A supercritical co2 dry gas sealed closed thermal management system based on a vortex tube

Abstract

The application relates to the field of supercritical CO2 Brayton cycle, and provides a supercritical CO2 dry gas sealed closed heat management system based on a vortex tube, which comprises a vortex chamber connected with a compressor working medium outlet through a vortex tube gas inlet pipeline, hot gas flowing out of a hot end pipe at a higher temperature enters a compressor end sealing cavity through a vortex tube hot end gas outlet pipeline; the compressor end sealing cavity is connected with a compressor medium outlet through a compressor end sealing cavity gas outlet gap, so that working medium flowing in the compressor end sealing cavity flows back to the vortex tube gas inlet pipeline; a vortex tube cold end gas outlet pipeline is connected with a cooling cavity gas inlet hole, so that cold gas flowing out of the cold end pipe at a lower temperature enters the cooling cavity; and the cooling cavity gas outlet hole is connected with the compressor medium outlet, so that working medium flowing in the cooling cavity flows back to the vortex tube gas inlet pipeline. The application has important significance for efficient, low-leakage and stable operation of a supercritical CO2 Brayton cycle power generation turbine unit.

Description

Technical Field

[0001] This application relates to the field of supercritical carbon dioxide Brayton cycle, and in particular to a supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes. Background Technology

[0002] A supercritical CO2 Brayton cycle power generation system is a Brayton cycle system that uses supercritical carbon dioxide as the working fluid. The cycle process is as follows: First, supercritical carbon dioxide is pressurized by a compressor; then, the working fluid is heated at isobaric pressure using a heat exchanger; second, the working fluid enters a turbine, which drives the turbine to do work, and the turbine drives a motor to generate electricity; finally, the working fluid enters a cooler to return to its initial state, and then enters the compressor to form a closed cycle.

[0003] Supercritical CO2 Brayton cycle power generation systems are among the most promising energy conversion systems for the future. To ensure the competitiveness of this energy conversion system, the high efficiency and low leakage operation of the compressor and high-temperature turbine, which are the heart of the system, are crucial. Non-contact dry gas seals have become the main form of shaft end seals for compressors and high-temperature turbines due to their excellent leakage control capabilities under high-parameter operating conditions.

[0004] When a supercritical CO2 turbine is operating, the supercritical CO2 medium drawn from the compressor diffuser outlet is filtered, heated, and pressure-regulated before being introduced into the compressor-end sealing cavity as the medium for the compressor-end dry gas seal. Simultaneously, some gas is drawn back to the compressor diffuser through the compressor impeller clearance (the outlet clearance of the compressor-end sealing cavity). Because the gas drawn from the compressor diffuser outlet passes through various flow resistance elements before entering the compressor-end sealing cavity, a significant temperature drop occurs. Without heating measures, its temperature upon entering the compressor-end sealing cavity would be low. At this low inlet temperature, the supercritical CO2 compressor-end dry gas seal may undergo a phase change during operation, potentially resulting in liquid or even solid CO2 on the sealing surface. This can disrupt the stability of the gas film and increase the risk of leakage. Furthermore, solid dry ice can directly cause frictional wear on the sealing surface, leading to premature seal failure. Therefore, avoiding unfavorable phase transitions (liquid or solid) at the sealing end face of supercritical CO2 is one of the key factors for ensuring stable operation of the dry gas seal at the compressor end. Increasing the inlet temperature within the compressor end sealing cavity is an effective means of controlling this unfavorable phase transition. Currently, the solution is to add a heating device to the inlet pipe of the compressor end sealing cavity to increase the inlet temperature. However, this temperature control method makes the auxiliary system very complex and occupies a large space, limiting its application in space-constrained situations. Furthermore, since the heating device is an energy-consuming component, it reduces the overall operating economy of the unit. For the dry gas seal at the high-temperature turbine end of supercritical CO2, the temperature within the turbine end sealing cavity is high (up to 500℃). At this temperature, the sealing end face will experience significant thermal deformation, and at the same time, supercritical CO2 causes severe corrosion to the sealing components under high-temperature conditions. Currently, the common approach is to reduce the temperature of the medium inside the turbine end sealing cavity by adding heat insulation devices or cooling systems. However, using heat insulation devices increases the overall axial dimension of the turbine unit, and adding a cooling system also requires energy-consuming components such as heat exchangers, thereby reducing the unit's operating economy and increasing its structural complexity. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a closed-loop thermal management system for supercritical CO2 dry gas seals based on vortex tubes. This system is ingeniously designed and economically efficient. By incorporating vortex tubes, it achieves the separation of hot and cold fluids in the high-pressure gas drawn from the supercritical CO2 compressor. The hot fluid is used as the sealing gas for the compressor-end dry gas seal to prevent liquid-phase condensation at the sealing surface, while the cold fluid cools the high-temperature turbine-end sealing cavity to prevent significant thermal deformation and severe corrosion of the sealing components. This application eliminates the need for energy-consuming components such as a medium gas heating device and a cooling system for the turbine-end dry gas seal pair, as well as insulation devices, reducing space requirements and significantly improving the overall operational economy of the unit. This is of great significance for the high-efficiency, low-leakage, and stable operation of supercritical CO2 Brayton cycle power generation turbine units. The technical solution adopted in this application is as follows:

[0006] A closed-loop thermal management system for supercritical CO dry gas based on vortex tubes, comprising:

[0007] A compressor-end sealing assembly includes a compressor-end sealing cavity, a compressor-end dry gas sealing pair, and a compressor-end sealing cavity outlet gap. The compressor-end sealing cavity is arranged around the outer periphery of the compressor-end dry gas sealing pair, and the compressor-end sealing cavity outlet gap is connected to the compressor-end sealing cavity. A turbine-end sealing assembly includes a turbine-end sealing cavity, a turbine-end dry gas sealing pair, and a cooling cavity. The turbine-end sealing cavity is arranged around the outer periphery of the turbine-end dry gas sealing pair, and the cooling cavity is located on the outer periphery of the turbine-end sealing cavity. The cooling cavity has a cooling cavity inlet and a cooling cavity outlet. A vortex tube includes a vortex chamber, a hot-end tube, and a cold-end tube. The hot-end tube and the cold-end tube are respectively connected to both sides of the vortex chamber. A medium temperature and pressure monitoring and control system includes a vortex tube inlet pipe, a vortex tube hot-end outlet pipe, and a vortex tube cold-end outlet pipe.

[0008] The vortex chamber is connected to the compressor diffuser outlet via the vortex tube inlet pipe. High-temperature hot gas flowing out of the hot-end tube enters the compressor end sealing cavity through the vortex tube hot-end outlet pipe. The compressor end sealing cavity is connected to the compressor diffuser via the compressor end sealing cavity outlet gap, allowing the working fluid in the compressor end sealing cavity to flow back to the vortex tube inlet pipe. The vortex tube cold-end outlet pipe is connected to the cooling cavity inlet, allowing lower-temperature cold gas flowing out of the cold-end tube to enter the cooling cavity. The cooling cavity outlet is connected to the compressor diffuser, allowing the working fluid in the cooling cavity to flow back to the vortex tube inlet pipe.

[0009] In some embodiments, the compressor end sealing assembly further includes a compressor end sealing cavity, a compressor end dynamic ring assembly, and a compressor end stationary ring assembly. The compressor end sealing cavity is disposed within the compressor end sealing cavity. The compressor end dynamic ring assembly includes a compressor end dynamic ring, and the compressor end stationary ring assembly includes a compressor end stationary ring. The compressor end dynamic ring and the compressor end stationary ring form the compressor end dry gas sealing pair.

[0010] In some embodiments, the turbine end sealing assembly further includes a turbine end sealing cavity, a turbine end dynamic ring assembly, and a turbine end stationary ring assembly. The turbine end sealing cavity is disposed within the turbine end sealing cavity, and the cooling cavity is opened on the turbine end sealing cavity. The turbine end dynamic ring assembly includes a turbine end dynamic ring, and the turbine end stationary ring assembly includes a turbine end stationary ring. The turbine end dynamic ring and the turbine end stationary ring form the turbine end dry gas sealing pair.

[0011] In some embodiments, the compressor end sealing assembly further includes a compressor wheel back pressure cover, which is disposed between the compressor end sealing cavity and the compressor impeller, and the compressor wheel back pressure cover and the impeller form an air outlet gap of the compressor end sealing cavity.

[0012] In some embodiments, the cooling chamber is provided with baffles.

[0013] In some embodiments, the vortex tube inlet pipe is provided with a first pressure regulating valve, a first temperature sensor and a first pressure sensor; the vortex tube hot end outlet pipe is provided with a second pressure regulating valve, a second temperature sensor and a second pressure sensor; the vortex tube cold end outlet pipe is provided with a third temperature sensor; and a fourth temperature sensor and a third pressure sensor are provided on the communication path between the cooling chamber outlet and the compressor diffuser.

[0014] This application provides a supercritical CO2 dry gas sealed closed-loop thermal management system based on vortex tubes, which has at least one of the following beneficial effects:

[0015] 1. This application provides a supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes. By setting up vortex tubes, the hot and cold fluids of the high-pressure gas drawn from the supercritical CO2 compressor are separated. The hot fluid is used as the sealing gas for the dry gas seal at the compressor end to avoid liquid phase condensation at the sealing end face, while the cold fluid is used to cool the high-temperature turbine end sealing cavity to avoid large thermal deformation at the sealing end face and severe corrosion of the sealing components. This is of great significance for the high-efficiency, low-leakage, and stable operation of supercritical CO2 Brayton cycle power generation turbine units.

[0016] 2. This application provides a closed-loop thermal management system for supercritical CO2 dry gas seals based on vortex tubes. Existing simulation systems for supercritical CO2 turbine shaft-end dry gas seals include heaters to increase the compressor-end inlet temperature and heat exchangers or cooling systems to reduce the turbine-end sealing cavity temperature. This system replaces energy-consuming components such as heaters and heat exchangers in the auxiliary system with vortex tubes that separate hot and cold fluids. This improves system operating efficiency and economy, simplifies the sealing auxiliary system, makes it more compact, and expands its application in space-constrained environments. This application eliminates the need for energy-consuming components such as a medium gas heating device and a cooling system for the turbine-end dry gas seal pair, as well as insulation devices, reducing space requirements and significantly improving the overall operating economy of the unit.

[0017] 3. The supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes provided in this application has a high outlet temperature at the hot end of the vortex tube. Using it as the sealing gas source for the dry gas seal at the compressor end can effectively avoid the problem of liquid phase condensation or even solid dry ice at the dry gas seal end face of the supercritical CO2 medium due to the low outlet temperature. This reduces the failure probability of the dry gas seal pair at the compressor end and improves the operational reliability.

[0018] 4. The supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes provided in this application can increase the flow path of the medium gas in the cooling chamber by setting baffles in the cooling chamber, thereby improving the heat exchange efficiency between the cooling chamber and the turbine end sealing chamber.

[0019] 5. This application provides a supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes. The cold end outlet gas temperature of the vortex tube is low. It is introduced into a cooling chamber with a tortuous flow channel to remove part of the heat in the turbine end sealing chamber, thus acting as a heat exchanger to achieve the cooling effect on the turbine end sealing chamber. The lower turbine end sealing chamber temperature helps to reduce the risk of thermal deformation and high-temperature corrosion failure of the sealing components. Attached Figure Description

[0020] The preferred embodiments will be described below in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of a supercritical CO2 dry gas sealed closed-loop thermal management system based on vortex tubes:

[0021] Figure 1 This is a schematic diagram of the overall structure of the closed-loop thermal management system of this application;

[0022] Figure 2 This is a cross-sectional view of the high-temperature turbine end sealing assembly;

[0023] Figure 3 This is a cross-sectional view of the compressor end sealing assembly;

[0024] Figure 4 This is a schematic diagram of a vortex tube structure.

[0025] Explanation of icon numbers:

[0026] Compressor end sealing assembly 1, impeller locking nut 11, impeller 121, compressor diffuser 122, compressor end sealing cavity 13, compressor impeller back cover 131, sealing cavity inlet 132, compressor end rotating ring assembly 14, compressor end rotating ring 141, compressor end rotating ring seat 142, compressor end rotating ring clamping sleeve 143, compressor end stationary ring assembly 15, compressor end stationary ring 151, compressor end stationary ring push ring 152, compressor end stationary ring spring 153, compressor end spring seat 154, compressor end sealing cavity 16, turbine end sealing assembly 2, high-temperature turbine 21, turbine end sealing cavity 22, cooling cavity 222, baffle 223, cooling cavity inlet 224, cooling cavity outlet 225, turbine end rotating ring assembly 23, turbine end rotating ring 231, turbine end rotating ring seat 232, turbine end rotating ring clamping sleeve 233, turbine end stationary ring Component 24, turbine end stationary ring 241, turbine end elastic element 242, turbine end stationary ring seat 243, turbine end locking nut 25, turbine end sealing cavity 26, vortex tube 3, vortex chamber 31, vortex tube inlet 311, inlet fluid 312, hot end pipe 32, conical hot end valve 321, vortex tube hot end outlet 322, hot gas 323, cold end pipe 33, cold orifice plate 331, vortex tube cold end outlet 332, cold gas 333, medium temperature and pressure monitoring and control system 4, vortex tube inlet pipe 41, first pressure regulating valve 411, first temperature sensor 412, first pressure sensor 413, vortex tube hot end outlet pipe 42, second pressure regulating valve 421, second temperature sensor 422, second pressure sensor 423, vortex tube cold end outlet pipe 43, third temperature sensor 431, fourth temperature sensor 432, third pressure sensor 433. Detailed Implementation

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0028] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0029] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0030] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] refer to Figures 1-4 This application provides a supercritical CO2 dry gas sealed closed thermal management system based on vortex tubes for use in a supercritical CO2 Brayton cycle power generation system, including: compressor end sealing assembly 1, turbine end sealing assembly 2, vortex tube 3 and medium temperature and pressure measurement and control system 4.

[0033] The compressor end sealing assembly 1 includes a compressor end sealing cavity 16, a compressor end dry gas sealing pair, and a compressor end sealing cavity outlet gap. The compressor end sealing cavity 16 is arranged around the outer periphery of the compressor end dry gas sealing pair, and the compressor end sealing cavity outlet gap is connected to the compressor end sealing cavity 16.

[0034] The turbine end sealing assembly 2 includes a turbine end sealing cavity 26, a turbine end dry gas sealing pair and a cooling cavity 222. The turbine end sealing cavity 26 is arranged around the outer periphery of the turbine end dry gas sealing pair. The cooling cavity 222 is arranged on the outer periphery of the turbine end sealing cavity 26. The cooling cavity 222 is provided with a cooling cavity inlet 224 and a cooling cavity outlet 225.

[0035] The vortex tube 3 includes a vortex chamber 31, a hot end tube 32, and a cold end tube 33, with the hot end tube 32 and the cold end tube 33 respectively connected to both sides of the vortex chamber 31; the medium temperature and pressure measurement and control system 4 includes a vortex tube inlet pipe 41, a vortex tube hot end outlet pipe 42, and a vortex tube cold end outlet pipe 43.

[0036] The vortex chamber 31 is connected to the outlet of the compressor diffuser 122 through the vortex tube inlet pipe 41. The hot gas 323 with a higher temperature flows out of the hot end pipe 32 and enters the compressor end sealing cavity 16 through the vortex tube hot end outlet pipe 42. The compressor end sealing cavity 16 is connected to the compressor diffuser 122 through the compressor end sealing cavity outlet gap, so that the working fluid in the compressor end sealing cavity 16 flows back to the vortex tube inlet pipe 41.

[0037] The cold end outlet pipe 43 of the vortex tube is connected to the air inlet 224 of the cooling chamber so that the cold air 333 flowing out of the cold end pipe 33 enters the cooling chamber 222; the air outlet 225 of the cooling chamber is connected to the compressor diffuser 122 so that the working fluid in the cooling chamber 222 flows back to the air inlet pipe 41 of the vortex tube.

[0038] refer to Figure 1 , Figure 3 In one embodiment, the compressor end sealing assembly 1 further includes a compressor end sealing cavity 13, a compressor end dynamic ring assembly 14, and a compressor end stationary ring assembly 15. The compressor end sealing cavity 16 is disposed within the compressor end sealing cavity 13. The compressor end dynamic ring assembly 14 includes a compressor end dynamic ring 141, and the compressor end stationary ring assembly 15 includes a compressor end stationary ring 151. The compressor end dynamic ring 141 and the compressor end stationary ring 151 form the compressor end dry gas sealing pair.

[0039] Specifically, the compressor-end rotating ring assembly 14 includes a compressor-end rotating ring 141, a compressor-end rotating ring seat 142, and a compressor-end rotating ring clamping sleeve 143. The compressor-end stationary ring assembly 15 includes a compressor-end stationary ring 151, a compressor-end stationary ring push ring 152, a compressor-end stationary ring spring 153, and a compressor-end spring seat 154. The compressor-end rotating ring 141 and the compressor-end stationary ring 151 form a compressor-end dry gas sealing pair. The impeller 121, the compressor-end rotating ring seat 142, and the compressor-end rotating ring clamping sleeve 143 are axially fixed to the rotor by the impeller locking nut 11. The compressor-end rotating ring 141 is fixedly installed on the compressor-end rotating ring seat 142 and is axially clamped by the compressor-end rotating ring clamping sleeve 143. The compressor-end stationary ring 151 is floatingly mounted on the compressor-end spring seat 154. A compressor-end stationary ring push ring 152 and a compressor-end stationary ring spring 153 are axially positioned between the compressor-end stationary ring 151 and the compressor-end spring seat 154. The compressor-end stationary ring spring 153 provides auxiliary closing force for the compressor-end stationary ring 151. The compressor-end sealing cavity 13 is provided with a sealing cavity inlet 132. Hot gas 323 flowing from the hot end outlet 322 of the vortex tube enters the compressor-end sealing cavity 16 after passing through the sealing cavity inlet 132. Because the hot gas 323 has a high temperature, when it leaks through the end face of the compressor-end dry gas seal, the medium gas is less likely to condense into liquid phase or even form solid dry ice due to excessively low temperature at the outlet of the sealing end face. This reduces the probability of phase change failure of the compressor-end dry gas seal and improves the reliability and stability of the seal operation.

[0040] refer to Figure 1 , Figure 2 In one embodiment, the turbine end sealing assembly 2 further includes a turbine end sealing cavity 22, a turbine end dynamic ring assembly 23, and a turbine end stationary ring assembly 24. The turbine end sealing cavity is disposed within the turbine end sealing cavity 22, and the cooling cavity 222 is opened on the turbine end sealing cavity 22. The turbine end dynamic ring assembly 23 includes a turbine end dynamic ring 231, and the turbine end stationary ring assembly 24 includes a turbine end stationary ring 241. The turbine end dynamic ring 231 and the turbine end stationary ring 241 form the turbine end dry gas sealing pair.

[0041] Specifically, the turbine end dynamic ring assembly 23 includes a turbine end dynamic ring 231, a turbine end dynamic ring seat 232, and a turbine end dynamic ring clamping sleeve 233. The turbine end stationary ring assembly 24 includes a turbine end stationary ring 241, a turbine end elastic element 242, and a turbine end stationary ring seat 243. The turbine end dynamic ring 231 and the turbine end stationary ring 241 form a turbine end dry gas sealing pair. The high-temperature turbine 21, the turbine end dynamic ring seat 232, and the turbine end dynamic ring clamping sleeve 233 are axially secured to the rotor by the turbine end locking nut 25. The turbine end dynamic ring 231 is fixedly installed on the turbine end dynamic ring seat 232 and is axially clamped by the turbine end dynamic ring clamping sleeve 233. The turbine end stationary ring 241 is floatingly installed on the turbine end stationary ring seat 243. The turbine end elastic element 242 is used to provide auxiliary closing force for the turbine end stationary ring 241. The turbine end elastic element 242 is preferably made of metal bellows to adapt to the high-temperature environment. A cooling chamber 222 is provided on the turbine end sealing cavity 22. The cooling chamber 222 is not connected to the turbine end sealing cavity 26. Multiple staggered baffles 223 are used in the cooling chamber 222 to form a tortuous flow channel to enhance the heat exchange effect. The cooling chamber 222 is connected to the cold end outlet pipe 43 of the vortex tube through the cooling chamber inlet 224 and the compressor diffuser 122 through the cooling chamber outlet 225. The cool air 333 with a lower temperature flows out from the cold end outlet 332 of the vortex tube and enters the cooling chamber 222 through the cooling chamber inlet 224. It flows along the tortuous flow channel formed by the baffles 223 towards the cooling chamber outlet 225. During the flow, it continuously absorbs the heat discharged from the high temperature turbine end sealing cavity 26, so that the temperature of the fluid gradually increases. At the same time, the ambient temperature in the turbine end sealing cavity 26 decreases, which improves the operating environment of the turbine end dry gas seal and reduces the thermal deformation and high temperature corrosion intensity of the sealing components.

[0042] refer to Figure 1 , Figure 3 In one embodiment, the compressor end sealing assembly 1 further includes a compressor wheel back pressure cover 131, which is disposed between the compressor end sealing cavity 16 and the compressor impeller 121, and forms an air outlet gap of the compressor end sealing cavity between the compressor wheel back pressure cover 131 and the impeller 121.

[0043] refer to Figure 4It is understood that the construction of the vortex tube 3 is existing technology. Specifically, the vortex tube 3 consists of a vortex chamber 31, a hot-end tube 32, and a cold-end tube 33. The intake fluid 312 drawn from the compressor diffuser 122 enters the vortex chamber 31 tangentially through the vortex tube inlet 311 and generates a vortex. The fluid generating the vortex enters the hot-end tube 32 and flows spirally along the inner wall towards the hot-end outlet 322 of the vortex tube. During the flow, on the one hand, the fluid heats up due to the viscous friction between the fluid and the tube wall, and on the other hand, the energy of the inner fluid of the hot-end tube 32 gradually transfers to the outside, the temperature of the outer fluid rises, and it becomes hot gas 323 with a higher temperature and enters the hot-end outlet pipe 42 of the vortex tube. The fluid in the hot-end tube 32 becomes an inner layer fluid after encountering the conical hot-end valve 321 inside the vortex tube 3 and gradually flows towards the cold-end outlet 332 of the vortex tube. During the flow, it cools down due to heat transfer to the outer layer fluid. At the same time, the temperature is further reduced when passing through the cold orifice plate 331, becoming cold air 333 at a lower temperature and entering the cold-end outlet pipe 43 of the vortex tube. The vortex tube 3 is a non-energy-consuming device. Through the ingenious design of the internal vortex chamber 31, cold-end tube 33 and hot-end tube 32, it achieves significant cooling of the cold-end fluid and significant heating of the hot-end fluid. Compared with the heaters, heat exchangers and other equipment in the previous dry gas seal auxiliary system, it has advantages such as good operating economy and simple and compact structure.

[0044] refer to Figure 1 In one embodiment, the vortex tube inlet pipe 41 is provided with a first pressure regulating valve 411, a first temperature sensor 412 and a first pressure sensor 413; the vortex tube hot end outlet pipe 42 is provided with a second pressure regulating valve 421, a second temperature sensor 422 and a second pressure sensor 423; the vortex tube cold end outlet pipe 43 is provided with a third temperature sensor 431; and a fourth temperature sensor 432 and a third pressure sensor 433 are provided on the communication path between the cooling chamber outlet 225 and the compressor diffuser 122.

[0045] Specifically, the first temperature sensor 412 and the first pressure sensor 413 are used to monitor whether the temperature and pressure of the vortex tube inlet pipe 41 are normal. If they are not normal, the first pressure regulating valve 411 needs to be adjusted. The second temperature sensor 422 and the second pressure sensor 423 are used to monitor the pressure and temperature of the vortex tube hot end outlet pipe 42, ensuring that the temperature of the vortex tube hot end outlet pipe 42 is far away from the critical temperature of CO2, and adjusting the second pressure regulating valve 421 to make the pressure of the vortex tube hot end outlet pipe 42 close to the pressure of the cooling chamber outlet 225. The third temperature sensor 431 is used to monitor the temperature of the cold fluid near the vortex tube cold end outlet 332, preventing the cold fluid from undergoing a phase change due to excessively low temperature.

[0046] It is worth noting that the vortex tube 3 is the core component of the entire closed-loop thermal management system. The medium gas from the outlet of the compressor diffuser 122 enters the vortex chamber 31 of the vortex tube 3 after passing through the vortex tube inlet pipe 41. It is heated to become hot gas 323 in the hot end pipe 32 and cooled to become cold gas 333 in the cold end pipe 33. The hot gas 323 enters the compressor end sealing cavity 16 after passing through the vortex tube hot end outlet pipe 42. Part of the fluid leaks from the gap between the end faces of the compressor end moving ring 141 and the compressor end stationary ring 151, while the other part... Part of the fluid flows back to the compressor diffuser 122 through the gap between the compressor impeller back cover 131 and the impeller 121 to form the first closed loop. The cold gas 333 enters the cooling chamber 222 on the turbine end sealing cavity 22 after passing through the cold end outlet pipe 43 of the vortex tube. As it flows through the tortuous flow channel of the cooling chamber 222, it gradually carries away some of the heat from the turbine end sealing cavity 26, thus cooling the internal environment. The gas flowing out of the cooling chamber 222 also flows back to the compressor diffuser 122 through the gas pipe to form the second closed loop. Through the rational design of the internal structure of the vortex tube 3, the hot end outlet temperature and the cold end outlet temperature can be controlled within a certain range. Through the tortuous flow channel design within the cooling chamber 222, the temperature rise of the cold end gas after passing through the cooling chamber 222 can be controlled, and the outlet temperature of the cooling chamber 222 can be made basically consistent with the mainstream temperature within the compressor diffuser 122. Pressure regulating valves and pressure sensors for gas pressure regulation and monitoring, as well as temperature sensors for temperature monitoring, are arranged on the vortex tube inlet pipe 41, the vortex tube cold end outlet pipe 43, and the vortex tube hot end outlet pipe 42, so as to realize real-time online regulation and monitoring of the closed thermal management system.

[0047] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A supercritical CO2 dry gas sealed closed-loop thermal management system based on a vortex tube, characterized in that, Comprise: A compressor end seal assembly (1) comprising a compressor end seal cavity (16), a compressor end dry gas seal pair and a compressor end seal cavity gas outlet gap, the compressor end seal cavity (16) is arranged around the outer periphery of the compressor end dry gas seal pair, the compressor end seal cavity gas outlet gap is communicated with the compressor end seal cavity (16); A turbine end seal assembly (2) comprising a turbine end seal cavity (26), a turbine end dry gas seal pair and a cooling cavity (222), the turbine end seal cavity (26) is arranged around the outer periphery of the turbine end dry gas seal pair, the cooling cavity (222) is arranged outside the outer periphery of the turbine end seal cavity (26), the cooling cavity (222) is provided with a cooling cavity inlet hole (224) and a cooling cavity outlet hole (225); A vortex tube (3) comprising a vortex chamber (31), a hot end tube (32) and a cold end tube (33), the hot end tube (32) and the cold end tube (33) are respectively communicated on both sides of the vortex chamber (31); A medium temperature and pressure measurement and control system (4) comprising a vortex tube inlet pipeline (41), a vortex tube hot end outlet pipeline (42) and a vortex tube cold end outlet pipeline (43); The vortex chamber (31) is communicated with the outlet of the compressor diffuser (122) through the vortex tube inlet pipeline (41), the hot gas (323) flowing out of the hot end tube (32) enters the compressor end seal cavity (16) through the vortex tube hot end outlet pipeline (42); the compressor end seal cavity (16) is communicated with the compressor diffuser (122) through the compressor end seal cavity gas outlet gap, so that the working medium flowing in the compressor end seal cavity (16) flows back to the vortex tube inlet pipeline (41); The vortex tube cold end outlet pipeline (43) is communicated with the cooling cavity inlet hole (224), so that the cold gas (333) flowing out of the cold end tube (33) enters the cooling cavity (222); the cooling cavity outlet hole (225) is communicated with the compressor diffuser (122), so that the working medium flowing in the cooling cavity (222) flows back to the vortex tube inlet pipeline (41).

2. A supercritical CO2 dry gas sealed closed-loop thermal management system based on a vortex tube according to claim 1, characterized in that, The compressor end seal assembly (1) further comprises a compressor end seal cavity body (13), a compressor end dynamic ring assembly (14) and a compressor end static ring assembly (15), the compressor end seal cavity (16) is arranged in the compressor end seal cavity body (13), the compressor end dynamic ring assembly (14) comprises a compressor end dynamic ring (141), the compressor end static ring assembly (15) comprises a compressor end static ring (151), the compressor end dynamic ring (141) and the compressor end static ring (151) constitute the compressor end dry gas seal pair.

3. A supercritical CO2 dry gas sealed closed loop thermal management system based on a vortex tube according to claim 2, wherein, The turbine end sealing assembly (2) further comprises a turbine end sealing cavity (22), a turbine end dynamic ring assembly (23) and a turbine end static ring assembly (24), the turbine end sealing cavity is arranged in the turbine end sealing cavity (22), the cooling cavity (222) is arranged on the turbine end sealing cavity (22), the turbine end dynamic ring assembly (23) comprises a turbine end dynamic ring (231), the turbine end static ring assembly (24) comprises a turbine end static ring (241), and the turbine end dynamic ring (231) and the turbine end static ring (241) constitute the turbine end dry gas seal pair.

4. A supercritical CO2 dry gas sealed closed loop thermal management system based on a vortex tube according to claim 3, wherein, The compressor end sealing assembly (1) further comprises a compressor wheel back pressure cover (131), the compressor wheel back pressure cover (131) is arranged between the compressor end sealing cavity (16) and an impeller (121) of the compressor, and the compressor wheel back pressure cover (131) and the impeller (121) form the compressor end sealing cavity gas outlet gap.

5. A supercritical CO2 dry gas sealed closed loop thermal management system based on a vortex tube according to any one of claims 1-4, characterized in that, The cooling cavity (222) is provided with a baffle (223).

6. A supercritical CO2 dry gas sealed closed loop thermal management system based on a vortex tube according to claim 5, wherein, The vortex tube inlet pipeline (41) is provided with a first pressure regulating valve (411), a first temperature sensor (412) and a first pressure sensor (413), the vortex tube hot end outlet pipeline (42) is provided with a second pressure regulating valve (421), a second temperature sensor (422) and a second pressure sensor (423), the vortex tube cold end outlet pipeline (43) is provided with a third temperature sensor (431), and the communication path between the cooling cavity gas outlet hole (225) and the compressor diffuser (122) is provided with a fourth temperature sensor (432) and a third pressure sensor (433).

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