 30, and an external commercial power source (−624.6 MW) is used. Then, the supercritical CO ₂ gas turbine 1b is started to drive (step 104), and heat reception from the primary circulation system 31 is prepared. This can be done by supplying electric power from an external commercial power source to the generator 15 so that the generator 15 functions as a motor and rotating the supercritical CO ₂ gas turbine 1b. At this time, the compressors 4 to 7 recompress the supercritical CO ₂ gas (14.26 Ton/s).

Next, using a 3 GB external thermal power source 50 (or commercial external power source (-1.933 MW or more)) for the primary circulation system 31 of FLiNaK at room temperature (300 K), up to the minimum melting temperature (657 K) for circulation. The temperature is raised, and the circulation drive of FLiNaK of the primary circulation system 31 is started using the pump 36 (FIG. 5) (step 106). When heat transfer is started from the primary circulation system 31 to the secondary circulation system 30 via the heat exchanger 20, the commercial external power supply of the secondary circulation system is turned off, and the 3GW external thermal power source/commercial power supply 50 is turned on. The self-power generation operation (+1386.2 MW) by the gas turbine power generation system of the supercritical CO ₂ gas heat-exchanged by the circulation of the used primary circulation system 31 is started (step 108).

When the operation of the primary circulation system 31 and the secondary circulation system 30 and the cooling system are stabilized (Yes at Step 110), a part (-312 MW) of the electric power of the supercritical CO ₂ gas turbine power generation system is supplied to the helical furnace 51. Then, the 3GW heat output operation is started (step 112).

When the plasma output rises, the external thermal power source 50 is gradually disconnected from the FLiNaK primary circulation system 31, and at the same time heat supply from the blanket 55 (FIG. 11C) to the secondary circulation system 30 via the primary circulation system 31 is started. (Step 114).

Heat is supplied from the 3 GW heat output plasma to the primary circulation system 30 and the secondary circulation system 30 via the blanket 55 (FIG. 11C), and the electric output from the supercritical CO ₂ gas turbine power generation system (+1386. 2 MW) and the helical operation maintenance power (-283 MW) are secured to stabilize the operation (+1103.2 MW) of the power generation system (step 116).

When the operation of the helical furnace 51 becomes stable (Yes at Step 118), the generated power is supplied to the outside (Step 120). At this time, the main body required power supply of the helical furnace 51 drops to −28.7 MW, and thus the net power generation amount increases to +1357.5 MW. When 0.5 MW of the electric output is used for the production of the hydrogen fuel for start-up, the externally supplied power amount is +1357 MW, and the power generation efficiency is 45.2%.

When there is a power generation stop request (Yes at Step 122), the operation required power of the helical furnace 51 is gradually reduced from the supercritical CO ₂ gas turbine power generation system to reduce the plasma output (Step 124). At the same time, the primary circulation system FLiNaK is transferred to the reservoir tank 32, and the compressor driving power (-624.6 MW) from the external commercial power source is supplied, whereby the secondary circulation system CO2 is stored. To the initial state where the entire power generation system is completely stopped (step 100).
(Third Embodiment)
The third embodiment relates to a power generation system using solar heat as a heat energy source. Hereinafter, the power generator 2c according to the third embodiment will be described with reference to FIG. Note that, in FIG. 12, the same components as those of the first and second embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 12, the power generation system 90c according to the third embodiment includes the tower 60, the primary circulation system 67 having the pipe 62 of the molten FLiNaK that circulates at least through the tower 60, and is described above. And a closed circulation system 30 as a secondary circulation system having the supercritical CO ₂ gas turbine 1.

The tower 60 is provided with a heat collecting portion 61 on its head, and the heat collecting portion 61 is heated by receiving sunlight. A FLiNaK pipe 62 is arranged in the heat collecting unit 61, and heat is generated when the heat collecting unit 61 receives sunlight, and the heat heats the FLiNaK in the pipe 62. A heliostat 63 configured as a plurality of mirrors is arranged around the tower 60, for example, on the ground. The heliostat 63 is oriented so that the reflected sunlight is collected on the heat collecting portion 61, and the direction of the sun automatically changes according to the movement of the sun on the celestial sphere, so that the sun comes out. As long as the heat collecting unit 61 is directly irradiated with sunlight, the sunlight reflected from the heliostat 63 is continuously irradiated.

The primary circulation system 67 is connected to a pipe 62 that descends from the heat collecting section 61, and a high temperature molten salt tank 64 that stores FLiNaK heated by sunlight, and a main heat of the secondary circulation system that extends from the high temperature molten salt tank 64. A pipe 62a connected to the inlet of the exchanger 20, a pipe 62b extending from the outlet of the main heat exchanger 20, and a pipe 62b connected to the main heat exchanger 20 to apply heat to the supercritical CO ₂ gas to lower the temperature. The low temperature molten salt tank 65 for storing the stored FLiNaK and the pump 66 for pumping the FLiNaK stored in the low temperature molten salt tank 65 to the heat collecting section 61 of the tower 60 again are provided.

According to the third embodiment, the FLiNaK stored in the low-temperature molten salt tank 65 is pumped by the pump 66 to the heat collecting section 61 of the tower 60 and is heated by solar heat while flowing through the heat collecting section 61. It flows down 62 and is temporarily stored in a high temperature molten salt tank 64. The high temperature FLiNaK in the high temperature molten salt tank 64 reaches the main heat exchanger 20 through the pipe 62a, where heat energy is exchanged with the supercritical CO ₂ gas flowing in the secondary circulation system 30. The FLiNaK that has lost the heat energy and becomes a low temperature exits the main heat exchanger 20, passes through the pipe 62b, reaches the low temperature molten salt tank 65, is circulated again, and is heated by solar heat. The supercritical CO ₂ gas heated by FLiNaK flowing through the primary circulation system 67 performs the work of rotating the supercritical CO ₂ gas turbine 1, and the power generator 15 rotates to generate power.

Since the thermal radiation energy increases in proportion to the fourth power of the absolute temperature, if the heat collecting section 61 becomes too hot, the radiant heat loss increases, but the thermal energy quickly transfers to the FLiNaK flowing through the heat collecting section 61. Therefore, radiant heat loss can be suppressed to be small.

Although FLiNaK is used as the heat storage material molten salt in the above example, the present invention is not limited to this example. For example, metallic aluminum can also be used as a molten salt of a solar heat storage material. Aluminum has a large thermal conductivity and is advantageous for heat transfer. Further, aluminum melts at 660° C. and has a large heat of fusion and specific heat, which is advantageous for heat storage (heat of fusion, sensible heat). Further, since heat can be stored on the spot where sunlight is irradiated, the molten aluminum pipe is not necessary. Further, since the performance is less deteriorated and it can be used semipermanently, the maintenance cost is also low.

When the temperature of metallic aluminum rises due to solar heat, the above-mentioned radiative heat loss occurs, so if a cooling system in which liquid sodium circulates is placed in metallic aluminum, the temperature should be kept below a certain level to reduce radiative heat loss. You can Then, if the circulation system of liquid sodium that has absorbed the heat energy is arranged in the main heat exchanger 20 of the power generation device 2 according to the first embodiment, it is possible to heat the supercritical CO ₂ gas to generate power.
(Fourth Embodiment)
The fourth embodiment relates to a combination of the supercritical CO ₂ gas turbine 1 and the power generation device 15 that is compatible with a commercial power source or the like. In the following description, the same components as those of the first embodiment and the like (FIGS. 1 to 3) will be denoted by the same reference numerals, detailed description will be omitted, and different parts will be described.

In FIG. 8, in the supercritical CO ₂ gas turbine 1, the control rotation speed (rpm) of the rotating shaft body 3 with respect to the input electric power (GW) and the design allowable rotation speed range of the compressors 4 to 6 ( indicated by upper and lower limit dot ranges ). ) And are shown. As shown in FIG. 8, the design limit of the power generation system which definitive in axial flow compressor uniaxial design severely subjected to the constraint in its control speed. When obtaining the generator tuning speed (3,600 rpm) for normal power generation of 50 to 60 Hz on the uniaxial compressor side, 1 to 2 GW power generation is possible. However, there is a low speed rotation range above 2 GW and a high speed rotation range below 1 GW, and a tuning operation/mechanism between the generator 15 and the constituent devices (compressors 4 to 6, gas turbine section 7) is required.

Therefore, in the fourth embodiment, as shown in FIG. 9, a power generation device 2a is provided in which a rotation speed conversion mechanism (for example, a planetary gear mechanism) 40 is provided in a connection portion between the gas turbine 1 and the generator 15. To do. This makes it possible to convert the rotation speed of the gas turbine 1 into the rotation speed (3600 rpm) corresponding to the generator 15 of 50 to 60 Hz. For example, in the case of a 0.1 GW power generator 2, the control speed 10,000 rpm of the gas turbine 1 can be converted into 3,600 rpm for the generator 15 of 50-60 Hz. Further, in the case of the 3 GW power generator 2, the control rotation speed of the gas turbine 1 of 2,000 rpm can be converted to 3,600 rpm. According to the fourth embodiment, the degree of freedom in designing the compressors 4 to 7 and the gas turbine unit 7 is increased, so that it is possible to easily design and construct the power generation device 2a having good power generation efficiency. In the case of the 1-2 GW power generator, the rotation speed conversion mechanism 40 may not be provided.
(Fifth Embodiment)
The fifth embodiment relates to a power generator that facilitates maintenance. In the following description, the same components as those of the first embodiment and the like (FIGS. 1 to 3) will be denoted by the same reference numerals, detailed description will be omitted, and different parts will be described.

FIG. 10 shows an example of a maintenance method for the 100 MW class power generator 2b. According to the present invention, since the gas turbine system can be miniaturized as described above, it is possible to realize the vertical arrangement which is effective in making the plant equipment compact. In the power generation device 2b of FIG. 10, the supercritical CO ₂ gas turbine 1 and the power generator 15 are connected to each other in a vertically rotatable manner in a container 17 with a lid 41. At least a part of the equipment/piping system 16 of the closed circulation system 30 shown in FIGS. 3 and 4 is also housed in the container 17 . For example, a part of the equipment/pipe system 16 may include the pipes 21 to 26, the regenerative heat exchangers (27a, 27b), the precooler 28, the intercooler 29, and the like. With respect to main heat exchanger 20, when the increase in size, it is not possible to accommodate in the container 17, the container 17 is provided with a port for connecting an external of the main heat exchanger to the pipes 21 and 23.

When disassembling and inspecting the supercritical CO ₂ gas turbine 1 and the generator 15, the lid 41 is removed, and the supercritical CO ₂ gas turbine 1 and the generator are uniaxially connected by pulling the lid 41 in one direction. All you have to do is take out 15 and. After the inspection and repair are completed, the supercritical CO ₂ gas turbine 1 and the generator 15 that have been inspected are put in the container 17 and closed by the lid 41, so that the assembly can be easily performed. Since the supercritical CO ₂ gas turbine 1 and the generator 15 are uniaxially connected to each other, they can be taken in and out very smoothly without being caught.

Further, it is possible to provide an openable/closable jet port (not shown) for jetting the supercritical CO ₂ gas circulating in the closed circulation system 30 to the outside as a coolant.
The effects of the present invention described above are summarized as follows for each item.
(1 ) Regarding the engineering feasibility exceeding 45.63% of thermal efficiency, it is possible to construct a power generation system with a design balance by the required heat quantity (Heat Duty) between each component by the heat mass balance in Fig. 4. ..
For (2) compactness, to achieve minimum compacted in the power generation system by uniaxial designing a low pressure compressor / high pressure compressor / bypass the compressor / gas turbine / generator, the more vertical arrangement, the heat source It is possible to minimize the total area of power generation equipment including the main body (by further vertically designing the turbine power generation system).
(3) Regarding the economic efficiency, the construction efficiency of (1) above and (2) downsizing can reduce the construction cost of the power generation facility to at least 1/10 of the steam power generation facility of the same scale.
(4) Concerning maintainability, the single axis design minimizes the number of main component devices, and the coaxial single axis design enables efficient disassembly and inspection by pulling out all models from the power container. Becomes Also, the spare components can be replaced as they are to shorten the maintenance and inspection period.
(5) Regarding the manufacturability, within this design range, there is a sufficient design tolerance range in terms of facility scale, structural strength, and material strength, and at the facility production scale, manufacturing /inspection is possible with existing manufacturing technology. is there.
(6) Regarding commerciality, it is an extremely versatile ultra-high-performance , low-cost, space-saving/light-weight device that can be used under various operating conditions with high-temperature heat sources depending on the heat source capacity (several tens to several GW). A critical CO2 gas turbine power generation system can be realized. In particular, the frequency of the power supply used in Japan is 50 to 60 Hz, and it is possible to adapt to commercial power supply by setting the rotation speed of the main body of this design to 3600 rpm.
(7) Regarding safety, CO ₂ is a non-flammable/inert coolant, and various fission products including tritium generated from the primary system of the reactor main body (hereinafter, FP: Fission Products) can be separated and collected without being compounded like a water coolant even when mixed and diffused in a secondary supercritical CO ₂ gas turbine power generation system. In addition, when a malfunction such as a steam explosion or a hydrogen explosion occurs in the primary system, it is possible to perform fire suppression and cooling operations using the secondary CO ₂ coolant as an extinguishing agent.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described example, and can be arbitrarily modified within the scope of the present invention.
For example, in the above-described embodiment, the heat energy sources of 100 MW class and 3 GW class are taken as an example, but the gas turbine and the power generation device of the present invention are supercritical CO ₂ so as to correspond to the heat energy source of electric power other than the example. It is possible to design and build gas turbines, power generators, and power generation systems. As an example, a thermal energy source of 1-2 GW class that does not reach the generated power of 3 GW can be considered.

1 Supercritical CO ₂ Gas Turbine 2, 2a, 2b Power Generation Device 3 Rotating Shaft Body 4 Low Pressure Compressor 5 High Pressure Compressor 6 Bypass Compressor 7 Gas Turbine Part 8 Stage Structure 9, 10 Journal Bearing 11 Balance Piston 12 Wing 13 Housing 14 Thrust bearing 15 Generator 16 At least a part of closed circulation system (piping, regenerative heat exchanger, cooler)
17 Container 20 Main Heat Exchanger 21 First Pipe 22 Second Pipe 23 Third Pipe 24 Fourth Pipe 25 Fifth Pipe 26 Sixth Pipe 27a First Regeneration Heat Exchanger 27b Second Regeneration Heat exchanger 28 Precooler 29 Intercooler 30 Closed circulation system of supercritical CO ₂ gas (secondary circulation system)
31 FLiNaK Primary Circulation System 32 FLiNaK Reservoir Tank 33 CO ₂ Reservoir Tank 34 Condenser 35 Pump 36 Pump 40 Rotation Speed Conversion Mechanism 41 Housing Lid 50 Thermal Power Source 51 Helical Furnace 52 Boiler 53 Steam Turbine 54 Generator 55 Blanket 60 Tower 61 Heat collecting part 62, 62a, 62b Pipe for molten FLiNaK 63 Heliostat 64 High temperature molten salt tank 65 Low temperature molten salt tank 66 Pump 67 Primary circulation system 90, 90a, 90b Power generation system

Claims (15)

A power generator using supercritical CO ₂ gas,
A supercritical CO ₂ gas turbine having an elongated rotating shaft body rotatable about one rotating shaft ;
A generator uniaxially connected to the end of the rotating shaft of the supercritical CO ₂ gas turbine;
External supercritical CO ₂ gas heated through the main heat exchanger by thermal energy source is circulated through the supercritical CO ₂ gas turbines, and the closed circulation system of the supercritical CO ₂ gas,
Equipped with
The supercritical CO ₂ gas turbine is
In series in the direction in which the supercritical CO ₂ gas flows along the rotating shaft
One low pressure compressor,
One high pressure compressor,
One bypass compressor,
One gas turbine section arranged to be rotated by the supercritical CO ₂ gas sequentially compressed by the low pressure compressor, the high pressure compressor and the bypass compressor;
, As a component device,
Thermal efficiency target cycle thermal efficiency is not less than 45.63% of the power generation device in the main heat exchanger wherein the inlet temperature of the supercritical CO ₂ gas to the supercritical CO ₂ gas turbine is above 550 ° C. Conditions in the closed circulation system And to achieve compactness,
The configuration device, a uniaxially connected together to the rotary shaft so as to rotate at the same rotational speed in the same direction Rutotomoni, the configuration device, each plurality of which are arranged in series in the rotational axis direction Equipped with a step structure,
Each of the plurality of step structures is
A plurality of blade portions extending in the radial direction from the rotary shaft has an axial flow type configuration arranged in the circumferential direction,
The bypass compressor can be operated at a higher temperature than the low pressure compressor and the high pressure compressor, and has a higher compression power for supercritical CO ₂ gas.
The rotating shaft is controlled so as to rotate at a specific rotation speed that is uniquely determined by a predetermined relationship according to the generated power that the power generation device targets,
Each of the low-pressure compressor, the high-pressure compressor and the bypass compressor has an adiabatic efficiency of 80% or more, and the gas turbine section achieves an adiabatic efficiency of 90% or more. The design limit range of each device is limited by the generated power, the design limit range becomes narrower as the generated power increases ,
The design limit range of each of the constituent devices is at least the allowable flow rate, the allowable inlet temperature range, the allowable number of stages of the step structure, the number of blades per the step structure, and the axial length and the length of each constituent device. Related to various conditions of diameter,
Values of various conditions of each of the constituent devices are selected from the performance limit range of the constituent devices so that the thermal efficiency target and compactness of the power generator are achieved , and the specific rotation speed is the constituent device. A power generation device using supercritical CO ₂ gas , which is within all allowable rotation speeds, and the flow rate of supercritical CO ₂ gas flowing along the rotating shaft is within the allowable flow rate of each component. In the range of 100 MW to 3 GW, the performance limit range of each of the constituent devices when the generated power per one power generation device is 100 MW is as shown in Table 1 below.

The performance limit range of each of the constituent devices in the range of 100 MW to 3 GW in the case where the generated power per one of the power generation devices is 3 GW is as shown in Table 2 below.

The power generator using the supercritical CO ₂ gas according to claim 1, characterized in that . As shown in Table 3 below, the shaft length and the shaft diameter of the entire one power generation device at the generated power of 100 MW and 3 GW are the minimum compactness,

Here, L represents the axial length, D represents the diameter, and the subscripts LPC, HPC, LPC, turbin are those of the low pressure compressor, the high pressure compressor, the bypass compressor and the gas turbine section. The power generator using the supercritical CO ₂ gas according to claim 2, which represents the above . The various conditions further include strength of each wing portion of the constituent device, inlet/outlet temperature/pressure/flow velocity, pressure loss, and a critical speed of the constituent device at the time of start-up. The power generator described. Wherein for supporting the rotating shaft body, each equipped with a magnetic journal bearings at both ends of the rotating shaft body, comprising a magnetic thrust bearing on one end, the power generation device according to any one of claims 1 4 .. The low pressure compressor, the high pressure compressor, the bypass compressor, and a balance piston for relieving the press-fitting between the gas turbine unit, thereby providing a full shaft on the magnetic journal bearing and the magnetic thrust bearing. The power generator according to claim 5, which reduces a directional force. The generator, the has the been detachably connected to the rotary shaft so as to rotate at the same rotational speed, the power generation device according to any one of claims 1 to 6. The power generator according to any one of claims 1 to 7, which is configured to generate generated power derived from the predetermined relationship with respect to a specific rotation speed of 3600 rpm corresponding to a common power supply frequency of 50 to 60 Hz. .. The closed supercritical CO ₂ gas circulation system is
A heat exchange pipe provided inside the main heat exchanger, wherein the main heat exchanger gives heat energy from the heat energy source to supercritical CO ₂ gas flowing in the heat exchange pipe, Heat exchange piping,
In order to supply the supercritical CO ₂ gas heated by the thermal energy source to the gas turbine section to rotate the rotating shaft body, the outlet side of the heat exchange pipe and the inlet side of the gas turbine section are connected. The first pipe,
A second pipe for guiding the supercritical CO ₂ gas emitted from the outlet side of the gas turbine section to the inlet side of the low pressure compressor;
A third pipe connecting the outlet side of the bypass compressor and the inlet side of the heat exchange pipe in order to return a part of the supercritical CO ₂ gas emitted from the bypass compressor to the main heat exchanger,
In order to return a part of the supercritical CO ₂ gas that has exited from the outlet side of the gas turbine unit to the bypass compressor, it is branched from the second pipe and connected to the inlet side of the bypass compressor. 4 pipes,
A first regenerative heat exchanger provided on the path of the second pipe, wherein the third pipe passes through the inside of the first regenerative heat exchanger, whereby the gas turbine unit The first regenerative heat exchanger, which reheats the supercritical CO ₂ gas returning from the bypass compressor to the main heat exchanger by the supercritical CO ₂ gas exiting from the outlet side of
In order to return a part of the supercritical CO ₂ gas compressed by the high-pressure compressor to the main heat exchanger, it extends from the outlet side of the high-pressure compressor at a position upstream of the first regenerative heat exchanger. A fifth pipe joining the third pipe;
A second regenerative heat exchanger provided downstream of the first regenerative heat exchanger on the path of the second pipe and upstream of a branch point of the fourth pipe, wherein the fifth pipe Passes through the inside of the second regenerative heat exchanger before joining with the third pipe, whereby the supercritical CO ₂ gas discharged from the outlet side of the gas turbine section causes the high pressure compressor to The second regenerative heat exchanger for further regenerative heating of the supercritical CO ₂ gas returning from the main heat exchanger to the main heat exchanger,
A precooler provided in the second pipe between the second regenerative heat exchanger and the low pressure compressor;
A sixth pipe connecting from the outlet side of the low pressure compressor to the inlet side of the high pressure compressor;
The intercooler provided in the sixth pipe for cooling a part of the gas compressed by the low-pressure compressor and supplying the gas to the high-pressure compressor, further comprising: The power generator according to item 1. The power generator according to any one of claims 1 to 9, further comprising a container that entirely covers the supercritical CO ₂ gas turbine, the generator, and the closed circulation system . The power generator according to claim 10, wherein the supercritical CO ₂ gas turbine and the power generator are housed vertically in the container . The container has an openable lid portion, by opening the lid portion, at least the supercritical CO ₂ gas turbine and the generator allows out from the container, according to claim 10 or 11 Power generator. The power generator according to any one of claims 1 to 12, wherein the closed circulation system further includes an openable and closable jet outlet for jetting supercritical CO ₂ gas as a coolant to the outside. The power generation according to any one of claims 1 to 13, wherein at the time of start-up, by supplying electric power of a commercial power source to the generator, the generator functions as a motor to rotate the supercritical CO ₂ gas turbine. apparatus. A power generation system comprising the power generation device according to any one of claims 1 to 14 ,
The thermal energy source is either a nuclear fission reactor, a nuclear fusion reactor, a thermal power source, or a heat source of natural energy such as solar heat or geothermal heat,
The fusion reactor is a tokamak reactor, a helical reactor, a laser implosion reactor, a tandem mirror reactor, or a cold fusion reactor, a power generation system,
In the embodiment where the thermal energy source is solar heat,
A heat collecting part heated by sunlight,
A primary circulation system for circulating a molten salt in at least the heat collecting section;
A tower provided with at least a part of the primary circulation system, wherein the heat collecting portion is provided in a head portion of the tower,
A heliostat that follows the operation of the sun to reflect sunlight and concentrate it on the heat collecting part,
A high temperature molten salt tank connected to the inlet side of the main heat exchanger for storing the molten salt heated in the heat collecting section and supplying the molten salt to the main heat exchanger,
A low temperature molten salt tank which is connected to the outlet side of the main heat exchanger and stores molten salt that has undergone heat exchange with supercritical CO ₂ gas in the main heat exchanger;
Equipped with
Since the primary circulation system exchanges heat with the supercritical CO ₂ gas flowing through the closed circulation system, which is a secondary circulation system, the primary heat exchanger is interposed,
The molten salt is FLiNaK,
In an aspect in which the thermal energy source is a fusion reactor,
The fusion reactor includes a blanket, and a primary circulation system in which FLiNaK circulates is arranged in the blanket. The primary circulation system is a supercritical CO ₂ gas flowing through the closed circulation system which is a secondary circulation system. To exchange heat with the main heat exchanger,
The said primary circulation system is a power generation system switchable so that heat is supplied from either a thermal power source or the said fusion reactor .