Efficient petroleum pipeline anti-drag conveying system based on photo-thermal coupling phase change temperature control

Abstract

The invention relates to an efficient petroleum pipeline anti-drag conveying system based on photo-thermal coupling phase change temperature control. The efficient petroleum pipeline anti-drag conveying system comprises an oil conveying unit, a photo-thermal conversion unit, a heat exchange unit and a heat storage unit. The oil conveying unit comprises two flexible flame-retardant PCMs which are attached to the wall of the oil conveying pipeline and have different phase transition temperatures, and the vortex-shaped coil pipe is coiled in the PCMs; the light-heat conversion unit comprises a groove type condenser erected on the bottom face, right opposite to the oil conveying pipeline, of the oil conveying pipeline and is controlled by a solar tracking device, a rotating shaft and a speed reducer to implement single-shaft tracking. The heat exchange unit comprises a U-shaped pipe type fluoroplastic heat exchanger communicating with the heat storage unit and the oil conveying unit, a fluoroplastic U-shaped pipe is fixed through a fixing rotary knob and is detachable, and a heat exchange cold medium is nanofluid with the Al2O3 mass fraction being 5 wt%. The heat storage unit comprises a double-cavity phase change heat storage tank with two cavities, and a spiral heat pipe of a high-temperature cavity is filled with heat storage microcapsules. According to the invention, efficient anti-drag transportation of the petroleum pipeline is realized by using the photo-thermal coupling phase change material.

Description

TECHNICAL FIELD

[0001] The present application relates to coupling clean energy to solve the problem of drag reduction in oil pipeline transportation, and in particular to an efficient oil pipeline drag reduction transportation system based on photothermal coupling phase change temperature control. BACKGROUND

[0002] From the current world energy structure, oil is still the main body of global energy consumption and occupies an important position. Oil pipeline transportation has become the main mode of oil transportation due to its convenience, safety, easy operation and other significant advantages. However, the physical properties of oil, such as high viscosity, bring many challenges to pipeline transportation. In the traditional pipeline transportation process, a large amount of additional heat energy needs to be consumed to maintain the fluidity of oil, which not only increases energy consumption, but also may cause the adhesion of oil on the pipeline wall, thereby causing loss. In addition, cleaning the oil adhered to the pipeline wall requires a lot of manpower and material resources, which seriously affects the transportation efficiency. Due to the discontinuity of the heating method, the heat supply to the crude oil is also intermittent, and how to realize continuous heat supply becomes a difficult problem to be solved. At the same time, the untimely heat recovery also causes a lot of energy waste.

[0003] With the development of thermal management technology, phase change materials (PCM) have gradually become the first choice in the temperature control field due to their high efficient heat exchange characteristics and latent heat characteristics. Phase change materials can absorb and release a large amount of latent heat at a specific temperature, thereby realizing effective storage and release of heat energy. In oil pipeline transportation, temperature control using phase change materials can effectively utilize renewable energy such as solar energy and reduce dependence on traditional heat energy. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide an efficient oil pipeline drag reduction transportation system based on photothermal coupling phase change temperature control, which can flexibly couple PCM and efficiently utilize solar energy to realize continuous and efficient heat supply to the oil transportation pipeline.

[0005] In order to solve the above technical problems, the technical scheme of the present application is: an efficient oil pipeline drag reduction transportation system based on photothermal coupling phase change temperature control, comprising:

[0006] The oil delivery unit comprises an oil delivery pipeline, flexible flame-retardant PCM I, flexible flame-retardant PCM II, a protective layer, a vortex coil, a coil inlet, a coil outlet, an oil delivery pipeline wall, a spiral fin, an oil pump and a water pump, the flexible flame-retardant PCM I with a lower phase change temperature is arranged on the upper half outer wall of the pipeline and faces the groove-shaped condenser, the flexible flame-retardant PCM II with a higher phase change temperature is arranged on the lower half outer wall of the pipeline and is between the two groove-shaped condensers, the phase change layer is encapsulated by the protective layer and plays a heat preservation role, the vortex coil is located in the flexible flame-retardant PCM I, the coil inlet is connected to the high-temperature cavity outlet of the double-cavity phase change heat storage tank, the coil outlet is connected to the low-temperature cavity inlet of the double-cavity phase change heat storage tank, the heat exchange medium is Al2O3 nano-fluid with a mass fraction of 5wt%, the water pump is used for driving, and the spiral fin is arranged on the pipeline wall at the light condensing position of the groove-shaped condenser along the oil flow direction.

[0007] The light-heat conversion unit comprises a main device groove-shaped condenser, a solar tracking device, a rotating shaft and a speed reducer, the solar tracking device and the speed reducer are located on one side of the rotating shaft, and the groove-shaped condenser is movably connected with the rotating shaft through a support.

[0008] The heat exchange unit comprises a U-shaped fluoroplastic heat exchanger, a hot medium inlet, a hot medium outlet, a cold medium inlet, a cold medium outlet, a tube side partition plate, a baffle, a fluoroplastic U-shaped tube, a fixing ring and a fixing knob, the hot medium inlet is connected to the high-temperature oil outlet of the oil delivery pipeline, the hot medium outlet is connected to the low-temperature oil inlet of the oil delivery pipeline after heat exchange, the oil pump is used for driving, the cold medium inlet is connected to the low-temperature cavity outlet of the double-cavity phase change heat storage tank, the cold medium outlet is connected to the high-temperature cavity inlet of the double-cavity phase change heat storage tank, the water pump is used for driving, the hot medium is oil heated by light condensation, the cold medium is Al2O3 nano-fluid with a mass fraction of 5wt%, the tube side partition plate is arranged in the tube box to divide the tube side fluid into multiple flows, the baffle is arranged in the shell to guide the flow of the shell side fluid, the fluoroplastic U-shaped tube is arranged in the shell and is fixed by the fixing ring and the fixing knob and can be disassembled and cleaned.

[0009] The heat storage unit comprises a double-cavity phase change heat storage tank, a low-temperature cavity, a low-temperature cavity inlet, a low-temperature cavity outlet, a high-temperature cavity, a high-temperature cavity inlet, a high-temperature cavity outlet, a partition plate, an inner cavity, an outer cavity, a vacuum heat insulation layer, a spiral heat pipe and a heat storage microcapsule, the inner cavity is arranged around the double-cavity phase change heat storage tank near the heat storage cavity, and the outer cavity is arranged at the outermost side, the vacuum heat insulation layer is arranged between the inner cavity and the outer cavity, the partition plate in the middle of the heat storage tank divides the low-temperature cavity and the high-temperature cavity, the spiral heat pipes are arranged in the two cavities, the heat exchange medium flowing in the pipes is Al2O3 nano-fluid with a mass fraction of 5wt%, the low-temperature cavity inlet is connected to the coil outlet of the vortex coil, the low-temperature cavity outlet is connected to the cold medium inlet of the U-shaped fluoroplastic heat exchanger, the high-temperature cavity inlet is connected to the cold medium outlet of the U-shaped fluoroplastic heat exchanger, and the high-temperature cavity outlet is connected to the coil inlet of the vortex coil, wherein the spiral heat pipe in the high-temperature cavity is filled with the heat storage microcapsule.

[0010] Furthermore, the outer wall of the oil pipeline is laid with flexible flame-retardant PCM with latent heat properties to efficiently store solar waste heat. On the one hand, it can play a role in uniform and constant temperature, keeping the temperature of the outer wall of the pipeline relatively stable; on the other hand, it can collect solar waste heat in the form of latent heat and release this heat at night for pipeline insulation, thereby achieving a good temperature control effect.

[0011] Furthermore, a flexible flame-retardant PCMⅠ with a low phase change point temperature is laid on the upper wall of the oil pipeline and directly opposite the trough concentrator, while a flexible flame-retardant PCMⅡ with a high phase change point temperature is laid on the lower wall of the oil pipeline and between the two trough concentrators.

[0012] Furthermore, a vortex coil is arranged only around the flexible flame-retardant PCMⅠ, wherein the inlet of the vortex coil is connected to the outlet of the high-temperature chamber of the dual-chamber phase change heat storage tank, and the outlet of the coil is connected to the inlet of the low-temperature chamber of the dual-chamber phase change heat storage tank.

[0013] Furthermore, the fluoroplastic U-tube is made of fluoroplastic, which is non-corrosive to petroleum and does not easily adhere to the wall. It is installed inside the U-tube type fluoroplastic heat exchanger by a retaining ring and a fixing knob, and can be disassembled for cleaning via the fixing knob.

[0014] Furthermore, the inner and outer cavities of the dual-cavity phase change thermal storage tank are separated by a vacuum insulation layer.

[0015] Furthermore, the dual-cavity phase change heat storage tank is divided into a low-temperature cavity and a high-temperature cavity by a partition. The spiral heat pipe in the high-temperature cavity is filled with heat storage microcapsules. These heat storage microcapsules have unique phase change characteristics and can absorb and release a large amount of heat within a specific temperature range. When the temperature rises, the heat storage microcapsules absorb heat and undergo a phase change, storing the heat in the form of latent heat. When the temperature drops, the heat storage microcapsules release the stored heat, thereby playing a role in regulating temperature and balancing thermal energy.

[0016] Furthermore, the cold medium in the U-shaped tube fluoroplastic heat exchanger and the heat exchange medium in the dual-cavity phase change heat storage tank are both nanofluids with an Al2O3 mass fraction of 5wt%.

[0017] This invention provides a high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control. It has the following beneficial effects:

[0018] 1. This invention aims to address numerous problems arising from the use of non-renewable energy sources for initial heating in traditional oil pipeline transportation, such as high energy consumption, severe environmental pollution, and the impact of excessively high oil viscosity on transportation efficiency. By innovatively introducing clean and renewable energy—solar energy—and combining it with advanced concentrating technology, this invention achieves highly efficient concentrated heating. Utilizing the principle of photothermal conversion, it significantly increases the temperature of the oil, thereby effectively reducing its viscosity and accelerating transportation speed. This process is not only energy-saving and environmentally friendly, reducing dependence on traditional energy sources, but also achieves green and sustainable energy utilization, providing an efficient, environmentally friendly, and sustainable solution for the oil pipeline transportation field.

[0019] 2. In oil pipeline transportation systems, precise and stringent temperature control of oil pipelines is achieved by cleverly coupling phase change materials (PCMs) and fully utilizing their latent heat characteristics at different phase change temperatures. This design not only ensures continuous and uninterrupted temperature control of the pipeline but also leverages the PCM's ability to absorb and release large amounts of heat during phase change to achieve efficient energy reuse, significantly improving energy efficiency and reducing energy consumption. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control of the present invention;

[0021] Figure 2 This is a schematic diagram of the light-concentrating principle of the present invention;

[0022] Figure 3 This is a schematic diagram of the focusing tracking structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the vortex coil layout of the present invention;

[0024] Figure 5 This is a schematic diagram of the spiral fin arrangement of the present invention;

[0025] Figure 6 This is a schematic diagram of the U-shaped tube fluoroplastic heat exchanger structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the dual-cavity phase change thermal storage tank structure of the present invention.

[0027] Figures 1-7The following are explanations of the designation numbers: 1-Oil pipeline; 111-Flexible flame-retardant PCMⅠ; 112-Flexible flame-retardant PCMⅡ; 12-Protective layer; 13-Vortex coil; 131-Coil inlet; 132-Coil outlet; 14-Oil pipeline wall; 15-Helical fins; 16-Oil pump; 17-Water pump; 2-Trough concentrator; 21-Solar tracking system; 22-Rotating shaft; 23-Reducer; 3-U-tube fluoroplastic heat exchanger; 311-Heat medium inlet; 312-Heat medium outlet; 3 13-Cold medium inlet; 314-Cold medium outlet; 32-Pipe-side partition; 33-Baffle; 34-Fluoroplastic U-tube; 35-Fixing retaining ring; 36-Fixing knob; 4-Dual-cavity phase change heat storage tank; 41-Low-temperature cavity; 411-Low-temperature cavity inlet; 412-Low-temperature cavity outlet; 42-High-temperature cavity; 421-High-temperature cavity inlet; 422-High-temperature cavity outlet; 43-Partition; 431-Inner cavity; 432-Outer cavity; 433-Vacuum insulation layer; 44-Spiral heat pipe; 45-Heat storage microcapsule. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example:

[0030] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0031] like Figure 1 , 2 As shown in Figures 3, 4, 5, 6, and 7, a high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control includes:

[0032] The oil transportation unit includes an oil pipeline 1, flexible flame-retardant PCMⅠ111, flexible flame-retardant PCMⅡ112, a protective layer 12, a vortex coil 13, a coil inlet 131, a coil outlet 132, an oil pipeline wall 14, spiral fins 15, an oil pump 16, and a water pump 17. The upper half of the outer wall of the pipeline, facing the trough concentrator 2, is covered with flexible flame-retardant PCMⅠ111 with a lower phase change temperature. The lower half of the outer wall of the pipeline, located between the two trough concentrators 2, is covered with flexible flame-retardant PCMⅡ112 with a higher phase change temperature. The outer edge of the layer is encapsulated by a protective layer 12 and serves as a heat insulation layer. The vortex coil 13 is coiled inside the flexible flame-retardant PCMⅠ111. The coil inlet 131 is connected to the high-temperature cavity outlet 422 of the dual-cavity phase change heat storage tank 4, and the coil outlet 132 is connected to the low-temperature cavity inlet 411 of the dual-cavity phase change heat storage tank 4. The heat exchange medium is a nanofluid with an Al2O3 mass fraction of 5wt%, driven by a water pump 17. Spiral fins 15 are installed on the inner side of the oil pipe wall 14 and on the pipe wall located at the concentrating part of the trough concentrator 2 in the direction of oil flow.

[0033] The light-to-thermal conversion unit includes a main device, a trough concentrator 2, a solar tracking device 21, a rotating shaft 22, and a reducer 23. The solar tracking device 21 and the reducer 23 are located on one side of the rotating shaft 22, and the trough concentrator 2 is movably connected to the rotating shaft 22 via a bracket.

[0034] The heat exchange unit includes a U-tube fluoroplastic heat exchanger 3, a hot medium inlet 311, a hot medium outlet 312, a cold medium inlet 313, a cold medium outlet 314, a tube-side partition 32, a baffle 33, a fluoroplastic U-tube 34, a retaining ring 35, and a retaining knob 36. The hot medium inlet 311 is connected to the high-temperature oil outlet of the oil pipeline 1, and the hot medium outlet 312 is connected to the low-temperature oil inlet after heat exchange in the oil pipeline 1, driven by an oil pump 16. The cold medium inlet 313 is connected to the low-temperature chamber of the dual-chamber phase change heat storage tank 4. The outlet 412 and the cold medium outlet 314 are connected to the high temperature chamber inlet 421 of the dual-chamber phase change thermal storage tank 4, driven by the water pump 17. The heat medium is petroleum heated by concentrated light, and the cold medium is nanofluid with a mass fraction of 5wt% Al2O3. The tube side baffle 32 is installed inside the tube box to divide the tube side fluid into multiple channels. The baffle 33 is installed inside the shell to guide the flow of the shell side fluid. The fluoroplastic U-tube is located inside the shell and is fixed by the fixing ring 35 and the fixing knob 36, and can be disassembled for cleaning.

[0035] The thermal storage unit includes a dual-cavity phase change thermal storage tank 4, a low-temperature cavity 41, a low-temperature cavity inlet 411, a low-temperature cavity outlet 412, a high-temperature cavity 42, a high-temperature cavity inlet 421, a high-temperature cavity outlet 422, a partition 43, an inner cavity 431, an outer cavity 432, a vacuum insulation layer 433, a spiral heat pipe 44, and thermal storage microcapsules 45. The inner cavity 431 surrounds the dual-cavity phase change thermal storage tank 4 near the thermal storage cavity body, and the outermost part is the outer cavity 432. The vacuum insulation layer 433 is located between the inner cavity 431 and the outer cavity 432. The partition 43 in the middle of the thermal storage tank separates the low-temperature cavity 41 and the high-temperature cavity 422. The cavity 42 has two spiral heat pipes 44 evenly distributed inside. The heat exchange medium flowing inside the pipes is a nanofluid with an Al2O3 mass fraction of 5wt%. The inlet 411 of the low temperature cavity is connected to the coil outlet 132 of the vortex coil 13, and the outlet 412 of the low temperature cavity is connected to the cold medium inlet 313 of the U-tube fluoroplastic heat exchanger 3. The inlet 421 of the high temperature cavity is connected to the cold medium outlet 314 of the U-tube fluoroplastic heat exchanger 3, and the outlet 422 of the high temperature cavity is connected to the coil inlet 131 of the vortex coil 13. The spiral heat pipes 44 of the high temperature cavity 42 are filled with heat storage microcapsules 45.

[0036] When there is sufficient sunlight during the day, the trough concentrator 2 begins to operate. Its solar tracking device 21 constantly tracks the sun's position. Driven by the reducer 23, the rotating shaft 22 rotates the trough concentrator 2 in a north-south direction, allowing the reflected sunlight to directly hit the lower wall of the oil pipeline 1, thereby raising the temperature of the oil inside the pipeline. As the distance of the trough concentrator 2 along the oil pipeline 1 increases, the increase in oil temperature also increases. Due to the special effect of concentrating sunlight, the temperature of the lower wall of the oil pipeline 1 is higher than that of the upper wall. Therefore, a flexible flame-retardant PCM I with a lower phase change point temperature is laid on the upper wall of the oil pipeline 1, while a flexible flame-retardant PCM II with a higher phase change point temperature is laid between the two trough concentrators 2. The PCMs at both locations serve two purposes: firstly, to achieve uniform and constant temperature; and secondly, to absorb the residual heat of the oil inside the pipeline and store it as latent heat. The PCMs are encapsulated by a protective layer 12 for insulation. Spiral fins are installed on the inner side of the oil pipeline wall 14 along the oil flow direction. These fins serve two purposes: firstly, to conduct residual heat from the oil to the PCM during the day; and secondly, to transfer the residual heat stored in the PCM back to the oil at night. After the concentrated light heats the oil to a certain temperature, the heat in the oil needs to be removed to prevent excessive temperature and achieve multiple utilization of the heat. The oil pump 16 is turned on, and hot oil is pumped into the pipeline 1 through the heat medium inlet 311 of the U-tube fluoroplastic heat exchanger 3. After heat transfer is completed through the fluoroplastic U-tube 34, the oil flows out through the heat medium outlet 312 and is then pumped back into the oil pipeline 1 by the oil pump 16. Simultaneously, the heat-exchanged nanofluid medium is pumped from the cold medium outlet 314 through the high-temperature chamber inlet 411 of the dual-chamber phase change heat storage tank 4 by the water pump 17 into the spiral heat pipe 44, where the residual heat is stored in the heat storage microcapsule 45.

[0037] When night falls or during rainy weather, water pump 17 is turned on. The high-temperature nanofluid stored in the high-temperature chamber 42 of the dual-chamber phase change thermal storage tank 4 is pumped out from the high-temperature chamber outlet 422 and enters the coil inlet 131 of the vortex coil 13 of the flexible flame-retardant PCMⅠ111. Considering that the flexible flame-retardant PCMⅡ has a higher temperature than the flexible flame-retardant PCMⅠ111 due to its light-concentrating characteristics, the vortex coil 13 is not installed inside the flexible flame-retardant PCMⅡ. The high-temperature nanofluid transfers heat with the flexible flame-retardant PCMⅠ111 through the vortex coil 13, and the heat is transferred to the oil by the spiral fins 15 on the inner side of the oil pipeline wall 14. After heat exchange, the nanofluid flows out through the coil outlet 132 and is pumped by water pump 17 into the low-temperature chamber 41 of the dual-chamber phase change thermal storage tank 4 through the low-temperature chamber inlet 411. When the daytime focusing operation is underway, the water pump 17 is turned on to pump the cold medium in the low-temperature chamber 41 from the low-temperature chamber outlet 412 into the cold medium inlet 313 of the U-tube fluoroplastic heat exchanger 3, so as to realize the recycling of the working medium.

[0038] In this embodiment, the cold medium in the U-tube fluoroplastic heat exchanger and the heat exchange medium in the dual-cavity phase change heat storage tank are both nanofluids with an Al2O3 mass fraction of 5wt%.

Claims

1. A high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control, characterized in that, include: The oil transportation unit includes an oil pipeline (1), a flexible flame-retardant PCMⅠ (111), a flexible flame-retardant PCMⅡ (112), a protective layer (12), a vortex coil (13), a coil inlet (131), a coil outlet (132), an oil pipeline wall (14), spiral fins (15), an oil pump (16), and a water pump (17). The upper half of the outer wall of the pipeline, facing the trough concentrator (2), is covered with a flexible flame-retardant PCMⅠ (111) with a lower phase change temperature, while the lower half of the outer wall of the pipeline, located between the two trough concentrators (2), is covered with a flexible flame-retardant PCMⅡ (112) with a higher phase change temperature. The outer edge of the phase change layer is encapsulated by a protective layer (12) and serves as a heat preservation layer. The vortex coil (13) is coiled inside the flexible flame-retardant PCMⅠ (111). The coil inlet (131) is connected to the high-temperature cavity outlet (422) of the dual-cavity phase change heat storage tank (4), and the coil outlet (132) is connected to the low-temperature cavity inlet (411) of the dual-cavity phase change heat storage tank (4). The heat exchange medium is a nanofluid with an Al2O3 mass fraction of 5wt%. It is driven by a water pump (17). Spiral fins (15) are installed on the inner side of the oil pipeline wall (14) and on the pipe wall located at the focusing part of the trough concentrator (2) in the direction of oil flow. The light-to-thermal conversion unit includes a main device, a trough concentrator (2), a solar tracking device (21), a rotating shaft (22), and a speed reducer (23), wherein the solar tracking device (21) and the speed reducer (23) are located on one side of the rotating shaft (22), and the trough concentrator (2) is movably connected to the rotating shaft (22) via a bracket; The heat exchange unit includes a U-tube fluoroplastic heat exchanger (3), a hot medium inlet (311), a hot medium outlet (312), a cold medium inlet (313), a cold medium outlet (314), a tube-side partition (32), a baffle (33), a fluoroplastic U-tube (34), a retaining ring (35), and a retaining knob (36). The hot medium inlet (311) is connected to the high-temperature oil outlet of the oil pipeline (1), and the hot medium outlet (312) is connected to the low-temperature oil inlet after heat exchange in the oil pipeline (1). It is driven by an oil pump (16). The cold medium inlet (313) is connected to a dual-chamber phase change storage tank. The outlet (412) of the low-temperature chamber of the hot tank (4) and the outlet (314) of the cold medium are connected to the inlet (421) of the high-temperature chamber of the dual-chamber phase change thermal storage tank (4), driven by a water pump (17). The hot medium is petroleum heated by concentrated light, and the cold medium is nanofluid with a mass fraction of 5wt% Al2O3. The tube side baffle (32) is installed inside the tube box to divide the tube side fluid into multiple flows. The baffle (33) is installed inside the shell to guide the flow of the shell side fluid. The fluoroplastic U-tube is located inside the shell and is fixed by a fixing ring (35) and a fixing knob (36), and can be disassembled for cleaning. The thermal storage unit includes a dual-cavity phase change thermal storage tank (4), a low-temperature cavity (41), a low-temperature cavity inlet (411), a low-temperature cavity outlet (412), a high-temperature cavity (42), a high-temperature cavity inlet (421), a high-temperature cavity outlet (422), a partition (43), an inner cavity (431), an outer cavity (432), a vacuum insulation layer (433), a spiral heat pipe (44), and thermal storage microcapsules (45). The inner cavity (431) surrounds the dual-cavity phase change thermal storage tank (4) near the thermal storage cavity body, and the outermost part is the outer cavity (432). The vacuum insulation layer (433) is between the inner cavity (431) and the outer cavity (432). The partition (43) in the middle of the thermal storage tank separates the low-temperature cavity (41). The system includes a high-temperature chamber (42) and a low-temperature chamber (43). Both chambers are equipped with spiral heat pipes (44). The heat exchange medium flowing inside the pipes is a nanofluid with an Al2O3 mass fraction of 5wt%. The inlet (411) of the low-temperature chamber is connected to the coil outlet (132) of the vortex coil (13). The outlet (412) of the low-temperature chamber is connected to the cold medium inlet (313) of the U-tube fluoroplastic heat exchanger (3). The inlet (421) of the high-temperature chamber is connected to the cold medium outlet (314) of the U-tube fluoroplastic heat exchanger (3). The outlet (422) of the high-temperature chamber is connected to the coil inlet (131) of the vortex coil (13). The spiral heat pipes (44) of the high-temperature chamber (42) are filled with heat storage microcapsules (45).

2. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: Flexible flame-retardant PCM with latent heat properties is laid on the outer wall of the oil pipeline (1) to efficiently store solar waste heat. On the one hand, it can play the role of uniform and constant temperature, so that the temperature of the outer wall of the pipeline remains relatively stable; on the other hand, it can collect solar waste heat in the form of latent heat and release this heat at night for pipeline insulation, thereby achieving good temperature control effect.

3. The flexible flame-retardant PCM with latent heat properties as described in claim 2, characterized in that, A flexible flame-retardant PCMⅠ (111) with a low phase change point temperature is laid on the upper wall of the oil pipeline (1) and directly opposite the trough concentrator (2), while a flexible flame-retardant PCMⅡ (112) with a high phase change point temperature is laid on the lower wall of the oil pipeline (1) and between the two trough concentrators (2).

4. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: A vortex coil (13) is arranged around the flexible flame-retardant PCMⅠ (111), wherein the inlet of the vortex coil (13) is connected to the high-temperature cavity outlet (422) of the dual-cavity phase change heat storage tank (4) via the inlet (131), and the coil outlet (132) is connected to the low-temperature cavity inlet (411) of the dual-cavity phase change heat storage tank (4).

5. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: The fluoroplastic U-tube (34) is made of fluoroplastic, which is non-corrosive to petroleum and does not easily stick to the wall. It is installed in the U-tube fluoroplastic heat exchanger (3) by a fixing ring (35) and a fixing knob (36), and can be disassembled and cleaned by the fixing knob (36).

6. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: The inner cavity (431) and outer cavity (432) of the dual-cavity phase change heat storage tank (4) are separated by a vacuum insulation layer (433).

7. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: The dual-cavity phase change heat storage tank (4) is divided into a low-temperature cavity (41) and a high-temperature cavity (42) by a partition (43). The spiral heat pipe (44) in the high-temperature cavity (42) is filled with heat storage microcapsules (45). The heat storage microcapsules have unique phase change characteristics and can absorb and release a large amount of heat within a specific temperature range. When the temperature rises, the heat storage microcapsules (45) will absorb heat and undergo a phase change, storing the heat in the form of latent heat. When the temperature drops, the heat storage microcapsules (45) will release the stored heat, thereby playing the role of regulating temperature and balancing thermal energy.

8. The high-efficiency oil pipeline drag reduction and transportation system based on photothermal coupling phase change temperature control as described in claim 1, characterized in that: The cold medium in the U-shaped tube fluoroplastic heat exchanger (3) and the heat exchange medium in the dual-cavity phase change heat storage tank (4) are both nanofluids with an Al2O3 mass fraction of 5wt%.

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