CN112670805B - Laser crystal direct-punching cooling type micro-channel radiator - Google Patents

Abstract

The invention discloses a laser crystal direct-impact cooling type micro-channel radiator, which comprises: the laser slab crystal and two groups of micro-channel radiators with the same structure; the microchannel heat sink includes a microchannel layer and a coverboard layer. The fluid working medium enters a concentrated heat dissipation area of the laser slab crystal from the middle part and is directly impacted at high speed and cooled quickly; the microchannel structure of the microchannel layer enhances the heat transfer of the fluid working medium. The fluid working medium flows to both sides after entering the microchannel layer, takes away the heat diffused by the laser slab crystal on the bottom surface, and greatly weakens the temperature distribution difference between the microchannel layer and the laser slab crystal. The whole width of the structure is equivalent to the width of the laser slab crystal in the light transmission direction, and the limitation of a narrow space formed by arranging other components of a laser system in the width direction of the laser slab crystal is met. The two groups of micro-channel radiators work together to realize simultaneous heat absorption at two sides of the laser slab crystal, and the requirement of high-power heat dissipation in the small-size laser slab crystal in a limited space is met.

Description

A laser crystal direct flush cooling type microchannel radiator

technical field

The invention belongs to the technical field of laser applications, and in particular relates to a laser crystal direct flush cooling type micro-channel radiator.

Background technique

The long-term stable operation of solid-state lasers places high demands on crystal heat dissipation. Especially for slab lasers, laser crystals are small in size and high in power. On a very small crystal surface, the output heat flux density can reach several hundred watts. If the heat dissipation capacity is poor, the temperature of the crystal will increase significantly, which will cause a series of problems such as the degradation of the laser beam quality and the low conversion efficiency. Therefore, high-power lasers must be equipped with a stable and efficient crystal cooling system.

At the same time, the laser system has high temperature uniformity on the crystal surface. Since the pump light hits the crystal, the heat flow distribution in the laser crystal changes exponentially along the light-passing direction, and there will be a large temperature gradient. Uneven heat dissipation can cause significant thermal stress effects, often causing crystal fractures and destroying the laser system. Therefore, the laser crystal heat sink should focus on the temperature distribution difference on the crystal surface.

In addition, unlike conventional heat sinks, laser crystal heat sinks often have special requirements for structural arrangement. For the slab laser, the pump light source is a stacked array of semiconductor lasers, which are converging and incident on the end face of the crystal after being shaped by the lens. If the size of the heat sink in the light-passing direction is too large, which greatly exceeds the width of the crystal itself, it will directly block part of the pump light. At the same time, considering the placement of the cavity mirror, the space for the crystal radiator to be arranged between the mirrors is very limited, and the design of the laser crystal radiator should fully consider the space conditions.

The existing laser crystal heat sinks cannot meet the above requirements at the same time. Therefore, it is necessary to design and develop a laser crystal heat sink with a new structure to simplify the structure in a limited layout space and achieve compactness and miniaturization. And meet the high-power heat dissipation requirements of the laser crystal, and consider the non-uniform heat flow distribution characteristics in the crystal, reduce the temperature distribution difference on the crystal surface, and improve the working life and stability of the laser crystal.

SUMMARY OF THE INVENTION

The technical solution of the present invention is to overcome the deficiencies of the prior art and provide a laser crystal direct flush cooling type micro-channel radiator, which can better utilize the long channel structure, improve the overall heat absorption of the fluid working medium, and can be used in all directions. Improve the uniformity of temperature on the surface of the laser strip crystal and the surface of the microchannel heat sink.

In order to solve the above technical problems, the present invention discloses a laser crystal direct flush cooling type microchannel radiator, comprising: a laser strip crystal, an upper microchannel radiator and a lower microchannel radiator;

The upper microchannel radiator and the lower microchannel radiator are microchannel radiators with the same structure; the upper and lower heat dissipation surfaces of the laser strip crystal are respectively combined with the bottom heat absorption surfaces of the upper microchannel radiator and the lower microchannel radiator.

In the above-mentioned laser crystal direct flush cooling type micro-channel radiator, the micro-channel radiator has a two-layer structure, including: a micro-channel layer and a cover plate layer;

The bottom surface of the microchannel layer is a heat-absorbing surface, which is combined with the laser slab crystal;

A micro-channel structure is arranged inside the micro-channel layer;

The cover plate layer is closely matched with the microchannel layer, and provides the inlet and outlet channels of the fluid working medium for the microchannel layer.

In the above-mentioned laser crystal direct flush cooling type microchannel radiator, the middle of the cover plate layer is provided with a fluid working medium inlet and an inlet header; the two sides of the cover plate layer are symmetrically provided with a fluid working medium outlet A, a fluid working medium outlet B, Export header A and export header B;

The fluid working medium inlet is communicated with the microchannel structure through the inlet header;

The fluid working medium outlet A is communicated with the microchannel structure through the outlet header A;

The fluid working medium outlet B communicates with the microchannel structure through the outlet header B.

In the above-mentioned laser crystal direct flush cooling type microchannel radiator, both ends of the microchannel structure are provided with fluid collecting grooves; wherein, the fluid working medium outlet A and the fluid working medium outlet B are respectively directly connected to the fluid collecting grooves at both ends of the microchannel structure.

In the above-mentioned laser crystal direct flush cooling type micro-channel heat sink, the cross-sectional aspect ratio of the micro-channel structure is 1:1 to 1:20.

In the above-mentioned laser crystal direct flush cooling type micro-channel heat sink, the length of the micro-channel structure is 1-10 times the width of the laser strip crystal in the same direction.

In the above-mentioned laser crystal direct flush cooling type microchannel radiator, the fluid working medium inlet, the fluid working medium outlet A and the fluid working medium outlet B are respectively arranged on the flange of the cover layer to reduce the overall weight of the cover layer.

In the above-mentioned laser crystal direct flush cooling type microchannel heat sink, the mating contact surface between the microchannel layer and the cover plate layer is a flat surface, and the layers are welded and sealed by paving or glued to form an integrated structure.

In the above-mentioned laser crystal direct flush cooling type micro-channel heat sink, a sub-mother groove is provided on the mating contact surface between the micro-channel layer and the cover layer, which is used for positioning, welding and sealing between the two layers; wherein, the sub-groove It is arranged on the micro-channel layer, and the mother groove is arranged on the cover plate layer; or the mother groove is arranged on the micro-channel layer, and the sub-channel is arranged on the cover plate layer.

In the above-mentioned laser crystal direct flushing cooling type microchannel radiator, the side extension of the microchannel layer forms a side lug structure, and the side lug structure is provided with bolt holes, which are used for the upper and lower groups of the microchannel radiator to adhere to the laser slat crystal. The overall reinforcement after the combination.

The present invention has the following advantages:

(1) The present invention discloses a laser crystal direct flush cooling type micro-channel radiator, which adopts two sets of upper and lower micro-channel radiators with the same structure to dissipate heat for the upper and lower sides of the laser slat crystal. The fluid working medium inlet on the cover layer is set in the middle. After the fluid working medium enters the micro-channel radiator, it directly scours the position of the laser slat crystal vertically. Here, the cold fluid has a strong heat-carrying ability, and the laser slat crystal is The concentrated heat dissipation area is rapidly cooled, and the fluid working medium flows to both sides of the microchannel structure after vertical scouring. The flow turning will cause local turbulent disturbance, so the direct rushing area has a higher local heat transfer coefficient. At the same time, the microchannel structure greatly enhances the heat transfer capacity, and the properties and flow parameters of the fluid working medium can be selected according to the overall heat dissipation and space environment, so as to realize single-phase flow or two-phase flow of the fluid working medium in the microchannel structure. After the lower part of the lower microchannel layer is in contact with the laser slat crystal, the heat spreads laterally at the same time, so the present invention can better utilize the long channel structure to improve the overall heat absorption of the fluid working medium.

(2) The present invention discloses a laser crystal flush cooling type micro-channel radiator, the high heat flux density area flush type fast heat exchange feature, so that the surface temperature difference of the laser strip crystal in contact with the bottom surface of the micro channel layer is reduced. In the length direction of the microchannel layer, the lateral thermal expansion is significant, and the fluid working medium in the microchannel layer absorbs heat downstream, so that the overall temperature difference on the bottom surface of the microchannel radiator is small. Therefore, the present invention can improve the uniformity of the temperature on the surface of the laser slab crystal and the surface of the microchannel heat sink in all directions.

(3) The present invention discloses a laser crystal direct flush cooling type micro-channel heat sink, and the overall width of the structure is equivalent to the width of the laser strip crystal. The strip-shaped design of the present invention has a compact overall structure, and the inlet and outlet of the working medium in the upper and middle part of the cover layer are designed with flanges, which effectively reduces the overall weight. After the upper and lower groups of microchannel radiators are bonded to the laser slat crystal, they are further reinforced by side lugs and bolts, thereby eliminating structural loosening and fluid leakage caused by long-term thermal expansion and external vibration under ground and space loads. and other risks.

Description of drawings

Fig. 1 is the front view of a kind of laser crystal direct flush cooling type micro-channel heat sink in the embodiment of the present invention;

2 is a side view of a laser crystal direct flush cooling type microchannel heat sink in an embodiment of the present invention;

3 is a structural front view and a top view of a microchannel layer in an embodiment of the present invention;

4 is a front view and a top view of the structure of a cover plate layer in an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

One of the verification ideas of the present invention is to provide a laser crystal direct flush cooling type microchannel radiator, including: a laser slat crystal and two sets of upper and lower microchannel radiators with the same structure; a single-sided microchannel radiator is two The layer structure includes a microchannel layer and a cover plate layer; a microchannel structure is arranged inside the microchannel layer, and the cover plate layer provides the inlet and outlet channels of the fluid working medium for the microchannel layer. The fluid working medium enters the micro-channel radiator from the middle of the cover plate layer, and the laser slat crystals on the bottom surface of the micro-channel layer are concentrated and cooled at a high speed. the local heat transfer coefficient. After the fluid enters the microchannel layer, it flows to both sides along the microchannel, and at the same time, it takes away the heat diffusing the laser slab crystal on the bottom surface, which greatly reduces the temperature distribution difference between the microchannel layer and the surface of the laser slab crystal. The overall width of the structure is equivalent to the width of the laser slat crystal in the light-passing direction, which satisfies the limitation of the narrow space formed by arranging other components of the laser system in the width direction of the laser slat crystal. The upper and lower groups of micro-channel radiators work together to absorb heat on the upper and lower sides of the laser slat crystal at the same time, which meets the high-power heat dissipation requirements in the small-sized laser slat crystal in a confined space.

As shown in FIGS. 1 to 4 , in this embodiment, the laser crystal is flush-cooled with a microchannel radiator, including: a laser strip crystal 1 , an upper microchannel radiator 21 and a lower microchannel radiator 22 . Among them, the upper micro-channel radiator 21 and the lower micro-channel radiator 22 are micro-channel radiators with the same structure; The endothermic surface is combined.

Preferably, a single-sided micro-channel heat sink is used as an example for description: the micro-channel heat sink has a two-layer structure, which may specifically include: a micro-channel layer 3 and a cover plate layer 4 . Among them, the bottom surface of the microchannel layer 3 is a heat-absorbing surface, which is combined with the laser strip crystal 1; the microchannel layer 3 is provided with a microchannel structure 5; Provide inlet and outlet channels for fluid working medium.

In this embodiment, a fluid working medium inlet 6 and an inlet header 7 are arranged in the middle of the cover plate layer 4, and the fluid working medium inlet 6 is communicated with the microchannel structure 5 through the inlet header 7; The working fluid inlet 6 enters the micro-channel radiator, and enters the middle of the micro-channel structure 5 through the inlet header 7 , which is the concentrated heat dissipation area of the laser strip crystal 1 .

Further, two sides of the cover plate layer 4 are symmetrically provided with a fluid working medium outlet A8, a fluid working medium outlet B9, an outlet header A10 and an outlet header B11, and the fluid working medium outlet A8 is connected to the microchannel structure 5 through the outlet header A10. Communication, the fluid working medium outlet B9 communicates with the microchannel structure 5 through the outlet header B11.

It can be seen that, in this embodiment, the fluid working medium forms a vertical direct-injection cooling method for the concentrated heat dissipation area, which has a good heat-carrying capability. After the fluid working medium scours the concentrated heat dissipation area, it flows through the micro-channel structure 5 to both ends of the micro-channel layer 3, and is collected into the outlet header A10 and the outlet header B11, and then passes through the fluid workers symmetrically arranged on both sides of the cover layer 4. The mass outlet A8 and the fluid working medium outlet B9 flow out of the microchannel radiator.

Further, the fluid working medium inlet 6 , the fluid working medium outlet A8 and the fluid working medium outlet B9 are respectively disposed on the flange of the cover plate 4 , which can reduce the overall weight of the cover plate 4 .

In this embodiment, both ends of the microchannel structure 5 are provided with fluid collecting grooves 12 . Wherein, the fluid working medium outlet A8 and the fluid working medium outlet B9 are respectively directly connected with the fluid collecting grooves 12 at both ends of the microchannel structure 5 . It can be seen that after adding the fluid collecting tank 12 , the fluid working medium outlet A8 and the fluid working medium outlet B9 on the cover plate layer 4 are directly connected to the fluid collecting groove 12 on the microchannel structure 5 . The fluid collection tank 12 also facilitates the processing of the microchannel structure 5 .

In this embodiment, the microchannel structure 5 can be a rectangular microchannel, and the cross-sectional aspect ratio can be: 1:1 to 1:20; The equivalent aspect ratio of the section can be: 1:1～1:20; the direction of the microchannel structure 5 is the same (can be in the form of parallel straight lines, curves or broken lines), and the spacing can be uniform or non-uniform; The length can be 1 to 10 times the width of the laser slab crystal 1 in the same direction.

In this embodiment, the mating contact surface between the microchannel layer 3 and the cover plate layer 4 is a flat surface, and the layers are welded and sealed by paving or glued to form an integrated structure, and the heat transfer effect between the layers is good. , the overall cooling power is high.

In this embodiment, a sub-mother groove may be provided on the mating contact surface between the microchannel layer 3 and the cover plate layer 4 for positioning, welding and sealing between the two layers. Wherein, the sub-slot 13 is arranged on the micro-channel layer 3 , and the mother-slot 14 is arranged on the cover layer 4 ;

In this embodiment, the lateral extension of the microchannel layer 3 forms a side lug structure 15, and the side lug structure 15 is provided with bolt holes, which are used for the bonding of the upper and lower two groups of microchannel heat sinks and the laser slab crystal 1. Overall reinforcement.

In summary, the present invention discloses a laser crystal direct flush cooling type micro-channel radiator, which adopts two sets of upper and lower micro-channel radiators with the same structure to dissipate heat for the upper and lower sides of the laser slat crystal. The fluid working medium inlet on the cover layer is set in the middle. After the fluid working medium enters the micro-channel radiator, it scours the position of the laser slat crystal vertically at high speed, and the laser slat crystal is concentrated and cooled rapidly in the heat dissipation area. The flow on both sides of the microchannel structure has good turbulent disturbance at the flow turning point, so the straight-through region has a high local heat transfer coefficient. At the same time, the rapid heat exchange feature of the direct-flush cooling also reduces the temperature difference between the surface of the laser strip crystal in contact with the bottom surface of the microchannel layer, and the bottom surface of the microchannel heat sink and the surface of the laser strip crystal have better temperature uniformity.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can use the methods and technical contents disclosed above to improve the present invention without departing from the spirit and scope of the present invention. The technical solutions are subject to possible changes and modifications. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention belong to the technical solutions of the present invention. protected range.

Contents that are not described in detail in the specification of the present invention belong to the well-known technology of those skilled in the art.

Claims (7)

1. The utility model provides a laser crystal direct-flushing cooled microchannel radiator which characterized in that includes: the device comprises a laser slab crystal (1), an upper micro-channel radiator (21) and a lower micro-channel radiator (22);

the upper micro-channel radiator (21) and the lower micro-channel radiator (22) are micro-channel radiators with the same structure; the upper and lower radiating surfaces of the laser slab crystal (1) are respectively combined with the bottom heat absorbing surfaces of an upper micro-channel radiator (21) and a lower micro-channel radiator (22);

the unilateral microchannel radiator is a two-layer structure, including: a microchannel layer (3) and a cover plate layer (4); wherein the bottom surface of the micro-channel layer (3) is a heat absorption surface and is combined with the laser slab crystal (1); a micro-channel structure (5) is arranged in the micro-channel layer (3); the cover plate layer (4) is tightly matched with the microchannel layer (3) and provides an inlet and outlet channel of fluid working medium for the microchannel layer (3); the middle part of the cover plate layer (4) is provided with a fluid working medium inlet (6) and an inlet header (7); a fluid working medium outlet A (8), a fluid working medium outlet B (9), an outlet header A (10) and an outlet header B (11) are symmetrically arranged on two sides of the cover plate layer (4); the fluid working medium inlet (6) is communicated with the micro-channel structure (5) through an inlet header (7); the fluid working medium outlet A (8) is communicated with the micro-channel structure (5) through an outlet header A (10); the fluid working medium outlet B (9) is communicated with the micro-channel structure (5) through an outlet header B (11); fluid collecting grooves (12) are arranged at two ends of the micro-channel structure (5); the fluid working medium outlet A (8) and the fluid working medium outlet B (9) are respectively and directly communicated with the fluid collecting grooves (12) at the two ends of the micro-channel structure (5);

fluid working medium enters the microchannel radiator from the middle part of the cover plate layer, and directly impacts and quickly cools the laser lath crystal concentrated heat dissipation area on the bottom surface of the microchannel layer at a high speed, and meanwhile, the microchannel structure strengthens the heat transfer of the fluid working medium; after entering the microchannel layer, the fluid working medium flows to two sides along the microchannel, and takes away the heat diffused by the laser slab crystal on the bottom surface to weaken the temperature distribution difference between the microchannel layer and the surface of the laser slab crystal; the upper and lower micro-channel radiators work together to absorb heat at the upper and lower sides of the laser slab crystal.

2. The laser crystal direct-impingement cooled microchannel heat sink according to claim 1, wherein the cross-sectional aspect ratio of the microchannel structure (5) is: 1:1 to 1: 20.

3. The laser crystal direct-impact cooling type micro-channel heat sink according to claim 1, wherein the length of the micro-channel structure (5) is 1-10 times the width of the laser slab crystal (1) in the same direction.

4. The laser crystal direct-impingement cooling microchannel heat sink of claim 1, wherein the fluid working medium inlet (6), the fluid working medium outlet a (8), and the fluid working medium outlet B (9) are respectively disposed on a flange of the cover plate layer (4) to reduce the overall weight of the cover plate layer (4).

5. The laser crystal direct-punching cooling type microchannel heat sink according to claim 1, wherein the matching contact surface between the microchannel layer (3) and the cover plate layer (4) is a flat surface, and a material spreading welding sealing mode or a bonding sealing mode is adopted between the layers to form an integrated structure.

6. The laser crystal direct-punching cooling type micro-channel radiator according to claim 1, wherein a primary-secondary groove is arranged on the matching contact surface between the micro-channel layer (3) and the cover plate layer (4) and is used for positioning, welding and sealing the two layers; wherein, the sub-groove (13) is arranged on the micro-channel layer (3), and the mother groove (14) is arranged on the cover plate layer (4); or the mother groove (14) is arranged on the micro-channel layer (3), and the son groove (13) is arranged on the cover plate layer (4).

7. The direct-flushing cooling type micro-channel heat sink for the laser crystal according to claim 1, wherein the side extension section of the micro-channel layer (3) forms a side lug structure (15), and bolt holes are formed in the side lug structure (15) for integral reinforcement after the upper and lower micro-channel heat sinks are bonded with the laser slab crystal (1).

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