One-way heat storage type ocean temperature difference energy power generation system for underwater vehicle

Abstract

The invention provides an underwater vehicle one-way heat storage type ocean temperature difference energy power generation system which comprises an underwater vehicle body, a one-way heat storage type evaporator power generation system and a diving system. The one-way heat storage type evaporator power generation system and the rising and diving system are arranged in the underwater vehicle body. The power generation system comprises a turbine generator set, a condenser, a working medium pump and a heat storage type evaporator. An outlet of the heat storage type evaporator is connected with an inlet of the turbine generator set, and the turbine generator set is sequentially connected with the turbine generator set, the condenser, the working medium pump and an inlet of the heat storage type evaporator. Sea surface temperature seawater heat is stored through the energy storage phase change material, heat is not released to the environment in the submerging process of the underwater vehicle, when the underwater vehicle reaches the seabed, the stored heat and the cold energy of environment cold seawater are used for constructing temperature difference, and Rankine cycle is formed to achieve power generation. Therefore, the underwater vehicle has the capability of autonomously generating power by using the ocean temperature difference in the navigation process, and the endurance mileage and the sensor carrying capability of the underwater vehicle are improved.

Description

Technical Field

[0001] This invention belongs to the field of ocean thermal energy utilization, specifically relating to a one-way thermal storage ocean thermal energy power generation system for submersibles. Background Technology

[0002] Submersible vehicles (UVs) are autonomous underwater navigation systems that can perform various tasks such as marine exploration, search and rescue, and environmental monitoring, depending on the different sensors they carry. Current UVs primarily use chemical batteries for power, which are limited by the energy density limitations of lithium-ion batteries and fuel cells, resulting in limited range, insufficient sensor carrying capacity, and a narrow range of mission capabilities.

[0003] To overcome the limitations of battery capacity in underwater vehicles and improve their endurance and payload capacity, a power generation system for underwater vehicles powered by ocean thermal energy conversion (OTEC) is urgently needed. However, existing shore-based OTEC systems are constrained by site conditions and cannot be directly applied to the underwater vehicle airframe. Summary of the Invention

[0004] The purpose of this invention is to provide a one-way thermal storage ocean thermal energy conversion system for submersibles.

[0005] A one-way thermal energy storage ocean thermal energy conversion power generation system for submersibles includes a submersible fuselage, a one-way thermal energy storage evaporator power generation system, and an ascent / descent system. The one-way thermal energy storage evaporator power generation system and the ascent / descent system are located inside the submersible fuselage. The power generation system includes a turbine generator set, a condenser, a working fluid pump, and a thermal energy storage evaporator. The outlet of the thermal energy storage evaporator is connected to the inlet of the turbine generator set, and the turbine generator set is sequentially connected to the turbine generator set, the condenser, the working fluid pump, and the inlet of the thermal energy storage evaporator.

[0006] Furthermore, the thermal storage evaporator includes a unidirectional heat transfer heat pipe, a thermal storage phase change material, a thermal storage chamber, and a power generation cycle working fluid; the thermal storage phase change material is encapsulated inside the thermal storage chamber; the unidirectional heat transfer heat pipe passes through the outer wall of the thermal storage evaporator and the submersible body and is placed inside the thermal storage chamber, in contact with the thermal storage phase change material.

[0007] Furthermore, the unidirectional heat transfer heat pipe includes a unidirectional heat transfer heat pipe evaporation section, a unidirectional heat transfer heat pipe condensation section, a unidirectional heat transfer heat pipe adsorbent, and a unidirectional heat transfer heat pipe refrigerant; the unidirectional heat transfer heat pipe evaporation section is exposed in the seawater environment, and the unidirectional heat transfer heat pipe condensation section is in contact with the heat storage phase change material.

[0008] Furthermore, the unidirectional heat transfer heat pipes are arranged along the circumferential direction of the heat storage evaporator.

[0009] Furthermore, the submersion system includes an inner oil tank, an outer oil bladder, a piston assembly, a heat exchange tube, an expansion phase change material, a rubber oil bladder, a transmission oil chamber, and an N2 accumulator; the rubber oil bladder is placed inside the heat exchange tube and is in contact with the expansion phase change material; the transmission oil inside the rubber oil bladder is connected to the transmission oil chamber via an oil pipeline; the piston assembly is placed between the transmission oil chamber and the inner oil tank; the transmission oil in the inner oil tank is connected to the outer oil bladder via an oil pipeline.

[0010] Furthermore, the N2 accumulator is located inside the transmission oil chamber. The N2 accumulator contains high-pressure N2, and the initial charging pressure is determined by the target working depth of the submersible. When the target working depth of the submersible is 1000 meters, the initial pre-charge pressure of the N2 accumulator should not be less than 10 MPa.

[0011] Furthermore, the expanding phase change material uses straight-chain alkanes, including but not limited to a mixture of n-hexadecane, n-octadecane, and n-tetracosane, which expand in volume when in warm seawater and contract in cold seawater.

[0012] Furthermore, the condenser is a plate or shell-and-tube heat exchanger, used to pump cold seawater into the condenser to provide a cold source for the power generation cycle working fluid when the submersible dives to the seabed.

[0013] Furthermore, the turbine generator set is a centripetal turbine unit, which converts the kinetic energy of the working fluid into steam into mechanical energy.

[0014] Furthermore, the turbine generator set (2), condenser (3), working fluid pump (4) and thermal storage evaporator (5) are connected through a circulating working fluid loop (18). The circulating working fluid loop (18) adopts an organic Rankine cycle working fluid, including but not limited to R134a and R245fa, which evaporates in warm sea surface water and condenses in cold seawater.

[0015] The beneficial effects of this invention are as follows: 1. Compared with existing fixed shore-based or island-based ocean thermal energy conversion technologies, this invention proposes for the first time a unidirectional thermal storage evaporator power generation cycle. This allows the storage of surface seawater heat through energy storage phase change materials, without releasing heat into the environment during the submersible's descent. When the submersible reaches the seabed, it utilizes the stored heat and the coldness of the surrounding seawater to create a temperature difference, forming a Rankine cycle to generate electricity. This enables the submersible to autonomously generate electricity using ocean thermal differences during navigation, improving the underwater vehicle's range and sensor carrying capacity.

[0016] 2. Compared with existing energy storage-type portable power generation systems, this invention proposes a unidirectional heat transfer heat pipe that replaces the original warm seawater pump, thereby reducing the power consumption of the warm seawater pump. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the unidirectional heat storage heat pipe structure of the present invention; Figure 3 Diagram of the working mode of the sea surface in this invention; Figure 4 Diagram of the working mode under seabed conditions of this invention.

[0018] In the diagram: 1. Submarine fuselage, 2. Turbine generator set, 3. Condenser, 3-1. Condenser inlet, 3-2. Condenser outlet, 4. Working fluid pump, 5. Thermal storage evaporator, 6. One-way heat transfer heat pipe, 6-1. One-way heat transfer heat pipe evaporation section, 6-2. One-way heat transfer heat pipe condensation section, 6-3. One-way heat transfer heat pipe adsorbent, 6-4. One-way heat transfer heat pipe refrigerant, 7. Inner oil tank, 8. Outer oil bladder, 9. Piston assembly, 10. Heat exchanger tube, 11. Expansion phase change material, 12. Rubber oil bladder, 13. Transmission oil chamber, 14. N2 accumulator, 15. Thermal storage phase change material, 16. Thermal storage chamber, 17. Power generation cycle working fluid, 18. Cycle working fluid loop, 19. Cold seawater pump. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings.

[0020] like Figures 1-4 As shown, a one-way thermal storage ocean thermal energy conversion system for submersibles includes a submersible body 1, a one-way thermal storage evaporator power generation system, and an ascent / descent system. The one-way thermal storage evaporator power generation system and the ascent / descent system are located inside the submersible body 1. The power generation system includes a turbine generator set 2, a condenser 3, a working fluid pump 4, and a thermal storage evaporator 5. The outlet of the thermal storage evaporator 5 is connected to the inlet of the turbine generator set 2, and the turbine generator set 2 is sequentially connected to the turbine generator set 2, the condenser 3, the working fluid pump 4, and the inlet of the thermal storage evaporator 5.

[0021] Condenser 3 is a plate or shell-and-tube heat exchanger used to pump cold seawater into the condenser to provide a cold source for the power generation cycle working fluid when the submersible descends to the seabed.

[0022] Turbine generator set 2, condenser 3, working fluid pump 4 and thermal storage evaporator 5 are connected through a circulating working fluid loop 18. The circulating working fluid loop 18 uses organic Rankine cycle working fluid, including but not limited to R134a and R245fa, which evaporates in warm sea surface water and condenses in cold seawater.

[0023] Turbine generator set 2 is a radial turbine unit that converts the kinetic energy of the working fluid into steam into mechanical energy.

[0024] The thermal storage evaporator 5 includes a one-way heat transfer tube 6, a thermal storage phase change material 15, a thermal storage chamber 16, and a power generation cycle working fluid 17; the thermal storage chamber 16 encapsulates the thermal storage phase change material 15; the one-way heat transfer tube 6 passes through the outer wall of the thermal storage evaporator 5 and the submersible body 1 and is placed inside the thermal storage chamber 16, in contact with the thermal storage phase change material 15.

[0025] The unidirectional heat transfer heat pipe 6 only transfers heat from the warm seawater to the thermal storage phase change material 15 due to its own start-up temperature setting, and does not transfer heat from the thermal storage phase change material 15 to the outside.

[0026] The unidirectional heat transfer heat pipes 6 are arranged along the circumference of the heat storage evaporator. Each unidirectional heat transfer heat pipe 6 includes an evaporation section 6-1, a condensation section 6-2, an adsorbent 6-3, and a refrigerant 6-4. The evaporation section 6-1 is exposed to seawater, while the condensation section 6-2 is in contact with the heat storage phase change material. Under warm seawater conditions (>20℃), the adsorbent has a weak adsorption capacity for the refrigerant, allowing the refrigerant to participate in the heat pipe cycle, resulting in excellent heat conduction. However, under conditions below warm seawater conditions (<20℃), the adsorbent has a strong adsorption capacity for the refrigerant, preventing the refrigerant from participating in the heat pipe cycle and thus preventing heat transfer.

[0027] The thermal storage evaporator 5 is a multi-working-fluid indirect heat exchanger. The internal working fluids are the power generation cycle working fluid 17, the thermal storage phase change material 15, and the unidirectional heat transfer pipe 6. At the sea surface, the warm seawater transfers heat to the thermal storage phase change material 15 through the unidirectional heat transfer pipe 6, causing the thermal storage phase change material 15 to undergo a solid-liquid phase change and store heat. When the operating conditions are cold seawater at the seabed, due to the unidirectional heat transfer effect of the unidirectional heat transfer pipe 6, the heat of the phase change thermal storage material 15 cannot be transferred to the cold seawater. The heat of the thermal storage material is used to heat the power generation cycle working fluid 17 to make it evaporate and enter the turbine generator set 2 to generate electricity. The exhaust steam from the turbine flows through the condenser 3. The cold source of the condenser is the cold seawater. After the power generation cycle working fluid encounters the cold water, it condenses and is recirculated by the working fluid pump back to the thermal storage evaporator 5 to complete the power generation cycle.

[0028] The submersion system includes an inner oil tank 7, an outer oil bladder 8, a piston assembly 9, a heat exchange tube 10, an expansion phase change material 11, a rubber oil bladder 12, a transmission oil chamber 13, and an N2 accumulator 14. The rubber oil bladder 12 is placed inside the heat exchange tube 10 and is in contact with the expansion phase change material 11. The transmission oil inside the rubber oil bladder 12 is connected to the transmission oil chamber 13 via an oil pipeline. The piston assembly 9 is placed between the transmission oil chamber 13 and the inner oil tank 7. The transmission oil in the inner oil tank 7 is connected to the outer oil bladder 8 via an oil pipeline.

[0029] The N2 accumulator 14 is located inside the transmission oil chamber 13. The N2 accumulator 14 contains high-pressure N2. The initial charging pressure is determined by the target working depth of the submersible. When the target working depth of the submersible is 1000 meters, the initial pre-charge pressure of the N2 accumulator should not be less than 10 MPa.

[0030] The expandable phase change material 11 uses straight-chain alkanes, including but not limited to a mixture of n-hexadecane, n-octadecane, and n-tetracosane. It expands in volume when the sea surface is warm and the seabed is cold.

[0031] The power oil tank and the inner oil tank 7 are connected by a coaxial piston assembly. Its working characteristic is that when the pressure of the power oil tank increases, the piston assembly achieves a linkage effect. That is, under the surface working condition, the oil volume inside the power oil tank increases, causing the piston assembly 9 to move to the left as a whole, while under the seabed working condition, due to the action of the N2 accumulator 14, the entire piston assembly 9 moves to the right.

[0032] When the submersible is on the sea surface, warm seawater transfers heat to the heat exchange tubes, causing the expanding phase change material to absorb heat and expand. This compresses the transmission oil in the rubber oil bladder, causing it to move towards the transmission oil chamber and push the piston assembly to the left. The N2 accumulator stores pressure energy, and the transmission oil in the outer oil bladder is pumped into the inner oil tank. This reduces the system volume and displacement, enabling autonomous descent. When the submersible is on the seabed, the expanding phase change material in the heat exchange tubes releases heat to the cold seawater, causing the volume to shrink. At this time, the N2 accumulator is activated to release pressure, causing the piston assembly to move to the right. The transmission oil in the transmission oil chamber is forced into the rubber oil bladder of the heat exchange tubes, while the oil in the inner oil tank is discharged to the outer oil bladder. This increases the system volume and displacement, enabling autonomous ascent.

[0033] The cold seawater pump 19 is a submersible pump whose function is to pump cold seawater from the sea surface into the condenser to provide a cold source for the working fluid.

[0034] Working principle When the submersible is at the sea surface, such as Figure 3 As shown, the adsorbent 6-3 inside the unidirectional heat transfer heat pipe 6 has a weak adsorption effect on the refrigerant 6-4 under warm seawater conditions. Therefore, the refrigerant 6-4 participates in the heat pipe circulation, transferring the heat from the warm seawater to the heat storage phase change material 15, causing it to undergo a solid-liquid phase change to store heat. At the same time, the heat exchange tube 10 absorbs the heat from the warm seawater, causing the expansion phase change material 11 to expand in volume. This compresses the transmission oil in the rubber oil bladder 12 and moves it into the transmission oil chamber 13, pushing the piston assembly 9 to the left. The N2 accumulator 14 stores energy, and the transmission oil in the outer oil bladder 8 flows into the inner oil tank 7. The system's drainage volume decreases, becoming negative buoyancy, and it autonomously submerges. Since the circulating working fluid loop 18 does not have a temperature difference, the system turbine generator set 2 does not generate electricity.

[0035] When the submersible is on the seabed, such as Figure 4As shown, the ambient seawater temperature is low. The unidirectional heat transfer heat pipe adsorbent 6-3 inside the unidirectional heat transfer heat pipe 6 has a strong adsorption effect on the unidirectional heat transfer heat pipe refrigerant 6-4. Therefore, the unidirectional heat transfer heat pipe refrigerant 6-4 does not participate in the heat pipe cycle. Only a small portion of the heat in the heat storage phase change material 15 is transferred to the environment through heat conduction, and the vast majority is stored in the form of latent heat of phase change. At this time, the cold seawater pump 19 is turned on to allow cold seawater to enter the condenser 3 from the condenser inlet 3-1 and be discharged into the seawater from the condenser outlet 3-2. At this time, a temperature difference is formed between the heat storage evaporator 5 and the condenser 3. The power generation cycle working fluid 17 is in the heat storage... The evaporator 5 absorbs heat and evaporates, which then generates electricity through the turbine generator set 2. The exhaust steam enters the condenser 3 for condensation and is then pumped by the working fluid pump 4 to the heat storage evaporator 5 to form a cycle. At the same time, the heat exchange tube 10 exchanges heat with the cold seawater, causing the expansion phase change material 11 to shrink in volume, leaving space for the rubber oil bladder 12. This opens the N2 accumulator 14, releasing the mechanical energy stored within it, causing the piston assembly 9 to move to the right. This forces the transmission oil in the transmission oil chamber 13 into the rubber oil bladder 12, while simultaneously forcing the transmission oil in the inner oil tank 7 into the outer oil bladder 8. As a result, the system volume and displacement increase, creating positive buoyancy and enabling autonomous buoyancy.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A one-way thermal storage ocean thermal energy conversion power generation system for submersibles, characterized in that, It includes a submersible body (1), a one-way thermal storage evaporator power generation system and a submersible ascent system; the one-way thermal storage evaporator power generation system and the submersible ascent system are located inside the submersible body (1), and the power generation system includes a turbine generator set (2), a condenser (3), a working fluid pump (4) and a thermal storage evaporator (5); the outlet of the thermal storage evaporator (5) is connected to the inlet of the turbine generator set (2), and the turbine generator set (2) is connected in sequence to the turbine generator set (2), the condenser (3), the working fluid pump (4) and the inlet of the thermal storage evaporator (5).

2. The submersible unidirectional thermal storage ocean thermal energy conversion system according to claim 1, characterized in that, The thermal storage evaporator (5) includes a one-way heat transfer heat pipe (6), a thermal storage phase change material (15), a thermal storage chamber (16), and a power generation cycle working fluid (17); the thermal storage chamber (16) encapsulates the thermal storage phase change material (15); the one-way heat transfer heat pipe (6) passes through the outer wall of the thermal storage evaporator (5) and the submersible body (1) and is placed inside the thermal storage chamber (16), in contact with the thermal storage phase change material (15).

3. The submersible unidirectional thermal storage ocean thermal energy conversion power generation system according to claim 1, characterized in that, The unidirectional heat transfer heat pipe (6) includes a unidirectional heat transfer heat pipe evaporation section (6-1), a unidirectional heat transfer heat pipe condensation section (6-2), a unidirectional heat transfer heat pipe adsorbent (6-3), and a unidirectional heat transfer heat pipe refrigerant (6-4); the unidirectional heat transfer heat pipe evaporation section (6-1) is exposed to the seawater environment, and the unidirectional heat transfer heat pipe condensation section (6-2) is in contact with the heat storage phase change material.

4. A one-way thermal storage ocean thermal energy conversion system for submersibles according to claim 1, characterized in that, The unidirectional heat transfer tubes (6) are arranged along the circumference of the heat storage evaporator.

5. A one-way thermal storage ocean thermal energy conversion system for submersibles according to claim 1, characterized in that, The submersion system includes an inner oil tank (7), an outer oil bladder (8), a piston assembly (9), a heat exchange tube (10), an expansion phase change material (11), a rubber oil bladder (12), a transmission oil chamber (13), and an N2 accumulator (14). The rubber oil bladder (12) is placed inside the heat exchange tube (10) and is in contact with the expansion phase change material (11). The transmission oil inside the rubber oil bladder (12) is connected to the transmission oil chamber (13) via an oil pipeline. The piston assembly (9) is placed between the transmission oil chamber (13) and the inner oil tank (7). The transmission oil in the inner oil tank (7) is connected to the outer oil bladder (8) via an oil pipeline.

6. A one-way thermal storage ocean thermal energy conversion power generation system for submersibles according to claim 5, characterized in that, The N2 accumulator (14) is located inside the transmission oil chamber (13). The N2 accumulator (14) contains high-pressure N2. The initial charging pressure is determined by the target working depth of the submersible. When the target working depth of the submersible is 1000 meters, the initial pre-charging pressure of the N2 accumulator should not be less than 10 MPa.

7. A one-way thermal storage ocean thermal energy conversion system for submersibles according to claim 5, characterized in that, The expanding phase change material (11) uses straight-chain alkanes, including but not limited to a mixture of n-hexadecane, n-octadecane, and n-tetracosane, which expand in volume when the sea surface is warm and contract in volume when the seabed is cold.

8. A one-way thermal storage ocean thermal energy conversion system for submersibles according to claim 1, characterized in that, The condenser (3) is a plate or shell-and-tube heat exchanger, used to pump cold seawater into the condenser to provide a cold source for the power generation cycle working fluid when the submersible dives to the seabed.

9. A one-way thermal storage ocean thermal energy conversion system for submersibles according to claim 1, characterized in that, The turbine generator set (2) is a centripetal turbine unit that converts the kinetic energy of the working fluid into steam into mechanical energy.

10. A one-way thermal storage ocean thermal energy conversion power generation system for submersibles according to claim 1, characterized in that, The turbine generator set (2), condenser (3), working fluid pump (4) and thermal storage evaporator (5) are connected through a circulating working fluid loop (18). The circulating working fluid loop (18) uses organic Rankine cycle working fluid, including but not limited to R134a and R245fa, which evaporates in warm sea surface water and condenses in cold seawater.

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