Air supplementing device of supercritical carbon dioxide power generation system and control method thereof

Abstract

This invention discloses a gas replenishment device and its control method for a supercritical carbon dioxide power generation system. The supercritical carbon dioxide power generation system includes: an internal circulation pipeline, a circulation mechanism, and a dry gas sealing mechanism. The internal circulation pipeline is connected to both the circulation mechanism and the dry gas sealing mechanism. The circulation mechanism includes a compressor. The gas replenishment device includes: a booster pump, an external gas pipeline, a compressor detection element, a dry gas detection element, and a control unit. The booster pump is located in the internal circulation pipeline, and the output end of the external gas pipeline is connected to the internal circulation pipeline. The compressor detection element is located inside the compressor and is used to detect the compressor pressure inside the compressor. The dry gas detection element is located in the dry gas sealing mechanism and is used to detect the dry gas sealing data inside the dry gas sealing mechanism. The control unit is used to confirm the gas replenishment mode of the gas replenishment device based on the dry gas sealing data, and based on the gas replenishment mode and the compressor pressure, controls the booster pump and / or the external gas pipeline to replenish gas to the internal circulation pipeline.

Description

Technical Field

[0001] This application relates to the field of carbon dioxide power generation technology, and in particular to a gas replenishment device and control method for a supercritical carbon dioxide power generation system. Background Technology

[0002] Supercritical carbon dioxide power generation technology has entered a new era of industrial application. Supercritical carbon dioxide power generation systems require ensuring a stable internal circulation of the carbon dioxide working fluid. Furthermore, dry gas seals, with their advantages of non-contact operation, low wear, zero leakage, and long lifespan, have become the "lifeline" for ensuring the safe and environmentally friendly operation of supercritical carbon dioxide power generation systems. Among related technologies, ensuring sufficient gas supply to the internal circulation system and the dry gas seal system of the entire power generation system has become a key technical problem that urgently needs to be solved in the current industrialization process of supercritical carbon dioxide power generation technology, and it has significant engineering application value. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0004] The first aspect of this application proposes a gas replenishment device for a supercritical carbon dioxide power generation system. The supercritical carbon dioxide power generation system includes: an internal circulation pipeline, a circulation mechanism, and a dry gas sealing mechanism. The internal circulation pipeline is connected to both the circulation mechanism and the dry gas sealing mechanism. The circulation mechanism includes a compressor. The gas replenishment device includes: a booster pump, an external gas pipeline, a compressor detection element, a dry gas detection element, and a control unit. The booster pump is located in the internal circulation pipeline. The output end of the external gas pipeline is connected to the internal circulation pipeline. The compressor detection element is located inside the compressor and is used to detect the compressor pressure inside the compressor. The dry gas detection element is located in the dry gas sealing mechanism and is used to detect the dry gas sealing data inside the dry gas sealing mechanism. The control unit is used to confirm the gas replenishment mode of the gas replenishment device based on the dry gas sealing data, and based on the gas replenishment mode and the compressor pressure, controls the booster pump and / or the external gas pipeline to replenish gas to the internal circulation pipeline.

[0005] In some technical solutions provided in this application, the control unit is also used to activate the booster pump to replenish gas through the internal circulation pipeline when the gas replenishment device is in normal mode; and to activate the external gas pipeline and determine whether the compressor pressure is less than or equal to the booster threshold when the gas replenishment device is in emergency mode. The control unit is also used to activate the booster pump when the compressor pressure is less than the booster threshold; and to control the external gas pipeline to input external gas into the internal circulation pipeline when the compressor pressure is greater than the booster threshold.

[0006] In some of the technical solutions provided in this application, the circulation mechanism further includes a turbine, which includes a front bearing and a rear bearing; the compressor includes a second-stage impeller and a third-stage impeller; the dry gas sealing mechanism includes a front bearing seal, a rear bearing seal, a second-stage seal, and a third-stage seal. Dry gas detection elements are respectively located at the front bearing seal, the rear bearing seal, the second-stage seal, and the third-stage seal.

[0007] In some of the technical solutions provided in this application, the external gas pipeline includes: a gas supply pipeline and a pressure pump. The output end of the gas supply pipeline is connected to the internal circulation pipeline. The gas supply pipeline is used to input external gas, and the pressure pump is located in the gas supply pipeline.

[0008] In some of the technical solutions provided in this application, the control unit is also used to compare the compressor pressure with the make-up gas pressure, and to confirm that the supercritical carbon dioxide power generation system is in the make-up gas state when the compressor pressure is less than the make-up gas pressure.

[0009] In some of the technical solutions provided in this application, the control unit includes a touch screen, which is used to determine control parameters and display operating information.

[0010] The second aspect of this application provides a control method for a gas replenishment device in a supercritical carbon dioxide power generation system. This control method is used in the gas replenishment device provided in any of the above embodiments, and the control method includes: The supercritical carbon dioxide power generation system has been confirmed to have entered the gas replenishment state. Based on the dry gas sealing data of the dry gas sealing mechanism, the gas replenishment mode of the gas replenishment device is confirmed. When the air replenishment device is operating in normal mode, the booster pump is turned on to replenish air through the internal circulation pipeline; When the gas supply device is in emergency mode, the external gas pipeline is opened; When the gas supply device is in emergency mode, the specific steps for opening the external gas pipeline include: Determine if the compressor pressure is lower than the boost threshold; When the compressor pressure is less than or equal to the booster threshold, the booster pump is turned on. When the compressor pressure is greater than the boosting threshold, the external gas pipeline is controlled to input external gas into the internal circulation pipeline.

[0011] In some technical solutions provided in this application, the step of confirming the gas replenishment mode of the gas replenishment device based on the dry gas sealing data of the dry gas sealing mechanism specifically includes: Compare the dry gas sealing data of any one of the front bearing seal, rear bearing seal, secondary seal, and tertiary seal with the sealing threshold. If the dry gas seal data is less than or equal to the seal threshold, confirm that the gas replenishment mode is the emergency mode. If the dry gas seal data is greater than the seal threshold, confirm that the gas replenishment mode is normal mode.

[0012] In some of the technical solutions provided in this application, the steps for confirming that the supercritical carbon dioxide power generation system enters the gas replenishment state specifically include: Compare the compressor pressure with the make-up air pressure; When the compressor pressure is lower than the make-up gas pressure, it is confirmed that the supercritical carbon dioxide power generation system is in the make-up gas state. When the compressor pressure is greater than the make-up gas pressure, it is confirmed that the supercritical carbon dioxide power generation system is in a non-make-up gas state.

[0013] In some of the technical solutions provided in this application, after the step of opening the external gas pipeline when the gas supply device is in emergency mode, the following steps are also included: Compare the dry gas seal data with the seal compliance value; If the dry gas seal data exceeds the seal compliance value, complete the gas replenishment.

[0014] Compared with related technologies, the present invention has at least the following beneficial effects: By coordinating the work of the booster pump, detection unit, and control unit, an integrated and intelligent gas replenishment system has been constructed to achieve automatic gas replenishment control of the supercritical carbon dioxide power generation system. Based on dry gas seal data and compressor pressure, the control unit selects the injection path and activates the booster pump, combining internal circulation gas replenishment with external gas replenishment. This precise control of the replenishment method makes it more flexible and accurate, enabling on-demand replenishment and avoiding over- or under-replenishment. It caters to the replenishment needs of various conditions, both conventional and special, ensuring pressure stability and operational safety of the supercritical carbon dioxide power generation system's internal circulation pipeline and dry gas sealing mechanism. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of some embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the structure of an air replenishment device according to an embodiment of this application; Figure 2 A schematic flowchart illustrating the control method of an air replenishment device according to an embodiment of this application.

[0016] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 100. Booster pump; 200. External gas pipeline; 210. Make-up gas pipeline; 220. Pressure pump; 300. Internal circulation pipeline; 400. Circulation mechanism; 500. Dry gas sealing mechanism; 600. External gas source unit outlet. Detailed Implementation

[0017] To better understand the above technical solutions, the technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0018] The first aspect of this application provides a gas replenishment device for a supercritical carbon dioxide power generation system, such as... Figure 1 As shown, the supercritical carbon dioxide power generation system includes: an internal circulation pipeline 300, a circulation mechanism 400, and a dry gas sealing mechanism 500. The internal circulation pipeline 300 is connected to both the circulation mechanism 400 and the dry gas sealing mechanism 500. The circulation mechanism 400 includes a compressor. The gas replenishment device includes: a booster pump 100, an external gas pipeline 200, a compressor detection element, a dry gas detection element, and a control unit. The booster pump 100 is located in the internal circulation pipeline 300, and the output end of the external gas pipeline 200 is connected to... The internal circulation pipeline 300 is connected, and the compressed air detection device is located inside the compressor. The compressed air detection device is used to detect the compressor pressure inside the compressor. The dry gas detection device is located in the dry gas sealing mechanism 500. The dry gas detection device is used to detect the dry gas sealing data inside the dry gas sealing mechanism 500. The control unit is used to confirm the gas replenishment mode of the gas replenishment device based on the dry gas sealing data, and based on the gas replenishment mode and the compressor pressure, control the booster pump 100 and / or the external gas pipeline 200 to replenish gas to the internal circulation pipeline 300.

[0019] In this embodiment, the supercritical carbon dioxide power generation system can be a 15MW unit. The internal circulation pipeline 300 is used to input carbon dioxide working fluid into the circulation mechanism 400 and the dry gas sealing mechanism 500. The internal circulation pipeline 300 is equipped with a booster pump 100 for increasing the working fluid pressure, and an external gas pipeline 200 for inputting external gas. The output end of the external gas pipeline 200 is located upstream of the booster pump 100. The external gas pipeline 200 provides clean, dry, inert gas to the supercritical carbon dioxide power generation system based on an independent backup gas source. The gas replenishment device is divided into two injection paths: the internal circulation pipeline 300 and the external gas pipeline 200.

[0020] The detection unit monitors the gas circulation data of key nodes in the circulation mechanism 400 and the dry gas sealing mechanism 500 in real time, and collects injection and replenishment gas data. This provides accurate data support for the control unit's logical judgment and command output, ensuring that the injection and replenishment gas flow matches the dry gas sealing requirements. The detection unit includes a pressure detection element located inside the compressor and a dry gas detection element located in the dry gas sealing mechanism 500 to collect dry gas sealing data. The pressure detection element can be a pressure sensor, and the dry gas detection element can be a pressure sensor or a flow sensor. The dry gas sealing data can be dry gas pressure or dry gas flow. For example, the pressure sensor is a PT1000 pressure transmitter with a measurement accuracy of ±0.1MPa and an output signal of 4mA to 20mA. The control unit receives the detection data from the detection unit and performs frequency conversion control and start / stop control on the booster pump 100.

[0021] After confirming that the supercritical carbon dioxide power generation system has entered the gas replenishment state, the control unit confirms the gas replenishment mode of the gas replenishment device based on the dry gas sealing data of the dry gas sealing mechanism 500. Based on the gas replenishment mode, the control unit confirms the gas injection path, i.e., whether the gas replenishment device replenishes gas through the internal circulation pipeline 300 or the external gas pipeline 200. Based on the compressor pressure, the control unit confirms whether to activate the booster pump 100 for pressurization when replenishing gas through the external gas pipeline 200.

[0022] By coordinating the booster pump 100, detection unit, and control unit, an integrated and intelligent gas replenishment system is constructed to achieve automatic gas replenishment control of the supercritical carbon dioxide power generation system. Based on dry gas sealing data and compressor pressure, the control unit selects the injection path and activates the booster pump 100, combining internal circulation gas replenishment with external gas replenishment. This precise control of the gas replenishment method makes it more flexible and accurate, enabling on-demand gas replenishment and avoiding over- or under-replenishment. It addresses the gas replenishment needs under both conventional and special operating conditions, ensuring pressure stability and operational safety of the internal circulation pipeline 300 and the dry gas sealing mechanism 500 of the supercritical carbon dioxide power generation system.

[0023] In some embodiments provided in this application, the control unit is further configured to: activate the booster pump 100 to replenish gas through the internal circulation pipeline 300 when the gas replenishment device is in normal mode; and activate the external gas pipeline 200 and determine whether the compressor pressure is less than or equal to the boosting threshold when the gas replenishment device is in emergency mode. The control unit is also configured to: activate the booster pump 100 when the compressor pressure is less than the boosting threshold; and control the external gas pipeline 200 to input external gas into the internal circulation pipeline 300 when the compressor pressure is greater than the boosting threshold.

[0024] In this embodiment, the gas replenishment mode includes a normal mode and an emergency mode. When the control unit confirms that the gas replenishment device is operating in normal mode, it indicates that the gas shortage is relatively small. The control unit then activates the booster pump 100 to increase the internal circulation delivery pressure, replenishing gas through the internal circulation pipeline 300. When the control unit confirms that the gas replenishment device is operating in emergency mode, it indicates that the gas shortage is relatively large, and the gas volume in the internal circulation pipeline 300 alone is insufficient to meet the replenishment requirements. The control unit then activates the external gas pipeline 200, adding external gas to the internal circulation mechanism 400 and the dry gas sealing mechanism 500 to improve the replenishment effect and meet the system pressure requirements and the flow rate requirements of the dry gas sealing mechanism 500.

[0025] When the control unit uses external gas for replenishment, it first checks the compressor pressure. If the compressor pressure is less than or equal to the booster threshold, it indicates that the amount of gas in the compressor is too low, resulting in a severe gas shortage. The control unit then activates the booster pump 100 to increase the input rate of the external gas and improve the replenishment efficiency. If the compressor pressure is greater than the booster threshold, it indicates that there is a certain gas shortage in the compressor. In this case, the control unit does not need to activate the booster pump 100; instead, it directly inputs the external gas from the external gas pipeline 200 into the internal circulation pipeline 300 for replenishment, thereby reasonably reducing the energy consumption required for the replenishment operation.

[0026] The control unit defines the gas replenishment execution strategy under different conditions and adopts differentiated gas replenishment strategies for different modes. In particular, in emergency mode, it combines the dual-condition control logic of compressor pressure threshold to avoid the limitations of a single gas replenishment method, improve the targeting and efficiency of gas replenishment, prevent the booster pump from starting ineffectively, reduce unnecessary energy consumption, and ensure the stable operation of the supercritical carbon dioxide power generation system.

[0027] In some embodiments provided in this application, the circulation mechanism 400 further includes a turbine, which includes a front bearing and a rear bearing; the compressor includes a second-stage impeller and a third-stage impeller; the dry gas sealing mechanism 500 includes a front bearing seal, a rear bearing seal, a second-stage seal, and a third-stage seal. Dry gas detection elements are respectively disposed on the front bearing seal, the rear bearing seal, the second-stage seal, and the third-stage seal.

[0028] In this embodiment, the front bearing seal and the rear bearing seal are used to provide dry gas seals for the front and rear bearings of the turbine, respectively. The compressor includes a coaxially arranged first-stage impeller, a second-stage impeller, and a third-stage impeller. The second-stage and third-stage impellers are connected by a connecting pipe. The second-stage and third-stage impellers are respectively equipped with second-stage and third-stage seals to provide dry gas seals for the working fluid inside the compressor. The dry gas seal data includes dry gas seal data at the positions of the front bearing seal, the rear bearing seal, the second-stage seal, and the third-stage seal. When the dry gas seal data at any of the above seal positions is too low, it indicates that an emergency has occurred in the power generation system. Emergency situations include unplanned shutdown, rapid decrease in turbine speed, and failure of the dry gas seal system booster pump to respond in time. The control unit opens the external gas pipeline 200 to replenish gas.

[0029] By precisely positioning dry gas detection components at key sealing locations such as the front and rear bearing seals of the turbine, and the secondary and tertiary seals of the compressor, full coverage monitoring of core sealing components can be achieved, avoiding the problem of local seal failures going undetected and improving the comprehensiveness and accuracy of seal status monitoring.

[0030] In some embodiments provided in this application, such as Figure 1 As shown, the external gas pipeline 200 includes: a gas supply pipeline 210 and a pressure pump 220. The output end of the gas supply pipeline 210 is connected to the internal circulation pipeline 300. The gas supply pipeline 210 is used to input external gas, and the pressure pump 220 is located in the gas supply pipeline 210.

[0031] In this embodiment, the input end of the gas replenishment pipeline 210 is connected to the outlet 600 of the external gas source unit. The gas replenishment pipeline 210 is equipped with a pressure pump 220 to enhance the delivery pressure of the external gas. The pressure pump 220 solves the technical problem of mismatch between the external gas source pressure and the working pressure of the dry gas seal by stabilizing the gas replenishment, ensuring that the external gas can be quickly and stably input into the internal circulation pipeline 300 to replenish the circulation mechanism 400 and the dry gas sealing mechanism 500, thereby improving the gas replenishment response speed under emergency conditions. After the external gas source passes through the high-precision filter element and enters the gas replenishment pipeline 210, it is pressurized by the pressure pump 220 and enters the circulation mechanism 400 and the dry gas sealing mechanism 500 through the start-up gas inlet pipeline.

[0032] For example, the pressure of the gas supply line 210 is greater than 22 MPa to prevent high-pressure gas leakage. The pressure pump 220 can be a variable frequency plunger pump to achieve precise pressure regulation. The gas supply line 210 is equipped with a flow regulating valve, which is an electric ball valve with an adjustment accuracy of ±1%, which can accurately control the gas supply flow rate to meet the requirements of high-pressure working conditions.

[0033] In some embodiments provided in this application, the control unit is also used to compare the compressor pressure with the make-up gas pressure, and to confirm that the supercritical carbon dioxide power generation system is in the make-up gas state when the compressor pressure is less than the make-up gas pressure.

[0034] In this embodiment, the control unit determines whether the compressor pressure is greater than the make-up gas pressure. When the compressor pressure is less than the make-up gas pressure, it indicates that the amount of gas in the compressor is less than the amount required for normal operation. The control unit confirms that the supercritical carbon dioxide power generation system is in make-up gas mode and activates the make-up gas device to replenish gas. When the compressor pressure is greater than the make-up gas pressure, it indicates that the amount of gas in the compressor is sufficient for normal operation. The control unit confirms that the supercritical carbon dioxide power generation system is in non-make-up gas mode. By establishing a comparison and determination mechanism between the compressor pressure and the make-up gas pressure, the control unit accurately identifies whether the system needs make-up gas, avoids blind make-up gas, reduces energy waste and ineffective equipment operation, and ensures that the system pressure is maintained within a reasonable range.

[0035] In some embodiments provided in this application, the control unit includes a touch screen, which is used to determine control parameters and display operating information.

[0036] In this embodiment, the touchscreen can be 10 to 12 inches. The touchscreen is used for parameter setting and displaying operating information, including operating status and fault information. The control unit is equipped with a touchscreen, supporting visual setting of control parameters and real-time display of operating information, improving the human-machine interface and operability of the device, and facilitating real-time monitoring and adjustment of the gas replenishment process by operators.

[0037] For example, the control unit can be a PLC (Programmable Logic Controller). The control unit includes a storage module and integrates parameter setting, logic judgment, pressure regulation, alarm, and data storage functions. The control unit includes an uninterruptible power supply (UPS) with a runtime of more than 2 hours to ensure that the control unit can continue to operate stably during unplanned shutdowns.

[0038] A second aspect of this application provides a control method for a gas supply device in a supercritical carbon dioxide power generation system. This control method is used in any of the gas supply devices provided in the above embodiments, and includes: Step 1: Confirm that the supercritical carbon dioxide power generation system has entered the gas replenishment state; Step 2: Based on the dry gas sealing data of the dry gas sealing mechanism, confirm the gas replenishment mode of the gas replenishment device; Step 3: With the air replenishment device operating in normal mode, turn on the booster pump to replenish air through the internal circulation pipeline; Step 4: With the gas supply device in emergency mode, open the external gas pipeline; When the gas supply device is in emergency mode, step 4 of opening the external gas pipeline specifically includes: Step 41: Determine if the compressor pressure is lower than the boost threshold; Step 42: When the compressor pressure is less than or equal to the booster threshold, turn on the booster pump; Step 43: When the compressor pressure is greater than the boosting threshold, control the external gas pipeline to input external gas into the internal circulation pipeline.

[0039] In this embodiment, after the control unit confirms that the supercritical carbon dioxide power generation system has entered the gas replenishment state, it confirms the gas replenishment mode of the gas replenishment device based on the dry gas sealing data of the dry gas sealing mechanism. The control unit then confirms the gas injection path based on the gas replenishment mode, i.e., whether the gas replenishment device replenishes gas through an internal circulation pipeline or an external gas pipeline. Based on the compressor pressure, the control unit confirms whether to activate the booster pump for pressurization when replenishing gas through an external gas pipeline.

[0040] The gas replenishment mode includes a normal mode and an emergency mode. If the control unit confirms that the gas replenishment device is operating in normal mode, it indicates a relatively small gas shortage. The control unit activates the booster pump to increase the internal circulation delivery pressure, replenishing gas through the internal circulation pipeline until the compressor pressure exceeds the replenishment pressure. If the control unit confirms that the gas replenishment device is operating in emergency mode, it indicates a relatively large gas shortage, and the gas volume in the circulation pipeline alone is insufficient to meet the replenishment needs. The control unit activates the external gas pipeline, adding external gas to the internal circulation mechanism and the dry gas sealing mechanism to improve the replenishment effect and meet the system pressure requirements and the flow requirements of the dry gas sealing mechanism.

[0041] When the control unit uses external gas for replenishment, it first checks the compressor pressure. If the compressor pressure is less than or equal to the booster threshold, it indicates that the amount of gas in the compressor is too low, resulting in a severe gas shortage. The control unit then activates the booster pump to increase the input rate of the external gas and improve the replenishment efficiency. If the compressor pressure is greater than the booster threshold, it indicates that there is a certain gas shortage in the compressor. In this case, the control unit does not need to activate the booster pump and directly inputs the external gas from the external gas pipeline into the internal circulation pipeline for replenishment, thereby reasonably reducing the energy consumption required for the replenishment operation.

[0042] The control unit defines the gas replenishment execution strategy under different conditions, employing differentiated replenishment strategies for different modes. Especially in emergency mode, it combines dual-condition control logic based on compressor pressure thresholds to avoid the limitations of a single replenishment method, improving the targeting and efficiency of replenishment, preventing ineffective booster pump startup, reducing unnecessary energy consumption, and ensuring stable operation of the supercritical carbon dioxide power generation system. Through the collaborative work of the booster pump, detection unit, and control unit, an integrated and intelligent gas replenishment system is constructed, achieving automatic gas injection and replenishment control of the supercritical carbon dioxide power generation system. Based on dry gas seal data and compressor pressure, the control unit selects the injection path and coordinates with the booster pump startup, combining internal circulation replenishment with external gas replenishment. This precise control of the replenishment method makes it more flexible and accurate, achieving on-demand replenishment and avoiding over- or under-replenishment. It addresses the replenishment needs of various conditions, both conventional and special, ensuring pressure stability and operational safety of the supercritical carbon dioxide power generation system's internal circulation pipeline and dry gas sealing mechanism.

[0043] In some embodiments provided in this application, step 2, which confirms the gas replenishment mode of the gas replenishment device based on the dry gas sealing data of the dry gas sealing mechanism, specifically includes: Step 21: Compare the dry gas sealing data of any one of the front bearing seal, rear bearing seal, secondary seal, and tertiary seal with the sealing threshold. Step 22: If the dry gas seal data is less than or equal to the seal threshold, confirm that the gas replenishment mode is emergency mode; Step 23: If the dry gas seal data is greater than the seal threshold, confirm that the gas replenishment mode is normal mode.

[0044] In this embodiment, the dry gas seal data includes dry gas seal data at the front bearing seal, rear bearing seal, secondary seal, and tertiary seal positions. When the dry gas seal data is less than or equal to its respective sealing threshold, it indicates a serious leak in the dry gas sealing mechanism, and the power generation system is in an emergency. Emergency situations include unplanned shutdowns, rapid decreases in turbine speed, and failure of the dry gas sealing system booster pump to respond promptly. The control unit opens the external gas pipeline to replenish gas and improve replenishment efficiency. Simultaneously, the control unit records the trigger time and initial parameters and stores them in the data storage module. When the dry gas seal data is greater than its respective sealing threshold, it indicates a minor leak in the dry gas sealing mechanism, confirming the replenishment mode as normal mode, and the control unit replenishes gas through the internal circulation pipeline.

[0045] By establishing quantified and mutually exclusive criteria for determining the gas replenishment mode, and comparing dry gas sealing data with thresholds, the system can accurately distinguish between normal and emergency operating conditions, ensuring that the activation conditions for different modes are clear and unique. This avoids invalid determinations and ensures that the emergency mode is activated only under risky conditions where the sealing data fails to meet the standards, while the normal operating condition uses a more energy-efficient internal circulation gas replenishment method, balancing system safety and energy utilization efficiency.

[0046] In some embodiments provided in this application, step 1, confirming that the supercritical carbon dioxide power generation system has entered the gas replenishment state, specifically includes: Step 11: Compare the compressor pressure with the make-up air pressure; Step 12: When the compressor pressure is lower than the make-up gas pressure, confirm that the supercritical carbon dioxide power generation system is in the make-up gas state; Step 13: When the compressor pressure is greater than the make-up gas pressure, confirm that the supercritical carbon dioxide power generation system is in a non-make-up gas state.

[0047] In this embodiment, the control unit determines whether the compressor pressure is greater than the make-up gas pressure. When the compressor pressure is less than the make-up gas pressure, it indicates that the amount of gas in the compressor is less than the amount required for normal operation. The control unit confirms that the supercritical carbon dioxide power generation system is in make-up gas mode and activates the make-up gas device to replenish gas. When the compressor pressure is greater than the make-up gas pressure, it indicates that the amount of gas in the compressor is sufficient for normal operation. The control unit confirms that the supercritical carbon dioxide power generation system is in non-make-up gas mode. By establishing a comparison and determination mechanism between the compressor pressure and the make-up gas pressure, the control unit accurately identifies whether the system needs make-up gas, avoids blind make-up gas, reduces energy waste and ineffective equipment operation, and ensures that the system pressure is maintained within a reasonable range.

[0048] For example, the compressor pressure can be the internal pressure of the compressor or the inlet pressure, and the make-up air pressure can be 8 MPa.

[0049] In some embodiments provided in this application, after step 4 of opening the external gas pipeline when the gas supply device is in emergency mode, the method further includes: Step 5: Compare the dry gas seal data with the seal compliance value; Step 6: If the dry gas seal data exceeds the seal compliance value, complete the gas replenishment.

[0050] In this embodiment, a comparison step between dry gas sealing data and sealing compliance value is added after the gas replenishment step to establish a verification mechanism for the gas replenishment effect, ensuring that the sealing performance meets safety standards after gas replenishment, avoiding the risk of sealing failure due to substandard gas replenishment, and further improving the operational safety of the system.

[0051] In a specific embodiment, such as Figure 2As shown, the control unit determines whether the compressor pressure is greater than the make-up gas pressure. When the compressor pressure is greater than the make-up gas pressure, the power generation system is in a non-make-up gas state and operates normally. When the compressor pressure is less than the make-up gas pressure, the power generation system is in a make-up gas state, and the control unit confirms the make-up gas mode based on the dry gas seal data. When the make-up gas device is in normal mode, the control unit starts the booster pump and uses the circulation pipeline to make up gas. The control unit determines whether the compressor pressure exceeds the make-up gas pressure. When the compressor pressure exceeds the make-up gas pressure, the make-up gas is completed. When the make-up gas device is in emergency mode, the control unit opens the external gas pipeline and determines whether the compressor pressure is less than the booster threshold. When the compressor pressure is less than the booster threshold, the control unit starts the booster pump. When the compressor pressure is greater than the booster threshold, the control unit directly makes up gas using external gas. After making up gas using external gas, the control unit determines whether the dry gas seal data exceeds the seal compliance value. When the dry gas seal data is less than the seal compliance value, the make-up gas is completed.

[0052] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The above are merely some embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gas replenishment device for a supercritical carbon dioxide power generation system, characterized in that, The supercritical carbon dioxide power generation system includes: an internal circulation pipeline, a circulation mechanism, and a dry gas sealing mechanism. The internal circulation pipeline is connected to both the circulation mechanism and the dry gas sealing mechanism. The circulation mechanism includes a compressor. The gas replenishment device includes: A booster pump is installed in the internal circulation pipeline; An external gas pipeline, the output end of which is connected to the internal circulation pipeline; A pressure detection device is disposed inside the compressor, and the pressure detection device is used to detect the compressor pressure inside the compressor; A dry gas detection element is disposed on the dry gas sealing mechanism, and the dry gas detection element is used to detect the dry gas sealing data in the dry gas sealing mechanism. The control unit is used to confirm the gas replenishment mode of the gas replenishment device based on the dry gas sealing data, and to control the booster pump and / or the external gas pipeline to replenish gas to the internal circulation pipeline based on the gas replenishment mode and the compressor pressure.

2. The gas supply device for the supercritical carbon dioxide power generation system according to claim 1, characterized in that, The control unit is also used to activate the booster pump to replenish gas through the internal circulation pipeline when the gas replenishment device is in normal mode; and to activate the external gas pipeline and determine whether the compressor pressure is less than the booster threshold when the gas replenishment device is in emergency mode. The control unit is also configured to activate the booster pump when the compressor pressure is less than the booster threshold, and to control the external gas pipeline to input external gas into the internal circulation pipeline when the compressor pressure is greater than the booster threshold.

3. The gas supply device for the supercritical carbon dioxide power generation system according to claim 1 or 2, characterized in that, The circulation mechanism further includes a turbine, which includes a front bearing and a rear bearing; the compressor includes a second-stage impeller and a third-stage impeller; the dry gas sealing mechanism includes a front bearing seal, a rear bearing seal, a second-stage seal, and a third-stage seal. The dry gas detection components are respectively installed on the front bearing seal, the rear bearing seal, the secondary seal, and the tertiary seal.

4. The gas supply device for a supercritical carbon dioxide power generation system according to claim 1 or 2, characterized in that, The external gas pipeline includes: A gas supply line, the output end of which is connected to the internal circulation line, is used to input external gas; A pressure pump is installed in the aforementioned air supply line.

5. The gas supply device for a supercritical carbon dioxide power generation system according to claim 1 or 2, characterized in that, The control unit is also used to compare the compressor pressure with the make-up gas pressure, and to confirm that the supercritical carbon dioxide power generation system is in a make-up gas state when the compressor pressure is less than the make-up gas pressure.

6. The gas supply device for a supercritical carbon dioxide power generation system according to claim 1 or 2, characterized in that, The control unit includes a touch screen, which is used to determine control parameters and display operating information.

7. A control method for a gas supply device in a supercritical carbon dioxide power generation system, characterized in that, The control method for the gas replenishment device according to any one of claims 1 to 6 includes: The supercritical carbon dioxide power generation system has been confirmed to have entered the gas replenishment state. Based on the dry gas sealing data of the dry gas sealing mechanism, the gas replenishment mode of the gas replenishment device is confirmed. When the air replenishment device is operating in normal mode, the booster pump is turned on to replenish air through the internal circulation pipeline; When the gas supply device is in emergency mode, the external gas pipeline is opened; When the gas supply device is in emergency mode, the steps for opening the external gas pipeline specifically include: Determine if the compressor pressure is lower than the boost threshold; When the compressor pressure is less than or equal to the booster threshold, the booster pump is activated; When the compressor pressure is greater than the boosting threshold, the external gas pipeline is controlled to input external gas into the internal circulation pipeline.

8. The control method for the gas supply device of the supercritical carbon dioxide power generation system according to claim 7, characterized in that, The step of confirming the gas replenishment mode of the gas replenishment device based on the dry gas sealing data of the dry gas sealing mechanism specifically includes: Compare the dry gas sealing data of any one of the front bearing seal, rear bearing seal, secondary seal, and tertiary seal with the sealing threshold. If the dry gas seal data is less than or equal to the seal threshold, the gas replenishment mode is confirmed to be an emergency mode. If the dry gas sealing data is greater than the sealing threshold, the gas replenishment mode is confirmed to be the normal mode.

9. The control method for the gas supply device of the supercritical carbon dioxide power generation system according to claim 7, characterized in that, The steps to confirm that a supercritical carbon dioxide power generation system has entered the gas replenishment state specifically include: Compare the compressor pressure with the make-up air pressure; When the compressor pressure is lower than the make-up gas pressure, it is confirmed that the supercritical carbon dioxide power generation system is in the make-up gas state; If the compressor pressure is greater than the make-up gas pressure, the supercritical carbon dioxide power generation system is confirmed to be in a non-make-up gas state.

10. The control method for the gas supply device of the supercritical carbon dioxide power generation system according to claim 8, characterized in that, After the step of opening the external gas pipeline when the gas supply device is in emergency mode, the method further includes: Compare the dry gas seal data with the seal compliance value; If the dry gas seal data exceeds the seal compliance value, gas replenishment is completed.

Images