A photovoltaic ribbon rapid cooling device

Abstract

This invention belongs to the field of photovoltaic solder ribbon manufacturing technology, specifically relating to a rapid cooling device for photovoltaic solder ribbons. It includes a cold source tank, a heat exchanger, a water pump, and a cooling water tank. The outlet of the cold source tank is connected to the air inlet of the heat exchanger, and the air outlet of the heat exchanger is connected to a cooling air knife. The cooling air knife is used to rapidly cool the molten solder on the surface of the solder ribbon passing through the cooling chamber. The water inlet of the heat exchanger is connected to the water outlet of the cooling water tank, and the water outlet of the heat exchanger is connected to the water inlet of the cooling water tank via the water pump. This invention utilizes liquid nitrogen as a cold source and fully leverages annealing cooling water as a heat exchange field. The low-temperature liquid nitrogen is vaporized to a lower temperature and blown onto the molten solder on the solder ribbon surface. After the solder coating reaches the target, it enters the rapid cooling chamber, thereby generating a fine and uniform solder layer. Because the cooling chamber is filled with low-temperature nitrogen gas, it completely isolates the high-temperature solder from air oxidation, keeping the surface of the low-temperature solder ribbon in a low-oxidation state.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic ribbon manufacturing technology, specifically relating to a photovoltaic ribbon rapid cooling device. Background Technology

[0002] Currently, the manufacturing process for photovoltaic solder ribbon typically involves hot-dip tin plating, air knife control of plating thickness, and cooling via fan or blower. This cooling method is sufficient for eutectic solders like Sn63Pb37 or Sn60Pb40, which are close to eutectic. Because these solders are close to the eutectic point, the temperature difference between the tin furnace and the solder solidification temperature is relatively small (the tin furnace temperature is typically around 230℃, and the solder liquidus temperature is around 187℃). During cooling, the resulting alloy consists of a eutectic composition, a small amount of tin-rich regions, and a small amount of lead-rich regions, resulting in a relatively uniform microstructure and minimal segregation. Therefore, the melting point is relatively consistent during soldering, and the solder composition is highly uniform after melting. This allows for rapid melting and the formation of an IMC (Integrated Molten Core) with the cell grid lines, achieving uniform soldering and ensuring the strong bond and conductivity between the solder ribbon and the cell.

[0003] However, the above situation changes when component welding enters the low-temperature welding process. First, low-temperature solders are basically ternary or multi-element alloys containing bismuth, with a more complex composition, an increased number of phases during cooling, and significant differences in microscopic composition. Second, the liquidus temperature of low-temperature solder is usually between 140 and 150°C, while the tin plating temperature is around 220°C. The temperature difference range from the time the solder leaves the furnace to solidification is larger, and the crystallization time is longer. If the same cooling scheme is used, severe solder segregation will occur, with excessively large bismuth grains forming coarse particles and significant differences in microscopic composition. When this type of solder is used for cell welding, due to the low welding temperature, different areas will melt at different rates. Some phases will have melted while others will remain solid, leading to inconsistent states at each solder joint and inconsistent welding results. At the same time, coarse bismuth grains will hinder the diffusion of tin into the silver paste layer and impede the formation of IMC, further reducing the welding quality. Overall, the low-melting-point solder results in poor welding performance and low solder joint strength. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a rapid cooling device for photovoltaic solder ribbons. To solve the aforementioned problems, it is necessary to increase the cooling rate of the cryogenic solder during solidification. During the transformation of the liquid solder into a solid state, the rapid cooling device of this invention reduces the size and disperses the precipitated primary phase (such as tin-rich or lead-rich phase) through rapid cooling. Simultaneously, it refines the eutectic reaction layers of the remaining liquid phase, forming a composite structure of "primary phase + fine eutectic". Furthermore, it reduces segregation, restricts solute atom diffusion, and lowers the composition gradient. In summary, rapid cooling effectively controls the microscopic uniformity of multi-element alloy solders and refines bismuth grain size. Under OBB (Zero-Busbar) cryogenic welding processes, multi-element alloy solders in this state exhibit significantly improved weld consistency and solder joint strength.

[0005] To achieve the above technical objectives, the technical solution adopted in this utility model embodiment is as follows:

[0006] A photovoltaic solder ribbon rapid cooling device includes a cold source storage tank, a heat exchanger, a water pump, and a cooling water tank. The outlet of the cold source storage tank is connected to the air inlet of the heat exchanger, and the air outlet of the heat exchanger is connected to a cooling air knife. The cooling air knife is used to rapidly cool the molten solder on the surface of the solder ribbon passing through the cooling chamber.

[0007] The inlet of the heat exchanger is connected to the outlet of the cooling water tank, and the outlet of the heat exchanger is connected to the inlet of the cooling water tank via a water pump.

[0008] Furthermore, the cold source storage tank is equipped with a flow regulating valve, a first pressure gauge and a first thermometer, and the cold source stored in the cold source storage tank is liquid nitrogen;

[0009] The heat exchanger is equipped with a second pressure gauge and a second thermometer; the temperature of the second thermometer is controlled between -20℃ and -10℃.

[0010] Furthermore, the heat exchanger includes a gas chamber and a water chamber. The gas chamber is divided into an outlet chamber and an inlet chamber by a partition. Each of the partitions is arranged parallel and staggered on the inner wall of the heat exchanger shell, and the height of a single partition in the vertical direction is less than the inner diameter of the heat exchanger.

[0011] A cooling copper pipe is installed in the air cavity, and the cooling copper pipe passes through the partition in a U-shape.

[0012] Furthermore, the cold source stored in the cold source storage tank enters the cooling copper pipe through the air inlet of the heat exchanger, and the coolant in the cooling water tank enters the water chamber through the water inlet of the heat exchanger. After heat exchange between the cold source and the coolant, the cold source enters the cooling air knife in gaseous form.

[0013] The coolant in the cooling water tank is annealing cooling water generated in the front-end manufacturing process of the welding strip, and the temperature of the annealing cooling water is higher than the temperature of the cold source.

[0014] Furthermore, the outlet of the heat exchanger is connected to the inlet of the water pump, and the outlet of the water pump is connected to the inlet of the cooling water tank.

[0015] Furthermore, after the solder strip is tinned, the thickness of the molten tin on its surface is adjusted by a tin-blowing air knife, and the molten tin on the surface of the solder strip is quickly cooled by the cooling air knife.

[0016] The solder strip is movable relative to the blowing air knife and the cooling air knife;

[0017] The cooling chamber is located between the solder blowing air knife and the cooling air knife. The solder ribbon travels within the cooling chamber, which is used to collect the low-temperature cold source from the cooling air knife and isolate external gas interference.

[0018] Furthermore, it also includes a fan for drying the cooled solder strip at room temperature.

[0019] The beneficial effects of the technical solution provided by this utility model embodiment are:

[0020] This invention utilizes liquid nitrogen as a cold source and fully leverages annealing cooling water as a heat exchange field. The cryogenic liquid nitrogen is vaporized into a low-temperature gas (-20℃ to -10℃) and blown onto the molten solder on the solder ribbon surface. After the solder coating reaches the target level, it enters a rapid cooling chamber, causing the solder to transform from liquid to solid within one second, thus generating a fine and uniform solder layer. Because the cooling chamber is filled with cryogenic nitrogen, it completely isolates the high-temperature solder from air oxidation, maintaining a low-oxidation state on the surface of the low-temperature solder ribbon. Simultaneously, the cryogenic nitrogen also cools the annealing cooling water, eliminating the need for additional heat dissipation devices and achieving energy and emission reduction effects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the photovoltaic ribbon rapid cooling device in the embodiment of this utility model.

[0022] Figure 2 for Figure 1 A schematic diagram of the structure of the photovoltaic welding ribbon rapid cooling device, which uses a low-temperature cold source to rapidly cool the welding ribbon.

[0023] Figure 3 for Figure 1 A schematic diagram of the heat exchanger in a photovoltaic ribbon rapid cooling device.

[0024] Figure 4 for Figure 3A schematic diagram of the cross-sectional structure of a heat exchanger.

[0025] Figure 5 for Figure 3 Schematic diagram of the AE-AE cross-section structure of the intermediate heat exchanger.

[0026] Figure 6 for Figure 3 Schematic diagram of the AA-AA cross-section structure of the heat exchanger.

[0027] Explanation of reference numerals in the attached drawings: 1. Cold source storage tank; 2. Heat exchanger; 3. Water pump; 4. Cooling air knife; 5. Solder blowing air knife; 6. Cooling chamber; 7. Solder strip; 8. Cooling water tank; 9. Flow regulating valve; 10. First pressure gauge; 11. First thermometer; 12. Heat exchanger inlet valve; 13. Heat exchanger outlet valve; 14. Second pressure gauge; 15. Second thermometer; 16. Air pipe tee; 17. Cooling water tank outlet valve; 18. Inlet; 19. Outlet; 20. Water pump inlet; 21. Water pump outlet; 22. Cooling water tank inlet valve; 23. Fan; 2-1. Cooling copper pipe; 2-2. Baffle; 2-3. Air outlet chamber; 2-4. Air outlet; 2-5. Air inlet; 2-6. Air inlet chamber; 2-7. Water chamber. Detailed Implementation

[0028] In the description of this utility model, it should be understood that the directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" indicate the orientation or positional relationship, which are usually based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as limiting the scope of protection of this utility model.

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0030] Example 1

[0031] like Figure 1-2 As shown, a photovoltaic solder ribbon rapid cooling device includes a cold source storage tank 1, a heat exchanger 2, a water pump 3 and a cooling water tank 8. The outlet of the cold source storage tank 1 is connected to the air inlet 2-5 of the heat exchanger 2, and the air outlet 2-4 of the heat exchanger 2 is connected to the cooling air knife 4. The cooling air knife 4 is used to rapidly cool the molten solder on the surface of the solder ribbon 7 that passes through the cooling chamber 6.

[0032] The inlet 18 of the heat exchanger 2 is connected to the outlet of the cooling water tank 8, and the outlet 19 of the heat exchanger 2 is connected to the inlet of the cooling water tank 8 through the water pump 3.

[0033] The inlet of the cooling water tank 8 is equipped with a cooling water tank inlet valve 22, and the outlet of the cooling water tank 8 is equipped with a cooling water tank outlet valve 17.

[0034] The cold source storage tank 1 is equipped with a flow regulating valve 9, a first pressure gauge 10 and a first thermometer 11. The cold source stored in the cold source storage tank 1 is liquid nitrogen.

[0035] The heat exchanger 2 is equipped with a second pressure gauge 14 and a second thermometer 15; the temperature of the second thermometer 15 is controlled between -20℃ and -10℃.

[0036] like Figure 3-6 As shown, the heat exchanger 2 includes an air chamber and a water chamber 2-7. The air chamber is divided into an outlet chamber 2-3 and an inlet chamber 2-6 by a partition 2-2. Each partition 2-2 is arranged parallel and staggered on the inner wall of the heat exchanger 2 shell, and the height of a single partition 2-2 in the vertical direction is less than the inner diameter of the heat exchanger 2.

[0037] A cooling copper pipe 2-1 is installed in the air chamber, and the cooling copper pipe 2-1 passes through the partition 2-2 in a U-shape.

[0038] Specifically, the air inlet 2-5 of the heat exchanger 2 is provided with a heat exchanger air inlet valve 12, and the air outlet 2-4 of the heat exchanger 2 is provided with a heat exchanger air outlet valve 13. The heat exchanger air inlet valve 12 and the heat exchanger air outlet valve 13 are located at the same end of the heat exchanger.

[0039] The cold source stored in the cold source storage tank 1 enters the cooling copper pipe 2-1 through the air inlet 2-5 of the heat exchanger 2. The coolant in the cooling water tank 8 enters the water chamber 2-7 through the water inlet 18 of the heat exchanger 2. After the cold source and the coolant exchange heat, the cold source enters the cooling air knife 4 in gas form through the air pipe tee 16.

[0040] The coolant in the cooling water tank 8 is the annealing cooling water generated in the front-end manufacturing process of the welding strip 7, and the temperature of the annealing cooling water is higher than the temperature of the cold source.

[0041] The outlet 19 of the heat exchanger 2 is connected to the inlet 20 of the water pump, and the outlet 21 of the water pump is connected to the inlet of the cooling water tank 8.

[0042] After the solder ribbon 7 is tinned, the thickness of the molten tin on its surface is adjusted by the tin blowing air knife 5, and the molten tin on the surface of the solder ribbon 7 is quickly cooled by the cooling air knife 4.

[0043] Solder strip 7 can move relative to the solder blowing air knife 5 and the cooling air knife 4;

[0044] The cooling chamber 6 is located between the blowing air knife 5 and the cooling air knife 4. The solder ribbon 7 travels in the cooling chamber 6. The cooling chamber 6 is used to gather the low-temperature cold source from the cooling air knife 4 and isolate external gas interference.

[0045] In one implementation, the cooling chamber 6 is a glass tube.

[0046] The photovoltaic ribbon rapid cooling device also includes a fan 23, which is used to dry the cooled ribbon 7 at room temperature. Since the ribbon 7 is at a low temperature after rapid cooling, the surface of the ribbon 7 will absorb moisture after it comes out of the cooling chamber 6. The fan 23 can blow the wet ribbon 7 dry, thus drying it at room temperature.

[0047] In one implementation, the solder strip 7 is a tin-plated copper strip. When cooling the solder strip 7, the flow regulating valve 9 on the cold source storage tank 1 is opened, the first pressure gauge 10 and the first thermometer 11 are monitored, and liquid nitrogen is introduced into the air inlet 2-5 of the heat exchanger 2. The heat exchanger 2 serves as a heat exchange field. The regulating cooling water tank inlet valve 22 is opened, and the annealing cooling water flows into the water chamber 2-7 inside the heat exchanger 2 through the water inlet 18 and flows out from the water outlet 19 of the heat exchanger 2. The water pump 3 is started to draw the annealing cooling water in the heat exchanger 2 and returns it to the cooling water tank 8 from the water pump outlet 21. The water flow rate is adjusted by regulating the cooling water tank inlet valve 22 to make full use of the annealing cooling. Water controls the temperature of the cryogenic cold source liquid nitrogen; liquid nitrogen flows from the inlet 2-5 into the cooling copper pipe 2-1 in the inlet chamber 2-6, completing the heat exchange process between the liquid nitrogen and the annealing cooling water in the water chamber 2-7, and then enters the outlet chamber 2-3 and is discharged from the outlet 2-4. The inlet chamber 2-6 and the outlet chamber 2-3 are separated by a partition 2-2. The outlet valve 13 of the heat exchanger is adjusted, the pressure value of the second pressure gauge 14 is monitored, and the temperature value of the second thermometer 15 is controlled within the range of -20℃ to -10℃; the cryogenic nitrogen is transmitted through the gas pipe tee 16 to the cooling air knife 4 to work with the tin blowing air knife 5 to quickly cool the molten solder on the surface of the solder strip 7. At the same time, the cryogenic nitrogen is collected in the pipe in the cooling chamber 6 to isolate external gas interference.

[0048] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A photovoltaic solder strip super-fast cooling device, characterized in that, It includes a cold source storage tank (1), a heat exchanger (2), a water pump (3) and a cooling water tank (8). The outlet of the cold source storage tank (1) is connected to the air inlet (2-5) of the heat exchanger (2), and the air outlet (2-4) of the heat exchanger (2) is connected to the cooling air knife (4). The cooling air knife (4) is used to rapidly cool the molten solder on the surface of the solder strip (7) passing through the cooling chamber (6). The inlet (18) of the heat exchanger (2) is connected to the outlet of the cooling water tank (8), and the outlet (19) of the heat exchanger (2) is connected to the inlet of the cooling water tank (8) via a water pump (3).

2. The photovoltaic solder strip quench device of claim 1, wherein, The cold source storage tank (1) is equipped with a flow regulating valve (9), a first pressure gauge (10) and a first thermometer (11), and the cold source stored in the cold source storage tank (1) is liquid nitrogen; The heat exchanger (2) is equipped with a second pressure gauge (14) and a second thermometer (15); the temperature of the second thermometer (15) is controlled between -20℃ and -10℃.

3. The photovoltaic solder strip quench device of claim 1, wherein, The heat exchanger (2) includes an air chamber and a water chamber (2-7). The air chamber is divided into an outlet chamber (2-3) and an inlet chamber (2-6) by a partition (2-2). Each partition (2-2) is arranged parallel and staggered on the inner wall of the shell of the heat exchanger (2), and the height of a single partition (2-2) in the vertical direction is less than the inner diameter of the heat exchanger (2). A cooling copper pipe (2-1) is provided in the air cavity, and the cooling copper pipe (2-1) passes through the partition (2-2) in a U-shape.

4. The photovoltaic buss band extreme cooling device of claim 3, wherein, The cold source stored in the cold source storage tank (1) enters the cooling copper pipe (2-1) through the air inlet (2-5) of the heat exchanger (2), and the coolant in the cooling water tank (8) enters the water chamber (2-7) through the water inlet (18) of the heat exchanger (2). After the cold source and the coolant exchange heat, the cold source enters the cooling air knife (4) in gaseous form. The coolant in the cooling water tank (8) is the annealing cooling water generated in the front-end manufacturing process of the welding strip (7), and the temperature of the annealing cooling water is greater than the temperature of the cold source.

5. The photovoltaic solder strip quench device of claim 1, wherein, The outlet (19) of the heat exchanger (2) is connected to the inlet (20) of the water pump, and the outlet (21) of the water pump is connected to the inlet of the cooling water tank (8).

6. The photovoltaic solder strip quench device of claim 1, wherein, After the solder strip (7) is tinned, the thickness of the molten tin on its surface is adjusted by the tin blowing air knife (5), and the molten tin on the surface of the solder strip (7) is quickly cooled by the cooling air knife (4). The solder strip (7) is movable relative to the tin blowing air knife (5) and the cooling air knife (4); The cooling chamber (6) is located between the blowing air knife (5) and the cooling air knife (4). The solder strip (7) travels in the cooling chamber (6). The cooling chamber (6) is used to gather the low-temperature cold source from the cooling air knife (4) and isolate external gas interference.

7. The photovoltaic solder strip quench device of claim 1, wherein, It also includes a fan (23) for drying the cooled solder strip (7) at room temperature.

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