A solar photovoltaic wafer production apparatus

Abstract

A kind of solar photovoltaic wafer production equipment, it is in heating furnace jacket by heating crucible to the crystal bar is heated melting, after melting liquid crystal is formed strip wafer by the blanking slit of the crucible on the crucible support, it is cooled by cooling pipe and increases viscosity, under the clamping of the traction roller of pair arrangement, realize the production of thinner photovoltaic wafer.The thickness limit of traditional wire cutting process 200 μm or so, can produce thinner photovoltaic wafer, significantly improve material utilization and reduce production cost, the setting of traction roller, guide plate and cooling pipe, can realize the accurate control of strip crystal thickness and transmission speed, ensure product thickness consistency, the vacuum environment and inert gas protection system in production process, can effectively reduce oxidation impurity, improve crystal purity and photoelectric conversion efficiency, temperature gauge and observation window real-time monitoring melting state and forming process, guarantee controllability of process parameters.

Description

Technical Field

[0001] This utility model relates to the field of solar panel technology, specifically to a solar photovoltaic wafer production equipment. Background Technology

[0002] Solar photovoltaic wafers are the core components of solar photovoltaic power generation systems. When sunlight shines on the surface of the wafer, photons interact with silicon atoms, and the energy of the photons is transferred to electrons, enabling the electrons to gain enough energy to break free from the atomic bonds and form free electrons and holes. Under the action of an electric field, electrons and holes move in a directional manner, thereby generating current and realizing the conversion of solar energy into electrical energy.

[0003] Traditional monocrystalline silicon and polycrystalline silicon solar photovoltaic wafers are generally produced by first pulling monocrystalline silicon or polycrystalline silicon ingots, and then cutting them into solar photovoltaic wafers of the required thickness using wire cutting. Because the diamond wire causes significant wear on the ingots during cutting, material waste cannot be avoided, and only products with a thickness of about 200um can be produced. Producing thinner photovoltaic wafers will lead to a decrease in yield and an increase in product cost. Summary of the Invention

[0004] The purpose of this invention is to provide a solar photovoltaic wafer production equipment. By heating and melting a crystal rod in a crucible and letting it fall through a slit, cooling it down, and then drawing it thin with traction rollers to form a strip crystal of the required thickness, this method can process thinner solar photovoltaic wafer products compared to traditional manufacturing processes. It makes full use of the crystal rod material, improves the utilization rate of raw materials, reduces production costs, and solves the problems in the prior art.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: a solar photovoltaic wafer production equipment, including a heating furnace jacket, a horizontally arranged crucible support installed inside the heating furnace jacket, a crucible set on the crucible support, the crucible being made of platinum or platinum alloy, a connected heating device installed on the crucible, a polished material feeding slit opened at the bottom of the crucible, a through hole opened on the crucible support allowing liquid crystals to flow through, and traction rollers arranged side by side installed inside the heating furnace jacket at the lower part of the crucible support, the two traction rollers being able to rotate synchronously in opposite directions, and a [missing information - likely a design feature] opened at the bottom of the heating furnace jacket. The furnace jacket features an openable and closable discharge port. The gap between the two traction rollers corresponds to the material drop slit and the discharge port. Guide plates are installed side-by-side between the traction rollers and the crucible support, and between the traction rollers and the discharge port. Cooling pipes are installed on the outer side of each guide plate. A furnace cover is installed on the top of the heating furnace jacket. A connected vacuum pipe and inert gas filling pipe are also connected inside the heating furnace jacket. A vacuum pump is installed at one end of the vacuum pipe. A thermometer is installed inside the heating furnace jacket on one side of the crucible. An observation window is installed on the heating furnace jacket between the traction rollers and the crucible support, corresponding to the guide plates. Two sets of traction rollers are installed side-by-side inside the heating furnace jacket, with guide plates arranged side-by-side between the two sets of traction rollers. Cooling pipes are installed on the outer side of each guide plate. A first drive motor is installed on the outside of the heating furnace jacket. The output shaft of the first drive motor extends into one end of the heating furnace jacket and is equipped with a first sprocket. A second sprocket and a third sprocket are installed on the shaft of the traction roller located on the lower side, and a fourth sprocket is installed on the shaft of the traction roller located on the upper side. The shafts of the two traction rollers arranged side by side are equipped with meshing gears. A first chain is installed between the first sprocket and the second sprocket, and a second chain is installed between the third sprocket and the fourth sprocket. When the first drive motor is started, it can drive the two sets of traction rollers arranged side by side to rotate synchronously in opposite directions. The guide plate between the traction roller and the crucible support can move closer together. Horizontally arranged guide rods are mounted on the guide plates. Guide sleeves that mate with the guide rods are provided on the inner wall of the heating furnace sleeve. Two sets of triangular-section weights are installed between the upper parts of the two guide plates. The material discharge slit is located between the two sets of weights. The weights always tend to move the guide plates apart. A rotating rod is installed on the heating furnace sleeve corresponding to the position of the guide plates. A handle is provided at the end of the rotating rod extending out of the heating furnace sleeve. Two clamping rods are arranged side-by-side at the end of the rotating rod located on the heating furnace sleeve. The two clamping rods are located on the outer sides of the guide plates. A guide frame is also installed at the bottom of the crucible support. The guide frame has arc-shaped grooves that mate with the clamping rods. Turning the handle drives the clamping rods, causing the guide plates on both sides to push the weights upwards and move closer together. A vertically arranged column is installed on each weight. A through hole that mates with the column is provided at the bottom of the crucible support, allowing the weights to rise and fall vertically under the guidance of the through hole.A rotatable baffle is installed inside the heating furnace sleeve at the discharge port. A second drive motor is installed at the bottom of the heating furnace sleeve, and the output shaft of the second drive motor extends into the heating furnace sleeve and is connected to the rotating shaft of the baffle. The width of the material discharge slit is 30-300 μm.

[0006] The positive effects of this invention are as follows: The solar photovoltaic wafer production equipment described herein involves heating and melting crystal rods in a heating crucible within a heating furnace. The molten liquid crystals are then fed through a slit in the crucible support to form ribbon-shaped wafers. These wafers are cooled by cooling pipes to increase viscosity, and then pulled down by paired traction rollers to produce thinner photovoltaic wafers. This breaks through the traditional wire cutting process's thickness limitation of approximately 200μm, enabling the production of thinner photovoltaic wafers, significantly improving material utilization and reducing production costs. The traction rollers, guide plates, and cooling pipes allow for precise control of the ribbon crystal thickness and transmission speed, ensuring consistent product thickness. The vacuum environment and inert gas protection system during production effectively reduce oxidation impurities, improving crystal purity and photoelectric conversion efficiency. A temperature measuring instrument and observation window monitor the melting state and forming process in real time, ensuring controllable process parameters. Compared to traditional wire cutting, the direct melting and forming process reduces mechanical wear and energy consumption, effectively lowering production energy consumption and improving material utilization. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of this utility model;

[0008] Figure 2 This is a schematic diagram of the internal structure of the heating furnace jacket in this utility model;

[0009] Figure 3 This is a schematic diagram of the structure of the other side of the interior of the heating furnace jacket in this utility model;

[0010] Figure 4 yes Figure 2 An enlarged view of the sectional view along the AA direction;

[0011] Figure 5 This is a schematic diagram of a structure with a guide plate installed between the traction roller and the crucible support;

[0012] Figure 6 yes Figure 5 A schematic diagram showing the movement and approach of the guide plate.

[0013] Figure 7 This is a schematic diagram of the structure between the weight and the crucible support. Detailed Implementation

[0014] The solar photovoltaic wafer production equipment described in this utility model, such as Figure 1-4As shown, the device includes a heating furnace jacket 1, within which a horizontally arranged crucible support 2 is installed. A crucible 3, made of platinum or a platinum alloy, is placed on the support 2. A connected heating device is mounted on the crucible 3, and a polished blanking slit 4 is provided at the bottom of the crucible 3. The crucible 3 is used to hold a crystal rod, which is then heated and melted to a liquid state by the heating device. The heating device can be an existing electric heater or an electric heating rod. Alternatively, the crystal rod in the crucible 3 can be heated using medium-frequency heating, silicon molybdenum rod heating, or by electrically heating the crucible 3.

[0015] A through hole is provided on the crucible support 2 to allow liquid crystals to flow through. A traction roller 5 is installed in the heating furnace sleeve 1 at the bottom of the crucible support 2. The two traction rollers 5 can rotate synchronously in opposite directions. A discharge port 6 that can be opened and closed is provided at the bottom of the heating furnace sleeve 1. The gap between the two traction rollers 5 is arranged in correspondence with the material drop slit 4 and the discharge port 6.

[0016] Liquid crystals fall through the feeding slit 4 under the influence of gravity. The width of the feeding slit 4 determines the thickness of the photovoltaic wafer produced. After falling through the feeding slit 4, the crystals are cooled to form a ribbon-like shape, which then enters between two traction rollers 5. The opposing rotation of the traction rollers 5 drives the ribbon-like crystals to continue moving downwards into the discharge port 6. The bottom of the crucible 3 has a wedge-shaped groove, and the feeding slit 4 is located at the bottom of the wedge-shaped groove.

[0017] To ensure the ribbon crystal maintains its shape during its downward movement, guide plates 7 are installed side-by-side between the traction roller 5 and the crucible support 2, and between the traction roller 5 and the discharge port 6. The ribbon crystal is clamped between two guide plates 7. To achieve cooling and shaping of the ribbon crystal, cooling pipes 8 are provided on the outer side of each guide plate 7. The cooling pipes 8 are connected to the external cooling system of the furnace body, and the cooling medium inside the cooling pipes 8 can be water-cooled, oil-cooled, or air-cooled, and the cooling medium can be recycled. The platinum alloy in the crucible 3 can refer to a surface-polished platinum-rhodium alloy or a platinum-iridium alloy.

[0018] To facilitate the placement of crystal rods into the furnace, a furnace cover 9 is installed on the top of the heating furnace sleeve 1. The furnace cover 9 can be detachably connected to the furnace body via a flange. A vacuum pipe 10 and an inert gas filling pipe 11 are also connected inside the heating furnace sleeve 1. A vacuum pump 12 is installed at one end of the vacuum pipe 10. Before heating the crystal rods, the heating furnace sleeve 1 can be evacuated by the vacuum pump 12 to prevent the crystal rods from reacting with the air inside the furnace during heating and generating oxidation impurities. During the evacuation process, inert gases such as argon can be added to the furnace through the inert gas filling pipe 11 to prevent reactions during heating and to ensure that the pressure inside the furnace is greater than the external pressure, preventing external air from entering the furnace, thus forming a relatively closed heating protection device.

[0019] A thermometer 13 is installed inside the heating furnace sleeve 1 on one side of the crucible 3. The thermometer 13 can monitor the temperature data inside the furnace in real time and provide feedback, so that the operator can adjust the heating temperature according to the melting state of the crystal rod. In order to allow the staff to monitor the forming process in real time and ensure the controllability of process parameters, an observation window 14 is installed on the heating furnace sleeve 1 between the traction roller 5 and the crucible support 2. The observation window 14 is set corresponding to the guide plate 7. Through the observation window 14, the state of the liquid crystal falling downward through the dropping slit 4 can be observed.

[0020] Furthermore, in order to ensure the downward guidance of the ribbon crystal and maintain the consistency of the thickness and shape of the wafer product before entering the discharge port 6, two sets of traction rollers 5 arranged in parallel can be installed inside the heating furnace sleeve 1. A guide plate 7 arranged in parallel is installed between the two sets of traction rollers 5. Cooling pipes 8 are provided on the outer side of each guide plate 7. The wafer thinning and forming channel is formed from the traction rollers 5 and the guide plate 7 between the dropping slit 4 and the discharge port 6.

[0021] Furthermore, to achieve the opposite rotation of the two sets of parallel traction rollers 5, a first drive motor 15 can be installed on the outside of the heating furnace sleeve 1. A first sprocket 16 is installed at one end of the output shaft of the first drive motor 15 extending into the heating furnace sleeve 1. A second sprocket 17 and a third sprocket 18 are installed on the shaft of the lower traction roller 5, and a fourth sprocket 19 is installed on the shaft of the upper traction roller 5. Meshing gears 20 are installed on the shafts of the two parallel traction rollers 5. A first chain 21 is fitted between the first sprocket 16 and the second sprocket 17, and a second chain 22 is fitted between the third sprocket 18 and the fourth sprocket 19. When the first drive motor 15 is started, it can drive the two sets of parallel traction rollers 5 to rotate synchronously in opposite directions.

[0022] Furthermore, in order to ensure that the liquid crystals can accurately enter the gap between the two traction rollers 5 after flowing out of the discharge slit 4, the guide plate 7 between the traction rollers 5 and the crucible support 2 can move closer to clamp and guide the liquid crystals, preventing them from accumulating on the upper part of the guide plate 7, and ensuring that the strip crystals can enter between the traction rollers 5 and continue to move downwards.

[0023] To achieve the movement and approach of guide plate 7, such as Figure 5-7 As shown, a horizontally arranged guide rod 23 is installed on the guide plate 7, and a guide sleeve 24 that cooperates with the guide rod 23 is provided on the inner wall of the heating furnace sleeve 1. The horizontal movement of the guide plate 7 can be achieved through the cooperation of the guide rod 23 and the guide sleeve 24.

[0024] Two sets of triangular-section weights 25 are installed between the upper parts of the two guide plates 7. The material discharge slit 4 is located between the two sets of weights 25. The weights 25 always tend to move and separate the two guide plates 7. An arc-shaped plate can be set on the upper part of the guide plates 7 to limit the weights 25. Under the action of gravity, the weights 25 move and separate the two guide plates 7. At this time, the guide rod 23 moves to the limit position within the guide sleeve 24, and the guide plates 7 no longer separate and move. The weights 25 also form a downward limit. At this time, the two guide plates 7 are in a state of separation with a large distance between them.

[0025] A rotating rod 26 is installed on the heating furnace sleeve 1 corresponding to the position of the guide plate 7. A handle 27 is provided at the end of the rotating rod 26 extending out of the heating furnace sleeve 1. Two clamping rods 28 are arranged side by side at the end of the rotating rod 26 located in the heating furnace sleeve 1. The two clamping rods 28 are located on the outer side of the guide plate 7. A guide frame 29 is also installed at the bottom of the crucible support 2. An arc-shaped groove 30 is opened on the guide frame 29 to cooperate with the clamping rods 28. When the handle 27 is turned, the clamping rods 28 rotate in the arc-shaped groove 30. The two clamping rods 28 rotate up and down respectively, which can drive the guide plates 7 on both sides to move closer to each other. At the same time, it can overcome the gravity of the weight block 25 and move it upward. At this time, the guide plates 7 on both sides are in a close proximity state.

[0026] After the liquid crystal falls through the drop slit 4, the operator can observe the state of the falling crystal in the observation window 14, and by turning the handle 27, move the guide plates 7 on both sides closer together to clamp and guide the falling liquid crystal, ensuring that the liquid crystal rod can accurately enter the gap between the two traction rollers 5.

[0027] Furthermore, in order to guide the vertical movement of the weight 25, a vertically arranged column 31 can be installed on the weight 25, and a through hole that cooperates with the column 31 is opened at the bottom of the crucible support 2, so that the weight 25 can be vertically raised and lowered under the guidance of the through hole.

[0028] Furthermore, to achieve the opening and closing of the discharge port 6, it is closed to maintain a sealed state inside the furnace during the heating and melting of the crystal rod, and opened after the ribbon crystal is formed to achieve normal material discharge. A rotatable baffle 32 can be installed inside the heating furnace sleeve 1 at the location of the discharge port 6. A second drive motor 33 is installed at the bottom of the heating furnace sleeve 1, and the output shaft of the second drive motor 33 extends into the heating furnace sleeve 1 and is connected to the rotating shaft of the baffle 32. The rotation and start / stop of the second drive motor 33 can realize the opening and closing of the discharge port 6 by the baffle 32. Through the above device, the material discharge can be automatically controlled, reducing manual intervention and improving production efficiency and safety.

[0029] Furthermore, in order to accommodate the production of wafers of different thicknesses, the width of the blanking slit 4 is 30-300um.

[0030] The solar photovoltaic wafer production process, combined with the above-mentioned device, can also be described as follows: First, the photovoltaic crystal rod is placed in the crucible 3, and a vacuum negative pressure is applied to the heating furnace jacket 1. The crystal rod is heated to a liquid state through the crucible 3. After the crystal rod is heated to a liquid state, inert gases such as argon are simultaneously added to the heating furnace jacket 1 to ensure that the gas pressure inside the furnace is greater than the external gas pressure, thus preventing external air from entering the furnace and causing crystal oxidation. After the liquid crystal rod undergoes a preliminary cooling slightly below its melting point, it flows downward through the feeding slit 4 to form a ribbon-like crystal. Guided by the guide plate 7 and cooled by the cooling pipe 8, the temperature is reduced and the viscosity is increased. Under the rotational traction of the paired traction rollers 5, it reaches the discharge port 6. At the discharge port 6, the temperature is reduced to below 600°C, and the traction rollers 5 pull it out of the vacuum furnace for cutting.

[0031] This invention solves the problems of material waste and thickness limitation in traditional wire cutting processes through equipment structure and process innovation, providing technical support for the production of high-efficiency, low-cost, and environmentally friendly photovoltaic wafers. It is of great significance for promoting the upgrading of the solar photovoltaic industry and achieving the "dual carbon" goal.

[0032] The technical solution of this utility model is not limited to the scope of the embodiments described herein. All technical contents not described in detail herein are publicly known technologies.

Claims

1. A solar photovoltaic wafer manufacturing equipment, characterized in that: The device includes a heating furnace sleeve (1), a horizontally arranged crucible support (2) installed inside the heating furnace sleeve (1), a crucible (3) placed on the crucible support (2), the crucible (3) being made of platinum or platinum alloy, a connected heating device installed on the crucible (3), a polished material drop slit (4) opened at the bottom of the crucible (3), a through hole allowing liquid crystals to flow through opened on the crucible support (2), traction rollers (5) arranged side by side installed inside the heating furnace sleeve (1) at the lower part of the crucible support (2), the two traction rollers (5) being able to rotate synchronously in opposite directions, a discharge port (6) that can be opened and closed opened at the bottom of the heating furnace sleeve (1), the gap between the two traction rollers (5) and the material drop slit (4) and discharge port (6) being connected. Correspondingly, guide plates (7) are installed side by side between the traction roller (5) and the crucible support (2) and between the traction roller (5) and the discharge port (6). Cooling pipes (8) are provided on the outer side of each guide plate (7). A furnace cover (9) is installed on the top of the heating furnace sleeve (1). A vacuum pipe (10) and an inert gas filling pipe (11) are connected inside the heating furnace sleeve (1). A vacuum pump (12) is installed at one end of the vacuum pipe (10). A thermometer (13) is installed inside the heating furnace sleeve (1) on the side of the crucible (3). An observation window (14) is installed on the heating furnace sleeve (1) between the traction roller (5) and the crucible support (2). The observation window (14) is set in correspondence with the guide plate (7).

2. The solar photovoltaic wafer production equipment according to claim 1, characterized in that: The heating furnace sleeve (1) is equipped with two sets of traction rollers (5) arranged in parallel, and guide plates (7) arranged in parallel are installed between the two sets of traction rollers (5). Cooling pipes (8) are provided on the outer side of each guide plate (7).

3. The solar photovoltaic wafer production equipment according to claim 2, characterized in that: A first drive motor (15) is installed on the outside of the heating furnace sleeve (1). The output shaft of the first drive motor (15) extends into one end of the heating furnace sleeve (1) and a first sprocket (16) is installed. A second sprocket (17) and a third sprocket (18) are installed on the shaft of the traction roller (5) in the lower position. A fourth sprocket (19) is installed on the shaft of the traction roller (5) in the upper position. The shafts of the two traction rollers (5) arranged side by side are equipped with meshing gears (20). A first chain (21) is installed between the first sprocket (16) and the second sprocket (17). A second chain (22) is installed between the third sprocket (18) and the fourth sprocket (19). When the first drive motor (15) is started, it can drive the two sets of traction rollers (5) arranged side by side to rotate synchronously in opposite directions.

4. The solar photovoltaic wafer production equipment according to claim 1, characterized in that: The guide plate (7) between the traction roller (5) and the crucible support (2) can move closer together. A horizontally arranged guide rod (23) is installed on the guide plate (7). A guide sleeve (24) that cooperates with the guide rod (23) is provided on the inner wall of the heating furnace sleeve (1). Two sets of weights (25) with triangular cross sections are installed between the upper parts of the two guide plates (7). The material drop slit (4) is located between the two sets of weights (25). The weights (25) always have a tendency to move and separate the two guide plates (7). The positions of the guide plates (7) are corresponding to the positions of the guide plates (7) installed on the heating furnace sleeve (1). There is a rotating rod (26), and a handle (27) is provided at one end of the rotating rod (26) extending out of the heating furnace sleeve (1). Two clamping rods (28) are arranged side by side at one end of the rotating rod (26) located in the heating furnace sleeve (1). The two clamping rods (28) are located on the outside of the guide plate (7). A guide frame (29) is also installed at the bottom of the crucible support (2). An arc groove (30) is opened on the guide frame (29) to cooperate with the clamping rods (28). When the handle (27) is turned, the clamping rods (28) can be driven to push the weight (25) on both sides of the guide plate (7) to move upward and move closer to each other.

5. The solar photovoltaic wafer production equipment according to claim 4, characterized in that: The weight (25) is equipped with a vertically arranged column (31), and the bottom of the crucible support (2) is provided with a through hole that matches the column (31). The weight (25) can be raised and lowered vertically under the guidance of the through hole.

6. The solar photovoltaic wafer production equipment according to claim 1, characterized in that: A rotatable baffle (32) is installed inside the heating furnace sleeve (1) at the discharge port (6). A second drive motor (33) is installed at the bottom of the heating furnace sleeve (1). The output shaft of the second drive motor (33) extends into the heating furnace sleeve (1) and is connected to the rotating shaft of the baffle (32).

7. The solar photovoltaic wafer production equipment according to claim 1, characterized in that: The width of the material drop slit (4) is 30-300 μm.

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