100 MW-class supercritical co 2 coaxial power generation system

Abstract

A 100 MW-class supercritical CO2 coaxial power generation system, comprising a re-compressor (1), a low-pressure expander (2), a high-pressure expander (3), a power generation drive device (4) and a main compressor (5) which are coaxially arranged and sequentially connected, wherein the re-compressor (1) and the low-pressure expander (2) are connected by means of a first gearbox (6), the power generation drive device (4) and the main compressor (5) are connected by means of a second gearbox (7), and the low-pressure expander (2) and the high-pressure expander (3) are directly connected to a main shaft of the power generation drive device (4). In the system, core apparatuses are coaxially arranged in a single column, and the compressors can thus be directly driven by means of the expanders during operation, thereby omitting electric motors and related electrical apparatuses; and the reduction in the number of apparatuses not only reduces the complexity of the system, but also helps to improve the operational reliability.

Description

A 100MW-class supercritical CO2 coaxial power generation system Technical Field

[0001] This invention relates to the field of steam turbine power generation technology, specifically to a 100MW supercritical CO2 coaxial power generation system. Background Technology

[0002] Existing 100MW-class supercritical CO2 cycle power generation systems generally adopt a split layout, where the core equipment, the compressor and expander, need to be equipped with electric motors and generators respectively, which has an adverse impact on system complexity, investment cost and operating efficiency.

[0003] Each compressor is driven by a separate electric motor, which directly leads to an increase in the number of electrical-related devices and an increase in the overall complexity of the system. The increase in the total number of devices not only increases the failure rate, but also brings great challenges to the installation, commissioning and subsequent operation and maintenance of the equipment. In addition, there are multiple levels of power loss during system operation. The power output of the expander is transmitted to the generator, converted by the generator and then transmitted to the electric motor, which finally drives the compressor. The power loss in this process leads to a reduction in the actual output power, which in turn reduces the cycle efficiency of the entire power generation system. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that requiring separate electric motors and generators for the compressor and expander negatively impacts system complexity, investment costs, and operating efficiency. Therefore, this invention provides a 100MW-class supercritical CO2 coaxial power generation system.

[0005] The technical solution of the present invention is: a 100MW supercritical CO2 coaxial power generation system, comprising: a recompressor, a low-pressure expander, a high-pressure expander, a power generation drive device, and a main compressor arranged coaxially and connected in sequence;

[0006] The recompressor and the low-pressure expander are connected via a first gearbox;

[0007] The power generation drive unit and the main compressor are connected via a second gearbox;

[0008] The low-pressure expander and the high-pressure expander are directly connected to the main shaft of the power generation drive device.

[0009] Furthermore, it also includes: a heater, wherein the main gas outlet of the heater is connected to the inlet of the main gas valve, the outlet of the main gas valve is connected to the inlet of the high-pressure expander, and the outlet of the high-pressure expander is connected to the reheat gas inlet of the heater.

[0010] Furthermore, the reheat gas outlet of the heater is connected to the inlet of the reheat gas valve, and the outlet of the reheat gas valve is connected to the inlet of the low-pressure expander.

[0011] Furthermore, it also includes: a high-temperature regenerator and a low-temperature regenerator, wherein the outlet of the low-pressure expander is connected to the high-temperature gas-side inlet of the high-temperature regenerator, and the high-temperature gas-side outlet of the high-temperature regenerator is connected to the high-temperature gas-side inlet of the low-temperature regenerator.

[0012] Furthermore, the high-temperature gas-side outlet of the low-temperature regenerator is connected to the inlet of the first diversion valve and the inlet of the second diversion valve, respectively. The outlet of the first diversion valve is connected to the inlet of the recompressor, and the outlet of the second diversion valve is connected to the high-temperature gas-side inlet of the high-temperature precooler.

[0013] Furthermore, the outlet of the recompressor is connected to the low-temperature gas-side inlet of the high-temperature regenerator.

[0014] Furthermore, the high-temperature gas-side outlet of the high-temperature precooler is connected to the high-temperature gas-side inlet of the low-temperature precooler.

[0015] Furthermore, the high-temperature gas outlet of the low-temperature precooler is connected to the inlet of the main compressor, the outlet of the main compressor is connected to the low-temperature gas inlet of the low-temperature regenerator, the low-temperature gas outlet of the low-temperature regenerator is connected to the low-temperature gas inlet of the high-temperature regenerator, and the low-temperature gas outlet of the high-temperature regenerator is connected to the main gas inlet of the heater.

[0016] Furthermore, the power generation drive device is an integrated generator-motor unit.

[0017] Furthermore, both the high-pressure expander and the low-pressure expander are axial flow expanders, and both the main compressor and the re-compressor are centrifugal compressors.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The 100MW supercritical CO2 coaxial power generation system provided by the present invention adopts a single-row coaxial arrangement of core equipment. When the system is running, the compressor can be directly driven by the expander, eliminating the need for electric motors and related electrical equipment. The reduction in the number of equipment not only reduces the complexity of the system, but also helps to improve the reliability of operation.

[0020] 2. The 100MW supercritical CO2 coaxial power generation system provided by this invention features a single-row coaxial arrangement of core equipment, which makes the system structure more compact, reduces the number of equipment, and has significant advantages in terms of space utilization and control costs.

[0021] 3. The 100MW supercritical CO2 coaxial power generation system provided by this invention directly drives the compressor by the expander during system operation, which reduces energy loss during energy transmission and effectively improves system operating efficiency. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the overall structure of the present invention.

[0023] In the diagram: 1. Recompressor; 2. Low-pressure expander; 3. High-pressure expander; 4. Generator drive unit; 5. Main compressor; 6. First gearbox; 7. Second gearbox; 8. Heater; 9. Main gas valve; 10. Reheat gas valve; 11. High-temperature regenerator; 12. Low-temperature regenerator; 13. First diversion valve; 14. Second diversion valve; 15. High-temperature precooler; 16. Low-temperature precooler. Detailed Implementation

[0024] Specific Implementation Method 1: Referring to Figure 1, this implementation method includes a recompressor 1, a low-pressure expander 2, a high-pressure expander 3, a power generation drive device 4, and a main compressor 5 arranged coaxially and connected in sequence. The recompressor 1 and the low-pressure expander 2 are connected through a first gearbox 6, and the power generation drive device 4 and the main compressor 5 are connected through a second gearbox 7. The low-pressure expander 2 and the high-pressure expander 3 are directly connected to the main shaft of the power generation drive device 4. In this implementation method, the working fluid is CO2 gas.

[0025] The 100MW supercritical CO2 coaxial power generation system of this embodiment adopts a single-row coaxial arrangement of core equipment. During system operation, the compressor can be directly driven by the expander, eliminating the need for electric motors and related electrical equipment. The reduction in the number of equipment not only reduces system complexity but also helps to improve operational reliability.

[0026] Specific Implementation Method Two: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method One is that it further includes a heater 8. The main gas outlet of the heater 8 is connected to the inlet of the main gas valve 9. The outlet of the main gas valve 9 is connected to the inlet of the high-pressure expander 3. The outlet of the high-pressure expander 3 is connected to the reheat gas inlet of the heater 8. The heater 8 can enhance the CO2 gas, bringing it to a high temperature for circulation. Other components and connections are the same as in Specific Implementation Method One.

[0027] Specific Implementation Method 3: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method 2 is that the reheat gas outlet of the heater 8 is connected to the inlet of the reheat gas valve 10, and the outlet of the reheat gas valve 10 is connected to the inlet of the low-pressure expander 2. The reheat gas valve 10 is located on the pipeline and is used to control the flow of CO2 gas to the low-pressure expander 2. The reheat gas valve 10 can be opened or closed according to actual conditions to change the operating state of the low-pressure expander 2. Other components and connections are the same as in Specific Implementation Method 2.

[0028] Specific Implementation Method Four: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method Three is that it further includes a high-temperature regenerator 11 and a low-temperature regenerator 12. The outlet of the low-pressure expander 2 is connected to the high-temperature gas inlet of the high-temperature regenerator 11, and the high-temperature gas outlet of the high-temperature regenerator 11 is connected to the high-temperature gas inlet of the low-temperature regenerator 12. The high-temperature regenerator 11 and the low-temperature regenerator 12 are used to heat the CO2 gas, facilitating its circulation. Other components and connections are the same as in Specific Implementation Method Three.

[0029] Specific Implementation Method Five: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method Four is that the high-temperature gas outlet of the low-temperature regenerator 12 is connected to the inlets of the first diversion valve 13 and the second diversion valve 14, respectively. The outlet of the first diversion valve 13 is connected to the inlet of the recompressor 1, and the outlet of the second diversion valve 14 is connected to the high-temperature gas inlet of the high-temperature precooler 15. The first diversion valve 13 controls the flow of CO2 gas to the recompressor 1, and the second diversion valve 14 controls the CO2 high-temperature precooler 15. Other components and connections are the same as in Specific Implementation Method Four.

[0030] Specific Implementation Method Six: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method Five is that the outlet of the recompressor 1 is connected to the low-temperature gas inlet of the high-temperature regenerator 11. CO2 gas enters the recompressor 1 and is pressurized. After reaching a certain pressure, the high-pressure CO2 gas passes through the high-temperature regenerator 11 and is heated. Other components and connections are the same as in Specific Implementation Method Five.

[0031] Specific Implementation Method Seven: This implementation method is illustrated in conjunction with Figure 1. The difference between this method and Specific Implementation Method Five is that the high-temperature gas outlet of the high-temperature precooler 15 is connected to the high-temperature gas inlet of the low-temperature precooler 16. The high-temperature precooler 15 and the low-temperature precooler 16 are used to cool the CO2 gas, which, after reaching a certain temperature, enters the main compressor 5 for pressurization. Other components and connections are the same as in Specific Implementation Method Five.

[0032] Specific Implementation Method Eight: This implementation method is illustrated in Figure 1. The difference between this method and Specific Implementation Method Seven is that the high-temperature gas outlet of the low-temperature precooler 16 is connected to the inlet of the main compressor 5; the outlet of the main compressor 5 is connected to the low-temperature gas inlet of the low-temperature regenerator 12; the low-temperature gas outlet of the low-temperature regenerator 12 is connected to the low-temperature gas inlet of the high-temperature regenerator 11; and the low-temperature gas outlet of the high-temperature regenerator 11 is connected to the main gas inlet of the heater 8. The pressurized high-pressure CO2 gas is heated by the low-temperature regenerator 12 and the high-temperature regenerator 11 before entering the heater 8 to complete the cycle. This implementation method achieves system circulation and outputs power. Other components and connections are the same as in Specific Implementation Method Seven.

[0033] Specific Implementation Method Nine: This implementation method is illustrated in conjunction with Figure 1. The difference between this implementation method and Specific Implementation Method One is that the power generation drive device 4 is an integrated power generator / motor unit. This integrated unit reduces the number of devices required, lowers direct costs for procurement, transportation, and storage, and eliminates the need to purchase separate equipment for power generation and motoring functions. Other components and connections are the same as in any of Specific Implementation Methods One through Eight.

[0034] Specific Implementation Method Ten: This implementation method is illustrated in conjunction with Figure 1. The difference between this implementation method and Specific Implementation Method One is that both the high-pressure expander 3 and the low-pressure expander 2 are axial flow expanders, and both the main compressor 5 and the re-compressor 1 are centrifugal compressors. Other components and connections are the same as in any of Specific Implementation Methods One through Eight.

[0035] The working principle of this implementation method is as follows:

[0036] When the system is started, the system parameters are not established. At this time, the power output of the high-pressure expander 3 and the low-pressure expander 2 is less than the power required by the main compressor 5 and the re-compressor 1. Therefore, the generator-motor integrated machine is required to run as the motor. The system is started by using external power input to drive the main compressor 5 and the re-compressor 1. The high-pressure CO2 gas at the outlet of the main compressor 5 enters the heater 8 for heating after passing through the low-temperature regenerator 12 and the high-temperature regenerator 11. The high-pressure CO2 gas at the outlet of the re-compressor 1 enters the heater 8 for heating after passing through the high-temperature regenerator 11. After being heated to a certain temperature, the high-temperature and high-pressure CO2 gas enters the high-pressure expander 3 through the main gas valve 9 to expand and do work. After doing work, the CO2 gas enters the heater 8 again for reheating. The reheated high-temperature and high-pressure CO2 gas enters the low-pressure expander 2 through the reheat gas valve 10 to expand and do work. In this embodiment, the start-up is completed by using external power input.

[0037] After startup, the power output of high-pressure expander 3 and low-pressure expander 2 gradually increases. When the output power of high-pressure expander 3 and low-pressure expander 2 exceeds the power required by main compressor 5 and recompressor 1, the generator-motor integrated unit operates as a generator to output power. High-pressure CO2 gas, heated to a certain temperature by heater 8, enters high-pressure expander 3 through main gas valve 9 to expand and perform work. The CO2 gas that has performed work re-enters heater 8 for reheating. The high-temperature, high-pressure CO2 gas, reheated to a certain temperature, enters low-pressure expander 2 through reheat gas valve 10 to perform work. After the CO2 gas is cooled by the high-temperature regenerator 11 and the low-temperature regenerator 12, part of it enters the compressor 1 through the diversion valve for pressurization. After reaching a certain pressure, the high-pressure CO2 gas is heated by the high-temperature regenerator 11 and then enters the heater 8 to complete the cycle. The other part enters the high-temperature precooler 15 and the low-temperature precooler 16 through the diversion valve for cooling. After reaching a certain temperature, it enters the main compressor 5 for pressurization. The pressurized high-pressure CO2 gas is heated by the low-temperature regenerator 12 and the high-temperature regenerator 11 and then enters the heater 8 to complete the cycle. In this way, the system cycle is realized and the power is output to the outside.

[0038] The content of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.

Claims

1. A 100 MW class supercritical CO2 coaxial power generation system characterized by, include: The recompressor (1), low-pressure expander (2), high-pressure expander (3), power generation drive unit (4) and main compressor (5) are arranged coaxially and connected in sequence. The recompressor (1) and the low-pressure expander (2) are connected by a first gearbox (6); The power generation drive device (4) and the main compressor (5) are connected by a second gearbox (7); The low-pressure expander (2) and the high-pressure expander (3) are directly connected to the main shaft of the power generation drive device (4).

2. The 100 MW class supercritical CO2 coaxial power generation system according to claim 1, characterized by, Also includes Heater (8), the main gas outlet of the heater (8) is connected to the inlet of the main gas valve (9), the outlet of the main gas valve (9) is connected to the inlet of the high pressure expander (3), and the outlet of the high pressure expander (3) is connected to the reheat gas inlet of the heater (8).

3. The 100 MW class supercritical CO2 coaxial power generation system according to claim 2, characterized by, The reheat gas outlet of the heater (8) is connected to the inlet of the reheat gas valve (10), and the outlet of the reheat gas valve (10) is connected to the inlet of the low-pressure expander (2).

4. The 100 MW class supercritical CO2 coaxial power generation system according to claim 3, characterized by, Also includes: The high-temperature regenerator (11) and the low-temperature regenerator (12) are connected, with the outlet of the low-pressure expander (2) connected to the high-temperature gas side inlet of the high-temperature regenerator (11) and the high-temperature gas side outlet of the high-temperature regenerator (11) connected to the high-temperature gas side inlet of the low-temperature regenerator (12).

5. The 100 MW class supercritical CO2 coaxial power generation system according to claim 4, characterized by, The high-temperature gas side outlet of the low-temperature regenerator (12) is connected to the inlet of the first diversion valve (13) and the second diversion valve (14), respectively. The outlet of the first diversion valve (13) is connected to the inlet of the recompressor (1), and the outlet of the second diversion valve (14) is connected to the high-temperature gas side inlet of the high-temperature precooler (15).

6. The 100 MW class supercritical CO2 coaxial power generation system according to claim 5, characterized by, The outlet of the recompressor (1) is connected to the low-temperature gas inlet of the high-temperature regenerator (11).

7. The 100 MW class supercritical CO2 coaxial power generation system according to claim 5, characterized by, The high-temperature gas-side outlet of the high-temperature precooler (15) is connected to the high-temperature gas-side inlet of the low-temperature precooler (16).

8. The 100 MW class supercritical CO2 coaxial power generation system according to claim 7, characterized by, The high-temperature gas outlet of the low-temperature precooler (16) is connected to the inlet of the main compressor (5), the outlet of the main compressor (5) is connected to the low-temperature gas inlet of the low-temperature regenerator (12), the low-temperature gas outlet of the low-temperature regenerator (12) is connected to the low-temperature gas inlet of the high-temperature regenerator (11), and the low-temperature gas outlet of the high-temperature regenerator (11) is connected to the main gas inlet of the heater (8).

9. A 100 MW class supercritical CO2 coaxial power generation system according to any one of claims 1-8, characterized in that, The power generation drive device (4) is an integrated generator and motor.

10. A 100 MW class supercritical CO2 coaxial power generation system according to any one of claims 1-8, characterized in that, Both the high-pressure expander (3) and the low-pressure expander (2) are axial flow expanders, and both the main compressor (5) and the re-compressor (1) are centrifugal compressors.

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