Dry-burn prevention control method and semiconductor laser apparatus

Abstract

The application provides a dry burning prevention control method and a semiconductor laser device, and relates to the technical field of semiconductor laser devices. The method comprises the following steps: obtaining a corresponding relationship between a saturation pressure and a saturation temperature of a phase change medium in a phase change heat transfer chamber; determining a target dryness value and first and second alarm dryness values; calculating a corresponding first medium temperature according to the first alarm dryness value, and then determining a first pressure threshold according to the corresponding relationship; calculating a corresponding second medium temperature according to the second alarm dryness value, and then determining a second pressure threshold according to the corresponding relationship; obtaining an internal pressure value of the phase change heat transfer chamber in real time; when the internal pressure value reaches the first pressure threshold, controlling a cooling system to increase the cooling capacity; when the internal pressure value reaches the second pressure threshold, cutting off a heat source, wherein the second pressure threshold is greater than the first pressure threshold. By determining the graded pressure threshold based on the dryness and performing graded regulation and control, the overheat and burning of the chip caused by the dryness of the phase change medium are avoided, and the reliability of the device is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser equipment technology, and more specifically, to a method for preventing dry burning and a semiconductor laser equipment. Background Technology

[0002] In related technologies, heat sinks in semiconductor laser devices often employ phase change heat transfer, which involves filling a sealed chamber with a phase change medium and utilizing the heat absorption during evaporation of the liquid medium and the heat release during condensation of the vapor to achieve heat transfer. Under normal operating conditions, the evaporation and condensation processes within the chamber maintain a dynamic balance, resulting in stable chamber pressure.

[0003] However, when the chip's operating current suddenly increases due to factors such as power supply fluctuations, the chip's heat generation surges, accelerating the evaporation rate of the liquid medium. The liquid medium within the chamber may gradually dry out, and the dryness level continues to rise. Because the phase change heat transfer chamber of the phase change heat sink is a closed cavity, and it operates under high temperature and pressure, it is difficult to measure the dryness level within the chamber in real time by directly installing sensors. Related technologies lack effective monitoring methods for changes in chamber dryness, making it impossible to take timely intervention measures before dry burning occurs, resulting in serious safety hazards for the heat sink. Summary of the Invention The present invention aims to provide a method for preventing dry burning and a semiconductor laser device that can take timely intervention measures when the risk of dry burning occurs, so as to prevent the chip from burning out due to overheating.

[0004] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a method for preventing dry burning of a phase change heat sink, the phase change heat sink comprising a sealed phase change heat transfer chamber and a cooling system for cooling the phase change heat transfer chamber, comprising: Obtain the relationship between the saturation pressure and saturation temperature of the phase change medium inside the phase change heat transfer chamber; Determine the target dryness value under normal operating conditions, as well as the first alarm dryness value and the second alarm dryness value, wherein the first alarm dryness value is higher than the target dryness value, and the second alarm dryness value is higher than the first alarm dryness value; Based on the first alarm dryness value, the corresponding first medium temperature in the phase change heat transfer chamber is calculated, and then the pressure value corresponding to the first medium temperature is determined according to the correspondence, which is used as the first pressure threshold. Based on the second alarm dryness value, the corresponding second medium temperature in the phase change heat transfer chamber is calculated, and then the pressure value corresponding to the second medium temperature is determined according to the correspondence, which is used as the second pressure threshold. The internal pressure value of the phase change heat transfer chamber is obtained in real time; When the internal pressure value reaches the first pressure threshold, the cooling system is controlled to increase its cooling capacity. When the internal pressure value reaches the second pressure threshold, the heat source is cut off, wherein the second pressure threshold is greater than the first pressure threshold.

[0005] In an optional implementation, the heat source includes multiple chips disposed on the phase change heat sink, and the anti-dry-burning control method further includes: The efficiency, power, and maximum operating temperature of the chip under operating conditions are obtained. Based on the chip's efficiency and power during operation, the thermal power consumption of the chip and the thermal power consumption of the phase change heat sink wall are determined. The phase change heat sink heat exchange surface temperature is obtained based on the chip's thermal power consumption, the phase change heat sink wall surface heat dissipation power consumption, and the chip's extreme operating temperature. It is determined that the saturation temperature of the phase change medium inside the phase change heat transfer chamber is lower than the temperature of the heat exchange surface of the phase change heat sink.

[0006] In an optional embodiment, the inner wall surface of the phase change heat transfer chamber is provided with grooves for storing the phase change medium; The anti-dry-burning control method further includes determining the initial pressure when initially loading the phase change medium, wherein determining the initial pressure includes: Obtain the total volume of the phase change heat transfer chamber, the maximum volume of the phase change medium stored in the trench, and the target dryness value under normal operating conditions; Based on thermodynamic relationships, determine the initial loading pressure value corresponding to when the internal pressure value reaches the ideal working pressure under the target dryness value; After injecting the phase change medium into the phase change heat transfer chamber, the internal pressure value is adjusted to the initial loading pressure value.

[0007] In an optional implementation, the step of adjusting the internal pressure value to the initial loading pressure value includes: After the phase change medium is injected into the phase change heat transfer chamber, the phase change heat transfer chamber is evacuated or injected with air to adjust the internal pressure value to the initial loading pressure.

[0008] In an optional implementation, it further includes: Calculate the heat transfer coefficient of the cooling system when the internal pressure reaches the ideal working pressure under the target dryness value; The cooling medium flow rate of the cooling system is calculated based on the heat transfer coefficient.

[0009] In an optional implementation, controlling the cooling system to increase its cooling capacity includes at least one of: increasing the flow rate of the cooling medium in the cooling system, decreasing the temperature of the cooling medium in the cooling system, and increasing the flow rate of the cooling medium in the cooling system.

[0010] In an optional implementation, controlling the cooling system to increase its cooling capacity includes: When the internal pressure value reaches the first pressure threshold, the flow rate of the cooling medium is increased, and / or the flow velocity of the cooling medium in the cooling system is increased; When the internal pressure value reaches a preset third pressure threshold, the temperature of the cooling medium is reduced, and the third pressure threshold is between the first pressure threshold and the second pressure threshold.

[0011] In an optional implementation, the step of increasing the flow rate of the cooling medium includes: When the internal pressure value reaches the first pressure threshold, the flow rate of the cooling medium is increased to the first flow rate value; The steps for determining the first flow rate value include: Increase the power of the heat source in advance to raise the internal pressure value to the first pressure threshold; The cooling medium flow rate is adjusted based on the first pressure threshold, and the internal pressure value is monitored; The cooling medium flow rate is dynamically adjusted according to the internal pressure value until the internal pressure value stabilizes, and the first flow rate value is determined.

[0012] In an optional implementation, the target dryness value is 25% to 40%, the first alarm dryness value is 50%, and the second alarm dryness value is 100%.

[0013] In a second aspect, the present invention provides a semiconductor laser device, comprising: A phase change heat sink, wherein the phase change heat sink has a sealed phase change heat transfer chamber inside; A cooling system is provided for cooling the phase change heat transfer chamber. A pressure sensor is used to acquire the internal pressure value of the phase change heat transfer chamber in real time; A controller, electrically connected to the pressure sensor and the cooling system, is configured to perform the anti-dry-burning control method as described in any of the foregoing embodiments.

[0014] The beneficial effects of the anti-dry-burning control method for the phase change heat sink and the semiconductor laser device provided in this invention include: The anti-dry-burning control method and semiconductor laser device provided in this invention obtain the correspondence between the saturation pressure and saturation temperature of the phase change medium, and pre-determine graded pressure thresholds based on the target dryness value and alarm dryness value, so that the pressure thresholds are directly related to the actual dryness state in the chamber. During operation, by acquiring the internal pressure value of the phase change heat transfer chamber in real time and comparing the pressure value with the preset graded pressure thresholds, indirect monitoring of the dryness change in the chamber is achieved. When the internal pressure value reaches the first pressure threshold, the cooling system is controlled to increase the cooling capacity and enhance the condensation rate to suppress the pressure; when the internal pressure value further reaches the second pressure threshold, it indicates that the dryness is close to the dryness critical point, and the heat source is immediately cut off to stop heating. By utilizing the thermodynamic chain relationship that the increase in dryness leads to an increase in the vapor volume ratio, which forces the saturation temperature to rise, and the saturation pressure to rise accordingly in a closed phase change heat transfer chamber with constant volume, pressure is used as an indirect monitoring indicator of dryness, overcoming the technical difficulty that the dryness in a closed chamber cannot be directly measured. This method can detect the risk of dry burning in a timely manner without directly measuring the dryness, and actively intervene before dry burning occurs through graded control, avoiding phase change heat transfer failure and chip overheating and burnout caused by the complete evaporation of the liquid medium, thus improving the operational reliability and safety of semiconductor laser equipment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the phase change heat sink provided in this embodiment; Figure 2 This is a cross-sectional view of the phase change heat sink provided in this embodiment.

[0017] Icons: 100 - Heat sink body; 10 - Phase change heat transfer chamber; 11 - Groove; 12 - Vacuum injection port; 20 - Cooling chamber; 30 - Pressure sensor. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0023] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0024] The following describes in detail the overall structure, working principle, and technical effects of the phase change heat sink provided by the present invention, as well as the detailed steps, implementation principle, and technical effects of the supporting anti-dry burning control method, through embodiments and in conjunction with the accompanying drawings.

[0025] Example 1 Please refer to Figure 1 and Figure 2 The phase change heat sink provided by this invention is applied in semiconductor laser equipment to dissipate heat from the laser chip.

[0026] The phase change heat sink includes a heat sink body 100, within which a sealed phase change heat transfer chamber 10 is disposed. The inner wall of the phase change heat transfer chamber 10 is provided with grooves 11 for storing the phase change medium. The phase change heat transfer chamber 10 is filled with the phase change medium. In operation, the liquid phase change medium absorbs heat and evaporates into steam in the groove 11 region. The steam rises to the condensation region, releases heat, and condenses back into liquid. Under gravity, it flows back to the groove 11 region, forming a phase change cycle.

[0027] The heat sink body 100 has a vacuum injection port 12 communicating with the phase change heat transfer chamber 10, and a pressure gauge interface for mounting the pressure sensor 30. The vacuum injection port 12 is used to evacuate the phase change heat transfer chamber 10 and inject liquid phase change medium during the manufacturing process, and can also be used to adjust the amount or pressure of the medium in the chamber during use and maintenance. The pressure gauge interface is used to mount the pressure sensor 30 to monitor the pressure value inside the phase change heat transfer chamber 10 in real time.

[0028] The phase change heat sink also includes a cooling chamber 20, which is located on one side of the condensation area of ​​the phase change heat transfer chamber 10. The cooling chamber 20 is used to circulate cooling medium for heat exchange with the phase change heat transfer chamber 10. The cooling chamber 20 has an inlet and an outlet, which are connected to an external cooling medium circulation system. The cooling medium flows in through the inlet, absorbs heat, and then flows out through the outlet.

[0029] The semiconductor laser device includes the aforementioned phase-change heat sink, at least one laser chip, a pressure sensor 30, a cooling medium circulation system, and a controller (not shown). The laser chip is attached to the outer surface of the heat sink body 100, corresponding to the area where the groove 11 is located. The pressure sensor 30 is mounted on a pressure gauge interface for real-time acquisition of the internal pressure value of the phase-change heat transfer chamber 10. The cooling medium circulation system is connected to the inlet and outlet of the cooling chamber 20. The controller is electrically connected to the pressure sensor 30 and the cooling medium circulation system.

[0030] Example 2 This invention provides a method for preventing dry burning of the above-mentioned phase change heat sink. It utilizes the thermodynamic relationship between the pressure and dryness in the chamber, indirectly judges the change in dryness by real-time monitoring of the pressure value, and takes graded intervention measures.

[0031] Dryness refers to the ratio of the mass of vapor in the phase change medium to the total mass (the sum of the mass of liquid and the mass of vapor). The higher the dryness, the less liquid medium is in the chamber, and the greater the risk of dry burning.

[0032] This method is implemented according to the following steps: Obtain the correspondence between the saturation pressure and saturation temperature of the phase change medium within the phase change heat transfer chamber; determine the target dryness value under normal operating conditions, as well as the first alarm dryness value and the second alarm dryness value, wherein the first alarm dryness value is higher than the target dryness value, and the second alarm dryness value is higher than the first alarm dryness value; calculate the corresponding first medium temperature within the phase change heat transfer chamber based on the first alarm dryness value, and then determine the pressure value corresponding to the first medium temperature based on the correspondence, as the first pressure threshold; calculate the corresponding second medium temperature within the phase change heat transfer chamber based on the second alarm dryness value, and then determine the pressure value corresponding to the second medium temperature based on the correspondence, as the second pressure threshold.

[0033] In this embodiment, the following parameters need to be predetermined: the correspondence between the saturation pressure and saturation temperature of the phase change medium, the target dryness value under normal operating conditions, the first alarm dryness value, the second alarm dryness value, the first pressure threshold, and the second pressure threshold. These parameters are the basic benchmarks for the anti-dry-burning control method and need to be predetermined before real-time control begins.

[0034] Specifically, the relationship between the saturation pressure and saturation temperature of the selected phase change medium (such as water, R134a, etc.) in the phase change heat transfer chamber 10 is first obtained. This relationship can be obtained by consulting a property data sheet or by experimental measurement, and is usually represented as a curve in which the saturation pressure increases with the increase of the saturation temperature. Since the phase change medium is in a saturated state in the phase change heat transfer chamber 10, the chamber pressure corresponds one-to-one with the medium temperature. Therefore, this relationship can be used to infer the medium temperature from the pressure value, and thus determine the dryness state.

[0035] The target dryness value is the ideal dryness designed for the phase change heat sink under stable operating conditions. It represents the ideal proportion of vapor mass in the phase change medium to the total mass during normal operation. The target dryness value is usually selected based on engineering experience; in this embodiment, it is selected as 25% to 40%. Once the target dryness value is determined, the required liquid medium filling amount during normal operation can be calculated by combining the trench storage volume and the total chamber volume.

[0036] The first alarm dryness value being higher than the target dryness value indicates that the dryness has exceeded the normal range, requiring attention and adjustment measures. In this embodiment, the first alarm dryness value is set to 50%. The second alarm dryness value being higher than the first alarm dryness value indicates that the liquid working fluid is close to a dangerous state of complete evaporation, requiring immediate shutdown for protection. In this embodiment, the second alarm dryness value is set to 100%.

[0037] Under the closed conditions of a phase change heat transfer chamber with a constant volume (10), an increase in dryness inevitably leads to an increase in the volume ratio of steam, forcing a rise in saturation temperature. Since there is a one-to-one correspondence between saturation pressure and saturation temperature, the current dryness change trend within the chamber can be indirectly calculated by monitoring the internal pressure value in real time. This indirect measurement method overcomes the technical difficulty of directly measuring dryness within a closed chamber, providing a reliable basis for subsequent graded control.

[0038] Since there is a one-to-one correspondence between the pressure and temperature of the phase change medium in the saturated state (i.e., the correspondence between saturated pressure and saturated temperature), and the change in temperature in the chamber directly reflects the equilibrium state of evaporation and condensation, the pressure value can indirectly reflect the change in dryness in the chamber.

[0039] In this context, saturation refers to the thermodynamic state in a closed cavity where the gas and liquid phases coexist and reach dynamic equilibrium. Specifically, when the rate at which the liquid medium evaporates into vapor equals the rate at which vapor condenses into liquid, the gas and liquid phases coexist in the chamber, and macroscopically, no further net evaporation or condensation occurs; at this point, the phase change medium is in a saturated state. In the saturated state, there is a strict correspondence between the pressure in the phase change heat transfer chamber and the temperature of the phase change medium (i.e., a one-to-one correspondence between saturation pressure and saturation temperature). This relationship is determined by the physical properties of the medium itself and is independent of the total fill volume. For a given phase change medium, each saturation temperature corresponds to a unique saturation pressure.

[0040] Next, the target dryness value under normal operating conditions, as well as the first alarm dryness value and the second alarm dryness value, are determined. The target dryness value is the ideal dryness designed for the heat sink under stable operating conditions, and is usually selected based on engineering experience. In this embodiment, the target dryness value is selected as 25% to 40%, indicating that approximately 25% to 40% of the liquid working fluid is in a state of evaporation into vapor during normal operation. The first alarm dryness value is set at 50%, which is higher than the target dryness value, indicating that the dryness has exceeded the normal range and requires attention and adjustment measures. The second alarm dryness value is set at 100%, indicating that the liquid working fluid has completely evaporated, leaving only vapor in the chamber, and dry burning is about to occur, requiring immediate shutdown for protection.

[0041] Then, the first pressure threshold and the second pressure threshold are determined respectively. Based on the first alarm dryness value, the corresponding first medium temperature in the phase change heat transfer chamber is calculated, and the pressure value corresponding to the first medium temperature is determined according to the correspondence, which is used as the first pressure threshold; based on the second alarm dryness value, the corresponding second medium temperature in the phase change heat transfer chamber is calculated, and the pressure value corresponding to the second medium temperature is determined according to the correspondence, which is used as the second pressure threshold.

[0042] Specifically, when the dryness is 50%, the corresponding medium temperature inside the chamber is calculated based on thermodynamic relationships. Then, the saturation pressure corresponding to that temperature is obtained through the correspondence between saturation pressure and saturation temperature; this is the first pressure threshold. Similarly, the saturation pressure corresponding to 100% dryness is the second pressure threshold. The pressure thresholds determined by the above method are directly related to the actual dryness state inside the chamber, ensuring the accuracy and timeliness of the alarm. The first and second pressure thresholds mentioned above are both predetermined fixed values. During the real-time control phase of the anti-dry-burning control method, it is only necessary to compare the real-time monitored internal pressure value with these predetermined thresholds to determine the current dryness state.

[0043] The internal pressure value of the phase change heat transfer chamber 10 is obtained in real time.

[0044] In this embodiment, the pressure sensor 30 installed on the pressure gauge interface collects the pressure data inside the phase change heat transfer chamber 10 in real time and transmits the data to the controller.

[0045] When the heat generated by the chip increases and evaporation intensifies, the amount of vapor in the chamber increases, and the pressure rises; when condensation intensifies, the vapor condenses into liquid, and the pressure drops. By monitoring the pressure value in real time, changes in the state of the medium inside the phase change heat transfer chamber 10 can be detected in a timely manner without directly measuring the dryness, providing a reference for subsequent graded control.

[0046] When the internal pressure reaches the preset first pressure threshold, the cooling system is controlled to increase its cooling capacity.

[0047] The controller compares the real-time pressure value with a preset first pressure threshold. The first pressure threshold corresponds to a level where the dryness within the chamber has risen to a point requiring attention. When the internal pressure reaches the first pressure threshold, it indicates that the evaporation rate has exceeded the current condensation rate, the dryness is increasing, and the liquid working fluid is decreasing. If no intervention is taken at this point, the dryness may continue to rise, eventually leading to dry burning. Therefore, the controller controls the cooling system to increase its cooling capacity to enhance the condensation rate, causing more vapor to condense into liquid and flow back to the trench 11 area, thereby stabilizing the chamber pressure and preventing further increases in dryness.

[0048] Specifically, controlling the cooling system to increase its cooling capacity includes at least one of increasing the flow rate of the cooling medium, decreasing the temperature of the cooling medium, and increasing the flow velocity of the cooling medium. In this embodiment, the cooling system is a water-cooled system. When the internal pressure reaches a first pressure threshold, the flow rate of the cooling medium is increased, and / or the flow velocity of the cooling medium in the cooling system is increased; when the internal pressure reaches a preset third pressure threshold, the temperature of the cooling medium is decreased, and the third pressure threshold is between the first pressure threshold and the second pressure threshold.

[0049] Specifically, in this embodiment, the cooling system is a water-cooled system. When the internal pressure reaches a first pressure threshold, the controller controls the cooling medium circulation system to increase the cooling water flow rate to the first flow rate value. Increasing the cooling water flow rate can improve the convective heat transfer coefficient in the cooling chamber 20, accelerate the rate of heat transfer from the condensation area to the cooling water, and thus enhance the steam condensation effect.

[0050] Specifically, when the internal pressure reaches a first pressure threshold, the flow rate of the cooling medium is increased to a first flow rate value. The steps for determining the first flow rate value include: pre-increasing the heat source power to raise the internal pressure to the first pressure threshold; adjusting the cooling medium flow rate based on the first pressure threshold and monitoring the internal pressure; and dynamically adjusting the cooling medium flow rate according to the internal pressure until the internal pressure stabilizes, thus determining the first flow rate value.

[0051] Specifically, the internal pressure value is monitored by gradually increasing the cooling medium flow rate; if the internal pressure value continues to rise, the cooling medium flow rate is further increased; if the rate of decrease of the internal pressure value reaches a preset value, the cooling medium flow rate is reduced; the above steps of increasing or decreasing the cooling medium flow rate are repeated until a first flow rate value that stabilizes the internal pressure value is obtained.

[0052] The internal pressure value stabilization refers to the following condition: within a preset observation time range, such as 30 consecutive seconds, the fluctuation range of the internal pressure value does not exceed a preset fluctuation range (e.g., ±2%), indicating that the internal pressure value has stabilized. Under this stable state, the currently applied cooling medium flow rate is the first flow rate value.

[0053] Specifically, the method for determining the first flow rate value is as follows: During the pre-use debugging phase, the optimal flow rate was determined through experimental calibration. This involved increasing the operating current of the laser chip to increase the heat source power, gradually raising the internal pressure to the first pressure threshold. Then, the cooling water flow rate was gradually increased while continuously monitoring the pressure changes in the phase change heat transfer chamber 10. If the pressure continued to rise, it indicated that the current flow rate was insufficient to suppress evaporation, so the flow rate was further increased. If the pressure drop rate reached a preset value (i.e., the pressure drop rate was too fast), it indicated that the flow rate was too high, leading to excessive condensation, so the flow rate was appropriately reduced. Through repeated adjustments, the first flow rate value that stabilized the internal pressure was finally obtained. This experimental calibration method can determine the optimal control parameters for a specific heat sink product, which is more in line with actual operating conditions than purely theoretical calculations.

[0054] Alternatively, finite element simulation can be used to calculate the required cooling water flow rate to completely remove the current heat, based on the actual operating parameters of the chip. This flow rate is then used as the first flow rate value.

[0055] When the internal pressure reaches the third pressure threshold, the required cooling water flow rate to completely remove the current heat can be obtained through finite element simulation calculations, so as to further increase the cooling medium flow rate. At the same time, the specific temperature drop of the cooling medium can also be obtained through finite element simulation calculations, such as reducing the cooling water temperature from 25°C to 20°C or 15°C, so as to provide a stronger condensation driving force.

[0056] When the internal pressure reaches a preset second pressure threshold, the heat source is cut off. The second pressure threshold is greater than the first pressure threshold.

[0057] Based on the adjustment of the first pressure threshold, the controller continues to monitor pressure changes. If the chip's heat generation increases abnormally, the chamber pressure may continue to rise even with increased cooling capacity. When the internal pressure value further reaches the preset second pressure threshold, it indicates that the dryness is approaching the critical point of desiccation, the liquid working fluid is about to be exhausted, and the phase change heat transfer mechanism faces the risk of failure. At this time, the controller immediately cuts off the heat source, that is, cuts off the power supply to the laser chip, and stops heating. The second pressure threshold is greater than the first pressure threshold, representing a higher level of danger. After the heat source is cut off, the chip no longer generates heat, the evaporation process stops, the temperature in the phase change heat transfer chamber 10 gradually decreases, and the pressure drops. When the internal pressure value drops below the first pressure threshold, the controller restores the power supply to the heat source, and the equipment can be restarted. This graded protection mechanism can take intervention measures of corresponding strength under different risk levels, avoiding frequent shutdowns during slight fluctuations while ensuring timely protection of the chip in extreme cases.

[0058] Optionally, when the internal pressure value reaches a preset third pressure threshold, the cooling system is controlled to reduce the temperature of the cooling medium.

[0059] In this embodiment, a third pressure threshold is also provided, which is between the first and second pressure thresholds. For example, the third pressure threshold corresponds to the chamber pressure when the dryness is 75%. When the pressure reaches the third pressure threshold, it indicates that the flow regulation measures at the first pressure threshold are insufficient to completely suppress the pressure rise, and the dryness continues to increase. At this time, the controller not only maintains the increased cooling water flow rate but also controls the cooling medium circulation system to reduce the cooling water temperature, for example, from the reference temperature of 25°C to 20°C or 15°C. Reducing the cooling water temperature can further increase the condensation temperature difference and improve the condensation rate. Through the dual measures of increased flow rate and reduced temperature, the condensation effect is further enhanced, providing a greater control margin to suppress the rise in dryness. The introduction of the third pressure threshold makes the graded control more refined, further reducing the probability of being forced to shut down when the second pressure threshold is reached.

[0060] In this embodiment, the inner wall of the phase change heat transfer chamber is provided with grooves for storing the phase change medium. The method for determining and adjusting the initial loading pressure includes: obtaining the total volume of the phase change heat transfer chamber, the maximum volume of the phase change medium stored in the grooves, and the target dryness value under normal operating conditions; determining the initial loading pressure value corresponding to the internal pressure value reaching the ideal working pressure under the target dryness value according to thermodynamic relationships; and adjusting the internal pressure value to the initial loading pressure value after injecting the phase change medium into the phase change heat transfer chamber 10.

[0061] To ensure that the heat sink achieves the expected target dryness during operation and operates stably near the ideal operating pressure, the initial pressure of the phase change heat transfer chamber 10 when initially loaded with the phase change medium needs to be determined during the design phase. The method for determining this pressure is as follows: First, obtain the total volume of the phase change heat transfer chamber 10, the maximum volume of the phase change medium stored in the trench 11, and the target dryness value under normal operating conditions. The total volume and the maximum liquid storage volume in the trench 11 can be calculated using a three-dimensional model of the heat sink, while the target dryness value is determined based on engineering experience.

[0062] Then, based on thermodynamic relationships, the required initial loading pressure is determined when the internal pressure reaches the ideal working pressure at the target dryness value. Specifically, given the maximum liquid volume in trench 11, a corresponding proportion of the liquid working fluid will evaporate into vapor at the target dryness value. Based on the ideal gas law and the properties of the phase change medium, it can be determined what initial pressure needs to be set in the closed chamber when the initial loading is entirely liquid, so that the pressure is exactly equal to the ideal working pressure when the dryness reaches the target value during operation.

[0063] Finally, after injecting the phase change medium into the phase change heat transfer chamber 10, the phase change heat transfer chamber 10 is evacuated or air is injected through the vacuum injection port 12 to adjust the internal pressure to the initial loading pressure. By precisely controlling the initial loading pressure, it can be ensured that the dryness of the phase change heat sink accurately reaches the target value during operation, and the chamber pressure is stabilized near the ideal working pressure, providing an accurate benchmark for subsequent anti-dry-burning monitoring.

[0064] This embodiment also includes a step of calculating the reference cooling medium flow rate. Through finite element simulation, the heat transfer coefficient of the cooling system is calculated when the internal pressure reaches the ideal working pressure at the target dryness value; the reference cooling medium flow rate of the cooling system is then calculated based on the heat transfer coefficient. This step determines the basic cooling capacity required by the heat sink under normal operating conditions, providing a reference value for increasing the flow rate during subsequent graded control.

[0065] In this embodiment, the heat source includes multiple laser chips mounted on a phase-change heat sink. During the heat sink design phase, it is also necessary to ensure that the saturation temperature is lower than the heat exchange surface temperature to guarantee that the heat sink can effectively absorb the heat from the chips. The specific method is as follows: First, obtain the chip's efficiency (PCE), power (P), and maximum operating temperature (T-max) under operating conditions. These parameters can be obtained from the chip's datasheet or through experimental testing.

[0066] Then, based on the chip's efficiency PCE and power P, the chip's thermal power consumption heat1 is calculated. that is, the part of power converted into heat when the chip is in operation. Meanwhile, according to parameters such as the number of chips N and coupling efficiency η, the stray heat consumption heat2 of the phase-change heat sink on the wall surface of the phase-change heat sink is calculated, .

[0067] Then, according to the chip heat consumption heat1, the stray heat consumption heat2 on the wall surface of the phase-change heat sink and the maximum operating temperature T-max of the chip, a finite element simulation method is adopted, with the three-dimensional model, material parameters and boundary conditions of the heat sink input, to calculate and obtain the temperature distribution of the heat exchange surface of the phase-change heat sink (that is, the wall surface where the groove 11 is located) of the phase-change heat sink, and the maximum temperature is taken as the temperature T-sur of the heat exchange surface of the phase-change heat sink, where T-sur = f(heat, heat2, T-max, model parameters, boundary conditions).

[0068] Finally, by adjusting the cooling parameters of the cooling system (such as cooling water flow rate, temperature, etc.), it is determined that the saturation temperature T-phasechange of the phase-change medium in the phase-change heat transfer chamber 10 always satisfies: T-phasechange < T-sur. In this way, heat can be transferred from the high-temperature heat exchange surface to the low-temperature phase-change medium, driving the evaporation process.

[0069] In summary, the dry-burn prevention control method and the semiconductor laser device provided by the embodiments of the present invention utilize the thermodynamic correspondence between the pressure in the chamber and the dryness, take pressure as a monitoring index, and automatically take intervention measures such as increasing the flow rate of the cooling medium, reducing the temperature of the cooling medium or cutting off the heat source before dry burning occurs through real-time monitoring and hierarchical regulation. This method can stabilize the pressure in time when the dryness rises abnormally, inhibit the dryness from continuing to rise, actively cut off the heat source when the dryness approaches a dangerous level, effectively avoid phase-change heat transfer failure and chip overheating burnout caused by complete evaporation of the liquid medium, and improve the operation reliability and safety of the semiconductor laser device.

[0070] The above description is only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that can be easily conceived by a skilled person in the art within the technical scope disclosed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preventing dry burning of a phase change heat sink, the phase change heat sink comprising a sealed phase change heat transfer chamber and a cooling system for cooling the phase change heat transfer chamber, characterized in that, include: Obtain the relationship between the saturation pressure and saturation temperature of the phase change medium inside the phase change heat transfer chamber; Determine the target dryness value under normal operating conditions, as well as the first alarm dryness value and the second alarm dryness value, wherein the first alarm dryness value is higher than the target dryness value, and the second alarm dryness value is higher than the first alarm dryness value; Based on the first alarm dryness value, the corresponding first medium temperature in the phase change heat transfer chamber is calculated, and then the pressure value corresponding to the first medium temperature is determined according to the correspondence, which is used as the first pressure threshold. Based on the second alarm dryness value, the corresponding second medium temperature in the phase change heat transfer chamber is calculated, and then the pressure value corresponding to the second medium temperature is determined according to the correspondence, which is used as the second pressure threshold. The internal pressure value of the phase change heat transfer chamber is acquired in real time. When the internal pressure value reaches a preset first pressure threshold, the cooling system is controlled to increase its cooling capacity. When the internal pressure value reaches a preset second pressure threshold, the heat source is cut off, wherein the second pressure threshold is greater than the first pressure threshold.

2. The method for preventing dry burning according to claim 1, characterized in that, The heat source includes multiple chips disposed on the phase change heat sink, and the anti-dry burning control method further includes: The efficiency, power, and maximum operating temperature of the chip under operating conditions are obtained. Based on the chip's efficiency and power during operation, the thermal power consumption of the chip and the thermal power consumption of the phase change heat sink wall are determined. The phase change heat sink heat exchange surface temperature is obtained based on the chip's thermal power consumption, the phase change heat sink wall surface heat dissipation power consumption, and the chip's extreme operating temperature. It is determined that the saturation temperature of the phase change medium inside the phase change heat transfer chamber is less than the temperature of the heat exchange surface of the phase change heat sink.

3. The method for preventing dry burning according to claim 1, characterized in that, The inner wall of the phase change heat transfer chamber is provided with grooves, which are used to store the phase change medium. The anti-dry-burning control method further includes determining the initial pressure when initially loading the phase change medium, wherein determining the initial pressure includes: Obtain the total volume of the phase change heat transfer chamber, the maximum volume of the phase change medium stored in the trench, and the target dryness value under normal operating conditions; Based on thermodynamic relationships, determine the initial loading pressure value corresponding to when the internal pressure value reaches the ideal working pressure under the target dryness value; After injecting the phase change medium into the phase change heat transfer chamber, the internal pressure value is adjusted to the initial loading pressure value.

4. The method for preventing dry burning according to claim 3, characterized in that, The step of adjusting the internal pressure value to the initial loading pressure value includes: After the phase change medium is injected into the phase change heat transfer chamber, the phase change heat transfer chamber is evacuated or injected with air to adjust the internal pressure value to the initial loading pressure.

5. The method for preventing dry burning according to claim 1, characterized in that, Also includes: Calculate the heat transfer coefficient of the cooling system when the internal pressure reaches the ideal working pressure under the target dryness value; The cooling medium flow rate of the cooling system is calculated based on the heat transfer coefficient.

6. The method for preventing dry burning according to claim 1, characterized in that, Controlling the cooling system to increase its cooling capacity includes at least one of: increasing the flow rate of the cooling medium in the cooling system, decreasing the temperature of the cooling medium in the cooling system, and increasing the flow rate of the cooling medium in the cooling system.

7. The method for preventing dry burning according to claim 6, characterized in that, Controlling the cooling system to increase its cooling capacity includes: When the internal pressure value reaches the first pressure threshold, the flow rate of the cooling medium is increased, and / or the flow velocity of the cooling medium in the cooling system is increased; When the internal pressure value reaches a preset third pressure threshold, the temperature of the cooling medium is reduced, and the third pressure threshold is between the first pressure threshold and the second pressure threshold.

8. The method for preventing dry burning according to claim 6, characterized in that, The step of increasing the flow rate of the cooling medium includes: When the internal pressure value reaches the first pressure threshold, the flow rate of the cooling medium is increased to the first flow rate value; The steps for determining the first flow rate value include: Increase the power of the heat source in advance to raise the internal pressure value to the first pressure threshold; The cooling medium flow rate is adjusted based on the first pressure threshold, and the internal pressure value is monitored; The cooling medium flow rate is dynamically adjusted according to the internal pressure value until the internal pressure value stabilizes, and the first flow rate value is determined.

9. The method for preventing dry burning according to claim 1, characterized in that, The target dryness value is 25% to 40%, the first alarm dryness value is 50%, and the second alarm dryness value is 100%.

10. A semiconductor laser device, characterized in that, include: A phase change heat sink, wherein the phase change heat sink has a sealed phase change heat transfer chamber inside; A cooling system is provided for cooling the phase change heat transfer chamber. A pressure sensor is used to acquire the internal pressure value of the phase change heat transfer chamber in real time; A controller, electrically connected to the pressure sensor and the cooling system, is configured to perform the anti-dry-burning control method as described in any one of claims 1 to 9.

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