A novel cross-media engine working medium unidirectional flow and heat transfer control structure and method

Abstract

The application discloses a novel cross-medium engine working medium one-way flow and heat transfer control structure and method, and belongs to the technical field of aero-engine combustion chamber and turbine structure. The structure comprises a turbine guide vane, an underwater combustion chamber, a sealing cover plate, an annular water channel, a radial water curtain nozzle and a radial water inlet. The underwater combustion chamber is provided with S-shaped water inlets with axial water curtain nozzles on both sides. During work, the axial water curtain nozzles spray water curtains to limit the radial diffusion of high-temperature gas and cool the combustion chamber wall surface; the radial water curtain nozzles form water curtains in front of the turbine guide vane to prevent gas backflow and cool the turbine guide vane; and the sealing cover plate prevents the leakage medium from flowing to the compressor end. The application realizes one-way axial flow of gas during work of the underwater combustion chamber, improves the gas utilization rate and turbine efficiency, effectively prolongs the service life of the combustion chamber and the turbine through water curtain cooling, and has compact structure and low process cost.

Description

Technical Field

[0001] This invention belongs to the field of mechanical structure technology, specifically relating to the combustion chamber and turbine structure of aero-engines, and particularly to a structure and method for controlling the unidirectional flow and heat transfer of the working medium in a cross-medium engine for underwater working environments. Background Technology

[0002] A cross-medium engine is a new type of power plant that can operate both in the air and underwater. In underwater operation, the engine combustion chamber (i.e., the underwater combustion chamber) generates high-temperature, high-pressure gas to drive the turbine. However, due to the lack of high-pressure gas from the compressor as a barrier in the underwater environment, the high-temperature gas can easily diffuse radially from the turbine guide region or flow counter-currently towards the compressor end, resulting in total pressure loss before the turbine, reduced power efficiency, and thermal damage to upstream components such as the compressor.

[0003] Currently, there are few publicly available solutions to this problem. Traditional aero engines mainly rely on aerodynamic seals and structural sealing to restrict gas flow, but these methods depend on high-pressure airflow and cannot be directly applied in underwater environments. Therefore, there is an urgent need for a new structure that can adapt to the special underwater environment, effectively control the unidirectional flow of the working medium (gas), and simultaneously possess efficient thermal management capabilities. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a structure and method for controlling the unidirectional flow and heat transfer of the working medium in a cross-medium engine. This solves the problem of high-temperature combustion gas easily flowing backward and radially diffusing during underwater combustion chamber operation, while also achieving effective cooling of key working components (such as the combustion chamber wall and turbine guide vanes), thereby improving the reliability, efficiency, and lifespan of the engine during underwater operation.

[0005] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides a control structure for unidirectional flow and heat transfer of the working medium of a cross-medium engine, which mainly includes a turbine guide vane, an underwater combustion chamber, a sealing cover, a radial water inlet, an annular water channel, and a radial water curtain nozzle.

[0006] The turbine guide is an annular structure with a fan-shaped notch on its annular wall for installing the underwater combustion chamber.

[0007] The underwater combustion chamber has a fan-shaped structure, and its outlet shape matches the fan-shaped notch of the turbine guide vane. S-shaped water inlets are integrated inside the left and right side shells of the underwater combustion chamber. These S-shaped water inlets are constant cross-section flow channels, and their outlet ends are equipped with axial water curtain nozzles. Ventilation holes are also provided on both sides of the underwater combustion chamber. The S-shaped water inlets and axial water curtain nozzles are integrally designed with the combustion chamber shell.

[0008] The sealing cover is an arc-shaped annular plate, one end of which is welded to the shell of the underwater combustion chamber. The axial position of the sealing cover is located at the inlet edge of the turbine guide vane, and its outer contour mates with the inner ring wall of the turbine guide vane to form an axial seal, used to close the upper openings of cavities A and B formed by the clearance between the underwater combustion chamber and the turbine guide vane (see...). Figure 4 ).

[0009] The annular water channel is a complete circular structure, fixedly mounted on the outer diameter arc surface of the turbine guide vane by a bracket. Multiple (e.g., 8) radial water inlets are uniformly welded to the outer ring wall of the annular water channel. Multiple (e.g., 52) radial water curtain nozzles are uniformly welded to the inner ring wall of the annular water channel.

[0010] The radial water inlet is a common nozzle structure with external threads and a conical sealing structure, used to connect to an external booster water supply device.

[0011] The radial water curtain nozzle is a cylindrical nozzle, and its outlet can be designed with different structures such as a contraction type or a contraction-expansion type as needed to control the shape of the water curtain. Multiple water inlets are correspondingly opened on the outer ring wall of the turbine guide. The outlet end of the radial water curtain nozzle is inserted into these water inlets, forming a small-gap overlapping fit, allowing the water flow to smoothly enter the flow channel.

[0012] Secondly, the present invention provides a control method based on the above structure, comprising the following steps: 1. Axial Water Curtain Formation and Combustion Constraint: During operation, external cooling water is pumped into the S-shaped inlet channels on both sides of the underwater combustion chamber. As the cooling water flows through the S-shaped channels, it provides initial cooling to the combustion chamber walls. Subsequently, it is ejected from the axial water curtain nozzles, forming an axial water curtain (first water curtain) in the annular space between the underwater combustion chamber outlet and the turbine guide vane inlet. This water curtain effectively restricts the radial diffusion of high-temperature combustion gases (i.e., in the directions of chambers A and B), forcing the combustion gases to concentrate along the axial flow path of the turbine guide vane, thereby reducing total pressure loss and improving turbine efficiency. Simultaneously, this water curtain directly washes over the combustion chamber outlet wall, enhancing cooling.

[0013] 2. Radial Water Curtain Formation and Backflow Prevention: Another stream of cooling water enters the annular water channel through a radial inlet and is simultaneously ejected through all radial water curtain nozzles. This water flow forms a dense radial water curtain (second water curtain) across the entire annular cross-section in front of the turbine guide vane. This water curtain completely blocks the reverse flow of the combustion gases after power output towards the engine compressor end, protecting upstream components. Furthermore, the radial water curtain also provides significant cooling to the turbine guide vane blades and inner wall surfaces.

[0014] 3. Sealing and Leakage Control: Despite the axial water curtain, a small amount of fuel gas may still leak from the edge of the water curtain into chambers A and B, and some of the water curtain medium will be vaporized by the high-temperature fuel gas. Sealing covers seal the upper openings of chambers A and B, preventing these leaked fuel gases and vapors from flowing towards the compressor end. Leaked media can only be guided and discharged to the outside of the engine or the atmosphere through the vents on the underwater combustion chamber shell.

[0015] 4. Synergistic Cooling and Flow Control: Axial and radial water curtains work together to construct a "water-based sealing and cooling system." This system not only forces the combustion gas to achieve strict axial unidirectional flow, but also efficiently cools the underwater combustion chamber and turbine guide vane, two high-temperature components, through water vaporization heat absorption and convective heat transfer, significantly extending their service life.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Highly efficient unidirectional flow control: By using two water curtains, one axial and one radial, the problem of gas backflow and radial leakage in underwater environment is fundamentally solved, ensuring that the working fluid energy is used to drive the turbine to do work to the maximum extent.

[0017] 2. Superior thermal management capabilities: The water curtain simultaneously achieves both sealing and cooling functions. The S-shaped water inlet and axial water curtain cooling of the combustion chamber, along with the radial water curtain cooling of the turbine guide vanes, significantly improve the durability of high-temperature components.

[0018] 3. Compact structure and high reliability: The underwater combustion chamber integrates the S-shaped water channel, nozzle and vent, reducing the number of parts and connection interfaces, simplifying assembly, and improving the overall structure and sealing reliability.

[0019] 4. Good adaptability: The shape and intensity of the water curtain can be flexibly controlled by changing the nozzle design (such as contraction and expansion) and adjusting the water supply pressure to adapt to different engine operating conditions.

[0020] 5. Low process cost: The integrated design and fewer independent parts reduce the complexity and cost of machining and assembly.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall axial cross-section of the structure of the present invention.

[0023] Figure 2 This is a radial cross-sectional schematic diagram of the structure of the present invention, mainly showing the arrangement of the annular waterway section.

[0024] Figure 3 This is a magnified schematic diagram of the location where the radial water curtain forms.

[0025] Figure 4 This is a partial cross-sectional schematic diagram of the area where the underwater combustion chamber and turbine guide vane meet, showing the positions of cavity A, cavity B, and the sealing cover.

[0026] Figure 5 This is a schematic diagram of the S-shaped water inlet inside the underwater combustion chamber.

[0027] The following are the labels in the attached diagram: 1-Turbine guide vane, 2-Underwater combustion chamber, 3-Sealing cover, 4-Radial water inlet, 5-Annular water channel, 6-Radial water curtain nozzle. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of this invention, but not all embodiments.

[0029] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0030] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0031] The following is in conjunction with the appendix Figure 1-5 The embodiments of the present invention will be described in detail below.

[0032] Example 1 like Figures 1 to 5 As shown, the unidirectional flow and heat transfer control structure of the transmedium engine working medium of the present invention has been specifically implemented on an experimental transmedium engine.

[0033] The turbine guide vane 1 is made of high-temperature alloy casting, and its fan-shaped notch is precisely machined to fit tightly with the fan-shaped outlet of the underwater combustion chamber 2. The underwater combustion chamber 2 is also made of high-temperature alloy, and its internal S-shaped water inlet is integrally formed by precision casting, while the axial water curtain nozzle is a narrow slit design. The sealing cover 3 is made of heat-resistant steel plate, stamped and then welded in place.

[0034] The annular water channel 5 is formed by bending and welding stainless steel pipes into a ring. The eight radial inlets 4 and 52 radial water curtain nozzles 6 on the channel are all welded and fixed using standard nozzle components. The outlet of the radial water curtain nozzles 6 is designed as a simple cylindrical straight hole. The diameter of the corresponding 52 inlets on the outer ring wall of the turbine guide 1 is approximately 0.5 mm larger than the outer diameter of the nozzles, creating an assembly gap.

[0035] When the engine switches to underwater operating mode, the control system first activates the water supply unit. Coolant is divided into two streams: one stream is injected at a certain pressure into the S-shaped inlet of the underwater combustion chamber 2; the other stream is injected at a higher pressure into the radial inlet 4. Subsequently, the underwater combustion chamber 2 is ignited.

[0036] During operation, the water jets ejected from the axial water curtain nozzles form an arc-shaped water curtain that covers the outer periphery of the fan-shaped area at the outlet of the underwater combustion chamber 2, "enveloping" the high-temperature combustion gases and guiding them towards the turbine rotor. The water jets ejected from the 52 radial water curtain nozzles 6 form a complete and uniform annular water wall in front of the turbine guide vane 1 inlet, completely isolating the reverse flow path.

[0037] Experiments show that this structure effectively confines the combustion gas within the preset flow channel, significantly improves the total pressure recovery coefficient before the turbine, and keeps the temperature at the compressor end monitoring point consistently within a safe range. Simultaneously, infrared thermal imaging shows that the temperatures at the underwater combustion chamber outlet section and the leading edge of the turbine guide vane are effectively controlled, verifying its excellent cooling effect.

[0038] Example 2 This invention discloses a control structure for unidirectional flow and heat transfer of the working medium in a transmedium engine.

[0039] I. Overall Structure and Assembly Relationship refer to Figure 1 and Figure 2 The control structure of this invention is integrated into the front part of the turbine section of the cross-medium engine. Its core is a "water-based sealing and cooling system" built around the turbine guide vane 1. The turbine guide vane 1 maintains the basic configuration of a traditional annular guide vane, but to adapt to underwater mode, a fan-shaped notch with an angle of approximately 60° is opened on its annulus. The underwater combustion chamber 2, with its matching fan-shaped shape, is embedded in this notch. This asymmetrical design is a key structural feature of this engine for switching between underwater and air modes.

[0040] The waterway of the entire system is divided into two independent but related subsystems: Subsystem 1 (Axial Cooling / Sealing Water Circuit): This water circuit is dedicated to the underwater combustion chamber 2, with the water source coming directly from outside the engine or from a separate water tank. The water circuit connects to the water inlet connector on the side wall of the underwater combustion chamber 2 via an external pipe, flowing into the S-shaped water inlet channel integrated inside the combustion chamber shell.

[0041] Subsystem 2 (Radial Sealing / Cooling Water Circuit): This water circuit serves the turbine guide 1 area. The water source is connected through multiple radial inlets 4, collected in an annular water channel 5 surrounding the outer diameter of the turbine guide 1, and then evenly distributed to all radial water curtain nozzles 6.

[0042] The sealing cover plate 3, as a mechanical seal component, is continuously welded to the upstream side shell of the fan-shaped outlet of the underwater combustion chamber 2 by argon arc welding. During installation, the arc-shaped outer edge of the sealing cover plate 3 must maintain a very small gap (0.1-0.3mm recommended) with the inner ring wall of the turbine guide 1 to form a labyrinth seal mating surface.

[0043] The annular water channel 5 is welded and fixed to the outer ring surface of the turbine guide 1 by several stainless steel brackets. After welding, a static pressure test is required to ensure that there is no leakage in the weld between the annular water channel 5, the radial inlet 4, and the radial water curtain nozzle 6.

[0044] II. Detailed Design and Functional Explanation of Core Components 1. Underwater combustion chamber (part 2) and its integrated water circuit design like Figure 5 As shown, the underwater combustion chamber 2 is a key innovative component of this invention. In addition to possessing the basic functions of a combustion chamber (such as fuel injection, mixing, ignition, and combustion), its shell structure has been carefully designed.

[0045] S-shaped inlet: This inlet is not a simple straight pipe, but rather a multi-bend "S"-shaped design, with the entire flow channel having a uniform cross-section (for example, a rectangular cross-section of 6mm x 8mm). This design serves three purposes: Increased heat exchange area: The S-shaped bend significantly increases the contact path and area of ​​cooling water as it flows through the high-temperature wall of the combustion chamber, enhancing the cooling effect on the combustion chamber shell (especially the outer wall of the flame tube).

[0046] Turbulence generation: Bends can disrupt the laminar flow of water, promote turbulence, and improve heat exchange efficiency.

[0047] Structural function: The S-shaped layout can better adapt to the complex spatial constraints inside the combustion chamber shell, achieving compact integration.

[0048] Axial water curtain nozzle: Located at the end of the S-shaped water inlet, inside the combustion chamber outlet edge. The nozzle is designed as a narrow slit extending along a fan-shaped arc (e.g., 0.5 mm wide). Its function is to create a thin, continuous "water curtain" that is sprayed tightly against the inner wall of the combustion chamber outlet. Main function: Gas confinement: The sprayed water curtain forms a physical barrier, blocking the diffusion of high-temperature gas to both sides (cavities A and B) and radially, forcing the gas to concentrate through the blade passage of turbine guide vane 1.

[0049] Wall cooling: The sprayed cooling water directly washes the inner wall of the high-temperature combustion chamber outlet section, and quickly removes heat through evaporation and convection.

[0050] Vent holes: These are located on both sides of the underwater combustion chamber 2, downstream of the sealing cover plate 3. Their main function is to balance the pressure in chambers A and B, and to guide the trace amounts of combustion gas leaking from the edge of the axial water curtain, as well as the water vapor vaporized by the high-temperature combustion gas, to the external atmospheric environment of the engine, preventing them from accumulating in the sealed chamber.

[0051] 2. Design of Water Curtain System in Turbine Guider Area like Figure 2 and Figure 3 As shown, the annular waterway 5 and its nozzle system constitute the second line of defense in front of the turbine.

[0052] Annular water channel 5: As a closed pressure vessel, its design requires a uniform internal flow field to ensure that the water flow rate and pressure exiting from all radial water curtain nozzles 6 are basically consistent. Its cross-sectional shape can be circular or rectangular, and needs to be optimized according to strength and spatial layout.

[0053] Radial water curtain nozzles 6: Numerous (52 in this example), evenly distributed circumferentially. The choice of nozzle structure directly affects the water curtain morphology. Converging nozzles: can accelerate water flow, forming a water curtain with high speed and strong penetration, but with a small diffusion angle, suitable for scenarios requiring strong impact cooling and precise pointing.

[0054] Laval nozzle (contraction-expansion nozzle): It can obtain supersonic flow at the exit, which makes the water atomization effect better, forming a wider and more uniform "water mist wall" with a large sealing area, but the structure is slightly more complex.

[0055] The axial direction of nozzle 6 is precisely calculated to ensure that the sprayed water curtain converges slightly upstream of the inlet cone of turbine guide vane 1 or the leading edge of the first row of stator vanes, forming a continuous annular barrier.

[0056] The interface is designed so that the diameter of the water inlet hole on the outer annular wall of the turbine guide 1 is slightly larger than the outer diameter of the nozzle 6, forming an annular gap of approximately 0.2-0.5 mm. This gap allows for a small thermal expansion difference between the nozzle 6 and the guide 1, while also allowing water to flow smoothly. This small gap also acts as a barrier, preventing the combustion gas from flowing back into the annular water channel 5 through the water inlet hole.

[0057] 3. Sealing mechanism of sealing cover plate (part 3) like Figure 4 As shown, the fit between the sealing cover 3 and the inner wall of the turbine guide vane 1 is not a complete contact hard seal. Its sealing mechanism is: Physical obstruction: Directly blocks the upstream (compressor direction) openings of chambers A and B.

[0058] Airflow organization: In conjunction with the axial water curtain, even if a small amount of gas enters chamber A / B, its main flow direction is restricted to flowing downstream (turbine direction) along the small gap between the sealing cover plate 3 and the inner wall of the turbine guide 1, eventually converging into the outlet path of the vent. This prevents the gas from "short-circuiting" upstream.

[0059] III. Workflow and Control Logic Examples Assuming the engine is ready to switch from air mode to underwater mode: Mode switching and pre-cooling: The control system first closes the fuel and air valves to the conventional combustion chamber, while simultaneously opening the water supply valves to the underwater combustion chamber 2 and the two water curtain systems. Cooling water is first introduced at a low flow rate to pre-cool the underwater combustion chamber 2 and the turbine guide area to prevent thermal shock during ignition.

[0060] Ignition and water curtain establishment are synchronized: After a few seconds of pre-cooling, the ignition procedure for underwater combustion chamber 2 is initiated. Simultaneously, the water supply pressures of the axial and radial water curtains are immediately increased to their operating settings (e.g., axial water curtain pressure P1, radial water curtain pressure P2, typically P2 > P1). This ensures that both water curtains are fully established before stable high-temperature combustion gases are generated in underwater combustion chamber 2.

[0061] Steady-state operation and adjustment: The engine enters steady-state operation underwater. Based on feedback from the turbine inlet temperature and pressure sensors, the control system fine-tunes the water supply pressure or flow rate of the two water curtain systems to optimize sealing and cooling effects. For example, if the turbine inlet temperature is detected to be too high, the radial water curtain flow rate P2 can be appropriately increased.

[0062] Shutdown and Aftercooling: When shutdown is required, first cut off the fuel supply to the underwater combustion chamber 2. However, the water supply of the water curtain system needs to be maintained for a period of time (e.g., 10-30 seconds) to perform "aftercooling" to remove the residual heat accumulated in the components until the temperature of critical parts drops below the safe value, and then the water supply is turned off.

[0063] IV. Material and Process Selection Recommendations High-temperature components: Turbine guide vane 1 and underwater combustion chamber 2 (especially the flame tube and outlet section) need to be cast or forged from nickel-based high-temperature alloys (such as Inconel 718) and then machined to withstand gas temperatures exceeding 1000°C.

[0064] Water channels and nozzles: The S-shaped water inlet can be integrally cast with the outer shell of the combustion chamber. The annular water channel 5, radial water inlet 4, and radial water curtain nozzle 6 can be made of corrosion-resistant and weldable stainless steel (such as 316L).

[0065] Sealing cover: It can be made of the same or similar alloy material as the combustion chamber shell to ensure welding performance and thermal expansion matching.

[0066] Key processes: The casting of the S-shaped waterway must ensure that the internal flow channel is smooth and free of sand holes; all waterway welds must undergo 100% penetrant testing or X-ray inspection to ensure no leakage; the assembly of the radial water curtain nozzle 6 with the water inlet hole on the turbine guide 1 must ensure circumferential positional accuracy to ensure accurate jet direction.

[0067] V. Effect Verification and Potential Variations Through the above specific implementation, the beneficial effects of the present invention are achieved: Gas utilization rate: By forcing unidirectional flow, the gas energy is applied to the turbine more effectively.

[0068] Component lifespan: Water curtain cooling significantly reduces the operating temperature of the combustion chamber and turbine guide vanes, thus reducing thermal stress.

[0069] System reliability: The integrated design and dual mechanical / hydraulic seals enhance the safety margin for underwater operations.

[0070] Potential variants: The radial water curtain nozzles 6 can be controlled in groups to achieve local flow regulation to adapt to asymmetric flow.

[0071] The S-shaped inlet can be replaced with a spiral shape or other structures that enhance heat exchange.

[0072] Corrosion inhibitors or antifreeze agents can be added to the cooling water to adapt to different water qualities or low-temperature environments.

[0073] Example 3 like Figures 1-5 The diagram shows a newly designed unidirectional flow and heat transfer control structure for the working medium of a transmedium engine.

[0074] Component 1: Turbine guide vane; Component 2: Underwater combustion chamber; Component 3: Sealing cover; Component 4: Radial water inlet; Component 5: Annular water channel; Component 6: Radial water curtain nozzle. Among them, component 2, the underwater combustion chamber, integrates the S-shaped water inlet, axial water curtain nozzle, and vent pipe into one unit. This simplifies the structure of this part, saves space, and reduces weight.

[0075] Component 1: The turbine guide vane has the same shape as the traditional annular guide vane, except that there is a fan-shaped notch where guide vanes are not installed. This area is used to install Component 2: the underwater combustion chamber. Component 2; Underwater combustion chamber, which is a fan-shaped combustion chamber specifically for underwater mode, with S-shaped water channels and vents arranged on its left and right sides, and a fan-shaped outlet, which matches the fan-shaped notch of component 1: turbine guide. Part 3: Sealing cover plate, which is in the shape of an arc ring. One end is fixed to the underwater combustion chamber shell by welding. Its axial position is located at the inlet of the turbine guide. Its shape is consistent with Part 1: Turbine guide and it cooperates with Part 1: Turbine guide to form a sealing structure. Component 4: Radial water inlet, a common nozzle structure, has threads and a conical surface. The threads ensure installation with the water inlet device, and the conical surface ensures a seal for the cooling water.

[0076] Component 5: Annular waterway, forming a complete circular structure, with Component 4: radial water inlet and Component 6: radial water curtain nozzle arranged on the wall, connected by welding. Component 6: Radial water curtain nozzle, a common type of cylindrical nozzle structure, with the outlet designed to control the direction and size of the water curtain.

[0077] Component 5: The annular water channel is installed and fixed on the outer diameter arc surface of the turbine guide of Component 1 via a bracket. On the outer side of the annular water channel, 8 parts are installed by welding. Component 4: Radial water inlet, and on the inner side, 52 parts of Component 6 radial water curtain nozzle are installed by welding. On the outer diameter arc surface of the turbine guide of Component 1, there are 52 water inlet holes that mate with the radial water curtain nozzle of Component 6. The diameter of the water inlet hole is slightly larger than that of the radial water curtain nozzle of Component 6, which is a small gap overlapping form.

[0078] Component 4: A radial water inlet is connected to an external pressurized water inlet device. Utilizing the pressure difference, cooling water flows through the water inlet device, into the annular water channel of component 5, and then is sprayed out through 52 water curtain nozzles to form a water curtain, which serves as the first water spraying method.

[0079] When the underwater combustion chamber of component 2 is working, it generates high-temperature and high-pressure combustion gas. This high-temperature gas passes through the turbine guide vane of component 1. Before reaching the turbine rotor, to prevent radial flow and losses, water from the S-shaped inlet of the underwater combustion chamber of component 2 is sprayed out through axial water curtain nozzles, forming a water curtain (as a second water spray method). This confines the high-temperature gas within the guide vane, preventing significant total pressure loss before the turbine and allowing as much high-temperature and high-pressure working fluid as possible to flow axially in one direction to perform work. Simultaneously, it prevents the gas from flowing towards the compressor end, thus avoiding burning and damage to compressor components. In actual operation, the water curtain in the underwater combustion chamber of component 2 cannot completely isolate the gas within the guide vane; a small portion of the gas leaks from the edge of the water curtain into chambers A and B (see...). Figure 4 (Refers to the two sides of the underwater combustion chamber), and as the working time continues to increase, part of the medium in the water curtain will be vaporized at high temperature, at which point the vent pipe will be activated. Component 3, the sealing cover plate, is located at the contact surface between component 2 (underwater combustion chamber) and component 1 (turbine guide), sealing the upper surfaces of chambers A and B to prevent leaked high-temperature combustion gas and vaporized water from flowing towards the compressor end, ensuring that these gases can only flow to the atmosphere through the vent pipe.

[0080] like Figure 5 As shown, the S-shaped water inlet of component 2's underwater combustion chamber adopts an S-shaped constant cross-section flow channel design. While ensuring the basic flow channel function, it can also cool the walls of the underwater combustion chamber, extending its service life. It also provides some protection for other components in contact with the underwater combustion chamber, preventing damage caused by high temperatures.

[0081] like Figure 3 As shown, when the underwater combustion chamber (part 2) is operating, another stream of water flows through the radial inlet (part 4) and the annular water channel (part 5), and is ejected from the radial water curtain nozzle (part 6). This forms a water curtain at the cross-section in front of the turbine guide vane (part 1), effectively preventing the combustion gas flowing past the turbine rotor from flowing into the compressor, protecting the compressor components, and ensuring that the working medium in the underwater combustion chamber flows unidirectionally along the axial direction. Furthermore, the formation of the radial water curtain also provides significant cooling to the turbine guide vane, extending the turbine's service life.

[0082] A novel cross-medium engine working medium unidirectional flow and heat transfer control structure has been designed. When the engine is underwater, the underwater combustion chamber operates, and the combustion gas flows unidirectionally towards the turbine, driving the engine. This design includes two water curtain structures.

[0083] Technical solution: 1. Core Invention Point: A novel cross-medium engine working medium unidirectional flow and heat transfer control structure, which utilizes the engine's environmental medium to restrict the flow direction of the working medium and control the temperature of the working components.

[0084] Secondary invention point: Make full use of environmental media.

[0085] Three key inventions: The design concept effectively realizes unidirectional gas flow, improving the working efficiency of the underwater combustion chamber.

[0086] Four key inventions: effectively prevents reverse flow of combustion gases, protecting other engine components that are not resistant to high temperatures.

[0087] Five key inventions: While sealing the underwater combustion chamber, the water curtain can also cool the walls of the underwater combustion chamber, thereby increasing its service life.

[0088] Six key inventions: The water curtain can cool the turbine while sealing it, thus extending its service life.

[0089] Seven key inventions: Integrated design, significantly reducing machining and assembly costs.

[0090] Eight key inventions: Water curtain nozzles are designed with different nozzle structures according to requirements, including converging nozzles and expanding / contracting nozzles.

[0091] This invention completely solves the problem of reverse gas flow during underwater combustion chamber operation, maximizing the utilization rate of the high-temperature gas generated in the underwater combustion chamber, ensuring the working efficiency of the turbine, and also ensuring the overall performance of the engine.

[0092] Thus, the objective of this invention has been achieved.

[0093] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. 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 control structure for unidirectional flow and heat transfer of the working medium in a cross-medium engine, characterized in that, include: The turbine guide (1) has a fan-shaped notch for mounting the underwater combustion chamber; The underwater combustion chamber (2) has a fan-shaped structure with S-shaped water inlets and vents on the left and right sides. The outlet is matched with the fan-shaped notch of the turbine guide to generate high-temperature combustion gas in underwater mode. The sealing cover (3) is in the shape of an arc ring and is fixed on the underwater combustion chamber shell. It cooperates with the turbine guide to form a sealing structure to prevent gas from leaking to the compressor end. An annular water channel (5) is arranged on the outer diameter arc surface of the turbine guide, and multiple radial water curtain nozzles (6) are provided inside. A radial inlet (4) is connected to the annular water channel for introducing cooling water; The S-shaped water inlet is equipped with an axial water curtain nozzle, which is used to spray a water curtain to limit the radial diffusion of the gas and cool the combustion chamber wall. The annular water channel forms a radial water curtain in front of the turbine guide via the radial water curtain nozzle, preventing the gas from flowing backward and cooling the turbine components.

2. The cross-medium engine working medium unidirectional flow and heat transfer control structure according to claim 1, characterized in that, The S-shaped water inlet is a constant cross-section flow channel used to cool the underwater combustion chamber wall while delivering cooling water.

3. The unidirectional flow and heat transfer control structure for the working medium of a cross-medium engine according to claim 1, characterized in that, The radial water curtain nozzle has a cylindrical nozzle structure, and the nozzle form is either a converging nozzle or a contracting-expanding nozzle.

4. The unidirectional flow and heat transfer control structure for the working medium of a cross-medium engine according to claim 1, characterized in that, The outer diameter arc surface of the turbine guide is provided with multiple water inlet holes, which form a small gap overlapping structure with the radial water curtain nozzle.

5. The unidirectional flow and heat transfer control structure for the working medium of a cross-medium engine according to claim 1, characterized in that, The sealing cover is fixed to the underwater combustion chamber shell by welding and forms an axial seal with the turbine guide.

6. The unidirectional flow and heat transfer control structure for the working medium of a cross-medium engine according to claim 1, characterized in that, The radial inlet is provided with a threaded and tapered structure for connecting to an external water inlet device and achieving a seal.

7. The cross-medium engine working medium unidirectional flow and heat transfer control structure according to claim 1, characterized in that, The underwater combustion chamber, S-shaped water inlet, axial water curtain nozzle, and vent are integrated into a single structure.

8. A method for controlling the unidirectional flow and heat transfer of the working medium in a cross-medium engine, characterized in that, Includes the following steps: When the underwater combustion chamber is working, a water curtain is sprayed out through the axial water curtain nozzle in its S-shaped water inlet to restrict the axial flow of high-temperature gas in the turbine guide vane and prevent radial diffusion and backflow to the compressor end. Cooling water is injected into the annular water channel through the radial inlet, and a radial water curtain is formed in front of the turbine guide vane through the radial water curtain nozzle, which prevents the gas from flowing in reverse and cools the turbine guide vane. The gap between the underwater combustion chamber and the turbine guide vane is sealed by a sealing cover to prevent leaked gas and vaporized medium from flowing to the compressor end; The water curtain ejected through the S-shaped water inlet and radial water curtain nozzles simultaneously cools the underwater combustion chamber walls and turbine guide vanes.

9. The method according to claim 8, characterized in that, Both the axial and radial water curtains control their shape, direction, and coverage by adjusting the nozzle structure and cooling water pressure.

10. The method according to claim 8, characterized in that, It also includes guiding leaked combustion gases and vaporized media to the atmosphere through vents on both sides of the underwater combustion chamber to prevent them from accumulating inside the engine.

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