A laser thermal management system and its management method combining phase change cold storage and temperature-controlled water tank.

Abstract

This invention relates to the field of laser thermal management technology. It provides a laser thermal management system and method combining phase change cold storage and a temperature-controlled water tank, enabling the implementation of laser heat pipes with low power consumption and small size. This invention uses a variable frequency pump to regulate flow and thus control the temperature of the temperature-controlled water tank, eliminating the need for a valve compared to valve regulation methods. Furthermore, the variable frequency pump's power is adjustable, saving power. A phase change cold storage device is used instead of traditional liquid sensible heat storage, reducing the cold storage volume.

Description

Technical Field

[0001] This invention relates to the field of laser thermal management technology, specifically to a laser thermal management system and management method that combines phase change cold storage with a temperature-controlled water tank. Background Technology

[0002] In recent years, with the increasing demand for high-power lasers in applications such as manufacturing and space exploration, achieving high-power, high-performance output from all-solid-state, fiber, and semiconductor lasers has become a key research focus for scientists. Lasers have low electro-optical conversion efficiency, with 50%–60% of electrical energy being converted into heat. Poor heat dissipation can cause the chip temperature to rise, directly affecting a range of performance characteristics of semiconductor lasers, including threshold current density, output power, and differential quantum efficiency. This can lead to a decrease in laser lifespan and reliability, and even damage to the chip. Therefore, heat dissipation has become a critical factor restricting further improvements in laser power and beam quality.

[0003] Lasers have high heat flux density and high-precision temperature control requirements. To ensure high-efficiency output, the inlet coolant temperature requirement is usually 25±1℃. Existing thermal management systems are relatively large in size and weight. Summary of the Invention

[0004] In view of this, the present invention provides a laser thermal management system and management method that combines phase change cold storage with a temperature-controlled water tank, which can realize laser thermal management with low power consumption and small size.

[0005] To achieve the above objectives, this invention provides a laser thermal management system combining phase change cold storage and a temperature-controlled water tank, comprising a laser, a water tank, an electric heating wire, a first water pump, a variable frequency pump, a phase change cold storage device, a second water pump, a three-way valve, an evaporator, an expansion valve, a compressor, a condenser, a radiator, and a fan; wherein, the electric heating wire is used to preheat the antifreeze in the laser and the temperature-controlled water tank; the temperature-controlled water tank is connected to the first water pump, and the laser is located between the first water pump and the temperature-controlled water tank; the variable frequency pump is connected to the temperature-controlled water tank and controls the water flow rate and water pressure by changing the frequency; the phase change cold storage device is connected to the variable frequency pump; the evaporator is connected to the phase change cold storage device; the second water pump is connected to the evaporator; the expansion valve is connected between the evaporator and the condenser; the three-way valve is connected to the cold storage device, the radiator, and the evaporator; the compressor is connected to the evaporator and the condenser; a fan is located next to the radiator; the second water pump is a variable frequency pump, which adjusts its speed and flow rate according to the water tank temperature to ensure the water tank temperature; the first water pump is downstream of the water tank, and the coolant returns to the water tank after its pressure decreases after passing through the laser.

[0006] The electric heating wire is installed in the temperature-controlled water tank.

[0007] The cold accumulator is a plate-fin phase change cold accumulator made of aluminum alloy and is placed vertically. The cold accumulator is configured in a counter-current manner, with one inlet and one outlet on the cold side and the hot side, respectively.

[0008] The cold storage device uses solid-liquid phase change material as the cold storage medium, and the phase change material temperature is between 5 and 20℃.

[0009] The pressure valve is screwed on the top of the water tank to ensure that the system does not overpressure.

[0010] This invention also provides a management method for a laser thermal management system combining phase change cold storage and a temperature-controlled water tank, comprising the following steps:

[0011] During the startup preparation phase, when the ambient temperature is between -40 and 24°C, the laser does not work, the first water pump works, and the system preheats the heat source and the antifreeze in the temperature-controlled water tank to 25±1°C through electric heating wires; when the ambient temperature is between 26 and 50°C, the first water pump, the variable frequency pump, the second water pump, and the fan work, the three-way valve switches to the evaporator circuit, and the refrigeration cycle works to cool the temperature-controlled water tank to 25±1°C and reduce the outlet temperature of the phase change cold storage to 16°C;

[0012] During the laser's operation, the laser generates heat. When the ambient temperature is between -40°C and +5°C: the first water pump works to cool the heat source, and the coolant returns to the temperature-controlled water tank. The variable frequency pump operates at a speed adjusted according to the temperature of the temperature-controlled water tank to extract part of the coolant from the tank and cool it through the phase change accumulator, maintaining the temperature of the temperature-controlled water tank at 25±1°C. At the same time, when the temperature of the accumulator is higher than 16°C, the second water pump starts, and the coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring heat from the accumulator to the radiator. The fan rotates to carry away the heat.

[0013] After the laser is turned on, it generates heat. When the ambient temperature is between 5 and +50℃, the first water pump works to cool the laser, and the coolant returns to the water tank. The variable frequency pump cools part of the coolant in the cold storage unit according to the detected water tank temperature, maintaining the water tank temperature at 25±1℃. At the same time, when the phase change cold storage unit temperature is higher than 16℃, the second water pump works to transfer heat from the cold storage unit to the evaporator, and the refrigeration cycle works. The fan rotates to remove the heat.

[0014] After the laser is turned off, when the ambient temperature is between -40 and 5℃: the first water pump works, and the coolant returns to the temperature-controlled water tank through the laser; the variable frequency pump operates at a variable speed according to the temperature of the temperature-controlled water tank, and extracts part of the coolant from the temperature-controlled water tank for cooling through the phase change accumulator, maintaining the temperature of the temperature-controlled water tank at 25±1℃; the second water pump and the fan continue to work, and the coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring the heat of the phase change accumulator to the environment until the hot side outlet temperature of the phase change accumulator is less than 16℃;

[0015] After the laser is turned off, when the ambient temperature is between 5 and +50℃: the first water pump, the variable frequency pump, the second water pump, and the fan work, the three-way valve switches to the evaporator circuit, the refrigeration cycle works to cool the temperature-controlled water tank to 25±1℃, and the outlet temperature of the phase change cold storage device is reduced to 16℃.

[0016] Beneficial effects:

[0017] 1. The system of this invention uses a variable frequency pump to regulate the flow rate and thus control the temperature of the temperature-controlled water tank, which eliminates the need for a valve compared to the valve regulation method. At the same time, the power of the variable frequency pump is adjustable, saving power consumption. A phase change accumulator is used instead of the traditional liquid sensible heat storage, reducing the storage volume.

[0018] 2. In the system of this invention, the temperature-controlled water tank adopts a method of direct mixing of cold and hot water, which improves heat exchange efficiency and eliminates the need for an intermediate heat exchanger.

[0019] 3. In the system of the present invention, a pressure valve is tightened at the top of the water tank to ensure that the system does not overpressure.

[0020] 4. In the system of the present invention, the cold accumulator adopts a plate-fin phase change cold accumulator made of aluminum alloy with rectangular fins. The cold accumulator adopts a counter-current configuration with one inlet and one outlet on the cold side and the hot side, respectively. Furthermore, the cold accumulator is placed vertically to prevent thermal resistance to the metal wall caused by shrinkage during the solidification process.

[0021] 5. In the system of this invention, the cold storage device uses a solid-liquid phase change material as the cold storage medium. To ensure the efficiency of the refrigeration cycle, the temperature of the phase change material is between 5 and 20°C, such as pure substances like n-tetradecane, octanoic acid, and polyethylene glycol, as well as their eutectic mixtures. The cold storage material can provide continuous cooling for a short time, thus stabilizing the cooling output.

[0022] 6. The method of the present invention is based on the system of the present invention. It uses a variable frequency pump to regulate the flow rate and thus control the temperature of the temperature-controlled water tank. Compared with the valve regulation method, it eliminates one valve. At the same time, the power of the variable frequency pump is adjustable, saving power consumption. It uses a phase change cold accumulator instead of the traditional liquid sensible heat cold storage, reducing the cold storage volume. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of an embodiment of the system of the present invention.

[0024] Figure 2 This is a schematic diagram of a single-cycle structure of a cold storage device according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the internal fin structure of the cold storage layer in a system embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the internal structure of the cold side in a system embodiment of the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] This invention provides a laser thermal management system that combines phase change cold storage with a temperature-controlled water tank, such as... Figure 1 As shown, the system includes a laser, a temperature-controlled water tank, an electric heating wire, a first water pump, a variable frequency pump, a phase change cold storage device, a second water pump, a three-way valve, an evaporator, an expansion valve, a compressor, a condenser, a radiator, and a fan. The second water pump is a variable frequency pump, which adjusts its speed and flow rate according to the temperature of the temperature-controlled water tank to ensure the temperature is maintained within 25±1℃. The first water pump is located downstream of the temperature-controlled water tank; the coolant returns to the tank after passing through the laser due to pressure reduction, thus reducing the tank pressure.

[0029] An electric heating wire is used to preheat the heat source (laser) and the antifreeze in the temperature-controlled water tank. In this embodiment, the electric heating wire is placed in the temperature-controlled water tank. The first water pump is the starting point of the system, responsible for delivering water to other parts of the system to ensure water circulation. The temperature-controlled water tank is connected to the first water pump and is used to regulate the water temperature, which is a key part of controlling the temperature of the air conditioning system. A laser is located between the first water pump and the temperature-controlled water tank. A variable frequency pump is connected to the temperature-controlled water tank and controls the water flow rate and water pressure by changing the frequency to adapt to different working requirements. A phase change cold storage device is connected to the variable frequency pump and may store or release heat to help regulate the water temperature and achieve more efficient temperature control. An evaporator is connected to the phase change cold storage device. In the refrigeration cycle, the coolant in the evaporator absorbs heat and evaporates, thereby playing a cooling role. A second water pump is connected to the evaporator. An expansion valve is connected between the evaporator and the condenser to regulate the flow rate of the refrigerant entering the evaporator and control the cooling effect. A three-way valve is connected to the cold storage device, radiator and evaporator. This valve can split or merge the fluid to help regulate the direction and flow rate of the water.

[0030] The compressor connects the evaporator and condenser. Its function is to compress the refrigerant gas, increasing its pressure and temperature to power the refrigeration cycle. The condenser, connected to the compressor, converts the gaseous refrigerant into a liquid state during the refrigeration process, releasing heat in the process. The radiator dissipates heat, cooling the air, and is a crucial component in the system for cooling the air. A fan is located next to the radiator to remove heat through airflow. The entire system achieves heating, cooling, and humidity control functions through the coordinated work of these components. Figure 1 It provides a detailed explanation of the system's working principle and the functions and connections of each component.

[0031] In this invention system, the accumulator is a plate-fin phase change accumulator made of aluminum alloy with rectangular fins. The accumulator is placed vertically to prevent thermal resistance to the metal wall caused by shrinkage during the solidification process. The accumulator is configured in a counter-current manner, with one inlet and one outlet on the cold and hot sides, respectively. Figure 2This is a schematic diagram of a single-cycle structure of a cold storage device according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the internal fin structure of the cold storage layer in a system embodiment of the present invention. Figure 4 This is a schematic diagram of the internal structure of the cold side in a system embodiment of the present invention.

[0032] Furthermore, the cold storage device uses solid-liquid phase change materials as the cold storage medium. To ensure the efficiency of the refrigeration cycle, the temperature of the phase change material is between 5 and 20°C, such as pure substances like n-tetradecane, octanoic acid, and polyethylene glycol, as well as their eutectic mixtures. The cold storage material can provide continuous cooling for a short period of time, thus stabilizing the cooling output.

[0033] Furthermore, tighten the pressure valve at the top of the water tank to ensure that the system does not overpressure.

[0034] This invention also provides a management method for a laser thermal management system combining variable cold storage and a temperature-controlled water tank, comprising the following steps:

[0035] During the startup preparation phase, when the ambient temperature is between -40°C and 24°C, the laser is not operating, but the first water pump operates. The system preheats the heat source and the antifreeze in the temperature-controlled water tank to 25±1°C using electric heating wires. When the ambient temperature is between 26°C and 50°C, the first water pump, the variable frequency pump, the second water pump, and the fan operate. The three-way valve switches to the evaporator circuit, and the refrigeration cycle operates to cool the temperature-controlled water tank to 25±1°C and lower the outlet temperature of the phase change cold storage unit to 16°C.

[0036] During laser operation, the laser generates heat. When the ambient temperature is between -40°C and +5°C: the first water pump cools the heat source, and the coolant returns to the temperature-controlled water tank. The variable frequency pump operates at a speed adjusted according to the temperature of the temperature-controlled water tank, drawing out a portion of the coolant and cooling it through a phase change accumulator to maintain the temperature of the temperature-controlled water tank at 25±1°C. Simultaneously, when the temperature of the accumulator exceeds 16°C, the second water pump starts. The coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring heat from the accumulator to the radiator. The fan rotates to carry away the heat. The fan speed varies according to the temperature at the hot-side outlet of the accumulator; the higher the temperature at the hot-side outlet, the faster the fan speed.

[0037] After the laser is turned on, it generates heat. When the ambient temperature is between 5 and +50℃: the first water pump operates to cool the laser, and the coolant returns to the water tank. A variable frequency pump, based on the detected water tank temperature, cools a portion of the coolant in the accumulator, maintaining the water tank temperature at 25±1℃. Simultaneously, when the phase change accumulator temperature exceeds 16℃, the second water pump operates to transfer heat from the accumulator to the evaporator, initiating the refrigeration cycle. A fan rotates to remove the heat. The fan speed varies according to the temperature at the hot side outlet of the accumulator; the higher the temperature at the hot side outlet, the faster the fan speed.

[0038] After the laser is turned off, when the ambient temperature is between -40°C and 5°C: the first water pump operates, and the coolant returns to the temperature-controlled water tank via the laser. Due to the heat generated by the first water pump, the temperature of the temperature-controlled water tank will slowly rise. The variable frequency pump operates at a speed adjusted according to the temperature of the temperature-controlled water tank, drawing out a portion of the coolant from the tank and cooling it through the phase change accumulator to maintain the temperature of the temperature-controlled water tank at 25±1°C. The second water pump and fan continue to operate, and the coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring heat from the phase change accumulator to the environment until the hot-side outlet temperature of the phase change accumulator is less than 16°C. The fan operates at a speed adjusted according to the temperature of the hot-side outlet of the accumulator; the higher the temperature of the hot-side outlet, the faster the fan speed.

[0039] After the laser is turned off, when the ambient temperature is between 5 and +50℃: the first water pump, the variable frequency pump, the second water pump, and the fan work, the three-way valve switches to the evaporator circuit, the refrigeration cycle works to cool the temperature-controlled water tank to 25±1℃, and the outlet temperature of the phase change cold storage device is reduced to 16℃.

[0040] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A management method for a laser thermal management system combining phase change cold storage and a temperature-controlled water tank, characterized in that, The laser thermal management system includes a laser, a water tank, an electric heating wire, a first water pump, a variable frequency pump, a phase change accumulator, a second water pump, a three-way valve, an evaporator, an expansion valve, a compressor, a condenser, a radiator, and a fan. The electric heating wire preheats the antifreeze in the laser and the temperature-controlled water tank. The temperature-controlled water tank is connected to the first water pump, and the laser is located between the first water pump and the temperature-controlled water tank. The variable frequency pump is connected to the temperature-controlled water tank and controls the water flow rate and pressure by changing the frequency. The phase change accumulator is connected to the variable frequency pump. The evaporator is connected to the phase change accumulator. The second water pump is connected to the evaporator. The expansion valve is connected between the evaporator and the condenser. The three-way valve is connected to the accumulator, the radiator, and the evaporator. The compressor is connected to the evaporator and the condenser. A fan is located next to the radiator. The second water pump is a variable frequency pump, which adjusts its speed and flow rate according to the water tank temperature to maintain the water tank temperature. The first water pump is downstream of the water tank; the coolant returns to the water tank after its pressure decreases after passing through the laser. The management method includes the following steps: During the startup preparation phase, when the ambient temperature is between -40°C and 24°C, the laser is not operating, but the first water pump operates. The system preheats the heat source and the antifreeze in the temperature-controlled water tank to 25±1°C using electric heating wires. When the ambient temperature is between 26°C and 50°C, the first water pump, the variable frequency pump, the second water pump, and the fan operate. The three-way valve switches to the evaporator circuit, and the refrigeration cycle cools the temperature-controlled water tank to 25±1°C, reducing the outlet temperature of the phase change regenerator to 16°C. During the laser operation phase, the laser... When the device generates heat, and the ambient temperature is between -40℃ and +5℃: the first water pump works to cool the heat source, and the coolant returns to the temperature-controlled water tank. The variable frequency pump operates at a speed that varies according to the temperature of the temperature-controlled water tank, drawing out a portion of the coolant from the temperature-controlled water tank and cooling it through the phase change accumulator to maintain the temperature of the temperature-controlled water tank at 25±1℃. At the same time, when the temperature of the accumulator is higher than 16℃, the second water pump starts, and the coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring heat from the accumulator to the radiator. The fan rotates to carry away the heat. After the laser is turned on, it generates heat. When the ambient temperature is between 5 and +50℃, the first water pump works to cool the laser, and the coolant returns to the water tank. The variable frequency pump cools part of the coolant in the cold storage unit according to the detected water tank temperature, maintaining the water tank temperature at 25±1℃. At the same time, when the phase change cold storage unit temperature is higher than 16℃, the second water pump works to transfer heat from the cold storage unit to the evaporator, and the refrigeration cycle works. The fan rotates to remove the heat. After the laser is turned off, when the ambient temperature is between -40 and 5℃: the first water pump works, and the coolant returns to the temperature-controlled water tank through the laser; the variable frequency pump operates at a variable speed according to the temperature of the temperature-controlled water tank, and extracts part of the coolant from the temperature-controlled water tank for cooling through the phase change accumulator, maintaining the temperature of the temperature-controlled water tank at 25±1℃; the second water pump and the fan continue to work, and the coolant flows through the second water pump, the phase change accumulator, and the radiator, transferring the heat of the phase change accumulator to the environment until the hot side outlet temperature of the phase change accumulator is less than 16℃; After the laser is turned off, when the ambient temperature is between 5 and +50℃: the first water pump, the variable frequency pump, the second water pump, and the fan work, the three-way valve switches to the evaporator circuit, the refrigeration cycle works to cool the temperature-controlled water tank to 25±1℃, and the outlet temperature of the phase change cold storage device is reduced to 16℃.

2. The method as described in claim 1, characterized in that, The electric heating wire is installed in the temperature-controlled water tank.

3. The method as described in claim 2, characterized in that... The cold accumulator is a plate-fin phase change cold accumulator made of aluminum alloy and is placed vertically. The cold accumulator is configured in a counter-current manner, with one inlet and one outlet on the cold side and the hot side, respectively.

4. The method as described in claim 3, characterized in that... The cold storage device uses solid-liquid phase change material as the cold storage medium. The phase change material temperature is between 5 and 20℃.

5. The method according to any one of claims 1-4, characterized in that... Tighten the pressure valve on the top of the water tank to ensure that the system does not overpressure.

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