A low-temperature propellant net curtain type on-orbit refueling system, a refueling method and a low-temperature storage tank

Abstract

The application provides a low-temperature propellant mesh curtain type on-orbit refueling system, which comprises a low-temperature storage tank, one side of the low-temperature storage tank is provided with a refueling port, the other side is provided with an exhaust port, an on-orbit refueling device is arranged in the low-temperature storage tank, the on-orbit refueling device is communicated with the refueling port and the exhaust port, the on-orbit refueling device comprises a single-leaf hyperboloid seepage pipe made of a metal mesh curtain, the single-leaf hyperboloid seepage pipe comprises a contraction zone and an expansion zone, the single-leaf hyperboloid seepage pipe inlet is communicated with the refueling port, and when refueling is carried out, the low-temperature propellant flows out from the single-leaf hyperboloid seepage pipe outlet after sequentially passing through the contraction zone and the expansion zone. The technical idea of the application ingeniously combines the air resistance and liquid permeability characteristics of the metal mesh curtain with the contraction and expansion structure of the single-leaf hyperboloid seepage pipe, and utilizes surface tension and pressure difference to drive, so that the gas-liquid separation in the propellant refueling process is realized.

Description

Technical Field

[0001] This invention relates to on-orbit refueling technology for cryogenic propellants. Background Technology

[0002] In-orbit refueling technology can effectively reduce the ground launch load of spacecraft and significantly lower launch costs; improve the reliability and effective carrying capacity of spacecraft, and expand the scale and scope of space exploration missions; and solve the problem of fuel depletion leading to failure of high-value spacecraft in orbit. Cryogenic propellants have advantages such as high specific impulse, non-toxicity, and no pollution, making them the preferred fuel for future spaceflight. Refueling spacecraft's cryogenic tanks with cryogenic propellants via in-orbit refueling is a reasonable and scientific method. However, due to the special physical properties of cryogenic propellants, such as low boiling point and low surface tension, vaporization is easily generated during the refueling process. Accompanied by rapid jetting, the gas and liquid mix violently, and a gushing phenomenon occurs. The gushing phenomenon refers to the phenomenon that, under microgravity conditions, when the injection rate is too high, the momentum of the liquid is much greater than the surface tension, forming a liquid column that sprays towards the tank outlet or wall. Collision causes the liquid column to break, intensifying gas-liquid mixing, and in severe cases, affecting the attitude and safety of the spacecraft.

[0003] To address the various problems that may arise during cryogenic propellant refueling, existing technologies have reported the use of a mesh-channel gas-liquid separation technique. The principle of this technique is that liquid forms a liquid film on the surface of a micron-sized mesh under capillary force. When a pressure difference exists across the mesh, the liquid penetrates the mesh, while the gas is blocked by the liquid film adhering to the mesh due to surface tension. When the pressure difference is less than the burst pressure, the gas cannot penetrate the mesh, thus achieving gas-liquid separation. However, existing mesh-channel gas-liquid separation technology is more suitable for relatively mild gas-liquid separation situations, such as liquid fuel acquisition in engines. Cryogenic propellant refueling is more prone to severe gas-liquid mixing. Current refueling technologies raise the tank inlet to suppress this mixing, but this design leads to more severe gushing. To suppress gushing, a perforated plate is installed at the tank inlet, which again leads to more severe gas-liquid mixing. This is the contradiction and difficulty of existing cryogenic propellant refueling technologies.

[0004] To date, there is no specific structural design for addressing gas-liquid mixing and springing phenomena during cryogenic propellant loading. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the problems existing in the prior art, and to provide a cryogenic propellant mesh-type on-orbit refueling system and refueling method that can solve the problem. The technical idea provided by the present invention ingeniously combines the gas-blocking and liquid-permeable characteristics of the metal mesh with the contraction and expansion structure of the single-leaf hyperboloid seepage pipe, and uses surface tension and pressure difference to drive the gas-liquid separation during the propellant refueling process.

[0006] This invention first provides a mesh-type on-orbit refueling system for cryogenic propellants. The system includes a cryogenic tank with a refueling port on one side and an vent on the other. An on-orbit refueling device is installed inside the cryogenic tank, connecting the refueling port and the vent. The device includes a single-leaf hyperboloidal seepage pipe made of a metal mesh. The seepage pipe includes a contraction zone and an expansion zone. The inlet of the seepage pipe is connected to the refueling port. During refueling, the cryogenic propellant passes sequentially through the contraction zone and the expansion zone before flowing out from the outlet of the seepage pipe.

[0007] Furthermore, the outlet of the single-leaf hyperboloid seepage pipe is higher than the liquid level in the cryogenic storage tank. This prevents gas backflow and also facilitates venting.

[0008] Furthermore, a locking ring is provided on the outside of the single-leaf hyperboloid seepage pipe. The locking ring is fitted on the outer wall of the single-leaf hyperboloid seepage pipe and divides the single-leaf hyperboloid seepage pipe into a contraction zone and an expansion zone. In the injection direction, the contraction zone is located before the expansion zone. During injection, the cryogenic propellant first enters the contraction zone and then enters the expansion zone after passing through the contraction zone.

[0009] Furthermore, the locking ring is positioned at the point of minimum diameter of the cross-sectional circle of the single-leaf hyperboloid seepage pipe to ensure the structural stability of the single-leaf hyperboloid during the filling process.

[0010] In some preferred embodiments, the locking ring is made of a polymer-based composite material; in some preferred embodiments, the locking ring may also have a certain degree of elasticity; and in some preferred embodiments, the locking ring may be configured to be size-adjustable.

[0011] Furthermore, the metal mesh curtain adopts at least one layer of metal mesh curtain with a pore size of micrometers. For example, it can be a single layer of metal mesh curtain or a multi-layer composite metal mesh curtain. The seepage pipe with a single-leaf hyperboloid structure made of metal mesh curtain has obvious structural characteristics of contraction and expansion.

[0012] Furthermore, the on-orbit refueling device also includes a fixed pressure plate, one end of which is connected to the outlet of the single-leaf hyperboloid seepage pipe, and the other end is connected to the exhaust port of the cryogenic storage tank.

[0013] Furthermore, the fixed pressure plate includes a connecting flange and a supporting fastener. The connecting flange is fixedly connected to the outlet end of the single-leaf hyperboloid seepage pipe by fasteners. The side of the supporting fastener has a hollowed-out portion. The upper part of the supporting fastener is fixedly connected to the inner wall of the exhaust port of the low-temperature storage tank and communicates with the exhaust port.

[0014] Furthermore, the inner wall of the filling port of the cryogenic storage tank has a connecting surface, and the inlet end of the single-leaf hyperboloid seepage pipe is fixedly connected to the connecting surface by a flange.

[0015] Furthermore, the exhaust port is connected to an exhaust pipe, which is equipped with a pressure relief valve. When the gas in the cryogenic storage tank accumulates to a certain level, the gas is released to relieve pressure, stabilize the pressure in the cryogenic storage tank, avoid violent pressure fluctuations, and effectively protect the propellant refueling power equipment.

[0016] Accordingly, based on the above system, this invention provides a mesh-type on-orbit refueling method for cryogenic propellants. The on-orbit refueling method involves installing a single-leaf hyperboloid seepage pipe inside the cryogenic tank, allowing the refueled cryogenic propellant to undergo gas-liquid separation within the seepage pipe, and discharging the gas from the vent of the cryogenic tank. The on-orbit refueling method specifically includes the following steps:

[0017] (1) Add cryogenic propellant to the filling port of the cryogenic storage tank so that the cryogenic propellant entering the filling port first enters the single-leaf hyperboloid seepage pipe;

[0018] (2) The cryogenic propellant is pressurized in the contraction zone of the single-leaf hyperboloid seepage tube, driving the liquid to seep out from the gaps in the metal mesh curtain for gas-liquid separation.

[0019] (3) After passing through the contraction zone of the single-leaf hyperboloid seepage tube, the cryogenic propellant enters the expansion zone of the single-leaf hyperboloid seepage tube. In the expansion zone, the liquid adheres to the metal mesh with a gradually increasing spreading area, which further promotes the escape of bubbles and achieves gas-liquid separation.

[0020] (4) The cryogenic propellant flows out from the outlet of the single-leaf hyperboloid seepage pipe. Under the action of surface tension and capillary force, the liquid enters the bottom of the cryogenic tank along the outer wall of the metal mesh curtain, and the gas accumulates on the upper part of the liquid surface in the cryogenic tank.

[0021] (5) Open the pressure relief valve at the exhaust port of the cryogenic storage tank to release the gas.

[0022] Furthermore, the present invention also provides a cryogenic storage tank for cryogenic propellant, wherein the cryogenic storage tank is equipped with a mesh-type on-orbit refueling device, the mesh-type on-orbit refueling device being connected to the refueling port and the venting port, the mesh-type on-orbit refueling device comprising a single-leaf hyperboloid seepage pipe made of a metal mesh, a locking ring being provided on the outside of the single-leaf hyperboloid seepage pipe, the locking ring being fitted onto the outer wall of the single-leaf hyperboloid seepage pipe, dividing the single-leaf hyperboloid seepage pipe into a contraction zone and an expansion zone; the inlet of the single-leaf hyperboloid seepage pipe is connected to the refueling port, and during refueling, the cryogenic propellant passes sequentially through the contraction zone and the expansion zone and then flows out from the outlet of the single-leaf hyperboloid seepage pipe.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The present invention sets up a single-leaf hyperboloid seepage pipe made of a single or multiple layers of metal mesh with a pore size of micron in the cryogenic storage tank. It cleverly combines the gas-blocking and liquid-permeable characteristics of the metal mesh with the contraction and expansion structure of the single-leaf hyperboloid seepage pipe. It utilizes surface tension and pressure difference to drive the gas-liquid separation during the propellant loading process.

[0025] (2) The present invention designs a locking ring, which, together with the structure of the single-leaf hyperboloid seepage pipe, effectively avoids the damage that may be caused by pressure buildup during the filling process, making the filling structure stable and reliable.

[0026] (3) Regarding the installation method of the single-leaf hyperboloid seepage pipe, the present invention adopts a two-end fixed method and uses a fixed pressure plate to fix the free end of the single-leaf hyperboloid seepage pipe with bolts. The structure is reliable and easy to implement.

[0027] (4) Regarding the release of gas, the present invention uses a pressure relief valve with a low threshold (the threshold usually depends on the load capacity of the power equipment, for example, 2-5 kPa in the embodiments of the present invention). When the gas accumulates to a certain extent, the pressure is released to stabilize the pressure in the cryogenic storage tank, avoid drastic pressure fluctuations, and effectively protect the propellant refueling power equipment.

[0028] In summary, this invention innovatively proposes the "separate first, then merge" refueling concept from the perspective of refueling principle, which can effectively avoid gas-liquid mixing and gushing phenomena during the refueling process, and significantly improve the quality, efficiency and safety of cryogenic propellant refueling in orbit. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, since there are cases where drawings are used interchangeably in the embodiments of the present invention, no special designation is made for the drawings and embodiments in the description of the drawings.

[0030] Figure 1 This is a cross-sectional view of the overall structure of the present invention.

[0031] Figure 2 This is an overall structural diagram of the on-orbit refueling device of the present invention.

[0032] Figure 3 This is the overall flowchart of the present invention.

[0033] The following are labeled in the diagram: Cryogenic storage tank 1, filling port 11, vent port 12, vent pipe 13, connecting surface 14, pressure relief valve 2, fixed pressure plate 3, connecting flange 31, support fastener 32, hollow part 33, single-leaf hyperboloid seepage pipe 4, contraction zone 41, expansion zone 42, inlet of single-leaf hyperboloid seepage pipe 43, outlet of single-leaf hyperboloid seepage pipe 44, locking ring 5, on-orbit filling device 100. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions of the present invention and to facilitate their better reproduction of the technical solutions of the present invention based on the description of the embodiments, some technical terms in the present invention will be explained first.

[0035] Metal mesh curtain (alternative terms: metal mesh, mesh curtain type) – Metal mesh curtain refers to a mesh curtain made of metal materials. It is usually thin and has a certain degree of flexibility, capable of deforming within a certain range (a relatively large range) and maintaining or recovering its shape. It is usually evenly or densely distributed with mesh (pores) throughout the material and has a certain degree of liquid permeability. Due to the size of the mesh (pores), it can also block some substances (such as solid particles or air bubbles). There are reports of mesh curtains being used in cryogenic propellant loading, such as the mesh curtain used in the mesh curtain type channel disclosed in Chinese invention patent application CN112983677A.

[0036] In this invention, a metal mesh with a pore size in the micrometer range is used. Due to the design of the pore size, under certain pressure, the metal mesh can allow liquid to pass through while blocking air bubbles mixed in the liquid. However, when the pressure exceeds a certain threshold, the air bubbles in the metal mesh will rupture due to the pressure, and gas-liquid separation cannot be achieved. This critical pressure is called the burst pressure of the metal mesh. The burst pressure of the metal mesh may vary due to factors such as thickness, material, mesh size, and mesh shape. However, the burst pressure is an inherent parameter of the metal mesh, and a specific specification of metal mesh must correspond to a specific burst pressure.

[0037] Regarding the material for the screen, the technical materials selected in this invention, such as stainless steel, aluminum, and titanium, are all currently available and their performance differences are not significant. Stainless steel, which is inexpensive and readily available, is commonly used because metal is currently the cheapest low-temperature resistant material. If new alternative materials are available in the future that can achieve the same effect, they may not be excluded from the scope of this invention.

[0038] A single-leaf hyperboloid seepage pipe—it possesses the characteristics of a seepage pipe, allowing liquid to pass through under certain pressure while blocking a portion of the substance. The seepage pipe in this invention has a special shape, namely a single-leaf hyperboloid shape. This shape typically has the smallest cross-section near the middle and gradually widens at both ends. In this invention, a single-leaf hyperboloid seepage pipe refers to a seepage pipe in which at least a part (or the whole) is in the shape of a single-leaf hyperboloid.

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] Example 1, refer to Appendix Figure 1-2 .

[0041] like Figure 1 As shown, this embodiment provides a cryogenic propellant mesh-type on-orbit refueling system. This system includes a cryogenic tank 1, with a refueling port 11 on one side and an vent port 12 on the other. The vent port 12 is connected to an vent pipe 13, and a pressure relief valve 2 is installed on the vent pipe 13. This pressure relief valve can be an automatic pressure relief valve with a low threshold pressure; it releases pressure when a certain threshold is reached, thereby stabilizing the pressure inside the cryogenic tank, avoiding drastic pressure fluctuations, and effectively protecting the propellant refueling power equipment. Figure 1 As shown, the cryogenic storage tank 1 is equipped with the following... Figure 2The on-orbit refueling device 100 shown is connected to the refueling port 11 and the venting port 12 to form a refueling route. Cryogenic propellant enters the on-orbit refueling device 100 located in the cryogenic storage tank 1 from the refueling port 11, and gas-liquid separation is performed in the on-orbit refueling device 100. The liquid falls into the bottom (storage area) of the cryogenic storage tank 1, and the gas continues to follow the refueling route until it accumulates at the top of the cryogenic storage tank 1. When the gas accumulates to a certain extent, the gas is vented and depressurized.

[0042] like Figure 1-2 As shown, the on-orbit refueling device 100 includes a single-leaf hyperboloid seepage pipe 4 made of metal mesh. A locking ring 5 is provided outside the single-leaf hyperboloid seepage pipe 4, which is fitted onto the outer wall of the pipe. Specifically, the locking ring 5 is located at the point of minimum diameter of the cross-sectional circle of the single-leaf hyperboloid seepage pipe 4 to ensure the structural stability of the single-leaf hyperboloid during refueling. The locking ring 5 divides the single-leaf hyperboloid seepage pipe 4 into a contraction zone 41 and an expansion zone 42, with the point of minimum diameter as the dividing line. Alternatively, a gap can be provided between the contraction zone 41 and the expansion zone 42, i.e., a buffer area near the locking ring 5. Figure 1 As shown by the dashed line inside the single-leaf hyperboloid seepage pipe 4, the pressure difference on both sides of the metal mesh curtain in the contraction zone is synergistically adjusted by controlling the length of the buffer zone. In the filling direction, the contraction zone 41 is located before the expansion zone 42. During filling, the cryogenic propellant enters the inlet 43 of the single-leaf hyperboloid seepage pipe from the filling port 11, then flows through the contraction zone 41 and the expansion zone 42 in sequence before exiting from the outlet 44 of the single-leaf hyperboloid seepage pipe.

[0043] In some preferred embodiments, the locking ring 5 is made of polymer-based composite material. In some preferred embodiments, the locking ring 5 can also have a certain degree of elasticity, for example, utilizing the inherent elasticity of the material itself to improve the adaptability of the single-leaf hyperboloid seepage pipe and avoid problems such as insufficient toughness due to rigidity. In some preferred embodiments, the locking ring 5 can be configured to be adjustable in size to suit different filling speeds or filling volumes. Generally, since the on-orbit filling device 100 is built into the cryogenic storage tank 1, the size of the locking ring 5 generally does not change after installation.

[0044] like Figure 1 As shown, in the cryogenic storage tank 1, the outlet 44 of the single-leaf hyperboloid permeation pipe 4 is higher than the liquid level in the cryogenic storage tank, which can prevent gas-liquid mixing and is also conducive to venting.

[0045] In this invention, the metal mesh curtain adopts at least one layer of metal mesh curtain with a pore size of micrometer. It can be a single layer of metal mesh curtain or a multi-layer composite metal mesh curtain. The seepage pipe with a single-leaf hyperboloid structure made of metal mesh curtain has obvious shrinkage and expansion characteristics. In this embodiment, a single layer of metal mesh curtain is used as an example for illustration.

[0046] like Figure 1-2 As shown, the on-orbit filling device 100 also includes a fixed pressure plate 3. One end of the fixed pressure plate 3 is connected to the outlet 44 of the single-leaf hyperboloid seepage pipe 4, and the other end is connected to the exhaust port 12 of the cryogenic storage tank. The fixed pressure plate 3 includes a connecting flange 31 and a supporting fastener 32. The connecting flange 31 is fixedly connected to the outlet end of the single-leaf hyperboloid seepage pipe 4 by fasteners (such as bolts, etc.) (the outlet end can also be provided with a corresponding flange structure). The inner side wall of the filling port 11 of the cryogenic storage tank has a connecting surface 14. The inlet end of the single-leaf hyperboloid seepage pipe 4 is fixedly connected to the connecting surface 14 by a flange and fasteners, thus realizing the installation of the single-leaf hyperboloid seepage pipe 4 in the cryogenic storage tank 1.

[0047] like Figure 2 As shown, the side of the support fixing member 32 has a hollow part 33, which can be used to allow liquid flowing out from the outlet 44 of the single-leaf hyperboloid seepage pipe 4 to pass through. Under the action of surface tension and capillary force, the liquid flows along the outer wall of the metal mesh curtain to the storage area at the bottom of the low temperature storage tank 1. The upper part of the support fixing member 32 is fixedly connected to the inner wall of the exhaust port 12 of the low temperature storage tank 1 and communicates with the exhaust port 12.

[0048] In this embodiment, the working principle and process of the mesh curtain type on-orbit refueling system are as follows:

[0049] During operation, cryogenic propellant (liquid hydrogen, liquid oxygen, etc.) is injected from the filling port 11 of the cryogenic storage tank 1 and enters the contraction zone 41 of the single-leaf hyperboloid percolation pipe 4. As the flow area gradually decreases in the contraction zone 41, it acts as a "pressure suppressor," effectively inhibiting the gushing phenomenon during filling and increasing the pressure difference between the inside and outside of the single-leaf hyperboloid percolation pipe 4 (larger inside, smaller outside). This drives the cryogenic propellant liquid to seep out through the pores of the metal mesh. The pressure difference across the mesh is controlled to not exceed the bursting pressure of the metal mesh (this can be achieved by setting the buffer zone length and adjusting the injection rate). This ensures gas-liquid separation in the contraction zone 41, and the seeping liquid directly enters the liquid phase pool of the cryogenic storage tank 1 (the part below the dotted line in the figure). Simultaneously, the gas remains in the contraction zone 41 and cannot penetrate the metal mesh to enter the cryogenic storage tank. Therefore, the gas concentrates and accumulates in the middle section of the single-leaf hyperboloid percolation pipe 4. The decrease in mass flow rate and increase in gas content of the fluid in the single-leaf hyperboloid seepage pipe 4 causes the liquid to pass through the contraction zone 41 and enter the expansion zone 42, where the flow area gradually increases. Due to the decrease in mass flow rate, the fluid velocity naturally decreases in the expansion zone 42, causing the liquid to adhere to the metal mesh with its gradually increasing spread area. The gas-liquid two-phase slip ratio increases, which can further promote bubble escape and suppress the fountain phenomenon until the liquid flows out from the outlet of the single-leaf hyperboloid seepage pipe 4. Under the action of surface tension and capillary force, the liquid flows along the outer wall of the metal mesh into the liquid phase pool of the cryogenic storage tank 1. After a certain period of filling, the gas will accumulate at the top of the cryogenic storage tank 1. When the pressure of the accumulated gas reaches the threshold of the pressure relief valve 2, the pressure relief valve 2 automatically opens to release the gas. The remaining unseeped liquid flows along the metal mesh into the liquid phase pool (the area below the liquid surface) under the action of surface tension and capillary force. Figure 1 In the diagram, thick arrows indicate the direction of liquid flow, thin arrows indicate the direction of gas flow, and dashed lines indicate the position of the liquid surface (the position of the liquid surface is not unique and is only for illustration).

[0050] Taking the liquid hydrogen refueling process as an example, a single-layer metal mesh curtain with specifications of DT-450×2750 is selected to make a single-leaf hyperboloid seepage pipe 4. The ratio of the diameter of the maximum cross-section circle to the diameter of the minimum cross-section circle is 5. The threshold of the pressure relief valve 2 is determined according to the load of the injection power equipment, and is currently set to 5 kPa. During operation, cryogenic propellant with a mass flow rate of 20 kg / (㎡·s) is injected from the filling port 11 of the cryogenic storage tank 1 and enters the contraction zone 41 of the single-leaf hyperboloid seepage pipe 4. The flow area of ​​the contraction zone 41 gradually decreases, playing a "pressure-holding" role, effectively suppressing the occurrence of the fountain phenomenon, and increasing the pressure difference inside and outside the single-leaf hyperboloid seepage pipe 4, driving the liquid to seep out from the pores of the metal mesh curtain. The maximum mass flow rate does not exceed 25.2 kg / (㎡·s), and the pressure difference on both sides of the metal mesh curtain does not exceed the burst pressure of the metal mesh curtain, 728 Pa. At this point, the gas cannot penetrate the metal mesh in the contraction zone 41 to enter the cryogenic tank 1. Instead, it concentrates and accumulates in the middle section of the single-leaf hyperboloid seepage pipe 4. At this time, the mass flow rate of the injected fluid decreases to below 5 kg / (m²·s), and the gas content increases. Subsequently, it enters the expansion zone 42, where the flow area gradually increases. In the expansion zone 42, the flow velocity of the fluid further decreases, and due to the influence of surface tension, the liquid adheres to the metal mesh with the gradually increasing spreading area. The gas-liquid two-phase slip ratio increases, further promoting bubble escape and suppressing the gushing phenomenon. Finally, the gas accumulates at the top of the cryogenic tank 1. When the pressure inside the cryogenic tank 1 reaches the pressure relief threshold of 5 kPa, the pressure relief valve 2 opens to discharge the gas. The remaining unseeped liquid flows along the metal mesh into the liquid phase pool of the cryogenic tank 1 under the action of surface tension and capillary force.

[0051] Example 2, refer to Appendix Figure 1 .

[0052] This embodiment provides a cryogenic storage tank 1 for cryogenic propellant. The cryogenic storage tank 1 is equipped with a mesh-type on-orbit refueling device 100 as described in Embodiment 1. The implementation method and working process of this embodiment are the same as those of Embodiment 1.

[0053] Example 3, refer to Appendix Figure 1-3 .

[0054] Based on the on-orbit refueling system provided in Example 1 and the cryogenic tank provided in Example 2, this embodiment provides a net-screen type on-orbit refueling method for cryogenic propellants, which includes the following steps:

[0055] S1, Design and build an on-orbit refueling system, including a single-leaf hyperboloid seepage pipe 4, inside the cryogenic storage tank 1;

[0056] S2, add cryogenic propellant to the filling port of cryogenic storage tank 1, so that the cryogenic propellant entering the filling port first enters the single-leaf hyperboloid seepage pipe 4;

[0057] S3, the cryogenic propellant is pressurized in the contraction zone 41 of the single-leaf hyperboloid seepage pipe 4, driving the liquid to seep out from the gaps in the metal mesh curtain for gas-liquid separation.

[0058] S4, the cryogenic propellant enters the expansion zone 42 of the single-leaf hyperboloid seepage pipe 4. In the expansion zone 42, the liquid adheres to the metal mesh with a gradually increasing spreading area, causing the bubbles to escape and achieving gas-liquid separation.

[0059] S5, the cryogenic propellant flows out from the outlet of the single-leaf hyperboloid seepage pipe 4 and enters the liquid phase pool of the cryogenic storage tank 1 along the outer wall of the metal mesh curtain, and the gas accumulates on the upper part of the liquid surface of the cryogenic storage tank 1.

[0060] S6, the pressure relief valve 2 at the exhaust port of the cryogenic storage tank 1 is opened to release gas.

[0061] The technical solutions regarding the system and structure in this invention are the same as those in Embodiment 1 or Embodiment 2.

[0062] The refueling method of this invention enables the cryogenic propellant to undergo gas-liquid separation in a single-leaf hyperboloid seepage tube during the refueling process. After separation, the gas and liquid are separately merged (rectified), which can effectively avoid gas-liquid mixing and gushing phenomena during the refueling process, and significantly improve the quality, efficiency and safety of cryogenic propellant refueling in orbit.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A net-screen type on-orbit refueling system for cryogenic propellants, characterized in that, The device includes a cryogenic storage tank, with a filling port on one side and an vent on the other side. An on-orbit refueling device is installed inside the cryogenic storage tank, connecting the filling port and the vent. The on-orbit refueling device includes a single-leaf hyperboloidal seepage pipe made of a metal mesh, comprising a contraction zone and an expansion zone. The inlet of the single-leaf hyperboloidal seepage pipe is connected to the filling port. During refueling, the cryogenic propellant passes sequentially through the contraction zone and the expansion zone before flowing out from the outlet of the single-leaf hyperboloidal seepage pipe.

2. The on-orbit refueling system for cryogenic propellants using a mesh curtain design according to claim 1, characterized in that, The outlet of the single-leaf hyperboloid seepage pipe is higher than the liquid level in the cryogenic storage tank.

3. The on-orbit refueling system for cryogenic propellants using a mesh curtain design according to claim 1, characterized in that, The single-leaf hyperboloid seepage pipe is provided with a locking ring, which is fitted on the outer wall of the single-leaf hyperboloid seepage pipe and divides the single-leaf hyperboloid seepage pipe into a contraction zone and an expansion zone.

4. The on-orbit refueling system for cryogenic propellants using a mesh curtain design according to claim 3, characterized in that, The locking ring is located at the point where the diameter of the cross-sectional circle of the single-leaf hyperboloid seepage pipe is the smallest.

5. The on-orbit refueling system for cryogenic propellants using a mesh curtain design according to claim 1, characterized in that, The metal mesh curtain uses at least one layer of metal mesh curtain with a pore size of micrometers.

6. The on-orbit refueling system for cryogenic propellants using a mesh curtain design according to claim 1, characterized in that, The on-orbit refueling device also includes a fixed pressure plate, one end of which is connected to the outlet of the single-leaf hyperboloid seepage pipe, and the other end is connected to the exhaust port of the cryogenic storage tank.

7. A net-screen type on-orbit refueling system for cryogenic propellants according to claim 6, characterized in that, The fixed pressure plate includes a connecting flange and a supporting fastener. The connecting flange is fixedly connected to the outlet end of the single-leaf hyperboloid seepage pipe by fasteners. The side of the supporting fastener has a hollowed-out part. The upper part of the supporting fastener is fixedly connected to the inner wall of the exhaust port of the low temperature storage tank and communicates with the exhaust port.

8. A net-screen type on-orbit refueling system for cryogenic propellants according to claim 1, characterized in that, The inner wall of the filling port of the cryogenic storage tank has a connecting surface, and the inlet end of the single-leaf hyperboloid seepage pipe is fixedly connected to the connecting surface by a flange.

9. A cryogenic storage tank for cryogenic propellant, characterized in that, The cryogenic storage tank has a filling port on one side and an exhaust port on the other side. A mesh-type on-orbit refueling device is installed inside the cryogenic storage tank, connecting the filling port and the exhaust port. The mesh-type on-orbit refueling device includes a single-leaf hyperboloid seepage pipe made of a metal mesh. A locking ring is provided outside the single-leaf hyperboloid seepage pipe, which is fitted onto the outer wall of the pipe, dividing it into a contraction zone and an expansion zone. The inlet of the single-leaf hyperboloid seepage pipe is connected to the filling port. During refueling, the cryogenic propellant passes sequentially through the contraction zone and the expansion zone before flowing out from the outlet of the single-leaf hyperboloid seepage pipe.

10. A net-screen type on-orbit refueling method for cryogenic propellants, characterized in that, The on-orbit refueling method involves installing a single-leaf hyperboloid seepage pipe inside the cryogenic tank, allowing the refueled cryogenic propellant to undergo gas-liquid separation within the seepage pipe, and then discharging the gas from the vent of the cryogenic tank. The on-orbit refueling method specifically includes the following steps: (1) Add cryogenic propellant to the filling port of the cryogenic storage tank so that the cryogenic propellant entering the filling port first enters the single-leaf hyperboloid seepage pipe; (2) The cryogenic propellant is pressurized in the contraction zone of the single-leaf hyperboloid seepage tube, driving the liquid to seep out from the gaps in the metal mesh curtain for gas-liquid separation. (3) After passing through the contraction zone of the single-leaf hyperboloid seepage tube, the cryogenic propellant enters the expansion zone of the single-leaf hyperboloid seepage tube. In the expansion zone, the liquid adheres to the metal mesh with a gradually increasing spreading area, which further promotes the escape of bubbles and achieves gas-liquid separation. (4) The cryogenic propellant flows out from the outlet of the single-leaf hyperboloid seepage pipe. Under the action of surface tension and capillary force, the liquid enters the bottom of the cryogenic tank along the outer wall of the metal mesh curtain, and the gas accumulates on the upper part of the liquid surface in the cryogenic tank. (5) Open the pressure relief valve at the exhaust port of the cryogenic storage tank to release the gas.

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