Multi-phase heat exchanger of metal-based fuel water-air dual-mode propelling device

Abstract

The invention aims to provide a multiphase heat exchanger of a metal-based fuel water-air bimodal propulsion device, and belongs to the field of cross-medium aircrafts, the multiphase heat exchanger comprises a gas / water inlet system, a gas compressor, a heat exchanger body and a gas / water conveying system, the gas / water inlet system comprises a gas inlet channel and a water inlet channel, the gas compressor is mounted behind the gas / water inlet system, and the gas / water inlet channel is mounted behind the gas / water inlet system; the heat exchanger body comprises a shell, a heat exchange tube bundle is arranged in the shell, a hot end channel is formed between the shell and the heat exchange tube bundle, a cold end channel is formed in the heat exchange tube bundle, and the heat exchanger body is provided with a hot end inlet, a hot end outlet, a cold end inlet and a cold end outlet. The cold-end outlet is connected with the buffer chamber through a heat exchanger conveying pipeline. A large amount of waste heat generated when the engine works can be efficiently recycled and used for preheating water and air which are about to enter the combustion chamber, so that the temperature of a medium entering the combustion chamber is increased, the medium can react rapidly, and the stable reaction rate is provided.

Description

Technical Field

[0001] The present invention relates to a heat exchanger, specifically a heat exchanger for a transmedium aircraft. Background Technology

[0002] Dual-mode water ramjet engines, powered by aluminum-based and other metallic fuels, represent a significant future technological direction for cross-medium aircraft systems, enabling operation in both water and air media. In underwater mode, aluminum powder reacts with seawater. This generates high-temperature, high-pressure gas and creates powerful thrust; in the air mode, the aluminum powder undergoes a combustion reaction with oxygen in the air. It uses combustion to drive the engine.

[0003] While the aforementioned existing technologies offer valuable ideas and solutions, they still have some key shortcomings: First, the reaction between aluminum and water requires a relatively high activation energy. Seawater has a relatively low average temperature; if the seawater entering the combustion chamber is too cold, the reaction rate will be very slow. For an engine, a stable and rapid reaction is essential for maintaining stability. Therefore, the seawater needs to be preheated to a certain temperature before entering the combustion chamber for combustion.

[0004] Secondly, aluminum powder needs to react with air at a specific temperature. If the air temperature entering the combustion chamber is too low, it will reduce the reaction rate in the combustion zone, potentially affecting the complete combustion of the aluminum powder and leading to a loss of thermal efficiency. Therefore, the air entering the combustion chamber needs to reach a certain temperature to better react with the aluminum powder.

[0005] Currently, the conventional approach to solving the preheating problem is to use an independent electric preheating system or a combustion starter propellant. However, these methods have significant drawbacks: electric preheating systems increase energy consumption and system complexity, reducing the overall engine energy density; while starter propellants are single-use and cannot meet the needs of multiple engine ignitions and operating condition switching.

[0006] On the other hand, during operation, the combustion chamber and nozzle of a dual-mode water ramjet engine are exposed to extreme high temperatures (typically exceeding 1500°C) generated by the aluminum reaction, causing a significant amount of waste heat to accumulate and dissipate on their outer walls. Currently, this heat is typically passively carried away and dissipated through external cooling systems (such as sweating cooling or regenerative cooling), resulting in substantial energy waste.

[0007] Therefore, there is an urgent need in this field for an innovative preheating solution that can comprehensively utilize the engine's own waste heat, effectively improve reaction efficiency, and solve the problem of reaction start-up. Summary of the Invention

[0008] The purpose of this invention is to provide a multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device that can increase the temperature of the medium entering the combustion chamber, enabling it to react rapidly and provide a stable reaction rate.

[0009] The objective of this invention is achieved as follows: This invention discloses a multiphase heat exchanger for a metal-based fuel-water-air dual-mode propulsion device, characterized by comprising an air / water intake system, a compressor, a heat exchanger body, and an air / water delivery system. The air / water intake system includes parallel air intake channels and water intake channels. The compressor is installed behind the air / water intake system, and a separator is provided between the compressor and the air / water intake system. The heat exchanger body includes a shell, inside which a heat exchange tube bundle is arranged. A hot-end channel is formed between the shell and the heat exchange tube bundle, and a cold-end channel is formed inside the heat exchange tube bundle. The heat exchanger body is respectively provided with a hot-end inlet, a hot-end outlet, a cold-end inlet, and a cold-end outlet. The hot end inlet and hot end outlet are located on both sides of the heat exchanger body and connected to the hot end channel. The cold end inlet and cold end outlet are located on both sides of the heat exchanger body and arranged in parallel with the hot end inlet and hot end outlet. Both the cold end inlet and cold end outlet are connected to the cold end channel. The hot end inlet is connected to the tail end of the metal-based fuel engine, and the hot end outlet is connected to the exhaust port of the tail end of the metal-based fuel engine. The cold end inlet is connected to the compressor through an isolation section. The gas / water transmission system includes a buffer chamber. The cold end outlet is connected to the buffer chamber through the heat exchanger transmission pipeline. The buffer chamber is connected to the combustion chamber of the metal-based fuel engine through the engine transmission pipeline.

[0010] The present invention may also include: 1. A filter screen is installed inside the air intake channel, and a first pneumatic / hydraulic valve is installed at the end of the air intake channel.

[0011] 2. A filter screen is installed inside the water inlet channel, and a second pneumatic / hydraulic valve is installed at the end of the water inlet channel.

[0012] 3. The heat exchanger body is located on the side of the combustion chamber of the metal-based fuel engine.

[0013] 4. Temperature sensors are installed at the hot end inlet, hot end outlet, cold end inlet, and cold end outlet respectively. Flow regulating valves are installed behind the isolation section and at the cold end inlet.

[0014] 5. Install flow valves in the engine delivery pipeline.

[0015] 6. The cold end inlet is located below the hot end outlet, and the cold end outlet is located below the hot end inlet.

[0016] 7. In underwater mode, the first pneumatic / hydraulic valve is closed, the second pneumatic / hydraulic valve is open, the compressor starts to draw in seawater, which flows into the cold end inlet after passing through the filter and separator; in air mode, the second pneumatic / hydraulic valve is closed, the first pneumatic / hydraulic valve is open, the compressor starts to draw in air, which flows into the cold end inlet after passing through the filter and separator.

[0017] The advantage of this invention is that it can efficiently recover a large amount of waste heat generated during engine operation and use it to preheat the water and air that are about to enter the combustion chamber, thereby increasing the temperature of the medium entering the combustion chamber, enabling it to react quickly and provide a stable reaction rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of a heat exchanger. Detailed Implementation

[0019] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1-2 This invention specifically provides a multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device, comprising an air / water system 1, a heat exchanger body 2, and an air / water delivery system 3. The air / water system 1 includes an air intake channel 4, a water intake channel 5, a compressor 6, an isolation section 7, a pneumatic / hydraulic valve 16, a multi-layer filter screen 17, and a separator 18. The heat exchanger body 2 includes a shell 8, hot-end inlet / outlet 9, cold-end inlet / outlet 10, a heat exchange tube bundle 11, and a temperature and flow control element 12. The air / water delivery system 3 includes a delivery pipeline 13, a buffer chamber 14, and a flow valve 15.

[0020] The air inlet channel 4 and the water inlet channel 5 are arranged side by side and connected at the rear end as a whole to the compressor 6. The isolation section 7 is located at the rear of the compressor 6 and is connected to the cold end inlet of the heat exchanger 2.

[0021] The air intake passage 4 is equipped with an openable and closable pneumatic valve, which opens in air mode to connect with the outside air and closes in underwater mode to prevent air from entering the engine. The passage integrates multiple layers of filters 17 and gas-liquid separator blades to prevent tiny solid and liquid impurities in the air from entering the engine.

[0022] The water inlet channel is equipped with an openable and closable hydraulic valve, which is closed in the air mode to isolate external air, and open in the underwater mode to connect with the external seawater. The channel integrates multi-stage filters 17 and a vortex separator to filter out impurities and air bubbles in the water.

[0023] The compressor 6 is located after the air intake passage 4 and the water intake passage 5. It is used to increase the intake air pressure and water flow velocity when the engine is started, so as to ensure a stable flow rate of the medium before entering the engine.

[0024] Isolation section 7 is located after compressor 6 to ensure stable air and water intake.

[0025] The heat exchanger body 2 is provided with a shell 8, hot end inlet and outlet, cold end inlet and outlet, heat exchange tube bundle 11, and temperature and flow control elements.

[0026] Hot end inlet / outlet 9 and cold end inlet / outlet 10 are respectively located at both ends of the shell 8. Heat exchange tube bundle 11 is located inside the shell 8. Temperature and flow control element 12 is located at hot end inlet / outlet 9 and cold end inlet / outlet 10.

[0027] The shell 8 is made of high-strength, high-thermal-conductivity high-temperature resistant alloy. Its shape is precisely machined into a small cavity three-dimensional structure, and its shape should match the outer wall curved surface of the dual-mode engine.

[0028] The hot end inlet and outlet 9 should be located on both sides of the housing 8. The hot end inlet is connected to the engine tail and is used to transport high-temperature gas after the engine runs. The hot end outlet is connected to the engine tail exhaust port and is used to discharge the medium after heat exchange.

[0029] The cold end inlet and outlet 10 should be located on both sides of the shell 8. The cold end inlet and the hot end inlet should be placed in parallel and connected to the isolation section. The cold end outlet and the hot end outlet should be placed in parallel and connected to the conveying pipeline 13.

[0030] The materials for the hot end inlet / outlet (9) and the cold end inlet / outlet (10) should be suitable for the flow of both gas and water media, and have the characteristics of high pressure resistance, high temperature resistance, and corrosion resistance.

[0031] The heat exchange tube bundle 11 is made of a material that is resistant to high temperature, high pressure, and corrosion and has good heat transfer performance. The internal flow medium is cold, and the space between the tube bundle 11 and the shell 8 is hot.

[0032] The temperature and flow control element 12 should include a temperature sensor, a flow regulating valve, and a controller. The temperature sensors are installed at the hot end inlet and outlet, and the cold end inlet and outlet, respectively, to monitor the temperature of the working fluid after preheating in real time. The flow regulating valve is a high-precision stepper motor driven valve, installed after the isolation section and before the cold end inlet of the heat exchanger. The controller receives the temperature sensor signal and, according to the engine operating mode command, dynamically adjusts the flow rate of water or air by controlling the opening of the flow regulating valve to ensure that the output flow rate remains stable within the set range.

[0033] The gas / water transmission system 3 is equipped with a transmission pipeline 13, a buffer chamber 14, and a flow valve 15.

[0034] The delivery pipeline 13 should be connected to the cold end outlet of the heat exchanger body 2 and then connected to the buffer chamber 14, and from the buffer chamber 14 to the engine combustion chamber.

[0035] The buffer chamber 14 is located between the heat exchanger 2 and the engine combustion chamber and is connected by the delivery pipeline 13 to ensure the stability of the gas flow rate.

[0036] The flow valve 15 is located between the buffer chamber 14 and the engine combustion chamber inlet to regulate the flow rate entering the combustion chamber.

[0037] The air / water intake system 1 is located in front of the engine fuel inlet at the nose of the aircraft and adopts a dual-channel scheme: the air intake channel 4 and the water intake channel 5 are arranged side by side. Both channels are equipped with pneumatic / hydraulic valves 16. The air intake channel 4 integrates multi-layer filter screens 17 and gas-liquid separators 18. The water intake channel 5 integrates multi-stage filter screens 17 and vortex separators 18. The tail is connected to the same inlet and connected to the compressor 6. The isolation section 7 is connected to the tail of the compressor 6 and connected to the inlet of the cold end inlet / outlet 10.

[0038] The heat exchanger body 2 is located on the side of the engine combustion chamber. The shell 8 is made of an alloy with good high-temperature resistance, corrosion resistance, high-pressure resistance, and thermal insulation properties. It contains multiple heat exchange tube bundles 11, which should be made of an alloy with good thermal conductivity. The hot-end inlet and outlet 9 are located on both sides of the shell. The hot-end inlet is connected to the engine tail section to transport high-temperature gas after engine operation, and the hot-end outlet is connected to the engine exhaust port for discharging the medium after heat exchange. The cold-end inlet and outlet 10 are located on both sides of the shell. The cold-end inlet is placed parallel to the hot-end inlet and connected to the isolation section 7. The cold-end outlet is placed parallel to the hot-end outlet and connected to the delivery pipeline. The temperature and flow control element 12 should include a sensor, a flow regulating valve, and a controller. Temperature sensors are installed at the hot-end inlet and outlet 9 and the cold-end inlet and outlet 10 respectively to monitor the temperature of the working fluid after preheating in real time. The flow regulating valve is a high-precision stepper motor driven valve, installed after the isolation section 7 and before the cold-end inlet of the heat exchanger. The controller receives signals from the temperature sensor and, according to the engine operating mode command, dynamically adjusts the flow rate of water or air by controlling the opening of the flow regulating valve to ensure that its output flow rate remains stable within the set range.

[0039] In the gas / water system 3, buffer chamber 14 is connected to the cold end outlet of heat exchanger body 2 via pipeline 13, and buffer chamber 14 is also connected to the engine combustion chamber. Buffer chamber 14 is positioned between the heat exchanger and the engine combustion chamber and connected by pipeline 13 to ensure stable gas flow. Flow valve 15 is positioned between buffer chamber 14 and the engine combustion chamber inlet to regulate the flow rate entering the combustion chamber.

[0040] This invention is divided into underwater mode and air mode. When the aircraft is in underwater mode, the air intake channel 4 is closed by the pneumatic / hydraulic valve 16, the water intake channel 5 is opened, and the compressor 6 is turned on to draw in seawater through the filter screen 17 and the separator 18, which flows into the inlet of the cold end inlet / outlet 10. When the aircraft is in air mode, the water intake channel 5 is closed by the pneumatic / hydraulic valve 16, the air intake channel 4 is opened, and the compressor 6 is turned on to draw in air through the filter screen 17 and the separator 18, which flows into the inlet of the cold end inlet / outlet 10.

[0041] The cold-end medium is located within the heat exchange tube bundle 11. High-temperature, high-pressure gas discharged from the engine after combustion enters through the inlet of the hot-end inlet / outlet 9, where it exchanges heat with the cold-end medium in the heat exchanger shell 8. After heat exchange, the cold-end medium, with its temperature increased, enters the buffer chamber 14 via the delivery pipeline 13 and then enters the combustion chamber for further reaction. The hot-end medium is then directly discharged after heat exchange.

Claims

1. A multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device, characterized in that: The system includes an air / water intake system, a compressor, a heat exchanger body, and an air / water delivery system. The air / water intake system includes parallel air intake channels and water intake channels. The compressor is installed behind the air / water intake system, and a separator is installed between the compressor and the air / water intake system. The heat exchanger body includes a shell, inside which a heat exchange tube bundle is installed. A hot-end channel is formed between the shell and the heat exchange tube bundle, and a cold-end channel is formed inside the heat exchange tube bundle. The heat exchanger body is provided with a hot-end inlet, a hot-end outlet, a cold-end inlet, and a cold-end outlet. The hot-end inlet and hot-end outlet are located at... The heat exchanger body has hot end channels on both sides. The cold end inlet and cold end outlet are located on both sides of the heat exchanger body and are arranged in parallel with the hot end inlet and hot end outlet. The cold end inlet and cold end outlet are both connected to the cold end channels. The hot end inlet is connected to the tail of the metal-based fuel engine, and the hot end outlet is connected to the exhaust port of the tail of the metal-based fuel engine. The cold end inlet is connected to the compressor through an isolation section. The gas / water transmission system includes a buffer chamber. The cold end outlet is connected to the buffer chamber through the heat exchanger transmission pipeline. The buffer chamber is connected to the combustion chamber of the metal-based fuel engine through the engine transmission pipeline.

2. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: A filter screen is installed inside the air intake channel, and a first pneumatic / hydraulic valve is installed at the end of the air intake channel.

3. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: A filter screen is installed inside the water inlet channel, and a second pneumatic / hydraulic valve is installed at the end of the water inlet channel.

4. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: The heat exchanger body is located on the side of the combustion chamber of the metal-based fuel engine.

5. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: Temperature sensors are installed at the hot end inlet, hot end outlet, cold end inlet, and cold end outlet respectively, and a flow regulating valve is installed behind the isolation section and at the cold end inlet.

6. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: Flow valves are installed in the engine delivery pipeline.

7. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: The cold end inlet is located below the hot end outlet, and the cold end outlet is located below the hot end inlet.

8. The multiphase heat exchanger for a metal-based fuel water-air dual-mode propulsion device according to claim 1, characterized in that: In underwater mode, the first pneumatic / hydraulic valve is closed, the second pneumatic / hydraulic valve is open, and the compressor starts to draw in seawater, which flows into the cold end inlet after passing through the filter and separator. In air mode, the second pneumatic / hydraulic valve is closed, the first pneumatic / hydraulic valve is open, and the compressor starts to draw in air, which flows into the cold end inlet after passing through the filter and separator.

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