A spray phase-change-impingement cooling hybrid cavity for laser crystal cooling

Abstract

The present application relates to the spray phase change-impact cooling technology of ultrahigh power laser, in order to solve the problems that the existing crystal thermal management technology cannot guarantee the uniformity of discrete droplet working medium distribution and the fluid flow rate is slow, and a spray phase change-impact cooling mixed cavity for laser crystal cooling is provided, comprising a mixed cavity body and a cylindrical mixed cavity arranged in the mixed cavity body; the front end of the mixed cavity body is provided with an aerosol mixing section, and the rear end is provided with a fluid accelerating device; the middle part of the aerosol mixing section is provided with a spray through hole and a plurality of main airflow through holes; the fluid accelerating device comprises a throat arranged in the mixed cavity body and coaxially communicated with the rear end of the mixed cavity, and a jet orifice plate arranged at the rear end of the throat; the throat is a quadratic curve structure, the extension section of the throat contraction section is connected with the rear end of the mixed cavity, and the extension section of the throat expansion section is provided with the jet orifice plate at the rear end; the throat is used for accelerating the mixed fluid and flowing out from the jet orifice plate.

Description

Technical Field

[0001] This invention relates to a spray phase change-impact cooling device for ultra-high power lasers, specifically to a spray phase change-impact cooling hybrid cavity for cooling laser crystals. Background Technology

[0002] Attosecond lasers are extremely short light pulses, lasting only 10 to the power of -18 seconds. Based on this laser technology, scientists can observe and study the rapid movement and interaction of electrons in the temporal region of atoms. The generation and application of attosecond lasers are based on the interaction between high-intensity femtosecond laser pulses and gas targets. They can be applied to the study of biological proteins, life phenomena, and atomic-scale dynamic processes, greatly promoting the development of scientific research.

[0003] Currently, ultra-high power lasers used to obtain attosecond laser sources are still in the research and development stage, and there are certain technical defects in the process. In particular, the thermal management technology of the crystal in ultra-high power lasers has become the most difficult part of the research and development stage. To address the above problems, the current solution is impingement jet cooling technology. The impingement jet cooling technology at room temperature can achieve a heat dissipation index of 50-500 W / cm2, which is close to the cooling limit of single-phase working fluid at room temperature. However, if it is necessary to effectively cool the laser crystal with ultra-high heat flux density, relying solely on single-phase working fluid is insufficient. Spray phase change cooling technology is expected to be an effective solution. However, the current spray phase change cooling technology cannot guarantee the uniformity of the discrete droplet working fluid distribution. The flow rate of the mixed fluid is slow, and droplet accumulation occurs, resulting in poor heat exchange effect of the gas-mist two-phase flow working fluid during impingement cooling. Summary of the Invention

[0004] The purpose of this invention is to solve the problems that existing ultra-high power laser crystal thermal management technology cannot guarantee the uniformity of discrete droplet working fluid distribution, the slow flow rate of the mixed fluid, and the poor heat exchange effect of the gas-mist two-phase flow working fluid during the impact cooling process due to droplet accumulation. Therefore, a spray phase change-impact cooling hybrid cavity for laser crystal cooling is proposed.

[0005] To achieve the above objectives, the technical solution proposed by this invention is as follows:

[0006] A spray phase change-impact cooling hybrid cavity for cooling laser crystals includes a hybrid cavity body and a cylindrical hybrid cavity disposed within the hybrid cavity body; its special feature is that: the front end of the hybrid cavity body is provided with a gas-mist mixing section and the rear end is provided with a fluid acceleration device.

[0007] The aerosol mixing section is provided with a spray through hole coaxial with the mixing chamber in the middle. Multiple main air flow holes are uniformly arranged on the aerosol mixing section along the periphery of the spray through hole. The aerosol mixing section is used to fully mix the spray with the main air flow.

[0008] The fluid acceleration device includes a throat disposed within the mixing chamber body and coaxially connected to the rear end of the mixing chamber, and a jet orifice plate disposed at the rear end of the throat and connected to the mixing chamber body.

[0009] The throat has a quadratic curve structure, including a throat contraction section and a throat expansion section. The extension of the throat contraction section is connected to the rear end of the mixing chamber, and the jet orifice plate is disposed at the rear end of the extension of the throat expansion section. The throat is used to accelerate the mixed fluid and allow it to flow out through the jet orifice plate.

[0010] Furthermore, the mixing chamber is also equipped with at least two sets of mixing and flow stabilizing components to ensure uniform mixing of the fluid and stable flow.

[0011] Each set of the mixing and stabilizing components includes a flow divider plate and a hexagonal honeycomb structure. The flow divider plate is located on one side near the aerosol mixing section, and the other side is connected to the hexagonal honeycomb structure. The flow divider plate is connected to the inner wall of the mixing chamber body. The flow divider plate is uniformly provided with multiple circular through holes. The hexagonal honeycomb structure is composed of multiple interconnected honeycomb channels with hexagonal cross-sections. The fluid movement direction in each honeycomb channel is parallel to the central axis of the mixing chamber.

[0012] Furthermore, the angle α between the central axis of each of the main air passages and the central axis of the spray passage satisfies: 0°≤a≤30°.

[0013] Furthermore, the outer side of the aerosol mixing section is provided with a spray interface pipe communicating with the spray through hole, and a main airflow communication pipe communicating with each of the main airflow holes respectively.

[0014] Furthermore, the thickness of the flow divider plate is 0.5mm to 3mm, and the diameter Do of the circular through hole provided on it is 0.5mm to 5mm;

[0015] The circular through holes on the flow divider plate are arranged in a ring shape, with the spacing between each ring layer being 1.2Do to 3Do, and the spacing between each circular through hole being 1.2Do to 6Do.

[0016] Furthermore, the wall thickness of the hexagonal honeycomb is 0.3mm to 2mm, and the diameter of the circumscribed circle of the hexagonal honeycomb is 5mm to 30mm.

[0017] Furthermore, the length of the hexagonal honeycomb is 0.3Dc to 2.5Dc, where Dc is the inner diameter of the mixing cavity.

[0018] Furthermore, the throat is connected to the rear end of the mixing chamber via an extension of the throat constriction section to form a Laval nozzle structure.

[0019] Furthermore, 4-12 main airflow holes are evenly distributed along the outer circumference of the spray through-hole.

[0020] Furthermore, the aerosol mixing section is connected to the front end of the mixing chamber body via a thread. The beneficial effects of this invention are:

[0021] [1] The present invention provides a spray phase change-impact cooling mixing cavity for laser crystal cooling. The spray and the main airflow are fully mixed through the gas-mist mixing section, which ensures the uniformity and stability of the heat exchange effect of the mixed fluid during the impact cooling process. Then, the flow rate of the mixed fluid is increased by the fluid acceleration device, which increases the inertial force of the mist droplets to destroy the thermal boundary layer and improves the heat exchange effect.

[0022] [2] The present invention can effectively improve the mixing effect of spray and main airflow by using multiple sets of mixing and stabilizing components, ensuring the uniformity of the distribution of discrete droplets in the main airflow, ensuring that the mixed fluid can be ejected vertically from the jet orifice plate, and further ensuring that the outlet cross section of the mixed fluid is uniformly distributed when it reaches the jet orifice plate.

[0023] [3] The circular through holes on the flow divider plate of the present invention are distributed in an annular pattern, which can effectively reform the motion state of the two-phase working fluid in space, so that the droplet particles are evenly distributed in space; then the flow is rectified by the hexagonal honeycomb device, so that the mixed fluid moves in a direction parallel to the central axis of the mixing chamber, which effectively reduces the turbulence of the mixed fluid and avoids the phenomenon of uneven distribution of discrete droplets in space caused by the turbulence of the mixed fluid, thereby effectively improving the heat transfer uniformity of the mixed fluid.

[0024] [4] The present invention effectively improves the flow rate of the mixed fluid by designing a quadratic curve throat, which is constrained by the throat contraction section. After rectification by the throat expansion section, it ensures that the mixed fluid can reach the jet orifice plate vertically, thereby ensuring that the mixed fluid impacts the external high-temperature target surface vertically. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of an embodiment of a spray phase change-impact cooling hybrid cavity for laser crystal cooling according to the present invention;

[0026] Figure 2 This is a front view of the aerosol mixing section in an embodiment of the present invention;

[0027] Figure 3 This is a three-dimensional structural diagram of the mixed current stabilizing component in an embodiment of the present invention;

[0028] Figure 4 This is a front view of the mixed current stabilizing component in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the flow divider plate in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the structure of the hexagonal honeycomb structure in an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the jet orifice plate in an embodiment of the present invention;

[0032] Figure label:

[0033] 01-Mixing chamber body, 1-Mixing chamber, 2-Aero-mist mixing section, 3-Fluid acceleration device, 4-Mixing and flow stabilizing component, 5-Spray interface pipe, 6-Main airflow connecting pipe, 7-Diverter orifice plate, 8-Hexagonal honeycomb device, 9-Throat, 901-Throat contraction section, 902-Throat expansion section, 10-Jet orifice plate. Detailed Implementation

[0034] A spray phase change-impact cooling hybrid cavity for laser crystal cooling is designed by dividing the hybrid cavity structure into a gas mist working medium inlet section, a gas mist mixing and stabilizing section, and a fluid acceleration section. The front section of the mixing chamber is designed as the inlet section for the atomizing working medium, which includes an atomizing nozzle interface and several high-speed pressurized gas structures evenly distributed around the atomizing nozzle interface. This ensures that the high-speed pressurized airflow intersects with the extension line of the spray working medium's flow direction, guaranteeing that the spray and the mainstream air can be fully mixed. The middle section of the mixing chamber is designed as the atomizing mixing and stabilizing flow section, with mixing and stabilizing plugs installed inside the chamber. This ensures that the discrete droplet medium in the atomizing two-phase flow working medium is evenly distributed across the cross-section of the mixing chamber's flow channel, while also ensuring that the flow of the atomizing two-phase flow working medium within the flow channel is as close to laminar as possible. Near the end of the atomizing mixing chamber, a fluid acceleration section is designed. After passing through this area, the fluid flows with approximately one-dimensional isentropic flow, accelerates and expands after passing through the throat, increasing the fluid velocity. However, this also ensures that the flow direction of the mixing medium is parallel to the centerline of the mixing chamber, allowing the mixing working medium to ultimately impact the jet orifice plate perpendicularly.

[0035] like Figure 1 As shown, the mixing cavity for laser crystal spray phase change-impact cooling includes a mixing cavity body 01 and a cylindrical mixing cavity 1 disposed within the mixing cavity body 01. The front end of the mixing cavity body 01 is provided with a gas-mist mixing section 2, which can fully mix the mist-like fluid working medium sprayed by the spray subsystem and the gas working medium output by the gas supply subsystem. The rear end is provided with a fluid acceleration device 3. After the fluid passes through the fluid acceleration device 3, it flows in an approximately one-dimensional isentropic manner, which can effectively increase the fluid velocity and at the same time ensure that the flow direction of the mixing medium fluid is parallel to the central axis of the mixing cavity 1.

[0036] At least two sets of mixing and flow stabilizing components 4 are provided in the mixing chamber 1. The mixing and flow stabilizing components 4 are used to ensure that the discrete droplet medium in the gas-mist two-phase flow working medium is uniformly distributed on the cross-section of the flow channel of the mixing chamber 1, and at the same time ensure that the flow of the gas-mist two-phase flow working medium in the flow channel is as close as possible to the laminar flow state.

[0037] Among them, such as Figure 2 As shown, the aerosol mixing section 2 is connected to the front end of the mixing chamber 1 via a thread, facilitating the replacement of the aerosol mixing section 2. A spray through-hole coaxial with the mixing chamber 1 is provided in the middle of the aerosol mixing section 2. Multiple main airflow holes are evenly arranged on the aerosol mixing section 2 along the circumferential direction of the spray through-hole. The angle α between the central axis of each main airflow hole and the central axis of the spray through-hole satisfies: 0°≤a≤30°, effectively ensuring sufficient mixing of the spray and the main airflow. A spray interface pipe 5 communicating with the spray through-hole and a main airflow connecting pipe 6 communicating with each main airflow hole are provided on the outer side of the aerosol mixing section 2.

[0038] like Figure 3 and 4 As shown, the mixing and stabilizing assembly 4 includes a flow divider plate 7 and a hexagonal honeycomb device 8. The flow divider plate 7 is located on one side near the aerosol mixing section 2, and the other side is connected to the hexagonal honeycomb device 8. The flow divider plate 7 is connected to the inner wall of the mixing chamber body 01. The flow divider plate 7 is uniformly provided with multiple circular through holes. The hexagonal honeycomb device 8 is composed of multiple interconnected honeycomb channels with hexagonal cross-sections. The fluid movement direction in each honeycomb channel is parallel to the central axis of the mixing chamber 1.

[0039] like Figure 5 As shown, the thickness of the flow divider plate 7 is 0.5mm to 3mm, and the diameter Do of the circular through holes on it is 0.5mm to 5mm. The circular through holes on the flow divider plate 7 are distributed in a ring, with the spacing between each ring layer being 1.2Do to 3Do, and the spacing between each circular through hole being 1.2Do to 6Do. The circular through holes are designed with equal spacing.

[0040] like Figure 7 As shown, the wall thickness of the hexagonal honeycomb unit 8 is 0.3mm to 2mm, and the outer diameter of the hexagonal honeycomb unit 8 is 5mm to 30mm. During the processing, in order to ensure that the gap between the hexagonal honeycomb unit 8 and the inner wall of the mixing cavity 1 is as small as possible, the hexagonal honeycomb unit 8 adopts laser cutting technology to ensure that the outer diameter of the hexagonal honeycomb unit 8 is the same as the inner diameter of the mixing cavity 1.

[0041] The fluid acceleration device 3 includes a throat 9 disposed within the mixing chamber body 01 and coaxially connected to the rear end of the mixing chamber 1, and a jet orifice plate 10 disposed at the rear end of the throat 9 and connected to the mixing chamber body 01. The throat 9 has a quadratic curve structure, including a throat contraction section 901 and a throat expansion section 902. The extension of the throat contraction section 901 is connected to the rear end of the mixing chamber 1 to form a Laval nozzle structure. The rear end of the extension of the throat expansion section 902 is connected to the jet orifice plate 10. The fluid used for acceleration flows out from the jet orifice plate 10. After passing through the fluid acceleration device 3, the fluid flows in an approximately one-dimensional isentropic manner. After being accelerated and expanded by the throat 9, the fluid velocity is rapidly increased. At the same time, under the rectification effect of the throat outlet expansion section, the flow direction of the mixed medium fluid is ensured to be parallel to the central axis of the mixing chamber 1, thereby achieving the purpose of ejection perpendicular to the jet orifice plate 10.

Claims

1. A spray phase-change-impingement cooling hybrid cavity for laser crystal cooling, comprising a hybrid cavity body (01) and a cylindrical hybrid cavity (1) arranged in the hybrid cavity body (01); characterized in that: The front end of the mixing cavity body (01) is provided with an aerosol mixing section (2), and the rear end is provided with a fluid accelerating device (3); The middle part of the aerosol mixing section (2) is provided with a spray through hole coaxial with the mixing cavity (1), a plurality of main airflow through holes are uniformly arranged on the aerosol mixing section (2) along the periphery of the spray through hole, and the aerosol mixing section (2) is used for fully mixing the spray and the main airflow; The fluid accelerating device (3) includes a throat (9) arranged in the mixing cavity body (01) and coaxially communicated with the rear end of the mixing cavity (1), and a jet orifice plate (10) arranged at the rear end of the throat (9) and connected to the mixing cavity body (01); The throat (9) is a quadratic curve structure, including a throat contraction section (901) and a throat expansion section (902), the extension section of the throat contraction section (901) is connected with the rear end of the mixing cavity (1), and the extension section of the throat expansion section (902) is provided with the jet orifice plate (10); the throat (9) is used for accelerating the mixed fluid and flowing out of the jet orifice plate (10); At least two groups of mixing and stabilizing components (4) are further arranged in the mixing cavity (1) to uniformly mix the mixed fluid and ensure the stability of the flow.

2. The spray phase change-impingement cooling mixing cavity for laser crystal cooling according to claim 1, characterized in that: Each group of the mixing and stabilizing components (4) comprises a flow dividing orifice plate (7) and a hexagonal honeycomb (8), the flow dividing orifice plate (7) is arranged on one side close to the aerosol mixing section (2) and connected with the hexagonal honeycomb (8) on the other side, and the flow dividing orifice plate (7) is connected with the inner wall of the mixing cavity body (01); a plurality of circular through holes are uniformly arranged on the flow dividing orifice plate (7), and the hexagonal honeycomb (8) is composed of a plurality of honeycomb channels connected with each other and having a hexagonal cross section, and the flow direction in each honeycomb channel is parallel to the central axis of the mixing cavity (1).

3. The spray phase change-impingement cooling mixing cavity for laser crystal cooling according to claim 1 or 2, characterized in that: The included angle a between the central axis of each main airflow through hole and the central axis of the spray through hole satisfies 0°≤a≤30°.

4. The spray phase change-impingement cooling mixing cavity for laser crystal cooling according to claim 3, characterized in that: The outer side of the aerosol mixing section (2) is provided with a spray interface pipe (5) communicated with the spray through hole, and a main airflow communication pipe (6) communicated with each main airflow through hole.

5. The spray phase change-impingement cooling mixing cavity for laser crystal cooling according to claim 2, characterized in that: The thickness of the flow dividing orifice plate (7) is 0.5mm~3mm, and the diameter Do of the circular through hole arranged thereon is 0.5mm~5mm; The circular through holes on the flow dividing orifice plate (7) are annularly distributed, the spacing between each ring layer is 1.2Do~3Do, and the spacing between each circular through hole is 1.2Do~6Do.

6. The spray phase change-impingement cooling mixing cavity for laser crystal cooling according to claim 5, characterized in that: The wall thickness of the hexagonal honeycomb device (8) is 0.3mm-2mm, and the diameter of the circumscribed circle of the hexagonal honeycomb device (8) is 5mm-30mm.

7. The spray phase change-impingement cooling hybrid cavity for laser crystal cooling according to claim 6, characterized in that: The length of the hexagonal honeycomb device (8) is 0.3Dc-2.5Dc, wherein Dc is the inner diameter of the hybrid cavity (1).

8. The spray phase change-impingement cooling hybrid cavity for laser crystal cooling according to claim 1, characterized in that: The throat (9) is connected with the rear end of the hybrid cavity (1) through the extension section of the throat contraction section (901) to form a Laval nozzle structure.

9. The spray phase change-impingement cooling hybrid cavity for laser crystal cooling according to claim 1, characterized in that: There are 4-12 main airflow through holes uniformly distributed along the peripheral circumference of the spray through hole.

10. The spray phase change-impingement cooling hybrid cavity for laser crystal cooling according to claim 9, characterized in that: The aerosol mixing section (2) is connected with the front end of the hybrid cavity body (01) through threads.

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