Diffusion furnace with air outlet circulation structure for TOPCon battery piece production

Abstract

The utility model discloses a TOPCon battery piece production diffusion furnace with an air outlet circulation structure, the diffusion furnace comprises a furnace body and a preheating box, the furnace body is internally provided with multiple layers of heating cavities and air supply pipes penetrating through the heating cavities from top to bottom, one side of the top of the furnace body is provided with a first air outlet, and the other side of the top of the furnace body is provided with a second air outlet; the top of the first air outlet is connected with a second air inlet of the preheating box through a circulation pipeline, a heat exchange mechanism is arranged in the preheating box and comprises a plurality of heat exchange branch pipes, a moving plate, a rotating plate and a rotating motor, and the tops of the heat exchange branch pipes are fixed to the bottom of the rotating plate. According to the utility model, reaction gas can be uniformly fed into each heating cavity, so that the reaction gas can be in full contact with a silicon wafer, high-temperature tail gas discharged by the diffusion furnace is fed into the preheating box, and heat of the high-temperature tail gas can be recycled to heat the reaction gas, so that the temperature difference between the reaction gas and the interior of the diffusion furnace is reduced, and adverse effects on reaction are avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery processing, and in particular relates to a diffusion furnace for producing TOPCon battery sheets with an exhaust circulation structure. Background Art

[0002] TOPCon cells are a type of photovoltaic crystalline silicon cells. In recent years, they have been gradually adopted by industry companies due to their obvious advantages such as high conversion efficiency, low attenuation performance, and high mass production cost performance. Structurally, TOPCon is a tunneling oxide layer passivation contact solar cell technology based on the principle of selective carriers. Its cell structure is an N-type silicon substrate cell. An ultra-thin silicon oxide layer is prepared on the back of the cell, and then a thin layer of doped silicon is deposited. The two together form a passivation contact structure, which effectively reduces surface recombination and metal contact recombination. During the production process, TOPCon cells will undergo a boron diffusion process, the main function of which is to prepare a PN junction. Due to the low solid solubility of boron in silicon, high temperature and longer time are required for diffusion. At the same time, the choice of diffusion source will also have an impact on the production process. Chlorides are highly corrosive, bromides are highly viscous, the cleaning process is cumbersome, and operation and maintenance costs are increased. The traditional diffusion furnace directly feeds the reaction gas into the diffusion furnace. There is no sufficient contact between the silicon wafer and the gas, which will make the production quality unstable. In addition, the temperature of the gas introduced is very different from the temperature in the diffusion furnace, which will make the temperature in the furnace inconsistent, which is not conducive to the reaction. In view of this, it is necessary to improve the traditional diffusion furnace. Summary of the invention

[0003] In order to address the deficiencies of the prior art, the purpose of the utility model is to provide a diffusion furnace for TOPCon cell production with an exhaust circulation structure, which can evenly deliver the reaction gas to each heating chamber so that the reaction gas and silicon wafer can be in more complete contact, and the high-temperature exhaust gas discharged from the diffusion furnace is delivered to a preheating box, and its heat can be recycled to heat the reaction gas, so as to reduce the temperature difference between the reaction gas and the inside of the diffusion furnace and avoid adverse effects on the reaction.

[0004] In order to achieve the above objectives, the utility model adopts the following technical solutions:

[0005] A diffusion furnace for producing TOPCon battery cells with an air outlet circulation structure, the diffusion furnace comprises a furnace body and a preheating box, the interior of the furnace body is provided with multiple layers of heating chambers and air supply pipes penetrating the heating chambers from top to bottom, a first air outlet is provided on one side of the top of the furnace body, the top of the first air outlet is connected to the second air inlet of the preheating box through a circulation pipeline, a heat exchange mechanism is provided inside the preheating box, the heat exchange mechanism comprises a plurality of heat exchange branch pipes, a movable plate, a rotating plate, and a rotating motor, the top of the heat exchange branch pipe is fixed to the bottom of the rotating plate, the rotating motor is fixed to the middle of the movable plate, the output end of the rotating motor is fixedly connected to the top of the rotating plate through a rotating shaft, the rotating plate is driven to rotate by the rotating motor, so as to drive the rotation of the heat exchange branch pipe, connecting rods are vertically fixed on both sides of the top of the movable plate, and the connecting rods are slidably connected to the top wall of the preheating box.

[0006] Preferably, a third air inlet and a third air outlet are respectively provided on the left and right sides of the aforementioned preheating box, and the third air inlet and the third air outlet are respectively connected to the heat exchange branch pipes located on the left and right sides through a retractable hose.

[0007] Preferably, the third air outlet is connected to the air supply pipe through a pipeline passing through the side wall of the furnace body.

[0008] Preferably, the air supply pipe is an elliptical structure, fixed on the rear side wall of the furnace body, and a plurality of evenly distributed air supply holes are arranged on the front side of the air supply pipe.

[0009] Preferably, a second gas outlet is provided at one side of the bottom of the preheating box, and the second gas outlet is connected to the gas purification device through a pipeline.

[0010] Preferably, the adjacent heat exchange branch pipes are connected via connecting pipes.

[0011] Preferably, the rotating plate is a circular plate structure.

[0012] The advantages of the utility model are as follows: the utility model has a simple structure, and by arranging an elliptical air supply pipe that runs through multiple heating chambers in the diffusion furnace, the reaction gas can be evenly delivered to each heating chamber, so that the reaction gas and the silicon wafer can be in more complete contact; the high-temperature exhaust gas discharged from the diffusion furnace is sent to the preheating box, and its heat can be recycled to heat the reaction gas, so as to reduce the temperature difference between the reaction gas and the inside of the diffusion furnace, and avoid adverse effects on the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model;

[0014] Figure 2 It is a structural schematic diagram of the preheating box in the utility model;

[0015] Figure 3 It is a structural schematic diagram of the transfer plate of the utility model.

[0016] The meanings of the reference numerals in the figure are: 1. furnace body, 1.1. first air outlet, 2. air supply pipe, 2.1. air supply hole, 3. circulation pipeline, 4. preheating box, 4.1. second air inlet, 4.2. third air inlet, 4.3. third air outlet, 4.4. second air outlet, 5. heat exchange branch pipe, 6. movable plate, 7. rotating plate, 8. rotating motor, 9. connecting rod, 10. connecting pipe. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] See also Figure 1 and Figure 2 The utility model discloses a diffusion furnace for producing TOPCon battery cells with an exhaust circulation structure. The diffusion furnace comprises a furnace body 1 and a preheating box 4. The interior of the furnace body 1 is provided with multiple layers of heating chambers and air supply pipes 2 penetrating the heating chambers from top to bottom. The air supply pipe 2 is an elliptical structure fixed on the rear side wall of the furnace body 1. The front side of the air supply pipe 2 is provided with a plurality of evenly distributed air supply holes 2.1.

[0019] A first air outlet 1.1 is provided on one side of the top of the furnace body 1, and the top of the first air outlet 1.1 is connected to a second air inlet 4.1 of a preheating box 4 through a circulation pipeline 3, so that the tail gas in the furnace body 1 is passed into the preheating box 4, and its heat can be recycled to heat the reaction gas, so as to reduce the temperature difference between the reaction gas and the inside of the diffusion furnace, and avoid adverse effects on the reaction.

[0020] The preheating box 4 is provided with a heat exchange mechanism inside, which includes a plurality of heat exchange branch pipes 5, a movable plate 6, a rotating plate 7, and a rotating motor 8. The rotating plate 7 is a circular plate structure. The top of the heat exchange branch pipe 5 is fixed to the bottom of the rotating plate 7, and the adjacent heat exchange branch pipes 5 are connected through a connecting pipe 10. The rotating motor 8 is fixed to the middle of the movable plate 6, and the output end of the rotating motor 8 is fixedly connected to the top of the rotating plate 7 through a rotating shaft. The rotating plate 7 is driven to rotate by the rotating motor 8 to drive the rotation of the heat exchange branch pipe 5, so as to facilitate more sufficient heat exchange between the reaction gas in the heat exchange branch pipe 5 and the high-temperature exhaust gas in the preheating box 4. In actual application, the rotation mode of the rotating motor 8 is set to forward rotation of 30 degrees and then reverse rotation of 30 degrees, and the rotation is repeated in this way. The left and right sides of the preheating box 4 are respectively provided with a third air inlet 4.2 and a third air outlet 4.3, which are respectively connected to the heat exchange branch pipes 5 located on the left and right sides through retractable hoses. The connection through the retractable hoses can avoid affecting the rotation of the heat exchange branch pipes 5.

[0021] Connecting rods 9 are vertically fixed on both sides of the top of the moving plate 6, and the connecting rods 9 are slidably connected to the top wall of the preheating box 4. The sliding connection method selects a slider, a slide rail and a sliding motor. The sliding connection method belongs to a commonly used technical solution in the prior art, so this application will not go into details. The left and right movement of the moving plate 6 can drive the left and right movement of the heat exchange branch pipe 5, so that the reaction gas and the high-temperature exhaust gas contact more evenly, and the heat exchange efficiency is improved.

[0022] The third gas outlet 4.3 is connected to the gas supply pipe 2 through a pipeline through the side wall of the furnace body 1. A second gas outlet 4.4 is arranged on one side of the bottom of the preheating box 4. The second gas outlet 4.4 is connected to the gas purification device through a pipeline, and the tail gas is discharged after purification to avoid environmental pollution.

[0023] The utility model has a simple structure. By arranging an elliptical air supply pipe 2 that passes through multiple heating chambers in the diffusion furnace, the reaction gas can be evenly delivered to each heating chamber, so that the reaction gas and the silicon wafer can be in more complete contact; the high-temperature exhaust gas discharged from the diffusion furnace is sent to the preheating box 4, and its heat can be recycled to heat the reaction gas, so as to reduce the temperature difference between the reaction gas and the inside of the diffusion furnace and avoid adverse effects on the reaction.

[0024] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the above embodiments do not limit the utility model in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the utility model.

Claims

1. A diffusion furnace for TOPCon cell production with an outlet gas circulation structure, characterized in that: The diffusion furnace comprises a furnace body and a preheating box (4); the furnace body (1) is provided with multiple layers of heating chambers from top to bottom and air supply pipes (2) penetrating each heating chamber; a first air outlet (1.1) is provided on one side of the top of the furnace body (1); the top of the first air outlet (1.1) is connected to a second air inlet (4.1) of the preheating box (4) via a circulation pipeline (3); a heat exchange mechanism is provided inside the preheating box (4); the heat exchange mechanism comprises a plurality of heat exchange branch pipes (5), a movable plate (6), a rotating plate (7), a rotating motor (8), the top of the heat exchange branch pipe (5) is fixed to the bottom of the rotating plate (7), the rotating motor (8) is fixed to the middle of the movable plate (6), the output end of the rotating motor (8) is fixedly connected to the top of the rotating plate (7) through a rotating shaft, the rotating plate (7) is driven to rotate by the rotating motor (8), so as to drive the heat exchange branch pipe (5) to rotate, and connecting rods (9) are vertically fixed on both sides of the top of the movable plate (6), and the connecting rods (9) are slidably connected to the top wall of the preheating box (4).

2. The diffusion furnace for producing TOPCon solar cells with an exhaust gas circulation structure according to claim 1, characterized in that: A third air inlet (4.2) and a third air outlet (4.3) are respectively arranged on the left and right sides of the preheating box (4); the third air inlet (4.2) and the third air outlet (4.3) are respectively connected to the heat exchange branch pipes (5) located on the left and right sides via retractable hoses.

3. The diffusion furnace for producing TOPCon solar cells with an exhaust circulation structure according to claim 2, characterized in that: The third air outlet (4.3) is connected to the air supply pipe (2) through a pipeline passing through the side wall of the furnace body (1).

4. The diffusion furnace for producing TOPCon solar cells with an exhaust gas circulation structure according to claim 1, characterized in that: The air supply pipe (2) is an elliptical structure and is fixed to the rear side wall of the furnace body (1). A plurality of evenly distributed air supply holes (2.1) are provided on the front side of the air supply pipe (2).

5. The diffusion furnace for producing TOPCon solar cells with an exhaust gas circulation structure according to claim 1, characterized in that: A second gas outlet (4.4) is provided on one side of the bottom of the preheating box (4), and the second gas outlet (4.4) is connected to a gas purification device via a pipeline.

6. The diffusion furnace for producing TOPCon solar cells with an exhaust gas circulation structure according to claim 1, characterized in that: Adjacent heat exchange branch pipes (5) are connected via connecting pipes (10).

7. The diffusion furnace for producing TOPCon solar cells with an exhaust circulation structure according to claim 1, characterized in that: The rotating plate (7) is a circular plate structure.

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