Pressure Regulation System and Method for In-Pipe Cold-Type Rotor Evaporative Cooling Experimental Platform

Abstract

The present invention provides a pressure regulation system and method for an in-pipe cold-type rotor evaporation cooling experimental platform. The system includes a pressure regulation device and a liquid volume regulation device. The pressure regulation device is installed on the side wall surface near the inlet of the condenser, and the liquid volume regulation device is installed at the inlet of the cooling pipe. The pressure regulation device realizes the regulation of the pressure in the pipe through the coordinated action of an internal solenoid valve and a piston, and the liquid volume regulation device realizes the regulation of the liquid volume through the centrifugal acceleration generated by the combined movement and rotation of an internal piston. The present invention can fully recover the working medium after the experiment, greatly reducing the waste of the working medium caused by the large amount of the working medium impacting the bottom of the collection vessel during liquid drainage and the violent evaporation caused by the intense flow compared with the previous experimental processes. At the same time, the boundary conditions of the rotor evaporation cooling experiment are increased, thereby promoting the research on the mechanism of rotor evaporation cooling.

Description

Technical Field

[0001] The present invention belongs to the field of pressure regulation of evaporation cooling systems, and particularly relates to a pressure regulation system and method for an in-pipe cooled rotor evaporation cooling experimental platform. Background Art

[0002] Hydro-generators are developing towards large capacity and high speed. In order to meet the requirements of improving power generation efficiency and reducing operating costs, it is necessary to further increase the single-unit capacity and the capacity per pole. As the capacity per pole of the generator increases, the rotor heating problem becomes more serious, and the temperature rise problem needs to be solved urgently. The rotor of the hydro-generator is close to the axis of the generator, with limited space and in a rotating state, making it difficult to install large cooling equipment to effectively cool it. The traditional air-cooling method can only be applied to low-speed hydro-generators and is difficult to meet the cooling requirements of high-speed and large-capacity hydro-generators required by current national hydraulic development.

[0003] Evaporation cooling technology is a newly emerging cooling technology in recent years, especially suitable for use in small spaces, high heat flux densities, and uneven temperature distributions. Compared with the water-cooling scheme, the cooling medium used in evaporation cooling technology is a fluorocarbon compound with an appropriate boiling point, which is non-toxic, pollution-free, non-corrosive to metals and other components of the motor, and has excellent properties of insulation, fire prevention, and arc extinguishing. In addition, the self-circulation evaporation cooling system is relatively simple in complexity and high in reliability.

[0004] The in-pipe cooled rotor evaporation cooling technology embeds cooling pipes in the rotor pole coils, and a fluorocarbon compound is introduced into the interior as a cooling working medium. The liquid working medium undergoes phase change boiling into a gaseous working medium, and the heat on the coil is carried away by using the principle of latent heat of phase change.

[0005] In order to study the rotor evaporation cooling technology, an in-pipe cooled rotor evaporation cooling experimental platform has been established, which can provide a rotating environment. The basic circulation principle of the in-pipe cooled rotor evaporation cooling experimental platform is as Figure 1 shown, including a gas collector 1, an upper pipeline joint 2, a condenser 5, a cooling pipe 6, a lower pipeline joint 7, a liquid return pipe 8, a first pressure sensor 13, a second pressure sensor 14, a temperature sensor 15, an exhaust valve 16, a drain valve 17, and a rotating shaft 100. The entire experimental bench rotates synchronously with the rotating shaft 100. Due to the action of centrifugal acceleration, the evaporation cooling working medium flows from the condenser 5 through the liquid return pipe 8 into the cooling pipe 6, absorbs heat and boils in the cooling pipe 6. The density of the gaseous evaporation cooling working medium is much lower than that of the liquid working medium. Therefore, a pressure difference is formed at the inlet and outlet of the cooling pipe 6, which pushes the two-phase working medium to flow towards the gas collector 1. The gaseous working medium enters the condenser 5 to complete the circulation process. Since the average density of the two-phase working medium in the gas collector 1 is lower than that of the single-phase working medium in the liquid return pipe 8, the liquid working medium in the liquid return pipe 8 is more affected by centrifugal acceleration, thus forming a self-circulation flow of the overall loop.

[0006] The general process of the rotor evaporation cooling experiment is divided into: liquid filling, preheating and exhausting, experiment, and liquid discharging. Among them, the processes with greater difficulty and prone to errors are liquid filling and exhausting, which directly affect the accuracy of the experiment. At the same time, during the experiment, the pressure in the cooling pipe 6 should also be monitored and regulated in real time to prevent excessive pressure in the pipe from affecting the safe progress of the experiment.

[0007] During the liquid filling process, because the boiling point of the working fluid is relatively low, using liquid drainage, pumping, injection and other liquid filling methods to fill the liquid from the exhaust valve 16 cannot avoid the evaporation and loss of the working fluid during the liquid filling process, resulting in the actual liquid filling volume being less than the expected value and affecting the experimental accuracy. At the same time, since both the cooling pipe 6 and the condenser 5 are made of opaque materials, the liquid level in the overall circulation loop is not easy to observe, which also poses a great challenge to accurate liquid filling.

[0008] The purpose of preheating and exhausting in the experiment is to discharge the air inside the circulation loop. Because air will not only hinder the circulation of the evaporation cooling working fluid in the two-phase state, but also air is a poor conductor of heat, affecting the heat transfer between the working fluid and the inner wall surface of the cooling pipe 6. More importantly, the exhausting process will make the inside of the circulation loop be in a negative pressure state at room temperature, the pressure in the cooling pipe 6 decreases, and the boiling point of the working fluid decreases accordingly, making it easier for the working fluid to reach the boiling state.

[0009] In the current in-pipe cooled rotor evaporation cooling experiment platform during preheating and exhausting, first, the experimental bench is rotated, and then the cooling pipe 6 is heated. Once the pressure in the pipe rises close to the set threshold, the rotation and heating process of the experimental bench are stopped. Subsequently, after waiting for the experimental bench to come to a complete stop, the exhaust valve 16 is manually opened, and after the heated air gushes out, the exhaust valve 16 is manually closed to complete the exhaust operation. This exhaust method is rather troublesome and cannot ensure the complete discharge of air. Moreover, when the exhaust valve 16 is opened, since the heating of the cooling pipe 6 stops, the overall experimental pipeline is actually exhausting while cooling down. At this time, the internal pressure decreases, and it is possible to suck in a small amount of air into the pipeline system, affecting the experiment.

[0010] After the experiment, it is necessary to drain the working fluid in the pipeline of the cold rotor evaporation cooling experimental platform of the pipeline. The general process is to wait for the experimental bench to stop heating and rotating, and be in a static state, and drain the liquid from the drain valve 17 at the lowest point of the overall circulation pipeline. This drainage method has some drawbacks: Since the experimental pipeline is usually wrapped with a heat insulation layer, the pipeline has a great thermal inertia, and opening the valve will expose the working fluid in the pipeline to the air, and these working fluids are very likely to evaporate, thus wasting a part of the working fluid. On the other hand, when draining the liquid from the drain valve 17, the working fluid flows out violently from a single valve, impacting the bottom of the collection vessel. During this intense flow process, the contact area between the working fluid and the air increases, and evaporation may also occur. Therefore, the traditional drainage process is often accompanied by inevitable loss of the working fluid.

[0011] Since the boiling point of the working fluid changes with the pressure, the pressure in the cooling pipeline 6 of the cold rotor evaporation cooling experimental platform of the pipeline has a great influence on the evaporation cooling effect. In some experimental conditions, due to various reasons, the pressure in the cooling pipeline 6 is too high, resulting in the working fluid temperature being below the boiling point, and the cooling system actually operates in a single-phase convection mode, and the cooling effect is greatly reduced.

[0012] In addition, Chinese Patent CN206726063U (pressure control device and cooling device of a cooling device) discloses a pressure control device of a cooling device, which is applied in the field of wind power generation. However, this device is only applicable to static equipment and a static circulation system, and is not applicable to equipment that needs to be cooled in a rotating state. And the driving principle of this pressure control device is pump drive, and applying it to a rotating environment will expose defects such as too many pipelines, complex systems, and heavy equipment, and is not applicable to applications on rotating components. Summary of the Invention

[0013] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a pressure regulation system and method for a cold rotor evaporation cooling experimental platform of a pipeline.

[0014] To achieve the above object, the present invention adopts the following technical solutions:

[0015] A pressure regulation system for a cold rotor evaporation cooling experimental platform of a pipeline, comprising a pressure regulation device and a liquid volume regulation device; the pressure regulation device is installed on the side wall surface near the inlet of the condenser, and the liquid volume regulation device is installed at the inlet of the cooling pipeline; the pressure regulation device realizes the pressure regulation in the pipeline through the coordinated action of an internal solenoid valve and a piston, and the liquid volume regulation device realizes the liquid volume regulation through the internal piston movement combined with the centrifugal acceleration generated by rotation.

[0016] Furthermore, the in-pipe cooled rotor evaporation cooling experimental platform includes a gas collecting pipe, an upper pipeline joint, an upper solenoid valve, a pressure regulating device, a condenser, a cooling pipeline, a lower pipeline joint, a liquid return pipe, a liquid volume regulating device, a lower solenoid valve, a pressure regulating pipe, a liquid volume regulating pipe, a first pressure sensor, a second pressure sensor, a temperature sensor, and a rotating shaft; the gas collecting pipe is connected to the upper end of the upper pipeline joint and the inlet of the condenser; the first pressure sensor and the temperature sensor are installed in the upper pipeline joint; the lower end of the upper pipeline joint is connected to the upper end of the cooling pipeline; the lower end of the cooling pipeline is connected to the upper end of the lower pipeline joint; the second pressure sensor is installed in the lower pipeline joint to realize real-time measurement of the pressure in the lower pipeline joint; an opening is added to the lower pipeline joint on the side away from the rotating shaft along the radial direction of the rotor, and the lower solenoid valve is connected, and the lower solenoid valve and the liquid volume regulating device are connected through the liquid volume regulating pipe; the lower end of the lower pipeline joint is connected to the lower outlet of the condenser through the liquid return pipe; an opening is added to the upper inlet of the condenser and is connected to the upper solenoid valve; the upper solenoid valve and the pressure regulating device are connected through the pressure regulating pipe; the upper inlet of the condenser is connected to the gas collecting pipe.

[0017] Furthermore, the pressure regulating device includes a first outer shell, a first piston, a first micro solenoid valve, a second micro solenoid valve, and a first electromagnetic actuator; the pressure regulating device is connected to the external pipeline along the radial direction of the rotor through the pressure regulating pipe of the in-pipe cooled rotor evaporation cooling experimental platform; the outer shell is responsible for packaging and sealing the overall device; the first electromagnetic actuator extends and retracts as needed, and the first electromagnetic actuator is connected to and drives the first piston to divide the inner cavity of the pressure regulating device into two mutually sealed cavities when the first micro solenoid valve is closed; the first micro solenoid valve is installed on the first piston, and the second micro solenoid valve is installed on the outer shell, and both can be opened and closed as needed.

[0018] Furthermore, the liquid volume regulating device includes a second outer shell, a second piston, a second electromagnetic actuator, a liquid injection valve, and a vent hole; the liquid volume regulating device is connected to the external pipeline through the liquid volume regulating pipe of the in-pipe cooled rotor evaporation cooling experimental platform; the second outer shell is responsible for protecting the internal components of the device and ensuring the sealed environment inside the device; the second piston is responsible for dividing the inner cavity of the device into two mutually sealed cavities, and the second electromagnetic actuator extends or retracts as needed to push or pull the second piston; the liquid injection valve is used for liquid injection and is opened during liquid injection, and the working medium is injected through the liquid injection valve; the vent hole is located on the side of the second outer shell away from the rotating shaft along the radial direction of the rotor, and does not affect the airtightness of the sealed cavity formed by the second piston and the part of the second outer shell on the side close to the rotating shaft along the radial direction of the rotor.

[0019] Furthermore, even when the second electromagnetic actuator reaches its maximum stroke, the position of the second piston within the liquid volume control device will not exceed the liquid injection valve, ensuring that all the liquid injected by the liquid injection valve is always pushed into the liquid volume control pipe by the second piston.

[0020] Furthermore, the liquid volume control device is made of a rigid outer shell, or in the form of a liquid bladder or an air bag, and is contracted and expanded by an extrusion device.

[0021] Furthermore, the liquid volume control device and the pressure control device change their volumes by using an electromagnetic actuator to push a piston or by using a hydraulic method to drive a piston.

[0022] The present invention also provides a pressure control method for an in-pipe cooled rotor evaporation cooling experimental platform, including: during the liquid filling process, the in-pipe cooled rotor evaporation cooling experimental platform is in a stationary and unheated state. Close the lower solenoid valve connected to the liquid volume control pipe. The second piston inside the liquid volume control device is at the maximum stroke position that the second electromagnetic actuator can reach along the radial direction of the rotor away from the axis of the shaft. The first piston inside the pressure control device is at the maximum stroke position that the first electromagnetic actuator can reach along the radial direction of the rotor away from the axis of the shaft. Open the liquid injection valve to fill the inside of the liquid volume control device with the working fluid, then re-close the liquid injection valve. Open the upper solenoid valve connected to the pressure control pipe, open the first micro electromagnetic valve and the second micro electromagnetic valve inside the pressure control device, and then open the lower solenoid valve connected to the liquid volume control pipe. The second electromagnetic actuator inside the liquid volume control device pushes the second piston to the bottom in the direction of approaching the axis of the shaft along the radial direction of the rotor, and injects all the working fluid into the circulation pipeline of the in-pipe cooled rotor evaporation cooling experimental platform through the liquid volume control pipe;

[0023] After the liquid filling is completed, close the lower solenoid valve connected to the liquid volume control pipe, then close the upper solenoid valve connected to the pressure control pipe, and finally close the first micro electromagnetic valve and the second micro electromagnetic valve inside the pressure control device.

[0024] Furthermore, during the preheating and exhaust process, first keep the in-pipe cooled rotor evaporation cooling experimental platform in a stable rotating state, then heat the wall surface of the cooling pipe. When the pressure at the outlet of the cooling pipe reaches stability, open the solenoid valve on the pressure control pipe, then open the first micro electromagnetic valve and the second micro electromagnetic valve on the pressure control device, so that the mixed gas of air and gaseous working fluid gushes out of the circulation pipeline through the pressure control device. Then close the solenoid valve connected to the pressure control pipe, then close the first micro electromagnetic valve of the pressure control device, and finally close the second micro electromagnetic valve, so that the pipeline returns to a sealed state.

[0025] Furthermore, during the experiment, the temperature and pressure in the upper pipeline joint at the outlet of the cooling pipeline are monitored by the first pressure sensor and the temperature sensor. If, under steady state conditions, the temperature at the outlet of the cooling pipeline is lower than the boiling point of the working fluid corresponding to this pressure, the internal pressure of the circulation loop is reduced through the pressure control device according to the experimental requirements, making it easier for the working fluid to reach boiling, and this is recorded as a new experimental condition. At the end of the experiment, the rotation of the pipe-internal cold-rotor evaporation cooling experimental platform is maintained, the heating of the cooling pipeline is stopped, the lower solenoid valve on the liquid volume control pipe is first opened, and the second electromagnetic actuator in the liquid volume control device drives the second piston to move radially away from the rotating shaft along the rotor, and the working fluid will flow back into the liquid volume control device under the action of the centrifugal acceleration and the negative pressure in the liquid volume control device. Then, the upper solenoid valve on the pressure control pipe is opened, and then the first micro electromagnetic valve and the second micro electromagnetic valve on the pressure control device are opened to allow air to flow into the circulation pipeline, which will cause the remaining working fluid to further flow into the liquid volume control device. Finally, the lower solenoid valve on the liquid volume control pipe is closed to complete the recovery of the working fluid.

[0026] Beneficial effects:

[0027] (1) The present invention can prevent the occurrence of excessive pressure in previous experiments, ensuring experimental safety.

[0028] (2) The present invention can simplify the exhaust process in previous experiments, and the exhaust is more complete, completely avoiding the temperature back-suction phenomenon caused by the reduction of the temperature of the cooling pipeline.

[0029] (3) The present invention can achieve precise and fully automatic liquid filling, solving the problems of cumbersome liquid filling process, working fluid loss, and poor accuracy in previous rotor evaporation cooling experiments. And it can accurately control the liquid volume in the circulation pipeline, precisely define the boundary conditions of the experiment, and reduce experimental errors.

[0030] (4) The present invention can fully recover the working fluid after the experiment, greatly reducing the waste of the working fluid caused by the large amount of working fluid impacting the bottom of the collection vessel during liquid drainage and the intense evaporation due to violent flow compared with previous experimental processes.

[0031] (5) The present invention can increase the boundary conditions of the rotor evaporation cooling experiment, thus promoting the research on the rotor evaporation cooling mechanism.

[0032] (6) The pressure control device at the outlet of the cooling pipeline in the present invention is expected to be practically applied to the rotor evaporation cooling system of future real machines, providing forward-looking exploration to assist the further development and application of rotor evaporation cooling technology in the future. Description of the drawings

[0033] Figure 1 It is a schematic diagram of the basic circulation principle of the rotary experimental platform for rotor evaporation cooling technology;

[0034] Figure 2 Schematic diagram of a pressure regulation system for an in-duct cold-rotor evaporative cooling experimental platform according to an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of a pressure regulation device;

[0036] Figure 4 Schematic diagram of a liquid volume regulation device.

[0037] Wherein, the reference numerals are: gas collecting pipe 1, upper pipeline joint 2, upper solenoid valve 3, pressure regulation device 4, condenser 5, cooling pipeline 6, lower pipeline joint 7, liquid return pipe 8, liquid volume regulation device 9, lower solenoid valve 10, pressure regulation pipe 11, liquid volume regulation pipe 12, first pressure sensor 13, second pressure sensor 14, temperature sensor 15, exhaust valve 16, drain valve 17, first housing 41, first piston 42, first micro solenoid valve 43, second micro solenoid valve 44, first electromagnetic actuator 45, second housing 91, second piston 92, second electromagnetic actuator 93, liquid injection valve 94, air vent 95, rotating shaft 100. Specific embodiments

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] As Figure 2 shown, a pressure regulation system for an in-duct cold-rotor evaporative cooling experimental platform according to an embodiment of the present invention includes a pressure regulation device and a liquid volume regulation device. The pressure regulation device is installed on the side wall surface near the inlet of the condenser, and the liquid volume regulation device is installed at the inlet of the cooling pipeline.

[0040] As Figure 2As shown in the figure, an in-pipe cooled rotor evaporation cooling experimental platform according to an embodiment of the present invention includes a gas collecting pipe 1, an upper pipeline joint 2, an upper electromagnetic valve 3, a pressure regulating device 4, a condenser 5, a cooling pipeline 6, a lower pipeline joint 7, a liquid return pipe 8, a liquid volume regulating device 9, a lower electromagnetic valve 10, a pressure regulating pipe 11, a liquid volume regulating pipe 12, a first pressure sensor 13, a second pressure sensor 14, a temperature sensor 15, and a rotating shaft 100. The gas collecting pipe 1 connects the upper end of the upper pipeline joint 2 to the inlet of the condenser 5. The first pressure sensor 13 and the temperature sensor 15 are installed in the upper pipeline joint 2 to realize real-time measurement of the temperature and pressure in the upper pipeline joint 2. The lower end of the upper pipeline joint 2 is connected to the upper end of the cooling pipeline 6. The lower end of the cooling pipeline 6 is connected to the upper end of the lower pipeline joint 7. The second pressure sensor 14 is installed in the lower pipeline joint 7 to realize real-time measurement of the pressure in the lower pipeline joint 7. The lower pipeline joint 7 is provided with an opening on the side away from the rotating shaft 100 along the radial direction of the rotor, and is connected to the lower electromagnetic valve 10. The lower electromagnetic valve 10 is connected to the liquid volume regulating device 9 through the liquid volume regulating pipe 12. The lower end of the lower pipeline joint 7 is connected to the lower outlet of the condenser 5 through the liquid return pipe 8. An opening is added at the upper inlet of the condenser 5 and is connected to the upper electromagnetic valve 3. The upper electromagnetic valve 3 is connected to the pressure regulating device 4 through the pressure regulating pipe 11. The upper inlet of the condenser 5 is connected to the gas collecting pipe 1.

[0041] As Figure 3 shown, the pressure regulating device 4 includes a first housing 41, a first piston 42, a first micro electromagnetic valve 43, a second micro electromagnetic valve 44, and a first electromagnetic actuator 45; the pressure regulating device 4 is connected to an external pipeline along the radial direction of the rotor through the pressure regulating pipe 11; the first housing 41 is responsible for packaging and sealing the overall device; the first electromagnetic actuator 45 elongates and shortens as needed, and the first electromagnetic actuator 45 is connected to and drives the first piston 42 to divide the inner cavity of the pressure regulating device 4 into two mutually sealed cavities when the first micro electromagnetic valve 43 is closed; the first micro electromagnetic valve 43 is installed on the first piston 42, and the second micro electromagnetic valve 44 is installed on the housing, and both can be opened and closed as needed.

[0042] As Figure 4As shown in the figure, the liquid volume control device 9 includes a second housing 91, a second piston 92, a second electromagnetic actuator 93, a liquid injection valve 94, and a vent hole 95. The liquid volume control device 9 is connected to an external pipeline through a liquid volume control pipe 12. The second housing 91 is responsible for protecting the internal components of the device and ensuring a sealed environment inside the device; the second piston 92 is responsible for dividing the internal cavity of the device into two mutually sealed cavities, and the second electromagnetic actuator 93 can extend or shorten as needed to push or pull the second piston 92; the liquid injection valve 94 is used for liquid filling and is opened during liquid filling, and the working medium is filled into the device through the liquid injection valve 94; the vent hole 95 is located on the side of the second housing 91 that is radially away from the rotating shaft 100 along the rotor, and does not affect the airtightness of the sealed cavity formed by the second piston 92 and the part of the second housing 91 on the side of the rotor that is radially close to the rotating shaft 100.

[0043] As Figure 4 shown in the figure, even when the second electromagnetic actuator 93 of the liquid volume control device 9 reaches its maximum stroke, the position of the second piston 92 will not exceed the liquid injection valve 94, so that the liquid injected by the liquid injection valve 94 can always be completely pushed by the second piston 92 into the liquid volume control pipe 12.

[0044] A pressure control method for an in-pipe cooled rotor evaporation cooling experimental platform according to an embodiment of the present invention includes:

[0045] During the liquid filling process, the in-pipe cooled rotor evaporation cooling experimental platform is in a stationary and unheated state. The lower solenoid valve 10 connected to the liquid volume control pipe 12 is closed. The second piston 92 inside the liquid volume control device 9 is at the maximum stroke position that the second electromagnetic actuator 93 can reach in the direction radially away from the rotating shaft 100 along the rotor. The first piston 42 inside the pressure control device 4 is at the maximum stroke position that the first electromagnetic actuator 45 can reach in the direction radially away from the rotating shaft 100 along the rotor. The liquid injection valve 94 is opened to fill the inside of the liquid volume control device 9 with the working medium, and then the liquid injection valve 94 is re-sealed. The upper solenoid valve 3 connected to the pressure control pipe 11 is opened. The first micro solenoid valve 43 and the second micro solenoid valve 44 inside the pressure control device 4 are opened. Subsequently, the lower solenoid valve 10 connected to the liquid volume control pipe 12 is opened. The second electromagnetic actuator 93 inside the liquid volume control device 9 pushes the second piston 92 to the bottom in the direction radially close to the rotating shaft 100 along the rotor, and all the working medium is injected into the circulating pipeline of the in-pipe cooled rotor evaporation cooling experimental platform through the liquid volume control pipe 12.

[0046] After the liquid filling is completed, the lower solenoid valve 10 connected to the liquid volume control pipe 12 is closed. Then the upper solenoid valve 3 connected to the pressure control pipe 11 is closed. Finally, the first micro solenoid valve 43 and the second micro solenoid valve 44 inside the pressure control device 4 are closed.

[0047] During the preheating and exhaust process, first keep the cold-rotor evaporation cooling experimental platform in the pipeline in a stable rotating state, then heat the wall surface of the cooling pipeline. When the pressure at the outlet of the cooling pipeline reaches stability, open the solenoid valve on the pressure control pipe 11, and then open the first micro solenoid valve 43 and the second micro solenoid valve 44 on the pressure control device 4, so that the mixed gas of air and gaseous working medium gushes out of the circulation pipeline through the pressure control device 4. Then close the solenoid valve 3 connected to the pressure control pipe 11, then close the first micro solenoid valve 43 of the pressure control device 4, and finally close the second micro solenoid valve 44 to restore the pipeline to a sealed state.

[0048] During the experiment, the temperature and pressure in the upper pipeline joint 2 at the outlet of the cooling pipeline 6 are monitored by the first pressure sensor 13 and the temperature sensor 15. If, in the stable state, the temperature at the outlet of the cooling pipeline 6 is lower than the boiling point of the working medium corresponding to this pressure, the internal pressure of the circulation loop can be reduced through the pressure control device 4 according to the experimental needs to make the working medium more likely to reach boiling, and record it as a new experimental condition. The specific method is as follows: keep the first micro solenoid valve 43 and the second micro solenoid valve 44 of the pressure control device 4 closed, open the upper solenoid valve 3 connected to the pressure control pipe 11, push the first piston 42 of the pressure control device 4 along the radial direction of the rotor towards the direction close to the rotating shaft 100. After the pressure reaches the regulated target value, close the upper solenoid valve 3.

[0049] After the experiment ends, keep the cold-rotor evaporation cooling experimental platform in the pipeline rotating, stop heating the cooling pipeline 6. First open the lower solenoid valve 10 on the liquid volume control pipe 12. The second electromagnetic actuator 93 in the liquid volume control device 9 drives the second piston 92 to move along the radial direction of the rotor away from the rotating shaft 100. The working medium will flow back into the liquid volume control device 9 under the action of the centrifugal acceleration and the negative pressure in the liquid volume control device 9. Then open the upper solenoid valve 3 on the pressure control pipe 11, and then open the first micro solenoid valve 43 and the second micro solenoid valve 44 on the pressure control device 4 to allow air to flow into the circulation pipeline, which will cause the residual working medium to further flow into the liquid volume control device. Finally, close the lower solenoid valve 10 on the liquid volume control pipe to complete the recovery of the working medium.

[0050] Preferably, in the present invention, the volume change of the liquid volume control device and the pressure control device is realized by an electromagnetic actuator pushing a piston. By the same principle, a hydraulic method can be used to drive the piston.

[0051] Preferably, the liquid volume control device in the present invention adopts a rigid outer shell, or it can also be in the form of a liquid bladder or an air bag, and is contracted and expanded through an extrusion device.

Claims

1. A pressure regulation system for an in-pipe cold-rotor evaporation cooling experimental platform, characterized in that It includes a pressure control device and a liquid volume control device; the pressure control device is installed on the side wall near the inlet of the condenser, and the liquid volume control device is installed at the inlet of the cooling pipeline; the pressure control device realizes the pressure control in the pipeline through the coordinated action of the internal solenoid valve and the piston, and the liquid volume control device realizes the liquid volume control through the centrifugal acceleration generated by the combined movement and rotation of the internal piston; The liquid volume control device includes a second housing, a second piston, a second electromagnetic actuator, a liquid injection valve, and a vent hole; the liquid volume control device is connected to the external pipeline through the liquid volume control pipe of the pipe-internal-cooled rotor evaporation cooling experimental platform; the second housing is responsible for protecting the internal components of the device and ensuring the sealed environment inside the device; the second piston is responsible for dividing the internal cavity of the device into two mutually sealed cavities, and the second electromagnetic actuator extends or shortens as needed to push or pull the second piston; the liquid injection valve is used for liquid filling and is opened during liquid filling, and the working medium is filled through the liquid injection valve; the vent hole is located on the side of the second housing away from the axis of rotation along the radial direction of the rotor, and does not affect the airtightness of the sealed cavity formed by the second piston and the part of the second housing on the side close to the axis of rotation along the radial direction of the rotor; In the pipe-internal-cooled rotor evaporation cooling experimental platform, the gas collecting pipe is connected to the upper end of the upper pipeline joint and the inlet of the condenser; the lower end of the upper pipeline joint is connected to the upper end of the cooling pipeline; the lower end of the cooling pipeline is connected to the upper end of the lower pipeline joint; an opening is added to the lower pipeline joint on the side away from the axis of rotation along the radial direction of the rotor to connect the lower solenoid valve, and the lower solenoid valve is connected to the liquid volume control device through the liquid volume control pipe; the lower end of the lower pipeline joint is connected to the lower outlet of the condenser through a return pipe; an opening is added to the upper inlet of the condenser to connect to the upper solenoid valve; the upper solenoid valve is connected to the pressure control device through the pressure control pipe; the upper inlet of the condenser is connected to the gas collecting pipe.

2. The pressure regulation system for the in-pipe cold-rotor evaporation cooling experimental platform according to claim 1, characterized in that, The pipe-internal-cooled rotor evaporation cooling experimental platform includes a gas collecting pipe, an upper pipeline joint, an upper solenoid valve, a pressure control device, a condenser, a cooling pipeline, a lower pipeline joint, a return pipe, a liquid volume control device, a lower solenoid valve, a pressure control pipe, a liquid volume control pipe, a first pressure sensor, a second pressure sensor, a temperature sensor, and a rotating shaft; a first pressure sensor and a temperature sensor are installed in the upper pipeline joint; a second pressure sensor is installed in the lower pipeline joint to realize the real-time measurement of the pressure in the lower pipeline joint.

3. The pressure regulation system for the in-duct cold-rotor evaporation cooling experimental platform according to claim 1, characterized in that, The pressure control device includes a first housing, a first piston, a first micro solenoid valve, a second micro solenoid valve, and a first electromagnetic actuator; the pressure control device is connected to the external pipeline along the radial direction of the rotor through the pressure control pipe of the pipe-internal-cooled rotor evaporation cooling experimental platform; the first housing is responsible for packaging and sealing the overall device; the first electromagnetic actuator extends and shortens as needed, and the first electromagnetic actuator is connected to and drives the first piston to divide the inner cavity of the pressure control device into two mutually sealed cavities when the first micro solenoid valve is closed; a first micro solenoid valve is installed on the first piston, and a second micro solenoid valve is installed on the first housing, both of which can be opened and closed as needed.

4. The pressure regulation system for the in-duct cold-rotor evaporation cooling experimental platform according to claim 1, characterized in that Even when the second electromagnetic actuator reaches its maximum stroke, the position of the second piston within the liquid volume control device will not exceed the liquid injection valve, ensuring that all the liquid injected by the liquid injection valve is always pushed into the liquid volume control pipe by the second piston.

5. The pressure regulation system for the in-pipe cold-rotor evaporation cooling experimental platform according to claim 1, wherein, The liquid volume control device uses a rigid outer shell, or is in the form of a liquid bladder or an air bag, and undergoes contraction and relaxation through an extrusion device.

6. The pressure regulation system for the in-pipe cold-rotor evaporation cooling experimental platform according to claim 1, wherein, The liquid volume control device and the pressure control device change their volumes by means of an electromagnetic actuator pushing a piston or by a hydraulic drive to actuate the piston.

7. A pressure regulation method using the pressure regulation system of the in-duct cold-rotor evaporation cooling experimental platform according to any one of claims 1-6, characterized in that, Including: During the liquid filling process, the in-pipe cold-rotor evaporation cooling experimental platform is in a stationary and unheated state. The lower solenoid valve connected to the liquid volume control pipe is closed. The second piston inside the liquid volume control device is at the maximum stroke position that the second electromagnetic actuator can reach along the radial direction of the rotor away from the axis of rotation. The first piston inside the pressure control device is at the maximum stroke position that the first electromagnetic actuator can reach along the radial direction of the rotor away from the axis of rotation. The liquid injection valve is opened to fill the interior of the liquid volume control device with the working fluid, and then the liquid injection valve is re-closed. The upper solenoid valve connected to the pressure control pipe is opened. The first micro electromagnetic valve and the second micro electromagnetic valve inside the pressure control device are opened. Subsequently, the lower solenoid valve connected to the liquid volume control pipe is opened. The second electromagnetic actuator inside the liquid volume control device pushes the second piston to the bottom in the direction of approaching the axis of rotation along the radial direction of the rotor, and all the working fluid is injected into the circulation pipeline of the in-pipe cold-rotor evaporation cooling experimental platform through the liquid volume control pipe. After the liquid filling is completed, the lower solenoid valve connected to the liquid volume control pipe is closed, then the upper solenoid valve connected to the pressure control pipe is closed, and finally the first micro electromagnetic valve and the second micro electromagnetic valve inside the pressure control device are closed. The pressure control device includes a first outer shell, a first piston, a first micro electromagnetic valve, a second micro electromagnetic valve, and a first electromagnetic actuator. The pressure control device is connected to the external pipeline along the radial direction of the rotor through the pressure control pipe of the in-pipe cold-rotor evaporation cooling experimental platform. The first outer shell is responsible for packaging and sealing the entire device. The first electromagnetic actuator elongates and shortens as needed. The first electromagnetic actuator is connected to and drives the first piston to divide the inner cavity of the pressure control device into two mutually sealed cavities when the first micro electromagnetic valve is closed. A first micro electromagnetic valve is installed on the first piston, and a second micro electromagnetic valve is installed on the first outer shell, both of which can be opened and closed as needed.

8. A pressure regulation method for an in-pipe cold-rotor evaporation cooling experimental platform according to claim 7, characterized in that Including: During the preheating and exhaust process, first, the in-pipe cold-rotor evaporation cooling experimental platform is in a stable rotating state, and then the wall surface of the cooling pipe is heated. When the pressure at the outlet of the cooling pipe reaches stability, the upper solenoid valve on the pressure control pipe is opened, and then the first micro electromagnetic valve and the second micro electromagnetic valve on the pressure control device are opened, so that the mixed gas of air and gaseous working fluid gushes out of the circulation pipeline through the pressure control device. Then the upper solenoid valve connected to the pressure control pipe is closed, then the first micro electromagnetic valve of the pressure control device is closed, and finally the second micro electromagnetic valve is closed to restore the pipeline to a sealed state.

9. A pressure regulation method for an in-pipe cold-rotor evaporation cooling experimental platform according to claim 8, characterized in that, Including: During the experiment, the temperature and pressure in the upper pipeline joint at the outlet of the cooling pipeline are monitored by the first pressure sensor and the temperature sensor. If, under steady-state conditions, the temperature at the outlet of the cooling pipeline is lower than the boiling point of the working fluid corresponding to this pressure, the internal pressure of the circulation loop is reduced through the pressure control device according to the experimental requirements, making it easier for the working fluid to reach boiling, and this is recorded as a new experimental condition. At the end of the experiment, the rotation of the in-pipe cold-rotor evaporation cooling experimental platform is maintained, the heating of the cooling pipeline is stopped, the lower solenoid valve on the liquid volume control pipe is first opened, and the second electromagnetic actuator in the liquid volume control device drives the second piston to move radially away from the rotating shaft along the rotor, and the working fluid will flow back into the liquid volume control device under the action of the centrifugal acceleration and the negative pressure in the liquid volume control device. Then the upper solenoid valve on the pressure control pipe is opened, and then the first micro electromagnetic valve and the second micro electromagnetic valve on the pressure control device are opened to allow air to flow into the circulation pipeline, which will cause the remaining working fluid to further flow into the liquid volume control device. Finally, the lower solenoid valve on the liquid volume control pipe is closed to complete the recovery of the working fluid.

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