Micro-channel flow boiling in-situ measurement method

Abstract

The invention relates to a micro-channel flow boiling in-situ measurement method, which comprises the following steps of: 1) establishing a micro-channel flow boiling test system (17), and testing to ensure the sealing performance and the stability of the test system; 2) building a synchrotron radiation X-ray imaging system; 3) performing a pre-test to ensure that synchrotron radiation X-rays can penetrate through the micro-channel, pass through the scintillation crystal (3) and the reflector (4) and then are received by the high-speed camera; (4) micro-channel flow boiling tests under different test working conditions are carried out, and after it is monitored that the wall surface temperature reaches an approximate steady state, the synchrotron radiation X-ray imaging system is used for shooting the flow boiling phenomenon in the micro-channel; meanwhile, a temperature and pressure sensor in the micro-channel flow boiling test system is used for collecting wall surface temperature and inlet and outlet pressure, and in-situ measurement results of the wall surface temperature and the inlet and outlet pressure are obtained. Compared with the prior art, the method has the advantages of solving the problem of view angle limitation existing in a micro-channel flow boiling observation means and the like.

Description

Technical Field

[0001] This invention relates to the technical field of microchannel flow boiling measurement, and in particular to an in-situ measurement method for microchannel flow boiling. Background Technology

[0002] As the integration and performance of electronic devices continue to improve, their power density is increasing significantly, making heat dissipation a more prominent issue. Microchannel flow boiling, with its advantages of compact structure, large heat exchange area, and high heat transfer coefficient, is a key technology for solving the heat dissipation problem of future electronic devices.

[0003] To facilitate visualization research, microchannel heat sink models with transparent covers are currently widely used. However, the key physical properties of these materials, such as thermal conductivity, surface energy, and roughness, differ significantly from those of the actual metal substrates used in these applications (e.g., copper, silicon). This leads to deviations in fundamental behaviors such as bubble nucleation, growth, and detachment, making it impossible for observational results to accurately reflect the physical processes within the microchannels. Furthermore, existing visible light observation methods are limited in perspective, only providing a macroscopic view of the channel from a top-down angle. This makes it difficult to observe the influence of the channel walls on the nucleation, growth, and stretching of individual bubbles, to analyze the relationship between gravity and surface tension on bubble dynamics, and to directly reveal the impact of channel surface wetting properties on bubble dynamics. These limitations restrict the observation of microchannel flow boiling characteristics and the analysis of heat transfer mechanisms. Summary of the Invention

[0004] The purpose of this invention is to provide an in-situ measurement method for microchannel flow boiling, which addresses the limitation of perspective in existing microchannel flow boiling observation methods.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for in-situ measurement of microchannel flow boiling, comprising the following steps: 1) Build a microchannel flow boiling test system 17 and conduct tests to ensure the sealing and stability of the test system; 2) Construct a synchrotron radiation X-ray imaging system; 3) Conduct preliminary tests to ensure that synchrotron X-rays can penetrate the microchannel, pass through the scintillation crystal 3 and the reflector 4, and be received by the high-speed camera; 4) Conduct microchannel flow boiling tests under different test conditions. After the wall temperature reaches an approximate steady state, use the synchrotron radiation X-ray imaging system to photograph the flow boiling phenomenon in the microchannel. At the same time, use the temperature and pressure sensors in the microchannel flow boiling test system to collect the wall temperature and inlet and outlet pressures to obtain the in-situ measurement results of the wall temperature and inlet and outlet pressures.

[0006] Furthermore, the microchannel flow boiling test system 17 includes a constant temperature water bath 9, a filter 10, a gear pump 11, a flow meter 12, a preheating section 13, a microchannel radiator test section 14, and a condenser 16.

[0007] Furthermore, the microchannel radiator test section 14 includes a microchannel radiator 15, a heating module, and a temperature and pressure sensor.

[0008] Furthermore, the synchrotron radiation X-ray imaging system includes, in sequence along the optical path, a synchrotron radiation source 1, a chopper 2, a scintillation crystal 3, a reflector 4, and a high-speed camera 5.

[0009] Furthermore, the microchannel heat sink sample is located between the chopper 2 and the scintillation crystal 3, and the X-rays pass through the chopper 2 and penetrate laterally from the microchannel heat sink sample to the scintillation crystal 3.

[0010] Furthermore, the microchannel width of the channel heat sink 15 allows synchrotron X-rays to penetrate, and the microchannel height is smaller than the viewing window range of synchrotron X-ray imaging.

[0011] Furthermore, the synchrotron radiation X-ray imaging system also includes a host 6, which is placed outside the test room to receive the output signal of the high-speed camera 5 and send a trigger signal to the signal generator 701. The first signal generator 701 is used to receive the trigger signal from the host 6 and send a synchronization signal to the high-speed camera 5 and the second signal generator 702. The second signal generator 702 is used to receive the synchronization signal from the first signal generator 701 and send a control signal to the chopper 2.

[0012] Furthermore, the specific steps for using a synchrotron radiation X-ray imaging system to image the flow boiling phenomenon within a microchannel are as follows: When the synchrotron radiation X-ray imaging system is working, after the host 6 sends a trigger signal, the trigger signal is received by the first signal generator 701 to generate two synchronization signals. One of them is sent to the second signal generator 702, and the other is sent to the high-speed camera 5 for shooting. After receiving the synchronization signal, the second signal generator 702 sends two control signals with a certain delay to control the mechanical slow shutter and mechanical fast shutter of the chopper 2. The X-rays emitted by the synchrotron radiation source 1 pass through the chopper 2 and then through the microchannel heat sink 15 in the microchannel heat sink test section 14. The phase change at the gas-liquid two-phase boundary in the microchannel heat sink 15 forms a phase contrast image. The phase contrast image is converted into a visible light image after passing through the scintillation crystal 3 along the optical path. Finally, it is received by the high-speed camera 5 through the reflector 4. The host 6 collects the camera output signal emitted by the high-speed camera 5 in real time.

[0013] Furthermore, the specific steps for determining the operating conditions during the microchannel flow boiling test under different test conditions are as follows: The heat flux density is controlled by the heating module, the inlet subcooling is controlled by the constant temperature water bath 9 and the preheating section 13, the initial cooling medium temperature is adjusted by the constant temperature water bath 9, and the inlet medium temperature of the microchannel radiator test section 14 is controlled by the preheating section 13.

[0014] Further testing is conducted to ensure the airtightness and stability of the test system. The specific steps are as follows: The heating module in the microchannel radiator test section 14 is driven by the gear pump 11 to circulate the cooling medium in the constant temperature water bath 9 within the microchannel flow boiling test system for a certain period of time, thereby eliminating all gas in the pipeline and monitoring the operating status of each component, pipeline and sensor of the test system to ensure stable system operation, normal heating and no gas leakage.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention, for the first time, combines synchrotron X-ray imaging technology with microchannel flow boiling, enabling in-situ measurements of microchannel flow boiling under different operating conditions. This reveals the in-situ heat transfer mechanism of microchannel flow boiling and optimizes its theoretical model, thereby guiding the design and development of high-efficiency microchannel heat sinks. Compared with existing technologies, this invention solves the data distortion problem caused by material property differences between non-metallic and metallic heat sinks. Furthermore, this invention overcomes the perspective limitations of visible light observation methods, enabling in-situ observation of microchannel flow boiling from a side-view rather than a top-view perspective, allowing for the analysis of the influence of parameters such as gravity and surface tension on bubble dynamics. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the microchannel flow boiling in-situ measurement system based on synchrotron X-ray radiation of the present invention. Figure 2 A schematic diagram of a microchannel heat sink; Figure 3 A schematic diagram illustrating the penetration of synchrotron X-rays through a microchannel heat sink. Figure 4 A schematic diagram of in-situ measurement results of bubble flow during microchannel boiling; In the figure, synchrotron radiation source 1, chopper 2, scintillation crystal 3, reflector 4, high-speed camera 5, main unit 6, first signal transmitter 701, second signal transmitter 702, constant temperature water bath 9, filter 10, gear pump 11, flow meter 12, preheating section 13, microchannel radiator test section 14, microchannel radiator 15, condenser 16, microchannel flow boiling test system 17, stainless steel cover plate 18, aluminum cover plate 19, PTFE clamp 20, PTFE base 21, microchannel 22, microchannel radiator substrate 23. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0018] This invention discloses a method and system for in-situ measurement of microchannel flow boiling based on synchrotron X-rays. The method comprises: 1) constructing a microchannel flow boiling test system and conducting tests to ensure the system's airtightness and stability; 2) constructing a synchrotron X-ray imaging system: placing a synchrotron X-ray source, a chopper, a scintillation crystal, a reflector, and a high-speed camera sequentially along the optical path; the microchannel heat sink sample is located between the chopper and the scintillation crystal; 3) conducting preliminary tests to ensure that synchrotron X-rays can penetrate the microchannel, pass through the scintillation crystal and the reflector, and be received by the high-speed camera; 4) conducting microchannel flow boiling tests under different experimental conditions, monitoring the wall temperature until it reaches a near-steady state, and then using the synchrotron X-ray imaging system to image the flow boiling phenomenon within the microchannel. This invention is the first to combine synchrotron X-ray imaging technology with microchannel flow boiling, enabling in-situ measurement of microchannel flow boiling under different operating conditions. This reveals the in-situ heat transfer mechanism of microchannel flow boiling and optimizes the theoretical model of microchannel flow boiling, thereby guiding the design and development of high-efficiency microchannel heat sinks.

[0019] The steps include: 1) Build a microchannel flow boiling test system and conduct tests to ensure the airtightness and stability of the test system; 2) Construct a synchrotron radiation X-ray imaging system: Place the synchrotron radiation X-ray source, chopper, scintillation crystal, reflector, and high-speed camera sequentially along the optical path; the microchannel heat sink sample is located between the chopper and the scintillation crystal; 3) Conduct preliminary tests to ensure that synchrotron X-rays can penetrate the microchannel, pass through the scintillation crystal and the reflector, and be received by the high-speed camera; 4) Conduct microchannel flow boiling tests under different experimental conditions. After the wall temperature reaches a near steady state, use the synchrotron radiation X-ray imaging system to photograph the flow boiling phenomenon in the microchannel. Simultaneously, use the temperature and pressure sensors in the microchannel flow boiling test system to collect data on the wall temperature and inlet / outlet pressure.

[0020] The microchannel heat sink sample is located between the chopper and the scintillation crystal. After passing through the chopper, the X-rays penetrate laterally from the microchannel heat sink sample to the scintillation crystal.

[0021] The test conditions are controlled by the microchannel flow boiling test system, and the test condition parameters include inlet flow rate, inlet subcooling and heat flux density.

[0022] The overall system includes a microchannel flow boiling test system and a synchrotron radiation X-ray imaging system.

[0023] The microchannel flow boiling test system includes a constant temperature water bath, a filter, a gear pump, a flow meter, a preheating section, a condenser, temperature sensors, pressure sensors, and a microchannel flow boiling test section. The constant temperature water bath is used for heating, cooling, heat preservation, and storing the cooling medium. The filter is used to remove impurities from the cooling medium. The gear pump is used to drive the cooling medium to circulate within the microchannel flow boiling test system piping. The flow meter is used to measure the flow rate of the cooling medium within the microchannel flow boiling test system piping. The preheating section heats the cooling medium to the inlet temperature required for the test conditions. The condenser is used to condense the cooling medium flowing out of the microchannel flow boiling test section. Temperature and pressure sensors are used to collect temperature and pressure data at various points within the microchannel flow boiling test system, including but not limited to inlet and outlet temperatures and pressures, and the wall temperature of the microchannel radiator. The microchannel flow boiling test section includes a microchannel radiator, fixtures, a heating module, a temperature acquisition module, and a pressure acquisition module. The microchannel heat sink comprises a single, flat microchannel. The width of the microchannel must allow synchrotron X-rays to pass through, and the channel height must be smaller than the viewing window of synchrotron X-ray imaging. The shape of the microchannel is not limited to a flat microchannel, and the surface finish of the microchannel can be modified as needed. The microchannel heat sink is made of pure aluminum, but other metals can be used as substitutes, provided they possess good thermal conductivity, machinability, and are permeable by synchrotron X-rays.

[0024] The microchannel flow boiling test section includes a microchannel radiator, fixture, heating module, temperature acquisition module, and pressure acquisition module.

[0025] The microchannel heat sink contains only a single flat microchannel. The width of the microchannel must be sufficient for synchrotron X-rays to pass through, and the height of the channel must be smaller than the viewing window of synchrotron X-ray imaging.

[0026] The shape of microchannels is not limited to straight microchannels, and their surface treatment can be changed as needed.

[0027] The microchannel heat sink is made of pure aluminum. Other metal materials can be used as substitutes, but they must have good thermal conductivity, machinability, and be able to be penetrated by synchrotron X-rays.

[0028] A synchrotron X-ray imaging system includes a synchrotron X-ray source, a chopper, a scintillation crystal, a mirror, a high-speed camera, a main unit, a first signal generator, and a second signal generator. The synchrotron X-ray source is white light from a synchrotron X-ray source. The chopper includes a mechanical slow shutter and a mechanical fast shutter, enabling periodic truncation of X-rays, ensuring the stability and safety of the optical system while acquiring clear dynamic images. The scintillation crystal is used to convert X-ray phase-contrast imaging into visible light imaging. The main unit is used to send trigger signals and receive camera output signals. The first signal generator receives the trigger signal and generates two synchronization signals, one of which is sent to the second signal generator, and the other is transmitted to the high-speed camera for imaging. The second signal generator receives one synchronization signal from the first signal generator and sends two delayed control signals to control the mechanical slow shutter and mechanical fast shutter of the chopper.

[0029] Synchrotron radiation X-ray sources are white light sources for synchrotron radiation X-rays.

[0030] Light choppers include mechanical slow shutters and mechanical fast shutters.

[0031] When the operator sends a trigger signal to the main unit, the trigger signal is received by the first signal generator, generating two synchronization signals. One signal is sent to the second signal generator, and the other is transmitted to the high-speed camera for imaging. The second signal generator, upon receiving the synchronization signal, sends two control signals with a certain delay to control the mechanical slow shutter and mechanical fast shutter of the chopper. The X-rays emitted by the synchrotron radiation source pass through the chopper and then through the microchannel heat sink in the microchannel heat sink test section. Due to the phase change at the gas-liquid boundary within the microchannel heat sink, phase-contrast imaging is formed. This phase-contrast image is then converted into visible light imaging along the optical path through a scintillation crystal and finally received by the high-speed camera via a reflector. The main unit acquires the camera output signal from the high-speed camera in real time.

[0032] like Figure 1 As shown, a microchannel flow boiling test system 17 was constructed, including a constant temperature water bath 9, a filter 10, a gear pump 11, a flow meter 12, a preheating section 13, a microchannel radiator test section 14, a microchannel radiator 15, a condenser 16, and various temperature and pressure sensors. Insulation cotton was wrapped between the connecting pipes of each test component to reduce heat loss. The microchannel radiator test section 14 includes the microchannel radiator 15, a heating module, and temperature and pressure sensors.

[0033] (2) Turn on the heating modules in the microchannel flow boiling test system 17 and the microchannel radiator test section 14. The gear pump 11 drives the cooling medium in the constant temperature water bath 9 to circulate in the microchannel flow boiling test system for 30 minutes to remove all gas in the pipeline. At the same time, monitor the operating status of each component, pipeline and sensor to ensure that the system operates stably, heating is normal and there is no gas leakage.

[0034] (3) such as Figure 1 As shown, a synchrotron radiation X-ray imaging system is constructed. A synchrotron radiation source 1, a chopper 2, a scintillation crystal 3, a reflector 4, and a high-speed camera 5 are placed sequentially along the optical path. The main unit 6 is placed outside the laboratory to receive the output signal from the high-speed camera 5 and to send a trigger signal to the signal generator 701. The signal generator 701 receives the trigger signal from the main unit 6 and sends synchronization signals to the high-speed camera 5 and the signal generator 702. The synchronization signal 702 receives the synchronization signal from the signal generator 701 and sends a control signal to the chopper 2. The synchrotron radiation X-ray imaging system operates as follows: when the operator activates the main unit 6 to send a trigger signal, the trigger signal is received by the signal generator 701, generating two synchronization signals. One signal is sent to the signal generator 702, and the other is transmitted to the high-speed camera 5 for imaging. After receiving the synchronization signal, the signal generator 702 sends two control signals with a certain delay to control the mechanical slow shutter and mechanical fast shutter of the chopper 2. The X-rays emitted by the synchrotron radiation source pass through the chopper 2 and then through the microchannel heat sink 15 in the microchannel heat sink test section 14. Due to the phase change at the gas-liquid two-phase boundary in the microchannel heat sink 15, a phase contrast image is formed. The phase contrast image is converted into a visible light image after passing through the scintillation crystal 3 along the optical path. Finally, it is received by the high-speed camera 5 through the reflector 4. The host 6 collects the camera output signal emitted by the high-speed camera 5 in real time.

[0035] (4) Place the microchannel heat sink 15 in the microchannel heat sink test section 14 between the chopper 2 and the scintillation crystal 3 to conduct a preliminary test to ensure that synchrotron X-rays can penetrate the microchannel heat sink 15, pass through the scintillation crystal 3 and the reflector 4, and be received by the high-speed camera. Figure 2 As shown, the microchannel heat sink 15 consists of a stainless steel cover plate 18, an aluminum cover plate 19, a PTFE clamp 20, a PTFE base 21, and a microchannel heat sink base 23, with dimensions of 80mm × 26mm × 121mm. Each of the four corners of the stainless steel cover plate 18, aluminum cover plate 19, PTFE clamp 20, and PTFE base 21 has a 6mm diameter hole for passing through M6 bolts to press the components together. During assembly, each bolt requires a force of 2.5Nm to ensure a tight fit and prevent leakage. A boss 2mm high and 1.4mm wide is machined on the microchannel heat sink base 23, and a single straight microchannel 22 is milled onto the boss. The microchannel 22 has dimensions of 5mm × 400μm × 400μm. Figure 3 As shown, X-rays pass through the microchannel 22 laterally (y-direction), then through the scintillation crystal 3 and the reflector 4 before being received by the high-speed camera 5. Therefore, unlike existing technologies, the microchannel heat sink of this invention is made entirely of metal without a transparent non-metallic cover, solving the data distortion problem caused by the difference in material properties between non-metallic and metallic heat sinks. Furthermore, this invention overcomes the viewing angle limitations of visible light observation methods, enabling in-situ observation of microchannel flow boiling from a side-view rather than a top-view perspective.

[0036] (5) The experimental conditions for microchannel flow boiling in this case were: mass flux G = 1000 kg / (m²∙s), heat flux q = 100 W / cm², and inlet subcooling ΔTsub = 20 K. The mass flux G was adjusted by gear pump 11. The heat flux q was controlled by the heating module in the microchannel radiator test section 14. The inlet subcooling ΔTsub was controlled by constant temperature water bath 9 and preheating section 13. Constant temperature water bath 9 adjusted the initial cooling medium temperature, and preheating section 13 controlled the inlet medium temperature of microchannel radiator test section 14. After determining the experimental conditions, the microchannel flow boiling test system 17 was run, and the changes in physical quantities during the test were monitored by temperature and pressure sensors. When the temperature signal collected by the temperature sensor in the microchannel radiator test section 14 reached an approximate steady state, the test chamber isolation door was closed, and the synchrotron radiation source 1 was turned on. The X-rays emitted by the synchrotron radiation source 1 passed through the microchannel radiator 15 along the optical path and formed an image, which was received by the high-speed camera 5. Meanwhile, the temperature and pressure sensors in the microchannel flow boiling test system 17 collect data on the temperature and inlet / outlet pressure at various points. Figure 4 These are the in-situ measurement results of the microchannel radiator 15 under this operating condition. At this time, the flow within the microchannel radiator 15 is dominated by bubbles, with clear bubble boundaries, sizes, and morphologies, allowing for further analysis of bubble dynamics. The quantitative results can be used to optimize existing microchannel flow boiling models. Furthermore, for the first time, the influence of surface tension at the bottom of the microchannel 22 on the bubbles within the metal microchannel radiator 15 was observed from a side-view perspective, allowing for further analysis of the relationship between inertial forces, gravity, and surface tension within the microchannel 22 and the bubble dynamics.

[0037] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for in-situ measurement of microchannel flow boiling, characterized in that, The method includes the following steps: 1) Build a microchannel flow boiling test system (17) and conduct tests to ensure the sealing and stability of the test system; 2) Construct a synchrotron radiation X-ray imaging system; 3) Conduct preliminary tests to ensure that synchrotron X-rays can penetrate the microchannel, pass through the scintillation crystal (3) and the reflector (4), and be received by the high-speed camera; 4) Conduct microchannel flow boiling tests under different test conditions. After the wall temperature reaches an approximate steady state, use the synchrotron radiation X-ray imaging system to photograph the flow boiling phenomenon in the microchannel. At the same time, use the temperature and pressure sensors in the microchannel flow boiling test system to collect the wall temperature and inlet and outlet pressures to obtain the in-situ measurement results of the wall temperature and inlet and outlet pressures.

2. The in-situ measurement method for microchannel flow boiling according to claim 1, characterized in that, The microchannel flow boiling test system (17) includes a constant temperature water bath (9), a filter (10), a gear pump (11), a flow meter (12), a preheating section (13), a microchannel radiator test section (14), and a condenser (16).

3. The in-situ measurement method for microchannel flow boiling according to claim 2, characterized in that, The microchannel radiator test section (14) includes a microchannel radiator (15), a heating module, and a temperature and pressure sensor.

4. The in-situ measurement method for microchannel flow boiling according to claim 2, characterized in that, The synchrotron radiation X-ray imaging system includes, in sequence along the optical path, a synchrotron radiation source (1), a chopper (2), a scintillation crystal (3), a mirror (4), and a high-speed camera (5).

5. The in-situ measurement method for microchannel flow boiling according to claim 4, characterized in that, The microchannel heat sink sample is located between the chopper (2) and the scintillation crystal (3). After passing through the chopper (2), the X-rays penetrate laterally from the microchannel heat sink sample to the scintillation crystal (3).

6. The in-situ measurement method for microchannel flow boiling according to claim 5, characterized in that, The microchannel width of the microchannel heat sink (15) allows synchrotron X-rays to penetrate, and the microchannel height is smaller than the viewing window range of synchrotron X-ray imaging.

7. The in-situ measurement method for microchannel flow boiling according to claim 6, characterized in that, The synchrotron radiation X-ray imaging system also includes a host (6), which is placed outside the test room to receive the output signal of the high-speed camera (5) and send a trigger signal to the signal generator (701). The first signal generator (701) is used to receive the trigger signal from the host (6) and send a synchronization signal to the high-speed camera (5) and the second signal generator (702). The second signal generator (702) is used to receive the synchronization signal from the first signal generator (701) and send a control signal to the chopper (2).

8. The in-situ measurement method for microchannel flow boiling according to claim 7, characterized in that, The specific steps for using a synchrotron radiation X-ray imaging system to photograph the flow boiling phenomenon within a microchannel are as follows: When the synchrotron radiation X-ray imaging system is working, after the host (6) sends a trigger signal, the trigger signal is received by the first signal generator (701) to generate two synchronization signals. One of them is sent to the second signal generator (702), and the other is sent to the high-speed camera (5) for shooting. After receiving the synchronization signal, the second signal generator (702) sends two control signals with a certain delay to control the mechanical slow shutter and mechanical fast shutter of the chopper (2). The X-rays emitted by the synchrotron radiation source (1) pass through the chopper (2) and then through the microchannel radiator (15) of the microchannel radiator test section (14). The phase change at the gas-liquid two-phase boundary in the microchannel radiator (15) forms a phase contrast image. The phase contrast image is converted into a visible light image after passing through the scintillation crystal (3) along the optical path. Finally, it is received by the high-speed camera (5) through the reflector (4). The host (6) collects the camera output signal emitted by the high-speed camera (5) in real time.

9. The in-situ measurement method for microchannel flow boiling according to claim 8, characterized in that, The specific steps for determining the operating conditions during microchannel flow boiling tests under different test conditions are as follows: The heat flux density is controlled by the heating module, the inlet subcooling is controlled by the constant temperature water bath (9) and the preheating section (13), the initial cooling medium temperature is adjusted by the constant temperature water bath (9), and the inlet medium temperature of the microchannel radiator test section (14) is controlled by the preheating section (13).

10. The in-situ measurement method for microchannel flow boiling according to claim 9, characterized in that, The specific steps for conducting tests to ensure the airtightness and stability of the test system are as follows: In the microchannel radiator test section (14), the heating module, driven by the gear pump (11), circulates the cooling medium in the constant temperature water bath (9) within the microchannel flow boiling test system for a certain period of time, eliminating all gas in the pipeline, and simultaneously monitoring the operating status of each component, pipeline and sensor of the test system to ensure stable system operation, normal heating and no gas leakage.

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