Supercritical fluid and gas turbine combined cycle system
The combined cycle system recovers gas turbine exhaust heat to enhance supercritical fluid expansion, addressing inefficiencies by integrating independent subsystems and optimizing rotor systems for improved power generation efficiency.
Patent Information
- Application Number
- CN202210026675.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-01-11
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2042-01-11
AI Technical Summary
Existing supercritical fluid and gas turbine combined cycle systems waste heat from the exhaust gas of the gas turbine, leading to inefficiencies and heat loss.
A supercritical fluid and gas turbine combined cycle system with independent subsystems, where the exhaust gas of the gas turbine is utilized to heat the supercritical fluid, enhancing its expansion performance, and incorporating a rotor system with multiple generators and fluid bearings to improve power generation efficiency.
The system effectively recovers waste heat from the gas turbine exhaust to enhance the thermal efficiency of the supercritical fluid cycle, improving overall power generation efficiency and reducing costs by balancing load and force with multiple generators.
Smart Images
Figure CN114320603B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a supercritical fluid and gas turbine combined circulation system, belonging to the technical field of supercritical fluid. Background Art
[0002] Supercritical fluids (such as supercritical carbon dioxide SCCO2) have special physical and chemical properties and are suitable for a variety of technical fields. For example, they can be used as dry cleaning solvents for preparing micron or nanometer particles. In addition, based on the very high thermal efficiency of supercritical fluids (about 45%), they can also be used in steam turbine combined cycles or in closed gas turbines (such as the Brayton energy cycle). This high efficiency can not only increase the fuel utilization of each power generation unit to 40% or more, but also reduce the cost of power plants by about 18% compared to conventional Rankine steam cycles.
[0003] There are documents in the prior art that disclose solutions for combining gas turbines with supercritical fluid cycles. For example, US9540999B2 discloses a solution for a dual-cycle power generation system of supercritical fluids. Specifically, the system includes two circulation systems, wherein the first circulation system is a circulation system based on a gas turbine, and the second circulation system is a circulation system based on a supercritical fluid. The two systems achieve heat exchange through a heat exchanger, and then the supercritical fluid in the second circulation system is used as a working fluid to drive the turbine to rotate, thereby driving the coaxially arranged generator to generate electricity. However, in the combined cycle scheme of the prior art, the exhaust gas of the gas turbine is not utilized and processed, but is directly discharged into the atmosphere, resulting in heat waste. Therefore, how to reduce or avoid the heat waste of the exhaust gas of the gas turbine in the combined cycle scheme of supercritical fluid and gas turbine has become a problem that needs to be solved urgently. Summary of the invention
[0004] In view of the above-mentioned prior art, the present invention provides a supercritical fluid and gas turbine combined cycle system.
[0005] The present invention is achieved through the following technical solutions:
[0006] A supercritical fluid and gas turbine combined cycle system, comprising a gas turbine subsystem and a supercritical fluid circulation subsystem, the gas turbine subsystem and the supercritical fluid circulation subsystem being independent of each other, the gas turbine subsystem comprising a first compressor, a combustion chamber, a first turbine and a first generator, the supercritical fluid circulation subsystem comprising a rotor system, a first heat exchanger and a second heat exchanger; wherein,
[0007] The first compressor, the first turbine and the first generator in the gas turbine subsystem are coaxially arranged, the exhaust end of the first compressor is connected to the intake end of the combustion chamber, the outlet end of the combustion chamber is connected to the intake end of the first turbine, and the outlet end of the first turbine is connected to the inlet end of the first passage of the first heat exchanger (the heat exchanger has two passages, and the fluids in the first passage and the second passage can exchange heat, for example, through fins, which is common knowledge and will not be repeated);
[0008] The rotor system in the supercritical fluid circulation subsystem includes a coaxially arranged second compressor, a second turbine and a second generator, the outlet end of the second compressor is connected to the inlet end of the second passage of the first heat exchanger, the outlet end of the second passage of the first heat exchanger is connected to the inlet end of the second turbine, and the outlet end of the second turbine is connected to the inlet end of the second heat exchanger.
[0009] Furthermore, the supercritical fluid circulation subsystem also includes a supercritical fluid storage tank for providing supercritical fluid in the initial stage or when pressurization is required, and the outlet end of the supercritical fluid storage tank is connected to the inlet end of the second compressor.
[0010] Furthermore, a solenoid valve is provided at the outlet end of the supercritical fluid storage tank to control the opening and closing of the supercritical fluid storage tank.
[0011] Furthermore, the supercritical fluid circulation subsystem is arranged in a sealed box, which is filled with supercritical fluid and has a pressure of 7 to 10 MPa; the outlet end of the second passage of the second heat exchanger is connected to the inlet end of the second compressor, or the outlet end of the second heat exchanger is directly connected to the interior of the sealed box (the supercritical fluid in the circulation pipeline can be directly discharged into the sealed box); the inlet end of the second compressor is also directly connected to the interior of the sealed box (that is, the supercritical fluid entering the second compressor comes partly from the circulation pipeline and partly from the inside of the sealed box).
[0012] Furthermore, a booster pump is provided in the sealed box, and the booster pump is connected to the supercritical fluid storage tank (can be located at the outlet of the supercritical fluid storage tank). When necessary, the booster pump can be used to provide pressurized supercritical fluid to the supercritical fluid circulation flow channel pipeline with the supercritical fluid storage tank as a supercritical fluid source; or: the booster pump is controllably connected to the external pipeline of the sealed box, so as to replenish gas from the external environment of the sealed box and pressurize the internal environment of the sealed box when necessary.
[0013] Furthermore, a guide cover is provided at the outlet end of the second turbine of the supercritical fluid circulation subsystem (the purpose is to protect the generator from being blown by the high-temperature supercritical fluid, avoiding corrosion or causing other problems), which is used to guide the working fluid discharged from the outlet end of the second turbine to the second heat exchanger.
[0014] Furthermore, the rotor system of the supercritical fluid circulation subsystem can be configured as a generator-to-generator structure to improve power generation efficiency (the speed of the rotor system driven by the supercritical fluid circulation can be as high as 10w-20w RPM).
[0015] Furthermore, the number of second generators of the rotor system of the supercritical fluid circulation subsystem is more than two. The second generators can be located at both ends of the rotating shaft (more than two second generators can be arranged at each end), or between the second compressor and the second turbine. The purpose of such arrangement is: 1. If the number and power of the motors at both ends are consistent, it is helpful to balance the force and load; 2. The motor can be a commercially available conventional motor, and by setting multiple motors, a suitable power generation capacity can be achieved, thus saving costs.
[0016] Furthermore, the supercritical fluid circulation subsystem also includes a fluid bearing (whose structure is similar to that of an air bearing, but its supporting air film is a supercritical fluid), and the supporting medium of the fluid bearing is a supercritical fluid in a sealed box.
[0017] Furthermore, the fluid bearing is a hydrodynamic fluid bearing or a hydrodynamic and static integrated bearing. When a hydrodynamic bearing (i.e., self-suspension by rotation) is selected, a film layer can be formed by a supercritical fluid, and the density of the supercritical fluid is greater than that of air and has better fluidity than that of a liquid, so it can provide better film layer stiffness, improve the rotational stability of the rotor system, and facilitate the increase of the rotor speed (the speed requirement of the rotor system of the supercritical fluid circulation is higher than that of the combustion engine).
[0018] Furthermore, the fluid bearing includes at least one radial bearing and at least one thrust bearing.
[0019] Furthermore, the structure of the rotor system of the critical fluid circulation subsystem is: it includes a rotating shaft, on which a generator A, a second compressor, a second turbine and a generator B are arranged in sequence, that is, the generator A and the generator B are respectively arranged at both ends or both sides of the rotating shaft to form a generator pair structure.
[0020] Furthermore, the radial bearing and / or thrust bearing can be arranged at the end of the rotating shaft, on the outside of generator A, between generator A and the second compressor, between the second compressor and the second turbine, between the second turbine and generator B and / or on the outside of generator B.
[0021] Preferably, the structure of the rotor system of the critical fluid circulation subsystem is one of the following:
[0022] ① comprising a rotating shaft, on which a first radial bearing, a first thrust bearing, a generator A, a second compressor, a second radial bearing, a second turbine, a generator B, a second thrust bearing and a third radial bearing are sequentially arranged;
[0023] ② comprising a rotating shaft, on which a first radial bearing, a generator A, a first thrust bearing, a second compressor, a second radial bearing, a second turbine, a second thrust bearing, a generator B and a third radial bearing are sequentially arranged;
[0024] ③ comprising a rotating shaft, on which a first thrust bearing, a first radial bearing, a generator A, a second compressor, a second radial bearing, a second turbine, a generator B, a third radial bearing and a second thrust bearing are sequentially arranged;
[0025] ④ comprising a rotating shaft, on which are arranged in sequence a first radial bearing, a first thrust bearing, a generator A, a fourth radial bearing, a second compressor, a second radial bearing, a second turbine, a fifth radial bearing, a generator B, a second thrust bearing and a third radial bearing;
[0026] ⑤ comprising a rotating shaft, on which are arranged in sequence a first thrust bearing, a first radial bearing, a generator A, a fourth radial bearing, a second compressor, a second radial bearing, a second turbine, a fifth radial bearing, a generator B, a third radial bearing and a second thrust bearing;
[0027] ⑥ comprising a rotating shaft, on which are arranged in sequence a first radial bearing, a generator A, a first thrust bearing, a fourth radial bearing, a second compressor, a second radial bearing, a second turbine, a fifth radial bearing, a second thrust bearing, a generator B and a third radial bearing;
[0028] ⑦ comprising a rotating shaft, on which are arranged in sequence a first radial bearing, a generator A, a fourth radial bearing, a first thrust bearing, a second compressor, a second radial bearing, a second turbine, a second thrust bearing, a fifth radial bearing, a generator B and a third radial bearing;
[0029] ⑧ comprising a rotating shaft, on which a first radial bearing, a generator A, a second compressor, a first thrust bearing, a second radial bearing, a second turbine, a sixth radial bearing, a generator B and a third radial bearing are sequentially arranged;
[0030] ⑨ includes a rotating shaft, on which are arranged in sequence a first radial bearing, a generator A, a fourth radial bearing, a second compressor, a first thrust bearing, a second radial bearing, a second turbine, a sixth radial bearing, a fifth radial bearing, a generator B and a third radial bearing.
[0031] Furthermore, the second heat exchanger is an air-cooled heat exchanger.
[0032] Furthermore, the components involved in the supercritical fluid circulation subsystem (the first heat exchanger, the second heat exchanger, the second compressor, the second turbine, the fairing, the pipes used for communication, etc.) are treated with corrosion protection (such as anti-corrosion coating, anti-corrosion materials, etc.), because the ideal operating temperature range of the supercritical fluid is 500-600°C, and above this temperature range, the supercritical fluid is highly corrosive. The pipes between the first compressor and the first heat exchanger, the first heat exchanger and the second turbine, and the second turbine and the second heat exchanger can be treated with heat insulation (insulation).
[0033] Furthermore, the pressure ratio of the second compressor of the supercritical fluid circulation subsystem is set at 2 to 3 times.
[0034] Furthermore, the pressure ratio of the first compressor of the gas turbine subsystem is set at 3 to 4 times.
[0035] The control method of the supercritical fluid and gas turbine combined cycle system comprises:
[0036] The first generator in the gas turbine subsystem switches to the motor mode to drive the first turbine to rotate until the speed of the first compressor reaches a preset speed and the pressure ratio reaches a preset pressure ratio (for example, 3 to 4 times the pressure ratio); then the first generator is controlled to switch to the power generation mode; the exhaust gas of the first turbine enters the first heat exchanger for heat exchange;
[0037] The second generator in the supercritical fluid circulation subsystem switches to the motor mode, driving the second turbine to rotate until the second compressor can output a supercritical fluid with a predetermined pressure ratio (for example, 2 to 3 times the pressure ratio); then the second generator is controlled to switch to the power generation mode.
[0038] The supercritical fluid and gas turbine combined cycle system of the present invention has the following working principles for the gas turbine subsystem: using air as the working fluid, the first compressor inhales air from the external atmospheric environment and compresses it, the compressed air is pressed into the combustion chamber to mix with the fuel and burn to produce high-temperature and high-pressure gas, the high-temperature and high-pressure gas (about 900°C) drives the first turbine to rotate and do work, thereby driving the first generator to work and generate electricity, the exhaust gas (about 650°C) discharged by the first turbine enters the first heat exchanger for heat exchange, thereby realizing the recovery and utilization of the waste heat of the gas turbine exhaust gas. The working principle of the supercritical fluid circulation subsystem is as follows: with supercritical fluid (supercritical carbon dioxide, supercritical water, etc.) as the working fluid, the second compressor compresses the supercritical fluid, and then exchanges heat at the first heat exchanger, that is, the exhaust gas preheating of the gas turbine subsystem is used to heat the supercritical fluid compressed by the compressor (the exhaust temperature of the first turbine is higher than that of the supercritical fluid, so the heat of the turbine exhaust will be transferred to the supercritical fluid after heat exchange) to improve its expansion effect; the supercritical fluid (high temperature and high pressure) after heat exchange drives the second turbine to rotate and work, and then drives the second generator to work and generate electricity. The exhaust gas discharged by the second turbine is cooled by the second heat exchanger and then flows to the second compressor for compression, thus forming a supercritical fluid cycle. In the initial stage of the supercritical fluid cycle, similar to the start-up of the gas turbine, motor dragging is also required. For example, in this stage, the second generator can be controlled to work in the motor mode, dragging the coaxially arranged second turbine and the second compressor until the second compressor and the second turbine can establish an autonomous power cycle, and then the second generator is controlled to switch to the generator working mode.
[0039] The supercritical fluid and gas turbine combined cycle system of the present invention can utilize the exhaust waste heat of the gas turbine subsystem to heat the supercritical fluid of the supercritical fluid circulation subsystem to improve its expansion performance, thereby realizing the combined cycle of the gas turbine and the supercritical fluid and improving the thermal efficiency of the gas turbine system. The high-temperature supercritical fluid discharged from the second turbine is guided to the second heat exchanger through the guide cover for heat exchange, thereby cooling the supercritical fluid before entering the second compressor, improving the compression effect of the second compressor, and improving the overall efficiency of the system. The rotor system in the supercritical fluid circulation subsystem can be set as a special generator towing structure, which is conducive to improving the power generation efficiency.
[0040] The various terms and phrases used in the present invention have the general meanings known to those skilled in the art. If the terms and phrases mentioned are inconsistent with the commonly known meanings, the meanings expressed in the present invention shall prevail. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Figure 1 : Schematic diagram of the structure of a critical fluid and gas turbine combined cycle system (Example 1).
[0042] Figure 2: Schematic diagram of the structure of a critical fluid and gas turbine combined cycle system (Example 1).
[0043] Figure 3 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 3).
[0044] Figure 4 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 3).
[0045] Figure 5 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 4).
[0046] Figure 6 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 5).
[0047] Figure 7 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 6).
[0048] Figure 8 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 7).
[0049] Fig. 9 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 8).
[0050] Fig.10 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 9).
[0051] Fig.11 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 10).
[0052] Fig.12 : Schematic diagram of the structure of the rotor system of the supercritical fluid circulation subsystem (Example 11).
[0053] Note: Figures 4 to 12 Only the structure on the left side of the second turbine is shown, and the structure on the right side of the second turbine is not shown. The structure on the right side of the second turbine is symmetrical to the structure on the left side of the second compressor shown in the figure.
[0054] Among them, 1. gas turbine subsystem; 2. supercritical fluid circulation subsystem; 3. first compressor; 4. combustion chamber; 5. first turbine; 6. first generator; 7. first heat exchanger; 8. second heat exchanger; 9. second generator; 10. sealed box; 11. fairing; 100. rotating shaft; 200. turbine; 300. compressor; 400. generator A; 401. generator B; 500. first radial bearing; 600. second radial bearing; 700. first thrust bearing; 800. fourth radial bearing; 801. sixth radial bearing; 900. second thrust bearing; 1000. third radial bearing. DETAILED DESCRIPTION
[0055] The present invention will be further described below in conjunction with the examples. However, the scope of the present invention is not limited to the following examples. Those skilled in the art will appreciate that various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention.
[0056] Example 1 Supercritical fluid and gas turbine combined cycle system
[0057] The invention comprises a gas turbine subsystem 1 and a supercritical fluid circulation subsystem 2, wherein the gas turbine subsystem 1 and the supercritical fluid circulation subsystem 2 are independent of each other; the gas turbine subsystem 1 comprises a first compressor 3, a combustion chamber 4, a first turbine 5 and a first generator 6, and the supercritical fluid circulation subsystem 2 comprises a rotor system, a first heat exchanger 7 and a second heat exchanger 8; wherein,
[0058] The first compressor 3, the first turbine 5 and the first generator 6 in the gas turbine subsystem 1 are coaxially arranged, the exhaust end of the first compressor 3 is connected to the intake end of the combustion chamber 4, the outlet end of the combustion chamber 4 is connected to the intake end of the first turbine 5, and the outlet end of the first turbine 5 is connected to the inlet end of the first passage of the first heat exchanger 7;
[0059] The rotor system in the supercritical fluid circulation subsystem 2 includes a coaxially arranged second compressor 300, a second turbine 200 and a second generator 9, the outlet end of the second compressor 300 is connected to the inlet end of the second passage of the first heat exchanger 7, the outlet end of the second passage of the first heat exchanger 7 is connected to the inlet end of the second turbine 200, and the outlet end of the second turbine 200 is connected to the inlet end of the second heat exchanger 8.
[0060] The supercritical fluid circulation subsystem 2 may further include a supercritical fluid storage tank for providing supercritical fluid in the initial stage or when pressurization is required, and the outlet of the supercritical fluid storage tank is connected to the inlet of the second compressor 300 .
[0061] The outlet end of the supercritical fluid storage tank may be provided with a solenoid valve to control the opening and closing of the supercritical fluid storage tank.
[0062] The supercritical fluid circulation subsystem 2 is arranged in a sealed box 10, which is filled with a supercritical fluid and has a pressure of 7-10 MPa; the outlet end of the second passage of the second heat exchanger 8 is connected to the inlet end of the second compressor 300 (such as Figure 1 As shown), or the outlet end of the second heat exchanger 8 is directly connected to the inside of the sealed box 10 (as shown Figure 2 As shown) (the supercritical fluid in the circulation pipeline can be directly discharged into the sealed box 10); the inlet end of the second compressor 300 is also directly connected to the interior of the sealed box 10 (that is, the supercritical fluid entering the second compressor 300 comes partly from the circulation pipeline and partly from the interior of the sealed box 10).
[0063] A booster pump may also be provided in the sealed box 10, and the booster pump is connected to the supercritical fluid storage tank (may be located at the outlet of the supercritical fluid storage tank). When necessary, the booster pump can be used to provide pressurized supercritical fluid to the supercritical fluid circulation flow channel pipeline with the supercritical fluid storage tank as a supercritical fluid source; or: the booster pump is controllably connected to the external pipeline of the sealed box, and is used to supplement gas from the external environment of the sealed box when necessary to pressurize the internal environment of the sealed box.
[0064] The outlet end of the second turbine 200 of the supercritical fluid circulation subsystem 2 is provided with a guide cover 11 (the purpose is to protect the generator from being blown by the high-temperature supercritical fluid, avoiding corrosion or causing other problems), which is used to guide the working fluid discharged from the outlet end of the second turbine 200 to the second heat exchanger 8.
[0065] The rotor system of the supercritical fluid circulation subsystem 2 can be configured as a generator-to-generator structure to improve power generation efficiency (the speed of the rotor system driven by the supercritical fluid circulation can be as high as 10w-20w RPM).
[0066] The supercritical fluid circulation subsystem 2 also includes a fluid bearing, and the supporting medium of the fluid bearing is a supercritical fluid in a sealed box. The fluid bearing is a hydrodynamic fluid bearing or a hydrodynamic and static pressure integrated bearing. When a hydrodynamic bearing (i.e., self-suspended by rotation) is selected (the structure of the hydrodynamic bearing can be referred to CN 211343734 U, CN 211343700 U), a film layer can be formed by a supercritical fluid, and the density of the supercritical fluid is greater than that of air and has better fluidity than that of a liquid, so it can provide better film layer stiffness, improve the rotational stability of the rotor system, and facilitate the increase of the rotor speed (the speed requirement of the rotor system of the supercritical fluid circulation is higher than the speed of the combustion engine).
[0067] The fluid bearing includes at least one radial bearing and at least one thrust bearing.
[0068] The second heat exchanger 8 may be an air-cooled heat exchanger.
[0069] The components involved in the supercritical fluid circulation subsystem 2 (the first heat exchanger 7, the second heat exchanger 8, the second compressor 300, the second turbine 200, the fairing 11, the pipes used for communication, etc.) can be treated with corrosion protection (such as anti-corrosion coating, anti-corrosion materials, etc.) because the ideal operating temperature range of the supercritical fluid is 500-600°C. Beyond this temperature range, the supercritical fluid is highly corrosive. The pipes between the first compressor 3 and the first heat exchanger 7, the first heat exchanger 7 and the second turbine 200, and the second turbine 200 and the second heat exchanger 8 can be treated with heat insulation (heat preservation).
[0070] The pressure ratio of the second compressor 300 of the supercritical fluid circulation subsystem 2 can be set at 2 to 3 times.
[0071] The pressure ratio of the first compressor 3 of the gas turbine subsystem 1 can be set at 3 to 4 times.
[0072] Example 2 Control method for supercritical fluid and gas turbine combined cycle system
[0073] include:
[0074] The first generator in the gas turbine subsystem switches to the motor mode to drive the first turbine to rotate until the speed of the first compressor reaches a preset speed and the pressure ratio reaches a preset pressure ratio (for example, 3 to 4 times the pressure ratio); then the first generator is controlled to switch to the power generation mode; the exhaust gas of the first turbine enters the first heat exchanger for heat exchange;
[0075] The second generator in the supercritical fluid circulation subsystem switches to the motor mode, driving the second turbine to rotate until the second compressor can output a supercritical fluid with a predetermined pressure ratio (for example, 2 to 3 times the pressure ratio); then the second generator is controlled to switch to the power generation mode.
[0076] Example 3 Supercritical fluid and gas turbine combined cycle system
[0077] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a first thrust bearing 700, a generator A 400, a second compressor 300, a second radial bearing 600, a second turbine 200, a generator B, a second thrust bearing and a third radial bearing are sequentially arranged. Figure 3 , 4 shown.
[0078] Example 4 Supercritical fluid and gas turbine combined cycle system
[0079] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a generator A 400, a first thrust bearing 700, a second compressor 300, a second radial bearing 600, a second turbine 200, a second thrust bearing, a generator B and a third radial bearing are sequentially arranged. Figure 5 shown.
[0080] Example 5 Supercritical fluid and gas turbine combined cycle system
[0081] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first thrust bearing 700, a first radial bearing 500, a generator A 400, a second compressor 300, a second radial bearing 600, a second turbine 200, a generator B, a third radial bearing and a second thrust bearing are sequentially arranged. Figure 6 shown.
[0082] Example 6 Supercritical fluid and gas turbine combined cycle system
[0083] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a first thrust bearing 700, a generator A 400, a fourth radial bearing 800, a second compressor 300, a second radial bearing 600, a second turbine 200, a fifth radial bearing, a generator B, a second thrust bearing and a third radial bearing are sequentially arranged. Figure 7 shown.
[0084] Example 7 Supercritical fluid and gas turbine combined cycle system
[0085] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first thrust bearing 700, a first radial bearing 500, a generator A 400, a fourth radial bearing 800, a second compressor 300, a second radial bearing 600, a second turbine 200, a fifth radial bearing, a generator B, a third radial bearing and a second thrust bearing are sequentially arranged. Figure 8 shown.
[0086] Example 8 Supercritical fluid and gas turbine combined cycle system
[0087] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a generator A 400, a first thrust bearing 700, a fourth radial bearing 800, a second compressor 300, a second radial bearing 600, a second turbine 200, a fifth radial bearing, a second thrust bearing, a generator B and a third radial bearing are sequentially arranged. Fig. 9 shown.
[0088] Example 9 Supercritical fluid and gas turbine combined cycle system
[0089] The structure is the same as that of Embodiment 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a generator A 400, a fourth radial bearing 800, a first thrust bearing 700, a second compressor 300, a second radial bearing 600, a second turbine 200, a second thrust bearing, a fifth radial bearing, a generator B and a third radial bearing are sequentially arranged. Fig.10 shown.
[0090] Example 10 Supercritical fluid and gas turbine combined cycle system
[0091] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a generator A 400, a second compressor 300, a first thrust bearing 700, a second radial bearing 600, a second turbine 200, a sixth radial bearing 801, a generator B and a third radial bearing are sequentially arranged. Fig.11 shown.
[0092] Example 11 Supercritical fluid and gas turbine combined cycle system
[0093] The structure is the same as that of Example 1. The structure of the rotor system of the supercritical fluid circulation subsystem is as follows: it includes a rotating shaft 100, on which a first radial bearing 500, a generator A 400, a fourth radial bearing 800, a second compressor 300, a first thrust bearing 700, a second radial bearing 600, a second turbine 200, a sixth radial bearing 801, a fifth radial bearing, a generator B and a third radial bearing are sequentially arranged. Fig.12 shown.
[0094] The above examples are provided to those skilled in the art to fully disclose and describe how to make and use the claimed embodiments, and are not intended to limit the scope of the disclosure herein. Modifications that are obvious to those skilled in the art will fall within the scope of the appended claims.
Claims
1. A supercritical fluid and gas turbine combined cycle system, characterized in that: The invention comprises a gas turbine subsystem and a supercritical fluid circulation subsystem, wherein the gas turbine subsystem and the supercritical fluid circulation subsystem are independent of each other, the gas turbine subsystem comprises a first compressor, a combustion chamber, a first turbine and a first generator, and the supercritical fluid circulation subsystem comprises a rotor system, a first heat exchanger and a second heat exchanger; wherein, The first compressor, the first turbine and the first generator in the gas turbine subsystem are coaxially arranged, the exhaust end of the first compressor is connected to the intake end of the combustion chamber, the outlet end of the combustion chamber is connected to the intake end of the first turbine, and the outlet end of the first turbine is connected to the inlet end of the first passage of the first heat exchanger; The rotor system in the supercritical fluid circulation subsystem includes a coaxially arranged second compressor, a second turbine and a second generator, the outlet end of the second compressor is connected to the inlet end of the second passage of the first heat exchanger, the outlet end of the second passage of the first heat exchanger is connected to the inlet end of the second turbine, and the outlet end of the second turbine is connected to the inlet end of the second heat exchanger; The supercritical fluid circulation subsystem further includes a supercritical fluid storage tank, the outlet end of the supercritical fluid storage tank is connected to the inlet end of the second compressor; The supercritical fluid circulation subsystem is arranged in a sealed box, which is filled with supercritical fluid and has a pressure of 7-10 MPa; the outlet end of the second passage of the second heat exchanger is connected to the inlet end of the second compressor, or the outlet end of the second heat exchanger is directly connected to the inside of the sealed box; The supercritical fluid circulation subsystem further includes a fluid bearing, wherein the fluid bearing is a hydrodynamic fluid bearing, and the supporting medium of the fluid bearing is a supercritical fluid in a sealed box; A booster pump is provided in the sealed box, and the booster pump is connected to the supercritical fluid storage tank; or: the booster pump is controllably connected to an external pipeline of the sealed box; The outlet end of the second turbine of the supercritical fluid circulation subsystem is provided with a guide cover.
2. The supercritical fluid and gas turbine combined cycle system according to claim 1, characterized in that: The number of the second generators of the rotor system of the supercritical fluid circulation subsystem is more than two.
3. The supercritical fluid and gas turbine combined cycle system according to claim 1, characterized in that: The fluid bearing includes at least one radial bearing and at least one thrust bearing.
4. The control method of a supercritical fluid and gas turbine combined cycle system according to any one of claims 1 to 3, characterized in that: include: The first generator in the gas turbine subsystem switches to the motor mode to drive the first turbine to rotate until the speed of the first compressor reaches a preset speed and the pressure ratio reaches a preset pressure ratio; then the first generator is controlled to switch to the power generation mode; the exhaust gas of the first turbine enters the first heat exchanger for heat exchange; The second generator in the supercritical fluid circulation subsystem switches to the motor mode, driving the second turbine to rotate until the second compressor can output the supercritical fluid with a predetermined pressure ratio; then the second generator is controlled to switch to the power generation mode.