An apparatus and method for studying evaporative cooling media

Abstract

This invention relates to the field of circuit device cooling technology, and discloses an apparatus and method for studying evaporative cooling media, including a boiling evaporation module, a cooling circulation module, a monitoring and analysis module, and a control module. The boiling evaporation module includes a boiling chamber and a composite functional component. The boiling chamber contains the cooling medium to be tested. The composite functional component includes a heating element and an electrode pair to heat the cooling medium and provide a high-voltage electric field for the cooling medium. The cooling circulation module includes a condenser, a medium storage tank, a cooling component, and a reflux component. The condensation circulation module is used to return the cooling medium to the boiling chamber. The monitoring and analysis module is used to monitor the state of the cooling medium. The control module is used to control the coordinated operation of each module. This invention greatly improves the research efficiency and convenience of cooling media by providing a thermo-electric coupling environment for the cooling medium through the composite functional component and detecting the state of the cooling medium through the monitoring and analysis module.

Description

Technical Field

[0001] This invention relates to the field of circuit device cooling technology, and in particular to an apparatus and method for studying evaporative cooling media. Background Technology

[0002] As the core equipment for power transmission in power grids, the high efficiency, environmental friendliness, and safety of power transformers are key aspects of technological innovation in green electrical equipment. With the development of power transformers towards higher voltage, larger capacity, and smaller size, heat dissipation has become an increasingly important factor restricting their performance improvement. Evaporative cooling technology, which achieves efficient heat dissipation by absorbing heat from the heating surface through a liquid medium and undergoing a liquid-gas phase change, has become an important technological direction for cooling high-power-density transformers.

[0003] In evaporative cooling transformers, the insulation and heat transfer characteristics in the gas-liquid two-phase state involve multi-field coupling issues involving the phase field, flow field, thermal field, and electric field. The bubbles generated during the boiling process of the cooling medium not only affect heat transfer efficiency but also distort the local electric field distribution, potentially inducing partial discharge and leading to medium decomposition. The decomposition products may further alter the insulation and heat transfer properties of the medium. This forms a complex mechanism of interaction between heat, electricity, and gas factors, directly affecting the safety and reliability of equipment operation. However, current analyses of heat transfer cooling media are limited to analyzing the insulation and heat transfer performance of the medium in a single field, without considering the mutual influence of multiple fields on the heat transfer medium. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an apparatus and method for studying evaporative cooling media, thereby solving the technical problem that the existing technology cannot analyze the synergy between the insulation and heat transfer characteristics of the cooling media under multi-field coupling conditions.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an apparatus and method for studying evaporative cooling media, including a boiling evaporation module, a cooling circulation module, a monitoring and analysis module, and a control module; The boiling evaporation module includes a boiling chamber and a composite functional component; the boiling chamber contains a cooling medium to be tested; the composite functional component is located at the bottom of the boiling chamber and includes a heating element and an electrode pair; the heating element is used to heat the cooling medium, and the electrode pair is used to provide a high-voltage electric field within the cooling medium. The cooling circulation module includes a condenser, a medium storage tank, a cooling component, and a reflux component. The condenser is connected to both the boiling tank and the medium storage tank. The cooling component is connected to both the condenser and the medium storage tank to control the temperature of the cooling medium. The two ends of the reflux component are connected to both the medium storage tank and the boiling tank to allow the cooling medium to flow back to the boiling tank. The monitoring and analysis module includes a partial discharge detection component, a gas analysis component, a camera component, and a measurement component. The partial discharge detection component is electrically connected to the electrode pair to adjust and control the electric field. The gas analysis component is connected to the boiling tank to detect and analyze the characteristic components after the decomposition of the cooling medium. The camera component is located on the side of the boiling tank to monitor bubbles inside the boiling tank. The measurement component includes multiple temperature sensors located in the boiling tank to monitor the temperature at various points within the boiling tank. The control module is electrically connected to the monitoring and analysis module, the cooling circulation module, and the boiling evaporation module. The control module is used to control the return flow of the cooling medium and the coordinated operation of each module.

[0006] In some embodiments, the boiling evaporation module includes a connected upper cover tube and a measuring tube. The upper cover tube is connected to the boiling chamber, and one end of the measuring tube is connected to the condenser. A pressure sensor, a first temperature sensor, and a steam flow meter are installed inside the measuring tube.

[0007] In some embodiments, the boiling evaporation module further includes a water heater, the two ends of which are respectively connected to the upper cover tube and the measuring tube, and the water heater is used to circulate and heat the gaseous cooling medium in the upper cover tube and the measuring tube; The outer side of the upper cover tube is provided with a detachable heat insulation sleeve to isolate the measuring tube from heat exchange with the outside.

[0008] In some embodiments, the boiling tank is connected to a vacuum valve and a suction / discharge valve. The vacuum valve is used to evacuate the boiling tank, and the suction / discharge valve is used to inject cooling medium into the boiling tank or extract cooling medium from the boiling tank.

[0009] In some embodiments, the cooling assembly includes a first chiller and a second chiller. The two ends of the first chiller are respectively connected to the two ends of the condenser to control the temperature of the cooling medium inside the condenser. The two ends of the second chiller are respectively disposed in the medium storage tank, and the second chiller is used to adjust and control the temperature of the cooling medium in the medium storage tank.

[0010] In some embodiments, the reflux assembly includes a variable gear pump, a regulating valve, a gear flow meter, and a liquid injection pump connected in sequence; the variable gear pump is connected to the medium storage tank, and the liquid injection pump is connected to the boiling tank; The variable gear pump and the gear flow meter are electrically connected to the control unit.

[0011] In some embodiments, the partial discharge detection assembly includes a voltage regulator, a protective resistor, a capacitive voltage divider, a coupling capacitor, a detection impedance, an oscilloscope, and a transformer. The voltage regulator is electrically connected to the transformer, the transformer is connected in series with the protective resistor, and the two ends of the transformer and the protective resistor are respectively connected to the two electrodes of the electrode pair. The capacitive voltage divider is respectively connected to the two electrodes of the electrode pair. The coupling capacitor is connected in series with the detection impedance, and the two ends of the coupling capacitor and the detection impedance are respectively connected to the two electrodes of the electrode pair. The oscilloscope is connected in parallel with the detection impedance.

[0012] In some embodiments, the gas analysis component includes a gas sampling port, a sampling bag, and a gas chromatograph-mass spectrometer connected in sequence, wherein the gas sampling port is connected to the upper part of the boiling box; The camera assembly includes a camera and a light source, with the camera and the light source positioned opposite each other on both sides of the boiling tank; The gas chromatograph-mass spectrometer and the camera are electrically connected to the control unit.

[0013] In some embodiments, the measuring component includes a second temperature sensor and a third temperature sensor. The second temperature sensor is fixedly disposed at the bottom of the boiling tank and is used to monitor the temperature at the bottom of the boiling tank. The third temperature sensor is disposed in the middle of the boiling tank and is used to monitor the temperature at the evaporation interface of the cooling medium.

[0014] Secondly, the present invention also provides a method for studying evaporative cooling media, comprising the following steps: S1. Pre-purge the air from the boiling chamber and inject the test cooling medium into the boiling chamber; S2. Activate the heating element of the composite functional component to raise the temperature of the cooling medium to a boiling state and discharge the non-condensable gas in the boiling chamber. S3. Start the cooling assembly, condenser and reflux assembly. The cooling assembly adjusts and stabilizes the temperature of the cooling medium to the saturation temperature. At the same time, the control unit adjusts and controls the reflux flow rate of the cooling medium through the reflux assembly to ensure that the reflux flow rate of the cooling medium in the boiling tank is consistent with the evaporation rate. S4. Set the initial heating power of the heating element to keep the temperature of the liquid cooling medium at the saturation temperature. When the temperature fluctuation of the cooling medium is less than the preset temperature range within a preset time, the system is determined to have entered a steady state. Then, the input power of the heating element is continuously adjusted, and the temperature of the heating element T0, the temperature of the inner surface of the bottom of the boiling tank T1, and the temperature of the cooling medium T2 are recorded in real time. S5. While heating, the heating element also conducts partial discharge experiments on the cooling medium through a partial discharge detection component at different heating powers, records the discharge amount and waveform of each discharge periodically, and collects and analyzes gas samples after the decomposition of the cooling medium through a gas analysis component. S6. After the partial discharge experiment, the control voltage is adjusted through the partial discharge detection component until the cooling medium is broken down. The breakdown voltage value is recorded. The gas sample after the decomposition of the cooling medium is collected and analyzed through the gas analysis component to evaluate the insulation resistance and chemical stability of the cooling medium under the action of thermo-electric coupling. S7. Calculate the input heat flow rate based on the one-dimensional steady-state heat conduction model, and then obtain the heat flux density and heat transfer coefficient; continuously increase the heat flux density, and when the superheat increases suddenly but the heat flux density no longer increases, the corresponding heat flux density value is the critical heat flux density; record the heat flux density and superheat under each steady-state condition in real time, and plot the boiling curve; and under constant power input conditions, record the heating time of the cooling medium from room temperature to saturation temperature to calculate the heating rate of the cooling medium. S8. After the experiment ends, shut down the composite functional components, condenser, cooling components, reflux components, partial discharge detection components, gas analysis components, and camera components; after the cooling medium in the boiling chamber has cooled down, shut down the control unit and disconnect the power supply.

[0015] The apparatus and method for studying evaporative cooling media provided in this embodiment of the invention have the following advantages compared to the prior art: In this embodiment, the cooling medium in the boiling chamber is heated and boiled under the action of the heating element, achieving a gas-phase transition. After being condensed by the condenser, the gaseous cooling medium gathers in the medium storage tank and can be returned to the boiling chamber through the reflux assembly, thereby ensuring the stability of the cooling medium quality in the boiling chamber and ensuring the smooth progress of subsequent experiments. The electrode pair arrangement can provide electric fields of different voltages in the boiling chamber as needed, so that the cooling medium in the boiling chamber is simultaneously in a thermal field and an electric field, which facilitates subsequent research on the insulation and heat transfer performance of the cooling medium under thermal-electric field coupling scenarios. The partial discharge detection component can adjust the voltage of the electrode pair and record the breakdown voltage value to determine the insulation performance of the cooling medium under different states. The measurement component can monitor the temperature at various points in the boiling chamber to determine the critical heat flux density and heating rate of the cooling medium, and thus determine the heat transfer performance of the cooling medium under different states. The gas analysis component can analyze and detect the gas composition after the electrolysis of the cooling medium, and the camera component can monitor the evaporation state of the cooling medium. This embodiment satisfies the requirements of experimental continuity and quantitative control of the cooling medium through the circulation of the cooling medium. The controllable voltage electrode pair provides a high-voltage electric field to the cooling medium, better simulating its actual operating conditions. Combined with multiple detection and analysis components, it enables a more comprehensive study of the insulation and heat transfer performance of the cooling medium under different thermal-electric field coupling states, greatly improving the efficiency and convenience of the research. Attached Figure Description

[0016] Figure 1 This is a system structure diagram of the present invention; Figure 2 This is a structural diagram of the heating element of the present invention; Figure 3 This is a flowchart illustrating the present invention.

[0017] In the diagram: 1. Boiling evaporation module; 11. Boiling chamber; 111. Vacuum valve; 112. Suction and discharge valve; 113. Gas valve; 12. Composite functional component; 121. Heating element; 122. Electrode pair; 123. Heat-conducting element; 13. Top cover tube; 14. Measuring tube; 141. Pressure sensor; 142. First temperature sensor; 143. Steam flow meter; 15. Water heater; 16. Insulation sleeve; 17. Replaceable sleeve; 2. Cooling circulation module; 21. Condenser; 22. Medium storage tank; 23. Cooling assembly; 231. First chiller; 232. Second chiller; 24. Reflux assembly; 241. Variable gear pump; 242. Control valve; 243. Gear flow meter; 244. Injection pump; 3. Monitoring and Analysis Module; 31. Partial Discharge Detection Component; 311. Voltage Regulator; 312. Protective Resistor; 313. Capacitive Voltage Divider; 314. Coupling Capacitor; 315. Detection Impedance; 316. Oscilloscope; 317. Transformer; 32. Gas Analysis Component; 321. Gas Sampling Port; 322. Sampling Bag; 323. Gas Chromatography-Mass Spectrometry System; 33. Camera Component; 331. Camera; 332. Light Source; 34. Measurement Component; 341. Second Temperature Sensor; 342. Third Temperature Sensor; 343. Fourth Temperature Sensor; 4. Control module; 41. Host computer. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, and are not used to describe a particular order, hierarchy, or importance of components.

[0020] It should be noted that, unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention. Furthermore, the use of terms such as "horizontal," "vertical," and "suspended" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, positioned in a specific orientation such as "horizontal," "vertical," or "suspended," can have an error / deviation of ±10% relative to that orientation, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still fulfill its function in the present invention.

[0021] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] In this application, "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0025] To address the technical problem that existing equipment cannot study the insulation and heat transfer properties of cooling media under thermal-electric field coupling conditions, this invention provides an apparatus and method for studying evaporative cooling media. The cooling media is circulated through a cooling circulation module, and then a stable thermal and electric field is provided within a boiling chamber via heating elements and electrode pairs, placing the cooling media simultaneously in both fields. Subsequently, a partial discharge detection component, a gas analysis component, a camera component, and a measurement component enable comprehensive detection and analysis of the insulation and heat transfer properties of the cooling media, significantly improving experimental efficiency and convenience.

[0026] like Figure 1 As shown, a preferred embodiment of the present invention provides an apparatus and method for studying evaporative cooling media, which includes a boiling evaporation module 1, a cooling circulation module 2, a monitoring and analysis module 3, and a control module 4; The boiling evaporation module 1 includes a boiling chamber 11 and a composite functional component 12. The boiling chamber 11 contains the cooling medium to be tested. The composite functional component 12 is located at the bottom of the boiling chamber 11. The composite functional component 12 includes a heating element 121 and an electrode pair 122. The heating element 121 is used to heat the cooling medium, and the electrode pair 122 is used to provide a high voltage electric field for the cooling medium. The cooling circulation module 2 includes a condenser 21, a medium storage tank 22, a cooling assembly 23, and a reflux assembly 24. The condenser 21 is connected to the boiling tank 11 and the medium storage tank 22 respectively. The cooling assembly 23 is connected to the condenser 21 and the medium storage tank 22 to control the temperature of the cooling medium. The two ends of the reflux assembly 24 are connected to the medium storage tank 22 and the boiling tank 11 respectively, so that the cooling medium flows back to the boiling tank 11. The monitoring and analysis module 3 includes a partial discharge detection component 31, a gas analysis component 32, a camera component 33, and a measurement component 34. The partial discharge detection component 31 is electrically connected to the electrode pair 122 to adjust and control the electric field; the gas analysis component 32 is connected to the boiling tank 11 to detect and analyze the characteristic components after the decomposition of the cooling medium; the camera component 33 is disposed on the side of the boiling tank 11 to monitor the bubbles inside the boiling tank 11; the measurement component 34 includes multiple temperature sensors disposed in the boiling tank 11 to monitor the temperature at various points in the boiling tank 11. The control module 4 is electrically connected to the monitoring and analysis module 3, the cooling circulation module 2, and the boiling evaporation module 1. The control module 4 is used to control the return flow of the cooling medium and the coordinated operation of each module.

[0027] In this embodiment, the boiling chamber 11 stores a certain amount of cooling medium to be tested. The heating element 121 in the composite functional component 12 can heat the cooling medium, causing it to boil and evaporate, thus simulating the phase change and heat absorption scenario of the cooling medium during actual use. The electrode pair 122 can provide an electric field in the cooling medium. Together with the heating element 121, it can more comprehensively simulate the working condition of the cooling medium under thermal-electric field coupling during actual cooling. This facilitates subsequent research on the synergistic characteristics of the insulation and heat transfer performance of the cooling medium, greatly simplifies and shortens the experimental process of the cooling medium, and improves experimental efficiency.

[0028] In this cooling cycle, the condenser 21 is connected to the boiling chamber 11. It condenses the gaseous cooling medium in its evaporating state into a liquid cooling medium, which is then collected in the medium storage tank 22. The liquid cooling medium in the medium storage tank 22 can be returned to the boiling chamber 11 through the reflux assembly 24, ensuring a constant mass of the cooling medium in the boiling chamber 11. This maintains the continuous and stable operation of the experiment, preventing the experiment from being interrupted due to the cooling medium drying out inside the boiling chamber 11, and eliminating experimental variables caused by changes in the mass of the cooling medium. The cooling assembly 23, in conjunction with the condenser 21, can better control the temperature of the condensed liquid cooling medium, preventing the reflux cooling medium temperature from being too high or too low, which could cause large fluctuations in the thermal field within the boiling chamber 11.

[0029] Furthermore, the partial discharge detection component 31 is electrically connected to the two electrodes of the electrode pair 122, thereby allowing adjustment of the voltage of the electrode pair 122 to adapt to different experimental requirements. It can also record the breakdown voltage of the cooling medium under different states, providing data support for the subsequent control module 4 to study the insulation performance of the cooling medium. The gas analysis component 32 is connected to the boiling chamber 11, enabling real-time monitoring of the composition and concentration of decomposition products of the cooling medium inside the boiling chamber 11 after decomposition in the electric field. The control module 4 can use the data from these decomposition products to study the insulation performance and durability of the cooling medium. The camera component 33 captures the bubble behavior of the cooling medium on the boiling heat exchange surface, and the control module can use this data to analyze the state of the cooling medium during the actual cooling process. The measurement component 34 monitors the temperature at various points inside the boiling chamber 11. This temperature data can be used by the control module 4 to analyze the heating rate and heat transfer efficiency of the cooling medium, facilitating the study of the heat transfer performance of the cooling medium under thermal-electric field coupling conditions.

[0030] Furthermore, such as Figure 2 As shown, in some embodiments, the heating element 121 and an electrode are fixedly disposed at the bottom of the boiling chamber 11. A heat-conducting element 123 is disposed between the heating element 121 and the motor. The heating element 121 has a tubular structure, while the heat-conducting element 123 is made of a high thermal conductivity metal material. The upper part of the heat-conducting element 123 is cylindrical, and the lower part is cuboid, forming an overall T-shaped structure. The heating element 121 is inserted into the bottom of the heat-conducting element 123 to provide a controllable heat flux density to the boiling heat exchange surface. The electrode is disposed at the top of the heat-conducting element 123 to apply a controllable electric field strength to the boiling heat exchange surface. Depending on experimental requirements, a needle-shaped or plate-shaped electrode can be selected to generate a uniform or non-uniform electric field. An insulating thermally conductive layer is disposed between the electrode and the heat-conducting element 123, and their upper surfaces are flush, together forming the boiling heat exchange surface. In addition, the upper end of the heat-conducting component 123 is provided with multiple temperature measuring channels along the axial direction for installing platinum resistance thermometers to measure the temperature gradient inside the heat-conducting component 123.

[0031] Furthermore, to maintain a relatively stable temperature distribution field inside the boiling chamber 11 for continuous measurement and analysis, in some embodiments, a mica heating plate is selected as an auxiliary heating element and installed at the inner bottom of the boiling chamber 11. This auxiliary heating element adopts a surface heating direction, resulting in uniform heat distribution. Its heating power is determined as follows: without considering the medium's heating process, the calculation is based solely on the power required for continuous evaporation and condensation at the maximum evaporation flow rate after reaching the evaporation temperature. In a specific embodiment, for example, the density of the low-boiling-point medium is 1.6 × 10³ kg / m³. 3The specific heat is 1013 J / kg·℃, and the latent heat of vaporization is 21.2 cal / g. Based on a maximum flow rate of 48 g / s, the heat absorbed by vaporization per unit time is 48 × 21.2 = 1017.6 cal / s, which translates to a vaporization power consumption of 4.25 kW. Considering external heat loss, a heating power of 4.5 kW is sufficient.

[0032] It should be noted that in some embodiments, the boiling tank 11 is welded from stainless steel, and the entire interior of the boiling tank 11 is a cylindrical sealed cavity with a transparent observation window on its side to facilitate observation of the internal cooling medium by the experimenter and the camera assembly 33. In other embodiments, depending on the cooling medium being tested, the boiling tank 11 may be made of other materials. The control unit generally includes a host computer 41 and a control chip; however, in other embodiments, the control unit may also be a server or other computer equipment.

[0033] In one embodiment, the boiling evaporation module 1 includes a connected upper cover tube 13 and a measuring tube 14. The upper cover tube 13 is connected to the boiling box 11. One end of the measuring tube 14 is connected to the condenser 21. A pressure sensor 141, a first temperature sensor 142, and a steam flow meter 143 are installed inside the measuring tube 14.

[0034] In this embodiment, the upper cover tube 13 is used to collect the gaseous cooling medium evaporated in the boiling tank 11 and sequentially introduce the cooling medium into the measuring tube 14 and the condenser 21. The pressure sensor 141, the first temperature sensor 142, and the steam flow meter 143 in the measuring tube 14 can measure the steam flow rate after the cooling medium is vaporized, providing data support for the subsequent reflux assembly 24 to adjust the reflux flow rate of the cooling medium, so as to ensure the balance of the cooling medium quality in the boiling tank 11.

[0035] Specifically, to obtain the mass flow rate of the cooling medium steam, the steam density needs to be calculated based on the steam's volumetric flow rate, temperature, and pressure. Since low-pressure steam can be approximated as an ideal gas, and the steam density is calculated as follows: ; Where ρ is the steam density, in kg / m³. 3P represents absolute pressure, which is the pressure measured by pressure sensor 141 plus atmospheric pressure, in Pa; M represents the molar mass of steam, an inherent property of the cooling medium, in kg / mol; R represents the universal gas constant, typically 8.314 J / (mol·K); T represents absolute temperature, which is the temperature measured by the first temperature sensor 142 plus 273.15, in K. Therefore, by combining this with the steam output volume obtained by steam flow meter 143, the mass of the cooling medium output from boiling tank 11 can be calculated. Control module 4 can then use this data to control the return flow rate of the cooling medium via return assembly 24 to ensure that the mass of the cooling medium in boiling tank 11 is in equilibrium.

[0036] In addition, in some other embodiments, a replaceable sleeve 17 is provided between the upper cover tube 13 and the measuring tube 14. The replaceable sleeve 17 can be provided with flow channels of different structures according to the test requirements to meet the test requirements of different flow states. The steam flow meter 143 can be a vortex flow meter, the range of which is determined according to the test requirements, and the accuracy is controlled below 0.5%FS.

[0037] In one embodiment, the boiling evaporation module 1 further includes a water heater 15, with the two ends of the water heater 15 connected to the upper cover tube 13 and the measuring tube 14 respectively. The water heater 15 is used to circulate and heat the gaseous cooling medium in the upper cover tube 13 and the measuring tube 14. A removable heat-insulating sleeve 16 is provided on the outside of the upper cover tube 13 to isolate the measuring tube 14 from the outside heat exchange.

[0038] In this embodiment, to ensure heat transfer along a predetermined direction and prevent premature condensation due to heat exchange between the steam and the outside environment, the upper cover pipe 13 and the measuring pipe 14 need to be insulated. Specifically, an insulating sleeve 16 is first fitted over the outer side of the upper cover pipe 13 and the measuring pipe 14. This insulating sleeve 16 can isolate the upper cover pipe 13 and the measuring pipe 14 from heat exchange with the outside environment. Furthermore, this embodiment also includes a water heater 15, which can drive the medium to flow between the upper cover pipe 13 and the insulating sleeve 16, and between the measuring pipe 14 and the insulating sleeve 16, thereby maintaining the temperature stability of the upper cover pipe 13 and the measuring pipe 14, preventing premature cooling of the cooling medium inside the upper cover pipe 13 and the measuring pipe 14, and ensuring the accuracy of the data measured by the steam flow meter 143. Of course, it is understood that the medium used by the water heater 15 can be the cooling medium to be measured, or other heat exchange media, as long as sealing and temperature stability are ensured. In some other embodiments, separate flow channels may be provided on the outside or inside of the insulation sleeve 16 to facilitate the flow of the driving medium by the water heater 15 to ensure the stability of the temperature of the cover tube 13 and the measuring tube 14.

[0039] In one embodiment, the boiling tank 11 is connected to a vacuum valve 111 and a suction / discharge valve 112. The vacuum valve 111 is used to evacuate the boiling tank 11, and the suction / discharge valve 112 is used to inject or extract the cooling medium into the boiling tank 11.

[0040] In this embodiment, to minimize interference, it is necessary to ensure that the boiling tank 11 contains only the cooling medium to be tested. Therefore, after injecting the cooling medium into the boiling tank 11 through the suction / discharge valve 112, other gases in the boiling tank 11 need to be extracted through the vacuum valve 111 to prevent these gases from interfering with the experiment. Furthermore, liquid cooling media often contain dissolved gases, which can also interfere with the experiment. Therefore, after evacuating the boiling tank 11, the cooling medium needs to be heated to allow non-condensable gases in the cooling medium to escape. These non-condensable gases are then discharged through the gas valve 113 to reduce interference and ensure the stability and reliability of the experiment. After the experiment, excess cooling medium in the boiling tank 11 can also be extracted through the suction / discharge valve 112 to ensure the cleanliness of the entire apparatus and facilitate subsequent experiments on other cooling media.

[0041] In one embodiment, the cooling assembly 23 includes a first chiller 231 and a second chiller 232. The two ends of the first chiller 231 are respectively connected to the two ends of the condenser 21 to control the temperature of the cooling medium inside the condenser 21. The two ends of the second chiller 232 are respectively disposed in the medium storage tank 22. The second chiller 232 is used to adjust and control the temperature of the cooling medium in the medium storage tank 22.

[0042] In this embodiment, the cooling medium rapidly condenses in the condenser 21 and flows to the medium storage tank 22 by gravity. To facilitate adjustment of the condensing efficiency of the condenser 21, a first chiller 231 is provided. The first chiller 231 adjusts the temperature of the refrigerant inside it to control the condensing efficiency of the condenser 21, ensuring that the cooling medium can rapidly condense into a liquid state and flow to the medium storage tank 22. In a specific embodiment, a condensing coil is provided inside the condenser 21 and its connected pipes, and a cooling jacket is provided on the outside of the condensing coil. The refrigerant flows within the cooling jacket. The first chiller 231 can achieve rapid condensation of the cooling medium by cooperating with the cooling jacket and the condensing coil. A second chiller 232 is connected to the medium storage tank 22. The coil connected to the second chiller 232 is located inside the medium storage tank 22. The second chiller 232 controls the circulation of the refrigerant within its coil to control the temperature of the cooling medium in the medium storage tank 22.

[0043] More specifically, in some embodiments, the temperature control accuracy of the first chiller 231 and the second chiller 232 is controlled within ±0.5℃.

[0044] Furthermore, in some embodiments, the medium storage tank 22 is equipped with a thermometer and a level gauge, which are used to monitor the temperature and level of the cooling medium in the medium storage tank 22, respectively, thereby facilitating the subsequent adjustment work of the control module 4.

[0045] In one embodiment, the reflux assembly 24 includes a variable gear pump 241, a regulating valve 242, a gear flow meter 243 and a liquid injection pump 244 connected in sequence; the variable gear pump 241 is connected to the medium storage tank 22 and the liquid injection pump 244 is connected to the boiling tank 11. The variable gear pump 241 and the gear flow meter 243 are electrically connected to the control unit.

[0046] In this embodiment, the liquid cooling medium in the medium storage tank 22 is returned to the boiling tank 11 through the reflux assembly 24. The variable gear pump 241 is dynamically adjusted based on the data fed back by the steam flow meter 143 to achieve continuous circulation of the evaporative cooling process. The injection pump 244 is used to inject the cooling medium into the boiling tank 11. The gear flow meter 243 and the regulating valve 242 are used to detect and control the reflux flow of the cooling medium, thereby providing feedback control to the injection pump 244 and the variable gear pump 241 to ensure the mass balance of the cooling medium in the boiling tank 11.

[0047] Furthermore, considering the limited space in the laboratory, the flow rate of the entire device should not be too high. Therefore, in a specific embodiment, the adjustment range of the variable gear pump 241 is controlled within 0–1.8 L / min, and the mass flow rate is 48 g / s when used for low-boiling-point cooling media. The maximum circulation flow rate of the selected variable gear pump 241 is used as the maximum evaporation capacity of the system under design conditions for estimation. If it runs continuously for 40 minutes, the corresponding total evaporation capacity is 72 L. Regarding volume design, to reduce the impact of the heat capacity and heat dissipation of the boiling tank 11 on the experiment, the boiling tank 11 should have sufficient volume to accommodate the test medium, with an effective volume of 25 L. Correspondingly, to ensure the relative stability of the temperature of the medium storage tank 22, the effective volume of the medium storage tank 22 is 100 L.

[0048] In one embodiment, the partial discharge detection assembly 31 includes a voltage regulator 311, a protective resistor 312, a capacitive voltage divider 313, a coupling capacitor 314, a detection impedance 315, an oscilloscope 316, and a transformer 317. The voltage regulator 311 is electrically connected to the transformer 317, and the transformer 317 is connected in series with the protective resistor 312. The two ends of the transformer 317 and the protective resistor 312 are respectively connected to the two electrodes of the electrode pair 122. The capacitive voltage divider 313 is respectively connected to the two electrodes of the electrode pair 122. The coupling capacitor 314 is connected in series with the detection impedance 315, and the two ends of the coupling capacitor 314 and the detection impedance 315 are respectively connected to the two electrodes of the electrode pair 122. The oscilloscope 316 is connected in parallel with the detection impedance 315.

[0049] In one specific embodiment, the voltage regulating stage 311 has a rated capacity of 50kVA and is used to provide experimental voltage. The voltage between electrode pairs 122 can be easily and quickly adjusted through the voltage regulating stage 311 to adapt to different experimental requirements. The protection resistor 312 is used for overcurrent protection. The capacitor voltage divider 313 is used to detect the power frequency AC voltage signal. The coupling capacitor 314 and the detection impedance 315 constitute a partial discharge detection circuit. The oscilloscope 316 is used to acquire the partial discharge signal, and its sampling frequency is 2.5MHz / s.

[0050] In one embodiment, the gas analysis component 32 includes a gas sampling port 321, a sampling bag 322 and a gas chromatograph-mass spectrometer connected in sequence, with the gas sampling port 321 connected to the upper part of the boiling box 11. The camera assembly 33 includes a camera 331 and a light source 332, with the camera and the light source 332 arranged opposite each other on both sides of the boiling tank 11; The gas chromatograph-mass spectrometer 323 and the camera 331 are electrically connected to the control unit.

[0051] In this embodiment, the sampling port of the gas analysis component 32 is located at the top of the boiling box 11 or on the side of the upper cover tube 13 near the boiling box 11. It can introduce gaseous substances in the boiling box 11 into the gas chromatograph-mass spectrometer 323. The gas chromatograph-mass spectrometer 323 can analyze the characteristic components of the products after the cooling medium decomposes in the thermal field-electric field, and then study the products of the cooling medium decomposed under different voltages, and thus determine the durability, safety and insulation of the cooling medium.

[0052] The camera 331 and the light source 332 are respectively located on both sides of the boiling tank 11, and the boiling tank 11 is provided with transparent viewing windows corresponding to the camera 331 and the light source 332. The camera is preferably equipped with a frame rate of 1000 frames / second or higher, which, together with the light source 332, can more clearly capture the bubble behavior on the boiling heat exchange surface of the cooling medium, thereby providing data support for subsequent research on the working state of the cooling medium.

[0053] In one embodiment, the measuring component 34 includes a second temperature sensor 341 and a third temperature sensor 342. The second temperature sensor 341 is fixedly disposed at the bottom of the boiling tank 11 and is used to monitor the temperature at the bottom of the boiling tank 11. The third temperature sensor 342 is disposed in the middle of the boiling tank 11 and is used to monitor the temperature at the evaporation interface of the cooling medium.

[0054] In this embodiment, in order to study the heat transfer performance of the cooling medium, it is necessary to comprehensively monitor the temperature state of the cooling medium. A second temperature sensor 341 and a third temperature sensor 342 are set up. Together with the temperature T0 of the heating element 121 monitored by the temperature sensor built into the heat-conducting element 123, the control module 4 can comprehensively analyze the heat transfer performance of the cooling medium under different operating conditions. The whole measurement process is more accurate and more convenient.

[0055] In some other embodiments, there is also a fourth temperature sensor 343, which can monitor the temperature of the outer shell of the boiling tank 11.

[0056] See Figure 3 The present invention also provides a method for studying the synergistic characteristics of insulation and heat transfer of evaporative cooling media, comprising the following steps: S1. First, purge the air from the boiling chamber 11 and inject the test cooling medium into the boiling chamber 11.

[0057] Specifically, cooling medium is injected into the boiling tank 11 through the suction and discharge valve 112, and air in the boiling tank 11 is discharged through the vacuum valve 111 to reduce interference factors.

[0058] S2. Activate the composite function component 12 to raise the temperature of the cooling medium to a boiling state and discharge the non-condensable gas in the boiling chamber 11.

[0059] Specifically, the heating element 121 in the composite functional component 12 is activated to heat the cooling medium to a boiling state. At this time, the non-condensable gas dissolved in the cooling medium dissipates and can be discharged through the gas valve 113 to further reduce interference factors and ensure the accuracy and reliability of subsequent experiments.

[0060] S3. Start the cooling assembly 23, condenser 21 and reflux assembly 24. Adjust the temperature of the cooling medium to the saturation temperature through the cooling assembly 23. At the same time, the control unit adjusts the reflux flow rate of the cooling medium through the reflux assembly 24 to ensure that the reflux flow rate of the cooling medium in the boiling box 11 is consistent with the evaporation rate.

[0061] At this point, the cooling medium is already in a boiling state. Therefore, it is necessary to start the first chiller 231, the second chiller 232, and the condenser 21 to cool and condense the steam-state cooling medium, and then introduce the condensed cooling medium into the medium storage tank 22. During this process, the control module 4 acquires the data measured by the steam flow meter 143 and calculates the output of the steam-state cooling medium. The control module 4 can then control the amount of liquid cooling medium output by the variable gear pump 241 and monitor the mass flow rate of the liquid cooling medium through the gear flow meter 243. Then, the injection pump 244 pumps the liquid cooling medium back to the boiling tank 11, thereby forming a stable circulation of the cooling medium and ensuring that the return flow rate of the cooling medium in the boiling tank 11 is consistent with the evaporation rate, making the quality of the cooling medium in the boiling tank 11 more stable.

[0062] S4. Set the initial heating power of the heating element 121 in the composite functional component 12 to keep the temperature of the liquid cooling medium at the saturation temperature. When the temperature fluctuation of the cooling medium is less than the preset temperature range within a preset time, the system is determined to enter a steady state. Then, the input power of the heating element 121 is continuously adjusted, and the temperature T0 of the heating element 121, the temperature T1 of the inner surface of the bottom of the boiling box 11, and the temperature T2 of the cooling medium are recorded in real time.

[0063] Specifically, once the cycle stabilizes, the initial heating power of the heating element 121 is controlled to maintain the temperature of the liquid cooling medium at its saturation temperature for a period of time, allowing the entire system to enter a steady state. In one specific embodiment, when the temperature fluctuation monitored by the second temperature sensor 341 at the bottom of the boiling tank 11 is less than ±0.2℃ within 5 minutes, the entire system is considered to have entered a steady state. Subsequently, the input power of the heating element 121 and the auxiliary heating element is continuously adjusted to gradually increase the heat flux density, and the temperature T0 of the heating element 121, the temperature T1 of the bottom surface of the boiling tank 11, and the temperature T2 of the cooling medium are recorded in real time under different input power levels.

[0064] S5. While heating, the heating element 121 also conducts partial discharge experiments on the cooling medium through the partial discharge detection component 31 at different heating powers, periodically records the discharge amount and discharge waveform of each experiment, and collects and analyzes the gas samples after the decomposition of the cooling medium through the gas analysis component 32.

[0065] Specifically, in order to study the characteristics of the cooling medium under the thermal-electric field coupling scenario, the voltage of the electrode pair 122 can be adjusted by the voltage regulating stage 311 while the heating element 121 is heating. By gradually increasing the experimental voltage, partial discharge experiments are carried out at different heating power levels. During the experiment, the discharge quantity and discharge waveform are recorded periodically, and decomposition gas samples are collected by the gas sampling bag. The characteristic components in the decomposition gas are qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry in a timely manner to provide data support for the subsequent analysis of the control module 4.

[0066] S6. After the partial discharge experiment, the control voltage is adjusted by the partial discharge detection component 31 until the cooling medium is broken down. The breakdown voltage value is recorded. The gas sample after the decomposition of the cooling medium is collected and analyzed by the gas analysis component 32 to evaluate the insulation resistance and chemical stability of the cooling medium under the action of thermo-electric coupling.

[0067] Specifically, after the local discharge experiment is completed, in order to further investigate the insulation performance of the cooling medium, the voltage can be continuously increased by the voltage regulating table 311 until the cooling medium is broken down. The voltage value at this time is recorded as the breakdown voltage value. Then, the composition of the decomposition gas is analyzed by gas chromatography-mass spectrometry to evaluate the insulation tolerance and chemical stability of the cooling medium under thermo-electric coupling.

[0068] S7. Calculate the input heat flow rate based on the one-dimensional steady-state heat conduction model to obtain the heat flux density and heat transfer coefficient; continuously increase the heat flux density, and when the superheat increases suddenly but the heat flux density no longer increases, the corresponding heat flux density value is the critical heat flux density; record the heat flux density and superheat under each steady-state condition in real time and plot the boiling curve; and under constant power input conditions, record the heating time of the cooling medium from room temperature to saturation temperature to calculate the heating rate of the cooling medium.

[0069] The specific calculation method is as follows: The input heat flow is calculated using a one-dimensional steady-state heat conduction model, and the formula is as follows: ; Where Φ1 represents the input heat in W; A represents the heat conduction area, which is the sum of the areas of the heating element 121 and the auxiliary heating element at the bottom of the boiling tank 11. This area can be obtained by measurement. When the auxiliary heating element covers the entire bottom of the boiling tank 11, this heat conduction area is also the area of ​​the bottom surface of the boiling tank 11, and its unit is m². 2λ1 is the thermal conductivity of the boiling box, which varies depending on the material of the boiling box; δ is the thickness of the heat transfer surface gap, specifically the thickness of the heating element 123, in meters; and T0 and T1, as described above, are the temperatures of the heating element 121 and the bottom surface of the boiling box 11, respectively. Therefore, the input heat flow can be calculated.

[0070] Then, according to the formula: ; The heat flux density can then be calculated, where q is the heat flux density and A is the heat transfer area. In this embodiment, the heat transfer area and the heat conduction area are the same, so both are referred to as A, and the unit is m. 2 .

[0071] Subsequently, during the continuous increase of input heat flow, when the superheat ΔT (i.e., the difference between the bottom surface temperature T1 and the saturation temperature T2 of the cooling medium in the boiling tank 11) suddenly increases significantly while the heat flux density q no longer increases or even decreases, this inflection point is determined to be the critical point, and the corresponding heat flux density is the critical heat flux density q. max The critical heat flux density is a key parameter for evaluating the boiling heat transfer performance of a cooling medium. The higher the critical heat flux density, the higher the heat transfer efficiency of the cooling medium, and vice versa.

[0072] During the process of gradually increasing the input heat flow, the heat flux density q and superheat ΔT under each steady-state condition are recorded in real time, and the boiling curve is plotted with ΔT as the abscissa and q as the ordinate.

[0073] Under a certain constant power input condition, the entire heating time of the cooling medium from room temperature to saturation temperature is recorded, and the heating rate of the cooling medium can be calculated using the following formula: ; Where n is the heating rate, in K / s; ΔTh is the temperature range of the cooling medium from room temperature to saturation temperature, in K; and t is the heating time, in seconds. The heating rate reflects the sensible heat absorption capacity of the cooling medium without phase change. The faster the heating rate, the smaller the specific heat capacity of the medium, and the worse its cooling effect without phase change; conversely, the slower the heating rate, the larger the specific heat capacity of the medium, and the stronger its sensible heat absorption capacity.

[0074] Finally, based on the heat flow rate, the heat transfer coefficient h of the cooling medium can be calculated, and the specific formula is as follows: ; Where: h is the heat transfer coefficient, with units of W / (m²). 2 ·K); A is the thermal conductivity area, in m² 2 .

[0075] In summary, the boiling heat transfer performance of a cooling medium can be determined by its heat transfer coefficient; and its tolerance under high heat flux conditions can be evaluated by measuring its critical heat flux density. The higher the critical heat flux density, the higher the heat transfer efficiency of the cooling medium. The heating rate reflects the sensible heat absorption capacity of the cooling medium without phase change, and can be used to determine whether the cooling medium has suitable heating characteristics.

[0076] Regarding insulation performance, the partial discharge detection component 31 can obtain the partial discharge initiation voltage of the cooling medium under thermal-electric field coupling conditions. This voltage is compared with the partial discharge initiation voltage under a single electric field condition to determine the impact of the thermal field on the partial discharge initiation voltage of the cooling medium. After continuous operation, the breakdown voltage of the cooling medium is measured to obtain its variation, which can be used to assess the degree of degradation of the insulation performance of the cooling medium caused by the accumulation of dielectric decomposition products due to partial discharge. Through decomposition gas analysis, the concentration variation patterns of characteristic gases (hydrogen, carbon monoxide, methane, acetylene, etc.) at different voltage levels can be obtained, which can be used to assess the discharge energy level and the chemical stability of the dielectric.

[0077] S8. The experiment ends. Turn off the composite function component 12, condenser 21, cooling component 23, reflux component 24, partial discharge detection component 31, gas analysis component 32 and camera component 33. After the cooling medium in the boiling chamber 11 has cooled down, turn off the control unit and disconnect the power supply.

[0078] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An apparatus for studying evaporative cooling media, characterized in that, include: A boiling evaporation module includes a boiling chamber and a composite functional component. The boiling chamber contains a cooling medium to be tested. The composite functional component is located at the bottom of the boiling chamber and includes a heating element and an electrode pair. The heating element is used to heat the cooling medium, and the electrode pair is used to provide a high-voltage electric field to the cooling medium. A cooling circulation module includes a condenser, a medium storage tank, a cooling component, and a reflux component. The condenser is connected to both the boiling tank and the medium storage tank. The cooling component is connected to both the condenser and the medium storage tank to control the temperature of the cooling medium. The two ends of the reflux component are connected to both the medium storage tank and the boiling tank to allow the cooling medium to flow back to the boiling tank. The monitoring and analysis module includes a partial discharge detection component, a gas analysis component, a camera component, and a measurement component. The partial discharge detection component is electrically connected to the electrode pair to adjust and control the electric field. The gas analysis component is connected to the boiling tank to detect and analyze the characteristic components after the decomposition of the cooling medium. The camera component is disposed on the side of the boiling tank to monitor bubbles inside the boiling tank. The measurement component includes multiple temperature sensors disposed in the boiling tank to monitor the temperature at various points in the boiling tank. The control module is electrically connected to the monitoring and analysis module, the cooling circulation module, and the boiling evaporation module. The control module is used to control the return flow of the cooling medium and the coordinated operation of each module.

2. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The boiling evaporation module includes a connected upper cover tube and a measuring tube. The upper cover tube is connected to the boiling chamber, and one end of the measuring tube is connected to the condenser. A pressure sensor, a first temperature sensor, and a steam flow meter are installed inside the measuring tube.

3. The apparatus for studying evaporative cooling media according to claim 2, characterized in that, The boiling evaporation module also includes a water heater, the two ends of which are respectively connected to the upper cover tube and the measuring tube. The water heater is used to circulate and heat the gaseous cooling medium in the upper cover tube and the measuring tube. The outer side of the upper cover tube is provided with a detachable heat insulation sleeve to isolate the measuring tube from heat exchange with the outside.

4. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The boiling tank is connected to a vacuum valve and a suction / discharge valve. The vacuum valve is used to evacuate the boiling tank, and the suction / discharge valve is used to inject cooling medium into the boiling tank or extract cooling medium from the boiling tank.

5. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The cooling assembly includes a first chiller and a second chiller. The two ends of the first chiller are respectively connected to the two ends of the condenser to control the temperature of the cooling medium inside the condenser. The two ends of the second chiller are respectively disposed in the medium storage tank, and the second chiller is used to adjust and control the temperature of the cooling medium in the medium storage tank.

6. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The reflux assembly includes a variable gear pump, a regulating valve, a gear flow meter, and a liquid injection pump connected in sequence; the variable gear pump is connected to the medium storage tank, and the liquid injection pump is connected to the boiling tank; The variable gear pump and the gear flow meter are electrically connected to the control unit.

7. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The partial discharge detection assembly includes a voltage regulator, a protective resistor, a capacitive voltage divider, a coupling capacitor, a detection impedance, an oscilloscope, and a transformer. The voltage regulator is electrically connected to the transformer. The transformer is connected in series with the protective resistor, and the two ends of the transformer and the protective resistor are respectively connected to the two electrodes of the electrode pair. The capacitive voltage divider is respectively connected to the two electrodes of the electrode pair. The coupling capacitor is connected in series with the detection impedance, and the two ends of the coupling capacitor and the detection impedance are respectively connected to the two electrodes of the electrode pair. The oscilloscope is connected in parallel with the detection impedance.

8. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The gas analysis component includes a gas sampling port, a sampling bag, and a gas chromatograph-mass spectrometer connected in sequence, with the gas sampling port connected to the upper part of the boiling box; The camera assembly includes a camera and a light source, with the camera and the light source positioned opposite each other on both sides of the boiling tank; The gas chromatograph-mass spectrometer and the camera are electrically connected to the control unit.

9. The apparatus for studying evaporative cooling media according to claim 1, characterized in that, The measuring component includes a second temperature sensor and a third temperature sensor. The second temperature sensor is fixedly disposed at the bottom of the boiling tank and is used to monitor the temperature at the bottom of the boiling tank. The third temperature sensor is disposed in the middle of the boiling tank and is used to monitor the temperature at the evaporation interface of the cooling medium.

10. A method for studying evaporative cooling media, employing the apparatus for studying evaporative cooling media as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Pre-purge the air from the boiling chamber and inject the test cooling medium into the boiling chamber; S2. Activate the heating element of the composite functional component to raise the temperature of the cooling medium to a boiling state and discharge the non-condensable gas in the boiling chamber. S3. Start the cooling assembly, condenser and reflux assembly. The cooling assembly adjusts and stabilizes the temperature of the cooling medium to the saturation temperature. At the same time, the control unit adjusts and controls the reflux flow rate of the cooling medium through the reflux assembly to ensure that the reflux flow rate of the cooling medium in the boiling tank is consistent with the evaporation rate. S4. Set the initial heating power of the heating element to keep the temperature of the liquid cooling medium at the saturation temperature. When the temperature fluctuation of the cooling medium is less than the preset temperature range within a preset time, the system is determined to have entered a steady state. Then, the input power of the heating element is continuously adjusted, and the temperature of the heating element T0, the temperature of the inner surface of the bottom of the boiling tank T1, and the temperature of the cooling medium T2 are recorded in real time. S5. While heating, the heating element also conducts partial discharge experiments on the cooling medium through a partial discharge detection component at different heating powers, records the discharge amount and waveform of each discharge periodically, and collects and analyzes gas samples after the decomposition of the cooling medium through a gas analysis component. S6. After the partial discharge experiment, the control voltage is adjusted through the partial discharge detection component until the cooling medium is broken down. The breakdown voltage value is recorded. The gas sample after the decomposition of the cooling medium is collected and analyzed through the gas analysis component to evaluate the insulation resistance and chemical stability of the cooling medium under the action of thermo-electric coupling. S7. Calculate the input heat flow rate based on the one-dimensional steady-state heat conduction model, and then obtain the heat flux density and heat transfer coefficient; The heat flux density is continuously increased. When the superheat increases suddenly and the heat flux density no longer increases, the corresponding heat flux density value is the critical heat flux density. The heat flux density and superheat are recorded in real time under various steady-state conditions, and the boiling curve is plotted. Under constant power input conditions, the heating time of the cooling medium from room temperature to saturation temperature is recorded to calculate the heating rate of the cooling medium. S8. After the experiment ends, shut down the composite functional components, condenser, cooling components, reflux components, partial discharge detection components, gas analysis components, and camera components; after the cooling medium in the boiling chamber has cooled down, shut down the control unit and disconnect the power supply.

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