Stability Control System and Method for SCO2 Brayton Cycle Power Generation System

Abstract

This invention discloses a stabilization and regulation system and method for an SCO2 Brayton cycle power generation system, belonging to the technical field of SCO2 Brayton cycle power generation systems. It includes a pressure-stabilized storage tank and a system tank. The system tank is connected to the SCO2 Brayton cycle power generation system and is connected to the pressure-stabilized storage tank via a first pipeline and a second pipeline. The pressure-stabilized storage tank has the function of regulating the temperature and pressure of the SCO2. A first temperature regulating device is installed on the first pipeline to regulate the temperature of the SCO2 in the first pipeline. The gas flow direction in the first pipeline is unidirectional from the system tank to the pressure-stabilized storage tank, and the gas flow direction in the second pipeline is unidirectional from the pressure-stabilized storage tank to the system tank. This invention can effectively isolate the SCO2 working fluid in the system from the pressure-stabilized storage tank, thereby eliminating pressure fluctuations in the SCO2 caused by temperature changes within the system.

Description

Technical Field

[0001] This invention belongs to the technical field of SCO2 Brayton cycle power generation system, and specifically relates to a stability regulation system and method for SCO2 Brayton cycle power generation system. Background Technology

[0002] Compared with existing steam power generation systems, SCO2 (Supercritical Carbon Dioxide) Brayton cycle power generation systems have advantages such as high efficiency in the medium and high temperature range, strong power adaptability, fewer equipment and high output power density. They have great application prospects in coal-fired power generation, ship propulsion and large-scale solar thermal energy storage.

[0003] The SCO2 Brayton cycle power generation system is a closed-loop system, mainly consisting of an intermediate heat exchanger, compressor, turbine, regenerator, and cooler. The system pressure is determined by the quantity and thermodynamic properties of the working fluid. The thermodynamic properties of the SCO2 fluctuate significantly with pressure and temperature, and the thermodynamic properties of the working fluid vary considerably between different equipment ends. Furthermore, the operating parameters (pressure and temperature) at various points within the system change with variations in the thermodynamic properties of the upstream and downstream working fluids. Therefore, pressure and temperature within the system are strongly coupled. Additionally, the SCO2 Brayton cycle power generation system is more prone to pressure fluctuations in the cold end region, exacerbating system instability. For example, the cooler is easily affected by changes in the cooling rate and temperature of the cooling medium, causing significant changes in the thermodynamic properties of the SCO2 near its critical point with temperature and pressure. This leads to oscillations in system operating parameters, making stable and rapid system control difficult.

[0004] Currently, in order to maintain a wide range of system pressure regulation and stability, it is common practice to add a storage tank and a back pressure valve assembly. The storage tank is generally used to collect and store the working fluid before system startup, and to collect or release the working fluid during system operation to ensure system pressure stability and that the supply of working fluid is within a reasonable range. The back pressure valve assembly is usually used to ensure pressure balance between the compressor outlet and the turbine outlet.

[0005] However, existing storage tanks are generally large tanks connected in series within the system, and their design volume is selected and adapted based on the system's circulating working mass. In order to cope with the system's pressure and temperature fluctuations, this method often uses an increased storage tank volume to act as a pressure stabilizing device, and installs heating and cooling devices on the storage tank to improve the stability of the supercritical carbon dioxide state within the pressure stabilizer and the performance of the pressure stabilizer. However, because the storage tank is connected in series within the system, it is very easy to generate problems of increased system thermal inertia due to system temperature and pressure fluctuations. Moreover, the larger the volume of the storage tank connected in series in the system, the greater the system inertia generated during heating, and excessive adjustment rates will cause strong system oscillations, making it impossible to balance. Therefore, it is impractical to eliminate system pressure fluctuations by setting up a large storage tank in series in the system and controlling the temperature.

[0006] Currently, there are also methods to introduce pressure stabilizing tank structures to maintain a wide range of system pressure regulation and stability; however, since nitrogen and other gases are filled into the top of the pressure stabilizing tank, SCO2 will continuously dissolve non-condensable gases during use, resulting in a continuous decrease in SCO2 purity. When the system pressure is below the critical point, non-condensable gases will precipitate from subcritical carbon dioxide and remain in various components within the system, hindering the safe and stable operation of the equipment during system operation. Furthermore, since the tank structure set up in this way mainly relies on the expansion and contraction of the gas to control the system pressure, it cannot solve the problems of regulation oscillation caused by large changes in the thermophysical properties of SCO2 in the critical region.

[0007] Therefore, how to eliminate the pressure fluctuations caused by temperature changes within the SCO2 Brayton cycle power generation system has become an urgent technical problem to be solved. Summary of the Invention

[0008] To address the technical problems existing in the prior art, the present invention provides a stabilization and regulation system and method for an SCO2 Brayton cycle power generation system, in order to solve the technical problem of pressure fluctuations in the SCO2 Brayton cycle power generation system caused by temperature changes within the system.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] This invention provides a stabilization and regulation system for an SCO2 Brayton cycle power generation system, comprising a pressure-stabilized storage integrated tank and a system storage tank;

[0011] The system storage tank is connected to the SCO2 Brayton cycle power generation system, and the system storage tank is connected to the pressure-stabilized storage tank through a first pipeline and a second pipeline; wherein, the pressure-stabilized storage tank has the function of regulating the temperature and pressure of SCO2; a first temperature regulating device is provided on the first pipeline, and the first temperature regulating device is used to regulate the temperature of SCO2 in the first pipeline;

[0012] Wherein, the gas flow direction in the first pipeline is unidirectional from the system storage tank to the pressure-stabilized storage integrated tank, and the gas flow direction in the second pipeline is unidirectional from the pressure-stabilized storage integrated tank to the system storage tank.

[0013] Preferably, a first regulating valve is provided on the first pipeline, and a second regulating valve is provided on the second pipeline.

[0014] Preferably, the first temperature regulating device is a heat dissipation fin.

[0015] Preferably, the pressure-stabilized storage tank is provided with a second temperature regulating device; wherein, the second temperature regulating device is used to heat or cool the SCO2 in the pressure-stabilized storage tank.

[0016] Preferably, the second temperature regulating device includes a heat pipe, or the second temperature regulating device includes a heat pipe and an electric heating element.

[0017] Preferably, one end of the heat pipe extends into the interior of the integrated pressure-stabilized storage tank, and the other end of the heat pipe is connected to a heat source or a cold source.

[0018] Preferably, the outer surface of the pressure-stabilized storage tank is provided with a heat insulation layer, and the heat insulation layer is provided with a heat tracing device.

[0019] Preferably, it also includes a liquid CO2 booster pump and a switching valve; the integrated pressure-stabilized storage tank is connected to a liquid CO2 source through the liquid CO2 booster pump and the switching valve.

[0020] Preferably, the first inlet of the system tank is connected to the SCO2 outlet of the cooler in the SCO2 Brayton cycle power generation system, and the first outlet of the system tank is connected to the inlet of the compressor in the SCO2 Brayton cycle power generation system.

[0021] The present invention also provides a stabilization regulation method for an SCO2 Brayton cycle power generation system, utilizing the aforementioned stabilization regulation system for an SCO2 Brayton cycle power generation system;

[0022] The stabilization and regulation method for the SCO2 Brayton cycle power generation system includes:

[0023] When the temperature of SCO2 in the SCO2 Brayton cycle power generation system is higher than the preset threshold, the first pipeline is opened and the second pipeline is closed, so that the SCO2 in the system storage tank is transported to the pressure-stabilized storage tank, and the temperature and pressure regulation function of the pressure-stabilized storage tank is activated so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank reach the preset stable state.

[0024] When the SCO2 temperature in the SCO2 Brayton cycle power generation system is lower than the preset threshold, the second pipeline is opened and the first pipeline is closed, so that the SCO2 delivery system storage tank in the pressure-stabilized storage tank is opened, and the temperature and pressure regulation function of the pressure-stabilized storage tank is activated so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank reach the preset stable state.

[0025] When the SCO2 Brayton cycle power generation system needs to be shut down, the temperature and pressure regulation function of the pressure stabilization and storage tank is activated to reduce the temperature of SCO2 in the pressure stabilization and storage tank to the preset temperature. The first pipeline is opened and the second pipeline is closed, so that the SCO2 at the preset temperature in the system storage tank is stored in the pressure stabilization and storage tank.

[0026] When the SCO2 Brayton cycle power generation system is started, the temperature and pressure regulation function of the pressure-stabilized storage tank is activated so that the temperature and pressure of the SCO2 in the pressure-stabilized storage tank reach the preset values. The thrust generated when the SCO2 in the pressure-stabilized storage tank is turned on instantaneously is used to assist in starting the SCO2 Brayton cycle power generation system.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The present invention provides a stabilization and regulation system and method for an SCO2 Brayton cycle power generation system. The system storage tank is connected to the SCO2 Brayton cycle power generation system and then connected to a pressure-stabilized storage tank via a first pipeline. A first temperature regulating device on the first pipeline regulates the temperature of the SCO2 in the first pipeline, thereby cooling the SCO2 in the system storage tank before it is delivered to the pressure-stabilized storage tank. Subsequently, based on the temperature and pressure regulation functions of the pressure-stabilized storage tank, the temperature and pressure within the pressure-stabilized storage tank are stabilized. Next, a second pipeline connects the system storage tank to the pressure-stabilized storage tank, allowing SCO2 at a preset temperature or pressure within the pressure-stabilized storage tank to be delivered to the system storage tank via the second pipeline, thus stabilizing the SCO2 in the system storage tank. O2 is kept at a suitable temperature or pressure; this invention can effectively isolate the SCO2 working fluid and the pressure-stabilized storage tank in the SCO2 Brayton cycle power generation system, ensuring that the temperature of the SCO2 working fluid does not affect each other when transferred between the pressure-stabilized storage tank and the SCO2 Brayton cycle power generation system, thus eliminating pressure fluctuations of SCO2 caused by temperature changes within the system. It decouples the operating temperature and pressure of SCO2 in a simple way and provides a storage / release site for SCO2; in addition, it can avoid contamination of SCO2 by other non-condensable gases or liquids, thereby improving the reliability of the system; this invention also has the advantages of simple and reliable adjustment method, fast adjustment rate, simple system equipment configuration, low manufacturing cost, and easy adoption and promotion. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic diagram of the stabilization system for the SCO2 Brayton cycle power generation system provided in Example 1;

[0031] Figure 2 This is a cross-sectional view of the pressure-stabilized storage tank in Example 1;

[0032] Figure 3 This is a schematic diagram of the stabilization system for the SCO2 Brayton cycle power generation system provided in Example 2;

[0033] Figure 4 This is a cross-sectional view of the pressure-stabilized storage tank in Example 2.

[0034] Among them, 1. Liquid CO2 booster pump; 2. Switch valve; 3. Pressure stabilizing storage tank; 4. Heat pipe; 5. Electric heating element; 6. Heat tracing and insulation device; 7. First regulating valve; 8. Second regulating valve; 9. First temperature regulating device; 10. System storage tank; 11. First pipeline; 12. Second pipeline. Detailed Implementation

[0035] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0036] This invention provides a stabilization and regulation system for an SCO2 Brayton cycle power generation system, comprising a system storage tank 10 connected to the SCO2 Brayton cycle power generation system, a pressure-stabilized storage tank 3 with temperature and pressure regulation functions, and a first temperature regulating device 9 with cooling function; the system storage tank 10 is connected to the pressure-stabilized storage tank 3 via a first pipeline 11 and a second pipeline 12, and the first temperature regulating device 9 is located on the first pipeline 11; the gas flow direction of the first pipeline 11 is unidirectional from the system storage tank 10 to the pressure-stabilized storage tank 3, and the gas flow direction of the second pipeline 12 is unidirectional from the pressure-stabilized storage tank 3 to the system storage tank 10; a first regulating valve 7 is provided on the first pipeline 11, and a second regulating valve 8 is provided on the second pipeline 12.

[0037] Example 1

[0038] As attached Figure 1As shown, this embodiment 1 provides a stabilization and regulation system for an SCO2 Brayton cycle power generation system, including a liquid CO2 booster pump 1, a switching valve 2, a pressure-stabilized storage tank 3, a first regulating valve 7, a second regulating valve 8, a first temperature regulating device 9, a system storage tank 10, a first pipeline 11, and a second pipeline 12.

[0039] The inlet of the liquid CO2 booster pump 1 is connected to a liquid CO2 source, and the outlet of the liquid CO2 booster pump 1 is connected to the inlet of the switch valve 2. The outlet of the switch valve 2 is connected to the liquid CO2 inlet of the pressure-stabilized storage tank 3. Preferably, the liquid CO2 inlet of the pressure-stabilized storage tank 3 is located at the bottom of the pressure-stabilized storage tank 3. The bottom of the pressure-stabilized storage tank 3 is connected to the liquid CO2 source through the liquid CO2 booster pump 1 and the switch valve 2 to facilitate the replenishment of liquid CO2 into the pressure-stabilized storage tank 3.

[0040] The system storage tank 10 is connected to the SCO2 Brayton cycle power generation system; specifically, the system storage tank 10 is provided with a first inlet, a second inlet, a first outlet, and a second outlet; the first inlet of the system storage tank 10 is connected to the SCO2 outlet end of the cooler in the SCO2 Brayton cycle power generation system, and the first outlet of the system storage tank 10 is connected to the inlet end of the compressor in the SCO2 Brayton cycle power generation system.

[0041] The system storage tank 10 is connected to the pressure-stabilized storage integrated tank 3 via a first pipeline 11 and a second pipeline 12. The gas flow direction in the first pipeline 11 is unidirectional, from the system storage tank 10 to the pressure-stabilized storage integrated tank 3, and the gas flow direction in the second pipeline 12 is unidirectional, from the pressure-stabilized storage integrated tank 3 to the system storage tank 10. Specifically, the inlet of the first pipeline 11 is connected to the second outlet of the system storage tank 10, and the outlet of the first pipeline 11 is connected to the working fluid inlet of the pressure-stabilized storage integrated tank 3. The inlet of the second pipeline 12 is connected to the working fluid outlet of the pressure-stabilized storage integrated tank 3, and the outlet of the second pipeline 12 is connected to the second inlet of the system storage tank 10.

[0042] The first regulating valve 7 and the first temperature regulating device 9 are both installed on the first pipeline 11. The first regulating valve 7 is used to control the opening and closing of the first pipeline 11, and the first temperature regulating device 9 is used to regulate the temperature of SCO2 in the first pipeline 11. The second regulating valve 8 is installed on the second pipeline 12, and the second regulating valve 8 is used to control the opening and closing of the second pipeline 12.

[0043] Both the first regulating valve 7 and the second regulating valve 8 are valves with adjustable opening. It should be noted that the diameter of the pipeline where the first regulating valve 7 and the second regulating valve 8 are located needs to be designed according to the possible mass flow rate, and the pressure difference at the inlet and outlet is adjusted by adjusting the valve opening to ensure that the flow rate of SCO2 is within the preset range. The first temperature regulating device 9 is a cooling pipe, cooling fan, cooling air conditioner or cooling fins for cooling. Preferably, the first temperature regulating device 9 is a cooling fin.

[0044] In this embodiment 1, the pressure-stabilized storage tank 3 has the function of regulating the temperature and pressure of SCO2; specifically, the pressure-stabilized storage tank 3 is equipped with a second temperature regulating device, which is used to heat or cool the SCO2 in the pressure-stabilized storage tank 3, so that the pressure-stabilized storage tank 3 has the function of regulating the temperature and pressure of SCO2; wherein, the second temperature regulating device is placed in the area of ​​high CO2 density in the pressure-stabilized storage tank 3, that is, the second temperature regulating device is set near the liquid CO2 inlet end of the pressure-stabilized storage tank 3; before the system is running, A liquid CO2 booster pump 1 is used to pre-charge the pressure-stabilized storage tank 3 with SCO2 at a set pressure and temperature. During system operation, when the pressure in the pressure-stabilized storage tank 3 is higher than the set value, the second temperature regulating device is activated to lower the temperature inside the tank, thereby reducing the pressure to the set value. When the pressure in the pressure-stabilized storage tank 3 is lower than the set value, the second temperature regulating device is activated to raise the temperature inside the tank, thereby raising the pressure to the set value. Preferably, the SCO2 in the pressure-stabilized storage tank 3 operates at 31~38℃ and 7.5~8MPa, and its density changes closely with temperature, thus allowing for rapid adjustment.

[0045] As attached Figure 2As shown, the second temperature regulating device includes a heat pipe 4 and an electric heating element 5. One end of the heat pipe 4 extends into the interior of the integrated pressure-stabilized storage tank 3, and the other end extends to the exterior of the integrated pressure-stabilized storage tank 3 and is connected to a heat source or a cold source. The electric heating element 5 is disposed inside the integrated pressure-stabilized storage tank 3, and the power supply end of the electric heating element 5 extends out to the exterior of the integrated pressure-stabilized storage tank 3 and is connected to an external power source. It should be noted that when the second temperature regulating device includes the heat pipe 4 and the electric heating element 5, and the heating capacity of the electric heating element 5 can meet the preset requirements, the end of the heat pipe 4 extending outside the integrated pressure-stabilized storage tank 3 is only connected to a cold source. If the heating capacity of the electric heating element 5 cannot meet the preset requirements, the end of the heat pipe 4 extending outside the integrated pressure-stabilized storage tank 3 is connected to a heat source or a cold source to compensate for the deficiencies of the electric heating element 5. Preferably, the electric heating element 5 is a heating rod. The heat pipe 4 is arranged radially so that the insertion depth of the end of the heat pipe 4 extending into the tank is the same, making the cooling / heating more uniform.

[0046] The outer surface of the pressure-stabilized storage tank 3 is provided with a heat insulation layer 6, and the heat insulation layer 6 is provided with a heat tracing and heat preservation device; the heat emitted by the heat tracing medium is used to compensate for the loss of the heat-traced pipeline through direct or indirect heat exchange, so as to achieve the normal working requirements of heating, heat preservation or antifreeze, and to prevent the heat loss of the working medium in the pressure-stabilized storage tank 3 due to long-term storage.

[0047] It should be noted that the dimensions of the integrated pressure-stabilized storage tank 3 are designed to match the quantity of the working fluid operating within the SCO2 Brayton cycle power generation system; wherein, the volume of the integrated pressure-stabilized storage tank 3 is 20% of the total volume of equipment and pipelines in the SCO2 Brayton cycle power generation system; the volume of the system storage tank 10 is determined based on the volume of the integrated pressure-stabilized storage tank 3; preferably, the volume of the system storage tank 10 is no more than 10% of its volume.

[0048] In this embodiment 1, the system storage tank 10 and the pressure-stabilized storage tank 3 are connected by the first pipeline 11 and the second pipeline 12. A first temperature regulating device 9 is installed on the first pipeline 11 to effectively isolate the working fluid in the SCO2 Brayton cycle power generation system from the pressure-stabilized storage tank 3, ensuring that the temperature of the working fluid does not affect each other when it is transferred between the pressure-stabilized storage tank 3 and the SCO2 Brayton cycle power generation system. Based on the function of the pressure-stabilized storage tank 3 in regulating the temperature and pressure of SCO2, the temperature and pressure fluctuations of the pressure-stabilized storage tank 3 are small and the adjustment is relatively easy. By adjusting the operating parameters of the working fluid in the pressure-stabilized storage tank 3, the operating temperature and pressure of SCO2 in the SCO2 Brayton cycle power generation system can be easily controlled at the required set value.

[0049] Adjustment method and working principle

[0050] This embodiment 1 also provides a stabilization method for the SCO2 Brayton cycle power generation system, namely, the working principle of the stabilization system for the SCO2 Brayton cycle power generation system described in this embodiment 1 is as follows:

[0051] (1) When the temperature of SCO2 in the SCO2 Brayton cycle power generation system is higher than the preset threshold, the first pipeline 11 is opened and the second pipeline 12 is closed, so that the SCO2 in the system storage tank 10 after heating and expansion is cooled by the first temperature regulating device 9 and transported to the pressure-stabilized storage tank 3. The temperature and pressure regulating function of the pressure-stabilized storage tank 3 is activated so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank 3 reach the preset stable state, that is, to ensure the stability of the temperature and pressure in the pressure-stabilized storage tank 3.

[0052] It should be noted that the operating conditions in which the SCO2 temperature in the SCO2 Brayton cycle power generation system exceeds the preset threshold include a decrease in the cooling capacity of the cold trap of the SCO2 Brayton cycle power generation system; for example, when the cooling water flow rate decreases or the cooling water temperature increases, the temperature inside the system storage tank 10 will also increase as the temperature in the SCO2 Brayton cycle power generation system increases.

[0053] It should also be noted that opening the first pipeline 11 means opening the first regulating valve 7, and closing the second pipeline 12 means closing the second regulating valve 8; similarly, closing the first pipeline 11 means closing the first regulating valve 7, and opening the second pipeline 12 means opening the second regulating valve 8.

[0054] Secondly, the process of activating the temperature and pressure regulation function of the integrated pressure stabilizing storage tank 3 includes: the integrated pressure stabilizing storage tank 3 is equipped with a heat pipe 4 and an electric heating element 5 inserted inside the tank body, the other end of the heat pipe 4 is connected to an external cold source, and the electric heating element 5 is equipped with an electric heating wire; before the system runs, the integrated pressure stabilizing storage tank 3 is filled with SCO2 working fluid at a set pressure and temperature; when the system runs, when the pressure of the integrated pressure stabilizing storage tank 3 is higher than the set value, the temperature inside the tank is reduced by turning on the external cold source, so that the pressure is reduced to the set value; when the pressure of the integrated pressure stabilizing storage tank 3 is lower than the set value, the temperature inside the tank is increased by turning on the electric heating element 5, so that the pressure is increased to the set value.

[0055] (2) When the temperature of SCO2 in the SCO2 Brayton cycle power generation system is lower than the preset threshold, the second pipeline 12 is opened and the first pipeline 11 is closed, so that the SCO2 transport system storage tank 10 in the pressure stabilization storage tank 3 is opened, and the temperature and pressure regulation function of the pressure stabilization storage tank 3 is turned on, so that the temperature and pressure of SCO2 in the pressure stabilization storage tank 3 reach the preset stable state, that is, to ensure the stability of the temperature and pressure in the pressure stabilization storage tank 3.

[0056] It should be noted that the operating conditions in which the SCO2 temperature in the SCO2 Brayton cycle power generation system is lower than the preset threshold include: a sudden increase in the cooling capacity of the cold trap of the SCO2 Brayton cycle power generation system; for example, when the cooling water flow rate increases or the cooling water temperature decreases. At this time, the SCO2 temperature at the outlet of the precooler of the SCO2 Brayton cycle power generation system decreases, and may even become subcritical or liquid CO2. The temperature and pressure in the system storage tank 10 will also decrease accordingly. Therefore, it is necessary to open the second regulating valve 8 to replenish SCO2 in the system storage tank 10. Since the volume of the pressure stabilizing storage tank 3 is larger than the volume of the system storage tank 10, the pressure and temperature of SCO2 in the pressure stabilizing storage tank 3 change more slowly. At this time, the pressure and temperature parameters inside the tank can be maintained at a reasonable value by the second temperature regulating device in the pressure stabilizing storage tank 3.

[0057] The operating conditions in which the SCO2 temperature in the SCO2 Brayton cycle power generation system is lower than the preset threshold also include: when the SCO2 Brayton cycle power generation system is operating at reduced power or when the system heat source is operating at reduced temperature, as well as when the system is starting up, the system output power is increasing, and the system maximum temperature is increasing; and when the system is starting up, the system output power is increasing, and the system maximum temperature is increasing, the temperature and pressure in the integrated storage tank 3 need to be adjusted to the required state by the second temperature regulating device before SCO2 is filled into the system storage tank 10.

[0058] (3) When it is necessary to fill the pressure-stabilized storage tank 3 with liquid CO2, the operation is as follows: open the switch valve 2 to fill the pressure-stabilized storage tank 3 with liquid CO2 until the pressure-stabilized storage tank 3 reaches the set pressure, then close the switch valve 2 to complete the filling.

[0059] (4) When the SCO2 Brayton cycle power generation system needs to be shut down, the temperature and pressure regulation function of the pressure-stabilized storage tank 3 is turned on to reduce the temperature of SCO2 in the pressure-stabilized storage tank 3 to the preset temperature, the first pipeline 11 is turned on and the second pipeline 12 is turned off, so that the SCO2 in the system storage tank 10 at the preset temperature is stored in the pressure-stabilized storage tank 3; when the SCO2 Brayton cycle power generation system is turned on, the temperature and pressure regulation function of the pressure-stabilized storage tank 3 is turned on so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank 3 reach the preset value, so as to use the thrust generated when the SCO2 in the pressure-stabilized storage tank 3 is turned on to assist in starting the SCO2 Brayton cycle power generation system; preferably, when the SCO2 Brayton cycle power generation system needs to be shut down, the temperature of the pressure-stabilized storage tank 3 is adjusted to 20-30°C, and the working fluid temperature in the SCO2 Brayton cycle power generation system is controlled at 40-50°C, so that the SCO2 working fluid in the system is stored in the pressure-stabilized storage tank 3 to the maximum extent.

[0060] The stabilization and regulation system for the SCO2 Brayton cycle power generation system described in Embodiment 1 connects the system storage tank 10 to the pressure-stabilized storage tank 3 via a system storage tank connected to the main system, a pressure-stabilized storage tank with temperature and pressure regulation functions, and a first temperature regulating device with cooling function. The system storage tank 10 is connected to the pressure-stabilized storage tank 3 via a first pipeline 11 and a second pipeline 12, and the first temperature regulating device 9 is placed in the first pipeline. This effectively isolates the working fluid in the SCO2 Brayton cycle power generation system from the pressure-stabilized storage tank, eliminating pressure fluctuations in SCO2 caused by temperature changes within the system. The system has a simple equipment configuration, low manufacturing cost, and the advantages of simple and reliable regulation method and fast regulation rate. Furthermore, the stabilization and regulation system does not contaminate SCO2 with other non-condensable gases or liquids during operation, thereby improving the reliability of the SCO2 Brayton cycle power generation system.

[0061] Example 2

[0062] The stabilization system for the SCO2 Brayton cycle power generation system provided in Embodiment 2 is basically the same in structure and principle as the stabilization system for the SCO2 Brayton cycle power generation system provided in Embodiment 1 above, except that:

[0063] The second temperature regulating device includes a heat pipe 4, one end of which extends into the interior of the pressure-stabilized storage tank 3, and the other end of which is connected to a heat source or a cold source, as shown in the attached figure. Figure 3-4Specifically, when the second temperature regulating device includes a heat pipe 4 and it is necessary to heat the pressure-stabilized storage tank 3, one end of the heat pipe 4 extending outside the pressure-stabilized storage tank 3 is connected to a heat source; when it is necessary to cool the pressure-stabilized storage tank 3, one end of the heat pipe 4 extending outside the pressure-stabilized storage tank 3 is connected to a cold source; in this embodiment 2, heating or cooling of the pressure-stabilized storage tank 3 can be flexibly achieved through the heat pipe 4 alone, so that the pressure-stabilized storage tank 3 has the function of regulating the temperature and pressure of SCO2, which is safe and reliable.

[0064] It should be noted that the arrangement and other structures of the heat pipe 4 described in this embodiment 2 are basically the same as those in embodiment 1 above, and will not be repeated here.

[0065] The stabilization and regulation system and method for an SCO2 Brayton cycle power generation system described in this invention, by installing a pipeline and a first temperature regulating device between the system storage tank and the integrated pressure-stabilized storage tank, allows for the cooling of the SCO2 in the system storage tank when its temperature is too high, before it is transferred to the integrated pressure-stabilized storage tank. Combined with the temperature and pressure regulation functions of the integrated pressure-stabilized storage tank, this achieves temperature and pressure stability within the tank. Specifically, "excessively high SCO2 temperature" means the SCO2 temperature in the system storage tank exceeds a preset temperature range; conversely, "excessively low SCO2 temperature" prevents the lower-temperature SCO2 from flowing into the integrated pressure-stabilized storage tank. The SCO2 in the SCO2 Brayton cycle power generation system is stored in a single integrated tank. The SCO2 at a suitable temperature within the integrated tank is then transported to the system storage tank via a second pipeline, ensuring that the SCO2 in the system storage tank remains at a suitable temperature. If the SCO2 temperature in the system storage tank is too low (i.e., below a preset temperature range), then the working fluid in the SCO2 Brayton cycle power generation system is effectively isolated from the integrated integrated tank. This ensures that the temperature of the working fluid does not affect the temperature of the SCO2 during transfer between the two systems, thus eliminating pressure fluctuations caused by temperature changes within the system. This simple method decouples the operating temperature and pressure of the SCO2 and provides a storage / release location for it.

[0066] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A method for stabilizing and regulating an SCO2 Brayton cycle power generation system, characterized in that, A stabilization and regulation system for the SCO2 Brayton cycle power generation system is used; the stabilization and regulation system for the SCO2 Brayton cycle power generation system includes a pressure-stabilized storage tank (3) and a system storage tank (10). The system storage tank (10) is connected to the SCO2 Brayton cycle power generation system. The system storage tank (10) is connected to the pressure-stabilized storage tank (3) through a first pipeline (11) and a second pipeline (12). The pressure-stabilized storage tank (3) has the function of regulating the temperature and pressure of SCO2. A first temperature regulating device (9) is provided on the first pipeline (11). The first temperature regulating device (9) is used to regulate the temperature of SCO2 in the first pipeline (11). Wherein, the gas flow direction in the first pipeline (11) is one-way from the system storage tank (10) to the pressure-stabilized storage integrated tank (3), and the gas flow direction in the second pipeline (12) is one-way from the pressure-stabilized storage integrated tank (3) to the system storage tank (10). The stabilization and regulation method for the SCO2 Brayton cycle power generation system includes: When the temperature of SCO2 in the SCO2 Brayton cycle power generation system is higher than the preset threshold, the first pipeline (11) is opened and the second pipeline (12) is closed, so that the SCO2 in the system storage tank (10) is transported to the pressure-stabilized storage tank (3), and the temperature and pressure regulation function of the pressure-stabilized storage tank (3) is activated so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank (3) reach the preset stable state. When the temperature of SCO2 in the SCO2 Brayton cycle power generation system is lower than the preset threshold, the second pipeline (12) is opened and the first pipeline (11) is closed, so that the SCO2 delivery system storage tank (10) in the pressure-stabilized storage tank (3) is opened, and the temperature and pressure regulation function of the pressure-stabilized storage tank (3) is activated so that the temperature and pressure of SCO2 in the pressure-stabilized storage tank (3) reach the preset stable state. When the SCO2 Brayton cycle power generation system needs to be shut down, the temperature and pressure regulation function of the pressure-stabilized storage tank (3) is activated to reduce the temperature of SCO2 in the pressure-stabilized storage tank (3) to the preset temperature, the first pipeline (11) is opened and the second pipeline (12) is closed, so that the SCO2 at the preset temperature in the system storage tank (10) is stored in the pressure-stabilized storage tank (3); When the SCO2 Brayton cycle power generation system is started, the temperature and pressure regulation function of the pressure-stabilized storage tank (3) is activated so that the temperature and pressure of the SCO2 in the pressure-stabilized storage tank (3) reach the preset value, so as to use the thrust generated when the SCO2 in the pressure-stabilized storage tank (3) is turned on to assist in starting the SCO2 Brayton cycle power generation system.

2. The stabilization and regulation method for an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, A first regulating valve (7) is provided on the first pipeline (11), and a second regulating valve (8) is provided on the second pipeline (12).

3. The stabilization and regulation method for an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, The first temperature regulating device (9) is a heat dissipation fin.

4. The stabilization and regulation method for an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, The pressure-stabilized storage tank (3) is equipped with a second temperature regulating device; wherein the second temperature regulating device is used to heat or cool the SCO2 in the pressure-stabilized storage tank (3).

5. A stabilization and regulation method for an SCO2 Brayton cycle power generation system according to claim 4, characterized in that, The second temperature regulating device includes a heat pipe (4), or the second temperature regulating device includes a heat pipe (4) and an electric heating element (5).

6. A method for stabilizing an SCO2 Brayton cycle power generation system according to claim 5, characterized in that, One end of the heat pipe (4) extends into the interior of the pressure-stabilized storage tank (3), and the other end of the heat pipe (4) is connected to a heat source or a cold source.

7. A stabilization and regulation method for an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, The outer surface of the pressure-stabilized storage tank (3) is provided with a heat insulation layer (6), and the heat insulation layer (6) is provided with a heat tracing and insulation device.

8. A method for stabilizing an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, It also includes a liquid CO2 booster pump (1) and a switching valve (2); the pressure-stabilized storage tank (3) is connected to the liquid CO2 source through the liquid CO2 booster pump (1) and the switching valve (2).

9. A method for stabilizing an SCO2 Brayton cycle power generation system according to claim 1, characterized in that, The first inlet of the system tank (10) is connected to the SCO2 outlet of the cooler in the SCO2 Brayton cycle power generation system, and the first outlet of the system tank (10) is connected to the inlet of the compressor in the SCO2 Brayton cycle power generation system.

Images