A nano-aerosol closed cooling cycle system for a gas turbine

Abstract

The present invention discloses a closed cooling cycle system for a gas turbine with nano-aerosol. The air sucked from the compressor for cooling the combustion chamber and the turbine first enters the nano-aerosol generator, atomizes the nanofluid from the nano-aerosol recovery and nanofluid preparation device, forms a stable and uniform nano-aerosol, and then enters the internal cooling channels of the combustion chamber and the turbine. After cooling, it flows back to the nano-aerosol recovery and nanofluid preparation device to be remade into nanofluid. In the present invention, nano-particles are added to the cooling air of the gas turbine to form nano-aerosol, which will not block or wear the internal cooling channels. The nano-particles enhance heat transfer by changing the thermal properties of the air and strengthening turbulent flow, and at the same time, phase change occurs, and the latent heat of phase change is used to further enhance heat transfer, so as to efficiently cool and protect the combustion chamber and the turbine.

Description

Technical Field

[0001] The present invention belongs to the technical field of heavy-duty gas turbines, and particularly relates to a closed cooling cycle system for nano-aerosol of a gas turbine. Background Art

[0002] The gas turbine cooling technology is the core technology for the development of advanced heavy-duty gas turbines. With the progress of heavy-duty gas turbine technology, the gas turbine combustion chamber and turbine are facing severe challenges of higher gas temperature, more complex gas thermal environment, and more diverse engineering structure characteristics, which bring huge technical problems to the gas turbine cooling technology. After decades of development, the gas turbine cooling technology has developed efficient internal cooling structures such as serpentine channels, ribbed channels, impingement cooling, and swirl cooling, as well as external cooling methods such as film cooling and transpiration cooling. However, up to now, the existing cooling technology using air as the cooling medium has been very mature, and the cooling potential that can be tapped has become very limited. In the cooling of the combustion chamber and turbine components that bear high heat loads, in addition to changing the cooling structure and layout targeted and increasing the amount of cold air used appropriately, there are no more and better technical means to further improve the cooling capacity of the existing air cooling technology. If facing more advanced heavy-duty gas turbines in the future, the combustion chamber and turbine will bear the heat load of ultra-high heat flux density, and the problem of the increasingly exhausted cooling potential of the existing air cooling technology will become very prominent, which will seriously restrict the research and development of a new generation of advanced heavy-duty gas turbines. Therefore, finding other more suitable alternative working media as the cooling medium has gradually become the focus of attention of scientific researchers and technical personnel in this field.

[0003] At present, the alternative working media that have been studied include water, fuel, steam, water mist, liquid metal, and supercritical carbon dioxide. Although these alternative working media have achieved better cooling effects due to their advantages such as larger specific heat capacity, thermal conductivity, and density than air, they have only remained in the basic research stage or been temporarily shelved due to the disadvantages of significantly increasing the complexity of the device, being prone to clogging or wearing the internal cooling channels, increasing the thermal stress of the component metal, and poor feasibility. Therefore, finding an alternative working medium with better heat transfer performance than air, strong feasibility, not significantly increasing the complexity of the device, and not clogging or wearing the internal cooling channels, and developing its cooling system to form an efficient cooling method for the hot-end components of the gas turbine is still a major technical problem that scientific researchers and technical personnel in the field of gas turbine cooling technology have been working hard to solve. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a closed cooling cycle system for a gas turbine nano-aerosol, which can significantly improve the heat transfer coefficient in the internal cooling channels of the gas turbine combustion chamber and turbine without significantly increasing the complexity of the gas turbine device and without blocking and wearing the internal cooling channels, eliminate the mixing loss of cooling air and high-temperature gas, and improve the overall efficiency of the gas turbine.

[0005] The present invention adopts the following technical solutions:

[0006] A closed cooling cycle system for a gas turbine nano-aerosol includes a nano-aerosol generator. The compressor is connected to the inlet of the nano-aerosol generator. The outlet of the nano-aerosol generator is divided into two paths. One path is connected to the inlet of the nano-aerosol recovery and nano-fluid preparation device through the combustion chamber, and the other path is connected to the inlet of the nano-aerosol recovery and nano-fluid preparation device through the turbine. The high-pressure air outlet of the nano-aerosol recovery and nano-fluid preparation device is connected to the nano-aerosol generator, and the low-pressure air outlet is connected to the compressor.

[0007] Specifically, the compressor is internally provided with a low-pressure part of the compressor and a high-pressure part of the compressor. The secondary air outlet of the high-pressure part of the compressor is connected to the atomizing nozzle provided in the nano-aerosol generator, and the mainstream outlet of the high-pressure part of the compressor is connected to the mainstream inlet of the combustion chamber. The secondary air inlet of the low-pressure part of the compressor is connected to the low-pressure air outlet of the nano-aerosol recovery and nano-fluid preparation device.

[0008] Specifically, the nano-aerosol generator is internally provided with an atomizing nozzle. The air inlet of the atomizing nozzle is connected to the high-pressure part of the compressor inside the compressor, and the nano-fluid inlet of the atomizing nozzle is connected to the nano-fluid outlet of the nano-aerosol recovery and nano-fluid preparation device through a liquid pump.

[0009] Specifically, the second outlet of the nano-aerosol generator is connected to the second cooling medium inlet of the combustion chamber. The second cooling medium outlet of the combustion chamber is connected to the nano-aerosol recovery inlet of the nano-aerosol recovery and nano-fluid preparation device. The gas outlet of the combustion chamber is connected to the gas inlet of the high-pressure part of the turbine inside the turbine. The melting point of the solid particles in the nano-aerosol in the nano-aerosol generator is between the air temperature of the high-pressure part of the compressor inside the compressor, the metal temperature of the combustion chamber and the high-pressure part of the turbine.

[0010] Specifically, a spoiler is provided inside the nano-aerosol generator.

[0011] Specifically, the turbine is internally provided with a high-pressure part of the turbine. The high-pressure part of the turbine is connected to the nano-aerosol recovery inlet of the nano-aerosol recovery and nano-fluid preparation device through the first cooling medium outlet.

[0012] Specifically, the nano-aerosol recovery and nano-fluid preparation device is respectively connected to the nanoparticle supply device and the nano-based liquid replenishment device. The particle size of the nanoparticles in the nanoparticle supply device is 10 - 100 nm. A liquid pump is provided on the connecting pipe between the nano-aerosol recovery and nano-fluid preparation device and the nano-based liquid replenishment device.

[0013] Specifically, the low-pressure air outlet is connected to other auxiliary equipment of the liquid pump or the gas turbine through the first flow path.

[0014] Specifically, the high-pressure part of the turbine includes the lower turbine wall and the upper turbine wall. Between the lower turbine wall and the upper turbine wall, a first-stage stator vane, a first-stage rotor blade, a second-stage stator vane, and a second-stage rotor blade are sequentially arranged at intervals; the nano-aerosol enters the cooling channel inside the first-stage stator vane through the second flow path, enters the cooling channel inside the first-stage rotor blade of the turbine through the fourth flow path, and enters the cooling channel inside the second-stage stator vane of the turbine through the sixth flow path.

[0015] Further, three internal cooling channels are provided in the first-stage stator vane of the turbine. The nano-aerosol flows into the first internal cooling channel, the second internal cooling channel, and the third internal cooling channel from the first internal cooling channel inlet, the second internal cooling channel inlet, and the third internal cooling channel inlet respectively; the first internal cooling channel is an impinging jet for cooling the leading edge of the stator vane, and the second internal cooling channel and the third internal cooling channel are ribbed cooling channels; after the nano-aerosol cools the first-stage stator vane of the turbine, it flows out from the first internal cooling channel outlet and the second internal cooling channel outlet, and then flows back to the nano-aerosol recovery and nano-fluid preparation device through the third flow path;

[0016] In the first-stage rotor blade of the turbine, the nano-aerosol enters the internal cooling channel of the first-stage rotor blade of the turbine through the fourth internal cooling channel inlet, first forms an impinging jet inside the leading edge of the first-stage rotor blade of the turbine, and then flows through the ribbed internal cooling channel. After cooling the first-stage rotor blade of the turbine, it flows out from the third internal cooling channel outlet and flows back to the nano-aerosol recovery and nano-fluid preparation device through the sixth flow path;

[0017] In the second-stage stator vane of the turbine, the nano-aerosol enters the ribbed cooling channel inside the second-stage stator vane through the fifth internal cooling channel inlet. After cooling the second-stage stator vane, it flows out from the fourth internal cooling channel outlet and flows back to the nano-aerosol recovery and nano-fluid preparation device through the sixth flow path.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] A nano-aerosol closed cooling cycle system for a gas turbine. On the basis of a gas turbine power cycle composed of a compressor, a combustion chamber, and a turbine, a nano-aerosol closed cooling cycle system with a nano-aerosol generator, a nano-aerosol recovery, and a nanofluid preparation device as the core is added; to facilitate the coupling of the nano-aerosol closed cooling cycle system with the gas turbine power cycle, the compressor and the combustion chamber turbine are each divided into a high-pressure part and a low-pressure part; the high-pressure air sucked from the high-pressure part of the compressor enters the atomizing nozzle in the nano-aerosol generator, atomizes the nanofluid sucked from the nano-aerosol recovery and nanofluid preparation device by a liquid pump, and forms nano-aerosols; subsequently, the nano-aerosols enter the internal cooling channels in the combustion chamber and the high-pressure part of the turbine respectively; after efficiently cooling the combustion chamber and the high-pressure part of the turbine, the nano-aerosols flow into the nano-aerosol recovery and nanofluid preparation device for recovery and are re-prepared into nanofluids. The nano-aerosol generator generates stable and uniform nano-aerosols and has the function of adjusting the flow rate of the nanofluid and the concentration of the nano-aerosols; the nano-aerosol recovery and nanofluid preparation device has the function of condensing the base liquid in the nano-aerosols in the internal cooling channels of the combustion chamber and the turbine, as well as the function of solidifying the nano-particles after melting or gasification; compared with the existing air open cooling system of the gas turbine, the nano-aerosol closed cooling enhances the heat transfer capacity of the nano-aerosols in the internal cooling channels of the combustion chamber and the turbine blades by changing the physical properties of the cooling working medium, enhancing the flow turbulence in the internal channels, and the phase change of the nano-particles, thereby greatly improving the cooling performance of the cooling working medium and at the same time eliminating the aerodynamic mixing loss caused by the mixing of cold air and the mainstream.

[0020] Furthermore, to reduce the complexity of the system, the high-pressure air from the high-pressure part of the compressor is introduced into the nano-aerosol generator to atomize the nanofluid, avoiding the need for high-pressure gas compression equipment in the closed cycle system. At the same time, to save the power consumption of the system, the low-pressure air of the nano-aerosol recovery and nanofluid preparation device is sent back to the low-pressure part of the compressor, reducing the compression work when the compressor compresses the gas.

[0021] Furthermore, to facilitate the transportation of nano-particles, the nano-particles are first prepared into nanofluids in the nano-aerosol recovery and nanofluid preparation device, and then sent to the atomizing nozzle by a liquid pump and atomized under the action of high-pressure air to obtain more stable and uniform nano-aerosols.

[0022] Furthermore, after the nano-aerosol has completed the cooling of the combustion chamber, in order to reuse the nano-particles therein, a nano-aerosol recovery and nano-fluid preparation device is used to recover the nano-particles therein and prepare them into a nano-fluid, which is sent into the atomizing nozzle by a liquid pump, and then a nano-aerosol for cooling the combustion chamber is formed again. The nano-aerosol is arranged in a nano-aerosol generator and is formed by uniformly dispersing nano-solid particles in the high-pressure air sucked from the high-pressure part of the compressor, and is used to replace the air cooling working medium currently used in the internal cooling channels of the combustion chamber and the high-pressure part of the turbine. The melting point of the solid particles in the nano-aerosol is between the air temperature of the high-pressure part of the compressor and the metal temperature of the combustion chamber and the high-pressure part of the turbine, with the aim of causing the nano-solid particles to melt or vaporize in the internal cooling channels and using their latent heat of phase change to further enhance the heat transfer in the internal cooling channels.

[0023] Furthermore, a spoiler is installed in the nano-aerosol generator to further disperse the nano-aerosol formed by the atomizing nozzle, thereby forming a stable and uniform nano-aerosol.

[0024] Furthermore, after the nano-aerosol has completed the cooling of the high-pressure part of the turbine, in order to reuse the nano-particles therein, a nano-aerosol recovery and nano-fluid preparation device is used to recover the nano-particles therein and prepare them into a nano-fluid, which is sent into the atomizing nozzle by a liquid pump, and then a nano-aerosol for cooling the high-pressure part of the turbine is formed again.

[0025] Furthermore, in order to ensure the long-term stable and reliable operation of the system, the nano-aerosol recovery and nano-fluid preparation device are respectively connected to the nano-particle supply device and the nano-base liquid replenishment device, so as to supplement the loss of nano-particles during the long-term operation of the nano-aerosol system. The diameter of the solid particles in the nano-aerosol is 10 - 100 nm, with the aim of preventing the nano-solid particles from blocking and wearing the internal cooling channels.

[0026] Furthermore, in order to save the power consumption of the nano-aerosol closed cooling system and improve the cycle thermal efficiency of the gas turbine, a part of the low-pressure air generated in the nano-aerosol recovery and nano-fluid preparation device is reinjected into the low-pressure part of the compressor, and the other part is used to drive the liquid pump or other auxiliary equipment of the gas turbine.

[0027] Furthermore, in order to facilitate the control and adjustment of the flow rate and temperature of the nano-aerosol entering the internal cooling channels of the first-stage stator blades, the first-stage rotor blades, and the second-stage stator blades, the nano-aerosol enters the cooling channels inside the first-stage stator blades through the second flow path, enters the cooling channels inside the first-stage rotor blades of the turbine through the fourth flow path, and enters the cooling channels inside the second-stage stator blades of the turbine through the sixth flow path.

[0028] Furthermore, the nano-aerosol has far better cooling performance than existing air cooling. The first-stage stator blade, the first-stage rotor blade, and the second-stage stator blade of the high-pressure part of the turbine can be cooled only by the internal cooling of the nano-aerosol, avoiding the need to machine film holes on the blade surface and the mixing loss that occurs when the cold air enters the mainstream through the film holes in the existing air cooling technology. That is, it not only saves the processing cost of the film holes but also improves the aerodynamic performance of the turbine.

[0029] In summary, the present invention uses nano-aerosol as the cooling medium. Under the same cooling air usage, it can significantly increase the heat transfer coefficient of the typical internal cooling structures of the gas turbine combustor and turbine, thereby achieving cooling protection for the combustor and turbine only from the inside, eliminating the aerodynamic loss caused by the mixing of cooling air and gas in the existing air cooling technology, and then significantly improving the overall efficiency of the gas turbine while meeting the cooling requirements of the gas turbine combustor and turbine.

[0030] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the nano-aerosol closed cooling cycle system for a gas turbine.

[0032] Figure 2 It is a schematic diagram of the internal cooling flow path for the nano-aerosol cooling of the turbine blade in an embodiment of the present invention.

[0033] Figure 3 It is a schematic diagram of the nano-aerosol ribbed internal cooling channel structure and the numerical calculation result diagram of the wall heat transfer coefficient in an embodiment of the present invention.

[0034] Figure 4 It is a numerical calculation result diagram of the average wall heat transfer coefficient and the heat transfer coefficient enhancement factor at different nano-particle volume fractions in the nano-aerosol ribbed internal cooling channel in an embodiment of the present invention.

[0035] Figure 5 It is a schematic diagram of the nano-aerosol internal impingement cooling structure and the numerical calculation result diagram of the impingement target surface heat transfer coefficient in an embodiment of the present invention.

[0036] Wherein: A. Compressor; A1. Low-pressure part of the compressor; A2. High-pressure part of the compressor; B. Atomizing nozzle; C. Liquid pump; D. Nano-aerosol recovery and nanofluid preparation device; E. Nanofluid; F. Nano-aerosol generator; G. Nano-aerosol; H. Flow spoiler; I. Turbine; I1. High-pressure part of the turbine; I2. Low-pressure part of the turbine; J. Combustion chamber; K. Connecting shaft; L. Output shaft; M. Liquid pump; N. Nanofluid base liquid replenishing device; O. Nanofluid base liquid; P. Nanoparticle replenishing device; Q. First-stage stationary blade of the turbine; R. First-stage moving blade of the turbine; S. Second-stage stationary blade of the turbine; T. Second-stage moving blade of the turbine; U. Lower end wall of the turbine; V. Upper end wall of the turbine; 1. Secondary air outlet; 2. Air inlet; 3. Nanofluid outlet; 4. Nanofluid inlet; 5. First outlet; 6. First cooling medium inlet; 7. First cooling medium outlet; 8. Second outlet; 9. Second cooling medium inlet; 10. Second cooling medium outlet; 11. Nano-aerosol recovery inlet; 12. Low-pressure air outlet; 13. First flow path; 14. Re-injection into the low-pressure part of the compressor; 15. Secondary air inlet; 16. Replenishing liquid outlet; 17. Replenishing liquid inlet; 18. Replenishment outlet; 19. Replenishment inlet; 20. Main flow outlet; 21. Main flow inlet; 22. Combustion gas outlet; 23. Combustion gas inlet; 24. Second flow path; 25. First internal cooling channel inlet; 26. Second internal cooling channel inlet; 27. Third internal cooling channel inlet; 28. Impinging jet; 29. First internal cooling channel outlet; 30. Second internal cooling channel outlet; 31. Third flow path; 32. Fourth flow path; 33. Fourth internal cooling channel inlet; 34. Impinging jet at the leading edge of the first-stage moving blade of the turbine; 35. Third internal cooling channel outlet; 36. Fifth flow path; 37. Fifth internal cooling channel inlet; 38. Fourth internal cooling channel outlet; 39. Sixth flow path. Detailed implementation mode

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0041] It should also be understood that the terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the description of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0042] It should be further understood that the term " / and" used in the description of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0044] The present invention provides a closed cooling cycle system for a gas turbine nano-aerosol. The air sucked from the compressor for cooling the combustion chamber and the turbine first enters the nano-aerosol generator, atomizes the nanofluid from the nano-aerosol recovery and nanofluid preparation device to form a stable and uniform nano-aerosol, and then enters the internal cooling channels of the combustion chamber and the turbine. After cooling, it flows back to the nano-aerosol recovery and nanofluid preparation device to be remade into nanofluid. By adding nano-particles to the cooling air of the gas turbine to form nano-aerosol in the present invention, the internal cooling channels will not be blocked or worn. The nano-particles enhance heat transfer by changing the thermal properties of the air and strengthening turbulent flow, and at the same time, phase change occurs, and the latent heat of phase change is used to further enhance heat transfer, providing efficient cooling protection for the combustion chamber and the turbine.

[0045] Please refer to Figure 1 , a closed cooling cycle system for a gas turbine nano-aerosol according to the present invention adds a closed cooling cycle system for a gas turbine nano-aerosol for cooling the combustion chamber and the turbine on the basis of the gas turbine power cycle; it includes a compressor A, a combustion chamber J, a turbine I, a connecting shaft K, and an output shaft L. Both the combustion chamber J and the turbine I adopt a closed cooling channel structure.

[0046] The main outlet 20 of the compressor A is connected to the main inlet 21 of the combustion chamber J. The gas outlet 22 of the combustion chamber J is connected to the gas inlet 23 of the turbine I. The compressor A and the turbine I are connected by a connecting shaft K. The turbine I is connected to the load through the output shaft L; the closed cooling cycle system for the nano-aerosol is arranged between the compressor A and the turbine I. The closed cooling cycle system for the nano-aerosol includes a high-pressure part A2 of the compressor, a nano-aerosol recovery and nanofluid preparation device D, a nano-aerosol generator F, a high-pressure part I1 of the turbine, a combustion chamber J, a low-pressure part A1 of the compressor, a nanofluid base liquid replenishing device N, a nano-particle replenishing device P, and liquid pumps C and M.

[0047] The secondary air outlet 1 of the high-pressure section A2 of the compressor is connected to the air inlet 2 of the atomizing nozzle B provided in the nano-aerosol generator F. The main stream outlet 20 of the high-pressure section A2 of the compressor is connected to the main stream inlet 21 of the combustion chamber J. The gas outlet 22 of the combustion chamber J is connected to the gas inlet 23 of the high-pressure section I1 of the turbine. The nano-fluid inlet 4 of the atomizing nozzle B is connected to the nano-fluid outlet 3 of the nano-aerosol recovery and nano-fluid preparation device D through the liquid pump C. The first outlet 5 of the nano-aerosol generator F is connected to the first cooling working medium inlet 6 of the high-pressure section I1 of the turbine. The second outlet 8 of the nano-aerosol generator F is connected to the second cooling working medium inlet 9 of the combustion chamber J. The second cooling working medium outlet 10 of the combustion chamber J is connected to the nano-aerosol recovery inlet 11 of the nano-aerosol recovery and nano-fluid preparation device D after converging with the first cooling working medium outlet 7 of the high-pressure section I1 of the turbine through a pipeline. The nano-based liquid replenishing device N is provided with a nano-fluid base liquid O. The nano-aerosol recovery and nano-fluid preparation device D is connected to the nano-fluid base liquid replenishing device N and the nano-particle replenishing device P to supplement the losses of the nano-fluid base liquid and nano-particles generated after the system operates for a long time. The low-pressure air outlet 12 of the nano-aerosol recovery and nano-fluid preparation device D is connected to the secondary air inlet 15 of the low-pressure section A1 of the compressor through the low-pressure section 14 of the re-injection compressor, or is connected to the liquid pump C and the liquid pump M or other auxiliary equipment of the gas turbine through the first flow path 13.

[0048] The nano-aerosol recovery and nano-fluid preparation device D has the functions of recovering the particles in the nano-aerosol, condensing the base liquid and the solid particles undergoing phase change in the nano-aerosol, and preparing nano-fluid.

[0049] Among them, the replenishing inlet 17 of the nano-aerosol recovery and nano-fluid preparation device D is connected to the replenishing outlet 16 of the nano-based liquid replenishing device N through the liquid pump M. The replenishing inlet 19 of the nano-aerosol recovery and nano-fluid preparation device D is connected to the replenishing outlet 18 of the nano-particle replenishing device P.

[0050] The nano-fluid uses water as the base liquid. The atomizing nozzle B is used to atomize the nano-fluid to form a nano-aerosol G, and the temperature of the high-pressure air in the nano-aerosol G is reduced by the atomized nano-fluid base liquid O.

[0051] The atomizing nozzle B has the function of adjusting the flow rate of the nano-fluid, and thus adjusts the concentration of nano-solid particles in the nano-aerosol according to the operation requirements of the system.

[0052] The nano-aerosol G is arranged in the nano-aerosol generator F and is formed by nano-solid particles being stably and uniformly dispersed in the high-pressure air sucked from the high-pressure section of the compressor, and is used to replace the air cooling working medium currently used in the internal cooling channels of the combustion chamber J and the high-pressure section I1 of the turbine.

[0053] The diameter of the solid particles in the nano-aerosol G is 10 - 100 nm, aiming to prevent the nano-solid particles from clogging and wearing the internal cooling channels.

[0054] The melting point of the solid particles in the nano-aerosol G is between the air temperature of the high-pressure part A2 of the compressor and the metal temperature of the combustion chamber J and the high-pressure part I1 of the turbine, aiming to make the nano-solid particles melt or vaporize in the internal cooling channels and utilize their latent heat of phase change to further enhance the heat transfer in the internal cooling channels.

[0055] A spoiler H is installed in the nano-aerosol generator F to further disperse the nano-aerosol formed by the atomizing nozzle B, thereby forming a stable and uniform nano-aerosol G.

[0056] The working process of a nano-aerosol closed cooling cycle system for a gas turbine according to the present invention is as follows:

[0057] The air sucked from the high-pressure part of the compressor flows from the secondary air outlet 1 to the air inlet 2 of the atomizing nozzle B. At the same time, the nano-fluid E is sent from the nano-fluid outlet 3 of the nano-aerosol recovery and nano-fluid preparation device D to the nano-fluid inlet 4 of the atomizing nozzle B by the liquid pump C. Under the action of high-pressure air, the atomizing nozzle B atomizes the nano-fluid E and forms a stable and uniformly distributed nano-aerosol G under the action of the spoiler H. During this process, the base liquid in the nano-fluid E is also atomized, thus playing a role in reducing the temperature of the nano-aerosol.

[0058] Subsequently, the nano-aerosol G flows through the first outlet 5 and the second outlet 8 respectively to the cooling channels inside the turbine I and the combustion chamber J to cool the turbine I and the combustion chamber J.

[0059] After the nano-aerosol G completes the cooling of the turbine I and the combustion chamber J, it flows out through the first cooling working medium outlet 7 and the second cooling working medium outlet 10, and then flows back to the nano-aerosol recovery and nano-fluid preparation device D through the nano-aerosol recovery inlet 11 to reform the nano-fluid E required by the nano-aerosol generator F; low-pressure air is generated simultaneously during the process of recovering the nano-aerosol G. The low-pressure air flows out through the low-pressure air outlet 12 and is re-injected into the compressor A through the secondary air inlet 15 of the low-pressure part A1 of the compressor, or is used to drive the liquid pumps C and M or other auxiliary equipment of the gas turbine through the first flow path 13.

[0060] To supplement the loss of the nanofluid base fluid during the operation of the system, the liquid pump M sends the nanofluid base fluid O in the nanofluid base fluid replenishing device N to the nanofluid aerosol recovery and nanofluid preparation device D through the replenishing outlet 16 and the replenishing inlet 17; the replenishing outlet 18 of the nanoparticle replenishing device P is connected to the nanofluid aerosol recovery and nanofluid preparation device D through the replenishing inlet 19, for supplementing the loss of nanoparticles during the operation of the system.

[0061] Please refer to Figure 2 , which is a specific embodiment of the closed cooling channel of the nanofluid aerosol inside the blade in the high-pressure part I1 of the turbine.

[0062] The high-pressure part I1 of the turbine includes the first-stage stator blade Q, the first-stage rotor blade R, the second-stage stator blade S, the second-stage rotor blade T, the turbine lower end wall U and the turbine upper end wall V. The first-stage stator blade Q, the first-stage rotor blade R and the second-stage stator blade S are cooled by the nanofluid aerosol G through the corresponding internal cooling channels respectively.

[0063] In the high-pressure part I1 of the turbine, after the nanofluid aerosol G in the first cooling working fluid inlet 6 enters the turbine I, it is divided into the second flow path 24, the fourth flow path 32 and the sixth flow path 36 according to the cooling requirements. The nanofluid aerosol G in the nanofluid aerosol generator F enters the cooling channel inside the first-stage stator blade Q through the second flow path 24, the nanofluid aerosol G enters the cooling channel inside the first-stage rotor blade R of the turbine through the fourth flow path 32, and the nanofluid aerosol G enters the cooling channel inside the second-stage stator blade S of the turbine through the sixth flow path 36.

[0064] Three internal cooling channels are arranged inside the first-stage stator blade Q of the turbine. The nanofluid aerosol G flows into the first internal cooling channel, the second internal cooling channel and the third internal cooling channel inside the first-stage stator blade respectively from the first internal cooling channel inlet 25, the second internal cooling channel inlet 26 and the third internal cooling channel inlet 27 for cooling.

[0065] Among them, the inside of the first internal cooling channel is the impinging jet 28 for cooling the leading edge of the stator blade, and the second internal cooling channel and the third internal cooling channel are ribbed cooling channels; after the nanofluid aerosol G cools the first-stage stator blade Q of the turbine, it flows out from the first internal cooling channel outlet 29 and the second internal cooling channel outlet 30 of the first-stage stator blade Q of the turbine, and then flows back to the nanofluid aerosol recovery and nanofluid preparation device D through the third flow path 31.

[0066] In the first-stage turbine rotor blade R, the nano-aerosol G enters the internal cooling channel of the first-stage turbine rotor blade R through the fourth internal cooling channel inlet 33. First, an impinging jet 34 is formed inside the leading edge of the first-stage turbine rotor blade R, and then it flows through the ribbed internal cooling channel. After completing the cooling of the first-stage turbine rotor blade R, it flows out from the third internal cooling channel outlet 35 and returns to the nano-aerosol recovery and nano-fluid preparation device D through the sixth flow path 39.

[0067] In the second-stage turbine stator blade S, the nano-aerosol G enters the ribbed cooling channel inside the second-stage stator blade S through the fifth internal cooling channel inlet 37. After completing the cooling of the second-stage stator blade S, it flows out from the fourth internal cooling channel outlet 38 and returns to the nano-aerosol recovery and nano-fluid preparation device D through the sixth flow path 39.

[0068] Please refer to Figure 3 , the heat transfer coefficient on the ribbed wall surface is the result obtained by using the numerical simulation method with the nano-aerosol G as the cooling working fluid. In order to compare with the heat transfer coefficient result with air as the working fluid, Figure 4 The average wall heat transfer coefficient of nano-aerosol cooling and the increase in heat transfer coefficient of nano-aerosol compared to air (heat transfer enhancement factor) obtained by numerical simulation calculation at different nano-particle volume fractions are given. When the Reynolds number is 10,000, the heat transfer coefficient of air is 141 W·m -2 ·K -1 , corresponding to Figure 4 the result with a nano-particle volume fraction of 0 in -2 ·K -1 . As the nano-particle concentration increases, the average wall heat transfer coefficient of the ribbed channel continuously increases. When the volume fraction of nano-particles is only 0.012%, the average wall heat transfer coefficient is 272 W·m Figure 4 . Compared with air, the heat transfer coefficient increases by 92.4%. It should be noted that Figure 4 the results in

[0069] Please refer to Figure 5 , which is a typical structure of impinging jet cooling. Among them, Figure 5 (a) and Figure 5 (b) are the heat transfer coefficients on the impinging jet target surface obtained by numerical simulation calculation with air and nano-aerosol as the cooling working fluids respectively. When the impinging Reynolds number is 10,000, comparing Figure 5 (a) and Figure 5(b) It can be clearly seen that when the nano-aerosol is used as the working medium, the heat transfer coefficient on the target surface is significantly higher. Through quantitative comparison, when the nano-aerosol (the volume fraction of nano-particles is 0.002%) is used as the working medium, the average heat transfer coefficient on the target surface is 35.8% higher than that when air is used as the working medium.

[0070] In summary, the nano-aerosol closed cooling cycle system for a gas turbine of the present invention has the following advantages:

[0071] (1) Using nano-aerosol instead of air in the existing cooling technology as the cooling working medium significantly increases the heat transfer coefficient in the internal cooling channels of the combustion chamber and the turbine, thus making it possible to achieve high-temperature protection for the combustion chamber and the turbine only from the inside. While saving cooling air, there is no aerodynamic loss caused by the mixing of the cooling working medium and the high-temperature gas, thereby significantly improving the overall efficiency of the gas turbine;

[0072] (2) The nano-solid particles in the nano-aerosol have a high melting point and can undergo a phase change after reaching the specified cooling location, thereby further improving the heat transfer capacity of the nano-aerosol;

[0073] (3) The system is simple, the cost of nano-aerosol is low, it is easy to prepare, and it does not affect the flexibility of the gas turbine device;

[0074] (4) The low-pressure air generated after the nano-aerosol is recycled can be fully utilized, further improving the overall efficiency of the gas turbine;

[0075] (5) The system is a closed-cycle system and there is no problem of pollution emissions.

[0076] According to the results of the above embodiments, the present invention has a very broad application prospect and obvious economic benefits in advanced heavy-duty gas turbines.

[0077] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the claims of the present invention.

Claims

1. A closed cooling cycle system of a gas turbine with nano-aerosol, Characterized in that, It includes a nano-aerosol generator (F). The compressor (A) is connected to the inlet of the nano-aerosol generator (F). The outlet of the nano-aerosol generator (F) is divided into two paths. One path is connected to the inlet of the nano-aerosol recovery and nano-fluid preparation device (D) through the combustion chamber (J), and the other path is connected to the inlet of the nano-aerosol recovery and nano-fluid preparation device (D) through the turbine (I); the nano-fluid outlet (3) of the nano-aerosol recovery and nano-fluid preparation device (D) is connected to the nano-aerosol generator (F), and the low-pressure air outlet (12) is connected to the compressor (A); Inside the compressor (A), there are a low-pressure part (A1) and a high-pressure part (A2) of the compressor. The secondary air outlet (1) of the high-pressure part (A2) of the compressor is connected to the atomizing nozzle (B) arranged in the nano-aerosol generator (F), and the main flow outlet (20) of the high-pressure part (A2) of the compressor is connected to the main flow inlet (21) of the combustion chamber (J); the secondary air inlet (15) of the low-pressure part (A1) of the compressor is connected to the low-pressure air outlet (12) of the nano-aerosol recovery and nano-fluid preparation device (D).

2. The closed cooling cycle system of a gas turbine with nano-aerosol according to claim 1, Characterized in that, An atomizing nozzle (B) is arranged inside the nano-aerosol generator (F). The air inlet (2) of the atomizing nozzle (B) is connected to the high-pressure part (A2) inside the compressor (A), and the nano-fluid inlet (4) of the atomizing nozzle (B) is connected to the nano-fluid outlet (3) of the nano-aerosol recovery and nano-fluid preparation device (D) through the first liquid pump (C).

3. The closed cooling cycle system of a gas turbine with nano-aerosol according to claim 1, Characterized in that, The second outlet (8) of the nano-aerosol generator (F) is connected to the second cooling medium inlet (9) of the combustion chamber (J). The second cooling medium outlet (10) of the combustion chamber (J) is connected to the nano-aerosol recovery inlet (11) of the nano-aerosol recovery and nano-fluid preparation device (D); the gas outlet (22) of the combustion chamber (J) is connected to the gas inlet (23) of the high-pressure part (I1) inside the turbine (I). The melting point of the solid particles in the nano-aerosol (G) inside the nano-aerosol generator (F) is between the air temperature of the high-pressure part (A2) inside the compressor (A), the metal temperatures of the combustion chamber (J) and the high-pressure part (I1) of the turbine.

4. The closed cooling cycle system of a gas turbine with nano-aerosol according to claim 1, Characterized in that, A spoiler (H) is arranged inside the nano-aerosol generator (F).

5. The closed cooling cycle system of a gas turbine with nano-aerosol according to claim 1, Characterized in that, There is a high-pressure part (I1) inside the turbine (I). The high-pressure part (I1) is connected to the nano-aerosol recovery inlet (11) of the nano-aerosol recovery and nano-fluid preparation device (D) through the first cooling medium outlet (7).

6. The closed cooling cycle system of a gas turbine nano-aerosol according to claim 1, characterized in that, the nano-aerosol recovery and nano-fluid preparation device (D) is respectively connected to the nano-particle supply device (P) and the nano-base liquid replenishment device (N). The particle size of the nano-particles in the nano-particle supply device (P) is 10 - 100 nm. A second liquid pump (M) is provided on the connecting pipeline between the nano-aerosol recovery and nano-fluid preparation device (D) and the nano-base liquid replenishment device (N).

7. The closed cooling cycle system of a gas turbine nano-aerosol according to claim 1, characterized in that, the low-pressure air outlet (12) is connected to the first liquid pump (C) and the second liquid pump (M) or other auxiliary equipment of the gas turbine through the first flow path (13).

8. The closed cooling cycle system of a gas turbine nano-aerosol according to claim 1, characterized in that, the high-pressure part of the turbine (I1) includes a turbine lower end wall (U) and a turbine upper end wall (V). A first-stage stator blade (Q), a first-stage rotor blade (R), a second-stage stator blade (S) and a second-stage rotor blade (T) are sequentially arranged at intervals between the turbine lower end wall (U) and the turbine upper end wall (V); the nano-aerosol (G) enters the cooling channel inside the first-stage stator blade (Q) through the second flow path (24), enters the cooling channel inside the first-stage rotor blade (R) of the turbine through the fourth flow path (32), and enters the cooling channel inside the second-stage stator blade (S) of the turbine through the sixth flow path (36).

9. The closed cooling cycle system of a gas turbine nano-aerosol according to claim 8, characterized in that, there are three internal cooling channels in the first-stage stator blade (Q) of the turbine. The nano-aerosol (G) flows into the first internal cooling channel, the second internal cooling channel and the third internal cooling channel from the first internal cooling channel inlet (25), the second internal cooling channel inlet (26) and the third internal cooling channel inlet (27) respectively; the first internal cooling channel is an impinging jet (28) for cooling the leading edge of the stator blade, and the second internal cooling channel and the third internal cooling channel are ribbed cooling channels; after the nano-aerosol (G) cools the first-stage stator blade (Q) of the turbine, it flows out from the first internal cooling channel outlet (29) and the second internal cooling channel outlet (30), and then flows back to the nano-aerosol recovery and nano-fluid preparation device (D) through the third flow path (31); in the first-stage rotor blade (R) of the turbine, the nano-aerosol (G) enters the internal cooling channel of the first-stage rotor blade (R) of the turbine through the fourth internal cooling channel inlet (33), first forms an impinging jet (34) inside the leading edge of the first-stage rotor blade (R) of the turbine, then flows through the ribbed internal cooling channel. After completing the cooling of the first-stage rotor blade (R) of the turbine, it flows out from the third internal cooling channel outlet (35) and flows back to the nano-aerosol recovery and nano-fluid preparation device (D) through the sixth flow path (39); In the second-stage stator blade (S) of the turbine, the nano-aerosol (G) enters the ribbed cooling channel inside the second-stage stator blade (S) through the fifth internal cooling channel inlet (37). After completing the cooling of the second-stage stator blade (S), it flows out through the fourth internal cooling channel outlet (38) and returns to the nano-aerosol recovery and nano-fluid preparation device (D) through the sixth flow path (39).

Images