Thermal control single-phase fluid loop suitable for high-power small satellite platform

Abstract

The invention discloses a thermal control single-phase fluid loop suitable for a high-power small satellite platform. The thermal control single-phase fluid loop comprises a pump set module, a temperature control module, a heat dissipation module, a heat collection module, a filtering module, a pipeline self-locking valve, a feeding and discharging valve and related pipelines. Through integrated design, multiple devices in the thermal control fluid loop are modularly designed into one or more assemblies to be installed in the satellite cabin, damage to the devices caused by space debris can be effectively prevented, and meanwhile disassembly and assembly are convenient. The heat dissipation module adopts a multi-branch parallel design, and a self-locking valve is arranged at an inlet and an outlet of each branch, so that a fault branch can be conveniently isolated, overtemperature and overpressure of the isolation branch can be ensured, and the safety is ensured. And the pipeline self-locking valve can reversely release pressure, so that the working pressure of a fluid loop is always stable. In order to facilitate ground testing, a ground heat dissipation module can be additionally arranged, the expansion device has a liquid storage function, and the expansion device can be quickly connected with or disconnected from the whole satellite through liquid.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft thermal control technology, specifically relating to a single-phase fluid loop design. Background Technology

[0002] Due to limitations in configuration size, mass, and power, the average heat dissipation of small satellites generally does not exceed 1000W.

[0003] With the enhancement of payload functions and the diversification of mission modes in recent years, small satellites face thermal control challenges such as high heat consumption in short time, large range of external heat flow variation, limited space and weight resources, a large number of high-power payloads with dispersed layout, and high risk of space debris puncturing pipelines. In addition, with the characteristics of low development cost and short cycle, traditional thermal control technology can no longer meet their thermal control requirements, which poses a great challenge to the overall satellite thermal control design. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a single-phase fluid circuit for thermal control suitable for high-power small satellite platforms, so as to meet the thermal control requirements under the situation of increasing heat consumption of small satellites.

[0005] The technical solution of this invention is: a single-phase fluid circuit for thermal control suitable for high-power small satellite platforms, comprising a pump module, a temperature control module, a heat dissipation module, a heat collection module, a filter module, a pipeline self-locking valve, and a fill / drain valve, wherein: Pump module: It serves as a power source to drive the working medium to circulate within the fluid circuit; it provides real-time compensation for changes in the working medium temperature or leakage in the fluid circuit to stabilize the internal pressure of the fluid circuit. Temperature control module: Distributes the flow rate of the working fluid, selects a portion of the working fluid to enter the heat dissipation module to dissipate heat from the working fluid, and sets the temperature of the mixed working fluid after heat dissipation and the unheated working fluid as the control value. Heat dissipation module: includes at least one heat dissipation circuit to dissipate heat from the flowing working fluid; Heat collection module: Collects heat generated by equipment inside the satellite by using the flow of a working fluid; Pipeline self-locking valve: It realizes the opening and closing of the fluid circuit during the process of adding and discharging working medium; when the pipeline self-locking valve is closed, it has a reverse pressure relief function, which, together with the pump module, makes the internal pressure of the fluid circuit stable. Filtration module: filters impurities in the working fluid; Addition and discharge valves: These serve as the inlet and outlet of the working fluid loop during the addition and discharge of the working fluid; the addition and discharge valve for the working fluid inlet is installed at the output end of the pump module, and the addition and discharge valve for the working fluid return port is installed at the input end of the pump module.

[0006] Furthermore, the single-phase fluid loop also includes a ground heat dissipation module, which is used to replace the heat dissipation module during ground testing and to dissipate heat from the flowing working fluid.

[0007] Preferably, the ground cooling module includes a chiller unit, a heat exchanger, a filter, an expander, and a disconnector. The disconnector is used to connect to the fluid circuit via a filler / drain valve. The expander is used to maintain the stability of the working fluid pressure inside the ground cooling module. The filter is used to filter impurities from the working fluid. The heat exchanger is used to receive and transfer the heat carried by the working fluid. The chiller unit is used to absorb the heat received by the heat exchanger.

[0008] Furthermore, there are three injection and discharge valves. The third injection and discharge valve is located at the output end of the pump module and is used for injecting the working fluid. The second injection and discharge valve is located at the input end of the pump module and is located on one side of the pipeline self-locking valve. It is used for discharging the working fluid. The first injection and discharge valve is located on the other side of the pipeline self-locking valve and is used to connect the ground heat dissipation module in conjunction with the second injection and discharge valve.

[0009] Preferably, when there are two or more heat dissipation circuits, the heat dissipation circuits are connected in parallel.

[0010] Furthermore, the heat dissipation circuit includes a radiator and self-locking valves at both ends of the radiator. The self-locking valve at the inlet end is installed in the correct direction, and the self-locking valve at the outlet end is installed in reverse. When both the self-locking valve at the inlet end and the self-locking valve at the outlet end are closed, the pressure is automatically released through the self-locking valve installed in reverse.

[0011] Furthermore, the radiator is a body-mounted radiator, a deployable radiator, or a combination of both.

[0012] Furthermore, the pump module includes a drive source and a compensator connected in parallel. Each drive source includes a mechanical pump and a check valve, with the input end of the check valve connected to the output end of the mechanical pump. The compensator is located at the input end of the mechanical pump.

[0013] Furthermore, the temperature control module includes two parallel temperature control branches, each including two self-locking valves and one temperature control valve, forming a main backup; the input end of the temperature control valve is connected in series with a positively mounted self-locking valve, the first output end of the temperature control valve is directly connected to the input end of the heat dissipation module, and the second output end of the temperature control valve is connected in series with a reverse-mounted self-locking valve and then connected to the output end of the heat dissipation module as the working fluid mixing point. The opening degree of the temperature control valve is determined according to the control value required for the working fluid mixing point.

[0014] Furthermore, the filter module includes two filters and a self-locking valve, with the two filters connected in parallel and one of the filters also connected in series with a self-locking valve installed in reverse.

[0015] The advantages of this invention compared to the prior art are: (1) Integrated modular design: This invention uses an integrated design method to modularize multiple devices (such as circulating pumps, sensors, and various valves) in the thermal control fluid circuit into one or more components and install them in the satellite cabin, which can effectively prevent damage to the equipment caused by space debris; at the same time, small satellites are generally limited in space, so the integrated design can save space and is also easy to disassemble and assemble; the modular design can also shorten the production cycle and facilitate large-scale mass production. (2) Safety design of heat dissipation module: Since the radiator is installed outside the star, it is easily affected by space debris. Therefore, a multi-branch parallel design is adopted. One self-locking valve is installed at the inlet and outlet of each branch. When a branch of the fluid circuit fails, it can be isolated by opening and closing the self-locking valve to ensure that the fluid circuit continues to maintain the heat dissipation function and does not completely lose its function. In addition, the self-locking valve at the outlet is installed in reverse. When a branch is isolated, in order to prevent the branch from overheating and overpressure, the self-locking valve has a reverse pressure relief function. That is, when the reverse pressure difference is too large, the self-locking valve can be opened to ensure safety. (3) Safety design of pipeline self-locking valve: The self-locking valve i at the ground heat dissipation module is installed in reverse. When the ground heat dissipation module is working normally, the feed valve a and feed valve b are open and the self-locking valve i is closed. When the feed valve a or feed valve b is abnormally closed, the one-way valve in the pump group module → the self-locking valve i is a blind cavity. When the liquid is over-temperature and over-pressure, the self-locking valve i can depressurize in reverse. That is, the self-locking valve i automatically opens under pressure difference and stays open. The system is connected. The compensator can ensure the stability of the working pressure of the circuit system, prevent the risk of over-temperature and over-pressure caused by misoperation of the valve, and ensure the safety of the system. (4) Filter module design: to filter impurities in the working fluid and ensure the safe operation of components such as the loop pump. The advantage of the filter forming a separate module is that it is easy to replace and does not affect other modules when replacing it, that is, other parts of the loop do not need to be disassembled; on-orbit backup, if the main filter is blocked, the loop can be kept running normally by controlling the corresponding self-locking valve; (5) Ground heat dissipation module design: An expander is designed at the inlet. Therefore, after the first filling of the ground heat dissipation module, no further filling is required. That is, the ground heat dissipation module can be stored with liquid. The expander can adapt to the influence of temperature on liquid pressure. It can be quickly connected or disconnected from the whole satellite with liquid through the disconnector. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the thermal control single-phase fluid circuit of the present invention; Figure 2 This is a schematic diagram of the operation of the thermal control single-phase fluid loop satellite refueling process (without ground heat dissipation module) of the present invention; Figure 3 This is a schematic diagram of the operation of the thermal control single-phase fluid loop satellite refueling process (with ground heat dissipation module) of the present invention; Figure 4This is a schematic diagram of the working condition of the thermal control single-phase fluid loop load test of the present invention; Figure 5 This is a schematic diagram of the thermal control single-phase fluid circuit ground heat dissipation module of the present invention. Detailed Implementation

[0017] like Figure 1 The diagram shown is a schematic of the fluid circuit proposed in this invention. It adopts a modular distributed layout design and mainly includes a pump module, a temperature control module, a heat dissipation module, a heat collection module, a filtration module, a ground heat dissipation module, pipeline self-locking valves, supply and discharge valves, and corresponding pipelines. The composition and function of each module are detailed in Table 1.

[0018] Table 1 Composition and Function of Fluid Circuit

[0019] The working principle of this fluid loop is as follows: the mechanical pump drives the single-phase fluid working medium to circulate in the loop. The cold working medium flows through the cold plate, support pipeline and pre-embedded pipeline, and exchanges heat with the load equipment. The working medium heats up and collects and carries away heat in the form of sensible heat. The collected heat is then transferred to the radiator and finally dissipated into the space environment. At the same time, the hot working medium is restored to the cold working medium and flows back to the mechanical pump, thus forming a flow and heat exchange cycle.

[0020] An intelligent adaptive control strategy is adopted. On the one hand, the temperature control of the mixing point uses a bypass mixing temperature control strategy. When the internal and external heat load of the satellite increases and the temperature of the mixing point at the radiator outlet rises, the temperature control valve opens wider, increasing the flow rate into the radiator and improving heat dissipation. Conversely, when the internal and external heat load of the satellite decreases and the temperature of the mixing point at the radiator outlet decreases, the temperature control valve opens narrower, reducing the flow rate into the radiator and thus reducing heat dissipation. The fluid loop temperature control point can also be adjusted in real time via on-orbit injection as needed. If necessary, the temperature control valve angle value can be directly injected, causing the temperature control valve to operate at a fixed angle without rotation, ensuring that the flow rates of the main fluid loop (not passing through the radiator) and the bypass fluid loop (passing through the radiator) are mixed in a fixed ratio. On the other hand, the performance curve of the mechanical pump, i.e., the flow-head curve, can be designed to be steeper, ensuring that even if the system flow resistance varies due to test conditions, the system flow rate changes little, thus achieving adaptive matching of flow rate to system resistance.

[0021] Since the radiators cannot dissipate heat during ground testing, a ground-based heat dissipation module (cold source equipment) is required. This module exchanges heat with the onboard loop via heat exchanger components, removing heat from the entire satellite and controlling the payload temperature. Changes in thermal load and external thermal environment cause variations in the temperature of the working fluid, leading to its contraction and expansion. The compensator's function is to compensate for or recover the liquid working fluid from the fluid loop under these conditions, and also to compensate for minor leaks of the working fluid.

[0022] The fluid circuit of this invention has multiple operating conditions: (a) Working propellant filling conditions: including filling conditions of the entire satellite without ground heat dissipation modules and filling conditions with ground heat dissipation modules.

[0023] 1. Whole-satellite refueling operation (without ground cooling module): such as Figure 2 As shown, the working fluid enters from valve c and exits from valve b, forming a cycle. Since there is a check valve after the mechanical pump, using the current valve design, when nitrogen is used to purge the satellite pipeline before injection, the check valve can prevent the mechanical pump from being backflushd, thus protecting the safety of the mechanical pump. 2. Operating with Ground Cooling Module: Install the ground cooling module on filler / exhaust valve a, and simultaneously fill both the satellite and the ground cooling module. Note that the ground cooling module should not be installed on filler / exhaust valve c, as it has an expander. The mechanical pump outlet is a high-pressure area, and during startup testing, the expander will open, affecting the accuracy of data interpretation.

[0024] (ii) Load test conditions: such as Figure 4 As shown, the ground cooling module is connected to the feed valve a and feed valve b via a quick disconnector. When the pipeline self-locking valve (self-locking valve i) is closed, the working fluid enters the ground cooling module from feed valve a and flows out from feed valve b, transferring heat to the chiller unit through the heat exchanger.

[0025] (III) Working fluid removal conditions: similar Figure 2 Nitrogen gas enters from valve c and exits from valve b, discharging the working fluid from the fluid circuit. The design of the check valve and the valve ensures that the mechanical pump is not backflushd, protecting the safety of the mechanical pump.

[0026] In this invention, the various sections of pipeline are connected to each other, as well as to the pipeline and equipment (such as pump module, temperature control module, heat dissipation module, etc.) through double O-rings. The double O-rings ensure good sealing and facilitate the disassembly and assembly of the pipeline and equipment.

[0027] To achieve effective heat dissipation, the fluid loop flow rate needs to remain relatively stable. This means that while the system's flow resistance varies significantly under different conditions, the flow rate should remain relatively stable. Therefore, it's necessary to analyze the entire satellite's testing process in advance and obtain flow resistance characteristic curves. Based on this, the characteristic curve of the mechanical pump is designed. The intersection of the mechanical pump's characteristic curve and the flow resistance characteristic curve represents the flow rate. By identifying the fluid loop's operating conditions in advance and through the mechanical pump's structural design, a steeper mechanical performance curve (i.e., a steeper (head-flow rate)) is achieved. Even with varying flow resistances in different states during ground testing and on-orbit operation, the system flow rate remains consistently between 400 and 500 L / h, meeting the satellite's overall heat dissipation requirements.

[0028] like Figure 5As shown, the ground cooling module consists of a chiller unit, heat exchanger, filter, expander, disconnector, and metal hoses. This ground cooling module can be quickly connected to or disconnected from the entire satellite via the disconnector; an expander is designed at the inlet to balance the fluctuations in working fluid volume and pressure caused by temperature changes in the heat exchange components and related piping systems, ensuring stable pressure in the heat exchange component system. When the ambient temperature rises, the working fluid in the fluid loop expands, leading to an increase in the system's working fluid temperature and pressure. The working fluid then enters the expander through the liquid connection. The helium gas sealed between the upper hemisphere and the gas bladder is compressed, its volume decreasing and pressure increasing until the gas pressure inside the expander matches the working fluid pressure, at which point the working fluid stops entering the expander from the loop. Conversely, when the ambient temperature decreases, the working fluid in the fluid loop contracts, leading to a decrease in the system's working fluid temperature and pressure. The working fluid then enters the fluid loop through the liquid connection from the expander. The helium gas sealed between the upper hemisphere and the gas bladder expands, its volume increasing and pressure decreasing until the gas pressure inside the expander matches the working fluid pressure, at which point the working fluid stops entering the loop from the expander, thus stabilizing the fluid loop system pressure. Therefore, after the initial filling of this ground cooling module, no further filling is required; the ground cooling module can be stored with liquid, and the expander can adapt to the temperature-induced changes in liquid pressure. A filter is designed at the outlet to remove impurities from the working fluid, ensuring that the working fluid entering the loop is clean and guaranteeing the safe operation of components such as the mechanical pump. The chiller unit generates cooling capacity and transfers the cooling capacity to the heat exchanger via refrigerant. The hot working fluid in the fluid loop flows through the heat exchanger, which transfers heat to the refrigerant, and finally dissipates the heat through the chiller unit.

[0029] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms, characterized in that: This includes a pump module, temperature control module, heat dissipation module, heat collection module, filtration module, pipeline self-locking valve, and supply / discharge valve, among which: Pump module: It serves as a power source to drive the working medium to circulate within the fluid circuit; it provides real-time compensation for changes in the working medium temperature or leakage in the fluid circuit to stabilize the internal pressure of the fluid circuit. Temperature control module: Distributes the flow rate of the working fluid, selects a portion of the working fluid to enter the heat dissipation module to dissipate heat from the working fluid, and sets the temperature of the mixed working fluid after heat dissipation and the unheated working fluid as the control value. Heat dissipation module: includes at least one heat dissipation circuit to dissipate heat from the flowing working fluid; Heat collection module: Collects heat generated by equipment inside the satellite by using the flow of a working fluid; Pipeline self-locking valve: It realizes the opening and closing of the fluid circuit during the process of adding and discharging working medium; when the pipeline self-locking valve is closed, it has a reverse pressure relief function, which, together with the pump module, makes the internal pressure of the fluid circuit stable. Filtration module: filters impurities in the working fluid; Addition and discharge valves: These serve as the inlet and outlet of the working fluid loop during the addition and discharge of the working fluid; the addition and discharge valve for the working fluid inlet is installed at the output end of the pump module, and the addition and discharge valve for the working fluid return port is installed at the input end of the pump module.

2. The single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 1, characterized in that: It also includes a ground cooling module, which is used to replace the cooling module during ground testing and to dissipate heat from the flowing working fluid.

3. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 2, characterized in that: The ground cooling module includes a chiller unit, a heat exchanger, a filter, an expander, and a disconnector. The disconnector is used to connect to the fluid circuit via a filler / drain valve. The expander is used to maintain the stability of the working fluid pressure inside the ground cooling module. The filter is used to filter impurities from the working fluid. The heat exchanger is used to receive and transfer the heat carried by the working fluid. The chiller unit is used to absorb the heat received by the heat exchanger.

4. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 2, characterized in that: There are three injection and discharge valves. The third injection and discharge valve is located at the output end of the pump module and is used for injecting the working fluid. The second injection and discharge valve is located at the input end of the pump module and is located on one side of the pipeline self-locking valve. It is used for discharging the working fluid. The first injection and discharge valve is located on the other side of the pipeline self-locking valve and is used to connect the ground heat dissipation module in conjunction with the second injection and discharge valve.

5. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 1, characterized in that: When there are two or more heat dissipation circuits, they are connected in parallel.

6. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 5, characterized in that: The heat dissipation circuit includes a radiator and self-locking valves at both ends of the radiator. The self-locking valve at the inlet end is installed in the correct direction, and the self-locking valve at the outlet end is installed in the reverse direction. When both the self-locking valves at the inlet and outlet ends are closed, the pressure is automatically released through the self-locking valve installed in the reverse direction.

7. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 6, characterized in that: The radiator is a body-mounted radiator, a deployable radiator, or a combination of both.

8. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 1, characterized in that: The pump module includes a drive source and a compensator connected in parallel. Each drive source includes a mechanical pump and a check valve. The input end of the check valve is connected to the output end of the mechanical pump. The compensator is located at the input end of the mechanical pump.

9. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 1, characterized in that: The temperature control module includes two parallel temperature control branches, each of which includes two self-locking valves and one temperature control valve, forming a main backup. The input end of the temperature control valve is connected in series with a positively mounted self-locking valve, the first output end of the temperature control valve is directly connected to the input end of the heat dissipation module, and the second output end of the temperature control valve is connected in series with a reverse-mounted self-locking valve and then connected to the output end of the heat dissipation module as the working fluid mixing point. The opening degree of the temperature control valve is determined according to the control value required for the working fluid mixing point.

10. A single-phase fluid circuit for thermal control suitable for high-power small satellite platforms according to claim 1, characterized in that: The filter module includes two filters and a self-locking valve. The two filters are connected in parallel, and one of the filters is also connected in series with a self-locking valve installed in reverse.

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