A full bladder diaphragm compensator for spacecraft fluid circuits

Abstract

The application discloses a full capsule type diaphragm compensator for a spacecraft fluid circuit, which comprises a storage tank body, a capsule, a pressure sensor, an end cover, a filling pipe and a grommet, wherein the port of the storage tank body is connected with the end cover; the space surrounded by the storage tank body and the end cover is an inner cavity of the compensator, the inner cavity of the compensator comprises a gas cavity and a liquid cavity; the capsule is arranged in the inner cavity, the outer wall of the capsule is attached to the cavity wall on one side of the inner cavity, and the open end of the capsule is connected with the end cover; the inside of the capsule is provided with the filling pipe, one end of the filling pipe is connected with the mounting boss of the end cover, and the other end of the filling pipe is in contact with the bottom of the capsule through the grommet; the pressure sensor is arranged at the other end of the storage tank body, the pressure sensing interface of the pressure sensor is communicated with the gas cavity, and the pressure sensor monitors the gas cavity pressure of the compensator in real time. The application has the advantages of high reliability, high extrusion efficiency, light weight and reusability.

Description

Technical Field

[0001] This invention belongs to the technical field of fluid loop compensators for spacecraft, and particularly relates to a full-capsule diaphragm compensator for spacecraft fluid loops. Background Technology

[0002] Space fluid loops are the primary means of active temperature control for space stations, satellites, and other spacecraft. They mainly consist of mechanical pumps that pump a heat-conducting working fluid through the loop, transferring heat to cooling devices and radiating it into space. Compensators in the loop primarily absorb pressure fluctuations and compensate for working fluid leakage, playing a crucial role in the stable operation of the fluid loop. When temperature changes occur, the fluid loop absorbs pressure fluctuations caused by thermal expansion and contraction of the working fluid, while also preventing pressure drops due to long-term leakage at sealed locations that reduces the amount of working fluid.

[0003] Compensators can be classified into spring type, weight type, and gas type according to the loading method. According to the spacecraft mission requirements, the deformation element of the liquid isolation chamber in the compensator is mainly metal bellows compensator and bladder compensator. Considering the zero-gravity space environment and the variability of spacecraft attitude, the limited extension and contraction of the spring itself and its insensitivity to pressure changes, the compensators in the space thermal control fluid circuit mostly adopt gas type metal bellows compensators. The bellows, which are welded by metal diaphragms, separate the gas and liquid chambers. The closed cavity formed by the bellows and the compensator shell is sealed with a certain pressure of inert gas. The pressure balance between the closed gas chamber and the two sides of the fluid circuit is achieved through the axial stretching and compression deformation of the bellows.

[0004] However, metal bellows compensators have limitations such as large weight, many welds (poor reliability), and poor reusability, which restrict the development of reusable active thermal control fluid loops for spacecraft. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a full-capsule diaphragm compensator for spacecraft fluid loops, which has the functions of real-time liquid level measurement and replacement and reuse, and has the advantages of high reliability, high extrusion efficiency, light weight and reusability.

[0006] The objective of this invention is achieved through the following technical solution: a full-capsule diaphragm compensator for a spacecraft fluid loop, comprising: a tank body, a capsule, a pressure sensor, an end cap, a filling tube, and a gasket; wherein, the port of the tank body is connected to the end cap; the space enclosed by the tank body and the end cap is the compensator cavity, which includes a gas chamber and a liquid chamber; the capsule is disposed within the compensator cavity, the outer wall of the capsule is in contact with the cavity wall on one side of the compensator cavity, and the open end of the capsule is connected to the end cap; the capsule divides the compensator cavity into a gas chamber and a liquid chamber; the filling tube is disposed inside the capsule, one end of the filling tube is connected to the mounting boss of the end cap, and the other end of the filling tube is in contact with the bottom of the capsule through the gasket; the pressure sensor is disposed at the other end of the tank body, the pressure sensing interface of the pressure sensor is connected to the gas chamber, and the pressure sensor monitors the pressure of the compensator gas chamber in real time.

[0007] The aforementioned full-capsule diaphragm compensator for spacecraft fluid circuits also includes: a double O-ring seal; wherein the pressure sensor is disposed at the other end of the tank body via the double O-ring seal.

[0008] The aforementioned full-capsule diaphragm compensator for spacecraft fluid loops also includes: screws; wherein the pressure sensor is connected to the tank body via the screws.

[0009] In the aforementioned full-capsule diaphragm compensator for spacecraft fluid loops, the tank body includes a nozzle end cap, a partition shell, and an inflation shut-off valve assembly; wherein, the nozzle end cap is connected to the partition shell; the partition shell is connected to the inflation shut-off valve assembly; the port of the nozzle end cap is connected to the end cap; and the pressure sensor is mounted on the inflation shut-off valve assembly.

[0010] In the aforementioned full-capsule diaphragm compensator for spacecraft fluid loops, the nozzle end cap is an elliptical end cap with a flange; the flange flange of the nozzle end cap is provided with a sealing groove, which is used to cooperate with the end cap to compress the capsule flange to form a static seal; the flange of the nozzle end cap is provided with multiple bolt holes arranged around its circumference for connection with the end cap by bolts.

[0011] In the aforementioned full-cap diaphragm compensator for spacecraft fluid loops, the diaphragm shell includes a cylindrical section and a second elliptical head; wherein, one end of the cylindrical section is connected to the nozzle head, and the other end of the cylindrical section is connected to the second elliptical head, which is disposed within the inner cavity of the compensator; a hemispherical recess that mates with a gasket is provided at the center of the second elliptical head; multiple small holes are provided in the portion of the second elliptical head excluding the hemispherical recess; multiple grooves are provided on the inner wall of the cylindrical section, and the bottom of each groove communicates with at least two small holes provided in the second elliptical head.

[0012] In the aforementioned full-capsule diaphragm compensator for spacecraft fluid loops, the inflation shut-off valve assembly includes a spherical surface of a central recess, an inflation valve, and a second cylindrical section; wherein, one end of the second cylindrical section is connected to the other end of the cylindrical section, and the other end of the second cylindrical section is connected to the spherical surface of the central recess; the inflation valve is disposed on the spherical surface of the central recess; and the pressure sensor is disposed at the central recess position on the spherical surface of the central recess.

[0013] In the aforementioned full-capsule diaphragm compensator for spacecraft fluid loops, the inflation valve includes a spring, a valve head, a gasket, a plug, and a cap; wherein, the gasket is disposed at the opening of the spherical surface of the intermediate recess; the plug is connected to the opening end of the spherical surface of the intermediate recess; the valve head is disposed inside the plug; the spring is disposed inside the valve head, and the bottom of the spring presses against the gasket; the cap is fitted onto the outer surface of the plug.

[0014] In the aforementioned full-capsule diaphragm compensator for spacecraft fluid loops, the filling tube is a hollow column structure, and multiple radial openings are arranged in the axial direction of the filling tube.

[0015] In the aforementioned full-capsule diaphragm compensator for the spacecraft fluid loop, the capsule is made of rubber, and the outer edge of the capsule's flanged portion is set as an O-ring structure to cooperate with the tank body and end cap to form a seal; the inner chamfer R1 of the capsule's flanged portion is smaller than the end cap chamfer R2, and the outer chamfer R3 is equal to the tank body chamfer R4.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The present invention uses a partition and a filling tube as limiting devices for capsule shrinkage and expansion deformation. The partition is provided with multiple through holes and multiple grooves are arranged in the circumferential direction on the inner side of the liquid cavity shell as gas flow channels. This helps to avoid the formation of a large volume gas dead space that affects the performance indicators of the compensator, making the capsule deformation highly consistent and avoiding scratches to the capsule by other parts, thus improving the reliability of the diaphragm compensator.

[0018] (2) The present invention uses a perforated partition as a support element, which can withstand a large internal pressure, improves the compensator’s ability to withstand high pressure difference between the gas and liquid sides, and makes up for the shortcomings of insufficient pressure difference resistance of previous compensators.

[0019] (3) The compensator air chamber of the present invention is equipped with a pressure sensor, which can monitor the pressure of the compensator air chamber in real time. The volume of the working fluid in the compensator liquid chamber can be calculated based on the ideal gas state equation, thereby monitoring the working status of the compensator.

[0020] (4) The present invention is equipped with a self-locking valve structure for inflation and deflation, and the end cap and the storage tank are connected by bolts for easy disassembly. The capsule, as the main working element of the compensator, can be replaced when it reaches its working life. The metal shell can be reused, and it has a reusable function and extremely high cost performance.

[0021] (5) The capsule of the present invention is lightweight. Under the same performance index of the compensator, the weight of the compensator is optimized by more than 2 / 3 compared with the metal bellows compensator used in previous spacecraft, which has a very high weight advantage. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the full-capsule diaphragm compensator for spacecraft fluid loop provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the tank structure provided in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the partition shell structure provided in an embodiment of the present invention;

[0026] Figure 4(a) is a schematic diagram of the compensator inflation valve assembly provided in an embodiment of the present invention;

[0027] Figure 4(b) is a schematic diagram of the air valve assembly provided in an embodiment of the present invention;

[0028] Figure 5(a) is a schematic cross-sectional view of the end cap provided in an embodiment of the present invention;

[0029] Figure 5(b) is a schematic diagram of the compensator end cap structure provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the capsule structure provided in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the valve head provided in an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the capsule flange provided in an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of the compensator flange seal provided in an embodiment of the present invention;

[0034] Figure 10 This is another structural schematic diagram of the full-capsule diaphragm compensator for spacecraft fluid loops provided in an embodiment of the present invention. Detailed Implementation

[0035] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Figure 1 This is a schematic diagram of the structure of a fully enclosed diaphragm compensator for a spacecraft fluid loop provided in an embodiment of the present invention. Figure 1 As shown, the spacecraft's fluid loop diaphragm compensator includes: a tank body 1, a capsule 2, a pressure sensor 3, an end cap 4, a filling pipe 6, and a gasket 7. Among these,

[0037] The port of the storage tank 1 is connected to the end cap 4; the space enclosed by the storage tank 1 and the end cap 4 is the compensator cavity, which includes an air cavity and a liquid cavity; the air cavity and the liquid cavity are separated by a capsule 2; the capsule 2 is set in the cavity, and the outer wall of the capsule 2 is in contact with the cavity wall on one side of the cavity, and the open end of the capsule 2 is connected to the end cap 4; a filling tube 6 is set inside the capsule 2, one end of the filling tube 6 is connected to the mounting boss of the end cap 4, and the other end of the filling tube 6 is in contact with the bottom of the capsule 2 through a gasket 7; a pressure sensor 3 is set at the other end of the storage tank 1, and the pressure sensing interface of the pressure sensor 3 is connected to the air cavity, and the pressure sensor 3 monitors the pressure of the compensator air cavity in real time.

[0038] Capsule 2 uses the inner filling tube 6 and the outer partition to limit the deformation of the capsule in both contraction and expansion states, so as to avoid excessive deformation of the capsule and ensure the consistency of the capsule in multiple expansion and contraction processes, and avoid damage and failure caused by repeated local deformation of the capsule.

[0039] like Figure 1 As shown, the spacecraft fluid loop full-capsule diaphragm compensator also includes: double O-ring seals 8; wherein, the pressure sensor 3 is disposed at the other end of the tank body 1 through the double O-ring seals 8.

[0040] The compensator tank body 1 and end cover 4 are connected by flanges with screws and nuts. The space enclosed by the tank body 1 and end cover 4 is the compensator cavity. The compensator cavity is divided into gas and liquid chambers. The liquid chamber is located on the side closer to end cover 4. The gas and liquid chambers are isolated by the entire capsule 2 with a flange and necking structure. The flange at the opening of capsule 2 is fixed by the sealing ring groove set at the flange of the tank body 1, which cooperates with the end cover 4 and the tank body 1 after the screw connection and is pressed together, and forms a seal in the O-ring structure of the capsule flange. At the same time, the rib plate and rounding on the inner side of end cover 4 can compress the flange of capsule 2 to form another sealing position.

[0041] The compensator tank 1 has a partition inside. One side of the partition is attached to the bottom of the capsule 2, and the other side is a pure gas cavity. Small holes are arranged on the partition to allow gas to flow through the gas cavity.

[0042] A filling tube 6 is provided at the center of the inner side of the compensator capsule 2. The filling tube 6 is a hollow straight tube with small holes in the tube wall. One end of the filling tube 6 is installed in conjunction with the mounting boss on the inner side of the end cover 4. The other end of the filling tube 6 contacts the capsule 2 through the non-metallic gasket 7. The capsule, the non-metallic gasket, and the tank body partition are set with a recessed structure at the mating position, which helps the capsule to be positioned.

[0043] On the other side of the compensator tank body 1, which is connected to the end cover 4, a pressure sensor 3 is arranged on the outside of the tank body 1. The pressure sensor 3 is connected to the tank body 1 by a plunger structure and a radial static seal by double O-rings 8. The pressure sensor 3 is fixed to the tank body 1 by screws 9. The pressure sensing interface of the pressure sensor 3 is connected to the air chamber of the tank body 1, which can monitor the air chamber pressure of the compensator in real time. In order to enhance the mechanical resistance of the product, multiple stiffening plates are provided between the pressure sensor installation position and the tank body shell to support the pressure sensor installation boss.

[0044] An inflation shut-off valve is arranged on the other side of the housing corresponding to the end of the end cover 4 of the compensator tank 1. The valve shares the housing with the tank and has a spring inside to enable it to have a self-locking function. Under normal conditions, the valve is closed and sealed. By using an external tool to open the valve head inside the inflation shut-off valve, the inflation and deflation functions of the compensator air chamber can be realized.

[0045] like Figure 1 As shown, the spacecraft fluid loop full-capsule diaphragm compensator also includes: screw 9; wherein, the pressure sensor 3 is connected to the tank body 1 via screw 9.

[0046] like Figure 2As shown, the storage tank 1 includes a nozzle end cap 11, a partition shell 12, and an inflation shut-off valve assembly 13; wherein, the nozzle end cap 11 is connected to the partition shell 12; the partition shell 12 is connected to the inflation shut-off valve assembly 13; the port of the nozzle end cap 11 is connected to the end cap 4; and the pressure sensor 3 is disposed on the inflation shut-off valve assembly 13.

[0047] The nozzle end cap 11 is an elliptical end cap with a flange; the flange flange of the nozzle end cap 11 is provided with a sealing groove, which is used to cooperate with the end cap to compress the capsule flange to form a static seal; the flange of the nozzle end cap 11 has multiple bolt holes arranged around its circumference for bolt connection with the end cap.

[0048] like Figure 3 As shown, the partition shell 12 includes a cylindrical section and a second elliptical head; one end of the cylindrical section is connected to the nozzle head 11, and the other end of the cylindrical section is connected to the second elliptical head. The second elliptical head is disposed in the inner cavity of the compensator, and part of the capsule 2 is in contact with the second elliptical head; a hemispherical recess that mates with the gasket 7 is provided at the center of the second elliptical head; multiple small holes are provided in the part of the second elliptical head excluding the hemispherical recess; multiple grooves are provided on the inner wall of the cylindrical section, and the bottom of each groove communicates with at least two small holes provided in the second elliptical head.

[0049] The sidewall of the partition shell 12 has 6 grooves evenly arranged along the inner wall of the shell in the circumferential direction. The grooves are 0.5 to 1 mm wide and connect to the bottom of the partition shell with an opening of 1 to 1.5 mm, which serves as a gas flow channel to avoid the formation of a large dead space between the outer side of the capsule and the inner side of the compensator tank during the capsule's expansion process, thus affecting the performance of the compensator.

[0050] As shown in Figures 4(a) and 4(b), the inflation shut-off valve assembly 13 includes a spherical surface with a central recess, an inflation valve, and a second cylindrical section; wherein,

[0051] One end of the second cylindrical section is connected to the other end of the cylindrical section, and the other end of the second cylindrical section is connected to the spherical surface of the central recess; the inflation valve is located on the spherical surface of the central recess; the pressure sensor 3 is located at the central recess position on the spherical surface of the central recess.

[0052] As shown in Figure 4(b), the inflation valve includes a spring 111, a valve head 112, a gasket 113, a plug 114, and a cap 115; wherein, the gasket 113 is disposed at the opening of the spherical surface of the central recess; the plug 114 is connected to the opening end of the spherical surface of the central recess; the valve head 112 is disposed inside the plug 114; the spring 111 is disposed inside the valve head 112, and the bottom of the spring 111 presses against the gasket 113; the cap 115 is sleeved on the outer surface of the plug 114.

[0053] The filling tube 6 is a hollow column structure, and multiple radial openings are arranged in the axial direction of the filling tube 6.

[0054] Capsule 2 is made of rubber. The outer edge of the flanged part of capsule 2 is set as an O-ring structure to cooperate with the storage tank body 1 and the end cap 4 to form a seal. The inner chamfer R1 of the flanged part of capsule 2 is smaller than the chamfer R2 of the end cap, and the outer chamfer R3 is equal to the chamfer R4 of the storage tank body.

[0055] The fully encapsulated diaphragm compensator uses a complete capsule as both the gas-liquid chamber separation component and the main deformable component. The compensator has an overall cylindrical structure, and its overall structural schematic diagram is attached. Figure 1 As shown, it mainly includes a storage tank body 1, a capsule 2, a pressure sensor 3, an end cap 4, bolts 5, a filling pipe 6, a gasket 7, a sealing ring 8, and screws 9.

[0056] The compensator tank body 1 is composed of three parts welded together in series: a nozzle end cap 11, a diaphragm shell 12, and an inflation shut-off valve assembly 13. The nozzle end cap 11 is an elliptical end cap with a flange. The flange flange has a sealing groove for forming a static seal with the end cap and the compression capsule flange. Multiple bolt holes are arranged around the circumference of the flange for bolt connection with the end cap. The diaphragm shell 12 is mainly a cylindrical shell section. One side of the cylindrical section is an elliptical end cap. A hemispherical recess is provided at the center of the elliptical end cap for installation with the filling pipe 6 and the gasket 7. The recess smoothly transitions with the elliptical end cap. Multiple through holes are arranged in the area between the recess and the shell on the elliptical end cap for the inflow and outflow of gas on both sides of the diaphragm. Multiple narrow grooves are arranged circumferentially on the inner side of the cylindrical shell wall. The bottom of the grooves is rounded and communicates with at least two openings on the diaphragm to avoid the formation of a large volume gas dead cavity in the cylindrical section, which would affect the working performance of the compensator. The inflation shut-off valve assembly 13 has a spherical surface with a central recess on one side and an opening for connection with the partition housing 12 on the other. A one-way valve structure for inflating and deflating the compensator's air chamber is arranged on the spherical surface. The valve housing and the assembly are integrally formed. Before welding the inflation shut-off valve assembly 13 to the partition housing 12, the internal components of the valve, such as the spring 111, valve head 112, gasket 113, and O-ring 116, are installed. Sealing plugs 114, O-rings 117 and 118, and a cap 115 are arranged on the outside of the valve. The bottom of the central recess of the inflation shut-off valve assembly 13 has screw holes and openings penetrating the inner cavity for connection and fixation with the pressure sensor 3. Considering weight optimization and improving the product's mechanical resistance, multiple reinforcing ribs are arranged at the screw hole locations within the inner cavity. These reinforcing ribs are still connected to the housing of the inflation shut-off valve assembly 13 via reinforcing plates. The ends of the reinforcing plates smoothly transition to the housing to avoid stress concentration. Figure 7 As shown.

[0057] like Figure 6 , Figure 8 and Figure 9As shown, the compensator capsule 2 is made of non-metallic rubber. Except for the flanged part, the outer dimensions of the capsule 2 are consistent with the inner wall dimensions of the liquid cavity side of the storage tank 1, so that the capsule fits tightly with the storage tank under internal pressure. The outer edge of the flanged part of the capsule 2 is set as an O-ring structure to cooperate with the storage tank 1 and the end cap 4 to form a seal. The chamfer of the flanged part is set so that the inner side R1 of the capsule is smaller than the chamfer R2 of the end cap, and the outer side chamfer R3 is equal to the chamfer R4 of the storage tank. After the end cap and the storage tank are connected by bolts, a second seal can be formed in the circumferential direction.

[0058] One end of the pressure sensor 3 is a plunger structure with a flange. The flange has multiple screw holes for connecting and fixing it to the tank body 1 with screws. The plunger has two annular sealing grooves for arranging O-rings to form two seals with the tank body 1. The other end of the pressure sensor 3 is equipped with an electrical connector for supplying power to the pressure sensor 3 and outputting pressure signals.

[0059] As shown in Figures 5(a) and 5(b), the compensator end cover 5 is a disc structure with a liquid chamber outlet interface in the middle. The outer side is provided with bolt holes for bolt connection 5. The inner side is provided with plane and circumferential stiffeners that cooperate with the tank body to compress the capsule. The outer side of the stiffeners and the chamfered part are used to form a second seal at the chamfered part of the compression capsule. The inner center of the end cover 5 is provided with a stepped hollow column for connection and fixation with the filling pipe. Multiple openings connecting the liquid chamber outlet are arranged in the circumferential direction of the hollow column and in the area between the hollow column and the stiffeners for the inflow and outflow of the working fluid in the liquid chamber.

[0060] The compensator filling pipe 6 is a hollow column structure with multiple radial openings arranged along the axial direction as flow channels for the working fluid in the liquid chamber. The openings are more dense on the side near the liquid chamber inlet and more sparse on the side near the partition. This is beneficial because when the working fluid in the liquid chamber flows into the compensator, the flow rate on the side near the interface is higher than that on the side near the partition. The gas between the outer side of the capsule and the tank can flow from the interface side to the partition side, which helps to avoid the formation of a large-volume gas dead space.

[0061] The compensator cap 7 is made of non-metallic material, such as polytetrafluoroethylene. One side of it is a hemispherical surface that fits into the capsule recess, and the other side is a groove that connects to the filling tube. This is used for the transition and to prevent the filling tube from damaging the capsule.

[0062] like Figure 1As shown, the perforated partition in the tank body 1 divides the inner cavity of the tank body 1 into two parts. The capsule 2 is installed near the nozzle end cap. In its free state, the capsule 2 is in contact with the inner side of the metal shell or has a small gap. The O-ring of the flange of the capsule 2 is assembled to the sealing groove of the flange of the nozzle end cap of the tank body. The filling pipe 6 and the gasket 7 are arranged at the center of the inner cavity of the capsule 2. The end cap 4 is connected and fixed to the tank body 1 by bolts 5. After the bolts 5 are tightened, they can both compress the flange of the capsule to form two static seals and limit the filling pipe 6 in the inner cavity of the capsule 2.

[0063] The seal at the folded edge of the capsule provides three sealing effects to prevent leakage between the air chamber and the outside, the liquid chamber and the outside, and the air chamber and the liquid chamber. A pressure sensor 3 is mounted on one side of the inflation shut-off valve assembly via screws. The plunger at one end of the pressure sensor 3 seals and contacts the gas in the air chamber, while the electrical connector at the other end powers the pressure sensor and outputs a voltage signal reflecting the pressure signal.

[0064] like Figure 10 As shown, end cap 4, filling pipe 6, gasket 7, capsule 2, and storage tank 1 are connected along the axis of the compensator. End cap 4 and storage tank 1 are connected by bolts to form a closed dimensional chain, and their constraint relationship is as follows:

[0065] ABD-(1-x1%)×E<C<ABD-(1-x2%)×E

[0066] Where A is the axial distance from the center of the bottom of the hemispherical recess in the inner cavity of the storage tank to the plane of the end cap flange; B is the axial distance from the plane of the end cap flange to the plane of the filling pipe; C is the axial length of the filling pipe; D is the axial distance from the plane of the gasket and the filling pipe to the center of the spherical surface; E is the wall thickness of the capsule at the hemispherical recess; x1% and x2% are the lower and upper limits of the capsule's allowable compression ratio, respectively, which can be achieved by adjusting the axial length E of the filling pipe.

[0067] Effects: This formula ① avoids localized damage to the capsule during assembly and operation due to excessive capsule compression ratio, which would affect the lifespan of the compensator; ② avoids the filling tube and capsule being in an unsecured state due to excessive capsule compression ratio, which would cause the filling tube to vibrate under mechanical conditions, and cause scraping at one end of the capsule during operation, which could easily lead to damage to parts and capsule and the risk of foreign objects.

[0068] The space enclosed by capsule 2 and end cap 4 is a liquid cavity, which is connected to the fluid circuit through the interface of end cap 4. The space enclosed by the outer side of capsule 2 and the inner side of storage tank 1 is a compensator gas cavity, which is a closed cavity. When the gas filling amount of the compensator gas cavity is constant, the constraint relationship between R (gas constant) and n (number of gas molecules per unit volume) is as follows:

[0069]

[0070] Where P1 is the inflation pressure of the air chamber when the capsule is in its free state (the outer side of the capsule is in contact with the inner side of the storage tank), V1 is the inflation volume of the air chamber when the capsule is in its free state, T1 is the inflation temperature, and V h P2 is the volume of the liquid chamber in the capsule's free state, P2 is the output pressure of the air chamber pressure sensor in a certain state during use, V2 is the volume of the air chamber in that state, T2 is the temperature of the air chamber in that state, and V l This represents the remaining volume of the capsule's liquid cavity in this state.

[0071] Effects: Through this formula, ① the working performance of the compensator can be predicted. By adjusting the diameter and length of the tank and capsule, the volume of the gas and liquid chambers can be adjusted, so that the volume of the working medium extruded and drawn in by the compensator meets the requirements within the system's required pressure range; ② combined with calibration tests, the pressure of the gas chamber can be monitored in real time by the compensator's gas chamber pressure sensor, thereby determining the remaining volume of the working medium in the liquid chamber and realizing real-time monitoring of the working status.

[0072] like Figure 1 As shown, after the full-capsule diaphragm compensator is assembled, the inner side of the compensator housing is divided into two parts: a liquid chamber and a gas chamber. The liquid chamber is the space enclosed by the inner side of capsule 2 and the inner side of end cap 4, and the liquid chamber is connected to the fluid circuit where the compensator is installed; the gas chamber is the inner cavity enclosed by the outer side of capsule and the metal shell, and the gas chamber is pre-filled with inert gas at a certain pressure through a one-way valve.

[0073] When the working fluid pressure in the liquid chamber is greater than or equal to the gas pressure in the gas chamber, capsule 2 is in contact with the inner side of storage tank 1, and the gas in the gas chamber is concentrated in the inner cavity formed by the partition and the inflation valve assembly. When the gas chamber is inflated, the gas and liquid chambers can be inflated simultaneously to ensure that the liquid chamber pressure is greater than the gas chamber pressure throughout the entire process. After being inflated to the specified pressure, the gas in the liquid chamber is released to control the inflation volume of the gas chamber.

[0074] The compensator connects the compensator liquid chamber to the fluid circuit via an interface on the end cap. When the working fluid in the fluid circuit expands due to heat and its pressure increases to a level greater than the compensator gas chamber pressure, the working fluid flows into the inner cavity of the filling pipe through the end cap interface, enters the compensator liquid chamber through the opening in the filling pipe, and causes the compensator capsule to expand. This forces the gas outside the capsule through the grooves on the inner side of the storage tank 1 and the small holes penetrating the perforated partition plate into the compensator gas chamber. The gas in the gas chamber is compressed, and the reading of the gas chamber pressure sensor increases until the pressure on both sides of the capsule reaches a new stable state, thus preventing the fluid circuit pressure from being too high. When the fluid circuit pressure drops below the compensator gas chamber pressure due to a decrease in temperature causing the working fluid to contract or leakage in the circuit, the gas in the gas chamber pushes the compensator capsule to contract through the small holes penetrating the partition shell. The working fluid in the compensator liquid chamber enters the inner cavity of the filling pipe through the opening in the filling pipe and the end cap, and then flows into the fluid circuit through the end cap interface to replenish the circuit working fluid, preventing circuit failures caused by excessively low circuit pressure, such as pump cavitation.

[0075] The actuating element of the compensator during operation is capsule 2, and the storage tank 1 is the pressure-bearing element. When the liquid chamber pressure is not greater than the gas chamber pressure, due to the small rigidity of the capsule, the pressure on both sides of the capsule is almost the same, and the capsule is not pressurized. Gas can flow on both sides of the partition shell without being pressurized. When the liquid chamber pressure is higher than the gas chamber pressure, the pressure difference is mainly borne by the partition shell, the nozzle end cap, and the end cap. The axial groove of the partition shell is relatively narrow, with a width and depth of 0.5 to 1 mm. The openings on the elliptical end cap of the partition shell are small holes with a diameter of about 1 mm to avoid excessive deformation of the capsule due to the pressure difference, which could cause damage.

[0076] During operation, the compensator can automatically start according to the pressure changes of the connected circuit, draw in or expel the working medium, stabilize the circuit pressure, compensate for working medium leakage in the circuit, and the air chamber pressure sensor monitors in real time throughout the process, so as to monitor the working status of the compensator in real time.

[0077] This invention is used in the active thermal control fluid loop of spacecraft. It can absorb loop pressure fluctuations and compensate for leaking working fluid. It features real-time liquid level measurement and reusability, and is characterized by high reliability, high extrusion efficiency, light weight, and reusability. This invention uses a diaphragm and filling pipe as limiting devices for capsule contraction and expansion deformation. The diaphragm has multiple through holes, and multiple grooves are arranged circumferentially on the inner side of the liquid chamber shell as gas flow channels. This helps avoid the formation of large-volume gas dead spaces that could affect the compensator's performance indicators, resulting in highly consistent capsule deformation and preventing scratches from other components, thus improving the reliability of the diaphragm compensator. This invention uses an open-hole diaphragm as a support element, allowing the capsule to withstand greater internal pressure, improving the compensator's ability to withstand high pressure differences between the gas and liquid sides, and overcoming the shortcomings of previous compensators in terms of insufficient pressure differential resistance. The compensator's gas chamber is arranged with pressure... The sensor can monitor the pressure in the compensator's gas chamber in real time, and calculate the working fluid volume in the compensator's liquid chamber based on the ideal gas law, thereby monitoring the compensator's working status. The invention features a self-locking valve structure for charging and discharging, and the end cap is bolted to the tank body for easy disassembly. The capsule, as the main working element of the compensator, can be replaced when it reaches its service life. The metal shell is reusable, providing reusability and extremely high cost-effectiveness. The capsule of this invention is lightweight. Under the same performance conditions, this compensator is more than 2 / 3 lighter than the metal bellows compensators used in previous spacecraft, offering a significant weight advantage.

[0078] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A fully encapsulated diaphragm compensator for a spacecraft fluid loop, characterized in that... include: The tank body (1), capsule (2), pressure sensor (3), end cap (4), filling pipe (6), and gasket (7); among which, The port of the storage tank (1) is connected to the end cap (4); The space enclosed by the tank body (1) and the end cap (4) is the inner cavity of the compensator; The capsule (2) is disposed in the inner cavity of the compensator. The outer wall of the capsule (2) is attached to the cavity wall on one side of the inner cavity of the compensator. The open end of the capsule (2) is connected to the end cap (4). The capsule (2) divides the inner cavity of the compensator into an air cavity and a liquid cavity. The capsule (2) is provided with the filling tube (6) inside. One end of the filling tube (6) is connected to the mounting boss of the end cap (4), and the other end of the filling tube (6) is in contact with the bottom of the capsule (2) through the gasket (7). The pressure sensor (3) is located at the other end of the tank body (1). The pressure sensing interface of the pressure sensor (3) is connected to the air chamber. The pressure sensor (3) monitors the pressure of the compensator air chamber in real time. The storage tank (1) includes a nozzle end cap (11), a partition shell (12), and an inflation shut-off valve assembly (13); wherein, The nozzle end cap (11) is connected to the partition shell (12); The partition housing (12) is connected to the inflation shut-off valve assembly (13); The port of the nozzle cap (11) is connected to the end cap (4); The pressure sensor (3) is mounted on the inflation shut-off valve assembly (13); The partition shell (12) includes a cylindrical section and a second elliptical head; wherein, One end of the cylindrical section is connected to the nozzle end cap (11), and the other end of the cylindrical section is connected to the second elliptical end cap, which is disposed inside the compensator cavity; The center of the second elliptical end cap is provided with a hemispherical recess that mates with the gasket (7); The second elliptical head has multiple small holes except for the hemispherical recess. The inner wall of the cylindrical section has multiple grooves, and the bottom of each groove is connected to at least two small holes in the second elliptical head.

2. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that... It also includes: double O-ring seals (8); among which, The pressure sensor (3) is located at the other end of the tank body (1) via the double O-ring seal (8).

3. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that... Also includes: Screw (9); wherein the pressure sensor (3) is connected to the tank body (1) via the screw (9).

4. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that: The spigot end cap (11) is an elliptical end cap with a flange; The flange of the nozzle cap (11) is provided with a sealing groove, which is used to cooperate with the end cap to compress the capsule to form a static seal. The flange of the spigot end cap (11) has multiple bolt holes arranged around its circumference for connection with the end cap by bolts.

5. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that: The inflation shut-off valve assembly (13) includes a spherical surface with a central recess, an inflation valve, and a second cylindrical section; wherein, One end of the second cylindrical segment is connected to the other end of the cylindrical segment, and the other end of the second cylindrical segment is connected to the spherical surface of the central recess. The inflation valve is disposed on the spherical surface of the central recess; The pressure sensor (3) is located at the middle recess of the spherical surface of the middle recess.

6. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 5, characterized in that: The inflation valve includes a spring (111), a valve head (112), a gasket (113), a plug (114), and a plug cap (115); wherein, The gasket (113) is disposed at the opening of the spherical surface of the central recess; The plug (114) is connected to the open end of the spherical surface of the intermediate recess; The valve head (112) is disposed inside the plug (114); The spring (111) is disposed inside the valve head (112), and the bottom of the spring (111) presses against the gasket (113); The cap (115) is fitted onto the outer surface of the plug (114).

7. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that: The filling tube (6) is a hollow column structure, and multiple radial openings are arranged in the axial direction of the filling tube (6).

8. The fully enclosed diaphragm compensator for spacecraft fluid loops according to claim 1, characterized in that: The capsule (2) is made of rubber. The outer edge of the flanged part of the capsule (2) is set as an O-ring structure to cooperate with the storage tank (1) and the end cap (4) to form a seal. The inner chamfer R1 of the flanged part of the capsule (2) is smaller than the chamfer R2 of the end cap, and the outer chamfer R3 is equal to the chamfer R4 of the storage tank.

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