A device for releasing liquid nitrogen for airborne and vehicle-mounted laser

Abstract

The application discloses a kind of liquid nitrogen cooling release device for airborne, vehicle-mounted laser, belongs to laser thermal management cooling technical field, including liquid nitrogen cooling release circuit, anti-freeze liquid outer circulation heat exchange circuit, sensing detection component, control unit.The present application relies on the huge latent heat of phase change of liquid nitrogen to realize efficient heat absorption, only filling liquid nitrogen can complete cold storage, without long time unit refrigeration, cold storage is sufficient, significantly improve the ability of battlefield continuous operation, continuous attack, cancel large refrigeration compressor, whole machine cold storage unit, only equipped with liquid nitrogen storage tank and plate heat exchanger, the volume and weight of whole machine are greatly reduced, adapt to armored vehicle square cabin, airborne narrow equipment cabin installation, cold storage is exhausted after directly filling liquid nitrogen can quickly recover cold storage, in the middle of operation can be supplied on site, not limited by ground cold charging station.

Description

Technical Field

[0001] This invention belongs to the field of laser thermal management and cooling technology, specifically referring to a liquid nitrogen cooling device for airborne and vehicle-mounted lasers. Background Technology

[0002] Currently, the mainstream cooling solutions for airborne and vehicle-mounted high-power lasers are divided into three categories: separate charging and cooling station + mobile cold storage bag, vehicle-mounted integrated cold storage and release unit, and compression direct cooling. Although the separate type can reduce the platform's weight, it can only return to the charging and cooling station for replenishment after the cooling capacity is exhausted, which limits the continuous working time of the laser. The integrated unit can autonomously store cold on the vehicle, but it has problems such as large size and weight, long cooling time, many parts and poor reliability. The direct cooling type has a simple structure, but the continuous vibration of the compressor will interfere with the laser aiming optical path and has a low upper limit of cooling capacity. All three types of solutions generally have common defects such as mutual constraints between the cold storage capacity and the size and weight of the equipment, inability to quickly replenish cooling on site, vibration affecting the accuracy of the strike, complex system structure and short life, and difficulty in ensuring the quality of light output in low-temperature environments without preheating methods. Moreover, industry research and development is mostly limited to compression refrigeration and solid-state cold storage routes, and liquid nitrogen phase change cooling is only used for fixed laboratory equipment. At the same time, the existing temperature control only adopts single-channel temperature feedback and lacks a composite control concept of inlet and outlet dual temperature collaborative correction. There is no complete technical solution for liquid nitrogen phase change cooling combined with proportional regulation and PID fuzzy control to adapt to mobile combat platforms. Summary of the Invention

[0003] In view of the above situation and to overcome the shortcomings of the prior art, the present invention provides a liquid nitrogen cooling device for airborne and vehicle-mounted lasers, which effectively solves the problems currently on the market.

[0004] The technical solution adopted by the present invention is as follows: The present invention proposes a liquid nitrogen cooling device for airborne and vehicle-mounted lasers, including a liquid nitrogen cooling circuit, an antifreeze external circulation heat exchange circuit, a sensing and detection component, and a control unit;

[0005] The liquid nitrogen cooling circuit includes a liquid nitrogen storage tank, a pressure reducing valve, a solenoid valve SV1, a first flow meter F1, an electric proportional regulating valve P, a cooling plate heat exchanger, and a ball valve HV1; the outlet of the liquid nitrogen storage tank is connected in series with the pressure reducing valve, the solenoid valve SV1, the first flow meter F1, and the electric proportional regulating valve P, and then connected to the liquid nitrogen side inlet of the cooling plate heat exchanger; the liquid nitrogen side outlet of the cooling plate heat exchanger is connected to the ball valve HV1 and vented to the atmosphere.

[0006] The external circulation heat exchange circuit for antifreeze includes a circulation pump CP1, a laser, a preheating plate heat exchanger, a second flow meter F2, and a cooling plate heat exchanger. The output end of the circulation pump CP1 is connected to the heat exchange channel of the laser, the outlet of the heat exchange channel of the laser is connected to the preheating plate heat exchanger, the output end of the preheating plate heat exchanger is connected to the second flow meter F2, the second flow meter F2 is connected to the antifreeze side inlet of the cooling plate heat exchanger, and the antifreeze side outlet of the cooling plate heat exchanger returns to the circulation pump CP1 to form a closed loop.

[0007] The sensing and detection components include an inlet temperature sensor T1 located at the laser inlet, an outlet temperature sensor T2 located at the laser outlet, and a pressure sensor P1 located on the side of the cooling plate where liquid nitrogen is exchanged.

[0008] The control unit has a built-in PID control module and a fuzzy control module. The control unit is electrically connected to the circulating pump CP1, the solenoid valve SV1, the electric proportional regulating valve P, and each sensing and detection component. It coordinates the liquid nitrogen supply opening and the antifreeze circulation flow rate based on the temperature collected by the inlet temperature sensor T1 and the outlet temperature sensor T2, the pressure collected by the pressure sensor P1, and the flow rate collected by the first flow meter F1 and the second flow meter F2.

[0009] Furthermore, the liquid nitrogen cooling circuit is also equipped with a pressure relief valve, which is connected in parallel to the liquid nitrogen side pipeline of the cooling plate. When the pressure sensor P1 detects that the liquid nitrogen side pressure exceeds the preset threshold, the pressure relief valve automatically opens to release pressure and outputs an alarm signal to the control unit. The control unit then simultaneously reduces the laser output power or cuts off the laser output.

[0010] Furthermore, the preheating plate heat exchanger is equipped with a preheating solenoid valve SV2, which is connected to the engine waste heat exchange pipeline. When the control unit detects that the temperatures T1 and T2 are lower than the preset low temperature threshold, it controls the preheating solenoid valve SV2 to open, using the engine waste heat to heat the antifreeze circuit to preheat the laser until the circuit temperature reaches the suitable working range of 20℃~30℃, after which the preheating solenoid valve SV2 is closed.

[0011] Furthermore, the preheating plate can be replaced with an electric heating component, which is connected to the external circulation heat exchange circuit of the antifreeze. The heating is started and stopped by the control unit according to the temperature signal, eliminating the need to install a preheating solenoid valve SV2 and an engine waste heat pipeline.

[0012] Furthermore, the control logic of the control unit includes:

[0013] The circulation pump control logic is as follows: The control unit sets the target circulation flow rate of the antifreeze, collects the real-time flow rate of the second flow meter F2, and adjusts the output power of the circulation pump CP1 through PID closed-loop to stabilize the antifreeze circulation flow rate.

[0014] Liquid nitrogen supply regulation logic: The inlet temperature of the T1 laser is the main control quantity and the outlet temperature of the T2 laser is the correction and compensation quantity. The dual temperature signal input is used to the PID + fuzzy control module to adjust the opening of the electric proportional regulating valve P in real time, accurately match the cooling capacity required by the laser waste heat, and eliminate the static temperature difference of T1.

[0015] Solenoid valve control logic: Solenoid valve SV1 is turned on when a laser emission and cooling signal is received; solenoid valve SV1 is forcibly turned off when a pressure relief and overpressure alarm signal is received, cutting off the liquid nitrogen supply.

[0016] Furthermore, the refrigerant can be replaced with liquid oxygen or liquid carbon dioxide cryogenic phase change media to adapt to different cryogenic cooling conditions.

[0017] Furthermore, the device adopts a modular integrated structure and is installed in the armored vehicle compartment or airborne equipment compartment. It can be quickly connected to the laser via an external hose and the cooling operation is completed by adding liquid nitrogen.

[0018] The beneficial effects achieved by the present invention using the above structure are as follows:

[0019] (1) It achieves efficient heat absorption by relying on the huge latent heat of liquid nitrogen phase change. It can complete the cold storage by simply adding liquid nitrogen, without the need for long-term unit refrigeration. The cold storage is sufficient, which significantly improves the ability to continuously fight and strike on the battlefield. It eliminates the need for large refrigeration compressors and whole-unit cold storage units, and is only equipped with liquid nitrogen storage tanks and plate heat exchangers. The overall size and weight are greatly reduced. It is suitable for installation in armored vehicle cabins and small airborne equipment cabins. After the cold storage is exhausted, liquid nitrogen can be added directly to quickly restore the cold storage. It can be replenished on-site during the operation and is not limited by ground cooling stations.

[0020] (2) The system has only a small moving part, the circulating pump, and no high-power compressor that vibrates continuously. This will not disturb the laser beam path and ensure the accuracy of target acquisition and strike. It eliminates the complex cooling and compression circuit and multiple sets of three-way switching valves. The number of pipelines and moving parts is greatly reduced, and there are fewer failure points. It is more stable in harsh outdoor environments for a long time. It adopts dual temperature sensing + fuzzy PID composite control to match the laser waste heat in real time. The temperature fluctuation of the cooling medium is small, which can stably ensure the laser beam quality. It is equipped with two preheating schemes: engine waste heat preheating or electric heating. In sub-zero low temperature environments, the laser can be preheated to the optimal working range in advance to avoid the low temperature deterioration of the light output performance. Liquid nitrogen can be replaced with low temperature phase change media such as liquid oxygen and liquid CO2 to adapt to different low temperature cooling requirements. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the liquid nitrogen cooling principle of a liquid nitrogen cooling device for airborne and vehicle-mounted lasers proposed in this invention. In the diagram, the green circuit is the liquid nitrogen cooling circuit; the green circuit is the antifreeze external circulation circuit; and the red arrow indicates the laser light output direction.

[0022] The components are as follows: 1. Liquid nitrogen storage tank; 2. Pressure reducing valve; 3. Solenoid valve SV1; 4. First flow meter F1; 5. Electric proportional regulating valve P; 6. Cooling heat exchanger; 7. Ball valve HV1; 8. Pressure relief valve; 9. Circulation pump CP1; 10. Laser; 11. Preheating heat exchanger; 12. Preheating solenoid valve SV2; 13. Second flow meter F2; 14. Inlet temperature sensor T1; 15. Outlet temperature sensor T2; 16. Pressure sensor P1.

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. 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. Therefore, they should not be construed as limitations on this invention.

[0026] like Figure 1 As shown, the present invention proposes a liquid nitrogen cooling device for airborne and vehicle-mounted lasers, including a liquid nitrogen cooling circuit, an antifreeze external circulation heat exchange circuit, a sensing and detection component, and a control unit;

[0027] The liquid nitrogen cooling circuit includes a liquid nitrogen storage tank 1, a pressure reducing valve 2, a solenoid valve SV13, a first flow meter F14, an electric proportional regulating valve P5, a cooling plate heat exchanger 6, and a ball valve HV17. The outlet of the liquid nitrogen storage tank 1 is connected in series with the pressure reducing valve 2, the solenoid valve SV13, the first flow meter F14, and the electric proportional regulating valve P5, and then connected to the liquid nitrogen side inlet of the cooling plate heat exchanger 6. The liquid nitrogen side outlet of the cooling plate heat exchanger 6 is connected to the ball valve HV17 and vented to the atmosphere.

[0028] The external circulation heat exchange loop for antifreeze includes a circulation pump CP19, a laser 10, a preheating plate heat exchanger 11, a second flow meter F213, and a cooling plate heat exchanger 6. The output of the circulation pump CP19 is connected to the heat exchange channel of the laser 10, the outlet of the heat exchange channel of the laser 10 is connected to the preheating plate heat exchanger 11, the output of the preheating plate heat exchanger 11 is connected to the second flow meter F213, the second flow meter F213 is connected to the antifreeze side inlet of the cooling plate heat exchanger 6, and the antifreeze side outlet of the cooling plate heat exchanger 6 returns to the circulation pump CP19 to form a closed loop.

[0029] The sensing and detection components include an inlet temperature sensor T114 located at the inlet of the laser 10, an outlet temperature sensor T215 located at the outlet of the laser 10, and a pressure sensor P116 located on the liquid nitrogen side of the cooling plate heat exchanger 6.

[0030] The control unit has a built-in PID control module and a fuzzy control module. The control unit is electrically connected to the circulating pump CP19, solenoid valve SV13, electric proportional regulating valve P5, and various sensor detection components. It coordinates the liquid nitrogen supply opening and the antifreeze circulation flow rate based on the temperature collected by the inlet temperature sensor T114 and outlet temperature sensor T215, the pressure collected by the pressure sensor P116, and the flow rate collected by the first flow meter F14 and the second flow meter F212.

[0031] The liquid nitrogen cooling circuit is also equipped with a pressure relief valve 8, which is connected in parallel to the liquid nitrogen side pipeline of the cooling plate heat exchanger 6. When the pressure sensor P116 detects that the liquid nitrogen side pressure exceeds the preset threshold, the pressure relief valve 8 automatically opens to release pressure and outputs an alarm signal to the control unit. The control unit then simultaneously reduces the output power of the laser 10 or cuts off the output of the laser 10.

[0032] The preheating plate heat exchanger 11 is equipped with a preheating solenoid valve SV212, which is connected to the engine waste heat exchange pipeline. When the control unit detects that the temperatures T1 and T2 are lower than the preset low temperature threshold, it controls the preheating solenoid valve SV212 to open, using the engine waste heat to heat the antifreeze circuit to preheat the laser 10 until the circuit temperature reaches the suitable working range of 20℃~30℃, after which the preheating solenoid valve SV212 is closed.

[0033] The preheating plate 11 can be replaced with an electric heating component. The electric heating component is connected to the external circulation heat exchange circuit of the antifreeze. The control unit starts and stops heating according to the temperature signal, eliminating the need to install the preheating solenoid valve SV212 and the engine waste heat pipeline.

[0034] The control logic of the control unit includes:

[0035] The circulation pump control logic is as follows: The control unit sets the target circulation flow rate of the antifreeze, collects the real-time flow rate of the second flow meter F213, and adjusts the output power of the circulation pump CP19 through PID closed-loop to stabilize the antifreeze circulation flow rate.

[0036] Liquid nitrogen supply regulation logic: The inlet temperature of laser 10 T1 is the main control variable and the outlet temperature of laser 10 T2 is the correction and compensation variable. The dual temperature signal input is used to the PID + fuzzy control module to adjust the opening of the electric proportional regulating valve P5 in real time, accurately match the cooling capacity required by the waste heat of laser 10, and eliminate the static temperature difference of T1.

[0037] Solenoid valve control logic: Solenoid valve SV13 is turned on when the laser 10 emits a light-releasing and cooling signal; Solenoid valve SV13 is forcibly turned off and the liquid nitrogen supply is cut off when the pressure relief and overpressure alarm signal is received.

[0038] The refrigerant can be replaced with liquid oxygen or liquid carbon dioxide as a low-temperature phase change medium to adapt to different low-temperature cooling conditions.

[0039] The device adopts a modular integrated structure and is installed in the armored vehicle compartment or airborne equipment compartment. It can be quickly connected to the laser 10 through an external hose and the cooling operation is completed by adding liquid nitrogen.

[0040] Example 1: Onboard engine waste heat preheating liquid nitrogen cooling device

[0041] The device is modularly integrated and installed inside the rear compartment of an armored off-road vehicle. It connects to the cooling interface of the vehicle-mounted laser 10 via a quick-connect hose. The device is equipped with an independent power supply module, which connects to the vehicle's power supply to complete a power-on self-test.

[0042] Operational procedure: The vehicle moves to the combat position, the radar searches and locks onto the target, the laser 10 is activated, and the cooling mode of the synchronous trigger device is activated.

[0043] Low-temperature preheating stage (ambient temperature < 20℃)

[0044] When the control unit collects the temperature T1 and T2 and finds it to be below the 20°C threshold, it outputs a signal to open the preheating solenoid valve SV212. The high-temperature waste heat from the vehicle engine enters the preheating plate heat exchanger 11 to heat the antifreeze. The circulating pump CP19 continuously drives the hot antifreeze to flow through the laser 10 until the collected temperature T1 and T2 reaches the 20-30°C range. The control unit automatically shuts off SV2, the preheating is completed, and the laser 10 can emit light normally.

[0045] Liquid nitrogen cooling and temperature control stage

[0046] Laser 10 emits light and generates a large amount of waste heat. Circulation pump CP19 drives the antifreeze to circulate in a closed loop according to the preset rated flow rate. The high-temperature antifreeze enters the heat release plate heat exchanger 6 to release heat. Liquid nitrogen in liquid nitrogen storage tank 1 is stabilized by pressure reducing valve 2, and then solenoid valve SV1 is turned on. Liquid nitrogen flows through flow meter F1 and electric proportional regulating valve P5 into heat release plate heat exchanger 6. Liquid nitrogen absorbs heat from the antifreeze and undergoes a liquid-gas phase change, completing the heat exchange. The nitrogen gas after absorbing heat is directly discharged into the atmosphere through ball valve HV1.

[0047] Control logic operation process:

[0048] ① The second flow meter F213 collects the antifreeze flow rate in real time, compares it with the preset flow rate, and adjusts the circulation pump speed with PID to stabilize the heat exchange medium flow rate;

[0049] ②T1 collects the inlet cooling temperature of laser 10, and T2 collects the outlet temperature. The dual temperature signals are sent to the fuzzy PID control unit to adjust the opening of the electric proportional regulating valve P5 in real time, match the real-time heat generation of laser 10, suppress inlet temperature fluctuations, and eliminate temperature static difference.

[0050] ③ The P1 pressure sensor monitors the internal pressure of the liquid nitrogen chamber of the heat exchanger 6 in real time. If the liquid nitrogen phase change expansion causes the pressure to exceed the safety threshold, the pressure relief valve 8 will automatically open to release the pressure. At the same time, the control unit will cut off the liquid nitrogen supply to SV1 and simultaneously reduce the output power of the laser 10. Under extreme high pressure, the laser 10 will stop emitting light directly to protect the heat exchanger from being damaged by high pressure.

[0051] Cooling operation

[0052] After the cooling capacity of liquid nitrogen storage tank 1 is exhausted, there is no need to return to the cooling station. Liquid nitrogen can be added directly through the filling port to complete the cooling supply. After the filling is completed, the cooling function will be restored immediately, without affecting continuous operation.

[0053] Example 2: Replacement solution for airborne electric heating preheating

[0054] The preheating plate 11, preheating solenoid valve SV212, and engine waste heat pipeline in Example 1 are removed and replaced with an electric heating assembly connected in series to the antifreeze circulation loop. In low-temperature environments, the control unit directly drives the electric heating assembly to heat the antifreeze. The remaining liquid nitrogen cooling loop and sensor control logic are completely consistent, making it suitable for use on airborne platforms without engine waste heat supply.

[0055] Example 3: Phase Change Medium Replacement Implementation Method

[0056] The liquid nitrogen storage tank 1 and its supporting medium pipeline are adapted and modified, and the storage medium is replaced with liquid oxygen or liquid carbon dioxide. The heat release and heat exchange are completed by relying on the latent heat of the low-temperature phase change of the corresponding medium. The control logic and heat exchange circuit structure remain unchanged, which is suitable for special laser equipment with different low-temperature cooling requirements.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0059] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A liquid nitrogen cooling device for airborne and vehicle-mounted lasers, characterized in that, Includes liquid nitrogen cooling circuit, antifreeze external circulation heat exchange circuit, sensing and detection components, and control unit; The liquid nitrogen cooling circuit includes a liquid nitrogen storage tank (1), a pressure reducing valve (2), a solenoid valve SV1 (3), a first flow meter F1 (4), an electric proportional regulating valve P (5), a cooling plate heat exchanger (6), and a ball valve HV1 (7); the outlet of the liquid nitrogen storage tank (1) is connected in series with the pressure reducing valve (2), the solenoid valve SV1 (3), the first flow meter F1 (4), and the electric proportional regulating valve P (5) and then connected to the liquid nitrogen side inlet of the cooling plate heat exchanger (6); the liquid nitrogen side outlet of the cooling plate heat exchanger (6) is connected to the ball valve HV1 (7) and opened to the atmosphere; The external circulation heat exchange circuit of the antifreeze includes a circulation pump CP1 (9), a laser (10), a preheating plate heat exchanger (11), a second flow meter F2 (13), and a cooling plate heat exchanger (6); the output end of the circulation pump CP1 (9) is connected to the heat exchange channel of the laser (10), the outlet of the heat exchange channel of the laser (10) is connected to the preheating plate heat exchanger (11), the output end of the preheating plate heat exchanger (11) is connected to the second flow meter F2 (13), the second flow meter F2 (13) is connected to the antifreeze side inlet of the cooling plate heat exchanger (6), and the antifreeze side outlet of the cooling plate heat exchanger (6) flows back to the circulation pump CP1 (9) to form a closed loop; The sensing and detection components include an inlet temperature sensor T1 (14) located at the inlet of the laser (10), an outlet temperature sensor T2 (15) located at the outlet of the laser (10), and a pressure sensor P1 (16) located on the liquid nitrogen side of the heat exchanger (6). The control unit has a built-in PID control module and a fuzzy control module. The control unit is electrically connected to the circulating pump CP1 (9), the solenoid valve SV1 (3), the electric proportional regulating valve P (5), and each sensing and detection component. It coordinates the liquid nitrogen supply opening and the antifreeze circulation flow rate based on the temperature collected by the inlet temperature sensor T1 (14) and the outlet temperature sensor T2 (15), the pressure collected by the pressure sensor P1 (16), the flow rate collected by the first flow meter F1 (4) and the second flow meter F2 (12).

2. The liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 1, characterized in that: The liquid nitrogen cooling circuit is also equipped with a pressure relief valve (8), which is connected in parallel to the liquid nitrogen side pipeline of the cooling plate heat exchanger (6). When the pressure sensor P1 (16) detects that the liquid nitrogen side pressure exceeds the preset threshold, the pressure relief valve (8) automatically opens to release pressure and outputs an alarm signal to the control unit. The control unit then simultaneously lowers the output power of the laser (10) or cuts off the output of the laser (10).

3. The liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 2, characterized in that: The preheating plate heat exchanger (11) is equipped with a preheating solenoid valve SV2 (12), which is connected to the engine waste heat exchange pipeline. When the control unit detects that the temperatures of T1 and T2 are lower than the preset low temperature threshold, it controls the preheating solenoid valve SV2 (12) to open and uses the engine waste heat to heat the antifreeze circuit to preheat the laser (10) until the circuit temperature reaches the suitable working range of 20℃~30℃ and then closes the preheating solenoid valve SV2 (12).

4. A liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 3, characterized in that: The preheating plate heat exchanger (11) can be replaced by an electric heating component. The electric heating component is connected to the external circulation heat exchange circuit of the antifreeze. The control unit starts and stops heating according to the temperature signal. There is no need to set up a preheating solenoid valve SV2 (12) and an engine waste heat pipeline.

5. A liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 4, characterized in that: The control logic of the control unit includes: (1) Circulation pump control logic: The control unit sets the target circulation flow rate of antifreeze, collects the real-time flow rate of the second flow meter F2 (13), and adjusts the output power of circulation pump CP1 (9) through PID closed loop to stabilize the circulation flow rate of antifreeze; (2) Liquid nitrogen supply regulation logic: The inlet temperature of T1 laser (10) is the main control quantity and the outlet temperature of T2 laser (10) is the correction compensation quantity. The dual temperature signals are input to the PID+fuzzy control module to adjust the opening of the electric proportional regulating valve P (5) in real time, accurately match the cooling capacity required by the waste heat of the laser (10), and eliminate the static temperature difference of T1. (3) Solenoid valve control logic: When the laser (10) emits light and releases cold signal, the solenoid valve SV1 (3) is turned on; when the pressure relief and overpressure alarm signal is received, the solenoid valve SV1 (3) is forcibly disconnected to cut off the liquid nitrogen supply.

6. A liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 5, characterized in that: The refrigerant can be replaced with liquid oxygen or liquid carbon dioxide as a low-temperature phase change medium to adapt to different low-temperature cooling conditions.

7. A liquid nitrogen cooling device for airborne and vehicle-mounted lasers according to claim 6, characterized in that: The device adopts a modular integrated structure and is installed in the armored vehicle cabin or airborne equipment cabin. It is quickly connected to the laser (10) through an external hose and the cooling operation is completed by adding liquid nitrogen.

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