In-pipe flow condensation experimental device capable of realizing variable gravity adjustment through centrifugal force

Abstract

The invention discloses an in-pipe flow condensation experiment device capable of realizing variable gravity adjustment through centrifugal force, and particularly relates to the field of low-gravity condensation experiments, which is characterized by consisting of three core part composition systems, namely a steam generation system, a transmission device and a data acquisition system. By accurately adjusting the rotating speed of the motor, the experiment device can control the centrifugal force borne by the round pipe, and therefore the gravity counteracting effect of different degrees is achieved. When the centrifugal force and the earth gravity reach dynamic balance, the fluid in the circular pipe is in a zero-gravity state. And the data acquisition system can obtain an image of flow in the circular pipe and an external temperature parameter. The experimental device provided by the invention provides ideal conditions for researching the condensation phenomenon in the microgravity environment, and provides an ideal experimental platform for observation and comprehensive systematic research of the condensation phenomenon in the pipe under different low-gravity environment conditions.

Description

Technical Field

[0001] The invention relates to the field of low-gravity condensation experiments, and more specifically to an in-tube flow condensation experiment device which realizes variable gravity regulation through centrifugal force. Background Art

[0002] With the rapid development of aerospace manufacturing technology, its onboard equipment is developing towards high power and miniaturization. The thermal control system is facing challenges such as efficient heat exchange, temperature uniformity and reliability. Compared with the traditional single-phase flow loop heat exchange system, the gas-liquid two-phase flow system has excellent isothermal characteristics and can achieve high energy transfer under small loop flow. Condensation heat transfer in a microgravity environment is an important physical process in space two-phase phase change heat transfer equipment. It is widely used in space fluid management, life support systems, spacecraft cooling, spacecraft fluid recycling and other occasions.

[0003] Gravity plays an important role in both film condensation and droplet condensation. In a normal gravity environment, the condensate film flows along the direction of gravity and gradually accumulates, and the thickness of the film increases along the direction of gravity. For microgravity film condensation, since the gravity driving the flow of the condensate film in a normal gravity environment is greatly weakened, the flow of the condensate film can only be achieved by other forces, and the surface tension and gradient effect may rise to a dominant position, which has a significant impact on the stability of the condensate film and the two-phase fluid dynamics behavior. The characteristics and regulation mechanism of film condensation under microgravity conditions are completely different from those under normal gravity. In addition, in a microgravity environment, the condensate will accumulate on the heat transfer wall, greatly increasing the heat transfer resistance, thereby worsening the heat transfer. Therefore, understanding and mastering the phase interface dynamics characteristics during the condensation process under microgravity conditions not only has important engineering guidance significance for the research and development and optimization of two-phase flow equipment for my country's spacecraft, but also has a guiding role in improving the operating efficiency of space electronic equipment, saving heat exchange equipment, and ensuring the effective implementation of equipment safety. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an in-tube flow condensation experimental device that realizes variable gravity regulation through centrifugal force to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an in-tube flow condensation experimental device that realizes variable gravity adjustment by centrifugal force, the variable gravity in-tube condensation experimental device is divided into three parts, namely, a steam generation system, a transmission device and a data acquisition system; The steam generation system is mainly composed of a liquid storage tank, a peristaltic pump, a steam generator and a flow meter; one side of the liquid storage tank is connected to a peristaltic pump through a pipeline, and one side of the peristaltic pump is connected to a steam generator through a pipeline, wherein a flow meter is distributed on the pipeline between the peristaltic pump and the steam generator, the liquid storage tank is used to store experimental liquid, and the peristaltic pump transports the liquid to the steam generator, where the liquid is heated and converted into steam, and the flow rate of the steam is controlled by the flow meter to ensure the stability and accuracy of the steam flow rate; the steam generation system is responsible for generating a stable steam flow required for the experiment, and one side of the liquid storage tank is connected to a subcooler through a pipeline, and an air bag is provided between the two; The transmission device includes a motor, a pulley, a bearing and a gear. Its main function is to provide power for the experimental device and adjust the centrifugal acceleration. The motor acts as a power source to adjust the rotation speed of the experimental device and transmits power through the pulley and gears. This design enables the experimenter to accurately control the magnitude of the centrifugal acceleration, thereby simulating different gravity environments.

[0006] The data acquisition system includes a camera, a thermocouple and a data collector; the camera is fixed just above the outside of the circular tube, with a set distance of about 15 cm to obtain a clear flow image, and the thermocouples are fixed above the circular tube at equal intervals to detect temperature changes in different parts; the data collector receives electrical signals from the thermocouples, amplifies the signals through a built-in amplifier circuit, and records and stores the signals for subsequent data analysis, and one side of the data collector is connected to a computer for data analysis and signal control through a conductive wire.

[0007] As a further improvement of the technical solution of the present invention, the condensation in the tube achieves the purpose of variable gravity through a transmission device, and the variable gravity device changes the magnitude of the centrifugal acceleration received by the circular tube through a variable frequency motor.

[0008] During the experiment, the centrifugal force acting on the tube can be precisely controlled by adjusting the speed of the motor. When the centrifugal force is equal to the earth's gravity and in opposite directions, the two can offset each other, thus achieving a zero-gravity environment.

[0009] An electric heating belt controlled by a temperature control switch is arranged around the circular tube to prevent heat loss.

[0010] There are four groups of thermocouples, which are arranged at equal intervals and located directly above the circular tube with a spacing of 60 mm.

[0011] Technical effects and advantages of the present invention: 1. The present invention uses centrifugal force to simulate different gravity conditions and provides a low-gravity environment similar to space on the earth. Compared with traditional drop tower and parabolic flight methods, this technology can provide a longer microgravity environment, which is conducive to more in-depth and long-lasting experimental research.

[0012] 2. The present invention simulates a microgravity environment through centrifugal force. Compared with traditional microgravity experiments, which are usually more expensive, the present invention can significantly reduce the experimental cost and provide a more efficient and effective experimental environment.

[0013] 3. The present invention can accurately control the gravity conditions in the experiment by adjusting the motor speed, and can quickly switch between different gravity conditions, thereby improving the efficiency of the experiment, and can obtain rich experimental results and experimental data under different acceleration values.

[0014] 4. The present invention can obtain images and temperature parameters of the flow in the tube, and provide intuitive visualization data of the condensation process, which are helpful for a deep understanding of the condensation phenomenon and for optimizing the design of heat transfer equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of an in-tube flow condensation experimental device for realizing variable gravity regulation by centrifugal force according to the present invention; Figure 2 It is a schematic diagram of the arrangement of the thermal couples of the present invention; Figure 3 It is a schematic diagram of the principle of the present invention; Figure 4 , 5 It is a schematic diagram of the flow pattern inside the tube and the temperature distribution outside the tube.

[0016] The components represented by the reference numerals in the accompanying drawings are as follows: 1 is a motor; 2 is a pulley; 3 is a test section; 4 is a bearing; 5 is a steam generator; 6 is a flow meter; 7 is a peristaltic pump; 8 is a liquid storage tank; 9 is an air bag; 10 is a subcooler; 11 is a camera; 12 is a computer; 13 is a data acquisition instrument; and 14 is a thermocouple. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] like Figure 1The shown device is a flow condensation experiment device in a tube that realizes variable gravity regulation by centrifugal force. The distilled water in the liquid storage tank 8 is supplied to the steam generator 5 under the action of the peristaltic pump 7, and the generated steam is transported to the condensation section through a stainless steel pipe. An electric heating belt controlled by a temperature control switch is arranged around the steel pipe to reduce heat loss. Only a part of the steam entering the condensation section condenses in the round tube, and the rest flows into the subcooler 10 to cool to liquid state and flow back to the liquid storage tank. In addition, an air bag 9 is installed in the experimental system to maintain the system pressure at about 0.1MPa. The flow rate of distilled water can be changed by changing the rotation speed of the peristaltic pump, and then the steam flow rate of the experimental system can be changed. The flow rate of distilled water can be measured by a glass rotor flowmeter 6. The temperature data is collected by a data acquisition instrument 13, and the condensation phenomenon is visualized by a camera 11.

[0019] like Figure 2 As shown, this figure is a partial diagram of the arrangement of the thermocouples 14 of the condensation experiment temperature detection device, wherein four thermocouples 14 are arranged at equal intervals and located directly above the circular tube 3, with a spacing of 60 mm.

[0020] like Figure 3 As shown, this figure is a schematic diagram of the principle of an in-tube flow condensation experimental device of the present invention that realizes variable gravity regulation through centrifugal force. When the motor 1 is started, the pulley 2 drives the round tube to rotate, generating centrifugal force. The speed of the motor can be accurately adjusted by the control system. The size of the speed directly affects the size of the centrifugal force generated in the round tube. By increasing or decreasing the speed, the centrifugal force can be increased or decreased accordingly. During the rotation of the round tube, the centrifugal force generated acts on the fluid in the tube. When the size of the centrifugal force is adjusted to be equal to the earth's gravity and in the opposite direction, the two can offset each other, thereby achieving a zero gravity state for the fluid in the tube.

[0021] like Figure 4 As shown, this figure is a schematic diagram of the flow in the tube.

[0022] Implementation steps: Preliminary preparation stage: 1. According to Figure 1 Install the equipment; Experimental stage: 1. Turn on the peristaltic pump to fill the tube with liquid; 2. Turn on the motor and adjust it to the appropriate speed to achieve the required centrifugal acceleration in the tube; 3. Turn on the peristaltic pump, steam generator, and supercooler. The distilled water in the liquid storage tank is supplied to the steam generator under the action of the peristaltic pump, and the generated steam is transported to the pipe through the stainless steel pipe. By changing the speed of the peristaltic pump to change the flow rate of the distilled water, the steam flow rate of the experimental system can be changed. The flow rate of the distilled water can be measured by a glass rotor flowmeter.

[0023] 4. Collect temperature data through a data acquisition instrument, and use a camera to visualize the condensation phenomenon. Adjust the camera focus, set it to record 15 frames per second, and place the camera directly above the round tube and aim it into the tube; 6. When the experiment is over, stop the motor, turn off the power, and turn off the camera and data logger; Post-processing stage: 1. Perform image analysis on the video recorded by the camera to obtain the flow pattern under different gravity conditions; the schematic diagram is as follows Figure 4 As shown, its gravity levels are 1g, 75%g, 37%g, and 0g; 2. Analyze the temperature data in the data logger to obtain the temperature distribution of different parts, as shown in the schematic diagram Figure 5 As shown, its gravity levels are 1g, 75%g, 37%g, and 0g; During the experiment, the motor speed can be adjusted to conduct experiments. Under different centrifugal accelerations, phenomena and experimental data under different gravity conditions can be obtained.

[0024] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change; Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other; Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An in-tube flow condensation experimental device that realizes variable gravity adjustment through centrifugal force, characterized in that: The variable gravity tube condensation experimental device is divided into three parts, namely, a steam generation system, a transmission device and a data acquisition system; The steam generation system is mainly composed of a liquid storage tank (8), a peristaltic pump (7), a steam generator (5) and a flow meter (6); one side of the liquid storage tank (8) is connected to the peristaltic pump (7) through a pipeline, and one side of the peristaltic pump (7) is connected to the steam generator (5) through a pipeline, wherein the flow meter (6) is distributed on the pipeline between the peristaltic pump (7) and the steam generator (5), and one side of the liquid storage tank (8) is connected to a subcooler (10) through a pipeline, and an air bag (9) is provided between the two; The transmission device comprises a motor (1), a pulley (2), a bearing (4) and a gear, and its main function is to provide power for the experimental device and adjust the centrifugal acceleration. The motor (1) serves as a power source, can adjust the rotation speed of the experimental device, and transmit power to the round tube (3) through the pulley (2); The data acquisition system comprises a camera (11), a thermocouple (14) and a data acquisition device (13); the camera (11) is fixed just above the outside of the circular tube (3) at a set distance of about 15 cm to obtain a clear flow image, and the thermocouples (14) are fixed above the circular tube at equal intervals to detect temperature changes at different parts; the data acquisition device (13) receives electrical signals from the thermocouples, and one side of the data acquisition device (13) is connected to a computer (12) for data analysis and signal control via a conductive line.

2. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 1, characterized in that: The gravity of the circular tube is adjusted by controlling the centrifugal force and offsetting the gravity to achieve the purpose of variable gravity.

3. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 2, characterized in that: During the experiment, the centrifugal force acting on the tube can be precisely controlled by adjusting the speed of the motor. When the centrifugal force is equal to the earth's gravity and in opposite directions, the two can offset each other, thus achieving a zero-gravity environment.

4. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 1, characterized in that: The control of the centrifugal force is achieved by adjusting the centrifugal force applied to the round tube through a variable frequency motor.

5. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 1, characterized in that: The variable frequency motor can adjust its output frequency according to experimental requirements, thereby changing the rotation speed of the motor.

6. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 1, characterized in that: An electric heating belt controlled by a temperature control switch is arranged around the circular tube to prevent heat loss.

7. The in-tube flow condensation experimental device for realizing variable gravity adjustment by centrifugal force according to claim 1, characterized in that: The number of the thermocouples (14) is four groups, and the thermocouples (14) are arranged at equal intervals and located directly above the circular tube (3), with an interval of 60 mm.

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