A high-power fiber laser heat cooling device and method

Abstract

The application discloses a high-power optical fiber laser heat cooling device and method, the device comprises ice slurry preparation and circulation subsystem, integrated spiral stirring heat exchange terminal, adiabatic packaging subsystem and intelligent sensing control subsystem. Through ice slurry machine, storage tank, delivery pump and backflow pump to form a circulation loop; the integrated spiral stirring heat exchange terminal comprises an ice chamber and an internal stirring device with spiral blades, the inner wall of the ice chamber is provided with fins or channels for enhanced heat dissipation; the adiabatic packaging subsystem is composed of a shell, a thermal insulation layer and a sealed cavity filled with dry gas; the intelligent control subsystem monitors the state of the ice chamber and the optical fiber laser through sensors and controls the operation of each component. The method comprises the steps of preparing and storing ice slurry, delivering to the ice chamber, stirring and enhancing heat exchange, backflow regeneration, real-time monitoring and intelligent regulation and control. The application has the advantages of strong heat dissipation capacity, good temperature uniformity, strong environmental adaptability and efficient and reliable operation, and is particularly suitable for the thermal management of high-power optical fiber lasers.

Description

Technical Field

[0001] This invention belongs to the field of high-power laser thermal management technology and is mainly applied to heat dissipation scenarios of kilowatt-level and above ultra-high-power fiber lasers. It involves phase change cooling and intelligent control technology, specifically a high-power fiber laser thermal cooling device and method, which aims to achieve efficient, uniform and reliable thermal management by utilizing the latent heat of ice slurry phase change, enhancing heat transfer and intelligent regulation. Background Technology

[0002] As industrial manufacturing continues to develop towards higher precision and efficiency, kilowatt-level and even megawatt-level ultra-high-power fiber lasers have been widely used in heavy-duty processing fields such as thick plate cutting and deep-penetration welding. During operation, these lasers generate highly concentrated heat flow in their core optical path components and pump source. If the large amount of waste heat generated cannot be dissipated in a timely, uniform, and efficient manner, it will directly lead to an exacerbation of the thermal lensing effect of the laser crystal and fiber, output wavelength drift, beam quality degradation, and a significant shortening of the lifespan of key components.

[0003] Currently, heat dissipation solutions for high-power lasers mainly include air cooling and liquid cooling. Traditional air cooling technology is limited by the low specific heat capacity and thermal conductivity of air, and its heat dissipation capacity is insufficient to meet the cooling requirements of continuous lasers above kilowatt level. Although conventional liquid cooling technology has improved heat exchange capacity, it mainly relies on the sensible heat change of the fluid for heat dissipation, resulting in a large cooling temperature difference, which easily leads to the formation of hot spots in local areas. Moreover, to achieve low temperatures, high-power refrigerator units are often required, resulting in high system energy consumption. In recent years, ice slurry cooling technology based on the latent heat of phase change has attracted attention due to its extremely high cold storage density and near-isothermal heat transfer characteristics, and is considered a highly promising solution.

[0004] However, existing ice slurry cooling technology still has several prominent drawbacks when adapted to the specific application of fiber lasers: the overall system integration is low and the size is large; inside the cold plate, which serves as the heat exchange terminal, the ice slurry is prone to uneven distribution or even blockage due to poor flow design, resulting in its excellent heat exchange potential not being fully utilized; the anti-condensation treatment of the low-temperature cold plate usually relies on a single insulation layer, which is not reliable enough in high-temperature and high-humidity environments; in addition, there is a lack of real-time monitoring and precise control of the ice-water ratio in the ice slurry, and the system cannot achieve adaptive and efficient operation according to dynamic heat load.

[0005] In summary, developing a highly integrated cooling system with strong heat exchange capabilities, reliable anti-condensation properties, and intelligent control over the state of ice slurry to address the severe heat dissipation challenges faced by ultra-high power fiber lasers has become an urgent and important technical issue in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a thermal cooling device and method for high-power fiber lasers, which solves the technical problems of insufficient heat exchange capacity of existing air cooling technology, high energy consumption and easy local overheating of traditional liquid cooling schemes, and low integration, uneven flow and heat exchange inside the heat exchange terminal, unreliable anti-condensation measures, and lack of real-time and precise control of the state of ice slurry when existing ice slurry cooling technology is applied to ultra-high-power fiber lasers.

[0007] The first objective of this invention is to provide a thermal cooling device for a high-power fiber laser, comprising an ice slurry preparation and circulation subsystem, an integrated spiral stirring heat exchange terminal, an insulating packaging subsystem, and an intelligent sensing and control subsystem.

[0008] The ice slurry preparation and circulation subsystem includes an ice slurry machine, an ice slurry storage tank, ice slurry conveying equipment, and a circulating water return system. The outlet of the ice slurry machine is connected to the inlet of the ice slurry storage tank. The ice slurry storage tank is connected to an integrated spiral stirring heat exchange terminal through the ice slurry conveying equipment. The fluid outlet of the integrated spiral stirring heat exchange terminal is connected back to the ice slurry machine through the circulating water return system.

[0009] The integrated spiral stirring heat exchange terminal includes an ice chamber and a stirring device; the outer wall of the ice chamber serves as a mounting base for mounting the LD pump source and fiber winding disk in the fiber laser, and its inner wall is provided with heat dissipation fins or channels; the stirring device is located inside the ice chamber, and its blade edges maintain a gap with the heat dissipation fins or channels on the inner wall.

[0010] The thermal insulation encapsulation subsystem includes an outer shell, an insulation layer, and a sealed cavity arranged from the outside to the inside; the sealed cavity is filled with dry gas.

[0011] The intelligent sensing and control subsystem includes a conductivity sensor, a temperature sensor, and a controller. The conductivity sensor is installed in the ice chamber, the temperature sensor is installed in the fiber laser, and the controller is connected to the conductivity sensor, the temperature sensor, the ice slurry machine, the ice slurry conveying equipment, the circulating water return equipment, and the stirring device in a communicable manner.

[0012] Furthermore, a fluid processing unit is also installed on the return path between the circulating water return equipment and the ice slurry machine; the fluid processing unit includes, in sequence along the fluid flow direction, a magnetic filter, an eddy current separator, and a concentration monitoring and replenishment module;

[0013] Magnetic filters are used to adsorb and remove metal shavings from the return fluid;

[0014] Eddy separators are used to separate unmelted ice crystals from the return fluid and send them directly back to the inlet of the ice slurry tank or ice chamber.

[0015] The concentration monitoring and replenishment module is used to monitor the ethylene glycol concentration of the reflux fluid in real time and automatically replenish high-concentration ethylene glycol solution or deionized water based on the monitoring results.

[0016] Furthermore, the heat dissipation fins installed on the inner wall of the ice chamber are made of shape memory alloy or thermodeformable material; the heat dissipation fins can undergo reversible deformation in response to temperature changes in the inner wall of the ice chamber in the area to which they are attached;

[0017] When the temperature of the local inner wall rises, the heat dissipation fins in that area can automatically change their curvature or expand to increase the surface area and disturb the flow of ice slurry; when the temperature drops, the heat dissipation fins return to their initial shape.

[0018] Furthermore, a layer of microencapsulated phase change material coating is provided on the inner wall of the ice chamber and / or the surface of the heat dissipation fins;

[0019] This microencapsulated phase change material has a specific phase change temperature range, which allows it to melt and absorb heat when the local temperature exceeds its phase change temperature, and to solidify and release heat when the temperature decreases.

[0020] This coating is used to buffer instantaneous thermal load shocks and promote temperature uniformity.

[0021] Furthermore, the thermal insulation encapsulation subsystem also includes a temperature and humidity sensor, a pressure sensor, and a miniature dehumidification module;

[0022] Temperature and humidity sensors and pressure sensors are installed inside the sealed cavity to monitor the dew point temperature, relative humidity and gas pressure inside the cavity in real time.

[0023] The air inlet of the miniature dehumidification module is connected to the external environment, and its air outlet is connected to the gas purging port through a pipeline.

[0024] The controller is electrically connected to the temperature and humidity sensor, the pressure sensor, the miniature dehumidification module, and the control valve installed in the gas purge port pipeline.

[0025] The second objective of this invention is to provide a thermal cooling method using the aforementioned high-power fiber laser thermal cooling device, comprising the following steps:

[0026] S1 Ice Slurry Preparation and Storage: Binary ice slurry is prepared using an ice slurry machine and stored in ice slurry storage tanks;

[0027] S2 Ice Slurry Transport: Ice slurry in the ice slurry storage tank is transported to the ice chamber via ice slurry transport equipment;

[0028] S3 Stirring and Heat Exchange: Drive the stirring device to rotate, forcing the ice slurry in the ice chamber to flow. The ice slurry absorbs the heat generated by the fiber laser installed on the outer wall of the ice chamber through the inner wall of the ice chamber and the heat dissipation fins or channels.

[0029] S4 Recirculation and Regeneration: The partially melted fluid that has absorbed heat in the ice chamber is extracted through the circulating water recirculation device and sent back to the ice slurry machine for recooling;

[0030] S5 Real-time Monitoring: Real-time monitoring of the conductivity of the ice slurry in the ice chamber and the temperature of the fiber laser using conductivity and temperature sensors;

[0031] S6 Intelligent Control: The controller receives signals from sensors, calculates the ice-water ratio in the ice chamber in real time based on the conductivity signal, and adjusts the ice-making power of the ice slurry machine and / or the conveying flow rate of the ice slurry conveying equipment according to the calculation results. At the same time, it adjusts the speed of the stirring device and / or performs over-temperature protection control according to the temperature signal.

[0032] The present invention has the following beneficial effects:

[0033] (1) The integrated heat exchange terminal of the present invention uses the outer wall of the high thermal conductivity ice chamber as the mounting base for the heating device, and combines the inner wall reinforcement structure and the spiral stirring device. This not only improves the compactness and adaptability of the device layout, but also solves the problems of uneven flow and local overheating in traditional ice slurry cooling through forced stirring and boundary layer scraping, thereby improving heat dissipation efficiency and temperature uniformity.

[0034] (2) The thermal insulation encapsulation subsystem of the present invention adopts a composite structure consisting of a shell, a high-performance thermal insulation layer and a sealed cavity. By filling the sealed cavity with dry gas and maintaining a slightly positive pressure environment, combined with a humidity and pressure monitoring and regulation mechanism, it can isolate the intrusion of environmental moisture and ensure the long-term safe and reliable operation of the laser under harsh conditions such as high temperature and high humidity.

[0035] (3) This invention realizes intelligent and precise control of the cooling process and optimization of system energy efficiency. The intelligent sensing and control subsystem calculates the ice-water ratio in real time based on the conductivity sensor and adjusts the ice-making power and delivery flow accordingly. At the same time, the combination of temperature monitoring and stepless speed regulation stirring enables the system to respond quickly to dynamic heat load changes. With the cooperation of low-shear ice slurry delivery and fluid regeneration treatment, the system reduces the overall energy consumption of the system while ensuring the stability of laser output. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the overall structure of the high-power fiber laser thermal cooling device according to an embodiment of the present invention.

[0038] Figure 2 This is a cross-sectional view of the ice chamber inside the high-power fiber laser thermal cooling device according to an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the thermal insulation packaging subsystem of the high-power fiber laser thermal cooling device according to an embodiment of the present invention.

[0040] Figure 4 This is a flowchart of a high-power fiber laser thermal cooling method according to an embodiment of the present invention.

[0041] Explanation of reference numerals in the attached drawings: 1-Ice slurry storage tank; 2-Filter device; 3-Circulating water recirculation equipment; 4-Ice chamber; 5-Fiber optic coil; 6-LD pump source; 7-Stirring rod; 8-Ice chamber inlet; 9-Ice chamber outlet; 10-Liquid outlet pipe; 11-Outer shell; 12-Insulation layer; 13-Sealed cavity; 14-Liquid inlet pipe; 15-Integrated spiral stirring heat exchange terminal; 16-Gas purging port; 17-Fin. Detailed Implementation

[0042] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0043] To fully understand this invention, detailed steps and structures will be presented in the following description to illustrate the technical solution of this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0044] Example 1

[0045] like Figures 1 to 3 In one embodiment of the high-power fiber laser thermal cooling device of the present invention, the high-power fiber laser thermal cooling device comprises four functional subsystems: an ice slurry preparation and circulation subsystem, an integrated spiral stirring heat exchange terminal 15, an insulation packaging subsystem, and an intelligent sensing and control subsystem.

[0046] The ice slurry preparation and circulation subsystem includes an ice slurry machine, an ice slurry storage tank 1, ice slurry conveying equipment, and a circulating water return system 3. The components are connected in sequence through pipelines to form a complete fluid loop, which is the basis for energy transport and conversion of this device.

[0047] The ice slurry machine employs a scraped surface heat exchanger (SSHE). This machine uses a specific concentration of ethylene glycol aqueous solution as the refrigerant. Its ice-making unit rapidly generates ice crystals on the tube wall surface, which are then immediately scraped off by a rotating scraper, producing a binary ice slurry with fine ice crystal particle size and excellent flowability. The scraped surface heat exchanger can produce ice slurry with a high ice content. The latent heat of phase change of ice crystals is much higher than the sensible heat of water, giving the ice slurry a large cold storage density per unit volume. This provides a guarantee for handling the transient and steady-state heat loads of lasers at kilowatt levels or even higher power. The uniform ice crystal particle size ensures the stability and pumpability of the slurry.

[0048] The high-concentration ice slurry produced by the ice slurry machine is first temporarily stored in ice slurry storage tank 1. Ice slurry storage tank 1 acts as a buffer container, suppressing fluctuations in the ice-making process, eliminating the impact of intermittent operation of the ice slurry machine on the cooling terminal, and ensuring a continuous and stable supply of cooling energy to the laser. Its sufficient volume also provides buffer time for the system to cope with sudden large heat loads. The output end of ice slurry storage tank 1 is connected to ice slurry conveying equipment, preferably a screw pump. The outlet of ice slurry storage tank 1 is connected to the inlet of the screw pump via a pipeline. Due to its volumetric conveying principle, the screw pump exerts low shear force on the ice slurry, effectively preventing ice crystals from agglomerating or breaking during transport due to compression, thus maintaining the stability and high heat exchange potential of the ice slurry, ensuring that the high-ice-content ice slurry can be transported to the integrated spiral stirring heat exchange terminal 15 without damage. The screw pump pumps the ice slurry in ice slurry storage tank 1 to the integrated spiral stirring heat exchange terminal 15 at a set flow rate and pressure via the inlet pipe 14.

[0049] After the integrated spiral stirring heat exchanger terminal 15 completes the heat absorption process, some of the ice crystals in the ice slurry melt, forming a cool, glycol-rich aqueous solution. This solution flows out from the outlet of the integrated spiral stirring heat exchanger terminal 15 and enters the return pipeline through the outlet pipe 10. A circulating water return device 3, specifically a centrifugal water pump, is installed along the return path. This pump draws back the melted fluid and transports it back to the inlet of the ice slurry machine, thus completing the circulation of the working fluid. Centrifugal water pumps are adept at transporting single-phase fluids and are highly efficient and low-cost. The ethylene glycol aqueous solution, after heat absorption and melting, has become a homogeneous single-phase liquid, which the centrifugal pump can efficiently draw back.

[0050] In one specific embodiment, a filter device 2 is also installed on the return path of the circulating water return device 3. This filter device 2 is used to remove minute impurities or abrasive particles that may be carried by the fluid during circulation, protecting critical equipment such as the ice slurry machine and pumps / valvees, and ensuring the long-term stable operation of the entire circulation subsystem. During long-term circulation, trace impurities may be generated in the pipeline, or extremely fine particles may be generated by ice crystal scraping. The filter device 2 can effectively intercept these impurities, preventing them from entering the ice slurry machine's scraper gaps or clogging the micro-flow channels, protecting core equipment, and improving the long-term reliability and maintenance cycle of the system.

[0051] In one specific embodiment, a fluid processing unit is integrated into the return pipeline between the circulating water return device 3 and the ice slurry machine. The fluid processing unit includes a magnetic filter, an eddy current separator, and a concentration monitoring and replenishment module in sequence along the fluid flow direction, which performs multi-stage fine processing on the fluid that flows out after heat absorption and is formed by partially melted ice slurry.

[0052] First, the return fluid enters the magnetic filter, which contains a permanent magnet or electromagnetic array. Metal particles in the fluid are efficiently adsorbed and captured under the action of a strong magnetic field, which can effectively purify the refrigerant and prevent grinding debris from entering the precision scraping gap of the ice slurry machine or causing wear and blockage of pipelines and sensors.

[0053] Subsequently, the pre-purified fluid enters the vortex separator, flowing tangentially into the separation chamber at high speed, creating a strong vortex. Under centrifugal force, denser, incompletely melted solid ice crystals are thrown against the outer wall of the chamber and slide down the surface, eventually being collected through the ice crystal outlet at the bottom and directly pumped back to the ice slurry storage tank 1 or the inlet of ice chamber 4. Meanwhile, the less dense liquid ethylene glycol solution concentrates at the center of the vortex and is discharged from the overflow port at the top, achieving direct recovery and reuse of solid ice crystals. This avoids ineffective melting of ice crystals in the return pipeline and pump, reduces system cooling loss, and improves overall energy efficiency.

[0054] Finally, the liquid ethylene glycol solution after solid-liquid separation flows through the concentration monitoring and replenishment module. This module, equipped with a built-in densitometer or refractometer, continuously monitors the mass concentration of ethylene glycol in the solution in real time. The controller compares this monitored value with the system's preset optimal operating concentration range. If the concentration is too high due to water evaporation or accidental leakage, a fixed amount of deionized water is automatically injected for dilution; if the concentration is too low, high-concentration ethylene glycol stock solution is automatically replenished, ensuring the stability of the refrigerant solution's freezing point and maintaining the ice slurry machine's efficient and stable ice production, as well as the long-term constant heat exchange performance of the entire system. The fluid handling unit regenerates and maintains the returned refrigerant, maximizing the recovery of cooling capacity, reducing ethylene glycol solution consumption, and minimizing system performance degradation, ensuring efficient and reliable operation of the cooling device throughout its entire lifecycle.

[0055] The integrated spiral stirring heat exchange terminal 15 is responsible for heat exchange with the high heat flux density components of the fiber laser. Its main body is an ice chamber 4. The ice chamber 4 is a cubic or near-cubic cavity structure made of a high thermal conductivity material, preferably copper, aluminum, or their alloy. The outer wall of the ice chamber 4 is precision milled and polished to form a flat, smooth mounting surface, which directly serves as the mounting base for the key heat-generating components of the laser. Specifically, the laser's LD pump source 6 is tightly attached to one side of the outer wall of the ice chamber 4 via a thermally conductive interface material, while the laser's fiber winding disk 5 is attached to the opposite outer wall, achieving the shortest heat conduction path between the heat source and the cold source and reducing contact thermal resistance. The inner wall of the ice chamber 4 is not a smooth surface; it is equipped with heat dissipation fins 17 or microchannels. The fins 17 or channels increase the contact heat exchange area between the inner wall of the ice chamber 4 and the internal flowing ice slurry, improving heat exchange efficiency.

[0056] In one specific embodiment, the heat dissipation fins 17 are precision-manufactured using shape memory alloys or thermodeformable materials, replacing traditional fixed metal fins. Each fin is fixedly connected to the inner wall of the ice chamber 4 through its base, and its initial shape maintains a state with low resistance to the flow of ice slurry at the system's base operating temperature. When heat generated by heat sources such as the laser's LD pump source 6 and the fiber winding disk 5 is conducted to the inner wall of the ice chamber 4, causing an abnormal increase in temperature in a local area, the inherent properties of the material cause it to automatically deform after reaching a specific transition temperature. This can be an increase in the bending angle or the partial unfolding of the wing-like structure, increasing the local heat transfer surface area of ​​the hot spot and improving the heat transfer capacity; it also changes the flow channel shape, enhancing the turbulence and disturbance when the ice slurry flows through this area, further disrupting the thermal boundary layer. When the temperature of local hot spots decreases due to enhanced heat exchange and the material temperature falls below the transition point, the fins automatically return to their original low flow resistance shape under the action of material hyperelasticity or internal stress. This achieves real-time, autonomous, and precise control of heat exchange capacity according to heat load distribution, effectively suppressing the formation of hot spots and promoting a highly uniform overall temperature field in ice chamber 4, thereby improving the uniformity, efficiency, and reliability of cooling.

[0057] In one specific embodiment, a microencapsulated phase change material (PCM) functional coating is added to the inner wall of the ice chamber 4, the heat dissipation fins 17, or the surface of the microchannels. This functional coating is composed of micron-sized capsules encapsulating solid-liquid phase change material and a highly thermally conductive binder, uniformly coated or embedded on the heat exchange surface. Its phase change temperature is slightly higher than the core operating temperature range of the ice slurry working fluid. This functional coating constitutes a distributed, passive thermal energy buffer layer. When the laser is in pulsed operation or during a power surge, and a localized high-temperature hotspot is generated on the inner wall of the ice chamber 4, the PCM coating in that area absorbs a large amount of heat and undergoes a solid-liquid phase change. The latent heat absorbed in this process buffers the peak heat flow transferred to the ice slurry, suppressing the rapid rise in wall temperature. During laser power reduction or pulse intervals, the temperature in this area decreases, the PCM coating releases the stored heat and re-solidifies, and the released heat is carried away by the continuously flowing ice slurry. This reversible phase change process smooths out fluctuations in heat load in both time and space.

[0058] An agitation device 7 is installed inside the ice chamber 4. The agitation device 7 mainly consists of an agitator rod and helical blades fixed thereon. The helical blades can be continuous along their entire length or segmented. The outer contour of the helical blades matches the contour of the heat dissipation fins 17 or channels on the inner wall of the ice chamber 4, maintaining a precise, minute gap between them. One end of the agitator rod extends out of the ice chamber 4 and is connected to a drive motor via a coupling. The drive motor is preferably a continuously variable speed servo motor, which can achieve continuous, smooth, and high-resolution speed regulation within the range of zero to rated speed.

[0059] During operation, the drive motor rotates the stirring device 7, and the spiral blades generate a strong axial pumping force, forcing the ice slurry in the ice chamber 4 to flow directionally and uniformly from the inlet to the outlet, avoiding stagnation or dead zones caused by viscosity. Simultaneously, the outer edge of the high-speed rotating blades scrapes against the fins 17 on the inner wall, continuously thinning and renewing the fluid boundary layer adhering to the surface of the fins 17. The boundary layer is the main source of resistance to heat exchange; this scraping action effectively breaks down the thermal boundary layer, enhancing the convective heat transfer coefficient between the ice slurry and the inner wall of the ice chamber 4. Furthermore, by adjusting the speed of the drive motor, the flow rate and turbulence intensity of the ice slurry can be flexibly controlled, thereby achieving dynamic adjustment of the heat exchange capacity.

[0060] It is important to emphasize that the rotating helical blades of this invention generate a powerful pumping force, driving the ice slurry to move strongly axially from the inlet to the outlet of the ice chamber 4. This solves the problems of ice slurry settling and uneven distribution under natural convection or low flow rates, ensuring uniform distribution of cooling capacity throughout the ice chamber. The outer edge of the rotating blades sweeps across the stationary fins 17 or channel surface at high speed, acting like a dynamic scraper, continuously and physically removing the viscous fluid boundary layer with the highest thermal resistance adhering to the fins or channel surface, and rapidly mixing it with the main fluid, thereby increasing the local convective heat transfer coefficient near the wall. The rotation of the helical blades also causes strong radial and circumferential disturbances in the ice slurry, promoting the mixing of ice crystals with liquid and cold fluid with hot fluid, avoiding temperature stratification, and maximizing the utilization of the latent heat of phase change of the ice slurry. Through the stirring device 7, thorough mixing and heat exchange are achieved within the ice chamber 4, resulting in an overall heat transfer coefficient higher than that of traditional heat exchangers.

[0061] To prevent the intrusion of ambient heat and condensation on the outer wall of the low-temperature ice chamber 4 in humid environments, this invention employs a multi-layered thermal insulation encapsulation subsystem. The thermal insulation encapsulation subsystem comprises three layers from the outside in. The outermost layer is a rigid shell 11, typically made of stainless steel, providing mechanical protection and support for the entire terminal. The middle layer is an insulation layer 12, which fills the space between the rigid shell 11 and the inner layers. It utilizes high-performance insulation materials, preferably rigid polyurethane foam or aerogel felt. Rigid polyurethane foam and aerogel felt have extremely low thermal conductivity, blocking the conduction of ambient heat to the internal low-temperature ice chamber, allowing the ice chamber temperature to be controlled within the range of -2 degrees Celsius to -35 degrees Celsius, minimizing system cooling loss and improving the overall energy efficiency ratio.

[0062] The innermost layer is a sealed cavity 13, tightly enclosing the integrated spiral stirring heat exchange terminal 15. The sealed cavity 13 is filled with dry gas, preferably dry nitrogen, and a positive pressure slightly higher than the ambient pressure is maintained within the cavity through a gas purging port 16 equipped with a valve. This ensures the absolute dryness of the air within the cavity, keeping its dew point temperature far below the operating temperature of the outer wall of the ice chamber 4, eliminating the risk of condensation and ensuring the safety of the laser's electronic components. A dry, positive pressure environment is crucial for preventing condensation. First, the dry gas itself contains no moisture; second, the positive pressure prevents humid ambient air from seeping into the cavity through any possible tiny gaps. Even if the temperature of the outer wall of the ice chamber 4 is far below the dew point of the ambient air, no water vapor can condense inside the cavity, avoiding the risks of electrical short circuits, component corrosion, and optical contamination caused by condensation, and ensuring the safe operation of the laser system in high-temperature and high-humidity environments.

[0063] In one specific embodiment, to further improve the reliability and environmental adaptability of the thermal insulation encapsulation subsystem, a temperature and humidity sensor and a pressure sensor are added inside the sealed cavity 13 to continuously monitor the internal temperature, relative humidity, and actual air pressure. Simultaneously, a miniature dehumidification module is installed externally, with its outlet connected to the existing gas purge port 16 via a pipeline, forming a gas renewal path. Control and management are handled by a controller. The controller presets two key thresholds: a safety margin for the cavity dew point temperature calculated based on temperature and humidity, and a minimum maintained positive pressure value. During system operation, the controller calculates the cavity dew point temperature in real time based on sensor data and continuously compares it with the air pressure value against the preset thresholds. If the calculated dew point temperature rises due to minor permeation or material moisture release, approaching or exceeding the safety margin, or if the air pressure falls below the minimum maintained value due to slow natural leakage from the seal, it is determined that there is a risk of condensation or a decrease in protective effectiveness. Upon assessing the risk, the controller immediately initiates regulation, activating the control valves of the micro dehumidification module and the gas purge port 16. The micro dehumidification module draws in air from the environment for deep dehumidification, generating dry gas with an extremely low dew point. This gas is continuously injected into the sealed cavity 13. On one hand, it directly dilutes and replaces the gas with higher humidity in the cavity, causing the dew point temperature to quickly drop back to a safe range. On the other hand, the continuous injection of gas restores and stabilizes the gas pressure in the cavity within the set micro-positive pressure range, re-establishing a reliable positive pressure barrier. This avoids the risk of condensation that may be caused by long-term operation, aging of seals, or drastic environmental changes, ensuring the safe operation of the laser under complex conditions.

[0064] The intelligent sensing and control subsystem comprises a sensing section and a control section. The sensing section includes multiple conductivity sensors and temperature sensors. The conductivity sensors are embedded or surface-mounted at key monitoring points of the ice chamber 4, preferably in its inlet, middle, and outlet areas, to collect the conductivity of the ice slurry flowing through the ice chamber 4 in real time and in situ. Temperature sensors are installed at multiple locations on the fiber laser to collect temperature signals. This multi-point arrangement provides comprehensive, three-dimensional monitoring of the heat exchange process.

[0065] The core of the control section is a controller, which is connected to the conductivity sensor, temperature sensor, ice slurry machine, screw pump, circulating water return equipment 3 and stirring device 7 via signal cables in a communicative connection manner.

[0066] The controller's control logic is based on an important physical characteristic: in a fixed-concentration ethylene glycol aqueous solution, the conductivity of ice is much lower than that of water. Therefore, there is a clear correlation between the volume ratio of ice to water in the ice slurry and its overall conductivity. The controller receives signals from the conductivity sensor in real time and calculates the average ice-to-water ratio in ice chamber 4 using a built-in algorithm model. When the calculated ice-to-water ratio is lower than the set optimal value, it indicates that the ice slurry's cooling capacity is decreasing. The controller then issues commands to increase the cooling power of the ice slurry machine to increase ice production and / or reduce the screw pump flow rate to extend the residence time of the ice slurry in the ice chamber and ensure sufficient heat exchange; conversely, it performs the opposite adjustment.

[0067] Meanwhile, the controller receives signals from the temperature sensor. When the laser temperature approaches or exceeds the safety threshold, the controller immediately increases the rotation speed of the stirring device 7 to enhance heat exchange and rapidly reduce the temperature; it also increases the flow rate of the screw pump to accelerate the delivery of cooling energy. If the temperature continues to rise and exceeds the alarm threshold, the controller will implement over-temperature protection control, triggering an audible and visual alarm, reducing the laser power, or initiating emergency cooling.

[0068] The workflow of this device begins with system startup and initialization: the controller first performs a self-test, then starts the circulating water return device 3 to fill the pipeline with liquid, and starts the ice slurry machine to prepare a binary ice slurry with a high ice content and store it in the ice slurry storage tank 1. At the same time, dry nitrogen is introduced into the sealed cavity 13 to establish and maintain a positive pressure anti-condensation environment. After entering steady-state cooling operation, the heat generated during laser operation is rapidly introduced through the high thermal conductivity outer wall of the ice chamber 4 in direct contact. The screw pump pumps the ice slurry in the ice slurry storage tank 1 into the bottom of the ice chamber 4. At the same time, the continuously variable speed servo motor drives the stirring device 7 to rotate at high speed, forcing the ice slurry to form a strong axial flow and radial mixing on the surface of the heat dissipation fins 17. The blade edges continuously scrape the boundary layer, thereby achieving highly efficient convective heat transfer. The low-temperature solution that has absorbed heat and melted is then pumped back to the ice slurry machine for regeneration by the circulating water return device 3. In this process, the intelligent sensing and control subsystem plays a core regulatory role: embedded conductivity and temperature sensors monitor the state of the ice chamber 4 and the fiber laser in real time; the controller calculates the ice-to-water ratio based on the conductivity signal, and dynamically adjusts the cooling power of the ice slurry machine and the delivery flow rate of the screw pump accordingly to maintain the optimal phase change working fluid state; simultaneously, based on multi-point temperature feedback, the controller adjusts the rotation speed and ice slurry flow rate of the stirring device 7 in real time to dynamically match the changing heat load of the laser, and performs over-temperature protection when the temperature exceeds the threshold. Ultimately, the entire system achieves rapid, uniform, and adaptive heat dissipation of concentrated heat flow from kilowatt-level and above high-power fiber lasers through the deep synergy of four technologies: high-density cold storage and release of the latent heat of phase change in ice slurry, active heat transfer enhancement through spiral stirring, positive pressure drying and thermal insulation encapsulation, and closed-loop intelligent control based on ice-to-water ratio calculation. At the same time, it ensures safe operation without condensation and optimal system energy efficiency in high-humidity environments.

[0069] Example 2

[0070] This embodiment describes in detail a thermal cooling method, such as... Figure 4 The above-mentioned high-power fiber laser thermal cooling device includes the following steps:

[0071] S1 Ice Slurry Preparation and Storage

[0072] The system's scraped surface heat exchanger is activated, using an aqueous ethylene glycol solution as the refrigerant. The refrigeration unit inside the ice slurry machine cools the heat exchange surface to sub-zero temperatures. A continuously rotating scraper instantly scrapes away ice crystals generated on the wall surface and mixes them with the remaining solution, thus preparing a binary ice slurry with uniform ice crystal particle size. The prepared high-concentration ice slurry is pumped to an ice slurry storage tank for temporary storage. The storage tank, acting as a cold energy buffer and energy storage unit, can smooth out fluctuations in the ice slurry preparation process and provide an immediately available high-density cold source to cope with sudden increases in the laser's heat load, ensuring the continuity and stability of the cold energy supply.

[0073] S2 Ice Slurry Delivery

[0074] When the laser starts operating or the system controller receives a cooling demand signal, the screw pump located on the outlet side of the ice slurry tank is activated. Leveraging its unique low-shear, volumetric delivery characteristics, the screw pump smoothly and continuously pumps the ice slurry from the tank, delivering it via insulated piping to the bottom inlet of the integrated spiral stirring heat exchanger terminal 15. This delivery method maximizes the preservation of the integrity and initial particle size distribution of the ice crystals in the ice slurry, preventing ice crystal breakage, agglomeration, or premature melting due to pumping shear, thus ensuring that the working fluid delivered to the integrated spiral stirring heat exchanger terminal 15 possesses optimal initial heat transfer potential.

[0075] S3 Stirring and Heat Exchange

[0076] After the ice slurry enters the ice chamber, a continuously variable servo motor mounted on the top of the ice chamber starts synchronously, driving the stirring device inside the ice chamber to rotate at high speed. The helical blades on the stirring device generate a powerful axial pumping force, forcing the ice slurry to flow strongly in a predetermined direction within the ice chamber. Simultaneously, the outer edge of the blades rotates with a small gap between itself and the precisely machined heat dissipation fins or channels on the inner wall of the ice chamber, generating a continuous boundary layer scraping effect that disrupts the viscous fluid layer adhering to the fin surface. During this flow and intense turbulence, the ice slurry absorbs the concentrated heat flow generated by the LD pump source and fiber winding disk installed close to the outer wall of the ice chamber through the surface area of ​​the fins or channels. The ice crystals in the ice slurry undergo a phase change and melt during the heat absorption process, utilizing their latent heat of phase change to absorb a large amount of heat, achieving a near-isothermal, high-intensity cooling effect and ensuring the temperature uniformity and stability of the laser's core components.

[0077] S4 Recirculation and Regeneration

[0078] After absorbing heat, some of the ice crystals melt into a low-temperature ethylene glycol aqueous solution, which, mixed with the remaining ice crystals, flows out from the top outlet of the ice chamber. This gas-liquid two-phase mixture is guided by the liquid outlet pipe to the circulating water recirculation device. The circulating water recirculation device extracts the fluid, which, before flowing back to the ice slurry machine, passes through a filter to remove any trace impurities that may be present in the system. The purified low-temperature ethylene glycol aqueous solution is finally transported back to the inlet of the ice slurry machine and re-enters the refrigeration cycle. In the ice slurry machine, the solution is cooled again to a supercooled state and scraped to generate new ice crystals, thereby achieving the regeneration and recycling of the refrigerant, forming a complete closed cooling loop.

[0079] S5 Real-time Monitoring

[0080] Throughout the operation, the intelligent sensing and control subsystem operates continuously. Conductivity sensors installed in the ice chamber's inlet and outlet areas measure the conductivity of the flowing ice slurry in real time. Simultaneously, multiple high-precision temperature sensors installed on the fiber laser collect temperature data at key points in real time. The conductivity and temperature sensors convert physical signals into electrical signals and transmit them to the system controller in real time, providing precise data input for control.

[0081] S6 Intelligent Control

[0082] The controller receives signals from conductivity and temperature sensors in real time and executes control measures. First, based on the conductivity difference between ice and water, it calculates the ice-to-water ratio in the ice chamber in real time. When this ratio falls below a preset optimal range, the controller simultaneously increases the cooling power of the ice slurry machine and reduces the flow rate of the ice slurry delivery equipment to increase the system's cooling capacity reserve and reduce heat load input, restoring the ice-to-water ratio to the set value. Simultaneously, the controller continuously monitors the temperature of key points on the fiber laser: when the temperature approaches the first-level warning threshold, it immediately increases the speed of the stirring device and the ice slurry delivery flow rate to enhance heat exchange and actively suppress overheating; if the temperature continues to rise and reaches the second-level safety threshold, while performing the aforementioned enhanced cooling, it sends a shutdown command to the laser and triggers an alarm, achieving graded over-temperature protection.

[0083] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, nor is it limited to a high-power fiber laser thermal cooling device and method. Devices and structures not described in detail herein should be understood as being implemented in a manner common to the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention are still within the scope of protection of the present invention.

Claims

1. A thermal cooling device for a high-power fiber laser, characterized in that, It includes an ice slurry preparation and circulation subsystem, an integrated spiral stirring heat exchange terminal, an insulation encapsulation subsystem, and an intelligent sensing and control subsystem; The ice slurry preparation and circulation subsystem includes an ice slurry machine, an ice slurry storage tank, ice slurry conveying equipment, and a circulating water return system. The outlet of the ice slurry machine is connected to the inlet of the ice slurry storage tank. The ice slurry storage tank is connected to an integrated spiral stirring heat exchange terminal through the ice slurry conveying equipment. The fluid outlet of the integrated spiral stirring heat exchange terminal is connected back to the ice slurry machine through the circulating water return system. The integrated spiral stirring heat exchange terminal includes an ice chamber and a stirring device; the outer wall of the ice chamber serves as a mounting base for mounting the LD pump source and fiber winding disk in the fiber laser, and the inner wall of the ice chamber is provided with heat dissipation fins or channels; the stirring device is located inside the ice chamber, and its blade edges maintain a gap with the heat dissipation fins or channels on the inner wall. The heat dissipation fins installed on the inner wall of the ice chamber are made of shape memory alloy or thermodeformable material; the heat dissipation fins can undergo reversible deformation in response to temperature changes in the inner wall of the ice chamber in the area to which they are attached; When the temperature of the local inner wall rises, the heat dissipation fins in that area can automatically change their curvature or expand to increase the surface area and disturb the flow of ice slurry; when the temperature drops, the heat dissipation fins return to their initial shape. The thermal insulation encapsulation subsystem includes an outer shell, an insulation layer, and a sealed cavity arranged from the outside in; the sealed cavity is filled with dry gas. The intelligent sensing and control subsystem includes a conductivity sensor, a temperature sensor, and a controller. The conductivity sensor is installed in the ice chamber, the temperature sensor is installed in the fiber laser, and the controller is connected to the conductivity sensor, the temperature sensor, the ice slurry machine, the ice slurry conveying equipment, the circulating water return equipment, and the stirring device in a communicable manner.

2. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: The ice slurry preparation and circulation subsystem also includes a filtration device, which is located on the return path of the circulating water return equipment.

3. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: The ice chamber is made of a material with high thermal conductivity; the stirring device consists of a drive motor, a stirring rod, and spiral blades.

4. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: The outer shell is made of stainless steel; the insulation layer is made of polyurethane foam or aerogel felt; the sealed cavity is equipped with a gas purging port.

5. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: The ice slurry machine uses a scraped surface heat exchanger to prepare binary ice slurry with ethylene glycol aqueous solution as the refrigerant; the ice slurry conveying equipment is a screw pump, located on the outlet side of the ice slurry storage tank; the circulating water return equipment is a centrifugal water pump.

6. The high-power fiber laser thermal cooling device according to claim 3, characterized in that: The high thermal conductivity material is copper, aluminum, or their alloys.

7. The high-power fiber laser thermal cooling device according to claim 3, characterized in that: The drive motor is a continuously variable speed motor.

8. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: Conductivity and temperature sensors are embedded in the inlet and outlet areas of the ice chamber.

9. The high-power fiber laser thermal cooling device according to claim 1, characterized in that: The controller calculates the ice-to-water ratio in the ice chamber in real time based on the signal collected by the conductivity sensor, and adjusts the ice-making power of the ice slurry machine and / or the conveying flow rate of the ice slurry conveying equipment according to the ratio.

10. A thermal cooling method, using the thermal cooling device for a high-power fiber laser as described in any one of claims 1-9, characterized in that, Includes the following steps: S1 Ice Slurry Preparation and Storage: Binary ice slurry is prepared using an ice slurry machine and stored in ice slurry storage tanks; S2 Ice Slurry Transport: Ice slurry in the ice slurry storage tank is transported to the ice chamber via ice slurry transport equipment; S3 Stirring and Heat Exchange: Drive the stirring device to rotate, forcing the ice slurry in the ice chamber to flow. The ice slurry absorbs the heat generated by the fiber laser installed on the outer wall of the ice chamber through the inner wall of the ice chamber and the heat dissipation fins or channels. S4 Recirculation and Regeneration: The partially melted fluid that has absorbed heat in the ice chamber is extracted through the circulating water recirculation device and sent back to the ice slurry machine for recooling; S5 Real-time Monitoring: Real-time monitoring of the conductivity of the ice slurry in the ice chamber and the temperature of the fiber laser using conductivity and temperature sensors; S6 Intelligent Control: The controller receives signals from sensors, calculates the ice-water ratio in the ice chamber in real time based on the conductivity signal, and adjusts the ice-making power of the ice slurry machine and / or the conveying flow rate of the ice slurry conveying equipment according to the calculation results. At the same time, it adjusts the speed of the stirring device and / or performs over-temperature protection control according to the temperature signal.

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