Magnetic compensation method simulation microgravity heat pipe comprehensive testing device and testing method

Abstract

The application discloses a kind of magnetic compensation method simulation microgravity heat pipe comprehensive testing device and testing method, testing device includes each other associated magnetic field generating system, magnetic field calibration system, force measurement system, heat pipe performance testing device and visual observation system;Magnetic field generating system includes rectangular coupling coil, cooling circulation system, power control cabinet;Magnetic field calibration system includes high-precision hall probe, three-dimensional stepping platform, control acquisition system;Force measurement system includes support bracket and force sensor;Heat pipe performance testing device includes heat pipe to be measured, electric heating system, heat insulation device and data acquisition system;Testing method includes electric control magnetic field generation stage, field parameter determination stage, heat pipe start-up operation and acquisition analysis stage in order of precedence.This application can provide large size microgravity environment suitable for heat pipe performance comprehensive test, can carry out reliability verification of space heat pipe for space reactor on ground, meet the demand of heat pipe deep research and development.

Description

Technical Field

[0001] This invention relates to the field of heat pipe performance testing technology under special conditions, specifically to a comprehensive testing device and method for heat pipes under microgravity using magnetic compensation. Background Technology

[0002] Heat pipes, as highly efficient heat transfer elements, have significant application value in space nuclear reactor power systems. For example, heat pipe heat exchangers can be used in waste heat removal systems, and heat pipes can connect the reactor core and thermoelectric conversion systems in heat transfer systems. Under microgravity conditions in space, surface tension dominates, capillary action becomes more pronounced, and the shape of the working fluid gas-liquid interface, the interaction between the liquid phase and the solid wall, and bubble entrainment and retention phenomena in heat pipes may differ significantly from experimental patterns under normal gravity. Currently, heat pipes are mainly designed and tested in normal gravity environments on Earth. Due to the high cost of space experiments, research on the relevant mechanisms and performance characteristics under microgravity is lacking. Conducting comprehensive microgravity heat pipe testing can not only study the special phenomena of heat pipes in the space environment but also verify the reliability of heat pipes designed and developed for space reactors. Because space experiments are costly and not suitable for repetitive testing, it is necessary to construct a large-scale microgravity environment on Earth that meets the requirements for heat pipe testing.

[0003] Magnetofluids exhibit ferromagnetic properties upon reaching saturation magnetization, generating volumetric magnetic forces at the microscopic level that counteract gravity. Therefore, achieving magnetic levitation of magnetofluids through gradient magnetic fields is an effective method for realizing microgravity. However, the effective magnetic compensation region generated by traditional circular Helmholtz-Maxwell coils exists only in the central region of the axis. The diameter and height of the cylindrical effective region are on the order of millimeters, and the gradient direction at the edge of the region deviates from the vertical direction. Such devices are far from meeting the performance testing requirements of heat pipes 1-2 meters long. In addition to generating a large-scale gradient magnetic field, the equipment schemes required for calibrating magnetic field parameters within the large-scale effective magnetic field region, measuring the stress on the heat pipe, and conducting heat pipe testing all need to be considered. Therefore, overcoming these difficulties is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To overcome the problems existing in the prior art, the present invention aims to provide a comprehensive testing device and method for simulating microgravity heat pipes using a magnetic compensation method. This fills the technological gap where, due to the high barriers and costs of space experiments, microgravity environment testing is generally lacking in the development of heat pipes, making it impossible to optimize heat pipe design for the special mechanistic phenomena of heat pipes used in space applications. Through a series of tests conducted using this device, the reliability of heat pipes used in space reactors can be effectively improved, thereby enhancing the overall reliability of the space reactor power system.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A comprehensive testing device for simulating microgravity heat pipes using a magnetic compensation method is provided. The testing device includes an interconnected magnetic field generation system, a magnetic field calibration system, a force measurement system, a heat pipe performance testing device, and a visualization observation system.

[0007] The magnetic field generating system is used to generate a large-size uniform gradient magnetic field with uniformity and linearity that meets the requirements through a rectangular coupling coil, and to effectively cool the rectangular coupling coil.

[0008] The magnetic field calibration system is used to measure and analyze the magnetic field and obtain parameters within the effective range of the magnetic field.

[0009] The force measurement system is used to support the heat pipe under test and monitor the force on the entire heat pipe. The magnetic field state and the force state of the heat pipe under test are checked by the magnetic field calibration system and the force measurement system. The current input is adjusted until the force on the entire heat pipe under test is exactly the difference between the net weight of the heat pipe under test and the filling volume. Then the working fluid inside the heat pipe under test achieves gravity compensation.

[0010] The heat pipe performance testing device is used to heat the evaporation section of the heat pipe under test, insulate the insulation section, and collect and record the start-up characteristics, isothermal properties, and heat transfer limit performance parameters of the heat pipe under test.

[0011] The visualization observation system is used to perform image analysis on the flow state of the working fluid through thermal imaging.

[0012] Optionally, the magnetic field generating system includes a rectangular coupling coil, a cooling circulation system for cooling the rectangular coupling coil, and a power control cabinet for supplying power to the rectangular coupling coil and the cooling circulation system.

[0013] Optionally, the rectangular coupling coil is composed of a rectangular Maxwell coil that generates a gradient magnetic field and a rectangular Helmholtz coil that eliminates magnetic field non-uniformity. The resulting magnetic field has high linearity of magnetic field strength gradient in the vertical direction and high uniformity of magnetic field strength in the horizontal direction. The effective area of ​​the magnetic field is large and adaptable to the size of the heat pipe under test. The cooling circulation system can be oil-cooled, water-cooled, or naturally air-cooled according to the required magnetic field strength of the working fluid and the magnetic field working time.

[0014] Optionally, the magnetic field calibration system includes a high-precision Hall probe, a three-dimensional stepping platform, and a control and acquisition system. Under the control of the control and acquisition system, the three-dimensional stepping platform uses the high-precision Hall probe (4) to measure and record the magnetic field parameters at each point in the effective area of ​​the magnetic field.

[0015] Optionally, the three-dimensional stepping platform includes a track platform, a three-dimensional stepper motor, and a fixing clamping assembly. A high-precision Hall probe is fixed on the track platform by the fixing clamping assembly, and the three-dimensional stepper motor controls the movement of the track platform.

[0016] Optionally, the force measurement system includes a support bracket and a force sensor. The heat pipe is fixed by the support bracket within the effective area of ​​the magnetic field, and the force sensor measures the force state of the entire heat pipe under test.

[0017] Optionally, the heat pipe performance testing device includes a heat pipe under test, an electric heating system, a heat insulation device, and a data acquisition system; the electric heating system is applied to the evaporation section of the heat pipe under test; the heat insulation device is applied to the insulation section of the heat pipe under test; the data acquisition system includes a thermocouple, a power meter sensing device, and a data processing terminal.

[0018] Optionally, the heat pipe under test uses a water-based magnetic fluid or an organic magnetic fluid of liquid metal as the working fluid; the liquid wick inside the heat pipe under test is a wire mesh type or a dry channel type.

[0019] The organic magnetic fluid is an alternative magnetic fluid with physical properties similar to liquid metal working fluid, such as density, thermal conductivity, surface tension, viscosity, and contact angle, to perform performance tests on two mechanisms in heat pipes that are greatly affected by gravity: capillary flow and bubble blockage.

[0020] Optionally, the visualization observation system includes an infrared thermal imaging device and an image analysis system for non-contact capture of thermal images of the heat pipe under test.

[0021] The test method of the magnetic compensation method for simulating microgravity heat pipe integrated test device firstly involves the generation of an electrically controlled magnetic field, that is, the power control system separately supplies a predetermined current value to the two sets of coils of the rectangular coupling coil to generate the target magnetic field, and then the Joule heat generated by the rectangular coupling coil is cooled by a cooling circulation system.

[0022] Then, the field parameter measurement stage is carried out, that is, the magnetic field strength is measured by the magnetic field calibration system, and the magnetic field uniformity and gradient linearity are analyzed to see if they meet the magnetic compensation parameter requirements of the selected magnetic fluid. Then, the heat pipe to be tested is placed in the test, and the force measurement system is used to measure the force on the entire heat pipe. The current input is adjusted until the force on the entire heat pipe is exactly the difference between the net weight of the heat pipe and the filling volume. Then the working fluid inside the heat pipe achieves gravity compensation.

[0023] Finally, the heat pipe startup and data acquisition and analysis stage is carried out. In the heat pipe performance testing device, the heat pipe under test is fully started by the electric heating system. Under steady-state operation, its thermal performance is analyzed by the data acquisition system, and the working fluid flow characteristics are analyzed by the infrared image system of the visualization observation system.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention completes the overall design of a magnetically compensated microgravity testing device and method suitable for heat pipes. Through a rectangular coupled coil design, it solves the problem of the extremely narrow effective gravity compensation area in existing room-temperature magnetic compensation methods. During the electrically controlled magnetic field generation stage, a large-scale effective magnetic field in a microgravity environment can be generated on the ground. During the field parameter measurement stage, the operation of the device and the suspension state of the working fluid inside the pipe can be confirmed by collecting and comparing magnetic field parameters and mechanical parameters. During the heat pipe startup, operation, and data collection and analysis stages, the heat pipe performance testing device can collect the operating parameters of the heat pipe in a microgravity environment, and the internal working fluid state can be analyzed non-contactly through a visualization observation system. This invention fills the technological gap where, due to the high threshold and cost of space experiments, microgravity environment testing is generally lacking in the development of heat pipes, making it impossible to optimize heat pipe design for the special mechanisms of heat pipes used in space applications. Through a series of tests conducted using this device, the reliability of heat pipes used in space reactors can be effectively improved, thereby enhancing the overall reliability of the space reactor power system. Attached Figure Description

[0026] 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 only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a structural diagram of a magnetic compensation method microgravity simulation environment heat pipe integrated testing device according to the present invention;

[0028] Figure 2 This is a schematic diagram of the main magnetic field component of a microgravity simulation environment heat pipe integrated testing device based on the magnetic compensation method of the present invention.

[0029] Among them, 1 is a rectangular coupling coil; 2 is a cooling circulation system; 3 is a power control cabinet; 4 is a high-precision Hall probe; 5 is a three-dimensional stepping platform; 6 is a control and acquisition system; 7 is a support bracket; 8 is a force sensor; 9 is a heat pipe under test; 10 is an electric heating system; 11 is a heat insulation device; 12 is a data acquisition system; and 13 is an infrared thermal imaging device. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention discloses a comprehensive testing device and method for simulating microgravity heat pipes using magnetic compensation. See [link to relevant documentation]. Figure 1 The testing apparatus includes an interconnected magnetic field generation system, magnetic field calibration system, force measurement system, heat pipe performance testing device, and visualization observation system. The testing methods include an electrically controlled magnetic field generation stage, a field parameter measurement stage, and a heat pipe start-up and operation and data acquisition and analysis stage.

[0032] In a specific embodiment, the magnetic field generating system includes a rectangular coupling coil (1), a cooling circulation system (2), and a power control cabinet (3). The rectangular coupling coil (1) is composed of a rectangular Maxwell coil that generates a gradient magnetic field and a rectangular Helmholtz coil that eliminates magnetic field non-uniformity. Compared with the traditional circular coil, it can provide a vertical uniform magnetic field gradient over a larger area to adapt to the heat pipe size.

[0033] The magnetic field is generated by energizing the two coils through the power control cabinet (3). The magnetic field and its distribution can be controlled by pre-experimentation or simulation. The specific parameters of the magnetic field are determined by the working fluid type of the heat pipe (9) under test. In one embodiment, the working fluid is a water-based magnetic fluid. The effective area of ​​the magnetic field is a cuboid with a length of not less than 1.2m, a height and width of not less than 75mm, a uniform magnetic field of not less than 350Gs, a uniformity better than 5%, a gradient magnetic field of not less than 0.8T / m, and a linearity better than 10%. The cooling circulation system is used to provide necessary cooling for the continuously running coils. Specifically, it can be oil cooling, water cooling, or natural air cooling.

[0034] In a specific embodiment, the magnetic field calibration system drives the three-dimensional stepping platform (5) to perform a fine scan of the test space through the PLC control program in the control acquisition system (6), and collects and analyzes the magnetic field parameters measured by the high-precision Hall probe (4) held by the three-dimensional stepping platform. In one embodiment, the positioning accuracy of the three-dimensional stepping platform (5) is <0.01mm, and the probe accuracy error is ±0.1%.

[0035] In one embodiment, such as Figure 2 As shown, the force sensor (8) is arranged at the contact point between the support bracket (7) and the heat pipe under test, with multiple measuring points evenly arranged along the radial direction of the heat pipe to obtain the stress state of the entire heat pipe. The microgravity level can be determined by comparing the weight difference before and after the magnetic field is generated with the amount of working fluid. Within the effective magnetic field region, simulation of different gravity environments from 0g to 1.0g should be possible, and the non-uniformity of the force within the field should be less than 10%.

[0036] In a specific embodiment, the evaporation section of the heat pipe (9) under test is heated by an electric heating system (10), wherein the electric heating element needs to be demagnetized, which can be achieved by symmetrically distributed wiring, using non-magnetic cable materials, etc. In one example, the heat insulation device (11) uses aluminum foil to wrap glass fiber insulation cotton to insulate the insulation section. In another example, thermocouples and other sensors are arranged in the grooves of the heat pipe (9) under test, and the heat pipe's start-up characteristics, isothermal properties, heat transfer limit, and other performance characteristics are collected and analyzed in real time by a data acquisition system (12).

[0037] The working fluid inside the heat pipe (9) to be tested can be a water-based magnetic fluid or an alternative organic magnetic fluid, and the wick can be a wire mesh type or a dry channel type. For alternative organic magnetic fluids, the liquid metal model analysis needs to be performed first, and the parameters need to be customized according to various physical properties to conduct performance tests on the mechanism problems that are greatly affected by gravity inside the heat pipe, such as capillary flow and bubble blockage.

[0038] In a specific embodiment, the visualization observation system includes an infrared thermal imaging device (13) and an image analysis system, which are used to capture thermal images of the heat pipe under test in a non-contact manner and analyze the heat transfer and flow state of the magnetohydrodynamic working fluid inside the heat pipe under test in a microgravity environment through visualization image analysis.

[0039] In a specific embodiment, the testing method is as follows: First, an electrically controlled magnetic field generation stage is performed. A predetermined current value is supplied to each of the two sets of coils of the rectangular coupling coil through a power control system to generate the target magnetic field. The Joule heat generated by the rectangular coupling coil is cooled by a cooling circulation system. Next, a field parameter measurement stage is performed. The magnetic field strength is measured by a magnetic field calibration system, and the uniformity and gradient linearity of the magnetic field are analyzed to determine whether they meet the magnetic compensation parameter requirements of the selected magnetic fluid. The heat pipe to be tested is placed in the test, and the force measurement system measures the force on the entire heat pipe. The current input is adjusted until the force on the entire heat pipe is exactly the difference between the net weight of the heat pipe and the filling volume, thus ensuring that the working fluid inside the heat pipe is fully compensated for gravity. Finally, the heat pipe is started up and the data is collected and analyzed. In the heat pipe performance testing device, the heat pipe is started up fully by an electric heating system. Under steady-state operation, its thermal performance is analyzed by a data acquisition system, and the flow characteristics of the working fluid are analyzed by infrared images from a visualization observation system.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0041] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A comprehensive testing device for simulating microgravity heat pipes using magnetic compensation method, characterized in that, The testing apparatus includes an interconnected magnetic field generation system, a magnetic field calibration system, a force measurement system, a heat pipe performance testing device, and a visualization observation system; The magnetic field generating system is used to generate a large-size uniform gradient magnetic field with uniformity and linearity that meets the requirements through a rectangular coupling coil, and to effectively cool the rectangular coupling coil. The magnetic field calibration system is used to measure and analyze the magnetic field and obtain parameters within the effective range of the magnetic field. The force measurement system is used to support the heat pipe under test and monitor the force on the entire heat pipe. The magnetic field state and the force state of the heat pipe under test are checked by the magnetic field calibration system and the force measurement system. The current input is adjusted until the force on the entire heat pipe under test is exactly the difference between the net weight of the heat pipe under test and the filling volume. Then the working fluid inside the heat pipe under test achieves gravity compensation. The heat pipe performance testing device is used to heat the evaporation section of the heat pipe under test, insulate the insulation section, and collect and record the start-up characteristics, isothermal properties, and heat transfer limit performance parameters of the heat pipe under test. The visualization observation system is used to perform image analysis on the flow state of the working fluid through thermal imaging.

2. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 1, characterized in that, The magnetic field generating system includes a rectangular coupling coil (1), a cooling circulation system (2) for cooling the rectangular coupling coil (1), and a power control cabinet (3) for supplying power to the rectangular coupling coil (1) and the cooling circulation system (2).

3. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 2, characterized in that, The rectangular coupling coil (1) is composed of a rectangular Maxwell coil that generates a gradient magnetic field and a rectangular Helmholtz coil that eliminates magnetic field non-uniformity. The magnetic field formed has high linearity of magnetic field strength gradient in the vertical direction and high uniformity of magnetic field strength in the horizontal direction. The effective area of ​​the magnetic field is large and is compatible with the size of the heat pipe to be tested. The cooling circulation system (2) is selected from oil cooling, water cooling or natural air cooling according to the required magnetic field strength of the working fluid and the working time of the magnetic field.

4. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 1, characterized in that, The magnetic field calibration system includes a high-precision Hall probe (4), a three-dimensional stepping platform (5), and a control and acquisition system (6). Under the control of the control and acquisition system (6), the three-dimensional stepping platform (5) uses the high-precision Hall probe (4) to measure and record the magnetic field parameters at each point in the effective area of ​​the magnetic field.

5. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 4, characterized in that, The three-dimensional stepping platform (5) includes a track platform, a three-dimensional stepper motor and a fixing clamping assembly. A high-precision Hall probe (4) is fixed on the track platform by the fixing clamping assembly, and the three-dimensional stepper motor controls the movement of the track platform.

6. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 1, characterized in that, The force measurement system includes a support bracket (7) and a force sensor (8). The heat pipe is fixed by the support bracket (7) within the effective area of ​​the magnetic field, and the force sensor (8) measures the force state of the entire heat pipe under test.

7. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 1, characterized in that, The heat pipe performance testing device includes a heat pipe under test (9), an electric heating system (10), a heat insulation device (11), and a data acquisition system (12); the electric heating system (10) is applied to the evaporation section of the heat pipe under test; the heat insulation device (11) is applied to the insulation section of the heat pipe under test; the data acquisition system (12) includes a thermocouple, a power meter sensing device, and a data processing terminal.

8. The magnetic compensation method for simulating microgravity heat pipes comprehensive testing device according to claim 7, characterized in that, The heat pipe under test (9) uses water-based magnetic fluid or organic magnetic fluid of liquid metal as working fluid; the liquid wick inside the heat pipe under test (9) is a wire mesh type or a dry channel type. The organic magnetic fluid is an alternative magnetic fluid with physical properties similar to liquid metal working fluid, such as density, thermal conductivity, surface tension, viscosity, and contact angle, to perform performance tests on two mechanisms in heat pipes that are greatly affected by gravity: capillary flow and bubble blockage.

9. The magnetic compensation method for simulating microgravity heat pipes as described in claim 1, characterized in that, The visualization observation system includes an infrared thermal imaging device (13) and an image analysis system for non-contact capture of thermal images of the heat pipe under test.

10. The testing method of the magnetic compensation method for simulating microgravity heat pipe integrated testing device according to any one of claims 1 to 9, characterized in that, The first stage is the generation of the electrically controlled magnetic field. This involves using a power control system to supply predetermined current values ​​to the two sets of coils of the rectangular coupling coil to generate the target magnetic field. The Joule heat generated by the rectangular coupling coil is then cooled by a cooling circulation system. Then, the field parameter measurement stage is carried out, that is, the magnetic field strength is measured by the magnetic field calibration system, and the magnetic field uniformity and gradient linearity are analyzed to see if they meet the magnetic compensation parameter requirements of the selected magnetic fluid. Then, the heat pipe to be tested (9) is placed in the test tube, and the force measurement system is used to measure the force on the entire heat pipe to be tested. The current input is adjusted until the force on the entire heat pipe to be tested is exactly the difference between the net weight of the heat pipe to be tested and the filling volume. Then the working fluid inside the heat pipe to be tested achieves gravity compensation. Finally, the heat pipe startup and data acquisition analysis stage is carried out. In the heat pipe performance testing device, the heat pipe (9) under test is fully started by the electric heating system (10). Under steady-state operation, its thermal performance is analyzed by the data acquisition system (12), and the working fluid flow characteristics are analyzed by the infrared image system of the visualization observation system.

Images