Spray phase change-impingement cooling mixing cavity for laser crystal cooling

Abstract

The invention relates to an ultrahigh-power laser spray phase change-impingement cooling technology, and aims to solve the problems that the existing crystal heat management technology cannot ensure the distribution uniformity of a discrete fog drop working medium, the fluid flow speed is low and the like. The spray phase change-impingement cooling mixing cavity for cooling the laser crystal comprises a mixing cavity body and a cylindrical mixing cavity arranged in the mixing cavity body, a gas-mist mixing section is arranged at the front end of the mixing cavity body, and a fluid accelerating device is arranged at the rear end; a spraying through hole and a plurality of main airflow through holes are formed in the middle of the gas-mist mixing section; the fluid accelerating device comprises a throat arranged in the mixing cavity body and coaxially communicated with the rear end of the mixing cavity, and a jet flow hole plate arranged at the rear end of the throat; the throat is of a quadratic curve structure, the extension section of the throat contraction section is connected with the rear end of the mixing cavity, and the jet flow hole plate is arranged at the rear end of the extension section of the throat expansion section; the throat is used for accelerating the mixed fluid and enabling the mixed fluid to flow out of the jet orifice plate.

Description

Technical Field

[0001] The invention relates to an ultra-high power laser spray phase change-impact cooling device, in particular to a spray phase change-impact cooling mixing cavity used for cooling laser crystals. Background Art

[0002] Attosecond laser is an extremely short light pulse with a duration of only 10 to the negative 18th power seconds. Based on this laser technology, scientists can observe and study the rapid movement and interaction of electrons in the atomic temporal part. The generation and application of attosecond laser is based on the interaction between high-intensity femtosecond laser pulses and gas targets. It can be used to study biological proteins, life phenomena and atomic-scale dynamic processes, greatly promoting the development of scientific research.

[0003] At present, the ultra-high power lasers used to obtain attosecond laser light sources are still in the research and development stage. There are certain technical defects in the process, especially the thermal management technology for the crystals in ultra-high power lasers has become the most difficult problem in the research and development stage. To address the above problems, the current treatment method is the impact jet cooling technology. The impact jet cooling technology at room temperature can achieve a heat dissipation index of 50 to 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 down the laser crystal with ultra-high heat flux density, relying solely on single-phase working fluid is insufficient. The use of spray phase change cooling technology is expected to become an effective solution, but the current spray phase change cooling technology cannot guarantee the uniformity of the distribution of discrete droplet working fluids. 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 the impact cooling process. Summary of the invention

[0004] The purpose of the present invention is to solve the problems that the thermal management technology of the crystal in the existing ultra-high power laser cannot ensure the uniformity of the distribution of discrete droplet working fluid, the flow rate of the mixed fluid is slow, and the accumulation of droplets leads to poor heat exchange effect of the gas-mist two-phase flow working fluid during the impact cooling process, and proposes a spray phase change-impact cooling mixing chamber for cooling the laser crystal.

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

[0006] A spray phase change-impact cooling mixing chamber for cooling laser crystals, comprising a mixing chamber body and a cylindrical mixing chamber arranged in the mixing chamber body; the special feature of the mixing chamber body is that an aerosol mixing section is arranged at the front end of the mixing chamber body, and a fluid acceleration device is arranged at the rear end;

[0007] A spray through hole coaxial with the mixing chamber is provided in the middle of the aerosol mixing section, and a plurality of main air flow holes are evenly provided on the aerosol mixing section along the outer circumference 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 comprises a throat disposed in 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 is a quadratic curve structure, including a throat contraction section and a throat expansion section. The extension section of the throat contraction section is connected to the rear end of the mixing chamber, and the jet orifice is arranged at the rear end of the extension section of the throat expansion section. The throat is used to accelerate the mixed fluid and let it flow out from the jet orifice.

[0010] Furthermore, at least two groups of mixing and stabilizing flow components are provided in the mixing chamber to make the mixed fluid mixed evenly and ensure the stability of its flow;

[0011] Each group of the mixing and stabilizing flow components includes a diverter orifice plate and a hexagonal honeycomb. The diverter orifice plate is arranged on one side close to the aerosol mixing section and is connected to the hexagonal honeycomb on the other side. The diverter orifice plate is connected to the inner wall of the mixing chamber body. A plurality of circular through holes are evenly arranged on the diverter orifice plate. The hexagonal honeycomb is composed of a plurality of honeycomb channels that are interconnected and have a hexagonal cross-section, and the direction of fluid movement in each honeycomb channel is parallel to the central axis of the mixing chamber.

[0012] Furthermore, the angle a between the central axis of each of the main air flow holes and the central axis of the spray through hole satisfies: 0°≤a≤30°.

[0013] Furthermore, a spray interface tube connected to the spray through hole and a main air flow connecting tube connected to each of the main air flow holes are provided on the outer side of the aerosol mixing section.

[0014] Furthermore, the thickness of the diversion orifice plate is 0.5 mm to 3 mm, and the diameter Do of the circular through hole provided thereon is 0.5 mm to 5 mm;

[0015] The circular through holes on the diversion orifice plate are distributed in an annular shape, the spacing between each annular layer is 1.2Do to 3Do, and the spacing between each circular through hole is 1.2Do to 6Do.

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

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

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

[0019] Furthermore, 4 to 12 main air flow holes are evenly distributed along the circumferential direction of the outer periphery of the spray through hole.

[0020] Furthermore, the aerosol mixing section is connected to the front end of the mixing chamber body through a thread.

[0021] [1] The present invention provides a spray phase change-impact cooling mixing chamber for cooling laser crystals. The spray and the main airflow are fully mixed through the aerosol mixing section, thereby ensuring the uniformity and stability of the heat transfer effect of the mixed fluid during the impact cooling process. Then, the flow rate of the mixed fluid is increased through a fluid acceleration device, thereby increasing the movement inertia force of the mist droplets to destroy the thermal boundary layer and improving the heat transfer effect.

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

[0023] [3] The circular through holes on the diversion orifice plate of the present invention are distributed in an annular shape, which can effectively reform the movement state of the gas-mist two-phase working medium in space, so that the droplet particles are evenly distributed in space; then the flow is rectified through the hexagonal honeycomb, so that the mixed fluid moves in a direction parallel to the central axis of the mixing chamber, effectively reducing the turbulence of the mixed fluid, avoiding the uneven distribution of discrete droplets in space caused by the turbulent action of the mixed fluid, thereby effectively improving the heat exchange 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 through the constraint of the throat contraction section, and then ensures that the mixed fluid can reach the jet orifice plate vertically after rectification through the throat expansion section, thereby ensuring that the mixed fluid vertically impacts the external high-temperature target surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an embodiment of a spray phase change-impact cooling hybrid cavity for cooling a laser crystal 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 It is a schematic diagram of the three-dimensional structure of the mixing and stabilizing flow component in an embodiment of the present invention;

[0028] Figure 4 This is a front view of a mixing and stabilizing flow assembly in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the structure of the diverter orifice plate in the embodiment of the present invention;

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

[0031] Figure 7 Schematic diagram of the structure of the jet orifice plate in the embodiment of the present invention;

[0032] Reference numerals:

[0033] 01-mixing chamber body, 1-mixing chamber, 2-aerosol mixing section, 3-fluid acceleration device, 4-mixing and stabilizing flow component, 5-spray interface tube, 6-main air flow connecting tube, 7-diversion orifice plate, 8-hexagonal honeycomb, 9-throat, 901-throat contraction section, 902-throat expansion section, 10-jet orifice plate. DETAILED DESCRIPTION

[0034] A spray phase change-impact cooling mixing cavity for cooling laser crystals has a design concept of dividing the mixing cavity structure into an aerosol working medium inlet section, an aerosol mixing steady flow section and a fluid acceleration section. The front section of the mixing chamber is designed as an aerosol working medium inlet section, which includes an atomizing nozzle interface and a number of high-speed pressurized gas structures evenly distributed around the atomizing nozzle interface, so that the high-speed pressurized airflow intersects with the extension line of the flow direction of the spray working medium, ensuring that the spray and the mainstream gas can be fully mixed; the middle section of the mixing chamber is designed as an aerosol mixing steady flow section, and a mixing and steady flow plug-in is installed in the cavity to ensure that the discrete droplet medium in the aerosol two-phase flow working medium is evenly distributed in the cross-section of the mixing chamber flow channel, and at the same time ensure that the flow of the aerosol two-phase flow working medium in the flow channel is as close to the laminar state as possible; the end of the aerosol mixing chamber is designed as a fluid acceleration section. After passing through this area, the fluid flows in an approximately one-dimensional isentropic manner, and is accelerated and expanded through the throat, so that the fluid flow rate is increased, but at the same time it can also ensure that the flow direction of the mixed medium fluid is parallel to the center line of the mixing chamber, so that the mixed working medium finally impacts the jet orifice plate vertically.

[0035] like Figure 1 As shown, a mixing chamber for laser crystal spray phase change-impact cooling comprises a mixing chamber body 01 and a cylindrical mixing chamber 1 arranged in the mixing chamber body 01; an aerosol mixing section 2 is arranged at the front end of the mixing chamber body 01, which can fully mix the mist fluid working medium sprayed by the spray subsystem and the gas working medium output by the gas supply subsystem; a fluid acceleration device 3 is arranged at the rear end, and the fluid can effectively increase the fluid flow rate in an approximately one-dimensional isentropic flow after passing through the fluid acceleration device 3, and can also ensure that the flow direction of the mixed medium fluid is parallel to the central axis of the mixing chamber 1;

[0036] At least two groups of mixing and stabilizing components 4 are arranged in the mixing chamber 1, and the mixing and stabilizing components 4 are used to ensure that the discrete droplet media in the aerosol two-phase flow medium are evenly 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 aerosol two-phase flow medium in the flow channel is as close to a laminar flow state as possible.

[0037] Among them, Figure 2 As shown, the aerosol mixing section 2 is connected to the front end of the mixing chamber 1 by a thread, which is convenient for replacing 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, and a plurality of main air flow holes are evenly provided on the aerosol mixing section 2 along the outer circumference of the spray through hole, and the angle a between the central axis of each main air flow hole and the central axis of the spray through hole satisfies: 0°≤a≤30°, which can effectively ensure the sufficient mixing of the spray and the main air flow; a spray interface pipe 5 connected to the spray through hole and a main air flow connecting pipe 6 respectively connected to each main air flow 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 flow component 4 includes a diverter orifice plate 7 and a hexagonal honeycomb 8. The diverter orifice plate 7 is arranged on one side close to the aerosol mixing section 2, and the other side is connected to the hexagonal honeycomb 8. The diverter orifice plate 7 is connected to the inner wall of the mixing chamber body 01; a plurality of circular through holes are evenly arranged on the diverter orifice plate 7, and the hexagonal honeycomb 8 is composed of a plurality of honeycomb channels that are interconnected and have a hexagonal cross-section, and the direction of fluid movement 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 diverter orifice plate 7 is 0.5 mm to 3 mm, and the diameter Do of the circular through holes arranged thereon is 0.5 mm to 5 mm; the circular through holes on the diverter orifice plate 7 are distributed in an annular shape, the spacing between each ring layer is 1.2 Do to 3 Do, the spacing between each circular through hole is 1.2 Do to 6 Do, and the circular through holes are designed to be equally spaced;

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

[0041] The fluid acceleration device 3 includes a throat 9 arranged in the mixing chamber body 01 and coaxially connected to the rear end of the mixing chamber 1, and a jet orifice 10 arranged at the rear end of the throat 9 and connected to the mixing chamber 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 to the rear end of the mixing chamber 1 to form a Laval nozzle structure, and the rear end of the extension section of the throat expansion section 902 is connected to the jet orifice 10, and the fluid used for acceleration flows out from the jet orifice 10. After passing through the fluid acceleration device 3, the fluid flows in an approximately one-dimensional isentropic manner, and is accelerated and expanded through the throat 9, so that the fluid flow rate is rapidly increased. At the same time, under the rectifying effect of the throat outlet expansion section, the flow direction of the mixed medium fluid is guaranteed to be parallel to the central axis of the mixing chamber 1, thereby achieving the purpose of being ejected perpendicular to the jet orifice 10.

Claims

1. A spray phase change-impact cooling mixing chamber for cooling a laser crystal, comprising a mixing chamber body (01) and a cylindrical mixing chamber (1) arranged in the mixing chamber body (01); Features: The front end of the mixing chamber body (01) is provided with an aerosol mixing section (2), and the rear end is provided with a fluid acceleration device (3); A spray through hole coaxial with the mixing chamber (1) is arranged in the middle of the aerosol mixing section (2), and a plurality of main air flow holes are evenly arranged on the aerosol mixing section (2) along the outer circumference of the spray through hole. The aerosol mixing section (2) is used to fully mix the spray with the main air flow; The fluid acceleration device (3) comprises a throat (9) arranged in the mixing chamber body (01) and coaxially connected to the rear end of the mixing chamber (1), and a jet orifice plate (10) arranged at the rear end of the throat (9) and connected to the mixing chamber body (01); The throat (9) is a quadratic curve structure, comprising a throat contraction section (901) and a throat expansion section (902); an extension section of the throat contraction section (901) is connected to the rear end of the mixing chamber (1), and the jet orifice plate (10) is arranged at the rear end of the extension section of the throat expansion section (902); the throat (9) is used to accelerate the mixed fluid and allow it to flow out through the jet orifice plate (10).

2. A spray phase change-impact cooling hybrid cavity for cooling laser crystals according to claim 1, Features: At least two groups of mixing and stabilizing flow components (4) are also arranged in the mixing chamber (1) to mix the mixed fluid evenly and ensure the stability of its flow; Each group of the mixing and stabilizing flow components (4) comprises a diverter orifice plate (7) and a hexagonal honeycomb (8); the diverter orifice plate (7) is arranged on one side close to the aerosol mixing section (2) and connected to the hexagonal honeycomb (8) on the other side; the diverter orifice plate (7) is connected to the inner wall of the mixing chamber body (01); a plurality of circular through holes are evenly arranged on the diverter orifice plate (7); the hexagonal honeycomb (8) is composed of a plurality of honeycomb channels that are interconnected and have a hexagonal cross section; the direction of fluid movement in each honeycomb channel is parallel to the central axis of the mixing chamber (1).

3. A spray phase change-impact cooling hybrid cavity for cooling laser crystals according to claim 1 or 2, Features: The angle a between the central axis of each of the main air flow holes and the central axis of the spray through hole satisfies: 0°≤a≤30°.

4. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 3, Features: The outer side of the aerosol mixing section (2) is provided with a spray interface tube (5) connected to the spray through hole, and a main air flow connecting tube (6) connected to each of the main air flow holes.

5. A spray phase change-impact cooling hybrid cavity for cooling laser crystals according to claim 4, Features: The thickness of the diversion orifice plate (7) is 0.5 mm to 3 mm, and the diameter Do of the circular through hole arranged thereon is 0.5 mm to 5 mm; The circular through holes on the diversion orifice plate (7) are distributed in an annular shape, the spacing between each annular layer is 1.2Do to 3Do, and the spacing between each circular through hole is 1.2Do to 6Do.

6. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 5, Features: The wall thickness of the hexagonal honeycomb (8) is 0.3 mm to 2 mm, and the diameter of the circumscribed circle of the hexagonal honeycomb (8) is 5 mm to 30 mm.

7. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 6, Features: The length of the hexagonal honeycomb (8) is 0.3Dc to 2.5Dc, wherein Dc is the inner diameter of the mixing chamber (1).

8. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 1, Features: The throat (9) is connected to the rear end of the mixing chamber (1) through an extension section of the throat contraction section (901) to form a Laval nozzle structure.

9. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 1, Features: 4 to 12 main air flow holes are evenly distributed along the circumferential direction of the outer periphery of the spray through hole.

10. A spray phase change-impact cooling hybrid cavity for cooling a laser crystal according to claim 9, Features: The aerosol mixing section (2) is connected to the front end of the mixing chamber body (01) via a thread.

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